EP1979112A1

EP1979112A1 - Work transport device

Info

Publication number: EP1979112A1
Application number: EP07700125A
Authority: EP
Inventors: Daniel Ruchti
Original assignee: Hatebur Umformmaschinen AG
Current assignee: Hatebur Umformmaschinen AG
Priority date: 2006-01-24
Filing date: 2007-01-19
Publication date: 2008-10-15
Anticipated expiration: 2027-01-19
Also published as: DE502007001577D1; US20100253107A1; EP1979112B1; CN101374616A; ES2331490T3; WO2007085102A1; UA91391C2; KR20080087008A; EA013444B1; ATE443584T1; EA200801625A1; CN101374616B

Abstract

A workpiece transport device for a forming machine includes at least one gripping tongs, which has two non-crossing gripper arms that are pivotable with respect to one another, where the arms each have a gripping end for gripping a workpiece. Each of the two gripper arms are articulated at ends opposite from the gripping end on a common guide head and, in a middle region between the two ends, and on its own link bar. The two link bars are each rotatable about a fixed pivot, wherein the fixed pivot of the link bar of one gripper arm is arranged closer to the other gripper arm than is the fixed pivot of the link bar of the other gripper arm.

Description

description

Workpiece transport device

The present invention relates to a workpiece transport device for a forming machine according to the preamble of independent claim 1.

In today usual forming machines workpieces are usually placed by means of workpiece transport devices in forming stations and / or removed after forming again from this. Multi-stage forming machines have a plurality of successively arranged forming stations, in which a workpiece is processed one after the other. The transport of the workpiece between the individual forming stations takes place by means of a workpiece transport device.

Known workpiece transport devices comprise several

Grippers with which the workpieces can be gripped, transported and then released at the same time in the individual forming stations. For this purpose, the grippers are driven together by a drive mechanism in the machine cycle.

Tongs of various kinds belong to the prior art. In DE 35 23 323 A1, for example, a gripping tongs is disclosed which has two non-intersecting, mutually pivotable gripper arms, each with a gripping end for gripping a workpiece. In this gripping pliers, each of the two gripper arms is articulated at the end opposite the gripping end on a common guide head and in a central region between the two ends on a separate link. The two links are rotatable about a common, fixed pivot point. By moving the guide head upwards, starting from a lower end position, the gripping ends of the two gripper arms are initially moved away from one another while simultaneously being lifted, and then swung back towards one another. When moving downwards the guide head, starting from an upper end position, the gripping ends of the two gripper arms with simultaneous lowering initially away from each other and then back to each other pivoted closed. A disadvantage of this gripping tongs that the two gripper arms are pivoted relatively far outwards, so that the lateral space requirement is relatively large.

[0005] In view of the disadvantages of the previously known workpiece transport devices, the object of the invention is to provide a workpiece transport device of the type mentioned at the beginning, in which the gripper arms of the at least one gripping pliers require less space laterally.

This object is achieved by the inventive workpiece transport device, as defined in the independent claim 1. Preferred embodiments will become apparent from the dependent claims.

The essence of the invention consists in the following: A workpiece transport device for a forming machine comprises at least one gripping tongs, the two non-intersecting, mutually pivotable gripper arms each having a gripping end for gripping a workpiece. Each of the two gripper arms is articulated at the end opposite the gripping end on a common guide head and in a central region between the two ends on a separate link. The two links are each rotatable about a fixed pivot point. According to the invention, the fixed pivot point of the arm of one gripper arm is arranged closer to the other gripper arm than the fixed pivot point of the arm of this other gripper arm.

Since the links of the two gripper arms are arranged such that they are rotatable about different fixed pivot points, and also the fixed pivot points of the links are each offset to the gripper arm, which is not hinged to the respective arm, the two gripper arms Swinging away swung less far to the outside. The lateral space requirement of the at least one gripping pliers is thus smaller than in comparable workpiece transport devices of the prior art.

