Electronic expansion valve

Abstract

The utility model relates to the technical field of valves, in particular to an electronic expansion valve. The electronic expansion valve comprises a valve body assembly, a valve rod assembly, a valve element assembly and an elastic element, the valve body assembly is provided with a valve port, the valve rod assembly and the valve element assembly are installed in the valve body assembly, the valve rod assembly and the valve element assembly are movably connected, and the valve rod assembly can drive the valve element assembly to move in the direction close to or away from the valve port in the axial direction. The elastic element is arranged between the valve rod assembly and the valve element assembly, the two ends of the elastic element are connected with the valve rod assembly and the valve element assembly respectively, and the elastic element is used for applying acting force to the valve element assembly to move towards the valve port. The electronic expansion valve has a full-closed state, when the electronic expansion valve is in the full-closed state, the valve rod assembly compresses the elastic element, and a gap is formed between the valve rod assembly and the valve element assembly in the axial direction. According to the electronic expansion valve provided by the invention, the problem of internal leakage caused by springback of a motor rotor of an existing electronic expansion valve is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of valves, in particular to an electronic expansion valve. BACKGROUND

[0002] In the related art, an electronic expansion valve includes a screw rod, a bearing, a valve needle and a bearing sleeve. The valve needle is fixedly connected to one end of the bearing sleeve and cooperates with the bearing sleeve to limit the installation of the bearing in the bearing sleeve. The screw rod passes through the bearing sleeve and is connected with the inner ring of the bearing. In this way, the screw rod, the bearing, the valve needle and the bearing sleeve are connected as a whole and can move along the axial direction of the electronic expansion valve as a whole. The valve needle adjusts the flow of the valve port.

[0003] In the related art, when the valve needle closes the valve port, the valve needle will abut against the valve port. However, since the screw rod is usually driven by a stepping motor, the motor rotor will continue to input pulses when the motor rotor drives the screw rod to rotate to the position where the valve needle abuts against the valve port and the screw rod cannot move in the closing direction any more. This makes the motor rotor drive the screw rod to rotate in the opposite direction by a certain angle, that is, the rotor and the screw rod will move away from the valve port by a certain distance. In this way, the valve needle will move away from the valve port by a certain distance along with the screw rod, which causes the valve needle to be separated from the valve port and increases the risk of internal leakage of the electronic expansion valve. CONTENT OF THE UTILITY MODEL

[0004] Therefore, it is necessary to provide an electronic expansion valve to solve the problem of internal leakage caused by the rebound of the motor rotor of the existing electronic expansion valve.

[0005] The present application provides an electronic expansion valve. The electronic expansion valve includes a valve body assembly, a valve rod assembly and a valve core assembly. The valve body assembly has a valve port. The valve rod assembly and the valve core assembly are installed in the valve body assembly. The valve rod assembly and the valve core assembly are movably connected, and the valve rod assembly can drive the valve core assembly to move along the axial direction towards or away from the valve port. The electronic expansion valve further includes an elastic element. The elastic element is arranged between the valve rod assembly and the valve core assembly, and the two ends of the elastic element are connected to the valve rod assembly and the valve core assembly, respectively, for applying an action force to the valve core assembly to move towards the valve port. The electronic expansion valve has a full-closed state. When the electronic expansion valve is in the full-closed state, the valve rod assembly compresses the elastic element, and there is a gap between the valve rod assembly and the valve core assembly along the axial direction.

[0006] In one embodiment, in the full-closed state, the size of the gap between the valve rod assembly and the valve core assembly along the axial direction is h, and the stroke of the valve core assembly is H, where 0 < h / H ≤ 0.2.

[0007] In one of the embodiments, the valve core assembly comprises a valve needle and a bearing sleeve, the valve needle is fixedly connected to the bearing sleeve and forms an assembly cavity with the bearing sleeve, wherein the inner wall of the assembly cavity away from the valve needle is provided with a limiting portion; the valve rod assembly comprises a screw rod and a bearing, the bearing is movably installed in the assembly cavity, one end of the screw rod extends into the assembly cavity and is fixedly connected to the inner ring of the bearing, and the limiting portion can be axially stopped at one end of the bearing; the two ends of the elastic element are respectively applied to the bearing and the valve needle, and when the electronic expansion valve is in the full-closed state, an axial gap h is formed between the limiting portion and the bearing.

