CN109441906B - Electro-hydraulic proportional load sensitive pump and pump valve combined control servo system - Google Patents

Electro-hydraulic proportional load sensitive pump and pump valve combined control servo system Download PDF

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Publication number
CN109441906B
CN109441906B CN201811612814.5A CN201811612814A CN109441906B CN 109441906 B CN109441906 B CN 109441906B CN 201811612814 A CN201811612814 A CN 201811612814A CN 109441906 B CN109441906 B CN 109441906B
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pressure
electro
valve
pump
shell
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CN109441906A (en
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张仲良
方沁林
张鑫彬
李勇
滕斌峰
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Shanghai Aerospace Control Technology Institute
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Shanghai Aerospace Control Technology Institute
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    • 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
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
    • F04B1/12—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis
    • F04B1/122—Details or component parts, e.g. valves, sealings or lubrication means
    • 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
    • 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
    • F15B21/08—Servomotor systems incorporating electrically operated control means
    • 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
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
    • F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
    • F15B13/044—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by electrically-controlled means, e.g. solenoids, torque-motors
    • F15B2013/0448—Actuation by solenoid and permanent magnet

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Control Of Positive-Displacement Pumps (AREA)
  • Reciprocating Pumps (AREA)

Abstract

The invention discloses an electro-hydraulic proportional load sensitive pump and a pump valve combined control servo system, wherein the electro-hydraulic proportional load sensitive pump mainly comprises: plug, shell, valve sleeve, valve core, pressure regulating spring, push rod, proportional electromagnet, return spring, swash plate and control piston, and outlet working pressure P of load sensitive pumpSWith external load PLThe constant differential pressure can be adjusted by the proportional electromagnet in the working process, the differential pressure adjustment response is fast, and the dynamic response of the electro-hydraulic proportional load sensitive pump can be greatly improved. And the pump valve combined control servo system has no overflow loss, and can greatly improve the working efficiency while meeting the dynamic characteristic of high frequency noise.

Description

Electro-hydraulic proportional load sensitive pump and pump valve combined control servo system
Technical Field
The invention relates to the field of hydraulic servo control systems, in particular to a combined control servo system of an electro-hydraulic proportional load sensitive pump and a pump valve.
Background
The pump valve combined control servo system is an important branch of power electric transmission, can fully combine the advantages of a pump control servo system and a valve control servo system, abandons the corresponding defects, is an ideal electro-hydraulic servo system, and is a hotspot and focus of international expert research.
The current load-sensitive pumps haveManual and electric control, wherein for manual load-sensitive pumps, the outlet pressure P is manually adjustedSAnd the load pressure PLThe pressure difference value of (2) cannot be remotely and automatically adjusted. When the initial pressure difference is adjusted to a large value, the purpose of energy saving cannot be achieved; when the initial pressure difference is adjusted to the minimum, although the working efficiency of the system can be improved, the dynamic frequency response of the valve control servo system cannot be achieved due to the fact that the dynamic response speed of the load sensitive pump is low.
For an electrically controlled load sensitive pump, a pressure sensor is adopted to collect a load signal, a controller directly drives an electromagnetic proportional valve to output acting force to be compared with outlet pressure of the load sensitive pump, so that constant pressure difference is formed, the constant pressure difference can be adjusted in the working process, but the outlet pressure of the load sensitive pump is large, the acting force is also large, the output acting force of the electromagnetic proportional valve is limited, and good acceleration performance cannot be formed, so that the response speed of adjusting the constant pressure difference value is influenced, namely the dynamic response of the load sensitive pump is influenced.
Disclosure of Invention
The invention aims to provide an electro-hydraulic proportional load sensing pump and pump valve combined control servo system for realizing the outlet working pressure P of a load sensing pumpSInlet pressure P capable of following external load chamberLThe constant differential pressure is kept to change, the constant differential pressure can be adjusted by a proportional electromagnet in the working process, the differential pressure adjustment response is fast, the dynamic response of the electro-hydraulic proportional load sensitive pump can be greatly improved, further, the pump-valve combined control servo system has no overflow loss, the adjustable electro-hydraulic proportional load sensitive pump can keep the minimum differential pressure when the response requirement is low, the energy-saving efficiency can reach the pump control servo system, the adjustable electro-hydraulic proportional load sensitive pump can keep higher differential pressure when the response requirement is high, the dynamic response can reach a valve control servo system, and most servo systems require shorter period of higher dynamic response, so the pump-valve combined control servo system can greatly improve the working efficiency while meeting the high-frequency dynamic characteristics, and is an ideal electro-hydraulic servo system.
