| 摘要 |
PURPOSE:To complete vulcanization simultaneously for lining and covering by a method wherein a shaft metal fitting and a blank piece are inserted into the shaft hole of a valve body and the side hole thereof respectively, unvulcanized rubber for lining is filled up in gaps from the inner surfaces of the holes, the shaft metal fitting and the blank piece are removed thereafter, an inner piece and a blank piece for actual vulcanization are inserted instead, and rubber for covering is pressed in. CONSTITUTION:A shaft metal fitting 4 and a blank piece 5 are inserted into a shaft hole 2 and a side hole 3 respectively with prescribed gaps for lining rubber from the inner surfaces thereof. Unvulcanized rubber heated to 70-80 deg.C is filled up in the gaps from an extruder 6. After completion of this operation, a valve body 1 is removed from the extruder 6, the shaft metal fitting 4 and the blank piece 5 are drawn off from the valve body 1 whereto lining rubber R1 is connected, and an inner piece 18 and a blank piece 19 for actual vulcanization are inserted instead and made to stick fast to the lining rubber R1. A metal mold 20 has two dies M1 and M2 wherein cavities corresponding to a desired outer shape of the valve body are formed, and the valve body 1 is supported in suspension in the cavities with a gap from the surfaces of the dies. Covering rubber R2 is injected from a rubber pot 21, the actual vulcanization is performed at the temperature of 155-185 deg.C, and simultaneously the actual vulcanization of the lining rubber R1 is completed. |
