EP0949021B1 - Device for the forming of wire, with a wire braking device - Google Patents

Description

The invention relates to a device according to the preamble of claim 1. Such a wire-forming device (WAFIOS-FTU 3) has been known from DE 42 29 294 C1. This device has a flange (118) which is fixed to the frame and has an extension arm (140) on which a wire guide insert (136) is mounted in a radially adjustable manner, which has an eccentric wire guide bore (137) and which interacts with a cutting tool (14). The wire guide (130) ending at the insert (136) always rotates around the wire axis in synchronism with the pairs of feed rollers. - This device has already been modified so that the boom on the now rotatable flange with the insert holding the wire can be guided as a unit on a circular path around the wire axis so that the friction between the wire and insert can be eliminated. This proposal is also made by DE 197 36 468 A1 (ITAYA), but where the stationary wire guide (80) between here stationary wire feed rollers (14 and 15) on the one hand and rotatable wire holder (70) on the other hand generates friction when the wire is rotated about its longitudinal axis.
A special feature in the case of DE 197 36 468 A1 is a remotely rotatable wire gripper (64) which is arranged on the rotatable wire guide (70) for the rotationally fixed clamping of the wire, which wire cannot rotate about its axis like jamming feed rollers.
Compared to the prior art, the device according to the invention is characterized by the characterizing features of claims 1 to 4; it is preferably a device according to claim 5.
The invention also relates to the method according to claim 6.

The object of the invention is the geometric shape accuracy of the, from DE 42 29 294 C1 known device for forming wire three-dimensional wire structures to improve substantially, and this consistently, and to increase the output of the device, d. H. an increase in quality of finished workpieces, and an increase in performance to achieve in a device for molding three-dimensional workpieces.

According to the invention, this is firstly achieved in that the rotatable on the bearing body Wire feed device of the device for forming wire according to DE 42 29 294 C1 rigid arranged output wire guide device by a known rotatable wire guide device is replaced, and secondly in that the rotating wire guide device with a program-controlled and force-controlled wire "brake" device according to the invention is provided, the servo drive for the shaping process, together with the servo drives of the other device units is controlled by the machine control.

Due to the common but separate arrangement 'rotating wire feed' and 'rotating wire guide' With synchronous operation, sliding friction in the direction of rotation is completely eliminated, because when turning the There is no relative movement between the wire feed and wire guide. This is special advantageous because of friction of the wire in the wire guide during the shaping process Leads to inaccuracies in the workpiece geometry. There is also an 'unlimited' turning of the wire (back and forth) also possible when the wire guide is stationary.

Of course, there is also asynchronous running of the rotating wire feed and rotating wire guide possible.

The aforementioned advantage of friction elimination can be optimized by the wire brake device according to the invention, which is program-controlled and force-controlled for each individual working section on a workpiece to be manufactured. For example, the braking force acting on the wire can be set in a program-controlled manner in such a way that a damping effect occurs during the shaping process, for example when a workpiece part that has already been produced is turned over in the wire forming area. Or, with an appropriate program-controlled braking force, a holding or stabilizing effect can be achieved during machining operations on the stationary wire, so that the wire, if necessary, cannot twist in the angular position of a section that has already been produced. Furthermore, the braking force acting on the incoming wire can be predefined by the computer in such a way that, for example during winding, the play between the incoming wire and the wire guide is reduced in such a targeted manner that an exact spring shape and spring pitch is achieved during the winding process, but the wire is still can be fed.

This would allow too much play between wire and guide, e.g. originating from the wear of the Wire guide (increasing wire guide hole), or too much play, resulting compensate by wire diameter tolerances.

Through these improvements in each individual manufacturing section, the quality of the finished falling workpiece significantly increased, and this even with a large number of manufactured Parts.

Fig. 1

die Ausführungsform in teilweise abgebrochener Darstellung in Seitenansicht

Fig. 2

eine Vorderansicht auf einen Teil der Ausführungsform

Fig. 3

eine teilweise geschnittene Vergrößerung der Einzelheit A in Fig. 1

The invention is explained in detail below with reference to the preferred embodiment schematically illustrated by the drawing. It shows

Fig. 1

the embodiment in a partially broken view in side view

Fig. 2

a front view of part of the embodiment

Fig. 3

a partially sectioned enlargement of detail A in Fig. 1st

1 and 2 is a rotatable wire feed device (10), a rotatable wire guide device (12) with a wire brake device (114), a wire forming station (14) and a cutting device (16) for cutting the workpiece from the endless wire (18) of a CNC-controlled device to see wire forming.

It becomes the rotatable CNC-controlled wire feed device known from DE 42 29 294 C1 (10) for intermittent advancement of the wire (18) into the wire forming station (14) and CNC-controlled turning of the wire (18) by a predetermined angle

For this purpose, the known CNC-controlled rotatable described in DE 42 29 294 C1 Wire feed device (12) has a feed housing (22) in which a total of four wire feed rollers (24) are rotatably mounted, which advance the wire (18) into the wire forming station (14). The Rollers (24) are arranged in pairs and are operated by a first CNC-controllable servo motor (26) via two toothed belt transmissions, of which only one (28) is shown here, program-controlled Speed-controlled intermittent, optionally driven forwards and backwards.

