CN110552923B

CN110552923B - Synchronous control hydraulic system

Info

Publication number: CN110552923B
Application number: CN201910678360.XA
Authority: CN
Inventors: 张三喜; ***亮
Original assignee: Wuhan Marine Machinery Plant Co Ltd
Current assignee: Wuhan Marine Machinery Plant Co Ltd
Priority date: 2019-07-25
Filing date: 2019-07-25
Publication date: 2020-12-08
Anticipated expiration: 2039-07-25
Also published as: CN110552923A

Abstract

The invention discloses a synchronous control hydraulic system, and belongs to the technical field of hydraulic pressure. The synchronous control hydraulic system comprises an oil tank, a power assembly, a synchronous control assembly and two execution assemblies, wherein the two execution assemblies are respectively a first execution assembly and a second execution assembly; the synchronous control assembly comprises a rocker and four pressure reducing valves, the four pressure reducing valves are respectively a first pressure reducing valve, a second pressure reducing valve, a third pressure reducing valve and a fourth pressure reducing valve, a spring of a first control end of the first pressure reducing valve extends to a first control end of the second pressure reducing valve, a spring of a first control end of the second pressure reducing valve extends to a first control end of the first pressure reducing valve, a spring of a first control end of the third pressure reducing valve extends to a first control end of the fourth pressure reducing valve, a spring of a first control end of the fourth pressure reducing valve extends to a first control end of the third pressure reducing valve, and springs of the four pressure reducing valves respectively offset with the rocker. The invention can meet higher explosion-proof requirements and is suitable for dangerous areas such as mines, offshore platforms and the like.

Description

Synchronous control hydraulic system

Technical Field

The invention relates to the technical field of hydraulic pressure, in particular to a synchronous control hydraulic system.

Background

Hydraulically driven actuators, particularly those requiring synchronization, are typically controlled using a hydraulic system consisting of electrically controlled proportional valves proportional to control signals. However, in some special working occasions, such as mines and offshore platforms, the explosion-proof requirement is high, and electric sparks are not allowed to occur. Because electric sparks can be generated in the generation and transmission processes of the control signals, the existing hydraulic system cannot be suitable for dangerous areas with high explosion-proof requirements.

Disclosure of Invention

The embodiment of the invention provides a synchronous control hydraulic system, which can meet higher explosion-proof requirements and is suitable for dangerous areas such as mines and offshore platforms. The technical scheme is as follows:

the embodiment of the invention provides a synchronous control hydraulic system, which comprises an oil tank, a power assembly, a synchronous control assembly and two execution assemblies, wherein the two execution assemblies are respectively a first execution assembly and a second execution assembly; the power assembly comprises a hydraulic pump, and an oil inlet of the hydraulic pump is communicated with the oil tank; the synchronous control assembly comprises a rocker and four pressure reducing valves, the four pressure reducing valves are respectively a first pressure reducing valve, a second pressure reducing valve, a third pressure reducing valve and a fourth pressure reducing valve, oil inlets of the four pressure reducing valves are communicated with oil outlets of the hydraulic pump, oil return ports of the four pressure reducing valves are communicated with the oil tank, the first control ends of the four pressure reducing valves are provided with springs, the springs of the first control end of the first pressure reducing valve extend towards the first control end of the second pressure reducing valve, the spring of the first control end of the second pressure relief valve extends toward the first control end of the first pressure relief valve, the spring of the first control end of the third pressure relief valve extends toward the first control end of the fourth pressure relief valve, the springs of the first control end of the fourth pressure reducing valve extend to the first control end of the third pressure reducing valve, and the springs of the four pressure reducing valves are respectively abutted against the rocker; the two executing assemblies respectively comprise a first hydraulic control proportional reversing valve, an oil inlet of the first hydraulic control proportional reversing valve is communicated with an oil outlet of the hydraulic pump, an oil return port of the first hydraulic control proportional reversing valve is communicated with the oil tank, two working oil ports of the first hydraulic control proportional reversing valve of the first executing assembly are respectively communicated with a first motor, two working oil ports of the first hydraulic control proportional reversing valve of the second executing assembly are respectively communicated with a second motor, a first control end of the first hydraulic control proportional reversing valve of the first executing assembly is communicated with an oil outlet of the first reducing valve, a second control end of the first hydraulic control proportional reversing valve of the first executing assembly is communicated with an oil outlet of the second reducing valve, a first control end of the first hydraulic control proportional reversing valve of the second executing assembly is communicated with an oil outlet of the third reducing valve, and a second control end of a first hydraulic control proportional reversing valve of the second execution assembly is communicated with an oil outlet of the fourth reducing valve.

Optionally, the two actuation assemblies further comprise a pressure compensator and a first shuttle valve; two oil inlets of the first shuttle valve are respectively communicated with two working oil ports of the first hydraulic control proportional reversing valve, and an oil outlet of the first shuttle valve is communicated with a first control end of the pressure compensator; the pressure compensator is connected between an oil outlet of the hydraulic pump and an oil inlet of the first hydraulic control proportional reversing valve in series, an oil inlet of the pressure compensator is communicated with the oil outlet of the hydraulic pump, and an oil outlet and a second control end of the pressure compensator are communicated with an oil inlet of the first hydraulic control proportional reversing valve.

Further, the two executing assemblies further comprise a switch control assembly, and the switch control assembly comprises a hydraulic control proportional direction valve and a second shuttle valve; two oil inlets of the second shuttle valve are respectively communicated with oil outlets of first shuttle valves of the two execution assemblies, and an oil outlet of the second shuttle valve is communicated with a first control end of the hydraulic control proportional directional valve; and the second control oil port and the oil inlet of the hydraulic control proportional direction valve are communicated with the oil outlet of the hydraulic pump, and the oil outlet of the hydraulic control proportional direction valve is communicated with the oil tank.

Still further, the switch control assembly further comprises a first throttle valve connected in series between an oil outlet of the hydraulic pump and an oil inlet of the pilot-controlled proportional directional valve.

Furthermore, the switch control assembly further comprises a fifth reducing valve, the fifth reducing valve is connected between the oil outlet of the hydraulic pump and the first throttling valve in series, the oil inlet of the fifth reducing valve is communicated with the oil outlet of the hydraulic pump, the oil outlet of the fifth reducing valve is communicated with the first throttling valve, and the first control oil port of the fifth reducing valve is communicated with the oil outlet of the fifth reducing valve.

Further, the hydraulic pump is a variable displacement pump.

