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AssigneesKayaba Kogyo Kabushiki Kaisha, Nissan Motor Co., Ltd.
InventorsSatoshi Chikamatsu, Noboru Kurita, Koji Morita, Yoshiyuki Eto
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This invention relates to a pressure reducing valve wherein a spool is driven axially by a first plunger which moves according to the magnetization state of a first solenoid, and a control port is connected to a supply port and a tank port according to the axial position of this spool. The pressure of the control port acts on the spool in the opposite direction to that of the plunger via a feedback passage, and the pressure increases or decreases according to the current flowing through the first solenoid. According to this invention, a second plunger is arranged in series with the first plunger, and a spring tends to push the second plunger toward the first plunger. A second magnetized solenoid however keeps the second plunger held back against the restoring force of the spring so that it is not in contact with the first plunger, and releases the second plunger so that it pushes the first plunger when the current fails. Hence, even if the current supplied to the first and second solenoids is cut off, the control port maintains the predetermined pressure, and a fail-safe mechanism is realized by means of a simple construction.
A pressure reducing valve comprising a supply port connected to an oil source, a tank port connected to a tank, a control port connected to a hydraulic actuator, a spool connecting said control port to said tank port depending on its axial position, a first plunger in contact with one end of said spool, a first solenoid which drives said first plunger axially by means of a driving force according to an magnetizing current provided, and a feedback oil passage for applying the pressure of said control port to the opposite end of said spool, wherein the pressure generated by said control port is increased and decreased according to the magnetizing current of said first solenoid, further comprising:
A pressure reducing valve comprising a supply port connected to an oil source, a tank port connected to a tank, a control port connected to a hydraulic actuator, a spool connecting said control port to said tank port depending on its axial position, a first plunger in contact with one end of said spool, a first solenoid which drives said first plunger axially by means of a driving force according to a magnetizing current provided, and a feedback oil passage for applying the pressure of said control port to the opposite end of said spool, wherein the pressure generated by said control port is increased and decreased according to the magnetizing current of said first solenoid, further comprising:
Dependencies are inferred from the claim text.