[0008] In one of the embodiments, the electronic expansion valve further comprises a gasket, the gasket is arranged between the elastic element and the bearing, and the two ends of the gasket are respectively in abutting cooperation with the elastic element and the bearing.

[0009] In one of the embodiments, the valve needle is provided with a mounting hole at one end close to the assembly cavity, and at least part of the elastic element is arranged in the mounting hole.

[0010] In one of the embodiments, the electronic expansion valve further has a full-open state in which the valve core assembly moves to the limit in the direction away from the valve port, and when the electronic expansion valve is in the full-open state, the elastic element has a preset deformation amount h.

[0011] In one of the embodiments, the elastic element is configured as a plate spring, and when the electronic expansion valve is in the full-open state, the gap between the end face close to the one end of the screw rod on the part of the elastic element abutting against the valve needle and the end face of the screw rod is equal to the size h of the preset deformation amount of the elastic element, and the stroke of the valve core assembly is H, wherein 0

[0012] In one of the embodiments, the elastic element is configured as a disc spring, and when the electronic expansion valve is in the full-open state, the gap between the end face of the screw rod and the end face of the valve needle is equal to the size h of the preset deformation amount of the elastic element, and the stroke of the valve core assembly is H, wherein 0

[0013] In one of the embodiments, the elastic element is configured as a spiral spring, and the electronic expansion valve further comprises a gasket, one end of the elastic element is connected to the gasket so that the gasket can be in abutting cooperation with the bearing; when the electronic expansion valve is in the full-open state, the gap between the end face close to the one end of the valve needle on the part of the gasket abutting against the bearing and the end face of the valve needle is equal to the size h of the preset deformation amount of the elastic element, and the stroke of the valve core assembly is H, wherein 0

[0014] In one of the embodiments, the valve body assembly is provided with an upper stop matching part, and the valve core assembly is provided with an upper stop part, when the electronic expansion valve is in the fully open state, the upper stop part abuts against the upper stop matching part.

[0015] In one of the embodiments, the electronic expansion valve further comprises a supporting spring, the supporting spring is sleeved on the outer periphery of the valve core assembly, and is used for exerting an action force on the valve core assembly to move away from the valve port.

[0016] In one of the embodiments, the action force exerted by the supporting spring on the valve core assembly is smaller than the action force exerted by the elastic element on the valve core assembly.

[0017] In one of the embodiments, when the electronic expansion valve is in the fully closed state, the valve core assembly abuts against and blocks the valve port.

[0018] Compared with the prior art, the electronic expansion valve provided by the application, by arranging an elastic element between the valve rod assembly and the valve core assembly, when the electronic expansion valve is in the fully closed state, the elastic element is compressed to deform by the valve rod assembly, and the deformation amount of the elastic element caused by the compression is converted into the gap between the valve rod assembly and the valve core assembly in the axial direction. Then, when the rotor reversely rotates and rebounds, the elastic element can also rebound correspondingly, at the same time, the gap between the valve rod assembly and the valve core assembly in the axial direction can make up the distance of the movement of the valve rod assembly away from the valve port, avoiding the situation that the valve core assembly moves upward synchronously with the valve rod assembly caused by the reverse rotation of the rotor after the fully closed state in the related art due to the existence of the integrated connection structure. That is, the application can ensure that the position of the valve core assembly does not change, thereby ensuring the stable cooperation between the valve core assembly and the valve port, and ensuring that the electronic expansion valve does not produce internal leakage. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0020] Figure 1 The cross-sectional view of the electronic expansion valve of one embodiment of the application (fully open state);

[0021] Figure 2 The cross-sectional view of the electronic expansion valve of one embodiment of the application (fully open state); Figure 1 The enlarged view of A in FIG. 4;

[0022] Figure 3A cross-sectional view of an electronic expansion valve according to an embodiment of the present application (full-closed state);

[0023] Figure 4 A cross-sectional view of an electronic expansion valve according to another embodiment of the present application (full-closed state); Figure 3 An enlarged view of the middle B;

