Digital valve

Abstract

The invention discloses a digital valve, and relates to the technical field of hydraulic pressure, the digital valve comprises a valve body assembly, a front end cover assembly and a rear end cover assembly are respectively mounted at the front end and the rear end of the valve body assembly, a distribution shaft assembly is rotatably arranged in the valve body assembly, and a driving assembly for driving the distribution shaft assembly to rotate is mounted on the front end cover assembly. A traditional valve element structure is decomposed into the distribution shaft and the hollow valve element, traditional linear and rotary double motion of the valve element is decomposed into linear motion of the hollow valve element and rotary motion of the distribution shaft, the driving structure of the valve element is greatly simplified, a mechanical closed loop is achieved, and the control precision and the response speed of the digital valve are improved.

Description

Technical Field

[0001] The invention relates to the field of hydraulic technology, and in particular to a digital valve. Background Art

[0002] A digital valve, or digital control valve, is a hydraulic valve that uses digital signals to directly control the flow, pressure and direction of oil.

[0003] The digital valve is composed of a motor, a valve core, a valve sleeve, a valve body and related connectors and seals. The motor includes a servo motor, a stepper motor, a voice coil motor, etc. The motor controller inputs a digital signal to the motor to control the rotation of the motor output shaft. The motor output shaft drives the valve core to achieve linear motion or rotational motion through the driver. The valve core structure and the valve core motion control structure directly affect the comprehensive performance of the digital valve. There are two main types of valve core motion, one is the valve core linear motion, and the other is the 2D digital valve valve core rotation and sliding dual motion. Among them, the driving methods of the valve core linear motion include electromagnetic drive, ball screw drive, eccentric wheel structure drive composed of connecting blocks, screw sleeve drive, etc. The control accuracy of this type of valve core is affected by the drive, and it is easy to produce dead zone and zero drift. In addition, if the output power is increased, it is necessary to increase the pilot control. For the 2D digital valve valve core rotation and sliding dual motion, a more complex conversion mechanism is required between the motor and the valve core, such as electromagnetic components, mechanical transmission components, etc., resulting in a more complex structure.

[0004] Therefore, how to provide a digital valve with a simple structure and low difficulty in manufacturing parts has become a difficult problem that needs to be solved urgently by technical personnel in this field. Summary of the invention

[0005] The purpose of the present invention is to provide a digital valve to solve the problems of complex structure and low control accuracy of existing digital valves.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] The present invention provides a digital valve, comprising a valve body assembly, wherein a front end cover assembly and a rear end cover assembly are respectively installed at the front and rear ends of the valve body assembly, a distribution shaft assembly is rotatably arranged inside the valve body assembly, and a driving assembly for driving the distribution shaft assembly to rotate is installed on the front end cover assembly.

[0008] Optionally, the valve body assembly includes a valve body, a valve sleeve, a hollow valve core and a steel ball, the valve sleeve is installed inside the valve body, and the hollow valve core is slidably connected to the inside of the valve sleeve through the steel ball.

[0009] Optionally, a columnar valve sleeve installation chamber is provided at the center of the valve body. An annular first oil outlet groove, first working groove, first oil inlet groove, second working groove, and second oil outlet groove are arranged in sequence from front to back on the side peripheral wall of the valve sleeve installation chamber. The cavities of the first oil outlet groove and the second oil outlet groove are connected by a process pipeline.

[0010] A first oil inlet, a first working port, a second working port, and a first oil outlet are provided on the side wall of the valve body. The first oil inlet is communicated with the first oil inlet groove, the first working port is communicated with the first working groove, the second working port is communicated with the second working groove, and the first oil outlet is communicated with the process pipeline.

[0011] Optionally, the valve sleeve is installed in the valve sleeve installation chamber. A chute parallel to the axis of the valve sleeve is provided on the inner wall of the valve sleeve. The steel ball is connected in the chute in a rolling manner. A plurality of through holes are arranged in an array on the side peripheral wall of the valve sleeve. The positions of the through holes correspond to the positions of the first oil outlet groove, the first working groove, the first oil inlet groove, the second working groove, and the second oil outlet groove respectively.

[0012] Optionally, a second oil inlet and a second oil outlet are provided on the side peripheral wall of the hollow chamber of the hollow valve core. A plurality of oil baffle plates are also installed on the side peripheral wall of the hollow valve core. The oil baffle plates are slidably connected with the inner wall of the valve sleeve. A hole groove is also provided on the side peripheral wall of the hollow valve core. The steel ball is connected in the hole groove in a rolling manner; springs are provided at both the front and rear ends of the hollow valve core.

