CN114458645B - Hydraulic system for an overhead working machine and overhead working machine - Google Patents

Hydraulic system for an overhead working machine and overhead working machine Download PDF

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Publication number
CN114458645B
CN114458645B CN202111668549.4A CN202111668549A CN114458645B CN 114458645 B CN114458645 B CN 114458645B CN 202111668549 A CN202111668549 A CN 202111668549A CN 114458645 B CN114458645 B CN 114458645B
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China
Prior art keywords
oil
valve
oil inlet
relief valve
hydraulic system
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CN202111668549.4A
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Chinese (zh)
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CN114458645A (en
Inventor
陈清
肖承丰
钟懿
马昌训
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Hunan Zoomlion Intelligent Aerial Work Machinery Co Ltd
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Hunan Zoomlion Intelligent Aerial Work Machinery Co Ltd
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Priority to CN202111668549.4A priority Critical patent/CN114458645B/en
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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/003—Systems with load-holding valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F15B11/22—Synchronisation of the movement of two or more servomotors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
    • F15B21/04—Special measures taken in connection with the properties of the fluid
    • F15B21/041—Removal or measurement of solid or liquid contamination, e.g. filtering

Abstract

The invention relates to the field of engineering machinery, and discloses a hydraulic system for an overhead working machine and the overhead working machine, wherein the overhead working machine comprises a working platform and an arm support connected with the working platform, and the hydraulic system comprises: the oil cylinder unit comprises a first oil cylinder and a second oil cylinder; the pump is used for pumping hydraulic oil in the oil tank to the first oil cylinder and the second oil cylinder; the working platform main valve unit is arranged on an oil path between the pump and the first oil cylinder and comprises a leveling valve core, a first differential pressure reducing valve and a first three-way pressure reducing valve; the main valve unit is arranged on an oil way between the pump and the second oil cylinder and comprises an arm support valve core, a first shuttle valve and a second constant-difference pressure reducing valve, the second shuttle valve is provided with a first oil inlet connected with an oil outlet of the first three-way pressure reducing valve, a second oil inlet of the second shuttle valve is connected with a load port of the main valve unit of the working platform, and an oil outlet of the second shuttle valve is connected with a second oil inlet of the first shuttle valve. The invention can accelerate the response speed.

Description

Hydraulic system for an overhead working machine and overhead working machine
Technical Field
The invention relates to the field of engineering machinery, in particular to a hydraulic system for an aerial working machine and the aerial working machine.
Background
The existing high-altitude working machine (such as a high-altitude working platform) has higher requirements on the reaction speed of operation in the use process, particularly the action of the platform comprises fly arms, leveling and swinging, wherein the reaction speed of the operation is directly determined by the response action of a leveling oil cylinder. The leveling system of the existing high-altitude working machine comprises a hydraulic system, when the existing hydraulic system works, a long-time establishment process is needed from zero to working pressure, and meanwhile, the response speed of the hydraulic system is slower due to the fact that a pipeline of a working platform is longer.
Disclosure of Invention
The embodiment of the invention aims to provide a hydraulic system for an aerial working machine and the aerial working machine, so as to solve the problem that the existing hydraulic system is low in response speed.
In order to achieve the above object, a first aspect of the present invention provides a hydraulic system for an aerial work machine including a work platform and a boom connected to the work platform, the hydraulic system including:
The oil cylinder unit comprises a first oil cylinder and a second oil cylinder, wherein the first oil cylinder is used for leveling a working platform, and the second oil cylinder is used for realizing the action of the arm support;
the pump is used for pumping hydraulic oil in the oil tank to the first oil cylinder and the second oil cylinder;
the working platform main valve unit is arranged on an oil way between the pump and the first oil cylinder, and comprises a leveling valve core, a first differential relief valve and a first three-way relief valve, wherein a first oil inlet of the leveling valve core is connected with an oil outlet of the pump, a second oil inlet of the leveling valve core is connected with a load port of the working platform main valve unit, an oil outlet of the leveling valve core is connected with an oil inlet of the first oil cylinder, an oil inlet of the first differential relief valve is connected with an oil outlet of the pump, an oil outlet of the first differential relief valve is connected with an oil inlet of the first three-way relief valve, an oil outlet of the first three-way relief valve is connected with a third oil inlet of the leveling valve core, and a spring end of the first differential relief valve is connected with a load port of the working platform main valve unit;
the main valve unit is arranged on an oil way between the pump and the second oil cylinder and comprises a boom valve core, a first shuttle valve and a second constant-difference pressure reducing valve, wherein a first oil inlet of the boom valve core is connected with an oil outlet of the pump, a second oil inlet of the boom valve core is connected with a first oil inlet of the first shuttle valve, a third oil inlet of the boom valve core is connected with a load port of the main valve unit, an oil outlet of the boom valve core is connected with an oil inlet of the second oil cylinder, an oil outlet of the first shuttle valve is connected with a load port of the main valve unit, an oil inlet of the second constant-difference pressure reducing valve is connected with an oil outlet of the pump, an oil outlet of the second constant-difference pressure reducing valve is connected with a fourth oil inlet of the boom valve core, and a spring end of the second constant-difference pressure reducing valve is connected with a load port of the main valve unit;
The first oil inlet of the second shuttle valve is connected with the oil outlet of the first three-way pressure reducing valve, the second oil inlet of the second shuttle valve is connected with the load port of the main valve unit of the working platform, and the oil outlet of the second shuttle valve is connected with the second oil inlet of the first shuttle valve.
In the embodiment of the invention, the main valve unit of the working platform further comprises a first overflow valve, the first overflow valve is arranged on an oil path between the first differential relief valve and the first three-way relief valve, an oil inlet of the first overflow valve is connected with an oil outlet of the first differential relief valve, and an oil outlet of the first overflow valve is connected with an oil inlet of the first three-way relief valve.
In the embodiment of the invention, the main valve unit of the working platform further comprises a first filter, the first filter is arranged on an oil path between the first overflow valve and the first three-way pressure reducing valve, an oil inlet of the first filter is connected with an oil outlet of the first overflow valve, and an oil outlet of the first filter is connected with an oil inlet of the first three-way pressure reducing valve.
In the embodiment of the invention, the main valve unit of the working platform further comprises a first compensator arranged on an oil path between the leveling valve core and the pump, an oil inlet of the first compensator is connected with an oil outlet of the pump, and an oil outlet of the first compensator is connected with a first oil inlet of the leveling valve core.
