An electronic expansion valve

Abstract

An electronic expansion valve includes a valve needle screw assembly, which includes a valve needle, a valve needle sleeve, a gasket portion, an elastic member and a screw member. Before the elastic member is further compressed, the valve needle is suspended on the screw member by the valve needle sleeve. The valve needle is not subjected to the elastic load of the elastic member, which can reduce the friction force exerted on the valve needle when the screw rotates.

Description

Technical field

[0001] The present invention relates to the technical field of refrigeration control, and in particular to an electronic expansion valve. [Background Technology]

[0002] Figure 10 The figure shows the structure of a typical valve needle assembly for an electronic expansion valve. This assembly includes a screw 16', which is limitedly connected to the valve needle 5' via a sleeve 25'. A second gasket 27' is positioned between the valve needle 5' and the sleeve 25'. A spring 8' is housed within the sleeve 25'. The upper end of the spring 8' abuts against a bushing at the lower end of the screw 16', while the lower end of the elastic member 8' abuts against a bearing 24'.

[0003] The elastic load of the spring 8' passes through the bearing 24' and the steel ball 35' and finally acts on the valve needle 5'.

[0004] In the electronic expansion valve using the valve needle assembly, the elastic load of the elastic member always acts on the valve needle, and the friction force on the valve needle when the screw rod rotates is relatively large. [Summary of the invention]

[0005] The object of the invention is to provide an electronic expansion valve, in which the valve needle is not subjected to the elastic load of the elastic member before the elastic member is further compressed, and the friction force on the valve needle when the screw rod rotates is small.

[0006] To achieve the above object, the following technical solution is adopted: an electronic expansion valve, comprising a valve needle screw assembly 1, wherein the valve needle screw assembly 1 comprises a valve needle 11, a valve needle sleeve 12, a gasket portion 13, an elastic member 14 and a screw member 15;

[0007] The screw rod component 15 includes a screw rod body 151, a first stopper 152, and a second stopper 153. The elastic member 14 is sleeved on the screw rod body 151. The first stopper 152 abuts against the elastic member 14, and the elastic member 14 abuts against the washer 13. The second stopper 153 can abut against the washer 13. The washer 13 is positionally connected to the screw rod component 15.

[0008] The valve needle sleeve 12 includes a valve needle sleeve top 121, a peripheral wall portion 122, and a valve needle sleeve bottom 123. The valve needle sleeve top 121 includes a top opening 1211. The screw component 15 passes through the top opening 1211. The valve needle sleeve 12 can be supported on the first stopper 152. The valve needle sleeve bottom 123 includes a bottom opening 1231. The valve needle 11 passes through the bottom opening 1231. The valve needle 11 can be supported on the valve needle sleeve bottom 123.

[0009] The valve needle 11 includes a support portion 111, and the support portion 111 includes a first support portion 1111 and a second support portion 1112. The first support portion 1111 can abut against the gasket portion 13, and the second support portion 1112 can abut against the bottom 123 of the valve needle sleeve.

[0010] When the second stopper 153 abuts against the gasket 13 , the distance between the valve needle sleeve bottom 123 and the gasket 13 is D1 , the distance between the valve needle sleeve bottom 123 and the first support portion 1111 is D2 , and D1 ≥ D2 .

[0011] In the electronic expansion valve provided by this solution, before the elastic member is further compressed, the valve needle is not subjected to the elastic load of the elastic member, and the friction force experienced by the valve needle when the screw rod rotates is relatively small.

Brief Description of the Drawings

[0012] Figure 1 is a cross-sectional view of a first embodiment of the electronic expansion valve of the present invention in a fully closed state;

[0013] Figure 2 yes Figure 1 Cross-sectional view of the middle valve needle screw assembly;

[0014] Figure 3 This is a partial cross-sectional view of the electronic expansion valve embodiment 1 of the present invention in a fully open state;

[0015] Figure 4 yes Figure 3 Cross-sectional view of the middle valve needle screw assembly;

[0016] Figure 5 This is a partial cross-sectional view of the electronic expansion valve embodiment 1 of the present invention when the valve needle sealing portion just contacts the valve port sealing portion;

[0017] Figure 6 yes Figure 5 Cross-sectional view of the middle valve needle screw assembly;

[0018] Figure 7 This is a partial cross-sectional view of a first embodiment of the electronic expansion valve of the present invention at a critical point where the compression elastic member has not been further compressed;

[0019] Figure 8 yes Figure 7 Cross-sectional view of the middle valve needle screw assembly;

[0020] Figure 9 A cross-sectional view of a valve needle screw assembly of another structure;

[0021] Figure 10 This is a typical valve needle assembly structure of an electronic expansion valve;

[0022] The above drawings include the following reference numerals:

