Control method and control device, electronic expansion valve

Abstract

The present disclosure relates to the technical field of automobiles and discloses a control method and a control device, an electronic expansion valve, the control method including: collecting first jumping signals in real time and recording a first timing when each first jumping signal is collected; collecting second jumping signals in real time and recording a second timing when each second jumping signal is collected; calculating a difference between the second timing and the corresponding first timing; increasing or decreasing a count by a set value when the difference value is a positive value, and decreasing or increasing a count by a set value when the difference value is a negative value; and determining that a stall has occurred in a stepping motor when the count has not increased or decreased within a set time period. Using this control method, the operating state of a stepping motor is determined more accurately, efficiently, and simply.

Description

[Technical field]

[0001] Related Applications This disclosure claims priority to a Chinese patent application filed on May 24, 2021, bearing application number 202110564209.0 and entitled “CONTROL METHOD AND CONTROL DEVICE FOR ELECTRONIC EXPANSION VALVE,” the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to the technical field of automobiles, and in particular to a control method and a control device, and an electronic expansion valve including the control device. [Background technology]

[0003] In vehicle systems, electronic expansion valves are used in cooling systems to adjust the flow rate of refrigerant. Electronic expansion valves include a stepping motor, which is controlled by a control device to rotate. When the stepping motor encounters an obstacle during its rotation, the stepping motor will stall. Since electronic expansion valves use open-loop control, when the valve stalls or steps out, the current state and position of the valve body cannot be accurately known. Especially during the return process, the valve core is in a fully closed state, so the return and stall continue for a long time, and the spring characteristics are easily changed, resulting in long return times and loud noise. When the valve core is stuck, the conversion of the back electromotive force becomes slow due to the flexible deformation of the spring, and the control device also has difficulty in accurately determining the stall due to the stall.

[0004] It should be noted that the information disclosed in the above background section is merely intended to enhance understanding of the background of the present disclosure and may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] SUMMARY OF THE DISCLOSURE The present disclosure aims to overcome the above-mentioned shortcomings of the prior art and provide a control method and device, and an electronic expansion valve.

[0006] According to one aspect of the present disclosure, Acquiring first jumping signals in real time and recording a first time when each first jumping signal was acquired; collecting second jumping signals in real time and recording a second time when each second jumping signal was collected; Calculating a difference between the second timing and the corresponding first timing; Incrementing or decrementing the count by a set value when the difference value is positive, and decrementing or incrementing the count by a set value when the difference value is negative; determining that a stall has occurred in the stepping motor if the count is not increasing or decreasing within the set time period; The present invention provides a control method including the steps of:

[0007] In one exemplary embodiment of the present disclosure, determining that a stall has occurred in the stepper motor when the count is not increasing or the count is not decreasing within the set time period includes: determining that a first stall has occurred in the stepping motor if the count is within a set time period and has not increased but decreased; or If the count is within the set time period and has not decreased but has increased, it is determined that a first stall has occurred in the stepping motor. Includes.

[0008] In one exemplary embodiment of the present disclosure, determining that a stall has occurred in the stepper motor when the count is not increasing or the count is not decreasing within the set time period includes: If the count remains unchanged within a set time period, it is determined that a second stall has occurred in the stepping motor.

[0009] In one exemplary embodiment of the present disclosure, if the difference value is a positive value, it is determined that the stepping motor is rotating forward, and if the difference value is a negative value, it is determined that the stepping motor is rotating backward.

[0010] According to another aspect of the present disclosure, a first collecting assembly for collecting first jumping signals in real time and recording a first time when each first jumping signal is collected; a second acquisition assembly for acquiring second jumping signals in real time and recording a second time when each second jumping signal was acquired; a calculation assembly for calculating a difference value between the second timing and the corresponding first timing; a counting assembly for incrementing or decrementing the count by a set value when the difference value is positive and for decrementing or incrementing the count by a set value when the difference value is negative; a determination assembly for determining that a stall has occurred in the stepping motor if the count is not increasing or the count is not decreasing within the set time period; A control device including:

[0011] In one exemplary embodiment of the present disclosure, determining that a stall has occurred in the stepper motor when the count is not increasing or the count is not decreasing within the set time period includes: determining that a first stall has occurred in the stepping motor if the count is within a set time period and has not increased but decreased; or If the count is within the set time period and has not decreased but has increased, it is determined that a first stall has occurred in the stepping motor. Includes.

