CN113639052A

CN113639052A - Electronic expansion valve

Info

Publication number: CN113639052A
Application number: CN202010392363.XA
Authority: CN
Inventors: 不公告发明人
Original assignee: Zhejiang Sanhua Intelligent Controls Co Ltd
Current assignee: Zhejiang Sanhua Intelligent Controls Co Ltd
Priority date: 2020-05-11
Filing date: 2020-05-11
Publication date: 2021-11-12
Also published as: KR20230009465A; WO2021228012A1; JP2023525102A

Abstract

Electronic expansion valve, including disk seat, nut component, valve shaft portion, needle, movable detent with valve shaft portion is direct or indirect fixed connection, the disk seat includes the valve port portion, nut component with disk seat fixed connection, nut component includes nut and connection piece, the nut includes first guide part, second guide part, internal thread portion and fixed detent, first guide part is relative internal thread portion is more close to the valve port portion, the second guide part is relative internal thread portion is farther away from the valve port portion, fixed detent can with movable detent is contradicted. The electronic expansion valve provided by the embodiment comprises the nut, wherein the nut comprises the first guide part, the second guide part, the internal thread part and the fixing and stopping part, the electronic expansion valve can be manufactured simply and conveniently through one-time injection molding, and the nut can provide a guiding and centering effect for the valve needle and the valve shaft part.

Description

Electronic expansion valve

[ technical field ] A method for producing a semiconductor device

The application relates to the technical field of refrigeration control, in particular to an electronic expansion valve.

[ background of the invention ]

The refrigerating system comprises a compressor, a throttling element, two heat exchangers and other parts, wherein the throttling element can adopt an electronic expansion valve and is used for throttling and adjusting a refrigerant, and the electronic expansion valve can realize relatively accurate control so as to improve the energy efficiency of the system. The basic principle of the electronic expansion valve is that a stator coil is introduced with a specified pulse current signal, so that a rotor assembly of the electronic expansion valve is excited and rotated, the rotation motion of the rotor is converted into the up-and-down movement of a valve shaft through the conversion of a spiral feeding mechanism, a valve core at the head of the valve shaft is close to or far away from a valve port, and the flow area of the valve port is changed, so that the refrigerant flow regulation and switching functions are achieved.

[ summary of the invention ]

An object of one embodiment of the present invention is to provide a new nut structure for an electronic expansion valve.

In order to achieve the above purpose, one embodiment of the present invention adopts the following technical solutions:

the electronic expansion valve is characterized by comprising a valve seat, a nut assembly, a valve shaft part, a valve needle and a movable stopping part, wherein the movable stopping part is directly or indirectly fixedly connected with the valve shaft part, the valve seat comprises a valve port part, the nut assembly is fixedly connected with the valve seat, the nut assembly comprises a nut and a connecting sheet, the nut comprises a first guide part, a second guide part, an internal thread part and a fixed stopping part, the first guide part is closer to the valve port part relative to the internal thread part, the second guide part is farther away from the valve port part relative to the internal thread part, and the fixed stopping part can be abutted against the movable stopping part;

the valve shaft portion comprises a valve shaft guide portion, the valve shaft guide portion is in clearance fit with the second guide portion, and the valve shaft portion can be relatively displaced along the axial direction of the nut relative to the nut; the valve shaft part comprises an external thread part, and the external thread part and the internal thread part form a spiral feeding mechanism;

the valve needle comprises a valve needle guiding part which is in clearance fit with the first guiding part, and the valve needle can be relatively displaced along the axial direction of the nut relative to the nut.

The electronic expansion valve provided by the embodiment comprises the nut, wherein the nut comprises the first guide part, the second guide part, the internal thread part and the fixing and stopping part, the electronic expansion valve can be manufactured simply and conveniently through one-time injection molding, and the nut can provide a guiding and centering effect for the valve needle and the valve shaft part.

[ description of the drawings ]

Fig. 1 is a schematic cross-sectional view of an electronic expansion valve according to a first embodiment in a closed state;

fig. 2 is a schematic cross-sectional view of the electronic expansion valve of the first embodiment in an open state;

FIG. 3 is a schematic view of the engagement of the first embodiment nut with the valve seat assembly;

FIG. 4 is a schematic view of the magnetic rotor assembly of the first embodiment in cooperation with a valve shaft portion and a valve needle;

fig. 5 is a schematic cross-sectional view illustrating the electronic expansion valve of the second embodiment in a closed state;

fig. 6 is a schematic sectional view of the electronic expansion valve of the second embodiment in an open state;

FIG. 7 is a schematic structural view of a nut assembly according to a second embodiment;

FIG. 8 is a partial cross-sectional view of the second embodiment of the magnetic rotor assembly in cooperation with the valve shaft portion and the valve needle;

FIG. 9 is a top view of the nut assembly of the second embodiment;

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 sectional view of the electronic expansion valve of the third embodiment in an open state;

FIG. 12 is a schematic structural view of a third embodiment of a nut assembly;

FIG. 13 is a schematic view showing a fitting structure of the valve shaft portion and the stopper member of the third embodiment;

FIG. 14 is a schematic view of the cooperating structure of the magnetic rotor assembly with the valve shaft portion, the valve needle and the stop member of the third embodiment;

FIG. 15 is a schematic view of a connection plate structure provided in the fourth embodiment;

fig. 16 is a partial sectional view of a magnetic rotor assembly in cooperation with a valve shaft portion, a valve needle, etc., provided in accordance with a fourth embodiment;

fig. 17 is a schematic view of a fifth embodiment electronic expansion valve in a fully closed position in a rest position;

FIG. 18 is an enlarged view of portion I of FIG. 17;

FIG. 19 is an enlarged view of section II of FIG. 17;

fig. 20 is a cross-sectional view of the fifth embodiment electronic expansion valve at a spring force unloading point;

FIG. 21 is an enlarged view of section III of FIG. 20;

FIG. 22 is an enlarged view of section IV of FIG. 20;

fig. 23 is a sectional view of the electronic expansion valve of the fifth embodiment at the opening critical point;

FIG. 24 is an enlarged view of the portion V of FIG. 23;

FIG. 25 is an enlarged view of section VI of FIG. 23;

fig. 26 is a sectional view of the fifth embodiment in a fully open state of the electronic expansion valve;

fig. 27 is a schematic structural view of an electronic expansion valve according to the sixth embodiment.

[ detailed description ] embodiments

In order to make those skilled in the art better understand the technical solutions provided in the present application, the following detailed description of the technical solutions in the present application is made with reference to the accompanying drawings and specific embodiments.

First embodiment

Referring to fig. 1 to 4, fig. 1 is a structural diagram illustrating a valve closing state of an electronic expansion valve according to a first embodiment, fig. 2 is a structural diagram illustrating a valve closing state of an electronic expansion valve according to a first embodiment, fig. 3 is a structural diagram illustrating a valve seat component according to a first embodiment, and fig. 4 is a structural diagram illustrating a rotor and a screw valve needle assembly according to a first embodiment.

As shown in fig. 1, the electronic expansion valve includes a valve body component and a coil component 40, wherein the valve body component includes a valve seat 11, a connector 50, and a housing 30, the valve seat 11 can be formed by metal cutting, the connector 50 is disposed on one side above the valve seat 11, and the connector 50 and the valve seat 11 can be fixedly connected by welding, and at the same time, fixedly connected with the housing 30, specifically by welding. The housing 30 is made of a thin-walled member, and is substantially cylindrical with one open end, and the open end is hermetically welded to the valve seat 11. The valve seat 11 and the connecting member 50 can be assembled and positioned conveniently by providing a step portion on the upper outer edge of the valve seat 11 and then installing the connecting member 50 from above the valve seat 11. Also, a stepped portion may be formed at an outer edge of an upper side of the connector 50 to facilitate assembly and positioning with the housing 30, so that the welding operation is facilitated. That is, the valve seat 11 is connected to the housing by a connecting member 50, and a cavity is formed above the valve seat 11 for accommodating a magnetic rotor assembly, a nut assembly, and the like described below.

The valve seat 11 includes a valve port portion 113, a first interface portion 111, and a second interface portion 112, where the first interface portion 111 and the second interface portion 112 are both used for connecting with a refrigerant channel of the system, and the valve port portion 113 is provided with a valve port 113 a. In the present embodiment, the first connection pipe 10b is fixedly connected to the first connection port 111, the second connection pipe 10c is fixedly connected to the second connection port 112, and the refrigerant can flow in from the first connection pipe 10b, flow out from the second connection pipe 10c after passing through the valve port 113a, or flow in from the second connection pipe 10c, and flow out from the first connection pipe 10b after passing through the valve port 113 a.

