Electronic expansion valve

Abstract

The invention provides an electronic expansion valve which comprises a valve seat assembly and a valve element assembly. A valve cavity of the valve seat assembly is provided with a first valve port; the valve element assembly comprises a first valve needle and a second valve needle. One end part of the first valve needle is in sealing fit with the first valve port; a circulation cavity, a transverse channel, a second valve port and a longitudinal channel are arranged in the first valve needle; the circulation cavity is located on the side, back to the first valve port, of the longitudinal channel. One end of the transverse channel is opened on the side of the first valve needle; one end of the second valve port communicates with the circulation cavity, and the other end communicates with the transverse channel; one end of the longitudinal channel is opened on the end face of the first valve needle facing the first valve port, and the other end is communicated with the circulation cavity; part of the second valve needle is inserted into the circulation cavity, and the end, facing the first valve port, of the second valve needle is in sealing fit with the second valve port.

Description

Technical Field

[0001] This disclosure relates to the field of valve technology, and more particularly to an electronic expansion valve. Background Technology

[0002] Electronic expansion valves, as throttling elements, are used to regulate the flow and interruption of fluid flow. In existing designs of electronic expansion valves, the valve core assembly is located within the valve cavity of the valve seat and includes a large valve needle and a small valve needle. The large valve needle engages with the large valve port of the valve cavity to open and close the large valve port. The large valve needle has both transverse and longitudinal channels. The large valve needle also has a small valve port, which is inserted through the large valve needle and engages with the small valve port to open and close the small valve port.

[0003] In the aforementioned existing design, the large valve needle contains a valve needle chamber with a small valve port. The two ends of the small valve port are connected to the valve needle chamber and the large valve port, respectively. Furthermore, the large valve needle also has a transverse channel, through which fluid from the valve chamber can enter the valve needle chamber. A balance channel runs through the large valve needle axially. During use, to prevent fluid from flowing out of the large valve needle through the gap between the small and large valve needles and the balance channel when the small valve port is closed, thus preventing the fluid from being shut off, a seal is required between the large and small valve needles. The installation of this seal often increases the overall manufacturing complexity.

[0004] Therefore, how to simplify the structural complexity of electronic expansion valves with dual-valve needle designs has become an important issue that urgently needs to be addressed in related fields. Summary of the Invention

[0005] A primary objective of this disclosure is to overcome at least one of the deficiencies of the prior art and to provide an electronic expansion valve with a simpler structure.

[0006] To achieve the above objectives, the present disclosure adopts the following technical solution:

[0007] According to one aspect of this disclosure, an electronic expansion valve is provided, comprising a valve seat assembly, a valve core assembly, and a drive assembly; the valve seat assembly has a valve cavity internally disposed therein, the valve cavity having a first valve port; the valve core assembly includes a first valve needle and a second valve needle; the first valve needle is disposed in the valve cavity; one end of the first valve needle is in sealing engagement with the first valve port; the first valve needle internally comprises a flow cavity, a transverse channel, a second valve port, and a longitudinal channel; the flow cavity is located on the side of the transverse channel and the longitudinal channel facing away from the first valve port; at least one end of the transverse channel opens onto the side of the first valve needle; one end of the second valve port communicates with the flow cavity, and the other end communicates with the transverse channel; one end of the longitudinal channel opens onto the end face of the first valve needle facing the first valve port, and the other end communicates with the flow cavity; the second valve needle is partially inserted into the flow cavity, and the end of the second valve needle facing the first valve port is in sealing engagement with the second valve port; the drive assembly is used to drive the first valve needle and the second valve needle to move axially to achieve opening and closing control of the first valve port and the second valve port.

[0008] According to one embodiment of this disclosure, the first valve needle includes a first assembly and a second assembly that are separately disposed and connected to each other. The first assembly has a groove on the side facing the first valve port, and the groove and the side of the second assembly facing away from the first valve port together form the flow cavity. The transverse channel, the second valve port and the longitudinal channel are disposed in the second assembly.

[0009] According to one embodiment of this disclosure, a valve core sealing ring is provided between the first valve needle and the valve seat assembly, and the portion of the valve cavity located on the side away from the first valve port of the valve core sealing ring is a back pressure cavity; the first valve needle is provided with a balance channel, and the two ends of the balance channel are respectively connected to the first valve port and the back pressure cavity; the balance channel includes the longitudinal channel and a flow channel disposed in the first valve needle; one end of the flow channel is connected to the flow cavity, and the other end is open and connected to the back pressure cavity.

[0010] According to one embodiment of this disclosure, wherein: the valve core sealing ring is installed on the first valve needle; the circular area corresponding to the sealing area between the valve core sealing ring and the valve seat assembly is S1, the circular area corresponding to the sealing area between the first valve needle and the first valve port is S3, and the circular area corresponding to the sealing area between the second valve needle and the second valve port is S4; wherein, S1 = S3 + S4; or, the valve core sealing ring is installed on the valve seat assembly; the circular area corresponding to the sealing area between the valve core sealing ring and the first valve needle is S2, the circular area corresponding to the sealing area between the first valve needle and the first valve port is S3, and the circular area corresponding to the sealing area between the second valve needle and the second valve port is S4; wherein, S2 = S3 + S4.

[0011] According to one embodiment of this disclosure, wherein: the valve core sealing ring is installed on the first valve needle; the circular area corresponding to the sealing area between the valve core sealing ring and the valve seat assembly is S1, the circular area corresponding to the sealing area between the first valve needle and the first valve port is S3, and the circular area corresponding to the sealing area between the second valve needle and the second valve port is S4; wherein, S1 < S3 + S4; or, the valve core sealing ring is installed on the valve seat assembly; the circular area corresponding to the sealing area between the valve core sealing ring and the first valve needle is S2, the circular area corresponding to the sealing area between the first valve needle and the first valve port is S3, and the circular area corresponding to the sealing area between the second valve needle and the second valve port is S4; wherein, S2 < S3 + S4.

[0012] According to one embodiment of this disclosure, wherein: the valve core sealing ring is installed on the first valve needle; the circular area corresponding to the sealing area between the valve core sealing ring and the valve seat assembly is S1, the circular area corresponding to the sealing area between the first valve needle and the first valve port is S3, and the circular area corresponding to the sealing area between the second valve needle and the second valve port is S4; wherein, S1 > S3 + S4; or, the valve core sealing ring is installed on the valve seat assembly; the circular area corresponding to the sealing area between the valve core sealing ring and the first valve needle is S2, the circular area corresponding to the sealing area between the first valve needle and the first valve port is S3, and the circular area corresponding to the sealing area between the second valve needle and the second valve port is S4; wherein, S2 > S3 + S4.

[0013] According to one embodiment of this disclosure, the first valve needle is provided with a through hole through which the second valve needle passes; wherein the flow channel and the through hole are connected in the circumferential direction to form an integral channel structure.

[0014] According to one embodiment of this disclosure, the sum of the flow areas of all the lateral channels is equal to the sum of the flow areas of all the longitudinal channels.

[0015] According to one embodiment of this disclosure, the second valve port is located at the axial position of the first valve needle, and the lateral channel extends in the radial direction of the first valve needle.

[0016] According to one embodiment of the present disclosure, the first valve needle is provided with at least one transverse channel that extends radially through the first valve needle, with both ends of the transverse channel opening onto the side of the first valve needle, and the second valve port communicating with the middle position of the transverse channel.

[0017] According to one embodiment of this disclosure, the number of longitudinal channels located on both sides of the transverse channel is equal; wherein, a reference plane is defined that is parallel to the radial direction and perpendicular to the axial direction, and on the reference plane, the orthographic projections of the longitudinal channels located on both sides of the transverse channel are arranged axially symmetrically, and the axis of symmetry is the center line of the orthographic projection of the transverse channel.

[0018] According to one embodiment of this disclosure, the electronic expansion valve further includes a first elastic element, which is connected between the end of the first valve needle facing away from the first valve port and the valve seat assembly; wherein, the end of the first valve needle facing away from the first valve port is provided with a receiving groove, and the first elastic element is partially received in the receiving groove.

