Electronic expansion valve

Abstract

An electronic expansion valve comprising a frame body (10), a magnetic rotor (40), a control circuit board (31), and a magnetoresistive sensor assembly (50), wherein the frame body (10) has a mounting chamber (30) and a housing chamber (20), the mounting chamber (30) is located outside the housing chamber (20) in the circumferential direction, the magnetic rotor (40) is movably mounted within the housing chamber (20) along the height direction of the housing chamber (20), the control circuit board (31) is mounted in the mounting chamber (30), and the magnetoresistive sensor assembly (50) is fixed to the control circuit board (31), and the range of movement of the magnetic rotor (40) is located within the sensing range of the magnetoresistive sensor assembly (50).

Description

Technical Field

[0001] (Cross-reference) This disclosure claims the priority of a Chinese patent application with an application number of 202321199298.4 and an application title of "Electronic Expansion Valve", which was filed with the Chinese Patent Office on May . All its contents are incorporated into this application by reference.

[0002] This disclosure relates to the technical field of flow control devices, and specifically to electronic expansion valves.

Background Art

[0003] Conventional sensors for electronic expansion valves usually use Hall sensors. When assembling the Hall sensor on a circuit board, first the Hall sensor is incorporated into a Hall mount, then the Hall sensor and the Hall mount assembly are assembled on the circuit board, and further the pins of the Hall sensor need to be welded to the circuit board. It consists of two assembly steps and one welding step. Moreover, during the assembly of the electronic expansion valve, the process is complex, the efficiency is relatively low, and the installation cost is relatively high.

Summary of the Invention

[0004] The main objective of this disclosure is to provide an electronic expansion valve to solve the problems in the prior art that the process is complex, the efficiency is relatively low, and the installation cost is relatively high during the assembly of the Hall sensor of the electronic expansion valve.

[0005] To achieve the above objective, according to one aspect of this disclosure, there is provided an electronic expansion valve including a frame body, a magnetic rotor, a control circuit board, and a magnetoresistive sensor assembly. The frame body has a mounting chamber and a housing chamber located on the outer side of the circumferential direction of the housing chamber. The magnetic rotor is provided movably in the housing chamber along the height direction of the housing chamber. The control circuit board is provided in the mounting chamber. The magnetoresistive sensor assembly is fixed to and in close contact with the control circuit board, and the movement range of the magnetic rotor is located within the sensing range of the magnetoresistive sensor assembly.

[0006] Selectively, the magnetoresistive sensor assembly includes at least two magnetoresistive sensors, which are patch-type sensors fixed to the control circuit board by a patch method.

[0007] Selectively, there is a gap between the bottom surface of the magnetoresistive sensor assembly and the bottom wall of the mounting chamber.

[0008] Selectively, the distance between the bottom surface of the magnetoresistive sensor assembly and the bottom wall of the mounting chamber is 0.1 mm to 1.0 mm.

[0009] Selectively, there is a gap between the side wall of the magnetoresistive sensor assembly and the side wall of the mounting chamber.

[0010] Selectively, the distance between the side wall of the magnetoresistive sensor assembly and the side wall of the mounting chamber is 0.1 mm to 1.0 mm.

[0011] Selectively, the mounting chamber wall includes a first circumferential side wall and a second circumferential side wall, the second side wall being located within the first side wall, the control circuit board being fitted outside the second side wall, the second side wall having a cross section, the control circuit board having an opening that fits the cross section, and the magnetoresistive sensor assembly on the control circuit board facing the cross section.

[0012] Selectively, the magnetoresistive sensor assembly includes a first magnetoresistive sensor and a second magnetoresistive sensor provided at intervals on a control circuit board.

[0013] Selectively, the centers of the first magnetoresistive sensor and the second magnetoresistive sensor are at the same distance from the center of the magnetic rotor.

[0014] Selectively, the centers of the first magnetoresistive sensor and the second magnetoresistive sensor and the center of the magnetic rotor have an angle α between their projections in the height direction of the housing chamber, and the magnetic pole pair n of the magnetic rotor and the angle α satisfy the following:

[0015]

number

[0016] Here, m is a positive integer, and β is

[0017]

number

[0018] It is a smaller positive number.

