To grasp the precision of precision mold processing, the working procedures are as follows: wipe the mold and spray release agent - put semi-finished products (oil seal framework and rubber ring) - turn over and close the mold - rack drive to send the mold to the vulcanization chamber - vacuum vulcanization - rack drive to send the mold to the trailer - open the mold - turn over - eject the product.
It is understood that two open rubber oil seal mold manufacturing. The two split oil seal mold is manufactured by processing single components and then assembling them to match. The processing technology is excellent and the mold detection is convenient. The material of single cavity mold is crlz, and the connecting plate is 45 steel. During mold processing, in addition to processing in strict accordance with the mold drawing to ensure the cavity size, the following points are the key to ensure the mold processing accuracy:
(l) Processing of glue flow groove: in the past, the precision mold processing of oil seal mold glue flow groove has not been paid enough attention. The glue flow groove is often processed too far away from the mold cavity or the size is not easy to control, which makes it difficult to trim the products and the products are not beautiful. The two split oil seal die has been improved to solve these problems. The inner end size of the triangular glue flow groove is consistent with the outer diameter of the product (zero to zero). The split upper and lower dies are used to form a sharp edge here. When the oil seal is molded, the excess flash is cut off, which not only simplifies the trimming process, but also improves the appearance of the product. Because the outer diameter of the flow groove and the cavity are located on different modules, the size does not interfere, and its accuracy is easy to ensure.
(2) Matching processing of upper die and upper die core 1: the matching of upper die and upper die core 1 is taper matching. In the past, the method of research and matching was used, and the contact rate is required to reach more than 80%. This traditional processing method is not only difficult, but also consumes a lot of man hours. It is still difficult to achieve the ideal effect without flash. The processing of the new structure die adopts the method that the inclination angle of the conical hole is slightly smaller than that of the conical shaft, so that the upper die and the upper die core are always closely bonded together at the parting surface B, in a state of no gap fit, so there is no flash here. And the die manufacturing process is improved.
(3) Press fit of upper die core 1 and upper die core 2: the press fit of upper die core 1 and upper die core 2 is the key to ensure the size and accuracy of oil seal auxiliary lip. The flash at the auxiliary lip of the three opening oil seal die has a great influence on the appearance of the auxiliary lip. In the new structure die, the upper die core 1 and the upper die core 2 adopt interference fit. After the monomer is processed, it is pressed into one by thermal expansion method, and then the upper die core 2 is tightly pulled by the fastening screw at the upper end to effectively prevent the loosening of the two die cores at the auxiliary lip.
(4) Connection between cavity molds: the connection between each single cavity mold and the connecting plate must have a certain floating amount to ensure flexible opening and closing of precision mold processing and accurate alignment. Generally, the gap between single mode and connecting plate is controlled at 0. 50-1. 0rnm。 Excessive clearance is easy to cause eccentric rotation when the die is used. The development inclination of the new structure die of rotating shaft oil seal is too large, the wear of the die is intensified, and the service life of the die is affected; If the gap is too small, there will be interference between each die cavity during die operation and it will get stuck too much.
The development of two opening die for rotary shaft oil seal changes the traditional three opening die structure, ensures the appearance and performance of oil seal products, and greatly improves the work efficiency.