The electronic expansion valve comprises a nut component 12, and the nut component 12 is fixedly connected with the valve seat 11. Specifically, the upper end of the valve seat 11 is provided with an opening, and the nut assembly 12 can be fitted into the valve seat 11 from the top down. The nut component 12 includes a nut 121 and a connecting piece 122, and the nut 121 is fixedly connected with the connecting piece 122. In a specific embodiment, the connecting piece 122 may be formed by stamping a metal plate, and the nut 121 is formed by injection molding using a non-metal material such as engineering plastic and the connecting piece 122 as an insert. The nut 121 is press-fitted into the valve seat 11, and the connecting piece 122 is fixedly connected with the valve seat 11 by welding. The nut can be made of PPS modified resin, PEEK modified resin, PTFE modified resin or the like.

The nut 121 has a through hole penetrating in the axial direction thereof, and a female screw portion 12b is provided on the inner wall of the through hole to form a screw feeding mechanism with a male screw portion 22c provided on the outer edge portion of the valve shaft portion 22 described below. The inner side wall of the nut is further provided with a first guide portion 12a, and the first guide portion 12a is arranged below the inner threaded portion 12b and can provide a guide centering effect on the valve needle 21 in the circumferential direction. The lower portion means that the first guide portion 12a is closer to the valve port portion 113 than the female screw portion 12 b. The needle 21 includes a needle guide portion 21b, that is, the first guide portion 12a and the needle guide portion 21b are in a small clearance fit, and the 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 is a portion provided on the inner wall of the nut, and the needle guide portion 21b is a portion provided on the outer edge of the needle. The second guide portion 12c is provided on the inner side wall of the nut at a position opposite to the upper portion, and can provide a circumferential guide centering action to the valve shaft portion 22. The valve shaft guide 22b is disposed on the outer edge of the valve shaft 22, the valve shaft guide 22b is in close clearance fit with the second guide 12c, and the valve shaft 22 can rotate or move up and down along the second guide 12c under the driving of the magnetic rotor assembly. The second guide portion 12c has an inner diameter larger than that of the first nut guide portion 12a, so that the second guide portion 12c does not interfere with the male screw portion 22c of the valve shaft portion 22 when the male screw portion 22c moves upward and gradually disengages from the female screw portion 12 b. The first guide portion 12a and the second guide portion 12c described above are portions of the inner wall of the nut through hole, and the shape of the nut outer edge portion and the position of the connecting piece 122 on the nut outer edge portion do not affect the arrangement of the first guide portion and the second guide portion.

The top outer edge of the nut 121 is provided with a fixed stop portion 12d, and the fixed stop portion 12d at least partially protrudes from the upper end surface of the nut 121, or at least a part of the fixed stop portion 12d protrudes from the annular base body of the nut in the axial direction, and may protrude from the annular base body in the radial direction or may be configured not to protrude. The fixed stop 12d is adapted to cooperate with a movable stop 20a provided on the magnetic rotor assembly to effect a stop of the magnetic rotor assembly. That is, in the present embodiment, the magnetic rotor member can be displaced in the axial direction while the nut assembly 12 is fixedly connected to the valve seat 11, and therefore, when the magnetic rotor member moves downward to the lowermost end of the stroke, the movable stopper 20a can be brought into contact with the fixed stopper 12d, so that the magnetic rotor member cannot rotate any more, and the stroke of the downward movement of the magnetic rotor member can be controlled. Since the magnetic rotor assembly is fixedly coupled to the valve shaft portion, the movable stopper portion is also directly or indirectly fixedly coupled to the valve shaft portion 22.

The magnetic rotor assembly 27 can induce the electromagnetic force of the electromagnetic coil to rotate, and includes a magnetic rotor 271 with magnetic poles in the circumferential direction and a connecting plate 272 fixedly connected with or integrally arranged with the magnetic rotor 271, wherein the connecting plate 272 is made of metal, such as powder metallurgy material, and the magnetic rotor 271 can be injection molded by using the connecting plate 272 as an insert. The connecting plate 272 is fixedly connected to the valve shaft 22, and specifically, a rotor fixing portion 22a located at an upper end outer edge portion of the valve shaft 22 is fitted to an inner edge portion of the connecting plate 272 and fixed by welding. The magnetic rotor assembly includes a movable stopper 20a, and as a specific embodiment, the movable stopper 20a may be integrally formed from the connecting plate 272, i.e., the movable stopper 20a may be a part of the connecting plate 272.

The valve shaft 22 is a substantially hollow cylindrical member, and includes a large diameter portion 221 and a small diameter portion 222. A part of the outer edge of the large diameter portion 221 is formed as a rotor fixing portion 22a for fixing and connecting with the connecting plate 272 of the magnet rotor assembly 27, and the fixing method such as welding or crimping may be adopted for connecting both. The other part of the outer edge of the large diameter portion 221 is formed as a valve shaft guide 22b for small clearance fit with the second guide 12c of the nut to thereby achieve guidance. That is, the second guide portion 12c of the nut provides the valve shaft portion 22 with a guide centering action in the circumferential direction during the rotation of the rotor. As shown in fig. 1, the rotor fixing portion 22a is located relatively above the valve shaft guide portion 22b, and the valve shaft guide portion 22b is located substantially in a space surrounded by the magnetic rotor 271. The small diameter portion 222 is provided at its outer edge portion with an external thread portion 22c for forming a screw feeding mechanism with an internal thread portion 12b provided in the nut. The valve shaft portion 22 includes a first through hole portion 22e and a second through hole portion 22d, wherein the first through hole portion 22e substantially corresponds to the inner hole portion of the large diameter portion 221, and the second through hole portion 22d substantially corresponds to the inner hole portion of the small diameter portion 222, so that the inner diameter of the first through hole portion 22e is larger than that of the second through hole portion 22d, and a step portion 22f is formed between the first through hole portion 22e and the second through hole portion 22 d. The nominal diameter of the screw feeding mechanism is smaller than the inner diameter of the first through hole portion 22e, and the nominal diameter of the screw feeding mechanism is slightly larger than the outer diameter of the needle guide portion 21 c. The term "slightly larger" as used herein means that the needle is not hindered or interfered by the internal thread portion 12b when moving upward.

The bush 25 is fixedly connected to the valve shaft portion 22, the bush 25 is substantially hollow and cylindrical, and at least a part of an outer edge of the bush 25 is fitted to at least a part of an inner edge of the first through hole portion 22 e. Thus, the large diameter portion 221 of the valve shaft portion 22 and the bush 25 form a space in which the compression spring 24 is located, 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 the bottom end of the bushing 25, either directly or indirectly, for example by providing a spacer between the spring and the bushing. The other end of the compression spring 24 abuts against the washer portion 23. The washer portion 23 has one end abutting against the compression spring 24 and the other end abutting against a 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 22 d. Therefore, under the condition that the electronic expansion valve with the same specification, such as the electronic expansion valve with the same rotor diameter, shell diameter, stator coil diameter and volume, the diameter of the compression spring can be made relatively larger, so that the spring force is increased, and the capability of resisting reverse pressure of the electronic expansion valve in a fully closed state is improved.

The valve needle 21 is arranged in a central channel defined by the bushing 25, the valve shaft portion 22 and the nut 12, and the compression spring 24 is sleeved on the periphery of part of the outer edge of the valve needle 21. The valve needle 21 is generally rod-shaped and has a plurality of different outer diameters, based on the views shown in fig. 1-5, the bottom end of the valve needle 21 is a needle point adjusting portion 21a, the shape of the needle point adjusting portion 21a is related to the shape of the valve port portion and the flow rate adjusting curve required by the electronic expansion valve, and different settings can be performed according to different requirements, and the specific shape of the needle point adjusting portion 21a is not limited in the present application. The needle 21 comprises a needle guide portion 21b for a small clearance fit with the first guide portion 12a of the nut, which first guide portion 12a provides circumferential guiding centering of the needle 21 during rotation of the magnetic rotor. The needle 21 includes a spacer abutting portion 21e for abutting against the spacer 23 so that the spacer 23 does not displace downward in the direction of the center axis of the needle after abutting against the needle. As a specific example, as shown in fig. 4, a first shaft-shaped portion 21c and a second shaft-shaped portion 21d are respectively disposed above the needle guide portion of the needle 21, wherein an outer diameter of the first shaft-shaped portion 21c is larger than an outer diameter of the second shaft-shaped portion 21d, and an outer diameter of the first shaft-shaped portion 21c is smaller than an outer diameter of the needle at the needle guide portion. Thus, a step is formed between the first shaft-like portion 21c and the second shaft-like portion 21d, and the step may be formed as a specific example of the pad abutting portion 21e, that is, the pad abutting portion 21e is formed at the top of the first shaft-like portion 21 c. The lower end surface of the washer 23 abuts against the washer abutting portion 21e, but in the present embodiment, when the number of the washers 23 is 2, the washer located on the lower side abuts against the washer abutting portion 21e, the compression spring 24 is attached to the upper portion of the washer 23, that is, the lower end of the compression spring 24 abuts against the washer 23, and the upper end of the compression spring 24 abuts against the bottom end of the bush 25. The washer 23 and the compression spring 24 are accommodated in a space defined by the large diameter portion of the valve shaft portion 22 and the bush 25. Specifically, during assembly, the valve needle 21 is inserted into the central through hole of the valve shaft 22 from the lower direction shown in fig. 4, so that the first shaft-shaped part is inserted into the through hole of the small-diameter part 222 of the valve shaft and can move with respect to the second shaft-shaped part; the second shaft-shaped portion 21d is inserted through the central through hole of the bushing 25 and is inserted through the upper end surface of the bushing 25. The upper end portion of the second shaft-shaped portion 21d is fitted and fixed with the needle cover 26, and the outer diameter of the needle cover 26 is larger than the inner diameter of the bush 25, so that the needle 21 is restrained by the needle cover 26, and after the needle 21 is fixedly connected with the needle cover 26, the needle 21 does not fall out of the central through hole of the bush 25 and the valve shaft portion 22. Further, the needle 21 and the magnetic rotor assembly 27 are connected in a floating manner, and when the 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 needle 21 and the valve shaft portion 22 can move relative to each other within a limited range. Since the first shaft-like portion 21c of the needle is in clearance fit with the second through-hole portion 22d of the valve shaft portion 22 and the second shaft-like portion 21d is also in clearance fit with the center through-hole of the bush 25, the needle 21 can also rotate relative to the valve shaft portion 22 in the circumferential direction.