[0012] In one exemplary embodiment of the present disclosure, determining that a stall has occurred in the stepper motor when the count is not increasing or the count is not decreasing within the set time period includes: If the count remains unchanged within a set time period, it is determined that a second stall has occurred in the stepping motor.

[0013] According to yet another aspect of the present disclosure, a stepping motor including a rotor and a stator, the rotor including a permanent magnet; a first sensor provided around the permanent magnet and configured to detect a change in the magnetic field of the rotor and output a first jumping signal; a second sensor disposed around the permanent magnet, detecting a change in the magnetic field of the rotor and outputting a second jumping signal, the second sensor being disposed at a position offset from the first sensor; A control device according to any one of claims 5 to 8, electrically connected to the first sensor and the second sensor; The present invention provides an electronic expansion valve including:

[0014] In one exemplary embodiment of the present disclosure, an included angle between the first sensor and the second sensor is α;

[0015]

number

[0016] In the formula, m is a positive integer, n is the number of magnetic pole pairs, and β is a positive number less than 360° / 2n.

[0017] In one exemplary embodiment of the present disclosure, the rotor includes at least one pair of magnetic poles, where each pair of magnetic poles includes one north pole and one south pole, and the first sensor generates a first jumping signal when it detects that the magnetic pole of the rotor changes from north pole to south pole or from south pole to north pole, and the second sensor generates a second jumping signal when it detects that the magnetic pole of the rotor changes from north pole to south pole or from south pole to north pole.

[0018] It is to be understood that the foregoing general description and the following detailed description are merely exemplary and explanatory and are not restrictive of the present disclosure. [Brief description of the drawings]

[0019] The drawings herein are incorporated in and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and are used together with the specification to interpret the principles of the present disclosure. The drawings in the following description are merely some embodiments of the present disclosure, and it is obvious to those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.

[0020] [Figure 1] FIG. 2 is a schematic block diagram of the flow of one exemplary embodiment of the control method of the present disclosure. [Diagram 2] FIG. 2 is a schematic diagram of a control flow of one exemplary embodiment of the control method of the present disclosure. [Diagram 3] 4 is a schematic diagram showing the time correspondence relationship between the number of operating steps, the magnetic poles of the rotor, and the first and second feedback signals when the stepping motor of the electronic expansion valve rotates in the forward direction; FIG. [Figure 4] 4 is a schematic diagram showing the time correspondence relationship between the number of operating steps, the magnetic poles of the rotor, and the first and second feedback signals when the stepping motor of the electronic expansion valve rotates in reverse; FIG. [Diagram 5] FIG. 1 is a schematic diagram of the principle when a stall stuck occurs in an electronic expansion valve. [Figure 6] FIG. 2 is a schematic diagram of the principle when stall rebound occurs in an electronic expansion valve; [Figure 7] FIG. 2 is a schematic block diagram of one exemplary embodiment of a control device of the present disclosure. [Figure 8] FIG. 2 is a structural schematic diagram of an exemplary embodiment of an electronic expansion valve of the present disclosure. [Figure 9] FIG. 9 is a schematic cross-sectional view taken along the line AA in FIG. [Figure 10] 10 is a partially enlarged schematic view of a portion indicated by I in FIG. 9. FIG.

