Electronic expansion valve

Abstract

This invention provides an electronic expansion valve, relating to the field of valve technology. The electronic expansion valve includes a housing, a drive assembly, a large valve needle, a small valve needle, and a seal. The housing has an inlet, an outlet, and a sealing seat. The large valve needle has a mounting through hole along its height and passage holes corresponding to the inlet and outlet; the large valve needle is movably mounted within the housing. The small valve needle is movably disposed within the mounting through hole. The drive assembly is mounted within the housing and is drively connected to the small valve needle. The drive assembly can move the small valve needle to close or open the passage holes, allowing for blocking or connection between the inlet and outlet. The small valve needle can also drive the large valve needle to move. The seal is disposed on the large valve needle; when the large valve needle is closed, the seal abuts against the sealing seat, and / or when the small valve needle is closed, the small valve needle abuts against the seal. This provides better sealing.

Description

Technical Field

[0001] This invention relates to the field of regulating valve technology, and more specifically, to an electronic expansion valve. Background Technology

[0002] Electronic expansion valves utilize electrical signals generated by the regulated parameters to control the voltage or current applied to the expansion valve, thereby regulating the refrigerant supply. Stepless variable capacity refrigeration systems require a wide range of refrigerant supply adjustment and fast response times, which traditional throttling devices (such as thermostatic expansion valves) often struggle to meet. Electronic expansion valves, however, can effectively satisfy these requirements.

[0003] Electronic expansion valves are generally installed in refrigerant circuits to regulate the refrigerant flow rate in the circuit to meet different operating conditions. Electronic expansion valves consist of three parts: motor, electrical control, and mechanical components. The electrical control system rotates the motor and transmits the power to the mechanical components to realize the opening and closing of the electronic expansion valve and its flow regulation.

[0004] The dual-needle electronic expansion valve has two valve needles, providing a wider adjustment range and making it suitable for scenarios requiring more precise control.

[0005] To address the issue of low internal leakage in existing dual-valve needle electronic expansion valves, complex sealing structures are required, leading to increased assembly and manufacturing costs and poor sealing performance. Summary of the Invention

[0006] The object of the present invention includes, for example, providing an electronic expansion valve that can reduce the assembly and manufacturing costs of the expansion valve while improving the sealing of the electronic expansion valve.

[0007] The embodiments of the present invention can be implemented as follows:

[0008] In a first aspect, the present invention provides an electronic expansion valve, comprising a housing, a drive assembly, a large valve needle, a small valve needle, and a seal;

[0009] The housing is provided with a liquid inlet, a liquid outlet, and a sealing seat;

[0010] The large valve needle is provided with a mounting through hole along the height direction, and is also provided with a liquid passage hole corresponding to the liquid inlet and the liquid outlet. The large valve needle is movably installed in the housing.

[0011] The small valve needle is movably disposed within the mounting through hole;

[0012] The drive assembly is installed inside the housing and is connected to the small valve needle. The drive assembly can drive the small valve needle to move to close or open the liquid passage, which can block or connect the liquid inlet and the liquid outlet. The small valve needle can drive the large valve needle to move.

[0013] The sealing element is disposed on the large valve needle. When the large valve needle is in the closed state, the sealing element abuts against the sealing seat and / or when the small valve needle is in the closed state, the small valve needle abuts against the sealing element.

[0014] In an optional embodiment, the sealing element is disposed at the bottom end of the large valve needle, and when the large valve needle is in the closed state, the bottom surface of the sealing element abuts against the sealing seat.

[0015] In an optional embodiment, the seal is provided with a sealing hole. When the small valve needle is in the closed state, the end of the small valve needle is inserted into the sealing hole and abuts against the side wall of the sealing hole.

[0016] In an optional embodiment, the sealing hole gradually increases in size towards the top of the seal; and / or,

[0017] The cross-section of the small valve needle near the sealing seat gradually decreases.

[0018] In an optional embodiment, the seal is snapped onto the large valve needle.

[0019] In an optional embodiment, the inner wall of the mounting through hole is provided with a positioning ring groove, and the inner wall of the positioning ring groove is provided with a limiting ring groove.

