WO2020082271A1

WO2020082271A1 - Location tracking type pilot-operated proportional hydraulic valve

Info

Publication number: WO2020082271A1
Application number: PCT/CN2018/111699
Authority: WO
Inventors: 邢朔; 盛玮
Original assignee: 武汉海力威机电科技有限公司
Priority date: 2018-10-24
Filing date: 2018-10-24
Publication date: 2020-04-30

Abstract

A location tracking type pilot-operated proportional hydraulic valve, wherein the main structure only consists of a drive motor (1), a pilot valve (4), and a main valve (8). The pilot valve (4) is provided with a cylindrical pilot valve core (3). The left end of the pilot valve core (3) is connected to the power output end of the drive motor (1) by means of a spline pair (2), and the right end is connected to a left piston (9) of the main valve (8) by means of a screw pair (5) and a feedback rod (6). Port A and port B of the pilot valve (4) communicate with a left oil cavity (7) and a right oil cavity (12), respectively. The location tracking type pilot-operated proportional hydraulic valve can automatically track input signals, and features a simple structure and accurate positioning.

Description

Position tracking type pilot proportional hydraulic valve

Technical field

The invention relates to hydraulic control equipment, in particular to a position tracking type pilot proportional hydraulic valve.

Background technique

Electro-hydraulic proportional valve is a very important control element in the hydraulic field, mainly used for speed and position control of hydraulic machinery. At present, electro-hydraulic proportional valves generally use proportional electromagnets to control the pilot valve. The pilot valve controls the hydraulic oil entering the left and right chambers of the main valve to control the position of the main spool, and has a position sensor as a spool feedback and special controller. The control algorithm performs position closed-loop control, the mechanism is complex, the control requirements are high, the cost of program development and debugging is high, and the use is difficult.

technical problem

The technical problem to be solved by the present invention is to provide a position-tracking pilot proportional hydraulic valve, which avoids complex processor algorithm control and a long debugging and development cycle, and realizes the proportional position control of the main valve control equipment with a simple and reliable hardware structure.

Technical solution

The position tracking type pilot proportional hydraulic valve is characterized in that the main body structure is only composed of a driving motor, a pilot valve and a main valve; wherein,

The pilot valve is a three-position four-way reversing hydraulic valve, which is provided with a valve body and a cylindrical pilot valve spool. The pilot valve spool can rotate around its axis and translate along the axis;

A left oil chamber and a right oil chamber are provided at both ends of the valve cavity of the main valve. The main valve spool is arranged between the left oil chamber and the right oil chamber of the valve chamber, and between the left oil chamber and the main valve spool There is a left piston movable along the axis and hermetically embedded with the valve cavity, and a right piston movable along the axis and hermetically embedded with the valve cavity is provided between the right oil cavity and the main valve spool;

One end of the pilot valve spool is connected to the power output rotating shaft of the drive motor through a spline pair, and the other end is connected to one end of the feedback rod through a threaded pair, and the other end of the feedback rod is connected to the left piston;

The port A and the port B of the pilot valve on the side far from the screw pair communicate with the left oil chamber, and the port B on the side near the screw pair communicates with the right oil chamber.

Preferably, all axial end surfaces of the feedback rod and the threaded pair are not in contact or communication with the left oil chamber.

The two sides connected by the spline pair are limited in the relative freedom of movement in the radial and circumferential directions, and have the freedom of axial movement at least in the axial stroke of the spool of the pilot valve.

The threaded rod side of the threaded pair is the pilot valve spool or fixedly connected to the pilot valve spool, the nut side of the threaded pair is connected to the feedback rod, and when the left piston makes an axial movement, the feedback rod drives the entire threaded pair and the pilot valve The spool moves axially.

The valve body of the pilot valve is relatively fixedly connected to the valve body of the main valve, and the left piston and the right piston are respectively connected or maintained in contact with the main valve spool.

The driving motor is a stepping motor or a servo motor or other rotating elements that can be positioned. .

Beneficial effect

The proportional control of the present invention adopts a position tracking method, which enables the main valve spool to automatically track the input signal without the need of a position sensor and controller, and has a simple structure, accurate positioning and fast response speed.

The invention directly affects the position of the main valve spool to the pilot valve spool. When the main valve spool is opened to the required opening, the pilot valve spool is automatically closed, so as to automatically track the rotation angle of the drive motor and complete opening the main valve spool The precise control of the degree does not require a spool displacement sensor and controller. The structure is simple, the reliability is high, the response speed is fast, the cost is low, a lot of development and debugging time is saved, and the maintenance is simple.

