Plastics moulding tool for components with strap areas - has punch moving in the ejection direction which guides an expanding element in a lateral direction to open out moulding straps and disengage the undercut areas from the tool

摘要

A tool(1) for die casting, injection or press moulding of plastic or elastic components with a main part(3) and one or more straps(4,5) comprises male and female tool parts forming a cavity in which the strap-forming cavity areas(4,5) are connected to the main cavity area(3) and bordered on one side by the male or female tool core(6) and on the opposite side by a sliding punch(7) which moves in the ejection direction(A). The punch(7) includes a laterally movable, product-expanding element(8) in the region of an undercut(21,22) in the strap-forming cavity area(4,5) for lifting the undercut area(21,22) away from the punch(7) during product ejection. In a claimed process using the tool(1), the expanding element(8) moves with the punch(7) during demoulding and then automatically moves in the expanding direction(S) either simultaneously with or following final punch(7) movement. The use of the tool and process for mfrg. plastic components with undercuts forming clipping hooks is also claimed, esp. components for vehicle bumpers.