FORMING TOOL

Abstract

A forming tool for forming a metal sheet, having an upper tool part and a movable sheet holder that is supported against the lower tool part, and having a locking device, which is provided between the sheet holder and a hold-down and has at least one spacer element that is supported so that it is able to move from a rest position into a working position as a function of a relative movement, which occurs during the closing of the forming tool. The forming tool also has a wedge drive with a slider and a driver, the slider that is equipped with the spacer element is supported so that it is able to move in contact with the driver as a function of the relative movement that occurs between the sheet holder and the upper tool part during the closing of the forming tool, in order to move the spacer element into its working position.

Claims

1. A forming tool, having comprising: a first tool part, which has an upper tool part and a matrix with a movably used hold-down that is supported against the upper tool part by a first pressing device; a second tool part, which has a lower tool part, a die that cooperates with the matrix for forming, and a movable sheet holder that is supported against the lower tool part by a second pressing device; a locking device, which is provided between the sheet holder and the hold-down and has at least one spacer element that is supported so that the at least one spacer element is able to move from a rest position into a working position as a function of a relative movement, which occurs during closing of the forming tool, which establishes a distance between the sheet holder and the hold-down during the opening of the forming tool; and at least one wedge drive having a slider and a driver, the slider that is equipped with the spacer element being supported so that the slider is able to move in contact with the driver as a function of the relative movement that occurs between the sheet holder and the upper tool part during the closing of the forming tool, in order to move the spacer element into its working position.

2. The forming tool according to claim 1, wherein in its working position, the spacer element forms a stop for the hold-down and/or sheet holder in order to establish the distance between the sheet holder and the hold-down.

3. The forming tool according to claim 2, wherein the hold-down has a shoulder that protrudes radially from the matrix and forms a counterpart stop for the stop of the spacer element.

4. The forming tool according to claim 1, wherein the driver is fastened to the upper tool part and the slider is supported so that the slider can slide on the sheet holder.

5. The forming tool according to claim 1, wherein the slider is supported so that the slider is able to move in contact with the driver in opposition to an action of a first spring.

6. The forming tool according to claim 5, wherein the spacer element is supported on the slider so that the spacer element is able to slide in opposition to the action of a second spring, whose direction of action is oriented opposite from the direction of action of the first spring.

7. The forming tool according to claim 1, wherein the slider is supported so that the slider is able to move in such a way that in the working position of the spacer element, the slider assumes its position situated closest to the matrix.

8. The forming tool according to claim 1, wherein the first and second pressing devices are gas pressure springs.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The subject of the invention is shown in greater detail by way of example i the form of an embodiment variant. In the drawings:

[0015] FIG. 1 shows a cut-away side view of an open forming tool with a sheet blank inserted,

[0016] FIG. 2 shows the forming tool in a partially closed position,

[0017] FIG. 3 shows the forming tool in a closed position, and

[0018] FIG. 4 shows the forming tool as it is being guided back into the open position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The forming tool 1, which is depicted as a simply functioning press by way of example in FIGS. 1 through 4, is used for deep drawing a sheet, a sheet blank (metal sheet blank), and/or a tailored blank. In FIG. 1, this forming tool 1 is in its open position in which the flat blank 2 to be formed has already been inserted. In this open position of the forming tool 1, the two tool pans 3, 4 of the forming; tool 1 are visible.

[0020] An upper tool part 5, a matrix 6, and a hold-down 7 belong to the first, upper tool part 3. The hold-down 7 is supported against the upper tool part 5 by means of a first pressing means 8, which in the exemplary embodiment is embodied in the form of a first gas pressure spring 108 see FIG. 3 with regard to the latter. The matrix 5 is rigidly connected to the upper tool part 5.

[0021] A lower tool part 9, a die 10, and a sheet holder 11 belong to the second, lower tool part 4. The sheet holder 11 is supported against the lower tool part 9 by means of a second pressing means 12, which is embodied in the form of a second gas pressure spring 112see FIG. 3 with regard to the latter. The forming tool 1 according to the invention therefore does not require any bottom air. The die 10 of the lower tool part 4 is fastened to the lower tool part 9 and cooperates with the matrix 6 of the upper tool part 3 to form the blank 2.