[0023] 1 Valve needle screw assembly, 11 valve needle, 11A valve needle sealing portion, 111 support portion, 1111 first support portion, 1112 second support portion, 12 valve needle sleeve, 121 valve needle sleeve top, 1211 top opening, 122 peripheral wall portion, 123 valve needle sleeve bottom, 1231 bottom opening, 13 gasket portion, 14 elastic member, 15 screw rod component, 151 screw rod body, 1511 screw rod upper groove portion, 1512 screw rod lower groove portion, 152 first stopper 1521 upper flange, 1522 upper retaining ring, 153 second stopper, 154 valve needle sleeve support, 2 valve seat assembly, 21 valve seat, 22 first connecting pipe, 23 second connecting pipe, 24 guide seat, 211 valve port, 211A valve port sealing portion, 3 nut assembly, 31 nut, 32 nut connector, 33 sliding ring, 34 spiral guide, 4 rotor assembly, 41 rotor magnet, 42 rotor connecting portion, 43 sliding ring, 44 spiral guide, 5 housing [Specific implementation method]

[0024] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Please refer to Figure 1-9 , Figure 1 is a cross-sectional view of a first embodiment of the electronic expansion valve of the present invention in a fully closed state; Figure 2 yes Figure 1 Cross-sectional view of the middle valve needle screw assembly; Figure 3 This is a partial cross-sectional view of the electronic expansion valve embodiment 1 of the present invention in a fully open state; Figure 4 yes Figure 3 Cross-sectional view of the middle valve needle screw assembly; Figure 5 This is a partial cross-sectional view of the electronic expansion valve embodiment 1 of the present invention when the valve needle sealing portion just contacts the valve port sealing portion; Figure 6 yes Figure 5 Cross-sectional view of the middle valve needle screw assembly; Figure 7 This is a partial cross-sectional view of the electronic expansion valve embodiment of the present invention when the compression elastic member has not been further compressed to the critical point. Figure 8 yes Figure 7 Cross-sectional view of the middle valve needle screw assembly, Figure 9 A cross-sectional view of a valve needle screw assembly of another structure;

[0026] In a specific embodiment, the electronic expansion valve provided by the present invention consists of a valve body and a stator coil (not shown in the figure). The valve body includes a valve needle screw assembly 1, a valve seat assembly 2, a nut assembly 3, a rotor assembly 4 and a housing 5. The stator coil of the electronic expansion valve is connected to a drive controller. When the drive controller is energized, a pulse drive signal is sent to the stator coil, and the stator coil generates a periodically changing magnetic field, thereby driving the rotor assembly 4 of the electronic expansion valve to rotate forward or reverse. The rotor assembly 4 is fixedly connected to the screw component 15 of the valve needle screw assembly 1. When the rotor assembly 4 rotates, it will synchronously drive the screw component 15 to rotate. The screw component 15 of the valve needle screw assembly 1 is provided with an external thread, and the inner hole of the nut 31 of the nut assembly 3 is provided with an internal thread. The screw component 15 and the nut 31 are threadedly matched. When the rotor assembly 4 rotates, the screw component 15 will displace along the axial direction, thereby driving the valve needle 11 to realize the opening and closing action of the valve port 211.

[0027] The valve seat assembly 2 provided in this embodiment includes a valve seat 21, a first connecting pipe portion 22, a second connecting pipe portion 23, and a guide seat 24. The first connecting pipe portion 22, the second connecting pipe portion 23, and the guide seat 24 are fixedly assembled with the valve seat 21. The first connecting pipe portion 22 and the second connecting pipe portion 23 serve as inflow or outflow channels for the fluid medium of the electronic expansion valve, and are generally used to connect with the system pipeline when the electronic expansion valve is installed in a cooling or heating system such as an air conditioner. The guide seat 24 is provided with a valve port 211 near the center of the second connecting pipe portion 23. The valve port 211 is provided with a valve port sealing portion 2111 that can be sealed with the valve needle 11 (mentioned below).

[0028] The central inner hole position of the guide seat 24 of the valve seat assembly 1 is provided with an inner hole guide portion 241 that cooperates with the outer wall of the valve needle screw assembly 1 (specifically the valve needle sleeve 12, which will be mentioned below). When the electronic expansion valve is opened and closed, the inner hole guide portion 241 can provide guidance and correction for the valve needle screw assembly 1.

[0029] A nut assembly 3 is coaxially mounted above the valve seat assembly 2. This assembly comprises a nut 31, a nut connector 32, a sliding ring 33, and a spiral guide 34. The nut 31 can be securely connected to the valve seat assembly 3 via the nut connector 32 by welding, interference fit, or other methods. A sliding ring 33 and a spiral guide 34 are mounted on the outer circumference of the nut 31, near the top. The sliding ring 33 can helically rotate along the spiral guide 34 within a defined upper and lower travel range. These sliding ring 33 and spiral guide 34, in conjunction with the rotor assembly 4, control the travel of the electronic expansion valve between fully open and fully closed.

