EP0718504A2 - Mono-block hydraulic control system - Google Patents
Mono-block hydraulic control system Download PDFInfo
- Publication number
- EP0718504A2 EP0718504A2 EP95118187A EP95118187A EP0718504A2 EP 0718504 A2 EP0718504 A2 EP 0718504A2 EP 95118187 A EP95118187 A EP 95118187A EP 95118187 A EP95118187 A EP 95118187A EP 0718504 A2 EP0718504 A2 EP 0718504A2
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- EP
- European Patent Office
- Prior art keywords
- proportional directional
- control device
- valve element
- longitudinal slide
- valve
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- 238000010276 construction Methods 0.000 claims abstract description 4
- 230000033001 locomotion Effects 0.000 claims description 15
- 230000000903 blocking effect Effects 0.000 claims description 2
- 238000001514 detection method Methods 0.000 claims description 2
- 230000001133 acceleration Effects 0.000 claims 1
- 230000036316 preload Effects 0.000 claims 1
- 230000011664 signaling Effects 0.000 description 7
- 238000007789 sealing Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000007935 neutral effect Effects 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- 238000013016 damping Methods 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B13/00—Details of servomotor systems ; Valves for servomotor systems
- F15B13/01—Locking-valves or other detent i.e. load-holding devices
Definitions
- the invention is based on a hydraulic control in monoblock design for lifting and lowering a load, which consists of at least two electromagnetically actuated proportional directional control valve elements and a pressure compensator as an input element for lifting the load independently of the load, the elements being at least partially arranged in a housing which has at least one Has pump connection, at least one consumer connection and at least one return connection.
- the drives, actuating elements and connections are arranged on almost all housing sides of the monoblock in such control devices in a monoblock design.
- valve blocks with large external dimensions result after the installation of the drives and connections, since the drives in particular often lie opposite one another or protrude from the monoblock housings in a corner arrangement.
- the hydraulic control device enables a small construction volume with regard to its housing dimensions and the overall size of the monoblock.
- the individual valve elements are arranged closely next to each other and are partially seated in a production-friendly manner constructed and arranged bores, which can save weight and machining time.
- all valve parts are housed in just two holes.
- a proportional directional valve element for lifting a load sits in one bore next to a pressure compensator.
- the hole is a through hole without any gradation.
- a proportional directional control valve element for lowering the aforementioned load is arranged next to a seat valve.
- Both holes have the same length and each end next to each other on the corresponding end faces of the common housing.
- the electromagnetic drives are arranged directly next to one another on one of the end faces, as a result of which the drives can also be controlled mechanically with simple means.
- the control device comprises, for example, a simple cast housing, which requires only a few screw connections.
- the proportional directional control valve elements are designed for very short response times in their combination by means of a corresponding hydraulic circuit and a selected electrical circuit.
- the hydraulic connection there is a connecting channel, which is divided into two channel sections, between the proportional directional control valve elements and flows through both when lifting and when lowering the load.
- the two channel sections are connected to the return via two control edges of the longitudinal slide of the valve element for lifting the load. Since the return flow is divided, the longitudinal slide has a smaller stroke.
- a control oil throttle in the valve element for lowering the load to dampen the lowering function.
- the pressure medium required to initiate the closing movement is conducted via this control oil throttle.
- a blocking valve is arranged coaxially next to the valve element for lowering the load and is hydraulically connected in parallel to the control oil throttle during the closing phase of the valve element.
- the check valve is in the form of a valve cartridge directly behind the valve element in the same Drilling. The cross-sectional enlargement due to the parallel connection accelerates the closing movement of the valve element considerably, so that it can perform its function better and faster as a check valve which shuts off the consumer connection.
- the proportional directional valve element for lowering the load is hydraulically connected to the pressure compensator via a load detection system.
- the electromagnetic drive of this valve element is energized at least for a short time to accelerate the closing movement of the pressure compensator, during the actuation of the electromagnetic drive of the other valve element to lift the load, after the return flow has been blocked. As a result, a large volume flow accelerates the closing movement of the pressure compensator in a short period of time.
- FIG. 1 shows a basic structure of a control device for an OC hydraulic system with two electromagnetically actuated proportional directional control valve elements (90, 120) and a pressure compensator (70).
- the control device is used to control a single-acting hydraulic cylinder, which is, for example, part of a self-propelled work machine, as is the case with the power lift of an electrohydraulic hoist control device.
- Both proportional directional control valve elements (90) and (120) are throttling directional control valves, the longitudinal spools of which can assume any intermediate positions in addition to the two end positions. They each have a proportional magnet (91, 121) on their left side and a return spring (108, 155) on their right side.
- the first proportional directional valve element (90) is a 3/2-way valve and the second (120) is a 2/2-way valve, both of which are connected in series via a connecting line (13), so that the pressure medium flow pump / consumer in both directions via both directional valves flows.
- the 3/2-way valve controls the pressure medium flow from the pump to the consumer, a single-acting hydraulic cylinder for lifting a load.
- the proportional directional valve element (90) is therefore called the lifting module in the following.
- the 2/2-way valve controls the pressure medium flow that returns from the single-acting hydraulic cylinder to the tank under load.
- the second proportional directional control valve element (120) is therefore referred to as a sink module. It is designed as a poppet valve and also works as a check valve that protects the load.
- a load signaling line (12) is connected to the pressure compensator (70) and branches off from the connecting line (13).
- the proportional magnet (91) of the lifting module (90) is energized.
- the return flow is blocked and pressure medium is conducted via the lifting module (90), the connecting line (13) and the check valve (21) of the sink module (120) to the consumer connection (50).
- the pressure compensator (70) is acted upon on the spring-loaded side via the load signaling line (12), whereby the pump current is throttled in accordance with the load pressure present at the consumer connection (50) and a known load pressure-independent lifting is achieved.
- the proportional magnet (121) of the lowering module (120) is activated in the case of a normally non-energized proportional magnet (91).
- the pressure medium flows from the consumer connection (50) via the two modules (120, 90) and the return line (17) to the return connection (52).
- the control device is shown in partial longitudinal section. It has an essentially cuboid-shaped housing (shown here in simplified form) (30) with two approximately square, flat surfaces, which here are the top and bottom sides (31) and (33), cf. Figure 3, are designated, but in practice can also assume a different position in a flanged block.
- a consumer connection (50) and two slot-shaped return channels (65) and (66) are arranged in the finely machined underside.
- the return channels open into an elongated hole flange (36).
- the consumer connection (50) and the elongated hole flange (36) each have a recess toward the underside, which is used to accommodate a respective sealing ring (37) and (37 ').
- the side surfaces (34, 35, 38, 39) aligned perpendicular to the cut surface each have a rectangular outline.
- the front (34) and the back (35) are flat, finely machined surfaces.
- the two proportional magnets (91) and (121) are flanged to the front. Opposite them sit in the back (35) the locking screws (114) and (157) for the holes (41, 42) and (44).
- the other two side surfaces (38) and (39) have bulges which are formed around the fastening bores (69, 69 ').
- the side surface (38) at the top in FIG. 3 has a connecting piece for receiving the pump connection (49).
- the pump connection (49) merges into an inlet ring channel (93) in the housing (30).
- the annular channel (93) penetrates a cylindrical through bore (41), which extends from the front (34) to the rear (35).
- the longitudinal slide (97) of the lifting module (90) is located in the left area of the through hole (41).
- three further channels (94, 95, 96) meet the through hole (41).
- the middle one (94) is a return ring channel which opens onto the return channel (65) formed in the underside (33).
- On both sides of this return ring channel (94) are the two ring channels (95) and (96), to which the two channel sections (57) and (58) are connected, which in turn unite to form the connecting channel (55).
- the longitudinal slide (97) of the lifting module (90) either connects - in the unactuated state - the connecting channel (55) to the return ring channel (94) or - in the actuated state - to the inlet ring channel (93) behind the pump connection (49).
- the cylindrical outer contour of the longitudinal slide (97) has the two ring grooves (99) and (100).
- the right ring groove (100) among others can connect the inlet ring channel (93) to the ring channel (96), in the area of their right-hand shaft collar it becomes fine control notches (103) which, in connection with the pressure compensator (70), have the function of a measuring throttle.
- the opening cross-sections of the fine control notches (103) decrease in the direction of the inlet ring channel (93) without, however, reaching them when the proportional magnet (91) is not energized.
- the fine control notches (103) are round notches here, for example.
- the left wall of the right annular groove (100) forms one of two control edges (101) and (102) on the longitudinal slide (97) which controls the return from the connecting channel (55) into the return ring channel (94).
- the other control edge (101) is the left wall of the left annular groove (99). It opens or closes the path from the channel section (57) to the return ring channel (94).
- the right wall of the annular groove (99) is located over the entire stroke of the longitudinal slide (97) in the area of the return ring channel (94) and does not close it.
- the longitudinal slide On the left edge of the outer contour of the longitudinal slide (97) there is a recess in the area of the sealing ring between the proportional magnet (91) and the housing (30). Below this recess, the longitudinal slide has a cylindrical recess (104), at the bottom of which the armature tappet (92) of the proportional magnet (91) is present.
- the longitudinal slide (97) is drilled out in stages from the right end face (98).
- the right area of the stepped bore (105) serves to guide the return spring (108).
- the left area has a smaller diameter and connects the stepped bore (105) with the depression (104) via an oblique compensating bore (106). The transition from the right to the left area of the stepped bore forms a flat collar on which the return spring (108) is supported.
- the other end of the return spring (108) rests on a stepped spring plate (109).
- the spring plate (109) is star-shaped in cross section in order to allow the pressure medium to pass unthrottled for the pressure compensation on the longitudinal slide (97). It sits on a rod (110) which extends centrally to the right in the through hole (41). The rod (110) protrudes into a cup-shaped pressure compensator piston (80) arranged to the right of the longitudinal slide (97) in order to hit a threaded pin (111) there.
- the rod (110) is guided in a bore in the end face (81) of the pressure compensator piston (80) in a tightly sliding manner.
- the spring plate (109) which is stationary in the longitudinal direction, is mounted together with the rod (110) in the two longitudinally movable valve parts (97) and (80), the outer envelope contour of the spring plate (109) is spherical. In this way, mutual tilting between the longitudinal slide (97) and the rod (110) is avoided.
- the set screw (111) extends in the extension of the rod (110) and ends in the screw plug (114).
- the locking screw (114) has an internal thread in which it is screwed.
- the head of the locking screw (114) has a cylindrical recess which serves to receive a lock nut (112).
- the threaded pin (111) it has a hexagon socket on its outer free end.
- the through hole (41) merges at its right end into a screw hole (42).
- the screw plug (114) is fastened in the internal thread of the bore (42).
