JPS6391555U

JPS6391555U -

Info

Publication number: JPS6391555U
Application number: JP18333986U
Authority: JP
Priority date: 1986-11-27
Filing date: 1986-11-27
Publication date: 1988-06-14

Description

[Brief explanation of drawings]

第１図および第２図は本考案の油圧回路図、第
３図は本考案の他の実施例油圧回路図、第４図は
従来技術の油圧回路図である。１Ｌ，１Ｒ……左、右走行モータ、１１Ｌ，１
１Ｒ……左、右走行弁、１６Ｌ，１６Ｒ，１７，
１８，１９，２０……サブバルブ、２１，２１′
……走行直進弁、３２，３２′……可変絞り部、
３３，３３′……絞り開口部調整機構。 1 and 2 are hydraulic circuit diagrams of the present invention, FIG. 3 is a hydraulic circuit diagram of another embodiment of the present invention, and FIG. 4 is a hydraulic circuit diagram of the prior art. 1L, 1R...Left, right travel motor, 11L, 1
1R...Left, right travel valve, 16L, 16R, 17,
18, 19, 20...Sub valve, 21, 21'
...straight travel valve, 32, 32'...variable throttle section,
33, 33'...Aperture opening adjustment mechanism.

Claims

[Scope of utility model registration request]

The various hydraulic actuators installed in construction machinery are divided into two groups A and B, and the left and right traveling valves are provided in the front row of each group, and this and all other actuator switching valves are connected in parallel to form the above group A. , B are actuated through the respective switching valves, and each of the above-mentioned various hydraulic actuator switching valves is provided with a sub-valve, so that when the left and right travel motor switching valve is in the neutral position, both of the sub-valves are in the cutoff position, and the sub-valve is in the neutral position. In addition, when the actuator switching valves other than the left and right travel motors are in the neutral position, all of their sub-valves are in the open position, and when they are in other than the neutral position, they are all in the closed position, and the pilot pump discharge The oil passage is communicated with the oil tank through the throttle part and the sub-valve opening position, and the first and second pumps are connected to the straight-travel valve, and either the left and right travel valves are both in the neutral position, or only the left and right travel valves are operated at the same time. In the first position, the oil passage from the first pump is opened and the oil passage from the second pump is closed, and the left/right traveling valve and any other actuator switching valve are in an operating position other than the neutral position. In a hydraulic circuit in which the oil passages from the first and second pumps can be switched to a parallel open oil passage position in the second case, the discharge side of the second pump when the above-mentioned straight travel valve is switched in the second case. A construction machine characterized in that a variable throttle part is provided in the middle of the oil passage that communicates the oil passage with the first pump discharge side oil passage, and the variable throttle part and the throttle opening adjustment mechanism are connected. Hydraulic circuit.