Electronic expansion valve

Abstract

The present application relates to the technical field of valves, and particularly to an electronic expansion valve. The electronic expansion valve includes a valve body assembly and a valve needle assembly. The valve body assembly is provided with a valve cavity, a valve port, and a flow port. The valve port is provided at one end of the valve body assembly and is communicated with the valve cavity. The flow port is provided on the circumferential side of the valve body assembly and is communicated with the valve cavity. The valve needle assembly is movably installed in the valve cavity to open or close the valve port. Among them, along the axial direction of the valve needle assembly, the end of the valve port close to the valve needle assembly protrudes from the bottom of the flow port. Moreover, the height L1 of the end of the valve port protruding from the bottom of the flow port, the distance L2 from the end of the valve needle assembly to the valve port when the electronic expansion valve is fully open, and the diameter D of the flow port satisfy L1 + L2 ≥ D / 2 and L1 + (L2 / 2) < D / 2. The electronic expansion valve provided by the present application solves the problem that the existing structural design of the electronic expansion valve cannot well balance the refrigerant flow resistance and flow rate.

Description

Technical Field

[0001] The present application relates to the field of valve technology, and in particular to an electronic expansion valve. Background Art

[0002] The electronic expansion valve includes a valve body and a valve needle. A valve port is provided at one end of the valve body, and a flow port is provided around the valve body. The valve needle is installed in the valve body and cooperates with the valve port to control the flow of the refrigerant to achieve throttling and pressure reduction. The flow port and the valve port can be used as the inlet or outlet of the refrigerant of the electronic expansion valve respectively.

[0003] In the related art, when the electronic expansion valve is in the fully open state, the end of the valve needle is lower than the middle position of the flow port. When the refrigerant flows into the valve cavity from the flow port, the area blocked by the valve needle is large, which will produce a large flow resistance. By raising the height of the valve port relative to the flow port, the height of the end of the valve needle relative to the flow hole in the fully open state can be raised accordingly. Although raising the height of the valve port can reduce the flow resistance, there is also a risk of excessive refrigerant flow rate. Utility Model Content

[0004] Based on this, it is necessary to provide an electronic expansion valve to solve the problem that the existing electronic expansion valve structure design cannot well take into account the refrigerant flow resistance and flow rate.

[0005] The present application provides an electronic expansion valve, which includes a valve body assembly and a valve needle assembly, wherein the valve body assembly is provided with a valve cavity, a valve port and a flow port, the valve port is arranged at one end of the valve body assembly and is communicated with the valve cavity, and the flow port is arranged at the peripheral side of the valve body assembly and is communicated with the valve cavity; the valve needle assembly can be movably installed in the valve cavity to open or close the valve port; wherein, along the axial direction of the valve needle assembly, the valve port is close to the end of the valve needle assembly and protrudes from the bottom of the flow port, and the end of the valve port protrudes from the bottom of the flow port by a height L1, the end of the valve needle assembly is at a distance L2 from the valve port when the electronic expansion valve is fully opened, and the diameter D of the flow port satisfies, L1+L2≥D / 2, L1+(L2 / 2) <D / 2。

[0006] In one of the embodiments, a mounting groove is formed on the circumferential side of the valve needle assembly, and the electronic expansion valve further comprises a sealing gasket, which is installed in the mounting groove and is used for sealingly cooperating with the valve port.

[0007] In one of the embodiments, a limiting protrusion is formed along the inner wall of the installation groove, and at least a portion of the limiting protrusion is embedded in the sealing gasket.

[0008] In one of the embodiments, the inner walls on both sides of the mounting groove along the axial direction of the valve needle assembly are defined as a first inner wall and a second inner wall respectively, and the two ends of the sealing gasket along the axial direction of the valve needle assembly are defined as a first end and a second end respectively, the length of the first end along the radial direction of the valve needle assembly is not less than the length of the second end along the radial direction of the valve needle assembly, and the first end is in contact with the first inner wall, and the second end is in contact with the second inner wall; wherein, the length of the first inner wall along the radial direction of the valve needle assembly is not less than the length of the first end along the radial direction of the valve needle assembly, and the length of the second inner wall along the radial direction of the valve needle assembly is not less than the length of the second end along the radial direction of the valve needle assembly; and, along the radial direction of the valve needle assembly, the maximum length of the inner circumference of the sealing gasket from the outer circumference is not greater than the length of the first end along the radial direction of the valve needle assembly.