[0024] Figure 5 A cross-sectional view of an electronic expansion valve according to another embodiment of the present application (full-closed state);

[0025] Figure 6 A cross-sectional view of an electronic expansion valve according to another embodiment of the present application (full-closed state);

[0026] Figure 7 A cross-sectional view of an electronic expansion valve according to another embodiment of the present application (full-closed state);

[0027] Figure 8 A cross-sectional view of an electronic expansion valve according to another embodiment of the present application (full-closed state);

[0028] Figure 9 A cross-sectional view of an electronic expansion valve according to another embodiment of the present application (full-closed state);

[0029] The symbols in the drawings represent the following meanings:

[0030] 100, electronic expansion valve; 10, valve body assembly; 101, valve port; 11, upper stopper fitting portion; 20, valve rod assembly; 21, screw rod; 22, bearing; 30, valve core assembly; 301, assembly cavity; 302, mounting hole; 31, valve needle; 32, bearing sleeve; 321, limiting portion; 322, upper stopper portion; 40, elastic element; 50, gasket; 60, support spring. DETAILED DESCRIPTION

[0031] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. It will be apparent, however, to one skilled in the art that the present application can be practiced without some or all of these details under other conditions. Therefore, the specific embodiments disclosed below are not intended to limit the scope of the present application, but to explain the present application to one skilled in the art.

[0032] It is to be noted that when a component is referred to as being "on" or "disposed on" another component, it can be directly on the other component or intervening components can also be present. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or intervening components can also be present. The terms "vertical", "horizontal", "upper", "lower", "left", "right", and similar terms as used in the description of the specification are for the purpose of illustration only and do not indicate the only position of the embodiment.

[0033] In addition, the terms "first", "second", etc. are used herein only to describe various conditions, and are not to be construed as indicating or implying relative importance or a specific number of the indicated technical features. Thus, the features defined with "first", "second", etc. can explicitly or implicitly include at least one of the features. In the description of the specification, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0034] In this application, unless otherwise explicitly specified and limited, the "on", "under", "above" and "over" of the first feature to the second feature can be that the first feature is in direct contact with the second feature, or the first feature is indirectly in contact with the second feature through an intermediate medium. Moreover, the "on", "above" and "over" of the first feature to the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the first feature is higher in horizontal height than the second feature. The "under", "below" and "under" of the first feature to the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the first feature is lower in horizontal height than the second feature.

[0035] Unless otherwise defined, all technical and scientific terms used in the specification of the present application have the same meaning as commonly understood by one skilled in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used in the specification of the present application includes any and all combinations of one or more related listed items.

[0036] In the related art, the electronic expansion valve includes a screw rod, a bearing, a valve needle and a bearing sleeve, the valve needle is fixedly connected to one end of the bearing sleeve, and cooperates with the bearing sleeve to limit the installation of the bearing in the bearing sleeve, the screw rod passes through the bearing sleeve and is connected with the inner ring of the bearing, so that the screw rod, the bearing, the valve needle and the bearing sleeve are connected as a whole and can move as a whole along the axis direction of the electronic expansion valve, and the valve needle is used to adjust the flow of the valve port.

[0037] In the related art, the valve needle will abut against the valve port when closing the valve port. However, since the screw rod is usually driven by a stepper motor, due to the characteristics of the stepper motor, when the motor rotor drives the screw rod to rotate to the position where the valve needle abuts against the valve port and the screw rod cannot move in the closing direction any more, the motor will continue to input pulses, which makes the motor rotor drive the screw rod to rotate in the opposite direction by a certain angle, that is, the rotor and the screw rod will move away from the valve port by a certain distance. In this way, the valve needle will move away from the valve port by a certain distance synchronously with the screw rod, causing the valve needle to be separated from the valve port, thereby increasing the risk of internal leakage of the electronic expansion valve.