[0019] Selectively, the magnetic rotor includes a detection rotor and a drive rotor, and the detection rotor and drive rotor are integrated into a single unit.

[0020] Selectively, a connecting member is fixed between the drive rotor and the detection rotor, and the drive rotor, detection rotor, and connecting member all form an H shape.

[0021] Selectively, a magnetoresistive sensor assembly includes one magnetoresistive sensor, which is a patch-type sensor fixed to the control circuit board by a patch method.

[0022] In the technical aspects of the present disclosure, the electronic expansion valve includes a frame body having a mounting chamber and a housing chamber located circumferentially outside the housing chamber, a magnetic rotor movably provided within the housing chamber along the height direction of the housing chamber, a control circuit board provided in the mounting chamber, and a magnetoresistive sensor assembly fixed to the control circuit board, wherein the movement range of the magnetic rotor is within the sensing range of the magnetoresistive sensor assembly.

[0023] By providing a housing chamber, the magnetic rotor can be moved along the height direction of the housing chamber, and at the same time, the magnetic rotor can also be rotated within the housing chamber. By installing the housing chamber, the interference of other structural members on the movement of the magnetic rotor can be reduced, and the magnetic rotor can operate stably. By providing a magnetoresistive sensor assembly, the magnetoresistive sensor assembly can collect the magnetic field of the magnetic rotor during the movement process to form a moving magnetic field curve. By analyzing the relationship between multiple moving magnetic field curves, the movement status of the magnetic rotor can be determined. At the same time, when using a magnetoresistive sensor, there is no need to use a separate fixing member, and it may be fixed to the control circuit board by a patching method, which simplifies the assembly of the electronic expansion valve and reduces the installation cost. The problems in the prior art that the process is complicated, the efficiency is relatively low, and the installation cost is relatively high during the assembly of the electronic expansion valve are solved.

Brief Description of the Drawings

[0024] The drawings of the specification constituting a part of this application are for providing a further understanding of the present disclosure. The schematic embodiments and their descriptions of the present disclosure are provided for interpreting the present disclosure and do not unduly limit the present disclosure.

[0025] [Figure 1] A structural schematic diagram of an electronic expansion valve according to one alternative embodiment of the present disclosure is shown. [Figure 2] A perspective view of the electronic expansion valve in FIG. 1 is shown. [Figure 3] A schematic diagram of the time correspondence relationship of the number of operating steps, rotor poles, and sensor signals when the stepping motor of the electronic expansion valve in FIG. 1 rotates forward is shown. [Figure 4] A schematic diagram of the time correspondence relationship of the number of operating steps, rotor poles, and sensor signals when the stepping motor of the electronic expansion valve in FIG. 1 rotates reversely is shown. [Figure 5] A schematic diagram of the principle when a stall stack occurs in the electronic expansion valve in FIG. 1 is shown. [Figure 6]Figure 1 shows a schematic diagram illustrating the principle when stall rebound occurs in the electronic expansion valve.

[0026] The following symbols are included in the above diagram. 10 Frame body, 20 Housing chamber, 30 Mounting chamber, 31 Control circuit board, 32 Protrusion, 33 Notch, 34 First side wall, 35 Second side wall, 36 Cross section, 37 Opening, 38 Mounting table, 40 Magnetic rotor, 41 Detection rotor, 42 Drive rotor, 43 Connecting member, 50 Magnetoresistive sensor assembly, 51 First magnetoresistive sensor, 52 Second magnetoresistive sensor. [Modes for carrying out the invention]

[0027] To enable those skilled in the art to better understand the embodiments of this disclosure, the technical embodiments of the embodiments of this disclosure will be clearly and completely described below with reference to the drawings of the embodiments of this disclosure, although it will be clear that the embodiments described are only a selection of embodiments of this application and not all embodiments. All other embodiments that a person skilled in the art could obtain without creative effort based on the embodiments of this disclosure are all within the scope of this disclosure.

[0028] It should be noted that the terms “First,” “Second,” etc., in the specification, claims, and drawings of this disclosure are provided to distinguish similar subjects and are not intended to describe a specific order or sequence. It should be understood that the data used in this manner are interchangeable, where appropriate, so that the embodiments of this disclosure described herein can be carried out in an order other than that illustrated or described herein. Furthermore, the terms “includes” and “have,” and any variations thereof, are intended to be non-exclusive. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to those steps or units explicitly listed, and may include steps or units not explicitly listed, or other steps or units specific to those processes, methods, products, or apparatus.