It should be noted that, in the present embodiment, the needle 21 can be roughly divided into a three-step shaft-like structure except the needle point adjusting portion 21a from the appearance, wherein the outer diameter of the needle section where the needle guiding portion 21b is located is the largest, the outer diameter of the needle section where the first shaft-like portion 21c is located is slightly smaller, and the outer diameter of the needle section where the second shaft-like portion 21d is located is the smallest, but this is just one specific example convenient for processing, and on this basis, various equivalent structural modifications or substitutions can be made. For example, as for the needle guide portion 21b, since the nut is fixed to the valve seat, the needle can move up and down in the axial direction, that is, the needle can move up and down relative to the nut and has a certain stroke, it is only required to ensure that a relatively smooth needle guide portion 21b for forming a guiding effect with the first guide portion 12a of the nut is arranged on the outer edge of the needle in the stroke, and it is not required that the whole segment of the outer edge of the needle with the largest outer diameter as shown in the embodiment is used as the needle guide portion, in other words, a groove or other uneven structure is completely arranged on the outer edge of the relatively upper portion or the relatively lower portion of the needle segment corresponding to the needle guide portion 21b, and it is only required to ensure that a segment of the needle guide portion 21b is always matched with the first guide portion 12a of the nut to realize the guiding effect in the stroke of the needle. In addition, the first shaft-shaped portion 21c and the second shaft-shaped portion 21d are not limited to be cylindrical shaft-shaped structures with equal diameters, for example, one more shaft-shaped step is provided on the first shaft-shaped portion 21c or the second shaft-shaped portion 21d, and such equivalent technical feature changes obviously also belong to the protection scope of the present application.

In addition, the valve needle guide, the first shaft, and the second shaft described herein are named after their roles in the present disclosure, and it is not mechanically understood or limited that the valve needle can only be assembled from three shafts as shown in fig. 4. Alternatively, the valve pin 21 may be formed in a segmented assembly, such as by screwing or welding between adjacent segments. Indeed, as noted above, the illustrated structure is merely one embodiment that facilitates processing.

The needle structure that this embodiment provided, second axle form portion, the external diameter of first axle form portion and needle guide part place needle section increases in proper order, it is relatively convenient to make, the axiality is relatively better, and second axle form portion can enclose into a space that is used for holding compression spring with valve shaft portion and bush, make compression spring's external diameter no longer receive the restraint of the external diameter size of needle guide part, make the electronic expansion valve at the same specification, if have the same rotor diameter, the shell diameter, under the condition of stator coil diameter and volume, can directly increase the valve port latus rectum, in order to obtain the electronic expansion valve of bigger bore flow regulation.

A return spring 28 is fitted around the outer periphery of the needle cover 26, and a lower end of the return spring 28 abuts against the bushing 25 or an upper end surface of the valve shaft portion 22, and a specific abutting position may be determined according to a relative positional relationship between the bushing 25 and the valve shaft portion 22 and a diameter of the return spring 28. As shown in fig. 4, the bushing 25 may be disposed to be flush or substantially flush with the tip end of the valve shaft 22, and in this case, the return spring may be disposed to abut against the valve shaft 22, the bushing 25, or both the valve shaft 22 and the bushing 25. The height of the return spring 28 is greater than the distance between the valve needle hub 26 and the housing 30 so that the return spring 28 does not fall off the outer periphery of the valve needle hub 26.

The coil 40 of the electronic expansion valve receives a driving pulse signal to generate a periodically changing magnetic field, the magnetic rotor 27 is excited to rotate, the valve shaft portion 22 is fixedly connected with the connecting plate 272, so that the valve shaft portion 22 and the magnetic rotor 27 synchronously rotate, and the magnetic rotor 27 can move in the axial direction while rotating through a screw feeding mechanism between the valve shaft portion and a nut, so as to drive the valve needle 21 to move in the axial direction, so that the needle point adjusting portion 21a of the valve needle 21 is close to or far away from the valve port 113a, and thus, the linear on-off adjustment function of the flow of the electronic expansion valve is realized. When the needle point regulating portion 21a moves downward to abut against the valve port portion 113, that is, the needle point regulating portion 21a is at the lowermost end of its stroke, the electronic expansion valve is in a fully closed state, as shown in fig. 1. When the needlepoint regulating part 21a is at a position far from the valve port part 113, the electronic expansion valve is in an open state, and fig. 2 is a sectional view showing the electronic expansion valve at about 80% opening degree. When the magnetic rotor assembly 27 continues to rotate upward in the valve opening direction from the state shown in fig. 2 until the male screw portion 22c of the valve shaft portion comes off the female screw portion 12b of the nut 12 upward, the upper end of the return spring 28 is already in contact with the top wall of the housing 30, and the return spring 28 is in a compressed state. Since the screw feed mechanism between the valve shaft portion and the nut has been disengaged at this time, the magnetic rotor assembly 27 does not continue to move upward. When the valve closing operation is required, the magnetic rotor assembly 27 is rotated while being subjected to the downward spring force of the return spring 28, which causes the male threaded portion 22c of the valve shaft portion 22 to be again brought into thread engagement with the female threaded portion 12b of the nut, thereby ensuring the screw feeding mechanism to be reconfigured.

In the electronic expansion valve provided by the embodiment, the valve shaft portion includes the first through hole portion and the second through hole portion, and since the outer diameter of the valve needle guide portion is larger than the inner diameter of the second through hole portion of the valve shaft portion, under the condition that the electronic expansion valve with the same specification, such as the electronic expansion valve with the same rotor diameter, the same casing diameter, the same stator coil diameter and the same volume, the nominal diameter of the screw feeding mechanism can be realized only by slightly being larger than the outer diameter of the valve needle guide portion, that is, the nominal diameter of the screw feeding mechanism can be made relatively smaller, which is beneficial to reducing the frictional resistance from the screw feeding mechanism.

Second embodiment

A second embodiment of the present application will be described below with reference to fig. 5 to 9.

For convenience of explanation, the same reference numerals are used for components of the present embodiment that have substantially the same structure and function as those of the first embodiment, and only a brief explanation is made, so that those skilled in the art can understand the components by referring to the description of the first embodiment, and the present embodiment focuses on the differences from the first embodiment.

Referring to fig. 5 to 9, fig. 5 is a cross-sectional view illustrating the electronic expansion valve of the second embodiment in a closed state, fig. 6 is a cross-sectional view illustrating the electronic expansion valve of the second embodiment in an open state, fig. 7 is a structural view illustrating a nut assembly of the second embodiment, fig. 8 is a partial cross-sectional view illustrating the rotor assembly of the second embodiment engaged with the valve needle, and fig. 9 is a top view illustrating the nut assembly of the second embodiment.

The electronic expansion valve includes a valve body part and a coil part 40, wherein the valve body part includes a valve seat 11, a connector 50, and a housing 30, and the structure and the matching manner of the valve seat 11, the connector 50, and the housing 30 can refer to the description of the first embodiment.

