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 valve body assembly is sequentially provided with an assembly hole and a valve port in the axial direction, one end of the screw unit extends into the assembly hole and is connected with the valve element assembly, and the valve element assembly can be driven by the screw unit to move in the direction close to or away from the valve port. The electronic expansion valve has a full-closing state and a valve pre-opening state, and in the full-closing state and the valve pre-opening state, a first preset gap is formed between the valve element assembly and the valve port. 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 an assembly hole and a valve port sequentially formed along the axial direction. One end of the screw unit extends into the assembly hole and is connected to the valve core assembly, and the valve core assembly can move towards or away from the valve port under the drive of the screw unit. The electronic expansion valve has a fully closed state and a pre-open valve state, and in the fully closed state and the pre-open valve state, a first preset gap is formed between the valve core assembly and the valve port.

[0006] In one embodiment, the end of the mounting hole near the valve port protrudes towards its own axis to form a lower stop portion. The screw unit is provided with an abutment portion, and the valve core assembly is provided with a lower stop fitting portion and an abutment fitting portion. The abutment portion and the abutment fitting portion form a second preset gap in the pre-open valve state. During the process from the fully closed state to the pre-open valve state, the size of the first preset gap remains unchanged, the gap between the abutment portion and the abutment fitting portion gradually increases to the size of the second preset gap, and the lower stop portion abuts and engages with the lower stop fitting portion.

[0007] In one embodiment, in the fully closed state, the abutting portion and the abutting mating portion abut and engage.

[0008] In one embodiment, the electronic expansion valve further includes a rotor assembly connected to the end of the screw unit away from the valve port, for driving the screw unit to rotate; wherein, the rotor assembly is provided with a second lower stop portion, and the valve body assembly is provided with a second lower stop mating portion; when the electronic expansion valve is in the fully closed state, the second lower stop portion and the second lower stop mating portion abut against each other, and the abutting portion and the abutting mating portion are spaced apart; when the electronic expansion valve is in the pre-open valve state, the second lower stop portion and the second lower stop mating portion are spaced apart, and the size of the gap formed by the second lower stop portion and the second lower stop mating portion is smaller than the size of the second preset gap.

[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 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 end of the mounting hole away from the valve port is provided with an upper stop portion, and the end of the valve core assembly away from the valve port is provided with an upper stop mating portion; wherein, when the electronic expansion valve is in the fully open state, the upper stop mating portion can abut against the upper stop portion.

[0014] In one embodiment, the size of the first preset gap is ΔH, the stroke of the valve core assembly is H, the axial distance from the upper stop to the valve port is H1, and the axial distance from the upper stop to the lower stop is H2; in the fully closed state, the axial distance from the upper stop mating part to the lower stop is H3, and the axial distance from any point on the projection of the inner sidewall of the valve port onto the outer sidewall of the valve core assembly along the axial direction to the upper stop is H4; wherein, H = H2 - H3, ΔH = H1 - H4.

[0015] In one embodiment, the upper stop portion and the upper stop mating portion are in surface-to-surface contact or line-to-surface contact.

[0016] In one embodiment, the lower stop portion and the lower stop mating portion are in surface-to-surface contact or line-to-surface contact; and / or, the abutting portion and the abutting mating portion are in surface-to-surface contact or line-to-surface contact.

[0017] 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. 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 and surrounds the nut sleeve to form the assembly hole. The valve port is located in the valve seat.

[0018] 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.

[0019] In one embodiment, a wear-reducing element is provided between the lower stop portion and the lower stop mating portion.

[0020] In one embodiment, the wear-reducing element is configured as any one of a bearing, a gasket, or a coating.

[0021] This application also provides an air conditioning system, which includes the electronic expansion valve described in any of the above embodiments.

