CN110939775B - Electronic expansion valve - Google Patents

Abstract

The invention discloses an electronic expansion valve, which comprises a valve seat, a valve core seat, a reduction gear device, a supporting part, a nut component and a valve needle component, wherein the valve seat is fixedly connected with the valve core seat; at least part of the output gear is propped against and supported by the supporting table, the supporting table can provide axial supporting force for the output gear, and when the electronic expansion valve works, the phenomenon that the output gear deviates from the center can be reduced due to the fact that the output gear is supported on the supporting table, and further the operation reliability of the electronic expansion valve is relatively improved.

Description

An electronic expansion valve

Technical field

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

Background technique

The electronic expansion valve generally includes a valve body and coil components. The electronic expansion valve is equipped with a valve cavity. The valve cavity houses a reduction gear device, transmission components and valve needle assembly. The working principle of the electronic expansion valve is: after the coil is energized, an electromagnetic force will be generated. , drives the rotor to rotate. After the rotor rotation is decelerated by the transmission reduction mechanism, it is converted into linear motion by the transmission component and transmitted to the valve needle assembly, making the valve needle close to or away from the valve port to adjust the refrigerant flow flowing through the valve port. The reduction gear device includes an output gear. The output gear is equipped with an output shaft. The output shaft cooperates with the transmission components. The entire reduction gear device of this structure is carried by the output shaft. When the product is frequently operated, the output shaft is prone to damage. The eccentricity causes unreliable operation of the electronic expansion valve.

Contents of the invention

The purpose of the present invention is to provide an electronic expansion valve that can provide a certain support for the reduction gear device and relatively improve the operating reliability of the electronic expansion valve.

The invention provides an electronic expansion valve, which is provided with a valve chamber, including a valve seat, a valve core seat, a reduction gear device, a support component, a nut assembly and a valve needle assembly. The valve seat is fixedly connected to the valve core seat, so The valve core seat is provided with a valve port, the valve cavity is provided with the reduction gear device, the valve seat is provided with an accommodating cavity, at least part of the nut assembly and at least part of the valve needle assembly are located in the accommodating cavity, and the The support component includes a support platform and legs, and the legs are fixedly connected to the valve seat. The reduction gear device includes an output gear, which offsets at least part of the support platform and is supported by the support platform. The support platform is provided with a through hole, and the output gear is provided with an output shaft. The output shaft passes through the through hole and is connected to the screw rod of the nut assembly. The nut assembly includes a nut, and the valve needle assembly passes through The screw rod cooperates with the thread of the nut to perform axial lifting movement to approach or move away from the valve port.

Through the optimized design of the electronic expansion valve, the present invention makes at least part of the output gear offset and supported by the support platform. The support platform can provide axial support force for the output gear. When working, the output gear is supported on the support platform. It can reduce the occurrence of the deviation of the output shaft from the center, thereby relatively improving the operating reliability of the electronic expansion valve.

Description of the drawings

Figure 1 is a schematic structural diagram of an electronic expansion valve in an embodiment of the present invention;

Figure 2 is a partial structural diagram of the electronic expansion valve shown in Figure 1;

Figure 3 is a schematic structural diagram of the support component of the electronic expansion valve shown in Figure 1;

Figure 4 is a schematic structural diagram of an electronic expansion valve in another embodiment of the present invention;

Figure 5 is a schematic structural diagram of the support component of the electronic expansion valve shown in Figure 4;

Figure 6 is a schematic structural diagram of a valve seat in an embodiment of the present invention.

Among them, in Figure 1 to Figure 6:

Valve core seat 10, valve seat 20, small diameter shaft section 21, large diameter shaft section 22, liquid flow hole section 20a, guide hole section 20b, nut mounting hole section 20c, groove 23, annular peripheral wall 231, guide sleeve 24, Support component 30, support table 31, connecting surface 32, leg 33, through hole 3a, cylinder 34, valve needle 3-1, spring 3-2, screw rod 3-3, housing 40, coil 50, rotor 60, fixed Gear 70, output gear 80, external pipeline 100, external pipeline 200, gear housing 300, nut 301.

Detailed ways

In the existing technology, the output gear is usually in a suspended state. In this way, the gear reduction device is equivalent to exerting pressure on the output shaft as a whole. When actuating, it is easy to cause eccentricity of the output gear. As a result, the reliability of the entire gear reduction device is relatively low, which greatly affects the The working reliability of the electronic expansion valve and therefore the stability of the refrigeration system are poor.

