JPS5833281Y2 - 2 Pump Kudugata Yuatsusagiyoukiniokel Yuatsu Cairo - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a hydraulic circuit for a two-pump-driven hydraulic working machine, such as a hydraulic power shovel, which drives various hydraulic actuators by supplying pressure oil from two pumps. The present invention aims to improve work performance by making the pressure oil supply form to various hydraulic actuators suitable for the operation of each hydraulic actuator through a rational circuit configuration.

Next, embodiments of the present invention will be described with reference to illustrative drawings.

FIG. 1 shows a power shovel as an example of a two-pump-driven hydraulic working machine, in which 1 and 2 are crawlers for running provided on the left and right sides of the vehicle body, and M1 and M1 drive the crawlers 1 and 2. 3 is a swivel mounted on the top of the crawlers 1 and 2 so that it can rotate for 360 m, M3 is a hydraulic motor for driving the swivel 3, 4 is a boom, 5 is an arm, and 6 is a packet. , 7 is a boom cylinder,
8 is an arm cylinder, and 9 is a packet cylinder.

The traveling hydraulic motor M2. M2 swing hydraulic motor M3
And various hydraulic actuators such as hydraulic cylinders 7, 8, 9 for excavation work, as shown in FIG. Hydraulic pressure switching valve v.

■2......It is supplied as appropriate by switching operation of ■6 and merging valve ■7, and the switching valve ■1 is supplied to the travel hydraulic motor M, and the switching valve v2 is supplied to the swing hydraulic motor M3. The switching valve v3 is connected to the packet cylinder 9, the switching valve ■4 is connected to the travel hydraulic motor M2, and the switching valve ■ is connected to the boom cylinder 7.
, and the switching valve 6 is connected to the arm cylinder 8, respectively.

Then, in the switching valve V,...■6, the switching valve V
,.

V, , V, are intercepted by the multiple valves as a first switching valve group A connected in parallel via a parallel pressure oil supply path 10 communicating with the first pump P, and switching valves V4. V5
．． V6 is a parallel pressure oil supply path 11 leading to the second pump P2
Another second switching valve group B connected in parallel via the valves is configured as a multiple valve.

In the first switching valve group A, each switching valve ■1. ■
2. ■ A neutral oil drain path 1 that guides the hydraulic pressure from the first pump P to the parallel pressure oil supply path 11 of the second switching valve group B through each switching valve V1, V2, and V3 when all the pumps 3 are in the neutral position.
2 is formed, and each switching valve V4.2 is also formed in the second switching valve group B. V5. When all V6 are in neutral, pressure oil from the second pump P2 is transferred to each switching valve V4. V, ,
A neutral oil drain path 13 is formed that leads to the oil drain path 14 through the V6.

Further, in the neutral oil drain path 12 of the first switching valve group A, each switching valve ■1. ■2. A merging valve ■7 of the same type as . In the forward/reverse switching position, the neutral drain oil is guided to the drain oil path 14 via the oil path 15.

Then, the switching valve V1. V2.・・・・・・V6.
The V6 and the merging valve 7 are collectively constituted as one multiple valve.

In the figure, 16.16 is a plug that closes the port of the merging valve 7.

According to the above configuration, the first switching valve group A is the first pump P.
Depending on the position of the merging valve 7, the second switching valve group B can receive pressure oil only from the second pump P2, or can receive the merging pressure oil from both pumps P, , P2. Hydraulic actuators belonging to the first switching valve group A that need to be operated at a constant speed by driving a single pump are selected in advance, and also belonging to the second switching valve group B. Hydraulic actuators are selected in advance that require constant speed operation by driving a single pump and increasing speed operation by driving two pumps.

Next, the specific operation will be explained.

■ First switching valve Group A switching valve ■1. ■2. (2) When only the arbitrary one in 3 is operated, the operated hydraulic actuator operates at a constant speed by driving the first pump P1.

For example, the orientation of the aircraft, the rotation of the swivel base 3, the operation of scooping up the packet 6, etc. are reliably performed at a constant speed by operating only the traveling hydraulic motor M1.

■ If you operate any one of the second switching valve group B at the same time as the operation of ■, in this case, there is no neutral drain oil of the first switching valve group A, so the hydraulic actuator of the second switching valve group B is only the second pump P2. is driven by.

For example, the left and right hydraulic motors M19M2 operate in the same direction at the same time for straight forward and backward movement, the hydraulic motors M19M2 simultaneously operate in reverse to turn the aircraft, the arm 5 and the packet 6 operate simultaneously for excavation, the boom 4 is raised and lowered, and the swivel base 3 is rotated. Two combined operations such as the rotational movement of the excavated earth and sand and the rotational return operation of the excavation equipment are performed reliably at a constant speed.