[0020] The outer peripheral wall of the seal is provided with a snap-fit ​​ring platform, the seal is at least partially assembled in the positioning ring groove, and the top wall of the seal is in contact with the top wall of the positioning ring groove, and the limiting ring groove is assembled in the limiting ring groove.

[0021] In an optional embodiment, the bottom end of the large valve needle is provided with a mounting ring platform, and the top wall of the seal is recessed with an assembly ring groove.

[0022] The mounting ring platform is assembled within the mounting ring groove.

[0023] In an optional embodiment, the outer peripheral wall of the mounting ring platform is provided with a first snap-fit ​​portion, and the outer side wall of the assembly ring groove is provided with a first snap-fit ​​groove, the first snap-fit ​​portion being assembled into the first snap-fit ​​groove; and / or,

[0024] The inner peripheral wall of the mounting ring platform is provided with a second snap-fit ​​part, and the inner side wall of the assembly ring groove is provided with a second snap-fit ​​groove, and the second snap-fit ​​part is assembled in the second snap-fit ​​groove.

[0025] In an optional embodiment, the electronic expansion valve further includes a first sealing ring, wherein the outer peripheral wall of the large valve needle is provided with a first sealing ring groove, the first sealing ring is disposed in the first sealing ring groove and abuts against the inner peripheral wall of the housing; and / or,

[0026] The electronic expansion valve also includes a second sealing ring. The outer peripheral wall of the small valve needle is provided with a second sealing ring groove. The second sealing ring is disposed in the second sealing ring groove and abuts against the inner wall of the mounting through hole.

[0027] In an optional embodiment, a sealing ring protrudes from the sealing seat, and when the large valve needle is in the closed state, the end of the sealing member abuts against the sealing ring.

[0028] In an optional embodiment, the sealing element includes a first sealing element and a second sealing element, the first sealing element being sleeved on the outside of the second sealing element, and the first sealing element and / or the second sealing element being connected to the large valve needle.

[0029] When the large valve needle is in the closed state, the first seal abuts against the sealing seat;

[0030] When the small valve needle is in the closed state, the small valve needle abuts against the second seal.

[0031] The first seal and the second seal are made of different materials.

[0032] In an optional embodiment, the first seal and the second seal are integrally formed or the two are fixedly connected.

[0033] In an optional embodiment, the seal is fixedly connected to the large valve needle by adhesive bonding or embedding.

[0034] In an optional embodiment, the seal is integrally formed.

[0035] The beneficial effects of the electronic expansion valve provided in the embodiments of the present invention include, for example:

[0036] This application utilizes a single sealing element, mounted on the large valve needle, to achieve sealing between the large valve needle and the sealing seat, as well as between the small valve needle and the large valve needle. This improves the sealing performance of the electronic expansion valve body while reducing assembly and manufacturing costs. Most importantly, compared to using two sealing rings, this application uses a single sealing element. During sealing, downward pressure is first applied to the sealing element via the large valve needle, followed by direct pressure application via the small valve needle. This further enhances the sealing strength between the sealing element and the sealing seat, thereby extending the service life of the sealing element. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used 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 should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 A schematic diagram of the electronic expansion valve structure provided in an embodiment of the present invention;

[0039] Figure 2 This is a schematic cross-sectional view of the electronic expansion valve provided in an embodiment of the present invention;

[0040] Figure 3 This is a first assembly method for the seal in an electronic expansion valve provided by an embodiment of the present invention;

[0041] Figure 4 This is a second assembly method for the seal in the electronic expansion valve provided in the embodiments of the present invention;

[0042] Figure 5 This is a third assembly method for the seal in the electronic expansion valve provided in this embodiment of the invention;

[0043] Figure 6 This is a fourth assembly method for the seal in the electronic expansion valve provided in the embodiments of the present invention;

[0044] Figure 7 This is the fifth assembly method for the seal in the electronic expansion valve provided in the embodiments of the present invention;

[0045] Figure 8 This is the sixth assembly method for the seal in the electronic expansion valve provided in the embodiments of the present invention;

[0046] Figure 9 This is the seventh assembly method for the seal in the electronic expansion valve provided in the embodiments of the present invention.

