Electronic expansion valve

Abstract

The embodiment of the utility model provides an electronic expansion valve, and relates to the technical field of valves. The electronic expansion valve comprises a valve body, a rotor assembly, a driving nut, a large valve needle, a limiting piece and a small valve needle. The valve body is provided with a mounting cavity, a first opening and a second opening. The rotor assembly is installed in the valve body and connected with a rotating shaft of the rotor assembly through threads. The large valve needle is installed in the installation cavity and provided with an assembly cavity, a blind hole is formed in the bottom wall of the assembly cavity, a plurality of side holes communicated with the blind hole are formed in the side wall of the large valve needle, and a plurality of through holes are formed in the outer periphery of the blind hole. The limiting piece is installed at the top end of the large valve needle, a center hole is formed in the limiting piece, and the inner periphery of the limiting piece partially extends into the assembling cavity. The small valve needle is movably installed in the assembling cavity, the bottom end of the small valve needle corresponds to the blind hole, the top end of the small valve needle penetrates through the center hole and is connected with the driving nut, and a limiting table is arranged on the portion, located in the assembling cavity, of the small valve needle. The structure of the valve body can be simplified, so that the machining difficulty of the valve body can be reduced.

Description

Technical Field

[0001] The utility model relates to the field of throttle valves, and more specifically, to an electronic expansion valve. Background Art

[0002] An electronic expansion valve is a precise flow control component in modern refrigeration systems, mainly used to accurately regulate the refrigerant flow rate to ensure that the refrigeration system maintains an ideal operating state under different working conditions.

[0003] A double-valve needle electronic expansion valve is a precision flow control device improved on the basis of traditional electronic expansion valves. Its main feature is the adoption of a double-valve needle structure, which enables the valve to have higher resolution and a larger adjustment range when controlling the flow rate. Each valve needle can be adjusted independently, thus achieving finer flow control. Especially during small-flow regulation, the double-valve needles can provide a smoother and more precise transition, avoiding the flow rate jump phenomenon that may occur with a single valve needle.

[0004] Existing double-valve needle electronic expansion valves, such as the invention patent with the publication number CN117028588A, have the problem that the flow passage holes are concentrated on the valve body, resulting in a complex valve body structure, low qualification rate, and high manufacturing cost. Summary of the Utility Model

[0005] The purpose of the utility model is to provide an electronic expansion valve, which can simplify the structure of the valve body, thereby facilitating the processing difficulty of the valve body cost.

[0006] The embodiments of the utility model are implemented as follows:

[0007] The utility model provides an electronic expansion valve, including:

[0008] A valve body, which has an installation cavity, a first opening and a second opening communicated with the installation cavity. The first opening is located at the end of the valve body, and the second opening is arranged on the side wall of the valve body;

[0009] A rotor assembly, which is installed in the valve body;

[0010] A drive nut, which is threadedly connected to the rotating shaft of the rotor assembly;

[0011] A large valve needle, which is installed in the installation cavity. The large valve needle is provided with an assembly cavity, the bottom wall of the assembly cavity is provided with a blind hole, the side wall of the large valve needle is provided with a plurality of side holes communicated with the blind hole, the side holes are communicated with the second opening, and the outer peripheral edge of the blind hole is provided with a plurality of through holes, and the plurality of through holes can make the assembly cavity communicate with the first opening;

[0012] A limiting member, which is installed at the top end of the large valve needle. The limiting member is provided with a central hole, and a part of the inner peripheral edge of the limiting member extends into the assembly cavity; and,

[0013] A small valve needle, which is movably installed in the assembly cavity, and the bottom end of the small valve needle corresponds to the blind hole. The top end of the small valve needle passes through the central hole and is connected to the driving nut. A limiting platform is provided on the part of the small valve needle located in the assembly cavity;

[0014] When the small valve needle moves upward, the large valve needle can be driven to move upward by abutting against the limiting platform through the limiting member.

[0015] In an optional embodiment, a first flow passage gap is formed between the outer peripheral edge of the small valve needle and the inner wall of the assembly cavity;

[0016] A second flow passage gap is formed between the small valve needle and the inner wall of the central hole;

[0017] The first flow passage gap and the second flow passage gap are communicated.

