Electronic expansion valve and air conditioning system

Abstract

The utility model relates to the technical field of expansion valves, in particular to an electronic expansion valve and an air conditioning system. The electronic expansion valve comprises a valve body assembly, a screw unit and a valve element assembly. The screw unit is provided with an abutting part, and the valve element assembly is provided with an abutting matching part. The electronic expansion valve has a full-closing state, a valve pre-opening state and a full-opening state, and in the full-closing state and the valve pre-opening state, the valve element assembly abuts against and blocks the valve port. When the electronic expansion valve is in a fully-closed state, the abutting part is matched with the abutting matching part in an abutting mode. When the electronic expansion valve is in a pre-opening state, a preset gap h is formed between the abutting part and the abutting matching part in the axial direction, the stroke of the valve element assembly is H, and h / (h + H) is larger than or equal to 0.02 and smaller than or equal to 0.15. According to the electronic expansion valve and the air conditioning system, the problem that an existing electronic expansion valve is poor in flow consistency due to the fact that a fixed pulse technology is adopted is solved.

Description

Technical Field

[0001] This application relates to the field of expansion valve technology, and in particular to an electronic expansion valve and an air conditioning system. Background Technology

[0002] Electronic expansion valves are commonly used in air conditioning systems. They move closer to or further away from the valve port by the movement of an internal valve needle, thereby regulating flow or throttling and reducing pressure.

[0003] In related technologies, electronic expansion valves typically include components such as a rotor, a screw valve needle assembly, and a nut seat. One end of the screw valve needle assembly is connected to the rotor, and part of the screw valve needle assembly passes through and is threadedly connected to the nut seat. The electronic expansion valve uses the rotor to drive the screw valve needle assembly to rotate and move it axially. Electronic expansion valves often employ a constant pulse process during assembly. That is, when installing the screw valve needle assembly, it is first rotated until it just contacts the valve port, and then rotated clockwise or counterclockwise by a certain angle according to the characteristic flow requirements before installing the rotor. This process of the screw valve needle assembly just contacting the valve port and then rotating by a certain angle is the constant pulse process. In related technologies, the constant pulse process makes it difficult to guarantee the consistency of the rotation angle, resulting in poor flow consistency in the electronic expansion valve. Utility Model Content

[0004] Therefore, it is necessary to provide an electronic expansion valve and an air conditioning system to solve the problem that the existing electronic expansion valves using a constant pulse process are prone to poor flow consistency.

[0005] This application provides an electronic expansion valve, which includes a valve body assembly, a screw unit, and a valve core assembly. The valve body assembly has a valve port. One end of the screw unit is connected to the valve core assembly to drive the valve core assembly to move towards or away from the valve port. The screw unit has an abutment portion, and the valve core assembly has an abutment mating portion. The electronic expansion valve has a fully closed state, a pre-open valve state, and a fully open state. In the fully closed state and the pre-open valve state, the valve core assembly abuts against and seals the valve port. When the electronic expansion valve is in the fully closed state, the abutment portion and the abutment mating portion abut against each other. When the electronic expansion valve is in the pre-open valve state, a preset gap h is formed axially between the abutment portion and the abutment mating portion. The stroke of the valve core assembly is H, where 0.02≤h / (h+H)≤0.15.

[0006] In one embodiment, the abutting portion and the abutting mating portion form a line-to-surface contact or a surface-to-surface contact.

[0007] In one embodiment, the valve body assembly is further provided with an assembly hole, and an upper stop portion is provided at the end of the assembly hole away from the valve port. The valve core assembly is provided with an upper stop mating portion. When the electronic expansion valve is in the fully open state, the upper stop mating portion can abut against the upper stop portion.

[0008] In one embodiment, the stroke of the screw unit is H0, and the axial distance from the upper stop to the valve port is H2; in the pre-open valve state, the axial distance from the upper stop mating part to the valve port is H1; wherein, H = H2 - H1, and H0 = H + h.

[0009] In one embodiment, the electronic expansion valve further includes an elastic element that is sleeved on a portion of the outer periphery of the screw unit, and the two ends of the elastic element act on the screw unit and the valve core assembly, respectively.

