To grasp the precision of precision mold processing, the working procedure is as follows: wipe the mold and spray release agent - put the semi-finished product (oil seal framework and rubber ring) - turn over and close the mold - rack drive to send the mold to the curing chamber - vacuum curing - rack drive to send the mold to the carriage - open the mold - turn over - eject the product.
It is understood that the two open rubber oil seal mold manufacturing. The mould for two oil seals is made of single components and then assembled to match. The processing technology is excellent and the mould inspection is convenient. The material of single cavity die is crlz, and the connecting plate is 45 steel. In the process of mold processing, in addition to strictly following the mold drawing to ensure the cavity size, the following points are the key to ensure the mold processing accuracy:
(l) Flow groove processing: in the past, the precision mold processing of oil seal mold flow groove did not get enough attention, flow groove is often processed too far from the cavity or the size is not easy to control, so that the product is difficult to trim and the product is not beautiful. The two split oil seal mould has been improved to solve these problems. The inner end size of the triangle flow groove is consistent with the outer diameter of the product (zero to zero). The split upper and lower mould forms 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 flow groove and the outer diameter of the cavity are on different modules, the size does not interfere, and the accuracy is easy to guarantee.
(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 matching method was used, and the contact rate is required to be more than 80%. This traditional processing method is not only difficult, but also costs a lot of man hours, and 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 taper hole is slightly smaller than that of the taper shaft, so that the upper die and the upper die core are always tightly bonded together at the parting surface B, in the state of no gap fit, so there is no flash in the product here. And the mold manufacturing process is improved.
(3) Pressing of the upper die core 1 and the upper die core 2: the pressing of the upper die core 1 and the upper die core 2 is the key to ensure the size and accuracy of the oil seal lip. The flash at the secondary lip of the three opening oil seal mold has a great influence on the appearance of the secondary lip. In the new structure mold, the upper mold core 1 and the upper mold core 2 adopt interference fit. After the monomer is processed, it is pressed into one by thermal expansion method, and then the upper mold core 2 is tightly pulled by the upper fastening screw to effectively prevent the loosening of the two mold cores at the auxiliary lip.
(4) Connection between the cavity molds: the connection between the single cavity mold and the connecting plate must have a certain floating amount to ensure the flexible opening and closing and accurate alignment of the precision mold processing. Generally, the gap between single-mode and coupling plate is controlled at 0. 50-1. 0rnm。 If the clearance is too large, it is easy to cause the deviation of the new structure of the rotary shaft oil seal when the die is used. The development of the new structure of the die is too large, and the wear of the die is intensified, which affects the service life of the die; If the gap is too small, there will be interference between the die cavities during the operation of the die, and the die will be stuck.
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.