[0009] In one embodiment, the first inner wall is arranged on a side of the second inner wall away from the valve port, the sealing gasket is formed with a sealing cone section for sealing with the valve port, and the sealing cone section tends to expand gradually along the direction from the second inner wall to the first inner wall.

[0010] In one of the embodiments, the valve needle assembly includes a first valve needle and a second valve needle, the first valve needle is provided with an assembly hole, one end of the second valve needle is passed through and protrudes from the assembly hole, and the other end of the second valve needle is spaced apart from and clamped with the end of the first valve needle to form the mounting groove; the first valve needle includes a second needle segment, the bottom end of the second needle segment is the side wall of the mounting groove and is in contact with the sealing gasket, and the bottom end of the second needle segment has a radial length of not less than a radial length of the sealing gasket along the valve needle assembly.

[0011] In one embodiment, the first valve needle further comprises a first needle segment, and the first needle segment is arranged at an end of the second needle segment away from the mounting groove; the outer diameter of the first needle segment is smaller than the outer diameter of the second needle segment.

[0012] In one embodiment, the valve cavity includes a guide section, a flow section and a transition section; a seal is provided between the valve needle assembly and the guide section, the valve needle assembly is sealed and movably cooperated with the guide section through the seal, the flow port is arranged in the flow section, the radial dimension of the flow section along the valve needle assembly is larger than the radial dimension of the guide section along the valve needle assembly, and the two ends of the transition section are respectively connected to the guide section and the flow section; wherein, when the electronic expansion valve is in a fully open state, the outer wall of the second needle section is spaced apart from the inner wall of the transition section.

[0013] In one embodiment, the second valve needle protrudes from the outer wall of one end of the assembly hole and is spaced from the inner wall of the first valve needle to form an assembly groove; the second valve needle is provided with a first through hole and a second through hole. One end of the first through hole communicates with the valve port, and the other end is close to the assembly groove. The second through hole is provided on the side wall of the second valve needle, and both ends of the second through hole communicate with the first through hole and the assembly groove respectively.

[0014] In one embodiment, the electronic expansion valve further includes a spring sleeve and a driving member. One end of the spring sleeve is connected to the driving member, and the other end is sleeved and connected to the end of the second valve needle protruding from the assembly hole; wherein, a third through hole is provided on the side wall of the spring sleeve, and the third through hole communicates with the assembly groove.

[0015] Compared with the prior art, for the electronic expansion valve provided in the present application, since the distance L2 from the end of the valve needle assembly to the valve port remains unchanged when the electronic expansion valve is in the fully open state, based on this, the present application raises the height of the valve port, that is, by setting L1 + L2 ≥ D / 2, the position of the valve needle assembly when it is fully open is correspondingly raised. At this time, the end of the valve needle assembly will be higher than the middle position of the flow port, thereby reducing the shielding area of the valve needle assembly for the flow port, which is beneficial to better reducing the flow resistance of the refrigerant flowing in from the flow port. Further, by setting L1 + (L2 / 2) < D / 2, it is possible to avoid excessive increase in the refrigerant flow rate caused by the elevation of the valve port. In this way, the refrigerant flow rate is more reasonable, and at the same time, it is also possible to avoid excessive elevation of the valve port, which is beneficial to reducing the processing difficulty and processing cost of the valve port. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0017] Figure 1 It is a side view of a partial structure of an electronic expansion valve according to an embodiment provided by the present application;

[0018] Figure 2 It is a cross-sectional view of an electronic expansion valve in a fully open state according to an embodiment provided by the present application;

[0019] Figure 3 It is a cross-sectional view of an electronic expansion valve in a closed state according to an embodiment provided by the present application;

[0020] Figure 4 It is a cross-sectional view of an electronic expansion valve according to an embodiment provided by the present application.

[0021] The symbols in the figure mean the following:

[0022] 100, electronic expansion valve; 10, valve body assembly; 101, valve cavity; 1011, transition section; 1012, guide section; 1013, flow section; 102, valve port; 103, flow port; 11, main valve body; 12, valve seat; 20, valve needle assembly; 201, mounting groove; 2011, limiting protrusion; 202, assembly groove; 21, first valve needle; 2101, assembly hole; 2102, sealing groove; 2103, welding groove; 211, first needle section; 212, second needle section; 22, second valve needle; 2201, first through hole; 2202, second through hole; 221, throttling section; 23, sealing gasket; 231, sealing cone section; 24, sealing member; 25, first elastic member; 30, spring sleeve; 301, third through hole; 40, driving member; 50, mounting seat; 501, mounting cavity. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0024] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it may be directly on the other component or there may also be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the specification of this application are for illustrative purposes only and do not represent the only implementation method.

