KR20230008854A - electronic expansion valve - Google Patents

Abstract

Electronic comprising valve seat (11), nut assembly (12), valve shaft portion (22), valve needle (21), and magnet rotor assembly (27) An expansion valve is provided. The valve seat 11 includes a valve port portion 113; The nut assembly 12 is fixedly connected to the valve seat 11; The nut assembly 12 includes a nut 121 and a connecting piece 122; The nut 121 includes a first guide portion 12a, an internally threaded portion 12b, and a second guide portion 12c; The first guide portion 12a is closer to the valve port portion 113 than the inner thread portion 12b, and the second guide portion 12c is further from the valve port portion 113 than the inner thread portion 12b. far away; The inner diameter of the first guide portion 12a is smaller than the inner diameter of the second guide portion 12c; The valve shaft portion 22 is fixedly connected to the magnet rotor assembly 27 and includes a valve shaft guide portion 22b; The valve shaft guide part 22b has a clearance fit with the second guide part 12c; The valve shaft portion 22 can perform a relative displacement relative to the nut 121 in an axial direction along the nut 121 .

Description

electronic expansion valve

This application claims priority to Chinese Patent Application No. 202010392210.5 entitled "Electronic Expansion Valve", filed with the State Intellectual Property Administration of China on May 11, 2020, the entire disclosure of this application is hereby incorporated by reference. integrated into

This application relates to the field of refrigeration control technology, and in particular to electronic expansion valves.

The refrigeration system includes a compressor, a throttling element, two heat exchangers and other components. The throttling element may consist of an electronic expansion valve used for adjusting the throttling of the refrigerant. The use of electronic expansion valves can achieve relatively precise control and improve system energy efficiency. The basic principle of the electromagnetic expansion valve is: by supplying a specified pulse current signal through the stator coil, the rotor component of the electronic expansion valve is excited and rotated, and the rotary motion of the rotor is driven by a screw supply mechanism to the valve shaft ( It is converted into up and down movement of the shaft, so that the valve core in the head of the valve shaft moves closer to or farther from the valve port. The flow area of the valve port is changed to adjust the flow of refrigerant and implement a switching function.

An object of one embodiment of the present application is to provide an electromagnetic expansion valve having relatively small frictional resistance from a screw feeding mechanism.

In order to achieve the above object, the following technical solution is provided according to an embodiment of the present application.

An electronic expansion valve is provided that includes a valve seat, a nut assembly, a valve shaft portion, a valve needle and a magnetic rotor assembly. The valve seat includes a valve port portion, and the nut assembly is fixedly connected to the valve seat. The nut assembly includes a nut and a connecting sheet. The nut includes a first guide portion, an internally threaded portion, and a second guide portion. The first guide portion is closer to the valve port portion than the internal thread portion. The second guide portion is farther away from the valve port portion than the inner thread portion. the inner diameter of the first guide portion is smaller than the inner diameter of the second guide portion;

The valve shaft portion is fixedly connected to the magnetic rotor assembly, and the valve shaft portion includes a valve shaft guide portion. The valve shaft guide portion is in a clearance fit with the second guide portion. The valve shaft portion can be moved relative to the nut along the axial direction of the nut; The valve shaft portion includes an external thread portion. The outer threaded portion and the inner threaded portion form a screw feeding mechanism; The valve shaft portion includes a first through hole portion and a second through hole portion. the inner diameter of the first through hole portion is larger than the inner diameter of the second through hole portion;

The valve needle includes a valve needle guide portion, and the valve needle guide portion is loosely fitted with the first guide portion. The valve needle can be moved relative to the nut along the axial direction of the nut; An outer diameter of the valve needle guide portion is larger than an inner diameter of the second through hole portion.

In the electromagnetic expansion valve provided in this embodiment, the valve shaft portion includes a first through hole portion and a second through hole portion. Since the outer diameter of the valve needle guide portion is larger than the inner diameter of the second through hole portion of the valve shaft portion, if the electronic expansion valves have the same specifications such as rotor diameter, housing diameter, stator coil diameter and volume, The nominal diameter of the screw feed mechanism only needs to be slightly larger than the outer diameter of the valve needle guide section. That is, the nominal diameter of the screw feeding mechanism can be made relatively small, which is advantageous for reducing the frictional resistance from the screw feeding mechanism.

1 is a schematic sectional view of an electronic expansion valve of a first embodiment in a closed state.
Fig. 2 is a schematic sectional view of the electromagnetic expansion valve of the first embodiment in an open state.
3 is a schematic diagram of the fit between the nut and the valve seat assembly in the first embodiment.
Fig. 4 is a schematic diagram of a valve shaft portion and a valve needle according to the first embodiment, and the matching of the magnetic rotor assembly.
5 is a schematic sectional view of the electromagnetic expansion valve of the second embodiment in a closed state.
6 is a schematic sectional view of the electromagnetic expansion valve of the second embodiment in an open state.
7 is a schematic structural diagram of a nut assembly in a second embodiment.
8 is a partial cross-sectional view of a magnet rotor assembly mated with a valve shaft portion and a valve needle according to a second embodiment.
9 is a plan view of the nut assembly of the second embodiment.
10 is a schematic sectional view of the electromagnetic expansion valve of the third embodiment in a closed state.
11 is a schematic sectional view of the electromagnetic expansion valve of the third embodiment in an open state.
12 is a schematic structural diagram of a nut assembly in a third embodiment.
Fig. 13 is a schematic diagram of a matching structure of a valve shaft portion and a stop portion according to a third embodiment;
14 is a schematic diagram of a matching structure of a magnetic rotor assembly, a valve shaft portion, a valve needle and a stop portion according to a third embodiment.
15 is a schematic structural diagram of a connection plate provided by a fourth embodiment.
Fig. 16 is a partial sectional view of a matching structure of a magnetic rotor assembly and a valve shaft portion, a valve needle and other components provided by a fourth embodiment.
17 is a schematic diagram of a fifth embodiment of an electronic expansion valve in a fully closed state in a rest position.
Fig. 18 is an enlarged view of part (I) of Fig. 17;
Fig. 19 is an enlarged view of part (II) of Fig. 17;
Fig. 20 is a sectional view of the electronic expansion valve of the fifth embodiment in a spring force unloading position.
Fig. 21 is an enlarged view of part (III) of Fig. 20;
FIG. 22 is an enlarged view of part IV of FIG. 20 .
Fig. 23 is a cross-sectional view of the electronic expansion valve of the fifth embodiment when it is at the opening threshold.
FIG. 24 is an enlarged view of part V of FIG. 23 .
FIG. 25 is an enlarged view of part VI of FIG. 23 .
26 is a sectional view of the electromagnetic expansion valve of the fifth embodiment in a fully open state.
27 is a schematic structural diagram of an electromagnetic expansion valve according to a sixth embodiment.

In order for those skilled in the art to better understand the technical solution provided by the present application, the technical solution of the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

Example 1

1 to 4, FIG. 1 is a schematic structural diagram of the electromagnetic expansion valve in the closed state of the first embodiment, and FIG. 2 is a schematic structural diagram of the electromagnetic expansion valve in the open state of the first embodiment. 3 is a schematic structural diagram of the valve seat component of the first embodiment, and FIG. 4 is a schematic structural diagram of the rotor and screw valve needle assembly of the first embodiment.

As shown in FIG. 1 , the electromagnetic expansion valve includes a valve body part and a coil part 40 . The valve body includes a valve seat 11, a connecting piece 50 and a housing 30, wherein the valve seat 11 can be machined by metal cutting. A connecting piece 50 is provided on the upper side of the valve seat 11 . The connection piece 50 may be fixedly connected to the valve seat 11 by welding, and may be specifically fixedly connected to the housing 30 by welding. The housing 30 is made of a thin-walled part, and is generally cylindrical with one end open, and the open end is tightly welded to the valve seat 11. The valve seat 11 and the connecting piece 50 can be assembled and positioned by providing a stepped portion on the upper outer edge of the valve seat 11 and then inserting the connecting piece 50 from above the valve seat 11. . A stepped portion is further provided on the outer edge of the upper side of the connecting piece 50 to facilitate assembly and positioning with the housing 30, facilitating the welding operation. That is, the valve seat 11 is connected to the housing through the connecting piece 50, and on the valve seat 11 there is a cavity capable of accommodating components such as a magnetic rotor assembly and a nut assembly described below. is formed

The valve seat 11 includes a valve port portion 113 , a first port portion 111 and a second port portion 112 . Both the first port portion 111 and the second port portion 112 are used to connect with the refrigerant passage of the system, and the valve port portion 113 is provided with a valve port 113a. In this embodiment, the first port portion 111 is fixedly connected to the first connecting pipe 10b, and the second port portion 112 is fixedly connected to the second connecting pipe 10c. The refrigerant may flow in from the first connection pipe 10b, pass through the valve port 113a and then flow out of the second connection pipe 10c, or may flow in from the second connection pipe 10c and flow through the valve port ( After passing through 113a), it may flow out of the first connection pipe 10b.

The electronic expansion valve includes a nut assembly (12), and the nut assembly (12) is fixedly connected to the valve seat (11). Specifically, the upper end of the valve seat 11 is provided with an opening, and the nut assembly 12 can be mounted into the valve seat 11 from top to bottom. The nut assembly 12 includes a nut 121 and a connecting sheet 122, and the nut 121 is fixedly connected to the connecting sheet 122. As a specific example, the connection sheet 122 may be formed by stamping a metal plate. The nut 121 is made of a non-metallic material such as engineering plastic, and the connecting sheet 122 is used as an insert for injection molding. The nut 121 is press-fitted to the valve seat 11, and the connection sheet 122 is fixedly connected to the valve seat 11 by welding. The material of the nut may be PPS-modified resin, PEEK-modified resin, or PTFE-modified resin.

