EP0041690A2 - Multistage metal-forming machine - Google Patents

Abstract

A blank (17), which has been sheared off from a coil of wire or from a rod, is rotated through 90 DEG , this rotation being required in connection with the forging of this blank. The gripping-jaws (19, 20), serving for the purpose of transport from one station to the adjacent metal-working station, are attached, for this purpose, to rotating devices (9c, 9d), which are mounted in a manner permitting rotation and are located, on the one hand, on a guide part (7a, 7b) which is driven to reciprocate (A) and to oscillate about an axis (93), and, on the other hand, are anchored to the stationary die-holder (3) via a guiding mechanism (23a, 23b). The guiding mechanism can be regarded as a spatial double-link mechanism, possessing a connecting rod (24), a coupling link (25), a stationary pin-joint (28), a ball-joint (30), and a pin-joint (29a, 29b) which travels with the rotation device (9c, 9d). The components are arranged in such a way that the greatest part of the intended 90 DEG rotation of the blank takes place in the first half of the translational transport movement.

Description

The present invention relates to a multi-stage forming machine for the chipless shaping of blanks, which are at the transition from one station to the adjacent station rotated with respect to a plane extending transversely to the longitudinal extent of the blanks and transversely to the pressing direction of the axis of rotation to practically 90 ^0, where for the transport of the blanks between the two A pair of pliers is provided in adjacent stations, the two pliers of which are fastened to guide parts via pliers carriers, which in turn are rigidly coupled to a main shaft which is driven back and forth and oscillates about its own axis.

In conventional multi-stage forming machines that form parts directly from the wire ring or bars, the starting material is pulled in the direction of the press axis next to the press slide against a stop and sheared off with a shear knife. The shear carriage also serves as a feed for the sheared blank in front of the 1st forming station or in a loading station, the longitudinal axis of the blank remaining parallel to the press axis.

If it is now a question of forming a pressed part whose transverse extent, in particular in one direction, is many times larger than the longitudinal dimensions, it can be very difficult or even impossible to manufacture such parts on such multi-stage presses because of the large degree of deformation and thus large pressing forces.

There are known indeed to such a metal forming devices may be by means of which blanks or pressing parts 180 ⁰ rotated. The rotary movement which can be achieved with these known devices, however, inevitably proceeds in such a way that each section of the path traversed in translation corresponds to an equal fraction of the total angle of rotation. On the last third of the transport movement, however, the rotation should, if possible, be largely completed, at least apart from a slight remaining rotation, in order to avoid a collision with the adjacent die or a structural modification thereof.

It is therefore the output of the present invention, an apparatus for rotating a blank about virtually 90 ⁰ to propose that rotates the blank at the beginning of the translational movement to larger angular units, as in the last section of the same, so that the blank halfway, for example, already at considerably more than 45 degrees, was 60 ^0, eg rotated. The device is also to be distinguished from the known designs by its structural simplicity.

This object is achieved according to the invention by the combination of features defined in independent claim 1. Preferred embodiments are defined in the dependent claims.

The invention is described below using an exemplary embodiment with reference to the accompanying drawings.

• 1 is a simplified perspective view of the part of a four-stage forming machine relevant to the present context,
• 2 schematically illustrates the sequence of movements of the guide gear used,
• 3 shows different phases of the rotational movement of the blank,
• 4 is a vertical section along a plane lying in the axis of the pliers,
• Fig. 5 is a vertical section along the line V-V in Fig. 4 and
• Fig. 6 illustrates the design of the jaws for the smallest and the largest blank.

1, a lower die holder 2 with four recesses for receiving dies is attached to a press frame 1. Four die holder covers 3, 4, 5 and 6 are attached above it. Clamp carrier boxes 7a, 7b are located above and below these die holders. These pliers carrier boxes are each attached to a shaft 8 by means of a clamp connection and have the task of connecting the pliers to be described with the shafts 8, of which only the upper one is visible. Each of these shafts 8 is rotatably and longitudinally displaceable in the press frame 1 and both are exactly in the same direction in the direction of the arrow "A" or in the opposite direction in the direction of the arrow "B", "A" being a translational movement in the direction of the shaft axis 93 and "B" an angular movement represent around the same axis. A not shown The drive mechanism transmits to these shafts the movement which is necessary to transport the compacts from one forming station to the next and to empty return.