[0029] When terms such as "center," "vertical," "horizontal," "length," "width," "thickness," "top," "bottom," "front," "back," "left," "right," "perpendicular," "horizontal," "top," "bottom," "inside," "outside," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" appear in the description of this disclosure, the orientations or positional relationships indicated are based on the orientations or positional relationships shown in the drawings and are merely for the purpose of making this disclosure easier to explain and simplifying the explanation. It should be understood that these terms do not indicate or imply that the shown devices or elements necessarily have a specific orientation or must be configured and operated in a specific orientation, and therefore should not be understood as limiting this disclosure.

[0030] To address the problems of conventional electronic expansion valves, such as complex assembly processes, relatively low efficiency, and relatively high installation costs, this disclosure provides an electronic expansion valve.

[0031] As shown in Figures 1 to 6, the electronic expansion valve includes a frame body 10, a magnetic rotor 40, a control circuit board 31, and a magnetoresistive sensor assembly 50. The frame body 10 has a mounting chamber 30 and a housing chamber 20, the mounting chamber 30 is located outside the housing chamber 20 in the circumferential direction, the magnetic rotor 40 is movably mounted within the housing chamber 20 along the height direction of the housing chamber 20, the control circuit board 31 is mounted in the mounting chamber 30, and the magnetoresistive sensor assembly 50 is fixed to and in close contact with the control circuit board 31, with the movement range of the magnetic rotor 40 being within the sensing range of the magnetoresistive sensor assembly 50. Specifically, the movement range of the magnetic rotor 40 being within the sensing range of the magnetoresistive sensor assembly 50 means that the installation position of the magnetoresistive sensor assembly 50 is located within the height range in which the magnetic rotor 40 moves along the valve axis direction.

[0032] Specifically, the control circuit board 31 is configured to engage with the magnetoresistive sensor in the magnetoresistive sensor assembly 50 and to detect the stalled state of the magnetic rotor 40.

[0033] It should be noted that the magnetic rotor 40 can also rotate within the housing chamber 20.

[0034] Selectively, in some embodiments of this disclosure, the containment chamber 20 is cylindrical.

[0035] By providing the housing chamber 20, the magnetic rotor 40 can be moved along the height direction of the housing chamber 20, and at the same time, the magnetic rotor 40 can be rotated within the housing chamber 20. The installation of the housing chamber 20 reduces interference of other structural members with the movement of the magnetic rotor 40, allowing the magnetic rotor 40 to operate stably. By providing the magnetoresistive sensor assembly 50, the magnetoresistive sensor assembly 50 can collect the magnetic field of the magnetic rotor 40 during the motion process and form a motion magnetic field curve. By analyzing the relationship between multiple motion magnetic field curves, the motion state of the magnetic rotor 40 can be determined. At the same time, using a magnetoresistive sensor eliminates the need for separate fixing members and may be fixed to the control circuit board 31 using a patch method, simplifying the assembly of the electronic expansion valve and reducing installation costs. This solves the problem of relatively complex assembly and high installation costs in conventional electronic expansion valves.

[0036] It should be explained that when installing a circuit board with a magnetoresistive sensor, the magnetoresistive sensor and other components are first patched onto the circuit board, and then a single welding pass is performed using a tunnel furnace to fix the magnetoresistive sensor to the circuit board and complete the assembly of the circuit board. On the other hand, the conventional method for processing a circuit board with a Hall sensor involves first patching other components onto the circuit board, welding them in a tunnel furnace after the patching is complete, then installing the Hall sensor into the Hall mount, then inserting the Hall sensor and Hall mount assembly into the circuit board, and finally welding the connection between the Hall sensor pins and the circuit board. It is clear that using a magnetoresistive sensor makes the assembly of the circuit board simpler and more convenient.

