Solenoid valve and control method

Abstract

An electromagnetic valve and a control method, the electromagnetic valve comprising a valve rod, a valve core, a magnetic ring and a Hall sensor, the electromagnetic valve having a valve port, the valve rod being fixedly connected with the valve core, the magnetic ring being fixedly connected with the valve rod, the position of the valve core relative to the valve port being controlled by a micro control unit acquiring the position of the magnetic ring, so that the position of the valve core relative to the valve port can be controlled by the micro control unit, that is, the electromagnetic valve can be flow-regulated.

Description

TECHNICAL FIELD

[0001] The present application relates to a valve, more particularly to a solenoid valve and a control method. BACKGROUND

[0002] The solenoid valve comprises a coil component, a moving iron core, a valve rod, and a valve core, the valve rod is fixedly connected with the moving iron core, the valve rod is fixedly connected with the valve core, under the magnetic field excitation of the coil component, the moving iron core can drive the valve rod to move up and down, so that the valve core acts relative to the valve port of the solenoid valve, to achieve the purpose of fluid switching or on-off, generally the solenoid valve cannot regulate the flow of fluid, in order to improve the flow control accuracy of the solenoid valve, how to make the solenoid valve be able to regulate the flow is a technical problem. SUMMARY

[0003] The purpose of the present application is to provide a solenoid valve and a control method, which can regulate the flow of the solenoid valve.

[0004] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0005] A solenoid valve comprises a coil, a position detection component, a valve rod, a valve core, a moving iron core, a static iron core, and an elastic element, the solenoid valve has a valve port, the position detection component comprises a magnetic ring, a Hall sensor, and a circuit board, the moving iron core is fixedly connected with the valve rod, the valve core is fixedly connected with the valve rod, the magnetic ring is fixedly connected with the valve rod, the static iron core is fixedly arranged, the elastic element is sleeved on the outer periphery of the valve rod, the elastic element is located between the moving iron core and the static iron core, at least part of the coil is located on the outer periphery of the moving iron core, the Hall sensor is electrically and / or signal connected with the circuit board, the Hall sensor can detect the position of the magnetic ring, the position of the valve core relative to the valve port is controlled by a micro control unit acquiring the position of the magnetic ring.

[0006] The present application also discloses a control method, which can control the position of the magnetic ring, and further control the position of the valve core relative to the valve port, so as to regulate the flow of the solenoid valve, the flow regulation comprises flow on-off and flow size regulation, the control method comprises the following steps:

[0007] The micro control unit acquires the actual position of the magnetic ring detected by the Hall sensor;

[0008] The micro control unit internally presets a preset position of the magnetic ring sent by an upper computer, and judges whether the actual position is same as the preset position;

[0009] If yes, the micro control unit controls the PWM module to output a current pulse signal;

[0010] If no, the micro control unit adjusts the effective duty cycle of the high level of the pulse signal output by the PWM module, so that the magnetic ring moves to the preset position.

[0011] The present application provides an electromagnetic valve and a control method, the electromagnetic valve comprises a valve rod, a valve core, a magnetic ring and a Hall sensor, the electromagnetic valve has a valve port, the valve rod is fixedly connected with the valve core, the magnetic ring is fixedly connected with the valve rod, and the position of the valve core relative to the valve port is controlled by the micro control unit to obtain the position of the magnetic ring, so that the position of the valve core relative to the valve port can be controlled by the micro control unit, that is, the flow of the electromagnetic valve can be adjusted. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a sectional structure schematic diagram of a first embodiment of the electromagnetic valve;

[0013] Figure 2 is Figure 1 is a schematic diagram of the relationship between the distance of the magnetic ring from the Hall sensor and the output voltage in the embodiment;

[0014] Figure 3 is a sectional structure schematic diagram of a second embodiment of the electromagnetic valve;

[0015] Figure 4 is Figure 3 is a schematic diagram of the positional relationship between the magnetic ring and the Hall sensor in the embodiment;

[0016] Figure 5 is Figure 3 is a partial sectional structure schematic diagram of another embodiment;

[0017] Figure 6 is Figure 3 is a schematic diagram of the X-axis, Y-axis and Z-axis direction relationship of the Hall sensor;

[0018] Figure 7 is Figure 3 is a schematic diagram of the magnetic field relationship of the Hall sensor in the Y-axis and Z-axis directions in the movement stroke of the magnetic ring;

