Views: 0 Author: Site Editor Publish Time: 2020-08-28 Origin: Site
4. Two-step ejection by grooved pin
The two ejection systems shown in Fig. 6.39 consisting of plates 12, 13, 16 and 17 start at the same time, because the lock 7, pushed by spring 6 and screw 5, is engaged with the up groove of pin 4 during ejection(Fig. 6. 39b). The workpiece seperated from forming core 20 with stripper plate 1. Upon contact of the system consisting of plates 16 and 17 with supporting plate 3, the ejector pin 19 and stripper I stop. In the second step only the ejector pin 18 fixed between the lower plates 6 and 7 moves furthrt (fig.6.39C)
5. Unswexyr Qoekpieces with Two-step Ejector
Fig 6.40 is an injection mold for undercut workpieces with two-step ejector. The two ejection systems start at the same time, the " upper"ejector system stops when it moves a distance, and in the second step only the "lower"ejector system moves further. The second ejection system disengages the workpiece from the undercut-forming, slightly springy part of the mold
Operation: following the mold opens, the ejector bar 17 of which soon engages the stop of the machine. The ejector bar 17 lifts the ejector plates 18 and 19, which in tum lift the ejector plates 8 and 9 with the aid of lock pin 14 and guide column 10. In the first ejector process, lock 14 catches the lower groove of column 10, hence the two ejection systems(ejector pins 20 and 21 and forming plate 23)start together and lift the workpiece out of the nest(Fig. 6.40b). When the ejector plate 8 is in contact with the supporting plate 6, the lock 14 is pressed out of the groove of colum 10 and the ejector pin 20 is lifted only by the ejection system consisting of plates 18 and 19. These push out the workpieces from the protruding nose of the undercut-forming plate 23. The undercut-forming plate 23 is plate spring to avoid deformation during ejection when the ejector pins 20 lift the workpiece(Fig. 6.40c)