[0037] It should be explained that this disclosure uses a magnetoresistive sensor instead of a Hall sensor in the prior art, but magnetoresistive sensors and Hall sensors have different characteristics. Specifically, magnetoresistive sensors and Hall sensors have different principles for sensing magnetic fields: magnetoresistive sensors use a magnetic focusing effect (changing resistance value due to an external magnetic field), while Hall sensors use the Hall effect (generating a voltage difference due to an external magnetic field). The sensing direction of the magnetic field does not coincide between magnetoresistive sensors and Hall sensors; Hall sensors sense vertical magnetic fields, and the magnetic rotor 40 and Hall sensor are installed vertically along the valve shaft. Magnetoresistive sensors sense horizontal magnetic fields, and the magnetic rotor 40 and magnetoresistive sensor are installed horizontally in the valve diameter direction, and the magnetoresistive sensor is located within the height range of the magnetic rotor 40. The power loss of magnetoresistive sensors and Hall sensors differs; the power loss of magnetoresistive sensors is at the microampere level, while the power loss of Hall sensors is at the milliampere level, making the power loss of magnetoresistive sensors lower.

[0038] Selectively, the magnetoresistive sensor assembly 50 includes one magnetoresistive sensor, which is a patch-type sensor.

[0039] Selectively, the magnetoresistive sensor assembly 50 includes at least two magnetoresistive sensors, which are patch-type sensors.

[0040] Specifically, the two patch-type magnetoresistive sensors may be fixed to the control circuit board 31 using a patch method.

[0041] Selectively, a projection 32 is provided at the bottom of the mounting chamber 30, and a notch 33 is provided on the control circuit board 31 that fits the projection 32, with the number of notches 33 corresponding one-to-one with the number of projections 32.

[0042] Specifically, referring to Figure 2, a projection 32 is provided at the bottom of the mounting chamber 30, and a notch 33 is provided on the control circuit board 31 that fits the projection 32, where the number of projections 32 and notches 33 are equal. In this embodiment, the notch 33 provided on the control circuit board 31 corresponds to the projection 32 provided at the bottom of the mounting chamber 30, and the projection 32 is visible through the notch 33. The notch 33 and the projection 22 are provided in a corresponding manner to prevent errors in the mounting direction of the control circuit board 31.

[0043] Selectively, the top surface of the projection 32 and the bottom surface of the control circuit board 31 have a pitch between them.

[0044] Selectively, the top surface of the projection 32 is in close contact with the bottom surface of the control circuit board 31.

[0045] Selectively, the projection 32 is inserted into the notch 33 of the control circuit board 31 in a one-to-one correspondence.

[0046] As can be understood, the projection 32 is inserted one-to-one into the notch 33 of the control circuit board 31, thereby securing the control circuit board 31 and further preventing it from wobbling within the mounting chamber 30 after it has been mounted, thereby increasing the stability of the control circuit board 31.

[0047] Selectively, the bottom of the mounting chamber 30 is provided with four mounting tables 38 distributed at the four corners of the bottom of the mounting chamber 30, and the control circuit board 31 is placed on the mounting tables 38.

[0048] Selectively, the control circuit board 31 is rectangular, has three protrusions 32, and the three notches 33 corresponding to the protrusions 32 on the control circuit board 31 are located on the three outer edges of the control circuit board 31.

[0049] For example, referring to Figure 2, three rectangular protrusions 32 are provided at the bottom of the mounting chamber 30, and three rectangular notches 33 are provided on the three outer edges of the control circuit board 31 to align with the protrusions 32.

[0050] As can be understood, the three protrusions 32 and three notches 33 facing different directions engage with each other, making it possible to more effectively avoid errors in the mounting direction of the control circuit board 31.

[0051] It should be noted that in some embodiments of this disclosure, the inner wall of the mounting chamber 30 may be provided with four, five, or more protrusions 32, and correspondingly, the number of notches 33 provided on the control circuit board 31 must be at least equal to the number of protrusions 32. At the same time, the shape of the protrusions 32 may be consistent with the shape of the notches 33.

[0052] Selectively, a gap is provided between the bottom surface of the magnetoresistive sensor assembly 50 and the bottom wall of the mounting chamber 30 to prevent the magnetoresistive sensor assembly 50 from being damaged by impact during the installation process.

[0053] Specifically, referring to Figure 1, the magnetoresistive sensor assembly 50 is provided on one surface of the control circuit board 31 that is close to the bottom wall of the mounting chamber 30, and there is a gap between the bottom surface of the magnetoresistive sensor assembly 50 and the bottom wall of the mounting chamber 30, so that when the control circuit board 31 is mounted, collision and damage between the magnetoresistive sensor assembly 50 and the bottom wall of the mounting chamber 30 can be avoided.