The nut 121 has a through hole penetrating along the axial direction, and is internally threaded on the inner side wall of the through hole to form a screw feeding mechanism together with an external threaded portion 22c provided on the outer edge of the valve shaft portion 22. A portion 12b is provided. The inner side wall of the nut is further provided with a first guide part 12a. The first guide portion 12a is provided below the inner threaded portion 12b and can provide a circumferential guiding and centering effect to the valve needle 21 . The lower part referred to here indicates that the first guide part 12a is closer to the valve port part 113 than the inner threaded part 12b. The valve needle 21 includes a valve needle guide portion 21b, that is, the first guide portion 12a and the valve needle guide portion 21b are fitted with a small gap. The valve needle 21 can be rotated or moved up and down along the first guide portion 12a of the nut driven by the valve shaft portion 22 . It should be noted here that the first guide part 12a means a part provided on the inner side wall of the nut. The valve needle guide portion 21b means a portion provided on the outer edge portion of the valve needle. A second guide portion 12c is provided on a relatively upper portion of the inner side wall of the nut, which can provide a guiding and centering effect for the valve shaft portion 22 in the circumferential direction. An outer edge portion of the valve shaft portion 22 is provided with a valve shaft guide portion 22b, and the valve shaft guide portion 22b and the second guide portion 12c are fitted with a small gap. The valve shaft portion 22 can be rotated or moved up and down along the second guide portion 12c driven by the magnetic rotor assembly. The inner diameter of the second guide part 12c is larger than the inner diameter of the first guide part 12a of the nut. In this way, since the outer threaded portion 22c of the valve shaft portion 22 is gradually disengaged from the inner threaded portion 12b while moving upward, it can not be interfered with by the second guide portion 12c. . In addition, it should be noted that both the first guide portion 12a and the second guide portion 12c described above are parts of the inner wall of the nut through hole. The shape of the outer edge of the nut and the arrangement position of the connecting sheet 122 on the outer edge of the nut do not affect the arrangement of the first guide portion 12a and the second guide portion 12c.

The top outer edge of the nut 121 is provided with a fixed stop portion 12d, and the fixed stop portion 12d projects at least partially from the upper end surface of the nut 121 . That is, at least a portion of the fixed stop portion 12d may or may not protrude from the annular body of the nut in the axial direction, and in the radial direction from the annular body of the nut. The stationary stop portion 12d is configured to stop the magnet rotor assembly in cooperation with the movable stop portion 20a provided on the magnet rotor assembly. That is, in this embodiment, the magnetic rotor assembly can be moved in the axial direction, and the nut assembly 12 is fixedly connected to the valve seat 11 . Thus, when the magnetic rotor assembly is moved down to the lowest end of the stroke, the movable stop portion 20a can abut against the fixed stop portion 12d, so that the magnetic rotor assembly can no longer rotate. and the downward stroke of the magnetic rotor assembly can be controlled.

The magnetic rotor assembly 27, which can be rotated by inducing electromagnetic force of an electromagnetic coil, includes a magnetic rotor 271 having magnetic poles in a circumferential direction, and a connection plate fixedly connected to or integrally arranged with the magnetic rotor 271. (272). The connecting plate 272 is made of a metal such as a powder metallurgical material. Specifically, the magnetic rotor 271 may be injection molded by using the connection plate 272 as an insert. The connection plate 272 is fixedly connected to the valve shaft portion 22 . Specifically, the rotor fixing portion 22a located at the outer edge portion of the upper end of the valve shaft portion 22 may cooperate with the inner edge portion of the connection plate 272 and be fixed by welding. The magnetic rotor assembly includes a movable stop portion 20a, and as a specific embodiment, the movable stop portion 20a may be integrally formed with the connecting plate 272, that is, the movable stop portion 20a ) may be part of the connecting plate 272 .

The valve shaft portion 22 is a substantially hollow cylindrical member, and includes a large diameter portion 221 and a small diameter portion 222 . A part of the outer edge of the large diameter portion 221 is formed as a rotor fixing portion 22a for fixed connection with the connecting plate 272 of the magnetic rotor assembly 27, wherein the rotor fixing portion is welded or crimped. It can be connected to the connection plate by crimping. Another part of the outer edge of the large-diameter portion 221 is formed as a valve shaft guide portion 22b, and is configured to fit into the second guide portion 12c of the nut with a small clearance to perform guiding. That is, while the rotor rotates, the second guide portion 12c of the nut provides a circumferential guiding and centering effect to the valve shaft portion 22 . As shown in FIG. 1, the rotor fixing portion 22a is positioned relatively above the valve shaft guide portion 22b, and the valve shaft guide portion 22b is substantially surrounded by the magnetic rotor 271. located in space The outer edge of the small diameter portion 222 is provided with an outer threaded portion 22c for forming a screw feeding mechanism together with an inner threaded portion 12b provided on the nut. The valve shaft portion 22 includes a first through hole portion 22e and a second through hole portion 22d. The first through hole portion 22e substantially corresponds to the inner hole portion of the large diameter portion 221 . The second through hole portion 22d substantially corresponds to the inner hole portion of the small diameter portion 222 . Thus, the inner diameter of the first through hole portion 22e is larger than the inner diameter of the second through hole portion 22d, and the valve shaft is interposed between the first through hole portion 22e and the second through hole portion 22d. A stepped portion 22f is formed. Further, the nominal diameter of the screw feeding mechanism is smaller than the inner diameter of the first through-hole portion 22e, and the nominal diameter of the screw feeding mechanism is slightly larger than the outer diameter of the valve needle guide portion 21c. Here, 'slightly larger' means that when the valve needle moves upward, it may not be hindered or interfered with by the inner threaded part 12b.

A bushing 25 is fixedly connected to the valve shaft portion 22, the bushing 25 is substantially hollow and cylindrical, and at least a portion of an outer edge of the bushing 25 forms a first through-hole portion 22e. Matches at least a portion of the inner edge of Thus, the large diameter portion 221 of the valve shaft portion 22 and the bushing 25 form a space, and the compression spring 24 is placed in the space, and the outer diameter of the compression spring 24 is the small diameter. greater than the inner diameter of portion 222. The upper end portion of the compression spring 24 abuts against the bottom end of the bushing 25 . The contact described herein may be direct contact or indirect contact. For example, a gasket may be provided between the compression spring 24 and the bushing 25 to achieve indirect contact. The other end of the compression spring 24 abuts against the gasket 23. In the case of the gasket 23, one end abuts against the compression spring 24 and the other end abuts against the valve needle 21 described below. The maximum outer diameter of the compression spring 24 is larger than the inner diameter of the second through hole portion 22d. Thus, for electromagnetic expansion valves with the same specifications, such as the same rotor diameter, housing diameter, stator coil diameter and volume, the diameter of the compression spring can be made relatively large, so that the spring force increases and the electromagnetic expansion valve is completely When in a closed state, the ability to resist back pressure is enhanced.

A valve needle 21 is provided passing through a central channel defined by the bushing 25 , the valve shaft portion 22 and the nut 12 . A compression spring 24 is sleeved on the periphery of a portion of the outer edge of the valve needle 21 . The valve needle 21 is rod-shaped as a whole and has multiple sections with different outer diameters. Based on the drawings shown in Figs. 1 to 5, the lowermost end of the valve needle 21 is the needle tip adjusting portion 21a. The shape of the needle tip adjustment part 21a depends on the shape of the valve port and the flow adjustment curve required by the electronic expansion valve, and can be set differently according to different needs. This application does not limit the specific shape of the needle tip adjusting portion 21a. The valve needle 21 includes a valve needle guide portion 21b fitted with the first guide portion 12a of the nut with a small gap. During rotation of the magnetic rotor, the first guide portion 12a of the nut provides a guiding and centering effect to the valve needle 21 in the circumferential direction. The valve needle 21 includes a gasket abutting portion 21e for abutting against the gasket 23, so that the gasket 23 can move downward along the direction of the central axis of the valve needle after abutting against the valve needle. none. As a specific embodiment, as shown in FIG. 4 , a first shaft-shaped portion 21c and a second shaft-shaped portion 21d are provided above the valve needle guide portion of the valve needle 21 . The outer diameter of the first shaft-shaped portion 21c is larger than the outer diameter of the second shaft-shaped portion 21d, and the outer diameter of the first shaft-shaped portion 21c is smaller than the outer diameter of the valve needle in the valve needle guide portion. . A step is formed between the first shaft-shaped portion 21c and the second shaft-shaped portion 21d. The step difference may be constituted by a specific embodiment of the gasket abutting portion 21e, that is, the gasket abutting portion 21e is formed on the upper end of the first shaft-shaped portion 21c. The lower end surface of the gasket 23 abuts against the gasket abutting portion 21e. In this embodiment, the number of gaskets 23 is two, and the gasket 23 located on the lower side abuts against the gasket abutting portion 21e. The compression spring 24 is mounted on the upper part of the upper gasket 23, that is, the lower end of the compression spring 24 abuts against the gasket 23, and the upper end of the compression spring 24 is a bushing ( 25) abut against the bottom end. The gasket 23 and the compression spring 24 are both accommodated in the space defined by the large diameter portion of the valve shaft portion 22 and the bushing 25 .

During assembly, the valve needle 21 is inserted into the central through hole of the valve shaft portion 22 from the bottom as shown in FIG. They are provided through through holes and can be moved to each other. The second shaft-shaped portion 21d is provided through the central through hole of the bushing 25 and penetrates the upper end surface of the bushing 25 . The upper end of the second shaft-shaped portion 21d is sleeved and fixed with the valve needle sleeve 26, and the outer diameter of the valve needle sleeve 26 is larger than the inner diameter of the bushing 25, so that the valve needle ( 21) is limited by the valve needle sleeve 26. After the valve needle 21 is fixedly connected to the valve needle sleeve 26, the valve needle 21 cannot come out downward from the bushing 25 and the central through hole of the valve shaft portion 22. Also, a floating connection is formed between the valve needle 21 and the magnetic rotor assembly 27 . When the valve needle 21 moves upward relative to the valve shaft portion 22, the compression spring 24 can be further compressed in the axial direction, and the valve needle 21 and the valve shaft portion 22 are within a limited range. can be moved relative to each other. The first shaft-shaped portion 21c of the valve needle and the second through-hole portion 22d of the valve shaft portion 22 are loosely fitted, and the second shaft-shaped portion 21d and the central through-hole of the bushing 25 Also has a loose fit. Thus, the valve needle 21 can also rotate relative to the valve shaft portion 22 in the circumferential direction.