[0022] Compared with existing technologies, the electronic expansion valve and air conditioning system provided in this application allow the valve core assembly to move axially under the drive of the screw unit. Because a gap exists between the valve core assembly and the valve port in the fully closed state, a certain flow of refrigerant still passes through the valve port, corresponding to a 0-pulse state. Furthermore, since the valve core assembly does not contact the valve port, friction between them is avoided, preventing wear and significantly extending the service life of the electronic expansion valve. Simultaneously, because a first preset gap exists between the valve core assembly and the valve port in both the fully closed and pre-open states—meaning the position of the valve core assembly near the valve port remains unchanged—the flow rate at the valve port remains constant during the initial opening phase of the electronic expansion valve, improving flow consistency. Attached Figure Description

[0023] 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.

[0024] Figure 1 A cross-sectional view of an electronic expansion valve according to an embodiment provided in this application;

[0025] Figure 2 A cross-sectional view of an electronic expansion valve in the fully closed state according to an embodiment of this application;

[0026] Figure 3 A cross-sectional view of an electronic expansion valve in a pre-open valve state according to an embodiment of this application;

[0027] Figure 4 A cross-sectional view of an electronic expansion valve in the fully open state according to an embodiment provided in this application;

[0028] Figure 5 A schematic diagram of the flow rate variation of an electronic expansion valve according to an embodiment of this application;

[0029] Figure 6 A cross-sectional view of an electronic expansion valve in the fully closed state, according to another embodiment of this application.

[0030] The symbols in the diagram represent the following meanings:

[0031] 100. Electronic expansion valve; 10. Valve body assembly; 101. Valve port; 102. Assembly hole; 103. Upper stop; 104. Lower stop; 105. Second lower stop mating part; 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. Lower stop mating part; 303. Upper stop mating part; 31. Spring sleeve; 311. Limiting part; 32. Valve needle; 321. Shoulder; 33. Pressure sleeve; 40. Elastic element; 50. Rotor assembly; 501. Second lower stop; 51. Rotor body; 52. Rotor connecting plate. Detailed Implementation

[0032] 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.

[0033] 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 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.

[0034] 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.

[0035] In this application, unless otherwise expressly specified or 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 that the first feature and the second feature are indirectly in contact through an intermediate medium. Furthermore, 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.

[0036] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as 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 of the relevant listed items.

[0037] 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.

[0038] 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.

[0039] Please see Figures 1-6To 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 an assembly hole 102 and a valve port 101 sequentially formed along the axial direction. The end of the assembly hole 102 near the valve port 101 protrudes towards its own axis, forming a lower stop portion 104. One end of the screw unit 20 extends into the assembly hole 102 and connects to the valve core assembly 30. The valve core assembly 30 can move towards or away from the valve port 101 under the drive of the screw unit 20. The screw unit 20 has an abutment portion 201, and the valve core assembly 30 has an abutment mating portion 301 and a lower stop mating portion 302. The electronic expansion valve 100 has a fully closed state and a pre-open valve state. In both the fully closed and pre-open valve states, a first preset gap is formed between the valve core assembly 30 and the valve port 101. When the valve is pre-opened, a second preset gap is formed between the contact part 201 and the contact mating part 301.

[0040] 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. Since a gap exists between the valve core assembly 30 and the valve port 101 in the fully closed state, a certain flow of refrigerant still passes through the valve port 101 when the electronic expansion valve 100 is fully closed, corresponding to a 0-pulse state. Furthermore, since the valve core assembly 30 does not contact the valve port 101, friction between them is avoided, thus preventing wear caused by friction and significantly extending the service life of the electronic expansion valve 100. Simultaneously, because a first preset gap exists between the valve core assembly 30 and the valve port 101 in both the fully closed and pre-open states of the electronic expansion valve 100—that is, the position of the end of the valve core assembly 30 near the valve port 101 remains unchanged—the flow rate at the valve port 101 remains constant during the initial opening phase of the electronic expansion valve 100, improving the flow consistency of the electronic expansion valve 100.