This sequence of movements takes place in two parts: on the one hand as a transverse transport movement of the compacts from one die to the other (arrow A), on the other hand for opening and closing the pliers or for gripping or releasing the compacts (swiveling movement around shaft 8, arrow B).

Three pairs of pliers 9, 10, 11 are releasably attached to the front of the pliers carrier box 7a, 7b. While the pairs of pliers 10 and 11 now correspond to the known shape and are provided with fixed lower grippers 12 and spring-supported upper grippers 13, the first pair of pliers was replaced by a rotatable device 9a and 9b, respectively.

The wire or rod is retracted in the axis 14 in the direction of the arrow against an adjustable stop (not shown), which sets the section length, and is sheared off with the shear knife 15 shown schematically.

The sheared section is held in place by a device (not shown) on the shear knife 15 and brought to the first station. In the above exemplary embodiment, this is not the first forming station, but a pure holding station, in which the section is held until it is taken over by the pliers 9a / 9b. A spring protruding and spring-supported from the first punch tool of the advancing press slide pin 16 presses the sheared blank 17 out of the holding device on the shear knife against a stop pin 18, which instead of a l. Matrix was installed in the opening provided. The holding pin 16 holds the blank until the pair of pliers, designated as a whole by 9, which has moved into the left end position with the transverse transport carriers, has gripped the latter by the pivoting movements “B”, while the press carriage, which is not visible and is to be thought in front of the drawing plane goes back to its rear position, and thus also pulls back the holding pin 16. The cross transport beams are now moved to their right end position. During this movement, an upper and a lower gripper 19 or 20, which is rotatable in the bearing holders 22a and 22b, rotates through 90 ° about the vertical axis 21. This gripping movement is obtained by a spatial, ie three-dimensionally movable two-stroke gear 23a and 23b , which has the function of a guide gear and whose task is to inevitably guide the pliers 9 holding the blank 17 during their translation movement so that on the one hand there is a rotation of the blank by 90 ° with respect to the vertical axis 21 and on the other hand this rotation to the translatory movement is coordinated so that a large part of the angular movement already takes place in the first half of the translatory tong path. The aim of this is to ensure that the guide gear required for its movement takes up the smallest possible space and, in particular, no, or only insignificant, structural changes, such as recesses, have to be made on the adjacent die housings.

Each of the spatial two-stroke transmissions is composed of a link 24 and a coupling 25. The link 24 has a bearing at its rear end on sleeve, which is rotatably mounted on a fixed pin, according to FIG. 5 about the axis 28. The connection between the link 24 and the coupling 25 forms a ball joint 30, while the coupling 25 has at its other end a pivot which engages in the part 9c (top) or 9d (bottom) of the device 9 which can be pivoted about the axis 21 and there is rotatably supported about the axis 29a (top) or 29b (bottom).

Fig. 2 shows schematically the representation of the sequence of movements of the spatial two-stroke gear, projected onto a horizontal plane. The solid lines show the position of the guide mechanism when the transverse transport is in the right end position, the pellet 17 is located so rotated 90 ⁰ prior to the forming station, while in dashed lines, the left end position is shown, the compact thus is still capable how it was brought into the charging station by the clipper.

The handlebar 24 is thus rotatably attached at one end to a fixed bearing about the vertical axis 28. This enables the other end, which is connected to the coupling 25 by the ball joint 30, to move on a circular arc 31, dash-dotted in FIG. 2. The coupling 25 is provided at its gripper-side end opposite the ball joint 30 with a pivot which engages in the part 9c or 9d 'of the device 9 which can be rotated about the vertical axis 21 and is rotatable about the axis 29a / 29b.

Now the pliers carrier, which is guided in a straight line by the shaft 8, moves from the left end position (the two-stroke gear 23 is therefore in the position shown in broken lines) into the right one (drawn out in FIG. 2). End position, the pliers rotation axis moves from 21 'along the line 32 to 21 and the ball joint point follows the circular arc 31 from 30' to 30. The selected geometry makes the coupling 25, which is on the one hand on the arc 31 and on the other hand on the straight line 32 is rotated by 90 °, at least as long as the gear (as shown in FIG. 2) moves in the projection plane, represented by the distance 25a 'or 25a. Since the pivot pin, which forms the axis 29 and is fastened in the coupling 25, engages in the device 9 which can be rotated about the vertical axis 21, it is thus also rotated through 90 °.