[0018] In an optional embodiment, the limiting platform is provided with a cutting plane in the height direction, and the first flow passage gap is formed between the cutting plane and the inner wall of the assembly cavity.

[0019] In an optional embodiment, a balance channel is arranged along the axial direction of the small valve needle, and the top end of the balance channel penetrates through the top surface of the small valve needle;

[0020] A first side channel communicated with the first flow passage gap and a second side channel communicated with the second flow passage gap are further arranged on the side wall of the small valve needle.

[0021] In an optional embodiment, the electronic expansion valve further includes a spring seat and a first spring;

[0022] The valve body includes a valve seat, a limiting seat and a sleeve;

[0023] The installation cavity, the first opening and the second opening are arranged on the valve seat;

[0024] An installation groove is arranged at the top of the valve seat;

[0025] The spring seat is installed in the installation groove, and the spring seat is provided with a through hole for the small valve needle to pass through. A third flow passage gap is formed between the side wall of the through hole and the side wall of the small valve needle;

[0026] The bottom end of the first spring abuts against the limiting member, and the top end of the first spring abuts against the spring seat

[0027] The limiting seat is installed in the installation groove and is located above the spring seat. The limiting seat is provided with a limiting groove, and the driving nut is movably installed in the limiting groove;

[0028] The sleeve is installed in the installation groove, and the rotor assembly is installed in the sleeve.

[0029] In an alternative embodiment, the limiting seat is provided with a channel hole, and the channel hole communicates with the third overflow gap.

[0030] In an alternative embodiment, the limiting member is convexly provided with a sleeving portion, and the bottom of the first spring is sleeved on the sleeving portion;

[0031] The sleeving portion is provided with a through hole communicating with the second overflow gap.

[0032] In an alternative embodiment, an annular groove is provided inside the valve body and corresponding to the position of the second opening;

[0033] The side hole communicates with the annular groove.

[0034] In an alternative embodiment, the electronic expansion valve further includes a sealing ring, and a sealing ring groove is provided on the outer peripheral edge of the large valve needle;

[0035] The sealing ring is arranged in the sealing ring groove, and sealing between the large valve needle and the side wall of the installation cavity can be achieved.

[0036] In an alternative embodiment, the electronic expansion valve further includes a second spring;

[0037] The top end of the small valve needle is provided with a spring cavity;

[0038] The driving nut is provided with a plugging groove, and the plugging groove is in a T shape;

[0039] The top of the small valve needle is provided with a clamping portion;

[0040] The clamping portion is clamped in the plugging groove and can move relative to the plugging groove;

[0041] The second spring is installed in the spring cavity, and the top end of the second spring abuts against the driving nut, and the bottom end abuts against the small valve needle.

[0042] The beneficial effects of the electronic expansion valve provided by the embodiment of the present utility model are:

[0043] In this application, an assembly cavity is provided in the large valve needle, a blind hole is provided in the bottom wall of the assembly cavity, a plurality of side holes communicating with the blind hole are provided in the side wall of the large valve needle, and the side holes are communicated with the second opening. A plurality of through holes are provided on the outer peripheral edge of the blind hole, and the plurality of through holes can communicate the assembly cavity with the first opening. In this way, only the first opening and the second opening need to be provided on the valve body, which can simplify the structure of the valve body, thereby reducing the processing cost of the valve body and improving the qualification rate. Moreover, the blind hole cooperates with the side holes to achieve pressure balance of the valve needle of the electronic expansion valve, so that the opening and closing of the valve can be better realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0045] Figure 1 It is a schematic cross-sectional structure diagram of an electronic expansion valve provided by an embodiment of the present invention;

[0046] Figure 2 It is a schematic cross-sectional structure diagram of the large valve needle of the electronic expansion valve provided by an embodiment of the present invention;

[0047] Figure 3 It is a schematic structure diagram of the small valve needle of the electronic expansion valve provided by an embodiment of the present invention;

[0048] Figure 4 It is a schematic cross-sectional structure diagram of the valve seat of the electronic expansion valve provided by an embodiment of the present invention.