[0038] Please refer to Figures 1-9 To solve the problem of internal leakage caused by motor rotor rebound in the existing electronic expansion valve, the present application provides an electronic expansion valve 100, which comprises a valve body assembly 10, a valve rod assembly 20 and a valve core assembly 30. The valve body assembly 10 has a valve port 101. The valve rod assembly 20 and the valve core assembly 30 are installed in the valve body assembly 10. The valve rod assembly 20 and the valve core assembly 30 are movably connected, and the valve rod assembly 20 can drive the valve core assembly 30 to move in the axial direction towards or away from the valve port 101, so as to realize the flow regulation of the valve core assembly 30 at the valve port 101.

[0039] Please continue to refer to Figures 1-9 The electronic expansion valve 100 provided by the present application further comprises an elastic element 40, which is arranged between the valve rod assembly 20 and the valve core assembly 30, and the two ends of the elastic element 40 are connected to the valve rod assembly 20 and the valve core assembly 30 respectively, for applying an action force to the valve core assembly 30 in the direction towards the valve port 101. The electronic expansion valve 100 has a full open state and a full closed state. When the electronic expansion valve 100 is in the full open state, the valve core assembly 30 moves to the limit in the direction away from the valve port 101, and the valve port 101 has the maximum opening degree. At this time, the elastic element 40 has a preset deformation amount for deformation. When the electronic expansion valve 100 is in the full closed state, the valve rod assembly 20 compresses the elastic element 40, and there is a gap between the valve rod assembly 20 and the valve core assembly 30 in the axial direction.

[0040] It can be understood that, by arranging the elastic element 40 between the valve rod assembly 20 and the valve core assembly 30, when the electronic expansion valve 100 is in the full-closed state, the elastic element 40 is compressed by the valve rod assembly 20 to deform, and the deformation amount of the elastic element 40 caused by compression is converted into the gap between the valve rod assembly 20 and the valve core assembly 30 in the axial direction. Then, when the rotor reverses to rebound, the elastic element 40 can rebound accordingly, and at the same time, the gap between the valve rod assembly 20 and the valve core assembly 30 in the axial direction can compensate for the distance that the valve rod assembly 20 moves away from the valve port 101, so as to avoid the situation that the valve core assembly 30 moves upward synchronously with the valve rod assembly 20 caused by the reverse rotation of the rotor after full-closed in the prior art. That is, the present application can ensure that the valve rod assembly 20 moves upward after the reverse rotation of the rotor after full-closed, while the position of the valve core assembly 30 remains unchanged, so as to ensure the stable cooperation between the valve core assembly 30 and the valve port 101, and to ensure that the electronic expansion valve 100 does not produce internal leakage.

[0041] In the full-closed state, the gap between the valve rod assembly 20 and the valve core assembly 30 in the axial direction is h, and in the full-open state, the preset deformation amount of the elastic element 40 is also h.

[0042] Specifically, the electronic expansion valve 100 also has a pre-open valve (pre-closed valve) state. It should be noted that the pre-open valve (pre-closed valve) state refers to the state when the valve core assembly 30 just abuts against the valve port 101. Taking the switching from the full-open state to the full-closed state as an example, the rotor rotates in the direction of closing the valve, driving the valve rod assembly 20 to move axially in the direction of closing the valve, until the valve core assembly 30 just abuts against the valve port 101. This state is the pre-closed valve state. In the process of switching from the full-open state to the pre-closed valve state, the preset deformation amount h of the elastic element 40 remains unchanged, that is, the elastic element 40 is not further compressed by the valve rod assembly 20. In the pre-closed valve state, the elastic element 40 still has the preset deformation amount h. Then, the rotor further rotates in the direction of closing the valve, driving the valve rod assembly 20 to further move axially in the direction of approaching the valve port 101. At this time, the valve core assembly 30 abuts against the valve port 101, and the position of the valve core assembly 30 remains unchanged. The valve rod assembly 20 continues to move downward to further compress the elastic element 40, until the valve rod assembly 20 cannot continue to move in the direction of approaching the valve port 101. In the process from the pre-closed valve to the full-closed state, the distance h that the valve rod assembly 20 can move in the axial direction to approach the valve port 101 is the preset deformation amount h of the elastic element 40, that is, the distance that the elastic element 40 can be compressed by the valve rod assembly 20 from the pre-closed valve state to the full-closed state. Therefore, it can be understood that, in the full-closed state, the gap h between the valve rod assembly 20 and the valve core assembly 30 in the axial direction or the preset deformation amount h of the elastic element 40 is the distance that the valve rod assembly 20 can move from the pre-open valve (pre-closed valve) state to the full-closed state.