[0025] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0026] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first feature is directly in contact with the second feature, or the first feature and the second feature are in contact indirectly through an intermediate medium. Moreover, a first feature being “above”, “above”, or “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, or “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0027] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in the specification of this application includes any and all combinations of one or more related listed items.

[0028] See also Figure 1-Figure 4 The present application provides an electronic expansion valve 100. The electronic expansion valve 100 includes a valve body assembly 10 and a valve needle assembly 20. The valve body assembly 10 is provided with a valve cavity 101, a valve port 102 and a flow port 103. The valve port 102 is provided at one end of the valve body assembly 10 and communicates with the valve cavity 101. The flow port 103 is provided on the circumference of the valve body assembly 10 and communicates with the valve cavity 101. The valve needle assembly 20 can be movably installed in the valve cavity 101 to open or close the valve port 102. In which, along the axial direction of the valve needle assembly 20, the end of the valve port 102 close to the valve needle assembly 20 is protruding from the bottom of the flow port 103, and the height L1 of the end of the valve port 102 protruding from the bottom of the flow port 103, the distance L2 from the end of the valve needle assembly 20 to the valve port 102 when the electronic expansion valve 100 is fully opened, and the diameter D of the flow port 103 satisfies, L1+L2≥D / 2, L1+(L2 / 2) <D / 2。

[0029] It can be understood that when the electronic expansion valve 100 is in the fully open state, the distance L2 from the end of the valve needle assembly 20 to the valve port 102 remains unchanged. Based on this, in this application, by raising the height of the valve port 102, that is, by setting L1 + L2 ≥ D / 2, the position of the valve needle assembly 20 when fully open is correspondingly raised. At this time, the end of the valve needle assembly 20 will be higher than the middle position of the flow port 103, thereby reducing the blocking area of the valve needle assembly 20 on the flow port 103, which is beneficial to better reducing the flow resistance of the refrigerant flowing in from the flow port 103. Further, by setting L1 + (L2 / 2) < D / 2, it is possible to avoid excessive increase in the refrigerant flow rate caused by the raising of the valve port 102. In this way, the refrigerant flow rate is relatively reasonable. At the same time, it is also possible to avoid excessive raising of the valve port 102, which is beneficial to reducing the processing difficulty and processing cost of the valve port 102.

[0030] It should be noted that the principle of reducing the blocking area of the flow port 103 by raising the valve port 102 and the valve needle assembly 20 is as follows: Since the flow port 103 is usually circular, the projections of the opposite end faces of the valve needle assembly 20 and the valve port 102 on the flow port 103 can form a figure composed of parallel lines and two arcs with the side wall of the flow port 103. When the refrigerant flows into the valve cavity 101 from the part of the flow port 103 within this figure, it will not be blocked by the outer wall of the valve needle assembly 20 or the valve port 102. When the valve port 102 and the valve needle assembly 20 are correspondingly raised, the center of the above figure will gradually move towards the center of the flow port 103, causing the area of the figure to gradually increase. Therefore, it is possible to increase the area of the flow port 103 that is not blocked by the outer wall of the valve port 102 or the outer wall of the valve needle assembly 20, which is beneficial to the improvement of the refrigerant flow rate.

[0031] It should also be noted that when the electronic expansion valve 100 is in the fully open state, the distance from the end face of the valve needle assembly 20 to the end face of the valve port 102 usually remains unchanged.

[0032] In one embodiment, as Figure 2 shown, the valve body assembly 10 includes a main valve body 11 and a valve seat 12 that are connected to each other. Among them, the valve port 102 is opened on the valve seat 12, and the flow port 103 is opened on the main valve body 11. In this way, the valve port 102 and the flow port 103 can be processed separately, and the height of the valve port 102 can be reasonably raised according to needs, thereby reducing the processing difficulty of the valve port 102.