Advantageously, the guide head is guided linearly displaceable on a fixed guide, so that upon rotation of a link of the guide head through a gripper arm, on which this link is articulated, is linearly displaced, whereby the other gripper arm mitschoben and is rotated due to the articulation of the other link in the direction opposite to a gripper arm direction. This allows opening and closing of the gripping tongs by turning a handlebar, ie, as a drive, a rotary drive can be used, which acts on one of the handlebars. An advantage of such a rotary drive is that it is easier to seal off than a linear drive, for example, attaching to the guide head. In addition, it is easier to implement and takes up less space than a linear drive.

Preferably, the workpiece transport device on a biasing device which exerts a force on the guide head towards the gripping ends of the gripper arms. By means of this biasing device, the gripper is held in gripping position or pressed into the gripping position when no active drive to open the gripping tongs takes place. The bias also prevents undefined fluttering of the gripper arms.

Advantageously, the two gripper arms are articulated in the guide head on a common axis of rotation. The guide head can be made relatively compact.

Preferably, the one end of each of the two links is rotatably mounted in each case in a fixed housing part of the gripping tongs around the fixed pivot belonging to the respective handlebar. This means that the respective pivot point of the link is located at one end of the handlebar and the entire length of the handlebars can be used by the other end of the link is articulated to the associated gripper arm.

Preferably, the workpiece transport device on a rotary drive, with which one of the links is rotatable. As already mentioned, a rotary drive has the advantage that it is easier to seal than a linear drive. In addition, it is easier to implement and takes up less space than a linear drive.

Advantageously, the rotary drive on a drive rod, which is displaceable in the longitudinal direction and via intermediate links with one of the links is connected, so that by a longitudinal displacement of the drive rod of the handlebar in question is rotatable. Such a drive rod can in principle be used for the simultaneous drive of a plurality of adjacently arranged grippers by being connected via intermediate links with one of the links of each gripping pliers.

Preferably, the workpiece transport device on a plurality of juxtaposed grippers, which are operable in parallel with a drive. The workpieces in the individual forming stations can be grabbed, transported and then released at the same time.

Advantageously, the gripper arms and the handlebars are designed and arranged such that upon rotation of the handlebars from one end position to the other, the gripping ends of the two gripper arms are initially moved away from one another and then swung back towards one another. In the two end positions, the at least one gripping tongs then occupy relatively little space laterally. A transverse displacement of the at least one grasping forceps with or without a workpiece takes place in time so that the opening course of the grasping forceps allows a collision-free movement. For reasons of time, the transverse movement usually begins before the gripping tongs reach one of the end positions.

In the following, the workpiece transport device according to the invention will be described in more detail with reference to the accompanying drawings with reference to an embodiment. Show it:

Fig. 1 - a die-side cutout of a multi-stage forming machine with an embodiment of an inventive workpiece transport device with four gripping tongs;

2A to 2C - essential elements of one of the four grippers of

Workpiece transporting device of Figure 1 with a workpiece from the front in a lower end position, a central position and an upper end position.

3A to 3C - the gripping forceps elements of Figure 2A with workpiece from behind in a lower end position, a central position and an upper end position. 4A to 4C - the gripping tongs elements of Figure 2A with workpiece in a perspective view obliquely from behind in a lower end position, a central position and an upper end position ..;

Fig. 5 - the gripper tongs elements of Figure 2A with other elements of the gripping tongs and a rotary drive in a perspective view obliquely from the front.

Fig. 6 - the Greifzangen- and rotary drive elements of Figure 5 in a perspective view obliquely from behind, with a housing part is omitted for clarity;

Fig. 7 - the Greifzangen- and rotary drive elements of Figure 5 from the rear, with a housing part is omitted for clarity;

Fig. 8 is a sectional view taken along the line A-A in Fig. 7, showing additional housing parts;

Figures 9A to 9C - the Greifzangen- and rotary drive elements of Figure 5 from the front in a lower end position, a central position and an upper end position ..;

Figures 10A to 10C - the Greifzangen- and rotary drive elements of Figure 5 without housing parts and biasing spring from behind in a lower end position, a central position and an upper end position.

