Fixed-distance tensioning mechanisms such as swing hooks and hasps are generally used in fixed mold core pulling or some secondary demolding molds. Because such mechanisms are arranged in pairs on both sides of the mold, their actions must be synchronized, that is, When the mold is closed, it is buckled at the same time, and when the mold is opened to a certain position, the hook is released at the same time. Once the synchronization is lost, the template of the drawn mold will be skewed and damaged. The parts of these mechanisms must have high rigidity and wear resistance, and the adjustment is also difficult. The service life of the mechanism is short.

When the core pulling force is relatively small, the method of pushing out the fixed mold by a spring can be used. When the core pulling force is relatively large, the core sliding when the moving mold retreats, and the core pulling action is completed first and then the mold is split. Hydraulic cylinders can be used to pull cores on the mold. The inclined pin slider core pulling mechanism is damaged. The most common faults of this kind of mechanism are that the processing is not in place and the materials used are too small. There are mainly the following two problems.

The inclined pin angle A is large, and the advantage is that a large core pulling distance can be generated in a short mold opening stroke. However, if the inclination angle A is too large, when the pulling force F is a certain value, the bending force P=F/COSA received by the oblique pin during the core pulling process is also larger, and the oblique pin deformation and oblique hole wear are prone to occur.

At the same time, the upward thrust N=FTGA generated by the oblique pin on the slider is also greater, and this force increases the positive pressure of the slider on the guide surface in the guide groove, thereby increasing the friction resistance when the slider slides. It is easy to cause uneven sliding and wear of the guide groove. As a rule of thumb, the inclination angle A should not be greater than 25.