Pump discharge flow-rate control device

Patent metadata

Field	Value
Publication number	US-2016003237-A1
Application number	US-201414769825-A
Country	US
Kind code	A1
Filing date	Mar 6, 2014
Priority date	Mar 27, 2013
Publication date	Jan 7, 2016
Grant date	—

Abstract

A pump discharge flow-rate control device includes a constant capacity pump driven by a common driving source with a variable capacity pump, a resistor interposed in a signal pressure passage through which a working fluid discharged from the constant capacity pump flows, and a control pressure actuator configured to lower the control pressure by driving the regulator in accordance with a rise in a differential pressure before and after the resistor. The resistor includes a fixed throttle and a check valve interposed in the signal pressure passage in parallel with each other. The check valve includes a seat interposed in the signal pressure passage, a poppet arranged on a downstream side of the seat, and a spring configured to press the poppet to the seat.

First claim

1 . A pump discharge flow-rate control device for controlling a discharge flow rate of a variable capacity pump in accordance with a control pressure adjusted by a regulator, comprising:
a constant capacity pump driven by a common driving source with the variable capacity pump; a resistor interposed in a signal pressure passage through which a working fluid discharged from the constant capacity pump flows; and a control pressure actuator configured to lower the control pressure by driving the regulator in accordance with a rise in a differential pressure before and after the resistor, wherein the resistor includes a fixed throttle and a check valve interposed in the signal pressure passage in parallel with each other; and the check valve includes: a seat interposed in the signal pressure passage; a poppet arranged on a downstream side of the seat; and a spring configured to press the poppet to the seat.

2 . The pump discharge flow-rate control device according to claim 1 , wherein
the fixed throttle is formed inside the poppet.

3 . The pump discharge flow-rate control device according to claim 1 , wherein
the fixed throttle has: an upstream side throttle hole opened in the poppet and communicating with an upstream side of the seat in the signal pressure passage; and a downstream side throttle hole connected to the upstream side throttle hole and communicating with a downstream side of the seat in the signal pressure passage; and a sectional area of the upstream side throttle hole is formed smaller than a sectional area of the downstream side throttle hole.

4 . The pump discharge flow-rate control device according to claim 1 , wherein
the poppet has: a valve body portion seated on a seat of the signal pressure passage; and a shaft which supports the valve body portion; wherein the pump discharge flow-rate control device further comprises: an accommodating chamber which accommodates the spring configured to urge the shaft in an axial direction; and a communication path having a downstream side of the seat in the signal pressure passage communicate with the accommodating chamber.

5 . The pump discharge flow-rate control device according to claim 1 , further comprising:
an adjuster rod configured to be displaced in an axial direction of the poppet and to adjust an urging force of the spring, wherein the adjuster rod configured to move to a position where a valve opening of the poppet is regulated.

Assignees

• Kayaba Industry Co Ltd

Inventors

• Aoyama Atsushi

Classifications

• F04B1/122

  Details or component parts, e.g. valves, sealings or lubrication means (for machines or pumps having rotary cylinder blocks F04B1/2014) · CPC title

• F04B19/22

  of reciprocating-piston type · CPC title

• F04B1/146

  Swash plates; Actuating elements · CPC title

• F04B1/295

  by changing the inclination of the swash plate · CPC title

• F04B1/143

  Cylinders · CPC title