Furthermore, the synchronous control hydraulic system further comprises a load control assembly, wherein the load control assembly comprises a first hydraulic oil cylinder, a second hydraulic control proportional reversing valve, a third hydraulic control proportional reversing valve, a second throttle valve and a third throttle valve; the rod end of the first hydraulic oil cylinder and the rod end of the second hydraulic oil cylinder are respectively and mechanically connected with the hydraulic pump, and the rodless end of the first hydraulic oil cylinder is communicated with the oil outlet of the hydraulic pump; an oil inlet and a first control oil port of the second hydraulic control proportional reversing valve, an oil inlet and a first control oil port of the third hydraulic control proportional reversing valve are communicated with an oil outlet of the hydraulic pump, an oil return port of the second hydraulic control proportional reversing valve and a second control oil port of the third hydraulic control proportional reversing valve are communicated with the oil tank, a second control oil port of the second hydraulic control proportional reversing valve is communicated with an oil outlet of the second shuttle valve, a working oil port of the second hydraulic control proportional reversing valve is communicated with an oil return port of the second hydraulic cylinder, and a working oil port of the third hydraulic control proportional reversing valve is communicated with a rodless end of the second hydraulic cylinder; the second throttling valve is respectively communicated with an oil return port and a working oil port of the third hydraulic control proportional reversing valve, and the third throttling valve is respectively communicated with the oil return port of the third hydraulic control proportional reversing valve and the oil tank.

Optionally, the two executing assemblies further include an overflow valve, an oil inlet and an oil outlet of the overflow valve are respectively communicated with the two working oil ports of the first hydraulic control proportional directional valve, a first control oil port of the overflow valve is communicated with the oil inlet of the overflow valve, and a second control oil port of the overflow valve is communicated with the oil outlet of the overflow valve.

Optionally, the power assembly further includes a check valve, the check valve is connected in series between an oil outlet of the hydraulic pump and an oil inlet of the first hydraulic control proportional directional valve, an oil inlet of the check valve is communicated with the oil outlet of the hydraulic pump, and an oil outlet of the check valve is communicated with the oil inlet of the first hydraulic control proportional directional valve.

Optionally, the hydraulic pump is a plunger pump, and the power assembly further comprises a motor, and the motor is mechanically connected to the hydraulic pump.

The technical scheme provided by the embodiment of the invention has the following beneficial effects:

the output pressure of the two pressure reducing valves is simultaneously controlled through the rotating action of the rocker in the horizontal or vertical direction, or the output pressure of the four pressure reducing valves is simultaneously controlled through the rotating action of the rocker in the inclined direction relative to the horizontal and vertical directions, the rotating angle of the rocker is limited according to the working requirement, the pressure difference between the opposite pressure reducing valves is changed, and then the two executing assemblies are utilized to realize the synchronous control of the two hydraulic motors. And the whole system adopts hydraulic control, electric sparks cannot be generated in the working process, and the system is an intrinsic safety type control mode and can be suitable for the working environment with the highest grade in an explosion-proof area.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a synchronous control hydraulic system according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The embodiment of the invention provides a synchronous control hydraulic system. Fig. 1 is a schematic structural diagram of a synchronous control hydraulic system according to an embodiment of the present invention. Referring to fig. 1, the synchronous control hydraulic system includes an oil tank 10, a power assembly 20, a synchronous control assembly 30, and two actuating assemblies, i.e., a first actuating assembly 41 and a second actuating assembly 42.

The power assembly 20 comprises a hydraulic pump 21, and an oil inlet of the hydraulic pump 21 is communicated with the oil tank 10. The synchronization control assembly 30 comprises a rocker 31 and four pressure reducing valves, a first 32, a second 33, a third 34 and a fourth 35 pressure reducing valve, respectively. Oil inlets of the four pressure reducing valves are communicated with an oil outlet of the hydraulic pump 21, oil return ports of the four pressure reducing valves are communicated with the oil tank 10, springs are arranged at first control ends of the four pressure reducing valves, a spring at a first control end of the first pressure reducing valve 32 extends towards a first control end of the second pressure reducing valve 33, a spring at a first control end of the second pressure reducing valve 33 extends towards the first control end of the first pressure reducing valve 32, a spring at a first control end of the third pressure reducing valve 34 extends towards a first control end of the fourth pressure reducing valve 35, a spring at a first control end of the fourth pressure reducing valve 35 extends towards the first control end of the third pressure reducing valve 34, and springs of the four pressure reducing valves are respectively abutted against the rocker 31.

In practical applications, the second control ends of the four pressure reducing valves may also be provided with springs. When the spring force of the first control end of one pressure reducing valve is greater than the sum of the spring force of the second control end of the pressure reducing valve and the oil pressure, the oil inlet of the pressure reducing valve is communicated with the oil outlet of the oil inlet; when the spring force of the first control end of one pressure reducing valve is smaller than the sum of the spring force of the second control end of the pressure reducing valve and the oil pressure, the oil inlet of the pressure reducing valve is not communicated with the oil outlet of the oil inlet.

Both of the actuator assemblies include a first pilot operated proportional directional valve 43. An oil inlet of the first hydraulic control proportional reversing valve 43 is communicated with an oil outlet of the hydraulic pump 21, and an oil return port of the first hydraulic control proportional reversing valve 43 is communicated with the oil tank 10. Two working oil ports of the first hydraulic control proportional directional valve 43 of the first execution assembly 41 are respectively communicated with the first motor 100, and two working oil ports of the first hydraulic control proportional directional valve 43 of the second execution assembly 42 are respectively communicated with the second motor 200. A first control end of a first hydraulic control proportional reversing valve 43 of the first execution assembly 41 is communicated with an oil outlet of the first reducing valve 32, and a second control end of the first hydraulic control proportional reversing valve 43 of the first execution assembly 41 is communicated with an oil outlet of the second reducing valve 33; a first control end of the first pilot-controlled proportional reversing valve 43 of the second execution assembly 42 is communicated with an oil outlet of the third reducing valve 34, and a second control end of the first pilot-controlled proportional reversing valve 43 of the second execution assembly 42 is communicated with an oil outlet of the fourth reducing valve 35.

In practical application, when the oil pressure of the first control end of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41 is equal to the oil pressure of the second control end of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41, the oil inlet of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41 is not communicated with both working oil ports of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41, and both working oil ports of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41 are not communicated with the oil return port of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41; when the oil pressure of the first control end of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41 is greater than the oil pressure of the second control end of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41, the oil inlet of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41 is communicated with the first working oil port of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41, and the second working oil port of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41 is communicated with the oil return port of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41; when the oil pressure of the first control end of the first hydraulic control proportional reversing valve 43 of the first execution assembly 41 is less than the oil pressure of the second control end of the first hydraulic control proportional reversing valve 43 of the first execution assembly 41, the oil inlet of the first hydraulic control proportional reversing valve 43 of the first execution assembly 41 is communicated with the second working oil port of the first hydraulic control proportional reversing valve 43 of the first execution assembly 41, and the first working oil port of the first hydraulic control proportional reversing valve 43 of the first execution assembly 41 is communicated with the oil return port of the first hydraulic control proportional reversing valve 43 of the first execution assembly 41.