For rotating the drawn-in wire (18) clamped between the wire feed rollers (24) the feed housing (22) of the wire feed device (10) is itself in one on the device for forming wire-fastened bearing body (30) rotatably mounted. The feeder housing (22) is program-controlled by a second controllable servo motor (34) via a toothed belt gear (36), intermittently driven either forwards or backwards.

On the left in Fig. 1, the wire inlet side of the rotatably mounted feed housing (22) a conventional wire straightening device (38) with horizontally and vertically arranged straightening rollers for straightening of the wire (18) attached to the extended feed housing. before this through the feed housing (22) is inserted between the feed rollers (24).

On the right side in FIG. 1 of the bearing body (30) is part of the wire guide device a two-part, consisting of an upper part (42) and a lower part (44) and on the feed housing (22) held wire guide (48) rotatably mounted in the bearing body (30). The wire guide (48) extends to the left up to the outlet of the right pair of wire feed rollers and back right up to an eccentric wire holder (52).

The wire holder (52) is part of the rotatable wire guide device (12). This also consists of one, outside of the front plate (58) of the machine frame in the plate (58) roller bearings around the Wire axis rotatable boom (60) on a rotatable flange (62) in the plate (58) with a Toothed pulley (64) of a toothed belt drive (66) is screwed. The toothed disc (64) is about a toothed belt (68) of the toothed belt drive (66) from a third CNC-controllable servo motor (70) Program-controlled, intermittent, optionally driven forwards and backwards.

At the free end of the boom (60) the wire holder (52) is releasably attached, which is axially in front of the front exit of the wire guide (48) which is rotatable with the wire feed device (10).

Now to the details of Fig. 3:
A pull rod (116) is slidably guided in the arm (60) of the rotatable wire guide device (12) to actuate the wire brake device (114). One end of the pull rod (116) is connected to a two-armed lever (120) by a bolt (118). The lever (120) is pivotally mounted in the arm (60) on a bolt (122). The free lever arm (124) of the lever (120) presses on the rounded end of a pressure bolt (128), which is preloaded via a compression spring (126) in the (two-part) wire holder (52) and has a prismatic recess at its other end . This prismatic end of the bolt (128) interacts with the wire (18) passing by, friction forces resulting in braking forces.

The end of the pull rod (116) opposite the lever (120) is connected to a switching ring (130) firmly connected. The switching ring (130) is mounted axially displaceably in a sliding bush (132), however held radially in the sleeve (132) not rotatable. When the flange (62) rotates Accordingly, the switching ring (130) rotates to the same extent. The switching ring (130) is with a Provided circumferential groove (134) on its outer circumference, in the two switching claws (136) of a two-armed Engage the shift lever (138).

The shift lever (138) can be pivoted approximately centrally in a bearing (140) on a bolt (142) stored. The bearing (140) is firmly connected to the front plate (58).

The arm of the shift lever (138) opposite the shifting claws (136) has an internal thread bearing lever eye (144) into which a threaded spindle (146) is screwed. The threaded spindle (146) can be controlled via a coupling (148) with the stub shaft (150) of a CNC Servo motor (152) non-rotatably connected.

For the shaping process on the advanced wire, the rotatable wire guide device can be used (12) the holder (52) can be brought into the most favorable position, e.g. for beating around of a partially manufactured workpiece, or that the wire holder (52) is turned so that when cutting a finished workpiece from the endless wire, the cutting knife (100) the cutting device (16) the wire (18) against the larger wall thickness of the holder (52), which also serves as a counter knife, cuts off.

The wire forming station (14) is on the front panel (58), which is also the shaping side of the device for forming wire is arranged. It consists of several radially around the wire guide hole (74) of the wire holder (52) attached processing units. 2 are three of these Units shown, namely a winch / bending unit (78), a CNC slewing gear (80) and one CNC pusher unit belonging to the cutting device (16). The winch / bending unit (78) is in DE 42 29 294.C1 and DE 39 15 784 C1 described in more detail. In Fig. 1 is to the right of the wire holder (52) a vertical shaft (80) of the winding / bending unit (78) perpendicular to the wire feed device arranged which is rotatably driven by a fourth CNC-controllable servo motor (84) is selected, the degree of shaft rotation, the direction of rotation and the standstill are freely selectable. In order to the shaft (80), in addition to its rotary movement, also a possibly simultaneous one Can perform longitudinal movement, another not shown CNC controllable servo motor is provided. The size of the longitudinal movement of the shaft (82) is also by the CNC control freely selectable.