[0043] Further, the stroke of the valve core assembly 30 is H, where 0 < h / H≤0.2. By reasonably setting the size of h, it is ensured that the distance of the movement of the rotor to rebound to drive the valve stem assembly 20 does not exceed the preset deformation amount of the elastic element 40, so as to ensure that the position of the valve core assembly 30 will not be affected by the movement of the valve stem assembly 20, and further reduce the probability of internal leakage of the electronic expansion valve 100.

[0044] It should be noted that the stroke of the valve core assembly 30 is the distance moved from the position of the full open state of the valve core assembly 30 to the position of the full closed state.

[0045] Specifically, as shown in Figure 1 and Figure 2 , the valve body assembly 10 is provided with an upper stop cooperation part 11, and the valve core assembly 30 is provided with an upper stop part 322, and when the electronic expansion valve 100 is in the full open state, the upper stop part 322 abuts against the upper stop cooperation part 11. In this way, the upper stop of the valve core assembly 30 moving along the axial direction is realized. Here, the upper stop part 322 can be formed by the end face of the bearing sleeve 32 away from one end of the valve port 101.

[0046] As shown in Figure 3 and Figure 4 , when the electronic expansion valve 100 is in the full closed state, the valve core assembly 30 abuts and blocks the valve port 101, and the valve stem assembly 20 cannot move along the axial direction towards the direction of approaching the valve port 101. In this way, the valve core assembly 30 directly abuts against the valve port 101, not only realizes the lower stop of the valve core assembly 30 moving along the axial direction, but also can close the valve port 101, so as to ensure that there is no flow through when the electronic expansion valve 100 is closed.

[0047] In an embodiment, as shown in Figures 1-9 , the valve core assembly 30 includes a valve needle 31 and a bearing sleeve 32, the valve needle 31 is fixedly connected to the bearing sleeve 32 and surrounds the bearing sleeve 32 to form an assembly cavity 301, and a limiting part 321 is arranged on the inner wall of the assembly cavity 301 away from one end of the valve needle 31. Here, the valve needle 31 and the bearing sleeve 32 can be a split structure or an integral structure. The valve stem assembly 20 includes a screw rod 21 and a bearing 22, the bearing 22 is movably installed in the assembly cavity 301, one end of the screw rod 21 extends into the assembly cavity 301 and is fixedly connected to the inner ring of the bearing 22, and the limiting part 321 can be axially stopped at one end of the bearing 22. The two ends of the elastic element 40 apply force to the bearing 22 and the valve needle 31 respectively, and when the electronic expansion valve 100 is in the full closed state, an axial gap h is formed between the limiting part 321 and the bearing 22.

[0048] It can be understood that the elastic element 40 in the embodiment generates a pre-tightening force after assembly is completed, so that the valve needle 31 and the bearing 22 have a mutual moving trend of moving away from each other, and in the full open state,Figure 2 , Figure 5 and Figure 7 As shown, the bearing 22, under the preload of the elastic element 40, tightly abuts against the limiting part 321 to achieve limiting, ensuring the reliability of the preload of the elastic element 40. Furthermore, due to the existence of a preset deformation on the elastic element 40, that is, a gap exists between the screw 21 and the valve needle 31 allowing the screw 21 and bearing 22 to move. During the closing process of the electronic expansion valve 100, the valve stem assembly 20 first drives the valve core assembly 30 to move until the valve needle 31 just abuts against the valve port 101. At this time, it is in a pre-closed state, and the elastic element 40 still maintains the preset deformation h. Afterward, the axial movement of the valve needle 31 is constrained, while the screw 21 can continue to move and can drive the bearing 22 to further compress the elastic element 40 until the screw 21 can no longer move downward, forming the fully closed state of the electronic expansion valve 100. At this time, as... Figure 4 , Figure 6 and Figure 8 As shown, during the process of the screw 21 moving from the pre-closed valve state to the fully closed state, the distance it moves axially is equal to the preset deformation of the elastic element 40 reduced by the screw 21. That is, the maximum distance the screw 21 moves axially is equal to the magnitude of the preset deformation of the elastic element 40. Furthermore, since the bearing sleeve 32 and the valve needle 31 are fixedly connected, the magnitude of the preset deformation of the elastic element 40 reduced by the screw 21 can be transferred to the gap between the limiting part 321 and the bearing 22. This gap provides space for the screw 21 to move upward when the rotor rebounds or the valve is opened.

