Electric valve

Abstract

The invention provides an electrically operated valve which comprises a nut (21) and a stop component, the stop component comprises a spring guide rail (61) and a sliding ring (62), the spring guide rail (61) is formed by winding a metal wire, the sliding ring (62) is formed by winding a metal wire, the spring guide rail (61) and the nut (21) are relatively limited, the sliding ring (62) can slide relative to the spring guide rail (61), and the nut (21) is connected with the spring guide rail (61). The spring guide rail (61) comprises a guide rail part (613), an upper stop part (611) and a clamping part (612), in a natural state, at least part of the guide rail part (613) close to one side of the upper stop part (611) has a first pitch (X1), at least part of the guide rail part (613) close to one side of the clamping part (612) has a second pitch (X2), and the following conditions are met: D2 is greater than X1-D1 and less than or equal to X2-D1; wherein D1 is the wire diameter of the guide rail part (613), and D2 is the wire diameter of the sliding ring matching part (621).

Description

Technical Field

[0001] The invention relates to the technical field of refrigeration, and in particular to an electric valve. Background Art

[0002] Electric valves are usually used in refrigeration systems. Their basic function is to output power according to system parameters to keep the valve opening at the required position to maintain the required liquid supply to the evaporator. At present, electric valves used in refrigeration systems usually consist of a coil mounted outside the valve body and a rotor inside the valve body to form a motor. During operation, the rotor drives the valve needle inside the valve body to move to adjust the valve opening.

[0003] CN102454819A discloses an electric valve and its stop device, wherein the stop device comprises a spring guide rail and a slip ring which are nested and spirally matched inside and outside, the spring guide rail is sleeved on the outer peripheral surface of the upper part of the plastic nut, and the nut assembly or the spring guide rail is provided with an upper stopper and a clamping part. The stopper rod located in the inner cavity of the electric valve rotor and fixedly connected to the rotor can drive the slip ring to slide spirally along the spring guide rail, and when the slip ring slides upward to the apex, the upper stopper will limit the slip ring from sliding upward further, thereby playing the role of an upper stopper; when the slip ring slides downward to the apex, the clamping part will limit the slip ring from sliding downward further, thereby playing the role of a lower stopper. There is a gap between the slip ring and the spring guide rail, and during the rotation process, except for the upper stopper and the clamping part, the slip ring can slide smoothly along the spring guide rail without being significantly hindered in the circumferential direction.

[0004] When the electric valve leaves the factory, it is usually in a fully open state. During the period from the time the electric valve leaves the factory to the time it is assembled to the main engine, the free rotor may rotate without being constrained due to some factors in the transportation and turnover processes. When the rotor rotates, it will drive the valve needle downward, which may cause the electric valve to be in a closed state. This will affect the subsequent operations of connecting the electric valve to the main engine, filling the refrigerant, and testing.

[0005] Therefore, how to provide an electric valve that can always remain in an open state before installation has become a technical problem that needs to be urgently solved by those skilled in the art. Summary of the invention

[0006] To this end, at least one embodiment of the present invention adopts the following technical solution:

[0007] An electric valve comprises a nut and a stop component, wherein the stop component comprises a spring guide rail and a slip ring, wherein the spring guide rail is formed by winding a metal wire, and the slip ring is formed by winding a metal wire, wherein the spring guide rail and the nut are relatively limited, and the slip ring can slide relative to the spring guide rail, wherein the spring guide rail comprises a guide rail portion, an upper stop portion, and a clamping portion, wherein in a natural state, at least a portion of the guide rail portion on a side close to the upper stop portion has a first pitch, and at least a portion of the guide rail portion on a side close to the clamping portion has a second pitch, and then the condition is satisfied: X1-D1<D2≤X2-D1; wherein D1 is the wire diameter of the guide rail portion, and D2 is the wire diameter of the slip ring mating portion.