[0030] The rotor assembly 4 includes a rotor magnet 41, a rotor connector 42, and a rotor stop 43. (The rotor stop 43 and rotor magnet 41 can be integrally formed, but in this embodiment, they are assembled separately.) The rotor assembly 4 is fixedly connected to the screw component 15 of the valve needle screw assembly 1 via the rotor connector 4 (e.g., by welding). Driven by the stator coil, the rotor assembly 4 drives the screw component 15 to rotate synchronously. A rotor stop 43 is provided on the inside of the rotor assembly 4. The rotor stop 43 cooperates with the sliding ring 33 and spiral guide 34 on the nut 31 to limit the rotation of the rotor assembly 4 within a specified range of travel.

[0031] In addition, the electronic expansion valve provided in this embodiment further includes a housing 5 with an opening at one end. The housing 5 is sleeved on the outside of the rotor assembly 4. The opening of the housing 5 is welded and sealed to the valve seat 21 to form a closed accommodating cavity.

[0032] The valve needle screw assembly 1 mainly includes a valve needle 11, a valve needle sleeve 12, a gasket 13, an elastic member 14 and a screw member 15. For details, please refer to Figure 2 ; The screw rod component 15 provided in this embodiment includes a screw rod body portion 151, a first stop portion 152, a second stop portion 153 and a valve needle sleeve support portion 154. In this embodiment, the elastic member 14 is a spring. The elastic member 14 is sleeved on the outer side of the peripheral wall of the screw rod body portion 151 and is located (restricted) between the first stop portion 152 and the second stop portion 153. Specifically, the upper end of the elastic member 14 is against the first stop portion 152, and the lower end of the elastic member 14 is against the second stop portion 153.

[0033] In addition, the valve needle screw assembly 1 provided in this embodiment is also provided with a gasket portion 13, which is roughly annular in structure. It is arranged on the outside of the peripheral wall of the screw body portion 151 and is located between the elastic member 14 and the second stop portion 153. The gasket portion 13 can be abutted against and supported by the second stop portion 153. Since the gasket portion 13 is restricted by the second stop portion 153, it will not fall off from the lower end of the screw component 15. At this time, the gasket portion 13 is limitedly connected to the screw body portion 151.

[0034] In this arrangement, when the structure formed by the screw component 15, the elastic component 14, and the washer portion 13 is not subjected to other external forces, the upper end of the elastic component 14 abuts against the first stop portion 152, the lower end abuts against the washer portion 13, and the washer portion 13 abuts against the second stop portion 153. At this time, the elastic component 14 and the second stop portion 153 also abut against each other through the washer portion 13.

[0035] The valve needle sleeve 12 is roughly a cylindrical component with openings at both ends and a hollow interior. It includes a valve needle sleeve top 121, a peripheral wall portion 122 and a valve needle sleeve bottom 123. A top opening 1211 is provided at the approximate center position of the valve needle sleeve top 121, and a bottom opening 1231 is provided at the approximate center position of the valve needle sleeve bottom 123.

[0036] The valve needle sleeve 12 can adopt different structural methods, such as the peripheral wall portion 122 and the valve needle sleeve bottom 123 are integrally formed, and the valve needle sleeve top 121 is fixedly connected to the peripheral wall portion 122; the peripheral wall portion 122 and the valve needle sleeve top 121 are integrally formed, and the valve needle sleeve bottom 123 is fixedly connected to the peripheral wall portion 122; the valve needle sleeve top 121, the peripheral wall portion 122, and the valve needle sleeve bottom 123 are fixedly connected; the valve needle sleeve top 121 and a portion of the peripheral wall portion 122 are integrally formed or fixedly connected, the valve needle sleeve bottom 123 and another portion of the peripheral wall portion 122 are integrally formed or fixedly connected, and then the two portions of the peripheral wall portion 122 are fixedly connected. In this embodiment, the peripheral wall portion 122 and the valve needle sleeve bottom 123 are integrally formed, and the valve needle sleeve top 121 is fixedly connected to the peripheral wall portion 122, or other molding methods are used. The valve needle sleeve 12 can be generally hollow with openings at both ends.

[0037] The valve needle sleeve 12 and the screw component 15 are connected in a position-limiting manner. Specifically, the lower end of the screw component 15 is located within the valve needle sleeve 12, and the other end extends out of the valve needle sleeve 12 through the top opening 1211 of the valve needle sleeve top 121. At this time, a portion of the screw component 15 passes through the top opening 1211. Moreover, when only subjected to gravity, the valve needle sleeve 12 can abut against and be supported by the valve needle sleeve support portion 154 of the screw component 15. In this embodiment, the outer circumference of the valve needle sleeve support portion 154 is generally circular, and the shape of the top opening 1211 is also generally circular. Therefore, in this embodiment, the diameter of the first stop portion 152 is greater than the diameter of the top opening 1211.