6 shows the takeover of the turned blank 33 by the spring pin 35 and the die 36 installed in the second punch 34 of the press slide. By advancing the press slide 34, the blank 33 is removed from the pliers jaws 37, 38 by the spring pin or springs 35 pressed until the blank rests on the engraving 39 of the die. The shape of the pliers jaws 37, 38 is designed such that the blank can be ejected on the die side, but is guided until it is pressed against the engraving 39 of the die 36, while it rests on a shoulder 40 on the other side . Now that the blank 33 is held with the spring pin 35, the upper and lower pliers carrier box pivot about the shaft 8 by a certain amount, (arrow B, Fig. L), so the pliers jaws let go of the blank, ie open the pliers and make 34 space for the approaching stamp. Because of the pivoting up of the pliers carrier box when returning to the starting position, it is necessary to use the joint 30 as a ball joint and the coupling 25 at their coupling point with the rotatable device 9c / 9d, on which the pliers jaws 37 and 38, respectively find to make the axis 29 rotatable. This ensures that the device 9 is turned back into the starting position even when the pliers are open. As a result of the described pivoting open, which causes the pliers to open, the rotatable device 9 is rotated by a small angle which has no influence and which is precisely compensated for when pivoting back, ie when the pliers are closed.

Fig. 6 shows the jaw design for the largest (dash-dotted) and the smallest blank. The surfaces between the pads 41 (Fig. 4) are slanted to prevent dirt from accumulating.

4 shows a central vertical section through the pair of pliers 9. A bearing holder 43 is screwed onto the plier carrier box 7b by means of screws 44. In the bearing holder 43 there are two plain bearing bushes 45 in which the rotating part 46 of the pliers unit is mounted. The axial position results from a shoulder 47 and a cover 48 screwed onto the lower end of the rotating part 46. Above the mounting of the rotating part 46, this has an opening for a bearing bush 49, in which a pin 50 rotatably engages, which firmly engages with the Coupling 25 is connected. The coupling 25 could encompass the pin 50 in a fork-like manner from both end faces. In order to rule out the risk of contamination, the coupling 25, as can be seen in FIG. 1, only engages on the pin 50 from one side, to which it is attached by known means. Also fixedly connected to the coupling 25 is a housing 51 which rearwardly a slot s ^- has, and which serves as a holder for the ball pivot pin 52 (Fig. 5). The bullet Articulated pin 52 surrounds a ball 53. The handlebar is provided with a spherical cap 53a, which surrounds the ball 53 and can be rotated relative to it in a known manner.

At the upper part of the rotating part 46, two parallel surfaces 54 are milled; as a counterpart to this, the jaw holder 55 has a slot 56, so that the jaw holder 55 engages over the two surfaces 54. This ensures the correct position of the jaw holder 55 relative to the rotating part 46 and the two parts are secured against relative rotation. As a connection between the rotating part 46 and the jaw holder 55, a clamping sleeve 57 is used, by means of which the rotating part 46 and the jaw holder 55 are fixed, i.e. be connected torsionally rigid. For exact height adjustment of the jaw holder, an adjusting screw 58 is used, which is screwed into an eyelet 59 which is firmly connected to the clamping sleeve 57, and which can be rotated after loosening a locking nut 60 and a clamping screw 61, and thereby the height of the stop 62 on the jaw holder 55 is molded, adjusted. The pliers jaw 63, which is used to hold the blank 64, is screwed onto the pliers jaw carrier with a screw 65, and corresponding guide surfaces ensure the correct position.

The upper half of the pliers is basically the same as the lower one, but has the difference that it is spring-loaded in the axial, ie vertical, direction. Therefore, the upper jaw holder 66 with a sleeve 67, which is only coupled to the rotating part 68 with a clamp connection, is mounted in a sleeve 69 so as to be longitudinally displaceable. A spring 70 in a central bore of the pliers jaw carrier is pressed, this and thus the pliers jaw 71 presses on the blank 64. The spring travel X is set by turning a screw 72 after loosening a lock nut 73. In order to prevent the spring from springing out when removing the jaw holder 66, a cross pin 96 is installed at the upper end of the jaw holder 66. The attachment to the upper jaw holder is the same as below, as is the rotary drive.