- the pressure compensator piston (80) sits in the through bore (41) between the adjusting screw (114) and the longitudinal slide (97) in a tightly sliding manner.
- the latter has a cylindrical outer contour which has a semicircular groove (84) at its right end, into which a spring ring (89) is inserted.
- the spring ring (89) lies - for example in the case of a control device free of pressure medium - against an inner housing collar serving as a stop, which is formed between the through bore (41) and the larger diameter screw plug bore (42).
- the locking screw (114) forms the right stop for the pressure compensator piston (80).
- On the left edge of the outer contour there are several fine control notches (83) distributed around the circumference, which are worked into the pressure compensator piston (80) from the left end face (81).
- the pressure compensator piston (80) is chamfered behind the semicircular groove (84). In the area in front of the spring washer (89), it has a series of relief grooves.
- a guide bore (87) for receiving the control spring (88) is machined into the pressure compensator piston (80) from its right end.
- the bottom of the guide bore (87) is narrowed in order to radially fix the control spring (88).
- a hole (115) with a comparable contour is also in the left end of the adjusting screw (114).
- a return ring channel (71) is located adjacent to the inlet ring channel (93).
- the connection from the inlet ring channel (93) to the return ring channel (71) is more or less completely closed, for example when a load is lifted - after the load pressure has been reached - by the pressure compensator piston (80), while it is fully open during neutral circulation.
- a load signaling channel (74) is arranged between the return ring channel (71) and the adjusting screw (114). He's standing with the channel section (58) via a load-sensing bore (63) parallel to the through bore (41).
- the connecting channel (55) is divided into the two channel sections (57) and (58).
- the two channel sections for connecting the two ring channels (95) and (96) have a streamlined, U-shaped contour.
- the channel sections (57) and (58) unite with the connecting channel (55). The latter leads approximately vertically into the area of the sink module (120).
- the sink module (120) has a stepped bore (44) which passes through the housing (30) and which is aligned parallel to the through bore (41) of the lifting module (90).
- the stepped bore (44) is closed on the left - as in the lifting module - by the proportional magnet (121) and on the right by a screw plug (157) with a hexagon socket and a sealing ring (158) arranged between the head and the thread.
- valve sleeve (130) In the middle area of the stepped bore (44) there is a valve sleeve (130) which receives two nested longitudinal slides.
- the valve sleeve (130) is axially secured in the stepped bore (44) between a left housing collar (124) and a screw ring (156) arranged on the right with an internal, continuous hexagon socket.
- the right area of the stepped bore (44) is provided with an internal thread (129).
- valve sleeve (130) is surrounded by a consumer ring channel (125) which is hydraulically connected to the consumer connection (50) shown in FIG. 3.
- a consumer ring channel (125) which is hydraulically connected to the consumer connection (50) shown in FIG. 3.
- an adjusting screw (150) in the internal thread (128).
- the connecting channel (55) opens into the stepped bore (44).
- the adjusting screw (150) - with the exception of a toothing (151) arranged on it - and the valve sleeve (130) with its two longitudinal slides is known from DE 41 40 604 A1. These components are shown in section in FIG.
- the sink module (120) is shown in the locked position.
- the main spool (140), which is mounted directly in the valve sleeve (130), is in contact with the main valve seat (132) of the valve sleeve (130) with its main valve plug (141). Its main control notches (142) - located at its left end - are concealed under the cylinder seat (133) next to an annular space (134). In order to hold the main control slide (140) on the main valve seat (132), pressure medium is present in a pressure chamber (135) on its right end.
- the pressure medium gets there from the consumer ring channel (125) via radial bores (131) in the valve sleeve (130), and in the main control slide via a throttle bore (144) and a subsequent longitudinal bore (145).
- the longitudinal bore (145) penetrates a control groove (143) with its base. The contact pressure is reduced by the counteracting force due to the pressure existing in the area of the outer contour of the main control spool (140) between the main valve cone (141) and relief grooves.
- the sink module (120) opens when the proportional magnet (121) is energized. Its anchor tappet (122) pushes the inner longitudinal slide, a pilot spool (147) slightly to the right. As a result, its pilot control notches (149) come under the control groove (143) of the main control spool (140). At the same time, its valve cone (148) located further to the left lifts from its valve seat (146) corresponding in the main control spool (140) from. The pressure chamber (135) is now connected to the return ring channel (94) via the longitudinal bore (145), the control groove (143), the pilot control notches (149), the valve seat (146) and the connecting channel (55).
- the pressure in the pressure chamber (135) drops.
- the main valve plug (141) lifts off the main valve seat (132) and the main control notches (142) reach the area of the annular space (134).
- the pressure medium flows between the valve sleeve (130) and the main control slide (140) in the direction of the connecting channel (55).
- the main control slide valve (140) lags behind the pilot control slide valve (147) due to its opening movement, as a result of which the opening cross section at the pilot control notches (149) becomes smaller.
- This allows a higher pressure to build up in the pressure chamber (135) via the throttle bore (144).
- the opening movement of the main control spool (140) is braked until an equilibrium state is reached.
- the return spring (155) is supported on the pilot spool (147) and on the adjusting screw (150).
- the pilot notches (149) are closed when the pilot spool (147) moves.
- the pressure in the pressure chamber (135) increases.
- the main valve plug (141) lies against the main valve seat (132).
- the sink module (120) locks.
- the proportional directional control valve element (120) thus operates in the manner of a sequence control.
- the adjusting screw (150) has helical teeth (151) in the central area of its outer contour, which at least temporarily engage the teeth of an adjusting worm.
- the adjusting worm is seated in an adjusting bore (68), which here extends from the front (34) into the stepped bore (44) and touches the connecting channel (55).
- the adjusting worm can be rotated with the help of an adjusting spindle, the free end of which protrudes from the housing (30), or a special tool that can be temporarily coupled to the end of the adjusting worm.
- the adjusting screw (150) is screwed to the right or left in the internal thread (128).
- the length of the adjustment range largely corresponds to the width of the toothing (151) of the adjusting screw (150).
- the lowering module (120) which has the function of a check valve in the control device during the lifting of the load, is relatively strongly damped by the throttle bore (144) due to the high demands on the fine controllability when lowering the load. This damping slows down the closing movement during the kickback function.
- a seat valve (160) can be connected in parallel to the throttle bore (144) to accelerate the closing movement when lifting the load.
- FIG. 4 is to the right of the valve sleeve (130) instead of the screw ring (156), cf. Figure 2, this seat valve (160) arranged.
- the seat valve has a disc-shaped body with a molded hexagon.
- the cylindrical part of its outer contour has a thread with an inserted sealing ring, with which it is screwed into the right area of the stepped bore (44).
- the screw ring (156) from FIG. 2 it fixes the valve sleeve (130).
- an annular channel (161) is formed between the bottom of the seat valve, the right edge area of the outer contour of the valve sleeve (130) and the housing (30) an annular channel (161) is formed.
- the channel (161) is connected via an oblique bore (162) to the consumer connection (51) integrally molded on the side surface (39) of the housing (30).
- the seat valve (160) has a longitudinal bore (165) on which a valve seat in the shape of a cone is formed towards the valve sleeve (130).
- a slide piston (164) is mounted and guided in the right part of the longitudinal bore (165).
- the right portion of the spool (164) has a cylindrical shape. This is followed by a valve plate on the left, which is connected to the cylindrical section via a waist.
- a stroke of the slide piston (164) to the right is limited by the contact between the valve plate and the valve seat, while a stroke to the left is terminated by the striking of a retaining ring on the slide piston on the front side of the hexagon.
- Several holes (166) extend from the longitudinal bore (165) in an approximately star shape in the region of the waist of the slide piston (164).
- annular groove for receiving a sealing ring (167) is machined in the area of the hexagon from the longitudinal bore.
- annular channel (163) between the poppet valve (160) and the screw plug (157), which is connected to the load signaling bore (63).
- the proportional magnet (91) When lifting the load, the proportional magnet (91) is energized, cf. also Figure 2, pressure medium via the pump connection (49), the inlet ring channel (93), the longitudinal slide (97), and the connecting channel (55) in front of the longitudinal slide (140) and (147) of the sink module (120).
- the longitudinal slide (97) initially only opens via its fine control notches (103). They form the measuring throttle in relation to the pressure compensator (70).
- the pressure medium flows on the way to the sink module (120) via the load reporting hole (63) and the Load signaling channel (74) on the back of the pressure compensator piston (80).
- the control pressure drop generated by the pressure compensator (70) during the closing process not only rests on the fine control notches (103), but also on both sides of the pressure compensator piston (80).
- the low pressure drop present, as well as the low volume flow which may be additionally reduced by a throttle point integrated in the load reporting bore (63) to stabilize the movement of the pressure compensator piston (80), necessitates a slow closing movement of the pressure compensator piston (80).
- the proportional magnet (121) of the sink module can be energized briefly, for example.
- FIG. 5 the energization of the two proportional magnets (91) and (121) is shown in a simplified representation when the load is raised and then lowered. The time t is plotted on the abscissa.
- the current I91 for the proportional magnet (91) and on the negative branch of the current I121 for the proportional magnet (121) is shown.
- the load is raised over the period t91 and lowered over the period t121.
- the lifting process is within the period t91 after the time t1 in which the longitudinal slide (97), see.
- Figure 2 as far as has been pushed to the right that the connections from the channel sections (57) and (58) to the return ring channel (94) are blocked, the proportional magnet (121) is energized for the time t2.
- pressure medium flows from the consumer connection (50) or (51) under load pressure via the main control spool (140) and the connecting channel (55), the load signaling bore (63) and the load signaling channel (74) to the rear of the pressure compensator piston (80).
- the one set in motion large volume flow allows the pressure compensating piston (80) to quickly block the return ring channel (71).
- the proportional magnet (91) is switched off to stop lifting the load.
- the longitudinal slide (97) wants to move to the left due to the return spring (108) in order to block the path between the inlet ring channel (93) and the channel section (58).
- the longitudinal slide (97) is blocked in unfavorable conditions, but before the main control slide (140) of the sink module (120), which is strongly damped due to the fine control, is blocked. If the main control slide (140) closes too slowly, the pressure medium flows back from the consumer connection (51) in the direction of the inlet ring channel (93). The flow forces can interfere with the longitudinal slide (97) when closing.
- the seat valve (160) eliminates this problem.
- the pressure in the flow direction is greater in front of the sink module (120) than behind it. Due to this pressure difference, the seat valve (160) opens, which is also connected in parallel to the control oil throttle (144) and increases the throttle cross-section when the load is lifted. As a result, the main control spool (140) closes almost undamped.
- a manual control element (25) in front of the rear ends of the two proportional magnets (91) and (121), for example in a swivel joint bearing (26), cf. .