It should be noted that in this embodiment, the valve needle 21 can be divided into a substantially three-section stepped shaft structure in addition to the needle tip adjusting portion 21a when viewed from the outside, wherein the valve needle guide portion 21b The outer diameter of the valve needle section where the first shaft-shaped portion 21c is positioned is the largest, the outer diameter of the valve needle section where the first shaft-shaped portion 21c is positioned is slightly smaller, and the valve needle section where the second shaft-shaped portion 21d is positioned. has the smallest outer diameter. However, this is only a specific embodiment convenient for processing, and various equivalent structural modifications or substitutions may also be made based thereon. For example, in the case of the valve needle guide portion 21b, as the nut is fixed to the valve seat, the valve needle can move up and down in the axial direction. That is, the valve needle can be moved up and down relative to the nut, and within this stroke, the valve needle is provided with a relatively smooth valve needle guide portion 21b at its outer edge, and this relatively smooth valve needle guide portion 21b is provided on the outer edge of the nut. 1 configured to form a guiding effect with the guide portion 12a, as long as it is ensured that the entire outer edge of the valve needle having the largest outer diameter as shown in this embodiment does not need to be used as the valve needle guide portion, the specific stroke have That is, as long as it ensures that there is always a section of the valve needle guide portion 21b cooperating with the first guide portion 12a of the nut to realize the guiding effect during the displacement of the valve needle, the valve needle guide portion 21b It is possible to provide a concave-convex structure such as a groove on the outer edge of a relatively upper portion or a relatively lower portion of the valve needle section corresponding to . Further, the first shaft-shaped portion 21c and the second shaft-shaped portion 21d are not limited to adopting cylindrical shaft-shaped structures having the same diameter. For example, additional shaft-shaped steps may be provided on the first shaft-shaped portion 21c or the second shaft-shaped portion 21d, etc., and such equivalent technical feature variations obviously fall within the protection scope of the present application.

In addition, the valve needle guide part, the first shaft-shaped part and the second shaft-shaped part described in this specification are all defined based on their functions in the present technical solution, so that the valve needle is as shown in FIG. It cannot be mechanically understood or limited to what can only be formed by combining the three sections of the shaft-shaped part. Alternatively, the valve needle 21 may be assembled section by section, for example by screwing or welding between two adjacent sections. In fact, as described above, the illustrated structure is merely an example for ease of manufacture.

In the valve needle structure provided by this embodiment, the outer diameters of the valve needle sections where the second shaft-shaped portion, the first shaft-shaped portion, and the valve needle guide portion are positioned are sequentially increased, and the manufacturing is relatively convenient; Coaxiality is relatively good. Further, the second shaft-shaped portion can form a space for accommodating the compression spring together with the valve shaft portion and the bushing, so that the outer diameter of the compression spring is no longer constrained by the outer diameter of the valve needle guide portion. In this case, for electromagnetic expansion valves with the same specifications, such as the same rotor diameter, casing diameter, stator coil diameter and volume, the valve port diameter can be directly increased to obtain an electromagnetic expansion valve with larger diameter flow adjustment. .

On the outer periphery of the valve needle sleeve 26, a return spring 28 is sleeved. The lower end of the return spring 28 abuts against the upper end surface of the bushing 25 or valve shaft portion 22, and the specific abutment position is the relative position between the bushing 25 and the valve shaft portion 22. relationship and the diameter of the return spring 28. As shown in FIG. 4 , the upper end of the bushing 25 may be set at or substantially the same height as the upper end of the valve shaft portion 22 . In that case, the return spring 28 may be provided to abut against the valve shaft portion 22, or the bushing 25, or both the valve shaft portion 22 and the bushing 25. Since the height of the return spring 28 is greater than the distance between the valve needle sleeve 26 and the housing 30, the return spring 28 cannot come out from the outer circumference of the valve needle sleeve 26.

The coil 40 of the electromagnetic expansion valve receives the drive pulse signal to generate a periodically changing magnetic field, and the magnetic rotor 27 is excited and rotates. Since the valve shaft portion 22 is fixedly connected to the connecting plate 272, the valve shaft portion 22 rotates synchronously with the magnetic rotor 27, and the magnetic rotor 27 also rotates with the valve shaft portion. It may be moved in the axial direction while rotating by a screw feeding mechanism between nuts. Therefore, the valve needle 21 is driven to move in the axial direction, and the needle tip adjusting portion 21a of the valve needle 21 is brought closer to or farther from the valve port 113a, thereby reducing the flow of the electronic expansion valve. Implement linear open/close adjustment function. When the needle tip adjusting portion 21a moves downward and abuts against the valve port portion 113, that is, the needle tip adjusting portion 21a is at the lowest end of the stroke. At this time, the electromagnetic expansion valve is in a fully closed state as shown in FIG. 1 . When the needle tip adjustment portion 21a is at a position remote from the valve port portion 113, the electronic expansion valve is in an open state. 2 is a cross-sectional view showing a state in which the electromagnetic expansion valve is about 80% open. When the magnetic rotor assembly 27 continues to rotate upward in the valve opening direction from the state shown in FIG. 2 until the outer thread 22c of the valve shaft portion comes out of the inner thread 12b of the nut 12 . At this time, the upper end of the return spring 28 abuts against the upper wall of the housing 30, and the return spring 28 is in a compressed state. At this time, since the screw feeding mechanisms between the valve shaft portion 22 and the nut 12 are disengaged from each other, the magnetic rotor assembly 27 cannot continue to move upward. When it is necessary to close the valve, the magnetic rotor assembly 27 receives the downward spring force of the return spring 28 while rotating. In this way, the external thread 22c of the valve shaft portion 22 and the internal thread 12b of the nut can be driven to regain screwing, thereby ensuring re-engaging of the screw feeding mechanism.

In the electromagnetic expansion valve provided in this embodiment, the valve shaft portion includes a first through hole portion and a second through hole portion. In addition, since the outer diameter of the valve needle guide portion 21b is larger than that of the first shaft-shaped portion 21c, the first shaft-shaped portion 21c and the second through-hole portion 22d are loosely fitted, The outer diameter of the valve needle guide portion 21b is also larger than the inner diameter of the second through hole portion 22d. The inner diameter of the second through hole portion 22d corresponds to the inner diameter of the screw feeding mechanism. Therefore, since the outer diameter of the valve needle guide portion 21b is larger than the inner diameter of the second through-hole portion 22d of the valve shaft portion 22, the nominal diameter of the screw feeding mechanism is the same as the rotor diameter of the electromagnetic expansion valve. , in the same specifications as housing diameter, stator coil diameter and volume, it only needs to be slightly larger than the outer diameter of the valve needle guide part. That is, the nominal diameter of the screw feeding mechanism can be made relatively small, which is advantageous for reducing the frictional resistance from the screw feeding mechanism.

Second embodiment

Hereinafter, a second embodiment of the present application will be described with reference to FIGS. 5 to 9 .

For convenience of description, the same reference numerals are used for components of the present embodiment and the first embodiment, which have substantially the same structure and function, and only a brief description is provided. Those skilled in the art can understand by referring to related descriptions of the first embodiment, and this embodiment is explained in detail focusing on differences from the first embodiment.

5 to 9, FIG. 5 is a schematic cross-sectional view of the electromagnetic expansion valve of the second embodiment in a closed state, FIG. 6 is a schematic cross-sectional view of the electromagnetic expansion valve of the second embodiment in an open state, and FIG. A schematic structural diagram of the nut assembly of the second embodiment, Figure 8 is a partial cross-sectional view of the rotor assembly and valve needle of the second embodiment, Figure 9 is a plan view of the nut assembly of the second embodiment.

The electronic expansion valve includes a valve body portion and a coil portion (40), wherein the valve body portion includes a valve seat (11), a connecting piece (50) and a housing (30). For the structures and mating manners of the valve seat 11, the connecting piece 50, and the housing 30, reference can be made to the description of the first embodiment.

The electronic expansion valve includes a nut assembly 120, and the nut assembly 120 is fixedly connected to the valve seat 11. Specifically, the nut assembly 120 includes a nut 1201 and a connecting sheet 1202, and the nut 1201 is fixedly connected to the connecting sheet 1202. The nut 1201 has a through hole penetrating along the axial direction, and is internally threaded on the inner side wall of the through hole to form a screw feeding mechanism together with an external threaded portion 22c provided on the outer edge of the valve shaft portion 22. Portion 120b is provided. The valve shaft portion 22 is fixedly connected to the magnetic rotor assembly 27 so that the valve shaft portion 22 can rotate synchronously with the rotation of the magnetic rotor. The magnetic rotor assembly 27, which can be rotated by inducing electromagnetic force of an electromagnetic coil, includes a magnetic rotor 271 having magnetic poles in a circumferential direction, and a connection plate fixedly connected to or integrally arranged with the magnetic rotor 271. (272). The connection plate 272 is fixedly connected to the valve shaft portion 22 . Generally, an interference fit connection or a riveting connection may be employed, or the connecting plate 272 may be welded to the valve shaft portion 22. The magnet rotor assembly includes a movable stationary portion 20a. In this embodiment, the movable stop portion 20a may be part of the linking plate 272, projecting axially relative to the linking plate 272 toward the valve seat 11, and fixing provided on the nut 12. Cooperate with the stop part to implement the stop function. The fixed stop portion is specifically a stop boss 1201c described below.

