Classifications

• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
  • E02F9/20—Drives; Control devices
  • E02F9/22—Hydraulic or pneumatic drives
  • E02F9/2221—Control of flow rate; Load sensing arrangements
  • E02F9/2225—Control of flow rate; Load sensing arrangements using pressure-compensating valves
  • E02F9/2228—Control of flow rate; Load sensing arrangements using pressure-compensating valves including an electronic controller
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
  • E02F9/20—Drives; Control devices
  • E02F9/22—Hydraulic or pneumatic drives
  • E02F9/2221—Control of flow rate; Load sensing arrangements
  • E02F9/2232—Control of flow rate; Load sensing arrangements using one or more variable displacement pumps
  • E02F9/2235—Control of flow rate; Load sensing arrangements using one or more variable displacement pumps including an electronic controller
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
  • E02F9/20—Drives; Control devices
  • E02F9/22—Hydraulic or pneumatic drives
  • E02F9/2278—Hydraulic circuits
  • E02F9/2296—Systems with a variable displacement pump
• • 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
  • F15B11/08—Servomotor systems without provision for follow-up action ; Circuits therefor with only one servomotor
• • 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
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
  • F15B2211/205—Systems with pumps
  • F15B2211/2053—Type of pump
  • F15B2211/20546—Type of pump variable capacity
• • 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
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/30—Directional control
  • F15B2211/305—Directional control characterised by the type of valves
  • F15B2211/3056—Assemblies of multiple valves
  • F15B2211/30565—Assemblies of multiple valves having multiple valves for a single output member, e.g. for creating higher valve function by use of multiple valves like two 2/2-valves replacing a 5/3-valve
  • F15B2211/3057—Assemblies of multiple valves having multiple valves for a single output member, e.g. for creating higher valve function by use of multiple valves like two 2/2-valves replacing a 5/3-valve having two valves, one for each port of a double-acting output member
• • 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
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/30—Directional control
  • F15B2211/31—Directional control characterised by the positions of the valve element
  • F15B2211/3105—Neutral or centre positions
  • F15B2211/3111—Neutral or centre positions the pump port being closed in the centre position, e.g. so-called closed centre
• • 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
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/30—Directional control
  • F15B2211/31—Directional control characterised by the positions of the valve element
  • F15B2211/3144—Directional control characterised by the positions of the valve element the positions being continuously variable, e.g. as realised by proportional 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
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/30—Directional control
  • F15B2211/32—Directional control characterised by the type of actuation
  • F15B2211/327—Directional control characterised by the type of actuation electrically or electronically
• • 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
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/50—Pressure control
  • F15B2211/505—Pressure control characterised by the type of pressure control means
  • F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
  • F15B2211/50536—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using unloading valves controlling the supply pressure by diverting fluid to the return line
• • 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
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/50—Pressure control
  • F15B2211/52—Pressure control characterised by the type of actuation
  • F15B2211/526—Pressure control characterised by the type of actuation electrically or electronically
• • 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
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/60—Circuit components or control therefor
  • F15B2211/63—Electronic controllers
  • F15B2211/6303—Electronic controllers using input signals
  • F15B2211/6306—Electronic controllers using input signals representing a pressure
  • F15B2211/6313—Electronic controllers using input signals representing a pressure the pressure being a load pressure
• • 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
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/60—Circuit components or control therefor
  • F15B2211/665—Methods of control using electronic components
  • F15B2211/6652—Control of the pressure source, e.g. control of the swash plate angle