- the manual control element (25) acts on the manual override elements (24) of the proportional magnets (91) and (121). With the manual control element (25) either the lifting (90) or the lowering module (120) can be controlled manually.
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- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Fluid-Pressure Circuits (AREA)
- Magnetically Actuated Valves (AREA)
- Multiple-Way Valves (AREA)
- Forklifts And Lifting Vehicles (AREA)
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Abstract
Die Erfindung betrifft eine hydraulische Steuervorrichtung in Monoblockbauweise zum Heben und Senken einer Last mit mindestens zwei elektromagnetisch betätigbaren Proportionalwegeventilelementen und einer Druckwaage als Eingangselement zum lastunabhängigen Heben der Last, wobei die Elemente zumindest teilweise in einem Gehäuse angeordnet sind, das mindestens einen Pumpenanschluß, mindestens einen Verbraucheranschluß und mindestens einen Rücklaufanschluß aufweist. Die Proportionalwegeventilelemente sind parallel zueinander angeordnet, wobei die elektromagnetischen Antriebe auf gleicher Höhe nebeneinander sitzen. Die Druckwaage sitzt koaxial neben dem ersten Proportionalwegeventilelement. Letzteres ist mit dem zweiten Proportionalwegeventilelement über einen Verbindungskanal verbunden, der sich im Bereich zwischen den Ventilelementen in zwei einzelne Kanalabschnitte aufteilt, wobei beide Kanalabschnitte die Bohrung zur Lagerung und Führung des Längsschiebers des ersten Proportionalwegeventilelementes schneiden und auf je eine einen Rücklaufkanal versperrbare Steuerkante des Längsschiebers treffen. Der Ventilblock hat ein kleines Bauvolumen. Die Proportionalwegeventilelemente sind in ihrer Kombination durch eine entsprechende hydraulische Verschaltung und eine ausgewählte elektrische Beschaltung für sehr kurze Ansprechzeiten ausgelegt. The invention relates to a hydraulic control device in monoblock construction for lifting and lowering a load with at least two electromagnetically actuated proportional directional control valve elements and a pressure compensator as an input element for load-independent lifting of the load, the elements being at least partially arranged in a housing, the at least one pump connection, at least one consumer connection and has at least one return connection. The proportional directional control valve elements are arranged parallel to each other, with the electromagnetic drives sitting next to each other at the same height. The pressure compensator sits coaxially next to the first proportional directional valve element. The latter is connected to the second proportional directional control valve element via a connecting channel, which divides into two individual channel sections in the area between the valve elements, both channel sections cutting the bore for mounting and guiding the longitudinal slide valve of the first proportional directional valve element and meeting one control edge of the longitudinal slide valve, which can be blocked by a return channel . The valve block has a small construction volume. The combination of the proportional directional control valve elements is designed for very short response times thanks to a corresponding hydraulic circuit and a selected electrical circuit.
Description
Die Erfindung geht von einer hydraulischen Steuerung in Monoblockbauweise zum Heben und Senken einer Last aus, die aus mindestens zwei elektromagnetisch betätigbaren Proportionalwegeventilelementen und einer Druckwaage als Eingangselement zum lastunabhängigen Heben der Last besteht, wobei die Elemente zumindest teilweise in einem Gehäuse angeordnet sind, das mindestens einen Pumpenanschluß, mindestens einen Verbraucheranschluß und mindestens einen Rücklaufanschluß aufweist.The invention is based on a hydraulic control in monoblock design for lifting and lowering a load, which consists of at least two electromagnetically actuated proportional directional control valve elements and a pressure compensator as an input element for lifting the load independently of the load, the elements being at least partially arranged in a housing which has at least one Has pump connection, at least one consumer connection and at least one return connection.
In der Regel werden bei solchen Steuervorrichtungen in Monoblockbauweise die Antriebe, Betätigungselemente und Anschlüsse an fast allen Gehäuseseiten des Monoblocks angeordnet. Dabei ergeben sich nach dem Anbau der Antriebe und Anschlüsse trotz kompakter Bauweise Ventilblöcke mit großen Außenabmessungen, da besonders die Antriebe oft gegenüberliegen oder über Eck angeordnet aus den Monoblockgehäusen herauskragen.As a rule, the drives, actuating elements and connections are arranged on almost all housing sides of the monoblock in such control devices in a monoblock design. Despite the compact design, valve blocks with large external dimensions result after the installation of the drives and connections, since the drives in particular often lie opposite one another or protrude from the monoblock housings in a corner arrangement.
Die erfindungsgemäße hydraulische Steuervorrichtung ermöglicht bezüglich ihrer Gehäuseabmessungen und der Gesamtgröße des Monoblocks ein kleines Bauvolumen. Die einzelnen Ventilelemente sind eng nebeneinander angeordnet und sitzen teilweise in fertigungsgünstig konstruierten und angeordneten Bohrungen, womit Gewicht und Bearbeitungszeit eingespart werden können. Dazu werden alle Ventilteile in nur zwei Bohrungen untergebracht. In der einen Bohrung sitzt ein Proportionalwegeventilelement zum Heben einer Last neben einer Druckwaage. Die Bohrung ist eine Durchgangsbohrung ohne jede Stufung. In der anderen, zu dieser parallelen Bohrung ist ein Proportionalwegeventilelement zum Senken der zuvor genannten Last neben einem Sitzventil angeordnet. Beide Bohrungen haben die gleiche Länge und enden jeweils nebeneinander an den entsprechenden Stirnseiten des gemeinsamen Gehäuses. Auf einer der Stirnseiten sind direkt nebeneinander die elektromagnetischen Antriebe angeordnet, wodurch die Antriebe mit einfachen Mitteln auch mechanisch ansteuerbar sind. Die Steuervorrichtung umfaßt beispielsweise ein einfaches Gußgehäuse, das nur wenige Verschraubungen benötigt.The hydraulic control device according to the invention enables a small construction volume with regard to its housing dimensions and the overall size of the monoblock. The individual valve elements are arranged closely next to each other and are partially seated in a production-friendly manner constructed and arranged bores, which can save weight and machining time. For this purpose, all valve parts are housed in just two holes. A proportional directional valve element for lifting a load sits in one bore next to a pressure compensator. The hole is a through hole without any gradation. In the other, parallel to this bore, a proportional directional control valve element for lowering the aforementioned load is arranged next to a seat valve. Both holes have the same length and each end next to each other on the corresponding end faces of the common housing. The electromagnetic drives are arranged directly next to one another on one of the end faces, as a result of which the drives can also be controlled mechanically with simple means. The control device comprises, for example, a simple cast housing, which requires only a few screw connections.
Des weiteren sind die Proportionalwegeventilelemente in ihrer Kombination durch eine entsprechende hydraulische Verschaltung und eine ausgewählte elektrische Beschaltung für sehr kurze Ansprechzeiten ausgelegt. Bezüglich der hydraulischen Verschaltung befindet sich zwischen den Proportionalwegeventilelementen ein sich in zwei Kanalabschnitte aufteilender Verbindungskanal, der sowohl beim Heben als auch beim Senken der Last durchströmt wird. Die beiden Kanalabschnitte stehen über zwei Steuerkanten des Längsschiebers des Ventilelements zum Heben der Last mit dem Rücklauf in Verbindung. Da sich der Rücklaufstrom aufteilt, kommt der Längsschieber mit einem kleineren Hub aus.Furthermore, the proportional directional control valve elements are designed for very short response times in their combination by means of a corresponding hydraulic circuit and a selected electrical circuit. With regard to the hydraulic connection, there is a connecting channel, which is divided into two channel sections, between the proportional directional control valve elements and flows through both when lifting and when lowering the load. The two channel sections are connected to the return via two control edges of the longitudinal slide of the valve element for lifting the load. Since the return flow is divided, the longitudinal slide has a smaller stroke.
Im Ventilelement zum Senken der Last befindet sich zur Dämpfung der Senkenfunktion eine Steueröldrossel. Über diese Steueröldrossel wird das zur Einleitung der Schließbewegung erforderliche Druckmittel geleitet. Koaxial neben dem Ventilelement zum Senken der Last ist ein Sperrventil angeordnet, das während der Schließphase des Ventilelements hydraulisch zur Steueröldrossel parallel geschaltet ist. Das Sperrventil sitzt in Form einer Ventilpatrone unmittelbar hinter dem Ventilelement in der gleichen Bohrung. Die Querschnittsvergrößerung aufgrund der Parallelschaltung beschleunigt die Schließbewegung des Ventilelements erheblich, so daß es seine Funktion als ein den Verbraucheranschluß absperrendes Rückschlagventil besser und schneller ausführen kann.There is a control oil throttle in the valve element for lowering the load to dampen the lowering function. The pressure medium required to initiate the closing movement is conducted via this control oil throttle. A blocking valve is arranged coaxially next to the valve element for lowering the load and is hydraulically connected in parallel to the control oil throttle during the closing phase of the valve element. The check valve is in the form of a valve cartridge directly behind the valve element in the same Drilling. The cross-sectional enlargement due to the parallel connection accelerates the closing movement of the valve element considerably, so that it can perform its function better and faster as a check valve which shuts off the consumer connection.
Das Proportionalwegeventilelement zum Senken der Last steht über ein Lastmeldesystem mit der Druckwaage hydraulisch in Verbindung. Der elektromagnetische Antrieb dieses Ventilelements wird zur Beschleunigung der Schließbewegung der Druckwaage, während der Betätigung des elektromagnetischen Antriebs des anderen Ventilelements zum Heben der Last, nach dessen Sperrung des Rücklaufs, zumindest kurzzeitig bestromt. Dadurch beschleunigt ein großer Volumenstrom in einer kurzen Zeitspanne die Schließbewegung der Druckwaage.The proportional directional valve element for lowering the load is hydraulically connected to the pressure compensator via a load detection system. The electromagnetic drive of this valve element is energized at least for a short time to accelerate the closing movement of the pressure compensator, during the actuation of the electromagnetic drive of the other valve element to lift the load, after the return flow has been blocked. As a result, a large volume flow accelerates the closing movement of the pressure compensator in a short period of time.
Weitere Einzelheiten der Erfindung ergeben sich aus der nachfolgenden Beschreibung zweier vereinfacht dargestellter Ausführungsformen:
- Figur 1:
- Hydraulikschaltplan für eine Steuervorrichtung mit elektromagnetisch betätigten Proportionalwegeventilelementen und einer Druckwaage;
- Figur 2:
- Schnitt durch eine Steuervorrichtung nach Figur 1;
- Figur 3:
- Unteransicht der Steuervorrichtung nach Figur 2;
- Figur 4:
- Schnitt durch eine Steuervorrichtung nach Figur 1 mit einem zusätzlichen Sitzventil;
- Figur 5:
- Strombeaufschlagung der elektromagnetischen Antriebe.