[0047] Icons: 100-Electronic expansion valve; 110-Housing; 111-Inlet; 113-Outlet; 115-Sealing seat; 117-Upper shell; 119-Middle shell; 121-Lower shell; 123-Through hole; 125-Positioning ring groove; 127-Limiting ring groove; 129-Sealing ring platform; 130-Drive assembly; 131-Rotor; 133-Shaft; 135-Drive nut; 150-Large valve needle; 151-Mounting through hole; 152-Liquid passage hole; 153-Body; 155-Cover; 157- Mounting ring; 159-First snap-fit ​​part; 161-Second snap-fit ​​part; 163-First sealing ring groove; 170-Small valve needle; 171-Second sealing ring groove; 190-Seal; 191-Sealing hole; 195-Snap-fit ​​ring; 197-Assembly ring groove; 199-First snap-fit ​​groove; 201-Second snap-fit ​​groove; 203-First seal; 205-Second seal; 211-First spring; 213-Washer; 215-Second spring; 217-First sealing ring; 219-Second sealing ring. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0049] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0050] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0051] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0052] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0053] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0054] Please refer to Figure 1 and Figure 2 To improve the sealing performance of the dual-needle electronic expansion valve 100 and reduce its manufacturing and assembly costs, this embodiment provides an electronic expansion valve 100. The electronic expansion valve 100 includes a housing 110, a drive assembly 130, a large valve needle 150, a small valve needle 170, and a sealing element 190. The housing 110 is provided with an inlet 111, an outlet 113, and a sealing seat 115. The large valve needle 150 has a mounting through hole 151 along its height direction and passage holes 152 corresponding to the inlet 111 and outlet 113. The large valve needle 150 is movably mounted within the housing 110. The small valve needle 170 is movably disposed within the mounting through hole 151. The drive assembly 130 is installed inside the housing 110 and is connected to the small valve needle 170. The drive assembly 130 can move the small valve needle 170 to close or open the liquid passage 152, allowing the liquid inlet and outlet 113 to be blocked or connected. The small valve needle 170 can move the large valve needle 150 to further open or close the flow channel. The seal 190 is disposed on the large valve needle 150. When the large valve needle 150 is in the closed state, the seal 190 abuts against the sealing seat 115. When the small valve needle 170 is in the closed state, the small valve needle 170 abuts against the seal 190.

[0055] This embodiment, by setting a sealing element 190 and installing it on the large valve needle 150, can achieve sealing between the large valve needle 150 and the sealing seat 115, and also between the small valve needle 170 and the large valve needle 150, using only one sealing element 190. This improves the sealing performance of the electronic expansion valve 100 while reducing assembly and manufacturing costs. Most importantly, compared to using two sealing rings, this application uses a single sealing element 190. During sealing, downward pressure can be applied to the sealing element 190 first through the large valve needle 150, and then pressure can be applied directly to the sealing element 190 through the small valve needle 170. This further improves the sealing strength between the sealing element 190 and the sealing seat 115, and also extends the service life of the sealing element 190.

[0056] Please refer to Figure 1 and Figure 2In this embodiment, the housing 110 includes an upper housing 117, a middle housing 119, and a lower housing 121 connected in sequence. The connection method can be welding or a detachable connection. The upper housing 117 is closed at the top and open at the bottom. The middle housing 119 is cylindrical. A through hole 123 is provided inside the lower housing 121 along its height direction. A liquid outlet is formed at the bottom of the through hole 123, and multiple liquid inlets are formed on the sidewall of the lower housing 121. A sealing seat 115 is formed within the through hole 123, and it can form a seal with the sealing element 190.

[0057] In this embodiment, the drive assembly 130 includes a rotor 131, a shaft 133, and a drive nut 135. The shaft 133 is fitted onto the rotor 131, and the rotor 131 is rotatably mounted within the upper housing 117. The bottom end of the shaft 133 is threaded. The drive nut 135 is movably mounted within the middle housing 119, and the middle housing 119 can restrict the rotation of the drive nut 135. The end of the shaft 133 is fitted onto the drive nut 135. The rotor 131 drives the shaft 133 to rotate, and the shaft 133 drives the drive nut 135 to move.

[0058] In this embodiment, a first spring 211 is provided inside the large valve needle 150. One end of the first spring 211 abuts against the large valve needle 150, and the other end is connected to the small valve needle 170. The small valve needle 170 is connected to the drive nut 135. The drive nut 135 moves up and down, which can drive the small valve needle 170 to move up and down. The small valve needle 170 moves up and down, which can drive the large valve needle 150 to move up and down.