In order to overcome the above-mentioned defects of the electronic expansion valve, this article conducted in-depth research and proposed a feasible technical solution, which is described in detail as follows.

In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Please refer to Figures 1 to 6. The present invention provides an electronic expansion valve, which is provided with a valve chamber. The electronic expansion valve includes a valve seat 20, a gear reduction device, a nut assembly 90, a valve needle assembly, a valve core seat 10, and a rotor 60. , housing 40 and coil component 50 and other main components. Among them, the valve core seat 10 is provided with a valve port, and the valve seat 20 is fixedly connected to the valve core seat 10 .

The gear reduction device in the present invention is located in the valve cavity, the valve seat 20 is provided with a first accommodation cavity and a second accommodation cavity, at least part of the nut assembly and at least part of the valve needle assembly are located in the first accommodation cavity, and the support component is located in the second accommodation cavity.

The support component of the present invention includes a support platform 31 and a support leg 33. The support leg 33 is fixedly connected to the valve seat 20. The reduction gear device includes an output gear 80. The output gear 80 offsets at least part of the support platform 31 and is supported by the support platform 31. The support platform 31 It is provided with a through hole, and the output gear is provided with an output shaft. The output shaft passes through the through hole and is connected to the screw rod 3-3 of the nut assembly. The nut assembly includes a nut 301. The valve needle assembly passes through the thread of the screw rod 3-3 and the nut 301. In cooperation with the action, the axial lifting movement is performed to approach or move away from the valve port. The reduction gear device may preferably be a planetary gear reduction device.

The valve needle assembly may specifically include a valve needle 3-1 and a spring 3-2, and the nut assembly may include a threaded screw rod 3-3 and a nut 301, wherein the valve needle 3-1 is connected to the lower end of the screw rod 3-3. , the screw rod 3-3 is threaded with the nut 301 installed on the valve seat. Of course, the screw rod 3 - 3 can also be integrated with the output shaft of the output gear 80 of the gear reduction device, that is, the thread is formed on the output shaft of the output gear 80 .

In order to ensure the coaxiality of the valve needle, a valve ball can also be provided between the screw rod 3-3 and the valve needle 3-1.

When the coil 50 is energized, it generates electromagnetic force to drive the rotor 60 to rotate. The rotating shaft of the rotor 60 is connected to the input shaft of the planetary gear reduction device. The output shaft of the planetary gear reduction device is connected to the screw rod 3-3 of the valve needle assembly. The power of the rotor 60 passes through the planetary gear. The gear reduction device then transmits it to the valve needle of the valve needle assembly through the screw rod 3-3. The screw rod 3-3 is threaded with the nut 301, and its main function is to convert the rotation of the rotor 60 into linear motion to realize the reciprocating motion of the valve needle 3-1 along the axial direction. In this way, by controlling the direction of the current in the coil 50, the valve needle 3-1 can move toward the valve port to block the valve port, or the valve needle 3-1 can move away from the valve port to open the valve port and control the opening of the valve port. .

The input gear of the planetary gear reduction device is connected to the rotor 60. The planetary gear reduction device usually includes a fixed gear 70 (ring gear), a sun gear (input gear) and at least one planetary gear. The input shaft of the sun gear is connected to the rotor 60. Finally, The output shaft of the first-stage planetary carrier is connected to the valve needle assembly and drives the valve needle 31 to reciprocate up and down to open or close the valve port.

The valve chamber has an upward opening, and the output shaft of the output gear 80 of the planetary gear reduction device passes through the opening to connect with the input end of the valve needle. The valve needle 3-1 of the valve needle assembly is connected to the lower end of the screw rod 3-3, and the screw rod 3-3 is threadedly matched with the nut 301 installed on the valve seat 20. Of course, the screw rod 3 - 3 can also be integrated with the output shaft of the output gear 80 of the planetary gear reduction device, that is, the thread is formed on the output shaft of the output gear 80 .

In order to ensure the coaxiality of the valve needle, a valve ball can also be provided between the screw rod 3-3 and the valve needle 3-1.

