Electronic Expansion Valve

Abstract

This application discloses an electronic expansion valve. The valve seat (11) includes a valve seat (11), a nut unit (12), a valve stem (22), a valve needle (21), and a movable stopper (20a), the movable stopper (20a) being directly or indirectly fixedly connected to the valve stem (22), the valve seat (11) including a valve opening (113), the nut unit (12) being fixedly connected to the valve seat (11), and including a nut (121) and a connecting seat (122), The port (121) includes a first guide portion (12a), a second guide portion (12c), a female thread portion (12b) and a fixed stopper portion (12d), the first guide portion (12a) is closer to the valve opening portion (113) than the female thread portion (12b), the second guide portion (12c) is farther from the valve opening portion (113) than the female thread portion (12b), and the fixed stopper portion (12d) can abut against the movable stopper portion (20a).

Description

[Technical field]

[0001] This application claims priority to a Chinese patent application filed with the China Patent Office on May 11, 2020, bearing application number 202010392363.X, and entitled "Electronic Expansion Valve", the entire contents of which are incorporated herein by reference.

[0002] This application relates to the technical field of refrigeration controls, and in particular to electronic expansion valves. [Background technology]

[0003] The refrigeration system includes a compressor, a throttling element, two heat exchangers and other components, the throttling element may adopt an electronic expansion valve for throttling adjustment of the refrigerant, the use of the electronic expansion valve can realize relatively accurate control and improve the energy efficiency of the system. The basic principle of the electronic expansion valve is as follows: a certain pulse current signal is introduced by the stator coil to excite the rotor unit of the electronic expansion valve to rotate, and the rotational motion of the rotor is converted into the up and down movement of the valve shaft by the screw feed mechanism conversion, so that the valve body of the head of the valve shaft approaches or moves away from the valve port, and the flow area of ​​the valve port portion is changed to realize the adjustment of the refrigerant flow rate and the opening and closing functions. Summary of the Invention [Problem to be solved by the invention]

[0004] One embodiment of the present invention aims to provide a novel nut design for application in an electronic expansion valve. [Means for solving the problem]

[0005] In order to achieve the above object, one embodiment of the present invention adopts the following technical solution: An electronic expansion valve comprising: a valve seat, a nut unit, a valve stem portion, a valve needle, and a movable stopper portion, the movable stopper portion is directly or indirectly fixedly connected to the valve stem portion, the valve seat includes a valve orifice portion, the nut unit is fixedly connected to the valve seat and includes a nut and a connecting sheet, the nut includes a first guide portion, a second guide portion, a female thread portion, and a fixed stopper portion, the first guide portion is closer to the valve orifice portion than the female thread portion, the second guide portion is farther from the valve orifice portion than the female thread portion, and the fixed stopper portion is capable of abutting against the movable stopper portion, the valve stem portion includes a valve stem guide portion that is clearance-fitted into the second guide portion, the valve stem portion is displaceable relative to the nut along an axial direction of the nut, the valve stem portion includes a male thread portion, and the male thread portion and the female thread portion form a screw feed mechanism, The valve needle includes a valve needle guide portion that is loosely fitted into the first guide portion, and the valve needle is capable of moving relative to the nut in an axial direction of the nut. Effect of the Invention

[0006] The electronic expansion valve provided in this embodiment includes a nut, which includes a first guide portion, a second guide portion, a female thread portion and a fixed stopper portion, and is molded by a one-time injection molding, which is convenient to manufacture and can provide a guiding and centering function for the valve needle and the valve stem. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a cross-sectional schematic view of the electronic expansion valve of the first embodiment in a closed state. [Diagram 2] FIG. 2 is a cross-sectional schematic view of the electronic expansion valve of the first embodiment in an open state. [Diagram 3] 5A and 5B are schematic views of engagement between a nut and a valve seat unit in the first embodiment. [Figure 4] 4A to 4C are schematic diagrams illustrating engagement between the magnetic rotor unit of the first embodiment and the valve stem and valve needle. [Diagram 5]FIG. 11 is a cross-sectional schematic view of an electronic expansion valve according to a second embodiment in a closed state. [Figure 6] FIG. 11 is a cross-sectional view illustrating the electronic expansion valve of the second embodiment in an open state. [Figure 7] FIG. 11 is a schematic diagram showing the configuration of a nut unit according to a second embodiment. [Figure 8] FIG. 11 is a local cross-sectional view of the engagement between the magnetic rotor unit of the second embodiment and the valve stem and valve needle. [Figure 9] FIG. 11 is a plan view of a nut unit according to a second embodiment. [Figure 10] FIG. 11 is a cross-sectional view illustrating the electronic expansion valve of the third embodiment in a closed state. [Figure 11] FIG. 11 is a cross-sectional schematic view of an electronic expansion valve according to a third embodiment in an open state. [Figure 12] FIG. 11 is a schematic diagram showing the configuration of a nut unit according to a third embodiment. [Figure 13] 13 is a schematic diagram showing an engagement configuration between a valve stem portion and a stopper member in a third embodiment. FIG. [Figure 14] 13 is a schematic diagram showing an engagement configuration between a magnetic rotor unit of a third embodiment, a valve stem portion, a valve needle, and a stopper member. FIG. [Figure 15] FIG. 11 is a schematic diagram of a connection plate provided in the fourth embodiment. [Figure 16] FIG. 11 is a local cross-sectional view of an engagement configuration between a magnetic rotor unit provided in a fourth embodiment and components such as a valve stem portion and a valve needle. [Figure 17] FIG. 11 is a schematic diagram showing a fully closed state of the electronic expansion valve of the fifth embodiment when it is in a stopper position. [Figure 18] FIG. 18 is an enlarged view of part I in FIG. [Figure 19] FIG. 18 is an enlarged view of part II in FIG. [Figure 20] FIG. 11 is a cross-sectional view of the electronic expansion valve of the fifth embodiment when the spring force is unloaded. [Figure 21] FIG. 21 is an enlarged view of part III in FIG. [Figure 22] FIG. 21 is an enlarged view of part IV in FIG. [Figure 23]FIG. 13 is a cross-sectional view of the electronic expansion valve of the fifth embodiment when the valve is at a critical point. [Figure 24] FIG. 24 is an enlarged view of a portion V in FIG. [Diagram 25] FIG. 24 is an enlarged view of a portion VI in FIG. [Figure 26] FIG. 11 is a cross-sectional view of the electronic expansion valve of the fifth embodiment in a fully open state. [Figure 27] FIG. 13 is a schematic diagram of the configuration of an electronic expansion valve according to a sixth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] In order to enable those skilled in the art to better understand the technical solution provided by the present application, the following will further describe the technical solution of the present application in detail in combination with drawings and specific examples.

[0009] Detailed explanation. First embodiment 1 to 4, FIG. 1 is a schematic diagram of the electronic expansion valve of the first embodiment in a closed state, FIG. 2 is a schematic diagram of the electronic expansion valve of the first embodiment in a closed state, FIG. 3 is a schematic diagram of the valve seat member of the first embodiment, and FIG. 4 is a schematic diagram of the rotor and screw valve needle unit of the first embodiment.

[0010] As shown in FIG. 1, the electronic expansion valve includes a valve body member and a coil member 40, and the valve body member includes a valve seat 11, a connecting member 50, and a housing 30. The valve seat 11 is formed by cutting a metal, and the connecting member 50 is provided on the upper side of the valve seat 11, and the connecting member 50 is fixedly connected to the valve seat 11 and the housing 30 by welding, and the welding method may be specifically used. The housing 30 is made of a thin-walled part, and generally has a cylindrical shape with an open end, and one end of the opening is hermetically welded to the valve seat 11. The valve seat 11 and the connecting member 50 are provided with a step on the outer edge of the upper side of the valve seat 11, and the connecting member 50 is installed from above the valve seat 11, which makes it easy to assemble and position the two. Similarly, the connecting member 50 is provided with a step on the outer edge of the upper side of the connecting member 50, which makes it easy to assemble and position the connecting member 50 with the housing 30, and thus makes it easy to carry out the welding operation. That is, the valve seat 11 is connected to the housing by a connecting member 50, and above the valve seat 11, a cavity is formed for accommodating parts such as a magnetic rotor unit and a nut unit, which will be described below.

[0011] The valve seat 11 includes a valve port portion 113, a first connection port portion 111, and a second connection port portion 112, the first connection port portion 111 and the second connection port portion 112 are all connected to the refrigerant passage of the system, and a valve port 113a is provided in the valve port portion 113. In this embodiment, the first connection port portion 111 is fixedly connected to the first connection pipe 10b, and the second connection port portion 112 is fixedly connected to the second connection pipe 10c, and the refrigerant may flow in from the first connection pipe 10b, pass through the valve port 113a, and then flow out from the second connection pipe 10c, or may flow in from the second connection pipe 10c, pass through the valve port 113a, and then flow out from the first connection pipe 10b.