[0059] Please refer to Figure 1 and Figure 2 In this embodiment, the electronic expansion valve 100 also includes a washer 213, which is installed inside the large valve needle 150. The small valve needle 170 is provided with a locking platform. In the initial stage of the small valve needle 170 moving upward, the large valve needle 150 does not move. When the locking platform abuts against the washer 213, the small valve needle 170 can drive the large valve needle 150 to move upward, and the medium flow rate increases.

[0060] In this embodiment, the small valve needle 170 and the drive nut 135 are connected by a pin and a slot, and a second spring 215 is provided between the small valve needle 170 and the drive nut 135, which allows the small valve needle 170 and the drive nut 135 to be flexibly connected.

[0061] In this embodiment, the sealing element 190 is disposed at the bottom end of the large valve needle 150. When the large valve needle 150 is in the closed state, the bottom surface of the sealing element 190 abuts against the sealing seat 115.

[0062] By placing the seal 190 at the bottom of the large valve needle 150, the assembly and sealing effect of the seal 190 can be better achieved.

[0063] Please refer to Figure 1 and Figure 2 In this embodiment, the sealing member 190 is provided with a sealing hole 191. When the small valve needle 170 is in the closed state, the end of the small valve needle 170 is inserted into the sealing hole 191 and abuts against the side wall of the sealing hole 191.

[0064] A sealing hole 191 is provided on the seal 190 to facilitate the insertion of the end of the small valve needle 170, thereby achieving a seal. This allows for better simultaneous sealing of both the large valve needle 150 and the small valve needle 170.

[0065] In this embodiment, the sealing hole 191 gradually increases in size towards the top of the seal 190. The cross-section of the small valve needle 170 near the sealing seat 115 gradually decreases. This arrangement allows a conical seal to be formed between the small valve needle 170 and the seal 190, thereby further improving the sealing effect of the seal 190.

[0066] Of course, in some other embodiments of this application, the sealing hole 191 may also be cylindrical.

[0067] In this embodiment, the seal 190 can be any one of fluororesin such as PTFE, FEP, PFA, ETFE, and modified PTFE, or any one of rubber such as NBR, HNBR, SIL, FKM, and EPDM, to achieve a soft-to-hard seal between the valve seat and the large valve needle 150 and the small valve needle 170, effectively solving the problem of low internal leakage sealing performance of the large valve needle 150 and the small valve needle 170. Please refer to... Figure 1 and Figure 2 In this embodiment, the seal 190 is snapped onto the large valve needle 150. This snap-fit ​​assembly method facilitates the assembly and replacement of the seal 190.

[0068] Please refer to Figure 3 In some embodiments of this application, the assembly method of the seal 190 is as follows:

[0069] The inner wall of the mounting through hole 151 is provided with a positioning ring groove 125, and the inner wall of the positioning ring groove 125 is provided with a limiting ring groove 127. The outer peripheral wall of the seal 190 is provided with a snap-fit ​​ring platform 195. The seal 190 is at least partially assembled in the positioning ring groove 125, and the top wall of the seal 190 is in contact with the top wall of the positioning ring groove 125. The snap-fit ​​ring platform 195 is assembled in the limiting ring groove 127.

[0070] In this embodiment, by setting a positioning ring groove 125, the installation position of the seal 190 can be limited by the abutting between the top wall of the seal 190 and the top wall of the positioning ring groove 125. This also prevents the seal 190 from moving upward due to force during the downward movement of the large valve needle 150. The assembly method of setting the engagement ring platform 195 and the limiting ring groove 127 can prevent the seal 190 from disengaging from the positioning ring groove 125 during the upward movement of the large valve needle 150.

[0071] The limiting annular groove 127 can be formed directly by machining. However, in this embodiment, in order to clamp the sealing element 190 within the limiting annular groove 127, the large valve needle 150 is configured as two parts, including a body 153 and a cover 155. The cover 155 has a through hole 123, and a limiting platform is provided around the periphery of the through hole 123. The sealing element 190 is installed in the through hole 123, and the bottom wall of the sealing element 190 abuts against the limiting platform. The cover 155 is installed at the end of the body 153 and connected to the outer periphery of the body 153. A limiting annular groove 127 is formed between the limiting platform and the end of the body 153. By applying a clamping force to the cover 155, the sealing element 190 can be pressed into the limiting annular groove 127.