By optimizing the design of the electronic expansion valve, the present invention makes at least part of the output gear 80 offset and supported by the support platform 31. The support platform 31 can provide axial support force for the output gear. When working, the output gear Being supported on the support platform 31 can reduce the occurrence of the output shaft being offset from the center, thereby relatively improving the operating reliability of the electronic expansion valve.

In a specific implementation, the end surface of the output gear 80 facing the support platform 31 includes a contact part and a non-contact part. The output gear 80 is supported on the support platform 31 through the contact part, and the area of the contact part is smaller than the non-contact part. That is, under the premise of stable support, the contact area of the output gear 80 can be as small as possible to improve transmission performance.

In order to further reduce the axial length of the electronic expansion valve, the following settings can also be made.

In the above embodiments, the upper end surface of the valve seat 20 may be provided with a groove 23, the fixed gear 70 is supported on the end surface of the annular peripheral wall 231 of the groove 23, the opening is provided at the bottom of the groove 23, and the second accommodation cavity is the In the groove 23, the bottom surface of the supporting member 30 is supported on the bottom of the groove 23.

In this way, the support member 30 is installed inside the groove 23, which can minimize the increase in the axial length of the electronic expansion valve caused by adding the support member 30. By setting the depth of the groove 23 , the support member 30 can be completely located inside the groove 23 , that is, the height of the support member is less than or equal to the depth of the groove 23 .

That is to say, the support surface of the support member in contact with the output gear is at the same level as the upper end surface of the annular peripheral wall of the groove, or the support surface is lower than the upper end surface of the annular peripheral wall of the groove.

Two specific implementations of the support component 30 are given below, and see the following description for details.

In the first specific embodiment, the support component 30 also includes a connection surface 32 extending downward and outward from the periphery of the support platform 31 . The lower edge of the connection surface 32 has legs 33 evenly distributed around it. The upper surface of the support platform 31 It is a support surface that contacts and supports the output gear 80. The support member 30 is supported on the bottom of the groove through the legs; and the through hole of the support platform is coaxial with the output shaft and the gap between the two is within a predetermined range, so that the output shaft is on the predetermined axis. Move within the deviation range.

In this embodiment, the support platform and the connecting surface can enclose a certain space. This space not only provides installation space for the nut 301 installed below, but also the weight of the support component is relatively light, which is beneficial to minimizing the weight of the electronic expansion valve.

In another specific embodiment, the support member 30 includes a column 34. The upper end surface of the column 34 is a support platform, which contacts and supports the output gear 80. The lower edge of the column 34 has legs 33 evenly distributed around the circumference. The support member 30 It is supported on the bottom of the groove by the legs 33; the column 34 is provided with a through hole 30a for the output shaft to pass through. The through hole 30a is coaxial with the output shaft and the gap between the two is within a predetermined range, so that the output shaft can deviate in the predetermined axial direction. Action within range.

In this embodiment, the support component 30 has a relatively simple structure and is easy to process and shape.

In the above two embodiments, a suitable gap is set between the through hole 30a on the support member 30 and the output shaft. The through hole 30a can guide the output shaft and ensure that the output shaft moves in the axial direction as much as possible.

In the above embodiments, the planetary gear reduction device may also include a gear housing 300. The fixed gear 70 is fixedly installed on the gear housing 300. The gear housing 300 is located on the periphery of the output gear 80. The lower end of the gear housing 300 is directly supported and fixed on the gear housing 300. Valve seat 20.

In a specific implementation, the lower end opening of the gear housing 300 is circumferentially provided with a flange, and the gear housing 300 is supported on the valve seat through the flange. That is to say, the gear housing 300 is supported on the groove 23 through the flange. Setting flanges on the upper end surface of the annular peripheral wall 231 and the lower end of the gear housing 300 is beneficial to increasing the support area of the valve seat 20 and the gear housing 300 and increasing the support stability.

From top to bottom, the valve seat 20 includes an integrally formed nut mounting hole section 20c, a guide hole section 20b and a liquid flow hole section 20a; the nut mounting hole section 20c is used to install a nut that cooperates with the screw rod 3-3, that is to say , the nut 301 is installed inside the nut mounting hole section 20c, the screw rod 3-3 connected to the output shaft has an external thread part that matches the nut 301, the lower end of the screw rod 3-3 is connected to the valve needle, and the rotor 60 moves along a certain When the direction rotates, due to the thread interaction between the screw rod 3-3 and the nut 301, the screw rod 3-3 moves downward, and then the screw rod 3-3 can push the valve needle to move toward the valve port, and the valve needle 3-1 moves downward. At the same time, the spring 3-2 is compressed; when the rotor 60 rotates in the opposite direction, under the action of the thread pair, the screw rod 3-3 moves upward, and under the action of the restoring force of the spring 3-2, the valve needle also moves upward away from the valve port.