Definitions

• the present invention relates to hydraulic control technology, and in particular to a hydraulic control system, and to an excavator including the hydraulic control system. Background technique
• the multi-way valve is an important part of the hydraulic system of the excavator and is the main part of the hydraulic system of the excavator.
• the multi-way valve determines the fuel supply route and fuel supply mode of the hydraulic pump to each actuator, the flow distribution when multiple actuators operate simultaneously, and how to realize the compound action, which determines the operating characteristics of the excavator during operation. Its emergence has made the multi-actuator hydraulic system compact and the tubing is single.
• the load sensing technology can automatically transmit the load pressure and flow information to the variable control mechanism of the sensitive control valve or the hydraulic pump through the signal processing of the controller, and then perform the flow control system or the hydraulic pump variable mechanism according to the load pressure and flow information. Proper adjustment allows the hydraulic pump to supply only the hydraulic oil of the required pressure and flow to the load, thereby reducing the loss of pressure and flow.
• negative flow control hydraulic systems and positive flow control hydraulic systems have been widely used in digging.
• the excavator is on.
• the displacement of the hydraulic pump is reduced by the negative flow rate as the pilot pressure signal increases, and vice versa.
• the negative flow control system is designed to eliminate the throttling loss caused by the three-position six-way reversing valve, and a flow detecting device is provided on the neutral returning oil path of the three-position six-way reversing valve, and the flow signal is obtained;
• the signal controls the hydraulic pump displacement.
• the positive flow control system uses the pilot pressure of the joystick to directly control the hydraulic pump displacement.
• the multi-way valve of the prior art hydraulic excavator is basically a three-position six-way reversing valve structure, and the inlet and outlet port control is realized by a single valve core, and the corresponding relationship between the inlet and outlet ports is designed and processed in the valve core. It has already been determined. In practical applications, it is impossible to control the relationship between the spool displacement and the opening area according to the actual working conditions, so that the flow or pressure through the inlet and outlet ports cannot be independently adjusted; thus, the spool is in the neutral state. When the hydraulic oil returns to the tank through the center of the spool, it also inevitably causes throttling loss, resulting in more energy consumption.
• the object of the present invention is to solve the problem that the structure of the three-position six-way reversing valve in the prior art cannot control the relationship between the displacement of the spool and the opening area according to the actual working condition, and reduce unnecessary energy consumption.
• the invention discloses a hydraulic control system, which comprises a hydraulic actuator.
• One chamber of the hydraulic actuator is connected to the first oil passage, and the other chamber is connected to the second oil passage.
• the hydraulic actuator may specifically be a cylinder, and the small chamber is connected to the first oil. Road, the large cavity is connected to the second oil circuit, where:
• the first oil passage is connected to the first valve, and the valve core of the first valve is controlled by the first electromagnetic proportional valve group to realize switching of the first oil passage and the hydraulic pump or the return tank;
• the second oil passage is connected to the second valve, and the valve core of the second valve is controlled by the second electromagnetic proportional valve group to realize switching of the second oil passage and the hydraulic pump or the return tank;
• a third valve is disposed between the hydraulic pump and the return tank, and a spool of the third valve is configured by a third The magnetic proportional valve group is controlled, the third valve is configured to control conduction between the hydraulic pump and the return tank; and further comprising:
• a controller connecting the first electromagnetic proportional valve group, the second electromagnetic proportional valve group, and the third electromagnetic proportional valve group;
• a hydraulic pump displacement control valve is coupled to the controller, and the hydraulic pump displacement control valve is configured to adjust a hydraulic pump displacement.
• the first valve is a three-position three-way reversing valve.
• the second valve is a three-position three-way reversing valve.
• the controller is provided with a control handle.
• a first pressure sensor is disposed in the first oil passage, the first pressure sensor is configured to detect a first oil circuit oil return pressure, and feed back a pressure signal to the controller;
• a second pressure sensor is disposed on the second oil passage, and the second pressure sensor is configured to detect a second oil passage return pressure and feed back a pressure signal to the controller.
• the above hydraulic control system further includes a pressure relief valve that connects the oil outlet of the hydraulic pump.
• the present invention provides an excavator provided with any of the above-described hydraulic control systems, and the excavator may be a crawler type excavator.
• the invention adopts a double valve core structure with one reversing valve to enter the oil and another reversing valve to return the oil, and independently controls the oil inlet valve core and the oil return valve core of the actuator, thereby enhancing the flexibility of the control function;
