Design of injection mould with a tunnel-two-stage-core-pulling mechanism for oil return cover
In order to solve the problem of difficult demoulding of complex local features in plastic parts,the area segmenta-tion method of local feature was first used in injection mould design to separate the local difficult demoulding models from the feature set.Then,based on the distribution of demoulding directions,the same direction integrated classification method was used to design single or multiple core-pulling mechanisms for each integrated demoulding direction,just as"demolding direction integrated classification demolding design method",effectively solving the problem of difficult demoulding design of plastic parts as a whole or in local areas caused by multiple demoulding directions.Based on the above design principles and combined with the difficulty of demoulding the lubricating-box oil return cover plastic part,a tunnel-two-stage-core-pulling mechanism was innovatively designed.In the mechanism,an angle pin was used to drive the tunnel-slider inside the main formed block to turn and drive another moveable block inside the main formed block for completing the first core pulling.During this process,the main-body-slider separated from the main formed block,while the main formed block remained stationary.Then the angle pin continued to drive the main-body-slider to drive the main formed block to complete the second core-pulling for achieving the demoulding of the local area of the plastic part.Based on the analysis of mechanism kinematics,in the structural design of the mechanism,the closed locking of the main-body-slider and the main formed block was carried out by the angle planes on both sides of the wedge block with different angles of 23° and 25°,respectively.Correspondingly,the angle pin of the main-body-slider had an angle of 20°.The tunnel-two-stage-core-pulling mechanism designed with this parameter has successfully overcome the design difficulties of the demoulding mechanism in the local area of the plastic part,and is applied to the plastic part mould,effectively realizing the automated injection molding production of the plastic part.The mould structure of the plastic part is a three-plate-mould with a single point gate,the layout is one-mould with one-cavity.
NETL
NSTL
万方数据