[0010] In one embodiment, the valve core assembly includes a spring sleeve and a valve needle. One end of the spring sleeve is connected to the screw unit, and the other end of the spring sleeve is connected to the valve needle. The spring sleeve and the valve needle are integral or separate structures. The elastic element is installed inside the spring sleeve, and the end face of the valve needle near the screw unit forms the abutment mating part.

[0011] In one embodiment, the spring sleeve and the valve needle are separate structures, and the valve core assembly further includes a pressure sleeve, which is sleeved on the outer periphery of the valve needle and fixedly connected to the spring sleeve; wherein, the outer periphery of the valve needle protrudes in a direction away from its own axis to form a shoulder, and the shoulder is axially limited and engaged with the pressure sleeve.

[0012] In one embodiment, the end of the spring sleeve near the screw unit protrudes towards its own axis to form a limiting portion; the screw unit includes a screw body, a bearing, and a spring seat, the bearing and the spring seat are both movably mounted inside the spring sleeve, and the spring seat abuts against one end of the outer ring of the bearing, the limiting portion can stop at the other end of the outer ring of the bearing, the screw body passes through the limiting portion and is fixedly connected to the inner ring of the bearing; wherein, the elastic element abuts against the spring seat, and the end face of the spring seat near the valve needle forms the abutting portion.

[0013] In one embodiment, the valve body assembly includes a valve seat, a nut sleeve, and a guide sleeve. The nut sleeve is fixedly connected to one end of the valve seat, and the screw unit passes through the nut sleeve and is threadedly connected to the nut sleeve. The guide sleeve is inserted into the end of the nut sleeve near the valve port. The valve port is located on the valve seat.

[0014] In one embodiment, the valve seat includes a main body and a valve port, which are separately disposed, the valve port being connected to the main body and the valve port being opened in the valve port.

[0015] This application also provides an air conditioning system, which includes the electronic expansion valve described in any of the above embodiments.

[0016] Compared with existing technologies, the electronic expansion valve and air conditioning system provided in this application achieve axial movement of the valve core assembly driven by the screw unit. The valve core assembly reaches its lower stop by abutting against the valve port. That is, during the transition from the fully closed state to the pre-open state, the electronic expansion valve of this application ensures no flow passes through the valve port, thus maintaining a constant flow rate and improving flow consistency. Furthermore, the abutting part and the abutting mating part change from abutting fit to a spaced arrangement as the screw unit moves, until the gap between them reaches a preset gap size, h. Here, the fully closed state corresponds to the 0-pulse state, and the number of pulses required for the screw unit to move axially by h is the number of opening pulses for the electronic expansion valve, corresponding to the flow inflection point. Subsequently, as the screw unit continues to move, it drives the valve core assembly to move synchronously. At this point, the flow rate at the valve port begins to change, thereby opening the electronic expansion valve. Compared to the traditional fixed-pulse process, this application eliminates the need for a fixed pulse during the installation of the electronic expansion valve. Instead, it achieves a fixed pulse by simply using a preset gap h between the screw unit and the valve core assembly. This simplifies installation and adjustment, improves the flow consistency of the electronic expansion valve, and by setting 0.02≤h / (h+H)≤0.15, the accuracy of the preset gap can be improved, thereby enhancing the valve opening pulse accuracy. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A cross-sectional view of an electronic expansion valve according to an embodiment provided in this application;

[0019] Figure 2 A cross-sectional view of an electronic expansion valve in the fully closed state according to an embodiment of this application;

[0020] Figure 3 A cross-sectional view of an electronic expansion valve in a pre-open valve state according to an embodiment of this application;

[0021] Figure 4 A cross-sectional view of an electronic expansion valve in the fully open state according to an embodiment of this application;

[0022] Figure 5 A schematic diagram of the flow rate change of an electronic expansion valve according to an embodiment of this application.