When the oil pressure of the first control end of the first hydraulic control proportional reversing valve 43 of the second executing assembly 42 is equal to the oil pressure of the second control end of the first hydraulic control proportional reversing valve 43 of the second executing assembly 42, the oil inlet of the first hydraulic control proportional reversing valve 43 of the second executing assembly 42 is not communicated with the two working oil ports of the first hydraulic control proportional reversing valve 43 of the second executing assembly 42, and the two working oil ports of the first hydraulic control proportional reversing valve 43 of the second executing assembly 42 are not communicated with the oil return port of the first hydraulic control proportional reversing valve 43 of the second executing assembly 42; when the oil pressure of the first control end of the first hydraulic control proportional reversing valve 43 of the second executing assembly 42 is greater than the oil pressure of the second control end of the first hydraulic control proportional reversing valve 43 of the second executing assembly 42, the oil inlet of the first hydraulic control proportional reversing valve 43 of the second executing assembly 42 is communicated with the second working oil port of the first hydraulic control proportional reversing valve 43 of the second executing assembly 42, and the first working oil port of the first hydraulic control proportional reversing valve 43 of the second executing assembly 42 is communicated with the oil return port of the first hydraulic control proportional reversing valve 43 of the second executing assembly 42; when the oil pressure of the first control end of the first hydraulic control proportional reversing valve 43 of the second execution assembly 42 is smaller than the oil pressure of the second control end of the first hydraulic control proportional reversing valve 43 of the second execution assembly 42, the oil inlet of the first hydraulic control proportional reversing valve 43 of the second execution assembly 42 is communicated with the first working oil port of the first hydraulic control proportional reversing valve 43 of the second execution assembly 42, and the second working oil port of the first hydraulic control proportional reversing valve 43 of the second execution assembly 42 is communicated with the oil return port of the first hydraulic control proportional reversing valve 43 of the second execution assembly 42.

The working principle of the synchronous hydraulic system provided by the embodiment of the invention is briefly described in the following with reference to fig. 1.

When the rocker 31 rotates towards the first reducing valve 32, a spring at a first control end of the first reducing valve 32 is pressed, and when the spring force at the first control end of the first reducing valve 32 is greater than the sum of the spring force at a second control end of the first reducing valve 32 and the oil pressure, an oil inlet of the first reducing valve 32 is communicated with an oil outlet of the first reducing valve 32; meanwhile, the spring at the first control end of the second reducing valve 33 is not pressed, the spring force at the first control end of the second reducing valve 33 is smaller than the sum of the spring force at the second control end of the second reducing valve 33 and the oil hydraulic pressure, and the oil inlet of the second reducing valve 33 is not communicated with the oil outlet of the second reducing valve 33. The oil pressure of the first control end of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41 is greater than the oil pressure of the second control end of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41, the oil inlet of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41 is communicated with the first working oil port of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41, and the second working oil port of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41 is communicated with the oil return port of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41. The hydraulic pump 21 drives the oil in the oil tank 10 to flow into the first hydraulic motor 100 through the first working fluid port of the first pilot-controlled proportional directional valve 43 of the first actuating assembly 41, and to flow back into the oil tank 10 through the second working fluid port of the first pilot-controlled proportional directional valve 43 of the first actuating assembly 41.

When the rocker 31 rotates towards the second reducing valve 33, a spring at a first control end of the second reducing valve 33 is pressed, and when the spring force at the first control end of the second reducing valve 33 is larger than the sum of the spring force at a second control end of the second reducing valve 33 and the oil pressure, an oil inlet of the second reducing valve 33 is communicated with an oil outlet of the second reducing valve 33; meanwhile, the spring at the first control end of the first reducing valve 32 is not pressed, the spring force at the first control end of the first reducing valve 32 is smaller than the sum of the spring force at the second control end of the first reducing valve 32 and the oil hydraulic pressure, and the oil inlet of the first reducing valve 32 is not communicated with the oil outlet of the first reducing valve 32. The oil pressure of the first control end of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41 is smaller than the oil pressure of the second control end of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41, the oil inlet of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41 is communicated with the second working oil port of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41, and the first working oil port of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41 is communicated with the oil return port of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41. The hydraulic pump 21 drives the oil in the oil tank 10 to flow into the first hydraulic motor 100 through the second working fluid port of the first pilot-controlled proportional directional valve 43 of the first actuating assembly 41, and flows back into the oil tank 10 through the first working fluid port of the first pilot-controlled proportional directional valve 43 of the first actuating assembly 41.

When the rocker 31 rotates towards the third reducing valve 34, the spring at the first control end of the third reducing valve 34 is pressed, and when the spring force at the first control end of the third reducing valve 34 is greater than the sum of the spring force at the second control end of the third reducing valve 34 and the oil pressure, the oil inlet of the third reducing valve 34 is communicated with the oil outlet of the third reducing valve 34; meanwhile, a spring at the first control end of the fourth reducing valve 35 is not squeezed, the spring force at the first control end of the fourth reducing valve 35 is smaller than the sum of the spring force at the second control end of the fourth reducing valve 35 and the oil hydraulic pressure, and the oil inlet of the fourth reducing valve 35 is not communicated with the oil outlet of the fourth reducing valve 35. The oil pressure of the first control end of the first hydraulic control proportional reversing valve 43 of the second execution assembly 42 is greater than the oil pressure of the second control end of the first hydraulic control proportional reversing valve 43 of the second execution assembly 42, the oil inlet of the first hydraulic control proportional reversing valve 43 of the second execution assembly 42 is communicated with the second working oil port of the first hydraulic control proportional reversing valve 43 of the second execution assembly 42, and the first working oil port of the first hydraulic control proportional reversing valve 43 of the second execution assembly 42 is communicated with the oil return port of the first hydraulic control proportional reversing valve 43 of the second execution assembly 42. The hydraulic pump 21 drives the oil in the oil tank 10 to flow into the second hydraulic motor 200 through the second working fluid port of the first pilot-controlled proportional directional valve 43 of the second actuating assembly 42, and flows back into the oil tank 10 through the first working fluid port of the first pilot-controlled proportional directional valve 43 of the second actuating assembly 42.

