JPS61204076U

JPS61204076U -

Info

Publication number: JPS61204076U
Application number: JP8894986U
Authority: JP
Priority date: 1986-06-11
Filing date: 1986-06-11
Publication date: 1986-12-22

Description

[Brief explanation of the drawing]

第１図はカウンターバランス弁を備えた従来の
油圧回路図、第２図はパイロツト流量制御弁付カ
ウンターバランス弁を備えた従来の油圧回路図、
第３図は第２図に示すパイロツト流量制御弁とカ
ウンターバランス弁の縦断面図、第４図は本考案
に係るパイロツト流量制御弁を取付けたカウンタ
ーバランス弁を備える油圧回路図、第５図は第４
図に示すパイロツト流量制御弁とカウンターバラ
ンス弁の縦断面図である。１……方向切換弁、２……油圧モータ、６……
チエツク弁、７……復帰用ばね、８……ポンプ、
１０……カウンターバランス弁、１２……パイロ
ツト管路、１４……制御スプール、２９……バル
ブ本体、３０……プランジヤ、３４……入側ポー
ト、３５……液室、３６……ばね室、３７……固
定絞り、４１……シリンダ部、４２，４４……ば
ね、４３……ピストン、４５……鍔部、４６……
液圧シリンダ、５０……荷。 Fig. 1 is a conventional hydraulic circuit diagram with a counterbalance valve, Fig. 2 is a conventional hydraulic circuit diagram with a counterbalance valve with a pilot flow control valve,
Fig. 3 is a vertical sectional view of the pilot flow control valve and counterbalance valve shown in Fig. 2, Fig. 4 is a hydraulic circuit diagram with a counterbalance valve to which the pilot flow control valve according to the present invention is attached, and Fig. 5 is a Fourth
FIG. 3 is a longitudinal sectional view of the pilot flow control valve and counterbalance valve shown in the figure. 1... Directional switching valve, 2... Hydraulic motor, 6...
Check valve, 7...Return spring, 8...Pump,
DESCRIPTION OF SYMBOLS 10...Counter balance valve, 12...Pilot pipe line, 14...Control spool, 29...Valve body, 30...Plunger, 34...Inlet port, 35...Liquid chamber, 36...Spring chamber, 37... Fixed throttle, 41... Cylinder part, 42, 44... Spring, 43... Piston, 45... Flange part, 46...
Hydraulic cylinder, 50...load.

Claims

[Scope of utility model registration request]

A plunger having a throttle part communicating with the pilot passage of the counterbalance valve in the valve body, a fixed throttle provided upstream of the throttle part, a spring disposed at one end of the plunger, communicating upstream of the fixed throttle, and the other end of the plunger. In a pilot flow control valve that communicates with the downstream side of a fixed throttle, the spring and the spring disposed in the cylinder part fixed to the valve body compress the piston fitted into the cylinder part , and the cylinder part The set load of the spring is higher than the piston pressing force due to the pilot pressure lower than the set load of the return spring of the counterbalance valve and the spring in contact with the plunger, and is higher than the set load of the return spring and the spring in contact with the plunger. It is set to be weaker than the piston pressing force, and set so that when the pilot pressure is higher than the set load of the return spring, the opening of the plunger's throttle part is approximately minimum, and the piston is locked at the retraction limit. A pilot flow control valve of a counterbalance valve, characterized in that a piston comes into contact with a plunger when the pilot pressure drops to a predetermined pressure.