[0038] In this embodiment, the first stop portion 152 is roughly composed of a component extending circumferentially away from the center of the screw body portion 151, and the component is the upper flange portion 1521. Specifically, the first stop portion 152 is roughly an end surface of the upper flange portion 1521 that abuts against the elastic member 14, and the valve needle sleeve support portion 154 is an end surface of the upper flange portion 1521 that supports the valve needle sleeve 12. The first stop portion 152 and the valve needle sleeve support portion 154 are formed on the same component (upper flange portion 1521). Of course, the upper flange portion 1521 and the screw body portion 151 can be integrally formed or fixedly connected by welding or the like. In this embodiment, the first stop portion 155 is the upper flange portion 1521.

[0039] It is worth noting that the first stop portion 152 and the valve needle sleeve support portion 154 can be formed in different components. For example, the screw component 15 is provided with two components extending circumferentially away from its center direction. The first stop portion 152 and the valve needle sleeve support portion 154 are respectively formed in the above two different components, that is, the first stop portion 152 and the valve needle sleeve support portion 154 are not limited to an integrated structure.

[0040] Of course, the first stop portion 152 of the present invention is not limited to the above structure. For example, the screw body portion 151 can also be provided with a screw upper groove portion 1511, which is formed roughly along the surface of the screw body portion 151 and circumferentially concave along its center. At this time, an upper retaining ring 1522 is provided on the screw upper groove portion 1511, and the end face of the upper retaining ring 1522 abutting against the elastic member 14 forms the first stop portion 152. The upper retaining ring 1522 is limitedly connected or fixedly connected to the screw upper groove portion 1511. When the valve needle sleeve support portion 154 and the first stop portion 152 are formed on the same component, the upper end face of the upper retaining ring 1522 forms the valve needle sleeve support portion 154. For another example, the screw component 15 of the valve needle screw assembly 1 is provided with an external thread, and the screw component 15 is threadedly connected to a first stop component provided with an internal thread. The screw component 15 is threadedly matched with the first stop component, and the end surface of the first stop component abutting against the elastic component 14 forms a first stop portion 152. When the valve needle sleeve support portion 154 and the first stop portion 152 are formed on the same component, the upper end surface of the first stop component forms the valve needle sleeve support portion 154.

[0041] Similarly, when the needle sleeve supporting portion 154 and the first stop portion 152 are not formed from the same component, the needle sleeve supporting portion 154 may also adopt a structure similar to the first stop portion 152 .

[0042] In addition, the axial projection shape of the first stop portion 152 and the shape of the top opening 1211 can also be selected from or all of other shapes. It is easy to understand that it is only necessary to ensure that the valve needle sleeve 12 can be supported on the first stop portion 152 and will not fall off from the screw rod component 15 from top to bottom. At this time, the gasket portion 13 is movably limitedly connected to the screw rod component 15.

[0043] The valve needle 11 provided in this embodiment includes a support portion 111, which is roughly in the shape of an annular wall. The support portion 111 includes a first support portion 1111 and a second support portion 1112. The upper end of the valve needle 1111 is located in the valve needle sleeve 12, and the other end can extend out of the valve needle sleeve 12 through the bottom opening 1231 of the valve needle sleeve bottom 123. In addition, the valve needle 12 can be abutted against the valve needle sleeve bottom 123 of the valve needle sleeve 12 and supported on the valve needle sleeve bottom 123 when only subjected to gravity. In this embodiment, the outer periphery of the support portion 111 is roughly circular, and the bottom opening 1231 of the valve needle sleeve bottom 123 is also roughly circular. Therefore, in this embodiment, the outer diameter of the support portion 111 is larger than the inner diameter of the bottom opening 1231. In addition, the valve needle 11 includes a valve needle sealing portion 11A, which can pass through the bottom opening 1231 to cooperate with the valve port sealing portion 211A to achieve the closure of the valve port 211. At this time, the inner diameter of the valve needle sealing portion 11A is smaller than the inner diameter of the bottom opening 1231.

[0044] Of course, the axial projection shape of the support portion 111 and the shape of the bottom opening 1231 can also be selected from or all of other shapes. It can be understood that it is only necessary to ensure that the valve needle 11 can be supported on the bottom 123 of the valve needle sleeve and the valve needle 11 will not fall out of the bottom opening 1231.

[0045] When the valve needle 11 moves up and down, its support portion 111 cannot be blocked by the second stop portion 153. In this embodiment, the outer periphery of the second stop portion 153 is roughly circular, and the axial projection of the inner wall of the support portion 111 is also roughly circular. At this time, the inner diameter of the support portion 111 is greater than or equal to the outer diameter of the second stop portion 153.

