JPH0290403U

JPH0290403U -

Info

Publication number: JPH0290403U
Application number: JP16824788U
Authority: JP
Priority date: 1988-12-28
Filing date: 1988-12-28
Publication date: 1990-07-18

Description

[Brief explanation of the drawing]

第１図は、本考案に従う遠隔操作流体圧システ
ムの一具体例を油圧シヨベルに適用した流体圧回
路図。第２図は、第１図の遠隔操作流体圧システ
ムにおける第２のリモコン弁を示す断面図。第３
図は、第１図の遠隔操作流体圧システムにおける
シリンダ作動圧力と外部パイロツト減圧弁にて生
成される信号圧力との関係を示す図。第４図は、
第１図の遠隔操作流体圧システムにおいて、メイ
ンリリーフ弁のベント流路が開放されているとき
及び上記ベント流路が閉鎖されているときのメイ
ンリリーフ弁を通過する圧力流体の流量とメイン
流体圧力の関係を示す図。第５図は、従来の遠隔
操作流体圧システムを示す流体圧回路図。２……ブーム、４……アーム、６……バケツト
、１０……アーム流体圧シリンダ機構、１２……
バケツト流体圧シリンダ機構、１４……第１の切
換弁、１６……第２の切換弁、１８……第３の切
換弁、２０……第１のリモコン弁、２２及び２２
′……第２のリモコン弁、２４及び２４′……第
３のリモコン弁、２６……流体圧供給源、２８及
び２８′……メインリリーフ弁、３０……流体溜
、３２……パイロツト流体圧源、６８及び７８…
…外部パイロツト減圧弁、７２……パイロツト流
体圧源、８６……操作レバー、９２……プツシユ
ロツド、９４……操作力低減ロツド、９６……減
圧用スプール、１１６……圧力増大機構、１１８
……切換スプール、１２４……開弁圧切換弁、１
２６……ベント流路、１３０……パイロツトリリ
ーフ弁。 FIG. 1 is a fluid pressure circuit diagram in which a specific example of the remote control fluid pressure system according to the present invention is applied to a hydraulic excavator. FIG. 2 is a sectional view showing a second remote control valve in the remote control fluid pressure system of FIG. 1; Third
2 is a diagram showing the relationship between the cylinder operating pressure and the signal pressure generated by the external pilot pressure reducing valve in the remote control fluid pressure system of FIG. 1. FIG. Figure 4 shows
In the remote control fluid pressure system of FIG. 1, the flow rate of the pressure fluid passing through the main relief valve and the main fluid pressure when the vent flow path of the main relief valve is open and when the vent flow path is closed. A diagram showing the relationship between. FIG. 5 is a fluid pressure circuit diagram showing a conventional remote control fluid pressure system. 2...Boom, 4...Arm, 6...Bucket, 10...Arm fluid pressure cylinder mechanism, 12...
Bucket fluid pressure cylinder mechanism, 14...first switching valve, 16...second switching valve, 18...third switching valve, 20...first remote control valve, 22 and 22
'...Second remote control valve, 24 and 24'...Third remote control valve, 26...Fluid pressure supply source, 28 and 28'...Main relief valve, 30...Fluid reservoir, 32...Pilot fluid Pressure sources, 68 and 78...
... External pilot pressure reduction valve, 72 ... Pilot fluid pressure source, 86 ... Operation lever, 92 ... Push rod, 94 ... Operation force reduction rod, 96 ... Pressure reduction spool, 116 ... Pressure increase mechanism, 118
...Switching spool, 124...Valve opening pressure switching valve, 1
26...Vent channel, 130...Pilot relief valve.

Claims

[Claims for Utility Model Registration] 1. A fluid pressure supply source for supplying pressure fluid;
A pilot pressure supply source for supplying pilot pressure fluid, a fluid pressure cylinder mechanism that expands and contracts by the action of pressure fluid from the fluid pressure supply source, and a switching valve that controls the expansion and contraction of the fluid pressure cylinder mechanism. , a remote control valve for controlling the pilot pressure fluid from the pilot pressure supply source and switching the switching valve, the remote controller using a signal pressure corresponding to the working fluid pressure acting on the fluid pressure cylinder mechanism as external pilot pressure. A remotely controlled fluid pressure system that acts on a valve. 2. The remote control valve includes a push rod that is moved up and down by an operating lever, an operating force reduction rod that is moved by the push rod, and a pressure reducing spool that is movably attached to the operating force reduction rod. an external pilot pressure reducing valve is disposed between the hydraulic cylinder mechanism and the remote control valve, and the external pilot pressure reducing valve has a signal pressure substantially proportional to the working fluid pressure acting on the hydraulic cylinder mechanism. 2. The remotely operated fluid pressure system of claim 1, wherein the signal pressure generated by the external pilot pressure reducing valve acts on the operating force reduction rod. 3. The remote control valve is provided with a pressure increasing mechanism that increases the signal pressure generated by the external pilot pressure reducing valve to act on the operating force reducing rod when the operating amount of the operating lever exceeds a predetermined value. 3. The remotely operated hydraulic system of claim 2. 4 a fluid pressure supply source for supplying pressure fluid;
a pilot pressure supply source for supplying pilot pressure fluid; a fluid pressure cylinder mechanism that expands and contracts by the action of pressure fluid from the fluid pressure supply source; and a fluid pressure cylinder mechanism for supplying pilot pressure fluid from the fluid pressure supply source to the fluid pressure cylinder mechanism. A main relief valve for maintaining the supplied pressure fluid at a predetermined pressure, a switching valve for controlling the expansion and contraction of the fluid pressure cylinder mechanism, and a switching valve for controlling the pilot pressure fluid from the pilot pressure supply source and for controlling the switching valve. and a remote control valve for switching, and when the remote control valve is operated by a predetermined amount or more, the opening pressure of the main relief valve becomes greater than the predetermined pressure, thereby increasing the fluid pressure of the pressure fluid supplied to the fluid pressure cylinder mechanism. a remotely controlled fluid pressure system in which the pressure is raised above the predetermined pressure. 5 A valve-opening pressure switching valve is connected to the main relief valve via a vent flow path, and the valve-opening pressure switching valve is normally located at the first position and connects the vent flow path to the pilot relief valve. 5. The main relief valve is connected to a fluid reservoir, and when the remote control valve is operated by a predetermined amount or more, it is switched to the second position to block the vent passage, thereby increasing the opening pressure of the main relief valve. remotely controlled hydraulic system.