[0019] Figure 8 is a schematic connection diagram of the position closed-loop control system of the electromagnetic valve;

[0020] Figure 9 is a specific circuit connection schematic diagram of the position closed-loop control system of the electromagnetic valve;

[0021] Figure 10 is a schematic diagram of the current relationship of the pulse signal output by the PWM module acting on the coil under different duty cycles;

[0022] Figure 11 is a connection schematic diagram of a third embodiment of the electromagnetic valve and a controller;

[0023] Figure 12 is a control flow diagram of the control method. DETAILED DESCRIPTION

[0024] The application will be further described below in conjunction with the drawings and specific embodiments:

[0025] The electromagnetic valve can be applied in the field of automobiles, see Figure 1 The electromagnetic valve 100 comprises a coil component 1, a valve seat 2, a moving iron core 3, a static iron core 4, a valve rod 5, valve cores 6, and an elastic element 7. The valve cores 6 are fixedly connected with the valve rod 5, the valve rod 5 is fixedly connected with the moving iron core 3, the static iron core 4 is fixedly arranged, at least part of the coil component 1 is located at the outer periphery of the moving iron core 3, the elastic element 7 is sleeved on the outer periphery of the valve rod 5 and located between the moving iron core 3 and the static iron core 4, the coil component 1 comprises a coil 11, the valve seat 2 has a valve port 21, the coil 11 generates an electromagnetic force after being electrified, the moving iron core 3 moves towards the static iron core 4 along the axial direction of the valve rod 5 under the action of the electromagnetic force, overcoming the elastic pressure of the elastic element 7, and simultaneously drives the valve rod 5 to act together; after the coil 11 is de-energized, the moving iron core 3 moves away from the static iron core 4 along the axial direction of the valve rod 5 under the action of the elastic pressure of the elastic element 7, and simultaneously drives the valve rod 5 to act together. That is, under the interaction of the electromagnetic force and the elastic pressure, the moving iron core 3 can drive the valve rod 5 to move up and down in the axial direction relative to the static iron core 4, so as to make the valve cores 6 move relative to the valve port 21; in this embodiment, the number of valve cores 6 is two, and correspondingly, the number of valve ports 21 is also two. Of course, as other embodiments, the valve cores and the valve ports can also be other numbers.

[0026] Referring to Figure 1 The electromagnetic valve 100 further comprises a position detection component 8, the position detection component 8 comprises a magnetic ring 81, a Hall sensor 82, and a circuit board 83. The moving iron core 3 is fixedly arranged at one end close to the valve rod 5, and the magnetic ring 81 is fixedly arranged at the other end away from the valve rod 5, that is, the magnetic ring 81 is arranged away from the coil component 1. This is conducive to reducing the magnetic leakage interference of the coil component 1 on the position detection component 8, that is, conducive to improving the detection accuracy. In this embodiment, the Hall sensor 82 is located directly below the magnetic ring 81, the Hall sensor 82 is arranged on the circuit board 83 and faces one side of the magnetic ring 81, and the Hall sensor 82 is electrically and / or signal connected with the circuit board 83. Of course, as other embodiments, the Hall sensor 82 can also be arranged away from the axial direction of the magnetic ring 81, as long as the Hall sensor 82 can detect the magnetic field of the magnetic ring 81.

[0027] In the embodiment, the Hall sensor 82 can be a linear Hall sensor, and the Hall sensor 82 can output different voltage signal values according to the size of the detected magnetic field strength. When the magnetic ring 81 moves in the axial direction of the valve rod 5, when the magnetic ring 81 is close to the Hall sensor 82, the Hall sensor 82 can detect a larger magnetic field strength, and the output voltage signal value is also larger. When the magnetic ring 81 is away from the Hall sensor 82, the Hall sensor 82 can detect a smaller magnetic field strength, and the output voltage signal value is also smaller. Specifically, see Figure 2 , the abscissa represents the distance between the magnetic ring 81 and the Hall sensor 82, and the ordinate represents the size of the voltage signal value output by the Hall sensor 82. When the distance between the magnetic ring 81 and the Hall sensor 82 is at the set closest distance, it is defined that the magnetic ring 81 is at the first position of the stroke, that is, the S1 point position (first position) in Figure 2 , and the voltage signal value output by the Hall sensor 82 is U1. When the distance between the magnetic ring 81 and the Hall sensor 82 is at the set farthest distance, it is defined that the magnetic ring 81 is at the second position of the stroke, that is, the S2 point position (second position) in Figure 2 , and the voltage signal value output by the Hall sensor 82 is U2, that is, the stroke of the electromagnetic valve is the distance between the S1S2 segment, and the distance between the magnetic ring 81 and the Hall sensor 82 can be calculated according to the voltage signal value output by the Hall sensor 82, so as to determine the specific position of the magnetic ring 81 in the stroke.

