| 摘要 |
<p>PURPOSE:To obtain a synthetic resin made ball valve of an excellent quality and property at a low cost, by injecting resin in the cavity shaped by the ball plug with a spindle, the seal ring having a relief groove on a sliding face and the core body provided with a seal holder, etc. CONSTITUTION:The cavity 20 of the shape of a valve body is shaped by putting the beforehand prepared ball plug 2 with a spindle 5, the seal ring 6 provided with a peripheral relief groove 7 on the sliding face 6a contacting the ball plug 2 and the core body 15a having the ring like seal holder 15c protruding to an axial direction in the internal space shaped by bottom and top forces 12, 14. The injection of resin is performed, contacting the seal holder 15c to the back of the seal ring 6. Because a part of the compression force due to a resin pressure is absorbed by the relief groove 7 by this, there is not essentially the possibility that the seal ring 6 is plastically deformed, then the valve body having an excellent sealing function is obtained.</p> |