[0008] The electric valve provided in the embodiment of the present invention has, in a natural state, a first pitch at least in a portion of the guide rail portion close to the upper stop portion, and a second pitch at least in a portion of the guide rail portion close to the engaging portion, X1-D1<D2≤X2-D1, and when the slip ring cooperates with the guide rail portion having the first pitch, the guide rail portion of this portion can clamp the slip ring cooperation portion, making it difficult for the slip ring to move circumferentially, thereby constraining the rotor from rotating, so that the electric valve that is in an open state when leaving the factory can always remain in the open state before installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of the closed valve state of an electric valve according to an embodiment of the present invention;

[0010] Figure 2 It is a schematic diagram of the valve opening state of an electric valve according to an embodiment of the present invention;

[0011] Figure 3 is a front view of a spring guide rail according to an embodiment of the present invention;

[0012] Figure 4 is a three-dimensional schematic diagram of a spring guide rail according to an embodiment of the present invention;

[0013] Figure 5 is a front view of a slip ring according to an embodiment of the present invention;

[0014] Figure 6 is a three-dimensional schematic diagram of a slip ring according to an embodiment of the present invention;

[0015] Figure 7 yes Figure 2 Enlarged view of part I. DETAILED DESCRIPTION

[0016] The specific implementation of the present invention is described below in conjunction with the accompanying drawings of the specification. It should be noted that the electric valve includes two major components, a coil and a valve body. Usually, the coil component and the valve body component are manufactured separately and then assembled to form a complete electric valve. The core of the present invention is to provide a preferred electric valve body structure. Based on the technical inspiration of the electric valve body provided by the present invention, those skilled in the art can select a suitable coil component for assembly. Therefore, the present invention no longer makes a detailed limitation on the specific implementation of the coil component.

[0017] In addition, all descriptions of the implementation methods of this specification are based on the contents of the drawings in the specification. The directional words such as up, down, inside, and outside in the text are all descriptions of the drawings in the specification. Their purpose is to more conveniently describe the present invention and should not be regarded as limitations on the present invention.

[0018] Please refer to Figure 1 , Figure 1 The present invention is a schematic diagram of the closed valve state of an electric valve provided by an implementation method.

[0019] The electric valve includes a valve seat assembly 1, which includes a valve core seat 11 and a valve seat 12, and a first connecting pipe 13 and a second connecting pipe 14 connected to the valve seat 12. The valve seat 12 is generally a cylindrical structure, and has a matching hole at the bottom for matching with the valve core seat 11, and is fixed to the valve core seat 11 by welding. A valve cavity 121 is formed inside the valve seat 12. The bottom of the valve seat 12 is connected to the second connecting pipe 14, and the circumferential side of the valve seat 12 is connected to the first connecting pipe 13.

[0020] The valve core seat 11 is roughly in the shape of a hollow cylinder, and its circumferential outer wall is provided with a plurality of refrigerant circulation holes 115, and its lower end is processed with a valve port 113 for the circulation of the refrigerant; and the opening of the valve port 113 is controlled by the up and down displacement of the valve needle to realize the flow regulation function of the electric valve. The valve core seat 11 has a cylindrical structure, and a first guide section 111 is provided on the outer edge portion away from the valve port. The first guide section 111 is used to cooperate with the nut component described later, and the two can be transitional, interference or small clearance fit, so that the valve core seat and the nut are matched and positioned. This matching structure is conducive to ensuring the coaxiality between the valve core seat 11 and the nut, and further combined with the cooperation of the guide section set between the valve core seat and the valve needle, the coaxiality of the valve needle and the nut is guaranteed. Of course, the valve core seat 11 can also be assembled using a split structure. For example, the cylindrical structure with the first guide section 111 is used as a separate part, and the refrigerant circulation hole 115 mentioned above is set on the cylindrical structure, and the part with the valve port 113 is used as another part. The two parts are then assembled and fixed by tight fit or welding to form the valve core seat 11.

[0021] A valve needle accommodating chamber 114 is also provided on the valve core seat 11. The valve core seat 11 is also provided with a second guide section 112. The second guide section 112 is formed at the inner edge of the accommodating chamber 114. The second guide section 112 of the valve core seat 11 cooperates with the valve needle (the valve needle is correspondingly provided with a valve needle guide section) so that the valve needle can be axially slidably set in the accommodating chamber 114 of the valve core seat 11.