[0013] Optionally, the distribution shaft assembly includes a bearing and a distribution shaft. The bearing is installed at the front end of the distribution shaft. The distribution shaft is rotatably arranged in the hollow chamber of the hollow valve core. Two spiral grooves are provided on the body of the distribution shaft. The positions of the two spiral grooves correspond to the positions of the second oil inlet and the second oil outlet respectively; the two ends of the spring at the front end of the hollow valve core are respectively abutted against the distribution shaft and the body of the hollow valve core. A left chamber is formed between the distribution shaft and the front-end body of the hollow valve core.

[0014] Optionally, the front end cover assembly includes a front end cover and a seal seat. The seal seat is installed on the front end cover. The front end of the distribution shaft is installed on the seal seat. The front end cover is installed on the valve body by second internal hexagonal screws; a first sealing ring is installed on the seal seat, a second sealing ring is installed on the front end cover, an oil seal hole is provided on the seal seat, and an oil seal is installed in the oil seal hole.

[0015] Optionally, the rear end cover assembly includes a retaining spring, a spring seat, a top seat and a rear end cover, the spring seat is fixed to the rear end cover by the retaining spring, a third sealing ring is installed on the rear end cover, a right cavity is opened on the body of the rear end cover, the top seat is inserted in the right cavity, the front end of the top seat and the rear end of the hollow valve core are abutted together, the two ends of the spring at the rear end of the hollow valve core are respectively abutted on the body of the hollow valve core and the spring seat, the right cavity is connected to the groove chamber of the first oil inlet groove through a process channel; the rear end cover is installed on the valve body by a third hexagon socket screw.

[0016] Optionally, the drive assembly includes a motor and a coupling, the motor is mounted on the front end cover by a first hexagon socket screw, one end of the coupling is transmission connected to the output end of the motor, and the other end passes through the front end cover and is transmission connected to the front end of the distribution shaft.

[0017] Compared with the prior art, the beneficial technical effects of the present invention are:

[0018] The present invention decomposes the traditional valve core structure into a distribution shaft and a hollow valve core, and decomposes the traditional valve core linear and rotational dual motion into the linear motion of the hollow valve core and the rotational motion of the distribution shaft, thereby greatly simplifying the valve core drive structure, realizing a mechanical closed loop, and improving the control accuracy and response speed of the digital valve.

[0019] The distribution shaft adopts the large pitch transmission principle and the sliding valve hydraulic half-bridge principle to realize the oil circuit control of the digital valve. At the same time, the distribution shaft adopts double spiral grooves to make the distribution shaft symmetrical in force and work smoothly.

[0020] The distribution shaft and the hollow valve core have a simple structure and are easy to process. The distribution shaft and the hollow valve core have high control accuracy and high dynamic response frequency, and can achieve high-pressure and large-flow control.

[0021] The present invention has a simple structure and high transmission efficiency, so the output power of the motor can be appropriately reduced, and the motor controller inputs a digital signal to the motor to control the motor speed, effectively realizing the digital control of the hydraulic valve, and can be integrated into the hydraulic control system. The digital valve provided by the present invention has extremely high integration and programmability. In addition, the input signal of the motor can also be an analog signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described below in conjunction with the accompanying drawings.

[0023] Figure 1 It is a cross-sectional view of the digital valve of the present invention;

[0024] Figure 2 A top view of the digital valve of the present invention;

[0025] Figure 3 It is the bottom view of the digital valve of the present invention;

[0026] Figure 4 It is the schematic structural diagram of the distribution shaft of the present invention;

[0027] Figure 5 It is the cross-sectional view of the hollow valve core of the present invention;

[0028] Figure 6 It is the schematic structural diagram of the assembly of the distribution shaft and the hollow valve core of the present invention;

[0029] Figure 7 It is the schematic structural diagram of the assembly of the rear end cover and the spring seat of the present invention;

[0030] Figure 8 It is the side view of the valve sleeve of the present invention;

[0031] Figure 9 It is the partial cross-sectional view of the valve sleeve of the present invention;

[0032] Figure 10 It is the schematic structural diagram of the assembly of the hollow valve core and the valve sleeve of the present invention;

[0033] Figure 11 It is the front view of the valve body of the present invention;

[0034] Figure 12 It is the bottom view of the valve body of the present invention;

[0035] Figure 13 It is the cross-sectional view at position A of the valve body of the present invention;

[0036] Figure 14 It is the cross-sectional view at position B of the valve body of the present invention;

[0037] Figure 15 It is the cross-sectional view at position C of the valve body of the present invention.

