| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a vacuum valve capable of directly and efficiently heating a valve element by a heater, easily mounting the heater on the valve element and a shaft, and simply replacing the heater. <P>SOLUTION: A cartridge heater 30 is accommodated in a heater bore inside the shaft 10 connected to the valve element 6, and a heating portion 30a at a leading end of the cartridge heater 30 is located at a joint 32 between the shaft 10 and the valve element 6. At the joint 32, a heat receiving groove and a pressurizing portion communicating with the heater bore are provided at opposite positions on surfaces in contact with each other between the valve element 6 and the shaft 10. An arcuate groove portion with a radius equal to that of the heating portion 30a of the cartridge heater 30 is formed in the heat receiving groove. The valve element and the shaft are fixed to each other with the heating portion 30a disposed between the heat receiving groove and the pressurizing portion, whereby the heating portion 30a is pressurized by the pressurizing portion 4 to come into tight plane-to-plane contact on an inner periphery of the arcuate groove portion of the heat receiving groove. <P>COPYRIGHT: (C)2012,JPO&INPIT |