[0021] Explanation of symbols 1 stepping motor, 11 rotor, 12 stator, 2 first sensor, 21 main body, 22 connection portion, 3 second sensor, 4 circuit board, 41 communication hole, 5 spindle, 6 valve seat, 7 valve body, 8 valve orifice member, 9 screw, 10 nut member, 11 elastic element, 121 first collecting assembly, 122 second collecting assembly, 123 calculation assembly, 124 counting assembly, 125 judgment assembly. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Next, the exemplary embodiments will be described in more detail with reference to the accompanying drawings. However, the exemplary embodiments can be implemented in various forms, and should not be understood to be limited to the embodiments described herein, but rather, these embodiments are provided so that the present disclosure will be thorough and complete, and the idea of ​​the exemplary embodiments will be fully conveyed to those skilled in the art. In the drawings, the same reference numerals indicate the same or similar structures, and therefore detailed descriptions thereof will be omitted. Furthermore, the drawings are merely schematic illustrations of the present disclosure, and are not necessarily drawn to scale.

[0023] Although relative terms such as "above" and "below" are used herein to describe the relative relationship of one illustrated assembly to another, such terms are used herein merely for convenience, such as the exemplary orientations depicted in the drawings. It will be understood that if the illustrated device is turned upside down, the assembly described as "above" would become the assembly described as "below." When a structure is "above" another structure, it can mean that the structure is integrally formed on the other structure, that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure via another structure.

[0024] The terms "a," "an," "this," "at least one," and "said" are used to indicate the presence of one or more elements / components / etc., the terms "comprising" and "having" are used to indicate an open-ended inclusion and indicate that other elements / components / etc. may be present in addition to the listed elements / components / etc., and terms such as "first," "second," and "third" are used merely as descriptive terms and do not limit the quantity of their objects.

[0025] The embodiment of the present disclosure first provides a control method, as shown in FIG. 1 and FIG. 2 , the control method includes: A step S10 of collecting first jumping signals in real time and recording a first time when each first jumping signal is collected; A step S20 of collecting second jumping signals in real time and recording a second timing of collecting each second jumping signal; A step S30 of calculating a difference value between the second timing and the corresponding first timing; Step S40: increasing or decreasing the count by a set value if the difference value is a positive value, and decreasing or increasing the count by the set value if the difference value is a negative value; If it is within the set time period and the count is not increasing or decreasing, it is determined in step S50 that a stall has occurred in the stepping motor; may include:

[0026] In the control method and control device disclosed herein, a positive difference between the second timing and the corresponding first timing means that the first timing at which the first jumping signal was collected is smaller than the second timing at which the second jumping signal was collected, and the first jumping signal exceeds the second jumping signal. Conversely, a negative difference between the second timing and the corresponding first timing means that the first timing at which the first jumping signal was collected is larger than the second timing at which the second jumping signal was collected, and the second jumping signal exceeds the first jumping signal. If the difference is a positive value, the count is increased by a set value, and if the difference is a negative value, the count is decreased by a set value. If the count is not increased or decreased within a set time period, it is determined that a stall has occurred in the stepping motor 1. If the stepping motor 1 is operating normally, the first jumping signal always exceeds the second jumping signal, or the second jumping signal always exceeds the first jumping signal, and the count continues to increase or decrease. When a stall stuck occurs in the stepping motor 1, the first jumping signal and the second jumping signal are not received, and the count remains unchanged within the set time period. When a stall rebound occurs in the stepping motor 1, the first jumping signal originally exceeds the second jumping signal, but the rebound causes the second jumping signal to exceed the first jumping signal, and the count that was originally constantly increasing decreases, and the second jumping signal originally exceeds the first jumping signal, but the rebound causes the first jumping signal to exceed the second jumping signal, and the count that was originally constantly decreasing increases. The control method and control device disclosed herein more accurately, efficiently, and simply determine the operating state of the stepping motor 1.

[0027] The control method and control device are used in an electronic expansion valve, and in order to more clearly explain the control method and control device, an electronic expansion valve will be described below.

[0028] In this exemplary embodiment, referring to Figures 8, 9 and 10, the electronic expansion valve may include a first sensor 2, a second sensor 3, a control device, a stepping motor 1, a valve, etc., and the operation of the stepping motor 1 is controlled by the control device, and the operation of the valve is linked with the stepping motor 1 to realize on / off.