When the rocker 31 rotates towards the fourth reducing valve 35, a spring at a first control end of the fourth reducing valve 35 is pressed, and when the spring force at the first control end of the fourth reducing valve 35 is greater than the sum of the spring force at a second control end of the fourth reducing valve 35 and the oil pressure, an oil inlet of the fourth reducing valve 35 is communicated with an oil outlet of the fourth reducing valve 35; meanwhile, a spring at the first control end of the third reducing valve 34 is not pressed, the spring force at the first control end of the third reducing valve 34 is smaller than the sum of the spring force at the second control end of the third reducing valve 34 and the oil hydraulic pressure, and the oil inlet of the third reducing valve 34 is not communicated with the oil outlet of the third reducing valve 34. The oil pressure of the first control end of the first hydraulic control proportional reversing valve 43 of the second execution assembly 42 is smaller than the oil pressure of the second control end of the first hydraulic control proportional reversing valve 43 of the second execution assembly 42, the oil inlet of the first hydraulic control proportional reversing valve 43 of the second execution assembly 42 is communicated with the first working oil port of the first hydraulic control proportional reversing valve 43 of the second execution assembly 42, and the second working oil port of the first hydraulic control proportional reversing valve 43 of the second execution assembly 42 is communicated with the oil return port of the first hydraulic control proportional reversing valve 43 of the second execution assembly 42. The hydraulic pump 21 drives the oil in the oil tank 10 to flow into the second hydraulic motor 200 through the first working fluid port of the first pilot-controlled proportional directional valve 43 of the second actuating assembly 42, and to flow back into the oil tank 10 through the second working fluid port of the first pilot-controlled proportional directional valve 43 of the second actuating assembly 42.

In addition, when the rocker 31 rotates between the first pressure reducing valve 32 and the fourth pressure reducing valve 35, which is equivalent to that the rocker 31 simultaneously rotates towards the first pressure reducing valve 32 and the fourth pressure reducing valve 35, at this time, the hydraulic pump 21 drives the oil in the oil tank 10 to flow into the first hydraulic motor 100 through the first working oil port of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41, and to flow back into the oil tank 10 through the second working oil port of the first hydraulic control proportional reversing valve 43 of the first executing assembly 41; meanwhile, the oil in the oil tank 10 is driven to flow into the second hydraulic motor 200 through the first working fluid port of the first pilot-controlled proportional directional valve 43 of the second actuating assembly 42, and flows back into the oil tank 10 through the second working fluid port of the first pilot-controlled proportional directional valve 43 of the second actuating assembly 42.

When the rocker 31 rotates between the first pressure reducing valve 32 and the third pressure reducing valve 34, which is equivalent to that the rocker 31 simultaneously rotates towards the first pressure reducing valve 32 and the third pressure reducing valve 34, at this time, the hydraulic pump 21 drives the oil in the oil tank 10 to flow into the first hydraulic motor 100 through the first working oil port of the first pilot-controlled proportional directional valve 43 of the first executing assembly 41, and to flow back into the oil tank 10 through the second working oil port of the first pilot-controlled proportional directional valve 43 of the first executing assembly 41; meanwhile, the oil in the oil tank 10 is driven to flow into the second hydraulic motor 200 through the second working fluid port of the first pilot-controlled proportional directional valve 43 of the second actuating assembly 42, and flows back into the oil tank 10 through the first working fluid port of the first pilot-controlled proportional directional valve 43 of the second actuating assembly 42.

When the rocker 31 rotates between the second reducing valve 33 and the third reducing valve 34, which is equivalent to that the rocker 31 simultaneously rotates towards the second reducing valve 33 and the third reducing valve 34, at this time, the hydraulic pump 21 drives the oil in the oil tank 10 to flow into the first hydraulic motor 100 through the second working oil port of the first pilot-controlled proportional reversing valve 43 of the first executing assembly 41, and to flow back into the oil tank 10 through the first working oil port of the first pilot-controlled proportional reversing valve 43 of the first executing assembly 41; meanwhile, the oil in the oil tank 10 is driven to flow into the second hydraulic motor 200 through the second working fluid port of the first pilot-controlled proportional directional valve 43 of the second actuating assembly 42, and flows back into the oil tank 10 through the first working fluid port of the first pilot-controlled proportional directional valve 43 of the second actuating assembly 42.

When the rocker 31 rotates between the second reducing valve 33 and the fourth reducing valve 35, which is equivalent to that the rocker 31 simultaneously rotates towards the second reducing valve 33 and the fourth reducing valve 35, at this time, the hydraulic pump 21 drives the oil in the oil tank 10 to flow into the first hydraulic motor 100 through the second working port of the first pilot-controlled proportional directional valve 43 of the first executing assembly 41, and to flow back into the oil tank 10 through the first working port of the first pilot-controlled proportional directional valve 43 of the first executing assembly 41; meanwhile, the oil in the oil tank 10 is driven to flow into the second hydraulic motor 200 through the first working fluid port of the first pilot-controlled proportional directional valve 43 of the second actuating assembly 42, and flows back into the oil tank 10 through the second working fluid port of the first pilot-controlled proportional directional valve 43 of the second actuating assembly 42.

Further, by adjusting the rotation angle of the rocker, the stress of the pressure reducing valve can be changed, and the oil pressure of the oil outlet of the pressure reducing valve, i.e., the oil pressure of the first control end and the second control end of the first hydraulic control proportional directional valve 43, is controlled, so as to control the oil pressure of the working oil port of the first hydraulic control proportional directional valve 43, i.e., the oil pressure flowing into the first hydraulic motor 100 and the second hydraulic motor 200.

According to the embodiment of the invention, the output pressures of two pressure reducing valves are simultaneously controlled through the rotating action of the rocker in the horizontal or vertical direction, or the output pressures of four pressure reducing valves are simultaneously controlled through the rotating action of the rocker in the inclined direction relative to the horizontal and vertical directions, the rotating angle of the rocker is limited according to the working requirement, the pressure difference between the opposite pressure reducing valves is changed, and further the two executing assemblies are utilized to realize the synchronous control of two hydraulic motors. And the whole system adopts hydraulic control, electric sparks cannot be generated in the working process, and the system is an intrinsic safety type control mode and can be suitable for the working environment with the highest grade in an explosion-proof area.

Optionally, as shown in fig. 1, the two actuator assemblies may further include a pressure compensator 44 and a first shuttle valve 45. Two oil inlets of the first shuttle valve 45 are respectively communicated with two working oil ports of the first hydraulic control proportional directional valve 43, and an oil outlet of the first shuttle valve 45 is communicated with a first control end of the pressure compensator 44. The pressure compensator 44 is connected in series between an oil outlet of the hydraulic pump 21 and an oil inlet of the first hydraulic control proportional directional valve 43, an oil inlet of the pressure compensator 44 is communicated with an oil outlet of the hydraulic pump 21, and an oil outlet and a second control end of the pressure compensator 44 are communicated with an oil inlet of the first hydraulic control proportional directional valve 43.

