Electromagnetic valve
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsHidehiro Soga, Kenji Nakao, Kouichi Ojima, Yuji Bando
Life of this patent
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Abstract
An electromagnetic valve of a reduced size capable of suppressing temperature rise of a coil regardless of continuous electrical energization over an extended time while preventing attracting force from lowering includes a coil cooling fluid passage (9a; 8a; 4a) for communicating a coil cooling fluid sump space (2a) with a controlled pressure region for allowing a fluid to flow into the coil cooling fluid sump space (2a) from the controlled pressure region. The coil cooling fluid passage includes a small-diameter communicating passage portion (9a) provided so as not to exert influence to a hydraulic pressure prevailing in the controlled pressure region.
Claims6
An electromagnetic valve, comprising:
- a valve seat assembly including a high pressure port opened in a controlled pressure region of a high pressure, a low pressure port opened in a drainage region of a low pressure, a fluid passage formed between said high pressure port and said low pressure port and a valve seat formed in said fluid passage;
- a plunger assembly including a plunger disposed to be slideable reciprocatively within a column-like hollow plunger chamber and a valve element provided at one end portion of said plunger so as to open and close said fluid passage in cooperation with said valve seat;
- a coil housed within a case for driving said plunger upon electrical energization of said coil to thereby displace said plunger assembly to a valve-closed position at which said fluid passage is closed by said valve element while upon electrical deenergization of said coil, said plunger assembly is displaced to a valve-opened position at which said fluid passage is opened by said valve element under the influence of hydraulic pressure prevailing in said controlled pressure region;
- a coil cooling fluid sump space provided between an outer peripheral portion of said coil and said case;
- and
- a coil cooling fluid passage provided so as to communicate said coil cooling fluid sump space with said controlled pressure region for allowing a fluid to flow into said coil cooling fluid sump space from said controlled pressure region, said coil cooling fluid passage including a small-diameter communicating passage portion provided so as not to exert influence to the hydraulic pressure prevailing in said controlled pressure region.
Dependencies are inferred from the claim text.