In order to achieve the above purpose, the invention is realized by the following technical scheme:
an electro-hydraulic proportional load sensing pump comprising: the valve comprises a plug 1, a shell 4, a valve sleeve 6, a valve core 8, a pressure regulating spring 10, a push rod 11 and a proportional electromagnet 12; the valve sleeve 6 is positioned in the housing 4, is close to the first end of the housing, and is in interference fit with the inner side wall of the housing 4, and the valve core 8 is positioned in the valve sleeve 6; the pressure regulating spring 10 and the push rod 11 are sequentially arranged in the shell 4 and close to the second end of the shell 4, and the pressure regulating spring 10 is positioned between the valve core 8 and the push rod 11; the proportional electromagnet 12 is arranged at the second end of the shell 4 and fixedly connected with the push rod 11, the proportional electromagnet 12 is further coated with a shell, the shell is connected with the end part of the second end of the shell 4, and the plug 1 is connected with the end part of the first end of the shell 4 and is used for being matched with the shell to seal the valve sleeve 6, the valve core 8, the pressure regulating spring 10 and the push rod 11 in the shell 4; the electro-hydraulic proportional load-sensitive pump further comprises a high-pressure chamber 17, a low-pressure chamber 16 and a first control chamber 18 which are positioned outside the shell 4; the end surface of the valve sleeve 6 close to the first end of the shell 4 is provided with symmetrical front windows 2, so that the outlet pressure Ps of the load-sensitive pump flows into the first end of the valve core 8; an oil source window 3, a control window 5 and an oil return window 7 are arranged on the valve sleeve 6 at intervals, and a first through hole, a second through hole and a third through hole are respectively formed in the positions, corresponding to the oil source window 3, the control window 5 and the oil return window 7, of the shell 4; the oil source window 3 is communicated with the high-pressure cavity 17 through the first through hole, the control window 5 is communicated with the first control cavity 18 through the second through hole, and the oil return window 7 is communicated with the low-pressure cavity 16 through the third through hole; the shell 4 is further provided with an external load connecting port, an external load is communicated with an external load cavity formed by the valve sleeve 6, the second end close to the valve core 8, the shell 4 and the shell of the proportional electromagnet 12 through the external load connecting port, and the inlet pressure of the external load cavity is PL(ii) a The valve core 8 is provided with a first convex shoulder structure which is respectively matched with the oil source window 3, the control window 5 and the oil return window 7, and the first convex shoulder structure controls the oil source window 3, the control window 5 and the oil return window 7Opening and closing an oil source window 3, a control window 5 and an oil return window 7; the proportional electromagnet 12 drives the push rod 11 to adjust the compression amount of the pressure regulating spring 10 so as to drive the valve core 8 to move back and forth along the central axis direction of the shell 4 until the outlet pressure Ps of the load sensitive pump is equal to the inlet pressure P of the outer load cavityLAnd a constant pressure difference, such that the first shoulder construction closes the control window 5.
Furthermore, a plurality of second shoulder structures are arranged on the outside of the valve sleeve 6 at intervals, an oil source cavity, a second control cavity and an oil return cavity are formed in the gap of the second shoulder structures and the inner side wall of the shell 4 respectively, the oil source window 3 is communicated with the oil source cavity, the control window 5 is communicated with the second control cavity, and the oil return window 7 is communicated with the oil return cavity.
Furthermore, the number of each oil source window 3, each control window 5 and each oil return window 7 is one or more.
Further, the electro-hydraulic proportional load sensing pump further comprises a swash plate 14 and a return spring 13 for controlling the rotation of the swash plate 14 and further controlling the pressure in the high pressure chamber 17, the low pressure chamber 16 and the first control chamber 18.
Further, the swash plate 14 is provided with a first adjusting section, a second adjusting section and a third adjusting section for respectively adjusting the cavity volumes of the low-pressure cavity 16, the high-pressure cavity 17 and the first control cavity 18, and the first adjusting section and the second adjusting section are rotatably installed on the third adjusting section.
Furthermore, the electro-hydraulic proportional load sensitive pump is also provided with a control piston 15 which is sleeved on the first control cavity 18 and is connected with the third adjusting section; the control piston 15 moves back and forth so that the chamber volume of the first control chamber 18 increases or decreases, thereby compressing or expanding the return spring 13.
Further, when the outlet pressure P of the electro-hydraulic proportional load sensitive pump is higher than the pump outlet pressure PSInlet pressure P to said outer load chamberLWhen a constant differential pressure is maintained, the valve slide 8 is in the rest position, i.e. the first shoulder of the valve slide 8 is exactly closedIn the control window 5, the swash plate 14 keeps a preset inclination angle, and the constant differential pressure value is determined by the pressure regulating spring 10;
when the outlet pressure P of the electro-hydraulic proportional load sensitive pumpSGreater than the inlet pressure P of the outer load chamberLAnd when the pressure difference value is the sum of the constant pressure difference values, the valve core 8 moves towards the second end of the shell 4, the oil source window 3 is communicated with the control window 5, and the working pressure P of the first control cavity 18 iskLifting and pushing the control piston 15 to move, so that the third adjusting section of the swash plate 14 swings clockwise, the inclination angle of the swash plate 14 is smaller than the preset inclination angle, and the outlet pressure P of the electro-hydraulic proportional load sensing pumpSDropping until the pump outlet pressure P of the electro-hydraulic proportional load sensing pumpSEqual to the inlet pressure P of the outer load chamberLIn addition to the constant differential pressure, the valve slide 8 returns to the rest position, the first shoulder of the valve slide 8 closes the control window 5 again, and the swash plate 14 returns to the predetermined inclination. When the outlet pressure P of the electro-hydraulic proportional load sensitive pumpSLess than the inlet pressure P of the outer load chamberLAnd when the pressure difference value is the sum of the constant pressure difference values, the valve core 8 moves towards the first end of the shell 4, the control window 5 is communicated with the oil return window 7, and the working pressure P of the first control cavity 18kLowering, pushing the control piston 15 to move, the return spring 13 pushing the swash plate 14 to swing anticlockwise, the inclination angle of the swash plate 14 increasing, and the outlet pressure P of the electro-hydraulic proportional load sensitive pumpSRising until the electro-hydraulic proportional load sensing pump outlet pressure PSEqual to the inlet pressure P of the outer load chamberLWhen the valve core 8 is restored to the balance position in the sum of the constant pressure difference, and the first shoulder structure of the valve core 8 closes the control window 5 again, the swash plate 14 is restored to the position of the preset inclination angle.