[0038] Explanation of reference numerals: 1. Motor; 2. Coupling; 3. Front end cover; 4. Sealing seat; 5. Bearing; 6. Spring; 7. Valve body; 8. Valve sleeve; 9. Distribution shaft; 10. Hollow valve core; 11. Steel ball; 12. Snap ring; 13. Spring seat; 14. Top seat; 15. Rear end cover; 16-1. First hexagon socket head cap screw; 16-2. Second hexagon socket head cap screw; 16-3. Third hexagon socket head cap screw; 17. Oil seal;

[0039] 71. Valve sleeve installation chamber; 72. First oil outlet groove; 73. First working groove; 74. First oil inlet groove; 75. Second working groove; 76. Second oil outlet groove;

[0040] 741. First oil inlet; 731. First working port; 751. Second working port; 726. First oil outlet;

[0041] 81. Slide groove;

[0042] 101. Second oil inlet; 102. Second oil outlet; 103. Oil baffle; 104. Hole groove;

[0043] 18-1. First sealing ring; 18-2. Second sealing ring; 18-3. Third sealing ring. Detailed implementation manner

[0044] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0045] As Figures 1-15 shown, a digital valve includes a valve body assembly, a front end cover assembly and a rear end cover assembly are respectively installed at the front and rear ends of the valve body assembly, a distribution shaft assembly is rotatably arranged inside the valve body assembly, and a driving assembly for driving the distribution shaft assembly to rotate is installed on the front end cover assembly.

[0046] Specifically, the valve body assembly includes a valve body 7, a valve sleeve 8, a hollow valve core 10 and a steel ball 11. The valve sleeve 8 is installed inside the valve body 7, and the hollow valve core 10 is slidably connected inside the valve sleeve 8 through the steel ball 11.

[0047] Specifically, a columnar valve sleeve installation chamber 71 is opened at the center of the valve body 7. An annular first oil outlet groove 72, a first working groove 73, a first oil inlet groove 74, a second working groove 75 and a second oil outlet groove 76 are arranged in sequence from front to back on the circumferential wall of the valve sleeve installation chamber 71. The cavity of the first oil outlet groove 72 and the cavity of the second oil outlet groove 76 are communicated through a process pipeline;

[0048] A first oil inlet 741, a first working port 731, a second working port 751 and a first oil outlet 726 are opened on the side wall of the valve body 7. The first oil inlet 741 is communicated with the first oil inlet groove 74, the first working port 731 is communicated with the first working groove 73, the second working port 751 is communicated with the second working groove 75, and the first oil outlet 726 is communicated with the process pipeline.

[0049] Specifically, the valve sleeve 8 is installed in the valve sleeve installation chamber 71. A chute 81 parallel to the axis of the valve sleeve 8 is provided on the inner wall of the valve sleeve 8. The steel ball 11 is in rolling connection in the chute 81. A plurality of through holes are arranged in an array on the side peripheral wall of the valve sleeve 8. The positions of the through holes correspond to the positions of the first oil outlet groove 72, the first working groove 73, the first oil inlet groove 74, the second working groove 75, and the second oil outlet groove 76 respectively.

[0050] Specifically, a second oil inlet 101 and a second oil outlet 102 are provided on the side peripheral wall of the hollow cavity of the hollow valve core 10. A plurality of oil baffle plates 103 are further installed on the side peripheral wall of the hollow valve core 10. The oil baffle plates 103 are in sliding connection with the inner wall of the valve sleeve 8. A hole groove 104 is further provided on the side peripheral wall of the hollow valve core 10. The steel ball 11 is in rolling connection in the hole groove 104; a spring 6 is provided at each of the front and rear ends of the hollow valve core 10.

[0051] Specifically, the distribution shaft assembly includes a bearing 5 and a distribution shaft 9. The bearing 5 is installed at the front end of the distribution shaft 9. The distribution shaft 9 is rotatably arranged in the hollow cavity of the hollow valve core 10. Two spiral grooves are provided on the body of the distribution shaft 9. The positions of the two spiral grooves correspond to the positions of the second oil inlet 101 and the second oil outlet 102 respectively; the two ends of the spring 6 at the front end of the hollow valve core 10 are respectively abutted against the distribution shaft 9 and the body of the hollow valve core 10. A left cavity is formed between the distribution shaft 9 and the front end body of the hollow valve core 10.