The electronic expansion valve comprises a nut component 120, and the nut component 120 is fixedly connected with the valve seat 11. Specifically, the nut assembly 120 includes a nut 1201 and a connecting piece 1202, and the nut 1201 is fixedly connected to the connecting piece 1202. The nut 1201 has a through hole penetrating in the axial direction thereof, and a female screw portion 120b is provided on the inner wall of the through hole to form a screw feeding mechanism with a male screw portion 22c provided on the outer edge portion of the valve shaft portion 22. The valve shaft portion 22 is fixedly connected to the magnetic rotor assembly 27 so that the valve shaft portion 22 can rotate synchronously with the rotation of the magnetic rotor. The magnetic rotor assembly 27 is capable of rotating by inducing electromagnetic force of the electromagnetic coil, and includes a magnetic rotor 271 having magnetic poles in a circumferential direction and a connection plate 272 fixedly connected to or integrally provided with the magnetic rotor 271, and the connection plate 272 is fixedly connected to the valve shaft portion 22. An interference press fit connection or a rivet connection, or a welded connection of the coupling plate 272 to the valve shaft portion 22 may generally be used. The magnetic rotor assembly includes a movable stopper 20a, and in this embodiment, the movable stopper 20a may be a part of the connecting plate 272 and protrude in the axial direction toward the valve seat with respect to the connecting plate for performing a stopper function in cooperation with a fixed stopper provided on the nut.

As shown in fig. 8, the magnetic rotor assembly 27 is fixedly connected to the valve shaft 22 through the connecting plate 272, the magnetic rotor assembly drives the valve shaft 22 to rotate, the valve shaft 22 further drives the valve needle 21 to rotate, and the valve needle 21 can move relatively to the valve shaft 22 in the axial direction within a limited elastic displacement range and can also perform a relative rotational movement. The way of matching the valve shaft part 22 with the valve needle 21 can refer to the description related to the first embodiment, and is not described in detail here.

The basic principle of the electronic expansion valve is that the coil 40 receives a driving pulse signal to generate a periodically changing magnetic field, the magnetic rotor 27 is excited to rotate, the valve shaft portion 22 is fixedly connected with the connecting plate 272, so that the valve shaft portion 22 and the magnetic rotor 27 rotate synchronously, and the magnetic rotor 27 can move in the axial direction while rotating through the screw feeding mechanism between the valve shaft portion and the nut, so as to drive the valve needle 21 to move in the axial direction, so that the needle point adjusting portion 21a of the valve needle 21 is close to or far away from the valve port 113a, and thus the flow rate of the electronic expansion valve is linearly adjusted by opening and closing. The electronic expansion valve shown in fig. 5 is at the stop position of the fully closed state, i.e. the needle tip adjusting part 21a of the valve needle 21 is at the lowest end of the stroke, and the valve port 113a is at the fully closed state or at the set minimum opening state. The coil 40 drives the magnetic rotor to move downwards, and when the needlepoint adjusting part 21a is in a fully closed state or at the lowest stroke position, a stop mechanism needs to be arranged to limit and stop the stroke of the downward movement of the magnetic rotor assembly, so in the embodiment, a fixed stop part is arranged at the upper end part of the nut 1201, and a corresponding movable stop part 20a is arranged on the magnetic rotor assembly 27. When the electronic expansion valve is in a fully closed state, the movable stopping part 20a will abut against the corresponding mating surface of the fixed stopping part, thereby realizing the limit stop of the magnetic rotor assembly, the valve shaft part and the valve needle.

Fig. 6 is a sectional view showing an open state of the electronic expansion valve according to the present embodiment, in which the opening position is about 80% open. At this time, the needle tip regulating portion 21a of the needle 21 is positioned away from the valve port 113a, and the movable stopper 20a is also positioned away from the fixed stopper 120 d.

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

At least one convex rib is arranged on the outer circumference of the nut 1201, extends to the end face of the nut and protrudes out of the upper end face 1201d of the nut, and defines a part of the nut 1201 protruding out of the upper end face thereof as a stop protrusion, and the stop protrusion forms a fixed stop part of the electronic expansion valve. As shown in fig. 9, in the present embodiment, two ribs are provided on the outer edge portion of the nut 1201, one rib 1201a projects from the upper end surface of the nut, the rib projecting from the upper end surface of the nut forms at least a part of the stopper projection 1201c, and the upper end portion of the other rib 1201b is flush with the upper end surface 1201 d. The stopper projection 1201c is a fixed stopper constituting the electronic expansion valve, and when the width of the force receiving surface where the stopper projection 1201 can receive the collision of the movable stopper 20a is defined as K and the thickness of the nut at the upper end is defined as t, the following conditions are satisfied: k is more than t.

The nut 1201 has at least one rib provided on its outer periphery, and a rib extending and protruding over the end surface of the nut forms a stop protrusion. The stop lug boss is arranged at the end part of the convex rib close to the resin nut, and the projection (K-t) of the stop lug boss relative to the nut body in the radial direction is the same as the projection (K-t) of the convex rib relative to the nut body in the radial direction, so that the structure of the die pressing die can be simplified, and the upper and lower demoulding is convenient. Meanwhile, the convex ribs and the stop lug bosses are integrally formed in an injection molding mode, so that the strength of the stop lug bosses is enhanced, and the service life of the stop mechanism of the electronic expansion valve is prolonged. In particular, due to the provision of the rib, the strength of the stopper projection is greatly reduced in association with the material thickness of the nut body (near the upper end portion), that is, even if a thinner nut body thickness is employed, the strength of the stopper mechanism is not greatly affected, so that the use amount cost of the resin material can be further reduced. In addition, generally, the more the resin nut base material is, the greater the thickness is, the higher the probability of the generation of the air holes in the interior due to injection molding is, and the nut structure provided by the embodiment can relatively adopt less resin on the premise of ensuring the strength of the stop lug boss, reduce the possibility of the generation of the air holes and improve the dimensional accuracy and dimensional consistency of the resin nut.

It should be noted that, in the present embodiment, the structure of the nut is mainly described in detail, and the structure of the magnetic rotor assembly matched with the structure of the nut only needs to satisfy that the magnetic rotor assembly is provided with a protruding portion on a side facing the nut as a movable stopping portion capable of abutting against a fixed stopping portion provided on the nut to realize stopping, and as to which structure the movable stopping portion specifically adopts, the implementation of the present embodiment is not affected, and it should be understood by those skilled in the art that all magnetic rotor assemblies satisfying the structure can be applied to the present embodiment. Any possible configuration of components such as valve seats, valve needles, valve shaft portions, etc. may be used to create more electronic expansion valve embodiments.

Third embodiment

A third embodiment of the present application will be described below with reference to fig. 10 to 14.

Referring to fig. 10-14, fig. 10 is a cross-sectional view illustrating a closed state of an electronic expansion valve according to a third embodiment, fig. 11 is a cross-sectional view illustrating an open state of the electronic expansion valve according to the third embodiment, fig. 12 is a structural view illustrating a nut assembly according to the third embodiment, fig. 13 is a structural view illustrating a valve shaft portion and a stopper according to the third embodiment, and fig. 14 is a structural view illustrating a magnetic rotor assembly, a valve shaft portion, a valve needle, and a stopper according to the third embodiment.

The electronic expansion valve comprises a nut component 12, and the nut component 12 is fixedly connected with the valve seat 11. Specifically, the nut assembly 12 includes a nut 121 and a connecting piece 122, and the nut 121 and the connecting piece 122 are fixedly connected. As a specific embodiment, the nut 121 may be injection molded by using a non-metal material such as a resin material, and specifically, the connecting piece 122 may be inserted into a cavity of a mold, and the resin nut 121 may be molded by using resin injection molding through an injection molding machine, and a portion of the connecting piece 122 is not covered by the nut. The nut can be made of PPS modified resin, PEEK modified resin, PTFE modified resin or the like. The nut component 12 is fixedly connected with the valve seat 11. Specifically, the portion of the connecting piece 122 that is not covered by the nut is fixed to the valve seat 11 by welding or riveting, and the nut 121 may be inserted into the upper end opening of the valve seat 11 by press-fitting. The nut 121 has a through hole penetrating in the axial direction thereof, and a female screw portion 12b is provided on the inner wall of the through hole to form a screw feeding mechanism with a male screw portion 22c provided on the outer edge portion of the valve shaft portion 22. The valve shaft portion 22 is fixedly connected to the magnetic rotor assembly 27 so that the valve shaft portion 22 can rotate synchronously with the rotation of the magnetic rotor. The magnetic rotor assembly 27 is capable of rotating by inducing electromagnetic force of the electromagnetic coil, and includes a magnetic rotor 271 having magnetic poles in a circumferential direction and a connection plate 272 fixedly connected to or integrally provided with the magnetic rotor 271, and the connection plate 272 is fixedly connected to the valve shaft portion 22. An interference press fit connection or a rivet connection, or a welded connection of the coupling plate 272 to the valve shaft portion 22 may generally be used. The top outer edge of the nut 121 is provided with a fixed stop portion 12d, and the fixed stop portion 12d at least partially protrudes from the upper end surface of the nut 121, or the fixed stop portion 12d at least partially protrudes from the annular base body of the nut in the axial direction.