[0023] The symbols in the diagram represent the following meanings:

[0024] 100. Electronic expansion valve; 10. Valve body assembly; 101. Valve port; 102. Assembly hole; 103. Upper stop; 11. Valve seat; 12. Nut sleeve; 13. Guide sleeve; 14. Outer cover; 20. Screw unit; 201. Abutment part; 21. Screw body; 22. Bearing; 23. Spring seat; 30. Valve core assembly; 301. Abutment mating part; 302. Upper stop mating part; 31. Spring sleeve; 311. Limiting part; 32. Valve needle; 321. Shoulder; 33. Pressure sleeve; 40. Elastic element; 50. Rotor assembly; 51. Rotor body; 52. Rotor connecting plate. Detailed Implementation

[0025] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0026] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or there may be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application's specification are for illustrative purposes only and do not represent the only possible implementation.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0028] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0029] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items.

[0030] Electronic expansion valves are commonly used in air conditioning systems. They move closer to or further away from the valve port by the movement of an internal valve needle, thereby regulating flow or throttling and reducing pressure.

[0031] In related technologies, electronic expansion valves typically include components such as a rotor, a screw valve needle assembly, and a nut seat. One end of the screw valve needle assembly is connected to the rotor, and part of the screw valve needle assembly passes through and is threadedly connected to the nut seat. The electronic expansion valve uses the rotor to drive the screw valve needle assembly to rotate and move it axially. Electronic expansion valves often employ a constant pulse process during assembly. That is, when installing the screw valve needle assembly, it is first rotated until it just contacts the valve port, and then rotated clockwise or counterclockwise by a certain angle according to the characteristic flow requirements before installing the rotor. This process of the screw valve needle assembly just contacting the valve port and then rotating by a certain angle is the constant pulse process. In related technologies, the constant pulse process makes it difficult to guarantee the consistency of the rotation angle, resulting in poor flow consistency in the electronic expansion valve.

[0032] Please see Figures 1-5To address the issue of poor flow consistency caused by the constant pulse process in existing electronic expansion valves, this application provides an electronic expansion valve 100. The electronic expansion valve 100 includes a valve body assembly 10, a screw unit 20, and a valve core assembly 30. The valve body assembly 10 has a valve port 101. One end of the screw unit 20 is connected to the valve core assembly 30 to move the valve core assembly 30 towards or away from the valve port 101. The screw unit 20 has an abutment portion 201, and the valve core assembly 30 has an abutment mating portion 301. The electronic expansion valve 100 has a fully closed state, a pre-open valve state, and a fully open state. In the fully closed and pre-open valve states, the valve core assembly 30 abuts against and seals the valve port 101. When the electronic expansion valve 100 is in the fully closed state, the abutment portion 201 and the abutment mating portion 301 engage. When the electronic expansion valve 100 is in the pre-open valve state, a preset gap h is formed axially between the abutment part 201 and the abutment mating part 301, and the stroke of the valve core assembly 30 is H, wherein 0.02≤h / (h+H)≤0.15.

[0033] It is understood that in the electronic expansion valve 100 provided in this application, the valve core assembly 30 moves axially under the drive of the screw unit 20. The valve core assembly 30 stops at the valve port 101 by abutting against it. That is, during the transition from the fully closed state to the pre-open state, the electronic expansion valve 100 ensures that no flow passes through the valve port 101, thus maintaining a constant flow rate and improving flow consistency. Furthermore, the abutting part 201 and the abutting mating part 301 change from abutting to a spaced-out arrangement as the screw unit 20 moves, until the gap between them reaches a preset gap size, h. Here, the fully closed state corresponds to the 0-pulse state, and the number of pulses required for the valve core assembly 30 to move axially by h is the number of opening pulses for the electronic expansion valve 100, which corresponds to the flow inflection point. Subsequently, as the screw unit 20 continues to move, it drives the valve core assembly 30 to move synchronously. At this time, the flow rate at the valve port 101 begins to change, thereby opening the electronic expansion valve 100. Compared with the traditional fixed pulse process, this application eliminates the need for a fixed pulse during the installation of the electronic expansion valve 100, requiring the valve core assembly 30 to come into contact with the valve port 101 before rotating it at a certain angle. Instead, a fixed pulse is achieved solely through the preset gap h between the screw unit 20 and the valve core assembly 30, facilitating installation and adjustment, improving the flow consistency of the electronic expansion valve 100, and further enhancing the accuracy of the opening pulse by setting 0.02≤h / (h+H)≤0.15.