[0029] The stepping motor 1 may include a rotor 11 and a stator 12, the rotor 11 may include a permanent magnet, the permanent magnet may include at least one pair of magnetic poles, the stator 12 may include a coil and a magnetic conductive part, a regularly changing current flows through the coil, and further, an excitation magnetic field is formed in the magnetic conductive part, and the magnetic field of the permanent magnet of the rotor 11 interacts with the excitation magnetic field of the magnetic poles of the stator 12 to enable the rotor 11 to rotate around the central axis.

[0030] The rotor 11 includes at least one pair of magnetic poles, each pair of magnetic poles including a north pole and a south pole, and the north poles and south poles are distributed at intervals along the circumference of the rotor 11. In this embodiment, the electronic expansion valve adopts a two-phase stepping motor 1 with 10 pairs of magnetic poles, and the rotor 11 includes 10 north poles and 10 south poles, that is, the rotor 11 includes 20 magnetic poles arranged along the circumference of the rotor 11.

[0031] The first sensor 2 and the second sensor 3 are located around the rotor 11 and are provided close to the rotor 11. When the rotor 11 rotates, the N pole and the S pole of the rotor 11 alternately pass the first sensor 2 and the second sensor 3. The first sensor 2 senses the change in the magnetic field of the rotor 11 and generates a periodic first feedback signal, which is a square wave and includes a plurality of first jumping signals. The second sensor 3 senses the change in the magnetic field of the rotor 11 and generates a periodic second feedback signal. The second feedback signal is a square wave, and the second feedback signal includes a plurality of second jumping signals, i.e., when changing from N pole to S pole or moving from S pole to N pole, the first sensor 2 generates one first jumping signal and the second sensor 3 generates one second jumping signal, and the first jumping signal and the second jumping signal jump from low level to high level or jump from low level to high level. When the stepping motor 1 runs once, i.e., when the rotor 11 rotates once, 20 first jumping signals and 20 second jumping signals are generated.

[0032] The control device may be a microprocessor, a single chip microcomputer, etc., and the control device is used to implement the above-mentioned control method.

[0033] Each step of the control method will now be described in detail.

[0034] Step S10: Collect first jumping signals in real time, and record the first timing at which each first jumping signal is collected.

[0035] In this exemplary embodiment, the first jumping signal is a signal that jumps from a low level to a high level or from a low level to a high level, generated by a change from a north pole to a south pole or a movement from a south pole to a north pole sensed by the first sensor 2. When the rotor 11 rotates once, 20 first jumping signals are generated, and the control device collects the 20 first jumping signals in real time and records the first timing at which each first jumping signal is collected, i.e., the control device records the 20 first timings, and the 20 first timings and the 20 first jumping signals correspond one-to-one.

[0036] Step S20: Collect second jumping signals in real time, and record the second timing at which each second jumping signal is collected.

[0037] In this exemplary embodiment, the second jumping signal is a signal that jumps from a low level to a high level or from a low level to a high level, which is generated by a change from a north pole to a south pole or a movement from a south pole to a north pole sensed by the second sensor 3. When the rotor 11 rotates once, 20 second jumping signals are generated, and the control device collects the 20 second jumping signals in real time and records the second timing at which each second jumping signal is collected, i.e., the control device records the 20 second timings, and the 20 second timings and the 20 second jumping signals correspond one-to-one.

[0038] It should be noted that the number of first jumping signals and second jumping signals is related to the number of magnetic pole pairs included in the rotor 11. In other exemplary embodiments of the present disclosure, when the number of magnetic pole pairs changes, the number of first jumping signals and second jumping signals also changes, all within the scope of protection of the present disclosure.

[0039] Step S30: Calculate the difference between the second timing and the corresponding first timing.

[0040] In this exemplary embodiment, the number of second timings is the same as the number of first timings. The 20 first timings are ranked in the order of recording, T101, T102, T103, ..., T119, T120. The 20 second timings are ranked in the order of recording, T201, T202, T203, ..., T219, T220. The first timing corresponding to the second timing means that their sequence numbers match. For example, it is inferred that the first timing corresponding to the second timing T101 is T201, and the first timing corresponding to the second timing T102 is T202. The difference value between the second timing and the corresponding first timing is calculated, that is, the first timing is subtracted from the second timing, for example, T201-T101.