BRIEF DESCRIPTION

Figure 1 is a schematic diagram of the overall structure of the present invention,

Figure 2 is an enlarged view of the pilot valve structure.

In the picture: 1—drive motor, 2—spline pair, 3—pilot valve spool, 4—pilot valve, 5—thread pair, 6—feedback lever, 7—left oil chamber, 8—main valve, 9—left Piston, 10-main valve spool, 11-right piston, 12-right oil chamber.

Best Mode of the Invention

The present invention will be further described below with reference to the drawings and embodiments. As shown in FIG. 1, the position-tracking pilot proportional hydraulic valve has a main structure consisting of only a drive motor 1, a pilot valve 4 and a main valve 8.

The pilot valve 4 is a three-position four-way reversing hydraulic valve, which is provided with a valve body and a cylindrical pilot valve spool 3. The pilot valve spool 3 can rotate around its own axis and translate along the axis.

It can be seen from FIG. 2 that the principle of the enlarged pilot valve is structured. The oil circuit interface with the outside world is provided on the annular groove on the inner wall of the valve body. The spool is provided with an annular convex edge corresponding to the position of the annular groove, as shown in FIG. 1, The valve core is provided with 4 ring-shaped convex edges, which are separated into 3 ring-shaped chambers in coordination with the valve body. The middle chamber communicates with the oil supply end P, and the two chambers communicate with the oil return end T. The middle The two convex edges of the are exactly closing the port A and the port B, as shown in the embodiment, port A is on the left, and port B is on the right. When the spool moves to the left at the current position, the oil supply port P communicates with the port A, and when the spool moves to the right at the current position, the oil supply port P communicates with the port B.

The main valve 8 is provided with a left oil chamber 7 and a right oil chamber 12 at both ends of the valve chamber. The main valve spool 10 is provided between the left oil chamber and the right oil chamber of the valve chamber. Between the left oil chamber 7 and the main valve Between the spool 10, there is a left piston 9 movable along the axis and hermetically embedded with the valve cavity, and between the right oil chamber 12 and the main valve spool 10, there is a right piston movable along the axis and hermetically embedded with the valve cavity Piston 11. When the pressure in the left oil chamber is greater than the right oil chamber, the main valve spool is pushed to move to the right, and when the pressure in the left oil chamber is less than the right oil chamber, the main valve spool is pushed to move to the left. During the movement of the main valve spool, different openings of the valve ports are generated.

All the axial end surfaces of the feedback rod 6 and the screw pair 5 do not contact or communicate with the left oil chamber 7. Therefore, the feedback lever 6 itself is not affected by the oil pressure of the left oil chamber. The feedback lever is only driven to move axially when the main valve spool is driven by the pressure difference between the left oil chamber and the right oil chamber.

One end of the spool 3 of the pilot valve is connected to the power output shaft of the drive motor 1 through a spline pair 2, and the two sides connected to the spline pair 2 are limited in relative radial and circumferential freedom of movement, at least in the pilot The valve spool 3 has an axial freedom of movement within the axial stroke. The two sides of the normal spline pair are the key and the key slot, and the key is embedded in the key slot to complete the torque transmission. When there is axial freedom between the key and the keyway, the distance between the key and the two end parts connected to the keyway can change with the relative movement between the key and the keyway.

The other end of the spool 3 of the pilot valve is connected to one end of the feedback rod 6 through a screw pair 5, and the other end of the feedback rod 6 is connected to the left piston 9. The threaded rod side of the threaded pair 5 is the pilot valve spool 3 or fixedly connected to the pilot valve spool 3, and the nut side of the threaded pair 5 is connected to the feedback rod 6. When the pilot valve spool 3 rotates, under the action of the screw pair 5, the pilot valve spool 3 simultaneously moves in the axial direction, thereby generating a change in the opening degree of the pilot valve port. At the same time, if the left piston 9 moves axially, the combined feedback rod 6 drives the entire screw pair 5 and the pilot valve spool 3 to move axially.

The valve body of the pilot valve 4 and the valve body of the main valve 8 are relatively fixedly connected, so that the movement of the spool of the pilot valve can be completely transmitted to the left piston 9, and the movement of the left piston 9 can also be directly transmitted to the spool of the pilot valve 3. The left piston 9 and the right piston 11 are connected or maintained in contact with the main valve spool 10, respectively. Therefore, the movement of the main valve spool is completely transmitted to the left piston 9 and the feedback rod 6.

The driving motor 1 is a stepping motor or a servo motor or other positionable rotating elements, which can all play the same role.