[0034] In this application, due to the existence of a preset gap h, the strokes of the valve core assembly 30 and the screw unit 20 are different. Specifically, the stroke of the valve core assembly 30 refers to the axial distance that the spring sleeve 31 or valve needle 32 on the valve core assembly 30 moves from the pre-open valve state to the fully open state, while the stroke of the screw unit 20 refers to the axial distance that the screw unit 20 moves from the fully closed state to the fully open state.

[0035] Furthermore, the valve body assembly 10 also has an assembly hole 102. An upper stop portion 103 is provided at the end of the assembly hole 102 away from the valve port 101. An upper stop mating portion 302 is provided on the portion of the valve core assembly 30 located within the assembly hole 102. When the electronic expansion valve 100 is in the fully open state, the upper stop mating portion 302 can abut against the upper stop portion 103 to achieve the upper limit of movement of the valve core assembly 30.

[0036] Specifically, the stroke of the screw unit 20 is H0, and the axial distance from the upper stop 103 to the valve port 101 is H2. In the pre-open valve state, the axial distance from the upper stop mating part 302 to the valve port 101 is H1. Wherein, H = H2 - H1, and H0 = H + h. This facilitates the dimensional design of each component within the electronic expansion valve 100.

[0037] It should be noted that, between the pre-open valve state and the fully open state, the gap between the abutment part 201 and the abutment mating part 301 of the electronic expansion valve 100 always maintains the size of the preset gap.

[0038] To ensure that the electronic expansion valve 100 maintains a preset gap between the abutment portion 201 and the abutment mating portion 301 during the valve closing process, specifically during the transition from the fully open state to the pre-open state, in one embodiment, the electronic expansion valve 100 further includes an elastic element 40. The elastic element 40 is sleeved on a portion of the outer periphery of the screw unit 20, and its two ends act on the screw unit 20 and the valve core assembly 30, respectively. Thus, the elastic element 40 provides a preload to the valve core assembly 30. When the valve core assembly 30 abuts against the valve port 101, it effectively reduces the impact force between the valve core assembly 30 and the valve port 101, thereby providing better protection for both the valve core assembly 30 and the valve port 101.

[0039] Specifically, during the closing process of the electronic expansion valve 100, when the valve core assembly 30 just abuts against the valve port 101, due to the existence of a preset axial gap between the screw unit 20 and the valve core assembly 30, the screw unit 20 can continue to move axially toward the valve port 101. During this process, the distance between the abutting part 201 and the abutting mating part 301 gradually decreases as the screw unit 20 moves downward, and the elastic element 40 is further compressed until the abutting part 201 and the abutting mating part 301 abut axially. In this way, the electronic expansion valve 100 is closed. The elastic element 40 provides a force to the valve core assembly 30 toward the valve port 101. The lower stop of the electronic expansion valve 100 does not need to use the circumferential stop in the related technology. The stop members do not need to achieve the stop through relative rotation. At the same time, there is no obvious impact in the circumferential direction, which can effectively reduce the noise when the lower stop abuts.

[0040] Furthermore, in one embodiment, the abutting portion 201 and the mating portion 301 preferably form a surface-to-surface contact. That is, both the abutting portion 201 and the mating portion 301 are planar, thus making the fit between them more stable. Of course, in other embodiments, the abutting portion 201 and the mating portion 301 may also have a line-to-surface contact, which can be reasonably set according to actual needs.

[0041] In one embodiment, such as Figure 1 As shown, the valve core assembly 30 includes a spring sleeve 31 and a valve needle 32. One end of the spring sleeve 31 is connected to the screw unit 20, and the other end of the spring sleeve 31 is connected to the valve needle 32. The spring sleeve 31 and the valve needle 32 can be integrally formed or separately. The elastic element 40 is installed inside the spring sleeve 31, and the end face of the valve needle 32 near the screw unit 20 forms an abutment mating part 301. Thus, the connection between the valve core assembly 30 and the screw unit 20 is simple, and the spring sleeve 31 enhances the protection of the elastic element 40.