[0041] Furthermore, during the transition from the fully closed state to the pre-open valve state, the size of the first preset gap remains unchanged, while the gap between the abutting part 201 and the abutting mating part 301 gradually increases to the size of the second preset gap, and the lower stop part 104 abuts and engages with the lower stop mating part 302. That is, during the transition from the fully closed state to the pre-open valve state, as the screw unit 20 moves axially, the gap between the abutting part 201 and the abutting mating part 301 gradually increases. Here, the number of pulses required for the screw unit 20 to move the gap between the abutting part 201 and the abutting mating part 301 is the number of opening pulses for the electronic expansion valve 100, meaning the pre-open valve state corresponds to the flow inflection point of the electronic expansion valve 100. During this period, the size of the first preset gap remains unchanged, thereby ensuring the consistency of the flow at the valve port 101. Afterward, as the screw unit 20 continues to move, it can drive the valve core assembly 30 to move synchronously. At this time, the flow at the valve port 101 begins to change, thereby realizing the opening of the electronic expansion valve 100. Compared to traditional constant pulse technology, the structure of this application is simpler and easier to adjust.

[0042] In this application, due to the existence of the second preset gap, 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 fully closed state or 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.

[0043] To achieve the rotation of the screw unit 20, 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.

[0044] The rotor assembly 50 and the screw unit 20 can be fixed together by welding. Specifically, the screw unit 20 includes a screw body 21, and 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.

[0045] In one embodiment, such as Figure 1-Figure 4As shown, in the fully closed state, the abutting part 201 and the abutting mating part 301 abut against each other. That is, in this embodiment, the screw unit 20 can transmit force through the abutting part 201 and the abutting mating part 301, so that the lower stop part 104 and the lower stop mating part 302 abut against each other tightly, thereby realizing the lower limit of the axial movement of the valve core assembly 30 and the screw unit 20. Here, the gap between the abutting part 201 and the abutting mating part 301 in the pre-open valve state is controlled to be h.

[0046] In another embodiment, such as Figure 6 As shown, the rotor assembly 50 is provided with a second lower stop portion 501, which is specifically formed by the end face of the rotor connecting plate 52 near the valve port 101. The valve body assembly 10 is provided with a second lower stop mating portion 105. When the electronic expansion valve 100 is in the fully closed state, the second lower stop portion 501 and the second lower stop mating portion 105 abut against each other. When the electronic expansion valve 100 is in the pre-open valve state, the second lower stop portion 501 and the second lower stop mating portion 105 are spaced apart. Specifically, by setting the size of the gap formed between the second lower stop portion 501 and the second lower stop mating portion 105 in the pre-open valve state to be smaller than the size of the second preset gap, the distance that the rotor assembly 50 moves when the valve is closed will be less than the gap between the abutting portion 201 and the abutting mating portion 301, so that the abutting portion 201 and the abutting mating portion 301 can be spaced apart in the closed valve state. That is, in this embodiment, the lower limit of the axial movement of the valve core assembly 30 and the screw unit 20 is achieved by the rotor assembly 50. The gap between the abutment portion 201 and the abutment mating portion 301 in the closed valve state can be maintained by the elastic element 40 described below, thereby achieving consistency in the position between the valve core assembly 30 and the valve port 101 and improving flow consistency. Here, the gap between the second lower stop portion 501 and the second lower stop mating portion 105 in the pre-open valve state is controlled to be h. At this time, the gap between the abutment portion 201 and the abutment mating portion 301 in the pre-open valve state is greater than h.

[0047] Furthermore, the second lower stop portion 501 and the second lower stop mating portion 105 are preferably in surface-to-surface contact. That is, both the second lower stop portion 501 and the second lower stop mating portion 105 are planar, thus making the fit between them more stable. Of course, in other embodiments, the second lower stop portion 501 and the second lower stop mating portion 105 can also be configured as line-to-surface contact, etc., as long as the same effect can be achieved.

[0048] In summary, this application achieves the limiting fit of the screw unit 20 and / or valve core assembly 30 along the axial direction of the electronic expansion valve 100 through the abutment part 201 and the abutment mating part 301, or the abutment between the second lower stop part 501 and the second lower stop mating part 105. This eliminates the need for circumferential stop structures such as limit springs, stop rings, and guide plates that provide a limiting effect in traditional structures. Compared to circumferential stop structures, this application has no obvious impact in the circumferential direction, which can effectively reduce the noise when the lower stop abuts, and reduce the number of parts required for the electronic expansion valve 100. This not only saves costs but also reduces the processing and assembly difficulty of the electronic expansion valve 100.