In the embodiment of FIG. 1, the port A and the port B of the pilot valve 4 on the side far from the screw pair communicate with the left oil chamber 7, and the port B on the side near the screw pair communicates with the right oil chamber 12. When the driving motor 1 rotates, the spline pair 2 drives the pilot valve spool 3 to rotate. Because the other end is a threaded pair 5, the pilot spool 3 generates an axial displacement when rotating, thereby opening the pilot valve port. The left oil chamber 7 or the right oil chamber 12 of the main valve supplies oil to move the main valve spool 10. Since the main valve spool 10 is connected to the nut of the threaded pair 5, the pilot valve is driven by the threaded pair 5 when the main valve spool 10 moves The spool 3 moves together. When the main valve spool 10 moves a distance equal to the distance of the pilot valve spool 3 driven by the drive motor 1, the pilot valve closes and the hydraulic oil is sealed in the left oil chamber 7 and the right oil of the main valve In the cavity 10, the main valve spool stops moving. This produces a valve opening that is proportional to the rotation angle of the drive motor.

For example, when the drive motor 1 rotates by an angle according to the set value, the pilot valve spool 3 rotates accordingly, and axial movement occurs under the action of the thread pair 5. Taking the embodiment of FIG. 1 as an example, the pilot valve spool Move to the right, at this time, the feedback lever 6 remains in its original position, the pilot valve spool only moves in the internal space of the threaded pair, the movement of the pilot valve spool relative to the pilot valve body causes the pilot valve port to open, and the pressure end of the pilot valve P communicates with the valve port b, and the oil return port T communicates with the valve port a. Since the valve port b communicates with the right oil chamber 12 of the main valve and the valve port a communicates with the left oil chamber 7, a hydraulic circuit is formed. The main valve spool 10, the right piston 11 and the left piston 9 move to the left, so the feedback lever 6 is also moved to the left, and the feedback lever 6 pushes the threaded pair 5 and the pilot valve spool 3 to the left until the pilot valve port is closed , The main valve spool stops moving. At this time, it is precisely that the pitch distance corresponding to the rotation angle of the drive motor is equal to the moving distance of the main valve spool, so that the pilot valve spool and the main valve spool are reset and closed again. A

Claims

A position tracking type pilot proportional hydraulic valve, characterized in that the main body structure is only composed of a driving motor (1), a pilot valve (4) and a main valve (8); wherein,

The pilot valve (4) is a three-position four-way reversing hydraulic valve, which is provided with a valve body and a cylindrical pilot valve spool (3). The pilot valve spool (3) can rotate around its own axis and translate along the axis;

A left oil cavity (7) and a right oil cavity (12) are provided at both ends of the valve cavity of the main valve (8), and a main valve spool (10) is provided between the left oil cavity and the right oil cavity of the valve cavity, Between the left oil chamber (7) and the main valve spool (10) there is a left piston (9) movable along the axis and tightly embedded with the valve chamber, the right oil chamber (12) and the main valve spool (10) ) There is a right piston (11) movable along the axis and tightly embedded with the valve cavity;

One end of the pilot valve spool (3) is connected to the power output shaft of the drive motor (1) through a spline pair (2), and the other end is connected to one end of a feedback lever (6) through a threaded pair (5). (6) The other end is connected to the left piston (9);

Port A and port B of the pilot valve (4) on the side far from the threaded pair communicate with the left oil chamber (7), and port B on the side close to the threaded pair communicates with the right oil chamber (12).
The hydraulic valve according to claim 1, characterized in that all axial end surfaces of the feedback rod (6) and the threaded pair (5) do not contact or communicate with the left oil chamber (7).
The hydraulic valve according to claim 1, characterized in that: the two sides connected by the spline pair (2) are limited in the radial and circumferential relative freedom of movement, at least in the pilot valve spool (3) There is freedom of axial movement within the axial stroke.
The hydraulic valve according to claim 1, characterized in that the threaded rod side of the threaded pair (5) is a pilot valve spool (3) or is fixedly connected to the pilot valve spool (3), and the threaded pair (5) The nut side is connected with the feedback rod (6). When the left piston (9) moves axially, the feedback rod (6) drives the threaded pair (5) and the pilot valve spool (3) to move axially.
The hydraulic valve according to claim 1, characterized in that the valve body of the pilot valve (4) is relatively fixedly connected to the valve body of the main valve (8), and the left piston (9) and the right piston (11) Connect or maintain contact with the main valve spool (10) respectively.
The hydraulic valve according to any one of claims 1 to 5, characterized in that the driving motor (1) is a stepping motor, a servo motor, or other rotating elements that can be positioned.