In an embodiment of the invention, the hydraulic system further comprises: the first balance valve is arranged on an oil way between the first oil cylinder and the leveling valve core, an oil inlet of the first balance valve is connected with an oil outlet of the leveling valve core, and an oil outlet of the first balance valve is connected with an oil inlet of the first oil cylinder.
In the embodiment of the invention, the main valve unit of the working platform further comprises a third shuttle valve, the third shuttle valve is arranged on an oil way between the second oil inlet of the leveling valve core and the load port of the main valve unit of the working platform, the oil outlet of the third shuttle valve is connected with the load port of the main valve unit of the working platform, and the first oil inlet of the third shuttle valve is connected with the second oil inlet of the leveling valve core.
In the embodiment of the invention, the main valve unit further comprises a second three-way pressure reducing valve, the second three-way pressure reducing valve is arranged on an oil path between an oil outlet of the second constant-difference pressure reducing valve and a fourth oil inlet of the cantilever crane valve core, an oil inlet of the second three-way pressure reducing valve is connected with the oil outlet of the second constant-difference pressure reducing valve, and the oil outlet of the second three-way pressure reducing valve is connected with the fourth oil inlet of the cantilever crane valve core.
In the embodiment of the invention, the main valve unit further comprises a second overflow valve, the second overflow valve is arranged on an oil path between the second constant-difference pressure reducing valve and the second three-way pressure reducing valve, an oil inlet of the second overflow valve is connected with an oil outlet of the second constant-difference pressure reducing valve, and an oil outlet of the second overflow valve is connected with an oil inlet of the second three-way pressure reducing valve.
In the embodiment of the invention, the main valve unit further comprises a second filter, the second filter is arranged on an oil path between the second overflow valve and the second three-way pressure reducing valve, an oil inlet of the second filter is connected with an oil outlet of the second overflow valve, and an oil outlet of the second filter is connected with an oil inlet of the second three-way pressure reducing valve.
In the embodiment of the invention, the main valve unit of the working platform further comprises a second compensator arranged on an oil path between the arm support valve core and the pump, an oil inlet of the second compensator is connected with an oil outlet of the pump, and an oil outlet of the second compensator is connected with a first oil inlet of the arm support valve core.
In an embodiment of the invention, the hydraulic system further comprises: the second balance valve is arranged on an oil path between the second oil cylinder and the cantilever crane valve core, an oil inlet of the second balance valve is connected with an oil outlet of the cantilever crane valve core, and an oil outlet of the second balance valve is connected with an oil inlet of the second oil cylinder.
In the embodiment of the invention, an oil return port of the first differential relief valve is connected with an oil tank to return oil; the oil return port of the first three-way pressure reducing valve is connected with the oil tank to return oil; the oil return port of the first overflow valve is connected with the oil tank for returning oil.
In the embodiment of the invention, an oil return port of the second constant difference reducing valve is connected with an oil tank to return oil; the oil return port of the second three-way pressure reducing valve is connected with the oil tank to return oil; the oil return port of the second overflow valve is connected with the oil tank for returning oil.
In the embodiment of the invention, the hydraulic system further comprises a one-way valve which is arranged on an oil path between the pump and the main valve unit and between the pump and the working platform.
In an embodiment of the invention, the hydraulic system further comprises a motor, and the motor is connected with the pump to drive the pump to work.
In the embodiment of the invention, the working platform main valve unit further comprises a first damping which is arranged on an oil path between a spring end of the first differential relief valve and a load port of the working platform main valve unit; the main valve unit also comprises a second damping which is arranged on an oil path between the spring end of the second constant difference pressure reducing valve and the load port of the main valve unit.
In the embodiment of the invention, the main valve unit further comprises a third overflow valve and a proportional valve, an oil inlet of the third overflow valve is connected with a fifth oil inlet of the cantilever crane valve core, an oil outlet of the third overflow valve is connected with the oil tank, an oil inlet of the proportional valve is connected with a fifth oil inlet of the cantilever crane valve core, and an oil outlet of the proportional valve is connected with an oil outlet of the third overflow valve.
A second aspect of the present invention provides an aerial work machine comprising: a working platform; the arm support is connected with the working platform; and a hydraulic system for an aerial working machine according to the above.
According to the technical scheme, the first oil inlet of the second shuttle valve is connected with the oil outlet of the first three-way pressure reducing valve, meanwhile, the oil inlet of the first three-way pressure reducing valve is connected with the oil outlet of the first differential pressure reducing valve, the second oil inlet of the second shuttle valve is connected with the load port of the main valve unit of the working platform, the oil outlet of the second shuttle valve is connected with the second oil inlet of the first shuttle valve, and the oil outlet of the first shuttle valve is connected with the load port of the main valve unit, so that when the main valve unit and the main valve unit of the working platform do not work, the load pressure of the working platform and the load pressure of the arm support are both zero, the standby pressure of the hydraulic system (namely, the pressure of the hydraulic system when the machine does not do any action) is the sum of the pressure of the first three-way pressure reducing valve and the pressure of the first differential pressure reducing valve, the hydraulic system can quickly respond through the standby pressure of the hydraulic system, the response speed of the hydraulic system is accelerated, the energy conservation of the hydraulic system is guaranteed, the standby pressure is lower than that of the constant pressure system, the energy consumption is also lower, and the energy waste caused by the fact that the hydraulic system is in a large power for a long time is avoided.
Additional features and advantages of embodiments of the invention will be set forth in the detailed description which follows.
Drawings
The accompanying drawings are included to provide a further understanding of embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain, without limitation, the embodiments of the invention. In the drawings:
fig. 1 schematically shows a schematic configuration of a hydraulic system for an overhead working machine in an embodiment of the present invention.
Description of the reference numerals
1. First cylinder 2 second cylinder
3. Pump 4 oil tank
5. Leveling valve core 6 first differential pressure reducing valve
7. Valve core of 8 arm support of first three-way pressure reducing valve
9. Second constant differential pressure reducing valve of first shuttle valve 10
11. Second shuttle valve 12 first overflow valve
13. First filter 14 first compensator
15. First balancing valve 16 third shuttle valve
17. Second three-way pressure reducing valve 18 second overflow valve
19. Second filter 20 second compensator
21. Second balance valve 22 check valve
23. First damping 24 second damping
25. Third relief valve 26 proportional valve
27. Main valve unit of motor 100 working platform
200. Main valve unit
Detailed Description
The following describes the detailed implementation of the embodiments of the present invention with reference to the drawings. It should be understood that the detailed description and specific examples, while indicating and illustrating the invention, are not intended to limit the invention.