As shown in fig. 14, the magnetic rotor assembly 27 is fixedly connected to the valve shaft 22 through the connecting plate 272, the magnetic rotor assembly drives the valve shaft 22 to rotate, the valve shaft 22 further drives the valve needle 21 to rotate, and the valve needle 21 can move relatively in the axial direction within a limited elastic displacement range relative to the valve shaft 22, and can also perform relative rotational movement. The way of matching the valve shaft part 22 with the valve needle 21 can refer to the description related to the first embodiment, and is not described in detail here.

The valve shaft 22 is a substantially hollow cylindrical member, and includes a large diameter portion 221 and a small diameter portion 222. The fitting relationship of the valve shaft portion 22 with the bush 25, the nut 12, and the needle 21 can be referred to the description of the first embodiment.

The basic principle of the electronic expansion valve is that the coil 40 receives a driving pulse signal to generate a periodically changing magnetic field, the magnetic rotor 27 is excited to rotate, the valve shaft portion 22 is fixedly connected with the connecting plate 272, so that the valve shaft portion 22 and the magnetic rotor 27 rotate synchronously, and the magnetic rotor 27 can move in the axial direction while rotating through the screw feeding mechanism between the valve shaft portion and the nut, so as to drive the valve needle 21 to move in the axial direction, so that the needle point adjusting portion 21a of the valve needle 21 is close to or far away from the valve port 113a, and thus the flow rate of the electronic expansion valve is linearly adjusted by opening and closing. The electronic expansion valve shown in fig. 10 is at the stop position of the fully closed state, i.e. the needle tip adjusting part 21a of the valve needle 21 is at the lowest end of the stroke, and the valve port 113a is at the fully closed state or at the set minimum opening state. The coil 40 drives the magnetic rotor to move downwards, and when the needle point adjusting part 21a is in a full-closed state or at the lowest end position of the stroke, a stop mechanism needs to be arranged to perform limit stop on the stroke of the downward movement of the magnetic rotor assembly.

In the present embodiment, a stopper 33 is further included, and the stopper 33 is fixedly connected to the valve shaft portion 22 directly or indirectly. The indirect connection means that the stopper 33 is fixedly connected to the valve shaft 22 by other members. The stopper 33 is formed by press-bending a metal plate, and has a ring-shaped main body, and at least a part of the material is bent in the axial direction to form a movable stopper 33 a. Specifically, a complete ring-shaped metal plate material may be cut at any position, and then one of the end portions may be bent toward the axial direction to form the movable stopper portion 33 a. As an alternative, it is also possible to fix the movable stopper portion and the stopper by welding or the like, instead of bending the annular stopper, and to project the movable stopper portion in the axial direction of the stopper.

For positioning convenience, in the present embodiment, the valve shaft portion 22 is provided with the annular convex ring portion 223 at the outer edge of the large diameter portion 221, so that the connecting plate 272 can be positioned by the upper surface of the convex ring portion 223, and at least a part of the stopper 33 can be positioned by the lower surface of the annular convex ring portion 223, so that the mounting position of the stopper 33 on the valve shaft portion 22 can be accurately positioned. Of course, the protruding ring portion 223 is not necessarily provided, and actually, the relative position of the stopper 33 and the valve shaft portion 22 may be accurately limited by using a tool positioning method. The valve shaft portion 22 and the stopper 33 may be fixedly connected by welding, or may be fixedly connected by another method such as caulking. The stop member 33 is fixedly connected to the valve shaft portion 22, and the valve shaft portion 22 is fixedly connected to the magnetic rotor assembly 27, so that the stop member 33 follows the magnetic rotor assembly 27 to rotate synchronously. When the electronic expansion valve is in a fully closed state, or the needle point adjusting portion 21a of the valve needle 21 of the electronic expansion valve is in a minimum opening degree set by the electronic expansion valve, the movable stop portion 33a bent downward by the stopper 33 collides with the fixed stop portion 12d provided at the upper end of the nut component 12, thereby realizing stop limit of the magnetic rotor component, as shown in fig. 10. When the magnetic rotor assembly is rotated in the opposite direction, the stopper 33 is displaced upward, and the movable stopper 33a is moved upward and disengaged from the fixed stopper 12d, as shown in fig. 11. Fig. 11 is a sectional view showing an open state of the electronic expansion valve according to the present embodiment, in which the opening position is about 80% open. At this time, the needle tip regulating portion 21a of the needle 21 is positioned away from the valve port 113a, and the movable stopper 33a is also positioned away from the fixed stopper 12 d.

According to the electronic expansion valve provided by the embodiment, the nut material is injection molded by PPS (polyphenylene sulfide) resin or PEEK (polyether-ether-ketone) resin or PTFE (polytetrafluoroethylene) resin, the upper end part of the resin nut is integrally injection molded to fix the stop part, the stop part can be formed by punching a metal plate, the processing technology of parts is relatively good, the stop part made of metal has better wear resistance, the service life of the stop mechanism can be prolonged, and the production cost is relatively low.

Fourth embodiment

A fourth embodiment of the present application will be described below with reference to fig. 15 to 16.

The present embodiment differs from the third embodiment in the movable stopper, and therefore the present embodiment will be described mainly with respect to the structure of the movable stopper. The remaining components may be understood with reference to the first and third embodiments.

Referring to fig. 15 and 16, fig. 15 is a schematic view of a connection plate structure provided in the fourth embodiment of the present application, and fig. 16 is a partial sectional view of a structure for engaging a magnetic rotor assembly with a valve shaft portion, a valve needle, and the like provided in the fourth embodiment of the present application. Fig. 15 is a schematic view of the connector plate from a bottom view, based on the orientation shown in fig. 16. In the present embodiment, the connecting plate 272 may be formed by die pressing and sintering metal powder, and has a substantially plate-shaped structure with a central through hole, and the inner wall 2721 of the central through hole is used for fixing the valve shaft 22, and may be generally formed by interference press-fit connection, riveting connection, or welding connection of the rotor connecting plate 33 and the screw 32. In order to increase the contact area between the connection plate and the valve shaft, the height of the inner wall 2721 may be increased to a level higher than the thickness of the connection plate body, so that the connection plate has a substantially L-shaped longitudinal section. As described in the first embodiment, the connection plate 272 and the magnetic rotor 271 may be fixedly connected by injection molding, that is, the magnetic rotor 271 is formed by placing the connection plate as an insert in a mold cavity and injecting a magnetic material, so that the plate-shaped outer edge portion 2723 of the connection plate 272 is covered with the magnetic material. The movable stopper 2722 is provided on the side of the connecting plate 272 facing the valve port, that is, the movable stopper 2722 protrudes from the surface of the connecting plate, and specifically, the movable stopper 2722 may be integrally molded by die pressing and sintering with a base of the connecting plate using metal powder. Of course, as an alternative manufacturing method, metal powder can be molded into a blank by injection molding through a die and then formed by winding.

When the magnetic rotor 271 is excited to rotate, the connecting plate 272 and the valve shaft 22 rotate in synchronization, and the valve shaft 22 rotates the needle 21 and other components provided inside the valve shaft. The valve needle 21 is sleeved in an inner hole of the valve shaft part 22, and the valve needle 21 is elastically connected with the valve shaft part 22. The valve needle 21 is relatively movable in the axial direction within a limited elastic displacement range with respect to the valve shaft portion 22, and is also relatively rotatable.

When the electronic expansion valve is in a fully closed state or the needle tip adjusting part of the valve needle of the electronic expansion valve is in a set minimum opening degree of the electronic expansion valve, the downward rotation stroke of the magnetic rotor assembly needs to be stopped and limited, and at this time, the movable stopping part 2722 protruding downwards of the connecting plate 272 abuts against the fixed stopping part 12d arranged at the upper end of the nut, so that the stopping and limiting effects are realized. When the magnetic rotor assembly rotates in the valve opening direction, the movable stopper 2722 rotates with the rotor member and displaces upward, and is disengaged from the fixed stopper 12 d.

Fifth embodiment

A fifth embodiment of the present application will be described below with reference to fig. 17 to 26.

The present embodiment is a further improvement of the first embodiment. Components of this embodiment that are substantially identical in structure and function to components of the first embodiment have been given the same reference numerals, and will only be briefly described, so that a person skilled in the art can understand the components by referring to the description of the first embodiment.

Fig. 17 is a schematic view of a fifth embodiment electronic expansion valve in a fully closed state at a stop position, fig. 18 is an enlarged view of a portion I in fig. 17, fig. 19 is an enlarged view of a portion II in fig. 17, fig. 20 is a cross-sectional view of the fifth embodiment electronic expansion valve at a spring force relief point, fig. 21 is an enlarged view of a portion III in fig. 20, fig. 22 is an enlarged view of a portion IV in fig. 20, fig. 23 is a cross-sectional view of the fifth embodiment electronic expansion valve at an opening threshold point, fig. 24 is an enlarged view of a portion V in fig. 23, fig. 25 is an enlarged view of a portion VI in fig. 23, and fig. 26 is a cross-sectional view of the fifth embodiment electronic expansion valve in a fully open state.