[0033] Among them, the valve port 102 of the electronic expansion valve 100 can be increased to be basically equal to the inner diameter of the valve cavity 101 to meet the large flow rate demand. Of course, the design of the traditional small valve port 102 can also be adopted, and no more limitations are imposed here.

[0034] In order to achieve the throttling effect of the electronic expansion valve 100, a throttling section 221 may be provided at one end of the valve needle assembly 20 close to the valve port 102, wherein the outer wall of the throttling section 221 gradually expands along the axial direction of the valve needle assembly 20. In this way, the outer wall of the throttling section 221 cooperates with the valve port 102 to form channels with different flow areas, thereby achieving the flow regulation of the valve needle assembly 20 on the valve port 102.

[0035] Specifically, after the valve port 102 is opened, as the valve needle assembly 20 moves away from the valve port 102, the channel area between the throttling section 221 and the valve port 102 gradually increases, so that the refrigerant flow rate increases accordingly.

[0036] In one embodiment, if Figure 2 As shown, a mounting groove 201 is provided on the peripheral side of the valve needle assembly 20, and the electronic expansion valve 100 further includes a sealing gasket 23, which is installed in the mounting groove 201 and is used to seal with the valve port 102. By providing the sealing gasket 23 and the valve port 102 to seal, the sealing performance of the valve port 102 when closed can be ensured, and leakage of the electronic expansion valve 100 at the valve port 102 when the valve is closed can be avoided, thereby improving the safety of the electronic expansion valve 100.

[0037] Specifically, the sealing gasket 23 can be generally made of elastic materials such as butyl rubber, fluororubber, polytetrafluoroethylene or polyurethane, and the sealing gasket 23 and the mounting groove 201 are interference fit to achieve reliable installation of the sealing gasket 23. In addition, the probability of refrigerant leakage from the gap between the sealing gasket 23 and the mounting groove 201 can be reduced, thereby further improving the sealing performance of the valve port 102 when it is closed.

[0038] Further, in one embodiment, if Figure 3 As shown, a limiting protrusion 2011 is formed on the inner wall of the installation groove 201 , and the height direction of the limiting protrusion 2011 extends along the axial direction of the valve needle assembly 20 . At least a part of the limiting protrusion 2011 is embedded in the sealing gasket 23 .

[0039] Since the sealing gasket 23 usually has a certain elasticity, when the limiting protrusion 2011 is embedded in the sealing gasket 23, the sealing gasket 23 can be partially deformed and fit tightly with the limiting protrusion 2011. In this way, the refrigerant can be further prevented from penetrating into the gap between the sealing gasket 23 and the installation groove 201, which not only improves the sealing performance, but also effectively prevents the sealing gasket 23 from being squeezed by the high-pressure refrigerant in the gap and deforming toward the notch of the installation groove 201. In addition, even if some high-pressure refrigerant penetrates into the gap, the stopper of the limiting protrusion 2011 can also ensure the firm installation of the sealing gasket 23.

[0040] Specifically, in this embodiment, the limiting protrusion 2011 is preferably provided on the side wall of the installation groove 201 along the axial direction of the valve needle assembly 20, and the number of the limiting protrusions 2011 is two, and the two limiting protrusions 2011 are respectively provided on the two side walls of the installation groove 201 along the axial direction of the valve needle assembly 20, so that the limiting effect of the limiting protrusion 2011 on the sealing gasket 23 can be further ensured. However, it is not limited to this. In other embodiments, the number of the limiting protrusions 2011 can also be set to three, four or five, etc., which can be reasonably set according to actual needs. Preferably, at least one limiting protrusion 2011 is provided on any one of the two side walls of the installation groove 201 along the axial direction of the valve needle assembly 20.

[0041] In one embodiment, if Figure 3 As shown, the inner walls on both sides of the mounting groove 201 along the axial direction of the valve needle assembly 20 are respectively the first inner wall and the second inner wall, the first inner wall is arranged on the side of the second inner wall away from the valve port 102, the sealing gasket 23 is formed with a sealing cone section 231 for sealing with the valve port 102, and the sealing cone section 231 gradually expands along the direction from the second inner wall to the first inner wall. In this way, the arrangement of the sealing cone section 231 facilitates the sealing cooperation between the sealing gasket 23 and the end of the valve port 102.