[0028] Since the linear Hall sensor is greatly affected by temperature changes, in the case of temperature interference, it may cause inaccurate position detection. In order to improve the above problems, a second embodiment of the electromagnetic valve 100 is provided, see Figure 3 , which is a second embodiment of the electromagnetic valve 100. In the embodiment, the Hall sensor 82 is a multi-axis Hall sensor, and along the radial direction of the magnetic ring 81, the Hall sensor 82 is located at the side of the magnetic ring 81. Specifically, see Figure 4 , the Hall sensor 82 includes a sensing point 821, and along the radial direction of the magnetic ring 81, the sensing point 821 can be located at the side when the magnetic ring 81 moves to the midpoint S3 of the stroke S1S2. See Figure 3 , the Hall sensor 82 is arranged on the circuit board 83 and faces one side of the magnetic ring 81, and the Hall sensor 82 is electrically and / or signal connected with the circuit board 83. Of course, as other embodiments, see Figure 5In order to reduce the influence of the magnetic ring 81 on the fluid flow resistance in the flow channel, a receiving cavity 22 can be arranged in the flow channel of the valve seat 2, and the valve rod 5 can be extended to extend into the receiving cavity 22, and the magnetic ring 81 is arranged in the receiving cavity 22 and fixedly arranged with the valve rod 5, so as to reduce the influence of the magnetic ring 81 on the fluid flow resistance in the flow channel. Of course, it is easy to think that in the first embodiment, the receiving cavity 22 can also be arranged in the flow channel of the valve seat 2, the valve rod 5 can be extended to extend into the receiving cavity 22, and the magnetic ring 81 is arranged in the receiving cavity 22 and fixedly arranged with the valve rod 5.

[0029] In the embodiment, referring to Figure 6 , the Hall sensor 82 can detect the magnetic field generated by the magnetic ring 81 in the X-axis, Y-axis and Z-axis directions, wherein the X-axis, Y-axis and Z-axis directions form a space rectangular coordinate system. When the magnetic ring 81 moves up and down with the valve rod 5 in the axial direction, the magnetic field detected by the Hall sensor 82 in the axial direction of the valve rod 5 is defined as the Z-axis direction magnetic field, the magnetic field detected in the radial direction is defined as the Y-axis direction magnetic field, and the other direction in the space rectangular coordinate system is defined as the X-axis direction. Since the magnetic field detected in the X-axis direction is very small during the movement of the electromagnetic valve 100, the position of the magnetic ring 81 is mainly determined by detecting the magnetic fields in the Z-axis direction and the Y-axis direction. Referring to Figure 7 (a), when the magnetic ring 81 moves up and down with the valve rod 5 in the axial direction, the magnetic fields of the magnetic ring 81 in the Z-axis and Y-axis directions detected between the strokes S1 and S2 of the electromagnetic valve 100 are approximately cosine wave distribution, the horizontal coordinate represents the movement stroke of the magnetic ring 81, and the vertical coordinate represents the magnetic field strength B detected by the Hall sensor 82, for the convenience of calculation, the magnetic field B Z detected in the Z-axis direction can be subjected to sine wave bias processing, and the magnetic flux amplitude of the Z-axis direction magnetic field B Z is equal to the magnetic flux amplitude m of the Y-axis direction magnetic field B Y , see Figure 7 (b) for details. In this way, within the strokes S1 and S2, the movement stroke s of the magnetic ring 81 can be calculated by formula (1):

[0030]

[0031] That is, the specific position of the stroke of the magnetic ring 81 can be calculated by detecting the magnetic fields of the magnetic ring 81 in the Z-axis direction and the Y-axis direction during the movement of the stroke S1 and S2 by the Hall sensor 82.

