CN111207238A - Pilot-operated proportional cartridge valve based on servo motor drive - Google Patents

Pilot-operated proportional cartridge valve based on servo motor drive Download PDF

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Publication number
CN111207238A
CN111207238A CN202010120674.0A CN202010120674A CN111207238A CN 111207238 A CN111207238 A CN 111207238A CN 202010120674 A CN202010120674 A CN 202010120674A CN 111207238 A CN111207238 A CN 111207238A
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CN
China
Prior art keywords
valve core
pilot
main valve
servo motor
main
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Pending
Application number
CN202010120674.0A
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Chinese (zh)
Inventor
孔晓武
王亚南
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Zhejiang University ZJU
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Zhejiang University ZJU
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Publication date
Application filed by Zhejiang University ZJU filed Critical Zhejiang University ZJU
Priority to CN202010120674.0A priority Critical patent/CN111207238A/en
Publication of CN111207238A publication Critical patent/CN111207238A/en
Pending legal-status Critical Current

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    • 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
    • F16K31/12—Actuating devices; Operating means; Releasing devices actuated by fluid
    • F16K31/36—Actuating devices; Operating means; Releasing devices actuated by fluid in which fluid from the circuit is constantly supplied to the fluid motor
    • F16K31/38—Actuating devices; Operating means; Releasing devices actuated by fluid in which fluid from the circuit is constantly supplied to the fluid motor in which the fluid works directly on both sides of the fluid motor, one side being connected by means of a restricted passage and the motor being actuated by operating a discharge from that side
    • F16K31/383—Actuating devices; Operating means; Releasing devices actuated by fluid in which fluid from the circuit is constantly supplied to the fluid motor in which the fluid works directly on both sides of the fluid motor, one side being connected by means of a restricted passage and the motor being actuated by operating a discharge from that side the fluid acting on a piston
    • 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
    • F16K1/00—Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces
    • 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
    • F16K31/12—Actuating devices; Operating means; Releasing devices actuated by fluid
    • F16K31/42—Actuating devices; Operating means; Releasing devices actuated by fluid by means of electrically-actuated members in the supply or discharge conduits of the fluid motor

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Servomotors (AREA)

Abstract

The invention discloses a pilot-operated proportional cartridge valve based on servo motor drive, which comprises: servo motor, apron, guide valve core, main valve core and valve barrel. The servo motor drives the pilot valve core to rotate, the hydraulic half bridge formed by the fixed damping hole and the variable damping hole converts the rotation angle of the pilot valve core into pressure of the control oil cavity to drive the main valve core to move, and follow-up control is achieved between the main valve core and the pilot valve core through negative feedback of the hydraulic half bridge. The servo motor drives the pilot valve core, only small inertia force, friction force and hydraulic unbalance force need to be overcome, and the servo motor with small power can be selected. The turning angle of the whole stroke of the pilot valve core is small, and the step response time of the pilot valve core is favorably shortened. The driving force of the main valve core is not limited by the power of the servo motor, the stroke of the main valve core is not limited by the stroke of the pilot valve core, and the maximum working pressure and the maximum working flow of the main valve are improved.