[0012] The electronic expansion valve includes a nut unit 12 fixedly connected to the valve seat 11. Specifically, an opening is provided at the upper end of the valve seat 11, and the nut unit 12 is mounted on the valve seat 11 from top to bottom. The nut unit 12 includes a nut 121 and a connection sheet 122 fixedly connected to each other. In a specific embodiment, the connection sheet 122 is formed by pressing a metal plate, and the nut 121 is made of a non-metallic material, such as engineering plastic, and is injection molded with the connection sheet 122 as an insert. The nut 121 is mounted on the valve seat 11 by press fitting, and the connection sheet 122 and the valve seat 11 are fixedly connected to each other by welding. The material of the nut may be PPS modified resin, PEEK modified resin, PTFE modified resin, or the like.

[0013] The nut 121 has a through hole penetrating along its axial direction, and the inner wall of the through hole is provided with a female thread portion 12b, which is used to form a screw feed mechanism together with a male thread portion 22c provided on the outer edge of the valve shaft portion 22 described below. The inner wall of the nut is provided with a first guide portion 12a, which is provided below the female thread portion 12b and can provide the valve needle 21 with a circumferential guide and centering action. The term "below" as used herein means that the first guide portion 12a is closer to the valve port portion 113 than the female thread portion 12b. The valve needle 21 includes a valve needle guide portion 21b, i.e., the first guide portion 12a and the valve needle guide portion 21b are a small clearance fit, and the valve needle 21 can rotate or move up and down along the first guide portion 12a of the nut by the valve shaft portion 22. Here, the first guide portion 12 refers to a portion provided on the inner wall of the nut, and the valve needle guide portion 21b refers to a portion provided on the outer edge of the valve needle. The second guide portion 12c is provided at a relatively upper portion of the inner wall of the nut, which can provide the valve stem portion 22 with a circumferential guide and centering function. The valve stem guide portion 22b is provided at the outer edge of the valve stem portion 22, and the valve stem guide portion 22b and the second guide portion 12c are fitted with a small clearance, and the valve stem portion 22 can rotate or move up and down along the second guide portion 12c by the magnetic rotor unit. The inner diameter of the second guide portion 12c is larger than the inner diameter of the nut first guide portion 12a, and thus, when the male thread portion 22c of the valve stem portion 22 moves upward and gradually disengages from the female thread portion 12b, it is not interfered with by the second guide portion 12c. Here, the first guide portion 12a and the second guide portion 12c described above are both part of the inner wall of the nut through hole, and the shape of the nut outer edge portion and the position of the connecting sheet 122 on the nut outer edge portion do not affect the positioning of the first guide portion 12a and the second guide portion 12c.

[0014] A fixed stopper portion 12d is provided on the outer edge of the ceiling of the nut 121, and at least a part of the fixed stopper portion 12d protrudes from the upper end surface of the nut 121. In other words, at least a part of the fixed stopper portion 12d protrudes from the annular base of the nut in the axial direction, and may be arranged so as not to protrude from the annular base in the radial direction. The fixed stopper portion 12d engages with the movable stopper portion 20a provided on the magnetic rotor unit to realize a stopper for the magnetic rotor unit. That is, in this embodiment, the magnetic rotor member can be displaced in the axial direction, and the nut unit 12 is fixedly connected to the valve seat 11, so that when the magnetic rotor unit moves down to the lowest end of the stroke, the movable stopper portion 20a abuts against the fixed stopper portion 12d, and the magnetic rotor unit cannot rotate continuously, and the downward movement stroke of the magnetic rotor member can be controlled. Since the magnetic rotor unit is fixedly connected to the valve stem portion, the movable stopper portion is also directly or indirectly fixedly connected to the valve stem portion 22.

[0015] The magnetic rotor unit 27 senses the electromagnetic force of the electromagnetic coil to rotate, and includes a magnetic rotor 271 having magnetic poles in the circumferential direction, and a connecting plate 272 fixedly connected to or integrally arranged with the magnetic rotor 271. The connecting plate 272 is made of metal, for example, powder metallurgy material, and specifically, the connecting plate 272 is used as an insert to form the magnetic rotor 271 by injection molding. The connecting plate 272 is fixedly connected to the valve stem 22, and specifically, the rotor fixing part 22a at the upper outer edge of the valve stem 22 engages with the inner edge of the connecting plate 272 and is fixed by welding. The magnetic rotor unit includes a movable stopper part 20a, and in a specific embodiment, the movable stopper part 20a is integrally manufactured with the connecting plate 272, that is, the movable stopper part 20a may be a part of the connecting plate 272.

[0016] The valve stem 22 is a member having a substantially hollow cylindrical shape, 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 forms the rotor fixing portion 22a for fixed connection to the connection plate 272 of the magnetic rotor unit 27, and the connection method between the two may adopt a fixing method such as welding or crimping. Another part of the outer edge of the large diameter portion 221 forms the valve stem guide portion 22b for fitting into the second guide portion 12c of the nut with a small gap, thereby realizing a guide. That is, during the rotor rotation, the nut second guide portion 12c provides the valve stem 22 with a circumferential guide and centering action. As shown in FIG. 1, the rotor fixing portion 22a is located relatively above the valve stem guide portion 22b, and the valve stem guide portion 22b is located approximately within the space surrounded by the magnetic rotor 271. The outer edge of the small diameter portion 222 is provided with a male thread portion 22c, which is used to form a screw feed mechanism together with the female thread portion 12b provided on the nut. The valve stem portion 22 includes a first through hole portion 22e and a second through hole portion 22d, where the first through hole portion 22e roughly corresponds to the inner hole portion of the large diameter portion 221, and the second through hole portion 22d roughly corresponds to the inner hole portion of the small diameter portion 222, and 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 a valve stem step portion 22f is formed between the first through hole portion 22e and the second through hole portion 22d. The nominal diameter of the screw feed mechanism is smaller than the inner diameter of the first through hole portion 22e and slightly larger than the outer diameter of the valve needle guide portion 21c. "Slightly larger" as used herein means that the valve needle may not be impeded or interfered with by the female threaded portion 12b when moving upward.

[0017] The bush 25 is fixedly connected to the valve shaft portion 22 and has a generally hollow tubular shape, and at least a part of the outer edge of the bush 25 engages with at least a part of the inner edge of the first through hole portion 22e. In this manner, the large diameter portion 221 of the valve shaft portion 22 and the bush 25 form a space, the compression spring 24 is located in the space, and the outer diameter of the compression spring 24 is larger than the inner diameter of the small diameter portion 222. The upper end of the compression spring 24 abuts against the bottom end of the bush 25, and the abutment described here may be a direct abutment or an indirect abutment. For example, a gasket is disposed between the compression spring 24 and the bush 25 to realize the indirect abutment. The other end of the compression spring 24 abuts against the washer portion 23. One end of the washer portion 23 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. In this way, when electronic expansion valves have the same specifications, for example, the same rotor diameter, housing diameter, stator coil diameter and volume, the diameter of the compression spring may be relatively larger, thereby increasing the spring force and improving the ability of the electronic expansion valve to withstand back pressure when it is in a fully closed state.

[0018] The valve needle 21 is disposed in a penetrating manner in a central passage jointly defined by the bush 25, the valve shaft portion 22 and the nut 12, and the compression spring 24 is fitted around a part of the outer edge of the valve needle 21. The valve needle 21 as a whole is rod-shaped and has a plurality of different outer diameters. With reference to Figs. 1 to 5, the bottom end of the valve needle 21 is the needle tip adjustment portion 21a, and the shape of the needle tip adjustment portion 21a is related to the shape of the valve port portion and the required flow rate adjustment curve of the electronic expansion valve, and may be arranged in different ways according to different needs, and the present application does not limit the specific shape of the needle tip adjustment portion 21a. The valve needle 21 includes a valve needle guide portion 21b for being fitted into the first guide portion 12a of the nut with a small clearance, and the first guide portion 12a of the nut provides the valve needle 21 with a circumferential guide and centering action during the rotation of the magnetic rotor. The valve needle 21 includes a gasket abutment portion 21e for abutting against the gasket 23, so that the gasket 23 will not be displaced downward along the central axis of the valve needle after abutting against the valve needle. 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, and the outer diameter of the first shaft-shaped portion 21c is larger than that of the second shaft-shaped portion 21d and smaller than that of the valve needle at the valve needle guide portion. In this way, a step is formed between the first shaft-shaped portion 21c and the second shaft-shaped portion 21d, which may be a specific embodiment of the gasket abutment portion 21e, that is, the gasket abutment portion 21e is formed on the ceiling portion of the first shaft-shaped portion 21c. The lower end surface of the gasket 23 abuts against the gasket abutment portion 21e, and in this embodiment, there are two gaskets 23, and the lower gasket 23 abuts against the gasket abutment portion 21e, and a compression spring 24 is attached to 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 abuts against the bottom end of the bush 25. The gasket 23 and the compression spring 24 are both housed in the space defined by the large diameter portion of the valve shaft portion 22 and the bush 25.