The electronic expansion valve comprises a valve body component and a coil component 40, wherein the valve body component comprises a valve seat 11, a connecting piece 50 and a shell 30, and the structures and matching modes of the valve seat 11, the connecting piece 50, the shell 30 and a nut 12 can refer to the description of the first embodiment. The valve seat 11 includes a valve port portion 113, a first port portion 111, and a second port portion 112, and defines a direction in which the refrigerant flows into the electronic expansion valve from the first port portion 111, flows out of the second port portion 112 through the valve port as a first flow direction, and defines a direction in which the refrigerant flows into the electronic expansion valve from the second port portion 112, and flows out of the first port portion 111 through the valve port as a second flow direction. The present embodiment will be described by taking the first flow direction as an example.

The electronic expansion valve comprises a nut component 12, and the nut component 12 is fixedly connected with the valve seat 11. The nut component 12 includes a nut 121 and a connecting piece 122, and the nut 121 is fixedly connected with the connecting piece 122. The nut 121 has a through hole penetrating in the axial direction thereof, and a female screw portion 12b is provided on the inner wall of the through hole to form a screw feeding mechanism together with a male screw portion 22c provided on the outer edge portion of the valve shaft portion 22. The inner side wall of the nut is further provided with a first guide portion 12a, the first guide portion 12a is arranged below the inner threaded portion 12b and can provide a guiding centering effect in the circumferential direction for the valve needle 21, the valve needle 21 comprises a valve needle guide portion 21b, namely, the first guide portion 12a and the valve needle guide portion 21b are in small clearance fit, and the valve needle 21 can rotate or move up and down along the first guide portion 12a of the nut under the driving of the valve shaft portion 22. The first guide portion 12 is a portion provided on the inner wall of the nut, and the needle guide portion 21b is a portion provided on the outer edge of the needle. The second guide portion 12c is provided on the inner side wall of the nut at a position opposite to the upper portion, and can provide a circumferential guide centering action to the valve shaft portion 22. The valve shaft guide 22b is disposed on the outer edge of the valve shaft 22, the valve shaft guide 22b is in close clearance fit with the second guide 12c, and the valve shaft 22 can rotate or move up and down along the second guide 12c under the driving of the magnetic rotor assembly. The first guide portion 12a and the second guide portion 12c are parts of the inner wall of the nut through hole, and the shape of the nut outer edge portion and the arrangement position of the connecting piece 122 on the nut outer edge portion do not affect the arrangement of the first guide portion and the second guide portion.

The top outer edge of the nut 121 is provided with a fixed stop part 12d, and the fixed stop part 12d at least partially protrudes from the upper end face of the nut 121 and is matched with a movable stop part 20a arranged on the magnetic rotor assembly so as to realize the stop of the magnetic rotor assembly. The movable stopper 20a and the fixed stopper 12d of the present embodiment are the same as those of the first embodiment, but it goes without saying that the movable stopper can be completely configured as in the third embodiment or the fourth embodiment, and the fixed stopper can be completely configured as in the second embodiment. When the magnetic rotor assembly moves down to the lowest end of the stroke, the movable stop 20a can abut against the fixed stop 12d so that the magnetic rotor assembly can no longer continue to rotate, thereby controlling the stroke of the downward movement of the magnetic rotor components.

The magnetic rotor assembly 27 is capable of rotating by inducing electromagnetic force of the electromagnetic coil, and includes a magnetic rotor 271 having magnetic poles in a circumferential direction and a connection plate 272 fixedly connected or integrally provided with the magnetic rotor 271. The valve shaft 22 is a substantially hollow cylindrical member, and includes a large diameter portion 221 and a small diameter portion 222. The valve shaft portion 22 is fixedly connected to the connecting plate 272. A part of the outer edge of the large diameter portion 221 is formed as a rotor fixing portion 22a for fixedly coupling with the connection plate 272 of the magnet rotor assembly 27, and another part of the outer edge of the large diameter portion 221 is formed as a valve shaft guide portion 22b for small clearance-fitting with the second guide portion 12c of the nut, thereby achieving guiding. The rotor fixing portion 22a is located relatively above the valve shaft guide portion 22b, and the valve shaft guide portion 22b is located substantially in a space surrounded by the magnetic rotor 271. The small diameter portion 222 is provided at its outer edge portion with an external thread portion 22c for forming a screw feeding mechanism with an internal thread portion 12b provided in the nut. The valve shaft portion 22 includes a first through hole portion 22e and a second through hole portion 22d, wherein the first through hole portion 22e substantially corresponds to the inner hole portion of the large diameter portion 221, and the second through hole portion 22d substantially corresponds to the inner hole portion of the small diameter portion 222, so that the inner diameter of the first through hole portion 22e is larger than that of the second through hole portion 22d, and a step portion 22f is formed between the first through hole portion 22e and the second through hole portion 22 d.

The bush 25 is fixedly connected to the valve shaft portion 22, the bush 25 is substantially hollow and cylindrical, and at least a part of an outer edge of the bush 25 is fitted to at least a part of an inner edge of the first through hole portion 22 e. The large diameter portion 221 of the valve shaft 22 and the bushing 25 form a space, the compression spring 24 is located in the space, the upper end of the compression spring 24 abuts against the bottom end of the bushing 25, and the abutment described herein may be direct abutment or indirect abutment, for example, a gasket is provided between the spring and the bushing to realize indirect abutment. The other end of the compression spring 24 abuts against the washer portion 23. The washer portion 23 has one end abutting against the compression spring 24 and the other end abutting against the needle 21.

The valve needle 21 is arranged in a central channel defined by the bushing 25, the valve shaft portion 22 and the nut 12, and the compression spring 24 is sleeved on the periphery of part of the outer edge of the valve needle 21. The valve needle 21 is integrally rod-shaped and has multiple different outer diameters, the bottom end of the valve needle 21 is a needle point adjusting part 21a, the valve needle 21 comprises a valve needle guide part 21b which is used for being in small clearance fit with the first guide part 12a of the nut, and in the rotating process of the magnetic rotor, the first guide part 12a of the nut provides a guide centering effect in the circumferential direction for the valve needle 21. Similar to the first embodiment, it is only necessary to ensure that the valve needle is provided with a relatively smooth valve needle guiding portion 21b at the outer edge for guiding with the first guiding portion 12a of the nut during the stroke of the valve needle. The needle 21 includes a spacer abutting portion 21e for abutting against the spacer 23 so that the spacer 23 does not displace downward in the direction of the center axis of the needle after abutting against the needle. A first shaft-shaped portion 21c and a second shaft-shaped portion 21d are respectively provided above the needle guide portion of the needle 21, wherein the outer diameter of the first shaft-shaped portion 21c is larger than the outer diameter of the second shaft-shaped portion 21d, and the outer diameter of the first shaft-shaped portion 21c is smaller than the outer diameter of the needle at the needle guide portion. In this way, a step is formed between the first shaft-shaped portion 21c and the second shaft-shaped portion 21d, and this step may be a specific example of the spacer abutting portion 21e, and the lower end surface of the spacer 23 abuts against the spacer abutting portion 21e, but in the present embodiment, if the number of the spacers 23 is 2, the spacer positioned on the lower side abuts against the spacer abutting portion 21e, the compression spring 24 is attached to the upper portion of the spacer 23, that is, the lower end of the compression spring 24 abuts against the spacer 23, and the upper end of the compression spring 24 abuts against the bottom end of the bush 25. The washer 23 and the compression spring 24 are accommodated in a space defined by the large diameter portion of the valve shaft portion 22 and the bush 25. Specifically, during assembly, the valve needle 21 is inserted into the central through hole of the valve shaft 22 from the lower direction shown in fig. 4, so that the first shaft-shaped part is inserted into the through hole of the small-diameter part 222 of the valve shaft and can move with respect to the second shaft-shaped part; the second shaft-shaped portion 21d is inserted through the central through hole of the bushing 25 and is inserted through the upper end surface of the bushing 25. The upper end portion of the second shaft-shaped portion 21d is fitted and fixed with the needle cover 26, and the outer diameter of the needle cover 26 is larger than the inner diameter of the bush 25, so that the needle 21 is restrained by the needle cover 26, and after the needle 21 is fixedly connected with the needle cover 26, the needle 21 does not fall out of the central through hole of the bush 25 and the valve shaft portion 22. Further, the needle 21 and the magnetic rotor assembly 27 are connected in a floating manner, and when the 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 needle 21 and the valve shaft portion 22 can move relative to each other within a limited range. Since the first shaft-like portion 21c of the needle is in clearance fit with the second through-hole portion 22d of the valve shaft portion 22 and the second shaft-like portion 21d is also in clearance fit with the center through-hole of the bush 25, the needle 21 can also rotate relative to the valve shaft portion 22 in the circumferential direction.

