CN116336024A - Electro-hydraulic reversing flow proportional control valve with load flow compensation - Google Patents

Electro-hydraulic reversing flow proportional control valve with load flow compensation Download PDF

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Publication number
CN116336024A
CN116336024A CN202310276452.1A CN202310276452A CN116336024A CN 116336024 A CN116336024 A CN 116336024A CN 202310276452 A CN202310276452 A CN 202310276452A CN 116336024 A CN116336024 A CN 116336024A
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China
Prior art keywords
oil
valve
flow
pilot valve
pilot
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Pending
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CN202310276452.1A
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Chinese (zh)
Inventor
韩江义
杜昀泽
夏长高
李航
凌建祥
赵映尊
王凡
刘恒源
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Jiangsu University
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Jiangsu University
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Priority to CN202310276452.1A priority Critical patent/CN116336024A/en
Publication of CN116336024A publication Critical patent/CN116336024A/en
Pending legal-status Critical Current

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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
    • F15B13/022—Flow-dividers; Priority 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
    • F15B11/08—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K11/00—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves
    • F16K11/02—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with all movable sealing faces moving as one unit
    • F16K11/06—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with all movable sealing faces moving as one unit comprising only sliding valves, i.e. sliding closure elements
    • F16K11/065—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with all movable sealing faces moving as one unit comprising only sliding valves, i.e. sliding closure elements with linearly sliding closure members
    • F16K11/07—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with all movable sealing faces moving as one unit comprising only sliding valves, i.e. sliding closure elements with linearly sliding closure members with cylindrical slides
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K31/00—Actuating devices; Operating means; Releasing devices
    • F16K31/02—Actuating devices; Operating means; Releasing devices electric; magnetic
    • F16K31/06—Actuating devices; Operating means; Releasing devices electric; magnetic using a magnet, e.g. diaphragm valves, cutting off by means of a liquid
    • F16K31/0603—Multiple-way valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K37/00—Special means in or on valves or other cut-off apparatus for indicating or recording operation thereof, or for enabling an alarm to be given
    • F16K37/0025—Electrical or magnetic means
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/20—Hydro energy

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Magnetically Actuated Valves (AREA)

Abstract

The invention discloses an electrohydraulic reversing flow proportional control valve with load flow compensation, pilot valves at two ends are driven by proportional electromagnets, and a pilot oil way is used for controlling the displacement of a main valve core relative to a valve body, so that the purpose of reversing valve body hydraulic oil is realized. The opening size of the pilot valve is regulated through the thrust of the proportional electromagnet at a certain side, the hydraulic oil thrust of the corresponding end of the main valve core is regulated, the hydraulic oil flow area between the valve core shoulder and the valve body sinking groove is regulated, and the output hydraulic oil flow is controlled. When the thrust of the electromagnet is unchanged, the load of the oil outlet working oil way is changed, so that the hydraulic oil outlet quantity of the working oil port is changed, the hydraulic flow quantity of the working oil port is changed, so that the stress of a feedback piston of a certain side flow quantity on the valve body is changed, the position of a pilot valve at a corresponding side is adjusted, the driving force of the pilot oil way to the main valve core is changed, the relative position of a shoulder on the main valve core relative to a valve body sinking groove is finely adjusted, the flow area of hydraulic oil is changed, the hydraulic oil flow quantity of the working oil port is adjusted, the hydraulic oil outlet flow quantity of the working oil port is not influenced by the load change, and the purpose of load flow compensation of the working oil port is achieved.