The first shuttle valve 45 can feed back the oil pressure of the working oil port of the first hydraulic control proportional reversing valve 43 to the pressure compensator 44, the pressure compensator 44 compares the oil pressure of the working oil port of the first hydraulic control proportional reversing valve 43 with the oil pressure of the oil inlet of the first hydraulic control proportional reversing valve 43, and then adjusts the oil pressure of the oil inlet of the first hydraulic control proportional reversing valve 43, so that the difference between the oil pressure of the oil port of the first hydraulic control proportional reversing valve 43 is kept stable, the influence of flow and load fluctuation is avoided, and accurate control is realized.

In practice, the first control end of the pressure compensator 44 may also be provided with a spring. When the sum of the spring force and the oil pressure at the first control end of the pressure compensator 44 is greater than the oil pressure at the second control end of the pressure compensator 44, the oil pressure at the oil outlet of the pressure compensator 44 is a set value; when the sum of the spring force and the oil hydraulic pressure at the first control end of the pressure compensator 44 is smaller than the oil hydraulic pressure at the second control end of the pressure compensator 44, the oil hydraulic pressure at the oil outlet of the pressure compensator 44 is equal to the oil hydraulic pressure at the oil inlet of the pressure compensator 44.

Further, as shown in fig. 1, the two actuating assemblies may further include a switching control assembly 50, and the switching control assembly 50 includes a pilot-controlled proportional directional valve 51 and a second shuttle valve 52. Two oil inlets of the second shuttle valve 52 are respectively communicated with oil outlets of the first shuttle valves 45 of the two execution assemblies, and an oil outlet of the second shuttle valve 52 is communicated with a first control end of the pilot-controlled proportional directional valve 51. A second control oil port and an oil inlet of the hydraulic control proportional directional valve 51 are communicated with an oil outlet of the hydraulic pump 21, and an oil outlet of the hydraulic control proportional directional valve 51 is communicated with the oil tank 10.

The hydraulic control proportional directional valve can directly return oil to the oil tank when the oil driven by the hydraulic pump is insufficient, and unload the oil pressure borne by the synchronous control assembly 30.

In practical applications, the first pilot end of the pilot-controlled proportional directional valve 51 may also be provided with a spring. When the spring force and the oil pressure of the first control end of the pilot-controlled proportional direction valve 51 are greater than the oil pressure of the second control end of the pilot-controlled proportional direction valve 51, the oil inlet of the pilot-controlled proportional direction valve 51 is communicated with the oil outlet of the pilot-controlled proportional direction valve 51; when the spring force and the oil pressure of the first control end of the pilot-controlled proportional direction valve 51 are less than the oil pressure of the second control end of the pilot-controlled proportional direction valve 51, the oil inlet of the pilot-controlled proportional direction valve 51 and the oil outlet of the pilot-controlled proportional direction valve 51 are not communicated.

Further, as shown in fig. 1, the switch control assembly 50 may further include a first throttle valve 53; the first throttle 53 is connected in series between the oil outlet of the hydraulic pump 21 and the oil inlet of the pilot-operated proportional directional valve 51. And controlling the oil flow by utilizing the first throttling valve.

Still further, as shown in fig. 1, the switching control assembly 50 may further include a fifth relief valve 54; the fifth reducing valve 54 is connected in series between the oil outlet of the hydraulic pump 21 and the first throttle 53, the oil inlet of the fifth reducing valve 54 is communicated with the oil outlet of the hydraulic pump 21, the oil outlet of the fifth reducing valve 54 is communicated with the first throttle 53, and the first control oil port of the fifth reducing valve 54 is communicated with the oil outlet of the fifth reducing valve 54. And controlling the oil hydraulic pressure by using a fifth pressure reducing valve.

Further, the hydraulic pump 21 may be a variable displacement pump, which may meet different flow requirements.

Further, as shown in fig. 1, the synchronous control hydraulic system may further include a load control assembly 60, and the load control assembly 60 includes a first hydraulic cylinder 61, a second hydraulic cylinder 62, a second hydraulic proportional directional valve 63, a third hydraulic proportional directional valve 64, a second throttle valve 65, and a third throttle valve 66.

The rod end of the first hydraulic oil cylinder 61 and the rod end of the second hydraulic oil cylinder 62 are respectively and mechanically connected with the hydraulic pump 21, and the rodless end of the first hydraulic oil cylinder 61 is communicated with the oil outlet of the hydraulic pump 21. An oil inlet and a first control oil port of the second hydraulic control proportional reversing valve 63, an oil inlet and a first control oil port of the third hydraulic control proportional reversing valve 64 are communicated with an oil outlet of the hydraulic pump 21; an oil return port of the second hydraulic control proportional reversing valve 63 and a second control oil port of the third hydraulic control proportional reversing valve 64 are communicated with the oil tank 10; a second control oil port of the second hydraulic proportional reversing valve 63 is communicated with an oil outlet of the second shuttle valve 52, and a working oil port of the second hydraulic proportional reversing valve 63 is communicated with an oil return port of the second hydraulic oil cylinder 62; the working port of the third pilot-controlled proportional directional valve 64 is communicated with the rodless end of the second hydraulic cylinder 62. The second throttle valve 65 is respectively communicated with an oil return port and a working oil port of the third pilot-controlled proportional directional control valve 64, and the third throttle valve 66 is respectively communicated with an oil return port of the third pilot-controlled proportional directional control valve 64 and the oil tank 10.

In practical application, the second control oil port of the second hydraulic proportional directional valve 63 may also be provided with a spring. When the oil pressure of the first control oil port of the second hydraulic control proportional reversing valve 63 is greater than the sum of the oil pressure of the second control oil port of the second hydraulic control proportional reversing valve 63 and the spring force, the oil inlet of the second hydraulic control proportional reversing valve 63 is communicated with the working oil port of the second hydraulic control proportional reversing valve 63, and the oil return port of the second hydraulic control proportional reversing valve 63 is not communicated with the working oil port of the second hydraulic control proportional reversing valve 63; when the oil pressure of the first control oil port of the second hydraulic control proportional reversing valve 63 is smaller than the sum of the oil pressure of the second control oil port of the second hydraulic control proportional reversing valve 63 and the spring force, the oil inlet of the second hydraulic control proportional reversing valve 63 is not communicated with the working oil port of the second hydraulic control proportional reversing valve 63, and the oil return port of the second hydraulic control proportional reversing valve 63 is communicated with the working oil port of the second hydraulic control proportional reversing valve 63.