The following describes specific embodiments of the present invention in detail with reference to the drawings. It should be understood that the detailed description and specific examples, while indicating and illustrating the invention, are not intended to limit the invention.
It should be noted that, if directional indications (such as up, down, left, right, front, and rear … …) are included in the embodiments of the present invention, the directional indications are merely used to explain the relative positional relationship, movement conditions, etc. between the components in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indications are correspondingly changed.
In addition, if there is a description of "first", "second", etc. in the embodiments of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present invention.
Fig. 1 schematically shows a schematic configuration of a hydraulic system for an overhead working machine in an embodiment of the present invention. As shown in fig. 1, in an embodiment of the present invention, there is provided a hydraulic system for an aerial work machine including a work platform and a boom connected to the work platform, the hydraulic system for an aerial work machine may include:
the oil cylinder unit comprises a first oil cylinder 1 and a second oil cylinder 2, wherein the first oil cylinder 1 is used for leveling a working platform, and the second oil cylinder 2 is used for realizing the action of the arm support.
It can be understood that the first oil cylinder 1 can realize the leveling of the working platform, the second oil cylinder 2 can realize the movement of the arm support, and in addition, the movement of the arm support can drive the movement of the working platform to realize the leveling of the working platform because the arm support is connected with the working platform.
And a pump 3 for pumping the hydraulic oil pump 3 in the oil tank 4 to the first oil cylinder 1 and the second oil cylinder 2.
It can be understood that the pump 3 can pump the hydraulic oil pump 3 in the oil tank 4 to the first oil cylinder 1 and the second oil cylinder 2, so that the actions of the first oil cylinder 1 and the second oil cylinder 2 can be realized, and further the leveling of the working platform and the actions of the arm support can be realized. In some embodiments, the pump 3 may include, but is not limited to, a gear pump 3 or the like.
The working platform main valve unit 100 is arranged on an oil way between the pump 3 and the first oil cylinder 1, the working platform main valve unit 100 comprises a leveling valve core 5, a first differential relief valve 6 and a first three-way relief valve 7, a first oil inlet of the leveling valve core 5 is connected with an oil outlet of the pump 3, a second oil inlet of the leveling valve core 5 is connected with a load port of the working platform main valve unit 100, an oil outlet of the leveling valve core 5 is connected with an oil inlet of the first oil cylinder 1, an oil inlet of the first differential relief valve 6 is connected with an oil outlet of the pump 3, an oil outlet of the first differential relief valve 6 is connected with an oil inlet of the first three-way relief valve 7, an oil outlet of the first three-way relief valve 7 is connected with a third oil inlet of the leveling valve core 5, and a spring end of the first differential relief valve 6 is connected with a load port of the working platform main valve unit 100.
It will be appreciated that the working platform main valve unit 100 is disposed on the oil path between the pump 3 and the first cylinder 1, so that the hydraulic oil delivered from the pump 3 to the first cylinder 1 can be treated accordingly to obtain the hydraulic oil of the pressure magnitude associated with the inclination angle of the working platform and delivered to the first cylinder 1. The leveling valve core 5 is used for driving the first oil cylinder 1 to act so as to level the working platform. The first differential relief valve 6 is used to remove excess hydraulic oil from the hydraulic system, for example, when the hydraulic system is not in operation, since the hydraulic system is a closed loop system, the hydraulic oil in the hydraulic system is always in a circulating state, and the first differential relief valve 6 can deliver part of the hydraulic oil back to the tank 4. The first three-way pressure reducing valve 7 may provide a pilot pressure.
Specifically, the main valve unit 100 of the working platform may include a leveling valve core 5, a first differential relief valve 6 and a first three-way relief valve 7, where a first oil inlet of the leveling valve core 5 is connected with an oil outlet of the pump 3, and an oil outlet of the leveling valve core 5 is connected with an oil inlet of the first oil cylinder 1, so that the leveling valve core 5 may receive hydraulic oil conveyed by the pump 3 and output the hydraulic oil to the first oil cylinder 1. Since the leveling valve core 5 is communicated with the first oil cylinder 1, the leveling valve core 5 can feed back the pressure of the first oil cylinder 1, that is, feed back the load pressure of the working platform, and the second oil inlet of the leveling valve core 5 is connected with the load port of the main valve unit 100 of the working platform (that is, the LS port of the main valve unit 100 of the working platform shown in fig. 1), so that the load pressure of the working platform fed back by the leveling valve core 5 can be fed back to the load port of the main valve unit 100 of the working platform. The spring end of the first differential relief valve 6 is connected with the load port of the main valve unit 100 of the working platform, that is, the load pressure of the working platform fed back by the leveling valve core 5 can be directly fed back to the spring end of the first differential relief valve 6 through the load port of the main valve unit 100 of the working platform, and at this time, the pressure of the spring end of the first differential relief valve 6 is the load pressure of the working platform, so that when the main valve unit 100 of the working platform works, the pressure of the spring end of the first differential relief valve 6 is the load pressure of the working platform. The oil inlet of the first differential pressure reducing valve 6 is connected with the oil outlet of the pump 3, that is, part of hydraulic oil conveyed to the first oil cylinder 1 by the pump 3 enters the leveling valve core 5, and part enters the first differential pressure reducing valve 6. The oil outlet of the first differential relief valve 6 is connected with the oil inlet of the first three-way relief valve 7, hydraulic oil of the oil outlet of the first relief valve is conveyed to the first three-way relief valve 7, the oil outlet of the first three-way relief valve 7 is connected with the third oil inlet of the leveling valve core 5, that is, the first three-way relief valve 7 can provide pilot pressure for the leveling valve core 5.