So that there is space between the die holder 2 and the lower pliers box support 7b for the rotary drive 23a / 23b, the die holder 2 must be in the area of the l. Matrix must be provided with a recess 74 (FIGS. 1 and 4).

5 shows, using a vertical section, the fixed bearing of the lower spatial two-stroke rotary drive. A console 75 is screwed to the die holder 2 at the bottom. With this console 75, which serves as an assembly aid, a holding plate 76 is detachably connected. A bearing journal 77 is rigidly connected to this holding plate 76. The link 24 provided with a bearing bush 78 is placed over the bearing journal 77 and secured with a cover 79 screwed onto the bearing journal 77. In order to prevent the ingress of dirt, the bearing bush 78 is provided with a seal 80 at the top, while the bearing is closed at the bottom with a cover 81. This bearing allows the handlebar 24 to rotate about the axis 28 (FIG. 2). At the other end of the link 24, the ball joint can be seen, which has already been described under FIG. 4. It can be seen here how the ball joint pin 52 is fastened to the housing 51 with a conical pin 82, which is firmly connected to the coupling 25.

The upper fixed bearing is mounted on a bracket 26 (Fig. L). This is pressed onto the die holder cover 3 by a hydraulically actuated cylinder 27, which at the same time serves to pivot the upper pliers carrier box 7a, and is thus held stationary.

In this device, it is a condition that when the blank has been pushed into the 1st station up to the stop 18 (FIG. 1), its center or center of gravity is located in the axis of rotation 21 of the pair of pliers 9. This means that if the section length is changed during the shearing process, the depth of penetration into the l. Station has to change, i.e. the stop 18 must be adjusted. If the section is shortened by dimension a, the stop must be moved forward by dimension a / 2. According to the present example, the stop 18 is mechanically or electrically coupled to the section length adjustment so that the position of the stop 18 always corresponds to the section length and the center of gravity of the blank is always the same distance from the front of the die as the axis of rotation 21 of the rotating device 9.

Fig. 3 shows the sequence of movements of the rotating blank. When the transverse transport device is in the initial position, the blank 83 lies against the stop pin 18, which is installed in a filler 84, which is used in the opening provided instead of the normal forming die. At the start of the transverse transport movement, the blank is immediately rotated started, the filler 84 is set back from the normal die front edge to leave room for the long blank. From the figure it can be seen that the rotating blank 85 with the dies holder 2 would collide. A recess 86 is therefore arranged there. The die 87 inserted in the second station also has a small adjustment 88. This adjustment 88 can be kept so low because the blank, because of the choice of the spatial two-stroke as a rotary drive and because of the geometrical arrangement of the joints, before going through half the translational stroke by much more than 45 °, in the present example by about 60 ^{0, is} rotated. As a result, the die 87 experiences practically no restriction and is therefore a fully-fledged forming die.

In order to maintain good accessibility when working on the tool space, the upper tong holder box 7a can be swung up around the shaft 8 (FIG. 1). For this purpose, the shaft 8 is uncoupled from the drive mechanism, not shown, and pushed beyond the left starting position (first pliers before first die) until the projecting profile piece 90, which is a continuation of the shaft 92 on which the bearing bracket 26 is attached, and which in is mounted on the same axis 93 as shaft 8, into which fitting opening 91 projects. Then the upper tong holder box 7a can be pivoted up with the cylinder 27. The bearing bracket 26 also rotates, including the rotary drive 23. The upper tong holder box 7a can thus be pivoted up without problems.

For the conversion to normal forming, ie without turning the blank, the rotatable device 9 can be replaced by an original pair of pliers (version 10, 11 Fig. L). The rotary drive 23 remains on the pliers units, ie the upper one is separated from the bearing bracket 26 by loosening the screws 95, while the lower rotary drive is released by loosening the screws 95 (FIG. 5) is separated from the guide device. This ensures a quick changeover for forming conventional parts.

In the exemplary embodiment described above, a holding station 1 was switched on between the shearing station and the first forming station II, the main function of which is to hold the sheared section until it has been securely gripped by the pliers 19 and 20. However, it would be entirely possible to carry out forming in station I. The turning device described could also very generally between any two neighboring stations, e.g. between the forming stations III and IV.