- Figure 1:
- Hydraulic circuit diagram for a control device with electromagnetically operated proportional directional control valve elements and a pressure compensator;
- Figure 2:
- Section through a control device according to Figure 1;
- Figure 3:
- Bottom view of the control device according to Figure 2;
- Figure 4:
- Section through a control device according to Figure 1 with an additional seat valve;
- Figure 5:
- Current applied to the electromagnetic drives.
Der in Figur 1 dargestellte Hydraulikschaltplan zeigt einen prinzipiellen Aufbau einer Steuervorrichtung für ein OC-Hydrauliksystem mit zwei elektromagnetisch betätigbaren Proportionalwegeventilelementen (90, 120) und einer Druckwaage (70). Die Steuervorrichtung dient der Ansteuerung eines einfach wirkenden Hydraulikzylinders, der beispielsweise Teil einer selbstfahrenden Arbeitsmaschine ist, wie dies beim Kraftheber einer elektrohydraulischen Hubwerksregeleinrichtung der Fall ist.The hydraulic circuit diagram shown in FIG. 1 shows a basic structure of a control device for an OC hydraulic system with two electromagnetically actuated proportional directional control valve elements (90, 120) and a pressure compensator (70). The control device is used to control a single-acting hydraulic cylinder, which is, for example, part of a self-propelled work machine, as is the case with the power lift of an electrohydraulic hoist control device.
Beide Proportionalwegeventilelemente (90) und (120) sind drosselnde Wegeventile, deren Längsschieber außer den beiden Endstellungen stufenlos beliebige Zwischenstellungen einnehmen können. Sie haben auf ihrer linken Seite je einen Proportionalmagneten (91, 121) und auf ihrer rechten Seite je eine Rückstellfeder (108, 155). Das erste Proportionalwegeventilelement (90) ist ein 3/2-Wegeventil und das zweite (120) ein 2/2-Wegeventil, wobei beide über eine Verbindungsleitung (13) hintereinandergeschaltet sind, so daß der Druckmittelstrom Pumpe/Verbraucher in beiden Richtungen über beide Wegeventile fließt. Das 3/2-Wegeventil steuert den Druckmittelstrom von der Pumpe zum Verbraucher, einen einfach wirkenden Hydraulikzylinder zum Heben einer Last. Das Proportionalwegeventilelement (90) wird daher im folgenden Hebenmodul genannt. Das 2/2-Wegeventil steuert den vom einfach wirkenden Hydraulikzylinder unter Last zum Tank zurücklaufenden Druckmittelstrom. Das zweite Proportionalwegeventilelement (120) wird folglich als Senkenmodul bezeichnet. Es ist in Sitzventilbauart ausgebildet und arbeitet zudem als ein die Last absicherndes Rückschlagventil.Both proportional directional control valve elements (90) and (120) are throttling directional control valves, the longitudinal spools of which can assume any intermediate positions in addition to the two end positions. They each have a proportional magnet (91, 121) on their left side and a return spring (108, 155) on their right side. The first proportional directional valve element (90) is a 3/2-way valve and the second (120) is a 2/2-way valve, both of which are connected in series via a connecting line (13), so that the pressure medium flow pump / consumer in both directions via both directional valves flows. The 3/2-way valve controls the pressure medium flow from the pump to the consumer, a single-acting hydraulic cylinder for lifting a load. The proportional directional valve element (90) is therefore called the lifting module in the following. The 2/2-way valve controls the pressure medium flow that returns from the single-acting hydraulic cylinder to the tank under load. The second proportional directional control valve element (120) is therefore referred to as a sink module. It is designed as a poppet valve and also works as a check valve that protects the load.
Zwischen dem Pumpenanschluß (49) und dem Hebenmodul (90) ist in einem Nebenzweig (10) die Druckwaage (70) angeordnet, die bei einem Neutralumlauf geöffnet ist und den nicht benötigten Druckmittelstrom nahezu ungedrosselt in die Rücklaufleitung (16) leitet. An der Druckwaage (70) ist neben der Regelfeder (88) eine Lastmeldeleitung (12) angeschlossen, die von der Verbindungsleitung (13) abzweigt.Between the pump connection (49) and the lifting module (90) is arranged in a secondary branch (10) the pressure compensator (70), which is open during a neutral cycle and the pressure medium flow that is not required leads almost unthrottled into the return line (16). In addition to the control spring (88), a load signaling line (12) is connected to the pressure compensator (70) and branches off from the connecting line (13).
Zum Heben einer Last wird der Proportionalmagnet (91) des Hebenmoduls (90) bestromt. Der Rücklauf wird gesperrt und Druckmittel wird über das Hebenmodul (90), die Verbindungsleitung (13) und das Rückschlagventil (21) des Senkenmoduls (120) zum Verbraucheranschluß (50) geleitet. Hierbei wird über die Lastmeldeleitung (12) die Druckwaage (70) auf ihrer federbelasteten Seite beaufschlagt, womit der Pumpenstrom entsprechend dem am Verbraucheranschluß (50) anliegenden Lastdruck angedrosselt wird und ein an sich bekanntes lastdruckunabhängiges Heben erreicht wird.To lift a load, the proportional magnet (91) of the lifting module (90) is energized. The return flow is blocked and pressure medium is conducted via the lifting module (90), the connecting line (13) and the check valve (21) of the sink module (120) to the consumer connection (50). Here, the pressure compensator (70) is acted upon on the spring-loaded side via the load signaling line (12), whereby the pump current is throttled in accordance with the load pressure present at the consumer connection (50) and a known load pressure-independent lifting is achieved.
Zum Senken einer Last wird bei einem in der Regel unbestromten Proportionalmagnet (91) der Proportionalmagnet (121) des Senkenmoduls (120) aktiviert. Das Druckmittel fließt vom Verbraucheranschluß (50) über die beiden Module (120, 90) und die Rücklaufleitung (17) zum Rücklaufanschluß (52).To lower a load, the proportional magnet (121) of the lowering module (120) is activated in the case of a normally non-energized proportional magnet (91). The pressure medium flows from the consumer connection (50) via the two modules (120, 90) and the return line (17) to the return connection (52).
In Figur 2 wird die realisierte Steuervorrichtung im teilweisen Längsschnitt gezeigt. Sie hat ein im wesentlichen quaderförmiges - hier vereinfacht dargestelltes - Gehäuse (30) mit zwei annähernd quadratischen, ebenen Flächen, die hier als Ober- und Unterseite (31) und (33), vgl. Figur 3, bezeichnet sind, in der Praxis aber in einem zusammengeflanschten Block auch eine andere Lage einnehmen können. In der feinbearbeiteten Unterseite sind ein Verbraucheranschluß (50) und zwei langlochförmige Rücklaufkanäle (65) und (66) angeordnet. Die Rücklaufkanäle münden in einen Langlochflansch (36). Der Verbraucheranschluß (50) und der Langlochflansch (36) weisen jeweils zur Unterseite hin je eine Ausnehmung auf, die der Aufnahme je eines Dichtrings (37) und (37') dient. Ferner sind drei Befestigungsbohrungen (69, 69', 69'') zu sehen, die senkrecht zur Unterseite (33) das Gehäuse (30) durchdringen.In Figure 2, the control device is shown in partial longitudinal section. It has an essentially cuboid-shaped housing (shown here in simplified form) (30) with two approximately square, flat surfaces, which here are the top and bottom sides (31) and (33), cf. Figure 3, are designated, but in practice can also assume a different position in a flanged block. A consumer connection (50) and two slot-shaped return channels (65) and (66) are arranged in the finely machined underside. The return channels open into an elongated hole flange (36). The consumer connection (50) and the elongated hole flange (36) each have a recess toward the underside, which is used to accommodate a respective sealing ring (37) and (37 '). There are also three mounting holes (69, 69 ', 69'') that penetrate the housing (30) perpendicular to the underside (33).
Die senkrecht zur Schnittfläche ausgerichteten Seitenflächen (34, 35, 38, 39) haben jeweils einen rechteckigen Umriß. Die Vorder- (34) und die Rückseite (35) sind ebene, feinbearbeitete Flächen. An der Vorderseite sind die beiden Proportionalmagnete (91) und (121) angeflanscht. Ihnen gegenüber sitzen in der Rückseite (35) die Verschlußschrauben (114) und (157) für die Bohrungen (41, 42) und (44). Die beiden anderen Seitenflächen (38) und (39) haben Ausbuchtungen, die um die Befestigungsbohrungen (69, 69') gebildet sind. Außerdem weist die in Figur 3 oben liegende Seitenfläche (38) einen Stutzen zur Aufnahme des Pumpenanschlusses (49) auf.The side surfaces (34, 35, 38, 39) aligned perpendicular to the cut surface each have a rectangular outline. The front (34) and the back (35) are flat, finely machined surfaces. The two proportional magnets (91) and (121) are flanged to the front. Opposite them sit in the back (35) the locking screws (114) and (157) for the holes (41, 42) and (44). The other two side surfaces (38) and (39) have bulges which are formed around the fastening bores (69, 69 '). In addition, the side surface (38) at the top in FIG. 3 has a connecting piece for receiving the pump connection (49).
Nach Figur 2 geht der mit einem Innengewinde versehene Pumpenanschluß (49) im Gehäuse (30) in einen Zulaufringkanal (93) über. Der Ringkanal (93) durchdringt eine zylindrische Durchgangsbohrung (41), die sich von der Vorderseite (34) bis zur Rückseite (35) erstreckt. Im linken Bereich der Durchgangsbohrung (41) sitzt der Längsschieber (97) des Hebenmoduls (90). Dort treffen auf die Durchgangsbohrung (41) drei weitere Kanäle (94, 95, 96). Der mittlere (94) ist ein Rücklaufringkanal, der auf den in die Unterseite (33) ausgebildeten Rücklaufkanal (65) mündet. Beidseits von diesem Rücklaufringkanal (94) befinden sich die beiden Ringkanäle (95) und (96), an die die beiden Kanalabschnitte (57) und (58) angeschlossen sind, die sich wiederum zum Verbindungskanal (55) vereinigen.According to FIG. 2, the pump connection (49), which is provided with an internal thread, merges into an inlet ring channel (93) in the housing (30). The annular channel (93) penetrates a cylindrical through bore (41), which extends from the front (34) to the rear (35). The longitudinal slide (97) of the lifting module (90) is located in the left area of the through hole (41). There, three further channels (94, 95, 96) meet the through hole (41). The middle one (94) is a return ring channel which opens onto the return channel (65) formed in the underside (33). On both sides of this return ring channel (94) are the two ring channels (95) and (96), to which the two channel sections (57) and (58) are connected, which in turn unite to form the connecting channel (55).