[0022] The nut assembly includes a nut 21 and a connecting piece 22, and the connecting piece 22 is formed integrally with the nut 21 as an insert. The connecting piece 22 is made of metal and fixed to the valve seat 12 by welding. The nut 21 is a roughly annular structure composed of a plurality of variable diameter cylinders, and the material is preferably engineering resin. The inner hole of the nut has an internal thread section 216 for matching with the screw thread. When processing the nut, the manufactured connecting piece 22 is placed in the mold, and the nut 21 is formed by injection molding, so that the connecting piece 22 is embedded in the nut 21 to form a nut assembly.

[0023] A screw rod 32 and a valve needle 35 are provided in the valve cavity of the electric valve. The valve needle 35 moves up and down along the second guide section 112 of the valve core seat 11. The valve needle 35 has a blind hole with an opening facing upward. The front end of the valve needle 35 is a conical structure, and the rest of the valve needle 35 is a cylindrical structure. The conical front end moves up and down in the cavity of the valve core seat 11, approaching or moving away from the valve port 113 to control the size of the valve port opening. The screw rod 32 and the valve needle 35 are connected in a floating manner, that is, the two can move relative to each other in the axial and circumferential directions, but will not be separated from each other as a whole. The lower end of the screw rod 32 is inserted into the blind hole of the valve needle. An external thread section 321 is provided on the circumferential surface of the screw rod 32, which is connected and matched with the internal thread section 216 of the nut 21. Therefore, the screw rod can rotate and lift relative to the nut 21. The upper end of the screw rod 32 is fixedly connected to the magnetic rotor assembly. When the magnetic rotor assembly rotates, the screw rod 32 is driven to rotate, and through thread transmission, the screw rod 32 moves up and down along the direction of the valve core seat 11.

[0024] The screw rod 32 and the valve needle 35 can rotate relative to each other in the radial direction, so that when the screw rod 32 rotates with the rotation of the magnetic rotor, the valve needle 35 can remain stationary, which is more conducive to the stability of the valve needle lifting movement and more convenient for achieving precise control of the valve opening.

[0025] The magnetic rotor assembly includes a magnetic rotor 42, a stop rod 41, and a connecting seat 43. The connecting seat 43 includes a body 431 that is roughly disc-shaped, and a boss-shaped screw rod matching portion 432 is provided in the middle of the body 431. A through hole is provided at the center of the screw rod matching portion 432 for matching with the screw rod 32. The body 431 is also provided with a socket 433 for assembling the stop rod 41.

[0026] The stop rod 41 includes an annular portion 411 and a rod-shaped portion 412 which is integral with the annular portion 411, and the angle between the rod-shaped portion 412 and the annular portion 411 is substantially a right angle. The annular portion 412 is used to cooperate with the outer fillet of the screw rod matching portion 432 of the above-mentioned connecting seat, and the rod-shaped portion 412 extends into the insertion hole 433 and is located in the cavity formed by the formed magnetic rotor 42.

[0027] During manufacturing, the connecting seat 43 can be placed in a mold first, and the magnetic rotor 42 integrated with the connecting seat can be formed by injection molding. Then, the rod-shaped portion 412 of the stop rod 41 is inserted into the socket 433 of the connecting seat 43, and the annular portion 411 of the stop rod 41 is positioned in cooperation with the outer circumference of the screw fitting portion 432 of the connecting seat 43, and fixed by welding.

[0028] The stop assembly includes a spring guide 61 and a slip ring 62 which are nested and spirally matched inside and outside. The spring guide 61 is sleeved on the upper outer peripheral surface of the nut 21, and its lower end is embedded in the slot on the outer periphery of the nut 21 for fixing, so that the spring guide and the nut are kept relatively limited. The spring guide 61 can be wound with a metal wire such as a steel wire. The main body of the spring guide 61 is spiral, and an upper stopper 611 is arranged on its upper part, and a clamping part 612 is arranged on its lower part. The clamping part 612 can be embedded in the nut slot for fixing or limiting, or can be clamped and limited with the connecting piece 22. The slip ring 62 is also wound with a metal wire such as a steel wire. Since the nut 21 is preferably made of plastic, when the slip ring 62 is spirally matched along the spring guide 61, the friction resistance of relative sliding between it and the outer peripheral surface of the plastic nut 21 is small, which can effectively reduce the resistance to the rotation of the electric valve rotor.