[0042] Furthermore, in one embodiment, when the spring sleeve 31 and the valve needle 32 are separate structures, the valve core assembly 30 also includes a pressure sleeve 33, which is sleeved on the outer periphery of the valve needle 32 and fixedly connected to the spring sleeve 31. The outer periphery of the valve needle 32 protrudes in a direction away from its own axis, forming a shoulder 321. The shoulder 321 can engage with the pressure sleeve 33 axially to ensure that the screw unit 20 can drive the valve needle 32 to move axially, while preventing the valve needle 32 from disengaging from the spring sleeve 31, thereby improving the safety and reliability of the overall structural connection.

[0043] Specifically, the pressure sleeve 33 and the spring sleeve 31 can be an integral structure or a separate structure. When the electronic expansion valve 100 is fully closed, the pulse is 0, the abutment part 201 abuts against the abutment mating part 301, and the valve core assembly 30 abuts against and seals the valve port 101. At this time, an axial gap is formed between the shoulder 321 and the end face of the pressure sleeve 33, and the size of this gap is equal to the size of a preset gap. During the opening process of the electronic expansion valve 100, the screw unit 20 first drives the spring sleeve 31 and the pressure sleeve 33 to move, gradually reducing the distance between the shoulder 321 and the end face of the pressure sleeve 33. Simultaneously, the distance between the abutment part 201 and the abutment mating part 301 gradually increases. During this period, the reduction value and the increase value remain equal until the distance between the abutment part 201 and the abutment mating part 301 reaches the preset gap size. Afterwards, because the shoulder 321 abuts against the pressure sleeve 33, the screw unit 20 can drive the valve core assembly 30 to move synchronously to continue opening the valve. During the valve closing process, when the valve core assembly 30 just comes into contact with the valve port 101, the screw unit 20 can still move axially by a preset gap. During this period, the spring sleeve 31 and the pressure sleeve 33 move under the action of gravity, causing the shoulder 321 to gradually move away from the pressure sleeve 33.

[0044] In one embodiment, such as Figure 1 As shown, the end of the spring sleeve 31 near the screw unit 20 protrudes towards its own axis to form a limiting portion 311. The screw unit 20 includes a screw body 21, a bearing 22, and a spring seat 23. Both the bearing 22 and the spring seat 23 are movably mounted inside the spring sleeve 31. The spring seat 23 abuts against one end of the outer ring of the bearing 22, and the limiting portion 311 can stop at the other end of the outer ring of the bearing 22. The screw body 21 passes through the limiting portion 311 and is fixedly connected to the inner ring of the bearing 22. The elastic element 40 abuts against the spring seat 23, and the end face of the spring seat 23 near the valve needle 32 forms an abutment portion 201.

[0045] By setting the bearing 22, not only can the reliability of the connection between the screw body 21 and the spring sleeve 31 be improved, preventing the screw body 21 from detaching from the spring sleeve 31, but the bearing 22 can also reduce the friction between the screw unit 20 and the valve core assembly 30, reducing the probability that the screw body 21 will drive the valve core assembly 30 to rotate when rotating. This reduces the friction between the valve core assembly 30 and the valve port 101 caused by relative rotation, preventing the valve core assembly 30 and the valve port 101 from being damaged by friction. Therefore, it can greatly extend the service life of the electronic expansion valve 100.

[0046] In this embodiment, an upper stop fitting part 302 is formed on the end face of the spring sleeve 31 or the upper limit part 311 of the spring sleeve 31 away from the valve port 101. In this way, the upper stop of the valve core assembly 30 is realized, and at this time the electronic expansion valve 100 is in the fully open state.

[0047] Furthermore, the outer wall of the spring sleeve 31 can be guided to move with the inner wall of the mounting hole 102, thereby improving the reliability of the movement of the valve core assembly 30 and ensuring the coaxiality of the valve core assembly 30 and the valve port 101.

[0048] In one embodiment, such as Figure 1 As shown, the valve body assembly 10 includes a valve seat 11, a nut sleeve 12, and a guide sleeve 13. The nut sleeve 12 is fixedly connected to one end of the valve seat 11, and the screw unit 20 passes through the nut sleeve 12 and is threadedly connected to it. The guide sleeve 13 is inserted into the end of the nut sleeve 12 near the valve port 101 and forms an assembly hole 102 with the nut sleeve 12. The valve port 101 is located in the valve seat 11. This facilitates the machining of the assembly hole 102 and the valve port 101, and also simplifies the assembly of the valve core assembly 30 and the screw unit 20, further improving the machining and assembly efficiency of the electronic expansion valve 100.