[0022] The forming tool 1 also has a locking device 13, which is provided between the sheet holder 11 and the hold-down 7. The locking device 13 includes a spacer element 14 with which the distance between the sheet holder 11 and the hold-down 7 can be established. This is necessary for the opening of the forming tool 1 in order, despite possibly different compressive forces of the first and second pressing means 8, 12, to ensure a high quality, e.g. in the formed blank 2. This locking device 13 is actuated by the closing movement of the forming tool 1, as shown in FIG. 2. When FIGS. 1 through 4 are considered in combination, it is clear that the spacer element 14 is supported so that it is able to move as a function of a relative movement, which occurs during the dosing of the forming tool 1specifically from a rest position 15 when the forming tool 1 is open according to FIG. 1 into a working position 16 according to FIG. 3 which establishes the distance between the sheet holder 11 and the hold-down 7 during the opening of the forming tool 1.

[0023] According to the invention, this movement of the spacer element 14 is implemented by a wedge drive 17, which belongs to the locking device 13. To accomplish this, the wedge drive 17 has a slider 18 and a driver 19, which form corresponding guide surfaces 20 on the wedge drive 17.

[0024] The slider 18 has the spacer element 14 and is supported in sliding fashion namely on the sheet holder 11 in the exemplary embodiment. As a function of the relative movement that occurs between the sheet holder 11 and the upper tool part 5, the slider 18 in contact with the driver 19, which is fastened to the upper tool part 5 in the exemplary embodimentis slid and thus moves the spacer element 14 under the hold-down 7, as a result of which the hold-down 7 strikes the spacer element 14 and thus the sheet holder 11. For this purpose, the spacer element 14 forms a stop 24 for the hold-down 7. This establishes the distance between the sheet holder 11 and the hold-down 7in the exemplary embodiment, specifically by means of the height of the spacer element 14 and its vertical offset relative to the sheet holder 11, which vertical offset results from the position of the spacer element 14 on the slider 18.

[0025] In this way, a particularly rugged locking device 13 is achieved, which can reliably set the established distance between the sheet holder 11 and the hold-down 7, even under high loads. The forming tool 1 according to the invention therefore has a particularly high durability.

[0026] As is also clear from FIG. 1, the slider 18 is supported so that it is able to move in contact with the driver in opposition to the action of a first spring 21, which is embodied in the form of a third gas pressure spring. This spring 21 acts between the slider 18 and the sheet holder 11 and pushes the slider 18 away from the matrix 6 along its first linear guide 22 on the sheet holder 11. As a result, in the working position 16 of the spacer element 14, the slider 18 comes into its position that is situated the closest to the matrix 6, which position 23 of the slider is shown in FIG. 3. In the rest position 15 of the spacer element 14, the slider 18 is positioned the farthest from the matrix 6. This prevents the occurrence of interfering contours during the loading of the forming tool 1.

[0027] It is also clear from FIG. 1 that the hold-down 7 forms a shoulder 25 that protrudes radially from the matrix 6 and forms a counterpart stop 26 for the stop 24 of the spacer element 14. This counterpart stop 26 is provided on the axially protruding section 27 of the radially protruding shoulder 25, which permits the spacer element 14 to be correspondingly embodied as reduced in height.

[0028] The spacer element 14 is supported on the slider 18 so that it is able to slide in opposition to the action of a second spring 28. This spring 21, which is embodied in the form of a fourth gas pressure spring, acts between the spacer element 14 and the slider 18 and loads the, spacer element 14 along its second linear guide 31 on the slider 18 with a direction of action 29 that is oriented opposite from the direction of action 30 of the first spring 21. As a result, the spacer element 14 can be brought into its working position 16 in a prestressed fashion, which prestressing is visible in FIG. 2 based on the support of the spacer element 14 in opposition to the action of the second spring 28.

[0029] FIGS. 1 through 4 also clearly show that the first and second linear guides 22 and 31 extend parallel to each other.

[0030] In general, it should be notedalthough this is not shownthat the slider 18 is also movably supported on the upper tool part 5 and the driver can be fastened to the sheet holder 11. In this case, the spacer element then also forms a stop 24 for the sheet holder 11 in order to establish the distance between the sheet holder 11 and the hold-down 7. It is also conceivable for the spacer element 14 to form a respective stop 24 for the sheet holder 11 and the hold-down 7but this is also not shown.