Electronic expansion valve

Abstract

The utility model discloses an electronic expansion valve, and relates to the technical field of electronic expansion valves, the electronic expansion valve comprises a shell, a first valve needle and a second valve needle, the shell is provided with a driving cavity, a liquid inlet and a large valve port, the liquid inlet and the large valve port are communicated with each other, and the driving cavity is used for installing a driving device; the first valve needle is movably arranged between the driving cavity and the large valve port so as to open or close the large valve port, the first valve needle is provided with a moving channel and a balance channel, and the balance channel is communicated with the driving cavity and the large valve port; a communicating port, communicating with the large valve port, of the balance channel is formed in the end face, blocking the large valve port, of the first valve needle, and the moving channel is provided with a small valve port communicating with the large valve port; the second valve needle is movably arranged in the moving channel so as to open or close the small valve port and drive the first valve needle to open or close the large valve port. According to the technical scheme, the pressure difference between the two opposite ends of the first valve needle and the second valve needle can be balanced.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic expansion valves, in particular to an electronic expansion valve. Background Art

[0002] As a new type of control element, the electronic expansion valve has already broken through the concept of throttling mechanism. It is an important part of the intelligentization of the refrigeration system, an important means and guarantee for the real realization of the optimization of the refrigeration system, and a symbol of the mechatronics of the refrigeration system. It has been applied in more and more fields.

[0003] Electronic expansion valves include single-valve electronic expansion valves and double-valve electronic expansion valves. Currently, the first valve needle and the second valve needle of the double-valve electronic expansion valve on the market are extremely difficult to operate. The main reason is that the pressure difference between the first valve needle and the second valve needle is large. Utility Model Content

[0004] The main purpose of the utility model is to provide an electronic expansion valve, aiming to solve the problem that the first valve needle and the second valve needle have a large pressure difference at both ends, which causes the electronic expansion valve to be difficult to operate.

[0005] To achieve the above-mentioned purpose, the electronic expansion valve proposed by the utility model comprises:

[0006] The housing is provided with a driving chamber, a liquid inlet and a large valve port which are connected to each other, wherein the driving chamber is used for installing the driving device;

[0007] a first valve needle, the first valve needle is movably disposed between the drive chamber and the large valve port to open or close the large valve port, the first valve needle is provided with a moving channel and a balancing channel, the balancing channel is communicated with the drive chamber and the large valve port respectively, a communication port of the balancing channel communicating with the large valve port is provided on the end surface of the first valve needle blocking the large valve port, and the moving channel is provided with a small valve port communicating with the large valve port; and

[0008] The second valve needle is movably disposed in the moving channel to open or close the small valve port and drive the first valve needle to open or close the large valve port.

[0009] In one embodiment, the moving channel includes a connected limiting section and a moving section, the small valve port is arranged at one end of the moving section away from the limiting section, and the second valve is provided with a limiting portion corresponding to the limiting section to limit the displacement of the limiting portion in the moving direction.

[0010] In one embodiment, the first valve needle also includes a first valve body and a pressing sleeve, the first valve body is provided with a mounting groove, the pressing sleeve is arranged in the mounting groove, a limiting section is formed between the pressing sleeve and the groove wall of the mounting groove, and the moving section is arranged in the first valve body and communicated with the groove bottom of the mounting groove.

[0011] In one embodiment, the installation groove includes a sinking groove section and a limiting groove section, the sinking groove section is arranged away from the small valve port, the pressing sleeve is arranged on the sinking groove section, and the limiting section is formed in the limiting groove section.

[0012] In one embodiment, the pressing sleeve includes a pressing section and a sleeve section connected to each other, the pressing section is arranged away from the small valve port, the sleeve section is provided with a sleeve groove, and the limiting section is formed in the sleeve groove.

[0013] In one embodiment, the balancing channel includes a first flow channel and a second flow channel that are connected to each other, the first flow channel is provided in the pressing sleeve, and the second flow channel is provided in the first valve needle.

