Knockout device for press machines

Abstract

The present invention provides a knockout device that can reliably separate the first lever and the second lever in the event of an overload. [Solution] The knockout device of the press machine comprises a motion conversion lever (3) that swings in conjunction with the raising and lowering of the press machine's slide, an extrusion lever (4) including a first lever (41) that swings under the action of the motion conversion lever and a second lever (42) that swings integrally with the first lever, and a shaft member (6) as a protective means that connects the first lever and the second lever in the normal state and separates the first lever and the second lever when an overload is applied to the extrusion lever via a knockout pin (5), wherein the shaft member (6) is mounted in such a way that it breaks due to shear deformation when an overload is applied to the extrusion lever.

Claims

1. A knockout device mounted on a press machine that pressure-forms a workpiece using a mold, A motion conversion lever that swings in conjunction with the raising and lowering of the slide of the press machine, A push lever including a first lever that swings in response to the action of the motion conversion lever, and a second lever that swings integrally with the first lever, A knockout pin, which ejects the molded product from the mold in response to the action of the second lever, The system includes a shaft member as a protective means that connects the first lever and the second lever in the normal state and separates the first lever and the second lever when an overload occurs on the push lever via the knockout pin, A knockout device for a press machine, characterized in that the shaft member is mounted in such a way that it breaks due to shear deformation when the extrusion lever is overloaded.

2. The first lever and the second lever are connected by a pivot shaft that serves as the pivot point. The knockout device for a press machine according to claim 1, wherein the shaft member is arranged parallel to the pivot shaft.

3. The aforementioned pivot axis extends in the horizontal direction, The knockout device for a press machine according to claim 2, wherein the shear surface of the shaft member is a vertical plane.

4. The first lever and the second lever are adjacent to each other along the axial direction of the pivot shaft and each has a first base end and a second base end through which the shaft member is inserted. The knockout device for a press machine according to claim 2, wherein the shaft member has an outer peripheral groove that is connected in the circumferential direction at the boundary position between the first base end and the second base end.

5. The knockout device for a press machine according to claim 1, wherein a plurality of the aforementioned shaft members are arranged to be parallel to one another.

6. A notch perpendicular to the axial direction is provided on a part of the outer circumferential surface of the axial end edge of the shaft member. The knockout device for a press machine according to any one of claims 1 to 5, wherein the shaft member is fixed to the outer surface of the extrusion lever by a fixing plate inserted into the notch.

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