EP1687104A1 - Adjusting roll in rolling frames, among others vertical upset forging frames - Google Patents

Abstract

An adjusting cylinder for long, rapid lifting movements in rolling stands, including vertical edging stands, wherein each adjusting cylinder has at least one piston which acts through the bearing chocks of at least one work roll or of an interposed roll to adjust a work roll on both sides, wherein each adjusting cylinder has a piston that is equipped with two oppositely directed piston rods, and each piston is inserted in a recess in the cylinder base or cylinder cover, such that the base and cover have coaxially arranged bores through which the piston rods pass. The surface formed by the piston and the piston rod is smaller than the surface formed by the piston and the piston rod.

Description

Positioning cylinders in roll stands, including vertical upsetting stands

The invention relates to positioning cylinders for long, fast lifting movements in roll stands, u. a. those in vertical edging stands, each comprising at least one piston which acts on both sides of a work roll for adjustment via bearing chocks of at least one work roll or an intermediate roll.

The adjusting device in vertical upsetting stands, like the ones in horizontal stands, has the task of setting, maintaining and regulating the required roll gap.

In vertical compression stands, adjustment devices are known as purely mechanical, as purely hydraulic or as a combination of mechanical and hydraulic adjustment. It is technically possible and sensible to arrange one or two positions on each side.

For example, a purely hydraulic adjusting device in vertical upsetting stands in the roughing stand upsetting of a hot strip mill is known. This is designed as a classic differential cylinder, consisting of a piston, cylinder cover and cylinder base.

However, this version has limits both in the required oil requirement and thus the travel speed as well as in the sensitivity to lateral force when the piston rod is fully extended.

The known problem has hitherto made a purely hydraulic adjustment in vertical upsetting stands for heavy plate systems appear to be difficult to control. Because it is important to have a very long to drive towards the stroke because after turning a sheet metal, it is necessary to move from the minimum roll gap to the maximum roll gap within a short time.

The document US 36 24 958 describes a positioning control device for vertical compression stands for width control of the rolling material by means of an electrical screw adjustment device, combined with hydraulic servo-controlled cylinder adjustment devices for adjustments against rolling load. The cylinders are arranged on the side of the column crossheads of the vertical frames and are connected to the sliding nuts of the screw adjustment by means of a coupling plate.

The document DE-OS 32 12 525 A1 describes an electrohydraulic roll gap control and adjustment device for, in particular, the rolls of a vertical stand, consisting of an adjustment cylinder, the adjustment piston of which can move in a cylinder bore under the effect of pressure changes in a pressure medium, and an immersion piston, the immersed in the pressure medium and whose movements controlled by a hydraulic lifting device cause the displacements of the adjusting piston, the hydraulic lifting device being controlled by a servo valve, as well as with a scanning device for detecting the rolling forces by pressure measurement, a measuring direction for determining the actual position of the plunger and from a comparator processing the actual position of the plunger for the purpose of obtaining a change signal. The adjusting spindle is designed as a hollow body with an axial through bore of different diameter sections, the through bore of the adjusting spindle accommodating the hydraulic piston-cylinder units for width and / or thickness control.

The document US-PS 4,658,622 A describes an edge rolling mill with a pair of oppositely arranged vertical rolls. Each roller is provided with a drive that comprises two drive sections in generally parallel orientations. The first drive section is coupled to a drive wheel by means of a serrated design, in particular for a relatively larger one Adjustment of the roll gap when the stand is not under load. The second drive section is connected to the first drive section, also by means of a splined connection, which enables lower settings of the roll gap when the roll stand is working under load.

The document EP 0 493 430 B1 describes an edge rolling mill with a vertically arranged, movable housing pair, and with means for displacing each movable housing in the horizontal direction towards and away from the other housing and with a pair of rollers, the longitudinal axes of which are arranged in the vertical direction are. The rollers are rotatably held in the corresponding cassettes. The cassettes are held by correspondingly movable housings so that they can be moved with them and are located inside the housing. Means are also provided for displacing each cassette in the vertical direction with respect to its associated movable housing.