As shown in FIG. 8 , the magnetic rotor assembly 27 is fixedly connected to the valve shaft portion 22 through a connecting plate 272 . The magnetic rotor assembly drives the valve shaft portion 22 to rotate, in which case the valve shaft portion 22 drives the valve needle 21 to rotate. The valve needle 21 can move relative to the valve shaft portion 22 in the axial direction within a limited flexible displacement range, and can also rotate relatively. Regarding the manner of matching the valve shaft portion 22 and the valve needle 21, reference may be made to the related description of the first embodiment, which is not repeated here.

The basic principle of the electromagnetic expansion valve is: the coil 40 receives a driving pulse signal to generate a periodically changing magnetic field, and the magnetic rotor 27 is excited and rotates. Since the valve shaft portion 22 is fixedly connected to the connecting plate 272, the valve shaft portion 22 rotates synchronously with the magnetic rotor 27, and the magnetic rotor 27 also rotates with the valve shaft portion and the nut. It can be moved in the axial direction while rotating by the screw supply mechanism between them. Therefore, the valve needle 21 is driven to move in the axial direction, and the needle tip adjusting portion 21a of the valve needle 21 is brought closer to or farther from the valve port 113a, so that the electronic expansion valve flow is linearly opened. /Implement the closure adjustment function. The electronic expansion valve shown in FIG. 5 is in a fully closed stop position. That is, the needle tip adjusting portion 21a of the valve needle 21 is at the lowest end of the stroke, and at this time the valve port 113a is in a fully closed state or a set minimum open state. The coil 40 drives the magnetic rotor to move downward. A stop mechanism is required to limit and stop the downward stroke of the magnetic rotor assembly when the needle tip adjusting portion 21a is in the fully closed state or at the lowest end of its stroke. Thus, in this embodiment, a fixed stop portion is provided at the upper end of the nut 1201, and a corresponding movable stop portion 20a is provided on the magnetic rotor assembly 27. When the electronic expansion valve is in the fully closed state, the movable stop portion 20a abuts against the corresponding mating surface of the fixed stop portion, so that the stop function for the magnetic rotor assembly, valve shaft portion and valve needle can be realized. there is.

Fig. 6 is a cross-sectional view of the electromagnetic expansion valve of this embodiment in an open state, the open position shown in the figure is about 80% of the opening degree, wherein the needle tip adjusting portion 21a of the valve needle 21 is the valve port ( 113a), and the movable stop 20a is also positioned away from the fixed stop.

7 is a schematic structural diagram of the nut assembly of the embodiment, and the nut assembly 120 includes a connecting sheet 1202 and a nut 1201. As a specific embodiment, the nut 1201 may be made of a non-metallic material such as a resin material by injection molding, and specifically, the connecting sheet 1202 may be placed in a mold cavity as an insert, and the resin nut 1201 may be It can be molded by resin injection by an injection molding machine. A portion of the connecting sheet 1202 is not covered by the nut. The material of the nut may be PPS-modified resin, PEEK-modified resin, or PTFE-modified resin. The nut assembly 120 is fixedly connected to the valve seat 11 . Specifically, the portion of the connecting sheet 1202 not covered by the nut and valve seat 11 is fixed by welding or riveting, and the nut 1201 is pushed into the upper end opening of the valve seat 11 by press-fitting. can be inserted.

The outer periphery of the nut 1201 is provided with at least one protruding rib 1201a, and the at least one protruding rib 1201a extends to the end surface of the nut and protrudes from the upper end surface 1201d of the nut. The portion of the nut 1201 protruding from the upper end surface is defined as a stop boss 1201c, which is constituted as a fixed stop portion of the electronic expansion valve. As shown in Fig. 9, in this embodiment, the outer edge of the nut 1201 is provided with two protruding ribs, and one of the protruding ribs 1201a protrudes from the surface of the upper end of the nut, so that the upper end of the nut The protruding rib protruding from the surface forms at least a part of the stop boss 1201c, and the upper end of the other protruding rib 1201b has the same height as the upper end surface 1201d. The stop boss 1201c is configured as a fixed stop portion of the electromagnetic expansion valve. The width of the load-bearing surface of the stop boss 1201c that can accommodate the impact of the movable stop portion 20a is defined as k, and the thickness of the opposite upper end of the nut is defined as t, which satisfies K > t do.

The nut 1201 is provided with at least one protruding rib 1201a at its outer edge, and the one protruding rib 1201a extends and protrudes from the end surface of the nut to form a part of the stop boss 1201c. A stop boss 1201c is provided at the end of the protruding rib 1201a in the vicinity of the resin nut, and the protrusion amount K-t of the stop boss 1201c in the radial direction relative to the nut body and the protruding rib in the radial direction relative to the nut body The protrusion amount K-t is set equal, which can simplify the structure of a molding die and facilitate upper and lower demolding. As shown in Fig. 7, the stop boss 1201c includes a portion protruding upward along the end surface of the nut, and a portion of the protruding rib 1201a protruding from the end surface of the nut. The circumferential length of the portion projecting upward along the end surface of the nut is longer than the circumferential length of the portion of the protruding rib 1201a protruding from the end surface of the nut, and the portion of the protruding rib 1201a protruding from the end surface of the nut. The circumferential length is the width of the projecting rib 1201a. On the other hand, the protruding rib and the stop boss are molded integrally by injection molding to improve the strength of the stop boss and extend the life of the stop mechanism of the electromagnetic expansion valve. In particular, due to the arrangement of the protruding ribs, the correlation between the strength of the stop boss and the material thickness of the nut body (near the upper end portion) is greatly reduced. That is, even if the thickness of the nut body is relatively thin, the strength of the stop mechanism may not be greatly affected, so that the cost of the resin material used can be further reduced. Also, generally speaking, the more resin material the nut body has and the thicker it is, the higher the possibility of internal porosity due to injection molding. However, in the nut structure provided by the present embodiment, since relatively little resin is used on the premise of securing the strength of the stop boss, the possibility of generating air holes can be reduced, and the dimensional accuracy and dimensional consistency of the resin nut can be improved. can be improved

It should be noted that in this embodiment, the structure of the nut is mainly explained in detail. The matched structure of the magnetic rotor assembly is that the magnetic rotor assembly is provided with a protruding portion as a movable stop portion on the side facing the nut that can abut against a fixed stop portion arranged on the nut to realize the stop function. You just need to meet the requirements. In the case of a specific structure of the movable stop portion, it may not affect the implementation of the present embodiment. Those skilled in the art should understand that all magnetic rotor assemblies satisfying this structure can be applied to this embodiment. For components such as valve seat, valve needle, valve shaft, etc., any conceivable structure may be used to create more electronic expansion valve embodiments.

Third embodiment

Hereinafter, a third embodiment of the present application will be described with reference to FIGS. 10 to 14 .

For convenience of description, the same reference numerals are used for components of the present embodiment and the first embodiment, which have substantially the same structure and function, and only a brief description is provided. Those skilled in the art can understand by referring to related descriptions of the first embodiment, and this embodiment is explained in detail focusing on differences from the first embodiment.

10 to 14, FIG. 10 is a schematic cross-sectional view of the electromagnetic expansion valve of the third embodiment in a closed state, FIG. 11 is a schematic cross-sectional view of the electromagnetic expansion valve of the third embodiment in an open state, and FIG. Fig. 13 is a schematic structural diagram of a nut assembly according to the third embodiment, Fig. 13 is a schematic diagram of a cooperative structure of a valve shaft part and a stopper according to a third embodiment, and Fig. 14 is a magnetic rotor assembly and a valve shaft part according to a third embodiment. , is a schematic diagram of the cooperative structure of the valve needle and stop.

The electronic expansion valve includes a valve body portion and a coil portion (40), wherein the valve body portion includes a valve seat (11), a connecting piece (50), and a housing (30). For the structure and cooperation manner of the valve seat 11, the connecting piece 50, and the housing 30, reference can be made to the description of the first embodiment.

The electronic expansion valve includes a nut assembly (12), and the nut assembly (12) is fixedly connected to the valve seat (11). Specifically, the nut assembly 12 includes a nut 121 and a connecting sheet 122, and the nut 121 is fixedly connected to the connecting sheet 122. As a specific embodiment, the nut 121 may be made of a non-metal material such as a resin material by injection molding, and specifically, the connecting sheet 122 may be placed into a mold cavity as an insert, and the resin nut 121 may be It can be molded by resin injection with an injection molding machine. A portion of the connecting sheet 122 is not covered by the nut. The material of the nut may be PPS-modified resin, PEEK-modified resin, or PTFE-modified resin. The nut assembly 12 is fixedly connected to the valve seat 11 . Specifically, the portion of the connecting sheet 122 not covered by the nut and the valve seat 11 is fixed by welding or riveting, and the nut 121 is pushed into the upper end opening of the valve seat 11 by press-fitting. can be inserted. The nut 121 has a through hole passing along the axial direction, and an inner threaded portion on an inner side wall of the through hole to form a screw feeding mechanism together with an outer threaded portion 22c provided on the outer edge of the valve shaft portion 22. (12b) is provided. The valve shaft portion 22 is fixedly connected to the magnetic rotor assembly 27 so that the valve shaft portion 22 can rotate synchronously with the rotation of the magnetic rotor. The magnetic rotor assembly 27, which can be rotated by inducing electromagnetic force of an electromagnetic coil, includes a magnetic rotor 271 having magnetic poles in a circumferential direction, and a connection plate fixedly connected to or integrally arranged with the magnetic rotor 271. (272). The connection plate 272 is fixedly connected to the valve shaft portion 22 . Generally, an interference fit connection or a riveting connection may be employed, or the connection plate 272 may be welded to the valve shaft portion 22. The top outer edge of the nut 121 is provided with a fixed stop portion 12d, and the fixed stop portion 12d projects at least partially from the upper end surface of the nut 121 . In other words, the fixed stop portion 12d at least partially protrudes from the annular body of the nut in the axial direction, and the fixed stop portion 12d shown in the drawing of this embodiment also protrudes from the annular body in the radial direction, of course. It can also be set not to.