[0052] Specifically, the front end cover assembly includes a front end cover 3 and a seal seat 4. The seal seat 4 is installed on the front end cover 3. The front end of the distribution shaft 9 is installed on the seal seat 4. The front end cover 3 is installed on the valve body 7 through a second hexagon socket head cap screw 16-2; a first sealing ring 18-1 is installed on the seal seat 4, a second sealing ring 18-2 is installed on the front end cover 3, an oil seal hole is provided on the seal seat 4, and an oil seal 17 is installed in the oil seal hole.

[0053] Specifically, the rear end cover assembly includes a circlip 12, a spring seat 13, a top seat 14, and a rear end cover 15. The spring seat 13 is fixed to the rear end cover 15 by the circlip 12. A third sealing ring 18-3 is installed on the rear end cover 15. A right cavity is formed in the body of the rear end cover 15. The top seat 14 is inserted into the right cavity. The front end of the top seat 14 abuts against the rear end of the hollow valve core 10. The two ends of the spring 6 at the rear end of the hollow valve core 10 respectively abut against the body of the hollow valve core 10 and the spring seat 13. The right cavity is communicated with the chamber of the first oil inlet groove 74 through a process hole. The rear end cover 15 is installed on the valve body 7 by a third hexagon socket head cap screw 16-3.

[0054] Specifically, the drive assembly includes a motor 1 and a coupling 2. The motor 1 is installed on the front end cover 3 by a first hexagon socket head cap screw 16-1. One end of the coupling 2 is drivingly connected to the output end of the motor 1, and the other end passes through the front end cover 3 and is drivingly connected to the front end of the distribution shaft 9.

[0055] The installation process of the digital valve of the present invention is as follows:

[0056] The first step is the cleaning operation: Before assembly, clean all components.

[0057] The second step is the installation of seals: Install the third sealing ring 18-3, the second sealing ring 18-2, and the first sealing ring 18-1 on the rear end cover 15, the front end cover 3, and the sealing seat 4 respectively. Install the oil seal 17 in the oil seal hole on the sealing seat 4.

[0058] The third step is the installation of the valve body assembly: Install the valve sleeve 8 in the valve sleeve installation chamber 71 of the valve body 7. Place the steel ball 11 in the hole groove 104 of the hollow valve core 10, and install the steel ball 11 and the hollow valve core 10 together in the valve sleeve 8.

[0059] The fourth step is the installation of the rear end cover assembly: Install the top seat 14 in the right cavity of the rear end cover 15, and then install the spring seat 13 and the circlip 12 on the rear end cover 15 in sequence.

[0060] The fifth step is the installation of the distribution shaft assembly: Install the bearing 5 on the distribution shaft 9.

[0061] The sixth step is the installation of the front end cover assembly: Install the sealing seat 4 into the front end cover 3, and install the distribution shaft assembly on the sealing seat 4.

[0062] The seventh step is the installation of the drive assembly: Install the coupling 2 on the output end of the motor 1.

[0063] Step 8, Final Assembly: Install two springs 66 into the mounting holes at the front and rear ends of the hollow valve core 10 respectively. Install the rear end cover assembly onto the valve body 7 and fix it with the third hexagon socket head cap screw 16-3. Install the front end cover assembly onto the valve body 7 and fix it with the second hexagon socket head cap screw 16-2. Install the drive assembly onto the front end cover 3 and fix it with the first hexagon socket head cap screw 16-1. Finally, install the plug onto the valve body 7 and the rear end cover 15 for sealing.

[0064] The working principle of the digital valve of the present invention is as follows:

[0065] When the distribution shaft 9 rotates, the spiral groove on the distribution shaft 9 controls the opening and closing states of the second oil inlet 101 and the second oil outlet 102 on the hollow valve core 10. There are three cases: Case 1, the second oil inlet 101 is closed and the second oil outlet 102 is closed at the same time; Case 2, the second oil inlet 101 is opened and the second oil outlet 102 is closed at the same time; Case 3, the second oil inlet 101 is opened and the second oil outlet 102 is opened at the same time.