Fig. 11 shows an essential part of the rotary drive of the workpiece transporting device of Fig. 1; and

12 is a partial sectional view of the forming machine with workpiece transport device of FIG. 1.

The illustrated in Fig. 1 embodiment of a multi-stage forming machine 8 comprises four forming stations, each of which a die 81, 82, 83 and 84 is visible. The dies 81, 82, 83, 84 are mounted in a stationary die holder 85, which is indirectly connected to a machine frame 86. For the transport of workpieces 9 to the individual forming stations and back away from these, a workpiece transport device is provided which has four grippers 1. The grippers 1 are on the one hand transversely displaceable, to which they are attached to a transverse transport block 4, which is transversely displaceable by means of a transverse transport tube. On the other hand, the gripping tongs 1 are open and lockable as well as simultaneously raised or lowered, which is done by means of a mechanism which will be explained in detail below. To open or close the gripping tongs 1, a drive rod 3, which is displaceable in its longitudinal direction, is provided, which is longitudinally displaceable by means of an adjusting device 5, as explained in more detail below in connection with FIG.

For the entire further description, the following definition applies. If reference numerals are included in a figure for the purpose of graphic clarity, but are not explained in the directly related descriptive text, or vice versa, reference is made to their mention in the preceding description of the figures.

In Figs. 2A, 2B, 2C, 3A, 3B, 3C, 4A, 4B and 4C, essential elements of a grasping forceps 1 are shown in a lower end position, a middle position and an upper end position. In the lower end position shown in FIGS. 2A ₁ 3A and 4A, the grasping forceps 1 is closed and grips a workpiece 9. In the middle position shown in FIGS. 2B, 3B and 4B, the grasping forceps 1 is maximally opened and raised to half the maximum height , In the upper end position shown in FIGS. 2C, 3C and 4C, the gripping tongs 1 are closed again and raised to their maximum height.

The gripper 1 comprises two non-intersecting, mutually pivotable gripper arms 11 and 12, each having a gripping end 111 and 121 for gripping the workpiece 9. At the gripping ends 111, 121 are each two gripping elements 112 and 113 and 122 and 123 screwed, which hold the workpiece 9 between them.

At the gripping end 111, 121 opposite end 114 and 124, each of the two gripper arms 11, 12 hinged to a common axis of rotation, which is not shown here. In a central region between the two ends, the gripper arms 11, 12 are articulated in each case via a non-visible axis of rotation at one end 131 or 141 of a separate arm 13 or 14. The two links 13, 14 are each rotatable about a fixed pivot point 130 and 140, which is located in the middle of the other end 132 and 142 of the arm 13 and 14, respectively. How out 4A, 4B and 4C, this is realized in the present embodiment by fixed rotational axes 133 and 143 in the middle of the handlebar ends 132 and 142, respectively. The pivot points 130, 140 and the fixed axes of rotation 133, 143 are stationary when opening and closing the gripping tongs 1, they only move with the transverse transport of the gripping tongs 1.

According to the invention, the fixed pivot point 130 of the arm 13 of the gripper arm 11 is arranged closer to the gripper arm 12 than the fixed pivot point 140 of the arm 14 of this gripper arm 12. In the illustrated embodiment, the fixed pivot point 130 of the arm 13 is practically directly behind the gripper arm 12th Accordingly, the fixed pivot point 140 of the arm 14 of the gripper arm 12 is arranged closer to the gripper arm 11 than the fixed pivot point 130 of the arm 13 of this gripper arm 11. In the illustrated embodiment, the fixed pivot point 140 of the arm 14 is practically directly in front of the gripper arm eleventh

At the handlebar end 131 of the handlebar 13, a prism 134 is attached, which has an attachment surface for a drive member, not shown here. The prism 134 is screwed by means of a screw 135 on the handlebar end 131.