[0046] Of course, the axial projection of the inner wall of the support portion 111 and the second stop portion 153 may also adopt other shapes or both of them, as long as it is ensured that when the flow rate of the electronic expansion valve changes, that is, when the valve needle 11 moves, it will not be restricted by the second stop portion 153.

[0047] For this valve needle screw assembly 1, when the valve needle 11 is not subjected to any force other than the force it is subjected to in the natural state, that is, when the second stop part 153 is subjected to the force of the elastic member and is offset by the gasket part 13, the distance between the bottom 123 of the valve needle sleeve and the gasket part 13 is D1, and the distance between the bottom 123 of the valve needle sleeve and the first support part 1111 is D2. At this time, D1≥D2. It is worth noting that: the distance D1 between the bottom 123 of the valve needle sleeve and the gasket part 13 refers to the axial displacement of the valve needle 11 relative to the screw part 15 from the time the valve needle 11 contacts the valve port 211 to the time the valve needle 11 contacts the gasket part 13, and the distance D2 between the bottom 123 of the valve needle sleeve and the first support part 1111 refers to the axial distance between the position where the bottom 123 of the valve needle sleeve supports the valve needle and the first support part 1111.

[0048] When the refrigerant flow of the electronic expansion valve provided in this embodiment changes from a fully open state to a fully closed state, the screw component 15 gradually descends, and the valve needle sleeve 12 suspended and supported on the screw component 15 also descends as the screw component 15 descends. Furthermore, the valve needle 11 suspended and supported on the valve needle sleeve 12 also descends accordingly. When the valve needle 11 has not yet contacted the valve port 211, there is a gap between the first support portion 1111 and the gasket portion 13, and the size of the gap is D1-D2.

[0049] As the valve needle 11 gradually descends, the valve needle sealing portion 11A will abut against the valve port sealing portion 211A. After the valve needle sealing portion 11A abuts against the valve port sealing portion 211A, the valve needle 11 is supported on the valve port 211. Therefore, the valve needle 11 will not descend as the screw rod component 15 further descends. At this time, the second support portion 1112 of the valve needle 11 and the valve needle sleeve bottom 123 of the valve needle sleeve 12 will change from an abutting state to a separated state. At this time, the valve needle 11 changes from being supported by the valve needle sleeve 12 to the valve port 211, and the distance between the second support portion 1112 and the valve needle sleeve bottom 123 will increase with the descending movement of the screw rod component 15.

[0050] At the same time, when D1 is greater than D2, the distance between the first support portion 1111 and the gasket portion 13 will decrease as the screw component 15 descends. At the same time, the distance between the second support portion 1112 and the bottom 123 of the valve needle sleeve will increase as the screw component 15 descends. When the distance between the first support portion 1111 and the gasket portion 13 becomes 0, the first support portion 1111 begins to contact the gasket portion 13. At this time, the valve needle 11 begins to be loaded by the elastic member 14. The valve needle 11 is At this time, the critical point of the load of the elastic member 14 is reached; when D1 and D2 are equal, the valve needle 11 and the valve needle sleeve 12 will synchronously descend with the downward movement of the screw rod component 15. When the valve needle 11 is against the valve port sealing portion 211A, the first support portion 1111 begins to abut against the gasket portion 13. The valve needle 11 reaches the critical point of the load of the elastic member 14 at this time. The valve needle 11 is about to be pressed against the valve port 211 by the load of the elastic member 14 to close the flow of the electronic expansion valve.

[0051] Therefore, in the electronic expansion valve provided in this embodiment, before the elastic member 14 is further compressed, the valve needle 11 is suspended on the bottom 1231 of the valve needle sleeve through the second support portion 1112, and the distance between the valve needle 11 and the gasket portion 13 is ≥0. The valve needle 11 does not directly abut against the gasket portion 13, so the elastic load of the elastic member 14 cannot be transmitted to the valve needle 11 through the gasket portion 13. Therefore, the valve needle 11 will not be affected by the elastic load of the elastic member 14, which can reduce the friction force exerted on the valve needle 11 when the screw rod component 15 rotates.

[0052] In addition, at the moment when the valve needle 11 begins to close the valve port 211, the force on the valve port 211 is only the gravity of the valve needle 11. Figure 10 Since the valve needle is always subjected to the elastic load of the elastic part, the force on the valve port at the moment it contacts the valve port is the elastic force of the elastic part and the gravity of the valve needle. The impact force on the valve port is large and the wear of the valve port is also serious.

[0053] In this embodiment, when the valve needle 11 is against the gasket portion 13, the elastic load of the elastic member 14 is transmitted to the valve needle 11 through the gasket portion 13, which can make the fit between the valve needle sealing portion 11A and the valve port sealing portion 211A tighter. At this time, the valve needle 11 is subjected to the elastic load of the elastic member 14. When the screw component 15 rotates, its rotational friction fitting surface is mainly between the retaining ring portion 13 and the support portion 222 of the valve needle 11. In order to further reduce the friction resistance of its relative rotation, it is preferred to spray or plate a coating with lubricating and wear-resistant functions (for example, a coating containing polytetrafluoroethylene, or graphite, or molybdenum disulfide), thereby increasing the service life of the electronic expansion valve.