[0032] In order to enable the electromagnetic valve 100 to perform flow regulation, the electromagnetic valve 100 can be subjected to closed-loop control, see Figure 8, the circuit board 83 is integrated with a micro control unit 84 and a driving circuit 85, the micro control unit 84 includes a communication module 841, a control module 842 and a PWM (Pulse width modulation) module 843, the communication module 841 is used for communication with the host computer, the host computer sends the preset position instruction of the magnetic ring 81 to the communication module 841, the communication module 841 receives the instruction of the host computer and sends it to the control module 842, at the same time, the control module 842 receives the actual position signal of the magnetic ring 81 sent by the Hall sensor 82 to the control module 842, the control module 842 compares the actual position signal fed back by the Hall sensor 82 with the preset position instruction sent by the host computer, and controls the PWM module 843 to output a series of pulse signals to the driving circuit through the PID (Proportion-Integral-Differential) control mode, so that the coil part 1 of the electromagnetic valve 100 is electrified, specifically, the coil 11 is electrified, the coil 11 generates a magnetic field force after electrification, the moving iron core 3 is controlled to act, so that the magnetic ring 81 reaches the preset position. It should be noted that the duty cycle of the pulse signal output by the PWM module 843 can be changed, and then the effective value of the current acting on the coil 11 can be changed, and then the electromagnetic force generated by the coil 11 can be changed, and then the specific position where the magnetic ring 81 stays can be changed, that is, the specific actual position where the magnetic ring 81 stays can be adjusted by changing the duty cycle of the pulse signal output by the PWM module 843, so that the magnetic ring 81 reaches the preset position. In this way, the electromagnetic valve 100 can change the effective value of the current acting on the coil 11 by adjusting the duty cycle of the pulse signal output by the PWM module 843 according to the preset position instruction sent by the host computer, so that the magnetic ring 81 stays at any position between the strokes S1 and S2, thereby controlling the position of the valve core 6 relative to the valve port 21, that is, the electromagnetic valve 100 can be adjusted.

[0033] Referring to Figure 9 , the specific circuit connection diagram of the position closed-loop control system of the electromagnetic valve 100 mainly includes a driving circuit 85 and a power supply circuit 86, the power supply circuit 86 includes a transient voltage suppression (TVS) diode and a π-type filter, a vehicle-mounted power supply V BAT is connected to one end of the transient voltage suppression (TVS) diode, and the other end of the transient voltage suppression (TVS) diode is grounded. The transient voltage suppression (TVS) diode is arranged to eliminate damage of a surge voltage to electrical components; the π-type filter includes a first capacitor C1, a second capacitor C2 and a first inductor L1, the first inductor L1 is arranged between the first capacitor C1 and the second capacitor C2, and the π-type filter is arranged to filter the vehicle-mounted power supply V BAT , reduce interference and noise, and make the voltage output more stable; in this embodiment, the vehicle-mounted power supply V BATThe output voltage of the power supply circuit 86 is 12V DC, while the power supply of the micro control unit 84 and the Hall sensor 82 only needs 5V, so the power supply circuit 86 further comprises a three-terminal voltage regulator, which comprises an input terminal, an output terminal and a ground terminal, the input terminal of the three-terminal voltage regulator is connected with the filtered vehicle power supply V BAT , the ground terminal of the three-terminal voltage regulator is grounded, and the output terminal of the three-terminal voltage regulator is connected with the micro control unit 84 and the Hall sensor 82 and supplies power to the micro control unit 84 and the Hall sensor 82. The three-terminal voltage regulator is arranged to convert the 12V vehicle power supply into 5V DC to supply power to the micro control unit 84 and the Hall sensor 82. In addition, in order to improve the electromagnetic compatibility of the circuit, the power supply circuit 86 further comprises a third capacitor C3, a fourth capacitor C4 and a fifth capacitor C5.