[0066] During operation, high-pressure oil enters the right chamber of the hollow valve core 10. The distribution shaft 9 rotates. Since the first oil inlet 741 is connected to the first working port 731 and the second working port 751 is connected to the first oil outlet 726 inside the hollow valve core 10, at this time, the pressures of the first working port 731 and the second working port 751 are 1 / 2 of the pressure of the first oil inlet 741. The area of the right chamber is half of the area of the left chamber, and the pressure of the left chamber is half of the pressure of the first oil inlet 741. At this time, the pressures of the left and right chambers are equal, and the hollow valve core 10 remains stationary at the equilibrium position.

[0067] When the hollow valve core 10 moves linearly, there will be three cases: Case 1, zero position. Case 2, the first oil inlet 741 is connected to the first working port 731, and the second working port 751 is connected to the first oil outlet 726. Case 3; the first oil inlet 741 is connected to the second working port 751, and the first working port 731 is connected to the first oil outlet 726.

[0068] The debugging process of the digital valve of the present invention is as follows:

[0069] Install the digital valve on the test bench. There are four oil ports on the digital valve, namely the first oil inlet 741, the first oil outlet 726, the first working port 731, and the second working port 751. The first oil inlet 741 and the first oil outlet 726 on the test bench are respectively connected to the inlet and return oil ports of the hydraulic system, and a flowmeter is connected between the first working port 731 and the second working port 751.

[0070] After the first oil inlet 741 is filled with oil, the high-pressure oil acts on the right chamber through the process channel. The high-pressure oil pushes the top seat 14, and the top seat 14 pushes the hollow valve core 10 to move leftward. During the movement, the first oil inlet 741 is connected to the first working port 731, and the first oil outlet 726 is connected to the second working port 751. During the movement of the hollow valve core 10, the second oil inlet 101 on the hollow valve core 10 is connected to the spiral groove, and the high-pressure oil enters the left chamber through the spiral groove. Through the matching calculation of the volume parameters of the left and right chambers and the opening area parameters of the spiral groove and the hollow valve core 10, after the overlapping area of the spiral groove and the second oil inlet 101 of the hollow valve core 10 reaches a certain value, the forces on both ends of the hollow valve core 10 are equal, and the hollow valve core 10 is in a balanced position and remains stationary. At this time, a stable flow output can be maintained. When it is necessary to change the flow rate, a control signal is given to the motor 1, and the motor 1 rotates, driving the distribution shaft 9 to rotate to achieve the flow control function.

[0071] The controller gives a control signal to the motor 1 to make the motor 1 rotate. During the rotation, observe the flow reading until the flow reaches the maximum value, which is the maximum flow of the first working port 731. At this time, record the motor control parameters.

[0072] The controller gives a control signal to the motor 1 to make the motor 1 rotate in the reverse direction. The flow will gradually decrease to zero. Record the control parameters of the motor 1 at this time. Continue to give a control signal to the motor 1 to make the motor 1 continue to rotate in this rotation direction. The first oil inlet 741 is connected to the second working port 751, and the first oil outlet 726 is connected to the first working port 731. Observe the flow reading until the maximum value, which is the maximum flow of the second working port 751. At this time, record the motor control parameters.

[0073] Due to the manufacturing errors of the components, the maximum flow values of the first working port 731 and the second working port 751 will not be exactly the same. To ensure the stability of the working flow output, take the smaller value of the two flows of the first working port 731 and the second working port 751 as the maximum output flow value of the digital valve.

[0074] Repeat the above process to make the motor 1 rotate forward and backward multiple times, and finally determine the control parameters of the motor 1 when the digital valve is at zero flow and maximum flow.

[0075] When designing the digital valve, there is always a margin. Therefore, the rated output flow of the digital valve is less than the maximum output flow. According to the above process, make the motor 1 rotate forward and backward multiple times to determine the control parameters of the motor 1 when the digital valve is at zero flow and rated flow.

[0076] When the user uses it, just operate according to the parameters set for the motor 1, which is convenient to operate.

[0077] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0078] The above-described embodiments are only descriptions of the preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A digital valve, characterized in that: It includes a valve body assembly, wherein a front end cover assembly and a rear end cover assembly are respectively installed at the front and rear ends of the valve body assembly, a distribution shaft assembly is rotatably arranged inside the valve body assembly, and a driving assembly for driving the distribution shaft assembly to rotate is installed on the front end cover assembly.

2. The digital valve according to claim 1, characterized in that: The valve body assembly comprises a valve body (7), a valve sleeve (8), a hollow valve core (10) and a steel ball (11); the valve sleeve (8) is installed inside the valve body (7); and the hollow valve core (10) is slidably connected to the inside of the valve sleeve (8) via the steel ball (11).