Description

Electro-hydraulic reversing flow proportional control valve with load flow compensation
Technical Field
The invention relates to the field of reversing valves, in particular to an electrohydraulic reversing flow proportional control valve with load flow compensation.
Background
With the advent of steam technology and the use of hydro-pneumatic technology in industrial development, reversing valves have also begun to emerge, and with the continued development and improvement of technology, existing reversing valves have been able to meet the flow direction changing functions in most hydraulic systems.
With the development of hydraulic technology, more and more electromechanical products have higher requirements on the hydraulic reversing valve, and the requirements are specifically shown in the following steps: the hydraulic reversing valve can realize stable adjustment in the hydraulic reversing process, and the flow ratio output of the working oil port of the reversing valve is realized according to an electric control signal; when the flow of the working oil port caused by the change of the load of the hydraulic actuating element is changed, the hydraulic actuating element can be automatically adjusted, and the stability of the flow of the working oil port is realized.
However, the existing reversing valve has the following defects and complements: (1) Most of reversing is difficult to control the movement speed of an executive component (such as a hydraulic cylinder and a hydraulic motor) due to no flow regulation, and particularly when the load of the executive component is changed, the flow is often changed, so that the speed of the executive component is difficult to control, and finally the movement control level of a hydraulic system is low, and the intelligent control requirement of the executive component of high-end hydraulic equipment is not met; (2) The existing hydraulic electromagnetic proportional reversing valves have the advantages of more middle-low end products, poor flow control precision and insensitivity to flow change adjustment caused by load change, while some high-end electro-hydraulic proportional reversing valves are such as foreign 'BOSCH', 'Rexroth' brands, a plurality of switching valves are adopted to establish a hydraulic flow control bridge to accurately control a main valve, so that the accurate proportional output of hydraulic oil can be realized, but the structure is complex, the requirement on the dynamic response performance of an electromagnetic actuating element is high, and the manufacturing cost is high; cannot be used in some low-added-value hydraulic intelligent control systems, such as an agricultural machinery electrohydraulic control system; 3) Some hydraulic flow servo valves adopt a nozzle baffle structure, and although the accuracy of flow control is high, the working pressure is usually below 20Mpa, and the hydraulic flow servo valves cannot work in high-pressure and high-flow working occasions.
Therefore, in the field of electric control hydraulic systems, there is an urgent need for a proportional reversing valve that has a relatively simple structure and low manufacturing cost, and can accurately control the output flow without causing the output flow to change due to load change,
disclosure of Invention
In order to solve the defects in the prior art, the application provides an electrohydraulic reversing flow proportional control valve with load flow compensation, the device can adjust the output flow of a working oil port according to a control signal, when the output flow changes due to load change, the device can automatically adjust the flow, the purpose of compensating the load flow change is achieved, and the accurate control of the output flow of the working oil port is realized.
The technical scheme adopted by the invention is as follows:
an electrohydraulic reversing flow proportional control valve with load flow compensation, comprising:
a valve body;
a main valve hole is formed in the valve body, a main valve core is arranged in the middle of the main valve hole, and centering springs are respectively arranged at two ends of the main valve core;
2 pilot valve sleeve holes are formed in the valve body, and the 2 pilot valve sleeve holes are arranged in parallel with the main valve hole; a pilot valve spring, a flow feedback piston, a pilot valve, a force transmission piston and a proportion electromagnet are sequentially arranged in each pilot valve sleeve hole from inside to outside; the 2 pilot valve sleeve holes are all connected with the working oil port through an oil duct;
a first sinking groove is formed in the middle of the valve body, and a second sinking groove and a third sinking groove are sequentially formed outwards on two sides of the first sinking groove; the first sinking groove is connected with the oil inlet through an oil duct, and is respectively communicated with the side where the force transmission piston in the pilot valve sleeve hole at the same side is located through a control oil duct;
the 2 second sinking grooves are respectively communicated with the side where the flow feedback piston is located in the pilot valve sleeve hole at the same side through oil ducts;
the 2 third settling tanks are communicated through an oil return passage, and the oil return passage is also connected with an oil return port;
the valve body is provided with 2 oil drain valve holes, the oil drain valve holes are connected with oil drain ports, the oil drain valve holes are communicated with the main valve hole through oil return channels, and the oil drain valve holes are communicated with pilot valve sleeve holes through pilot oil channels; and an oil drain valve spring and an oil drain valve core are arranged in the oil drain valve hole.
Further, the main valve core is a revolution body, the main valve core comprises 3 revolution convex shoulders which are sequentially connected, each revolution convex shoulder is cylindrical, oil holes are formed in each revolution convex shoulder in the radial direction, an inner oil hole is formed in the main valve core in the axial direction, and the inner oil holes are communicated with the oil holes in the 3 revolution convex shoulders.
Further, the two ends of the pilot valve are respectively connected with a force transmission piston and a flow feedback piston, the flow feedback piston is provided with a plurality of through holes which are axially arranged, and the effective oil liquid action area of the force transmission piston is equal to that of the flow feedback piston.
Furthermore, the two ends of the main valve hole are respectively provided with a pre-tightening screw which is arranged at the two ends of the main valve core hole of the valve body through threads; the pre-tightening force of the centering springs at the two ends of the main valve core is adjusted by adjusting the screwing positions of the pre-tightening screws at the two sides, so that the main valve core is positioned at the middle position of the main valve core hole.