[0049] Icons: 100 - Electronic expansion valve; 110 - Valve body; 111 - Installation cavity; 113 - First opening; 115 - Second opening; 117 - Valve seat; 119 - Limit seat; 121 - Sleeve; 123 - Installation groove; 125 - Limit groove; 127 - Channel hole; 129 - Annular groove; 130 - Rotor assembly; 150 - Driving nut; 151 - Insertion groove; 170 - Large valve needle; 171 - Assembly cavity; 173 - Blind hole; 175 - Side hole; 177 - Through hole; 179 - First flow - through gap; 180 - Second spring; 181 - Sealing ring groove; 190 - Limiting part; 191 - Central hole; 193 - Sleeved part; 195 - Through hole; 210 - Small valve needle; 211 - Limit platform; 213 - Second flow - through gap; 215 - Cutting plane; 216 - Balance channel; 217 - First side channel; 219 - Second side channel; 221 - Spring cavity; 223 - Clamping part; 230 - Spring seat; 231 - Through hole; 233 - Third flow - through gap; 250 - First spring; 270 - Sealing ring. Detailed implementation mode

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. The components of the embodiments of the present utility model described and illustrated herein can generally be arranged and designed in a variety of different configurations.

[0051] Therefore, the following detailed description of the embodiments of the present utility model provided in the drawings is not intended to limit the scope of the claimed present utility model, but merely represents selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts fall within the scope of protection of the present utility model.

[0052] It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0053] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the utility model product is usually placed during use. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. In addition, terms such as "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0054] In addition, terms such as "horizontal" and "vertical" do not mean that the components are required to be absolutely horizontal or hanging vertically, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0055] In the description of the present utility model, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0056] Embodiment

[0057] Please refer to Figure 1 , this embodiment provides an electronic expansion valve 100, and the valve body 110 of the electronic expansion valve 100 has a simple structure and is easy to manufacture.

[0058] Please refer to Figure 1 , Figure 2 and Figure 3, this embodiment provides an electronic expansion valve 100, which includes a valve body 110, a rotor assembly 130, a drive nut 150, a large valve needle 170, a limiting member 190, and a small valve needle 210. The valve body 110 has an installation cavity 111, a first opening 113, and a second opening 115 that communicate with the installation cavity 111. The first opening 113 is located at the end of the valve body 110, and the second opening 115 is provided on the side wall of the valve body 110. The rotor assembly 130 is installed inside the valve body 110 and is threadedly connected to the rotating shaft of the rotor assembly 130. The large valve needle 170 is installed in the installation cavity 111. The large valve needle 170 is provided with an assembly cavity 171. A blind hole 173 is provided on the bottom wall of the assembly cavity 171. A plurality of side holes 175 communicating with the blind hole 173 are provided on the side wall of the large valve needle 170. The side holes 175 communicate with the second opening 115. A plurality of through holes 177 are provided on the outer peripheral edge of the blind hole 173. The plurality of through holes 177 can make the assembly cavity 171 communicate with the first opening 113. The limiting member 190 is installed at the top end of the large valve needle 170. The limiting member 190 is provided with a central hole 191. A part of the inner peripheral edge of the limiting member 190 extends into the assembly cavity 171. The small valve needle 210 is movably installed in the assembly cavity 171, and the bottom end of the small valve needle 210 corresponds to the blind hole 173. The top end of the small valve needle 210 passes through the central hole 191 and is connected to the drive nut 150. A limiting platform 211 is provided on the part of the small valve needle 210 located in the assembly cavity 171. When the small valve needle 210 moves upward, the large valve needle 170 can be driven to move upward by abutting against the limiting platform 211 through the limiting member 190.

[0059] In this embodiment, an assembly cavity 171 is provided in the large valve needle 170, a blind hole 173 is provided on the bottom wall of the assembly cavity 171, a plurality of side holes 175 communicating with the blind hole 173 are provided on the side wall of the large valve needle 170, and the side holes 175 communicate with the second opening 115. A plurality of through holes 177 are provided on the outer peripheral edge of the blind hole 173. The plurality of through holes 177 can make the assembly cavity 171 communicate with the first opening 113. In this way, only the first opening 113 and the second opening 115 need to be provided on the valve body 110, which can simplify the structure of the valve body 110, thereby reducing the processing cost of the valve body 110 and improving the qualification rate. Moreover, the blind hole 173 cooperates with the side holes 175 to achieve pressure balance of the valve needle of the electronic expansion valve 100, so that opening and closing the valve can be better achieved.