[0019] According to one embodiment of this disclosure, the electronic expansion valve further includes a second elastic element; wherein: the drive assembly includes a first screw and a spring sleeve; the second valve needle is fixedly connected to the spring sleeve, the spring sleeve is limitedly connected to the first screw and can move axially relative to the spring sleeve; the second elastic element is located inside the spring sleeve and between the second valve needle and the first screw; or, the electronic expansion valve further includes a support base connected to the valve seat assembly; the drive assembly includes a second screw, the second elastic element is sleeved on the outer periphery of the second screw and located between the support base and the second screw.

[0020] According to one embodiment of this disclosure, a first sealing structure is provided between the end of the first valve needle facing the first valve port and the first valve port, the first sealing structure including a first sealing ring, the material hardness of the first sealing ring being less than the material hardness of the first valve port; wherein, when the first valve port is closed, the first sealing ring contacts the first valve needle or the first valve port to achieve a soft seal; or, when the first valve port is closed, the first valve needle directly contacts the first valve port to achieve a hard seal.

[0021] According to one embodiment of this disclosure, a transmission part is provided on the outer periphery of the second valve needle. The transmission part is integrally disposed with the second valve needle and is located in the flow cavity along the axial direction. The thickness of the transmission part is less than the height of the flow cavity. The driving assembly drives the second valve needle to move away from the first valve port, thereby causing the transmission part to abut against the cavity wall on the side of the flow cavity away from the first valve port, so as to drive the first valve needle to move away from the first valve port.

[0022] According to one embodiment of this disclosure, the second valve port is provided with a second sealing ring, the material hardness of the second sealing ring being less than the material hardness of the second valve needle; wherein, when the second valve port is closed, the second sealing ring contacts the second valve needle to achieve a soft seal; or, the end of the second valve needle facing the first valve needle is provided with a sealing head, the material hardness of the sealing head being less than the material hardness of the second valve port; wherein, when the second valve port is closed, the sealing head contacts the second valve port to achieve a soft seal; or, when the second valve port is closed, the second valve needle directly contacts the second valve port to achieve a hard seal.

[0023] As can be seen from the above technical solution, the advantages and positive effects of the electronic expansion valve proposed in this disclosure are as follows:

[0024] The electronic expansion valve disclosed herein includes a valve seat assembly and a valve core assembly; the valve cavity of the valve seat assembly is provided with a first valve port; the valve core assembly includes a first valve needle and a second valve needle; one end of the first valve needle is sealed to the first valve port; the first valve needle is provided with a flow cavity, a transverse channel, a second valve port and a longitudinal channel; the flow cavity is located on the side of the longitudinal channel opposite to the first valve port; one end of the transverse channel opens to the side of the first valve needle; one end of the second valve port is connected to the flow cavity and the other end is connected to the transverse channel; one end of the longitudinal channel opens to the end face of the first valve needle facing the first valve port and the other end is connected to the flow cavity; a portion of the second valve needle is inserted into the flow cavity, and the end of the second valve needle facing the first valve port is sealed to the second valve port. Through the above design, when the second valve port is open, this disclosure enables the throttling refrigerant to flow through the flow chamber of the first valve needle before flowing out of the first valve port. This allows the second valve needle to achieve a non-internal balance structure. Compared to existing solutions using an internal balance structure for the small valve needle, this disclosure utilizes the longitudinal channel as both a flow path and a balance channel, thereby preventing the longitudinal channel from being blocked by oil in the valve chamber. Furthermore, by employing the aforementioned non-internal balance structure for the second valve needle, this disclosure sequentially connects the transverse channel, the second valve port, the flow chamber, and the longitudinal channel, thus forming a fluid flow path. Based on this, since one end of the second valve port faces the flow chamber instead of the first valve port, when the second valve port is closed, even if there is no seal between the second valve needle and the first valve needle, the fluid entering the first valve needle will be shut off by the second valve needle, ensuring that the flow rate of the second valve port is zero. This avoids the need to set an additional seal between the first valve needle and the second valve needle, reduces the number of parts in the electronic expansion valve, and lowers the structural complexity. Since the setting of the above-mentioned seal is avoided, this disclosure also does not require welding of the corresponding pressure plate, which can reduce welding processes and improve the production efficiency of the product. Attached Figure Description

[0025] The various objectives, features, and advantages of this disclosure will become more apparent from the following detailed description of preferred embodiments of the disclosure taken in conjunction with the accompanying drawings. The drawings are merely illustrative illustrations of the disclosure and are not necessarily drawn to scale. In the drawings, the same reference numerals always denote the same or similar parts. Wherein:

[0026] Figure 1 This is a three-dimensional structural schematic diagram of an electronic expansion valve according to an exemplary embodiment;

[0027] Figure 2 yes Figure 1 A bottom view;

[0028] Figure 3 and Figure 4 They are along Figure 2 A schematic diagram of the cross-sections constructed using lines AA and BB in the diagram;

[0029] Figure 5 and Figure 6 They are Figure 3 and Figure 4 An enlarged cross-sectional schematic diagram of the valve core assembly is shown;

[0030] Figure 7 yes Figure 3 and Figure 4 A three-dimensional structural schematic diagram of the valve core assembly is shown;

[0031] Figure 8 yes Figure 7 A three-dimensional structural diagram of some of the components is shown;

[0032] Figure 9 and Figure 10 They are Figure 8 A three-dimensional exploded diagram from two different perspectives;

[0033] Figure 11 This is a three-dimensional structural schematic diagram of the second assembly of an electronic expansion valve according to another exemplary embodiment;

[0034] Figure 12 This is a schematic cross-sectional view of a second assembly of an electronic expansion valve according to another exemplary embodiment;

[0035] Figure 13 This is a partial cross-sectional schematic diagram of an electronic expansion valve according to another exemplary embodiment;

[0036] Figure 14 and Figure 15 These are cross-sectional schematic diagrams of the valve core assembly of an electronic expansion valve according to two other exemplary embodiments.

[0037] Figure 16 This is a schematic cross-sectional view of an electronic expansion valve according to another exemplary embodiment;

[0038] Figure 17 yes Figure 16 An enlarged schematic diagram of part C in the diagram;

[0039] Figure 18 This is a schematic cross-sectional view of an electronic expansion valve according to another exemplary embodiment;

[0040] Figure 19 yes Figure 18 An enlarged schematic diagram of part E in the diagram;

[0041] Figure 20 This is a schematic cross-sectional view of an electronic expansion valve according to another exemplary embodiment;

[0042] Figure 21 yes Figure 20 An enlarged schematic diagram of part of the structure is shown;

[0043] Figure 22 yes Figure 20 A three-dimensional structural schematic diagram of the valve core assembly of the electronic expansion valve is shown.

[0044] Figure 23 yes Figure 22 A three-dimensional structural schematic diagram of the first assembly is shown.

[0045] The annotations in the attached figures are explained as follows:

[0046] 100. Valve seat assembly; 2104. Longitudinal passage; 250. Sliding part;

[0047] 101. Valve cavity; 2105. Flow channel; 260. Drainage groove;

[0048] 1011. First valve port; 2106. Through hole; 261. Drain hole;

[0049] 1012. First positioning surface; 2107. Receiving groove; 270. Guide section;

[0050] 1013. Positioning protrusion; 211. First assembly; 2701. Guide surface;

[0051] 1014. Back pressure chamber; 212. Second assembly; 300. Guide seat;

[0052] 110. Valve core sleeve; 213. Valve core sealing ring; 3101. Second positioning surface;

[0053] 120. Valve cover; 220. Second valve needle; 400. Drive assembly;

[0054] 130. Support base; 221. Transmission unit; 410. First elastic element;

[0055] 200. Valve core assembly; 231. First sealing ring; 420. Second elastic element;

[0056] 210. First valve needle; 232. First pressure plate; 430. First screw;

[0057] 2101. Flow chamber; 241. Second sealing ring; 440. Spring sleeve;

[0058] 2102. Second valve port; 242. Sealing head; 450. Second screw;

[0059] 2103. Transverse channel; 243. Second tablet; 500. Outer shell. Detailed Implementation

[0060] Typical embodiments embodying the features and advantages of this disclosure will be described in detail in the following description. It should be understood that this disclosure can have various variations in different embodiments without departing from the scope of this disclosure, and the descriptions and drawings therein are illustrative in nature and not intended to limit this disclosure.

