Classical Moulds Series: No.5 Gear-rack Thread Demoulding
Gear-rack Thread Demoulding Structure is often used to make relatively complex mould. It requires the threaded core to be in core clearance fit with the top clamp plate. In general, H7/f6 fit would be adopted.
Before delving into this kind of demoulding structure, we should firstly learn the parts of it. There is a fixed top clamp plate and a movable stripper plate. A threaded sprue puller is set in the middle of them. Beside the puller is a threaded core. This two parts move together with the stripper plate during manufacture. When moving back, they will rotate themselves to promote demoulding. What's more, gears are also fixed at the front of them.
There is an axis that control movement of the machine. It moves back and forth all the time during the whole production process, and never stops rotating itself. These actions are made with the support of a guide pillar.
When the manufacture begins, the guide pillar will pull the axis to move back. Through the transmission of bevel gears and spur gears, the threaded core would rotate together with the sprue pillar. Therefore, mould products and aggregate of gating system would be stripped off the machine at the same time.
The threaded core and sprue pillar rotate in completely different direction of rotation. Thus, the thread on them should also have different rotary direction, with the same pitches.