[0049] When the electronic expansion valve 100 rebounds, Figure 9 As shown, when the screw 21 rotates upward due to the rotor's rebound, the elastic element 40 returns to its original position, maintaining a preload on the screw 21 and the valve needle 31. That is, during the rotor's rebound, the valve needle 31 is still subjected to a downward preload from the elastic element 40, ensuring a tight fit with the valve port 101 and preventing leakage. The gap h1 between the screw 21 and the valve needle 31, and the gap h2 between the bearing 22 and the limiting part 321, satisfy h1 + h2 = h.

[0050] It should be noted that this example uses a disc spring with elastic element 40 as the case, and, as Figure 7 and Figure 8 As shown, when the electronic expansion valve 100 is fully open, the elastic element 40 abuts against the bearing 22 and the valve needle 31 respectively through its two axial ends. Based on the disc spring structure, there is a gap between the end face of the screw 21 and the end face of the valve needle 31, and the size of this gap is equal to the preset deformation h of the elastic element 40, where 0 < h / H ≤ 0.2. At the same time, the screw 21 can directly abut against the valve needle 31 when it is fully closed. Therefore, when springback occurs, the gap generated by the movement of the screw 21 exists between the screw 21 and the valve needle 31.

[0051] In other embodiments, the elastic element 40 can also be configured as a leaf spring as shown in Figure 5 and Figure 6 When the electronic expansion valve 100 is in the fully open state, the elastic element 40 abuts against the bearing 22 and the valve needle 31 through the end faces at the two axial ends thereof, respectively. Based on the structure of the leaf spring, there is a gap between the end face of the elastic element 40 close to the end of the screw rod 21 and the end face of the screw rod 21, and the size of the gap is equal to the preset deformation amount h of the elastic element 40, where 0 < h / H ≤ 0.2. At the same time, the screw rod 21 can abut against the elastic element 40 in the fully closed state, so that the gap generated by the movement of the screw rod 21 exists between the screw rod 21 and the elastic element 40 when rebounding occurs.

[0052] Of course, the elastic element 40 can also be configured as a coil spring as shown in Figures 1-4 .

[0053] Further, in an embodiment, as shown in Figures 1-4 , the electronic expansion valve 100 further comprises a gasket 50, which is arranged between the elastic element 40 and the bearing 22, and the two ends of the gasket 50 abut against the elastic element 40 and the bearing 22, respectively. That is, one end of the elastic element 40 is connected to the valve rod assembly 20 through abutting cooperation with the gasket 50, which is conducive to improving the reliability of the cooperation between the elastic element 40 and the bearing 22 and preventing the elastic element 40 from invading the bearing 22 to cause the bearing 22 to be stuck. In addition, the elastic element 40 can also directly apply force to the inner ring or the outer ring of the bearing 22.

[0054] When the elastic element 40 is configured as a coil spring as shown in Figures 1-4 , it can usually cooperate with the gasket 50 to reduce the risk of being stuck. One end of the elastic element 40 is connected to the gasket 50, so that the gasket 50 can abut against the bearing 22, and when the electronic expansion valve 100 is in the fully open state, the end face of the gasket 50 close to the end of the valve needle 31 abuts against the end face of the valve needle 31, and there is a gap between the end face of the gasket 50 close to the end of the valve needle 31 and the end face of the valve needle 31, and the size of the gap is equal to the preset deformation amount h of the elastic element 40, where 0 < h / H ≤ 0.2. At the same time, in the fully closed state, the gasket 50 compresses the elastic element 40 to abut against the end of the valve needle 31, so that if rebounding occurs in the fully closed state, the gap generated by the movement of the screw rod 21 and the bearing 22 exists between the gasket 50 and the valve needle 31.