3. The digital valve according to claim 2, characterized in that: A columnar valve sleeve installation chamber (71) is provided at the center of the valve body (7), and a first oil outlet groove (72), a first working groove (73), a first oil inlet groove (74), a second working groove (75) and a second oil outlet groove (76) are provided on the side peripheral wall of the valve sleeve installation chamber (71) in an annular shape and arranged in sequence from front to back, and the groove cavity of the first oil outlet groove (72) and the groove cavity of the second oil outlet groove (76) are connected through a process pipeline; The side wall of the valve body (7) is provided with a first oil inlet (741), a first working port (731), a second working port (751), and a first oil outlet (726); the first oil inlet (741) is connected to the first oil inlet groove (74); the first working port (731) is connected to the first working groove (73); the second working port (751) is connected to the second working groove (75); and the first oil outlet (726) is connected to the process pipeline.

4. The digital valve according to claim 3, characterized in that: The valve sleeve (8) is installed in the valve sleeve installation chamber (71), and a slide groove (81) parallel to the axis of the valve sleeve (8) is opened on the inner wall of the valve sleeve (8), and the steel ball (11) is rollingly connected in the slide groove (81). A plurality of through holes are arranged in an array on the side wall of the valve sleeve (8), and the positions of the through holes correspond to the positions of the first oil outlet groove (72), the first working groove (73), the first oil inlet groove (74), the second working groove (75) and the second oil outlet groove (76).

5. The digital valve according to claim 4, characterized in that: A second oil inlet (101) and a second oil outlet (102) are provided on the side circumferential wall of the hollow chamber of the hollow valve core (10); a plurality of oil baffles (103) are also installed on the side circumferential wall of the hollow valve core (10); the oil baffles (103) are slidably connected to the inner wall of the valve sleeve (8); a hole groove (104) is also provided on the side circumferential wall of the hollow valve core (10); the steel ball (11) is rollingly connected in the hole groove (104); a spring (6) is respectively provided at the front and rear ends of the hollow valve core (10).

6. The digital valve according to claim 5, characterized in that: The distribution shaft assembly comprises a bearing (5) and a distribution shaft (9), wherein the bearing (5) is mounted at the front end of the distribution shaft (9), and the distribution shaft (9) is rotatably arranged in the hollow chamber of the hollow valve core (10), and the body of the distribution shaft (9) is provided with two sections of spiral grooves, and the positions of the two sections of the spiral grooves respectively correspond to the positions of the second oil inlet (101) and the second oil outlet (102); the two ends of the spring (6) at the front end of the hollow valve core (10) are respectively abutted against the distribution shaft (9) and the body of the hollow valve core (10), and a left chamber is formed between the distribution shaft (9) and the front end body of the hollow valve core (10).

7. The digital valve according to claim 6, characterized in that: The front end cover assembly comprises a front end cover (3) and a sealing seat (4); the sealing seat (4) is mounted on the front end cover (3); the front end of the distribution shaft (9) is mounted on the sealing seat (4); the front end cover (3) is mounted on the valve body (7) via a second hexagon socket screw (16-2); a first sealing ring (18-1) is mounted on the sealing seat (4); a second sealing ring (18-2) is mounted on the front end cover (3); an oil seal hole is provided on the sealing seat (4), and an oil seal (17) is mounted in the oil seal hole.

8. The digital valve according to claim 6, characterized in that: The rear end cover assembly comprises a retaining spring (12), a spring seat (13), a top seat (14) and a rear end cover (15); the spring seat (13) is fixed to the rear end cover (15) by the retaining spring (12); a third sealing ring (18-3) is installed on the rear end cover (15); a right cavity is opened on the body of the rear end cover (15); the top seat (14) is inserted into the right cavity; the front end of the top seat (14) and the rear end of the hollow valve core (10) are abutted together; the two ends of the spring (6) at the rear end of the hollow valve core (10) are respectively abutted against the body of the hollow valve core (10) and the spring seat (13); the right cavity is connected to the groove chamber of the first oil inlet groove (74) through a process channel; the rear end cover (15) is installed on the valve body (7) by a third hexagon socket screw (16-3).

9. The digital valve according to claim 6, characterized in that: The drive assembly comprises a motor (1) and a coupling (2); the motor (1) is mounted on the front end cover (3) via a first hexagon socket screw (16-1); one end of the coupling (2) is drivingly connected to the output end of the motor (1), and the other end passes through the front end cover (3) and is drivingly connected to the front end of the distribution shaft (9).

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