It should be noted that, similarly to the first embodiment, the needle guide portion, the first shaft-shaped portion, and the second shaft-shaped portion are named after their functions in the present embodiment, and it cannot be understood mechanically or limited that the needle can be combined only by the three-segment shaft-shaped portion shown in fig. 4. Alternatively, the valve pin 21 may be formed in a segmented assembly, such as by screwing or welding between adjacent segments. Indeed, as noted above, the illustrated structure is merely one embodiment that facilitates processing.

The coil 40 of the electronic expansion valve receives a driving pulse signal to generate a periodically changing magnetic field, the magnetic rotor 27 is excited to rotate, the valve shaft portion 22 is fixedly connected with the connecting plate 272, so that the valve shaft portion 22 and the magnetic rotor 27 synchronously rotate, and the magnetic rotor 27 can move in the axial direction while rotating through a screw feeding mechanism between the valve shaft portion and a nut, so as to drive the valve needle 21 to move in the axial direction, so that the needle point adjusting portion 21a of the valve needle 21 is close to or far away from the valve port 113a, and thus, the linear on-off adjustment function of the flow of the electronic expansion valve is realized. The electronic expansion valve shown in fig. 17 is at the stop position of the fully closed state, i.e. the needle tip adjusting portion 21a of the valve needle is at the lowest end of the stroke, and the valve needle is in contact with the valve port portion 113, and the valve port 113a is in the fully closed state. When the magnetic rotor assembly 27 continues to rotate upward in the valve opening direction from the state shown in fig. 17 until the male screw portion 22c of the valve shaft portion comes off the female screw portion 12b of the nut 12 upward, the upper end of the return spring 28 is already in contact with the top wall of the housing 30, and the return spring 28 is in a compressed state. Since the screw feed mechanism between the valve shaft portion and the nut has been disengaged at this time, the magnetic rotor assembly 27 does not continue to move upward. When the valve closing operation is required, the magnetic rotor assembly 27 is rotated while being subjected to the downward spring force of the return spring 28, which causes the male threaded portion 22c of the valve shaft portion 22 to be again brought into thread engagement with the female threaded portion 12b of the nut, thereby ensuring the screw feeding mechanism to be reconfigured.

Referring to fig. 18 and 19, fig. 18 is an enlarged view of a portion I in fig. 17, and fig. 19 is an enlarged view of a portion II in fig. 17. Fig. 17 shows the stop position of the electronic expansion valve in the fully closed state, i.e. the position where the movable stop portion 20a just hits the fixed stop portion 12d, and the needle point adjusting portion 21a of the valve needle 21 is at the lowest end of the stroke, and the valve needle abuts against the valve port portion 113. As shown in fig. 19, the valve needle 21 receives the spring force from the compression spring 24 transmitted downward in the figure through the gasket 23, and the spring force is transmitted to the valve port portion 113 through the valve needle 21 to a portion in contact with the valve needle. In the present embodiment, the number of the spacers is 2, the spacer 23 includes a first spacer 231 and a second spacer 232, and the first spacer 231 is positioned above the second spacer 232 with reference to the diagram of fig. 17, and the first spacer 231 and the second spacer 232 are in contact with each other. As an alternative embodiment, the number of the spacers may be 1, or may be 2 or more.

The upper end of the compression spring 24 abuts against the lower end of the bushing 25, the lower end of the compression spring abuts against the upper end surface of the first shim 231, and the lower end of the second shim 232 abuts against the shim abutment portion 21e of the valve needle 21, at this time, the lower end surface of the second shim 232 is a certain distance k away from the valve shaft stepped portion 22f of the valve shaft portion 22, and it can also be understood that the second shim 232 can also generate a displacement amount of k toward the lower side of the figure. At this time, the spring force of the compression spring 24 is transmitted through the gasket 23 and the needle 21, and finally acts on the seal portion of the valve port portion, which is in contact with the needle.

The upper end of the valve needle 21 is sleeved and fixed with a valve needle sleeve 26, the lower end of the valve needle sleeve 26 has a certain distance h from the upper end of the bushing 25, and the following requirements are met: h is more than k. As shown in fig. 19, the outer diameter of the needle sleeve 26 of the present embodiment is smaller than the outer diameter of the bush 25. It will be appreciated by those skilled in the art that the outer diameter of the needle sleeve 26 may alternatively be arranged larger than the outer diameter of the bushing 25, in which case, when the valve shaft portion 22 is higher in the axial direction than the bushing 25, the needle sleeve 26 will in any case not interfere with the bushing 25, but will interfere with the valve shaft portion 22 when moving downwards. H at this time is the distance from the lower end of the needle hub 26 to the upper end of the valve shaft 22.

At the starting point of the state shown in fig. 17, the magnetic rotor assembly 27 is driven to rotate upward by the excitation of the stator coil 40, the movable stopper 20a starts to rotate away from the fixed stopper 12d, the magnetic rotor assembly 27 is displaced upward in synchronization with the valve shaft 22 by the screw feeding mechanism, and the electronic expansion valve is at the spring force unloading point when the lifting height is just k.

Referring to fig. 20-22, fig. 20 is a sectional view of the fifth embodiment of the electronic expansion valve at a spring force unloading point; FIG. 21 is an enlarged view of section III of FIG. 20; fig. 22 is an enlarged view of the portion IV of fig. 20.

At this time, the distance between the lower end of the second shim 232 and the valve shaft stepped portion 22f of the valve shaft portion is 0, that is, the spring force of the compression spring 24 is transferred from the shim contact portion 21e acting on the valve needle 21 shown in fig. 17 to the valve shaft stepped portion 22f acting on the valve shaft portion 22 shown in fig. 20 by the transmission of the shim 23, that is, 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, the lower end of the needle hub 26 is now at a distance h-k from the upper end of the bushing 25. Of course, in the case where the outer diameter of the needle hub 26 is set larger than the outer diameter of the bush 25, the lower end portion of the needle hub 26 is also located at a distance h-k from the upper end portion of the valve shaft portion 22.

From the fully closed state shown in fig. 17 to the spring force unloading point state shown in fig. 20, the upward displacement amount of the valve shaft portion 22 and the magnet rotor assembly 27 is k, and the upward displacement amount of the needle 21 is 0.

Based on the graph shown in fig. 20, the magnetic rotor assembly 27 is driven by the excitation of the stator coil 40 to rotate upwards, and under the conversion action of climbing of the screw feeder, the magnetic rotor assembly 27 and the valve shaft portion 22 are displaced upwards synchronously, and when the lifting height is h-k, the electronic expansion valve is at the opening critical point.

Referring to fig. 23-25, fig. 23 is a cross-sectional view of an electronic expansion valve of a fifth embodiment at an opening critical point; FIG. 24 is an enlarged view of the portion V of FIG. 23; fig. 25 is an enlarged view of the VI portion in fig. 23. At this time, the valve needle 21 is in a state of being in contact with the valve port portion 113, or it can be understood that the valve needle 21 can be separated from the valve port portion 113 as long as the valve needle 21 continues to be displaced upward. At this time, the lower end of the second shim 232 abuts against the valve shaft stepped portion 22f of the valve shaft 22, and the spring force of the compression spring 24 acts on the valve shaft stepped portion 22f through the transmission of the shim 23. As shown in fig. 24, at this time, the lower end portion of the needle cover 26 is at a distance of 0 from the upper end portion of the bush 25, that is, in the state from fig. 20 to fig. 23, the valve shaft portion 22 is displaced upward in synchronization with the rotor by h-k. At this point, the valve needle 21 is no longer subjected to the spring force transmitted by the compression spring 24, the spring force has been relieved from the valve needle 21, and the frictional force of the rotational movement of the valve needle 21 relative to the valve shaft portion 22 is significantly reduced. That is, at the moment when the valve needle contacts and separates from the valve port, the valve needle 21 is no longer subjected to the spring force of the compression spring 24, so that the friction impact force of relative rotation between the valve needle and the valve port can be reduced, thereby reducing the abrasion of the contact part between the valve needle and the valve port and prolonging the service life of the electronic expansion valve.

From the fully closed state shown in fig. 17 to the open limit state shown in fig. 23, the valve shaft portion 22 and the magnet rotor assembly 27 are displaced upward by an amount h, and the needle 21 is displaced upward by an amount 0.

Referring to fig. 26, fig. 26 is a sectional view of the electronic expansion valve of the fifth embodiment in a fully open state. At this time, the valve needle 21 is separated from the valve port portion 113, and in the operation process from fig. 23 to fig. 26, that is, in the process of the reciprocating operation of the electronic expansion valve from the opening limit point to the maximum opening degree, the valve needle 21 follows the valve shaft portion 22 to perform the lifting movement in the axial direction synchronously, and the valve needle 21 is not always subjected to the spring force of the compression spring 24, so that the friction force of the relative rotation between the valve needle 21 and the valve shaft portion 22 can be reduced, the abrasion between the valve needle guide portion 21b and the first guide portion 12a of the nut can be reduced, and the service life of the electronic expansion valve can be prolonged. From the opening limit point shown in fig. 23 to the fully open state shown in fig. 26, the relative position of the needle 21 and the valve shaft portion 22 in the axial direction is kept constant.