[0029] The slip ring 62 can slide along the spiral path defined by the spring guide 61. In the design of the background technology, in order to ensure the relative flexible movement between the spring guide and the slip ring, the spring guide is set to an equal pitch structure, that is, the spring guide is used for the part where the slip ring slides, and the pitch is set to be the same everywhere (ignoring the inevitable errors caused by reasons such as processing accuracy). The spring pitch described in this specification refers to the axial distance between the corresponding points of two adjacent circles of the spring on the middle diameter, excluding the supporting circle. In other words, the pitch at the upper end of the spring guide is the same as the second pitch at the lower end. In addition, the pitch at the upper end of the spring guide minus the wire diameter of the spring guide is greater than the wire diameter of the slip ring to ensure that during the movement of the slip ring, there is always a clearance fit between the spring guide and the slip ring. When the electric valve leaves the factory, it is usually in a fully open state. During the period from the time the electric valve leaves the factory to the time it is assembled to the main engine, the free rotor may rotate without being constrained due to some factors in the transportation and turnover processes. When the rotor rotates, the valve needle will move downward, which may cause the electric valve to be in a closed state. This will affect a series of problems in the subsequent connection between the electric valve and the main engine, refrigerant filling, and testing. The spring guide rail and the slip ring are always in a clearance fit, and the slip ring cannot limit the rotation of the rotor.

[0030] To this end, in this embodiment, the spring guide rail is designed with a variable pitch, such as Figure 3 and Figure 4 As shown, the spring guide 61 includes a guide rail portion 613, an upper stop portion 611, and a snap-fit ​​portion 612. The upper stop portion 611 is located above the guide rail portion 613, and the snap-fit ​​portion 612 is located below the guide rail portion 613. The entire spring guide is wound with metal wires such as steel wires. The guide rail portion 613 serves as the main body of the spring guide. After the spring guide and the nut are assembled, fixed or limited, the slip ring can slide along the guide rail portion 613. The upper stop portion 611 is located at the upper end of the guide rail portion 613, and the snap-fit ​​portion 612 is located at the lower end of the guide rail portion 613. The snap-fit ​​portion 612 is used to limit and fix with the nut 21, and can also be used as a lower stop portion in a certain structure, that is, when the slip ring rotates downward to the extreme position, it can abut against the snap-fit ​​portion 612 to stop. As shown Figure 5 and Figure 6 As shown, the slip ring 62 includes a slip ring matching portion 621 and a slip ring first abutting portion 622. The slip ring matching portion 621 can slide along the guide rail portion 613 of the spring guide rail, and the slip ring first abutting portion 622 is used to abut against and stop the upper stop portion 611 of the spring guide rail 61. Specifically, when the stop rod 41 of the magnetic rotor assembly drives the slip ring 62 to slide upward along the guide rail portion 613, when the slip ring first abutting portion 622 abuts against the upper stop portion 611, the slip ring is blocked by the upper stop portion 611 and stops sliding, thereby stopping the rotation of the magnetic rotor assembly.

[0031] The slip ring 62 includes a second abutting portion 623 of the slip ring, which is used to abut against the lower stop portion to stop. Specifically, when the stop rod 41 of the magnetic rotor assembly drives the slip ring 62 to slide downward along the guide rail portion 613, when the second abutting portion 623 of the slip ring abuts against the lower stop portion, the slip ring is blocked by the lower stop portion and stops sliding, thereby stopping the rotation of the magnetic rotor assembly. The lower stop portion here, in some embodiments, can be the engaging portion 612 of the spring guide rail mentioned above. Of course, the lower stop portion can also be set independently of the spring guide rail, such as directly forming the lower stop portion on the nut so that it can abut against the second abutting portion 623 of the slip ring.