[0061] In the following description of various exemplary embodiments of this disclosure, reference is made to the accompanying drawings, which form part of this disclosure, and which illustrate by way of example different exemplary structures, systems, and steps that can implement various aspects of this disclosure. It should be understood that other specific embodiments of the components, structures, exemplary devices, systems, and steps may be used, and structural and functional modifications may be made without departing from the scope of this disclosure. Furthermore, while the terms “above,” “between,” “within,” etc., may be used in this specification to describe different exemplary features and elements of this disclosure, these terms are used herein only for convenience, such as the orientation according to the examples described in the accompanying drawings. Nothing in this specification should be construed as requiring a specific three-dimensional orientation of the structure to fall within the scope of this disclosure.

[0062] See Figure 1 The illustration shows a three-dimensional structural diagram of the electronic expansion valve proposed in this disclosure. In this exemplary embodiment, the electronic expansion valve proposed in this disclosure is described using a valve applied to a refrigeration system as an example. It will be readily understood by those skilled in the art that various modifications, additions, substitutions, deletions, or other changes may be made to the specific embodiments described below in order to apply the relevant designs of this disclosure to other application scenarios, and these changes are still within the scope of the principle of the electronic expansion valve proposed in this disclosure.

[0063] like Figure 1 As shown, in one embodiment of this disclosure, the electronic expansion valve includes a valve seat assembly 100, a valve core assembly 200, and a drive assembly 400. (See also...) Figures 2 to 9 , Figure 2 China representatively shows Figure 1 A bottom view; Figure 3 The middle section represents the direction along Figure 2 A schematic diagram of the cross-section constructed by line AA in the diagram; Figure 4 The middle section represents the direction along Figure 2 A schematic diagram of the cross-section made by the straight line BB in the diagram; Figure 5 China representatively shows Figure 3 Enlarged schematic diagram of the cross-sectional structure of the valve core assembly 200; Figure 6 China representatively shows Figure 4 Enlarged schematic diagram of the cross-sectional structure of the valve core assembly 200; Figure 7A three-dimensional structural schematic diagram of the valve core assembly 200 is shown in the figure. Figure 8 China representatively shows Figure 7 A three-dimensional structural schematic diagram of some components (e.g., the second assembly 212 and the sealing head 242) is shown; Figure 9 and Figure 10 The text represents the characteristics of each element. Figure 8 An exploded three-dimensional diagram from two different perspectives. The following will, in conjunction with the above figures, provide a detailed description of the structure, connection method, and functional relationship of the main components of the electronic expansion valve proposed in this disclosure.

[0064] like Figures 1 to 9As shown, in one embodiment of this disclosure, a valve seat assembly 100 has a valve cavity 101 inside, and the valve cavity 101 has a first valve port 1011. A valve core assembly 200 includes a first valve needle 210 and a second valve needle 220. The first valve needle 210 is disposed in the valve cavity 101, and one end of the first valve needle 210 is in a sealing fit with the first valve port 1011. The first valve needle 210 has a flow cavity 2101, a transverse channel 2103, a second valve port 2102, and a longitudinal channel 2104 inside. The flow cavity 2101 is located on the side of the transverse channel 2103 and the longitudinal channel 2104 facing away from the first valve port 1011. At least one end of the transverse channel 2103 opens onto the side of the first valve needle 210. One end of the second valve port 2102 communicates with the flow cavity 2101, and the other end of the second valve port 2102 communicates with the transverse channel 2103. One end of the longitudinal channel 2104 opens onto the end face of the first valve needle 210 facing the first valve port 1011, and the other end of the longitudinal channel 2104 connects to the flow cavity 2101. Therefore, the longitudinal channel 2104 can simultaneously serve as a balancing channel and a flow path. The second valve needle 220 is partially inserted into the flow cavity 2101; for example, in actual installation, the second valve needle 220 can be inserted outwards from the flow cavity 2101. The end of the second valve needle 220 facing the first valve port 1011 is sealed to the second valve port 2102. The drive assembly 400 is used to drive the first valve needle 210 and the second valve needle 220 to move axially, thereby controlling the opening and closing of the first valve port 1011 and the second valve port 2102. For example, the drive assembly 400 can be disposed in a housing 500 and located at the end of the valve seat assembly 100 away from the first valve port 1011. Through the above design, when the second valve port 2102 is open, this disclosure enables the throttling refrigerant to first flow through the flow chamber 2101 of the first valve needle 210 before flowing out of the first valve port 1011. Specifically, the throttling refrigerant flows sequentially through the transverse channel 2103, the second valve port 2102, the flow chamber 2101, the longitudinal channel 2104, and the first valve port 1011, which is forward flow. This disclosure can also achieve reverse flow, specifically, the throttling refrigerant flows sequentially through the first valve port 1011, the longitudinal channel 2104, the flow chamber 2101, the second valve port 2102, and the transverse channel 2103. Compared with the existing scheme using an internal balance structure for the small valve needle, this disclosure can utilize the longitudinal channel 2104 as both a flow path and a balance channel, thereby preventing the longitudinal channel 2104 from being blocked by the oil in the valve chamber 101. Meanwhile, this disclosure connects the transverse channel 2103, the second valve port 2102, the flow chamber 2101 and the longitudinal channel 2104 in sequence to form a fluid flow path.Based on this, since one end of the second valve port 2102 opens towards the flow chamber 2101 instead of the first valve port 1011, when the second valve port 2102 is closed, even if there is no seal between the second valve needle 220 and the first valve needle 210, the fluid entering the first valve needle 210 will be shut off by the second valve needle 220, ensuring that the flow rate of the second valve port 2102 is zero. This avoids the need to set an additional seal between the first valve needle 210 and the second valve needle 220, reduces the number of parts in the electronic expansion valve, and lowers the structural complexity. Since the above-mentioned seal is avoided, this disclosure also does not require welding the corresponding pressure plate for fixing the seal, which reduces welding processes and helps improve the production efficiency of the product.

[0065] like Figures 5 to 7 As shown, in one embodiment of this disclosure, the first valve needle 210 includes a first assembly 211 and a second assembly 212 that are separately disposed and interconnected. A groove is provided on the side of the first assembly 211 facing the first valve port 1011. The groove and the side of the second assembly 212 facing away from the first valve port 1011 together form the aforementioned flow cavity 2101. A transverse channel 2103, a second valve port 2102, and a longitudinal channel 2104 are disposed in the second assembly 212.

[0066] like Figures 3 to 7 As shown, in one embodiment of this disclosure, a valve core sealing ring 213 may be provided between the first valve needle 210 and the valve seat assembly 100, and the portion of the valve cavity 101 located on the side of the valve core sealing ring 213 away from the first valve port 1011 is a back pressure cavity 1014. The first valve needle 210 is provided with a balance channel, the two ends of which are respectively connected to the first valve port 1011 and the back pressure cavity 1014. The balance channel includes the aforementioned longitudinal channel 2104 and a flow channel 2105 disposed within the first valve needle 210. One end of the flow channel 2105 is connected to the flow cavity 2101, and the other end of the flow channel 2105 is open and connected to the back pressure cavity 1014. Through the above design, this disclosure can realize the internal balance structure design of the first valve needle 210, and connect the back pressure cavity 1014 and the first valve port 1011 through the balance channel, thereby reducing the force exerted by the fluid on the first valve needle 210.

[0067] In one embodiment of this disclosure, the first assembly 211 and the second assembly 212 can be connected by means such as press-fitting or welding, and the first assembly 211 is located on the side of the second assembly 212 away from the first valve port 1011. Based on this, the transverse channel 2103, the second valve port 2102, and the longitudinal channel 2104 are all disposed in the second assembly 212. Through the above design, this disclosure can further improve the structural rationality of the first valve needle 210. Using a smaller number of parts and a simpler part structure, the formation of each channel and cavity of the first valve needle 210 can be achieved, resulting in a more rational structure that is easy to process and assemble.