The second control oil port of the third pilot-controlled proportional directional valve 64 can also be provided with a spring. When the oil pressure of the first control oil port of the third hydraulic control proportional reversing valve 64 is greater than the sum of the oil pressure of the second control oil port of the third hydraulic control proportional reversing valve 64 and the spring force, the oil inlet of the third hydraulic control proportional reversing valve 64 is communicated with the working oil port of the third hydraulic control proportional reversing valve 64, and the oil return port of the third hydraulic control proportional reversing valve 64 is not communicated with the working oil port of the third hydraulic control proportional reversing valve 64; when the oil pressure of the first control oil port of the third hydraulic control proportional reversing valve 64 is smaller than the sum of the oil pressure of the second control oil port of the third hydraulic control proportional reversing valve 64 and the spring force, the oil inlet of the third hydraulic control proportional reversing valve 64 is not communicated with the working oil port of the third hydraulic control proportional reversing valve 64, and the oil return port of the third hydraulic control proportional reversing valve 64 is communicated with the working oil port of the third hydraulic control proportional reversing valve 64.

Further, the rodless end of the first hydraulic cylinder 61 may be provided with a spring.

When the hydraulic pump 21 is not started, the oil pressure of the hydraulic system is 0, the oil pressure of the first control oil port of the second hydraulic control proportional directional valve 63 is smaller than the sum of the oil pressure of the second control oil port of the second hydraulic control proportional directional valve 63 and the spring force, the oil inlet of the second hydraulic control proportional directional valve 63 is not communicated with the working oil port of the second hydraulic control proportional directional valve 63, and the oil return port of the second hydraulic control proportional directional valve 63 is communicated with the working oil port of the second hydraulic control proportional directional valve 63. The rodless end oil pressure of the first hydraulic oil cylinder 61 and the rodless end oil pressure of the second hydraulic oil cylinder 62 are both 0, the sum of the rodless end spring force and the rodless end oil pressure of the first hydraulic oil cylinder 61 is larger than the rodless end oil pressure of the second hydraulic oil cylinder 62, the rod end of the first hydraulic oil cylinder 61 extends, the rod end of the second hydraulic oil cylinder 62 shortens, and the hydraulic pump 21 is at the maximum displacement.

When the hydraulic pump 21 is activated, the oil pressure of the hydraulic system is small, and the hydraulic pump 21 is at the maximum displacement, similar to the case when the hydraulic pump 21 is not activated.

After the hydraulic pump 21 is started, if the oil pressure of the first control end of the first hydraulic control proportional directional valve 43 is equal to the oil pressure of the second control end of the first hydraulic control proportional directional valve 43, the oil inlet and the oil return of the first hydraulic control proportional directional valve 43 are not communicated with the two working oil ports of the first hydraulic control proportional directional valve 43. The oil pressure of the first control oil port of the second hydraulic control proportional reversing valve 63 is greater than the sum of the oil pressure of the second control oil port of the second hydraulic control proportional reversing valve 63 and the spring force, the oil inlet of the second hydraulic control proportional reversing valve 63 is communicated with the working oil port of the second hydraulic control proportional reversing valve 63, and the oil return port of the second hydraulic control proportional reversing valve 63 is not communicated with the working oil port of the second hydraulic control proportional reversing valve 63. The rodless end oil pressure of the first hydraulic oil cylinder 61 and the rodless end oil pressure of the second hydraulic oil cylinder 62 are both equal to the oil pressure of the hydraulic pump 21, and due to the fact that the acting areas of the first hydraulic oil cylinder 61 and the second hydraulic oil cylinder 62 are different, the sum of the rodless end spring force and the oil pressure of the first hydraulic oil cylinder 61 is smaller than the rodless end oil pressure of the second hydraulic oil cylinder 62, the rod end of the first hydraulic oil cylinder 61 is shortened, the rod end of the second hydraulic oil cylinder 62 is extended, and the hydraulic pump 21 is at the minimum displacement.

If the oil pressure of the first control end of the first hydraulic control proportional reversing valve 43 is greater than or less than the oil pressure of the second control end of the first hydraulic control proportional reversing valve 43, the oil inlet and the oil return port of the first hydraulic control proportional reversing valve 43 are respectively communicated with the two working oil ports of the first hydraulic control proportional reversing valve 43. When the first pilot-controlled proportional directional valve 43 is shifted, the hydraulic pump 21 is at the maximum displacement, similar to the case when the hydraulic pump 21 is started.

After the first hydraulic control proportional reversing valve 43 is switched, considering the action of the first hydraulic control proportional reversing valve 43 on the hydraulic pressure, the hydraulic pressure of the first control port of the second hydraulic control proportional reversing valve 63 may be equal to the sum of the hydraulic pressure and the spring force of the second control port of the second hydraulic control proportional reversing valve 63, the hydraulic pressure of the first control port of the second hydraulic control proportional reversing valve 63 may be smaller than the sum of the hydraulic pressure and the spring force of the second control port of the second hydraulic control proportional reversing valve 63, and the hydraulic pressure of the first control port of the second hydraulic control proportional reversing valve 63 may be larger than the sum of the hydraulic pressure and the spring force of the second control port of the second hydraulic control proportional reversing valve 63.

If the hydraulic pressure at the first control port of the second hydraulic proportional directional valve 63 is equal to the sum of the hydraulic pressure at the second control port of the second hydraulic proportional directional valve 63 and the spring force, the second hydraulic proportional directional valve 63 is in the neutral position, the rodless end of the second hydraulic cylinder 62 is closed, and the hydraulic pump 21 is in the constant displacement.

If the oil pressure of the first control oil port of the second hydraulic control proportional reversing valve 63 is smaller than the sum of the oil pressure of the second control oil port of the second hydraulic control proportional reversing valve 63 and the spring force, the oil inlet of the second hydraulic control proportional reversing valve 63 is not communicated with the working oil port of the second hydraulic control proportional reversing valve 63, and the oil return port of the second hydraulic control proportional reversing valve 63 is communicated with the working oil port of the second hydraulic control proportional reversing valve 63. The rodless end of the second hydraulic cylinder 62 is communicated with the oil tank 10, the rodless end oil pressure of the second hydraulic cylinder 62 is reduced, the rodless end oil pressure of the first hydraulic cylinder 61 is kept unchanged, the sum of the rodless end spring force and the oil pressure of the first hydraulic cylinder 61 is larger than the rodless end oil pressure of the second hydraulic cylinder 62, the rod end of the first hydraulic cylinder 61 extends, the rod end of the second hydraulic cylinder 62 is shortened, the displacement of the hydraulic pump 21 is increased, the oil pressure of the first control oil port of the second hydraulic proportional reversing valve 63 is increased until the sum of the oil pressure and the spring force of the second control oil port of the second hydraulic proportional reversing valve 63 is equal to the sum of the oil pressure and the spring force of the second control oil.

