JPH01111880U

JPH01111880U -

Info

Publication number: JPH01111880U
Application number: JP693588U
Authority: JP
Priority date: 1988-01-22
Filing date: 1988-01-22
Publication date: 1989-07-27
Anticipated expiration: 2003-01-22
Also published as: JPH073041Y2

Description

[Brief explanation of drawings]

第１図ないし第４図は本考案の第１の実施例を
示し、第１図は油圧回路図、第２図は圧力制御弁
の縦断面図、第３図は第２図中の―矢示方向
断面図、第４図はブレーキ圧の特性線図、第５図
ないし第７図は第２の実施例を示し、第５図は油
圧回路図、第６図は圧力制御弁の縦断面図、第７
図は第６図中の―矢示方向断面図、第８図お
よび第９図は従来技術を示し、第８図は油圧回路
図、第９図はブレーキ圧の特性線図、第１０図な
いし第１２図は他の従来技術を示し、第１０図は
油圧回路図、第１１図はブレーキ圧の特性線図、
第１２図は第１１図とは異なるブレーキ圧の特性
線図である。１……油圧モータ、２Ａ，２Ｂ……主管路、３
……油圧ポンプ、４……タンク、５……方向切換
弁、６……ブレーキ弁、７Ａ，７Ｂ……リリーフ
弁、８……カウンタバランス弁、９Ａ，９Ｂ……
チエツク弁、１０Ａ，１０Ｂ，１１Ａ，１１Ｂ…
…分岐管路、２１……圧力制御弁、２２……弁本
体、２３……スプール摺動穴、２４Ａ，２４Ｂ，
２６Ａ，２６Ｂ……油溝、２５Ａ，２５Ｂ……油
圧源側ポート、２７Ａ，２７Ｂ……アクチユエー
タ側ポート、２９Ａ，２９Ｂ……油室、３０，５
０……スプール、３１，５１……油路、３２，５
２……中央ランド、３３Ａ，３３Ｂ，５３Ａ，５
３Ｂ……ノツチ、３４Ａ，３４Ｂ，５４Ａ，５４
Ｂ……切換ランド、３７，５７……油通路、３８
……絞り、３９Ａ，３９Ｂ，５９Ａ，５９Ｂ……
絞り通路、４０Ａ，４０Ｂ……ストツパ、４１Ａ
，４１Ｂ……ばね、４２Ａ，４２Ｂ……チエツク
弁、５８……油穴。 1 to 4 show a first embodiment of the present invention, FIG. 1 is a hydraulic circuit diagram, FIG. 2 is a vertical cross-sectional view of the pressure control valve, and FIG. 4 is a brake pressure characteristic diagram, FIGS. 5 to 7 show the second embodiment, FIG. 5 is a hydraulic circuit diagram, and FIG. 6 is a longitudinal section of the pressure control valve. Figure, 7th
The figure is a sectional view in the direction of the - arrow in Fig. 6, Figs. 8 and 9 show the prior art, Fig. 8 is a hydraulic circuit diagram, Fig. 9 is a brake pressure characteristic diagram, and Figs. Fig. 12 shows another conventional technique, Fig. 10 is a hydraulic circuit diagram, Fig. 11 is a characteristic diagram of brake pressure,
FIG. 12 is a characteristic diagram of brake pressure different from FIG. 11. 1...Hydraulic motor, 2A, 2B...Main pipe, 3
... Hydraulic pump, 4 ... Tank, 5 ... Directional switching valve, 6 ... Brake valve, 7A, 7B ... Relief valve, 8 ... Counter balance valve, 9A, 9B ...
Check valve, 10A, 10B, 11A, 11B...
... Branch pipe line, 21 ... Pressure control valve, 22 ... Valve body, 23 ... Spool sliding hole, 24A, 24B,
26A, 26B...Oil groove, 25A, 25B...Hydraulic pressure source side port, 27A, 27B...Actuator side port, 29A, 29B...Oil chamber, 30,5
0...Spool, 31,51...Oil path, 32,5
2...Central land, 33A, 33B, 53A, 5
3B...Notsuchi, 34A, 34B, 54A, 54
B...Switching land, 37, 57...Oil passage, 38
...Aperture, 39A, 39B, 59A, 59B...
Throttle passage, 40A, 40B...stopper, 41A
, 41B... Spring, 42A, 42B... Check valve, 58... Oil hole.

Claims

[Scope of utility model registration request]

a valve body having a pair of oil pressure source side ports and a pair of actuator side ports; a spool that is slidably provided within the valve body and opens and closes between each of the oil pressure source side ports and each actuator side port; , a pair of oil chambers located at both ends of the spool and formed within the valve body; a throttle passage that communicates each oil chamber with each oil pressure source side port; and a throttle passage provided within each oil chamber. and a pair of springs that always bias the spool to a neutral position, and the spool has an oil passage that extends in the axial direction sandwiching the central land and constantly communicates between the actuator side ports. An oil passage is provided in the central land of the spool, which is shut off when the spool is in the neutral position, and communicates with the oil passage a port on the return side among the actuator side ports when returning from the fully open position to the neutral position. , and the oil passage is provided with a pair of check valves that allow pressure oil to flow only from the return side port to the suction side port among the actuator side ports. control valve.