[0068] In one embodiment of this disclosure, the valve core sealing ring 213 can be installed on the first valve needle 210, for example, in conjunction with... Figure 5 and Figure 6 As shown, the valve core sealing ring 213 is installed in the sealing groove opened on the outer periphery of the first valve needle 210. In this case, the circular area corresponding to the sealing area between the valve core sealing ring 213 and the valve seat assembly 100 is defined as S1. Furthermore, the circular area corresponding to the sealing area between the first valve needle 210 and the first valve port 1011 is defined as S3, and the circular area corresponding to the sealing area between the second valve needle 220 and the second valve port 2102 is defined as S4. Therefore, S1 = S3 + S4. In other embodiments not shown in this disclosure, the valve core sealing ring 213 can also be installed on the valve seat assembly 100. In this case, the circular area corresponding to the sealing area between the valve core sealing ring 213 and the first valve needle 210 is defined as S2. Based on this, still using the above definitions of S3 and S4 as an example, S2 = S3 + S4. Based on the above design, the valve core assembly 200 can be used in both directions, i.e., it allows bidirectional flow. The above relationship allows the fluid force on the first valve needle 210 to be close to zero based on the internal balance design, avoiding the fluid at the inlet and outlet of the electronic expansion valve from exerting force on the first valve needle 210, and preventing the first valve needle 210 in the closed state from being lifted up due to the large force.

[0069] Unlike the area relationship design described above, other area relationship designs can also be adopted in other embodiments of this disclosure. For example, when the fluid in the electronic expansion valve is side-inlet and bottom-outlet (i.e., forward fluid), the circular area corresponding to the sealing region between the first valve needle 210 and the first valve port 1011 can be increased (i.e., S3 mentioned above). Based on this, taking the valve core sealing ring 213 installed on the first valve needle 210 as an example, then S1 < S3 + S4. Or, taking the valve core sealing ring 213 installed on the valve seat assembly 100 as an example, then S2 < S3 + S4. Through the above design, this disclosure enables the inlet and outlet fluids to exert a force on the first valve needle 210, using this force to close the first valve port 1011 and prevent leakage from the first valve port 1011. As another example, when the fluid in the electronic expansion valve is bottom-inlet and side-outlet (i.e., reverse fluid), the circular area corresponding to the sealing region between the first valve needle 210 and the first valve port 1011 can be reduced (i.e., S3 mentioned above). Based on this, taking the valve core sealing ring 213 installed on the first valve needle 210 as an example, then S1 > S3 + S4. Alternatively, taking the valve core sealing ring 213 installed on the valve seat assembly 100 as an example, then S2 > S3 + S4. Through the above design, this disclosure can also enable the inlet and outlet fluids to exert a force on the first valve needle 210, using this force to close the first valve port 1011 and prevent leakage from the first valve port 1011.

[0070] like Figure 7 As shown, in one embodiment of this disclosure, the first valve needle 210 may be provided with a through hole 2106, through which the second valve needle 220 can pass. Furthermore, the flow channel 2105 of the first valve needle 210 and the through hole 2106 can be connected circumferentially to form an integral channel structure. Through this design, by adopting an integral channel structure for the flow channel 2105 and the through hole 2106, this disclosure simplifies the structural complexity of the first valve needle 210 and reduces the processing difficulty. Furthermore, while utilizing the flow channel 2105 to connect the valve cavity 101 and the flow cavity 2101, this disclosure prevents the second valve needle 220 from entering the flow channel 2105, ensuring the fit between the second valve needle 220 and the through hole 2106, and improving the stability and reliability of the relative movement between the second valve needle 220 and the first valve needle 210.

[0071] like Figure 7As shown, based on the design of the first valve needle 210 having a through hole 2106 and the through hole 2106 and the flow channel 2105 forming an integral channel structure, in one embodiment of this disclosure, the first valve needle 210 may be provided with at least two flow channels 2105, such as, but not limited to, the two flow channels 2105 shown in the figure, and these flow channels 2105 may be evenly distributed along the circumference of the through hole 2106. Through the above design, this disclosure can improve the balance of fluid flow between the valve cavity 101 and the flow cavity 2101 via the flow channel 2105, and at the same time make the force on the first valve needle 210 more uniform, further ensuring the stress stability of the component.

[0072] In one embodiment of this disclosure, the flow area of ​​the transverse channel 2103 can be equal to the flow area of ​​the longitudinal channel 2104, ensuring the consistency of the forward and reverse flow curves. Specifically, the above-mentioned relationship of flow areas refers to a comparison between all transverse channels 2103 and all longitudinal channels 2104, that is, the sum of the flow areas of all transverse channels 2103 (or the flow area of ​​a single transverse channel 2103 when there is only one transverse channel 2103) is equal to the sum of the flow areas of all longitudinal channels 2104 (or the flow area of ​​a single transverse channel 2103 when there is only one longitudinal channel 2104).

[0073] like Figures 3 to 6 As shown, in one embodiment of this disclosure, the second valve port 2102 can be located at the axial position of the first valve needle 210. In this case, the extension direction of the transverse channel 2103 can be radial to the first valve needle 210. In some embodiments, the second valve port 2102 can also be located at other positions of the first valve needle 210. In this case, the extension direction of the transverse channel 2103 can be radial to the first valve needle 210, or it can be in other directions perpendicular to the axial direction.

[0074] like Figures 3 to 6 As shown, based on the radial extension direction of the transverse channel 2103, in one embodiment of this disclosure, the first valve needle 210 may be provided with at least one transverse channel 2103, and the at least one transverse channel 2103 extends radially through the first valve needle 210. That is, both ends of the at least one transverse channel 2103 open onto the side of the first valve needle 210, and the second valve port 2102 is connected to the middle position of the transverse channel 2103. In other words, the transverse channel 2103 extending radially through the first valve needle 210 can also be understood as two transverse channels 2103, both extending in the same direction, and their opposite ends opening onto the side of the first valve needle 210. The opposite ends of the two channels are connected together to form the second valve port 2102.

[0075] like Figures 3 to 6As shown, based on the radial extension direction of the transverse channel 2103, in one embodiment of this disclosure, the first valve needle 210 can be provided with a transverse channel 2103, that is, a transverse channel 2103 that radially penetrates the first valve needle 210. Furthermore, a longitudinal channel 2104 can be provided on both sides of the transverse channel 2103. In other words, since the transverse channel 2103 radially penetrates the first valve needle 210, the first valve needle 210 is divided into two regions circumferentially by the transverse channel 2103, and accordingly, a longitudinal channel 2104 can be provided in each region. Through the above design, this disclosure can improve the uniformity of fluid flow. In some embodiments, when the first valve needle 210 is provided with a radially penetrating transverse channel 2103, two or more longitudinal channels 2104 can also be provided on both sides of the transverse channel 2103, and the number of longitudinal channels 2104 provided on both sides of the transverse channel 2103 can be, but is not limited to, equal.

[0076] like Figures 2 to 6 As shown, based on the design of having at least one longitudinal channel 2104 on both sides of the transverse channel 2103, in one embodiment of this disclosure, the number of longitudinal channels 2104 on both sides of the transverse channel 2103 can be equal, for example, but not limited to, one as shown in the figures. Based on this, a reference plane is defined parallel to the radial direction and perpendicular to the axial direction. On this reference plane, the orthographic projections of the longitudinal channels 2104 on both sides of the transverse channel 2103 can be arranged axially symmetrically, with the axis of symmetry being the center line of the orthographic projection of the transverse channel 2103. Through the above design, this disclosure can further improve the uniformity of fluid flow.

[0077] See Figure 11 , Figure 11 The diagram shows a three-dimensional structural schematic of the second assembly 212 of the electronic expansion valve, which embodies the principles of this disclosure, in another exemplary embodiment.

[0078] Different from Figures 2 to 6 The illustrated embodiment employs a design where a longitudinal channel 2104 is provided on both sides of the transverse channel 2103, such as... Figure 11 As shown, in another embodiment of this disclosure, taking the first valve needle 210 as having a radially penetrating transverse channel 2103 as an example, the first valve needle 210 may have four longitudinal channels 2104. These four longitudinal channels 2104 are distributed in pairs on both sides of the transverse channel 2103, and with the center line of the orthographic projection of the transverse channel 2103 as the axis of symmetry, the orthographic projections of the four longitudinal channels 2104 are arranged in pairs to form an axisymmetric arrangement.

[0079] See Figure 12 , Figure 12The diagram shows a cross-sectional schematic of a second assembly 212 of an electronic expansion valve that embodies the principles of this disclosure in another exemplary embodiment.