[0042] Furthermore, in one embodiment, the two ends of the sealing gasket 23 along the axial direction of the valve needle assembly 20 are defined as the first end and the second end, respectively, the length of the first end along the radial direction of the valve needle assembly 20 is not less than the length of the second end along the radial direction of the valve needle assembly 20, and the first end is in contact with the first inner wall, and the second end is in contact with the second inner wall. The length of the first inner wall along the radial direction of the valve needle assembly 20 is not less than the length of the first end along the radial direction of the valve needle assembly 20, and the length of the second inner wall along the radial direction of the valve needle assembly 20 is not less than the length of the second end along the radial direction of the valve needle assembly 20. In addition, along the radial direction of the valve needle assembly 20, the maximum length of the inner circumference of the sealing gasket 23 from the outer circumference is not greater than the length of the first end along the radial direction of the valve needle assembly 20.

[0043] That is, the two axial side surfaces of the sealing gasket 23 along the valve needle assembly 20 are both covered by the inner walls on both sides of the mounting groove 201, and only the outer peripheral surface of the sealing gasket 23 is exposed. This is beneficial for utilizing the outer peripheral surface of the sealing cone section 231 and the valve port 102 to achieve sealing cooperation, and the inner walls on both sides of the mounting groove 201 can provide stable support for the sealing gasket 23 to prevent the sealing gasket 23 from deforming during use.

[0044] In one embodiment, if Figure 2As shown, the valve needle assembly 20 includes a first valve needle 21 and a second valve needle 22. The first valve needle 21 is provided with an assembly hole 2101. One end of the second valve needle 22 is passed through and protrudes from the assembly hole 2101. The other end of the second valve needle 22 is spaced apart from and sandwiched with the end of the first valve needle 21 to form an installation groove 201. In this way, the molding of the installation groove 201 is simple, which can reduce the difficulty of assembling the sealing gasket 23, thereby facilitating the improvement of the overall assembly efficiency.

[0045] The end of the first valve needle 21 close to the valve port 102 forms the above-mentioned throttling section 221 .

[0046] In order to fix the first valve needle 21 and the second valve needle 22, a welding groove 2103 extending circumferentially along the first valve needle 21 can be opened on the circumferential side of the first valve needle 21. In this way, the first valve needle 21 can be laser penetrated and welded to the second valve needle 22 through the welding groove 2103, thereby effectively reducing the difficulty of connecting the first valve needle 21 and the second valve needle 22.

[0047] In one embodiment, if Figure 2 and Figure 3 As shown, the first valve needle 21 includes a first needle segment 211 and a second needle segment 212, and the first needle segment 211 is arranged at one end of the second needle segment 212 away from the mounting groove 201. The bottom end of the second needle segment 212 is the side wall of the mounting groove 201 and is in contact with the sealing gasket 23, and the length of the bottom end of the second needle segment 212 along the radial direction of the valve needle assembly 20 is not less than the length of the sealing gasket 23 along the radial direction of the valve needle assembly 20.

[0048] It should be noted that the bottom end of the second needle segment 212 is an end of the second needle segment 212 close to the valve port 102 .

[0049] The present application specifically implements stable support of the sealing gasket 23 by the side wall of the mounting groove 201 by setting the length of the bottom end of the second needle segment 212 to be not less than the length of the sealing gasket 23, thereby preventing the sealing gasket 23 from being deformed.

[0050] Furthermore, in one embodiment, the outer diameter of the first needle segment 211 is smaller than the outer diameter of the second needle segment 212. The first needle segment 211 is used to flexibly cooperate with the valve body assembly 10, and in order to meet the large flow demand, ensure the force balance of the valve needle assembly 20, and reduce the driving force of the switch valve, the outer diameter of the first needle segment 211 of this embodiment is substantially equal to the inner diameter of the valve port 102. In this way, by setting the first valve needle 21 as two parts, the first needle segment 211 and the second needle segment 212, only the second needle segment 212 needs to be processed to increase its outer diameter to match the length of the sealing pad 23, which is conducive to reducing the processing difficulty and processing cost.

[0051] In this embodiment, the welding groove 2103 is preferably disposed at the junction of the first needle segment 211 and the second needle segment 212, so as to facilitate the molding of the second needle segment 212 and shorten the length of the second needle segment 212 to further reduce material costs. Of course, the welding groove 2103 can also be disposed on the first needle segment 211 or the second needle segment 212, as long as the same welding effect can be achieved.