[0049] Specifically, the valve seat 11 can be configured as an integral structure. Of course, the valve seat 11 can also include a separate main body and a valve port, with the valve port connected to the main body and the valve port 101 opened in the valve port, so as to reduce the machining difficulty of the valve port 101 and improve the machining accuracy through the separate structure.

[0050] Furthermore, the valve body assembly 10 also includes an outer cover 14, which covers the outer periphery of the nut sleeve 12 and is connected to the valve seat 11 to protect the components inside the valve body assembly 10.

[0051] In one embodiment, such as Figure 1 As shown, the electronic expansion valve 100 also includes a rotor assembly 50, which is installed inside the valve body assembly 10 and connected to the end of the screw unit 20 away from the valve port 101, for driving the screw unit 20 to rotate. This enables the screw unit 20 to rotate relative to the nut sleeve 12.

[0052] Furthermore, in one embodiment, the rotor assembly 50 is welded and fixed to the screw unit 20. This simplifies the connection between the rotor assembly 50 and the screw unit 20. Specifically, the rotor assembly 50 includes a rotor body 51 and a rotor connecting plate 52, which is connected to both the rotor body 51 and the screw body 21. The rotor body 51 rotates in conjunction with an external motor and drives the screw body 21 to rotate synchronously via the rotor connecting plate 52, thereby driving the valve core assembly 30.

[0053] When assembling the electronic expansion valve 100, the valve core assembly 30 and the screw unit 20 can be connected as one unit, and the screw unit 20 can be connected with the nut sleeve 12. Then, the nut sleeve 12 is welded to the valve seat 11, and the screw unit 20 is welded to the rotor assembly 50. Finally, the outer cover 14 is assembled to achieve sealing.

[0054] In summary, the electronic expansion valve 100 provided in this application has the following characteristics: Figure 2 As shown, in the fully closed state, that is, when the abutting part 201 and the abutting mating part 301 are in contact, the valve core assembly 30 is in the fully closed lower stop position where it abuts against the valve port 101. It also has, as shown... Figure 3 As shown, this is the lower stop position in the pre-open valve state, i.e., when the valve core assembly 30 and the valve port 101 are just abutting and engaging. The upper stop position is as follows... Figure 4 As shown, this is achieved through the abutment engagement of the upper stop fitting part 302 and the upper stop part 103. The valve core assembly 30 moves to the position driven by the screw unit 20. Figure 2 When the screw unit 20 is in the fully closed position, it cannot continue to move toward the valve port 101. The axial direction of the valve core assembly 30 is limited. The axial component of the driving force of the rotor assembly 50 is greater than the preload force of the elastic element 40 on the screw unit 20 after the screw unit 20 moves down h, thus ensuring that the screw unit 20 effectively limits the valve core assembly 30 in the axial direction when it is in the fully closed position.

[0055] Furthermore, in the pre-opening state, the preset gap size formed between the screw unit 20 and the valve core assembly 30 can determine the number of opening pulses of the electronic expansion valve 100, so that the electronic expansion valve 100 can open as expected. Figure 5 As shown, within a certain initial pulse, the valve core assembly 30 is always in contact with the valve port 101, keeping the flow rate always zero.

[0056] This application also provides an air conditioning system, which includes the electronic expansion valve 100 described in any of the above embodiments.

[0057] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0058] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. Therefore, the patent protection scope of this application should be determined by the appended claims.