[0080] Different from Figures 2 to 6 The illustrated embodiment employs a design where a transverse channel 2103 radially penetrates the first valve needle 210, as shown. Figure 12 As shown, in another embodiment of this disclosure, taking the extension direction of the transverse channel 2103 as the radial direction of the first valve needle 210 as an example, the transverse channel 2103 may not penetrate the first valve needle 210, that is, the transverse channel 2103 may only have one end open to the side of the first valve needle 210. Specifically, one end of the transverse channel 2103 opens to the side of the first valve needle 210, and the other end of the transverse channel 2103 is connected to the second valve port 2102.

[0081] like Figure 12 As shown, based on the design that the transverse channels 2103 do not penetrate the first valve needle 210, in another embodiment of this disclosure, the first valve needle 210 may be provided with three transverse channels 2103. One end of each of the three transverse channels 2103 opens onto the side of the first valve needle 210, and the other ends of the three transverse channels 2103 converge at one point (e.g., at the axis of the first valve needle 210) and are connected to the second valve port 2102. In some embodiments, the first valve needle 210 may also be provided with two, four, or more transverse channels 2103 that do not penetrate the first valve needle 210, and is not limited to the above embodiments.

[0082] like Figure 12 As shown, based on the design that each end of at least two transverse channels 2103 is connected to the second valve port 2102, in another embodiment of this disclosure, the at least two transverse channels 2103 can be uniformly arranged along the circumference of the first valve needle 210. Through the above design, this disclosure can make the fluid force on the second valve needle 220 more uniform and the overall resultant force of the fluid force smaller, thereby reducing the influence of the fluid force on the second valve needle 220.

[0083] like Figure 12As shown, based on the design that the transverse channel 2103 does not penetrate the first valve needle 210, in another embodiment of this disclosure, a longitudinal channel 2104 can be provided between any two adjacent transverse channels 2103. In other words, since the extension direction of the transverse channel 2103 is the radial direction of the first valve needle 210, at least two transverse channels 2103 that converge at one end divide the first valve needle 210 into at least two regions in the circumferential direction (e.g., the three regions shown in the figure). Accordingly, this disclosure can provide a longitudinal channel 2104 in each region. Through the above design, this disclosure can improve the uniformity of fluid flow. In some embodiments, when the first valve needle 210 is provided with at least two non-penetrating transverse channels 2103, two or more longitudinal channels 2104 can also be provided in the at least two regions of the first valve needle 210 separated by the at least two transverse channels 2103, and the number of longitudinal channels 2104 provided in each region can be, but is not limited to, equal.

[0084] like Figure 12 As shown, based on the design that the transverse channels 2103 do not penetrate the first valve needle 210, in another embodiment of this disclosure, the first valve needle 210 may be provided with at least three transverse channels 2103, such as, but not limited to, the three transverse channels 2103 shown in the figures. These transverse channels 2103 can be evenly arranged at intervals along the circumference of the first valve needle 210, and a longitudinal channel 2104 is provided between any two adjacent transverse channels 2103. Each longitudinal channel 2104 is evenly distributed in the circumference of the first valve needle 210. Through the above design, this disclosure can further improve the uniformity of fluid flow. It should be noted that when the first valve needle 210 is provided with two non-penetrating transverse channels 2103 and the two transverse channels 2103 are evenly arranged in the circumference, that is, the two transverse channels 2103 extend in the same direction and can form a similar Figures 3 to 6 The structure of the transverse channel 2103 in the illustrated embodiment.

[0085] like Figure 3 and Figure 4As shown, in one embodiment of this disclosure, the electronic expansion valve may further include a first elastic element 410, which is connected between the end of the first valve needle 210 facing away from the first valve port 1011 and the valve seat assembly 100 (e.g., the cavity wall of the valve chamber 101 away from the first valve port 1011). Based on this, a receiving groove 2107 may be provided at the end of the first valve needle 210 (e.g., the first assembly 211 described above) facing away from the first valve port 1011, and the first elastic element 410 may be partially accommodated in the receiving groove 2107. Through the above design, this disclosure can use the compensation of the first elastic element 410 to achieve the sealing of the first valve port 1011 when the second valve port 2102 is open. On this basis, this disclosure can use the receiving groove 2107 to arrange the first elastic element 410, ensuring the installation space of the first elastic element 410, while ensuring that the first valve needle 210 has a certain length along the axial direction, ensuring that the first valve needle 210 has sufficient length to guide and cooperate with the valve seat assembly 100 (e.g., valve core sleeve 110).

[0086] like Figure 3 and Figure 4 As shown, in one embodiment of this disclosure, the electronic expansion valve may further include a second elastic element 420. Specifically, the drive assembly 400 includes a first screw 430 and a spring sleeve 440. The second valve needle 220 is fixedly connected to the spring sleeve 440, and the spring sleeve 440 is limitedly connected to the first screw 430 and can move axially relative to the spring sleeve 440. The second elastic element 420 is located inside the spring sleeve 440 and between the second valve needle 220 and the first screw 430. After the second valve port 2012 is closed, the first screw 430 moves relative to the second valve needle 220 towards the second valve port 2012, the compression degree of the second elastic element 420 increases, and the second valve needle 220 presses against the second valve port 2012.

[0087] like Figure 16 As shown, in another embodiment of this disclosure, after the second valve port 2012 is closed, the first screw 430 moves away from the second valve port 2012 relative to the second valve needle 220, the degree of compression of the second elastic member 420 increases, and the second valve needle 220 presses against the second valve port 2012.

[0088] like Figures 3 to 8As shown, in one embodiment of this disclosure, a first sealing structure may be provided at the end of the first valve needle 210 facing the first valve port 1011. The first sealing structure includes a first sealing ring 231, the material hardness of which is less than the material hardness of the first valve port 1011. Based on this, when the first valve port 1011 is closed, the first sealing ring 231 contacts the first valve port 1011 to achieve a soft seal. In some embodiments, still taking the design of achieving a soft seal between the first valve needle 210 and the first valve port 1011 by providing a first sealing ring 231 as an example, the first sealing structure including the first sealing ring 231 can also be provided at the first valve port 1011. Accordingly, when the first valve port 1011 is closed, the first sealing ring 231 contacts the first valve needle 210 to achieve a soft seal.

[0089] like Figure 5 , Figure 6 , Figure 9 and Figure 10 As shown, based on the design of the first valve needle 210 with a first sealing ring 231, in one embodiment of this disclosure, the first sealing structure may further include a first pressure plate 232, which is used to press against the first sealing ring 231 to assemble it at the first valve needle 210. The first pressure plate 232 can be connected to the first valve needle 210 by welding or riveting.

[0090] See Figure 13 , Figure 13 The diagram shows a partial cross-sectional schematic of an electronic expansion valve that embodies the principles of this disclosure in another exemplary embodiment.

[0091] Different from Figures 3 to 6 The illustrated embodiment employs a soft-seal design between the first valve needle 210 and the first valve port 1011, such as... Figure 13 As shown, in another embodiment of this disclosure, when the first valve port 1011 is closed, the first valve needle 210 can directly contact the first valve port 1011, that is, the first valve needle 210 and the first valve port 1011 are in a hard seal.

[0092] It should be noted that in some embodiments of this disclosure, regardless of whether the first valve needle 210 and the first valve port 1011 are connected by a soft seal or a hard seal, the sealing mating area between the first valve port 1011 and the first valve needle 210 can be configured as a tapered chamfered structure or an arc-shaped chamfered structure. The chamfered design can refer to the shape of the first valve needle 210 and the first valve port 1011, or it can refer to the shape of the first sealing ring 231 and the sealing mating area therewith.

[0093] like Figure 5 and Figure 6As shown, in one embodiment of this disclosure, a transmission part 221 may be provided on the outer periphery of the second valve needle 220. Specifically, the transmission part 221 is integrally formed with the second valve needle 220, and is located within the flow cavity 2101 along the axial direction. The thickness of the transmission part 221 is less than the height of the flow cavity 2101. Based on this, the drive assembly 400 can drive the second valve needle 220 away from the first valve port 1011, causing the transmission part 221 to abut against the side wall of the flow cavity 2101 away from the first valve port 1011, thereby driving the first valve needle 210 away from the first valve port 1011.