Document EP 0 491 785 B1 describes a vertical rolling train with two vertically movable housings, two rollers arranged vertically with their longitudinal axes and rotatably fastened in associated cassettes, the cassettes being supported by movable housings and being arranged within the housings. Means are provided for displacing each movable housing and the associated cassette in the horizontal direction towards or away from the other housing and a device for displacing each cassette relative to its housing in the horizontal direction towards and away from the other cassette. Each housing has a drive mechanism, the output side of which is in drive relationship with the lower end of the roller in the associated cassette and the input side of which is in drive relationship with a horizontal drive shaft. Each drive mechanism has a universal joint which enables a drive to be transmitted from the shaft to the roller, even if the cassette is offset by a certain amount horizontally relative to its housing. The document DE-OS 2 047 240 discloses a method for rolling in a vertical stand, the roll gap being controlled automatically during the rolling. First a flat edge profile is rolled across its side edges in a vertical stand and then in a horizontal stand. The rolling gap of the vertical stand is automatically changed when the end pieces of the flat profile are rolled so that their dimensions do not differ significantly from those of the other flat profile during subsequent flat rolling.

The document EP 0 868 946 A2 discloses a compression frame downstream of a continuous caster and upstream of a finishing train. This is to be controlled in such a way that the sliver can safely run into the first stand of the finishing train, with a structural change in the strip edge region being to be ensured in order to avoid cracks in the strip edge region. For this purpose, it is proposed that pressure control loops for the compression degree monitoring as well as overload limitation and differential load monitoring are superimposed on the position control loops for the compression frame.

Document EP 0 450 294 B1 discloses an adjusting device for adjusting the roller spacing in rolling stands, in particular in strip rolling stands for hot or cold rolling, with at least two hydraulic adjusting cylinders which work on both sides of a work roll to be adjusted in each case via chocks and, if necessary, an intermediate support roller. The positioning cylinders each have a hat piston guided in a cylinder housing on a cylinder journal and in a cylinder collar, the central piston surface of which is formed by the inner hat bottom and the ring piston surface which is formed by the hat rim can be acted upon independently of one another or individually or jointly with pressure medium.

Starting from the aforementioned prior art, the invention comprises the object of making it possible to improve the known purely hydraulic adjusting devices, the number of adjusting cylinders not being fixed should be, so that the arrangement of only one cylinder per side should remain technically possible.

The object is achieved with the invention for pitch cylinders of the type mentioned in the preamble of claim 1 in that the pitch cylinder is equipped with a second piston rod in such a way that each pitch cylinder has a piston with two piston rods in opposite directions Is equipped with directions, and the piston is inserted in a recess in the cylinder base or cylinder cover, these having coaxially arranged bores for the passage of the piston rods.

The design of the adjusting cylinder according to the invention is based on a support length that is the same over the entire cylinder stroke, the cross-sectional area of the second piston rod considerably reducing the required oil requirement and thus achieving a higher travel speed with the same pump output. Thus, the application of the invention is not limited to a vertical compression frame in heavy plate systems, but can also be used with advantage in other frames of other systems. A further advantage of this invention enables an optimization of oil demand and travel speed:

The invention is further developed in subclaims.

The proposed encapsulation of the second piston rod is designed as an additional cylinder oil space. A corresponding control can be used to produce a short circuit between the emptying and the additional filling oil space of the cylinder during the rolling force-free movement in the direction of the rolling stock. This reduces the additional pump output. During rolling, a short circuit can be created between the two oil spaces on the additional rod side. This makes it possible to apply the required rolling force with the complete piston surface. The invention is described with the aid of partially schematic figures:

Figure 1 shows the schematic adjusting cylinder with piston, piston rod, seals and the like;

FIG. 2 shows the schematic control of the positioning cylinder for fast forward movement, upsetting and fast return movement;

FIG. 3 shows the positioning cylinders in the installation situation, for example in a compression frame;

Figure 4 shows a positioning cylinder with two pressure chambers;

FIG. 5 an adjusting cylinder with three pressure spaces;

Figure 6 shows a plunger cylinder with a pressure chamber;

Figure 7 shows a plunger cylinder with two pressure chambers.

According to Figure 1, the positioning cylinder consists of the piston (KO) with the rod (ST1) and the rod (ST2). The piston is embedded in the cylinder cover (ZD) and the cylinder base (ZB), both of which have coaxially arranged bores for the passage of the piston rods. In the latter two bores there are receptacles for piston guide elements, which are designed here as metal bushings (BU1), (BU2). Both metal bushings (BU1), (BU2) are held by corresponding covers (DE1), (DE2). The seals belonging to the cylinder (DM - DI3) are located in the cover (DE1), in the piston (KO) and in the cylinder base (ZB). The cylinder base (ZB) and cylinder cover (ZD) are screwed together with the screws (SR2). The complete positioning cylinder is screwed to the stand of the roll stand with the screws (SR1). In demand rod (ST1) is a pressure piece (DS). The rod (ST1) is protected with a bellows (FB). The bellows (FB) is either supported on the rod (ST1) by means of sliding disks or is held by means of loops on guide rods (not shown here).