[0052] In one embodiment, the valve cavity 101 includes a guide section 1012 and a flow section 1013, and a seal 24 is provided between the valve needle assembly 20 and the guide section 1012, and the valve needle assembly 20 is sealed and movably matched with the guide section 1012 through the seal 24. Specifically, a sealing groove 2102 is provided on the outer wall of the first valve needle 21, and the seal 24 is installed in the sealing groove 2102. Here, the valve needle assembly 20 is mainly movably matched with the guide section 1012 through the first needle section 211 on the first valve needle 21. In order to ensure the force balance of the valve needle assembly 20 and reduce the driving force of the switch valve, the sealing cone section 231 on the sealing pad 23 forms a sealing diameter D1 when it is abutted and sealed with the valve port 102, and the outer diameter of the first needle section 211 needs to be approximately equal to D1 to ensure the force balance of the valve needle assembly 20. At the same time, since the sealing cone section 231 is in sealing contact with the valve port 102, the maximum outer diameter D2 of the sealing cone section 231 needs to be greater than D1, and the minimum outer diameter D3 of the outer wall of the second needle section 212 is not less than D2. Therefore, the outer diameter of the second needle section 212 is larger than the outer diameter of the first needle section 211.

[0053] Furthermore, the flow port 103 is disposed in the flow section 1013, and the radial dimension of the flow section 1013 along the valve needle assembly 20 is larger than the radial dimension of the guide section 1012 along the valve needle assembly 20. Thus, by increasing the radial dimension of the flow section 1013, the movement of the second needle section 212 in the flow section 1013 is facilitated.

[0054] Since the outer diameter of the second needle segment 212 is larger than that of the first needle segment 211, when the electronic expansion valve 100 is in a fully open state, the second needle segment 212 may interfere with the inner wall of the guide segment 1012 to a certain extent, thereby hindering the movement of the valve needle assembly 20 and even causing collision damage. Based on this, in order to reduce the probability of interference between the second needle segment 212 and the inner wall of the guide segment 1012, in one embodiment, as shown in FIG. Figure 2 As shown, the valve cavity 101 also includes a transition section 1011, and the two ends of the transition section 1011 are respectively connected to the guide section 1012 and the flow section 1013. Along the axial direction of the valve needle assembly 20, and from the guide section 1012 to the flow section 1013, the transition section 1011 tends to gradually expand. Among them, when the electronic expansion valve 100 is in a fully open state, the outer wall of the second needle section 212 is spaced from the inner wall of the transition section 1011. In this way, the safety of the valve needle assembly 20 when the electronic expansion valve 100 is fully opened is greatly improved.

[0055] In one embodiment, if Figure 2 and Figure 3 As shown, the outer wall of the second valve needle 22 protruding from one end of the assembly hole 2101 is spaced apart from the inner wall of the first valve needle 21 and forms an assembly groove 202, in which the first elastic member 25 is installed, and one end of the first elastic member 25 extending out of the assembly groove 202 abuts against the inner wall of the valve cavity 101. The first elastic member 25 is used to apply a force toward the valve port 102 to the valve needle assembly 20, thereby ensuring the movement stability of the valve needle assembly 20 during the axial movement or after the valve port 102 is opened and closed, reducing the probability of the valve needle assembly 20 shaking after being impacted by the fluid, thereby greatly improving the operating reliability of the electronic expansion valve 100.

[0056] Furthermore, since the valve needle assembly 20 and the inner wall of the valve cavity 101 are fitted in an active seal, there will be a pressure difference between the portion of the valve cavity 101 located at the end of the valve needle assembly 20 close to the valve port 102 and the portion of the end of the valve needle assembly 20 away from the valve port 102, that is, the pressure of the valve cavity 101 at the assembly groove 202 is different from the pressure at the valve port 102, and the existence of the pressure difference is not conducive to the axial movement of the valve needle assembly 20.

[0057] In order to eliminate the pressure difference between the two axial ends of the valve needle assembly 20, in one embodiment, as shown in FIG. Figure 2 and Figure 3 As shown, the second valve needle 22 is provided with a first through hole 2201 and a second through hole 2202, one end of the first through hole 2201 is connected to the valve port 102, and the other end is arranged close to the assembly groove 202, the second through hole 2202 is arranged on the side wall of the second valve needle 22, and the two ends of the second through hole 2202 are respectively connected to the first through hole 2201 and the assembly groove 202. In this way, the first through hole 2201, the second through hole 2202 and the assembly groove 202 can form a partial balance channel, so that the refrigerant at the valve port 102 flows into the assembly groove 202 through the first through hole 2201 and the second through hole 2202, thereby eliminating the pressure difference between the two axial ends of the valve needle assembly 20, which is conducive to the smooth operation of the valve needle assembly 20.