[0094] like Figures 5 to 7 As shown, based on the design of the second valve needle 220 having a transmission part 221, in one embodiment of this disclosure, when the first valve needle 210 has a through hole 2106 (i.e., the guide hole provided by the guide part 270) and the through hole 2106 and the flow channel 2105 (e.g., a through groove design) adopt an integral channel structure, the shape of the transmission part 221 can match the shape of the channel structure. That is, during the assembly process of the valve core assembly 200, part of the second valve needle 220 protrudes through the flow cavity 2101, and the maximum outer diameter of the transmission part 221 is smaller than the inner diameter of the through hole 2106, thereby ensuring that the part of the second valve needle 220 with the transmission part 221 will not axially dislodge from the flow cavity 2101. Through the above design, this disclosure can reduce the assembly difficulty of the valve core assembly 200 and improve the assembly efficiency.

[0095] like Figure 5 , Figure 6 , Figure 8 and Figure 9 As shown, in one embodiment of this disclosure, a sealing head 242 may be provided at the end of the second valve needle 220 facing the first valve needle 210. The material hardness of the sealing head 242 is less than that of the material hardness of the second valve port 2102. Based on this, when the second valve port 2102 is closed, the sealing head 242 contacts the second valve port 2102 to achieve a soft seal.

[0096] like Figure 5 and Figure 6As shown, based on the design of the second valve needle 220 with a sealing head 242, in one embodiment of this disclosure, a second pressure plate 243 may be provided at the end of the second valve needle 220 facing the first valve needle 210. The second pressure plate 243 is used to press against the sealing head 242 to assemble it into the second valve needle 220. The second pressure plate 243 is riveted to the sealing head 242. Further, the axial cross-section of the sealing head 242 may be approximately "T"-shaped, having a horizontal portion and a vertical portion. The horizontal portion is pressed against the end of the second valve needle 220 facing the first valve port 1011 by the second pressure plate 243. The second pressure plate 243 is approximately annular and surrounds the vertical portion. One end of the vertical portion is connected to the horizontal portion, and the other end extends axially toward the second valve port 2102. The sealing head 242 is sealed with the second valve port 2102 through the vertical portion.

[0097] See Figure 14 , Figure 14 The diagram shows a cross-sectional schematic of the valve core assembly 200 of an electronic expansion valve that embodies the principles of this disclosure in another exemplary embodiment.

[0098] Different from Figure 5 and Figure 6 The illustrated embodiment employs a "T"-shaped design for the axial cross-section of the sealing head 242, such as... Figure 14 As shown, in one embodiment of this disclosure, taking the second valve needle 220 with a sealing head 242 as an example, the side of the sealing head 242 facing the second valve port 2102 can also be planar, for example, the axial cross-section of the sealing head 242 is rectangular. Based on this, the sealing head 242 seals against the second valve port 2102 with the planar side facing the second valve port 2102. Further, the second valve port 2102 can be provided with a sealing protrusion extending axially toward the second valve needle 220, and the second valve port 2102 penetrates the sealing protrusion. Therefore, the second valve port 2102 facilitates the sealing cooperation between the sealing protrusion and the aforementioned planar surface of the sealing head 242, and is not limited to the above embodiment.

[0099] See Figure 15 , Figure 15 The diagram shows a cross-sectional schematic of the valve core assembly 200 of an electronic expansion valve that embodies the principles of this disclosure in another exemplary embodiment.

[0100] like Figure 15 As shown, in one embodiment of this disclosure, a second sealing structure may be provided at the end of the second valve port 2102 facing the second valve needle 220. The second sealing structure includes a second sealing ring 241, the material hardness of which is less than that of the second valve needle 220. Based on this, when the second valve port 2102 is closed, the second sealing ring 241 contacts the second valve needle 220 to achieve a soft seal.

[0101] like Figure 15 As shown, based on the design of the second valve port 2102 with the second sealing ring 241, in one embodiment of this disclosure, the second sealing structure may further include a second pressure plate 243, which is used to press against the second sealing ring 241 to assemble it at the second valve port 2102.

[0102] Different from Figures 3 to 6 or Figures 14 to 15 The illustrated embodiment employs a soft-seal design between the second valve needle 220 and the second valve port 2102, such as... Figure 13 As shown, in another embodiment of this disclosure, when the second valve port 2102 is closed, the second valve needle 220 can directly contact the second valve port 2102, that is, the second valve needle 220 and the second valve port 2102 are in a hard seal.

[0103] See Figure 16 and Figure 17 , Figure 16 A cross-sectional schematic diagram of an electronic expansion valve that embodies the principles of this disclosure is shown in another exemplary embodiment. Figure 17 China representatively shows Figure 16 An enlarged schematic diagram of part C in the diagram.

[0104] like Figure 16 and Figure 17 As shown, in one embodiment of this disclosure, the electronic expansion valve further includes a guide seat 300. Specifically, at least a portion of the guide seat 300 is disposed in the valve cavity 101 of the valve seat assembly 100 and fixedly connected to the valve seat assembly 100. The material hardness of the guide seat 300 is less than that of the valve seat assembly 100. Based on this, the cavity wall of the valve cavity 101 is provided with a first positioning surface 1012, which faces the guide seat 300 and is located on the side of the guide seat 300 facing the first valve port 1011. The guide seat 300 has a second positioning surface 3101 facing the first positioning surface 1012. The first positioning surface 1012 is provided with a positioning protrusion 1013, which presses against the guide seat 300 (e.g., the second positioning surface 3101), causing the guide seat 300, which has relatively lower material hardness, to deform, thereby achieving the positioning function of the valve seat assembly 100 and the guide seat 300 in the axial and circumferential directions. Through the above structural design, this disclosure can use the positioning protrusion 1013 to press against the valve seat assembly 100 or the guide seat 300 to deform it, thereby making the deformed guide seat 300 and the valve seat assembly 100 in a circumferential upper limit fit, avoiding relative rotation of the guide seat 300 and the valve seat assembly 100 in the circumferential direction or relative displacement in the axial direction, and realizing reliable positioning of the guide seat 300.

[0105] It should be noted that, in an embodiment not illustrated in this disclosure, the material hardness of the guide seat 300 may also be greater than that of the valve seat assembly 100. Based on this, a positioning protrusion 1013 may be disposed on the guide seat 300, i.e., the positioning protrusion 1013 is located on the second positioning surface 3101. Accordingly, the positioning protrusion 1013 presses against the valve seat assembly 100 (e.g., the first positioning surface 1012), causing deformation of the valve seat assembly 100, which has a relatively lower material hardness, thereby achieving the positioning function of the valve seat assembly 100 and the guide seat 300 in the axial and circumferential directions. In other words, in various possible embodiments conforming to the design concept of this disclosure, the material hardness of the guide seat 300 is different from that of the valve seat assembly 100, and the one with the higher material hardness is provided with the positioning protrusion 1013. The positioning protrusion 1013 is located on the first positioning surface 1012 or the second positioning surface 3101, and the positioning protrusion 1013 presses against the other of the valve seat assembly 100 and the guide seat 300 (i.e., the one with the lower material hardness).

[0106] like Figure 16 As shown, in one embodiment of this disclosure, the electronic expansion valve may further include a second elastic element 420. Specifically, the electronic expansion valve also includes a support 130 connected to the valve seat assembly 100. The drive assembly 400 includes a second screw 450, and the second elastic element 420 is sleeved on the outer periphery of the second screw 450 and located between the support 130 and the second screw 450.

[0107] See Figure 18 and Figure 19 , Figure 18 A cross-sectional schematic diagram of an electronic expansion valve that embodies the principles of this disclosure is shown in another exemplary embodiment. Figure 19 China representatively shows Figure 18 An enlarged diagram of part E in the diagram.

[0108] like Figure 18 and Figure 19As shown, in one embodiment of this disclosure, the valve core assembly 200 further includes a drainage groove 260. Specifically, the drainage groove 260 is disposed on the outer periphery of the first valve needle 210, the groove opening of the drainage groove 260 faces the first valve needle 210 and is closed by the first valve needle 210, the groove wall of the drainage groove 260 is provided with a drainage hole 261, and the transverse channel 2103 is connected to the valve cavity 101 through the groove cavity of the drainage groove 260 and the drainage hole 261. With the above design, since the transverse channel 2103 can be connected to the valve chamber 101 through the cavity of the flow channel 260 and the flow hole 261, the fluid can flow through the flow hole 261 to the cavity of the flow channel 260, and then through the cavity of the flow channel 260 to the transverse channel 2103. Due to the existence of the flow channel 260, this disclosure does not require the flow hole 261 and the transverse channel 2103 to be arranged one-to-one, thereby reducing the processing difficulty of setting the transverse channel 2103 in the valve core assembly 200 and improving the processing convenience.