[0055] In order to improve the reliability of the assembled elastic element 40, in an embodiment, as shown in Figures 1-6 , the electronic expansion valve 100 further comprises a gasket 50, which is arranged between the elastic element 40 and the bearing 22, and the two ends of the gasket 50 abut against the elastic element 40 and the bearing 22, respectively. That is, one end of the elastic element 40 is connected to the valve rod assembly 20 through abutting cooperation with the gasket 50, which is conducive to improving the reliability of the cooperation between the elastic element 40 and the bearing 22 and preventing the elastic element 40 from invading the bearing 22 to cause the bearing 22 to be stuck. In addition, the elastic element 40 can also directly apply force to the inner ring or the outer ring of the bearing 22.As shown, the valve needle 31 is provided with a mounting hole 302 near one end of the assembly cavity 301, and at least part of the elastic element 40 is arranged in the mounting hole 302. In this way, the elastic element 40 can be limited through the mounting hole 302, facilitating the installation and deformation of the elastic element 40.

[0056] In an embodiment, as shown in Figure 1 and Figure 3 As shown, the electronic expansion valve 100 further comprises a supporting spring 60, which is sleeved on the outer periphery of the valve core assembly 30 and is used to apply a force to the valve core assembly 30 in the direction away from the valve port 101. That is, the supporting spring 60 is always in a compressed state during the operation.

[0057] Generally, the screw rod 21 is provided with external threads, and the part of the valve body assembly 10 that is threadedly connected with the screw rod 21 is provided with internal threads. In this embodiment, the force applied by the supporting spring 60 to the valve core assembly 30 can be transmitted to the screw rod 21, so that the upper end surface of the flange of the external threads can always abut against the lower end surface of the flange of the internal threads, thereby eliminating the gap between the upper end surface of the flange of the external threads and the lower end surface of the flange of the internal threads, so that the gap between the threads will not be affected by the pressure difference, friction and gravity, etc. That is, the screw rod 21 of the electronic expansion valve 100 will not shake during the circumferential rotation due to the gap between the threads, the pressure difference, the friction and the gravity, etc., thereby avoiding the collision and effectively eliminating the mechanical noise.

[0058] Further, the force applied by the supporting spring 60 to the valve core assembly 30 is smaller than the force applied by the elastic element 40 to the valve core assembly 30. In this way, the situation that the valve core assembly 30 moves upward due to the greater force applied by the supporting spring 60 to the valve core assembly 30 after the rotor rebounds to drive the screw rod 21 to move upward can be avoided, and the reliability of the valve core assembly 30 in sealing the valve port 101 in the closed state is further improved, preventing the internal leakage.

[0059] The technical features of the above-described embodiments can be combined arbitrarily. In order to make the description simple, all possible combinations of the technical features in the above-described embodiments are not described, but as long as the combinations of the technical features do not exist, they should be considered as the scope of the description.

[0060] The above-described embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the patent application scope. It should be pointed out that for ordinary skilled persons in the art, several modifications 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 patent protection scope of the present application should be subject to the appended claims.

Claims

1. An electronic expansion valve comprising a valve body assembly (10), a valve stem assembly (20) and a valve core assembly (30), the valve body assembly (10) having a valve port (101), the valve stem assembly (20) and the valve core assembly (30) being installed in the valve body assembly (10), the valve stem assembly (20) and the valve core assembly (30) being movably connected, and the valve stem assembly (20) being capable of moving the valve core assembly (30) along an axial direction towards or away from the valve port (101); characterized in that the electronic expansion valve further comprising an elastic element (40), the elastic element (40) being arranged between the valve stem assembly (20) and the valve core assembly (30), and two ends of the elastic element (40) being connected to the valve stem assembly (20) and the valve core assembly (30) respectively, for applying an action force to the valve core assembly (30) to move towards the valve port (101); the electronic expansion valve having a full-closed state, when the electronic expansion valve is in the full-closed state, the valve stem assembly (20) compresses the elastic element (40), and there is a gap between the valve stem assembly (20) and the valve core assembly (30) along an axial direction.