[0054] Selectively, the distance between the bottom surface of the magnetoresistive sensor assembly 50 and the bottom wall of the mounting chamber 30 is 0.1 mm to 1.0 mm.

[0055] Optionally, the magnetoresistive sensor assembly 50 may be provided on one surface of the control circuit board 31 that is close to the top wall of the mounting chamber 30.

[0056] Selectively, a gap is provided between the side wall of the magnetoresistive sensor assembly 50 and the side wall of the mounting chamber 30 to prevent the magnetoresistive sensor assembly 50 from being damaged by impact during the installation process.

[0057] Specifically, referring to Figure 1, the magnetoresistive sensor assembly 50 is provided on one side of the control circuit board 31 adjacent to the housing chamber 20, and has a gap between it and the side wall of the mounting chamber 30. The size of this gap is determined according to the actual performance of the magnetoresistive sensor.

[0058] Selectively, the distance between the side wall of the magnetoresistive sensor assembly 50 and the side wall of the mounting chamber 30 is 0.1 mm to 1.0 mm.

[0059] Selectively, the wall surface of the mounting chamber 30 includes a circumferential first side wall 34 and a circumferential second side wall 35, the second side wall 35 is located within the first side wall 34, the control circuit board 31 is fitted outside the second side wall 35, the second side wall 35 is provided with a cross section 36, the control circuit board 31 is provided with an opening 37 that fits the cross section 36, and the magnetoresistive sensor assembly 50 on the control circuit board 31 faces the cross section 36.

[0060] As can be understood, the provision of a cross section 36 on the second side wall 35, and the fact that the magnetoresistive sensor assembly 50 and the cross section 36 face each other, reduces the distance of the magnetoresistive sensor assembly 50 from the magnetic rotor 40 in the housing chamber 20, and further improves the accuracy of the sensing results of the magnetoresistive sensor assembly 50.

[0061] Selectively, the magnetoresistive sensor assembly 50 includes a first magnetoresistive sensor 51 and a second magnetoresistive sensor 52, which are spaced apart on the control circuit board 31.

[0062] Specifically, referring to Figure 2, the magnetoresistive sensor assembly 50 includes a first magnetoresistive sensor 51 and a second magnetoresistive sensor 52, and the first magnetoresistive sensor 51 and the second magnetoresistive sensor 52 are spaced apart in their mounting positions on the control circuit board 31, that is, the two magnetoresistive sensors are mounted in different orientations on the control circuit board 31.

[0063] It should be noted that the first magnetoresistive sensor 51 and the second magnetoresistive sensor 52 may be fixed to the control circuit board 31 using a patch method.

[0064] Selectively, the centers of the first magnetoresistive sensor 51 and the second magnetoresistive sensor 52 are at the same distance from the center of the magnetic rotor 40.

[0065] As can be understood, the fact that the distances from the center of the first magnetoresistive sensor 51 and the center of the second magnetoresistive sensor 52 to the center of the magnetic rotor 40 are the same ensures that the magnetic field strength sensed by the two magnetoresistive sensors is the same, and furthermore, allows for a more accurate determination of the motion of the magnetic rotor 40.

[0066] Selectively, referring to Figure 2, the centers of the first magnetoresistive sensor 51 and the second magnetoresistive sensor 52 and the center of the magnetic rotor 40 have an angle α between them and the projection in the height direction of the housing chamber 20, and the magnetic pole pair n of the magnetic rotor 40 and the angle α satisfy the following:

[0067]

number

[0068] Here, m is a positive integer, and β is

[0069]

number

[0070] It is a smaller positive number.

[0071] Selectively, the magnetic rotor 40 includes a detection rotor 41 and a drive rotor 42, and the detection rotor 41 and the drive rotor 42 have an integrated structure.