Further, the pilot valve is provided with a pilot valve sleeve, the pilot valve sleeve is fixed in a pilot valve sleeve hole of the valve body, and the pilot valve has a movement degree of freedom relative to the left pilot valve sleeve.
Further, the proportional electromagnet is fixed on the outer end face of the pilot valve sleeve hole of the valve body, the proportional electromagnet push rod of the proportional electromagnet is in end face contact with the force transmission piston of the pilot valve, the pilot valve spring is arranged in the pilot valve sleeve hole, one end of the proportional electromagnet push rod is in end face contact with the end face of the flow feedback piston of the pilot valve, and the other end of the proportional electromagnet push rod is in end face contact with the bottom end face of the pilot valve sleeve hole; under the action of the pre-tightening force of the pilot valve spring, the pilot valve is in a closed state.
Further, an oil drain valve core and an oil drain spring are sequentially arranged in the oil drain valve hole from inside to outside.
Further, an oil return port check valve is arranged in a connecting oil duct between the oil return duct and the oil return port.
Further, the direction of the installation of the oil return check valve is: the oil return duct of the valve body is conducted to the oil return port direction of the valve body, and the oil return port is cut off to the oil return duct direction.
Further, the oil inlet and the oil return port are connected with the oil tank through an oil duct, and the working oil port is connected with the hydraulic cylinder through an oil duct.
The invention has the beneficial effects that:
(1) The electro-hydraulic reversing flow proportional control valve with load flow compensation can control the oil outlet direction of a working oil port of the control valve by driving the pilot valve to open through the thrust of the proportional electromagnets at the left side and the right side; the opening of the pilot valve is controlled and regulated by the thrust proportion of the proportion electromagnets on the two sides, so that the output hydraulic flow of the working oil port is regulated; when the output flow of the working oil port changes due to load change, the pressure drop of the oil flowing through the two ends of the flow feedback piston changes, the thrust of the flow piston, the spring force of the pilot valve and the thrust of the electromagnet reach displacement balance again, so that the opening of the pilot valve is adjusted, the opening of the pilot valve changes in inverse proportion to the load, the output flow of the working oil port flowing through the pilot valve is automatically adjusted, the purpose of compensating the load flow change is achieved, and the output flow of the working oil port is accurately controlled; the intelligent control requirement of the existing high-end hydraulic equipment executive component can be met.
(2) According to the method, the opening degree of the pilot valve can be adjusted through the sensitivity of the flow feedback piston to the flow when the load of the oil outlet changes to cause the flow change through the cooperation of the pilot valves on the left side and the right side, the pilot valve springs on the left side and the right side and the flow feedback piston on the two sides, the output flow of the working oil port is compensated, and the stability of the flow of the oil outlet is maintained; compared with the foreign high-end electro-hydraulic proportional valve which utilizes a flow control bridge established by a plurality of switch valves, the core component of the invention only has the flow feedback piston and the pilot valve, the structure on the core flow control component is simple, the manufacturing is easy, the processing cost is reduced, and the design of the flow compensation mechanism of the electro-hydraulic proportional valve is simpler than that of the traditional high-end electro-hydraulic proportional valve. Can be used in domestic low-added-value hydraulic intelligent control equipment.
(3) Because the main valve core, the main valve hole of the valve body, the main valve Kong Chencao, the flow feedback pistons at the left side and the right side and the left pilot valve spring are not limited in design size, the proportional electromagnet pushes the main valve core to displace through pilot hydraulic oil for controlling pilot, and the hydraulic oil on-off of the working oil port is indirectly controlled, and the structure can meet the requirements of a high-pressure control occasion of a hydraulic system; the sinking grooves of the main valve core boss and the main valve hole can meet the requirement of high-flow hydraulic oil output through size design. Therefore, the electrohydraulic reversing flow proportional control valve designed by the invention can be well suitable for the working occasions of high pressure and large flow of a hydraulic control system.
Drawings
FIG. 1 is a block diagram of an electrohydraulic reversing flow proportional control valve with load flow compensation.
Fig. 2 is a schematic diagram of the valve body structure.
Fig. 3 is a left pilot valve structure diagram.
Fig. 4 is a right pilot valve structure diagram.
FIG. 5 is a block diagram of a main valve.
Fig. 6 is a schematic diagram of the oil return operation from the P port to the O port.
Fig. 7 is a schematic diagram of the oil return operation from port P to port a.
Fig. 8 is a schematic diagram of the oil return operation from port P to port B.
Fig. 9 is a schematic diagram of the electro-hydraulic reversing flow proportional control valve designed in the application to uniform speed control of a hydraulic cylinder.
In the drawings, 1, a left proportional solenoid, 2, a left proportional solenoid push rod, 3, a left force-transmitting piston, 4, a left pilot valve housing, 5, a left pilot valve, 6, a left flow feedback piston, 7, a left pilot valve spring, 8, a control oil passage, 9, a right pilot valve spring, 10, a right flow feedback piston, 11, a right pilot valve, 12, a right pilot valve housing, 13, a right force-transmitting piston, 14, a right proportional solenoid push rod, 15, a right proportional solenoid, 16, a right pilot oil passage, 17, 18, a right oil drain valve spring, 19, a right oil drain valve core, 20, a right oil drain passage, 21, a right pretension screw, 22, a right centering spring, 23, a working oil port A,24, an oil drain passage, 25, an oil inlet P,26, an oil drain port O,27, an oil drain port one-way valve, 28, a working oil port B,29, a one-way valve mounting groove, 30, a valve body, 31, a left main valve core, 32, a left centering spring, 33, a left pretension screw, 34, 35, a left oil drain valve core, 36, a left drain valve core, 37, a left drain oil drain port, 38, a left pilot valve bore, 39, a left oil drain hole, 40, a right oil drain hole, a main oil drain hole, 45, a valve bore, 42, a left oil drain hole, and 44.
Detailed Description
The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