[0014] In one embodiment, the first flow channel is communicated with the moving channel.

[0015] In one embodiment, the first flow channel passes through the press sleeve.

[0016] In one embodiment, in the radial direction, the distance from the second flow channel to the central axis of the first valve needle is smaller than the distance from the cavity wall of the limiting section to the central axis of the first valve body.

[0017] In one embodiment, the electronic expansion valve further comprises a gasket, and the gasket is arranged on a side wall of the mounting groove facing the compression sleeve.

[0018] In one embodiment, when the radius of the gasket is greater than or equal to the distance from the second flow channel to the central axis of the first valve body, a third flow channel is provided on the gasket, and the first flow channel is connected to the second flow channel through the third flow channel.

[0019] In one embodiment, when the second valve needle closes the small valve port, a gap is provided between the limiting portion and the gasket.

[0020] In one embodiment, the range of the gap is greater than or equal to 0.3 mm.

[0021] In one embodiment, the limiting portion is configured as a limiting convex ring.

[0022] In one embodiment, in the radial direction, the distance from the balancing channel to the central axis of the second valve needle is less than or equal to the distance from the limiting protruding ring to the central axis of the second valve needle.

[0023] In one embodiment, the thickness of the limiting protruding ring ranges from 0.5 mm to 2 mm.

[0024] In one embodiment, when the second valve needle closes the small valve port, the distance between the limiting portion and the side wall of the limiting section facing the limiting portion ranges from 1 mm to 2.5 mm.

[0025] In one embodiment, the balancing channel is provided in plurality.

[0026] In one embodiment, the width of the balancing channel is greater than or equal to 0.8 mm.

[0027] The technical solution of the utility model is that a driving chamber, a connected liquid inlet and a large valve port are provided in the shell, and the driving chamber is used for installing the driving device; the first valve needle is movably arranged between the driving chamber and the large valve port to open or close the large valve port, the first valve needle is provided with a moving channel and a balancing channel, the balancing channel is respectively connected with the driving chamber and the large valve port, the connecting port of the balancing channel connected with the large valve port is provided at the end face of the first valve needle blocking the large valve port, and the moving channel is provided with a small valve port connected with the large valve port; the second valve needle is movably arranged in the moving channel to open or close the small valve port, and drive the first valve needle to open or close the large valve port. The solution uses the balancing channel to balance the pressure difference between the first valve needle and the second valve needle under different working conditions of the electronic expansion valve, so as to improve and solve the problem that the first valve needle and the second valve needle are not easy to operate due to the pressure difference problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0029] Figure 1 A structural schematic diagram of a first embodiment of an electronic expansion valve provided by the utility model;

[0030] Figure 2 for Figure 1 A schematic diagram of the structure of the electronic expansion valve part is provided;

[0031] Figure 3 for Figure 1 A schematic structural diagram of a first valve body of an electronic expansion valve is provided;

[0032] Figure 4 for Figure 1 A first cross-sectional structural schematic diagram of a first valve body of an electronic expansion valve is provided;

[0033] Figure 5 for Figure 1 A second cross-sectional structural schematic diagram of a first valve body of an electronic expansion valve is provided;

[0034] Figure 6 for Figure 1 A schematic diagram of the structure of a compression sleeve of an electronic expansion valve is provided;

[0035] Figure 7 for Figure 1 A schematic cross-sectional view of the compression sleeve of the electronic expansion valve;

[0036] Figure 8 A schematic structural diagram of a second embodiment of an electronic expansion valve provided by the utility model;

[0037] Fig. 9 for Figure 8 A schematic diagram of the structure of the electronic expansion valve part is provided;

[0038] Fig.10 for Figure 8 A first cross-sectional structural schematic diagram of a first valve body of an electronic expansion valve is provided;