[0072] Specifically, as shown in Figure 1, the magnetic rotor 40 includes a drive rotor 42 and a detection rotor 41. The detection rotor 41 and the drive rotor 42 are an integrated structure, the drive rotor 42 is provided in the housing chamber 20, and the detection rotor 41 is provided on one side of the drive rotor 42 that is close to the mounting chamber 30. The drive rotor 42 drives the detection rotor 41 to rotate, and the number of magnetic poles of the drive rotor 42 and the detection rotor 41 are the same. Because the drive rotor 42 drives the detection rotor 41 to rotate, and the number of magnetic poles of the drive rotor 42 and the detection rotor 41 are the same, the influence of the magnetic poles of the drive rotor 42 on the magnetic field generated by the detection rotor 41 can be avoided, and stable operation of the magnetoresistive sensor assembly 50 can be ensured.

[0073] It should be noted that the integrated structure of the drive rotor 42 and the detection rotor 41 makes the assembly of the electronic expansion valve more convenient, and at the same time, the integrated structure ensures that the drive rotor 42 and the detection rotor 41 are made of the same material, thus avoiding the problem of their magnetic fields influencing each other.

[0074] Selectively, a connecting member 43 is fixed between the drive rotor 42 and the detection rotor 41, and the drive rotor 42, the detection rotor 41, and the connecting member 43 all form an H shape.

[0075] Specifically, as shown in Figure 1, the structure of the drive rotor 42, the detection rotor 41, and the connecting member 43 as a whole is H-shaped, with the connecting member 43 performing the function of power transmission, the drive rotor 42 moving in conjunction with the connecting member 43, and the connecting member 43 rotating in conjunction with the spindle of the electronic expansion valve connected to it.

[0076] It should be noted that if the containment chamber 20 is cylindrical, the detection rotor 41 is also cylindrical.

[0077] It should be explained that the drive rotor 42 drives the detection rotor 41 to rotate, and the drive rotor 42 and the detection rotor 41 are integrated, so when the drive rotor 42 rotates, the detection rotor 41, which is integrated with it, rotates synchronously. Alternatively, when the drive rotor 42 rotates, the detection rotor 41 rotates, and when the drive rotor 42 is in the upward phase, the detection rotor 41 is in the upward phase, and when the drive rotor 42 is in the downward phase, the detection rotor 41 is in the downward phase. In other words, the motion of the detection rotor 41 can indicate the motion of the drive rotor 42. The motion status of the drive rotor 42 can also be determined by analyzing the relationship between multiple motion magnetic field curves, and furthermore, it can be determined whether the drive rotor 42 is in the upward phase or the downward phase, and whether the drive rotor 42 is rotating or not.

[0078] One point to explain is that because the rotation direction of the drive rotor 42 differs during the upward phase and the downward phase, the phase difference between the two motion magnetic field curves is reversed. When designing an electronic expansion valve, it is necessary to specify which curve precedes the upward phase or the downward phase. Alternatively, the system can be designed to determine whether the drive rotor 42 is in the upward or downward phase by specifying whether the positive or negative phase difference between the two motion curves corresponds to the upward or downward phase.

[0079] As can be understood, since the detection rotor 41 rotates at a constant speed, the motion magnetic field curve of the detection rotor 41 collected by the magnetoresistive sensor assembly 50 is regular. If the drive rotor 42 stops rotating or stops rotating at a constant speed, the period of the motion magnetic field curve of the detection rotor 41 changes, and by observing the period of the motion magnetic field curve, it is possible to determine whether or not a stall has occurred in the electronic expansion valve. When designing the electronic expansion valve, the period of the motion magnetic field curve when the detection rotor 41 is moving normally is collected in advance. If, during the operation of the electronic expansion valve, the period of the motion magnetic field curve is smaller than the period of the motion magnetic field curve when the detection rotor 41 is moving normally, the drive rotor 42 will stop rotating or stop rotating at a constant speed.

[0080] Specifically, when the electronic expansion valve determines the motion of the detection rotor 41 using the first magnetoresistive sensor 51 and the second magnetoresistive sensor 52, the principle is as follows.