Description

Pilot-operated proportional cartridge valve based on servo motor drive
Technical Field
The invention relates to a pilot-operated proportional cartridge valve based on servo motor driving.
Background
The traditional proportional cartridge valve adopts an electro-hydraulic servo valve as a pilot stage, the electro-hydraulic servo valve has complex manufacturing process and high cost, and simultaneously has high requirement on the cleanliness of oil liquid, high use cost and difficult maintenance, thus preventing the electro-hydraulic servo valve from being widely applied. In addition, compared with the traditional proportional cartridge valve, the proportional cartridge valve which directly drives the main valve element by the servo motor and the ball screw simplifies the structure, but the driving force and the response speed required by the main valve element cannot be considered under the application occasions of high pressure and large flow because the motor power is in inverse proportion to the response speed.
Disclosure of Invention
In order to solve the defects of the prior art, the invention provides a pilot type proportional cartridge valve based on servo motor drive, which can solve the problems.
In order to achieve the above object, the present invention adopts the following technical solutions:
the utility model provides a pilot-operated formula proportional cartridge valve based on servo motor drive, its structure includes: servo motor, apron, guide valve core, main valve core and valve barrel. The servo motor shell is fixedly connected with the cover plate; the cover plate is fixedly connected with the valve sleeve; an output shaft of the servo motor is fixedly connected with a pilot valve core, and the pilot valve core rotates around the axis of the pilot valve core; the pilot valve core is arranged in an inner hole of the main valve core, and the excircle of the pilot valve core is in clearance fit with the inner hole of the main valve core; the main valve core is arranged in an inner hole of the valve sleeve, and the excircle of the main valve core is in clearance fit with the inner hole of the valve sleeve; a variable damping hole is formed between the pilot valve core and the main valve core, and the flow area of the variable damping hole changes along with the rotation angle of the pilot valve core and the axial displacement change of the main valve core; a control oil cavity is formed at the top of the main valve core; the control oil cavity is communicated with the second main valve port through a variable damping hole; the control oil chamber is communicated with the first main valve port through an oil inlet channel containing a fixed damping hole.
Optionally, a guide is provided between the main spool and the valve housing, the guide preventing the main spool from rotating about its axis and allowing the main spool to move linearly along its axis.
Optionally, the pilot valve element can only rotate about its axis.
Optionally, the control oil cavity is surrounded by a cover plate, a pilot valve core, a main valve core and a valve sleeve.
Optionally, an oil inlet passage between the control oil chamber and the first main valve port is located in the main valve core.
Optionally, a pilot oil path is arranged in the cover plate, the pilot oil path is communicated with the first main valve port through an external oil path, and the pilot oil path and the external oil path jointly form an oil inlet channel between the control oil chamber and the first main valve port.
The invention has the advantages that:
the provided pilot type proportional cartridge valve driven by the servo motor drives the pilot valve core to rotate through the servo motor, a variable damping hole formed between the pilot valve core and the main valve core and a fixed damping hole on the pilot oil inlet channel form a hydraulic half-bridge together, high-pressure oil output through the hydraulic half-bridge drives the main valve core to move, and meanwhile servo control is achieved between the main valve core and the pilot valve core through hydraulic negative feedback. The servo motor drives the pilot valve core, only the influence of smaller inertia force, friction force and hydraulic unbalance force is overcome, and the servo motor with smaller power is favorably selected, so that the response speed of the servo motor is improved. The full-stroke corner of the pilot valve core is smaller, and the step response time of the pilot valve core is favorably shortened. The two characteristics are beneficial to improving the response speed of the main valve core; the hydraulic half-bridge converts the rotation angle of the pilot valve core into the pressure of the control oil cavity, so that enough driving force can be provided for the main valve core, and the driving force of the main valve core is not limited by the power of the servo motor. The stroke of the main valve core is only related to the lead of the pilot valve core and is not limited by the stroke of the pilot valve core. The two characteristics are beneficial to improving the maximum working pressure and the maximum working flow of the main valve port.
Drawings
FIGS. 1(a) and 1(b) are schematic cross-sectional views illustrating a servo motor drive-based pilot-operated proportional cartridge valve of two embodiments of the present invention mounted on a valve block;
FIG. 2 is a schematic cross-sectional view of a servo motor drive based pilot-operated proportional cartridge valve according to an embodiment of the present invention;
FIG. 3 is an external view of a servo motor drive based pilot operated proportional cartridge valve according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of different operating positions of the pilot spool relative to the main spool according to an embodiment of the present invention.
The hydraulic control valve comprises a cover plate 1, a cover plate sealing ring 2, a return spring 3, a mounting hole 4, a first stepped hole 5, a second stepped hole 6, a third stepped hole 7, a bearing outer ring locking nut 8, a motor base 9, a coupler 10, a servo motor 11, a pilot valve core 12, a bearing inner ring locking nut 13, an angular contact ball bearing 14, a GREEN pressing plate 15, a shaft rotating GREEN 16, a first channel 17, a fixed damping hole 18, a process hole 19, a process plug 20, a second channel 21, a pilot oil path 22, a pilot oil path sealing ring 23, a control oil cavity 24, a guide screw 25, a guide bearing 26, a fifth channel 27, a guide groove 28, a third channel 29, a first main valve port 30, a second O-shaped ring 31, a fourth channel 32, a second main valve port 33, a mounting counter bore 34, a main valve core 35, a valve sleeve 36, a first O-shaped ring 37, a valve block 38, a variable damping hole 39 and a valve sleeve fixing.