Further, the pressure regulating spring 10 is used for regulating the constant pressure difference;
when the voltage applied to the proportional electromagnet 12 increases, the iron core of the proportional electromagnet 12 moves towards the first end of the shell, and the pre-compression amount of the pressure regulating spring 10 increases, so that the constant differential pressure value increases; when the voltage applied to the proportional electromagnet 12 is reduced, the iron core of the proportional electromagnet 12 moves towards the second end of the shell, and the pre-compression amount of the pressure regulating spring 10 is reduced, so that the constant differential pressure value is reduced; when the input voltage of the proportional electromagnet 12 is not changed, the precompression amount of the pressure regulating spring 10 is not changed, and the constant differential pressure value is not changed.
In another aspect, a pump-valve combined control servo system includes: the control system comprises a motor 100, an electro-hydraulic proportional load-sensitive pump as described above, a coarse filter 400, an overflow valve 600, an oil tank 700, a check valve 800, a fine filter 900, an electro-hydraulic servo valve 101, a shuttle valve 110, a hydraulic cylinder 120, a position sensor 130 and a controller 140; the motor 100 is used for driving the electro-hydraulic proportional load sensitive pump; the outlet of the electro-hydraulic proportional load sensitive pump is communicated with the oil inlet of the electro-hydraulic servo valve 101 through a one-way valve 800 and a fine filter 900; the inlet of the electro-hydraulic proportional load sensing pump is communicated with the outlet of the oil tank 700; the proportional electromagnet 12 of the electro-hydraulic proportional load sensitive pump is connected with the controller 140; an oil return port of the electro-hydraulic servo valve 101 is communicated with an inlet of the oil tank 700; the first control port and the second control port of the electro-hydraulic servo valve 101 are respectively communicated with the first chamber and the second chamber of the hydraulic cylinder 120; the first and second comparison input ports of the shuttle valve 110 are in communication with the first and second chambers of the hydraulic cylinder 120, respectively; the pressure signal output port of the shuttle valve 110 is connected with the outer load cavity of the electro-hydraulic proportional load sensitive pump; the outlet of the coarse filter 400 is communicated with the inlet of the electro-hydraulic proportional load sensitive pump through a first hydraulic flow passage; the inlet of the coarse filter 400 is communicated with the outlet of the oil tank 700 through a second hydraulic flow passage; the inlet of the overflow valve 600 is communicated with the outlet of the electro-hydraulic proportional load sensitive pump through a third hydraulic flow channel; the outlet of the overflow valve 600 is communicated with the inlet of the oil tank 700 through a fourth hydraulic flow passage; the position sensor 130 is used for acquiring the displacement of the piston rod of the hydraulic cylinder 120; the position sensor 130 is electrically connected to the controller 140; the output end of the controller 140 is electrically connected to the control end of the electro-hydraulic servo valve 101 for controlling the flow rate of the electro-hydraulic servo valve 101.
Further, when the response speed required by the pump and valve combined control servo system is low, the proportional electromagnet 12 of the electro-hydraulic proportional load sensing pump is adjusted to reduce the precompression amount of the pressure regulating spring 10, so that the constant pressure difference reaches a first preset value; when the response speed required by the pump and valve combined control servo system is high, the proportional electromagnet 12 of the electro-hydraulic proportional load sensing pump is adjusted to increase the pre-compression amount of the pressure regulating spring 10, so that the constant pressure difference reaches a second preset value, and the first preset value is smaller than the second preset value.
The invention has the following technical effects:
the invention can ensure that the outlet working pressure P of the load sensitive pumpSInlet pressure P capable of following external load chamberLThe constant differential pressure is kept to change, the constant differential pressure can be adjusted by a proportional electromagnet in the working process, the differential pressure adjustment response is fast, the dynamic response of the electro-hydraulic proportional load sensitive pump can be greatly improved, further, the pump-valve combined control servo system has no overflow loss, the adjustable electro-hydraulic proportional load sensitive pump can keep the minimum differential pressure when the response requirement is low, the energy-saving efficiency can reach the pump control servo system, the adjustable electro-hydraulic proportional load sensitive pump can keep higher differential pressure when the response requirement is high, the dynamic response can reach a valve control servo system, and most servo systems require shorter period of higher dynamic response, so the pump-valve combined control servo system can greatly improve the working efficiency while meeting the high-frequency dynamic characteristics, and is an ideal electro-hydraulic servo system.
Drawings
FIG. 1 is a schematic cross-sectional view of the main structure of an electro-hydraulic proportional load sensing pump according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of a pump-valve combined control servo system according to an embodiment of the present invention.
The reference numbers illustrate: the device comprises a plug 1, a front window 2, an oil source window 3, a shell 4, a control window 5, a valve sleeve 6, an oil return window 7, a valve core 8, a load window 9, a pressure regulating spring 10, a push rod 11, a proportional electromagnet 12, a return spring 13, a swash plate 14, a control piston 15, a low-pressure cavity 16, a high-pressure cavity 17 and a first control cavity 18.
Detailed Description
The present invention will now be further described by way of the following detailed description of a preferred embodiment thereof, taken in conjunction with the accompanying drawings.