[0054] The gasket portion 13 provided in this embodiment can be formed by combining an open retaining ring 131 and a gasket 132. That is, in this embodiment, the gasket portion 13 includes both the open retaining ring 131 and the gasket 132. Of course, based on the functional principle of the present invention, the open retaining ring 131 of the gasket portion 13 in this embodiment is not limited to the C-shaped open retaining ring shown in the figure, and can also be replaced by open retaining rings of other shapes; similarly, the gasket 132 in this embodiment is not limited to the circular gasket shown in the figure, and can also be replaced by other retaining rings that can play the same role, for example, an open retaining ring can also be used. In addition, the gasket portion 13 of the present invention can only use one of the open retaining ring 131 and the gasket 132, and the technical effect of the gasket portion 13 can also be achieved. Of course, the gasket portion 13 can also use more than three parts. The open retaining ring described in the present invention refers to a component with an opening and a hollow interior; the gasket 132 described in the present invention refers to a component without an opening and a hollow interior.

[0055] In addition, the screw rod body 151 provided in this embodiment can also be provided with a screw rod lower groove portion 1512, which is formed by being roughly recessed along the circumferential direction of the surface of the screw rod body 151. At this time, the second stop portion 153 is located below the screw rod groove portion 1512, and a washer portion 13 is provided in the screw rod lower groove portion 1512. At this time, the washer portion 13 is limitedly connected to the screw rod lower groove portion 1512. In this embodiment, the second stop portion 153 and the screw rod body 151 are integrally molded. The second stop portion 153 is located in a structure formed by extending circumferentially away from the center of the screw rod body 151. The end face of this structure that abuts against the elastic member 14 forms the second stop portion 153, and the screw rod body 151 is provided with a screw rod lower groove portion 1512.

[0056] In this embodiment, the diameter of the second stop portion 153 is larger than the inner diameter of the washer portion 13. At this time, the washer portion 13 can also be supported on the second stop portion 153 and will not fall off from the lower end of the screw component 15. Of course, the outer contour of the second stop portion 153 and the inner hole shape of the washer portion 13 can be selected or not set to be circular. At this time, it is sufficient to ensure that the washer portion 13 can be supported on the second stop portion 153 and the washer portion 13 does not fall off from the screw component 15.

[0057] It is worth noting that the second stop portion 153 can also be formed in a different way. For example, the second stop portion 153 is located in the screw body portion 151 and is formed in an integrally formed manner. The structure extends circumferentially away from the center of the screw body portion 151. The end face of the structure that abuts against the elastic member 14 forms the second stop portion 153, and the screw body portion 151 does not have a screw lower groove portion 1512, or the second stop portion 153 is formed by the screw body portion 151 using a fixed connection method such as welding or threaded connection. For example, the lower end of the screw body portion 151 is provided with a thread, and the nut is connected to the screw body portion 151 through a thread, and the end face of the nut abutting against the elastic member 14 forms the second stop portion 153.

[0058] In the electronic expansion valve provided in this embodiment, the elastic member 14 is sheathed on the screw rod 151, and the upper end of the elastic member 14 abuts against the first stop portion 155, and the lower end of the elastic member 14 abuts against the second stop portion 153. The elastic member 14 cooperates with the screw rod component 15 to relatively reduce the deflection of the elastic member 14, thereby reducing the eccentric wear of the valve needle 11.

[0059] Please refer to Figure 3-4 , Figure 3 This is a partial cross-sectional view of the first embodiment of the electronic expansion valve provided by the present invention in a fully open state. Figure 4 for Figure 3 Cross-sectional view of the middle valve needle screw assembly.

[0060] When the electronic expansion valve is fully open, the distance between the valve needle sealing portion 11A and the valve port sealing portion 211A is L. At this point, the valve needle screw assembly 1 is at its uppermost end, the elastic member 14 is in its initial compression state, and the slidable washer portion 13 disposed on the valve needle screw assembly 1 abuts against the second stop portion 153. The valve needle 11 is not directly or indirectly subjected to the elastic load generated by the elastic member 11. The valve needle 11 is suspended from the valve needle sleeve bottom 123 by the valve needle sleeve 12. The lower surface of the washer portion 13 abuts against the upper surface of the second stop portion 153. At this point, there is a certain gap D1-D2 between the lower surface of the washer portion 13 and the upper surface of the first support portion 1111. Therefore, the valve needle 11 is not subjected to the elastic load generated by the elastic member 14. At this point, the valve needle 11 is supported by the valve needle sleeve bottom 123 of the valve needle sleeve 12.