The main valve unit 200 is arranged on an oil path between the pump 3 and the second oil cylinder 2 and comprises a cantilever crane valve core 8, a first shuttle valve 9 and a second constant differential pressure reducing valve 10, wherein a first oil inlet of the cantilever crane valve core 8 is connected with an oil outlet of the pump 3, a second oil inlet of the cantilever crane valve core 8 is connected with a first oil inlet of the first shuttle valve 9, a third oil inlet of the cantilever crane valve core 8 is connected with a load port of the main valve unit 200, an oil outlet of the cantilever crane valve core 8 is connected with an oil inlet of the second oil cylinder 2, an oil outlet of the first shuttle valve 9 is connected with a load port of the main valve unit 200, an oil inlet of the second constant differential pressure reducing valve 10 is connected with an oil outlet of the pump 3, an oil outlet of the second constant differential pressure reducing valve 10 is connected with a fourth oil inlet of the cantilever crane valve core 8, and a spring end of the second constant differential pressure reducing valve 10 is connected with a load port of the main valve unit 200.
The first oil inlet of the second shuttle valve 11 is connected with the oil outlet of the first three-way pressure reducing valve 7, the second oil inlet of the second shuttle valve 11 is connected with the load port of the main valve unit 100 of the working platform, and the oil outlet of the second shuttle valve 11 is connected with the second oil inlet of the first shuttle valve 9.
It will be appreciated that the main valve unit 200 is provided on the oil path between the pump 3 and the second cylinder 2, so that the hydraulic oil delivered to the second cylinder 2 by the pump 3 can be treated accordingly to obtain the hydraulic oil of the pressure magnitude associated with the angle of motion of the boom and delivered to the second cylinder 2. The valve core 8 of the arm support has the function of driving the second oil cylinder 2 to act so as to realize the action of the arm support, and further, the leveling of a working platform can be realized. The first shuttle valve 9 and the second shuttle valve 11 are used for pressure selection, and are valves with valve bodies and actuators integrated into a whole, and the valves comprise two oil inlets and one oil outlet, that is, the first shuttle valve 9 and/or the second shuttle valve 11 can select the pressure with the larger pressure value in the two oil inlets as the pressure of the respective oil outlet. The second differential pressure reducing valve 10 is used to remove excess hydraulic oil from the hydraulic system, for example, when the hydraulic system is not in operation, since the hydraulic system is a closed loop system, the hydraulic oil in the hydraulic system is always in a circulating state, and the second differential pressure reducing valve 10 can convey part of the hydraulic oil back to the tank 4.
Specifically, the main valve unit 200 may include a boom spool 8, a first shuttle valve 9, and a second differential relief valve 10, where a first oil inlet of the boom spool 8 is connected to an oil outlet of the pump 3, and an oil outlet of the boom spool 8 is connected to an oil inlet of the second oil cylinder 2, so that the boom spool 8 may receive hydraulic oil conveyed by the pump 3 and output the hydraulic oil to the second oil cylinder 2. Because the boom valve core 8 is communicated with the second oil cylinder 2, the boom valve core 8 can feed back the pressure of the second oil cylinder 2, that is, feed back the load pressure of the boom, and the third oil inlet of the boom valve core 8 is connected with the load port of the main valve unit 200 (that is, the LS port of the main valve unit 200 shown in fig. 1), so that the load pressure of the boom fed back by the boom valve core 8 can be fed back to the load port of the main valve unit 200. The spring end of the second constant-difference pressure reducing valve 10 is connected with the load port of the main valve unit 200, that is, the load pressure of the arm rest fed back by the arm rest valve core 8 can be directly fed back to the spring end of the second constant-difference pressure reducing valve 10 through the load port of the main valve unit 200, and at this time, the pressure of the spring end of the second constant-difference pressure reducing valve 10 is the load pressure of the arm rest, so that when the main valve unit 200 works, the pressure of the spring end of the second constant-difference pressure reducing valve 10 is the load pressure of the arm rest. The oil inlet of the second constant-difference pressure reducing valve 10 is connected with the oil outlet of the pump 3, the oil outlet of the second constant-difference pressure reducing valve 10 is connected with the fourth oil inlet of the boom spool 8, that is, part of hydraulic oil conveyed to the second oil cylinder 2 by the pump 3 enters the boom spool 8 and the other part enters the second constant-difference pressure reducing valve 10, and the oil outlet of the second constant-difference pressure reducing valve 10 is connected with the fourth oil inlet of the boom spool 8 to provide pilot pressure for the boom spool 8.
The first oil inlet of the second shuttle valve 11 is connected with the oil outlet of the first three-way pressure reducing valve 7, that is, the pressure of the first oil inlet of the second shuttle valve 11 is the sum of the pressure of the first three-way pressure reducing valve 7 and the pressure of the first differential pressure reducing valve 6. The second oil inlet of the second shuttle valve 11 is connected to the load port of the working platform main valve unit 100, that is, the pressure of the second oil inlet of the second shuttle valve 11 is the load pressure of the working platform. The pressure of the oil outlet of the second shuttle valve 11 is the pressure with larger value in the pressure of the first oil inlet of the second shuttle valve 11 and the pressure of the second oil inlet of the second shuttle valve 11, namely the pressure of the first three-way pressure reducing valve 7 and the pressure of the first differential pressure reducing valve 6 are the sum of the pressure of the first shuttle valve 9 and the pressure of the working platform, the oil outlet of the second shuttle valve 11 is connected with the second oil inlet of the first shuttle valve 9, so that the pressure with larger value in the sum of the pressure of the first three-way pressure reducing valve 7 and the pressure of the first differential pressure reducing valve 6 and the pressure of the working platform is used as the pressure of the second oil inlet of the first shuttle valve 9, the oil outlet of the first shuttle valve 9 is connected with the load arm support of the main valve unit 200, and the pressure of the oil outlet of the first shuttle valve 9 is used as the load pressure of the arm support, namely the second oil inlet of the first shuttle valve 8 is connected with the first oil inlet of the first shuttle valve 9, and the first shuttle valve 9 can be used as the pressure of the second shuttle valve 6 and the load arm support of the working platform, the pressure of the first differential pressure reducing valve 7 and the pressure of the working platform is used as the load pressure of the load arm support of the main valve 200, and the load arm support of the load of the main valve 200 is used as the load pressure of the load arm support of the main valve, and the load of the main valve and the load of the working platform. When the main valve unit 200 and the main valve unit 100 of the working platform work, the load pressure of the working platform or the load pressure of the arm support is greater than the sum of the pressure of the first three-way pressure reducing valve 7 and the pressure of the first differential pressure reducing valve 6, and the pressure of the hydraulic system is the load pressure of the working platform or the load pressure of the arm support.