[0041] Step S40: If the difference value is a positive value, the count is increased or decreased by a set value, and if the difference value is a negative value, the count is increased or decreased by the set value.

[0042] In this exemplary embodiment, the difference value between the second timing and the corresponding first timing being a positive value means that the first timing at which the first jumping signal is collected is smaller than the second timing at which the second jumping signal is collected, and the first jumping signal exceeds the second jumping signal, i.e., the first sensor 2 senses that the pole has changed from N pole to S pole first, or moved from S pole to N pole, and it can be determined that the stepping motor 1 is rotating forward. The set value may be 1, i.e., if the difference value is a positive value, the count is increased by 1.

[0043] Conversely, if the difference between the second timing and the corresponding first timing is a negative value, it means that the first timing at which the first jumping signal is collected is greater than the second timing at which the second jumping signal is collected, and the second jumping signal exceeds the first jumping signal, i.e., the second sensor 3 detects that the pole has changed from N pole to S pole first, or moved from S pole to N pole, and it can be determined that the stepping motor 1 is rotating in the reverse direction. The set value may be 1, i.e., if the difference is a negative value, the count is decreased by 1.

[0044] Of course, the above-mentioned set values ​​are merely examples and may be set as necessary, and the numerical values ​​of the above-mentioned set values ​​do not constitute limitations on the present disclosure.

[0045] It should be noted that in other exemplary embodiments of the present disclosure, a different counting scheme may be adopted, for example, where the count is decreased by a set value when the difference value is positive, and the count is increased by a set value when the difference value is negative.

[0046] Step S50: If it is within the set time period and the count has not increased or decreased, it is determined that a stall has occurred in the stepping motor 1.

[0047] In this exemplary embodiment, when the stepping motor 1 is operating normally, for example rotating in the forward direction, as shown in FIG. 3, the first jumping signal always exceeds the second jumping signal and the count keeps gradually increasing, and when the stepping motor 1 is rotating in the reverse direction, as shown in FIG. 4, the second jumping signal always exceeds the first jumping signal and the count keeps gradually decreasing.

[0048] The stall may include a first stall and a second stall. The first stall may be a stall rebound, where the first stall typically occurs near top dead center and bottom dead center. The second stall may be a stall stack, where the second stall typically occurs between top dead center and bottom dead center.

[0049] Referring to Figure 5, when a stall stack (i.e., a second stall) occurs in the stepping motor 1, as shown by M in the figure, the rotor 11 does not rotate, and therefore the first jumping signal and the second jumping signal are not received, and the count remains unchanged within the set time period.

[0050] 6, as shown by N in the figure, when a stall rebound (i.e., a first stall) occurs in the stepping motor 1, the first jumping signal originally exceeds the second jumping signal, but due to the rebound, the second jumping signal exceeds the first jumping signal, and the count, which originally kept gradually increasing, decreases, so that it is determined that a first stall has occurred in the stepping motor 1 if it is within the set time period and the count does not increase but decreases, and thus it is determined that a first stall has occurred in the stepping motor 1. Similarly, the second jumping signal originally exceeds the first jumping signal, but due to the rebound, the first jumping signal exceeds the second jumping signal, and the count, which originally kept gradually decreasing, increases, and thus it is determined that a first stall has occurred in the stepping motor 1 if it is within the set time period and the count does not decrease but increases, and thus it is determined that a first stall has occurred in the stepping motor 1.

[0051] In this exemplary embodiment, the stepping motor 1 of the electronic expansion valve adopts a 32-microstep control mode, one full step includes 32 microsteps, and the stepping motor 1 runs two full steps to correspond to one change in the magnetic pole of the rotor 11, that is, the running duration after jumping of one jumping signal includes the time corresponding to two full steps, that is, the time of theoretical 64 microsteps.