[0019] 4, the first shaft-shaped portion is inserted into the through-hole of the valve shaft 22 so as to move relative to each other, and the second shaft-shaped portion 21d is inserted into the through-hole of the bushing 25 and passes through the upper end surface of the bushing 25. The valve needle sleeve 26 is fixed to the upper end of the second shaft-shaped portion 21d so as to be fitted over the bushing 25. Since the outer diameter of the valve needle sleeve 26 is larger than the inner diameter of the bushing 25, the valve needle 21 is restricted by the valve needle sleeve 26, and the valve needle 21 will not escape downward from the central through-hole of the bushing 25 and the valve shaft 22 after being fixed to the valve needle sleeve 26. A floating connection is formed between the valve needle 21 and the magnetic rotor unit 27, and when the valve needle 21 moves upward relative to the valve stem 22, the compression spring 24 can be further compressed in the axial direction, allowing the valve needle 21 and the valve stem 22 to move relative to each other within a limited range. There is a clearance fit between the first shaft portion 21c of the valve needle and the second through-hole portion 22d of the valve stem 22, and there is also a clearance fit between the second shaft portion 21d and the central through-hole of the bush 25, so that the valve needle 21 can also rotate relative to the valve stem 22 in the circumferential direction.

[0020] Here, in this embodiment, from the outside, except for the needle tip adjustment portion 21a, the valve needle 21 is roughly divided into a three-stage axial structure, the outer diameter of the valve needle stage where the valve needle guide portion 21b is located is the largest, the outer diameter of the valve needle stage where the first axial portion 21c is located is slightly smaller, and the outer diameter of the valve needle stage where the second axial portion 21d is located is the smallest. However, this is only a specific example for convenience of processing, and various equivalent structural modifications or substitutions may be made based on this. For example, with regard to the valve needle guide portion 21b, since the nut is fixed relative to the valve seat, the valve needle can be displaced up and down in the axial direction, that is, the valve needle can move up and down relative to the nut and has a certain stroke. It is not required that the entire outer edge of the valve needle with the largest outer diameter shown in the drawings of this embodiment be used as the valve needle guide portion. It is only required to ensure that within this stroke, the outer edge of the valve needle is provided with a smooth valve needle guide portion 21b to form a guiding effect with the first guide portion 12a of the nut. In other words, a non-flat structure such as a groove may be disposed on the outer edge of the relatively upper or lower part of the valve needle stage corresponding to the valve needle guide portion 21b, and it is only required to ensure that during the stroke of the valve needle, there is always one stage of valve needle guide portion 21b to engage with the first guide portion 12a of the nut and realize a guiding effect. Furthermore, the first shaft-shaped portion 21c and the second shaft-shaped portion 21d are not limited to a cylindrical shaft-shaped configuration of equal diameter; for example, the first shaft-shaped portion 21c or the second shaft-shaped portion 21d may be provided with another shaft-shaped step, and these equivalent technical feature modifications obviously fall within the scope of protection of the present application.

[0021] In addition, the valve needle guide portion, the first shaft portion, and the second shaft portion described in this specification are all named according to the functions they play in the technical solution, and the valve needle should not be mechanically understood or limited to be formed by combining the three-stage shaft portion in Fig. 4. Alternatively, the valve needle 21 is manufactured in a staged assembly form, for example, by adopting a method of threading or welding between two adjacent stages. In fact, as described above, the illustrated configuration is only an example for convenience of processing.

[0022] In the valve needle configuration provided by this embodiment, the outer diameter of the valve needle stage where the second axial portion, the first axial portion and the valve needle guide portion are located increases gradually in sequence, which is relatively convenient to manufacture and has relatively good coaxiality. The second axial portion, the valve stem and the bushing can be surrounded to form a space for accommodating the compression spring, so that the outer diameter of the compression spring is not restricted by the outer diameter size of the valve needle guide portion. When an electronic expansion valve with the same specifications, for example, with the same rotor diameter, housing diameter, stator coil diameter and volume, is used, the valve port diameter can be directly increased to obtain an electronic expansion valve with larger aperture and flow rate adjustment.

[0023] A return spring 28 is fitted around the outer periphery of the valve needle sleeve 26, and the lower end of the return spring 28 abuts against the upper end surface of the bush 25 or the valve stem 22. The specific abutment position may be determined according to the relative positional relationship between the bush 25 and the valve stem 22 and the diameter of the return spring 28. As shown in Fig. 4, the tips of the bush 25 and the valve stem 22 are aligned or essentially aligned. In this case, the return spring 28 may be arranged to abut against the valve stem 22, may be arranged to abut against the bush 25, or may be arranged to abut against the valve stem 22 and the bush 25 simultaneously. The height of the return spring 28 is greater than the distance between the valve needle sleeve 26 and the housing 30, so that the return spring 28 will not fall off the outer periphery of the valve needle sleeve 26.

[0024] The coil 40 of the electronic expansion valve receives the driving pulse signal, generates a periodically changing magnetic field, and the magnetic rotor 27 is excited to rotate. The valve shaft 22 is fixedly connected to the connecting plate 272, so that it rotates synchronously with the magnetic rotor 27. The screw feed mechanism between the valve shaft and the nut allows the magnetic rotor 27 to move axially while rotating, so as to move the valve needle 21 axially, and move the needle tip adjustment part 21a of the valve needle 21 closer to or farther from the valve port 113a, thereby realizing the linear opening and closing adjustment function of the flow rate of the electronic expansion valve. As shown in FIG. 1, when the needle tip adjustment part 21a is moved downward until it abuts against the valve port 113, that is, when the needle tip adjustment part 21a is at the lowest end of its stroke, the electronic expansion valve is in a fully closed state. When the needle tip adjustment part 21a is in a position away from the valve port 113, the electronic expansion valve is in an open state, and FIG. 2 is a cross-sectional view of the electronic expansion valve at about 80% opening. When the magnetic rotor unit 27 continues to rotate upward from the state shown in FIG. 2 in the valve opening direction until the male threaded portion 22c of the valve stem escapes upward from the female threaded portion 12b of the nut 12, the upper end of the return spring 28 has already abutted against the top wall of the housing 30, and the return spring 28 is in a compressed state. At this time, the screw feed mechanism between the valve stem 22 and the nut 12 has already been separated from each other, so the magnetic rotor unit 27 does not continue to move upward. When it is necessary to perform the valve closing operation, the magnetic rotor unit 27 receives the downward spring force of the return spring 28 while rotating, which promotes the male threaded portion 22c of the valve stem 22 and the female threaded portion 12b of the nut to be screw-engaged again, ensuring that the screw feed mechanism is reassembled.

[0025] In the electronic expansion valve provided by this embodiment, the valve shaft includes a first through hole portion and a second through hole portion, the outer diameter of the valve needle guide portion 21b is larger than the outer diameter of the first shaft portion 21c, and the first shaft portion 21c and the second through hole portion 22d are clearance-fitted, so that the outer diameter of the valve needle guide portion 21b is larger than the inner diameter of the second through hole portion 22c, and the inner diameter of the second through hole portion 22c corresponds to the inner diameter of the screw feed 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, when the electronic expansion valve has the same specifications, for example, the same rotor diameter, housing diameter, stator coil diameter and volume, the nominal diameter of the screw feed mechanism can be slightly larger than the outer diameter of the valve needle guide portion 21b, that is, the nominal diameter of the screw feed mechanism can be relatively small, thereby reducing the friction resistance from the screw feed mechanism.

[0026] Second embodiment The second embodiment of the present application will be described below in conjunction with FIGS.

[0027] For ease of explanation, in this embodiment, the same reference numerals are used for components that are basically similar in configuration and function to those of the first embodiment, and only a brief description will be given. Those skilled in the art can refer to the description of the first embodiment to understand, and this embodiment will mainly describe in detail the differences from the first embodiment.

[0028] 5 to 9, FIG. 5 is a schematic cross-sectional view of the electronic expansion valve of the second embodiment in a closed state, FIG. 6 is a schematic cross-sectional view of the electronic expansion valve of the second embodiment in an open state, FIG. 7 is a schematic configuration diagram of a nut unit of the second embodiment, FIG. 8 is a local cross-sectional view of the engagement between the rotor unit and the valve needle of the second embodiment, and FIG. 9 is a plan view of the nut unit of the second embodiment.

[0029] The electronic expansion valve includes a valve body member and a coil member 40. The valve body member includes a valve seat 11, a connecting member 50, and a housing 30. For the configurations and engagement forms of the valve seat 11, the connecting member 50, and the housing 30, the description of the first embodiment may be referred to.

[0030] The electronic expansion valve includes a nut unit 120 fixedly connected to the valve seat 11. Specifically, the nut unit 120 includes a nut 1201 and a connection sheet 1202 fixedly connected to each other. The nut 1201 has a through hole penetrating along its axial direction, and a female thread portion 120b is provided on the inner wall of the through hole, and the female thread portion 120b is used to form a screw feed mechanism together with a male thread portion 22c provided on the outer edge of the valve shaft portion 22. The valve shaft portion 22 is fixedly connected to the magnetic rotor unit 27, so that it can rotate synchronously with the rotation of the magnetic rotor. The magnetic rotor unit 27 senses the electromagnetic force of the electromagnetic coil and rotates, and includes a magnetic rotor 271 having magnetic poles in the circumferential direction, and a connection plate 272 fixedly connected to or integrally arranged with the magnetic rotor 271, and the connection plate 272 is fixedly connected to the valve shaft portion 22. Generally, the connection is made by press-fitting or crimping, or by welding the connection plate 272 to the valve shaft 22. The magnetic rotor unit includes a movable stopper portion 20a, which in this embodiment may be a part of the connection plate 272, protruding from the connection plate 272 toward the valve seat 11 along the axial direction and engaging with a fixed stopper portion provided on the nut 12 to realize a stopper function, and the fixed stopper portion is specifically the stopper protrusion portion 1201c described below.