According to the hydraulic system for the high-altitude operation machine, the first oil inlet of the second shuttle valve 11 is connected with the oil outlet of the first three-way pressure reducing valve 7, the oil inlet of the first three-way pressure reducing valve 7 is connected with the oil outlet of the first differential pressure reducing valve 6, the second oil inlet of the second shuttle valve 11 is connected with the load port of the main valve unit 100 of the working platform, the oil outlet of the second shuttle valve 11 is connected with the second oil inlet of the first shuttle valve 9, and the oil outlet of the first shuttle valve 9 is connected with the load port of the main valve unit 200, so that when the main valve unit 200 and the main valve unit 100 of the working platform do not work, the load pressure of the working platform and the load pressure of the arm support are zero, the standby pressure of the hydraulic system (namely the pressure of the hydraulic system when the machine does not do any action) is the sum of the pressure of the first three-way pressure reducing valve 7 and the pressure of the first differential pressure reducing valve 6, the hydraulic system can respond quickly through the standby pressure of the hydraulic system, the response speed of the hydraulic system is accelerated, meanwhile, the energy conservation of the hydraulic system is guaranteed, the pressure is lower compared with the system, the energy consumption is low, and the energy consumption is avoided, and the hydraulic system is wasted for a long time.
In one embodiment, the working platform main valve unit 100 further includes a first relief valve 12 disposed on an oil path between the first differential relief valve 6 and the first three-way relief valve 7, an oil inlet of the first relief valve 12 is connected to an oil outlet of the first differential relief valve 6, and an oil outlet of the first relief valve 12 is connected to an oil inlet of the first three-way relief valve 7.
It will be appreciated that the first relief valve 12 acts to maintain pressure in the hydraulic system so that the pressure can stabilize, and when the pressure in the hydraulic system exceeds a certain range, the first relief valve 12 can reduce the flow rate to ensure that the pressure in the hydraulic system does not exceed a predetermined range, thereby reducing the occurrence of an accident. The first relief valve 12 is provided on the oil passage between the first differential relief valve 6 and the first three-way relief valve 7, and can prevent the pressure of the hydraulic oil that enters the first three-way relief valve 7 from being excessively high, for example, exceeding a preset pressure.
In one embodiment, the working platform main valve unit 100 further includes a first filter 13 disposed on an oil path between the first relief valve 12 and the first three-way pressure reducing valve 7, an oil inlet of the first filter 13 is connected to an oil outlet of the first relief valve 12, and an oil outlet of the first filter 13 is connected to an oil inlet of the first three-way pressure reducing valve 7.
It will be appreciated that the function of the first filter 13 is to filter the hydraulic oil. The first filter 13 is provided on an oil path between the first relief valve 12 and the first three-way pressure reducing valve 7, so that the hydraulic oil that enters the first three-way pressure reducing valve 7 can be filtered to ensure the cleanliness of the hydraulic oil.
In one embodiment, the working platform main valve unit 100 further comprises a first compensator 14 disposed on the oil path between the leveling spool 5 and the pump 3, an oil inlet of the first compensator 14 is connected with an oil outlet of the pump 3, and an oil outlet of the first compensator 14 is connected with a first oil inlet of the leveling spool 5.
It will be appreciated that the first compensator 14 is primarily intended to ensure a constant differential pressure. The first compensator 14 is provided on the oil path between the leveling spool 5 and the pump 3, and can ensure that the pressure difference between the leveling spool 5 and the pump 3 is at or near a constant value.
In one embodiment, the hydraulic system further comprises: the first balance valve 15 is arranged on an oil way between the first oil cylinder 1 and the leveling valve core 5, an oil inlet of the first balance valve 15 is connected with an oil outlet of the leveling valve core 5, and an oil outlet of the first balance valve 15 is connected with an oil inlet of the first oil cylinder 1.
It will be appreciated that the function of the first balancing valve 15 is to regulate the pressure difference or flow difference of the hydraulic oil in the conduit. The first balance valve 15 is arranged on an oil path between the first oil cylinder 1 and the leveling valve core 5, and can balance the pressure difference in the pipeline between the first oil cylinder 1 and the leveling valve core 5, so that the safe operation of the first oil cylinder 1 is ensured.
In one embodiment, the working platform main valve unit 100 further includes a third shuttle valve 16, the third shuttle valve 16 is disposed on an oil path between the second oil inlet of the leveling valve spool 5 and the load port of the working platform main valve unit 100, the oil outlet of the third shuttle valve 16 is connected to the load port of the working platform main valve unit 100, and the first oil inlet of the third shuttle valve 16 is connected to the second oil inlet of the leveling valve spool 5.
It will be appreciated that the function of the third shuttle valve 16 is also to perform pressure selection, which is a valve with a valve body and an actuator combined into one, and includes two oil inlets and one oil outlet, that is, the third shuttle valve 16 may select the pressure with the greater pressure value of the two oil inlets as the pressure of the oil outlet. The third shuttle valve 16 is arranged on an oil way between the second oil inlet of the leveling valve core 5 and the load port of the main valve unit 100 of the working platform, and the oil outlet of the third shuttle valve 16 is connected with the load port of the main valve unit 100 of the working platform, so that the load pressure of the working platform can be obtained, and the first oil inlet of the third shuttle valve 16 is connected with the second oil inlet of the leveling valve core 5 to realize leveling action. In some embodiments, the second oil inlet of the third shuttle valve 16 may be connected with a load port (e.g., LS port) of other actions.
In one embodiment, the main valve unit 200 further includes a second three-way pressure reducing valve 17, which is disposed on an oil path between an oil outlet of the second differential pressure reducing valve 10 and a fourth oil inlet of the boom spool 8, an oil inlet of the second three-way pressure reducing valve 17 is connected to an oil outlet of the second differential pressure reducing valve 10, and an oil outlet of the second three-way pressure reducing valve 17 is connected to a fourth oil inlet of the boom spool 8.
It will be appreciated that the second three-way pressure relief valve 17 may provide the pilot pressure. The second three-way pressure reducing valve 17 is arranged on an oil path between the oil outlet of the second constant differential pressure reducing valve 10 and the fourth oil inlet of the boom spool 8, the oil inlet of the second three-way pressure reducing valve 17 is connected with the oil outlet of the second constant differential pressure reducing valve 10, and the oil outlet of the second three-way pressure reducing valve 17 is connected with the fourth oil inlet of the boom spool 8, that is, the second three-way pressure reducing valve 17 can provide pilot pressure for the boom spool 8.