[0060] Please refer to Figure 1 , Figure 2 and Figure 3 , in this embodiment, a first flow gap 179 is formed between the outer peripheral edge of the small valve needle 210 and the inner wall of the assembly cavity 171. A second flow gap 213 is formed between the small valve needle 210 and the inner wall of the central hole 191. The first flow gap 179 and the second flow gap 213 communicate with each other.

[0061] In this embodiment, a first overflow gap 179 and a second overflow gap 213 are provided, so that the fluid entering the assembly cavity 171 can flow upward along the first overflow gap 179 and the second overflow gap 213, thereby achieving internal balance at both ends of the large valve needle 170 and the small valve needle 210. Secondly, the liquid in the upper part of the installation cavity 111 can also flow downward, which can prevent the accumulation of lubricating oil and the like in the valve body 110.

[0062] In this embodiment, the limiting platform 211 is provided with a cutting plane 215 in the height direction, and a first overflow gap 179 is formed between the cutting plane 215 and the inner wall of the assembly cavity 171. By providing the cutting plane 215, the small valve needle 210 can have an arc-shaped side wall that cooperates with the side wall of the assembly cavity 171, so that the small valve needle 210 can slide stably relative to the large valve needle 170. And a first overflow gap 179 can be formed between the cutting plane 215 area and the side wall of the assembly cavity 171 to allow fluid to flow.

[0063] Please refer to Figure 1 、 Figure 2 and Figure 3 In this embodiment, a balance channel 216 is provided along the axial direction of the small valve needle 210. The top end of the balance channel 216 penetrates the top surface of the small valve needle 210, and the bottom end does not penetrate the bottom end of the small valve needle 210. A first side channel 217 communicating with the first overflow gap 179 and a second side channel 219 communicating with the second overflow gap 213 are also provided on the side wall of the small valve needle 210.

[0064] In this embodiment, a balance channel 216 is provided in the small valve needle 210, and a first side channel 217 and a second side channel 219 are provided, so that the upper, middle, and lower chambers of the separated installation cavity 111 can be sequentially communicated, thereby balancing the pressure and maintaining pressure balance.

[0065] Please refer to Figure 1 、 Figure 2 、 Figure 3 and Figure 4, in this embodiment, the electronic expansion valve 100 further includes a spring seat 230 and a first spring 250. The valve body 110 includes a valve seat 117, a limit seat 119, and a sleeve 121. An installation cavity 111, a first opening 113, and a second opening 115 are provided in the valve seat 117. An installation groove 123 is provided at the top of the valve seat 117. The spring seat 230 is installed in the installation groove 123, and the spring seat 230 is provided with a through hole 231 for the small valve needle 210 to pass through. A third flow passage gap 233 is formed between the side wall of the through hole 231 and the side wall of the small valve needle 210. The bottom end of the first spring 250 abuts against the limiting member 190, and the top end of the first spring 250 abuts against the spring seat 230. The limit seat 119 is installed in the installation groove 123 and is located above the spring seat 230. The limit seat 119 is provided with a limit groove 125, and the drive nut 150 is movably installed in the limit groove 125. The sleeve 121 is installed in the installation groove 123, and the rotor assembly 130 is installed in the sleeve 121.

[0066] This embodiment provides the first spring 250, so that the small valve needle 210 can operate independently relative to the large valve needle 170. By providing the third flow passage gap 233, the chamber above the spring seat 230 can communicate with the chamber below the spring seat 230.

[0067] In this embodiment, the limit seat 119 is provided with a through hole 127, and the through hole 127 communicates with the third flow passage gap 233.

[0068] This embodiment provides the through hole 127, so that the chamber above the limit seat 119 can communicate with the third flow passage gap 233, so that the fluid accumulated in the chamber above the limit seat 119 can flow into the third flow passage gap 233 through the through hole 127, and finally be discharged through the second flow passage gap 213, the first flow passage gap 179, and the through hole 177.

[0069] Please refer to Figure 1 、 Figure 2 and Figure 3 , in this embodiment, the limiting member 190 is convexly provided with a sleeved portion 193, and the bottom of the first spring 250 is sleeved on the sleeved portion 193. The sleeved portion 193 is provided with a through hole 195 communicating with the second flow passage gap 213.

