Title:
CHANGE-OVER VALVE
Document Type and Number:
Japanese Patent JPS57179476
Kind Code:
A
Abstract:
PURPOSE:To permit pressure in the interior and exterior of a main valve to be balanced with each other forcibly to improve operation factor by providing a communicating hole in the main valve to which is connected an auxiliary valve for opening and closing this communicating hole and which is operated by connecting the auxiliary valve to a drive source. CONSTITUTION:When difference of pressure between the interior and exterior of a main valve 28 is 15-20kg/cm<2> and current is supplied to a coil 36, an auxiliary valve 29 is pivoted about a fulcrum 29b counterclockwise to open a communicating hole 28a in the main valve 28 for achieving forcibly pressure balance. When current to the coil 36 is stopped, the auxiliary valve 29 is pivoted clockwise about the fulcrum 29b to open the communicating hole 28a in the main valve 28. Thus, high pressure and low one communicate to each other to achieve forcibly pressure balance, and thereafter the main valve 28 is pivoted about a pivot 28b by the action of a tension spring 30 until the communicating hole 28a is closed, so that a return valve is changed over.
Inventors:
SATOU SHIYOUICHI
TAKAHASHI KIKUJI
TAKAHASHI KIKUJI
Application Number:
JP6390181A
Publication Date:
November 05, 1982
Filing Date:
April 30, 1981
Export Citation:
Assignee:
HITACHI LTD
International Classes:
F16K11/06; F16K39/04; F25B41/04; (IPC1-7): F16K11/06; F25B41/04
Domestic Patent References:
| JPS5228813U | 1977-02-28 | |||
| JPS5326533B2 | 1978-08-02 |