[0052] Specifically, referring to FIG. 3, when the electronic expansion valve is operating normally, the stepping motor 1 operates for a time corresponding to two full steps, the first sensor 2 rotates from one end of the N pole to the boundary between the N pole and the S pole corresponding to the magnetic pole of the rotor 11, and the corresponding first jumping signal is at a high level. As the stepping motor 1 operates, the first sensor 2 changes from the N pole to the S pole corresponding to the magnetic pole of the rotor 11, and the first jumping signal jumps to a low level. The stepping motor 1 operates for two full steps, and the first sensor 2 rotates from one end of the N pole to the boundary between the N pole and the S pole corresponding to the magnetic pole of the rotor 11. As the stepping motor 1 operates, the first sensor 2 changes from a S pole to a N pole corresponding to the magnetic pole of the rotor 11, and the first jumping signal jumps to a high level. By operating in this manner, when the rotor 11 makes one rotation, the stepping motor 1 operates 40 full steps and generates 20 first jumping signals, and the operating duration of the high and low levels of the first jumping signal is equal to the time corresponding to two full steps.

[0053] In this exemplary embodiment, the set time period is defined as a time corresponding to at least two full steps of the stepping motor 1, and the set time period T is related to the motor's rotation speed n, the number of pole pairs p of the rotor 11, and the number of phases m of the motor, with the specific relationship being T=60 / (n*m*P), where n is in revolutions / minute, m=2, and p=10.

[0054] Although the steps of the control method of the present disclosure are described in a particular order in the figures, this does not require or imply that the steps must be performed in this particular order, or that all steps shown must be performed to achieve a desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined and performed as one step, and / or a single step may be broken down into multiple steps and performed, etc. For example, steps S10 and S20 may be interchangeable, and steps S30 and S40 may be combined and performed as one step.

[0055] Further, the embodiment of the present disclosure further provides a control device, and referring to FIG. 7, the control device may include a first collecting assembly 121, a second collecting assembly 122, a calculating assembly 123, a counting assembly 124 and a judging assembly 125, the first collecting assembly 121 may be used to collect a first jumping signal in real time and record a first timing at which each first jumping signal is collected, the second collecting assembly 122 may be used to collect a second jumping signal in real time and record a second timing at which each second jumping signal is collected, the calculating assembly 123 may be used to calculate a difference value between the second timing and the corresponding first timing, the counting assembly 124 may be used to increase or decrease the count by a set value if the difference value is a positive value, and may be used to decrease or increase the count by a set value if the difference value is a negative value, and the judging assembly 125 may be used to judge that a stall has occurred in the stepping motor 1 if it is within a set time period and the count has not increased or decreased.

[0056] In this exemplary embodiment, determining that a stall has occurred in the stepping motor 1 if it is within the set time period and the count is not increasing or the count is not decreasing includes determining that a first stall has occurred in the stepping motor 1 if it is within the set time period and the count is not increasing and is decreasing, or determining that a first stall has occurred in the stepping motor 1 if it is within the set time period and the count is not decreasing and is increasing.

[0057] In this exemplary embodiment, determining that a stall has occurred in the stepping motor 1 if it is within a set time period and the count is not increasing or the count is not decreasing includes determining that a second stall has occurred in the stepping motor 1 if the count remains unchanged within the set time period.

[0058] In this exemplary embodiment, if the difference value is a positive value, it is determined that the stepping motor 1 is rotating forward, and if the difference value is a negative value, it is determined that the stepping motor 1 is rotating reversely.

[0059] The specific contents of each assembly in the above-mentioned control device have already been described in detail in the corresponding control method, so the description thereof will be omitted here.

[0060] Furthermore, the embodiment of the present disclosure further provides an electronic expansion valve, and reference is made to the structural schematic diagrams of the electronic expansion valve shown in Figures 8, 9 and 10. The electronic expansion valve may include a stepping motor 1, a first sensor 2, a second sensor 3 and a control device, the stepping motor 1 may include a rotor 11 and a stator 12, the rotor 11 includes a permanent magnet, the first sensor 2 is provided around the permanent magnet, the first sensor 2 senses the change in the magnetic field of the rotor 11 and outputs a first jumping signal, the second sensor 3 is provided around the permanent magnet, the second sensor 3 senses the change in the magnetic field of the rotor 11 and outputs a second jumping signal, the second sensor 3 and the first sensor 2 are provided at different positions, the control device is electrically connected to the first sensor 2 and the second sensor 3, and the control device is the control device according to any one of the above-mentioned claims.