Der Längsschieber (97) des Hebenmoduls (90) verbindet entweder - im unbetätigten Zustand - den Verbindungskanal (55) mit dem Rücklaufringkanal (94) oder - im betätigten Zustand - mit dem Zulaufringkanal (93) hinter dem Pumpenanschluß (49). Dazu weist die zylindrische Außenkontur des Längsschiebers (97) die beiden Ringnuten (99) und (100) auf. Die rechte Ringnut (100), die u.a. den Zulaufringkanal (93) mit dem Ringkanal (96) verbinden kann, geht im Bereich ihres rechten Wellenbundes in Feinsteuerkerben (103) über, die im Zusammenhang mit der Druckwaage (70) die Funktion einer Meßdrossel haben. Die Öffnungsquerschnitte der Feinsteuerkerben (103) verringern sich in Richtung Zulaufringkanal (93), ohne ihn jedoch - bei unbestromtem Proportionalmagnet (91) - zu erreichen. Die Feinsteuerkerben (103) sind hier beispielsweise Rundkerben.The longitudinal slide (97) of the lifting module (90) either connects - in the unactuated state - the connecting channel (55) to the return ring channel (94) or - in the actuated state - to the inlet ring channel (93) behind the pump connection (49). For this purpose, the cylindrical outer contour of the longitudinal slide (97) has the two ring grooves (99) and (100). The right ring groove (100), among others can connect the inlet ring channel (93) to the ring channel (96), in the area of their right-hand shaft collar it becomes fine control notches (103) which, in connection with the pressure compensator (70), have the function of a measuring throttle. The opening cross-sections of the fine control notches (103) decrease in the direction of the inlet ring channel (93) without, however, reaching them when the proportional magnet (91) is not energized. The fine control notches (103) are round notches here, for example.
Die linke Wandung der rechten Ringnut (100) bildet eine von zwei Steuerkanten (101) und (102) am Längsschieber (97) die den Rücklauf vom Verbindungskanal (55) in den Rücklaufringkanal (94) steuert. Die andere Steuerkante (101) ist die linke Wandung der linken Ringnut (99). Sie öffnet oder verschließt den Weg vom Kanalabschnitt (57) zum Rücklaufringkanal (94). Die rechte Wandung der Ringnut (99) befindet sich über den gesamten Hub des Längsschiebers (97) im Bereich des Rücklaufringkanals (94) und verschließt diesen nicht.The left wall of the right annular groove (100) forms one of two control edges (101) and (102) on the longitudinal slide (97) which controls the return from the connecting channel (55) into the return ring channel (94). The other control edge (101) is the left wall of the left annular groove (99). It opens or closes the path from the channel section (57) to the return ring channel (94). The right wall of the annular groove (99) is located over the entire stroke of the longitudinal slide (97) in the area of the return ring channel (94) and does not close it.
Am linken Rand der Außenkontur des Längsschiebers (97) befindet sich im Bereich des Dichtrings zwischen dem Proportionalmagnet (91) und dem Gehäuse (30) ein Einstich. Unterhalb dieses Einstichs weist der Längsschieber eine zylindrische Vertiefung (104) auf, an deren Grund der Ankerstößel (92) des Proportionalmagneten (91) ansteht.On the left edge of the outer contour of the longitudinal slide (97) there is a recess in the area of the sealing ring between the proportional magnet (91) and the housing (30). Below this recess, the longitudinal slide has a cylindrical recess (104), at the bottom of which the armature tappet (92) of the proportional magnet (91) is present.
Von der rechten Stirnseite (98) her ist der Längsschieber (97) gestuft aufgebohrt. Der rechte Bereich der Stufenbohrung (105) dient der Führung der Rückstellfeder (108). Der linke Bereich hat einen kleineren Durchmesser und verbindet über eine schräg verlaufende Ausgleichsbohrung (106) die Stufenbohrung (105) mit der Vertiefung (104). Der Übergang vom rechten zum linken Bereich der Stufenbohrung bildet ein ebener Gehäusebund, auf dem sich die Rückstellfeder (108) abstützt.The longitudinal slide (97) is drilled out in stages from the right end face (98). The right area of the stepped bore (105) serves to guide the return spring (108). The left area has a smaller diameter and connects the stepped bore (105) with the depression (104) via an oblique compensating bore (106). The transition from the right to the left area of the stepped bore forms a flat collar on which the return spring (108) is supported.
Das andere Ende der Rückstellfeder (108) liegt an einem abgestuften Federteller (109) an. Der Federteller (109) ist im Querschnitt sternförmig ausgebildet, um für den Druckausgleich am Längsschieber (97) das Druckmittel ungedrosselt passieren zu lassen. Er sitzt auf einer Stange (110), die sich nach rechts zentral in der Durchgangsbohrung (41) erstreckt. Die Stange (110) ragt in einen rechts neben dem Längsschieber (97) angeordneten, topfförmigen Druckwaagenkolben (80) hinein, um dort auf einen Gewindestift (111) zu stoßen. Hierbei ist die Stange (110) in einer Bohrung in der Stirnseite (81) des Druckwaagenkolbens (80) dichtgleitend geführt. Da der in Längsrichtung ortsfeste Federteller (109) zusammen mit der Stange (110) in den zwei längsbeweglichen Ventilteilen (97) und (80) gelagert ist, ist die äußere Hüllkontur des Federtellers (109) ballig ausgeführt. Auf diese Weise wird ein gegenseitiges Verkanten zwischen dem Längsschieber (97) und der Stange (110) vermieden.The other end of the return spring (108) rests on a stepped spring plate (109). The spring plate (109) is star-shaped in cross section in order to allow the pressure medium to pass unthrottled for the pressure compensation on the longitudinal slide (97). It sits on a rod (110) which extends centrally to the right in the through hole (41). The rod (110) protrudes into a cup-shaped pressure compensator piston (80) arranged to the right of the longitudinal slide (97) in order to hit a threaded pin (111) there. The rod (110) is guided in a bore in the end face (81) of the pressure compensator piston (80) in a tightly sliding manner. Since the spring plate (109), which is stationary in the longitudinal direction, is mounted together with the rod (110) in the two longitudinally movable valve parts (97) and (80), the outer envelope contour of the spring plate (109) is spherical. In this way, mutual tilting between the longitudinal slide (97) and the rod (110) is avoided.
Der Gewindestift (111) erstreckt sich in der Verlängerung der Stange (110) und endet in der Verschlußschraube (114). Um den Gewindestift (111) in der Längsrichtung verstellen zu können, weist die Verschlußschraube (114) ein Innengewinde auf, in dem dieser eingeschraubt sitzt. Um die Baulänge der Steuervorrichtung kurz zu gestalten, hat der Kopf der Verschlußschraube (114) eine zylindrische Vertiefung, die der Aufnahme einer Kontermutter (112) dient. Zum Verstellen und Kontern des Gewindestifts (111), weist dieser an seinem äußeren freien Ende einen Innensechskant auf.The set screw (111) extends in the extension of the rod (110) and ends in the screw plug (114). In order to be able to adjust the threaded pin (111) in the longitudinal direction, the locking screw (114) has an internal thread in which it is screwed. In order to make the overall length of the control device short, the head of the locking screw (114) has a cylindrical recess which serves to receive a lock nut (112). To adjust and counter the threaded pin (111), it has a hexagon socket on its outer free end.
Die Durchgangsbohrung (41) geht an ihrem rechten Ende in eine Verschlußschraubenbohrung (42) über. Im Innengewinde der Bohrung (42) ist die Verschlußschraube (114) befestigt. Ein im Bereich zwischen Kopf und Gewinde sitzender Dichtring (118) dichtet die Verschlußschraubenbohrung (42) nach außen ab.The through hole (41) merges at its right end into a screw hole (42). The screw plug (114) is fastened in the internal thread of the bore (42). A sealing ring (118) in the area between the head and the thread seals the screw plug bore (42) from the outside.
In der Durchgangsbohrung (41) sitzt zwischen der Verstellschraube (114) und dem Längsschieber (97) dichtgleitend der Druckwaagenkolben (80). Letzterer hat eine zylindrische Außenkontur, die an ihrem rechten Ende einen Halbrundeinstich (84) aufweist, in den ein Federring (89) eingesetzt ist. Der Federring (89) liegt - beispielsweise bei druckmittelfreier Steuervorrichtung - an einem als Anschlag dienenden inneren Gehäusebund an, der zwischen der Durchgangsbohrung (41) und der im Durchmesser größeren Verschlußschraubenbohrung (42) gebildet ist. Den rechten Anschlag für den Druckwaagenkolben (80) bildet die Verschlußschraube (114). Am linken Rand der Außenkontur befinden sich mehrere auf dem Umfang verteilte Feinsteuerkerben (83), die von der linken Stirnseite (81) her in den Druckwaagenkolben (80) eingearbeitet sind.The pressure compensator piston (80) sits in the through bore (41) between the adjusting screw (114) and the longitudinal slide (97) in a tightly sliding manner. The latter has a cylindrical outer contour which has a semicircular groove (84) at its right end, into which a spring ring (89) is inserted. The spring ring (89) lies - for example in the case of a control device free of pressure medium - against an inner housing collar serving as a stop, which is formed between the through bore (41) and the larger diameter screw plug bore (42). The locking screw (114) forms the right stop for the pressure compensator piston (80). On the left edge of the outer contour there are several fine control notches (83) distributed around the circumference, which are worked into the pressure compensator piston (80) from the left end face (81).
Hinter dem Halbrundeinstich (84) ist der Druckwaagenkolben (80) angefast. Im Bereich vor dem Federring (89) trägt er eine Reihe von Entlastungsnuten.The pressure compensator piston (80) is chamfered behind the semicircular groove (84). In the area in front of the spring washer (89), it has a series of relief grooves.
In den Druckwaagenkolben (80) ist von seiner rechten Stirnseite her eine Führungsbohrung (87) zur Aufnahme der Regelfeder (88) eingearbeitet. Die Führungsbohrung (87) ist in ihrem Grund verengt, um die Regelfeder (88) radial zu fixieren. Eine Bohrung (115) mit einer vergleichbaren Kontur befindet sich auch in der linken Stirnseite der Verstellschraube (114).A guide bore (87) for receiving the control spring (88) is machined into the pressure compensator piston (80) from its right end. The bottom of the guide bore (87) is narrowed in order to radially fix the control spring (88). A hole (115) with a comparable contour is also in the left end of the adjusting screw (114).