As shown in fig. 1, the present embodiment provides an electro-hydraulic proportional load sensing pump, including: the device comprises a plug 1, a shell 4, a valve sleeve 6, a valve core 8, a pressure regulating spring 10, a push rod 11, a proportional electromagnet 12, a return spring 13, a swash plate 14 and a control piston 15; the valve sleeve 6 is positioned in the housing 4, is close to the first end of the housing, and is in interference fit with the inner side wall of the housing 4, and the valve core 8 is positioned in the valve sleeve 6; the pressure regulating spring 10 and the push rod 11 are sequentially arranged in the shell 4 and close to the second end of the shell 4, and the pressure regulating spring 10 is positioned between the valve core 8 and the push rod 11; the proportional electromagnet 12 is arranged at the second end of the shell 4 and fixedly connected with the push rod 11, the proportional electromagnet 12 is further coated with a shell, the shell is connected with the end part of the second end of the shell 4, and the plug 1 is connected with the end part of the first end of the shell 4 and is used for being matched with the shell to seal the valve sleeve 6, the valve core 8, the pressure regulating spring 10 and the push rod 11 in the shell 4; the electro-hydraulic proportional load-sensitive pump further comprises a high-pressure chamber 17, a low-pressure chamber 16 and a first control chamber 18 which are positioned outside the shell 4; the end surface of the valve sleeve 6 close to the first end of the shell 4 is provided with symmetrical front windows 2, so that the outlet pressure Ps of the load-sensitive pump flows into the first end of the valve core 8; an oil source window 3, a control window 5 and an oil return window 7 are arranged on the valve sleeve 6 at intervals, and a first through hole, a second through hole and a third through hole are respectively formed in the positions, corresponding to the oil source window 3, the control window 5 and the oil return window 7, of the shell 4; the oil source window 3 is communicated with the high-pressure cavity 17 through the first through hole, the control window 5 is communicated with the first control cavity 18 through the second through hole, and the oil return window 7 is communicated with the low-pressure cavity 16 through the third through hole; the housing 4 is further provided with an external load connection port through which an external load passes through the valve housing 6 and the second end adjacent to the valve core 8 and the housing 4 toAnd an outer load cavity formed by the shell of the proportional electromagnet 12, wherein the inlet pressure of the outer load cavity is PL(ii) a The valve core 8 is provided with a first convex shoulder structure which is respectively matched with the oil source window 3, the control window 5 and the oil return window 7, and the first convex shoulder structure controls the opening and closing of the oil source window 3, the control window 5 and the oil return window 7; the proportional electromagnet 12 drives the push rod 11 to adjust the compression amount of the pressure regulating spring 10 so as to drive the valve core 8 to move back and forth along the central axis direction of the shell 4 until the outlet pressure Ps of the load sensitive pump is equal to the inlet pressure P of the outer load cavityLAnd a constant pressure difference, such that the first shoulder construction closes the control window 5.
A plurality of second shoulder structures are arranged on the outer portion of the valve sleeve 6 at intervals, an oil source cavity, a second control cavity and an oil return cavity are formed in the gap of the second shoulder structures and the inner side wall of the shell 4 respectively, the oil source window 3 is communicated with the oil source cavity, the control window 5 is communicated with the second control cavity, and the oil return window 7 is communicated with the oil return cavity.
The number of each oil source window 3, each control window 5 and each oil return window 7 is one or more.
The electro-hydraulic proportional load sensing pump further comprises a swash plate 14, and a return spring 13 for controlling the rotation of the swash plate 14 and thus the pressure in the chambers of the high pressure chamber 17, the low pressure chamber 16 and the first control chamber 18.
The swash plate 14 is provided with a first adjusting section, a second adjusting section and a third adjusting section which are used for respectively adjusting the cavity volumes of the low-pressure cavity 16, the high-pressure cavity 17 and the first control cavity 18, and the first adjusting section and the second adjusting section are rotatably arranged on the third adjusting section.
The electro-hydraulic proportional load sensitive pump is also provided with a control piston 15 which is sleeved on the first control cavity 18 and is connected with the third adjusting section; the control piston 15 moves back and forth so that the chamber volume of the first control chamber 18 increases or decreases, thereby compressing or expanding the return spring 13.
When the outlet pressure of the electro-hydraulic proportional load sensitive pumpForce PSInlet pressure P to said outer load chamberLWhen a constant differential pressure is maintained, the valve core 8 is in a balanced position, that is, when the first shoulder structure of the valve core 8 just closes the control window 5, the swash plate 14 maintains a preset inclination angle, and the constant differential pressure value is determined by the pressure regulating spring 10.
When the outlet pressure P of the electro-hydraulic proportional load sensitive pumpSGreater than the inlet pressure P of the outer load chamberLAnd when the pressure difference value is the sum of the constant pressure difference values, the valve core 8 moves towards the second end of the shell 4, the oil source window 3 is communicated with the control window 5, and the working pressure P of the first control cavity 18 iskLifting and pushing the control piston 15 to move, so that the third adjusting section of the swash plate 14 swings clockwise, the inclination angle of the swash plate 14 is smaller than the preset inclination angle, and the outlet pressure P of the electro-hydraulic proportional load sensing pumpSDropping until the pump outlet pressure P of the electro-hydraulic proportional load sensing pumpSEqual to the inlet pressure P of the outer load chamberLIn addition to the constant differential pressure, the valve slide 8 returns to the rest position, the first shoulder of the valve slide 8 closes the control window 5 again, and the swash plate 14 returns to the predetermined inclination. When the outlet pressure P of the electro-hydraulic proportional load sensitive pumpSLess than the inlet pressure P of the outer load chamberLAnd when the pressure difference value is the sum of the constant pressure difference values, the valve core 8 moves towards the first end of the shell 4, the control window 5 is communicated with the oil return window 7, and the working pressure P of the first control cavity 18kLowering, pushing the control piston 15 to move, the return spring 13 pushing the swash plate 14 to swing anticlockwise, the inclination angle of the swash plate 14 increasing, and the outlet pressure P of the electro-hydraulic proportional load sensitive pumpSRising until the electro-hydraulic proportional load sensing pump outlet pressure PSEqual to the inlet pressure P of the outer load chamberLWhen the valve core 8 is restored to the balance position in the sum of the constant pressure difference, and the first shoulder structure of the valve core 8 closes the control window 5 again, the swash plate 14 is restored to the position of the preset inclination angle.