[0061] The specific structure of the control device and the control method have already been described in detail, so a description thereof will be omitted here.

[0062] The specific structure of the stepping motor 1 has already been described in detail, so a description thereof will be omitted here.

[0063] Here, the first sensor 2 may be a Hall sensor or a position sensor, and the first jumping signal may be a Hall signal. The second sensor 3 may also be a Hall sensor or a position sensor, and the second jumping signal may also be a Hall signal. The first sensor 2 and the second sensor 3 are provided at offset positions, so that the first sensor 2 and the second sensor 3 cannot simultaneously detect the change in the magnetic field of the rotor 11. Specifically, the included angle between the first sensor 2 and the second sensor 3 is α, that is, the included angle between the center line of the first sensor 2 and the center line of the second sensor 3 is α.

[0064]

number

[0065] In the formula, m is a positive integer, m is equal to or less than 2n, n is the number of magnetic pole pairs, and β is a positive number less than 360° / 2n.

[0066] In this exemplary embodiment, the included angle α between the centerline of the first sensor 2 and the centerline of the second sensor 3 is approximately 154°.

[0067] The first sensor 2 may include a main body portion 21 and a connection portion 22, the connection portion 22 being electrically connected to the circuit board 4, and the connection portion 22 being welded and fixed to the circuit board 4; specifically, a communication hole 41 is formed in the circuit board 4, and the connection portion 22 is provided passing through the communication hole 41 and is connected to the circuit board 4 by welding and fixed thereto.

[0068] The electronic expansion valve may further include a valve, which may include a spindle 5, a valve seat 6, a valve body 7 and a valve orifice member 8, the spindle 5 moves in conjunction with the rotor 11, the spindle 5 moves between the top dead center and the bottom dead center, when the spindle 5 is at the bottom dead center, the flow paths on both sides of the valve orifice are blocked and the valve orifice is closed, as the spindle 5 moves from the bottom dead center to the top dead center, the valve orifice is gradually opened, and the flow paths on both sides are communicated through the gap between the valve orifice and the spindle 5, when the spindle 5 reaches the top dead center, the opening of the valve orifice is maximum. In this embodiment, the flow paths on both sides of the valve orifice are both formed on the valve body 7, the valve orifice is located between the flow paths on both sides, the valve orifice member 8 is formed with a valve orifice, the valve orifice member 8 is fixedly connected to the valve body 7, the valve seat 6 is fixedly connected to the valve body 7, and the spindle 5 is connected to the rotor 11.

[0069] The electronic expansion valve may further include a screw 9, a nut member 10 and a stop rod, the nut member 10 is fitted around the screw, the nut member 10 and the screw are engaged by a screw, the nut member 10 is fixed to the valve seat 6, and the nut member 10 is fixed to the inner ring of the rotor 11, the rotor 11 allows the nut member 10 to rotate in conjunction with the nut member 10, and the screw moves upwards or downwards relative to the nut member 10. The stop rod and the screw are fixedly connected by a connecting plate, the stop rod moves upwards or downwards relative to the nut member 10, and the stop rod and the nut member 10 are engaged to limit the movement of the screw between the top dead center and the bottom dead center, and the spindle 5 and the screw are relatively fixedly connected to each other, so that the movement of the spindle 5 is further limited within the distance between the top dead center and the bottom dead center. An elastic element 11 is provided between the spindle 5 and the screw 9. The elastic element 11 may be a spring. In this way, when the spindle 5 moves to the bottom dead center, the spindle 5 and the valve member 8 come into elastic contact with each other, which is advantageous in cushioning the spindle 5 and the valve member 8 and improving the service life of the two members. However, if a stall occurs near the top dead center or the bottom dead center, a rebound occurs due to the elastic flexible deformation of the elastic element 11, and a periodic vibration waveform appears in the pulse fed back by the first sensor and the second sensor, which may make it impossible to determine that a stall has occurred or may lead to a false determination that a stall has occurred.