[0109] In one embodiment of this disclosure, the drainage channel 260 may be an annular groove structure, and the drainage channel 260 is arranged around the outer periphery of the first valve needle 210. Through the above structural design, this disclosure enables the fluid to flow more uniformly into each transverse channel 2103 via the drainage channel 260.

[0110] See Figures 20 to 23 , Figure 20 A cross-sectional schematic diagram of an electronic expansion valve that embodies the principles of this disclosure is shown in another exemplary embodiment. Figure 21 China representatively shows Figure 20 An enlarged schematic diagram of part of the structure is shown; Figure 22 China representatively shows Figure 20 A three-dimensional structural schematic diagram of the valve core assembly 200 is shown; Figure 23 The diagram shows a three-dimensional structural schematic of the first assembly 211.

[0111] like Figures 20 to 23As shown, in one embodiment of this disclosure, the first valve needle 210 is provided with a guide portion 270, which is located at the opening of the flow cavity 2101 and has a guide surface 2701. The guide surface 2701 matches the shape of at least a portion of the outer periphery of the second valve needle 220 to guide the second valve needle 220. The gap between the guide surface 2701 and the second valve needle 220 connects the aforementioned back pressure cavity 1014 and the flow cavity 2101 (and may also connect via the flow channel 2105). The drive assembly 400 includes a first screw 430, which is connected to the second valve needle 220 and can drive the second valve needle 220 to move axially relative to the first valve needle 210. Through the above design, this disclosure utilizes the guide portion 270 to achieve the guiding function of the second valve needle 220, avoiding large-angle tilting of the second valve needle 220 during movement, and ensuring the stability and reliability of the valve core assembly 200 movement.

[0112] The gap between the guide surface 2701 and the second valve needle 220 connects the back pressure chamber 1014 and the flow chamber 2101, meaning that the second valve needle 220 and the first valve needle 210 have no sealing structure, and the second valve needle 220 has a non-internal balance structure. Because the first valve needle 210 of this disclosure adopts the aforementioned non-internal balance structure, it avoids the need for an additional sealing ring between the first valve needle 210 and the second valve needle 220, reducing the number of components in the electronic expansion valve and lowering structural complexity. Since the sealing ring is avoided, this disclosure also eliminates the need to weld corresponding pressure plates, reducing welding processes and improving product production efficiency. Furthermore, compared to existing solutions, eliminating the additional sealing ring between the first valve needle 210 and the second valve needle 220 makes the second valve needle 220 more prone to large-angle tilting during movement. This disclosure, through the guiding function of the guide portion 270, further adapts to the guiding needs of the second valve needle 220 in this situation, facilitating the implementation of the design that eliminates the additional sealing ring. Of course, the design of the valve core assembly 200 in this disclosure can also adopt the above-mentioned internal balance structure design. In this case, through the guiding function of the guide part 270, this disclosure can still improve the guiding effect on the second valve needle 220 and further reduce the possibility of it tilting at a large angle during movement.

[0113] It should be noted that the electronic expansion valves shown in the accompanying drawings and described in this specification are merely a few examples among many electronic expansion valves capable of employing the principles of this disclosure. It should be clearly understood that the principles of this disclosure are by no means limited to any detail or component of the electronic expansion valves shown in the accompanying drawings or described in this specification.

[0114] In summary, the electronic expansion valve disclosed herein includes a valve seat assembly 100 and a valve core assembly 200; the valve cavity 101 of the valve seat assembly 100 is provided with a first valve port 1011; the valve core assembly 200 includes a first valve needle 210 and a second valve needle 220; one end of the first valve needle 210 is sealed to the first valve port 1011; the first valve needle 210 has a flow cavity 2101, a transverse channel 2103, a second valve port 2102, and a longitudinal channel 2104 inside; the flow cavity 2101 is located behind the longitudinal channel 2104. The first valve port 1011 is located on one side; the transverse channel 2103 opens at one end to the side of the first valve needle 210; the second valve port 2102 is connected at one end to the flow chamber 2101 and at the other end to the transverse channel 2103; the longitudinal channel 2104 opens at one end to the end face of the first valve needle 210 facing the first valve port 1011 and at the other end to the flow chamber 2101; a portion of the second valve needle 220 is inserted into the flow chamber 2101, and the end of the second valve needle 220 facing the first valve port 1011 is sealed to the second valve port 2102. Through the above design, when the second valve port 2102 is open, this disclosure enables the throttling refrigerant to first flow through the flow chamber 2101 of the first valve needle 210 before flowing out of the first valve port 1011. Specifically, the throttling refrigerant flows sequentially through the transverse channel 2103, the second valve port 2102, the flow chamber 2101, the longitudinal channel 2104, and the outflow path of the first valve port 1011. This allows the second valve needle 220 to achieve a non-internal balance structure. Compared to existing solutions using an internal balance structure for small valve needles, this disclosure utilizes the longitudinal channel 2104 as both a flow path and a balance channel, thereby preventing the longitudinal channel 2104 from being blocked by the oil in the valve chamber 101. Simultaneously, this disclosure sequentially connects the transverse channel 2103, the second valve port 2102, the flow chamber 2101, and the longitudinal channel 2104 to form a fluid flow path. Based on this, since one end of the second valve port 2102 opens towards the flow chamber 2101 instead of the first valve port 1011, when the second valve port 2102 is closed, even if there is no seal between the second valve needle 220 and the first valve needle 210, the fluid entering the first valve needle 210 will be shut off by the second valve needle 220, ensuring that the flow rate of the second valve port 2102 is zero. This avoids the need to set an additional seal between the first valve needle 210 and the second valve needle 220, reduces the number of parts in the electronic expansion valve, and lowers the structural complexity. Since the above-mentioned seal is avoided, this disclosure also does not require welding the corresponding pressure plate for fixing the seal, which reduces welding processes and helps improve the production efficiency of the product.

[0115] The exemplary embodiments of the electronic expansion valve proposed in this disclosure have been described and / or illustrated in detail above. However, the embodiments of this disclosure are not limited to the specific embodiments described herein; rather, components and / or steps of each embodiment may be used independently and separately from other components and / or steps described herein. Each component and / or step of one embodiment may also be used in combination with other components and / or steps of other embodiments. In describing the elements / components / etc. described and / or illustrated herein, the terms “a,” “an,” and “the above” are used to indicate the presence of one or more elements / components / etc. The terms “comprising,” “including,” and “having” are used to indicate an open-ended inclusion and to mean that additional elements / components / etc. may exist in addition to those listed. Furthermore, the terms “first” and “second” in the claims and description are used only as illustrative marks and are not intended to limit the numerical scope of the object.

[0116] Although the electronic expansion valve proposed in this disclosure has been described according to different specific embodiments, those skilled in the art will recognize that modifications may be made to the implementation of this disclosure within the spirit and scope of the claims.

Claims

1. An electronic expansion valve, characterized in that, include: A valve seat assembly (100) has a valve chamber (101) inside, and the valve chamber (101) has a first valve port (1011); Valve core assembly (200), including: A first valve needle (210) is disposed in the valve cavity (101); one end of the first valve needle (210) is sealed to the first valve port (1011); the first valve needle (210) is provided with a flow cavity (2101), a transverse channel (2103), a second valve port (2102), and a longitudinal channel (2104); the flow cavity (2101) is located on the side of the transverse channel (2103) and the longitudinal channel (2104) facing away from the first valve port (1011); at least one end of the transverse channel (2103) opens to the side of the first valve needle (210); one end of the second valve port (2102) is connected to the flow cavity (2101), and the other end is connected to the transverse channel (2103); one end of the longitudinal channel (2104) opens to the end face of the first valve needle (210) facing the first valve port (1011), and the other end is connected to the flow cavity (2101); and A second valve needle (220) is partially inserted into the flow cavity (2101), and the end of the second valve needle (220) facing the first valve port (1011) is sealed to the second valve port (2102); and A drive assembly (400) is used to drive the first valve needle (210) and the second valve needle (220) to move axially, so as to realize the opening and closing control of the first valve port (1011) and the second valve port (2102).