The pressure regulating spring 10 is used for regulating the constant pressure difference; when the voltage applied to the proportional electromagnet 12 increases, the iron core of the proportional electromagnet 12 moves towards the first end of the shell, and the pre-compression amount of the pressure regulating spring 10 increases, so that the constant differential pressure value increases; when the voltage applied to the proportional electromagnet 12 is reduced, the iron core of the proportional electromagnet 12 moves towards the second end of the shell, and the pre-compression amount of the pressure regulating spring 10 is reduced, so that the constant differential pressure value is reduced; when the input voltage of the proportional electromagnet 12 is not changed, the precompression amount of the pressure regulating spring 10 is not changed, and the constant differential pressure value is not changed.
The outlet pressure of the low pressure chamber 16 is PtThe outlet pressure of the high pressure cavity 17 is Ps (electro-hydraulic proportional load sensing pump outlet pressure P)S) And the outlet pressure of the first control chamber 18 is PkThe inlet pressure of the outer load chamber is PL(external load pressure P)L)。
In this embodiment, the left end of fig. 1 is defined as a first end, and the right end of fig. 1 is defined as a second end.
The working principle of the embodiment is as follows: when the outlet pressure P of the electro-hydraulic proportional load sensing pumpSWith the load pressure PLWhen a constant differential pressure is maintained, the valve element 8 is in a balanced position, i.e. when the first shoulder structure of the valve element 8 just closes the control window 5, the swash plate 14 maintains a predetermined inclination angle, and the constant differential pressure value is determined by the pressure regulating spring 10. When the outlet pressure P of the electro-hydraulic proportional load sensitive pumpSGreater than the external load pressure PLWhen the sum of the constant pressure difference values is obtained, the valve core 8 moves rightwards, the oil source window 3 is communicated with the control window 5, the working pressure of the first control cavity 18 is increased to push the swash plate 14 to swing clockwise, the inclination angle of the swash plate 14 is smaller than the preset inclination angle, the outlet oil flow of the electro-hydraulic proportional load sensitive pump is reduced, namely the outlet pressure P is reducedSDecreases until the outlet pressure PSAnd the external load pressure PLWhen the sum of the constant pressure differences is equal, the valve core 8 returns to the equilibrium position, the first shoulder structure of the valve core 8 just closes the control window 5, and the swash plate 14 returns to the preset inclination angle. In the same way, when the outlet pressure P of the electro-hydraulic proportional load sensitive pump is higher than the outlet pressure P of the electro-hydraulic proportional load sensitive pumpSLess than the external load pressure PLWith constant pressureWhen the difference is summed, the valve core 8 moves leftwards, the control window 5 is communicated with the oil return window 7, the working pressure of the first control cavity 18 is reduced, the return spring 13 pushes the swash plate 14 to swing anticlockwise, the inclination angle of the swash plate 14 is increased, the oil flow at the outlet of the electro-hydraulic proportional load sensitive pump is increased, namely the outlet pressure P is increasedSUp to the outlet pressure PSWith external load pressure PLWhen the sum of the constant pressure differences is equal, the valve core 8 returns to the balance position, and when the first shoulder structure of the valve core 8 just closes the control window 5, the swash plate 14 returns to the position of the preset inclination angle.
Therefore, when the precompression quantity of the pressure regulating spring 10 is not changed, namely the voltage of the proportional electromagnet 12 is not changed, the pump outlet pressure P of the novel electric proportional load sensitive pump is not changedSWith the load pressure PLA constant pressure differential is maintained throughout. When the voltage applied to the proportional electromagnet 12 is increased, the iron core of the proportional electromagnet 12 moves leftwards, the precompression amount of the pressure regulating spring 10 is increased, the constant differential pressure value is increased, namely the same load pressure PL needs larger pump outlet pressure PSTherefore, the throttling loss of the system is larger, the working efficiency is reduced, when the voltage applied to the proportional electromagnet 12 is reduced, the iron core of the proportional electromagnet 12 moves rightwards, the precompression quantity of the pressure regulating spring 10 is reduced, and the constant differential pressure value is reduced, namely the same load pressure P is reducedLA smaller pump outlet pressure P is requiredSTherefore, the system throttling loss is reduced, and the working efficiency is improved.