[0032] The spring guide rail 61 has a guide rail portion 613. In a natural state, the pitch of at least part of the guide rail portion 613 on the side close to the upper stop portion 611 is smaller than the pitch of at least part of the guide rail portion 613 on the side close to the locking portion 612. Assuming that the pitch of at least part of the guide rail portion on the side close to the upper stop portion 611 is a first pitch, set as X1, and the pitch of at least part of the guide rail portion 613 on the side close to the locking portion 612 is a second pitch, set as X2, the wire diameter of the guide rail portion 613 is a first wire diameter, set as D1, and the wire diameter of the slip ring mating portion 621 is a second wire diameter, set as D2, then X1<X2, X1-D1<D2≤X2-D1 are satisfied. In this way, since the difference between the first pitch and the wire diameter of the guide rail portion is smaller than the wire diameter D2 of the slip ring matching portion 621, when the slip ring slides to the position abutting against the upper stop portion 611, the guide rail portion of this part will undergo elastic deformation, thereby forming a third pitch X3, and the slip ring matching portion 621 will be clamped by the partially stretched guide rail portion, and the clamping force applied by the guide rail portion to the slip ring matching portion is sufficient to ensure that the slip ring will not slide easily without external force. As in the usage scenario described in the background technology, the electric valve is in a fully open state when it leaves the factory. At this time, the state, that is, the first elastic contact portion 622 of the slip ring abuts against the upper stop portion 611 of the spring guide rail. Since the slip ring matching portion 621 is clamped by the guide rail portion, the stop rod 41 is limited to a relatively fixed position, and the circumferential rotation of the rotor is constrained by the slip ring through the stop rod. In this way, the electric valve is always in a fully open state in various use scenarios such as transportation, turnover, vibration, etc., which is conducive to a series of operations such as subsequent connection of the electric valve with the host, refrigerant filling, and testing. In addition, in the fully open state, the system pressure differential force borne by the valve needle component is much smaller than the system pressure differential force in the closed state, and the friction resistance between the spring guide rail and the slip ring will not have an adverse effect on the product's performance.

[0033] It should be noted that the natural state of the spring guide described in this specification refers to the state of the portion of the guide that is not matched with the slip ring, even if the slip ring has been assembled with the spring guide. For example, when the slip ring is located below the guide, the portion of the spring guide above the slip ring is in the natural state; when the slip ring is located above the guide, the portion of the spring guide below the slip ring is in the natural state.

[0034] In this embodiment, the wire diameter D2 of the slip ring fitting portion can be set to be greater than the wire diameter D1 of the guide rail portion or can be set to be the same.

[0035] At the same time, since D2 ≤ X2 - D1, that is, on the side close to the engaging portion 612, the difference between the second pitch and the wire diameter of the guide rail portion is greater than or equal to the wire diameter D2 of the slip ring fitting portion 621. Therefore, in this section of the guide rail portion, the slip ring fitting portion 621 can slide smoothly, and can slide smoothly to displace upward in the axial direction or can slide smoothly to displace downward in the axial direction. The advantage of this structure is that when the electric valve is in the closed valve state and needs to be opened, there is only a circumferential sliding friction resistance between the slip ring and the spring guide rail, and there is no additional resistance in the axial direction, which is beneficial to minimizing the starting difficulty of opening the valve and ensuring the action reliability of the product.

[0036] In a further embodiment, the setting positions of the first pitch and the second pitch can be further optimized. The guide rail portion is in a spiral structure. The first pitch can be set as follows: starting from the portion of the guide rail portion 613 that is connected to the upper stop portion 611, extending at least one turn from this starting portion, and at least part of the guide rail portion has the first pitch X1, as Figure 3 shown in the position. The partial guide rail portion less than one turn can be set to have the second pitch, that is, except for the partial guide rail portion with the first pitch, the remaining partial guide rail portion close to the engaging portion 612 has the second pitch. That is, it is only necessary to ensure that when the electric valve is fully open, the guide rail portion with the first pitch can apply a clamping force to the slip ring fitting portion, and the remaining positions of the guide rail portion are available for the slip ring to slide smoothly.

