How to ensure the precision of mold processing

The procedure is as follows: wipe the mold and spray release agent - insert semi-finished products (oil seal skeleton and rubber ring) - flip and close the mold - send the mold to the vulcanization chamber with rack drive - vacuum vulcanization - send the mold out to the trailer with rack drive - open the mold - flip - top the product.     

It is understood that two rubber oil seal molds are manufactured. The manufacturing of the two-piece oil seal mold adopts single component processing, followed by assembly and matching, with excellent processing technology and convenient testing. The material of the single cavity mold is CrlZ, and the connecting plate is made of 45 steel. In the process of mold processing, in addition to strictly following the mold drawings to ensure the size of the mold cavity, the following points are key to ensuring the accuracy of mold processing:   

(l) Processing of flow groove: In the past, the processing quality of the flow groove of oil seal molds was not fully valued. The flow groove was often processed too far away from the mold cavity or the size was difficult to control, making it difficult to trim the product and making it unattractive. Two sets of oil seal molds have been improved to address these issues. The inner end size of the triangular flow groove is consistent with the outer diameter of the product (zero to zero), and the upper and lower molds are used to form a sharp blade shape at this point. When the oil seal is molded, excess burrs are cut off, simplifying the trimming process and improving the appearance quality of the product. Due to the fact that the flow groove and the outer diameter of the mold cavity are located on different modules, their dimensions do not interfere and their accuracy is easily guaranteed.     

(2) The matching processing between the upper mold and the upper mold core 1: The matching between the upper mold and the upper mold core 1 is a tapered fit, which used to be a research and assembly method, requiring a contact rate of over 80%. This traditional processing method is not only difficult, but also consumes a lot of labor hours, and it is still difficult to achieve the ideal effect without burrs. The processing of the new structure mold adopts the method that the inclination angle of the taper hole is slightly smaller than the inclination angle of the taper axis, so that the upper mold and the upper mold core are always tightly adhered to each other at the parting surface b, in a seamless fit state, so there is no flash in the product at this point. And the manufacturing process of the mold has been improved.     

(3) The pressing of upper mold core 1 and upper mold core 2: The pressing of upper mold core 1 and upper mold core 2 is the key to ensuring the size and accuracy of the oil seal lip. The flying edge at the secondary lip of the three open oil seal mold has a significant impact on the appearance quality of the secondary lip. The new structure mold adopts interference fit between upper mold core 1 and upper mold core 2. After individual processing, they are pressed together by thermal expansion method, and then the upper mold core 2 is tightly pulled by the fastening screw at the upper end, effectively preventing the loosening of the two mold cores at the secondary lip.     

(4) The connection between each cavity mold: The connection between each single cavity mold and the connecting plate must have a certain amount of float to ensure flexible opening and closing of the mold and accurate alignment. The gap between the single-mode and the connecting plate is generally controlled at 0. 50 to 1. 0rnm。 Excessive clearance can easily cause the mold to deviate from the rotation axis during use. The development of a new structure mold with oil seal has a too large inclination, which exacerbates mold wear and affects the service life of the mold; If the gap is too small, it will cause interference between the various mold cavities during mold operation, resulting in excessive jamming.     

The development of a two part mold for rotating shaft oil seals has changed the traditional three part mold structure, ensuring the appearance and performance of oil seal products and greatly improving work efficiency. The successful development of this new structural mold has promotional significance for domestic oil seal enterprises.