By pressing the drive member from below against the prism 134 of the handlebar 13 is rotated, whereby the gripper arm 11, starting from the lower end position shown in FIGS. 2A, 3A and 4A initially pivoted away from the gripper arm 12 and up until the Middle position according to FIGS. 2B, 3B and 4B is achieved. In this case, the upper Greiferarmende 114 of the gripper arm 11 pulls the gripper arm 12 upwards, which due to the articulation of the gripper arm 12 leads to the handlebar 14 with the fixed pivot point 140 that also the gripper arm 12 is pivoted away from the gripper arm 11 to the outside. By further turning up the handlebar 13 after reaching the middle position, the two gripper arms 11, 12 are further upwards, but again pivoted towards each other, until finally the upper end position according to FIGS. 2C, 3C and 4C is reached.

From FIGS. 5, 6 and 7 it can be seen that the handlebar ends 132, 142 of the link 13, 14 in fixed housing parts 161 and 162 of a fixed housing 16 are rotatably mounted. The upper Greiferarmenden 114, 124 of the gripper arms 11, 12 are hinged to the aforementioned common axis of rotation in a common guide head 15 which is mounted linearly displaceable on two vertical guide rods 151, 152 in the vertical direction. On the top of the guide head 15, a rod 172 and a bearing pin 173 of a biasing means 17 are mounted around which a coil spring 171 is arranged. The coil spring 171, the upper end rests against a fixed housing part, not shown here, is biased by compression and exerts on the guide head 15, a force in the direction of the gripping ends 111, 121 of the gripper arms 11, 12 out. The acted upon by the coil spring 171 guide head 15 thus has the tendency to move the gripper arms 11, 12 in the lower end position or to hold in this. Thus, the closing of the gripping tongs 1 by the biasing means 17 is effected while the opening is accomplished with an active rotary drive.

From the rotary drive here designed as a double lever drive lever 2 is shown, which attaches a lever arm 21 as a drive member on the prism 134 of the arm 13. At the second lever arm 22 of the drive lever 2, a neck portion 221 is rotatably screwed with a Ansetzfläche 222 for a power transmission member.

8 shows, in addition to the already explained components, how the upper gripper arm ends 114, 124 of the gripper arms 11, 12 are articulated in the guide head 15 to a common axis of rotation 153. In addition, here also the fixed housing part 163 of the fixed housing 16 is shown, against which the upper end of the coil spring 171 rests.

In Figs. 9A, 9B and 9C already explained parts of the gripper tongs 1 are again shown in a front view in the lower end position, the middle position and the upper end position. It is clearly visible here how the guide head 15 in the fixed housing 16 is displaced linearly upward and thereby compresses the spiral spring 171.

10A, 10B and 10C show in particular the rotation of the handlebar 13 by means of the drive lever 2 based on the lower end position, the center position and the upper end position of the gripping tongs 1. It is clear it can be seen that the lever arm 21 engaging the prism 134 of the handlebar end 131 rotates the handlebar 13 with the prism 134, while the pivotally mounted on the lever arm 22 neck portion 221 maintains its orientation relative to the forming machine with simultaneous rotation of the lever arm 22 below it. The attachment part 221 with the attachment surface 222 is moved on a circular arc path from right to left. This allows rotation of the drive lever 2 by a linear movement of a voltage applied to the Ansetzfläche 222 power transmission member.

In Fig. 11 four juxtaposed drive lever 2 are shown, wherein for a drive lever 2 and parts of the associated gripping tongs 1 are drawn. At the attachment surfaces 222 of the attachment parts 221 of the drive lever 2 is in each case a force transmission member 31 at. All four power transmission members 31 are fixed to a common power transmission rod 32, which is connected via a connecting part 33 with the drive rod 3. By moving the drive rod 3 in its longitudinal direction so all four drive lever 2 can be rotated together.