[0058] In one embodiment, the electronic expansion valve 100 further includes a spring sleeve 30 and a driving member 40, one end of the spring sleeve 30 is connected to the driving member 40, and the other end is sleeved and connected to one end of the second valve needle 22 protruding from the assembly hole 2101. That is, the driving member 40 is connected to the valve needle assembly 20 through the spring sleeve 30, so as to facilitate the movement of the valve needle assembly 20 in the axial direction, so as to realize the opening and closing and flow regulation functions of the electronic expansion valve 100.

[0059] Furthermore, a second elastic member and a bearing are installed in the spring sleeve 30, and a third through hole 301 is formed on the side wall of the spring sleeve 30, and the third through hole 301 is connected to the assembly groove 202. The bearing is used to adjust the axis of the valve needle assembly 20 to prevent it from deviating from the axis of the valve port 102.

[0060] It can be understood that in this embodiment, the second valve needle 22 is blocked at one end of the spring sleeve 30, and the first through hole 2201 on the second valve needle 22 is not directly connected to the inside of the spring sleeve 30, thereby preventing impurities mixed in the refrigerant from directly entering the spring sleeve 30 and affecting the bearings in the spring sleeve 30, etc., effectively improving the impurity resistance and service life of the bearings. At the same time, a third through hole 301 is opened on the side wall of the spring sleeve 30, and the internal space of the spring sleeve 30 can be connected to the assembly groove 202 through the third through hole 301, so as to further increase the flow area of ​​the balance channel, thereby better balancing the pressure difference.

[0061] It should be noted that when the electronic expansion valve 100 is in the fully open state, although the third through hole 301 of the spring sleeve 30 will be blocked by the valve body assembly 10 structure, thereby reducing the flow at the third through hole 301, the second through hole 2202 can still be used to eliminate the pressure difference at the axial ends of the balance valve needle assembly 20.

[0062] In one embodiment, if Figure 4 As shown, the electronic expansion valve 100 further includes a mounting seat 50, in which a mounting cavity 501 is provided, and at least part of the valve body assembly 10 is installed in the mounting cavity 501. By providing the mounting seat 50, it is convenient to fix the electronic expansion valve 100 with the outside world, which can effectively improve the assembly efficiency of the electronic expansion valve 100.

[0063] For example, the electronic expansion valve 100 provided in the present application is mainly used in an automobile thermal management system or an air-conditioning system, and the arrangement of the mounting seat 50 enables the electronic expansion valve 100 to be better adapted to a use environment such as a vehicle.

[0064] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0065] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the scope of patent protection of the present application shall be subject to the attached claims.

Claims

1. An electronic expansion valve, characterized in that: The invention comprises a valve body assembly (10) and a valve needle assembly (20), wherein the valve body assembly (10) is provided with a valve cavity (101), a valve port (102) and a flow port (103), wherein the valve port (102) is arranged at one end of the valve body assembly (10) and is in communication with the valve cavity (101), and the flow port (103) is arranged at the peripheral side of the valve body assembly (10) and is in communication with the valve cavity (101); the valve needle assembly (20) can be movably installed in the valve cavity (101) to open or close the valve port (102); Wherein, along the axial direction of the valve needle assembly (20), the end of the valve port (102) close to the valve needle assembly (20) is arranged to protrude from the bottom of the circulation port (103), and the end of the valve port (102) protrudes from the bottom of the circulation port (103) by a height L1, the distance L2 from the end of the valve needle assembly (20) to the valve port (102) when the electronic expansion valve is fully opened, and the diameter D of the circulation port (103) satisfy the following conditions: L1+L2≥D / 2, L1+(L2 / 2) <D / 2。 2. The electronic expansion valve according to claim 1, characterized in that: The valve needle assembly (20) is provided with a mounting groove (201) on its circumferential side. The electronic expansion valve further comprises a sealing gasket (23). The sealing gasket (23) is installed in the mounting groove (201) and is used for sealingly cooperating with the valve port (102).