[0072] Specifically, the cover 155 can be integrally formed with the body 153, or the cover 155 can be installed on the end of the body 153 by means of threads.

[0073] Please refer to Figures 4-6 In some other embodiments of this application, the sealing element 190 is assembled as follows:

[0074] The bottom end of the large valve needle 150 is provided with a mounting ring platform 157, and the top wall of the seal 190 is recessed with an assembly ring groove 197, into which the mounting ring platform 157 is assembled. The outer peripheral wall of the mounting ring platform 157 is provided with a first snap-fit ​​portion 159, and the outer side wall of the assembly ring groove 197 is provided with a first snap-fit ​​groove 199, into which the first snap-fit ​​portion 159 is assembled. The inner peripheral wall of the mounting ring platform 157 is provided with a second snap-fit ​​portion 161, and the inner side wall of the assembly ring groove 197 is provided with a second snap-fit ​​groove 201, into which the second snap-fit ​​portion 161 is assembled.

[0075] In this embodiment, by providing a first snap-fit ​​portion 159 and a second snap-fit ​​portion 161 on the mounting ring platform 157, and providing a first snap-fit ​​groove 199 and a second snap-fit ​​groove 201 on the inner and outer sides of the assembly ring groove 197, the seal 190 can be prevented from falling off.

[0076] The bottom ends of the bottom surfaces of the first snap-fit ​​part 159 and the second snap-fit ​​part 161 are provided with guide slopes, so that the first snap-fit ​​part 159 and the second snap-fit ​​part 161 can be snapped into the first snap-fit ​​groove 199 and the second snap-fit ​​groove 201 respectively.

[0077] The number of the first latching part 159 and the second latching part 161 can be set according to actual needs, and only needs to be set at intervals in the height direction.

[0078] Please refer to Figure 7 Of course, in some embodiments of this application, only the first card receiving part 159 and the first card receiving slot 199, or the second card receiving part 161 and the second card receiving slot 201 may be provided.

[0079] Please refer to Figure 8 Secondly, in some other embodiments of this application, the seal 190 can also be attached to the bottom end of the large valve needle 150 by means of fasteners or adhesives, or the seal 190 can be connected to the large valve needle 150 by means of inlay.

[0080] It should be noted that the seals 190 in the above examples are all integrally molded. This facilitates the installation of the seals 190.

[0081] Please refer to Figure 9 In other embodiments of this application, the sealing element 190 includes a first sealing element 203 and a second sealing element 205. The first sealing element 203 is sleeved on the outside of the second sealing element 205, and both the first sealing element 203 and the second sealing element 205 are connected to the large valve needle 150. When the large valve needle 150 is in the closed state, the first sealing element 203 abuts against the sealing seat 115. When the small valve needle 170 is in the closed state, the small valve needle 170 abuts against the second sealing element 205. The first sealing element 203 and the second sealing element 205 are made of different materials. In this way, the sealing element 190 can be integrally formed by the first sealing element 203 and the second sealing element 205. Alternatively, they can be processed separately and then fixedly connected, for example, by bonding. This allows for the selection of different materials to meet different requirements for the deformation, hardness, etc., of the sealing element 190. The first seal 203 may be made of a harder rubber material and the second seal 205 may be made of a softer rubber material, or the second seal 205 may be made of a harder material and the first seal 203 may be made of a softer material.

[0082] Please continue to refer to Figure 2 In this embodiment, a sealing ring platform 129 protrudes from the sealing seat 115. When the large valve needle 150 is in the closed state, the end of the sealing member 190 abuts against the sealing ring platform 129. The sealing ring platform 129 is provided with rounded corners, which allows a line seal to be formed between the sealing member 190 and the sealing ring platform 129, thereby enhancing the sealing performance.

[0083] In this embodiment, the electronic expansion valve 100 also includes a first sealing ring 217. The outer peripheral wall of the large valve needle 150 is provided with a first sealing ring groove 163. The first sealing ring 217 is disposed in the first sealing ring groove 163 and abuts against the inner peripheral wall of the housing 110, thereby achieving better sealing between the large valve needle 150 and the housing 110.