Im Bereich der Druckwaage befinden sich im Gehäuse (30) zwei Kanäle (71) und (74). Benachbart zum Zulaufringkanal (93) liegt ein Rücklaufringkanal (71). Die Verbindung vom Zulaufringkanal (93) zum Rücklaufringkanal (71) ist beispielsweise beim Heben einer Last - nach dem Erreichen des Lastdruckes - durch den Druckwaagenkolben (80) mehr oder weniger vollständig geschlossen, während sie bei Neutralumlauf voll geöffnet ist.In the area of the pressure compensator there are two channels (71) and (74) in the housing (30). A return ring channel (71) is located adjacent to the inlet ring channel (93). The connection from the inlet ring channel (93) to the return ring channel (71) is more or less completely closed, for example when a load is lifted - after the load pressure has been reached - by the pressure compensator piston (80), while it is fully open during neutral circulation.
Zwischen dem Rücklaufringkanal (71) und der Verstellschraube (114) ist ein Lastmeldekanal (74) angeordnet. Er steht mit dem Kanalabschnitt (58) über eine zur Durchgangsbohrung (41) parallele Lastmeldebohrung (63) in Verbindung.A load signaling channel (74) is arranged between the return ring channel (71) and the adjusting screw (114). He's standing with the channel section (58) via a load-sensing bore (63) parallel to the through bore (41).
Auf der Höhe der Lastmeldebohrung (63) liegt die Stelle, an der sich der Verbindungskanal (55) in die beiden Kanalabschnitte (57) und (58) aufteilt. Innerhalb der in Figur 2 und 4 dargestellten Schnittfläche haben die beiden Kanalabschnitte zur Verbindung der beiden Ringkanäle (95) und (96) eine strömungsgünstige, u-förmige Kontur. Am Verbindungsabschnitt zwischen den beiden U-Schenkeln vereinigen sich die Kanalabschnitte (57) und (58) mit dem Verbindungskanal (55). Letzterer führt annähernd senkrecht in den Bereich des Senkenmoduls (120).At the level of the load reporting hole (63) is the point at which the connecting channel (55) is divided into the two channel sections (57) and (58). Within the sectional area shown in FIGS. 2 and 4, the two channel sections for connecting the two ring channels (95) and (96) have a streamlined, U-shaped contour. At the connecting section between the two U-legs, the channel sections (57) and (58) unite with the connecting channel (55). The latter leads approximately vertically into the area of the sink module (120).
Das Senkenmodul (120) hat eine das Gehäuse (30) durchquerende Stufenbohrung (44), die parallel zur Durchgangsbohrung (41) des Hebenmoduls (90) ausgerichtet ist. Die Stufenbohrung (44) ist links - wie auch im Hebenmodul - durch den Proportionalmagnet (121) und rechts durch eine Verschlußschraube (157) mit Innensechskant und zwischen Kopf und Gewinde angeordnetem Dichtring (158) druckmitteldicht verschlossen.The sink module (120) has a stepped bore (44) which passes through the housing (30) and which is aligned parallel to the through bore (41) of the lifting module (90). The stepped bore (44) is closed on the left - as in the lifting module - by the proportional magnet (121) and on the right by a screw plug (157) with a hexagon socket and a sealing ring (158) arranged between the head and the thread.
Im mittleren Bereich der Stufenbohrung (44) sitzt eine Ventilbüchse (130), die zwei ineinandergeschachtelte Längsschieber aufnimmt. Die Ventilbüchse (130) ist in der Stufenbohrung (44) zwischen einem linken Gehäusebund (124) und einem rechts angeordneten Schraubring (156) mit einem innenliegenden, durchgehenden Innensechskant axial gesichert. Der rechte Bereich der Stufenbohrung (44) ist dazu mit einem Innengewinde (129) versehen.In the middle area of the stepped bore (44) there is a valve sleeve (130) which receives two nested longitudinal slides. The valve sleeve (130) is axially secured in the stepped bore (44) between a left housing collar (124) and a screw ring (156) arranged on the right with an internal, continuous hexagon socket. The right area of the stepped bore (44) is provided with an internal thread (129).
Die Ventilbüchse (130) wird von einem Verbraucherringkanal (125) umgeben, der mit dem in Figur 3 gezeigten Verbraucheranschluß (50) hydraulisch in Verbindung steht. Links neben der Ventilbüchse (130) sitzt eine Einstellschraube (150) in dem Innengewinde (128). Im Bereich dieser Einstellschraube (150) mündet der Verbindungskanal (55) in die Stufenbohrung (44).The valve sleeve (130) is surrounded by a consumer ring channel (125) which is hydraulically connected to the consumer connection (50) shown in FIG. 3. To the left of the valve sleeve (130) there is an adjusting screw (150) in the internal thread (128). In the area of this adjusting screw (150), the connecting channel (55) opens into the stepped bore (44).
Die Einstellschraube (150) - mit Ausnahme einer auf ihr angeordneten Verzahnung (151) - und die Ventilbüchse (130) mit ihren beiden Längsschiebern ist aus der DE 41 40 604 A1 bekannt. In Figur 4 sind diese Bauteile geschnitten gezeigt.The adjusting screw (150) - with the exception of a toothing (151) arranged on it - and the valve sleeve (130) with its two longitudinal slides is known from
Das Senkenmodul (120) ist in Sperrstellung dargestellt. Das Druckmittel, das am Verbraucheranschluß (50), bzw. in Figur 4 am Anschluß (51), und damit am Verbraucherringkanal (125) ansteht, kann nicht in den Verbindungskanal (55) strömen. Der in der Ventilbüchse (130) direkt gelagerte Längsschieber, der Hauptsteuerschieber (140), steht mit seinem Hauptventilkegel (141) am Hauptventilsitz (132) der Ventilbüchse (130) an. Seine - an seinem linken Ende angeordneten - Hauptsteuerkerben (142) liegen verdeckt unter dem Zylindersitz (133) neben einem Ringraum (134). Um den Hauptsteuerschieber (140) auf dem Hauptventilsitz (132) zu halten, steht auf seiner rechten Stirnseite in einem Druckraum (135) Druckmittel an. Dorthin gelangt das Druckmittel aus dem Verbraucherringkanal (125) über Radialbohrungen (131) in der Ventilbüchse (130), sowie im Hauptsteuerschieber über eine Drosselbohrung (144) und eine daran anschließende Längsbohrung (145). Die Längsbohrung (145) durchdringt mit ihrem Bohrungsgrund eine Steuernut (143). Die Anpreßkraft wird vermindert durch die entgegengesetzt wirkende Kraft aufgrund des im Bereich der Außenkontur des Hauptsteuerschiebers (140) zwischen Hauptventilkegel (141) und Entlastungsnuten anstehenden Druckes.The sink module (120) is shown in the locked position. The pressure medium that is present at the consumer connection (50), or in FIG. 4 at the connection (51), and thus at the consumer ring channel (125), cannot flow into the connecting channel (55). The main spool (140), which is mounted directly in the valve sleeve (130), is in contact with the main valve seat (132) of the valve sleeve (130) with its main valve plug (141). Its main control notches (142) - located at its left end - are concealed under the cylinder seat (133) next to an annular space (134). In order to hold the main control slide (140) on the main valve seat (132), pressure medium is present in a pressure chamber (135) on its right end. The pressure medium gets there from the consumer ring channel (125) via radial bores (131) in the valve sleeve (130), and in the main control slide via a throttle bore (144) and a subsequent longitudinal bore (145). The longitudinal bore (145) penetrates a control groove (143) with its base. The contact pressure is reduced by the counteracting force due to the pressure existing in the area of the outer contour of the main control spool (140) between the main valve cone (141) and relief grooves.
Das Senkenmodul (120) öffnet mit der Bestromung des Proportionalmagneten (121). Sein Ankerstößel (122) schiebt den inneren Längsschieber, einen Vorsteuerschieber (147) geringfügig nach rechts. Dadurch gelangen seine Vorsteuerkerben (149) unter die Steuernut (143) des Hauptsteuerschiebers (140). Gleichzeitig hebt sein weiter links angeordneter Ventilkegel (148) von seinem im Hauptsteuerschieber (140) korrespondierenden Ventilsitz (146) ab. Der Druckraum (135) steht nun über die Längsbohrung (145), die Steuernut (143), die Vorsteuerkerben (149), den Ventilsitz (146) und den Verbindungskanal (55) mit dem Rücklaufringkanal (94) in Verbindung. In Abhängigkeit vom Öffnungsquerschnitt der Vorsteuerkerben (149) sinkt der Druck im Druckraum (135). Der dortige Druck stellt sich entsprechend dem Verhältnis des Querschnitts der Drosselbohrung (144) und dem Öffnungsquerschnitt der Vorsteuerkerben (149) ein. Fällt bei entsprechend weit nach rechts geschobenem Vorsteuerschieber (147) der Druck im Druckraum (135) so weit, daß die vom Druckmittel auf den Hauptsteuerschieber (140) im Bereich unterhalb der Radialbohrungen (131) nach rechts ausgeübte Kraft überwiegt, wird der Hauptsteuerschieber (140) ebenfalls nach rechts verschoben. Der Hauptventilkegel (141) hebt vom Hauptventilsitz (132) ab und die Hauptsteuerkerben (142) gelangen in den Bereich des Ringraumes (134). Das Druckmittel strömt, vom Verbraucher kommend, zwischen der Ventilbüchse (130) und dem Hauptsteuerschieber (140) in Richtung Verbindungskanal (55). Der Hauptsteuerschieber (140) eilt durch seine Öffnungsbewegung dem Vorsteuerschieber (147) nach, wodurch der Öffnungsquerschnitt an den Vorsteuerkerben (149) kleiner wird. Damit kann sich im Druckraum (135) über die Drosselbohrung (144) ein höherer Druck aufbauen. Folglich wird die Öffnungsbewegung des Hauptsteuerschiebers (140) gebremst, bis sich ein Gleichgewichtszustand einstellt.The sink module (120) opens when the proportional magnet (121) is energized. Its anchor tappet (122) pushes the inner longitudinal slide, a pilot spool (147) slightly to the right. As a result, its pilot control notches (149) come under the control groove (143) of the main control spool (140). At the same time, its valve cone (148) located further to the left lifts from its valve seat (146) corresponding in the main control spool (140) from. The pressure chamber (135) is now connected to the return ring channel (94) via the longitudinal bore (145), the control groove (143), the pilot control notches (149), the valve seat (146) and the connecting channel (55). Depending on the opening cross section of the pilot notches (149), the pressure in the pressure chamber (135) drops. The pressure there is adjusted according to the ratio of the cross section of the throttle bore (144) and the opening cross section of the pilot notches (149). If, when the pilot spool (147) is pushed far enough to the right, the pressure in the pressure chamber (135) drops so far that the force exerted by the pressure medium on the main spool (140) to the right in the area below the radial bores (131) predominates, the main spool (140 ) also shifted to the right. The main valve plug (141) lifts off the main valve seat (132) and the main control notches (142) reach the area of the annular space (134). Coming from the consumer, the pressure medium flows between the valve sleeve (130) and the main control slide (140) in the direction of the connecting channel (55). The main control slide valve (140) lags behind the pilot control slide valve (147) due to its opening movement, as a result of which the opening cross section at the pilot control notches (149) becomes smaller. This allows a higher pressure to build up in the pressure chamber (135) via the throttle bore (144). As a result, the opening movement of the main control spool (140) is braked until an equilibrium state is reached.