Based on the above embodiment, as shown in fig. 2, the present invention further discloses a pump-valve combined control servo system, including: the control system comprises a motor 100, an electro-hydraulic proportional load-sensitive pump as described above, a coarse filter 400, an overflow valve 600, an oil tank 700, a check valve 800, a fine filter 900, an electro-hydraulic servo valve 101, a shuttle valve 110, a hydraulic cylinder 120, a position sensor 130 and a controller 140; the motor 100 is used for driving the electro-hydraulic proportional load sensitive pump; the outlet of the electro-hydraulic proportional load sensitive pump is communicated with the oil inlet of the electro-hydraulic servo valve 101 through a one-way valve 800 and a fine filter 900; the inlet of the electro-hydraulic proportional load sensing pump is communicated with the outlet of the oil tank 700; the proportional electromagnet 12 of the electro-hydraulic proportional load sensitive pump is connected with the controller 140; an oil return port of the electro-hydraulic servo valve 101 is communicated with an inlet of the oil tank 700; the first control port and the second control port of the electro-hydraulic servo valve 101 are respectively communicated with the first chamber and the second chamber of the hydraulic cylinder 120; the first and second comparison input ports of the shuttle valve 110 are in communication with the first and second chambers of the hydraulic cylinder 120, respectively; the pressure signal output port of the shuttle valve 110 is connected with the outer load cavity of the electro-hydraulic proportional load sensitive pump; the outlet of the coarse filter 400 is communicated with the inlet of the electro-hydraulic proportional load sensitive pump through a first hydraulic flow passage; the inlet of the coarse filter 400 is communicated with the outlet of the oil tank 700 through a second hydraulic flow passage; the inlet of the overflow valve 600 is communicated with the outlet of the electro-hydraulic proportional load sensitive pump through a third hydraulic flow channel; the outlet of the overflow valve 600 is communicated with the inlet of the oil tank 700 through a fourth hydraulic flow passage; the position sensor 130 is used for acquiring the displacement of the piston rod of the hydraulic cylinder 120; the position sensor 130 is electrically connected to the controller 140; the output end of the controller 140 is electrically connected to the control end of the electro-hydraulic servo valve 101 for controlling the flow rate of the electro-hydraulic servo valve 101.
When the response speed required by the pump and valve combined control servo system is low, the proportional electromagnet 12 of the electro-hydraulic proportional load sensitive pump is adjusted to reduce the precompression amount of the pressure regulating spring 10, so that the constant pressure difference reaches a first preset value (the minimum value of the constant pressure difference), at the moment, the pressure loss of the pump and valve combined control servo system reaches the minimum value, and although the dynamic response of the pump and valve combined control servo system is slow, the working efficiency of the pump and valve combined control servo system is close to that of the pump control servo system.
When the response speed required by the pump and valve combined control servo system is high, the proportional electromagnet 12 of the electro-hydraulic proportional load sensing pump is adjusted to increase the pre-compression amount of the pressure regulating spring 10, so that the constant pressure difference reaches a second preset value, and the first preset value is smaller than the second preset value. When the constant differential pressure is increased to a certain value, at the moment, although the pressure loss of the pump-valve combined control servo system is increased, the dynamic characteristic of the pump-valve combined control servo system can completely reach the dynamic frequency response of the valve control servo system, and most servo systems require shorter periods with higher frequency response, so that the overall working efficiency of the pump-valve combined control servo system is very high, and the dynamic frequency response can reach the level of the valve control servo system when in need, therefore, the pump-valve combined control servo system is an ideal pump-valve combined control servo system.
While the present invention has been described in detail with reference to the preferred embodiments, it should be understood that the above description should not be taken as limiting the invention. Various modifications and alterations to this invention will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, the scope of the invention should be determined from the following claims.

Claims (10)

1. An electro-hydraulic proportional load sensing pump, comprising: the valve comprises a plug (1), a shell (4), a valve sleeve (6), a valve core (8), a pressure regulating spring (10), a push rod (11) and a proportional electromagnet (12); the valve sleeve (6) is positioned in the shell (4), is close to the first end of the shell (4) and is in interference fit with the inner side wall of the shell (4), and the valve core (8) is positioned in the valve sleeve (6);
the pressure regulating spring (10) and the push rod (11) are sequentially arranged in the shell (4) and close to the second end of the shell (4), and the pressure regulating spring (10) is positioned between the valve core (8) and the push rod (11);
the proportional electromagnet (12) is arranged at the second end of the shell (4) and fixedly connected with the push rod (11), the proportional electromagnet (12) is further coated with a shell, the shell is connected with the end of the second end of the shell (4), the plug (1) is connected with the end of the first end of the shell (4) and is used for being matched with the shell to seal the valve sleeve (6), the valve core (8), the pressure regulating spring (10) and the push rod (11) in the shell (4);
the electro-hydraulic proportional load-sensitive pump further comprises a high-pressure cavity (17), a low-pressure cavity (16) and a first control cavity (18) which are positioned outside the shell (4);
the end surface of the valve sleeve (6) close to the first end of the shell (4) is provided with symmetrical front windows (2), so that the outlet pressure Ps of the load-sensitive pump flows into the end part of the valve core (8) close to the first end of the shell (4);
an oil source window (3), a control window (5) and an oil return window (7) are arranged on the valve sleeve (6) at intervals, and a first through hole, a second through hole and a third through hole are respectively formed in the positions, corresponding to the oil source window (3), the control window (5) and the oil return window (7), on the shell (4);
the oil source window (3) is communicated with the high-pressure cavity (17) through the first through hole, the control window (5) is communicated with the first control cavity (18) through the second through hole, and the oil return window (7) is communicated with the low-pressure cavity (16) through the third through hole;
the shell (4) is also provided with an external load connecting port, an external load is communicated with an external load cavity formed by the valve sleeve (6), the second end close to the valve core (8), the shell (4) and the shell of the proportional electromagnet (12) through the external load connecting port, and the inlet pressure of the external load cavity is PL；
A first convex shoulder structure which is respectively matched with the oil source window (3), the control window (5) and the oil return window (7) is arranged on the valve core (8), and the first convex shoulder structure controls the opening and closing of the oil source window (3), the control window (5) and the oil return window (7);
the proportional electromagnet (12) drives the push rod (11) to adjust the compression amount of the pressure adjusting spring (10) so as to drive the valve core (8) to move back and forth along the central axis direction of the shell (4) until the outlet pressure Ps of the load sensitive pump is equal to the inlet pressure P of the outer load cavityLAnd a constant pressure difference, such that the first shoulder construction closes the control window (5).
