Flow control apparatus
AssigneeToyoda Koki Kabushiki Kaisha
InventorNoriyuki Okamoto
Life of this patent
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Abstract
In a flow control apparatus, a fluid pressure is introduced from downstream of a metering orifice to a rear room of a spool while a relief valve in the spool is assembled in advance. A front section of a relief valve sub-assembly is press fitted to a hole provided on the spool and is opening to rear room of the spool so that a receiving room of a valve body in a relief valve casing communicates to a bypass path. A communicating path provided in a rod communicates to the rear room of the spool through outside of the relief valve sub-assembly. The relief valve casing is received in a receiving hole provided in the spool and a cylindrical room between the relief valve casing and the receiving room is used as a part of a communicating path.
Claims6
A flow control apparatus comprising:
- a housing providing a flow control valve hole and a bypass path communicating to intermediate portion in axial direction of said flow control valve hole;
- a spool slidably inserted in axial direction into said flow control valve hole to open and close communicating between a fluid introducing room communicating to said flow control valve hole and said bypass path, providing a rear room of said spool and a front room of said spool where operating fluid is introduced from an oil pump, and forced toward a side of said front room of said spool to close communicating to said bypass path;
- an opening provided as coaxially with said flow control valve hole on a member provided bodily on said housing at a side of said front room of said spool, and communicating said front room of said spool to an outlet of said housing;
- a rod provided as coaxially and bodily with said spool, passing through said opening with a clearance and providing a metering orifice between said opening;
- a communicating path passing through said rod in axial direction and providing a communicating path between said front room of said spool and said outlet of said housing;
- and
- a relief pressure mechanism received in said spool, releasing high pressure in rear room of said spool to said bypass path and protecting said oil pump from overload;
- wherein
- said relief pressure mechanism is comprising a relief pressure valve casing and a valve body elastically forced to a seat valve face of a seat valve member provided on said relief pressure valve casing;
- said relief pressure mechanism is assembled in advance as a relief pressure valve sub-assembly;
- a front section of opposite side of said seat valve member provided on said relief pressure valve casing is press fitted to a press fitting hole opening to said rear room of said spool so that a receiving room of said valve body in said relief pressure valve casing communicates to said bypass path;
- and
- said communicating path communicates to said rear room of said spool through outside of said relief pressure valve sub-assembly.
Dependencies are inferred from the claim text.