• the bypass proportional valve unloads the spool return oil and reduces the hydraulic oil throttling loss. By monitoring the pressure of the return passage, the return pressure is reduced to a minimum, which reduces the system energy loss.
• FIG. 1 is a schematic diagram showing the principle of a hydraulic control system for a multi-way valve of a crawler excavator according to an embodiment of the present invention.
• DETAILED DESCRIPTION OF THE INVENTION The present invention will be further described in detail below in conjunction with the drawings and specific embodiments. The specific embodiments described herein are merely illustrative of the invention and are not intended to limit the scope of the invention.
• the hydraulic control system includes a cylinder 1 having a small chamber (a hydraulic chamber) connected to the first oil passage 11 and a large chamber (the other hydraulic chamber) connected to the second oil passage 12, wherein: the first oil passage 11 is connected to the first The reversing valve 2; the spool of the first reversing valve 2 is controlled by the first electromagnetic proportional valve group (not labeled in FIG.
• the second oil passage 12 is connected to the second reversing valve 3; the spool of the second reversing valve 3 is controlled by the second electromagnetic proportional valve group (not labeled in FIG. 1) to realize the conduction of the second oil passage 12 and the hydraulic pump p or Switching of the return tank 22; a third reversing valve 4 is disposed between the hydraulic pump p and the return tank 22, and the spool of the third reversing valve 4 is controlled by a third electromagnetic proportional valve group (not labeled in FIG.
• the first electromagnetic proportional valve group includes two electromagnetic proportional valves (not labeled in FIG.
• the second electromagnetic proportional valve group includes two electromagnetic The proportional valve is connected to the pilot valve A3 and the pilot valve A4 of the second reversing valve 3, respectively;
• the third electromagnetic proportional valve group includes an electromagnetic proportional valve that is connected to the pilot valve A5 of the third reversing valve 4.
• the electromagnetic proportional valve outputs a secondary pilot pressure according to the current signal of the controller k; the secondary pilot pressure controls the closing of the third switching valve 4 on the one hand, and controls the first switching valve 2 and the second switching on the other hand respectively.
• the displacement of the spool to the valve 3; at the same time, the controller k also jointly adjusts the displacement of the hydraulic pump to finally control the flow of hydraulic oil to the actuator.
• the first reversing valve 2 is a three-position three-way reversing valve.
• the second reversing valve 3 is a three-position three-way reversing valve.
• Two independent three-position three-way reversing valves have a more flexible control than the three-position six-way reversing valve used in the prior art; at the same time, the spool length is reduced by half.
• the third reversing valve 4 is a bypass proportional valve.
• the controller k is provided with a control handle 100; when the control handle 100 is operated, a voltage signal can be sent to the controller k, and the controller k performs a logic calculation on the received voltage signal to the connected electromagnetic ratio.
• the valve emits a current signal of a certain size.
• the crawler excavator multi-way valve hydraulic control system provided by the embodiment of the present invention further includes: a first pressure sensor pi disposed on the first oil passage 11; and a first pressure sensor pi for detecting the first
• the oil return pressure of the oil passage 11 is fed back to the controller k, that is, the first pressure sensor P1 is connected to the controller K
• the second pressure sensor p2 is disposed on the second oil passage 12
• the second pressure sensor P2 is used for detecting the oil return pressure of the second oil passage 12, and feeding back the pressure signal to the controller k, that is, the second pressure sensor P2 is connected to the controller K
• the above pressure signal is logically calculated by the controller k, and Adjusting the opening of the first reversing valve 2 and the second reversing valve 3, so that the actuator can maximize the spool opening without reducing the air pressure, and reduce the oil return pressure. Force, thereby reducing pressure loss and reducing energy consumption.
• the embodiment of the present invention may further include a pressure relief valve 5 connected to the oil outlet of the hydraulic pump p.
• the present invention also provides an excavator provided with any of the above hydraulic control systems, and the excavator may be a crawler excavator.
• the hydraulic control system provided by the invention adopts a reversing valve to enter the oil, and the other reversing valve returns the oil to the double valve core structure, and independently controls the oil inlet valve core and the oil return valve core of the actuator, and enhances the control function.
• the flexibility reduces hydraulic oil throttling losses. Therefore, the present invention has industrial applicability.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Mining & Mineral Resources (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Mechanical Engineering (AREA)
• Fluid-Pressure Circuits (AREA)
• Operation Control Of Excavators (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (2)

Cited By (3)

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Citations (5)

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• 2012
  • 2012-02-23 CN CN2012100417735A patent/CN102587443A/zh active Pending
  • 2012-12-04 WO PCT/CN2012/085797 patent/WO2013123792A1/fr not_active Ceased

Patent Citations (5)

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