2. The electronic expansion valve according to claim 1, characterized in that, The first valve needle (210) includes a first assembly (211) and a second assembly (212) that are separately arranged and connected to each other. The first assembly (211) has a groove on the side facing the first valve port (1011). The groove and the side of the second assembly (212) facing away from the first valve port (1011) together form the flow cavity (2101). The transverse channel (2103), the second valve port (2102) and the longitudinal channel (2104) are disposed in the second assembly (212).

3. The electronic expansion valve according to claim 1, characterized in that, A valve core sealing ring (213) is provided between the first valve needle (210) and the valve seat assembly (100). The portion of the valve cavity (101) located on the side of the valve core sealing ring (213) away from the first valve port (1011) is a back pressure cavity (1014). The first valve needle (210) is provided with a balance channel, the two ends of which are respectively connected to the first valve port (1011) and the back pressure cavity (1014). The balance channel includes the longitudinal channel (2104) and a flow channel (2105) provided in the first valve needle (210). One end of the flow channel (2105) is connected to the flow cavity (2101), and the other end is open and connected to the back pressure cavity (1014).

4. The electronic expansion valve according to claim 3, characterized in that: The valve core sealing ring (213) is installed on the first valve needle (210); the circular area corresponding to the sealing area between the valve core sealing ring (213) and the valve seat assembly (100) is S1, the circular area corresponding to the sealing area between the first valve needle (210) and the first valve port (1011) is S3, and the circular area corresponding to the sealing area between the second valve needle (220) and the second valve port (2102) is S4; wherein, S1 = S3 + S4; or, The valve core sealing ring (213) is installed on the valve seat assembly (100); the circular area corresponding to the sealing area between the valve core sealing ring (213) and the first valve needle (210) is S2, the circular area corresponding to the sealing area between the first valve needle (210) and the first valve port (1011) is S3, and the circular area corresponding to the sealing area between the second valve needle (220) and the second valve port (2102) is S4; wherein, S2 = S3 + S4.

5. The electronic expansion valve according to claim 3, characterized in that: The valve core sealing ring (213) is installed on the first valve needle (210); the circular area corresponding to the sealing area between the valve core sealing ring (213) and the valve seat assembly (100) is S1, the circular area corresponding to the sealing area between the first valve needle (210) and the first valve port (1011) is S3, and the circular area corresponding to the sealing area between the second valve needle (220) and the second valve port (2102) is S4; wherein, S1 < S3 + S4; or, The valve core sealing ring (213) is installed on the valve seat assembly (100); the circular area corresponding to the sealing area between the valve core sealing ring (213) and the first valve needle (210) is S2, the circular area corresponding to the sealing area between the first valve needle (210) and the first valve port (1011) is S3, and the circular area corresponding to the sealing area between the second valve needle (220) and the second valve port (2102) is S4; wherein, S2 < S3 + S4.

6. The electronic expansion valve according to claim 3, characterized in that: The valve core sealing ring (213) is installed on the first valve needle (210); the circular area corresponding to the sealing area between the valve core sealing ring (213) and the valve seat assembly (100) is S1, the circular area corresponding to the sealing area between the first valve needle (210) and the first valve port (1011) is S3, and the circular area corresponding to the sealing area between the second valve needle (220) and the second valve port (2102) is S4; wherein, S1 > S3 + S4; or, The valve core sealing ring (213) is installed on the valve seat assembly (100); the circular area corresponding to the sealing area between the valve core sealing ring (213) and the first valve needle (210) is S2, the circular area corresponding to the sealing area between the first valve needle (210) and the first valve port (1011) is S3, and the circular area corresponding to the sealing area between the second valve needle (220) and the second valve port (2102) is S4; wherein, S2 > S3 + S4.

7. The electronic expansion valve according to claim 3, characterized in that, The first valve needle (210) is provided with a through hole (2106) through which the second valve needle (220) passes; wherein, the flow channel (2105) and the through hole (2106) are connected in the circumferential direction to form an integral channel structure.

8. The electronic expansion valve according to claim 1, characterized in that, The sum of the flow areas of all the transverse channels (2103) is equal to the sum of the flow areas of all the longitudinal channels (2104).

9. The electronic expansion valve according to claim 1, characterized in that, The second valve port (2102) is located at the axial position of the first valve needle (210), and the extension direction of the transverse channel (2103) is radial to the first valve needle (210).

10. The electronic expansion valve according to claim 9, characterized in that, The first valve needle (210) is provided with at least one of the transverse channels (2103), which penetrate the first valve needle (210) radially. Both ends of the transverse channel (2103) are open on the side of the first valve needle (210), and the second valve port (2102) is connected to the middle position of the transverse channel (2103).

11. The electronic expansion valve according to claim 10, characterized in that, The number of longitudinal channels (2104) located on both sides of the transverse channel (2103) is equal; wherein, a reference plane is defined that is parallel to the radial direction and perpendicular to the axial direction, and on the reference plane, the orthographic projections of the longitudinal channels (2104) located on both sides of the transverse channel (2103) are arranged axially symmetrically, and the axis of symmetry is the center line of the orthographic projection of the transverse channel (2103).

12. The electronic expansion valve according to any one of claims 1 to 11, characterized in that, The electronic expansion valve further includes a first elastic element (410), which is connected between the end of the first valve needle (210) facing away from the first valve port (1011) and the valve seat assembly (100); wherein, the end of the first valve needle (210) facing away from the first valve port (1011) is provided with a receiving groove (2107), and the first elastic element (410) is partially received in the receiving groove (2107).

13. The electronic expansion valve according to any one of claims 1 to 11, characterized in that, The electronic expansion valve further includes a second elastic element (420); wherein: The drive assembly (400) includes a first screw (430) and a spring sleeve (440); a second valve needle (220) is fixedly connected to the spring sleeve (440), the spring sleeve (440) is limitedly connected to the first screw (430) and can move axially relative to the spring sleeve (440); a second elastic element (420) is located inside the spring sleeve (440) and between the second valve needle (220) and the first screw (430); or, The electronic expansion valve further includes a support base (130) connected to the valve seat assembly (100); the drive assembly (400) includes a second screw (450), and a second elastic element (420) is sleeved on the outer periphery of the second screw (450) and located between the support base (130) and the second screw (450).

14. The electronic expansion valve according to any one of claims 1 to 11, characterized in that: A first sealing structure is provided between the end of the first valve needle (210) facing the first valve port (1011) and the first valve port (1011). The first sealing structure includes a first sealing ring (231), the material hardness of which is less than that of the first valve port (1011). When the first valve port (1011) is closed, the first sealing ring (231) contacts the first valve needle (210) or the first valve port (1011) to achieve a soft seal; or, When the first valve port (1011) is closed, the first valve needle (210) is in direct contact with the first valve port (1011) to achieve a hard seal.

15. The electronic expansion valve according to any one of claims 1 to 11, characterized in that, The outer periphery of the second valve needle (220) is provided with a transmission part (221), which is integrally formed with the second valve needle (220). The transmission part (221) is located in the flow cavity (2101) along the axial direction, and the thickness of the transmission part (221) is less than the height of the flow cavity (2101). The drive assembly (400) drives the second valve needle (220) to move away from the first valve port (1011), thereby causing the transmission part (221) to abut against the side wall of the flow cavity (2101) away from the first valve port (1011), so as to drive the first valve needle (210) to move away from the first valve port (1011).

16. The electronic expansion valve according to any one of claims 1 to 11, characterized in that: The second valve port (2102) is provided with a second sealing ring (241), the material hardness of the second sealing ring (241) being less than the material hardness of the second valve needle (220); wherein, when the second valve port (2102) is closed, the second sealing ring (241) contacts the second valve needle (220) to achieve a soft seal; or, The second valve needle (220) has a sealing head (242) at one end facing the first valve needle (210). The material hardness of the sealing head (242) is less than that of the material hardness of the second valve port (2102). When the second valve port (2102) is closed, the sealing head (242) contacts the second valve port (2102) to achieve a soft seal; or, When the second valve port (2102) is closed, the second valve needle (220) is in direct contact with the second valve port (2102) to achieve a hard seal.

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