If the oil pressure of the first control oil port of the second hydraulic control proportional reversing valve 63 is greater than the sum of the oil pressure of the second control oil port of the second hydraulic control proportional reversing valve 63 and the spring force, the oil inlet of the second hydraulic control proportional reversing valve 63 is communicated with the working oil port of the second hydraulic control proportional reversing valve 63, and the oil return port of the second hydraulic control proportional reversing valve 63 is not communicated with the working oil port of the second hydraulic control proportional reversing valve 63. The rodless end of the second hydraulic cylinder 62 is communicated with the hydraulic pump 21, the rodless end hydraulic pressure of the second hydraulic cylinder 62 is increased, the rodless end hydraulic pressure of the first hydraulic cylinder 61 is kept unchanged, the sum of the rodless end spring force and the hydraulic pressure force of the first hydraulic cylinder 61 is smaller than the rodless end hydraulic pressure of the second hydraulic cylinder 62, the rod end of the first hydraulic cylinder 61 is shortened, the rod end of the second hydraulic cylinder 62 is extended, the displacement of the hydraulic pump 21 is reduced, and the hydraulic pressure force of the first control oil port of the second hydraulic proportional reversing valve 63 is reduced until the sum of the hydraulic pressure force and the spring force of the second control oil port of the second hydraulic proportional reversing valve 63 is equal.

In the above process, the oil return port of the third pilot-controlled proportional directional valve 64 is communicated with the working oil port of the third pilot-controlled proportional directional valve 64, that is, the working oil port of the second pilot-controlled proportional directional valve 63 is communicated with the rodless end of the second hydraulic cylinder 62, and at this time, switching may be performed without considering the third pilot-controlled proportional directional valve 64 (the spring forces of the second pilot-controlled proportional directional valve 63 and the third pilot-controlled proportional directional valve 64 are different). As can be seen from the above, the load control assembly 60 can control the oil pressure of the hydraulic system to be constant according to the load change, so as to avoid being affected by the flow and the load fluctuation, thereby realizing the precise control.

When the rod end of the first hydraulic cylinder 61 and the rod end of the second hydraulic cylinder 62 cannot extend and retract continuously, the hydraulic pressure of the first control oil port of the second hydraulic proportional directional valve 63 is equal to the hydraulic pressure of the second control oil port of the second hydraulic proportional directional valve 63, the hydraulic pressure of the first control oil port of the second hydraulic proportional directional valve 63 is smaller than the sum of the hydraulic pressure of the second control oil port of the second hydraulic proportional directional valve 63 and the spring force, the oil inlet of the second hydraulic proportional directional valve 63 is not communicated with the working oil port of the second hydraulic proportional directional valve 63, and the oil return port of the second hydraulic proportional directional valve 63 is communicated with the working oil port of the second hydraulic proportional directional valve 63. The displacement of the hydraulic pump 21 increases and the pressure of the hydraulic pump 21 increases. When the oil hydraulic pressure of the first control port of the third hydraulic control proportional directional control valve 64 is greater than the sum of the oil hydraulic pressure of the second control port of the third hydraulic control proportional directional control valve 64 and the spring force, an oil inlet of the third hydraulic control proportional directional valve 64 is communicated with a working oil port of the third hydraulic control proportional directional valve 64, an oil return port of the third hydraulic control proportional directional valve 64 is not communicated with the working oil port of the third hydraulic control proportional directional valve 64, a rodless end of the second hydraulic cylinder 62 is communicated with the hydraulic pump 21, the rodless end hydraulic pressure of the second hydraulic cylinder 62 is increased, the rodless end hydraulic pressure of the first hydraulic cylinder 61 is kept unchanged, the sum of the rodless end spring force and the rodless end hydraulic pressure of the first hydraulic cylinder 61 is smaller than the rodless end hydraulic pressure of the second hydraulic cylinder 62, the rod end of the first hydraulic cylinder 61 is shortened, the rod end of the second hydraulic cylinder 62 is extended, and the displacement of the hydraulic pump 21 is reduced to the minimum.

If the oil pressure of the first control end of the first hydraulic control proportional reversing valve 43 is equal to the oil pressure of the second control end of the first hydraulic control proportional reversing valve 43, the oil inlet and the oil return port of the first hydraulic control proportional reversing valve 43 are not communicated with the two working oil ports of the first hydraulic control proportional reversing valve 43. The displacement of the hydraulic pump 21 is kept to a minimum.

Optionally, as shown in fig. 1, the two actuating assemblies may further include a relief valve 46; an oil inlet and an oil outlet of the overflow valve 46 are respectively communicated with two working oil ports of the first hydraulic control proportional directional valve 43, a first control oil port of the overflow valve 46 is communicated with an oil inlet of the overflow valve 46, and a second control oil port of the overflow valve 46 is communicated with an oil outlet of the overflow valve 46. The overflow valve is used to avoid overload of the hydraulic motor.

Optionally, as shown in fig. 1, the power assembly 20 may further include a check valve 22, the check valve 22 is connected in series between an oil outlet of the hydraulic pump 21 and an oil inlet of the first pilot-controlled proportional directional valve 43, an oil inlet of the check valve 22 is communicated with the oil outlet of the hydraulic pump 21, and an oil outlet of the check valve 22 is communicated with the oil inlet of the first pilot-controlled proportional directional valve 43. The check valve is used for preventing oil from flowing backwards to damage the hydraulic pump.

Alternatively, as shown in fig. 1, the hydraulic pump 21 may be a plunger pump, and the power assembly 20 may further include an electric motor 23, and the electric motor 23 is mechanically connected to the hydraulic pump 21. Is driven by a motor and is convenient to realize