In one embodiment, the main valve unit 200 further includes a second relief valve 18 disposed on an oil path between the second differential relief valve 10 and the second three-way relief valve 17, an oil inlet of the second relief valve 18 is connected to an oil outlet of the second differential relief valve 10, and an oil outlet of the second relief valve 18 is connected to an oil inlet of the second three-way relief valve 17.
It will be appreciated that the second relief valve 18 acts to maintain pressure in the hydraulic system so that the pressure can stabilize, and when the pressure in the hydraulic system exceeds a certain range, the second relief valve 18 reduces the flow rate to ensure that the pressure in the hydraulic system does not exceed a predetermined range, thereby reducing the occurrence of an accident. The second relief valve 18 is provided on the oil passage between the second constant differential pressure reducing valve 10 and the second three-way pressure reducing valve 17, and can prevent the pressure of the hydraulic oil that enters the second three-way pressure reducing valve 17 from being excessively high, for example, exceeding a preset pressure.
In one embodiment, the main valve unit 200 further includes a second filter 19 disposed on an oil path between the second relief valve 18 and the second three-way pressure reducing valve 17, an oil inlet of the second filter 19 is connected to an oil outlet of the second relief valve 18, and an oil outlet of the second filter 19 is connected to an oil inlet of the second three-way pressure reducing valve 17.
It will be appreciated that the function of the second filter 19 is to filter the hydraulic oil. The second filter 19 is provided on the oil path between the second relief valve 18 and the second three-way pressure reducing valve 17, so that the hydraulic oil that enters the second three-way pressure reducing valve 17 can be filtered to ensure the cleanliness of the hydraulic oil.
In one embodiment, the main valve unit 100 of the working platform further includes a second compensator 20 disposed on the oil path between the boom spool 8 and the pump 3, an oil inlet of the second compensator 20 is connected to an oil outlet of the pump 3, and an oil outlet of the second compensator 20 is connected to the first oil inlet of the boom spool 8.
It will be appreciated that the second compensator 20 is primarily intended to ensure a constant differential pressure. The second compensator 20 is arranged on the oil path between the boom spool 8 and the pump 3, so that the pressure difference between the boom spool 8 and the pump 3 can be ensured to be at or near a constant value.
In one embodiment, the hydraulic system further comprises: the second balance valve 21 is arranged on an oil path between the second oil cylinder 2 and the arm support valve core 8, an oil inlet of the second balance valve 21 is connected with an oil outlet of the arm support valve core 8, and an oil outlet of the second balance valve 21 is connected with an oil inlet of the second oil cylinder 2.
It will be appreciated that the second balancing valve 21 functions to regulate the pressure difference or flow difference of the hydraulic oil in the conduit. The second balance valve 21 is arranged on an oil path between the second oil cylinder 2 and the arm support valve core 8, and can balance the pressure difference in the pipeline between the second oil cylinder 2 and the arm support valve core 8, so that the safe operation of the second oil cylinder 2 is ensured.
In one embodiment, the oil return port of the first differential relief valve 6 is connected to the oil tank 4 for returning oil; the oil return port of the first three-way pressure reducing valve 7 is connected with the oil tank 4 for returning oil; the return port of the first relief valve 12 is connected to the tank 4 for returning oil.
It will be appreciated that the return port of the first differential relief valve 6, the return port of the first three-way relief valve 7 and the return port of the first relief valve 12 are all intended to convey excess hydraulic oil back to the tank 4. Further, the oil return port of the first differential relief valve 6, the oil return port of the first three-way relief valve 7, and the oil return port of the first relief valve 12 may be connected to each other to share one oil return path.
In one embodiment, the oil return port of the second constant difference reducing valve 10 is connected with the oil tank 4 to return oil; the oil return port of the second three-way pressure reducing valve 17 is connected with the oil tank 4 for returning oil; the return port of the second relief valve 18 is connected to the tank 4 for returning oil.
It will be appreciated that the return port of the second constant differential pressure relief valve 10, the return port of the second three-way pressure relief valve 17 and the return port of the second relief valve 18 are all intended to convey excess hydraulic oil back to the tank 4. Further, the oil return port of the second constant differential pressure reducing valve 10, the oil return port of the second three-way pressure reducing valve 17, and the oil return port of the second relief valve 18 may be connected to each other to share one oil return path.
In one embodiment, the hydraulic system further comprises a one-way valve 22 arranged in the oil path between the pump 3 and the main valve unit 100, 200 of the working platform.
It will be appreciated that the check valve 22 may allow hydraulic oil in the hydraulic tank 4 to be transferred from the tank 4 to the pump 3 only in one direction, and not back from the pump 3 to the hydraulic tank 4.
In one embodiment, the hydraulic system further comprises a motor 27, the motor 27 being connected to the pump 3 to drive the pump 3 into operation.
In one embodiment, the working platform main valve unit 100 further includes a first damper 23 disposed on an oil path between the spring end of the first differential relief valve 6 and the load port of the working platform main valve unit 100; the main valve unit 200 further includes a second damper 24 disposed on an oil path between the spring end of the second constant difference reducing valve 10 and the load port of the main valve unit 200.
It will be appreciated that the first damping 23 and the second damping 24 act to filter the fluctuating pressure, making the action smoother. Specifically, the first damper 23 is provided on the oil path between the spring end of the first differential relief valve 6 and the load port of the working platform main valve unit 100, and can filter out the fluctuating pressure in the pipe between the first differential relief valve 6 and the load port of the working platform main valve unit 100. The second damper 24 is provided on an oil path between the spring end of the second differential pressure reducing valve 10 and the load port of the main valve unit 200, and can filter out the fluctuating pressure in the pipe between the second differential pressure reducing valve 10 and the load port of the main valve unit 200.
In one embodiment, the main valve unit 200 further comprises a third overflow valve 25 and a proportional valve 26, wherein an oil inlet of the third overflow valve 25 is connected with a fifth oil inlet of the boom spool 8, an oil outlet of the third overflow valve 25 is connected with the oil tank 4, an oil inlet of the proportional valve 26 is connected with a fifth oil inlet of the boom spool 8, and an oil outlet of the proportional valve 26 is connected with an oil outlet of the third overflow valve 25.