[0081] When the detection rotor 41 rotates, the north and south poles of the detection rotor 41 alternately pass through the first magnetoresistive sensor 51 and the second magnetoresistive sensor 52. The first magnetoresistive sensor 51 senses the change in the magnetic field of the detection rotor 41 and generates a periodic first feedback signal, which is a square wave and includes multiple first jumping signals. The second magnetoresistive sensor 52 senses the change in the magnetic field of the detection rotor 41 and generates a periodic second feedback signal, which is a square wave and includes multiple second jumping signals. That is, when the rotation changes from north to south or from south to north, the first magnetoresistive sensor 51 generates one first jumping signal and the second magnetoresistive sensor 52 generates one second jumping signal. Here, the first jumping signal and the second jumping signal are jumps from low level to high level or from low level to high level.

[0082] It should be explained that in Figures 3, 4, 5, and 6, the sensor signals are collected by the first magnetoresistive sensor 51 and the second magnetoresistive sensor 52. In the phase diagrams corresponding to the sensor signals, the solid line corresponds to the curve corresponding to the first feedback signal sensed by the first magnetoresistive sensor 51, and the dashed line corresponds to the curve corresponding to the second feedback signal sensed by the second magnetoresistive sensor 52.

[0083] Referring to Figure 3, when the detection rotor 41 in the electronic expansion valve is rotating in the forward direction, the first jumping signal corresponding to the first magnetoresistive sensor 51 always exceeds the second jumping signal corresponding to the second magnetoresistive sensor 52. Referring to Figure 4, when the detection rotor 41 in the electronic expansion valve is rotating in the reverse direction, the second jumping signal corresponding to the second magnetoresistive sensor 52 always exceeds the first jumping signal corresponding to the first magnetoresistive sensor 51.

[0084] Referring to Figure 5, if a stall stack occurs in the stepping motor, as shown by M in the figure, the detection rotor 41 does not rotate, and therefore does not receive a jumping signal, and the count is kept constant within the set time period.

[0085] Referring to Figure 6, if a stall rebound occurs in the stepping motor, as shown by N in the figure, the first jumping signal originally exceeded the second jumping signal, but due to the rebound, the second jumping signal now exceeds the first jumping signal, and the count, which was originally constantly increasing, decreases. Therefore, if it is within the set time period and the count has not increased and has decreased, it is determined that a stall rebound has occurred in stepping motor 1. Similarly, if the second jumping signal originally exceeded the first jumping signal, but due to the rebound, the first jumping signal now exceeds the second jumping signal, and the count, which was originally constantly decreasing, increases. Therefore, if it is within the set time period and the count has not decreased and has increased, it is determined that a stall rebound has occurred in stepping motor.

[0086] It should be explained that a positive difference value in the count indicates that the count increases or decreases the setpoint, and conversely, a negative difference value indicates that the count decreases or increases the setpoint, where the difference value is the difference between the corresponding timing at which the second jumping signal was collected and the corresponding timing at which the first jumping signal was collected. When the stepping motor is operating normally, for example when rotating in the forward direction, as shown in Figure 3, the first jumping signal always exceeds the second jumping signal, and the count always continues to gradually increase. When rotating in the reverse direction, for example, as shown in Figure 4, the second jumping signal always exceeds the first jumping signal, and the count always continues to gradually decrease.

[0087] It is clear that the embodiments described above represent only a portion of the embodiments of this disclosure, and not all embodiments. All other embodiments that a person skilled in the art could obtain without creative effort based on the embodiments in this disclosure are all within the scope of this disclosure.

[0088] It should be noted that the terminology used herein is solely for the purpose of describing specific embodiments and is not intended to limit the exemplary embodiments described herein. Unless otherwise explicitly indicated in the surrounding text, singular forms of terms used herein are also intended to include plural forms. Furthermore, when the terms “include” and / or “contain” are used herein, it should be understood that they indicate the presence of features, procedures, operations, devices, assemblies, and / or combinations thereof.

[0089] The foregoing describes only preferred embodiments of the Disclosure and is not intended to limit it. Those skilled in the art can modify and alter the Disclosure in various ways. Any modifications, equivalent substitutions, or improvements within the spirit and principles of the Disclosure are all within the scope of protection of the Disclosure.