[0039] Fig.11 for Figure 8 A second cross-sectional structural schematic diagram of a first valve body of an electronic expansion valve is provided;

[0040] Fig.12 for Figure 8 A schematic diagram of the structure of a compression sleeve of an electronic expansion valve is provided;

[0041] Fig.13 for Figure 8 A schematic cross-sectional structure diagram of a compression sleeve of an electronic expansion valve is provided;

[0042] Fig.14 for Figure 8 A schematic diagram of the structure of a gasket of an electronic expansion valve is provided;

[0043] Fig.15 for Figure 8 A schematic cross-sectional structure diagram of a gasket of an electronic expansion valve is provided;

[0044] Fig.16 A schematic structural diagram of a first embodiment of a second valve needle of an electronic expansion valve provided;

[0045] Fig.17 A schematic structural diagram of a second embodiment of a second valve needle of an electronic expansion valve is provided.

[0046] Description of Figure Numbers:

[0047] 100, shell; 110, drive chamber; 120, liquid inlet; 130, large valve port; 200, first valve needle; 210, moving channel; 211, small valve port; 212, limiting section; 213, moving section; 220, balance channel; 221, first flow channel; 222, second flow channel; 230, first valve body; 231, mounting groove; 231a, sinking groove section; 231b, limiting groove section; 240, pressing sleeve; 241, pressing section; 242, sleeve section; 300, second valve needle; 310, limiting portion; 400, gasket; 410, third flow channel; 500, drive device.

[0048] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0050] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0051] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the utility model.

[0052] The utility model provides an electronic expansion valve; the utility model can be applied not only to the refrigeration system of vehicles, but also to refrigeration equipment such as household air conditioners.

[0053] See also Figure 1 , Figure 2 , Figure 3 , Figure 8 and Fig. 9 In one embodiment of the utility model, the electronic expansion valve comprises a housing 100, a first valve needle 200 and a second valve needle 300. The housing 100 is provided with a driving chamber 110, a connected liquid inlet 120 and a large valve port 130. The driving chamber 110 is used for installing a driving device 500. The first valve needle 200 is movably arranged between the driving chamber 110 and the large valve port 130 to open or close the large valve port 130. The first valve needle 200 is provided with a moving channel 210 and a balancing channel 220. The balancing channel 220 is communicated with the driving chamber 110 and the large valve port 130 respectively. The communication port of the balancing channel 220 and the large valve port 130 is arranged on the end surface of the first valve needle 200 blocking the large valve port 130. The moving channel 210 is provided with a small valve port 211 communicated with the large valve port 130. The second valve needle 300 is movably arranged in the moving channel 210 to open or close the small valve port 211 and drive the first valve needle 200 to open or close the large valve port 130.

[0054] It can be understood that if there is a pressure difference force between the first valve needle 200 and the second valve needle 300, the resistance is very large, and the first valve needle 200 and the second valve needle 300 are difficult to operate; the technical solution of the utility model is to set a balancing channel 220 on the first valve needle 200, so that when the first valve needle 200 and the second valve needle 300 are both in a closed state, the driving chamber 110, the balancing channel 220 and the large valve port 130 are connected in sequence, and the balancing channel 220 can make the pressure at both ends of the second valve needle 300 in a balanced state, thereby reducing the driving force required to drive the second valve needle 300, thereby achieving the effect of facilitating the operation of the driving device 500 to drive the second valve needle 300 and reducing the torque requirement of the driving device 500. When the second valve needle 300 is in an open state and the first valve needle 200 is in a closed state, the driving chamber 110, the balancing channel 220 and the large valve port 130 are connected in sequence, and the balancing channel 220 can make the pressure at both ends of the first valve needle 200 in a balanced state, thereby reducing the driving force required to drive the first valve needle 200, thereby achieving the effect of facilitating the driving of the first valve needle 200 to open the large valve port 130. When the second valve needle 300 and the first valve needle 200 are both in an open state, the driving chamber 110, the balancing channel 220 and the large valve port 130 are connected in sequence, and the balancing channel 220 can make the pressure at both ends of the first valve needle 200 and the second valve needle 300 in a balanced state, thereby reducing the driving force required to drive the second valve needle 300 and the first valve needle 200, thereby achieving the effect of facilitating the operation of driving the second valve needle 300 and the first valve needle 200. This solution utilizes the balance channel 220 to balance the pressure difference between the first valve needle 200 and the second valve needle 300 of the electronic expansion valve under different working conditions, thereby improving and solving the problem that the first valve needle 200 and the second valve needle 300 are difficult to open due to the pressure difference.