Claims

1. An electronic expansion valve, characterized in that, It includes a valve body assembly (10), a screw unit (20) and a valve core assembly (30), wherein the valve body assembly (10) has a valve port (101); One end of the screw unit (20) is connected to the valve core assembly (30) to drive the valve core assembly (30) to move toward or away from the valve port (101). The screw unit (20) is provided with an abutment part (201), and the valve core assembly (30) is provided with an abutment mating part (301). The electronic expansion valve has a fully closed state, a pre-open valve state, and a fully open state. In the fully closed state and the pre-open valve state, the valve core assembly (30) abuts against and seals the valve port (101). When the electronic expansion valve is in the fully closed state, the abutting part (201) abuts and engages with the abutting mating part (301); When the electronic expansion valve is in the pre-open valve state, a preset gap h is formed axially between the abutting part (201) and the abutting mating part (301), and the stroke of the valve core assembly (30) is H, wherein 0.02≤h / (h+H)≤0.

15.

2. The electronic expansion valve according to claim 1, characterized in that, The abutting part (201) and the abutting mating part (301) form a line-to-surface contact or a surface-to-surface contact.

3. The electronic expansion valve according to claim 1, characterized in that, The valve body assembly (10) is also provided with an assembly hole (102), and an upper stop (103) is provided at one end of the assembly hole (102) away from the valve port (101), and the valve core assembly (30) is provided with an upper stop mating part (302). When the electronic expansion valve is in the fully open state, the upper stop mating part (302) can abut against the upper stop part (103).

4. The electronic expansion valve according to claim 3, characterized in that, The stroke of the screw unit (20) is H0, and the axial distance from the upper stop (103) to the valve port (101) is H2; in the pre-open valve state, the axial distance from the upper stop mating part (302) to the valve port (101) is H1; where H = H2 - H1, and H0 = H + h.

5. The electronic expansion valve according to claim 1, characterized in that, The electronic expansion valve also includes an elastic element (40), which is sleeved on a portion of the outer periphery of the screw unit (20), and the two ends of the elastic element (40) act on the screw unit (20) and the valve core assembly (30) respectively.

6. The electronic expansion valve according to claim 5, characterized in that, The valve core assembly (30) includes a spring sleeve (31) and a valve needle (32). One end of the spring sleeve (31) is connected to the screw unit (20), and the other end of the spring sleeve (31) is connected to the valve needle (32). The spring sleeve (31) and the valve needle (32) are either integral or separate structures. The elastic element (40) is installed inside the spring sleeve (31), and the end face of the valve needle (32) near the end of the screw unit (20) forms the abutment mating part (301).

7. The electronic expansion valve according to claim 6, characterized in that, The spring sleeve (31) and the valve needle (32) are separate structures. The valve core assembly (30) also includes a pressure sleeve (33), which is sleeved on the outer periphery of the valve needle (32) and fixedly connected to the spring sleeve (31). The valve needle (32) has a shoulder (321) protruding from its outer periphery in a direction away from its own axis. The shoulder (321) is axially matched with the pressure sleeve (33).

8. The electronic expansion valve according to claim 6, characterized in that, The spring sleeve (31) protrudes from one end near the screw unit (20) toward its own axis to form a limiting part (311); The screw unit (20) includes a screw body (21), a bearing (22), and a spring seat (23). The bearing (22) and the spring seat (23) are both movably installed in the spring sleeve (31). The spring seat (23) abuts against one end of the outer ring of the bearing (22), and the limiting part (311) can stop at the other end of the outer ring of the bearing (22). The screw body (21) passes through the limiting part (311) and is fixedly connected to the inner ring of the bearing (22). The elastic element (40) abuts against the spring seat (23), and the end face of the spring seat (23) near the valve needle (32) forms the abutment portion (201).

9. The electronic expansion valve according to claim 1, characterized in that, The valve body assembly (10) includes a valve seat (11), a nut sleeve (12), and a guide sleeve (13). The nut sleeve (12) is fixedly connected to one end of the valve seat (11). The screw unit (20) passes through the nut sleeve (12) and is threadedly connected to the nut sleeve (12). The guide sleeve (13) is inserted into one end of the nut sleeve (12) near the valve port (101). The valve port (101) is located on the valve seat (11).

10. The electronic expansion valve according to claim 9, characterized in that, The valve seat (11) includes a main body and a valve port, which are separately configured. The valve port is connected to the main body, and the valve port (101) is opened in the valve port.

11. An air conditioning system, characterized in that, Includes the electronic expansion valve as described in any one of claims 1-10.

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