[0070] Those skilled in the art will be able to readily devise other embodiments of the present disclosure upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any modifications, uses or adaptations of the present disclosure, which modifications, uses or adaptations adhere to the general principles of the present disclosure and include common knowledge or customary means in the art that are not disclosed in the present disclosure. It is intended that the specification and examples be considered as merely exemplary, with a true scope and spirit of the present disclosure being indicated by the appended claims.

Claims

1. Acquiring first jumping signals in real time and recording a first time when each of the first jumping signals is acquired; Acquiring second jumping signals in real time and recording a second time when each of the second jumping signals is acquired; Calculating a difference between the second timing and the corresponding first timing; Incrementing or decrementing a count by a set value when the difference value is a positive value, and decrementing or incrementing the count by a set value when the corresponding difference value is a negative value; determining that a stall has occurred in the stepping motor if the count is not increasing or decreasing within a set time period; A control method comprising:

2. If the count is not increasing or decreasing within a set time period, it is determined that a stall has occurred in the stepping motor. determining that a first stall has occurred in the stepping motor if the count is not increasing but is decreasing within a set time period; or If the count is within a set time period and the count does not decrease but increases, it is determined that a first stall has occurred in the stepping motor. The control method of claim 1 , comprising:

3. If the count is not increasing or decreasing within a set time period, it is determined that a stall has occurred in the stepping motor.

2. The control method according to claim 1, further comprising: determining that a second stall has occurred in the stepping motor if the count remains unchanged within a set time period.

4. 2. The control method according to claim 1, wherein the stepping motor is determined to be rotating forward when the difference value is a positive value, and the stepping motor is determined to be rotating reversely when the difference value is a negative value.

5. a first acquisition assembly for acquiring first jumping signals in real time and recording a first time when each of the first jumping signals is acquired; a second acquisition assembly for acquiring second jumping signals in real time and recording a second time when each said second jumping signal was acquired; a calculation assembly for calculating a difference value between said second timing and the corresponding first timing; a counting assembly for increasing or decreasing a count by a set value when the difference value is positive and for increasing or decreasing the count by a set value when the difference value is negative; a determination assembly for determining that a stall has occurred in the stepping motor if the count is not increasing or the count is not decreasing within a set time period; A control device including:

6. If the count is not increasing or decreasing within a set time period, it is determined that a stall has occurred in the stepping motor. determining that a first stall has occurred in the stepping motor if the count is not increasing but is decreasing within a set time period; or If the count is within a set time period and the count does not decrease but increases, it is determined that a first stall has occurred in the stepping motor. The control device of claim 5 .

7. If the count is not increasing or decreasing within a set time period, it is determined that a stall has occurred in the stepping motor.

6. The control device according to claim 5, further comprising determining that a second stall has occurred in the stepping motor if the count remains unchanged within a set time period.

8. a stepping motor including a rotor and a stator, the rotor including a permanent magnet; a first sensor provided around the permanent magnet and configured to detect a change in the magnetic field of the rotor and output a first jumping signal; a second sensor provided around the permanent magnet, configured to detect a change in the magnetic field of the rotor and output a second jumping signal, and configured at a position offset from that of the first sensor; The control device according to claim 5 , electrically connected to the first sensor and the second sensor; Including an electronic expansion valve.

9. the included angle between the first sensor and the second sensor is α; [0010] 9. The electronic expansion valve of claim 8, wherein m is a positive integer, n is the number of pole pairs, and β is a positive number less than 360° / 2n.

10. 9. The electronic expansion valve of claim 8, wherein the rotor includes at least one pair of magnetic poles, where each pair of magnetic poles includes one north pole and one south pole, the first sensor generates one of the first jumping signals when it detects that the magnetic pole of the rotor changes from north pole to south pole or from south pole to north pole, and the second sensor generates one of the second jumping signals when it detects that the magnetic pole of the rotor changes from north pole to south pole or from south pole to north pole.

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