The structure of the electrohydraulic reversing flow proportional control valve with load flow compensation is shown in fig. 1-5, and comprises a valve body 30; a main valve hole 41 is formed in the valve body 30 along a horizontal axis, and as shown in fig. 2, a first sink groove (hereinafter referred to as sink groove P) is formed in a middle portion of the main valve hole 41, a second sink groove and a third sink groove are sequentially formed outwardly on both sides of the sink groove P with a center line in a vertical direction of the sink groove P as an axis, the second sink groove is referred to as sink groove B1 and sink groove A1, and the third sink groove is referred to as sink groove O2 and sink groove O1.
The main valve hole 41 is provided with a main valve element 25, and the main valve element 25 is structured as shown in fig. 5: the main valve core 25 is a revolution body, the main valve core 25 comprises 3 revolution convex shoulders which are connected in sequence, and the revolution convex shoulders are cylindrical; the 3 rotation shoulders are provided with oil holes which penetrate through in the radial direction, and the oil holes are positioned in the middle of the rotation shoulders; the main valve core 25 is also provided with an inner oil hole 44 in the axial direction, and the inner oil hole 44 penetrates through the 3 rotation shoulders to communicate the oil holes on the 3 rotation shoulders.
The valve body 30 is also provided with a left pilot valve sleeve hole 43 and a right pilot valve sleeve hole 39, the left pilot valve sleeve hole 43 and the right pilot valve sleeve hole 39 are respectively symmetrical and symmetrical about the central line of the sinking groove P in the vertical direction, and a left pilot valve spring 7 and a left pilot valve 5 are sequentially arranged in the left pilot valve sleeve hole 43 from inside to outside; the tail end of the left pilot valve sleeve hole 43 is provided with a left proportional electromagnet 1; more specifically, in combination with the left pilot valve structure schematic diagram shown in fig. 3, two ends of the left pilot valve 5 are respectively connected with the left force-transmitting piston 3 and the left flow feedback piston 6, a plurality of through holes are formed in the left flow feedback piston 6, and the effective oil acting area of the M surface of the left force-transmitting piston 3 is equal to the effective oil acting area of the N surface of the left flow feedback piston 6. The left pilot valve 5 is also provided with a left pilot valve sleeve 4. The left pilot valve spring 7 is disposed between the left flow feedback piston 6 and the inner wall of the left pilot valve sleeve hole 43. The left force-transmitting piston 3 is contacted with the left proportion electromagnet push rod 2 of the left proportion electromagnet 1.
Similarly, as shown in fig. 4, the structure of the right pilot valve 11 is that two ends of the right pilot valve 11 are respectively connected with a right force-transmitting piston 13 and a right flow feedback piston 10, a plurality of through holes are formed in the right flow feedback piston, and the effective oil liquid acting area of the M surface of the right force-transmitting piston 13 is equal to the effective oil liquid acting area of the N surface of the right flow feedback piston 10. The right pilot valve 11 is also provided with a right pilot valve sleeve 12. The right pilot valve spring 9 is disposed between the right flow feedback piston 10 and the inner wall of the right pilot valve sleeve bore 39. The right force-transmitting piston 13 is in contact with a right proportional electromagnet push rod 14 of a right proportional electromagnet 15.
Wherein the sinking groove O1 and the sinking groove O2 are communicated through an oil return passage 24; the oil return channel 24 is communicated with an oil return port O26 through an oil return one-way valve groove 29, the sinking channel P is communicated with an oil inlet P25 through an oil channel, and the sinking channel P is respectively communicated with a left pilot valve sleeve hole 43 and a right pilot valve sleeve hole 39 through a control oil channel 8; the working oil port A23 is communicated with the right pilot valve sleeve hole 39 through an oil duct; the working oil port B28 is communicated with the left pilot valve sleeve hole 43 through an oil duct; the left pilot valve sleeve hole 43 is communicated with the main valve core hole 41 and the left oil drain valve hole 42 through the left pilot oil duct 38; the right pilot valve sleeve hole 39 communicates with the main spool hole 41 and the right drain valve hole 40 through the right pilot oil passage 16.
The connection and assembly of the components of the inventive device are shown in fig. 1 and 2:
the left pilot valve sleeve 4 is fixed in the left pilot valve sleeve hole 43 of the valve body 30, and the right pilot valve sleeve 12 is fixed in the right pilot valve sleeve hole 39 of the valve body 30; the left pilot valve 5 is arranged in the left pilot valve sleeve 4, and the left pilot valve 5 can have a movement degree of freedom relative to the left pilot valve sleeve 4; the left proportional electromagnet 1 is fixed on the outer end surface of a left pilot valve sleeve hole 43 of the valve body 30, a left proportional electromagnet push rod 2 of the left proportional electromagnet 1 is in contact with the end surface of a left force transmission piston 3 of a left pilot valve 5, a left pilot valve spring 7 is arranged in the left pilot valve sleeve hole 43, one end of the left pilot valve spring 7 is in contact with the end surface of a flow feedback piston 6 of the left pilot valve 5, and the other end of the left pilot valve spring is in contact with the bottom end surface of the left pilot valve sleeve hole 43; under the action of the pretightening force of the left pilot valve spring 7, the left pilot valve 5 is in a closed state; the right pilot valve 11 is arranged in the right pilot valve sleeve 12, and the right pilot valve 11 has a movement degree of freedom relative to the right pilot valve sleeve 12; the right proportional electromagnet 15 is fixed on the outer end surface of a right pilot valve sleeve hole 39 of the valve body 30, a right proportional electromagnet push rod 14 of the right proportional electromagnet 15 is in contact with the end surface of a right force transmission piston 13 of the right pilot valve 11, a right pilot valve spring 9 is arranged in the right pilot valve sleeve hole 39, one end of the right pilot valve spring 9 is in contact with the end surface of a flow feedback piston 10 of the right pilot valve 11, and the other end of the right pilot valve spring is in contact with the bottom end surface of the right pilot valve sleeve hole 39; under the action of the pretightening force of the right pilot valve spring 9, the right pilot valve 11 is in a closed state.