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A synchronous control hydraulic system is characterized by comprising an oil tank (10), a power assembly (20), a synchronous control assembly (30) and two execution assemblies, wherein the two execution assemblies are a first execution assembly (41) and a second execution assembly (42) respectively; the power assembly (20) comprises a hydraulic pump (21), and an oil inlet of the hydraulic pump (21) is communicated with the oil tank (10); synchronous control subassembly (30) include rocker (31) and four relief pressure valves, four relief pressure valves are first relief pressure valve (32), second relief pressure valve (33), third relief pressure valve (34) and fourth relief pressure valve (35) respectively, the oil inlet of four relief pressure valves with the oil-out intercommunication of hydraulic pump (21), the oil return port of four relief pressure valves with oil tank (10) intercommunication, the first control end of four relief pressure valves is equipped with the spring, the spring of the first control end of first relief pressure valve (32) to the first control end of second relief pressure valve (33) extends, the spring of the first control end of second relief pressure valve (33) to the first control end of first relief pressure valve (32) extends, the spring of the first control end of third relief pressure valve (34) to the first control end of fourth relief pressure valve (35) extends, the spring of the first control end of fourth relief pressure valve (35) to the first control end of third relief pressure valve (34) extends The manufacturing end extends, and the springs of the four pressure reducing valves are respectively propped against the rocker (31); the two execution assemblies respectively comprise a first hydraulic control proportional reversing valve (43), a pressure compensator (44) and a first shuttle valve (45), an oil inlet of the first hydraulic control proportional reversing valve (43) is communicated with an oil outlet of the hydraulic pump (21), an oil return port of the first hydraulic control proportional reversing valve (43) is communicated with the oil tank (10), two working oil ports of the first hydraulic control proportional reversing valve (43) of the first execution assembly (41) are respectively communicated with a first motor (100), two working oil ports of the first hydraulic control proportional reversing valve (43) of the second execution assembly (42) are respectively communicated with a second motor (200), a first control end of the first hydraulic control proportional reversing valve (43) of the first execution assembly (41) is communicated with an oil outlet of the first reducing valve (32), a second control end of the first hydraulic control proportional reversing valve (43) of the first execution assembly (41) is communicated with an oil outlet of the second reducing valve (33), a first control end of a first hydraulic control proportional reversing valve (43) of the second execution assembly (42) is communicated with an oil outlet of the third pressure reducing valve (34), a second control end of the first hydraulic control proportional reversing valve (43) of the second execution assembly (42) is communicated with an oil outlet of the fourth pressure reducing valve (35), two oil inlets of the first shuttle valve (45) are respectively communicated with two working oil ports of the first hydraulic control proportional reversing valve (43), and an oil outlet of the first shuttle valve (45) is communicated with a first control end of the pressure compensator (44); the pressure compensator (44) is connected in series between an oil outlet of the hydraulic pump (21) and an oil inlet of the first hydraulic control proportional reversing valve (43), an oil inlet of the pressure compensator (44) is communicated with an oil outlet of the hydraulic pump (21), and an oil outlet and a second control end of the pressure compensator (44) are communicated with an oil inlet of the first hydraulic control proportional reversing valve (43).

2. The synchronously controlled hydraulic system of claim 1, wherein said two actuating assemblies further comprise a switching control assembly (50), said switching control assembly (50) comprising a pilot operated proportional directional valve (51) and a second shuttle valve (52); two oil inlets of the second shuttle valve (52) are respectively communicated with oil outlets of first shuttle valves (45) of the two execution assemblies, and an oil outlet of the second shuttle valve (52) is communicated with a first control end of the hydraulic control proportional directional valve (51); and a second control oil port and an oil inlet of the hydraulic control proportional directional valve (51) are communicated with an oil outlet of the hydraulic pump (21), and an oil outlet of the hydraulic control proportional directional valve (51) is communicated with the oil tank (10).

3. The synchronously controlled hydraulic system of claim 2, characterized in that said switch control assembly (50) further comprises a first throttle valve (53), said first throttle valve (53) being connected in series between an oil outlet of said hydraulic pump (21) and an oil inlet of said pilot operated proportional directional valve (51).

4. The synchronously-controlled hydraulic system of claim 3, characterized in that said switch control assembly (50) further comprises a fifth pressure reducing valve (54), said fifth pressure reducing valve (54) being connected in series between an oil outlet of said hydraulic pump (21) and said first throttle valve (53), an oil inlet of said fifth pressure reducing valve (54) being in communication with an oil outlet of said hydraulic pump (21), an oil outlet of said fifth pressure reducing valve (54) being in communication with said first throttle valve (53), a first control port of said fifth pressure reducing valve (54) being in communication with an oil outlet of said fifth pressure reducing valve (54).

5. Synchronous control hydraulic system according to any of claims 2 to 4, characterized in that the hydraulic pump (21) is a variable displacement pump.

6. The synchronously controlled hydraulic system of claim 5, characterized in that it further comprises a load control assembly (60), said load control assembly (60) comprising a first hydraulic ram (61), a second hydraulic ram (62), a second hydraulic proportional directional control valve (63), a third hydraulic proportional directional control valve (64), a second throttle valve (65) and a third throttle valve (66); the rod end of the first hydraulic oil cylinder (61) and the rod end of the second hydraulic oil cylinder (62) are respectively and mechanically connected with the hydraulic pump (21), and the rodless end of the first hydraulic oil cylinder (61) is communicated with an oil outlet of the hydraulic pump (21); an oil inlet and a first control oil port of the second hydraulic control proportional reversing valve (63), an oil inlet and a first control oil port of the third hydraulic control proportional reversing valve (64) are communicated with an oil outlet of the hydraulic pump (21), an oil return port of the second hydraulic control proportional reversing valve (63) and a second control oil port of the third hydraulic control proportional reversing valve (64) are communicated with the oil tank (10), a second control oil port of the second hydraulic control proportional reversing valve (63) is communicated with an oil outlet of the second shuttle valve (52), a working oil port of the second hydraulic control proportional reversing valve (63) is communicated with an oil return port of the second hydraulic cylinder (62), and a working oil port of the third hydraulic control proportional reversing valve (64) is communicated with a rodless end of the second hydraulic cylinder (62); the second throttle valve (65) is respectively communicated with an oil return port and a working oil port of the third hydraulic control proportional reversing valve (64), and the third throttle valve (66) is respectively communicated with the oil return port of the third hydraulic control proportional reversing valve (64) and the oil tank (10).

7. The synchronous control hydraulic system according to any one of claims 1 to 4, wherein the two execution assemblies further comprise an overflow valve (46), an oil inlet and an oil outlet of the overflow valve (46) are respectively communicated with two working oil ports of the first hydraulic control proportional directional valve (43), a first control oil port of the overflow valve (46) is communicated with an oil inlet of the overflow valve (46), and a second control oil port of the overflow valve (46) is communicated with an oil outlet of the overflow valve (46).

8. The synchronous control hydraulic system according to any one of claims 1-4, characterized in that the power assembly (20) further comprises a check valve (22), the check valve (22) is connected in series between an oil outlet of the hydraulic pump (21) and an oil inlet of the first hydraulic control proportional directional valve (43), an oil inlet of the check valve (22) is communicated with an oil outlet of the hydraulic pump (21), and an oil outlet of the check valve (22) is communicated with an oil inlet of the first hydraulic control proportional directional valve (43).

9. Synchronous control hydraulic system according to any of claims 1 to 4, characterized in that the hydraulic pump (21) is a plunger pump and the power assembly (20) further comprises an electric motor (23), the electric motor (23) being mechanically connected to the hydraulic pump (21).