12.4 特种脱模机构12.4.1 两级推顶机构对于面积较大的薄壁件通常要分段脱模。特别是对于推杆不能发挥作用的部位,如侧边或筋,这样就增加了脱模抗力。因而需采取更有效的措施,以使脱模力能安全地作用在塑件上。图316所示的塑件,如果推杆作用在侧壁上是不能完满地脱模的。现在采用了两级推顶系统。开模后,塑件首先由卸料板6将其中从型芯7上脱出。这时由于蝶形弹簧具有足够的 12.4 Special stripping mechanism 12.4.1 Two-stage ejector mechanism For the larger area of ​​the thin-walled parts usually demoulding. Especially for the push rod can not play a role, such as the side or ribs, thus increasing the demoulding resistance. Therefore, we must take more effective measures to make the release force can be safely applied to plastic parts. The plastic part shown in Fig. 316 can not be demolded satisfactorily if the push rod acts on the side wall. Now using a two-stage push system. After the mold is opened, the plastic part is first removed from the core 7 by the discharge plate 6. At this time due to the butterfly spring has enough