As shown in FIG. 14 , the magnetic rotor assembly 27 is fixedly connected to the valve shaft portion 22 through a connecting plate 272 . The magnetic rotor assembly drives the valve shaft portion 22 to rotate, and the valve shaft portion 22 drives the valve needle 21 to rotate. The valve needle 21 can move relative to the valve shaft portion 22 in an axial direction within a limited flexible displacement range, and can also rotate relatively. As for the cooperation manner of the valve shaft portion 22 and the valve needle 21, reference may be made to the related description of the first embodiment, which is not repeated here.

The valve shaft portion 22 is a substantially hollow cylindrical member, and includes a large diameter portion 221 and a small diameter portion 222 . For the assembly relationship between the valve shaft portion 22 and the bushing 25, the nut 12 and the valve needle 21, reference can be made to the description of the first embodiment.

The basic principle of the electromagnetic expansion valve is: the coil 40 receives a driving pulse signal to generate a periodically changing magnetic field, and the magnetic rotor 27 is excited and rotates. Since the valve shaft portion 22 is fixedly connected to the connecting plate 272, the valve shaft portion 22 rotates synchronously with the magnetic rotor 27, and the magnetic rotor 27 also rotates with the valve shaft portion. It can be moved in the axial direction while rotating by the screw feeding mechanism between the nuts. Therefore, the valve needle 21 is driven to move in the axial direction, and the needle tip adjusting portion 21a of the valve needle 21 is brought closer to or farther from the valve port 113a, so that the electronic expansion valve flow is linearly opened. /Implement the closure adjustment function. The electronic expansion valve shown in FIG. 10 is in a fully closed stop position. That is, the needle tip adjustment portion 21a of the valve needle 21 is at the lowest end of the stroke, and at this time the valve port 113a is in a fully closed state or in a set minimum open state. The coil 40 drives the magnetic rotor to move downward. The stop mechanism needs to be set to limit and stop the downward displacement of the magnetic rotor assembly when the needle tip adjusting portion 21a is in a fully closed state or at the lowest end of its stroke.

In this embodiment, the electronic expansion valve further includes a stop 33. The stop 33 is fixedly connected directly or indirectly to the valve shaft part 22 . The indirect connection referred to here means that the stop 33 is fixedly connected to the valve shaft part 22 via other parts. The stop portion 33 is formed by stamping and bending a metal plate, its main body is annular, and at least a portion of the material is bent in the axial direction to form the movable stop portion 33a. Specifically, the complete annular metal plate can be cut at any position, and then one end portion can be bent axially to form a movable stop portion 33a. Of course, as an alternative, it is also possible not to bend the annular stop after shaping. Instead, it is possible that the movable stop portion and the stop portion are fixed by welding, so that the movable stop portion protrudes along the axial direction of the stop portion.

To facilitate positioning, in this embodiment, the valve shaft portion 22 is provided with an annular convex ring portion 223 at the outer edge of the large diameter portion 221 . In this way, the connection plate 272 can be positioned by the top surface of the convex ring portion 223 . At least part of the stop 33 can be positioned by the lower surface of the annular convex ring portion 223, so that the installation position of the stop 33 on the valve shaft portion 22 can be easily and accurately positioned. Of course, the convex ring portion 223 need not be provided, and in practice, the relative position of the stop portion 33 and the valve shaft portion 22 can also be accurately limited by tool positioning. The valve shaft portion 22 and the stop portion 33 may be fixedly connected by welding, or may be fixedly connected by other methods such as riveting. The stop portion 33 is fixedly connected to the valve shaft portion 22, and the valve shaft portion 22 is fixedly connected to the magnetic rotor assembly 27. Thus, the stop 33 rotates synchronously with the magnet rotor assembly 27 . When the electronic expansion valve is in the fully closed state, or when the needle tip adjusting portion 21a of the valve needle 21 of the electronic expansion valve is at the minimum opening degree set by the electronic expansion valve, as shown in FIG. , the movable stop portion 33a of the stop portion 33 bent downward collides with the fixed stop portion 12d provided at the upper end of the nut assembly 12, thereby realizing the stop and limit of the magnetic rotor assembly. . When the magnetic rotor assembly rotates in the opposite direction, the stop 33 also moves upward, and as shown in Figure 11, the movable stop 33a also moves upward and away from the fixed stop 12d. are uncoupled Fig. 11 is a cross-sectional view of the electromagnetic expansion valve of this embodiment in an open state, and the open position shown in the figure is an opening degree of about 80%. The needle tip adjustment part 21a of the valve needle 21 is at a position far from the valve port 113a, and the movable stop part 33a is also at a position far from the fixed stop part 12d.

As shown in FIG. 14 , the magnetic rotor assembly 27 is fixedly connected to the valve shaft portion 22 through a connecting plate 272 . The magnetic rotor assembly drives the valve shaft portion 22 to rotate, and the valve shaft portion 22 drives the valve needle 21 to rotate. The valve needle 21 can move relative to the valve shaft portion 22 in an axial direction within a limited flexible displacement range, and can also rotate relatively. Regarding the manner of matching the valve shaft portion 22 and the valve needle 21, reference may be made to the related description of the first embodiment, which is not repeated here.

In the electromagnetic expansion valve provided in this embodiment, the nut material is injection molded with PPS resin, PEEK resin, or PTFE resin. The upper end of the resin nut is integrally injected into the fixed stop, and the stop can be stamped into a metal plate. The processing technology of the parts is relatively good, and the wear resistance of the metal stopper is excellent, which can improve the life of the stop mechanism, and the production cost is relatively low.

4th embodiment

A fourth embodiment of the present application is described below with reference to FIGS. 15 to 16 .

It should be noted that since the difference between this embodiment and the third embodiment lies in the difference in the movable stop portion, this embodiment mainly describes the structure of the movable stop portion. The rest can be understood with reference to the first and third embodiments.

15 to 16, FIG. 15 is a schematic structural diagram of a connection plate provided by a fourth embodiment of the present application, and FIG. 16 is a magnetic rotor assembly provided by a fourth embodiment of the present application and A partial cross-sectional view of the cooperating structure of the valve shaft portion, valve needle and other components. Taking the orientation shown in FIG. 16 as a reference, FIG. 15 shows a schematic view of the connecting plate viewed from the bottom. In this embodiment, the connection plate 272 may be formed by pressing and sintering metal powder, and generally has a plate-like structure with a central through hole. The inner wall portion 2721 of the central through hole is used for fixed connection with the valve shaft portion 22 . Generally, an interference fit connection or a riveting connection may be employed, or the connection plate 272 may be welded to the valve shaft portion 22. In order to increase the contact area between the connecting plate 272 and the valve shaft portion 22, the height of the inner wall portion 2721 may be appropriately increased so that the longitudinal section of the connecting plate 272 is generally L-shaped. there is. As described in the first embodiment, the connection plate 272 and the magnetic rotor 271 may be fixedly connected by injection molding. That is, the inner cavity of the mold is disposed with the connection plate 272 as an insert, and then a magnetic material is injected to form the magnetic rotor 271 . In this way, the plate-shaped outer edge portion 2723 of the connection plate 272 is covered with the magnetic material. A movable stop portion 2722 is provided on the side of the connecting plate 272 facing the valve port direction, that is, the movable stop portion 2722 protrudes from the surface on the side of the connecting plate. Specifically, the movable stop portion 2722 may be integrally molded with the base of the connection plate and sintered with metal powder. With this processing method, the strength of the movable stop portion 2722 can be effectively improved, the processing is simple, and the movable stop portion 2722 can be integrally manufactured with the connecting plate, so that the fixed stop portion of the nut and There is no need to add additional movable stop parts for mating. Of course, as an alternative manufacturing method, the metal powder may also be injected into the blank through a mold and then sintered and formed.

When the magnetic rotor 271 is excited and rotates, the connecting plate 272 and the valve shaft portion 22 can rotate synchronously, and the valve shaft portion 22 is inside the valve needle 21 and the valve shaft portion. Other arranged components may be driven to rotate. The valve needle 21 is sleeved in the inner hole of the valve shaft portion 22, and the valve needle 21 and the valve shaft portion 22 are flexibly connected. The valve needle 21 can move relative to the valve shaft portion 22 in an axial direction within a limited flexible displacement range, and can also rotate relatively.

When the electronic expansion valve is in the fully closed state, or the needle tip adjustment part of the valve needle of the electronic expansion valve is at the minimum opening degree set by the electronic expansion valve, the downward rotational motion of the magnetic rotor assembly needs to be stopped and limited. there is At this time, the movable stop portion 2722 protruding downward of the connecting plate 272 abuts against the fixed stop portion 12d provided at the upper end of the nut, realizing the function of stopping and limiting. When the magnetic rotor assembly rotates in the direction of opening the valve, the movable stop portion 2722 rotates with the rotor component and moves upward, allowing it to disengage from the fixed stop portion 12d.

Example 5

Hereinafter, a fifth embodiment of the present application will be described with reference to FIGS. 17 to 26 .

This embodiment is further improved based on the first embodiment. The same reference numerals are used for components of the present embodiment and the first embodiment, which have substantially the same structures and functions, and only brief descriptions are provided. A person skilled in the art can understand by referring to the related description of the first embodiment.