The drive rod 3 is longitudinally displaceable by means of an adjusting device 5, as shown in FIGS. 12 and 1. The adjusting device 5 comprises in the present case a drive shaft 51 which drives a transmission shaft 52 via gears 511 and 521. The transmission shaft 52 is provided with a curve 522 which presses on a freely rotating roller 531 of a rotary member 53. The rotary member 53 in turn presses on a roller 543 which is freely rotatably mounted at a free end of a lever arm 541 of a double lever 54. The double lever 54 with the two lever arms 541 and 542 is thereby rotated about a fixed axis of rotation 544, wherein the lever arm 542 pulls the hinged thereto link 55 and thus the hinged to this drive rod 3 to the outside.

To the above-described workpiece transport device further constructive variations can be realized. It should be expressly mentioned here that instead of the pretensioning device 17 with spiral spring 171, for example, a pneumatic pretensioning device could also be used.

Claims

claims

1. workpiece transport device for a forming machine, comprising at least one gripping tongs (1), the two non-intersecting, mutually pivotable gripper arms (11, 12) each having a gripping end (111, 121) for gripping a workpiece (9), wherein each of two gripper arms (11, 12) on which the gripping end (111, 121) opposite end (114, 124) on a common guide head (15) and in a central region between the two ends to a separate link (13, 14) is articulated and the two links (13, 14) each about a fixed pivot point (130, 140) are rotatable, characterized in that the fixed pivot point (130, 140) of the link (13, 14) of the one gripper arm (11, 12) closer at the other gripper arm (11, 12) is arranged as the fixed pivot point (130, 140) of the link (13, 14) of this other gripper arm (11, 12).

2. Workpiece transport device according to claim 1, characterized in that the guide head (15) is guided linearly displaceable on a fixed guide (151, 152), so that upon rotation of a link (13, 14) of the guide head (15) through the one Gripper arm (11, 12) on which this arm (13, 14) is articulated, is linearly displaced, whereby the other gripper arm (11, 12) along and due to the articulation of the other arm (13, 14) in the one Gripper arm (11, 12) is rotated opposite direction.

3. workpiece transport device according to claim 1 or 2, characterized in that it comprises a biasing means (17) which on the guide head (15) exerts a force in the direction of the gripping ends (111, 121) of the gripper arms (11, 12) out.

4. Workpiece transport device according to one of claims 1 to 3, characterized in that the two gripper arms (11, 12) are articulated in the guide head (15) on a common axis of rotation (153).

5. workpiece transport device according to one of claims 1 to 4, characterized in that the one end (132, 142) of each of the two links (13, 14) in each case in a fixed housing part (161, 162) of the gripping tongs (1) to the the respective link (13, 14) belonging to the fixed pivot point (130, 140) is rotatably mounted around.

6. workpiece transport device according to one of claims 1 to 5, characterized in that it comprises a rotary drive with which one of the links (13, 14) is rotatable.

7. workpiece transport device according to claim 6, characterized in that the rotary drive comprises a drive rod (3) which is displaceable in the longitudinal direction and via intermediate members (2, 31, 32, 33) with one of the links (13, 14), so that by a longitudinal displacement of the drive rod (3) of the handlebar (13, 14) in question is rotatable.

8. workpiece transport device according to one of claims 1 to 7, characterized in that it comprises a plurality of juxtaposed gripping tongs (1) which are operable in parallel with a drive.

9. workpiece transport device according to one of claims 1 to 8, characterized in that the gripper arms (11, 12) and the links (13, 14) are designed and arranged such that upon rotation of the link (13, 14) from an end position in the other, the gripping ends (111, 121) of the two gripper arms (11, 12) initially away from one another and then pivoted back to each other.