[0090] (Industrial applicability) The electronic expansion valve provided by the embodiments of this disclosure allows the magnetic rotor to be moved along the height direction of the housing chamber and rotated within the housing chamber by providing a housing chamber. The installation of the housing chamber reduces interference from other structural members to the movement of the magnetic rotor, allowing the magnetic rotor to operate stably. By providing a magnetoresistive sensor assembly, the magnetoresistive sensor assembly can collect the magnetic field of the magnetic rotor during the motion process and form a motion magnetic field curve. The motion state of the magnetic rotor can be determined by analyzing the relationship between multiple motion magnetic field curves. At the same time, using a magnetoresistive sensor eliminates the need for separate fixing members and may be fixed to the control circuit board by a patch method, simplifying the assembly of the electronic expansion valve, reducing installation costs, and solving the problems of the conventional electronic expansion valve, which have a complex process, relatively low efficiency, and relatively high installation costs during assembly.

Claims

1. It includes a frame body (10), a magnetic rotor (40), a control circuit board (31), and a magnetoresistive sensor assembly (50), The frame body (10) has a mounting chamber (30) and a housing chamber (20), the mounting chamber (30) is located on the circumferential outer side of the housing chamber (20), The magnetic rotor (40) is provided so as to be movable within the housing chamber (20) along the height direction of the housing chamber (20). The control circuit board (31) is provided in the mounting chamber (30), The magnetoresistive sensor assembly (50) is fixed to the control circuit board (31) and is in close contact with the control circuit board (31), and the movement range of the magnetic rotor (40) is located within the sensing range of the magnetoresistive sensor assembly (50), in an electronic expansion valve.

2. The electronic expansion valve according to claim 1, wherein the magnetoresistive sensor assembly (50) includes at least two magnetoresistive sensors, which are patch-type sensors fixed to the control circuit board (31) by a patch method.

3. The electronic expansion valve according to claim 1, wherein there is a gap between the bottom surface of the magnetoresistive sensor assembly (50) and the bottom wall of the mounting chamber (30).

4. The electronic expansion valve according to claim 3, wherein the distance between the bottom surface of the magnetoresistive sensor assembly (50) and the bottom wall of the mounting chamber (30) is 0.1 mm to 1.0 mm.

5. The electronic expansion valve according to claim 1 or 3, wherein there is a gap between the side wall of the magnetoresistive sensor assembly (50) and the side wall of the mounting chamber (30).

6. The electronic expansion valve according to claim 1 or 3, wherein the distance between the side wall of the magnetoresistive sensor assembly (50) and the side wall of the mounting chamber (30) is 0.1 mm to 1.0 mm.

7. The mounting chamber (30) has a wall surface including a circumferential first side wall (34) and a circumferential second side wall (35), the second side wall (35) is located within the first side wall (34), the control circuit board (31) is fitted outside the second side wall (35), the second side wall (35) has a cross section (36), the control circuit board (31) has an opening (37) that fits the cross section (36), and the magnetoresistive sensor assembly (50) on the control circuit board (31) faces the cross section (36), as described in claim 1.

8. The electronic expansion valve according to claim 1, wherein the magnetoresistive sensor assembly (50) includes a first magnetoresistive sensor (51) and a second magnetoresistive sensor (52), and the first magnetoresistive sensor (51) and the second magnetoresistive sensor (52) are provided on the control circuit board (31) at intervals.

9. The electronic expansion valve according to claim 8, wherein the center of the first magnetoresistive sensor (51) and the center of the second magnetoresistive sensor (52) are at the same distance from the center of the magnetic rotor (40).

10. The centers of the first magnetoresistive sensor (51) and the second magnetoresistive sensor (52) and the center of the magnetic rotor (40) have an angle α between their projections in the height direction of the housing chamber (20), and the magnetic pole pair n of the magnetic rotor (40) and the angle α satisfy the following: [Math 1] Here, m is a positive integer and β is [Math 2] The electronic expansion valve according to claim 8, wherein the positive number is smaller.

11. The electronic expansion valve according to claim 1, wherein the magnetic rotor (40) includes a detection rotor (41) and a drive rotor (42), and the detection rotor (41) and the drive rotor (42) have an integrated structure.

12. An electronic expansion valve according to claim 11, wherein a connecting member (43) is fixed between the drive rotor (42) and the detection rotor (41), and the drive rotor (42), the detection rotor (41), and the connecting member (43) are all H-shaped.

13. The electronic expansion valve according to claim 1, wherein the magnetoresistive sensor assembly (50) includes one magnetoresistive sensor which is a patch-type sensor fixed to the control circuit board (31) by a patch method.

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