Patent ID: 6070613
Filing Date: 2000-06-06
Classification: F16K,F25B,Y10T

Abstract:
A rotary flow-path exchanging valve comprising:a cylindrical valve housing;a valve seat plate having a low pressure side port secured to said valve housing and connected to a low pressure side conduit, a high pressure side port connected to a high pressure side conduit and an exchanging port;a valve element rotatably provided within said cylindrical valve housing and brought into contact with said valve seat plate in its one end surface so that said exchanging port is selectively communicated with either one of said low pressure side port and said high pressure side port by rotation; andan actuator including a multi-pole magnet attached to said valve element, an electromagnetic solenoid, a pair of main magnetic pole pieces, and a pair of auxiliary magnetic pole pieces, whereinsaid multi-pole magnet includes an S-polarity and N-polarity alternately arranged in a rotary direction attached to said valve element,said pair of main magnetic pole pieces are magnetically coupled with one of said N-polarity and said S-polarity generated when said electromagnetic solenoid is energized and magnetized with the one polarity, and is opposed to the one polarity of said N-polarity and S-polarity at rotary positions out of phase by 180.degree. from each other;said pair of auxiliary magnetic pole pieces are magnetically coupled with the other polarity of said N-polarity and said S-polarity generated when said electromagnetic solenoid is energized and magnetized with the other polarity, and is opposed to the other polarity of said N-polarity and S-polarity at rotary positions out of phase by 180.degree. from each other; andsaid main magnetic pole pieces each has a larger sectional area and is magnetized with stronger magnetic force than said auxiliary magnetic pieces.