Bewegt sich der Ankerstößel (122) nach links, folgt ihm aufgrund einer in der Einstellschraube (150) integrierten Rückstellfeder (155) der Vorsteuerschieber (147). Die Rückstellfeder (155) stützt sich am Vorsteuerschieber (147) und an der Einstellschraube (150) ab. Bei der Bewegung des Vorsteuerschiebers (147) werden die Vorsteuerkerben (149) verschlossen. Der Druck im Druckraum (135) steigt. Der Hauptventilkegel (141) legt sich am Hauptventilsitz (132) an. Das Senkenmodul (120) sperrt. Das Proportionalwegeventilelement (120) arbeitet somit nach Art einer Folgesteuerung.If the armature plunger (122) moves to the left, it is followed by the pilot spool (147) due to a return spring (155) integrated in the adjusting screw (150). The return spring (155) is supported on the pilot spool (147) and on the adjusting screw (150). The pilot notches (149) are closed when the pilot spool (147) moves. The pressure in the pressure chamber (135) increases. The main valve plug (141) lies against the main valve seat (132). The sink module (120) locks. The proportional directional control valve element (120) thus operates in the manner of a sequence control.
Um die Vorspannkraft der Rückstellfeder (155) bei montierter Steuervorrichtung einstellen zu können, weist die Einstellschraube (150) im mittleren Bereich ihrer Außenkontur eine Schrägverzahnung (151) auf, in die zumindest zeitweise die Verzahnung einer Einstellschnecke eingreift. Die Einstellschnecke sitzt dazu in einer Einstellbohrung (68), die sich hier von der Vorderseite (34) bis in die Stufenbohrung (44) erstreckt und den Verbindungskanal (55) tangiert. Die Einstellschnecke kann mit Hilfe einer Einstellspindel, deren freies Ende aus dem Gehäuse (30) ragt, oder einem Spezialwerkzeug, das zeitweise mit der Einstellschnecke stirnseitig gekuppelt werden kann, in Drehung versetzt werden. Je nach Drehrichtung der Einstellspindel bzw. der Einstellschnecke wird die Einstellschraube (150) in dem Innengewinde (128) nach rechts oder links geschraubt. Die Länge des Verstellbereiches entspricht weitgehend der Breite der Verzahnung (151) der Einstellschraube (150).In order to be able to adjust the pretensioning force of the return spring (155) when the control device is mounted, the adjusting screw (150) has helical teeth (151) in the central area of its outer contour, which at least temporarily engage the teeth of an adjusting worm. For this purpose, the adjusting worm is seated in an adjusting bore (68), which here extends from the front (34) into the stepped bore (44) and touches the connecting channel (55). The adjusting worm can be rotated with the help of an adjusting spindle, the free end of which protrudes from the housing (30), or a special tool that can be temporarily coupled to the end of the adjusting worm. Depending on the direction of rotation of the adjusting spindle or the adjusting screw, the adjusting screw (150) is screwed to the right or left in the internal thread (128). The length of the adjustment range largely corresponds to the width of the toothing (151) of the adjusting screw (150).
Das Senkenmodul (120), das in der Steuervorrichtung während des Hebens der Last die Funktion eines Rückschlagventils hat, ist aufgrund der hohen Anforderungen an die Feinsteuerbarkeit beim Senken der Last durch die Drosselbohrung (144) relativ stark gedämpft. Diese Dämpfung bremst die Schließbewegung bei der Rückschlagfunktion. Zur Beschleunigung der Schließbewegung beim Lastheben kann der Drosselbohrung (144) ein Sitzventil (160) parallel geschaltet werden.The lowering module (120), which has the function of a check valve in the control device during the lifting of the load, is relatively strongly damped by the throttle bore (144) due to the high demands on the fine controllability when lowering the load. This damping slows down the closing movement during the kickback function. A seat valve (160) can be connected in parallel to the throttle bore (144) to accelerate the closing movement when lifting the load.
In Figur 4 ist rechts neben der Ventilbüchse (130) anstelle des Schraubringes (156), vgl. Figur 2, dieses Sitzventil (160) angeordnet. Das Sitzventil hat einen scheibenförmigen Körper mit einem angeformten Sechskant. Der zylindrische Teil seiner Außenkontur trägt ein Gewinde mit eingesetztem Dichtring, mit dem es in den rechten Bereich der Stufenbohrung (44) eingeschraubt ist. Wie der Schraubring (156) aus Figur 2 fixiert es die Ventilbüchse (130). Zwischen dem Boden des Sitzventils, dem rechten Randbereich der Außenkontur der Ventilbüchse (130) und dem Gehäuse (30) ist ein ringförmiger Kanal (161) ausgebildet. Der Kanal (161) steht über eine Schrägbohrung (162) mit dem hier an der Seitenflache (39) des Gehäuses (30) stutzenförmig angeformten Verbraucheranschlusses (51) in Verbindung.In Figure 4 is to the right of the valve sleeve (130) instead of the screw ring (156), cf. Figure 2, this seat valve (160) arranged. The seat valve has a disc-shaped body with a molded hexagon. The cylindrical part of its outer contour has a thread with an inserted sealing ring, with which it is screwed into the right area of the stepped bore (44). Like the screw ring (156) from FIG. 2, it fixes the valve sleeve (130). Between the bottom of the seat valve, the right edge area of the outer contour of the valve sleeve (130) and the housing (30) an annular channel (161) is formed. The channel (161) is connected via an oblique bore (162) to the consumer connection (51) integrally molded on the side surface (39) of the housing (30).
Das Sitzventil (160) weist eine Längsbohrung (165) auf, an der zur Ventilbüchse (130) hin ein kegelmantelförmiger Ventilsitz ausgebildet ist. Im rechten Teil der Längsbohrung (165) ist ein Schieberkolben (164) gelagert und geführt. Der rechte Abschnitt des Schieberkolbens (164) hat eine zylindrische Form. Daran schließt sich links ein Ventilteller an, der über eine Taille mit dem zylindrischen Abschnitt verbunden ist. Ein Hub des Schieberkolbens (164) nach rechts wird durch den Kontakt zwischen Ventilteller und Ventilsitz begrenzt, während ein Hub nach links durch das Anschlagen eines auf dem Schieberkolben sitzenden Sicherungsrings an der Stirnseite des Sechskants beendet wird. Von der Längsbohrung (165) gehen im Bereich der Taille des Schieberkolbens (164) annähernd sternförmig mehrere Bohrungen (166) weg. Sie enden im Übergangsbereich von Außengewinde und Boden des Sitzventils. Des weiteren ist im Bereich des Sechskants von der Längsbohrung aus eine Ringnut zur Aufnahme eines Dichtrings (167) eingearbeitet. In der Stufenbohrung (44) befindet sich zwischen dem Sitzventil (160) und der Verschlußschraube (157) ein Ringkanal (163), der mit der Lastmeldebohrung (63) in Verbindung steht.The seat valve (160) has a longitudinal bore (165) on which a valve seat in the shape of a cone is formed towards the valve sleeve (130). A slide piston (164) is mounted and guided in the right part of the longitudinal bore (165). The right portion of the spool (164) has a cylindrical shape. This is followed by a valve plate on the left, which is connected to the cylindrical section via a waist. A stroke of the slide piston (164) to the right is limited by the contact between the valve plate and the valve seat, while a stroke to the left is terminated by the striking of a retaining ring on the slide piston on the front side of the hexagon. Several holes (166) extend from the longitudinal bore (165) in an approximately star shape in the region of the waist of the slide piston (164). They end in the transition area between the external thread and the bottom of the seat valve. In addition, an annular groove for receiving a sealing ring (167) is machined in the area of the hexagon from the longitudinal bore. In the stepped bore (44) there is an annular channel (163) between the poppet valve (160) and the screw plug (157), which is connected to the load signaling bore (63).
Beim Heben der Last strömt bei bestromtem Proportionalmagnet (91), vgl. auch Figur 2, Druckmittel über den Pumpenanschluß (49), den Zulaufringkanal (93), den Längsschieber (97), und den Verbindungskanal (55) vor die Längsschieber (140) und (147) des Senkenmoduls (120). Um ein ruckfreies Anfahren der Last zu ermöglichen, öffnet der Längsschieber (97) zunächst nur über seine Feinsteuerkerben (103). Sie bilden im Bezug auf die Druckwaage (70) die Meßdrossel. Das Druckmittel fließt auf dem Weg zum Senkenmodul (120) über die Lastmeldebohrung (63) und den Lastmeldekanal (74) auf die Rückseite des Druckwaagenkolbens (80). Folglich bewegt sich dieser nach links und verringert zunehmend den Druckmittelstrom vom Zulaufringkanal (93) zum Rücklaufringkanal (71), bis der am Verbraucheranschluß (50) bzw. (51) anstehende Lastdruck erreicht ist. Beim Heben wird die Rückschlagventilfunktion des Proportionalwegeventilelements (120) ausgenutzt, um die Last abzusichern.When lifting the load, the proportional magnet (91) is energized, cf. also Figure 2, pressure medium via the pump connection (49), the inlet ring channel (93), the longitudinal slide (97), and the connecting channel (55) in front of the longitudinal slide (140) and (147) of the sink module (120). In order to enable the load to start up smoothly, the longitudinal slide (97) initially only opens via its fine control notches (103). They form the measuring throttle in relation to the pressure compensator (70). The pressure medium flows on the way to the sink module (120) via the load reporting hole (63) and the Load signaling channel (74) on the back of the pressure compensator piston (80). As a result, it moves to the left and increasingly reduces the pressure medium flow from the inlet ring channel (93) to the return ring channel (71) until the load pressure present at the consumer connection (50) or (51) is reached. When lifting, the check valve function of the proportional directional control valve element (120) is used to secure the load.