■ All switching valves V1 of the first switching valve group A. V2゜■
, when operating only the second switching valve group B with neutral, if the merging valve v7 is set in neutral, the neutral drain oil of the first switching valve group A passes through the neutral drain oil passage 12 to the second switching valve. Since it merges with the parallel pressure oil supply path 11 of group B, the hydraulic actuators belonging to the second switching valve group B can be driven at increased speed with hydraulic oil containing hydraulic oil.

For example, the boom 4 or the arm 5 can be undulated and extended at high speed to perform powerful excavation.

■ When operating the second switching valve group B with the first switching valve group A in neutral, if the merging valve ■7 is switched to a position other than neutral, the neutral waste oil from the first switching valve group A will pass through the oil line 15. Since the oil flows out into the drain path 14, the second switching valve group B is driven only by the second pump P2.

For example, the aircraft orientation, constant low-speed operation of the boom 4 or arm 5, etc. are reliably performed by operating only the travel hydraulic motor M2.

■ Set all first switching valve group A to neutral, and merge valve ■7
is operated for merging, and by operating, for example, only ■ of the second switching valve group B, only the boom cylinder 7 can be driven to increase the speed while the arm cylinder 8 and hydraulic motor M2 are stopped.

As explained in the embodiments above, according to the present invention, when a plurality of hydraulic actuators are driven by two pumps, a hydraulic actuator that requires constant speed operation by driving a single pump, and a hydraulic actuator that requires constant speed operation by driving a single pump, Hydraulic actuators that require low-speed operation and merging speed-up operation by driving two pumps can be easily driven at will with pressure oil supply conditions suitable for each operation, which is effective in improving work performance. It became.

In particular, in the present invention, the merging valve 7 for merging and draining oil is provided separately from the other switching valves and is configured to be operated independently, so the first switching valve group A is all set to neutral, When the merging valve (7) for merging and draining oil is operated for merging, and for example, only (5) of the second switching valve group B is operated, the oil pressure of the switching valve (2) of the second switching valve group B decreases. Increase the speed of only the actuator and operate the other switching valves ■4. The V6 hydraulic actuator can be stopped.

In other words, in the present invention, it is possible to increase the speed of any of the hydraulic actuators capable of increasing the speed while stopping the other hydraulic actuators, and the range of use can be extremely widened.

Also, if the merging valve 7 for merging and draining oil is not to be operated in conjunction with the switching operation of the switching valve 6 of the second switching valve group A, the switching valve 6 may be operated in series. Just by switching with the movement of In the design, as mentioned above, it is not possible to operate the merging valve ■7 for merging and draining oil alone, so when this merging valve ■7 is operated, the second switching valve group B will be operated to increase the speed from now on. It is possible to operate the merging valve (7) after reliably recognizing this, and therefore, it is possible to reliably avoid the risk of suddenly increasing the speed of the hydraulic actuator that is currently operating at a constant speed.

In addition, each switching valve■2. ...■6 and merging valve ■7
By making them the same type and forming one multiple valve, the shape is compact and can be easily attached to a working machine, and the structure is inexpensive.

[Brief explanation of the drawing]

The drawings illustrate an embodiment of a hydraulic circuit in a two-pump-driven hydraulic working machine according to the present invention, and FIG. 1 is a side view of the working machine, and FIG. 2 is a hydraulic circuit diagram. 11... Parallel pressure oil supply path, 12... Neutral oil drain path, A... First switching valve group, B...
...Second switching valve group, Pl...First pump, P2...Second pump.

Claims (1)

[Scope of utility model registration request] A first switching valve group is connected to a first switching valve group, which is made up of switching valves for actuators that require constant operating speed, and a second switching valve group is made up of switching valves for actuators that require constant operating speed and increased operating speed. In a two-pump-driven hydraulic working machine in which a second pump is connected to the switch valve group B and the neutral drain oil of the first switch valve group is connected to the pressure supply side of the second switch valve group, each switch valve of the second switch valve group B V4. A merging valve 7 is interposed between the first switching valve group A and the second switching valve group B, and the independent speed increasing operation of the actuators of V, , V6 is performed by the neutral drain oil of the first switching valve group A. The switching valve V1 of the first switching valve group A. ■2. ■ Hydraulic circuit in which switching valves V, , V, , V6 and merging valve V7 of 3 and 2nd switching valve group B are all of the same type and integrated into one multiple valve.