| 摘要 |
<p>This invention relates to a solenoid valve for heat insulating pipes, which is suitably used for a transport pipe, the outer circumferential portion of which is heat insulated, for a low- or high-temperature fluid. In a conventional solenoid valve of this kind for heat insulating pipes, it is necessary that the magnetic flux density of a solenoid coil be increased by increasing the number of turns thereof and the level of current to be applied thereto, and this causes an increase in the manufacturing cost and running cost. In the solenoid valve for a heat insulating pipe according to the present invention, a fixed iron core (23) constituting a magnetic circuit between a solenoid coil (17) and a movable iron core (18) is provided on the inner side of an insulating layer (6) which tubularly surrounds flow passages (7, 20, 21, 26, 33). Therefore, the magnetic resistance between the solenoid coil and movable iron core can be reduced without enlarging the movable iron core, and the manufacturing cost and running cost can be reduced.</p> |
