JPH01180558U

JPH01180558U -

Info

Publication number: JPH01180558U
Application number: JP7678488U
Authority: JP
Priority date: 1988-06-07
Filing date: 1988-06-07
Publication date: 1989-12-26
Anticipated expiration: 2003-06-07
Also published as: JPH0649633Y2

Description

[Brief explanation of the drawing]

第１図はこの考案にかかる油圧回路をそなえた
ホイール式シヨベルの側面図、第２図はこの考案
にかかる油圧回路図、第３図は従来技術ホイール
式シヨベルの側面図、第４図は従来技術上部旋回
体に配置されている機器などを示す平面視図であ
る。２，１８……下部走行体、３，１９……上部旋
回体、５，２０……エンジン、１２，１２′……
第１ポンプ、１３，１３′……第２ポンプ、１４
，１４′……パイロツトポンプ、２３……旋回ジ
ヨイント、２４，２５，２６，２７……アクチユ
エータ用切換弁、２８，２９，３０，３１，３６
……サブバルブ、３２……パイロツト弁、３３，
３４……パイロツト開閉弁、３５……パイロツト
走行弁、３７……パイロツト逆止弁、３８……パ
イロツト切換弁、４１……走行モータ。 Figure 1 is a side view of a wheel type shovel equipped with a hydraulic circuit according to this invention, Figure 2 is a hydraulic circuit diagram according to this invention, Figure 3 is a side view of a conventional wheel type shovel, and Figure 4 is a conventional wheel type shovel. FIG. 2 is a plan view showing equipment and the like arranged on the technical upper revolving structure. 2, 18... Lower traveling body, 3, 19... Upper rotating body, 5, 20... Engine, 12, 12'...
First pump, 13, 13'...Second pump, 14
, 14'... Pilot pump, 23... Swivel joint, 24, 25, 26, 27... Actuator switching valve, 28, 29, 30, 31, 36
...Sub valve, 32...Pilot valve, 33,
34... Pilot on/off valve, 35... Pilot travel valve, 37... Pilot check valve, 38... Pilot switching valve, 41... Travel motor.

Claims

[Scope of utility model registration request]

In a hydraulic excavator in which the upper rotating body is equipped with a hydraulic actuator for the working machine, and the lower traveling body is equipped with an engine, its necessary equipment, and a travel motor for driving the traveling device, the hydraulic actuator for the working machine is equipped on the upper rotating body. into two groups A,
The actuator switching valves of groups A and B are all connected in parallel, and a pilot pressure oil sub-valve is provided so that the actuator switching valve can be interlocked with each actuator switching valve, and when the actuator switching valve is in the neutral position, Set the sub-valve to the oil passage opening position, and when the actuator switching valve is in a position other than neutral, set it to the oil passage blocking position,
In addition, a pilot valve is provided on the upstream side of groups A and B to enable switching of the oil passage for pump discharge pressure oil, and a pilot on-off valve is provided on the outlet side of the center bypass oil passage of each of groups A and B. A first and second pump, a pilot pump, a pilot travel valve, and a travel motor are arranged in the pilot valve, and a pilot pressure oil sub-valve is provided so as to be interlocked with the pilot travel valve, and when the pilot travel valve is in the neutral position, the sub-valve is connected to the oil path. When the pilot travel valve is in a position other than neutral, the oil passage is set to the open position.The first and second pump discharge sides are connected via the pilot check valve, and when the pilot travel valve is in the neutral position, the oil passage is opened. The pressure oil discharged from the first pump is transferred to group A via the pilot switching valve and the swing joint, and the pressure oil discharged from the second pump is transferred to group B via the pilot travel valve and the swing joint.
When only the pedal device for the travel motor is depressed, the pressure oil discharged from the first pump flows through the pilot check valve to the discharge side of the second pump so that it can be supplied to the travel motor, and the hydraulic actuator for the travel motor and the work machine can be supplied. A hydraulic excavator characterized in that the pressure oil discharged from the first pump can be supplied to a pressure oil actuator for a working machine and the pressure oil discharged from the second pump can be supplied to a travel motor when the two pumps are operated simultaneously. Hydraulic circuit.