[0055] Since the second valve needle 300 is movably arranged in the first valve needle 200, considering that the dual-valve electronic expansion valve must be compatible with the function of large-caliber full circulation, the large valve port 130 has a larger diameter, and the small flow section adjustment area needs to accurately adjust the flow, so the diameter specification of the small valve port 211 is much smaller than that of the large valve port 130. Therefore, the volume of the second valve needle 300 is much smaller than that of the first valve needle 200. If the balancing channel 220 is arranged on the second valve needle 300, due to the small volume of the second valve needle 300, the balancing channel 220 0 will also be limited, resulting in a smaller caliber of the balancing channel 220; it is understandable that the processing difficulty of a channel with a smaller caliber is also very high, which will not only increase the processing difficulty of the second valve needle, but also easily lead to the risk of drilling through the outer wall when the second valve needle 300 drills the center hole, thereby increasing the scrap rate of the second valve needle 300, and the balancing channel 220 will also cause the second valve needle 300 cone seal to deform, affecting the sealing of the second valve needle 300 and the small valve port 211, resulting in internal leakage exceeding the standard and failure, or even stuck. In this solution, the balancing channel 220 is set on the first valve needle 200. Due to the large volume of the first valve needle 200, the caliber setting of the balancing channel 220 is more flexible, that is, the width range of the balancing channel 220 is also expanded, and the difficulty of the processing technology is also reduced, thereby improving the yield of the first valve body 230, thereby improving the comprehensive cost of components of the electronic expansion valve, and improving the market competitiveness of the product.

[0056] Secondly, since the first valve needle 200 is large in size and has a thicker solid wall, the balancing channel 220 has less influence on the second valve needle 300, thereby reducing the probability of deformation of the sealing end seal of the first valve needle 200 and avoiding affecting the seal between the first valve needle 200 and the large valve port 130. In addition, the problem of internal leakage failure or jamming that may be caused by setting the balancing channel 220 on the second valve needle 300 is also avoided. Therefore, the adoption of this solution can well balance the pressure difference between the first valve needle 200 and the second valve needle 300, while reducing the difficulty of the processing and molding process of the balancing channel 200, and can realize the platformization, standardization, and serialization development of the product series, meet the requirements of various refrigeration systems, have a wide market coverage, and have greater market competitiveness.

[0057] It should be noted that, in this embodiment, the transverse cross-sections of the first valve needle 200 and the second valve needle 300 are circular.

[0058] Reference Figure 4 and Fig.10Optionally, the moving channel 210 includes a communicating limiting section 212 and a moving section 213, the small valve port 211 is arranged at one end of the moving section 213 away from the limiting section 212, and the second valve needle 300 is provided with a limiting portion 310 corresponding to the limiting section 212 to limit the displacement of the limiting portion 310 in the moving direction. It can be understood that the side wall of the limiting section 212 facing the small valve port 211 and the side wall facing away from the small valve port 211 are respectively used to limit the displacement of the limiting portion 310, and such a limiting structure is simple and easy to process.

[0059] The second valve needle 300 and the inner wall of the moving section are matched with a small gap; the range of the matching gap is between 0.05-0.10mm, which can prevent the second valve needle 300 from shaking while not affecting the movement effect of the second valve needle 300.