[0070] This embodiment provides the through hole 195, so that the inside and outside of the limiting member 190 can communicate, so that the fluid accumulated outside the limiting member 190 can flow to the second flow passage gap 213 through the side hole 175.

[0071] In this embodiment, an annular groove 129 is provided inside the valve body 110 and corresponding to the position of the second opening 115. The side hole 175 communicates with the annular groove 129. The annular groove 129 is provided to facilitate the flow of fluid more conveniently.

[0072] Please refer to Figure 1 , Figure 2 and Figure 3 , in this embodiment, the electronic expansion valve 100 further includes a sealing ring 270. A sealing ring groove 181 is provided on the outer peripheral edge of the large valve needle 170. The sealing ring 270 is disposed in the sealing ring groove 181, which can achieve the seal between the large valve needle 170 and the side wall of the installation cavity 111.

[0073] This embodiment provides the sealing ring 270, thereby avoiding internal leakage between the large valve needle 170 and the side wall of the installation cavity 111.

[0074] Please refer to Figure 1 , Figure 2 and Figure 3 , in this embodiment, the electronic expansion valve 100 further includes a second spring 180. A spring cavity 221 is provided at the top end of the small valve needle. The driving nut 150 is provided with a plugging groove 151, and the plugging groove 151 is in a T shape. A clamping portion 223 is provided at the top of the small valve needle 210. The clamping portion 223 is clamped with the plugging groove and can move relative to the plugging groove. The second spring 180 is installed in the spring cavity 221, and the top end of the second spring 180 abuts against the driving nut 150, and the bottom end abuts against the small valve needle 210.

[0075] In this embodiment, the second spring 180 is disposed between the small valve needle 210 and the driving nut 150, which can avoid overpressure between the small valve needle and the large valve needle 170, and also avoid overpressure between the large valve needle 170 and the valve body 110, thereby improving the sealing performance.

[0076] In summary, the working principle and beneficial effects of the electronic expansion valve 100 provided by the embodiment of the present invention are as follows:

[0077] In this embodiment, an assembly cavity 171 is provided on the large valve needle 170, a blind hole 173 is provided on the bottom wall of the assembly cavity 171, and a plurality of side holes 175 communicating with the blind hole 173 are provided on the side wall of the large valve needle 170, and the side holes 175 are communicated with the second opening 115. And a plurality of through holes 177 are provided on the outer peripheral edge of the blind hole 173, and the plurality of through holes 177 can communicate the assembly cavity 171 with the first opening 113. In this way, only the first opening 113 and the second opening 115 need to be provided on the valve body 110, which can simplify the structure of the valve body 110, thereby reducing the processing cost of the valve body 110 and improving the qualification rate. And the blind hole 173 cooperates with the side holes 175 to achieve the pressure balance of the valve needle of the electronic expansion valve 100, so that the opening and closing of the valve can be better realized. Most importantly, by providing the first flow gap 179, the second flow gap 213, the third flow gap 233, as well as the channel hole 127 and the through hole 195, etc., the upper, middle and lower regions of the installation cavity 111 can be communicated, thereby avoiding the accumulation of fluid in the valve body 110.

[0078] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. For those skilled in the art, the present utility model may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. An electronic expansion valve, characterized in that: include: A valve body (110), the valve body (110) having a mounting cavity (111) and a first opening (113) and a second opening (115) communicating with the mounting cavity (111), the first opening (113) being located at an end of the valve body (110), and the second opening (115) being arranged on a side wall of the valve body (110); a rotor assembly (130), wherein the rotor assembly (130) is installed in the valve body (110); A driving nut (150) connected to the rotating shaft of the rotor assembly (130) via threads; A large valve needle (170), the large valve needle (170) being installed in the installation cavity (111), the large valve needle (170) being provided with an assembly cavity (171), the bottom wall of the assembly cavity (171) being provided with a blind hole (173), the side wall of the large valve needle (170) being provided with a plurality of side holes (175) communicating with the blind hole (173), the side holes (175) being communicated with the second opening (115), the outer periphery of the blind hole (173) being provided with a plurality of through holes (177), the plurality of through holes (177) enabling the assembly cavity (171) to communicate with the first opening (113); a limiting member (190), the limiting member (190) being mounted on the top end of the large valve needle (170), the limiting member (190) being provided with a central hole (191), and the inner peripheral edge portion of the limiting member (190) extending into the assembly cavity (171); and, A small valve needle (210), the small valve needle (210) is movably installed in the assembly cavity (171), and the bottom end of the small valve needle (210) corresponds to the blind hole (173), the top end of the small valve needle (210) passes through the central hole (191) and is connected to the driving nut (150), and a limiting platform (211) is provided at the part of the small valve needle (210) located in the assembly cavity (171); When the small valve needle (210) moves upward, the large valve needle (170) can be driven to move upward by the contact between the limiting member (190) and the limiting platform (211).