Detailed Description
The invention is described in detail below with reference to the figures and the embodiments.
As shown in fig. 1(a), a pilot-operated proportional cartridge valve driven by a servo motor 11 includes: servo motor 11, cover plate 1, pilot valve element 12, main valve element 35 and valve sleeve 36. The servo motor 11 is fixedly mounted to the cover plate 1 through the motor base 9. The cover plate 1 is formed with mounting holes 4. One end of the pilot valve core 12 passes through the mounting hole 4 and is fixedly connected to an output shaft of the servo motor 11. The other end of the pilot valve spool 12 is slidably disposed in an inner hole of the main valve spool 35 in a clearance fit manner. A variable orifice 39 having a variable flow area is formed between pilot valve element 12 and main valve element 35. The main valve spool 35 is slidably disposed in the bore of the valve sleeve 36 in a clearance fit. The valve housing 36 is formed with a first main valve port 30, a second main valve port 33 for connection to an application. The cover plate 1, the pilot valve core 12, the main valve core 35 and the valve sleeve 36 together form a control oil chamber 24. The control chamber 24 communicates with the second main valve port 33 through a variable orifice 39.
As a preferred embodiment, as shown in fig. 1(a), a fixed orifice 18, a first passage 17 for connecting the control oil chamber 24 and the fixed orifice 18, and a second passage 21 for connecting the fixed orifice 18 and the pilot oil passage 22 are formed in the cover plate 1. In a particular application, the valve sleeve 36 is mounted in the mounting counterbore 34 of the valve block 38. The valve block 38 is formed with a third passage 29 for connecting the system with the first main valve port 30, a fourth passage 32 for connecting the system with the second main valve port 33, and a fifth passage 27 for connecting the third passage 29 and the pilot oil passage 22. The high-pressure oil is branched into two branches after flowing from the third passage 29. The first branch flows to the fourth passage 32 through the first main valve port 30, the second main valve port 33, and the second branch flows to the fourth passage 32 in the valve block 38 through the fifth passage 27 in the valve block 38, the pilot oil passage 22, the second passage 21 in the cover plate 1, the fixed orifice 18, the first passage 17 in the cover plate 1, the control oil chamber 24, the variable orifice 39, the second main valve port 33, and finally.
As another preferred embodiment, as shown in FIG. 1(b), the main valve element 35 is formed with a fixed orifice 18 ', a first passage 17 ' for connecting the control chamber 24 and the fixed orifice 18 ', and a second passage 21 ' for connecting the fixed orifice 18 ' and the first main valve port 30. In a particular application, the valve sleeve 36 is mounted in the mounting counterbore 34 of the valve block 38. The valve block 38 is formed with a third passage 29 for connecting the system with the first main valve port 30, a fourth passage 32 for connecting the system with the second main valve port 33. High pressure oil from the third passage 29 in the valve block 38 splits into two branches after flowing into the first main valve port 30. The first branch flows through the first main valve port 30 and the second main valve port 33 to the fourth passage 32 in the valve block 38, and the second branch flows through the second passage 21 ' in the main valve spool 35, the fixed orifice 18 ', the first passage 17 ' in the main valve spool 35, the control oil chamber 24, the variable orifice 39, the second main valve port 33 and finally to the fourth passage 32 in the valve block 38.
In a preferred embodiment, the fixed damping hole may be formed by a screw plug having a through hole with a fixed diameter and installed on the oil path or directly machined on the oil path.
In a preferred embodiment, the outer wall of main valve element 35 is formed with a guide groove 28 along the axial direction of main valve element 35. The valve sleeve 36 is provided with a guide screw 25 for cooperating with the guide groove 28 to guide the movement of the main spool 35.
In a preferred embodiment, a guide bearing 26 is sleeved on one end of the guide screw 25, which is matched with the guide groove 28.
As a preferred embodiment, the upper end portion of the pilot valve spool 12 is formed with an external thread for mounting a bearing inner race lock nut 13 that axially presses the pilot valve spool 12 and a bearing inner race.
In a preferred embodiment, the valve housing 36 is formed with a plurality of first main ports 30. The first main valve ports 30 are distributed uniformly in the circumferential direction of the valve sleeve 36.
In a preferred embodiment, a return spring 3 is mounted on the upper end of the main valve element 35, and the return spring 3 applies a downward biasing force to the main valve element 35 to ensure that the main valve element 35 is at the lowermost position when the pilot oil pressure supplied from the first main valve port 30 is insufficient.
As a preferred embodiment, the cap plate 1 is formed with a first stepped hole 5, a second stepped hole 6, and a third stepped hole 7. The first stepped hole 5 is provided with a rotary GREEN 16 for a shaft. The second stepped hole 6 is internally provided with a GREEN pressing plate 15 and an angular contact ball bearing 14. And a bearing outer ring locking nut 8 is arranged in the third stepped hole 7. The rotary GREEN 16 for the shaft, the GREEN pressing plate 15, the angular contact ball bearing 14 and the bearing outer ring locking nut 8 are sequentially arranged from bottom to top in the vertical direction. The bearing outer ring and the GREEN pressing plate 15 are pressed on the cover plate 1 together by the bearing outer ring locking nut 8. The bearing inner ring lock nut 13 presses the pilot valve spool 12 and the inner ring of the angular contact ball bearing 14 together. Thus, the pilot spool 12 can only undergo rotational movement about its axis and cannot undergo translational movement along its axis. The angular contact ball bearing 14 can reduce the friction resistance when the pilot valve rotates, and make the pilot valve core 12 bear certain axial unbalance force. The rotary GREEN 16 for the shaft prevents the high-pressure oil in the control oil chamber 24 from overflowing from a gap between the pilot spool 12 and the cover plate 1.
