Negative-angle press-working die

Abstract

To enable forming a negative angle with deep bending and forming a high-quality panel, a negative-angle press-working die includes an elevatable pad fixed to an upper die, a slide cam supported slidable laterally on the upper die or a lower die and having a bending blade, a rotary cam rotatable about a rotational center having a bending part which forms a negative-angle portion on a workpiece and a cam surface abutting on the slide cam, an elevatable slide body disposed under the pad rotatably together with the rotary cam and having a hold part provided at an upper portion on a bending part side of the rotary cam and constituting a part of a male die for workpiece forming, a drive unit that rotates the rotary cam to a workpiece working position, and a slide drive unit that slides the slide body in an up and down direction.

Description

technical field [0001] The present invention relates to a negative-angle forming press die for performing bending work on sheet materials for automobiles by negative-angle forming. Background technique [0002] Among automobile panels, the side panels of the body are difficult to perform negative-angle forming across the front pillar, roof, and rear window due to their complex cross-sectional shape. In particular, the cross-sectional shape from the front pillar to the roof side is particularly difficult because strength must be maintained with a small cross-section. As a press molding die for overcoming such difficulties, conventionally known is, for example, a press die disclosed in JP-A-59-197318. Such as Figure 8A As shown, the stamping die is a stamping die of a cylindrical cam type in which a column (workpiece 12) is subjected to complex bending processing through a rotary cam 17. It has a cylindrical rotary cam 17 on the lower die, and the hanging cam and the lining ...

AI Technical Summary

Problems solved by technology

[0003] However, in recent years, the cross-sectional shape of the required processing object has become more complicated, such as from Figure 8A The shape shown becomes Figure 8B In the shape shown, negative angle forming is difficult even with conventional negative angle forming stamping dies.

That is, if Figure 8B As shown, the shape is small and the degree of bending is deep, so the width of the fixing punch 16a as the holding part cannot be set. If the gap 18 for taking out the plate is provided, the gap will become larger, and the lining of the upper die cannot be formed. The pads reliably push against the blank sheet, incurring a reduction in the quality of sheet forming

In this way, if the curvature of the curved surface of the workpiece is deep and the height difference in the vertical direction is large, the height of the dividing line between the fixing punch and the rotary cam will be different in each section, and it cannot be designed as a single section. For example, there are the following problems , that is, the forming process must be separated, such as Figure 9 As shown, the above-mentioned cylindrical cam type metal mold 20 is divided into front pillar A, roof B, C, rear window D, etc., arranged along the inclination of each workpiece, and the forming process is performed in a plurality of steps.

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