[0049] Furthermore, during the process of the electronic expansion valve 100 changing from a fully closed state to a pre-open state, a small flow of refrigerant can be ensured to pass through the valve port 101, and the flow rate remains constant, thereby achieving precise control of the refrigerant flow and meeting the usage requirements of the air conditioning system. (Refer to this application) Figure 5 The fully closed state corresponds to the 0-pulse state. The screw unit 20 continues to move axially away from the valve port 101 from the fully closed state to the pre-open valve state. During this process, the screw unit 20 moves axially away from the valve port 101, but the lower stop mating part 302 of the valve core assembly 30 still abuts against the lower stop part 104. The flow rate at the valve port 101 does not change. The number of pulses required for the screw unit 20 to move h is the number of valve opening pulses. This corresponds to the flow inflection point. The screw unit 20 continues to move away from the valve port 101 from the pre-open valve state, and drives the valve core assembly 30 to start moving away from the valve port 101. At this time, the flow rate at the valve port 101 begins to change.

[0050] For ease of explanation, this application only describes the structure of the abutment part 201 and the abutment mating part 301 in the fully closed state, that is, as shown below. Figure 1-Figure 4 The structure shown will be explained. Based on this, the gap between the abutment part 201 and the abutment mating part 301 of the electronic expansion valve 100 is always maintained at the size of the second preset gap, i.e., h, between the pre-open valve state and the fully open state.

[0051] 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, ensuring the consistency of position between the valve core assembly 30 and the valve port 101. When the lower stop portion 104 abuts against the lower stop mating portion 302, the impact force on the movement of the valve core assembly 30 is reduced, thereby providing better protection for the valve core assembly 30.

[0052] Furthermore, in one embodiment, the lower stop portion 104 and the lower stop mating portion 302 are preferably in surface-to-surface contact. That is, both the lower stop portion 104 and the lower stop mating portion 302 are planar, thus making the fit between them more stable. Of course, in other embodiments, the lower stop portion 104 and the lower stop mating portion 302 can also be configured as line-to-surface contact, etc., as long as the same effect can be achieved.

[0053] Furthermore, in one embodiment, the abutting portion 201 and the mating portion 301 are preferably in 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 be in line-to-surface contact, which can be reasonably set according to actual needs.

[0054] In one embodiment, the end of the mounting hole 102 away from the valve port 101 is provided with an upper stop portion 103, and the end of the valve core assembly 30 away from the valve port 101 is provided with an upper stop mating portion 303. When the electronic expansion valve 100 is in the fully open state, the upper stop mating portion 303 can abut against the upper stop portion 103 axially. At this time, the screw unit 20 can no longer drive the valve core assembly 30 to move away from the valve port 101. In this way, the upper stop of the valve core assembly 30 is achieved.

[0055] Specifically, if Figure 2As shown, the size of the first preset gap is ΔH, the stroke of the valve core assembly 30 is H, the axial distance from the upper stop 103 to the valve port 101 is H1, and the axial distance from the upper stop 103 to the lower stop 104 is H2. In the fully closed state, the axial distance from the upper stop mating part 303 to the lower stop 104 is H3, and the axial distance from any point on the projection of the inner sidewall of the valve port 101 along the axial direction onto the outer sidewall of the valve core assembly 30 to the upper stop 103 is H4. Wherein, H = H2 - H3, ΔH = H1 - H4. In this way, it is convenient to design the dimensions of each component in the electronic expansion valve 100, and ensures that when the lower stop 104 and the lower stop mating part 302 abut during the assembly process of the electronic expansion valve 100, the first preset gap is formed.

[0056] Furthermore, in one embodiment, the upper stop portion 103 and the upper stop mating portion 303 are preferably in surface-to-surface contact. That is, both the upper stop portion 103 and the upper stop mating portion 303 are planar, thus making the fit between them more stable. Of course, in other embodiments, the upper stop portion 103 and the upper stop mating portion 303 can also be configured as line-to-surface contact or other methods as needed, as long as the same effect can be achieved.