In this embodiment, a cover seal 2 and a pilot oil path seal 23 are provided between the cover 1 and the valve block 22. The cover plate seal ring 2 and the pilot oil passage seal ring 23 are used for preventing high-pressure oil in the control oil chamber 24 and the pilot oil passage 22 from overflowing through a gap between the cover plate 1 and the valve block 22, respectively. Specifically, the cover plate 1 is provided with a seal ring 2 sleeved on the periphery of the valve sleeve 36, and the pilot oil path seal ring 23 is provided in a seal ring groove coaxial with the pilot oil path 22 on the cover plate 1. A first O-ring 37 and a second O-ring 31 are provided between the valve block 22 and the valve sleeve 36. The first and second O- rings 37 and 31 are used to prevent high pressure oil from the first and second main ports 30 and 33, respectively, from escaping through the gap between the valve block 22 and the valve sleeve 36. Specifically, a first O-ring 37 and a second O-ring 31 are provided at both ends of the valve housing 36, respectively.
Based on the above structure, main valve element 35 can only move linearly in the axial direction, but cannot rotate, under the cooperation of guide screw 25 and guide groove 28. Further, the guide bearing 26 provided at one end of the guide screw 25 and the guide groove 28 form a rolling fit, thereby reducing wear and friction on the contact surface of the two.
Fig. 4 shows the relationship between the flow area of the variable orifice and the angle of rotation of pilot valve element 12 and the displacement of main valve element 35. The lower end of the pilot valve core 12 is inserted into an inner hole at the upper end of the main valve core 35 in a clearance fit mode, the lower end of the pilot valve core 12 forms a spiral notch along the circumference, and the upper end of the main valve core 35 is provided with a rectangular notch. The relative position of the overlapping part of the spiral notch at the lower end of the pilot valve and the rectangular throttling groove at the upper end of the main valve core 35 determines the flow area of the variable throttling hole. Movement of main spool 35 in the axial direction or rotation of pilot spool 12 about the axis changes the flow area of the variable orifice.
The main function of the invention is to change the flow area of the variable damping hole 39 by driving the pilot valve core 12 to rotate through the servo motor 11. The high-pressure oil is output through a hydraulic half-bridge consisting of the fixed damping hole 18 and the variable damping hole 39 to drive the main valve core 35 to move relative to the valve sleeve 36, and finally the flow area of the variable throttling opening of the main valve is changed.
The sequence of actions controlling the movement of main spool 35 in the direction away from second main valve port 33 in the direction of its axis is as follows:
the servo motor 11 drives the pilot valve core 12 to rotate clockwise, the flow area of the variable damping hole 39 is increased, the pressure of the control oil cavity 24 is reduced, and the main valve core 35 moves in the direction away from the second main valve port 33 under the action of axial hydraulic unbalance force. At this time, the main valve port flow area of the cartridge valve gradually increases. Along with the movement of the main valve core 35, the flow area of the variable damping hole 39 is gradually reduced, the pressure of the control oil cavity 24 is increased until the axial stress of the main valve core 35 reaches the balance state again, and the flow area of the main valve opening of the cartridge valve is kept stable.
The sequence of actions controlling the movement of main spool 35 along its axis in the direction approaching second main valve port 33 is as follows:
the servo motor 11 drives the pilot valve core 12 to rotate anticlockwise, the flow area of the variable damping hole 39 is reduced, the pressure of the control oil cavity 24 is increased, and the main valve core 35 moves towards the direction close to the second main valve port 33 under the action of axial hydraulic unbalance force. At this time, the main valve port flow area of the cartridge valve gradually decreases. Along with the movement of the main valve core 35, the flow area of the variable damping hole 39 is gradually increased, the pressure of the control oil cavity 24 is reduced until the axial stress of the main valve core 35 reaches the balance state again, and the valve port flow area of the cartridge valve is kept stable.
In summary, the servo motor 11 drives the pilot valve element 12 to rotate by a certain angle, and the main valve element 35 can be proportionally controlled to move by a certain distance along the axial direction, so that the proportional control of the rotation angle of the servo motor 11 on the opening of the main valve port is realized.
The cartridge valve mentioned above is a pilot type proportional cartridge valve provided by the present invention and driven by the servo motor 11.
The pilot type proportional cartridge valve driven by the servo motor drives the pilot valve core 12 to rotate through the servo motor 11, the variable damping hole 39 formed between the pilot valve core 12 and the main valve core 35 and the fixed damping hole 18 on the pilot oil inlet channel form a hydraulic half bridge, the main valve core 35 is driven to move through high-pressure oil output by the hydraulic half bridge, and meanwhile follow-up control is achieved between the main valve core 35 and the pilot valve core 12 through hydraulic negative feedback. The servo motor 11 drives the pilot valve core 12, and only the influence of smaller inertia force, friction force and hydraulic unbalance force needs to be overcome, so that the servo motor 11 with smaller power can be selected, and the response speed of the servo motor 11 is improved. The full stroke rotation angle of the pilot valve core 12 is small, which is beneficial to shortening the step response time of the pilot valve core 12. These two features are beneficial to improving the response speed of main spool 35; the hydraulic half-bridge converts the rotation angle of pilot valve element 12 into the pressure of control oil cavity 24, and can provide enough driving force for main valve element 35, and the driving force of main valve element 35 is not limited by the power of servo motor 11. The stroke of the main valve element 35 is related only to the lead of the pilot valve element 12, and is not limited by the stroke of the pilot valve element 12. The two characteristics are beneficial to improving the maximum working pressure and the maximum working flow of the main valve port.
The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It should be understood by those skilled in the art that the above embodiments do not limit the present invention in any way, and all technical solutions obtained by using equivalent alternatives or equivalent variations fall within the scope of the present invention.