[0034] The driving circuit 85 comprises a level conversion circuit 851 and a MOS tube. The pulse signal output by the PWM module 843 is connected with the gate of the MOS tube through the level conversion circuit 851, and is used to drive the on-off of the MOS tube. Specifically, the level conversion circuit 851 comprises a first transistor Q1, a second transistor Q2, a third transistor Q3, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and a sixth capacitor C6. The PWM module 843 is connected with one end of the first resistor R1, the second resistor R2, the third resistor R3 and the fifth resistor R5. The other end of the first resistor R1 is connected with the vehicle power supply V BAT . The other end of the second resistor R2 is connected with the base of the first transistor Q1. The other end of the third resistor R3 is grounded. The other end of the fifth resistor R5 is connected with the base of the third transistor Q3. The collector of the first transistor Q1 is connected with one end of the fourth resistor R4 and the base of the second transistor Q2. The emitter of the first transistor Q1 is grounded. The other end of the fourth resistor R4 is connected with the vehicle power supply V BAT . The collector of the second transistor Q2 is connected with the vehicle power supply V BATThe connection of the emitter of the second triode Q2 and one end of the sixth resistor R6, the collector of the third triode Q3, the emitter of the third triode Q3 connected to the ground, and the other end of the sixth resistor R6 connected to the gate of the MOS tube. The first resistor R1 and the third resistor R3 are set to superimpose the voltage of the pulse signal output by the PWM module 843. When the pulse signal output by the PWM module 843 itself cannot drive the triode to work, the voltage of the pulse signal needs to be superimposed to drive the triode to work. Of course, if the pulse signal output by the PWM module 843 itself can drive the triode to work, the level conversion circuit 851 can not include the first resistor R1 and the third resistor R3. When the pulse signal output by the PWM module 843 is at a high level, the first triode Q1 is turned on. Since the collector of the first triode Q1 is connected to the base of the second triode Q2, when the first triode Q1 is turned on, the second triode Q2 is also turned on. In the case where the second triode Q2 is turned on, since the base of the third triode Q3 is connected to the pulse signal through the fifth resistor R5, that is, the third triode Q3 is also turned on at the same time. In this way, the vehicle power V BAT The MOS tube is also turned on by connecting the sixth resistor R6 to the gate of the MOS tube. Of course, as another embodiment, if the pulse signal output by the PWM module 843 can directly drive the MOS tube to work, the drive circuit 85 can not include the level conversion circuit 851. One end of the coil 11 of the electromagnetic valve 100 is connected to the vehicle power V BAT The other end of the coil 11 is connected to the drain of the MOS tube, and the source of the MOS tube is connected to the ground. In this way, when the MOS tube is turned on, the vehicle power V BAT acts on the coil 11 to make the coil 11 energized and generate electromagnetic force. When the pulse signal output by the PWM module 843 is at a low level, the first triode Q2 is turned off, and the second triode Q2 and the third triode Q3 are also turned off accordingly. The gate of the MOS tube is also turned off without voltage drive, so that the coil 11 is de-energized. In addition, the seventh resistor R7 is set to make the gate of the MOS tube have good grounding performance, and the sixth capacitor C6 is set to improve the electromagnetic compatibility of the circuit, or the seventh resistor R7 and the sixth capacitor C6 are set to protect the MOS tube. See Figure 10Since the current flowing through the coil 11 (equivalent to inductance) lags behind the voltage, that is, when the coil 11 is powered off, the current flowing through the coil 11 does not disappear immediately, and the carrier frequency of the pulse signal output by the PWM module 843 is generally kHz level, so when the pulse signal is at low level, the coil 11 is powered off, and the current flowing through the coil 11 begins to drop. Before the current flowing through the coil 11 disappears, the pulse signal jumps from low level to high level in the next period, thereby making the coil 11 powered on again, and the current flowing through the coil 11 begins to rise again. The current flowing through the coil 11 repeatedly goes through the above process, thereby forming a chopping current; when the duty cycle of the high level of the pulse signal is 100%, the coil 11 is always in a powered-on state, and the current flowing through the coil 11 has a maximum value. At this time, the magnetic ring 81 is located at the S1 point position, that is, the first position. When the duty cycle of the high level is 0%, the coil 11 is always in a powered-off state. At this time, under the action of the elastic element 7, the magnetic ring 81 is located at the S2 point position, that is, the second position. Therefore, by adjusting the duty cycle of the pulse signal, specifically adjusting the effective duty cycle of the high level in the pulse signal, the effective value of the current acting on the coil 11 can be changed, and the electromagnetic force generated by the coil 11 can be changed, so that the magnetic ring 81 stays at any position between the strokes S1S2, thereby controlling the position of the valve core 6 relative to the valve port 21, and further adjusting the flow of the electromagnetic valve 100.