As shown in fig. 1 and 2, the left relief valve spool 35 and the left relief spring 36 are installed in the left relief valve hole 42 of the valve body 30; the right drain spool 19 and the right drain spring 18 are installed in the right drain valve hole 40 of the valve body 30. The main valve core 31, the right centering spring 22 and the left centering spring 32 are installed at both ends of the main valve core 31; the right pre-tightening screw 21 and the left pre-tightening screw 33 are respectively arranged at two ends of the main valve core hole 41 of the valve body 30 through threads; by adjusting the screwing positions of the left and right pre-tightening screws 33, 21, the pre-tightening forces of the left and right centering springs 32, 22 are adjusted so that the main spool 31 is at the intermediate position of the main spool hole 41.
The return check valve 27 is installed in the check valve installation groove 29 of the valve body 30, and the direction of installation of the return check valve 27 is: the return oil passage 24 of the valve body 30 is conducted to the return oil port O26 direction of the valve body 30, and the return oil port O26 is blocked to the return oil passage 24 direction.
The working principle of the electro-hydraulic reversing flow proportional control valve designed by the invention is combined to further explain the electro-hydraulic reversing flow proportional control valve:
(1) P-port to O-port oil return working schematic diagram
The left proportion electromagnet 1 and the right proportion electromagnet 15 are not electrified, the oil inlet P25 is filled with oil, and the oil flows out from the oil return port O26. As shown in fig. 6, when the left proportional electromagnet 1 and the right proportional electromagnet 15 are not powered, neither the left proportional electromagnet push rod 2 nor the right proportional electromagnet push rod 14 generates a thrust. At this time, both the left pilot valve 5 and the right pilot valve 11 are in the closed state. The pressure oil from the oil inlet P25 passes through the valve body sinking groove P and enters the control oil way 8, and cannot enter the left cavity of the main valve core 31 through the left pilot valve 5 and the left pilot oil duct 38; meanwhile, the oil in the control oil path 8 cannot enter the right cavity of the main valve core 31 through the right pilot valve 11 and the right pilot oil path 16; therefore, main spool 31 is always in the neutral operating position by the action of left centering spring 32 and right centering spring 22. The main valve core 31 is in the middle working position, a sinking groove P on the valve body 30 is communicated with a shoulder oil hole of the main valve core 31, and pressure oil of an oil inlet P25 is communicated with valve body sinking grooves O1 and O2 through an inner oil hole 44 of the main valve core 31; the pressure oil in the oil inlet P flows out from the oil return port 0 through the valve body sink P, the inner oil hole 44 of the main spool 31, the valve body sink O1, the valve body sink O2, and the oil return check valve 27. Sink P and sink B1 on valve body 30, sink A1 is closed by a shoulder on main valve core 31, namely: the sinking tank P is not communicated with the sinking tank B1 and the sinking tank A1. Therefore, when the left proportional electromagnet 1 and the right proportional electromagnet 15 are not electrified, all the oil flows out from the oil return port O26 of the valve body 30 when the pressure oil enters from the oil inlet P.
(2) Oil return working schematic diagram from P port to A port
The left proportion electromagnet 1 is electrified, the right proportion electromagnet 15 is not electrified, the oil inlet P25 is filled with oil, the oil flows out from the working oil port B28, and the flow is stable. As shown in fig. 7, when the left proportional electromagnet 1 is powered on and the right proportional electromagnet 15 is not powered on, the left proportional electromagnet push rod 2 generates thrust to the left pilot valve 5, when the thrust is larger than the pretightening force of the left pilot valve spring 7, the left pilot valve 5 is opened, the pressure oil from the oil inlet P25 enters the control oil duct 8 through the sinking groove P of the valve body 30, then the pressure oil enters the oil cavity on the left side of the main valve core 31 through the left pilot valve 5, and due to the pressure loss effect of the left oil return channel 34, the left oil drain valve core 35 overcomes the pretightening force of the left oil drain valve spring 36, and moves leftwards and blocks the oil path from the left oil return channel 34 to the left oil drain port 37; at this time, the left oil cavity of the main valve core 31 is pressurized to push the main valve core 31 to overcome the pretightening force of the right centering spring 22 and generate a displacement to the right, so that the sinking groove P and the sinking groove B1 of the valve body 30 are communicated, and meanwhile, the sinking groove A1 and the sinking groove O1 are communicated; part of the pressure oil in the oil inlet P25 flows out of the working oil port B28 through the oil duct through the P sinking groove, the B1 sinking groove and the holes in the left flow feedback piston 6 of the valve body 30. At the same time, as the main spool 31 moves rightward, a part of the area of the oil port 44 on the middle shoulder of the main spool 31 is covered by the main valve Kong Zhezhu, resulting in an increase in the differential pressure from the sink P to the oil return port O26 and a decrease in the amount of oil flowing from the sink P to the oil return port O26. If the hydraulic executive component has oil return, the oil return can be connected with the working oil port A23, the oil return oil can enter the sinking groove A1 through the working oil port A23, the oil passage of the valve body and the small hole on the right flow feedback piston 10, and can flow out through the sinking groove O1, the oil return oil passage 24, the oil return one-way valve 27 and the oil return port 26.
When the oil load pressure of the working oil port B28 is increased, the pressure difference from the valve body sink groove P to the sink groove B1 is reduced, and the flow of the sink groove P flowing into the oil return port O26 is increased and the flow of the sink groove P flowing into the sink groove B1 is reduced because the pressure difference from the sink groove P to the oil return port O26 is unchanged; as the flow passing through the left flow feedback piston 6 is reduced, according to the hydrodynamic resistance calculation theory, the pressure loss at the two ends of the left flow feedback piston 6 is reduced, and the resistance of the left flow feedback piston 6 to the left proportional electromagnet push rod 2 is reduced; under the condition that the thrust of the left proportion electromagnetic push rod 2 is unchanged, the left pilot valve spring 7 is further compressed; the opening of the left pilot valve 5 is increased, the pressure difference between the front and the rear of the left pilot valve 5 is reduced, the pressure of an oil inlet P is unchanged, the pressure of an oil cavity at the left side of the main valve core 31 is increased, the thrust