2. The electronic expansion valve according to claim 1, characterized in that: A first flow gap (179) is formed between the outer periphery of the small valve needle (210) and the inner wall of the assembly cavity (171); A second flow gap (213) is formed between the small valve needle (210) and the inner wall of the central hole (191); The first flow gap (179) and the second flow gap (213) are in communication.

3. The electronic expansion valve according to claim 2, characterized in that: The limiting platform (211) is provided with a cutting plane (215) along the height direction, and the first flow gap (179) is formed between the cutting plane (215) and the inner wall of the assembly cavity (171).

4. The electronic expansion valve according to claim 2, characterized in that: The small valve needle (210) is provided with a balancing channel (216) along the axial direction of the small valve needle (210), and the top end of the balancing channel (216) passes through the top surface of the small valve needle (210); The side wall of the small valve needle (210) is also provided with a first side channel (217) communicating with the first flow gap (179) and a second side channel (219) communicating with the second flow gap (213).

5. The electronic expansion valve according to claim 4, characterized in that: The electronic expansion valve further comprises a spring seat (230) and a first spring (250); The valve body (110) comprises a valve seat (117), a limit seat (119) and a sleeve (121); The installation cavity (111), the first opening (113), and the second opening (115) are arranged on the valve seat (117); The top of the valve seat (117) is provided with a mounting groove (123); The spring seat (230) is installed in the installation groove (123), and the spring seat (230) is provided with a through hole (231) for the small valve needle (210) to pass through, and a third flow gap (233) is formed between the side wall of the through hole (231) and the side wall of the small valve needle (210); The bottom end of the first spring (250) abuts against the limiting member (190), and the top end of the first spring (250) abuts against the spring seat (230); The limiting seat (119) is installed in the installation groove (123) and is located above the spring seat (230). The limiting seat (119) is provided with a limiting groove (125), and the driving nut (150) is movably installed in the limiting groove (125); The sleeve (121) is installed in the installation groove (123), and the rotor assembly (130) is installed in the sleeve (121).

6. The electronic expansion valve according to claim 5, characterized in that: The limiting seat (119) is provided with a channel hole (127), and the channel hole (127) is connected to the third flow gap (233).

7. The electronic expansion valve according to claim 5 or 6, characterized in that: The limiting member (190) is provided with a protruding sleeve portion (193), and the bottom of the first spring (250) is sleeved on the sleeve portion (193); The sleeve portion (193) is provided with a through hole (195) communicating with the second flow gap (213).

8. The electronic expansion valve according to any one of claims 1 to 6, characterized in that: An annular groove (129) is provided inside the valve body (110) and at a position corresponding to the second opening (115); The side hole (175) is in communication with the annular groove (129).

9. The electronic expansion valve according to any one of claims 1 to 6, characterized in that: The electronic expansion valve further comprises a sealing ring (270), and a sealing ring groove (181) is provided on the outer periphery of the large valve needle (170); The sealing ring (270) is arranged in the sealing ring groove (181) to achieve sealing between the large valve needle (170) and the side wall of the installation cavity (111).

10. The electronic expansion valve according to any one of claims 1 to 6, characterized in that: The electronic expansion valve further includes a second spring (180); A spring chamber (221) is provided at the top end of the small valve needle; The driving nut (150) is provided with an inserting groove (151), and the inserting groove (151) is T-shaped; A clamping portion (223) is provided on the top of the small valve needle (210); The clamping portion (223) is clamped with the plug-in slot (151) and can move relative to the plug-in slot; The second spring (180) is installed in the spring chamber (221), and the top end of the second spring (180) abuts against the drive nut (150), and the bottom end of the second spring (180) abuts against the small valve needle (210).

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