[0035] Referring to Figure 1 and Figure 3 , the electromagnetic valve 100 further comprises a first interface part 20 and a second interface part 30. The first interface part 20 comprises a first pin 201, and the second interface part 30 comprises a second pin 301. One end of the first pin 201 is fixedly connected with the circuit board 83, and the other end of the first pin 201 is used for fixedly connecting with the outside. The circuit board 83 is electrically and / or signal connected with the outside through the first pin 201. One end of the second pin 301 is fixedly connected with the coil 11, and the other end of the second pin 301 is used for fixedly connecting with the outside. The coil 11 is electrically and / or signal connected with the outside through the second pin 301. In order to enable the coil 11 to be controlled by the MOS tube, the coil 11 and the circuit board 83 need to be electrically and / or signal connected, that is, the first interface part 20 and the second interface part 30 need to be electrically and / or signal connected. Specifically, the first interface part 20 and the second interface part 30 can be electrically and / or signal connected through an external connector. Meanwhile, the first interface part 20 is also electrically and / or signal connected with the upper computer. Of course, as another embodiment, the circuit board 83 and the coil 11 can be electrically and / or signal connected inside the electromagnetic valve 100. In this way, the electromagnetic valve 100 can only comprise the first interface part 20, and the electromagnetic valve 100 is electrically and / or signal connected with the upper computer through the first interface part 20.

[0036] Referring to Figure 11 For the third embodiment, in which the circuit board 83 does not integrate the micro control unit 84 and the driving circuit 85, specifically, the electromagnetic valve 100 is position closed loop controlled by means of an external controller 9, which includes a circuit board on which the micro control unit 84 and the driving circuit 85 are integrated, the specific position closed loop control circuit on the circuit board is the same as the previous embodiments, and will not be repeated here, the controller 9 is electrically and / or signal connected with the first interface part 20 and the second interface part 30 respectively, and the controller 9 is electrically and / or signal connected with the host computer.

[0037] A control method can control the position of the magnetic ring 81, and further control the position of the valve core 6 relative to the valve port 21, so that the electromagnetic valve 100 can perform flow regulation, which includes flow on-off and flow size regulation. Referring to Figure 12 , the control method includes the following steps:

[0038] After the electromagnetic valve 100 is started, the micro control unit 84 acquires the actual position of the magnetic ring 81 detected by the Hall sensor 82;

[0039] The micro control unit 84 is internally provided with a preset position of the magnetic ring 81 sent by the host computer, and judges whether the actual position is the same as the preset position;

[0040] If yes, the micro control unit 84 controls the PWM module 843 to output the current pulse signal to the driving circuit 85, so as to control the coil 11 to work under the current;

[0041] If not, the micro control unit 84 changes the effective duty ratio of the pulse signal output by the PWM module 843, and further changes the effective value of the current flowing through the coil 11, changes the electromagnetic force generated by the coil 11, controls the magnetic ring 81 to move to the preset position, and further changes the position of the valve core 6 relative to the valve port 21.

[0042] It should be noted that the above embodiments are only used to illustrate the technical solutions described in the present application and not to limit the technical solutions described in the present application. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the skilled in the art can still modify or equivalently replace the present application, and all technical solutions and improvements which do not deviate from the spirit and scope of the present application should be covered in the scope of the claims of the present application.

Claims

1. An electromagnetic valve comprising a coil, a position detection component, a valve rod, a valve core, a moving iron core, a static iron core and an elastic element, the electromagnetic valve having a valve port, the position detection component comprising a magnetic ring, a Hall sensor and a circuit board, the moving iron core being fixedly connected with the valve rod, the valve core being fixedly connected with the valve rod, the magnetic ring being fixedly connected with the valve rod, the static iron core being fixedly arranged, the elastic element being sleeved on the outer periphery of the valve rod, the elastic element being located between the moving iron core and the static iron core, at least part of the coil being located on the outer periphery of the moving iron core, the Hall sensor being electrically connected and / or signal connected with the circuit board, the Hall sensor being capable of detecting the actual position of the magnetic ring, characterized in that: The position of the valve core relative to the valve port is controlled by a micro control unit acquiring the actual position of the magnetic ring; The micro control unit and the coil further comprise a driving circuit, the micro control unit compares the actual position signal of the magnetic ring fed back by the Hall sensor with the preset position instruction sent by the upper computer, and outputs a series of pulse signals to the driving circuit to change the effective value of the current acting on the coil, so that the magnetic ring reaches the preset position under the interaction of the electromagnetic force of the coil and the elastic pressure of the elastic element.

2. The electromagnetic valve according to claim 1, characterized by: The micro control unit and the coil further comprise a driving circuit, the micro control unit and the driving circuit are located on the circuit board, the Hall sensor is electrically and / or signal connected with the micro control unit, the micro control unit is electrically and / or signal connected with the driving circuit, and the driving circuit is electrically and / or signal connected with the coil.