[0061] In addition, as the rotor assembly 4 rotates, the screw rod 151 will move along the axial direction, and the distance between the valve needle sealing portion 11A of the valve needle 11 and the valve port sealing portion 211A of the valve port 211 will also change.

[0062] Please refer to Figure 5 , Figure 5 This is a partial cross-sectional view of the first embodiment of the electronic expansion valve provided by the present invention when the valve needle 11 and the valve port sealing portion 211A just come into contact. Figure 6 for Figure 5 Cross-sectional view of the middle valve needle screw assembly;

[0063] At this time, the electronic expansion valve is in a fully open state, and the valve needle sealing part 11A just contacts the valve port sealing part 211A. At this time, the downward displacement of the valve needle 11 is L. During this process, the elastic member 11 is always in its initial compression state, and the gasket portion 13 provided on the screw rod component 15 always rests against the second stop portion 153 of the screw rod component 15. In this state, the valve needle 11 is not subjected to the elastic load generated by the compressed elastic member 11. At this time, the lower surface of the gasket portion 13 and the first support portion 1111 of the valve needle 11 still maintain a certain amount of gap D1-D2.

[0064] Please refer to Figure 7-8 , Figure 7 A partial cross-sectional view of the first embodiment of the electronic expansion valve provided by the present invention at a critical point where the elastic member 14 has not been further compressed; Figure 8 for Figure 7 Cross-sectional view of the middle valve needle screw assembly.

[0065] and Figure 5-6 Compared with the status in Figure 7The screw component 15 continues to move downward by the displacement of D1-D2. At this time, the lower surface of the gasket part 13 and the first support part 1111 of the valve needle 11 are just at the critical point of contact. At this time, the elastic part 14 is at the critical point to be further compressed, which is equivalent to the valve needle 11 being at the critical point to withstand the elastic load of the further compressed compression elastic part 12.

[0066] Please refer to Figure 1-2 , Figure 1 This is a partial cross-sectional view of the first embodiment of the electronic expansion valve provided by the present invention in a fully closed state. Figure 2 for Figure 1 Cross-sectional view of the valve needle screw assembly. Figure 7-8 Compared with the status in Figure 1 The screw member 15 in the valve stem moves downward by a displacement of α. At this point, the lower surface of the gasket portion 13 is in contact with the first support portion 1111 of the valve needle 11. The elastic member 14 is further compressed, and the needle sealing portion 11A of the valve needle screw assembly 1 is in contact with the valve port sealing portion 211A of the valve seat member 2. The valve needle 11 is loaded by the elastic force generated by the further compressed elastic member 14. At this point, the electronic expansion valve is in the fully closed state, and the screw member 151 is at the lowest position of its travel. The downward travel of the screw member 151 from the fully open state to the fully closed state is L + α.

[0067] At this time, the first supporting portion 1111 of the valve needle 11 abuts against the washer portion 13 , and the washer portion 13 pushes the valve needle 11 upward and moves a certain distance.

[0068] At this time, the valve needle 11 is subjected to the elastic load of the elastic part 14 (transmitted to the valve needle 11 by the gasket part 13). At this time, the elastic load can provide the valve closing force of the valve needle 11, thereby minimizing the situation in which the refrigerant overcomes the elastic force of the elastic part 14 and the gravity of the valve needle 11 to open the valve port 211 when the electronic expansion valve is in the closed state and the second connecting pipe part 23 is used as the inlet pipe.

[0069] In addition, the guide seat 24 is provided with an inner hole guide portion 241, which is a roughly cylindrical inner ring wall structure, and the valve needle sleeve 12 can be loosely matched with the guide seat 24. Specifically, the peripheral wall portion 122 of the valve needle sleeve 12 is loosely matched with the inner hole guide portion 241 of the guide seat 24, and the valve needle 11 can be guided by the guide seat 24 during the up and down movement of the valve needle 11, which is more conducive to ensuring the coaxiality of the valve port 211 and the valve needle 11, reducing the deflection of the valve needle 11 relative to the valve port 211, reducing the eccentric wear of the valve needle 11, improving the life of the electronic expansion valve, and reducing the noise generated by the coaxiality of the valve port 211 and the valve needle 11. It is worth noting that the guide seat 24 provided by the present invention is not limited to an integrally formed structure. The guide seat 24 can also be assembled from two or more parts. Unless otherwise specified, the other parts provided by the present invention are also applicable.

[0070] This embodiment illustrates that: in the present invention, the first supporting portion 1111 can counteract the elastic member 14 , which is not limited to direct counteracting between the two, but also includes indirect counteracting between the two.

[0071] It should be pointed out that the purpose of the present invention is mainly to improve the valve needle screw assembly 1 of the electronic expansion valve. For other components of the electronic expansion valve, such as the rotor assembly 4, the nut assembly 3 and other components, general technology can be used, and other electronic expansion valve structures that can achieve the same function can also be used.