Fig. 17 is a schematic diagram of a fifth embodiment of an electromagnetic expansion valve in a fully closed state in a rest position, Fig. 18 is an enlarged view of part (I) in Fig. 17, and Fig. 19 is an enlarged view of part (II) in Fig. 17 20 is a cross-sectional view of the electromagnetic expansion valve of the fifth embodiment in the spring force unloading position, FIG. 21 is an enlarged view of part (III) in FIG. 20, and FIG. 22 is an enlarged view of part (IV) in FIG. 20 , Fig. 23 is a cross-sectional view of the electromagnetic expansion valve of the fifth embodiment when at the opening threshold, Fig. 24 is an enlarged view of part V in Fig. 23, and Fig. 25 is an enlarged view of part VI in Fig. 23. 26 is a sectional view of the electromagnetic expansion valve of the fifth embodiment in a fully open state.

The electromagnetic expansion valve includes a valve body portion and a coil portion (40), and the valve body portion includes a valve seat (11), a connecting piece (50) and a housing (30). For the structure and cooperation manner of the valve seat 11, the connecting piece 50, the housing 30 and the nut 12, reference can be made to the description of the first embodiment. The valve seat 11 includes a valve port portion 113 , a first port portion 111 , and a second port portion 112 . The first flow direction is defined as the direction in which the refrigerant flows into the electronic expansion valve from the first port portion 111 and flows out of the second port portion 112 through the valve port, and the second flow direction is defined as the direction in which the refrigerant flows It is defined as a direction flowing into the electronic expansion valve from the second port portion 112 and flowing out of the first port portion 111 through the valve port. This embodiment is described taking the first flow direction as an example.

The electronic expansion valve includes a nut assembly (12), and the nut assembly (12) is fixedly connected to the valve seat (11). The nut assembly 12 includes a nut 121 and a connecting sheet 122, and the nut 121 is fixedly connected to the connecting sheet 122. The nut 121 has a through hole penetrating along the axial direction, and an inner side wall of the through hole is provided with an inner threaded portion 12b, and an outer threaded portion 22c provided on the outer edge of the valve shaft portion 22 and together form a screw feeding mechanism. The inner side wall of the nut is further provided with a first guide portion 12a. The first guide portion 12a is provided below the inner threaded portion 12b and can provide a circumferential guiding and centering effect to the valve needle 21 . The valve needle 21 includes a valve needle guide portion 21b, that is, the first guide portion 12a and the valve needle guide portion 21b are fitted with a small gap. The valve needle 21 can be rotated or moved up and down along the first guide portion 12a of the nut driven by the valve shaft portion 22 . Here, the first guide part 12a refers to a part provided on the inner side wall of the nut. The valve needle guide portion 21b refers to a portion provided on the outer edge portion of the valve needle. A second guide portion 12c may be provided at an upper portion of the inner side wall of the nut to provide a guiding and centering effect for the valve shaft portion 22 in the circumferential direction. An outer edge portion of the valve shaft portion 22 is provided with a valve shaft guide portion 22b, and the valve shaft guide portion 22b and the second guide portion 12c are fitted with a small gap. The valve shaft portion 22 can be rotated or moved up and down along the second guide portion 12c driven by the magnetic rotor assembly. Both the first guide portion 12a and the second guide portion 12c described above are parts of the inner wall of the nut through hole. The shape of the outer edge of the nut and the arrangement position of the connecting sheet 122 on the outer edge of the nut do not affect the arrangement of the first guide portion and the second guide portion.

The top outer edge of the nut 121 is provided with a fixed stop portion 12d, and the fixed stop portion 12d projects at least partially from the upper end surface of the nut 121 . The fixed stop portion is used to realize the stop function of the magnet rotor assembly, in cooperation with the movable stop portion 20a provided on the magnet rotor assembly. The movable stop portion 20a and the fixed stop portion 12d of this embodiment are the same as the movable stop portion and the fixed stop portion of the first embodiment. Of course, the movable stop portion may adopt the overall structure of the third or fourth embodiment, and the fixed stop portion may completely adopt the structure of the second embodiment. When the magnetic rotor assembly moves down to the bottom end of its stroke, the movable stop portion 20a can abut against the fixed stop portion 12d, so that the magnetic rotor assembly can no longer rotate, and the magnetic rotor Downward displacement of the assembly can be controlled.

The magnetic rotor assembly 27, which can be rotated by inducing electromagnetic force of an electromagnetic coil, includes a magnetic rotor 271 having magnetic poles in a circumferential direction, and a connection plate fixedly connected to or integrally arranged with the magnetic rotor 271. (272). The valve shaft portion 22 is a substantially hollow cylindrical member, and includes a large diameter portion 221 and a small diameter portion 222 . The valve shaft portion 22 is fixedly connected to the connecting plate 272 . A part of the outer edge of the large diameter portion 221 is formed as a rotor fixing portion 22a fixedly connected to the connecting plate 272 of the magnetic rotor assembly 27. Another part of the outer edge of the large diameter portion 221 is formed as a valve shaft guide portion 22b, and is configured to be fitted with a small clearance to the second guide portion 12c of the nut to realize a guide function. The rotor fixing portion 22a is positioned relatively above the valve shaft guide portion 22b, and the valve shaft guide portion 22b is positioned in a space substantially surrounded by the magnetic rotor 271. The outer edge of the small diameter portion 222 is provided with an outer threaded portion 22c for forming a screw feeding mechanism together with an inner threaded portion 12b provided on the nut. The valve shaft portion 22 includes a first through hole portion 22e and a second through hole portion 22d. The first through hole portion 22e substantially corresponds to the inner hole portion of the large diameter portion 221 . The second through hole portion 22d substantially corresponds to the inner hole portion of the small diameter portion 222 . The inner diameter of the first through hole portion 22e is larger than the inner diameter of the second through hole portion 22d, and the valve shaft stepped portion 22f is formed between the first through hole portion 22e and the second through hole portion 22d. ) formed between

A bushing 25 is fixedly connected to the valve shaft portion 22, the bushing 25 is substantially hollow and cylindrical, and at least a portion of an outer edge of the bushing 25 is an inner edge of the first through hole portion 22e. matches at least part of The large diameter portion 221 of the valve shaft portion 22 and the bushing 25 form a space in which the compression spring 24 is positioned. The upper end portion of the compression spring 24 abuts against the bottom end of the bushing 25 . The abutment described herein may be direct contact or indirect contact. For example, a gasket is provided between the spring and the bushing to achieve indirect contact. The other end of the compression spring 24 abuts against the gasket 23. In the case of the gasket 23 , one end abuts against the compression spring 24 and the other end abuts against the valve needle 21 .

A valve needle 21 is provided passing through a central channel defined by the bushing 25 , the valve shaft portion 22 and the nut 12 . A compression spring 24 is sleeved on the periphery of a portion of the outer edge of the valve needle 21 . The valve needle 21 is rod-shaped as a whole and has multiple sections with different outer diameters. The lowermost end of the valve needle 21 is the needle tip adjusting portion 21a. The valve needle 21 includes a valve needle guide portion 21b for fitting with the first guide portion 12a of the nut with a small clearance. During rotation of the magnetic rotor, the first guide portion 12a of the nut provides a guiding and centering effect to the valve needle 21 in the circumferential direction. Similar to the first embodiment, within the stroke of the valve needle, the valve needle is provided with a relatively smooth valve needle guide portion 21b on the outer edge configured to form a guiding effect together with the first guide portion 12a of the nut. It just needs to be guaranteed. Since the valve needle 21 includes a gasket abutting portion 21e that abuts against the gasket 23, the gasket 23 cannot move downward along the direction of the central axis of the valve needle after abutting against the valve needle. Above the valve needle guide portion of the valve needle 21, a first shaft-shaped portion 21c and a second shaft-shaped portion 21d are provided. The outer diameter of the first shaft-shaped portion 21c is larger than the outer diameter of the second shaft-shaped portion 21d, and the outer diameter of the first shaft-shaped portion 21c is smaller than the outer diameter of the valve needle in the valve needle guide portion. . Therefore, a step is formed between the first shaft-shaped portion 21c and the second shaft-shaped portion 21d, which can be constituted as specific examples of the gasket abutting portion 21e, and the lower end surface of the gasket 23 Abuts against the gasket abutting portion 21e. In this embodiment, the number of gaskets 23 is two, the gasket located on the lower side abuts against the gasket abutting portion 21e, and the compression spring 24 is attached to the upper portion of the gasket 23. do. That is, the lower end of the compression spring 24 abuts against the gasket 23, and the upper end of the compression spring 24 abuts against the bottom end of the bushing 25. The gasket 23 and the compression spring 24 are both accommodated in the space defined by the large diameter portion of the valve shaft portion 22 and the bushing 25 . Specifically, during assembly, the valve needle 21 is inserted into the central through hole of the valve shaft portion 22 from the bottom as shown in FIG. can be moved to each other through the through hole of; The second shaft-shaped portion 21d penetrates the central through hole of the bushing 25 and penetrates out of the upper end surface of the bushing 25 . The upper end of the second shaft-shaped portion 21d is sleeved and fixed with a valve needle sleeve 26, and the outer diameter of the valve needle sleeve 26 is larger than the inner diameter of the bushing 25, so that the valve needle 21 ) is limited by the valve needle sleeve 26. After the valve needle 21 is fixedly connected to the valve needle sleeve 26, the valve needle 21 cannot come out downward from the bushing 25 and the central through hole of the valve shaft portion 22. Also, a floating connection is formed between the valve needle 21 and the magnetic rotor assembly 27. When the valve needle 21 moves upward relative to the valve shaft portion 22, the compression spring 24 can be further compressed in the axial direction, and the valve needle 21 and the valve shaft portion 22 are within a limited range. can be moved relative to The first shaft-shaped portion 21c of the valve needle and the second through-hole portion 22d of the valve shaft portion 22 are loosely fitted, and the second shaft-shaped portion 21d and the central through-hole of the bushing 25 Also has a loose fit. Thus, the valve needle 21 can also rotate relative to the valve shaft portion 22 in the circumferential direction.