The cylinder piston has an anti-rotation device, which is either designed as a frame connection (not shown here) between the pressure pieces (DS) of two stacking cylinders arranged one above the other or consists of extensions of the pressure piece (DS) which are guided in the guide rods already mentioned. In continuation of the cylinder base (ZB) there is a capsule (KA), which protects the rod (ST2) on the one hand and on the other hand has the option of being used as an additional oil chamber (OL3). In the extension of the capsule (KA) there is a position measuring system, here designed as a position encoder (PG), which takes up the position of the cylinder piston.

The design of the adjusting cylinder in FIGS. 4 and 5 is analogous. 6 and 7, the cylinder cover and cylinder base are part (PB) and the piston (KO) consists only of the adjusting cylinder rods (ST3, ST4).

Depending on the design, the oil spaces (OL1, OL2, OL3) shown in FIG. 5 form the force-relevant ring areas A1 and A2 or the circular area A3.

In Figure 2, the control is schematically explained for a fast forward and backward movement of the positioning cylinder with a low volume flow or compression of the rolling stock with high force. The individual operating phases 1 to 3, i.e. rapid advancement, upsetting with high force and rapid retraction can be seen clearly from FIG. 2.

Phase 1: fast approach with reduced force: pressure on surface A2; Areas A1 and A3 are as depressurized as possible (P ₂ »0; pι * 0) optimal: A1 «A3; Lines 1 and 3 can be connected, oil then flows from line 1 to line 3 or the corresponding exchange of areas A2 and A3

Phase 2: upsetting with high force pressure on surface A2 and surface A3; Area A1 <areas A2 + A3

Phase 3: rapid return pressure on area A1; Areas A2 and A3 are depressurized or pressurized.

FIG. 3 shows the installation situation of four different types of positioning cylinders in a compression frame. The design with two piston rods is common to all designs. When the starting cylinder is used in a compression frame, it is installed four times in accordance with FIG. 3; Two adjusting cylinders on each side, which are arranged above and below the center plane (9). Technically, however, it is also possible to arrange only one positioning cylinder on each side. The cylinders are inserted in corresponding bores in the upsetting stand (8) and act on the upsetting rollers (7). In conjunction with a balancing crossbeam (6), the balancing cylinder (5) pushes the play out of the overall system. The balancing cylinder (5) can also act as a retraction cylinder.

The following cylinder embodiments are shown in FIGS. 4 to 7:

FIG. 4 shows a positioning cylinder with 2 pressure spaces and the effective areas A1 and A2, FIG. 5 shows a positioning cylinder with 3 pressure spaces and the effective areas A1, A2 and A3, FIG. 6 shows a plunger cylinder with 1 pressure space and the effective area A2, Figure 7 shows a plunger cylinder with 2 pressure chambers and the effective areas A2 and A3.

The driving style of the individual construction methods can be selected according to the necessary specifications, e.g. B. according

Figure 4: Double-acting cylinder with pressurization of the ring surface A2 for rapid advancement and for applying the rolling force, ring surface A1 is pressurized for retracting the cylinder

Figure 5: Double-acting cylinder with pressurization of the annular surface A2 and / or circular surface A3 for rapid advancement and use of the annular surface A2 and / or circular surface A3 to apply the rolling force, annular surface A1 is pressurized to retract the cylinder

Figure 6 Plunger cylinder with pressurization of the ring surface A2 for rapid advancement and for applying the rolling force, balancing cylinder (5) acts as a retraction cylinder

FIG. 7 plunger cylinder with pressurization of the annular surface A2 and / or circular surface A3 for rapid advancement and use of the annular surface A2 and / or circular surface A3 for applying the rolling force, balancing cylinder (5) acts as a retracting cylinder

or single-acting cylinder with pressurization of the ring surface

5 before A2 and / or circular area A3 for rapid advancement and use of the annular area A2 and / or circular area A3 for applying the rolling force, annular area A1 is depressurized, balancing cylinder (5) acts as a retraction cylinder. or single-acting cylinder with pressurization of the ring surface

Figure 4 before A2 for rapid advancement and for applying the rolling force, ring surface A1 is depressurized, balancing cylinder (5) acts as a retraction cylinder.

Differential circuits of the pressure spaces A1 and / or A2 and / or A3 z. B. to apply the required amounts of oil are also conceivable. The individual pressure chambers are pressurized via solenoid valves, servo valves, non-return valves, pumps, containers, pressure vessels, accumulators etc. in accordance with the state of the art.