2. The electro-hydraulic proportional load sensing pump of claim 1,
the valve sleeve is characterized in that a plurality of second convex shoulder structures are arranged on the outer portion of the valve sleeve (6) at intervals, an oil source cavity, a second control cavity and an oil return cavity are formed in the inner side wall of the shell (4) respectively through gaps of the second convex shoulder structures, the oil source window (3) is communicated with the oil source cavity, the control window (5) is communicated with the second control cavity, and the oil return window (7) is communicated with the oil return cavity.
3. The electro-hydraulic proportional load sensing pump according to claim 1 or 2, wherein the number of each of the oil source window (3), the control window (5) and the oil return window (7) is one or more.
4. Electro-hydraulic proportional load sensing pump according to claim 3, characterized in that it further comprises a swash plate (14) and a return spring (13) for controlling the rotation of said swash plate (14) and thus the pressure in the chambers of said high pressure chamber (17), low pressure chamber (16) and first control chamber (18).
5. Electro-hydraulic proportional load sensing pump according to claim 4, wherein said swash plate (14) is provided with a first, a second and a third adjustment section for adjusting the cavity volumes of said low pressure chamber (16), high pressure chamber (17) and first control chamber (18), respectively, said first and second adjustment sections being rotatably mounted on said third adjustment section.
6. The electro-hydraulic proportional load sensing pump according to claim 5, further comprising a control piston (15) sleeved on the first control chamber (18) and connected to the third adjusting section; the control piston (15) moves in a reciprocating manner, so that the cavity volume of the first control cavity (18) is increased or reduced, and the return spring (13) is compressed or expanded.
7. The electro-hydraulic proportional load sensing pump of claim 6,
when the outlet pressure P of the electro-hydraulic proportional load sensitive pumpSInlet pressure P to said outer load chamberLWhen a constant differential pressure is kept, the valve core (8) is in a balance position, namely when the first shoulder structure of the valve core (8) just closes the control window (5), the swash plate (14) keeps a preset inclination angle, and the constant differential pressure value is determined by the pressure regulating spring (10);
when the outlet pressure P of the electro-hydraulic proportional load sensitive pumpSGreater than the inlet pressure P of the outer load chamberLWhen the pressure difference value is the sum of the constant pressure difference value, the valve core (8) moves towards the second end of the shell (4), the oil source window (3) is communicated with the control window (5), and the working pressure P of the first control cavity (18)kLifting, pushing a control piston (15) to move, so that a third adjusting section of the swash plate (14) swings clockwise, the inclination angle of the swash plate (14) is smaller than the preset inclination angle, and the outlet pressure P of the electro-hydraulic proportional load sensitive pumpSDropping until the pump outlet pressure P of the electro-hydraulic proportional load sensing pumpSEqual to the inlet pressure P of the outer load chamberLWhen the constant differential pressure is added, the valve core (8) is restored to the balance position, the first shoulder structure of the valve core (8) closes the control window (5) again, and the swash plate (14) is restored to the preset inclination angle;
when the outlet pressure P of the electro-hydraulic proportional load sensitive pumpSLess than the inlet pressure P of the outer load chamberLWhen the pressure difference value is the sum of the constant pressure difference values, the valve core (8) moves towards the first end of the shell (4), the control window (5) is communicated with the oil return window (7), and the working pressure P of the first control cavity (18)kLowering, pushing a control piston (15) to move, pushing the swash plate (14) to swing anticlockwise by the return spring (13), increasing the inclination angle of the swash plate (14), and increasing the outlet pressure P of the electro-hydraulic proportional load sensitive pumpSRising until the electro-hydraulic proportional load sensing pump outlet pressure PSEqual to the inlet pressure P of the outer load chamberLAnd when the valve core (8) is restored to the balance position and the first shoulder structure of the valve core (8) closes the control window (5) again, the swash plate (14) is restored to the position of the preset inclination angle.
8. The electro-hydraulic proportional load sensing pump of claim 7, wherein the pressure regulating spring (10) is used to regulate the constant pressure differential;
when the voltage applied to the proportional electromagnet (12) is increased, the iron core of the proportional electromagnet (12) moves towards the first end of the shell, and the pre-compression amount of the pressure regulating spring (10) is increased, so that the constant differential pressure value is increased; when the voltage applied to the proportional electromagnet (12) is reduced, the iron core of the proportional electromagnet (12) moves towards the second end of the shell, and the pre-compression amount of the pressure regulating spring (10) is reduced, so that the constant differential pressure value is reduced; when the input voltage of the proportional electromagnet (12) is unchanged, the precompression quantity of the pressure regulating spring (10) is unchanged, and the constant differential pressure value is unchanged.