of oil to the right of the main valve core 31 is increased, the main valve core 31 is driven to move right further, the opening of the valve body sinking groove P to B1 is increased, the opening of an oil hole 44 on the shoulder of the main valve core 31 in the sinking groove P is further blocked and reduced, the flow of the sinking groove P to the sinking groove B1 is increased, the flow of the sinking groove P to an oil hole 44 in the valve core is reduced, and the oil outlet flow of the work B23 is stabilized. Conversely, when the oil load pressure of the working oil port B28 decreases, the pressure difference from the sink P to the sink B1 increases, the oil output of the working oil port B28 increases, the flow passing through the left flow feedback piston 6 increases, the pressure loss at both ends of the left flow feedback piston 6 increases, the resistance of the left flow feedback piston 6 to the left proportional electromagnet push rod 2 increases, the thrust of the left proportional electromagnet push rod 2 is small, the left pilot valve spring 6 is further stretched, the opening of the left pilot valve 5 decreases, the pressure difference between the front and rear of the left pilot valve 5 increases, the left oil cavity pressure of the main valve 31 decreases, the thrust of the oil to the right of the main valve 31 decreases, the main valve 31 moves leftwards, the opening of the valve body sink P to B1 decreases, the opening of the oil hole 44 on the shoulder of the main valve 31 in the sink P increases, the flow of the sink P to the sink B1 decreases, and the flow of the sink P to the oil hole 44 in the valve core increases, thereby stabilizing the oil output flow of the working B23.
(3) P-port to B-port oil return working schematic diagram
The left proportion electromagnet 1 is not electrified, the right proportion electromagnet 15 is electrified, the oil inlet P25 is filled with oil, the oil flows out from the working oil port A23, and the flow is stable. As shown in fig. 8, when the left proportional electromagnet 1 is not powered, the right proportional electromagnet 15 is powered, and the right proportional electromagnet push rod 14 generates thrust to the right pilot valve 11; when the thrust is greater than the pretightening force of the right pilot valve spring 9, the right pilot valve 11 is opened, the pressure oil from the oil inlet P25 enters the control oil duct 8 through the sinking groove P of the valve body 30, then the pressure oil enters the oil cavity on the right side of the main valve core 31 through the right pilot valve 11 and the right pilot oil duct 16, and due to the pressure loss effect of the right oil return channel 20, the right oil return valve core 19 overcomes the pretightening force of the right oil return valve spring 18, and moves rightwards and blocks the oil path from the right oil return channel 20 to the right oil drain port 17; at this time, the oil cavity pressure at the right side of the main valve core 31 is raised, the main valve core 31 is pushed to overcome the pretightening force of the left centering spring (32), and a displacement is generated leftwards, so that the sinking groove P of the valve body 30 is communicated with the sinking groove A1, and the sinking groove B1 is communicated with the sinking groove O2; part of the pressure oil in the oil inlet P25 flows out from the working oil port A23 through the oil passage through the P sinking groove, the A1 sinking groove of the valve body 30 and the holes on the right flow feedback piston 10. At the same time, as main spool 31 moves leftward, a part of the area of oil port 44 on the middle shoulder of main spool 31 is blocked by main valve hole 41, resulting in an increase in the pressure difference from sink P to oil return port O26, and a decrease in the amount of oil flowing from sink P to oil return port O26. If the hydraulic element has oil return, the oil return oil way is connected with the working oil port B, and the oil return passes through the working oil port B, the hole on the left flow feedback piston (6), the sinking groove B, the sinking groove O2, the oil return oil duct 24 and the oil return one-way valve 27, and finally flows out from the oil return port O26.
When the oil load pressure of the working oil port A23 is increased, the pressure difference from the valve body sink groove P to the sink groove A1 is reduced, and the flow of the sink groove P flowing into the oil return port O26 is increased and the flow of the sink groove P flowing into the sink groove A1 is reduced because the pressure difference from the sink groove P to the oil return port O26 is unchanged; because the flow passing through the right flow feedback piston 10 is reduced, the pressure loss at two ends of the right flow feedback piston 10 is reduced according to the hydrodynamic resistance calculation theory, the resistance of the right flow feedback piston 10 to the right proportion electromagnet push rod 14 is reduced, under the condition that the thrust of the right proportion electromagnet push rod 12 is unchanged, the right pilot valve spring 9 is further compressed, the opening of the right pilot valve 11 is increased, the pressure difference between the front and rear of the right pilot valve 11 is reduced, the pressure of an oil cavity on the right side of the main valve core 31 is increased due to the unchanged pressure of an oil inlet P, the thrust of oil to the left of the main valve core 31 is increased, the main valve core 31 is driven to further move left, the opening of the valve body sinking groove P to A1 is increased, the opening of an oil hole 44 on the shoulder of the main valve core 31 in the sinking groove P is further blocked and reduced, the flow of the sinking groove P to the oil hole 44 in the valve core is reduced, and the oil outlet flow of the working A23 is stabilized. Conversely, when the oil load pressure of the working oil port A23 is reduced, the pressure difference from the sink P to the sink A1 is increased, the oil output of the working oil port A23 is increased, the flow passing through the right flow feedback piston 10 is increased, the pressure loss at the two ends of the right flow feedback piston 10 is increased, and the resistance of the right flow feedback piston 10 to the left proportional electromagnet push rod 2 is increased; under the condition that the thrust of the electromagnetic push rod 14 in the right proportion is unchanged, the right pilot valve spring 9 is further stretched, the opening of the right pilot valve 11 is reduced, the pressure difference between the front and rear of the right pilot valve 11 is increased, the pressure of an oil cavity on the right side of the main valve core 31 is reduced, the thrust of oil to the left of the main valve core 31 is reduced, the main valve core 31 moves rightwards, the opening of the valve body sinking groove P to A1 is reduced, the opening of an oil hole 44 on the shoulder of the main valve core 31 in the sinking groove P is further increased, the flow of the sinking groove P to the sinking groove A1 is reduced, and the flow of the sinking groove P to the oil hole 44 in the valve core is increased, so that the oil outlet flow of the work A23 is stabilized.