Similar to the first embodiment, the valve needle guide portion, the first shaft shape portion and the second shaft shape portion described herein are all defined based on their functions in the present technical solution, so that the valve needle is also It should be noted that it cannot be mechanically understood or limited to what can be formed only by combining the three sections of the shaft-shaped part as shown in 4. Alternatively, the valve needle 21 may be assembled section by section, for example by screwing or welding between two adjacent sections. In fact, as described above, the illustrated structure is merely an example for ease of manufacture.

A return spring 28 is sleeved around the outer circumference of the valve needle sleeve 26 . The lower end of the return spring 28 abuts against the upper end surface of the bushing 25 or the valve shaft part 22, and the specific contact position is the relative positional relationship between the bushing 25 and the valve shaft part 22. and the diameter of the return spring 28. As shown in Fig. 4, the upper ends of the bushing 25 and the valve shaft portion 22 may be set flush or substantially flush. In that case, the return spring may be provided to abut against either the valve shaft portion 22 or the bushing 25, or against both the valve shaft portion 22 and the bushing 25 simultaneously. Since the height of the return spring 28 is greater than the distance between the valve needle sleeve 26 and the housing 30, the return spring 28 cannot but come out from the outer circumference of the valve needle sleeve 26.

The coil 40 of the electromagnetic expansion valve receives the drive pulse signal to generate a periodically changing magnetic field, and the magnetic rotor 27 is excited and rotates. Since the valve shaft portion 22 is fixedly connected to the connecting plate 272, the valve shaft portion 22 rotates synchronously with the magnetic rotor 27, and the magnetic rotor 27 also rotates with the valve shaft portion and the nut. It can be moved in the axial direction while rotating through the screw supply mechanism between them. Therefore, the valve needle 21 is driven to move in the axial direction, and the needle tip adjusting portion 21a of the valve needle 21 is brought closer to or farther from the valve port 113a, so that the electronic expansion valve flow is linearly opened. /Implement the closure adjustment function. The electronic expansion valve shown in FIG. 17 is in a fully closed stop position. That is, the needle tip adjusting portion 21a of the valve needle is at the lowest end of the stroke, the valve needle abuts against the valve port portion 113, and the valve port 113a is in a fully closed state. When the magnetic rotor assembly 27 continues to rotate upward in the valve opening direction from the state shown in FIG. 17 until the outer thread 22c of the valve shaft portion comes out of the inner thread 12b of the nut 12 . At this time, the upper end of the return spring 28 abuts against the upper wall of the housing 30, and the return spring 28 is in a compressed state. At this time, since the screw feeding mechanism between the valve shaft portion and the nut is disengaged from each other, the magnetic rotor assembly 27 cannot be continuously moved upward. When it is necessary to close the valve, the magnetic rotor assembly 27 can receive the downward spring force of the return spring 28 while rotating. In this way, the external thread 22c of the valve shaft portion 22 and the internal thread 12b of the nut can be pressed to resume screwing again, thereby ensuring re-engaging of the screw feeding mechanism.

Referring to FIGS. 18 and 19 , FIG. 18 is an enlarged view of part (I) of FIG. 17 , and FIG. 19 is an enlarged view of part (II) of FIG. 17 . The electronic expansion valve shown in FIG. 17 is in a fully closed stop position. That is, the movable stop portion 20a comes into contact with the fixed stop portion 12d. The needle tip adjustment portion 21a of the valve needle 21 is at the lowest end of the stroke, and the valve needle abuts against the valve port portion 113. As shown in FIG. 19 , the valve needle 21 receives a spring force transmitted from the compression spring 24 through the gasket 23 toward the lower portion in the drawing. Then, the spring force is transmitted through the valve needle 21 to the portion on the valve port portion 113 that contacts the valve needle. In this embodiment, the number of gaskets is two, and the gasket 23 includes a first gasket 231 and a second gasket 232 . Based on the example of FIG. 17 , the first gasket 231 is positioned over the second gasket 232 , and the first gasket 231 and the second gasket 232 abut against each other. As an alternative embodiment, the number of gaskets may be one or more than two.

The upper end of the compression spring 24 abuts against the lower end of the bushing 25 . The lower end of the compression spring abuts against the upper end surface of the first gasket 231, and the lower end of the second gasket 232 abuts against the gasket abutting portion 21e of the valve needle 21. The lower end surface of the second gasket 232 is still spaced apart from the valve shaft stepped portion 22f of the valve shaft portion 22 by a certain distance k. In addition, it can be understood that the second gasket 232 can also be moved by a distance k toward the downward direction shown in the figure. The spring force of the compression spring 24 is transmitted through the gasket 23 and the valve needle 21, and finally acts on the sealing portion of the valve port portion in contact with the valve needle.

The upper end of the valve needle 21 is covered and fixed with the valve needle sleeve 26, and the lower end of the valve needle sleeve 26 is spaced apart from the upper end of the bushing 25 by a certain distance h, h > satisfies k 19, the outer diameter of the valve needle sleeve 26 in this embodiment is smaller than that of the bushing 25. A person skilled in the art can understand that the outer diameter of the valve needle sleeve 26 can also be set larger than the outer diameter of the bushing 25 as an alternative. In this case, if the axial height of the valve shaft portion 22 is greater than the height of the bushing 25, the valve needle sleeve 26 may not interfere with the bushing 25 in any case, and the valve shaft when moving downward. may interfere with portion 22. At this time, h is equal to the distance between the lower end of the valve needle sleeve 26 and the upper end of the valve shaft portion 22.

From the starting point of the state shown in Fig. 17, the magnet rotor assembly 27 is driven to rotate upward by excitation of the stator coil 40, and the movable stop portion 20a is moved away from the fixed stop portion 12d. start to rotate Under the action of the screw feeding mechanism, the magnetic rotor assembly 27 and the valve shaft portion 22 are synchronously moved upward. When the lifting height is equal to k, the electronic expansion valve is in the unloading position of the spring force.

20 to 22, where FIG. 20 is a sectional view of the electromagnetic expansion valve of the fifth embodiment in a spring force unloading position; Fig. 21 is an enlarged view of part (III) of Fig. 20; FIG. 22 is an enlarged view of part IV of FIG. 20 .

The distance between the lower end of the second gasket 232 and the valve shaft stepped portion 22f of the valve shaft portion is now zero. That is, the spring force of the compression spring 24 is transmitted through the gasket 23, and the valve shaft portion shown in FIG. 20 is transmitted from the gasket abutting portion 21e acting on the valve needle 21 shown in FIG. 22) and is transmitted to the valve shaft stepped portion 22f acting on it. That is, in this case, the electronic expansion valve is in the unloading position of the spring force of the compression spring 24, and the valve needle 21 no longer receives the spring force transmitted by the compression spring 24. As shown in Fig. 21, the lower end of the valve needle sleeve 26 is spaced apart from the upper end of the bushing 25 by a certain distance, the distance being equal to h-k. Of course, when the outer diameter of the valve needle sleeve 26 is set larger than that of the bushing 25, the lower end of the valve needle sleeve 26 is separated from the upper end of the valve shaft portion 22 by a certain distance (h-k). are separated

From the fully closed state shown in FIG. 17 to the spring force unloading position state shown in FIG. 20, the upward displacement amount of the valve shaft portion 22 and magnetic rotor assembly 27 is equal to k, and the The upward displacement amount is zero.

20, the magnetic rotor assembly 27 continues to rotate upward driven by the excitation of the stator coil 40, and the magnetic rotor assembly 27 and the valve shaft portion 22 are of the screw feed mechanism. Continuing the upward movement synchronously through the transition to rise. When the height of the lift is equal to h-k, the electronic expansion valve is at the critical point of opening.

Referring to Figs. 23 to 25, Fig. 23 is a sectional view of the electromagnetic expansion valve of the fifth embodiment when it is at the opening threshold; Fig. 24 is an enlarged view of portion V of Fig. 23; FIG. 25 is an enlarged view of part VI of FIG. 23 . It will be appreciated that the valve needle 21 is now in direct contact with the valve port portion 113, or can be disengaged from the valve port portion 113 as long as the valve needle 21 continues to move upward. there is. At this time, the lower end of the second gasket 232 abuts against the valve shaft stepped portion 22f of the valve shaft portion 22, and the spring force of the compression spring 24 is transmitted through the gasket 23 to the valve shaft portion 22. It acts on the shaft step portion 22f. As shown in Fig. 24, the distance between the lower end of the valve needle sleeve 26 and the upper end of the bushing 25 is 0, that is, in the state of Figs. 20 to 23, the valve shaft portion 22 rotates Synchronized with the former, it moves upward by h-k. The valve needle 21 no longer receives the spring force transmitted by the compression spring 24, the spring force is unloaded from the valve needle 21, and the valve needle 21 rotates relative to the valve shaft 22. The frictional force of is obviously reduced. That is, the moment the valve needle comes into contact with the valve port portion and is separated, the valve needle 21 no longer receives the spring force of the compression spring 24, so the frictional force due to relative rotation between the valve needle and the valve port portion is reduced. can Therefore, the wear of the contact portion of the valve needle and the valve port portion can be reduced, and the life of the electromagnetic expansion valve can be improved.

From the fully closed state shown in FIG. 17 to the open critical state shown in FIG. 23, the upward displacement amount of the valve shaft portion 22 and the magnetic rotor assembly 27 is equal to h, and the upward displacement amount of the valve needle 21 is is zero

Referring to Fig. 26, Fig. 26 is a cross-sectional view of the electromagnetic expansion valve of the fifth embodiment in a fully open state. The valve needle 21 is now remote from the valve port portion 113 . 23 to 26, i.e., while the electronic expansion valve reciprocates from the opening critical point to the maximum opening, the valve needle 21 moves up and down in the axial direction synchronously with the valve shaft portion 22, The valve needle 21 is always released from the spring force of the compression spring 24 . In this way, the frictional force of relative rotation between the valve needle 21 and the valve shaft portion 22 can be reduced, and the wear between the valve needle guide portion 21b and the first guide portion 12a of the nut is reduced. Therefore, the life of the electronic expansion valve can be extended. From the opening critical point shown in FIG. 23 to the fully open state shown in FIG. 26, the relative positions of the valve needle 21 and the valve shaft portion 22 in the axial direction remain unchanged.