At the lower end of the shaft (82) is known in a conical receptacle on DE 89 15 888 U1 Tool holder (86) rigid, but releasably attached, the multiple tools on its circumference arranged and can wear distributed over its length. In the embodiment shown this two winding tools (88) and (90) with several effective zones for the running wire (18) and a bending tool (92).

The slide unit belonging to the cutting device (16) is controlled by another CNC Servo motor (96) via a crank mechanism (not shown) and one that is also not shown Conrod driven. The cutting knife (100) is at the free end of the in a slide guide the cutting device (16) in a longitudinally displaceably slidable cutting slide (102) in a receptacle (104) held interchangeably.

The mode of operation of the device according to the invention is as follows in the exemplary embodiment:

The straight wire and clamped between the feed rollers (24) is endless wire (18) upon activation of the first servo motor (26) through the wire guide (48) and the holder (52) by means of the CNC-controlled feed rollers (24) intermittently horizontally in a straight line advanced into the wire-forming station (14) and in accordance with those arranged on the tool holder (86), effective tools are deformed. The CNC controlled withdrawal of the wire is also possible by reversing the direction of motor rotation.

The positioning of the individual tools before the shaping process and the active one Tool movement for shaping the workpiece is carried out by the CNC control of the servo motors of the winch and bending unit (78) and are from the exemplary DE 39 15 784 C1 known.

The endless wire (18) fed by means of the feed rollers (24) is fed by the second servo motor (34) via the toothed belt gear (36) and the feed housing (22) CNC-controlled in the predetermined Angle and at the right time, if necessary, simultaneously with the feeding of the wire (18) by the feed rollers (24), for each individual shaping section of the wire in the most favorable spatial processing position before carrying out the next processing step turned.

Simultaneously with the wire turning by the rotatable wire feed device (10) is in synchronous operation of 'rotating wire feed' and 'rotating wire guide' by the wire holder (52) the CNC control of the third controllable servo motor (70) for the molding process most favorable location rotated. At the same time, the program-controlled and force-controlled Wire brake device (114) by activating the CNC-controllable servo motor (152) to be brought. The size of those transferred to the wire (18) via the pressure pin (128) The braking force is dependent on the respective shaping process from the CNC machine control given.

Claims (6)

1. Device for forming wire into wire products, with a straight wire guide (48), a wire intake device (10) which is arranged at the inlet opening thereof and the parts (24), which clamp the rectilinearly drawn-in wire (18) to be secure against rotation, of which are rotatable in common with the wire guide (48) about the wire axis, and with a wire holder (52) which is arranged at an arm (60) at the outlet opening of the wire guide (48), conducts onward the wire (18) issuing therefrom and co-operates at its outlet opening with a cutting tool (100) movable transversely to the wire axis, wherein the wire advance towards and in a given case a wire retraction from this wire holder outlet opening by the wire intake device (10) as well as the partial rotation thereof about the wire axis are program-controllable matched to one another, characterised in that in the case of such a device with an arm (60), which can be guided on a circular path about the wire axis, with a wire holder (52) the unit thereof is provided with a remotely controllable wire braking device (114) which acts radially on the wire (18) pushed past and is program-controllable for that purpose.
2. Device according to claim 1, characterised in that the wire braking device (114) comprises a spring-loaded braking element (128) at a lever (120), which is rotatable about an axis (118) perpendicularly intersecting the wire axis by means of a pivoted push and pull rod (116) guided in the arm (60) parallelly to the wire axis.
3. Device according to claim 2, characterised in that in the case of such a device with a flange (62), which is mounted at the machine frame to be rotatable about the wire axis, at the arm (60), the drive (66) of the flange (62) being program-controllable, a drum (130) is mounted coaxially in the flange (62) and on the wire guide (48) to be axially displaceable and rotatable, the end, which is remote from the element, of the rod (116) being fastened as an axial entrainer to the drum (130).
4. Device according to claim 3, characterised in that the drum (130) comprises a circumferential groove (134) which runs around the wire guidance axis and in which a free end of a switching lever (138) mounted at the machine frame (58) engages in shape-locking manner, the lever being rotatable by means of a program-controllable drive (152) which generates the braking force.
5. Device according to one of claims 1 to 4, with a shaft (82) which is rotatably arranged at the outlet opening of the wire holder (52) and the longitudinal and rotational axis of which is disposed adjacent to the linear wire path outside the wire holder (52), and with a tool holder (86) which is arranged at the free end of the shaft (82) and which carries at least one tool (88 or 90) for coiling and/or bending the fed wire (18), wherein the rotating and displacing movements of the shaft (82) are program-controllable for moving the tool (88 or 90) in the wire path or relative thereto.
6. Method for forming wire into wire products in which the wire, which is straightened at the intake and which is to be formed, is advanced in its longitudinal direction in program-controlled manner to the forming station or retracted therefrom and is rotated back and forth about its straight longitudinal axis in program-controlled manner, characterised in that the longitudinal movement and/or the rotation of the wire, which is to be formed, is or are braked in program-controlled manner in the vicinity of the forming station.

Images