[0060] Reference Figure 2 , Figure 4 , Fig. 9 and Fig.10 Further, the first valve needle 200 further includes a first valve body 230 and a pressing sleeve 240, the first valve body 230 is provided with a mounting groove 231, the pressing sleeve 240 is arranged in the mounting groove 231, a limiting section 212 is formed between the pressing sleeve 240 and the groove wall of the mounting groove 231, the moving section 213 is arranged in the first valve body 230, and is communicated with the groove bottom of the mounting groove 231. It can be understood that the side wall of the pressing sleeve 240 facing the small valve port 211 and the limiting section facing the pressing sleeve The side walls of the first valve body 230 and the second valve body 231 together limit the displacement of the limiting portion in the moving direction. In this solution, the limiting section 212 is formed by the pressing sleeve 240 and the groove wall of the installation groove 231, which can facilitate the installation of the second valve needle 300. Specifically, in this solution, the second valve needle 300 can be installed into the moving section 213 of the first valve body 230 first, and then the pressing sleeve 240 can be installed into the installation groove 231, so that the limiting portion 310 is placed in the limiting section 212, which can reduce the installation difficulty of the second valve needle 300, thereby improving the installation efficiency. Of course, in other embodiments, the present application is not limited to this. The first valve needle 200 can also include a first valve part and a second valve part that are sealed and covered with each other, the first valve part is provided with a first positioning groove, the second valve part is provided with a second positioning groove, the first valve part and the second valve part are covered with each other, and a limiting section is formed between the first positioning groove and the second positioning groove.

[0061] When the second valve needle 300 drives the first valve needle 200 to operate, the limiting portion 310 pushes against the side wall of the mounting groove 231 away from the small valve port 211 , thereby driving the first valve needle 200 to operate and block the large valve port 130 .

[0062] It should be noted that the moving channel 210 also passes through the pressing sleeve 240 .

[0063] In one embodiment, the installation groove 231 includes a sinking groove section 231a and a limiting groove section 231b, the sinking groove section 231a is arranged away from the small valve port 211, the pressing sleeve 240 is arranged in the sinking groove section 231a, and the limiting section 212 is formed in the limiting groove section 231b; it can be understood that the side wall of the pressing sleeve 240 facing the small valve port 211 and the side wall of the limiting groove section 231b facing the pressing sleeve jointly limit the displacement of the limiting part in the moving direction, such an installation groove 231 is simple to form and is convenient for installing the pressing sleeve 240.

[0064] The width of the sinking groove section 231a is greater than the width of the limiting groove section 231b, and a step surface is formed between the sinking groove section 231a and the limiting groove section 231b. When the pressing sleeve 240 is installed, the step surface can abut against the pressing sleeve 240 to limit the position of the pressing sleeve 240, thereby increasing the installation stability of the pressing sleeve 240. Of course, the utility model is not limited to this, and in other embodiments, the width of the sinking groove section 231a can also be equal to the width of the limiting groove section 231b.

[0065] Furthermore, a mounting groove is provided on the side wall of the limiting groove section 231 b facing the pressing sleeve 240 , and the mounting groove is used for installing the gasket 400 , which can increase the stability of the installation of the gasket 400 .

[0066] The outer diameter of the gasket 400 is smaller than or equal to the distance from the limiting portion 310 to the central axis of the second valve body.

[0067] In the second embodiment, the pressing sleeve 240 includes a pressing section 241 and a sleeve section 242 that are connected to each other. The pressing section 241 is arranged away from the small valve port 211, and the sleeve section 242 is provided with a sleeve groove, and the limiting section 212 is formed in the sleeve groove; specifically, the side wall of the pressing section 241 facing the small valve port 211 and the side wall of the installation groove 231 facing the pressing sleeve 240 jointly limit the displacement of the limiting portion in the moving direction, and the limiting portion 310 moves in the sleeve groove, and the edge of the limiting portion 310 slides along the side groove wall of the sleeve groove. The setting of the sleeve section 242 can better limit the displacement of the limiting portion 310 and prevent the second valve needle 300 from shaking during the movement.