[0031] 8, the magnetic rotor unit 27 is fixedly connected to the valve stem 22 by a connecting plate 272, the magnetic rotor unit rotates the valve stem 22, the valve stem 22 rotates the valve needle 21, and the valve needle 21 may move along the axial direction or rotate relative to the valve stem 22 within a limited elastic displacement range. The engagement mode between the valve stem 22 and the valve needle 21 can be referred to the description of the first embodiment, and will not be described in detail here.

[0032] The basic principle of the electronic expansion valve is as follows: the coil 40 receives a driving pulse signal to generate a periodically changing magnetic field, which excites the magnetic rotor 27 to rotate, and the valve stem 22 is fixedly connected to the connecting plate 272, so that it rotates synchronously with the magnetic rotor 27, and the screw feed mechanism between the valve stem and the nut allows the magnetic rotor 27 to move axially while rotating, so that the valve needle 21 moves axially, and the needle tip adjustment part 21a of the valve needle 21 approaches or moves away from the valve port 113a, thereby realizing the linear opening and closing adjustment function of the electronic expansion valve flow rate. The electronic expansion valve in FIG. 5 is in the stopper position of the fully closed state, that is, the needle tip adjustment part 21a of the valve needle 21 is at the lowest end of its stroke, in which case the valve port 113a is in the fully closed state or the set minimum opening state. The coil 40 drives the magnetic rotor to move downward, and when the needle tip adjustment part 21a is in a fully closed state or at the lowest end position of its stroke, a stopper mechanism must be provided to limit and stop the downward movement stroke of the magnetic rotor unit, so in this embodiment, a fixed stopper part is provided at the upper end of the nut 1201, and a corresponding movable stopper part 20a is provided on the magnetic rotor unit 27. When the electronic expansion valve is in a fully closed state, the movable stopper part 20a abuts against the corresponding engagement surface of the fixed stopper part to realize the position limit and stop for the magnetic rotor unit, the valve stem, and the valve needle.

[0033] 6 is a cross-sectional view of the electronic expansion valve of this embodiment in an open state, and the opening position in the drawing is about 80% opening. In this case, the needle tip adjustment part 21a of the valve needle 21 is in a position away from the valve port 113a, and the movable stopper part 20a is also in a position away from the fixed stopper part.

[0034] FIG. 7 is a schematic diagram of the nut unit of this embodiment, in which the nut unit 120 includes a connecting sheet 1202 and a nut 1201. In a specific embodiment, the nut 1201 is injection molded from a nonmetallic material, for example, a resin material. Specifically, the connecting sheet 1202 is placed in a mold cavity as an insert, and the resin nut 1201 is molded by a resin injection method using an injection molding machine, and a part of the connecting sheet 1202 is not covered by the nut. PPS modified resin, PEEK modified resin, or PTFE modified resin may be adopted as the material of the nut. The nut unit 120 is fixedly connected to the valve seat 11. Specifically, the part of the connecting sheet 1202 that is not covered by the nut is fixed to the valve seat 11 by welding or crimping, and the nut 1201 is inserted so as to be pressed into the upper end opening of the valve seat 11.

[0035] At least one protruding rib 1201a is provided on the outer circumference of the nut 1201, and at least one protruding rib 1201a extends to the end face of the nut and protrudes from the upper end face 1201d of the nut. The part of the nut 1201 protruding from the upper end face is defined as a stopper protrusion 1201c, and the stopper protrusion 1201c constitutes a fixed stopper part of the electronic expansion valve. As shown in Fig. 9, in this embodiment, two protruding ribs are provided on the outer edge of the nut 1201, one of which, the protruding rib 1201a, protrudes from the upper end face of the nut, and the protruding rib protruding from the upper end face of the nut forms at least a part of the stopper protrusion 1201c, and the upper end of the other protruding rib 1201b is aligned with the upper end face 1201d. The stopper protrusion 1201c constitutes the fixed stopper portion of the electronic expansion valve, and if the width of the force-receiving surface of the stopper protrusion 1201 that can receive a collision from the movable stopper portion 20a is defined as K and the relative thickness of the upper end of the nut is defined as t, then K>t is satisfied.

[0036] At least one protruding rib 1201a is provided on the outer edge of the nut 1201, and one of the protruding ribs 1201a extends and protrudes from the end face of the nut to form a part of the stopper protrusion 1201c. If the stopper protrusion 1201c is arranged at the end of the protruding rib 1201a close to the resin nut, and the protruding amount (Kt) of the stopper protrusion in the radial direction relative to the nut body and the protruding amount (Kt) of the protruding rib in the radial direction relative to the nut body are arranged in the same manner, the configuration of the compression mold can be simplified, and it is convenient for upper and lower demolding. As shown in FIG. 7, the stopper protrusion 1201c includes a part that protrudes upward along the end face of the nut and a part of the protruding rib 1201a that protrudes toward the end face of the nut, and the length of the former along the circumferential direction is greater than the length of the latter along the circumferential direction, and the length of the latter along the circumferential direction is the width of the protruding rib 1201a. In addition, the convex rib and the stopper protrusion are integrally injection molded to increase the strength of the stopper protrusion and improve the operating life of the electronic expansion valve stopper mechanism. In particular, the arrangement of the convex rib greatly reduces the correlation between the strength of the stopper protrusion and the material thickness of the nut body (the portion adjacent to the upper end), that is, even if a thin nut body is adopted, the strength of the stopper mechanism is not seriously affected, thus further reducing the dosage cost of the resin material. In addition, generally, the more the resin nut base material and the larger the thickness, the higher the probability of air holes occurring inside due to injection. In the nut configuration provided by this embodiment, on the premise of ensuring the strength of the stopper protrusion, a smaller amount of resin is adopted to reduce the possibility of air holes occurring and improve the size accuracy and size consistency of the resin nut.

[0037] Here, in this embodiment, the configuration of the nut is mainly described in detail, and the corresponding magnetic rotor unit configuration is that a protrusion that can abut against a fixed stopper portion provided on the nut is provided on one side of the magnetic rotor unit facing the nut as a movable stopper portion, and a stopper is realized, and the specific configuration of the movable stopper portion does not affect the realization of this embodiment, and it should be understood by those skilled in the art that all magnetic rotor units that satisfy this configuration can be applied to this embodiment. Components such as the valve seat, valve needle, valve shaft, etc. may also adopt any possible configuration, thereby generating more embodiments of the electronic expansion valve.

[0038] Third embodiment The third embodiment of the present application will be described below in combination with FIGS.

[0039] For ease of explanation, in this embodiment, the same reference numerals are used for components that are basically similar in configuration and function to those of the first embodiment, and only a brief description will be given. Those skilled in the art can refer to the description of the first embodiment to understand, and this embodiment will mainly describe in detail the differences from the first embodiment.

[0040] 10 to 14, FIG. 10 is a schematic cross-sectional view of the electronic expansion valve of the third embodiment in a closed state, FIG. 11 is a schematic cross-sectional view of the electronic expansion valve of the third embodiment in an open state, FIG. 12 is a schematic configuration diagram of a nut unit of the third embodiment, FIG. 13 is a schematic configuration diagram of the engagement between the valve stem portion and the stopper member of the third embodiment, and FIG. 14 is a schematic configuration diagram of the engagement between the magnetic rotor unit of the third embodiment and the valve stem portion, the valve needle, and the stopper member.

[0041] The electronic expansion valve includes a valve body member and a coil member 40. The valve body member includes a valve seat 11, a connecting member 50, and a housing 30. For the configurations and engagement forms of the valve seat 11, the connecting member 50, and the housing 30, the description of the first embodiment may be referred to.

[0042] The electronic expansion valve includes a nut unit 12 fixedly connected to the valve seat 11. Specifically, the nut unit 12 includes a nut 121 and a connection sheet 122 fixedly connected to each other. In a specific embodiment, the nut 121 is injection molded from a non-metallic material, for example, a resin material. Specifically, the connection sheet 122 is placed in a mold cavity as an insert, and the resin nut 121 is molded by using an injection molding machine to inject resin, and a part of the connection 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 unit 12 is fixedly connected to the valve seat 11. Specifically, the part of the connection sheet 122 that is not covered by the nut is fixed to the valve seat 11 by welding or crimping, and the nut 121 is inserted into the upper end opening of the valve seat 11 by press-fitting. The nut 121 has a through hole penetrating along its axial direction, and the inner wall of the through hole is provided with a female screw portion 12b, which forms a screw feed mechanism together with a male screw portion 22c provided on the outer edge of the valve stem portion 22. The valve stem portion 22 is fixedly connected to the magnetic rotor unit 27, so that it can rotate synchronously with the rotation of the magnetic rotor. The magnetic rotor unit 27 senses the electromagnetic force of the electromagnetic coil and rotates, and includes a magnetic rotor 271 having magnetic poles in the circumferential direction, and a connecting plate 272 fixedly connected to or integrally disposed with the magnetic rotor 271, and the connecting plate 272 is fixedly connected to the valve stem portion 22. In general, a press-fit connection or a crimp connection is adopted, or the connecting plate 272 and the valve stem portion 22 are connected by welding. A fixed stopper portion 12d is provided on the outer edge of the ceiling portion of the nut 121, and at least a part of the fixed stopper portion 12d protrudes from the upper end surface of the nut 121. In other words, at least a part of the fixed stopper portion 12d protrudes from the annular base of the nut in the axial direction, and the fixed stopper portion 12d in the drawings of this embodiment also protrudes from the annular base in the radial direction, but of course it may be arranged so as not to protrude.

