| 摘要 |
PURPOSE:To provide a blow forming method for a resin boot in which good sealing is obtained without applying large compressive load to a ring portion, in a resin boot with a seal lip formed inside the ring portion. CONSTITUTION:In forming a blow of a resin boot, having a seal lip 24A on the inner surface of at least one of the two seal rings 14,18, the boot comprises a first ring portion 14 fitted in a joint housing 12, a second ring portion 18 fitted in a joint shaft portion 16 and a bellows portion connecting together both ring portions 14,18. A seal lip forming protrusion 28A of a blow forming metal mold 26 is, in section, tapered in tip, so that the seal tip 24A is indirectly formed by the protrusion 28A. |