[0068] Furthermore, the electronic expansion valve also includes a gasket 400, which is arranged on the side wall of the installation groove 231 facing the pressing sleeve 240; when the pressing sleeve 240 is installed into the installation groove 231, the sleeve section 242 presses the gasket 400, which can increase the stability of the installation of the gasket 400.

[0069] Among them, the outer radius of the gasket 400 is greater than the distance from the edge of the limiting portion 310 to the central axis of the second valve needle 300, which can increase the sealing performance inside the electronic expansion valve and ensure that the refrigerant flows along a predetermined path inside the electronic expansion valve to avoid leakage and mixing.

[0070] Optionally, the limiting portion 310 is configured as a limiting convex ring, and such a limiting convex ring has a simple manufacturing process. Of course, the present invention is not limited thereto, and in other embodiments, the limiting portion 310 is configured as a plurality of limiting protrusions spaced around the outer circumference of the outer second valve body.

[0071] Optionally, the second valve body 300 is integrally formed. This is because the processing technology of integral forming is simple, which can improve production efficiency, and the integrally formed product has high rigidity, which can increase the strength of the limiting portion 310.

[0072] Furthermore, the outer diameter of the gasket 400 is equal to or slightly smaller than the diameter of the limiting protruding ring.

[0073] Further, in the radial direction, the distance from the balancing channel 220 to the central axis of the second valve needle 300 is less than or equal to the distance from the limiting convex ring to the central axis of the second valve needle 300; specifically, in the radial direction, the balancing channel 220 is partially exposed outside the limiting convex ring, so that when the second valve body rotates, the limiting portion 310 can avoid blocking the balancing channel 220. Of course, the utility model is not limited to this. In other embodiments, the distance from the balancing channel 220 to the central axis of the second valve needle 300 can also be greater than the distance from the limiting convex ring to the central axis of the second valve needle 300.

[0074] Wherein, when the limiting portion 310 is configured as a limiting convex ring, the distance from the balancing channel 220 to the central axis of the second valve needle 300 is less than or equal to the radius of the limiting convex ring.

[0075] Reference Figure 5 , Figure 6 , Figure 7 and Figures 11 to 13In one embodiment, the balancing channel 220 includes a first flow channel 221 and a second flow channel 222 which are connected to each other. The first flow channel 221 is arranged on the pressing sleeve 240, and the second flow channel 222 is arranged on the first valve needle 200. It can be understood that the first valve body 230 is also provided with a mounting groove 231. If the balancing channel 220 is arranged as a whole on the first valve body 230, the balancing channel 220 needs to pass through the groove wall of the mounting groove 231, which will reduce the thickness of part of the groove wall of the mounting groove 231, thereby affecting the rigidity of the first valve body 230. In this scheme, the balancing channel 220 is divided into a first flow channel 221 and a second flow channel 222, which are respectively arranged on the pressing sleeve 240 and the first valve body 230. In this way, the first flow channel 221 can be prevented from passing through the groove wall of the mounting groove 231, thereby ensuring the rigidity of the first valve body 230. Of course, the present invention is not limited thereto. In other embodiments, the balancing channel 220 may also penetrate the first valve body 230 along the axial direction of the first valve body 23 , without providing the first flow channel 221 on the pressing sleeve 240 .

[0076] In one embodiment, the first flow channel 221 is connected to the moving channel 210, which can reduce the difficulty of forming the first flow channel 221, thereby improving production efficiency. Of course, the utility model is not limited to this, and in other embodiments, the first flow channel 221 may not be connected to the moving channel 210.

[0077] In one embodiment, the first flow channel 221 passes through the pressing sleeve 240 , so as to prevent the limiting portion 310 from blocking the first flow channel 221 .