[0043] 14, the magnetic rotor unit 27 is fixedly connected to the valve stem 22 by a connecting plate 272, and the magnetic rotor unit rotates the valve stem 22, which in turn rotates the valve needle 21, and the valve needle 21 may move along the axial direction or rotate relative to the valve stem 22 within a limited elastic displacement range. The engagement between the valve stem 22 and the valve needle 21 can be seen in the description of the first embodiment, and will not be described in detail here.

[0044] The valve stem portion 22 is a member having a substantially hollow cylindrical shape, and includes a large diameter portion 221 and a small diameter portion 222. For the assembly relationship between the valve stem portion 22, the bush 25, the nut 12, and the valve needle 21, refer to the description of the first embodiment.

[0045] The basic principle of the electronic expansion valve is as follows: the coil 40 receives a driving pulse signal to generate a periodically changing magnetic field, which excites the magnetic rotor 27 to rotate, and the valve stem 22 is fixedly connected to the connecting plate 272, so that it rotates synchronously with the magnetic rotor 27, and the screw feed mechanism between the valve stem and the nut allows the magnetic rotor 27 to move axially while rotating, so that the valve needle 21 moves axially, and the needle tip adjustment part 21a of the valve needle 21 approaches or moves away from the valve port 113a, thereby realizing the linear opening and closing adjustment function of the electronic expansion valve flow rate. The electronic expansion valve in FIG. 10 is in the stopper position of the fully closed state, that is, the needle tip adjustment part 21a of the valve needle 21 is at the lowest end of its stroke, and in this case, the valve port 113a is in the fully closed state or the set minimum opening state. The coil 40 drives the magnetic rotor to move downward, and when the needle tip adjustment portion 21a is in a fully closed state or at the lowest end position of its stroke, the stopper mechanism is arranged to provide a position limit / stop for the downward movement stroke of the magnetic rotor unit.

[0046] In this embodiment, the valve shaft portion 22 further includes a stopper member 33 fixedly connected directly or indirectly to the valve shaft portion 22. The indirect connection described here means that the stopper member 33 is fixedly connected to the valve shaft portion 22 by another part. The stopper member 33 is formed by pressing and bending a metal plate material, and its main body is annular, and at least a part of the material is bent in the axial direction to form the movable stopper portion 33a. Specifically, a completely annular metal plate material is cut at an arbitrary position, and one end of the cut metal plate is bent in the axial direction to form the movable stopper portion 33a. Of course, as an alternative form, the same can be realized by fixing the movable stopper portion to the stopper member by a method such as welding separately without bending after forming the annular stopper member, and making the movable stopper portion protrude along the axial direction of the stopper member.

[0047] For convenience of positioning, in this embodiment, the valve stem 22 is provided with an annular convex ring portion 223 on the outer edge of the large diameter portion 221, so that the connecting plate 272 is positioned by the upper surface of the convex ring portion 223, and at least a part of the stopper member 33 is positioned by the lower surface of the annular convex ring portion 223, so that the mounting position of the stopper member 33 can be accurately positioned on the valve stem 22. Of course, the convex ring portion 223 is not necessarily positioned, and in fact, the relative position of the stopper member 33 and the valve stem 22 can be accurately limited by a jig positioning method. The valve stem 22 and the stopper member 33 can be fixedly connected by other methods such as welding or crimping. The stopper member 33 is fixedly connected to the valve stem 22, and the valve stem 22 is fixedly connected to the magnetic rotor unit 27, so that the stopper member 33 rotates synchronously with the magnetic rotor unit 27. As shown in FIG. 10, when the electronic expansion valve is in a fully closed state or when the needle tip adjustment portion 21a of the valve needle 21 of the electronic expansion valve is at the minimum opening set in the electronic expansion valve, the movable stopper portion 33a bent downward in the stopper member 33 collides with the fixed stopper portion 12d provided at the upper end of the nut unit 12, realizing the stopper position restriction for the magnetic rotor unit. As shown in FIG. 11, when the magnetic rotor unit rotates in the opposite direction, the stopper member 33 is also displaced upward accordingly, and in this case, the movable stopper portion 33a moves upward and is separated from the fixed stopper portion 12d. FIG. 11 is a cross-sectional view of the electronic expansion valve of this embodiment in an open state, and the opening position in the drawing is at about 80% opening. In this case, the needle tip adjustment portion 21a of the valve needle 21 is at a position away from the valve port 113a, and the movable stopper portion 33a is also at a position separated from the fixed stopper portion 12d.

[0048] 14, the magnetic rotor unit 27 is fixedly connected to the valve stem 22 by a connecting plate 272, and the magnetic rotor unit rotates the valve stem 22, which in turn rotates the valve needle 21, and the valve needle 21 may move along the axial direction relative to the valve stem 22 within a limited elastic displacement range, or may rotate relative to the valve stem 22. The description of the first embodiment may be referred to for the engagement form between the valve stem 22 and the valve needle 21, and no detailed description will be given here.

[0049] In the electronic expansion valve provided by this embodiment, the nut material is made of PPS resin, or PEEK resin, or PTFE resin, and a fixed stopper part is integrally injection molded at the upper end of the resin nut. The stopper part is formed by pressing a metal plate, so that the processing of the parts is relatively easy, the metal stopper part has better wear resistance, which improves the service life of the stopper mechanism, and the manufacturing cost is relatively low.

[0050] Fourth embodiment The fourth embodiment of the present application will be described below with reference to FIGS.

[0051] Here, the difference between this embodiment and the third embodiment is in the movable stopper portion, so the configuration of the movable stopper portion will be mainly described in this embodiment. Other parts can be understood by referring to the first and third embodiments.

[0052] Referring to FIG. 15 and FIG. 16, FIG. 15 is a schematic diagram of the structure of the connecting plate provided by the fourth embodiment of the present application, and FIG. 16 is a local cross-sectional view of the engagement structure between the magnetic rotor unit and the valve shaft, valve needle, and other components provided by the fourth embodiment of the present application. Based on the orientation of FIG. 16, FIG. 15 shows a schematic diagram of the connecting plate at the bottom viewing angle. In this embodiment, the connecting plate 272 is formed by compressing and sintering metal powder, and is generally a plate-like structure with a central through hole, and the inner wall 2721 of the central through hole is fixedly connected to the valve shaft 22, and generally adopts a press-fit connection or a crimp connection, or the connecting plate 272 and the valve shaft 22 are connected by welding. In order to increase the contact area between the connecting plate 272 and the valve shaft 22, the height of the inner wall 2721 may be appropriately increased, so that the vertical section of the connecting plate 272 is approximately L-shaped. As described in the first embodiment, the connecting plate 272 and the magnetic rotor 271 are fixedly connected by injection, that is, the connecting plate is placed in the cavity of the mold as an insert, and then the magnetic material is injected to form the magnetic rotor 271, so that the plate-shaped outer edge 2723 of the connecting plate 272 is covered with the magnetic material. The connecting plate 272 is provided with a movable stopper part 2722 on one side facing the valve port direction, that is, the movable stopper part 2722 protrudes from the surface of one side of the connecting plate, and specifically, the movable stopper part 2722 and the base body of the connecting plate are integrally compressed and sintered from metal powder, which processing method effectively improves the strength of the movable stopper part 2722, is convenient to process, and does not require additional parts of the movable stopper part to engage with the fixed stopper part of the nut, and can be manufactured integrally with the connecting plate. Of course, an alternative manufacturing method may be to adopt a metal powder that is injected into a billet by a mold and then sintered.

[0053] When the magnetic rotor 271 is excited to rotate, the connecting plate 272 and the valve shaft 22 also rotate synchronously, and the valve shaft 22 rotates the valve needle 21 and other components provided inside the valve shaft. The valve needle 21 is fitted into the inner hole of the valve shaft 22, and there is an elastic connection between the valve needle 21 and the valve shaft 22. The valve needle 21 may move axially relative to the valve shaft 22 within a limited elastic displacement range, and may also rotate relative to the valve shaft 22.

[0054] When the electronic expansion valve is in a fully closed state, or when the needle tip adjustment part of the valve needle of the electronic expansion valve is at the minimum opening set in the electronic expansion valve, it is necessary to perform a stopper / position limit for the downward rotation stroke of the magnetic rotor unit, and in this case, the movable stopper part 2722 protruding downward of the connection plate 272 abuts against the fixed stopper part 12d provided at the upper end of the nut to realize the stopper / position limit function. When the magnetic rotor unit rotates in the valve opening direction, the movable stopper part 2722 rotates together with the rotor member, displaces upward, and separates from the fixed stopper part 12d.