Hierbei liegt das durch die Druckwaage (70) erzeugte Regeldruckgefälle bei dem Schließvorgang nicht nur an den Feinsteuerkerben (103), sondern auch beidseits des Druckwaagenkolbens (80) an. Das dabei vorhandene geringe Druckgefälle, sowie der geringe Volumenstrom, der ggf. durch eine zur Stabilsierung der Bewegung des Druckwaagenkolbens (80) in der Lastmeldebohrung (63) integrierten Drosselstelle zusätzlich verringert wird, bedingt eine langsame Schließbewegung des Druckwaagenkolbens (80). Zur Beschleunigung der Schließbewegung kann beispielsweise kurzzeitig der Proportionalmagnet (121) des Senkenmoduls bestromt werden. In Figur 5 wird dazu die Bestromung der beiden Proportionalmagnete (91) und (121) bei einem Heben und anschließenden Senken der Last in vereinfachter Darstellung gezeigt. Auf der Abszisse ist die Zeit t aufgetragen. Auf dem positiven Ast der Ordinate ist der Strom I₉₁ für den Proportionalmagnet (91) und auf dem negativen Ast der Strom I₁₂₁ für den Proportionalmagnet (121) dargestellt. Die Last wird über den Zeitraum t₉₁ gehoben und über den Zeitraum t₁₂₁ abgesenkt. Während des Hebevorgangs wird innerhalb des Zeitraums t₉₁ nach der Zeit t₁, in der der Längsschieber (97), vgl. Figur 2, soweit nach rechts geschoben worden ist, daß die Verbindungen von den Kanalabschnitten (57) und (58) zum Rücklaufringkanal (94) gesperrt sind, der Proportionalmagnet (121) für die Zeit t₂ bestromt. Dadurch strömt vom Verbraucheranschluß (50) bzw. (51) Druckmittel unter Lastdruck über den Hauptsteuerschieber (140) und den Verbindungskanal (55), die Lastmeldebohrung (63) und den Lastmeldekanal (74) auf die Rückseite des Druckwaagenkolbens (80). Der dabei in Bewegung gesetzte große Volumenstrom läßt den Druckwaagenkolben (80) den Rücklaufringkanal (71) schnell sperren.Here, the control pressure drop generated by the pressure compensator (70) during the closing process not only rests on the fine control notches (103), but also on both sides of the pressure compensator piston (80). The low pressure drop present, as well as the low volume flow, which may be additionally reduced by a throttle point integrated in the load reporting bore (63) to stabilize the movement of the pressure compensator piston (80), necessitates a slow closing movement of the pressure compensator piston (80). To accelerate the closing movement, the proportional magnet (121) of the sink module can be energized briefly, for example. In FIG. 5, the energization of the two proportional magnets (91) and (121) is shown in a simplified representation when the load is raised and then lowered. The time t is plotted on the abscissa. On the positive branch of the ordinate, the current I₉₁ for the proportional magnet (91) and on the negative branch of the current I₁₂₁ for the proportional magnet (121) is shown. The load is raised over the period t₉₁ and lowered over the period t₁₂₁. During the lifting process is within the period t₉₁ after the time t₁ in which the longitudinal slide (97), see. Figure 2, as far as has been pushed to the right that the connections from the channel sections (57) and (58) to the return ring channel (94) are blocked, the proportional magnet (121) is energized for the time t₂. As a result, pressure medium flows from the consumer connection (50) or (51) under load pressure via the main control spool (140) and the connecting channel (55), the load signaling bore (63) and the load signaling channel (74) to the rear of the pressure compensator piston (80). The one set in motion large volume flow allows the pressure compensating piston (80) to quickly block the return ring channel (71).
Zum Beenden des Hebens der Last wird der Proportionalmagnet (91) abgeschaltet. Der Längsschieber (97) will sich aufgrund der Rückstellfeder (108) nach links bewegen, um den Weg zwischen dem Zulaufringkanal (93) und dem Kanalabschnitt (58) zu sperren. Das Sperren des Längsschiebers (97) erfolgt bei ungünstigen Bedingungen aber vor dem Sperren des Hauptsteuerschiebers (140) des wegen der Feinsteuerung stark gedämpften Senkenmoduls (120). Bei einem zu langsamen Schließen des Hauptsteuerschiebers (140) fließt vom Verbraucheranschluß (51) das Druckmittel zurück in Richtung Zulaufringkanal (93). Dabei können die Strömungskräfte den Längsschieber (97) beim Schließen stören. Dieses Problem beseitigt das Sitzventil (160). Bei der Hebenfunktion der Steuervorrichtung, wenn also das Senkenmodul (120) als Rückschlagventil arbeitet, ist der Druck in Durchflußrichtung gesehen vor dem Senkenmodul (120) größer als hinter ihm. Aufgrund dieses Druckunterschieds öffnet das Sitzventil (160), das zusätzlich parallel zur Steueröldrossel (144) geschaltet ist und beim Heben der Last den Drosselquerschnitt vergrößert. Folglich schließt der Hauptsteuerschieber (140) nahezu ungedämpft.The proportional magnet (91) is switched off to stop lifting the load. The longitudinal slide (97) wants to move to the left due to the return spring (108) in order to block the path between the inlet ring channel (93) and the channel section (58). The longitudinal slide (97) is blocked in unfavorable conditions, but before the main control slide (140) of the sink module (120), which is strongly damped due to the fine control, is blocked. If the main control slide (140) closes too slowly, the pressure medium flows back from the consumer connection (51) in the direction of the inlet ring channel (93). The flow forces can interfere with the longitudinal slide (97) when closing. The seat valve (160) eliminates this problem. In the lifting function of the control device, ie when the sink module (120) works as a check valve, the pressure in the flow direction is greater in front of the sink module (120) than behind it. Due to this pressure difference, the seat valve (160) opens, which is also connected in parallel to the control oil throttle (144) and increases the throttle cross-section when the load is lifted. As a result, the main control spool (140) closes almost undamped.
Bei dieser Steuervorrichtung besteht aufgrund der parallelen Anordnung der Module (90) und (120) die Möglichkeit, vor den rückseitigen Enden der beiden Proportionalmagneten (91) und (121) ein Handbedienungselement (25) beispielsweise in einem Schwenkgelenklager (26) zu lagern, vgl. Figur 2. Das Handbedienungselement (25) wirkt jeweils auf die Handnotbetätigungselemente (24) der Proportionalmagnete (91) und (121). Mit dem Handbedienungselement (25) kann manuell wahlweise entweder das Heben- (90) oder das Senkenmodul (120) angesteuert werden.In this control device, due to the parallel arrangement of the modules (90) and (120), it is possible to mount a manual control element (25) in front of the rear ends of the two proportional magnets (91) and (121), for example in a swivel joint bearing (26), cf. . Figure 2. The manual control element (25) acts on the manual override elements (24) of the proportional magnets (91) and (121). With the manual control element (25) either the lifting (90) or the lowering module (120) can be controlled manually.
Da der Hub des Proportionalmagneten (91) sehr kurz ist, wird der vom Senkenmodul (120) kommende Volumenstrom beim Senken auf die beiden Ringkanäle (95) und (96) geteilt und über die zwei Steuerkanten (101) und (102) in den Rücklaufringkanal (94) abgeführt. Hierdurch können relativ große Volumenströme bei einer kompakten und trotzdem einfachen Bauweise beherrscht werden.Since the stroke of the proportional magnet (91) is very short, the volume flow coming from the sink module (120) is divided into the two ring channels (95) and (96) when lowering and via the two control edges (101) and (102) into the return ring channel (94) removed. As a result, relatively large volume flows can be controlled with a compact, yet simple design.
Claims (12)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE4446144A DE4446144A1 (en) | 1994-12-23 | 1994-12-23 | Hydraulic control in monoblock design from at least two interlinked electromagnetically actuated proportional directional control valve elements |
| DE4446144 | 1994-12-23 |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| EP0718504A2 true EP0718504A2 (en) | 1996-06-26 |
| EP0718504A3 EP0718504A3 (en) | 1997-01-22 |
| EP0718504B1 EP0718504B1 (en) | 2000-05-03 |
Family
ID=6536810
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP95118187A Expired - Lifetime EP0718504B1 (en) | 1994-12-23 | 1995-11-18 | Mono-block hydraulic control system |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0718504B1 (en) |
| JP (1) | JP3639657B2 (en) |
| DE (2) | DE4446144A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0965763A1 (en) | 1998-06-17 | 1999-12-22 | HEILMEIER & WEINLEIN Fabrik für Oel-Hydraulik GmbH & Co. KG | Hydraulic control device |
| AT407662B (en) * | 1999-03-18 | 2001-05-25 | Hoerbiger Hydraulik | HYDRAULIC CONTROL UNIT |
| CN106949110A (en) * | 2017-04-10 | 2017-07-14 | 四川长江液压件有限责任公司 | A kind of pump flow stabilizing valve |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10006141A1 (en) * | 2000-02-11 | 2001-09-06 | Zf Lenksysteme Gmbh | Electro-hydraulic control device |
| KR100912597B1 (en) * | 2009-05-13 | 2009-08-19 | 신우공업 주식회사 | Parallel control valve body of fluid control valve |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3415265A (en) * | 1966-03-03 | 1968-12-10 | Parker Hannifin Corp | Directional control valve with priority flow divider |
| US3827453A (en) * | 1972-05-05 | 1974-08-06 | Parker Hannifin Corp | Directional control valve |
| DE3317605A1 (en) * | 1981-11-17 | 1984-11-15 | Robert Bosch Gmbh, 7000 Stuttgart | Arrangement for controlling pressure medium |
| DE3844336A1 (en) * | 1988-12-30 | 1990-07-05 | Bosch Gmbh Robert | ELECTROHYDRAULIC PORPORTIONAL WAY VALVE |
| DE4234742A1 (en) * | 1992-10-15 | 1994-04-21 | Deere & Co | Valve unit for position control of harvester - has pressure-limiting valve and non-return valve, spring for latter being weaker than for former |
-
1994
- 1994-12-23 DE DE4446144A patent/DE4446144A1/en not_active Withdrawn
-
1995
- 1995-11-18 DE DE59508271T patent/DE59508271D1/en not_active Expired - Lifetime
- 1995-11-18 EP EP95118187A patent/EP0718504B1/en not_active Expired - Lifetime
- 1995-12-19 JP JP33037395A patent/JP3639657B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0965763A1 (en) | 1998-06-17 | 1999-12-22 | HEILMEIER & WEINLEIN Fabrik für Oel-Hydraulik GmbH & Co. KG | Hydraulic control device |
| US6176261B1 (en) | 1998-06-17 | 2001-01-23 | Heilmeier & Weinlein Fabrik F. Oel-Hydraulik Gmbh & Co. Kg | Hydraulic control device |
| AT407662B (en) * | 1999-03-18 | 2001-05-25 | Hoerbiger Hydraulik | HYDRAULIC CONTROL UNIT |
| CN106949110A (en) * | 2017-04-10 | 2017-07-14 | 四川长江液压件有限责任公司 | A kind of pump flow stabilizing valve |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0718504A3 (en) | 1997-01-22 |
| DE4446144A1 (en) | 1996-06-27 |
| DE59508271D1 (en) | 2000-06-08 |
| JP3639657B2 (en) | 2005-04-20 |
| EP0718504B1 (en) | 2000-05-03 |
| JPH08233147A (en) | 1996-09-10 |
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