| 摘要 |
PURPOSE:To provide both effects of preventing overload and preventing an empty shooting fault to a titled device by making an oil storage means having a pneumatic chamber communicate with a hydraulic chamber, providing a pneumatic control means to the pneumatic chamber and changing the volume of an oil chamber. CONSTITUTION:When a die is overloaded, a cylinder 12 moves downward and the oil pressure in a hydraulic chamber 17 increases. When the lifting force of a plunger 27 exceeds the depressing force of a pneumatic chamber 31, the plunger 27 rises to expand the volume of an oil chamber 29 thus admitting the oil 18 in the chamber 17 into the chamber 29. The cylinder 12 is then lowered and the bottom dead point position of a slide 15 is raised. In the case of empty shooting, a control valve 32 is closed to stop the supply of the air pressure to the chamber 31 and the chamber 31 is opened to the atm. The force for depressing the plunger 29 is thereby lost and the volume of the chamber 29 is expanded so that the oil 18 in the chamber 17 flows into the chamber 29. Then the cylinder 12 descends with respect to the slide 15. The damage of the die is prevented by such mechanism. |