[0055] Fifth embodiment The fifth embodiment of the present application will be described below with reference to FIGS.

[0056] This embodiment is a further improvement based on the first embodiment. In this embodiment, the same reference numerals are used for components that are basically the same in configuration and function as those in the first embodiment, and only a brief description is given, and those skilled in the art can refer to the description of the first embodiment to understand.

[0057] FIG. 17 is a schematic diagram of the electronic expansion valve of the fifth embodiment in a fully closed state at the stopper position, FIG. 18 is an enlarged view of part I in FIG. 17, FIG. 19 is an enlarged view of part II in FIG. 17, FIG. 20 is a cross-sectional view of the electronic expansion valve of the fifth embodiment at the spring force unloading point, FIG. 21 is an enlarged view of part III in FIG. 20, FIG. 22 is an enlarged view of part IV in FIG. 20, FIG. 23 is a cross-sectional view of the electronic expansion valve of the fifth embodiment at the opening critical point, FIG. 24 is an enlarged view of part V in FIG. 23, FIG. 25 is an enlarged view of part VI in FIG. 23, and FIG. 26 is a cross-sectional view of the electronic expansion valve of the fifth embodiment in a fully open state.

[0058] The electronic expansion valve includes a valve body member and a coil member 40, and the valve body member includes a valve seat 11, a connection member 50, and a housing 30. The configurations and engagement forms of the valve seat 11, the connection member 50, the housing 30, and the nut 12 may refer to the description of the first embodiment. The valve seat 11 includes a valve port portion 113, a first connection port portion 111, and a second connection port portion 112. The direction in which the refrigerant flows into the electronic expansion valve from the first connection port portion 111 and flows out to the second connection port portion 112 through the valve port is defined as a first flow direction, and the direction in which the refrigerant flows into the electronic expansion valve from the second connection port portion 112 and flows out to the first connection port portion 111 through the valve port is defined as a second flow direction. This embodiment will be described taking the first flow direction as an example.

[0059] The electronic expansion valve includes a nut unit 12 fixedly connected to the valve seat 11. The nut unit 12 includes a nut 121 and a connection seat 122 fixedly connected to each other. The nut 121 has a through hole penetrating along its axial direction, and an internal thread portion 12b is provided on the inner wall of the through hole, and the internal thread portion 12b is used to form a screw feed mechanism together with an external thread portion 22c provided on the outer edge of the valve shaft portion 22. A first guide portion 12a is provided on the inner wall of the nut, and the first guide portion 12a is provided below the internal thread portion 12b, which can provide a circumferential guide and centering function for 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 small clearance fit, and the valve shaft portion 22 allows the valve needle 21 to rotate or move up and down along the first guide portion 12a of the nut. The first guide portion 12 described here refers to a portion provided on the inner wall of the nut, and the valve needle guide portion 21b refers to a portion provided on the outer edge of the valve needle. The second guide portion 12c is provided at a relatively upper portion of the inner wall of the nut, which can provide the valve stem portion 22 with a circumferential guide and centering action. The valve stem guide portion 22b is provided at the outer edge of the valve stem portion 22, and the valve stem guide portion 22b and the second guide portion 12c are a small clearance fit, and the valve stem portion 22 can rotate or move up and down along the second guide portion 12c by the magnetic rotor unit. The first guide portion 12a and the second guide portion 12c described above are both part of the inner wall of the nut through hole, and the shape of the nut outer edge portion and the position of the connection sheet 122 on the nut outer edge portion do not affect the arrangement of the first guide portion and the second guide portion.

[0060] A fixed stopper portion 12d is provided on the outer edge of the ceiling of the nut 121, and at least a part of the fixed stopper portion 12d protrudes from the upper end surface of the nut 121 and engages with the movable stopper portion 20a provided on the magnetic rotor unit to realize a stopper for the magnetic rotor unit. The movable stopper portion 20a and the fixed stopper portion 12d of this embodiment are the same as those of the first embodiment, and of course, the movable stopper portion can completely adopt the configuration of the third or fourth embodiment, and the fixed stopper portion can completely adopt the configuration of the second embodiment. When the magnetic rotor unit moves down to the lowest end of the stroke, the movable stopper portion 20a abuts against the fixed stopper portion 12d, and the magnetic rotor unit cannot continue to rotate, and the downward movement stroke of the magnetic rotor member can be controlled.

[0061] The magnetic rotor unit 27 senses the electromagnetic force of the electromagnetic coil and rotates, and includes a magnetic rotor 271 having magnetic poles in the circumferential direction, and a connection plate 272 fixedly connected to the magnetic rotor 271 or disposed integrally. The valve stem 22 is a member having a substantially hollow cylindrical shape, and includes a large diameter portion 221 and a small diameter portion 222. The valve stem 22 is fixedly connected to the connection plate 272. A part of the outer edge of the large diameter portion 221 is formed as a rotor fixing portion 22a for fixing to the connection plate 272 of the magnetic rotor unit 27, and another part of the outer edge of the large diameter portion 221 is formed as a valve stem guide portion 22b for fitting into the second guide portion 12c of the nut with a small gap, thereby realizing a guide. The rotor fixing portion 22a is located relatively above the valve stem guide portion 22b, and the valve stem guide portion 22b is located approximately within the space surrounded by the magnetic rotor 271. An external thread 22c is provided on the outer edge of the small diameter portion 222, and the external thread 22c is used to form a screw feed mechanism together with the internal thread 12b provided on the nut. The valve stem portion 22 includes a first through hole portion 22e and a second through hole portion 22d, the first through hole portion 22e roughly corresponds to the inner hole portion of the large diameter portion 221, and the second through hole portion 22d roughly 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 a valve stem step portion 22f is formed between the first through hole portion 22e and the second through hole portion 22d.

[0062] The bush 25 is fixedly connected to the valve stem 22 and has a generally hollow tubular shape, with at least a portion of the outer edge thereof engaging with at least a portion of the inner edge of the first through-hole 22e. The large diameter portion 221 of the valve stem 22 and the bush 25 form a space, the compression spring 24 is located in the space, and the upper end of the compression spring 24 abuts against the bottom end of the bush 25. The abutment described here may be direct abutment or indirect abutment. For example, the indirect abutment is realized by disposing a gasket between the spring and the bush. The other end of the compression spring 24 abuts against the washer portion 23. One end of the washer portion 23 abuts against the compression spring 24, and the other end abuts against the valve needle 21.

[0063] The valve needle 21 is drilled into a central passage jointly defined by the bush 25, the valve stem 22 and the nut 12, and the compression spring 24 is fitted around a part of the outer edge of the valve needle 21. The valve needle 21 is rod-shaped and has a plurality of different outer diameters. The bottom end of the valve needle 21 is a needle tip adjustment portion 21a, and the valve needle 21 includes a valve needle guide portion 21b for small clearance fit into the first guide portion 12a of the nut, and the first guide portion 12a of the nut provides a circumferential guide and centering effect for the valve needle 21 during the rotation of the magnetic rotor. Similar to the first embodiment, it is only necessary to ensure that the outer edge of the valve needle is provided with a smooth valve needle guide portion 21b for forming a guide effect with the first guide portion 12a of the nut within the stroke of the valve needle. The valve needle 21 includes a gasket abutment portion 21e for abutting against the gasket 23, so that the gasket 23 does not displace downward along the central axis of the valve needle after it is abutted against the valve needle. A first shaft portion 21c and a second shaft portion 21d are provided above the valve needle guide portion of the valve needle 21, and the outer diameter of the first shaft portion 21c is larger than the outer diameter of the second shaft portion 21d and smaller than the outer diameter of the valve needle at the valve needle guide portion. In this way, a step is formed between the first shaft portion 21c and the second shaft portion 21d, and the step may be a specific example of the gasket abutment portion 21e, and the lower end surface of the gasket 23 abuts against the gasket abutment portion 21e, and in this embodiment, the number of gaskets 23 is two, the lower gasket abuts against the gasket abutment portion 21e, and the compression spring 24 is attached to the upper part of the 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 abuts against the bottom end of the bush 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 bush 25. Specifically, when assembling, the valve needle 21 is inserted into the central through-hole of the valve shaft portion 22 from below upward in Figure 4, so that the first shaft-shaped portion is arranged to penetrate within the through-hole of the valve shaft portion small diameter portion 222 and can move relative to each other, and the second shaft-shaped portion 21d is arranged to penetrate within the central through-hole of the bushing 25 and protrudes from the upper end surface of the bushing 25.The valve needle sleeve 26 is fixed to the upper end of the second shaft-shaped portion 21d so as to be fitted thereon. Since the outer diameter of the valve needle sleeve 26 is larger than the inner diameter of the bush 25, the valve needle 21 is restricted by the valve needle sleeve 26. After the valve needle 21 is fixedly connected to the valve needle sleeve 26, it will not escape downward from the central through-hole of the bush 25 and the valve shaft portion 22. A floating connection is formed between the valve needle 21 and the magnetic rotor unit 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 can move relative to each other within a limited range. 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 bush 25 are also loosely fitted, so that the valve needle 21 can also rotate relative to the valve shaft portion 22 in the circumferential direction.