[0078] Specifically, when the pressing sleeve 240 includes the pressing section 241 and the sleeve section 242 , the first flow channel 221 sequentially penetrates the pressing section 241 and the sleeve section 242 , thereby communicating with the second flow channel 222 .

[0079] Furthermore, in the radial direction, the distance from the second flow channel 222 to the center axis of the first valve needle 200 is smaller than the distance from the cavity wall of the limiting section 212 to the center axis of the first valve body 230, so that when the pressing sleeve 240 is installed, the first flow channel 221 is directly connected to the second flow channel 222.

[0080] Reference Fig.14 and Fig.15Furthermore, when the radius of the gasket 400 is greater than or equal to the distance from the second flow channel 222 to the central axis of the first valve body 230, the gasket 400 is provided with a third flow channel 410, and the first flow channel 221 is connected with the second flow channel 222 through the third flow channel 410, which can reduce the difficulty of the processing technology of the balancing channel 220. Of course, the utility model is not limited to this. In other embodiments, a connecting channel extending along the radial direction of the first valve needle 200 can be provided on the groove wall of the pressing sleeve 240 and the installation groove 231, and the first flow channel 221 and the second flow channel 222 are connected through the connecting channel.

[0081] Reference Fig.16 and Fig.17 Furthermore, in this embodiment, the limiting convex ring is provided with a plurality of flow gaps, which can increase the communication effect between the first flow channel 221 and the second flow channel 222. Of course, the present invention is not limited thereto, and in other embodiments, the limiting convex ring may not be provided with flow gaps.

[0082] Optionally, when the second valve needle 300 closes the small valve port 211, a gap is provided between the limiting portion 310 and the gasket 400, so as to avoid processing errors, resulting in the second valve needle 300 still being unable to block the small valve port 211 when the second valve needle 300 presses against the gasket 400, thereby affecting the sealing performance of the second valve needle 300 in blocking the small valve port 211.

[0083] Furthermore, the range of the gap is greater than or equal to 0.3 mm, which can ensure the sealing performance of the second valve needle 300 in blocking the small valve port 211. When the range of the gap is less than 0.3 mm, the processing error may not be covered, affecting the sealing performance of the second valve needle 300 in blocking the small valve port 211.

[0084] Optionally, the thickness of the limiting protruding ring is in the range of 0.5 mm to 2 mm, which can ensure the rigidity of the limiting protruding ring while reducing the mass of the second valve needle 300 .

[0085] In one embodiment, when the second valve needle 300 closes the small valve port 211, the distance between the limiting portion 310 and the side wall of the limiting section 212 facing the limiting portion 310 ranges from 1 mm to 2.5 mm, which can facilitate accurate flow regulation.

[0086] In one embodiment, the balancing channels 220 are provided in plurality, so that when a part of the balancing channels 220 is prevented from being accidentally blocked, the remaining balancing channels 220 can normally communicate with both sides of the first valve needle 200 and the second valve needle 300 .

[0087] In this embodiment, four balancing channels 220 are provided. Of course, the present invention is not limited thereto. In other embodiments, two balancing channels 220 may also be provided.

[0088] The four balancing channels 220 are arranged opposite to each other in pairs, and the four balancing channels 220 are located on the same circle.

[0089] Furthermore, the number of the first flow channels 211 and the number of the second flow channels 222 may be equal or different.

[0090] Furthermore, the width of the balancing channel 220 is greater than or equal to 0.8 mm. It can be understood that if the size of the balancing channel 220 is too small, the processing difficulty will increase. Limiting the width of the balancing channel 220 to be greater than or equal to 0.8 mm can reduce the process difficulty while ensuring the pressure balance effect at the opposite ends of the first valve needle 200 and the second valve needle 300.