[0084] In this embodiment, the electronic expansion valve 100 further includes a second sealing ring 219. The outer peripheral wall of the small valve needle 170 is provided with a second sealing ring groove 171, and the second sealing ring 219 is disposed in the second sealing ring groove 171 and abuts against the inner wall of the mounting through hole 151. This can better achieve the sealing between the large valve needle 150 and the small valve needle 170.

[0085] In this embodiment, the small valve needle 170 has a hollow structure, allowing its lower end to communicate with the chamber of the second spring 215. Thus, when both the large valve needle 150 and the small valve needle 170 are closed, the first sealing ring 217 and the second sealing ring 219 enclose a first cavity, a second cavity, and a third cavity. The first cavity is formed by the inner wall of the lower shell 121, the seal 190, the outer wall of the small valve needle 170, and the first and second sealing rings 217 and 219; this area communicates with the inlet 111. The second cavity is formed by the outlet 113, the seal 190, and the interior of the small valve needle 170. The third cavity is formed by the area above the first and second sealing rings 217 and 219. When both the large valve needle 150 and the small valve needle 170 are fully closed, the refrigerant in the first chamber cannot enter the second and third chambers. The hollow design of the small valve needle 170 allows the second and third chambers to be connected, making their pressures the same and forming an internal balance. When flow regulation is required, the force required to open the valve is small, which is beneficial for the opening and closing of the small valve needle 170.

[0086] Please continue to refer to Figure 2The movement process of the electronic expansion valve 100 is as follows: the rotor 131 rotates in the forward direction, the middle shell 119 restricts the rotation of the drive nut 135, the rotor 131 drives the rotating shaft 133 to rotate, the thread of the rotating shaft 133 drives the drive nut 135 to move upward, the drive nut 135 moves upward and drives the small valve needle 170 to move upward, the small valve needle 170 moves upward for a certain stroke and is restricted by the gasket and drives the large valve needle 150 to move upward, the large valve needle 150 and the small valve needle 170 move upward as a whole, and reach the maximum stroke after being restricted by the middle shell 119. Thus, the fully open action is completed. Rotor 131 rotates in the opposite direction, and the middle shell 119 restricts the rotation of drive nut 135. Rotor 131 drives shaft 133 to rotate, and the thread of shaft 133 drives drive nut 135 to move downward. Drive nut 135 moves downward, which drives small valve needle 170 to move downward. Small valve needle 170 presses down to compress spring, and the compression spring acts downward on large valve needle 150. Thus, large valve needle 150 moves downward to complete valve closing first, and then small valve needle 170 moves downward to complete valve closing. Thus, the full closing action is completed.

[0087] In summary, the embodiments of the present invention provide an electronic expansion valve 100 whose working principle and beneficial effects include:

[0088] This embodiment, by setting a sealing element 190 and installing it on the large valve needle 150, can achieve sealing between the large valve needle 150 and the sealing seat 115, and also between the small valve needle 170 and the large valve needle 150, using only one sealing element 190. This improves the sealing performance of the electronic expansion valve 100 while reducing assembly and manufacturing costs. Most importantly, compared to using two sealing rings, this application uses a single sealing element 190. During sealing, downward pressure can be applied to the sealing element 190 first through the large valve needle 150, and then pressure can be applied directly to the sealing element 190 through the small valve needle 170. This further improves the sealing strength between the sealing element 190 and the sealing seat 115, and also extends the service life of the sealing element 190.

