| 摘要 |
PURPOSE:To prevent damaging of dies by dividing the moving region of the press dies to a free area and a press working area and stopping the press work when abnormal pressure acts upon the press dies in the free area. CONSTITUTION:When the press work is in a normal state, a lower die 2 ascends in the free area A3 while receiving low oil pressure. When it reaches the position P3, it ascends in the press working area A2 while receiving high oil pressure by the changeover command of a limit switch S3. If foreign matter 4 interposes in addition to the work 3, the hydraulic circuit becomes abnormally high in pressure before the lower die 2 reaches the position P3 and therefore a solenoid valve is operated to cut off the oil feed to the hydraulic circuit. Thereby, the press work of the lower die 2 is automatically stopped and the damaging accident of the dies may be prevented. |
