| 摘要 |
PURPOSE:To perform tight clamping by providing a bolster for coining with a mechanism which closes squeesing dies independently of press motion using a hydraulic cylinder, and thus bringing the squeezing dies in closer contact. CONSTITUTION:Firstly, a moving cylinder 1 is extended to put a squeezing die B close to and in contact with a squeezing die A fixed to a bolster body C, thereby clamping a workpiece. Then, a wedge cylinder 3 is contracted to draw a wedge 2 to a flank of a bevel base 21, and the slope surface of the wedge 2 is slid on the slope surface of the bevel base 21 to bring the squeezing die B into closer contact with the squeezing die A, thus clamping the workpiece tightly. In this state, coining operation is carried out. A cylindrical case 32 is used for a cylinder rod 31, whose projecting-side internal diameter is made less than the opposite-side internal diameter; and the base end of the rod 31 is fixed to a piston 33 sliding in the case 32, a large-diameter piston 34 is inserted into the case 32, and oiling openings 36, 37, and 38 are provided. |