The exemplary embodiment shows a multi-stage forming machine with horizontal press ram movement. The principle claimed can also be applied equally to vertical machines.

According to a preferred embodiment of the invention, both pliers 19 and 20 (FIG. 1) are coupled to a guide gear 23. However, it would also be possible to inevitably guide only one pair of pliers over such a guide gear and to arrange the other loosely rotatable.

Claims (9)

1.Multi-stage forming machine for the non-cutting forming of blanks, which are rotated by practically 90 during the transition from one station to the neighboring station with respect to an axis of rotation (21) running transversely to the length dimension of the blanks and transversely to the pressing direction, the blanks being transported between the two neighboring ones Stations are provided with a pair of pliers, the two pliers (19, 20) of which are fastened to guide parts (7a / 7b) via pliers carriers (9), which in turn are rigid with a reciprocating (A) and swinging about their own axis (B) driven main shaft (8) are coupled, characterized in that at least one of the two pliers carriers (9a, 9b) is connected in a rotationally rigid manner to a transmission member (9c, 9d) which is rotatably mounted about the axis of rotation (21) and on which one end of a guide gear ( 23) attacks, the other end of which is anchored in a fixed position with respect to the reciprocating tong holder (9a, 9b) and a handlebar (24) and a coupling El (25), wherein the coupling (25) is connected to the handlebar (24) via an articulated coupling (30, 53) which allows any spatial angular movement of the coupling (25) and also the coupling (25) on assigned transmission member (46) via a joint (50), which ensures a torsionally rigid entrainment of the transmission member (46) through the coupling (25) in the sense of a rotation about the said axis of rotation (21), in contrast with regard to the opening and closing movement the pliers allow the transmission member (46) and the coupling (25) to pivot relative to one another in a plane passing through the axis of rotation (21), such that the coupling (30, 53) under the influence of the translational movement of the pliers carrier (9) on a Arc is guided around the fixed pivot axis (28) of the handlebar (24) and thereby the transmission part (9c, 9d), and with it the tong holder (9a, 9b) and the tong ( ^{19, 20} ), rotates by 90 °. 2. Forming machine according to claim 1, characterized in that the guide gear (23) is arranged with respect to the two adjacent stations so that the intended rotation of the blank takes place predominantly in the first half of the translation movement. 3. Forming machine according to one of claims 1 and 2, dadurph characterized in that the articulated, between coupling (25) and handlebar (24) arranged coupling (53) is a ball joint. 4. Forming machine according to one of claims 1 to 3, characterized in that the coupling (25) is fork-shaped at its end facing the transmission part (46) and thus comprises a pin (50) penetrating the transmission part (46), while the other End of the coupling (25) forms a housing (51), the pin (52) of which the handlebar (24) engages via the ball joint (53). 5. Forming machine according to claim 4, characterized in that the coupling (25) is only connected on one side to the pin (50). 6. Forming machine according to one of claims 1 to 5, characterized in that the pliers carrier (55) is positively coupled to the adjacent transmission part (46) that their mutual distance can be changed by means of a regulating member (58), wherein one tong holder (55) of each pair of pliers can be fixed in its respective position in the direction of its gripping movement relative to the transmission part (46), while the other tong holder (66) is resiliently mounted (70) in the direction of its gripping movement. 7. Forming machine according to one of claims 1 to 6, with horizontal forming direction, characterized in that the upper guide gear (23a) is attached to a bracket (26) which is pivotally mounted on a shaft (92), which in turn with the main shaft (8) can be coupled via a releasable coupling (90) in such a way that the entire tong holder apparatus (7a) including the upper guide gear (23a) swings up around the main shaft (8) by a drive element (27) engaging on the bracket (26) leaves. 8. Forming machine according to one of claims 1 to 7, in which the rotation is to take place before the first forming station, characterized in that between the shearing station (15) and the first forming station (II) a supply station (I) is switched on, in which the Blank (17) is held between a stop pin (18) and a movable retaining pin (l6). 9. Forming machine according to claim 8, wherein the stop (18) is mounted to be longitudinally displaceable and adjustable with regard to the processing of blanks of different lengths, characterized in that the length adjustment on the shearing mechanism (15) is coupled to the adjusting device of the stop (1 &) , in such a way that the stop (l8) automatically adapts to the same on a blank of different lengths.

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