The electronic expansion valve is called from the spring force unloading point in fig. 20 to the opening critical point state shown in fig. 23, the upward displacement amount of the valve shaft portion 22 and the magnetic rotor assembly 27 is h-k, and the upward displacement amount of the valve needle 21 is 0. From the fully closed state shown in fig. 17 to the fully open state shown in fig. 26, the upward displacement of the valve shaft portion 22 and the magnetic rotor assembly 27 is L, and the upward displacement of the valve needle 21 is L-h.

In the present embodiment, the first shim and the second shim are both plate-shaped, and the bottom surface of the second through hole portion of the valve shaft portion (i.e., the valve shaft stepped portion) is also flat, so the marks of h and k in the drawings are also shown as the distance between the two flat surfaces in the axial direction, and actually, the contact portion of the shim or the second through hole portion is not limited to the contact of the two flat surfaces, but may be variously changed to, for example, the contact of two inclined surfaces in the axial direction, or the contact of other irregular shapes.

In the fifth embodiment, the first flow direction is taken as an example, and the fluid pressure of the first port is higher than the fluid pressure of the second port, so that the valve needle of the electronic expansion valve is always subjected to a downward differential pressure of the fluid medium in each of the above states.

In the state of the rotor component shown in fig. 26, the valve needle 21 is not acted on by the spring force generated by the compression spring 24, and when there is no pressure difference between the fluid in the first interface part and the fluid in the second interface part, the valve needle 21 is acted on by its own weight, that is, after the valve needle 21 is fixedly connected to the valve needle sleeve 26, the valve needle 21 has a certain movable gap in the axial direction relative to the valve shaft part 22 in the state of not being acted on by the spring force generated by the compression spring 24, and the gap is h-k, which is the same as the gap shown in fig. 25.

In the electronic expansion valve provided by the embodiment, the moment when the valve needle is in sealing contact with the valve port from the opening state to the closing state; and from closing to the open mode, the moment that the valve needle breaks away from valve port, the spring force of the compression spring is not applied to the valve needle, can reduce the relative rotatory friction impact force of two sealed positions, thus reduce the wearing and tearing of the contact position, improve the life of electronic expansion valve. In addition, in the reciprocating action process of the electronic expansion from the minimum opening degree to the maximum opening degree, the spring force of the compression spring is not applied to the valve needle all the time, the rotation friction force between the valve needle and the valve shaft part is reduced, the abrasion between the valve needle guiding part and the nut can be reduced, and the service life of the electronic expansion valve is further prolonged.

Sixth embodiment

Next, a sixth embodiment of the present application will be described with reference to fig. 27.

In the above five embodiments, the first connection port of the electronic expansion valve is connected with the first connection pipe 10b, and the second connection port is connected with the second connection pipe 10a, that is, the electronic expansion valve is connected with the refrigeration system in a connection pipe manner. In fact, the electronic expansion valve of the above embodiments may be applied to a plurality of fields, and the connection between the electronic expansion valve and the refrigeration system is not limited to the connection manner using the connection pipe. For example, when the valve seat is applied to occasions needing quick maintenance such as automobile air conditioners, the valve seat can be directly fixedly connected with the integrated valve body integrated with a plurality of channels without adopting the structures of the first connecting pipe and the second connecting pipe, for example, a flange sealing connection mode is adopted.

Referring to fig. 27, fig. 27 is a schematic structural view of an electronic expansion valve according to a sixth embodiment of the present invention. The present embodiment is an example in which an electronic expansion valve is applied to an automotive air conditioning system. The valve seat 11 and the connecting member 51a are fixed by welding and then fixedly connected as a whole to the valve body 80. Wherein the connecting piece 51a can be adaptively designed to a shape suitable for connection with the valve body. Specifically, the connecting member 51a may be fixedly connected to the valve body 80 by a flange seal (not shown), for example, by providing a screw hole at a disk-shaped portion of the connecting member, and then fixedly connecting the connecting member to the valve body by a screw connection. And a first seal 803 is provided before the connection with the valve body in order to ensure sealing performance. In addition, a second sealing element 804 is arranged between the valve seat 11 and the valve body 80, and after the assembly is completed, the connecting piece 51, the valve seat 11 and the valve body 80 are fixedly connected, and good sealing performance is kept.

The valve body 80 may be machined from metal and form a first interface end 801 and a second interface end 802, where the first interface end 801 and the second interface end 802 are used to connect with other components of the air conditioning system. Of course, the structure of the first interface end 801 and the second interface end 802 is not limited to that shown in fig. 27, and different layouts can be made according to the needs of the system. Therefore, when the electronic expansion valve needs to be disassembled for maintenance, the valve seat and the connecting piece of the electronic expansion valve can be conveniently separated from the valve body.

It should be noted that, the terms of orientation such as up, down, left, right, etc. mentioned herein are used as the reference for the drawings of the specification and are introduced for the convenience of description; and ordinal numbers such as "first", "second", etc. in the names of the components are also introduced for convenience of description, and do not imply any limitation on any order of the components, and since the functions of some parts between the components provided in the above-described embodiments are the same, the present specification adopts a uniform naming manner for these parts. The electronic expansion valve provided in the related art is described in detail above, and specific embodiments are used for illustration, and the description of the embodiments is only for assisting understanding of the method and the core idea of the present invention, and is not intended to limit the present invention in any way.

Claims

1. The electronic expansion valve is characterized by comprising a valve seat, a nut assembly, a valve shaft part, a valve needle and a movable stopping part, wherein the movable stopping part is directly or indirectly fixedly connected with the valve shaft part, the valve seat comprises a valve port part, the nut assembly is fixedly connected with the valve seat, the nut assembly comprises a nut and a connecting sheet, the nut comprises a first guide part, a second guide part, an internal thread part and a fixed stopping part, the first guide part is closer to the valve port part relative to the internal thread part, the second guide part is farther away from the valve port part relative to the internal thread part, and the movable stopping part can be abutted against the fixed stopping part;

2. The electronic expansion valve of claim 1, wherein the nut is injection molded from an engineering plastic, and at least a portion of the fixed stop portion protrudes from an end surface of the nut on a side opposite to the valve port portion.

3. The electronic expansion valve according to claim 2, wherein at least a part of the fixed stopper protrudes from an outer peripheral portion of the nut, and a width K of a force receiving surface of the fixed stopper, which is capable of colliding with the movable stopper, is larger than a thickness t of a side of the nut relatively distant from the valve port portion.

4. The electronic expansion valve according to any of claims 1-3, wherein at least one rib is provided on an outer circumferential portion of the nut, and the at least one rib extends and protrudes from an end surface of the nut on a side relatively away from the valve port, and the rib protruding from the end surface of the nut on a side relatively away from the valve port forms at least a part of the fixed stopper.

5. The electronic expansion valve according to claim 4, wherein the outer circumferential portion of the nut is provided with two ribs, one of the ribs extending and protruding from an end surface of the nut on a side relatively away from the valve port portion, the rib protruding from an end surface of the nut on a side relatively away from the valve port portion forming at least a part of the fixed stopper, and the other rib being not higher than the end surface of the nut on the side relatively away from the valve port portion.

6. The electronic expansion valve of claim 4, wherein the fixed stop portion protrudes in a radial direction from the body of the nut by an amount equal to that of the rib, which is injection molded as a unitary structure with the nut.

7. The electronic expansion valve of claim 1, wherein the first guide portion has an inner diameter smaller than an inner diameter of the second guide portion, the connecting piece at least partially protrudes from the nut, and the connecting piece is fixedly connected to the valve seat.

8. The electronic expansion valve according to claim 1, wherein the valve shaft 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 port portion relative to the small diameter portion, the male screw portion is provided at an outer edge portion of the small diameter portion, the valve shaft guide portion is provided at an outer edge portion of the large diameter portion, and an outer edge portion of the large diameter portion is provided with a rotor fixing portion.

9. The electronic expansion valve according to claim 1, wherein a nominal diameter of a thread of the screw feed mechanism is smaller than an inner diameter of the first through-hole portion, and the nominal diameter of the thread of the screw feed mechanism is slightly larger than an outer diameter of the needle guide portion.

10. The electronic expansion valve according to claim 1, wherein the electronic expansion valve comprises a connecting member, a first interface portion, a second interface portion, and a valve body, wherein the valve body is formed by cutting and comprises a first interface end and a second interface end, the valve seat is fixedly connected with the connecting member, the connecting member is connected with the valve body by a flange, a first sealing member is arranged between the connecting member and the valve body, and a second sealing member is arranged between the valve seat and the valve body.