In the present invention, the valve seat 20 is processed into an integrated structure, which can greatly improve the assembly efficiency.

The guide hole section 20b is mainly used to install the spring 3-2 and guide the valve needle 31 to ensure that the valve needle is axially vertical and avoid eccentricity. The liquid flow hole section 20a is provided with a valve port, and the radial dimensions of the nut mounting hole section 20c and the liquid flow hole section 20a are both larger than the guide hole section 20b.

The valve cavity with the above structure is conducive to the assembly of various components in the valve cavity, and can reduce the processing difficulty of the valve cavity to a certain extent.

The closer the guide hole section 20b is to the valve port, the better the guiding performance of the valve needle 31 will be, but this will also affect the liquid flow rate of the liquid flow hole section 20a and the processing dimensions of the first port and the second port. Therefore, in order to take into account both the higher guideability and higher flow requirements of the valve needle 31, the following settings are made in this article.

In a specific embodiment, the lower edge of the guide hole section 20b extends downward to form a guide sleeve 24. The guide sleeve 24 is located inside the liquid flow hole section 20a, and the guide sleeve 24 is in contact with the circumferential direction of the liquid flow hole section 20a. There is space between the inner walls.

The guide sleeve 24 can be as close as possible to the valve port to guide the lower end of the valve needle to ensure that the valve needle moves in the axial direction as much as possible, and there is space in the circumferential direction between the guide sleeve 24 and the liquid flow hole section 20a, so as not to affect the interface setting as much as possible And try to reduce the space occupied by the liquid flow hole section 20a.

At the same time, the above arrangement can also reduce the height of the valve seat 20 .

In the above embodiments, the nut 301 can be completely located inside the nut mounting hole section 20c, and the upper end surface of the nut 301 is lower than the bottom of the groove.

In the above embodiments, the valve seat 20 may include a small diameter shaft section 21 and a large diameter shaft section 22. A shoulder is formed between the small diameter shaft section 21 and the large diameter shaft section 22. The electronic expansion valve also has a valve cavity formed and one end open. Housing 40, the opening of housing 40 is circumferentially sealed and supported on the shoulder.

This can reduce the weight of the electronic expansion valve as much as possible.

In the above embodiments, the side wall of the valve seat 20 can also be provided with a first connection interface, and the lower end of the valve core seat is provided with a second connection interface, both of which are used for external connection to external pipelines. The first connection interface is fixedly connected with the first pipe 100 , and the second connection interface is fixedly connected with the second pipe 200 . The first connection interface and the second connection interface can be connected through the valve port. The first connection interface can be a refrigerant inlet or a refrigerant outlet. Correspondingly, when the first connection interface is a refrigerant inlet, the second connection interface is a refrigerant outlet; when the first connection interface is a refrigerant outlet , the second connection interface is the refrigerant inlet. The external refrigerant medium flows from the external pipeline of the first connection interface (or the second connection interface) to the inside of the valve cavity. After passing through the valve port, it flows out from the external pipeline of the second connection interface (or the first connection interface).

The electronic expansion valve provided by the present invention has been introduced in detail above. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and the core idea of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of the claims of the present invention.

Claims (9)

1. The electronic expansion valve is characterized by comprising a valve seat (20), a valve cavity, a valve core seat (10), a reduction gear device, a supporting component (30), a nut component and a valve needle component, wherein the valve seat (20) is fixedly connected with the valve core seat (10), the valve core seat (10) comprises a valve port, the valve cavity is provided with the reduction gear device, the valve seat (20) comprises a first accommodating cavity and a second accommodating cavity, at least part of the nut component and at least part of the valve needle component are positioned in the first accommodating cavity, the supporting component (30) is positioned in the second accommodating cavity, the supporting component (30) comprises a supporting table (31) and a supporting foot (33), the supporting foot (33) is fixedly connected with the valve seat, the reduction gear device comprises an output gear (80) and an output shaft, at least part of the output gear (80) is propped against the supporting table (31) and is supported by the supporting table (31), the supporting component (30) is provided with a through hole, the output shaft passes through the through hole and is connected with a nut component (3-3), and the second supporting component (23) is positioned in the groove (23); the supporting surface of the supporting table is lower than the upper end surface of the annular peripheral wall (231) of the groove (23);

the valve seat (20) comprises a nut mounting hole section (20 c) which is integrally formed, the nut (301) is mounted on the nut mounting hole section (20 c), and the valve needle assembly performs axial lifting movement to approach or depart from the valve port under the action of screw thread matching of the screw rod (3-3) and the nut (301).