[0057] 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. 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 around the nut sleeve 12. The valve port 101 is located within the valve seat 11. This facilitates the machining of 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. Figure 6 As shown, the second lower stop fitting part 105 can be formed by the end face of the nut sleeve 12 away from the valve port 101.

[0058] 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.

[0059] 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.

[0060] In one embodiment, 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 or separately configured. An elastic element 40 is installed inside the spring sleeve 31. The end face of the valve needle 32 near the screw unit 20 forms an abutment mating portion 301, and the end face of the spring sleeve 31 away from the valve port 101 forms an upper stop mating portion 303. 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.

[0061] The outer wall of the spring sleeve 31 can be guided and engaged 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.

[0062] Furthermore, in one embodiment, the valve core assembly 30 further 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.

[0063] Specifically, the pressure sleeve 33 and the spring sleeve 31 can be an integral structure or a separate structure.

[0064] 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.

[0065] 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.

[0066] In this embodiment, the end face of the spring sleeve 31 or the upper limit portion 311 of the spring sleeve 31 away from the valve port 101 forms an upper stop fitting portion 303, thereby realizing the upper stop of the valve core assembly 30, and at this time the electronic expansion valve 100 is in the fully open state.

[0067] 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.

[0068] In the fully closed state, the electronic expansion valve 100 has zero pulses. The abutment part 201 abuts against the abutment mating part 301, and the lower stop part 104 abuts against the lower stop mating part 302. At this time, a gap is formed axially between the limiting part 311 and the bearing 22. The size of this gap is equal to the size of the second preset gap, i.e., both are h. During the opening process of the electronic expansion valve 100, the screw unit 20 first drives the bearing 22 to move, so as to gradually reduce the distance between the bearing 22 and the limiting part 311. At the same time, 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 always remain equal until the distance between the abutment part 201 and the abutment mating part 301 forms the size of the second preset gap. After that, since the bearing 22 abuts against the limiting part 311, 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 lower stop fitting part 302 just comes into contact with the lower stop part 104, the screw unit 20 can still move axially by the size of the second preset gap, so that the bearing 22 and the limiting part 311 gradually move away from each other.

[0069] When the electronic expansion valve 100 is fully closed, the lower stop portion 104 and the lower stop mating portion 302 are in contact. Therefore, to reduce the friction between the lower stop portion 104 and the lower stop mating portion 302 and lower the valve opening resistance, in one embodiment, a friction-reducing element (not shown) can be provided between the lower stop portion 104 and the lower stop mating portion 302 to reduce friction. Further, in one embodiment, the friction-reducing element is configured as any one of a bearing, a gasket, or a coating. This achieves a better friction reduction effect. For example, the friction-reducing element can be a PPS gasket, but it is not limited to this; the friction-reducing element can also be made of other wear-resistant, low-friction coefficient materials.

[0070] 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.

[0071] 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 lower stop part 104 abuts against the lower stop mating part 302 in the fully closed lower stop position. It also has, as shown... Figure 3 As shown, in the pre-open valve state, that is, the lower stop position when the lower stop part 104 and the lower stop mating part 302 are just abutting and mating. The upper stop position is as follows... Figure 4 As shown, this is achieved through the abutment engagement of the upper stop portion 103 and the upper stop mating portion 303. The valve core assembly 30 moves to the position driven by the screw unit 20. Figure 2 When the valve core assembly 30 is in the fully closed position, 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 downward by 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.

[0072] Furthermore, in the pre-opening state, the size of the second preset gap 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... Figure 5 As shown, within a certain initial pulse, the axial distance between the valve core assembly 30 and the valve port 101 remains the same, thus maintaining a constant flow rate.

[0073] This application also provides an air conditioning system, which includes the electronic expansion valve 100 described in any of the above embodiments.

[0074] 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.