[0037] As a further embodiment, the proportional relationship between the first pitch X1 and the second pitch can also be set. In a specific embodiment, the ratio of the first pitch X1 to the second pitch X2 satisfies: 81% < X1 / X2 < 90%. Further, it can be set to 76% < X1 / X2 < 85%. The advantage of such a setting is that the difference between the first pitch and the second pitch is controlled within a certain range, which is convenient for matching with the wire diameter of the slip ring. If the ratio of the first pitch to the second pitch is too small, that is, the difference between the two is too large, it will be unfavorable for the selection of the slip ring. Because to ensure that the slip ring can slide smoothly in the portion of the spring guide rail with the second pitch, the wire diameter of the slip ring should be set to be approximately the same as the value obtained by subtracting the wire diameter of the guide rail portion from the second pitch; when the first pitch is too small, the guide rail portion will generate too large a clamping force and firmly clamp the slip ring, resulting in the magnetic rotor being unable to drive the slip ring to slide along the spring guide rail, thereby affecting the performance of the product. Within the above ratio range, an appropriate balance can be maintained between the clamping force of the guide rail portion and the electromagnetic force for driving the magnetic rotor to rotate.

[0038] As another embodiment, the limitation may be made not by the number of turns of the guide rail portion but by the portion where the guide rail portion can clamp the slip ring, that is, when the first abutting portion 622 of the slip ring abuts against the upper stop portion 611, along the extension direction of the slip ring mating portion 621, the portion of the guide rail portion 613 that can contact the slip ring mating portion 621 has a first pitch X1 at least at one place in a natural state, and when the slip ring mating portion is mated with the guide rail portion of this portion, the guide rail portion of this portion can undergo elastic deformation to form a third pitch X3, X3>X1, that is, the pitch is increased along the axial direction, thereby clamping the slip ring mating portion 621.

[0039] As another embodiment, the pitch of the guide rail portion from top to bottom can be set to gradually increase, or only the first pitch X1 can be set at the upper end of the guide rail portion, and the second pitch X2 can be set at the lower end of the guide rail portion. The middle section between the two can be set to gradually increase or remain unchanged.

[0040] Since the spring guide is made of steel wire, the relevant winding procedures of the spring winding machine can be directly set during the winding operation to achieve the pitch size of different positions of the guide part, without adding additional processes, which will not affect production efficiency and increase additional production and management costs. Through the above structural design of the spring guide, without adding parts and processes, it is possible to prevent the valve body from automatically closing due to vibration during transportation and turnover, effectively reducing the production costs of manufacturers and customers.

[0041] Combine the following Figure 1 and Figure 2 , explaining the working principle of the electric valve:

[0042] Figure 1 The figure is a schematic diagram of the closed valve state of an electric valve according to an embodiment of the present invention. In this state, when the valve needs to be opened, the magnetic rotor 42 senses the electromagnetic force of the coil component and performs rotational motion, causing the screw rod 32 to rotate accordingly. Since the screw rod 32 and the nut 21 are threadedly matched, the screw rod can also rise along the axial direction of the nut while rotating, thereby driving the valve needle 35 to gradually move away from the valve port 113. At this time, there is only circumferential sliding friction resistance between the slip ring and the spring guide rail, and there is no additional resistance in the axial direction, which is conducive to minimizing the difficulty of starting to open the valve and ensuring the reliability of the product's operation. When the screw rod 32 drives the valve needle 35 to rise to the limit position, the stop rod 42 drives the slip ring 62 to abut against the upper stop portion 611 of the spring guide rail 61 and stop, as shown in FIG. Figure 2 As shown, at this time, the clamping force applied by the guide rail part to the slip ring mating part is sufficient to ensure that the slip ring will not easily break when not subjected to external force.

[0043] Taking the first connecting pipe 13 as an example, the refrigerant enters from the first connecting pipe 13, flows into the valve cavity 121, and enters the valve needle accommodating cavity 114 through a plurality of refrigerant flow holes 115 opened on the valve core seat 11, and then flows out of the second connecting pipe 14 along the gap between the valve needle 35 and the valve port 115.