2. The electronic expansion valve according to claim 1, wherein an end face of the output gear (30) facing the support table (31) includes a contact portion and a non-contact portion, the output gear is supported to the support table (31) through the contact portion, and an area of the contact portion is smaller than that of the non-contact portion.

3. An electronic expansion valve according to claim 2, wherein the upper end surface of the valve seat (20) is provided with the groove (23), a fixed gear (70) is supported on the end surface of the annular peripheral wall (231) of the groove (23), and the bottom surface of the support member (30) is supported on the bottom of the groove (23).

4. An electronic expansion valve according to claim 3, wherein the supporting member (30) further comprises a connecting surface (32) extending downward and outward from the periphery of the supporting table (31), the legs (33) are uniformly distributed on the periphery of the lower edge of the connecting surface (32), the upper surface of the supporting table (31) is a supporting surface which is supported in contact with the output gear (80), and the supporting member (32) is supported on the bottom of the groove by the legs (33); and the through hole (30 a) is coaxial with the output shaft and the clearance between the through hole and the output shaft is within a preset range, so that the output shaft acts within a preset axial deviation range;

or, the supporting component (30) comprises a column body (34), the upper end surface of the column body (34) is the supporting table, the supporting table is in contact with the output gear (80) for supporting, the supporting legs (33) are uniformly distributed on the lower edge of the column body (34) in the circumferential direction, and the supporting component (30) is supported at the bottom of the tank through the supporting legs (33); the cylinder (34) is provided with the through hole (30 a) for the output shaft to pass through, and the through hole (30 a) is coaxial with the output shaft and the clearance between the through hole and the output shaft is within a preset range so as to enable the output shaft to act within a preset axial deviation range.

5. The electronic expansion valve according to any one of claims 1 to 4, wherein the reduction gear means is a planetary gear reduction means comprising a gear housing (300), the fixed gear (70) being fixed to the gear housing (300), the gear housing (300) being located at the periphery of the output gear (80), the lower end portion of the gear housing (300) being directly supported and fixed to the valve seat (20).

6. The electronic expansion valve according to claim 5, wherein a flange is circumferentially provided at a lower end opening of the gear housing (300), and the gear housing (300) is supported to the valve seat (20) through the flange.

7. An electronic expansion valve according to any of claims 3 to 4, wherein the valve needle assembly further comprises a spring (3-2); the valve seat (20) comprises a nut mounting hole section (20 c), a guide hole section (20 b) and a liquid flow hole section (20 a) which are integrally formed, wherein the nut mounting hole section (20 c) is used for mounting a nut (301) matched with the screw rod (33); the guide hole section (20 b) is used for installing the spring (3-2) and guiding the valve needle (3-1); the liquid flow hole section (20 a) is provided with a valve port, a first port and a second port are formed in the cavity wall of the liquid flow hole section (20 a), and the first port and the second port can be communicated through the valve port; the radial dimensions of the nut mounting bore section (20 c) and the flow bore section (20 a) are both larger than the pilot bore section (20 b).

8. The electronic expansion valve of claim 7, wherein a lower edge of the pilot bore section (20 b) extends downwardly to form a pilot sleeve (24), the pilot sleeve (24) being located inside the flow bore section (20 a) with a gap between the pilot sleeve (24) and a circumferential inner wall of the flow bore section (20 a).

9. The electronic expansion valve according to any one of claims 1 to 5, wherein the valve seat (20) comprises a small diameter shaft section (21) and a large diameter shaft section (22) from top to bottom, a shaft shoulder is formed between the small diameter shaft section (21) and the large diameter shaft section (22), the electronic expansion valve further comprises a housing (40) forming the valve cavity and having one end opened, and the opening of the housing (40) is supported on the shaft shoulder in a circumferential sealing manner.