Claims

claims 1. Positioning cylinder for long, fast lifting movements in roll stands, inter alia, in vertical upsetting stands, each comprising at least one piston which acts on both sides of a work roll for positioning via bearing chocks of at least one work roll or an intermediate roll, characterized in that each position cylinder has a piston (KO), which is equipped with two piston rods (ST1, ST2) pointing in opposite directions, and that the piston (KO) is inserted in a recess in the cylinder base (ZB) or cylinder cover (ZD), these being coaxial have arranged holes for the passage of the piston rods (ST1, ST2). 2. Adjusting cylinder according to claim 1, characterized in that receptacles for piston rod guide elements are provided in the aforementioned bores, which are preferably designed as metal bushings (BU1, BU2), or as guide bands and are preferably held by covers (DE1, DE2). 3. Adjusting cylinder according to one of claims 1 or 2, characterized in that seals belonging to the cylinder (DM, DI2, DI3) are located in the cover (DE1) and (DE2) and in the piston (KO) (FIG. 1) or guide bands with the seals in the covers (DE1) and (DE2). 4. adjusting cylinder according to one or more of claims 1 to 3, characterized in that the cylinder base (ZB) is connected to the cylinder cover (ZD) by means of screws (SR2). 5. pitch cylinder according to one or more of claims 1 to 4, characterized in that the complete pitch cylinder by means of screws (SR1) is connected to the scaffold stand. 6. adjusting cylinder according to one or more of claims 1 to 5, characterized in that there is a capsule (KA) in continuation of the cylinder base (ZB), which either protects the piston rod (ST2), or can be used as an additional oil chamber (OL3) , 7. adjusting cylinder according to one or more of claims 1 to 6, characterized in that in the extension of the capsule (KA) is a position encoder (PG) designed as a position measuring system or the like, which receives the position of the piston (KO). 8. adjusting cylinder according to one or more of claims 1 to 7, characterized in that the extension of the piston rod (ST1) is arranged a pressure piece (DS) for acting on the roller chocks. 9. adjusting cylinder according to one or more of claims 1 to 8, characterized in that the piston (KO) has an anti-rotation device. 10. adjusting cylinder according to one or more of claims 1 to 9, characterized in that the piston rod (ST1) connected to the pressure piece (DS) is surrounded by a bellows. 11. A method of operating the adjusting cylinder, comprising a non-positively movable in an at least two-part housing (G1, G2) between pressure surfaces (A1, A2, A3), which acts on an installation piece (ES) of a rolling stand in three working phases (KO) that, for phase 1, pressure is applied to area A2 to reduce the force, while areas A1 and A3 are depressurized; that for phase 2, high pressure is applied to surfaces A2 and / or A3; and that for phase 3, pressure is applied to area A1 with areas A2 and A3 as unpressurized as possible (FIG. 2). 12. A method of operating the adjusting cylinder, comprising a non-positively movable in an at least two-part housing (G1, G2) between pressure surfaces (A1, A2, A3), which acts on an installation piece (ES) of a roll stand in three working phases (KO) that, for phase 1, pressure is applied to area A3 to reduce the force, while areas A1 and A2 are depressurized; that for phase 2, high pressure is applied to surfaces A2 and / or A3; and that for phase 3, pressure is applied to area A1 with areas A3 and A2 as unpressurized as possible (FIG. 2). 13. Method for operating the adjusting cylinder, comprising a in an at least two-part housing (G1, G2) between pressure surfaces (A1, A2, A3) non-positively movable working piston (KO) acting on an installation piece (ES) of a roll stand in three working phases, characterized in that for phase 1, pressure is applied to surfaces A2 and A3 for reduced advancement with reduced force, whereas surfaces A1 and A3 or A2 are depressurized if possible; that for phase 2, high pressure compression is applied to both surfaces A2 and / or A3 and pressure to surface A1; and that for phase 3, pressure is applied to area A1 with areas A2 or A3 and A3 or A2 as unpressurized as possible (FIG. 2). 14. Method for operating the adjusting cylinder, comprising a work piston (KO) which can be moved in a force-fitting manner in an at least two-part housing (G1, G2) between pressure surfaces (A1, A2, A3) and acts on an installation piece (ES) of a roll stand in three work phases. , according to one of claims 11, 12 or 13, characterized in that a separate retraction cylinder is used in phase 3 for rapid retraction, with areas A2 and A3 that are as unpressurized as possible, wherein the size of area A1 can also be zero (plunger cylinder).