[0064] Here, similar to the first embodiment, the valve needle guide portion, the first shaft portion, and the second shaft portion are all named according to the functions they play in the technical solution, and the valve needle should not be mechanically understood or limited to be formed by combining the three-stage shaft portion in Fig. 4. Alternatively, the valve needle 21 is manufactured in a staged assembly form, for example, by adopting a manner of threading or welding between two adjacent stages. In fact, as mentioned above, the illustrated configuration is only an example for convenience of processing.

[0065] A return spring 28 is fitted around the outer periphery of the valve needle sleeve 26, and the lower end of the return spring 28 abuts against the upper end surface of the bush 25 or the valve stem 22. The specific abutment position may be determined according to the relative positional relationship between the bush 25 and the valve stem 22 and the diameter of the return spring 28. As shown in Fig. 4, the tips of the bush 25 and the valve stem 22 are aligned or essentially aligned. In this case, the return spring may be arranged to abut against the valve stem 22, may be arranged to abut against the bush 25, or may be arranged to abut against the valve stem 22 and the bush 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 will not fall off the outer periphery of the valve needle sleeve 26.

[0066] The coil 40 of the electronic expansion valve receives the driving pulse signal, generates a periodically changing magnetic field, excites the magnetic rotor 27 to rotate, and the valve stem 22 is fixedly connected to the connecting plate 272, so that it rotates synchronously with the magnetic rotor 27, and the screw feed mechanism between the valve stem and the nut allows the magnetic rotor 27 to move axially while rotating, so that the valve needle 21 moves axially, and the needle tip adjustment part 21a of the valve needle 21 approaches or moves away from the valve port 113a, thereby realizing the linear opening and closing adjustment function of the electronic expansion valve flow rate. The electronic expansion valve of FIG. 17 is in the stopper position of the fully closed state, that is, the needle tip adjustment part 21a of the valve needle is at the lowest end of its stroke, and the valve needle abuts against the valve port 113, in this case, the valve port 113a is in the fully closed state. When the magnetic rotor unit 27 continues to rotate upward in the valve opening direction from the state shown in FIG. 17 until the male threaded portion 22c of the valve stem escapes from the female threaded portion 12b of the nut 12, the upper end of the return spring 28 has already abutted against the top wall of the housing 30, and the return spring 28 is in a compressed state. In this case, the screw feed mechanism between the valve stem and the nut has already been separated from each other, so the magnetic rotor unit 27 does not continue to move upward. When it is necessary to perform the valve closing operation, the magnetic rotor unit 27 receives the downward spring force of the return spring 28 while rotating, which promotes the male threaded portion 22c of the valve stem 22 and the female threaded portion 12b of the nut to be screw-engaged again, ensuring that the screw feed mechanism is reassembled.

[0067] 18 and 19, 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. Fig. 17 shows the stopper position where the electronic expansion valve is in a fully closed state, that is, the position where the movable stopper part 20a collides with and contacts the fixed stopper part 12d, in this case, the needle tip adjustment part 21a of the valve needle 21 is at the lowest end of its stroke, and the valve needle abuts against the valve orifice part 113. As shown in Fig. 19, in this case, the valve needle 21 receives the spring force transmitted downward in the drawing by the compression spring 24 through the gasket 23, and the spring force is transmitted by the valve needle 21 to the part of the valve orifice part 113 that contacts the valve needle. This embodiment describes the case where the number of gaskets is two, and the gasket 23 includes a first gasket 231 and a second gasket 232. Based on the illustration of Fig. 17, the first gasket 231 is positioned above the second gasket 232 and abuts against the second gasket 232. As an alternative embodiment, the number of gaskets may be one or more.

[0068] The upper end of the compression spring 24 abuts against the lower end of the bush 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 abutment portion 21e of the valve needle 21, and in this case, there is a certain distance k from the lower end surface of the second gasket 232 to the valve stem step portion 22f of the valve stem portion 22, and here, the second gasket 232 can further generate a displacement amount of distance k toward the bottom of the drawing. In this case, 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 in the valve orifice that contacts the valve needle.

[0069] A valve needle sleeve 26 is fitted and fixed on the upper end of the valve needle 21, and there is a certain distance h from the lower end of the valve needle sleeve 26 to the upper end of the bush 25, and h>k is satisfied. In addition, as shown in FIG. 19, the outer diameter of the valve needle sleeve 26 in this embodiment is smaller than that of the bush 25. As can be understood by those skilled in the art, as an alternative embodiment, the outer diameter of the valve needle sleeve 26 may be larger than that of the bush 25, and in this case, when the axial height of the valve stem 22 is greater than that of the bush 25, the valve needle sleeve 26 will not abut against the bush 25 in any case, but will abut against the valve stem 22 when moving downward. In this case, h is the distance from the lower end of the valve needle sleeve 26 to the upper end of the valve stem 22.

[0070] Starting from the state of FIG. 17, the magnetic rotor unit 27 rotates upward by the excitation drive of the stator coil 40, the movable stopper portion 20a rotates and begins to separate from the fixed stopper portion 12d, and due to the action of the screw feed mechanism, the magnetic rotor unit 27 displaces upward synchronously together with the valve shaft portion 22, and when the raised height is exactly k, the electronic expansion valve is at the spring force unloading point.

[0071] 20 to 22, Fig. 20 is a cross-sectional view of the electronic expansion valve of the fifth embodiment when it is at the spring force unloading point. Fig. 21 is an enlarged view of part III in Fig. 20. Fig. 22 is an enlarged view of part IV in Fig. 20.

[0072] In this case, the distance between the lower end of the second gasket 232 and the valve stem step 22f of the valve stem is 0, that is, the spring force of the compression spring 24 is transferred from the gasket abutment 21e of the valve needle 21 shown in FIG. 17 to the valve stem step 22f of the valve stem 22 shown in FIG. 20 through the transmission of the gasket 23, that is, in this case, the electronic expansion valve is at the spring force unloading point of the compression spring 24, and the valve needle 21 is no longer subjected to the spring force transmitted by the compression spring 24. As shown in FIG. 21, in this case, there is a certain distance from the lower end of the valve needle sleeve 26 to the upper end of the bush 25, and the distance is hk. Of course, if the outer diameter of the valve needle sleeve 26 is larger than the outer diameter of the bush 25, there is a certain distance from the lower end of the valve needle sleeve 26 to the upper end of the valve stem 22, which is hk.

[0073] 17 to the spring force unloading point state in FIG. 20, the upward displacement amount of the valve stem portion 22 and the magnetic rotor unit 27 is k, and the upward displacement amount of the valve needle 21 is 0.

[0074] Based on FIG. 20, the magnetic rotor unit 27 rotates upward continuously by the excitation drive of the stator coil 40, and due to the climbing conversion action of the screw feed mechanism, the magnetic rotor unit 27 displaces upward continuously and synchronously together with the valve shaft 22, and when the raised height is hk, the electronic expansion valve is at the opening critical point.

[0075] 23 to 25, FIG. 23 is a cross-sectional view of the electronic expansion valve of the fifth embodiment when it is at the critical point of opening. FIG. 24 is an enlarged view of the V part in FIG. 23. FIG. 25 is an enlarged view of the VI part in FIG. 23. In this case, the valve needle 21 is in contact with the valve orifice 113, or the valve needle 21 can be separated from the valve orifice 113 by continuously displacing upward. In this case, the lower end of the second gasket 232 is abutted against the valve stem step 22f of the valve stem 22, and the spring force of the compression spring 24 acts on the valve stem step 22f through the transmission of the gasket 23. As shown in FIG. 24, in this case, the distance from the lower end of the valve needle sleeve 26 to the upper end of the bush 25 is 0, that is, in the states of FIG. 20 to FIG. 23, the upward synchronous displacement of the valve stem 22 and the rotor is hk. In this case, the valve needle 21 is no longer subjected to the spring force transmitted by the compression spring 24, the spring force has already been released from the valve needle 21, and the frictional force of the rotational movement of the valve needle 21 relative to the valve stem 22 is significantly reduced. That is, at the moment when the valve needle contacts or separates from the valve orifice, the valve needle 21 is no longer subjected to the spring force of the compression spring 24, so that the frictional impact force caused by the relative rotation between the valve needle and the valve orifice is reduced, the wear at the contact points between the two is reduced, and the service life of the electronic expansion valve is improved.

[0076] From the fully closed state in FIG. 17 to the critical opening state in FIG. 23, the upward displacement of the valve stem 22 and the magnetic rotor unit 27 is h, and the upward displacement of the valve needle 21 is zero.

[0077] Referring to Fig. 26, Fig. 26 is a cross-sectional view of the electronic expansion valve in the fully open state of the fifth embodiment. In this case, the valve needle 21 has already left the valve port portion 113, and in the operation process of Figs. 23 to 26, that is, in the process of the electronic expansion valve reciprocating from the critical opening point to the maximum opening degree, the valve needle 21 synchronously moves up and down in the axial direction along with the valve shaft portion 22, and the valve needle 21 is not always subjected to the spring force of the compression spring 24, thereby reducing the frictional force caused by the relative rotation between the valve needle 21 and the valve shaft portion 22, reducing the wear between the valve needle guide portion 21b and the first guide portion 12a of the nut, and improving the service life of the electronic expansion valve. From the critical opening point of Fig. 23 to the fully open state of Fig. 26, the relative position of the valve needle 21 and the valve shaft portion 22 in the axial direction is maintained as it is.