Application cases:
the electrohydraulic reversing flow proportional control valve with load flow compensation is applied to displacement uniform control of a hydraulic cylinder, and aims to keep the uniformity of the extension speed of a piston rod under the condition of load change in the extension process of the piston rod of the hydraulic cylinder. In particular, as shown in fig. 9, an oil outlet of a hydraulic pump 45 is connected with an oil inlet P25 of the device, a working oil port a 23 is connected with a rodless cavity oil port of a hydraulic cylinder 47, a working oil port B28 is connected with a rod cavity of the hydraulic cylinder 47, an oil return port 26 is connected with a hydraulic oil tank 46, and a load of a piston rod of the hydraulic cylinder 47 is F, and the direction is shown in the figure.
Purpose of application case: and the piston rod of the hydraulic oil cylinder 47 is controlled to stretch at a constant speed through the electrohydraulic reversing flow proportional control valve with load flow compensation.
According to the connection, the left proportional electromagnet 1 is not electrified, current is supplied to the right proportional electromagnet 15, the right proportional electromagnet push rod 14 generates thrust to the right pilot valve 11, when the thrust is larger than the pretightening force of the right pilot valve spring 9, the right pilot valve 11 is opened, pressure oil from the oil inlet P25 enters the control oil duct 8 through the sinking groove P of the valve body 30, then the pressure oil enters an oil cavity on the right side of the main valve core 31 through the right pilot valve 11 and the right pilot oil duct 16, and due to the pressure loss effect of the right oil return duct 20, the right oil drain valve core 19 overcomes the pretightening force of the right oil drain valve spring 18, and the oil path from the right oil return duct 20 to the right oil drain port 17 is moved rightward and blocked; at this time, the oil cavity pressure at the right side of the main valve core 31 is raised, the main valve core 31 is pushed to overcome the pretightening force of the left centering spring 32, and a displacement is generated leftwards, so that the sinking groove P of the valve body 30 is communicated with the sinking groove A1, and the sinking groove B1 is communicated with the sinking groove O2; part of the pressure oil in the oil inlet P25 flows out from the working oil port A23 through the oil passage through the P sinking groove, the A1 sinking groove of the valve body 30 and the holes on the right flow feedback piston 10. The hydraulic oil flowing out from the working oil port A23 enters the rodless cavity of the hydraulic cylinder 47, and the oil in the rod cavity of the hydraulic cylinder 47 flows into the oil tank 46 from the oil return port O26 through the working oil port B, the hole on the left flow feedback piston 6, the sink tank B, the sink tank O2, the oil return oil duct 24 and the oil return check valve 27. The piston rod of the hydraulic cylinder 47 is extended leftward against the load F.
When the load F of the piston rod of the hydraulic cylinder 47 increases, the oil load pressure of the working oil port A23 rises, the pressure difference from the valve body sink groove P to the sink groove A1 decreases, and the flow rate of the sink groove P flowing into the oil return port O26 increases and the flow rate of the sink groove P flowing into the sink groove A1 decreases because the pressure difference from the sink groove P to the oil return port O26 is unchanged; because the flow passing through the right flow feedback piston 10 is reduced, the pressure loss at two ends of the right flow feedback piston 10 is reduced according to the hydrodynamic resistance calculation theory, the resistance of the right flow feedback piston 10 to the right proportional electromagnet push rod 14 is reduced, under the condition that the thrust of the right proportional electromagnet push rod 14 is unchanged, the right pilot valve spring 9 is further compressed, the opening of the right pilot valve 11 is increased, the pressure difference between the front and rear of the right pilot valve 11 is reduced, the pressure of an oil cavity on the right side of the main valve core 31 is increased due to the unchanged pressure of the oil inlet P, the thrust of oil to the left of the main valve core 31 is increased, the main valve core 31 is driven to further move left, the opening of the valve body sinking groove P to A1 is increased, the opening of the oil hole 44 on the shoulder of the main valve core 31 in the sinking groove P is further blocked and reduced, the flow of the sinking groove P to the oil hole 44 in the valve core is reduced, and the oil outlet flow of the working A23 is stabilized, and the aim of controlling the extension speed of the piston rod of the hydraulic cylinder 47 to be stabilized under the condition that the load F is increased is achieved.
Conversely, when the piston rod load F of the hydraulic cylinder 47 decreases, the oil load pressure of the working oil port a 23 decreases, the pressure difference from the sink P to the sink A1 increases, the oil output of the working oil port a 23 increases, the flow passing through the right flow feedback piston 10 increases, the pressure loss at both ends of the right flow feedback piston 10 increases, and the resistance of the right flow feedback piston 10 to the left proportional electromagnet push rod 2 increases; under the condition that the thrust of the electromagnetic push rod 14 in the right proportion is unchanged, the right pilot valve spring 6 is further stretched, the opening of the right pilot valve 11 is reduced, the pressure difference between the front and rear of the right pilot valve 11 is increased, the pressure of an oil cavity on the right side of the main valve core 31 is reduced, the thrust of oil to the left of the main valve core 31 is reduced, the main valve core 31 moves rightwards, the opening of a valve body sinking groove P to A1 is reduced, the opening of an oil hole 44 on the shoulder of the main valve core 31 in the sinking groove P is further increased, the flow of the sinking groove P to the sinking groove A1 is reduced, and the flow of the sinking groove P to the oil hole 44 in the valve core is increased, so that the oil outlet flow of the work A23 is stabilized; further, the purpose of controlling the hydraulic cylinder 47 to stabilize the extension speed of the piston rod when the piston rod load F is reduced is achieved.
The above embodiments are merely for illustrating the design concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement the same, the scope of the present invention is not limited to the above embodiments. Therefore, all equivalent changes or modifications according to the principles and design ideas of the present invention are within the scope of the present invention.

