| 摘要 |
PURPOSE:To prevent the development of dents and breakages of molds by performing clamping in such a way that, at first, it is performed with a low pressure mold clamping force and when the contacting space between upper and lower molds becomes less than a certain distance, it is performed with a high pressure mold clamping force and further, when a lead frame slips from the required position, the movement of the molds is made to stop. CONSTITUTION:An SV2 in a high and low pressure change-over solenoid valve 7 as well as an SV3 in a vertical movement change-over valve 6 are operated ON and a clamping cylinder 5 is made to go up under a low pressure. In the case where the contacting space between upper and lower molds 1 and 2 is detected by a distance sensor 14 and no slip of a lead frame is found from the required position, the SV2 is turned OFF and the SV1 is turned ON and then clamping is performed with a high pressure mold clamping force. If the slippage of the lead frame is found from the required position by a control part 20, SVs 2 and 3 are operated OFF and this device not only stops a cylinder 5 but also indicates the display of an alarm. This approach prevents the occurrences of defective products caused by dents at the faces of the lower and upper molds and the breakage development of the molds because of slippage from the required positions. |
