JPH0454303U

JPH0454303U -

Info

Publication number: JPH0454303U
Application number: JP9619690U
Authority: JP
Priority date: 1990-09-13
Filing date: 1990-09-13
Publication date: 1992-05-11

Description

[Brief explanation of the drawing]

第１図は本考案の液圧回路の一例を示すバツク
ホー作業車の液圧回路図、第２図はバツクホー作
業車の側面図、第３図は第２図の−矢視図で
ある。図中、８はブーム起伏用シリンダ（アクチユエ
ータ）、９はアーム起伏用シリンダ（アクチユエ
ータ）、１０はバケツト回動用シリンダ（アクチ
ユエータ）、１３は第１走行用モータ（アクチユ
エータ）、１４は第２走行用モータ（アクチユエ
ータ）、１７は旋回用モータ（アクチユエータ）
、２３は第１ポンプ、２４は第１圧油供給管、２
５は第１走行操作弁（操作弁）、２６はブーム操
作弁（操作弁）、２７はバケツト操作弁（操作弁
）、２９は第２ポンプ、３０は第２圧油供給管、
３１は第２走行操作弁（操作弁）、３２はアーム
操作弁（操作弁）、３８はタンク、４０ａ，４１
ａ，４４ａはマイクロスイツチ（検出器）、５８
は第３ポンプ、５９は第３圧油供給管、６３は連
通弁、６４はパイロツトポート、７１はパイロツ
ト管路、７３は第２電磁切換弁（切換弁）、７５
はソレノイド、１０８はパイロツトポンプ、１１
７，１１８，１２０は信号電流、１２３は励磁電
流、１２４は増幅器を示す。 FIG. 1 is a hydraulic circuit diagram of a backhoe working vehicle showing an example of the hydraulic circuit of the present invention, FIG. 2 is a side view of the backhoe working vehicle, and FIG. 3 is a view taken along the - arrow in FIG. 2. In the figure, 8 is a boom hoisting cylinder (actuator), 9 is an arm hoisting cylinder (actuator), 10 is a bucket rotation cylinder (actuator), 13 is a first traveling motor (actuator), and 14 is a second traveling motor. Motor (actuator), 17 is a turning motor (actuator)
, 23 is a first pump, 24 is a first pressure oil supply pipe, 2
5 is a first travel operation valve (operation valve), 26 is a boom operation valve (operation valve), 27 is a bucket operation valve (operation valve), 29 is a second pump, 30 is a second pressure oil supply pipe,
31 is a second travel operation valve (operation valve), 32 is an arm operation valve (operation valve), 38 is a tank, 40a, 41
a, 44a is a micro switch (detector), 58
59 is the third pressure oil supply pipe, 63 is the communication valve, 64 is the pilot port, 71 is the pilot pipe line, 73 is the second electromagnetic switching valve (switching valve), 75
is a solenoid, 108 is a pilot pump, 11
7, 118, and 120 are signal currents, 123 is an excitation current, and 124 is an amplifier.

Claims

[Scope of utility model registration request]

First pressure oil supply pipe 24 communicating with first pump 23
A plurality of operation valves 25, 26, 27 are connected in tandem from the upstream side to the downstream side, and each operation valve 25, 2
6, 27 to the actuators 13, 8, 10, further communicate the downstream end of the first pressure oil supply pipe 24 to the tank 39, and connect the second pressure oil supply pipe 30 to the second pump 29, Multiple operation valves 31, 3
2 are connected in tandem in order from the upstream side to the downstream side, the actuators 14 and 9 are connected to each operation valve 31 and 32, and the downstream end of the second pressure oil supply pipe 30 is communicated with the tank 38, and the operation valves 26, 27
, 32 from the neutral position to the fluid supply position, the detectors 40a, 41a, 44a capable of outputting signal currents 117, 118, 120 are connected to each operating valve 26.
. The actuator 17 is connected to the valve 60, and the portion of the third pressure oil supply pipe 59 downstream of the communication valve 63 is connected to the upstream side of each operation valve 26, 27, 32 in the fluid supply direction, and the pilot pump 108 is connected to the actuator 17. An electromagnetic switching valve 73 is connected to a pilot pipe 71 communicating with the pilot pipe 71, and the downstream end of the pilot pipe 71 in the fluid supply direction is communicated with the pilot port 64 of the communication valve 63, so that the signal currents 117, 118 ,120
and an excitation current 123 obtained by amplifying the signal currents 117, 118, and 120 by the amplifier 124 to a solenoid 75 of the switching valve 73.