[0075] The above-described embodiments merely represent several implementation methods of the present application. 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 a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of patent protection for the present application shall 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) is provided with an assembly hole (102) and a valve port (101) in sequence along the axial direction; One end of the screw unit (20) extends into the mounting hole (102) and is connected to the valve core assembly (30), and the valve core assembly (30) can move towards or away from the valve port (101) under the drive of the screw unit (20); The electronic expansion valve has a fully closed state and a pre-open valve state, and in the fully closed state and the pre-open valve state, a first preset gap is formed between the valve core assembly (30) and the valve port (101).

2. The electronic expansion valve according to claim 1, characterized in that, The assembly hole (102) near the valve port (101) protrudes towards its own axis to form a lower stop (104), the screw unit (20) is provided with an abutment (201), and the valve core assembly (30) is provided with a lower stop mating part (302) and an abutment mating part (301). The abutting part (201) and the abutting mating part (301) form a second preset gap in the pre-open valve state. During the process of changing from the fully closed state to the pre-open valve state, the size of the first preset gap remains unchanged, and the gap between the abutting part (201) and the abutting mating part (301) gradually increases to the size of the second preset gap. The lower stop part (104) and the lower stop mating part (302) abut and engage.

3. The electronic expansion valve according to claim 2, characterized in that, In the fully closed state, the abutting part (201) and the abutting mating part (301) abut and engage.

4. The electronic expansion valve according to claim 2, characterized in that, The electronic expansion valve further includes a rotor assembly (50), which is connected to one end of the screw unit (20) away from the valve port (101) and is used to drive the screw unit (20) to rotate; wherein, the rotor assembly (50) is provided with a second lower stop (501) and the valve body assembly (10) is provided with a second lower stop mating part (105). When the electronic expansion valve is in the fully closed state, the second lower stop (501) abuts against the second lower stop mating part (105), and the abutting part (201) and the abutting mating part (301) are spaced apart. When the electronic expansion valve is in the pre-open valve state, the second lower stop part (501) and the second lower stop mating part (105) are spaced apart, and the size of the gap formed by the second lower stop part (501) and the second lower stop mating part (105) is smaller than the size of the second preset gap.

5. The electronic expansion valve according to claim 3 or 4, 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 valve core assembly (30) further 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 2, characterized in that, The assembly hole (102) is provided with an upper stop (103) at one end away from the valve port (101), and the valve core assembly (30) is provided with an upper stop mating part (303) at one end away from the valve port (101); When the electronic expansion valve is in the fully open state, the upper stop mating part (303) can abut against the upper stop part (103).

10. The electronic expansion valve according to claim 9, characterized in that, The size of the first preset gap is ΔH, the stroke of the valve core assembly (30) is H, the axial distance from the upper stop (103) to the valve port (101) is H1, and the axial distance from the upper stop (103) to the lower stop (104) is H2; in the fully closed state, the axial distance from the upper stop mating part (303) to the lower stop (104) is H3, and the axial distance from any point on the projection of the inner wall of the valve port (101) along the axial direction onto the outer wall of the valve core assembly (30) to the upper stop (103) is H4; Where H = H2 - H3, ΔH = H1 - H4.

11. The electronic expansion valve according to claim 9, characterized in that, The upper stop portion (103) and the upper stop mating portion (303) are in surface-to-surface contact or line-to-surface contact.

12. The electronic expansion valve according to claim 2, characterized in that, The lower stop portion (104) and the lower stop mating portion (302) are in surface-to-surface contact or line-to-surface contact; And / or, the contact portion (201) and the contact mating portion (301) are in surface-to-surface contact or line-to-surface contact.

13. 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) and surrounds the nut sleeve (12) to form the assembly hole (102). The valve port (101) is located on the valve seat (11).

14. The electronic expansion valve according to claim 13, 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.

15. The electronic expansion valve according to claim 2, characterized in that, A wear-reducing component is provided between the lower stop portion (104) and the lower stop mating portion (302).

16. The electronic expansion valve according to claim 15, characterized in that, The wear-reducing component is configured as any one of a bearing, a gasket, or a coating.

17. An air conditioning system, characterized in that, Includes the electronic expansion valve as described in any one of claims 1-16.

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