[0091] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An electronic expansion valve, characterized in that: include: The housing is provided with a driving chamber, a liquid inlet and a large valve port which are connected to each other, wherein the driving chamber is used for installing the driving device; a first valve needle, the first valve needle is movably arranged between the driving chamber and the large valve port to open or close the large valve port, the first valve needle is provided with a moving channel and a balancing channel, the balancing channel is communicated with the driving chamber and the large valve port respectively, a communication port of the balancing channel communicating with the large valve port is arranged on the end surface of the first valve needle blocking the large valve port, and the moving channel is provided with a small valve port communicating with the large valve port; and The second valve needle is movably disposed in the moving channel to open or close the small valve port and drive the first valve needle to open or close the large valve port.

2. The electronic expansion valve according to claim 1, characterized in that: The moving channel includes a connected limiting section and a moving section, the small valve port is arranged at one end of the moving section away from the limiting section, and the second valve is provided with a limiting portion corresponding to the limiting section to limit the displacement of the limiting portion in the moving direction.

3. The electronic expansion valve according to claim 2, characterized in that: The first valve needle also includes a first valve body and a pressing sleeve. The first valve body is provided with a mounting groove. The pressing sleeve is arranged in the mounting groove. A limiting section is formed between the pressing sleeve and the groove wall of the mounting groove. The moving section is arranged in the first valve body and is connected to the groove bottom of the mounting groove.

4. The electronic expansion valve according to claim 3, characterized in that: The installation groove comprises a sinking groove section and a limiting groove section, the sinking groove section is arranged away from the small valve opening, the pressing sleeve is arranged on the sinking groove section, and the limiting section is formed in the limiting groove section.

5. The electronic expansion valve according to claim 3, characterized in that: The pressing sleeve comprises a pressing section and a sleeve section which are connected to each other. The pressing section is arranged away from the small valve opening. The sleeve section is provided with a sleeve groove, and the limiting section is formed in the sleeve groove.

6. The electronic expansion valve according to claim 3, characterized in that: The balancing channel includes a first flow channel and a second flow channel that are connected to each other. The first flow channel is arranged on the pressing sleeve, and the second flow channel is arranged on the first valve needle.

7. The electronic expansion valve according to claim 6, characterized in that: The first flow channel is in communication with the moving channel.

8. The electronic expansion valve according to claim 6, characterized in that: The first flow channel passes through the pressing sleeve.

9. The electronic expansion valve according to claim 6, characterized in that: In the radial direction, the distance from the second flow channel to the central axis of the first valve needle is smaller than the distance from the cavity wall of the limiting section to the central axis of the first valve body.

10. The electronic expansion valve according to claim 6, characterized in that: The electronic expansion valve further comprises a gasket, which is arranged on a side wall of the mounting groove facing the compression sleeve.

11. The electronic expansion valve according to claim 10, characterized in that: When the radius of the gasket is greater than or equal to the distance from the second flow channel to the central axis of the first valve body, the gasket is provided with a third flow channel, and the first flow channel is connected to the second flow channel through the third flow channel.

12. The electronic expansion valve according to claim 10, characterized in that: When the second valve needle closes the small valve opening, a gap is provided between the limiting portion and the gasket.

13. The electronic expansion valve according to claim 12, characterized in that: The range of the gap is greater than or equal to 0.3 mm.

14. The electronic expansion valve according to claim 2, characterized in that: The limiting portion is configured as a limiting convex ring.

15. The electronic expansion valve according to claim 14, characterized in that: The thickness of the limiting protruding ring ranges from 0.5 mm to 2 mm.

16. The electronic expansion valve according to claim 2, characterized in that: When the second valve needle closes the small valve port, the distance between the limiting portion and the side wall of the limiting section facing the limiting portion ranges from 1 mm to 2.5 mm.

17. The electronic expansion valve according to claim 1, characterized in that: There are multiple balancing channels.

18. The electronic expansion valve according to any one of claims 1 to 17, characterized in that: The width of the balancing channel is greater than or equal to 0.8 mm.

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