2. The electronic expansion valve according to claim 1, characterized in that In the full-closed state, the size of the gap between the valve stem assembly (20) and the valve core assembly (30) along the axial direction is h, and the stroke of the valve core assembly (30) is H, wherein 0 3. The electronic expansion valve according to claim 1, wherein The valve core assembly (30) comprises a valve needle (31) and a bearing sleeve (32), the valve needle (31) being fixedly connected to the bearing sleeve (32) and surrounding the bearing sleeve (32) to form an assembly cavity (301), wherein a limiting portion (321) is arranged at an end of the assembly cavity (301) away from the valve needle (31); The valve stem assembly (20) comprises a screw rod (21) and a bearing (22), the bearing (22) being movably installed in the assembly cavity (301), one end of the screw rod (21) extending into the assembly cavity (301) and being fixedly connected to an inner ring of the bearing (22), and the limiting portion (321) being capable of being axially stopped at one end of the bearing (22); The two ends of the elastic element (40) apply forces to the bearing (22) and the valve needle (31) respectively, when the electronic expansion valve is in the full-closed state, a gap h is formed between the limiting portion (321) and the bearing (22) along the axial direction.

4. The electronic expansion valve according to claim 3, characterized in that The electronic expansion valve further comprises a gasket (50), the gasket (50) being arranged between the elastic element (40) and the bearing (22), and the two ends of the gasket (50) being in abutting cooperation with the elastic element (40) and the bearing (22) respectively.

5. The electronic expansion valve according to claim 3, wherein One end of the valve needle (31) close to the assembly cavity (301) is provided with a mounting hole (302), and at least part of the elastic element (40) is arranged in the mounting hole (302).

6. The electronic expansion valve according to claim 3, wherein The electronic expansion valve further has a full open state in which the valve core assembly (30) moves to a limit in a direction away from the valve port (101), and when the electronic expansion valve is in the full open state, the elastic element (40) has a preset deformation amount h.

7. The electronic expansion valve according to claim 6, characterized in that The elastic element (40) is configured as a plate spring, and when the electronic expansion valve is in the full open state, a gap between an end face close to one end of the screw rod (21) on a portion where the elastic element (40) abuts against the valve needle (31) and an end face of the screw rod (21) has a size equal to that of the preset deformation amount h of the elastic element (40), and a stroke of the valve core assembly (30) is H, wherein 0 8. The electronic expansion valve according to claim 6, wherein The elastic element (40) is configured as a disc spring, and when the electronic expansion valve is in the full open state, a gap between an end face of the screw rod (21) and an end face of the valve needle (31) has a size equal to that of the preset deformation amount h of the elastic element (40), and a stroke of the valve core assembly (30) is H, wherein 0 9. The electronic expansion valve according to claim 6, wherein The elastic element (40) is configured as a coil spring, and the electronic expansion valve further comprises a gasket (50), one end of the elastic element (40) is connected to the gasket (50) so that the gasket (50) can abut against the bearing (22); When the electronic expansion valve is in the full open state, a gap between an end face close to one end of the valve needle (31) on a portion where the gasket (50) abuts against the bearing (22) and an end face of the valve needle (31) has a size equal to that of the preset deformation amount h of the elastic element (40), and a stroke of the valve core assembly (30) is H, wherein 0 10. The electronic expansion valve according to claim 6, wherein The valve body assembly (10) is provided with an upper stop cooperation portion (11), and the valve core assembly (30) is provided with an upper stop portion (322), and when the electronic expansion valve is in the full open state, the upper stop portion (322) abuts against the upper stop cooperation portion (11).

11. The electronic expansion valve according to claim 1, wherein The electronic expansion valve further comprises a supporting spring (60) which is sleeved on an outer periphery of the valve core assembly (30) and is used to apply an acting force to the valve core assembly (30) in a direction away from the valve port (101).

12. The electronic expansion valve according to claim 11, wherein The acting force applied by the supporting spring (60) to the valve core assembly (30) is smaller than the acting force applied by the elastic element (40) to the valve core assembly (30).

13. The electronic expansion valve of claim 1, wherein, When the electronic expansion valve is in the full closed state, the valve core assembly (30) abuts against and blocks the valve port (101).

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