3. The electronic expansion valve according to claim 2, characterized in that: A limiting protrusion (2011) is formed on the inner wall of the installation groove (201), and at least a portion of the limiting protrusion (2011) is embedded in the sealing gasket (23).

4. The electronic expansion valve according to claim 2, characterized in that: The inner walls on both sides of the mounting groove (201) along the axial direction of the valve needle assembly (20) are defined as a first inner wall and a second inner wall respectively, and the two ends of the sealing gasket (23) along the axial direction of the valve needle assembly (20) are defined as a first end and a second end respectively, the radial length of the first end along the valve needle assembly (20) is not less than the radial length of the second end along the valve needle assembly (20), and the first end is in contact with the first inner wall, and the second end is in contact with the second inner wall; Wherein, the radial length of the first inner wall along the valve needle assembly (20) is not less than the radial length of the first end along the valve needle assembly (20), and the radial length of the second inner wall along the valve needle assembly (20) is not less than the radial length of the second end along the valve needle assembly (20); and, along the radial direction of the valve needle assembly (20), the maximum length of the inner circumference of the sealing gasket (23) from the outer circumference is not greater than the radial length of the first end along the valve needle assembly (20).

5. The electronic expansion valve according to claim 4, characterized in that: The first inner wall is arranged on a side of the second inner wall away from the valve port (102), and the sealing gasket (23) is formed with a sealing cone section (231) for sealingly cooperating with the valve port (102), and along the direction from the second inner wall to the first inner wall, the sealing cone section (231) tends to expand gradually.

6. The electronic expansion valve according to any one of claims 2 to 5, characterized in that: The valve needle assembly (20) comprises a first valve needle (21) and a second valve needle (22), the first valve needle (21) being provided with an assembly hole (2101), one end of the second valve needle (22) passing through and protruding from the assembly hole (2101), and the other end of the second valve needle (22) being spaced apart from and sandwiched with the end of the first valve needle (21) to form the installation groove (201); The first valve needle (21) includes a second needle segment (212), the bottom end of the second needle segment (212) is the side wall of the mounting groove (201) and is in contact with the sealing gasket (23), and the radial length of the bottom end of the second needle segment (212) along the valve needle assembly (20) is not less than the radial length of the sealing gasket (23) along the valve needle assembly (20).

7. The electronic expansion valve according to claim 6, characterized in that: The first valve needle (21) further comprises a first needle segment (211), wherein the first needle segment (211) is arranged at an end of the second needle segment (212) away from the mounting groove (201); an outer diameter of the first needle segment (211) is smaller than an outer diameter of the second needle segment (212).

8. The electronic expansion valve according to claim 6, characterized in that: The valve cavity (101) comprises a guide section (1012), a flow section (1013) and a transition section (1011); a sealing member (24) is provided between the valve needle assembly (20) and the guide section (1012); the valve needle assembly (20) is in sealing cooperation with the guide section (1012) through the sealing member (24); the flow port (103) is provided in the flow section (1013); the radial dimension of the flow section (1013) along the valve needle assembly (20) is larger than the radial dimension of the guide section (1012) along the valve needle assembly (20); and two ends of the transition section (1011) are respectively connected to the guide section (1012) and the flow section (1013); Wherein, when the electronic expansion valve is in a fully open state, the outer wall of the second needle section (212) is spaced apart from the inner wall of the transition section (1011).

9. The electronic expansion valve according to claim 6, characterized in that: The outer wall of the second valve needle (22) protruding from one end of the assembly hole (2101) is spaced apart from the inner wall of the first valve needle (21) and is formed with an assembly groove (202); The second valve needle (22) is provided with a first through hole (2201) and a second through hole (2202), one end of the first through hole (2201) is connected to the valve port (102), and the other end is arranged close to the assembly groove (202), the second through hole (2202) is arranged on the side wall of the second valve needle (22), and the two ends of the second through hole (2202) are respectively connected to the first through hole (2201) and the assembly groove (202).

10. The electronic expansion valve according to claim 9, characterized in that: The electronic expansion valve further comprises a spring sleeve (30) and a driving member (40), one end of the spring sleeve (30) being connected to the driving member (40), and the other end being sleeved and connected to an end of the second valve needle (22) protruding from the assembly hole (2101); Wherein, a third through hole (301) is formed on the side wall of the spring sleeve (30), and the third through hole (301) is communicated with the assembly groove (202).

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