9. A pump-valve joint control servo system, comprising: the electro-hydraulic proportional load-sensitive pump comprises a motor (100), an electro-hydraulic proportional load-sensitive pump according to any one of claims 1-8, a coarse filter (400), an overflow valve (600), an oil tank (700), a check valve (800), a fine filter (900), an electro-hydraulic servo valve (101), a shuttle valve (110), a hydraulic cylinder (120), a position sensor (130) and a controller (140);
the motor (100) is used for driving the electro-hydraulic proportional load sensitive pump;
the outlet of the electro-hydraulic proportional load sensitive pump is communicated with the oil inlet of the electro-hydraulic servo valve (101) through a one-way valve (800) and a fine filter (900);
the inlet of the electro-hydraulic proportional load sensing pump is communicated with the outlet of the oil tank (700);
the proportional electromagnet (12) of the electro-hydraulic proportional load sensitive pump is connected with the controller (140); an oil return port of the electro-hydraulic servo valve (101) is communicated with an inlet of the oil tank (700);
the first control port and the second control port of the electro-hydraulic servo valve (101) are respectively communicated with the first chamber and the second chamber of the hydraulic cylinder (120);
the first comparison input port and the second comparison input port of the shuttle valve (110) are respectively communicated with the first chamber and the second chamber of the hydraulic cylinder (120);
a pressure signal output port of the shuttle valve (110) is connected with an outer load cavity of the electro-hydraulic proportional load sensitive pump;
the outlet of the coarse filter (400) is communicated with the inlet of the electro-hydraulic proportional load sensitive pump through a first hydraulic flow passage;
the inlet of the coarse filter (400) is communicated with the outlet of the oil tank (700) through a second hydraulic flow passage; the inlet of the overflow valve (600) is communicated with the outlet of the electro-hydraulic proportional load sensitive pump through a third hydraulic flow channel;
the outlet of the overflow valve (600) is communicated with the inlet of the oil tank (700) through a fourth hydraulic flow passage; the position sensor (130) is used for acquiring the displacement of a piston rod of the hydraulic cylinder (120);
the position sensor (130) is electrically connected with the controller (140);
the output end of the controller (140) is electrically connected with the control end of the electro-hydraulic servo valve (101) and is used for controlling the flow of the electro-hydraulic servo valve (101).
10. Pump-valve joint control servo system according to claim 9,
when the response speed required by the pump valve combined control servo system is low, the proportional electromagnet (12) of the electro-hydraulic proportional load sensitive pump is adjusted to reduce the precompression amount of the pressure regulating spring (10), so that the constant pressure difference reaches a first preset value; when the response speed required by the pump and valve combined control servo system is high, the proportional electromagnet (12) of the electro-hydraulic proportional load sensitive pump is adjusted to increase the pre-compression amount of the pressure regulating spring (10), so that the constant pressure difference reaches a second preset value, and the first preset value is smaller than the second preset value.
CN201811612814.5A 2018-12-27 2018-12-27 Electro-hydraulic proportional load sensitive pump and pump valve combined control servo system Active CN109441906B (en)

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CN110285048B (en) * 2019-07-19 2024-03-19 宁波克泰液压有限公司 Screw thread plug-in type speed sensitive load control valve
CN111486147B (en) * 2020-06-03 2024-04-26 江苏科迈液压控制系统有限公司 Load-sensitive proportional multi-way valve

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2513918A1 (en) * 1974-03-28 1975-10-09 Gen Signal Corp PRESSURE COMPENSATED HYDRAULIC DRIVE DEVICE WITH A MULTIPLE WORK FUNCTIONS
DE2854593A1 (en) * 1978-12-18 1980-07-03 Nordhydraulic Ab Hydraulic circuit with variable pump and hydraulic motor - has pump output controlled by pressure in pump and motor for multi way valve actuation
US5085051A (en) * 1988-06-29 1992-02-04 Hitachi Construction Machinery Co., Ltd. Displacement of variable displacement pump controlled by load sensing device having two settings for low and high speed operation of an actuator
CN104728196A (en) * 2015-03-18 2015-06-24 北京航空航天大学 Load-sensitive electro-hydrostatic actuator
CN104728193A (en) * 2015-03-18 2015-06-24 北京航空航天大学 Load-sensitive electro-hydrostatic actuator
CN104747515A (en) * 2015-03-18 2015-07-01 北京航空航天大学 Electro-hydrostatic actuator sensitive to load
CN104863911A (en) * 2015-05-26 2015-08-26 天津捷强动力装备有限公司 Hydraulic circuit used for controlling no-load rotation speed of hydraulic motor to be stable through load-sensitive variable pump
CN105351278A (en) * 2015-12-10 2016-02-24 上海新跃仪表厂 Novel compound electro-hydraulic servo control system
CN102562694B (en) * 2010-10-19 2016-06-01 林德液压两合公司 Load-sensing regulating type hydrostatic drive system

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2513918A1 (en) * 1974-03-28 1975-10-09 Gen Signal Corp PRESSURE COMPENSATED HYDRAULIC DRIVE DEVICE WITH A MULTIPLE WORK FUNCTIONS
DE2854593A1 (en) * 1978-12-18 1980-07-03 Nordhydraulic Ab Hydraulic circuit with variable pump and hydraulic motor - has pump output controlled by pressure in pump and motor for multi way valve actuation
US5085051A (en) * 1988-06-29 1992-02-04 Hitachi Construction Machinery Co., Ltd. Displacement of variable displacement pump controlled by load sensing device having two settings for low and high speed operation of an actuator
CN102562694B (en) * 2010-10-19 2016-06-01 林德液压两合公司 Load-sensing regulating type hydrostatic drive system
CN104728196A (en) * 2015-03-18 2015-06-24 北京航空航天大学 Load-sensitive electro-hydrostatic actuator
CN104728193A (en) * 2015-03-18 2015-06-24 北京航空航天大学 Load-sensitive electro-hydrostatic actuator
CN104747515A (en) * 2015-03-18 2015-07-01 北京航空航天大学 Electro-hydrostatic actuator sensitive to load
CN104863911A (en) * 2015-05-26 2015-08-26 天津捷强动力装备有限公司 Hydraulic circuit used for controlling no-load rotation speed of hydraulic motor to be stable through load-sensitive variable pump
CN105351278A (en) * 2015-12-10 2016-02-24 上海新跃仪表厂 Novel compound electro-hydraulic servo control system

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