It will be appreciated that the third relief valve 25 acts to maintain pressure in the hydraulic system so that the pressure can stabilize, and that when the pressure in the hydraulic system exceeds a certain range, the third relief valve 25 can reduce the flow rate to ensure that the pressure in the hydraulic system does not exceed a predetermined range, thereby reducing the occurrence of an accident. The oil inlet of the third overflow valve 25 is connected with the fifth oil inlet of the boom spool 8, and the oil outlet of the third overflow valve 25 is connected with the oil tank 4, that is, the third overflow valve 25 can adjust the pressure of hydraulic oil entering the boom spool 8, and can convey redundant hydraulic oil back to the oil tank 4. The function of the proportional valve 26 is to regulate the pressure of the third relief valve 25, i.e. the pressure setting of the third relief valve 25 can be regulated by the proportional valve 26.
In a specific embodiment of the present invention, as shown in fig. 1, a main valve unit 100 and a main valve unit 200 of a working platform of a hydraulic system for an overhead working machine are connected in parallel to a pump 3, when the main valve unit 200 and/or the main valve unit 100 of the working platform work, the pump 3 can be driven by a motor 27 to work, the hydraulic oil passes through a check valve 22 to reach a P port of the main valve unit 200 and the main valve unit 100 of the working platform, after the hydraulic oil passes through a three-way pressure reducing valve of the main valve unit 100 of the working platform, the hydraulic oil at the other end passes through a first compensator 14 and a leveling valve core 5, the load pressure is fed back to an LS port, the pressures of the two are connected to a second shuttle valve 11, and after the selection comparison, the large pressure is connected to a Y port at the tail of the main valve unit 200. When the main valve unit 200 and the working platform main valve unit 100 are both not working, the standby pressure of the hydraulic system is the pressure of the first three-way pressure reducing valve 7 plus the pressure of the first differential pressure reducing valve 6 spring, and when the main valve unit 200 and the working platform main valve unit 100 are both working, the load pressure is greater than the sum of the pressure of the first three-way pressure reducing valve 7 and the pressure of the first differential pressure reducing valve 6 spring, so the pressure fed back is the load pressure. In the embodiment of the invention, the standby pressure is the sum of the pressure of the first three-way pressure reducing valve 7 and the pressure of the spring of the first differential pressure reducing valve 6, and the system can quickly respond through the high pressure, and meanwhile, the energy conservation of the system is ensured. According to the embodiment of the application, the system standby pressure is equal to the sum of the pressure of the first three-way pressure reducing valve 7 and the pressure of the spring of the first differential pressure reducing valve 6, so that the response speed of the action is improved, the product performance can be embodied, the problem that the response speed of a common hydraulic system is slow is solved, the response speed is faster, and compared with a constant pressure system, the embodiment of the application uses lower pressure and is more energy-saving.
The embodiment of the invention provides an aerial working machine, which comprises: a working platform; the arm support is connected with the working platform; and the hydraulic system for an overhead working machine according to the above embodiment.
The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the specific details of the above embodiments, and various simple modifications can be made to the technical solution of the present invention within the scope of the technical concept of the present invention, and all the simple modifications belong to the protection scope of the present invention.
In addition, the specific features described in the above embodiments may be combined in any suitable manner without contradiction. The various possible combinations of the invention are not described in detail in order to avoid unnecessary repetition.
Moreover, any combination of the various embodiments of the invention can be made without departing from the spirit of the invention, which should also be considered as disclosed herein.

Claims (18)

1. A hydraulic system for an aerial work machine, the aerial work machine including a work platform and a boom connected to the work platform, the hydraulic system comprising:
The oil cylinder unit comprises a first oil cylinder and a second oil cylinder, wherein the first oil cylinder is used for leveling the working platform, and the second oil cylinder is used for realizing the action of the arm support;
the pump is used for pumping hydraulic oil in the oil tank to the first oil cylinder and the second oil cylinder;
the working platform main valve unit is arranged on an oil way between the pump and the first oil cylinder, and comprises a leveling valve core, a first differential relief valve and a first three-way relief valve, wherein a first oil inlet of the leveling valve core is connected with an oil outlet of the pump, a second oil inlet of the leveling valve core is connected with a load port of the working platform main valve unit, an oil outlet of the leveling valve core is connected with an oil inlet of the first oil cylinder, an oil inlet of the first differential relief valve is connected with an oil outlet of the pump, an oil outlet of the first differential relief valve is connected with an oil inlet of the first three-way relief valve, an oil outlet of the first three-way relief valve is connected with a third oil inlet of the leveling valve core, and a spring end of the first differential relief valve is connected with a load port of the working platform main valve unit;
the main valve unit is arranged on an oil path between the pump and the second oil cylinder and comprises an arm support valve core, a first shuttle valve and a second constant-difference pressure reducing valve, wherein a first oil inlet of the arm support valve core is connected with an oil outlet of the pump, a second oil inlet of the arm support valve core is connected with a first oil inlet of the first shuttle valve, a third oil inlet of the arm support valve core is connected with a load port of the main valve unit, an oil outlet of the arm support valve core is connected with an oil inlet of the second oil cylinder, an oil outlet of the first shuttle valve is connected with a load port of the main valve unit, an oil inlet of the second constant-difference pressure reducing valve is connected with an oil outlet of the pump, an oil outlet of the second constant-difference pressure reducing valve is connected with a fourth oil inlet of the arm support valve core, and a spring end of the second constant-difference pressure reducing valve is connected with a load port of the main valve unit;
The first oil inlet of the second shuttle valve is connected with the oil outlet of the first three-way pressure reducing valve, the second oil inlet of the second shuttle valve is connected with the load port of the main valve unit of the working platform, and the oil outlet of the second shuttle valve is connected with the second oil inlet of the first shuttle valve.
2. The hydraulic system of claim 1, wherein the work platform main valve unit further comprises a first relief valve disposed on an oil path between the first differential relief valve and the first three-way relief valve, an oil inlet of the first relief valve being connected to an oil outlet of the first differential relief valve, an oil outlet of the first relief valve being connected to an oil inlet of the first three-way relief valve.
3. The hydraulic system of claim 2, wherein the work platform main valve unit further comprises a first filter disposed on an oil path between the first relief valve and the first three-way pressure relief valve, an oil inlet of the first filter being connected to an oil outlet of the first relief valve, an oil outlet of the first filter being connected to an oil inlet of the first three-way pressure relief valve.