[0072] It should be noted that the "offsetting" mentioned in this specification includes direct offsetting and indirect offsetting, and the "supporting" mentioned in this specification includes direct supporting and indirect supporting. The directional nouns such as up, down, left, and right mentioned in this embodiment are all based on the drawings in the specification and are introduced for the convenience of description; and the ordinal numbers such as "first" and "second" in the component names are also introduced for the convenience of description and do not mean any limitation on any order of the components.

[0073] The electronic expansion valve provided by the present invention has been described 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 intended to help understand the core concept of the present invention. It should be noted that those skilled in the art may make various improvements and modifications to the present invention without departing from the principles of the present invention, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. An electronic expansion valve, characterized in that: The valve needle screw assembly (1) comprises a valve needle (11), a valve needle sleeve (12), a gasket portion (13), an elastic member (14) and a screw member (15); The screw rod component (15) includes a screw rod body (151), a first stopper (152), a second stopper (153) and a valve needle sleeve support portion (154); the elastic member (14) is sleeved on the screw rod body (151); the elastic member (14) abuts against the first stopper (152); the elastic member (14) abuts against the gasket portion (13); the second stopper (153) can abut against the gasket portion (13); and the gasket portion (13) is connected to the screw rod component (15) in a limiting manner; The valve needle sleeve (12) includes a valve needle sleeve top (121), a peripheral wall portion (122) and a valve needle sleeve bottom (123); the valve needle sleeve top (121) includes a top opening (1211), a portion of the screw rod component (15) passes through the top opening (1211), and the valve needle sleeve (12) can be supported on the valve needle sleeve support portion (154); the valve needle sleeve bottom (123) includes a bottom opening (1231), a portion of the valve needle (11) passes through the bottom opening (1231), and the valve needle (11) can be supported on the valve needle sleeve bottom (123); The valve needle (11) includes a support portion (111), and the support portion (111) includes a first support portion (1111) and a second support portion (1112), wherein the first support portion (1111) can abut against the gasket portion (13), and the second support portion (1112) can abut against the bottom portion (123) of the valve needle sleeve; When the second supporting portion (1112) abuts against the bottom of the valve needle sleeve (123), the distance between the bottom of the valve needle sleeve (123) and the gasket portion (13) is D1, and the distance between the bottom of the valve needle sleeve (123) and the first supporting portion (1111) is D2, and D1 ≥ D2.

2. The electronic expansion valve according to claim 1, characterized in that: The first stop portion (155) includes an upper flange portion (1551), the upper flange portion (1551) extending along the circumference of the screw body portion (151), the upper flange portion (1551) and the screw body portion (151) being integrally formed or fixedly connected, and the upper flange portion (1551) abuts against the elastic member (14).

3. The electronic expansion valve according to claim 1, characterized in that: The first stop portion (152) includes an upper retaining ring (1522), the screw body portion (151) includes a screw upper groove portion (1511), the screw upper groove portion (1511) and the upper retaining ring (1522) are limitedly connected or fixedly connected, and the upper retaining ring (1552) is against the elastic member (14).

4. The electronic expansion valve according to claim 1, characterized in that: The second stop portion (153) extends along the circumference of the screw body portion (151), and the second stop portion (153) and the screw body portion (151) are integrally formed or fixedly connected.

5. The electronic expansion valve according to claim 4, characterized in that: The screw body (151) includes a screw lower groove portion (1512). In the axial direction, the second stop portion (153) is located below the screw groove portion (1512). The washer portion (13) is located in the screw lower groove portion (1512). The washer portion (13) is connected to the screw lower groove portion (1512) in a limiting manner.

6. The electronic expansion valve according to claim 1, characterized in that: The outer circumference of the first stop portion (152) is circular, the shape of the top opening (1211) is circular, and the diameter of the first stop portion (152) is greater than the diameter of the top opening (1211).

7. The electronic expansion valve according to any one of claims 1 to 6, characterized in that: The valve seat assembly (2) further comprises a valve seat assembly (2), wherein the valve seat assembly (2) comprises a valve seat (21) and a guide seat (24), wherein the guide seat (24) is fixedly connected to the valve seat (21), and the guide seat (24) comprises an inner hole guide portion (241), wherein the inner hole guide portion (241) is a generally cylindrical inner ring wall structure, and the valve needle sleeve (12) is clearance-fitted with the guide seat (24).

8. The electronic expansion valve according to any one of claims 1 to 6, characterized in that: The surface of the gasket portion (13) includes a coating, and the coating includes polytetrafluoroethylene, graphite, or molybdenum disulfide.

9. The electronic expansion valve according to any one of claims 1 to 6, characterized in that: 0≤D1-D2≤0.03mm.

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