[0044] The upper stopper and the lower stopper provided on the spring guide rail 61 and the nut 21 define the upper and lower limit positions of the sliding ring on the spring guide rail. The stopper rod 41 rotates with the magnetic rotor 42 and drives the sliding ring to rotate. When the sliding ring slides to the upper stopper and the lower stopper respectively, the distance between the valve needle 35 and the valve port 113 is the maximum and minimum respectively. In the process of the valve needle moving up and down, the flow rate of the refrigerant flowing through the valve port 113 also changes accordingly, thereby achieving the purpose of accurately controlling the flow rate.

[0045] It should be noted that the above embodiments describe the stopper in detail with a specific electric valve structure, and those skilled in the art can understand that the above stopper is not dependent on the above electric valve structure. Without changing the technical concept of the stopper, the stopper in the above embodiments can be transplanted as a whole into an electric valve of other structures.

[0046] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An electric valve, comprising a nut (21) and a stopper, wherein the stopper comprises a spring guide rail (61) and a slip ring (62), wherein the spring guide rail (61) is formed by winding a metal wire, and the slip ring (62) is formed by winding a metal wire, wherein the spring guide rail (61) and the nut (21) are relatively limited, and the slip ring (62) can slide relative to the spring guide rail (61), wherein the spring guide rail (61) comprises a guide rail portion (613), an upper stopper portion (611), and a clamping portion (612), wherein in a natural state, at least a portion of the guide rail portion (613) on a side close to the upper stopper portion (611) has a first pitch (X1), and at least a portion of the guide rail portion (613) on a side close to the clamping portion (612) has a second pitch (X2), and then the following conditions are satisfied: X1-D1<D2≤X2-D1; wherein, D1 is the wire diameter of the guide rail portion (613), and D2 is the wire diameter of the slip ring matching portion (621).

2. The electric valve according to claim 1, characterized in that: The slip ring (62) comprises a slip ring matching portion (621) and a slip ring first abutting portion (622); the slip ring matching portion (621) can slide along the guide rail portion (613); and the slip ring first abutting portion (622) can abut against the upper stop portion (611).

3. The electric valve according to claim 2, characterized in that: The guide rail portion (613) is in a spiral structure and extends at least one circle along the direction toward the locking portion (612), starting from the portion of the guide rail portion (613) connected to the upper stop portion (611), and at least a portion of the guide rail portion (613) has the first pitch (X1).

4. The electric valve according to claim 3, characterized in that: In addition to the partial guide rail portion having the first pitch (X1), the remaining partial guide rail portion close to the locking portion (612) has the second pitch (X2).

5. The electric valve according to claim 2, characterized in that: When the first abutting portion (622) of the slip ring abuts against the upper stop portion (611), along the extension direction of the slip ring matching portion (621), the portion of the guide rail portion (613) that can contact the slip ring matching portion (621), at least a part of the guide rail portion has the first pitch (X1) in a natural state.

6. The electric valve according to claim 5, characterized in that: When the slip ring fitting portion (621) contacts the guide rail portion (613) having the first pitch (X1) in a natural state, the guide rail portion of the contact portion forms a third pitch (X3), wherein X3>X1.

7. The electric valve according to any one of claims 1 to 6, characterized in that: The ratio of the first pitch (X1) to the second pitch (X2) satisfies: 81% <X1 / X2<90%。 8. The electric valve according to any one of claims 1 to 6, characterized in that: The ratio of the first pitch (X1) to the second pitch (X2) satisfies: 76% <X1 / X2<85%。 9. The electric valve according to claim 3 or 5, characterized in that: The portion of the guide rail portion (613) having the first pitch (X1) and the portion of the guide rail portion (613) having the second pitch (X2) have the same pitch.

10. The electric valve according to claim 3 or 5, characterized in that: The pitch of the guide rail portion between the portion of the guide rail portion (613) having the first pitch (X1) and the portion of the guide rail portion (613) having the second pitch (X2) gradually increases.

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