Claims (6)

1. The utility model provides a pilot-operated formula proportional cartridge valve based on servo motor drive, its structure includes: servo motor, apron, guide valve core, main valve core and valve barrel, characterized by: the servo motor shell is fixedly connected with the cover plate; the cover plate is fixedly connected with the valve sleeve; the output shaft of the servo motor is fixedly connected with the pilot valve core, and the pilot valve core can rotate around the axis of the pilot valve core; the pilot valve core is arranged in an inner hole of the main valve core, and the excircle of the pilot valve core is in clearance fit with the inner hole of the main valve core; the main valve core is arranged in an inner hole of the valve sleeve, and the excircle of the main valve core is in clearance fit with the inner hole of the valve sleeve; a variable damping hole is formed between the pilot valve core and the main valve core, and the flow area of the variable damping hole changes along with the change of the rotation angle of the pilot valve core and the axial displacement of the main valve core; a control oil cavity is formed at the top of the main valve core; the control oil cavity is communicated with a second main valve port through the variable damping hole; the control oil chamber is communicated with the first main valve port through an oil inlet channel containing a fixed damping hole.
2. The servo motor drive based pilot operated proportional cartridge valve of claim 1, wherein:
a guide device is arranged between the main valve core and the valve sleeve, and the guide device prevents the main valve core from rotating around the axis of the main valve core and allows the main valve core to linearly move along the axis of the main valve core.
3. The servo motor drive based pilot operated proportional cartridge valve of claim 1, wherein:
the pilot valve core can only rotate around the axis of the pilot valve core.
4. The servo motor drive based pilot operated proportional cartridge valve of claim 1, wherein:
the control oil cavity is surrounded by a cover plate, a pilot valve core, a main valve core and a valve sleeve.
5. The servo motor drive based pilot operated proportional cartridge valve of claim 1, wherein:
an oil inlet passage between the control oil chamber and the first main valve port is located in the main valve core.
6. The servo motor drive based pilot operated proportional cartridge valve of claim 1, wherein:
the cover plate is internally provided with a pilot oil way, the pilot oil way is communicated with the first main valve port through an external oil way, and the pilot oil way and the external oil way jointly form an oil inlet channel between the control oil cavity and the first main valve port.
CN202010120674.0A 2020-02-26 2020-02-26 Pilot-operated proportional cartridge valve based on servo motor drive Pending CN111207238A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010120674.0A CN111207238A (en) 2020-02-26 2020-02-26 Pilot-operated proportional cartridge valve based on servo motor drive

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010120674.0A CN111207238A (en) 2020-02-26 2020-02-26 Pilot-operated proportional cartridge valve based on servo motor drive

Publications (1)

Publication Number Publication Date
CN111207238A true CN111207238A (en) 2020-05-29

Family

ID=70783758

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010120674.0A Pending CN111207238A (en) 2020-02-26 2020-02-26 Pilot-operated proportional cartridge valve based on servo motor drive

Country Status (1)

Country Link
CN (1) CN111207238A (en)

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