From the unloading position of the spring force in FIG. 20 to the opening critical point in FIG. 23, the upward displacement amount of the valve shaft portion 22 and the magnetic rotor assembly 27 is equal to h-k, and the upward displacement amount of the valve needle 21 is zero . When the electromagnetic expansion valve changes from the fully closed state shown in FIG. 17 to the fully open state shown in FIG. 26, the upward displacement amount of the valve shaft portion 22 and the magnetic rotor assembly 27 is equal to L, and the valve needle ( 21) is equal to L-h.

Further, in this embodiment, both the first gasket and the second gasket are plate-shaped, and the bottom surface of the second through-hole portion of the valve shaft portion (ie, the valve shaft stepped portion) is also flat. Accordingly, the signs of h and k in the figure are also illustrated as the distance between the two planes in the axial direction. In fact, the gasket or the contact portion of the second through hole is not limited to contact between two planes, and can be changed in various ways. For example, contact of two inclined surfaces in an axial direction, or other irregularly shaped contact. In this case, h and k can be regarded as the displacement difference between the two components in the axial direction.

It should be noted that the fifth embodiment takes the first flow direction as an example, and the fluid pressure in the first port portion is greater than the fluid pressure in the second port portion. Therefore, the valve needle of the electromagnetic expansion valve is always subjected to the downward differential pressure of the fluid medium in the above conditions.

In the state of the rotor member shown in FIG. 26 , the valve needle 21 is not affected by the spring force generated by the compression spring 24 . When there is no pressure difference between the fluid in the first port portion and the fluid in the second port portion, the valve needle 21 is only under the action of its own gravity. That is, after the valve needle 21 is fixedly connected to the valve needle sleeve 26, the state in which the valve needle 21 is not affected by the spring force generated by the compression spring 24 is the valve needle 21 This means that it still has a certain movable clearance to the valve shaft part 22 in its axial direction. The gap size is the same as the gap size shown in FIG. 25, which equals h-k.

In the electronic expansion valve provided by the embodiment, the spring force of the compression spring is not applied to the valve needle at two moments: the first moment is the moment when the valve needle seals contact with the valve port portion from the open state to the closed state; The second moment is the moment when the valve needle and valve port portions are separated from the closed state to the open state. The frictional force of the relative rotation of the two sealing parts can be reduced, thereby reducing the wear of the contacting parts and improving the life of the electromagnetic expansion valve. In addition, while the electromagnetic expansion valve reciprocates from the minimum opening to the maximum opening, the spring force of the compression spring is never applied to the valve needle, reducing the rotational friction between the valve needle and the valve shaft, thus reducing the valve needle guide portion and It reduces the wear between the nuts and further prolongs the life of the electronic expansion valve.

6th embodiment

A sixth embodiment of the present application is described below with reference to FIG. 27 .

In the above five embodiments, the first port portion of the electromagnetic expansion valve is connected to the first connecting pipe 10b, and the second port portion is connected to the second connecting pipe 10a. That is, the electronic expansion valve is connected to the refrigeration system in the form of a connecting pipe. Actually, the electronic expansion valve of the above embodiment can be applied to many fields, and the connection between the electronic expansion valve and the refrigeration system is not limited to the connecting pipe method. When applied to a case requiring quick maintenance, such as, for example, an automobile air conditioning system, instead of adopting the structure of the first connecting pipe and the second connecting pipe, the valve seat is, for example, in the form of a flange sealing connection, It can be fixedly connected directly with the integral valve body integrated with multiple channels.

Referring to FIG. 27, FIG. 27 is a schematic structural diagram of an electronic expansion valve according to a sixth embodiment of the present application. This embodiment is an example of an electronic expansion valve applied to an automobile air conditioning system. The valve seat 11 and the connecting piece 51a are fixed by welding, and then fixedly connected to the valve body 80 as a whole. The connection piece 51a can be adaptively designed into a shape suitable for connection with the valve body. Specifically, the connecting piece 51a may be fixedly connected to the valve body 80 by a flange sealing connection (not shown in the figure). For example, a screw hole is arranged in a disk-shaped portion of the connecting piece, and then the connecting piece is fixedly connected with the valve body through a screw connection. To ensure the sealing performance, a first sealing piece 803 is further provided for the connecting piece and the valve body. In addition, a second sealing piece 804 is provided between the valve seat 11 and the valve body 80 . When the assembly is completed, the connecting piece 51 and the valve seat 11 are fixedly connected to the valve body 80 to maintain good sealing performance.

The valve body 80 may be machined by metal cutting and forms a first port end 801 and a second port end 802 . The first port end 801 and the second port end 802 are used to connect with other components of the air conditioning system. Of course, the structures of the first port end 801 and the second port end 802 are not limited to those shown in Fig. 27, and other layouts can be made according to system requirements. In this way, when disassembly and maintenance are required, the connecting piece and valve seat of the electromagnetic expansion valve can be easily separated from the valve body.

Orientation terms such as up, down, left, and right mentioned in the embodiments are all introduced for convenience of description based on the drawings in the description; It should be noted that ordinal terms such as "first" and "second" in component names are also introduced for convenience of description, and are not intended to place any limitation on any order of components. In addition, since the functions of some parts of the components provided in this embodiment are the same, a unified naming method for these parts is adopted in this specification. The electronic expansion valve provided by the above related technical solutions is introduced in detail, and specific examples are used in this specification. The description of the above examples is only used to help understand the method and core idea of the present application, and does not limit the present application in any way.

Claims (10)

An electronic expansion valve comprising a valve seat, a nut assembly, a valve shaft portion, a valve needle and a magnetic rotor assembly,
The valve seat includes a valve port portion, the nut assembly is fixedly connected to the valve seat, the nut assembly includes a nut and a connecting sheet, and the nut is a first guide portion, an inner thread portion, and a second guide portion, wherein the first guide portion is closer to the valve port portion than the inner thread portion, and wherein the second guide portion is closer to the valve port portion than the inner thread portion. further apart, the inner diameter of the first guide portion is smaller than the inner diameter of the second guide portion;
The valve shaft portion is fixedly connected to the magnetic rotor assembly, the valve shaft portion includes a valve shaft guide portion, the valve shaft guide portion is in a clearance fit with the second guide portion, and a valve shaft portion is movable relative to the nut along an axial direction of the nut; the valve shaft portion includes an external threaded portion, the external threaded portion and the internal threaded portion form a screw feeding mechanism; the valve shaft portion includes a first through hole portion and a second through hole portion, wherein an inner diameter of the first through hole portion is larger than an inner diameter of the second through hole portion;
the valve needle includes a valve needle guide portion, the valve needle guide portion is loosely fitted with the first guide portion, and the valve needle is movable relative to the nut along an axial direction of the nut; and the outer diameter of the valve needle guide portion is larger than the inner diameter of the second through hole portion. According to claim 1,
The valve shaft portion includes a large diameter portion and a small diameter portion, the outer diameter of the large diameter portion is larger than the outer diameter of the small diameter portion, and the large diameter portion is farther from the valve port portion than the small diameter portion. and the external threaded portion is provided on an outer edge portion of the small diameter portion, and the valve shaft guide portion is provided on an outer edge portion of the large diameter portion. According to claim 2,
A rotor fixing portion is provided on the outer edge portion of the large diameter portion, the magnetic rotor assembly includes a magnetic rotor and a connecting plate, and the magnetic rotor and the connecting plate are fixedly connected or The electronic expansion valve is formed in an integrated structure, wherein the rotor fixing portion is fixedly connected to the connecting plate. According to any one of claims 1 to 3,
the electromagnetic expansion valve includes a bushing, at least a portion of an outer edge portion of the bushing is mated with at least a portion of an inner edge portion of the first through hole portion, and the bushing is in fixed connection with the valve shaft portion; That is, an electronic expansion valve. According to claim 4,
The electromagnetic expansion valve includes a compression spring and a gasket, one end of the compression spring abuts against the bushing, the other end of the compression spring abuts against the gasket, and the valve needle An electromagnetic expansion valve comprising a gasket abutting portion, wherein the gasket abuts against the gasket abutting portion. According to claim 5,
and a valve shaft stepped portion is arranged between the first through hole portion and the second through hole portion, and the valve shaft stepped portion can abut against the gasket. According to claim 5 or 6,
wherein the compression spring is accommodated in a space formed by the valve shaft portion and the bushing, and a maximum outer diameter of the compression spring is larger than the inner diameter of the second through hole portion. According to claim 1,
The nominal diameter of the screw of the screw supply mechanism is smaller than the inner diameter of the first through hole portion, and the nominal diameter of the screw of the screw feed mechanism is slightly larger than the outer diameter of the valve needle guide portion. expansion valve. According to claim 1,
The valve needle includes a first shaft-shaped portion and a second shaft-shaped portion, the outer diameter of the first shaft-shaped portion is larger than the outer diameter of the second shaft-shaped portion, and an outer diameter is smaller than the outer diameter of the valve needle guide portion. According to claim 1,
The electromagnetic expansion valve includes a connecting piece, a first port part, a second port part and a valve body, the valve body being formed by cutting and including a first port end and a second port end; the valve seat is fixedly connected with the connecting piece, the connecting piece and the valve body are connected by a flange, a first sealing piece is arranged between the connecting piece and the valve body, and a second sealing piece is arranged between the valve seat and the valve body.

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