JPS62137386U

JPS62137386U -

Info

Publication number: JPS62137386U
Application number: JP2536886U
Authority: JP
Priority date: 1986-02-24
Filing date: 1986-02-24
Publication date: 1987-08-29

Description

[Brief explanation of the drawing]

第１図は本考案の一実施例を示す液体ポンプの
吐出圧力制御装置の回路図、第２図は第１図の縦
断面図、第３図は他の実施例を示す液体ポンプの
吐出圧力制御装置の回路図、第４図は第３図の要
部を断面で示した図、第５図はさらに他の実施例
を示す液体ポンプの吐出圧力制御装置の回路図、
第６図は第５図の要部を断面で示した図である。１，６０，６７……圧力制御弁、３……吐出流
路、５……斜板、６……操作ピストン、７……作
用室、８，６６……切換弁、３６，６１，６８…
…弁体、４０，６２，６９……第１作用面、４１
，６３，７０……第２作用面、４４……第１ばね
、４７……第２ばね。 Fig. 1 is a circuit diagram of a liquid pump discharge pressure control device showing one embodiment of the present invention, Fig. 2 is a vertical sectional view of Fig. 1, and Fig. 3 is a liquid pump discharge pressure control device showing another embodiment. A circuit diagram of a control device, FIG. 4 is a cross-sectional view of the main part of FIG. 3, and FIG. 5 is a circuit diagram of a liquid pump discharge pressure control device showing another embodiment.
FIG. 6 is a cross-sectional view of the main part of FIG. 5. 1, 60, 67... Pressure control valve, 3... Discharge channel, 5... Swash plate, 6... Operation piston, 7... Action chamber, 8, 66... Switching valve, 36, 61, 68...
... Valve body, 40, 62, 69 ... First working surface, 41
, 63, 70... second action surface, 44... first spring, 47... second spring.

Claims

[Scope of utility model registration request]

A valve body whose primary side communicates with the discharge flow path of the liquid pump and whose secondary side communicates with an action chamber formed on the back side of the operating piston that operates the variable discharge amount control element, and which is slidably inserted into the interior. It has a first spring and a second spring for arbitrarily adjusting the opening pressure at one end and the other end, and a first working surface and a second spring on which the discharge pressure of the discharge passage acts on the one end and the other end of the valve body. A pressure control valve having two working surfaces is provided between the discharge flow path of the liquid pump and the pressure control valve, and the discharge flow path is formed on the first and second working surfaces of the valve body of the pressure control valve by a switching operation. A two-position switching valve that selectively acts on the discharge pressure is provided, and the pressure control valve controls the discharge pressure of the discharge passage acting on the first working surface of the valve element to exceed the opening pressure caused by the second spring by the switching operation of the switching valve. The first position minimizes the discharge amount of the liquid pump by introducing the discharge liquid of the discharge passage into the action chamber formed on the back side of the operation piston, and the second position of the valve body by switching the switching valve.
When the discharge pressure of the discharge flow path acting on the working surface exceeds the opening pressure of the first spring, the discharge liquid is introduced into the working chamber formed on the back side of the operating piston to minimize the discharge amount of the liquid pump. In the second position, when the discharge pressure of the discharge flow path acting on each working surface is less than the opening pressure of each spring, the liquid in the working chamber formed on the back side of the operation piston is discharged to the low pressure side and the liquid pump is discharged. and a neutral position for maximizing the discharge pressure of a liquid pump.