3. The electromagnetic valve according to claim 1, characterized by: The micro control unit and the coil further comprise a driving circuit, the micro control unit and the driving circuit are located on the circuit board of an external controller, the Hall sensor is electrically and / or signal connected with the micro control unit, the micro control unit is electrically and / or signal connected with the driving circuit, and the driving circuit is electrically and / or signal connected with the coil.

4. The electromagnetic valve according to claim 2 or 3, characterized by: The electromagnetic valve comprises a valve seat, the moving iron core is arranged close to one end of the valve rod, the magnetic ring is arranged close to the other end of the valve rod, the magnetic ring is arranged away from the coil component, the valve core is located between the moving iron core and the magnetic ring along the axial direction of the valve rod, and the magnetic ring is located in the flow channel formed by the valve seat or the magnetic ring is located in the accommodating cavity formed by the valve seat.

5. The solenoid valve according to claim 4, characterized in that: Along the axial direction of the magnetic ring, the Hall sensor is located below the magnetic ring, and the Hall sensor is arranged on the circuit board and faces one side of the magnetic ring.

6. The electromagnetic valve according to claim 4, characterized by: Along the radial direction of the magnetic ring, the Hall sensor is located beside the magnetic ring, and the Hall sensor is arranged on the circuit board and faces one side of the magnetic ring.

7. The electromagnetic valve according to claim 5 or 6, characterized in that: The micro control unit comprises a communication module, a control module and a PWM module, the driving circuit comprises a level conversion circuit and a MOS tube, the communication module is used for communicating with the upper computer, the communication module sends the preset position instruction of the magnetic ring sent by the upper computer to the control module, the Hall sensor sends the actual position of the magnetic ring to the control module after detection, the control module controls the PWM module to output a pulse signal acting on the level conversion circuit by comparing the actual position with the preset position, the level conversion circuit is electrically connected with the MOS tube, the MOS tube is electrically connected with the coil, the level conversion circuit controls the on-off of the MOS tube according to the pulse signal output by the PWM module, and then controls the effective value of the current flowing through the coil, so that the magnetic ring moves to the preset position, and the position of the magnetic ring is controlled.

8. The electromagnetic valve according to claim 7, characterized by: When the effective duty cycle of the high level of the pulse signal is 100%, the current effective value flowing through the coil is maximum, and the magnetic ring is located at the first position; when the effective duty cycle of the high level of the pulse signal is 0%, no current flows through the coil, and the magnetic ring is located at the second position; The control module adjusts the effective duty cycle of the high level of the pulse signal according to the deviation between the actual position and the preset position, so that the magnetic ring operates to the preset position, which is any position between the first position and the second position.

9. The solenoid valve according to claim 8, characterized in that: The level conversion circuit comprises a first transistor, a second transistor, a third transistor, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor and a sixth resistor. The PWM module is connected with one end of the first resistor, the second resistor, the third resistor and the fifth resistor. The other end of the first resistor is connected with a vehicle power supply. The other end of the second resistor is connected with the base of the first transistor. The other end of the third resistor is grounded. The other end of the fifth resistor is connected with the base of the third transistor. The collector of the first transistor is connected with one end of the fourth resistor and the base of the second transistor. The emitter of the first transistor is grounded. The other end of the fourth resistor is connected with the vehicle power supply. The collector of the second transistor is connected with the vehicle power supply. The emitter of the second transistor is connected with one end of the sixth resistor and the collector of the third transistor. The emitter of the third transistor is grounded. The other end of the sixth resistor is connected with the MOS tube.

10. A control method, which can be applied to the electromagnetic valve according to any one of claims 1-9, and can control the position of the magnetic ring, and further control the position of the spool relative to the valve port, so that the electromagnetic valve performs flow regulation, which includes flow on-off and flow size regulation. The control method comprises the following steps: The micro control unit acquires the actual position of the magnetic ring detected by the Hall sensor; The micro control unit is internally preset with the preset position of the magnetic ring sent by the upper computer, and judges whether the actual position is same as the preset position; If yes, the micro control unit controls the PWM module to output the current pulse signal; If no, the micro control unit adjusts the effective duty cycle of the high level of the pulse signal output by the PWM module, changes the size of the current effective value acting on the coil, and makes the magnetic ring move to the preset position.

Images