Claims (10)

1. An electrohydraulic reversing flow proportional control valve with load flow compensation, characterized by comprising:
a valve body (30);
a main valve hole (41) is formed in the valve body (30), a main valve core (31) is arranged in the middle of the main valve hole (41), and centering springs are respectively arranged at two ends of the main valve core (31);
2 pilot valve sleeve holes are formed in the valve body (30), and the 2 pilot valve sleeve holes are arranged in parallel with the main valve hole (41); a pilot valve spring, a flow feedback piston, a pilot valve, a force transmission piston and a proportion electromagnet are sequentially arranged in each pilot valve sleeve hole from inside to outside; the 2 pilot valve sleeve holes are all connected with the working oil port through an oil duct;
a first sinking groove is formed in the middle of the valve body (30), and a second sinking groove and a third sinking groove are sequentially formed outwards on two sides of the first sinking groove; the first sinking groove is connected with the oil inlet through an oil duct, and the first sinking groove is respectively communicated with the side where the force transmission piston is located in the pilot valve sleeve hole at the same side through a control oil duct (8);
the 2 second sinking grooves are respectively communicated with the side where the flow feedback piston is located in the pilot valve sleeve hole at the same side through oil ducts;
the 2 third settling tanks are communicated through an oil return duct (24), and the oil return duct (24) is also connected with an oil return port;
2 oil drain valve holes are formed in the valve body (30), the oil drain valve holes are connected with oil drain ports, the oil drain valve holes are communicated with the main valve hole (41) through oil return channels, and the oil drain valve holes are communicated with pilot valve sleeve holes through pilot oil channels; and an oil drain valve spring and an oil drain valve core are arranged in the oil drain valve hole.
2. The electrohydraulic reversing flow proportional control valve with load flow compensation according to claim 1, wherein the main valve core (25) is a revolution body, the main valve core (25) comprises 3 revolution shoulders which are sequentially connected, the revolution shoulders are cylindrical, each revolution shoulder is provided with an oil hole along the radial direction, the inside of the main valve core (25) is provided with an inner oil hole (44) along the axial direction, and the inner oil holes (44) are communicated with the oil holes on the 3 revolution shoulders.
3. The electrohydraulic reversing flow proportional control valve with load flow compensation of claim 1, characterized in that, the two ends of the main valve hole (41) are respectively provided with a pre-tightening screw, the pre-tightening screws are arranged at the two ends of the main valve core hole (41) of the valve body (30) through threads; the screwing positions of the pre-tightening screws at the two sides are adjusted, and the pre-tightening force of the centering springs at the two ends of the main valve core (31) is adjusted, so that the main valve core (31) is positioned at the middle position of the main valve core hole (41).
4. The electrohydraulic reversing flow proportional control valve with load flow compensation of claim 1, wherein the two ends of the pilot valve are respectively connected with a force-transmitting piston and a flow feedback piston, the flow feedback piston is provided with a plurality of through holes which are axially arranged, and the effective oil acting area of the force-transmitting piston is equal to the effective oil acting area of the flow feedback piston.
5. The electrohydraulic reversing flow proportional control valve with load flow compensation of claim 4 wherein said pilot valve is provided with a pilot valve sleeve fixed in a pilot valve sleeve bore of the valve body (30), the pilot valve having a degree of freedom of movement relative to the left pilot valve sleeve.
6. The electrohydraulic reversing flow proportional control valve with load flow compensation according to any of claims 1-5, characterized in that the proportional electromagnet is fixed on the outer end surface of the pilot valve sleeve hole of the valve body (30), the proportional electromagnet push rod of the proportional electromagnet is in end surface contact with the force transmission piston of the pilot valve, the pilot valve spring is installed in the pilot valve sleeve hole, one end is in contact with the end surface of the flow feedback piston of the pilot valve, and the other end is in contact with the bottom end surface of the pilot valve sleeve hole; under the action of the pre-tightening force of the pilot valve spring, the pilot valve is in a closed state.
7. The electro-hydraulic reversing flow proportional control valve with load flow compensation according to claim 6, wherein a drain valve core and a drain spring are sequentially arranged in the drain valve hole from inside to outside.
8. The electro-hydraulic reversing flow proportional control valve with load flow compensation according to claim 6, wherein an oil return port check valve (27) is arranged in a connecting oil duct between the oil return duct (24) and the oil return port.
9. The electrohydraulic reversing flow proportional control valve with load flow compensation of claim 8 wherein the direction of installation of the return check valve (27) is: the oil return duct (24) of the valve body (30) is communicated with the oil return opening of the valve body (30), and the oil return opening is blocked in the direction of the oil return duct (24).
10. The electro-hydraulic reversing flow proportional control valve with load flow compensation according to claim 6, wherein the oil inlet and the oil return port are connected with an oil tank (46) through an oil passage, and the working oil port is connected with a hydraulic cylinder (47) through an oil passage.
CN202310276452.1A 2023-03-21 2023-03-21 Electro-hydraulic reversing flow proportional control valve with load flow compensation Pending CN116336024A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310276452.1A CN116336024A (en) 2023-03-21 2023-03-21 Electro-hydraulic reversing flow proportional control valve with load flow compensation

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310276452.1A CN116336024A (en) 2023-03-21 2023-03-21 Electro-hydraulic reversing flow proportional control valve with load flow compensation

Publications (1)

Publication Number Publication Date
CN116336024A true CN116336024A (en) 2023-06-27

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Family Applications (1)

Application Number Title Priority Date Filing Date
CN202310276452.1A Pending CN116336024A (en) 2023-03-21 2023-03-21 Electro-hydraulic reversing flow proportional control valve with load flow compensation

Country Status (1)

Country Link
CN (1) CN116336024A (en)

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