[0078] When the electronic expansion valve moves from the spring force unloading point in Fig. 20 to the open critical point state in Fig. 23, the upward displacement of the valve stem 22 and the magnetic rotor unit 27 is hk, and the upward displacement of the valve needle 21 is 0. When the electronic expansion valve moves from the fully closed state in Fig. 17 to the fully open state in Fig. 26, the upward displacement of the valve stem 22 and the magnetic rotor unit 27 is L, and the upward displacement of the valve needle 21 is Lh.

[0079] In addition, in this embodiment, the first gasket and the second gasket are both plate-shaped, and the bottom surface of the second through-hole portion of the valve stem portion (i.e., the valve stem step portion) is also planar, so the symbols h and k in the drawings are also shown as the axial distance between two planes. However, in reality, the contact portion of the gasket or the second through-hole portion is not limited to contact between two planes and may be modified in various ways, for example, to axial contact between two inclined surfaces or contact of other irregular shapes. In this case, h and k may be understood to be the axial displacement difference of the two components.

[0080] Here, the fifth embodiment is described taking the first flow direction as an example, in which the fluid pressure at the first connection port is greater than the fluid pressure at the second connection port, so the valve needle of the electronic expansion valve is always subjected to the downward differential pressure of the fluid medium in each of the above states.

[0081] In the state of the rotor member in FIG. 26 , when the valve needle 21 is not subjected to the spring force of the compression spring 24 and there is no pressure difference between the fluid in the first connection port and the fluid in the second connection port, the valve needle 21 is only subjected to the force of its own gravity, that is, after the valve needle 21 is fixedly connected to the valve needle sleeve 26, in a state where it is not subjected to the spring force of the compression spring 24, it further has a certain movable gap along its axial direction with respect to the valve shaft portion 22, the size of which is the same as the gap in FIG. 25 , that is, hk.

[0082] In the electronic expansion valve provided by this embodiment, the spring force of the compression spring is not applied to the valve needle at the moment when the valve needle and the valve orifice come into sealed contact from the open state to the closed state, and at the moment when the valve needle and the valve orifice separate from each other from the closed state to the open state, thereby reducing the frictional impact force caused by the relative rotation of the two sealing parts, reducing the wear of the contact parts, and improving the service life of the electronic expansion valve. During the reciprocating movement of the electronic expansion valve from the minimum opening to the maximum opening, the spring force of the compression spring is not applied to the valve needle at all times, thereby reducing the rotational friction force between the valve needle and the valve shaft part, reducing the wear between the valve needle guide part and the nut, and improving the service life of the electronic expansion valve.

[0083] Sixth embodiment The sixth embodiment of the present application will be described below in conjunction with FIG.

[0084] In the above five embodiments, the first connection port of the electronic expansion valve is connected to the first connecting pipe 10b, and the second connection port 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. In reality, the electronic expansion valve of the above embodiments is applied to many fields, and the connection between the electronic expansion valve and the refrigeration system is not limited to the connection method using a connecting pipe. For example, when applied to a case that requires quick repair, such as a car air conditioner, the configuration of the first and second connecting pipes is not adopted, and the valve seat is directly fixed and connected to an integrated valve body in which multiple passages are integrated, for example, a flange sealed connection method is adopted.

[0085] Referring to FIG. 27, FIG. 27 is a schematic diagram of the electronic expansion valve according to the sixth embodiment of the present invention. This embodiment is an example in which the electronic expansion valve is applied to an automobile air conditioning system. The valve seat 11 is fixed to the connecting member 51a by welding, and the whole is fixedly connected to the valve body 80. The connecting member 51a may be adaptively arranged in a shape suitable for connecting to the valve body. Specifically, the connecting member 51a is fixedly connected to the valve body 80 in the manner of flange sealing connection (not shown), for example, a screw hole is arranged in the disk-shaped part of the connecting member, and the connecting member is fixedly connected to the valve body by screw connection. In order to ensure the sealing performance, a first sealing member 803 is arranged in front of the connecting member and the valve body. In addition, a second sealing member 804 is provided between the valve seat 11 and the valve body 80. After the assembly is completed, the connecting member 51 and the valve seat 11 realize a fixed connection with the valve body 80 and maintain good sealing performance.

[0086] The valve body 80 is machined from metal to form a first connection end 801 and a second connection end 802, which are connected to other components of the air conditioning system. Of course, the configuration of the first connection end 801 and the second connection end 802 is not limited to that shown in FIG. 27, and may be arranged differently according to the needs of the system. In this way, the valve seat and the connecting members of the electronic expansion valve can be conveniently separated from the valve body when it is required to be removed for repair.

[0087] Here, all directional nouns such as up, down, left, right, etc. mentioned in this specification are introduced for convenience of description based on the drawings of the specification, and ordinal numbers such as "first" and "second" in the names of components are introduced for convenience of description, and do not impose any restriction on the order of components, and since the functions of some parts among the components provided in the above embodiment are similar, this specification will unify the names of these parts. Above, the electronic expansion valve provided by the related technical solution is introduced in detail, and this specification is described using specific embodiments, and the description of the above embodiments does not impose any restriction on the form of the present invention, but is only for understanding the method and the central idea of ​​the present invention.

Claims

1. a valve seat, a nut unit, a valve stem portion, a valve needle, and a movable stopper portion, the movable stopper portion is directly or indirectly fixedly connected to the valve stem portion, the valve seat includes a valve orifice portion, the nut unit is fixedly connected to the valve seat and includes a nut, the nut includes a first guide portion, a second guide portion, a female thread portion, and a fixed stopper portion, the first guide portion is closer to the valve orifice portion than the female thread portion and the second guide portion is farther from the valve orifice portion than the female thread portion, and the movable stopper portion is capable of abutting against the fixed stopper portion, the valve stem includes a valve stem guide portion that is clearance-fitted into the second guide portion, the valve stem is displaceable relative to the nut along an axial direction of the nut, the valve stem includes a male thread portion, and the male thread portion and the female thread portion form a screw feed mechanism, the valve needle includes a valve needle guide portion that is gap-fitted into the first guide portion, and the valve needle is displaceable relative to the nut along an axial direction of the nut, the nut is provided on its outer periphery with two convex ribs, one of which extends and protrudes from an end face of the nut relatively remote from the valve orifice, the convex rib protruding from the end face of the nut relatively remote from the valve orifice forming at least a part of the fixed stopper portion, and the other of which is not higher than the end face of the nut relatively remote from the valve orifice.

2. 2. The electronic expansion valve according to claim 1, wherein the nut is made of an engineering plastic by injection molding, and at least a part of the fixed stopper portion protrudes from an end face of the nut that is relatively far from the valve opening portion.

3. 3. The electronic expansion valve according to claim 2, wherein at least a portion of the fixed stopper portion protrudes from an outer periphery of the nut, and a width K of a force-receiving surface of the fixed stopper portion that can collide with the movable stopper portion is greater than a thickness t of the nut on a side relatively away from the valve orifice portion.

4. 2. The electronic expansion valve according to claim 1, wherein a radial protrusion amount of the fixed stopper portion relative to the body of the nut is the same as a radial protrusion amount of the convex rib relative to the body of the nut, and the convex rib and the nut are injection molded as an integral structure.

5. 2. The electronic expansion valve according to claim 1, wherein an inner diameter of the first guide portion is smaller than an inner diameter of the second guide portion, the nut unit further includes a connecting sheet, at least a portion of the connecting sheet protrudes from the nut, and the connecting sheet is fixedly connected to the valve seat.

6. 2. The electronic expansion valve according to claim 1, wherein the valve stem portion includes a large diameter portion and a small diameter portion, an outer diameter of the large diameter portion is larger than an outer diameter of the small diameter portion, the large diameter portion is farther from the valve orifice portion than the small diameter portion, the male thread portion is provided on an outer edge of the small diameter portion, the valve stem guide portion is provided on an outer edge of the large diameter portion, and a rotor fixing portion is provided on the outer edge of the large diameter portion.

7. 2. The electronic expansion valve as claimed in claim 1, wherein the valve shaft further comprises a first through-hole portion, a nominal thread diameter of the screw feed mechanism is smaller than an inner diameter of the first through-hole portion, and a nominal thread diameter of the screw feed mechanism is slightly larger than an outer diameter of the valve needle guide portion.

8. 2. The electronic expansion valve according to claim 1, wherein the electronic expansion valve comprises a connecting member, a first connecting port, a second connecting port and a valve body, the valve body being formed by cutting and comprising a first connecting port end and a second connecting port end, the valve seat being fixedly connected to the connecting member, the connecting member and the valve body being flange-connected, a first sealing member being provided between the connecting member and the valve body, and a second sealing member being provided between the valve seat and the valve body.

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