[0089] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An electronic expansion valve, characterized in that, It includes a housing (110), a drive assembly (130), a large valve needle (150), a small valve needle (170), and a seal (190). The housing (110) is provided with a liquid inlet (111), a liquid outlet (113) and a sealing seat (115). The large valve needle (150) is provided with a mounting through hole (151) along the height direction, and is provided with a liquid passage hole (152) corresponding to the liquid inlet (111) and the liquid outlet (113). The large valve needle (150) is movably installed in the housing (110). The small valve needle (170) is movably disposed within the mounting through hole (151); The drive assembly (130) is installed inside the housing (110) and is connected to the small valve needle (170) in a transmission manner. The drive assembly (130) can drive the small valve needle (170) to move to close or open the liquid passage (152) so that the liquid inlet (111) and the liquid outlet (113) can be blocked or connected. The small valve needle (170) can drive the large valve needle (150) to move. The sealing element (190) is disposed on the large valve needle (150). When the large valve needle (150) is in the closed state, the sealing element (190) abuts against the sealing seat (115) and / or when the small valve needle (170) is in the closed state, the small valve needle (170) abuts against the sealing element (190). The sealing element (190) is disposed at the bottom end of the large valve needle (150). When the large valve needle (150) is in the closed state, the bottom surface of the sealing element (190) abuts against the sealing seat (115). The sealing element (190) is provided with a sealing hole (191). When the small valve needle (170) is in the closed state, the end of the small valve needle (170) is inserted into the sealing hole (191) and abuts against the side wall of the sealing hole (191). The sealing element (190) includes a first sealing element (203) and a second sealing element (205), the first sealing element (203) is sleeved on the outside of the second sealing element (205), and the first sealing element (203) and / or the second sealing element (205) are connected to the large valve needle (150); When the large valve needle (150) is in the closed state, the first seal (203) abuts against the sealing seat (115); When the small valve needle (170) is in the closed state, the small valve needle (170) abuts against the second seal (205); The first seal (203) and the second seal (205) are made of different materials.

2. The electronic expansion valve according to claim 1, characterized in that, The sealing hole (191) gradually increases in size towards the top of the seal (190); and / or, The cross-section of the small valve needle (170) near the sealing seat (115) gradually decreases.

3. The electronic expansion valve according to claim 1, characterized in that, The seal (190) is engaged with the large valve needle (150).

4. The electronic expansion valve according to claim 3, characterized in that, The inner wall of the mounting through hole (151) is provided with a positioning ring groove (125), and the inner wall of the positioning ring groove (125) is provided with a limiting ring groove (127). The outer peripheral wall of the seal (190) is provided with a snap ring platform (195), the seal (190) is at least partially assembled in the positioning ring groove (125), and the top wall of the seal (190) is in contact with the top wall of the positioning ring groove (125), and the limiting ring groove (127) is assembled in the limiting ring groove (127).

5. The electronic expansion valve according to claim 3, characterized in that, The bottom end of the large valve needle (150) is provided with an mounting ring platform (157), and the top wall of the sealing element (190) is recessed with an assembly ring groove (197). The mounting ring platform (157) is assembled in the mounting ring groove (197).

6. The electronic expansion valve according to claim 5, characterized in that, The outer peripheral wall of the mounting ring platform (157) is provided with a first snap-fit ​​portion (159), and the outer side wall of the assembly ring groove (197) is provided with a first snap-fit ​​groove (199), and the first snap-fit ​​portion (159) is assembled into the first snap-fit ​​groove (199); and / or, The inner peripheral wall of the mounting ring platform (157) is provided with a second snap-fit ​​part (161), and the inner side wall of the assembly ring groove (197) is provided with a second snap-fit ​​groove (201). The second snap-fit ​​part (161) is assembled in the second snap-fit ​​groove (201).

7. The electronic expansion valve according to claim 1, characterized in that, The electronic expansion valve further includes a first sealing ring (217), and the outer peripheral wall of the large valve needle (150) is provided with a first sealing ring groove (163). The first sealing ring (217) is disposed in the first sealing ring groove (163) and abuts against the inner peripheral wall of the housing (110); and / or, The electronic expansion valve also includes a second sealing ring (219). The outer peripheral wall of the small valve needle (170) is provided with a second sealing ring groove (171). The second sealing ring (219) is disposed in the second sealing ring groove (171) and abuts against the inner wall of the mounting through hole (151).

8. The electronic expansion valve according to claim 1, characterized in that, The sealing seat (115) is provided with a sealing ring platform (129). When the large valve needle (150) is in the closed state, the end of the sealing element (190) abuts against the sealing ring platform (129).

9. The electronic expansion valve according to claim 1, characterized in that, The first seal (203) and the second seal (205) are integrally formed or fixedly connected.

10. The electronic expansion valve according to claim 1, characterized in that, The sealing element (190) is fixedly connected to the large valve needle (150) by adhesive bonding or embedding.

11. The electronic expansion valve according to any one of claims 1-8, characterized in that, The seal (190) is integrally formed.

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