4. The hydraulic system of claim 1, wherein the work platform main valve unit further comprises a first compensator disposed on an oil path between the leveling spool and the pump, an oil inlet of the first compensator being connected to an oil outlet of the pump, an oil outlet of the first compensator being connected to a first oil inlet of the leveling spool.
5. The hydraulic system of claim 1, further comprising:
the first balance valve is arranged on an oil way between the first oil cylinder and the leveling valve core, an oil inlet of the first balance valve is connected with an oil outlet of the leveling valve core, and an oil outlet of the first balance valve is connected with an oil inlet of the first oil cylinder.
6. The hydraulic system of claim 1, wherein the work platform main valve unit further comprises a third shuttle valve disposed on an oil path between the second oil inlet of the leveling spool and the load port of the work platform main valve unit, an oil outlet of the third shuttle valve being connected to the load port of the work platform main valve unit, a first oil inlet of the third shuttle valve being connected to the second oil inlet of the leveling spool.
7. The hydraulic system of claim 1, wherein the main valve unit further comprises a second three-way relief valve disposed on an oil path between an oil outlet of the second differential relief valve and a fourth oil inlet of the boom spool, an oil inlet of the second three-way relief valve is connected to an oil outlet of the second differential relief valve, and an oil outlet of the second three-way relief valve is connected to a fourth oil inlet of the boom spool.
8. The hydraulic system of claim 7, wherein the main valve unit further comprises a second relief valve disposed in an oil path between the second differential relief valve and the second three-way relief valve, an oil inlet of the second relief valve being connected to an oil outlet of the second differential relief valve, and an oil outlet of the second relief valve being connected to an oil inlet of the second three-way relief valve.
9. The hydraulic system of claim 8, wherein the main valve unit further comprises a second filter disposed on an oil path between the second relief valve and the second three-way relief valve, an oil inlet of the second filter being connected to an oil outlet of the second relief valve, an oil outlet of the second filter being connected to an oil inlet of the second three-way relief valve.
10. The hydraulic system of claim 1, wherein the work platform main valve unit further comprises a second compensator disposed on an oil path between the boom spool and the pump, an oil inlet of the second compensator being connected to an oil outlet of the pump, an oil outlet of the second compensator being connected to a first oil inlet of the boom spool.
11. The hydraulic system of claim 1, further comprising:
the second balance valve is arranged on an oil way between the second oil cylinder and the cantilever crane valve core, an oil inlet of the second balance valve is connected with an oil outlet of the cantilever crane valve core, and an oil outlet of the second balance valve is connected with an oil inlet of the second oil cylinder.
12. The hydraulic system of claim 2, wherein an oil return port of the first differential relief valve is connected to the oil tank for returning oil; the oil return port of the first three-way pressure reducing valve is connected with the oil tank to return oil; and an oil return port of the first overflow valve is connected with the oil tank for returning oil.
13. The hydraulic system of claim 8, wherein an oil return port of the second differential relief valve is connected to the oil tank for returning oil; the oil return port of the second three-way pressure reducing valve is connected with the oil tank to return oil; and an oil return port of the second overflow valve is connected with the oil tank for returning oil.
14. The hydraulic system of claim 1, further comprising a one-way valve disposed in an oil path between the pump and the working platform main valve unit, the main valve unit.
15. The hydraulic system of claim 1, further comprising a motor coupled to the pump to drive the pump to operate.
16. The hydraulic system of claim 1, wherein the work platform main valve unit further comprises a first damper disposed on an oil path between a spring end of the first differential relief valve and a load port of the work platform main valve unit;
the main valve unit further comprises a second damping arranged on an oil path between the spring end of the second constant difference pressure reducing valve and the load port of the main valve unit.
17. The hydraulic system of claim 1, wherein the main valve unit further comprises a third relief valve and a proportional valve, an oil inlet of the third relief valve is connected with a fifth oil inlet of the boom spool, an oil outlet of the third relief valve is connected with the oil tank, an oil inlet of the proportional valve is connected with a fifth oil inlet of the boom spool, and an oil outlet of the proportional valve is connected with an oil outlet of the third relief valve.
18. An aerial work machine, comprising:
a working platform;
the arm support is connected with the working platform; and
A hydraulic system for an aerial work machine as claimed in any one of claims 1 to 17.
CN202111668549.4A 2021-12-31 2021-12-31 Hydraulic system for an overhead working machine and overhead working machine Active CN114458645B (en)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN2890448Y (en) * 2005-12-08 2007-04-18 常德信诚液压有限公司 Hydraulic combined control valve
CN105402182A (en) * 2015-12-09 2016-03-16 广西柳工机械股份有限公司 Load sensing multi-way directional valve and hydraulic control system of loader
JP2017057926A (en) * 2015-09-16 2017-03-23 キャタピラー エス エー アール エル Hydraulic pump control system in hydraulic work machine
CN206600313U (en) * 2017-01-21 2017-10-31 三一汽车制造有限公司 Support leg hydraulic system, anchoring car and engineering machinery
CN107664146A (en) * 2016-07-29 2018-02-06 徐工集团工程机械股份有限公司科技分公司 Hydraulic system and there is its engineering truck
CN113266612A (en) * 2021-06-21 2021-08-17 徐州恒兴金桥机械科技有限公司 Load sensitive control hydraulic system of pile driver

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN2890448Y (en) * 2005-12-08 2007-04-18 常德信诚液压有限公司 Hydraulic combined control valve
JP2017057926A (en) * 2015-09-16 2017-03-23 キャタピラー エス エー アール エル Hydraulic pump control system in hydraulic work machine
CN105402182A (en) * 2015-12-09 2016-03-16 广西柳工机械股份有限公司 Load sensing multi-way directional valve and hydraulic control system of loader
CN107664146A (en) * 2016-07-29 2018-02-06 徐工集团工程机械股份有限公司科技分公司 Hydraulic system and there is its engineering truck
CN206600313U (en) * 2017-01-21 2017-10-31 三一汽车制造有限公司 Support leg hydraulic system, anchoring car and engineering machinery
CN113266612A (en) * 2021-06-21 2021-08-17 徐州恒兴金桥机械科技有限公司 Load sensitive control hydraulic system of pile driver

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