Electronic expansion valve

Abstract

An electronic expansion valve (100), comprising: a valve seat assembly (101), a screw assembly (20), and a valve needle assembly (50). A valve port (32) is formed in the valve seat assembly (101), the valve seat assembly (101) is connected to and communicated with a first connecting pipe (110), and the first connecting pipe (110) is communicated with the valve port (32); the screw assembly (20) comprises a threaded sleeve (21), and the threaded sleeve (21) is fixedly mounted on the valve seat assembly (101); the valve needle assembly (50) can control the opening / closing of the valve port (32) under the drive of the screw assembly (20); the threaded sleeve (21) is provided with a first portion (211), and the first portion (211) is in guide fit with the valve needle assembly (50); and in the axial direction of the threaded sleeve (21), the end surface (2111) of the end of the first portion (211) facing the valve port (32) is not lower than the inner circumferential wall (111) of the first connecting pipe (110).

Description

Electronic expansion valve

[0001] Related applications

[0002] This application claims priority to Chinese patent applications filed on June 18, 2024, with application number 202421394783.1 entitled "Electronic Expansion Valve"; filed on December 5, 2024, with application number 202423003167.1 entitled "Electronic Expansion Valve"; and filed on June 18, 2024, with application number 202421394241.4 entitled "Electronic Expansion Valve", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention belongs to the technical field of control valves, and in particular relates to an electronic expansion valve. Background Technology

[0004] An electronic expansion valve is a throttling element that controls the refrigerant flow in a refrigeration cycle system according to a preset program. It is typically installed between the outdoor and indoor heat exchangers in the refrigeration cycle system. When the refrigeration cycle system is in cooling mode, the electronic expansion valve throttles and depressurizes the refrigerant from the outdoor heat exchanger and directs it to the indoor heat exchanger; when the refrigeration cycle system is in heating mode, the electronic expansion valve throttles and depressurizes the refrigerant from the indoor heat exchanger and directs it to the outdoor heat exchanger.

[0005] Currently, electronic expansion valves in related technologies typically use threaded sleeves to guide the movement of the valve needle assembly. However, because the lower end face of the part of the threaded sleeve used to guide the valve needle assembly extends beyond the inner circumferential wall of the connecting pipe on the valve seat assembly, the flow capacity of the electronic expansion valve is affected during operation. Summary of the Invention

[0006] In view of this, it is necessary to provide an electronic expansion valve.

[0007] An electronic expansion valve includes a valve seat assembly, a screw assembly, and a valve needle assembly; the valve seat assembly has a valve port and is connected to a first connecting pipe, the first connecting pipe communicating with the valve port; the screw assembly includes a threaded sleeve, the threaded sleeve being fixedly mounted on the valve seat assembly; wherein the threaded sleeve has a first portion, the first portion being guided and engaged with the valve needle assembly; and along the axial direction of the threaded sleeve, the end face of the first portion facing the valve port is not lower than the inner peripheral wall of the first connecting pipe.

[0008] In one embodiment, the end of the first connecting pipe used to connect with the valve seat assembly is defined as an open end, and there is a preset gap between the end face of the open end and the outer wall of the first part opposite to the open end. The preset gap is defined as A, where 0.5mm≤A≤2.5mm.

[0009] In one embodiment, the threaded sleeve further has a second part, and the valve seat assembly has a valve seat connection part, wherein the second part is connected to the valve seat connection part by means of interference fit or transition fit.

[0010] In one embodiment, the valve seat assembly has a first stepped surface that can abut against the second part pressed into the valve seat connection portion, thereby limiting the pressing depth of the second part on the valve seat connection portion; in the axial direction of the threaded sleeve, the axial height of the second part pressed into the valve seat connection portion is defined as B, where 5mm ≥ B ≥ 1.5mm.

[0011] In one embodiment, the electronic expansion valve further includes a connecting plate, which is fitted onto the threaded sleeve and abuts against the second part; wherein the connecting plate is welded to the valve seat connection part.

[0012] In one embodiment, in the axial direction of the threaded sleeve, the connecting plate protrudes outward relative to the valve seat connecting portion, and the thickness of the portion of the connecting plate protruding from the valve seat connecting portion is defined as E, wherein 0.8mm > E ≥ 0.1mm; and / or, the threaded sleeve has a foolproof part, the connecting plate has a foolproof mating part, and the foolproof mating part can be limited to fit with the foolproof part.

[0013] In one embodiment, the threaded sleeve further has a second part and a connecting part, the threaded sleeve being fixedly connected to the valve seat assembly via the second part, and the connecting part being disposed between the second part and the first part; wherein the first part, the second part, and the connecting part enclose a cavity, and the cavity is in communication with the first connecting pipe.

[0014] In one embodiment, the difference between the thickness of the first part, the thickness of the second part, and the thickness of any two of the connecting parts is less than or equal to 1 mm.

[0015] In one embodiment, the screw assembly further includes a screw, a portion of which extends into the valve needle assembly, a bearing being fitted on the portion of the screw extending into the valve needle assembly, and the screw being interference-fitted with the inner ring of the bearing; and / or, the axis of the threaded sleeve is aligned with the axis of the valve port.

[0016] In one embodiment, the valve seat assembly includes a valve seat, a first valve seat core, and a second valve seat core; the valve seat has a mounting hole; the first valve seat core is independently disposed relative to the valve seat, disposed in the mounting hole and connected to the valve seat, and has a first refrigerant flow port; the second valve seat core is independently disposed relative to the first valve seat core and connected to the first valve seat core, and has a second refrigerant flow port, which communicates with the first refrigerant flow port; the valve needle assembly is movably mounted on the valve seat and can control the opening / closing of the first refrigerant flow port; the centerline of the first refrigerant flow port and the centerline of the second refrigerant flow port are disposed on the same straight line, and along the axial direction of the electronic expansion valve, the second refrigerant flow port and the first refrigerant flow port are coaxially arranged and have the same channel diameter.

[0017] In one embodiment, the threaded sleeve is fixedly mounted on the valve seat; the threaded sleeve includes an internal thread section and a guide section; the screw assembly further includes a screw, a portion of which extends into the valve needle assembly, a bearing is fitted on the portion of the screw extending into the valve needle assembly, and the screw is interference-fitted with the inner ring of the bearing; the screw has an external thread section, which is threadedly engaged with the internal thread section of the threaded sleeve; the valve needle assembly is partially disposed within the threaded sleeve, and the guide section is clearance-fitted with at least a portion of the valve needle assembly to guide the valve needle assembly.

[0018] In one embodiment, the guide section includes an upper guide section and a lower guide section, which are disposed on both sides of the internal thread section along the axial direction of the electronic expansion valve.

[0019] In one embodiment, the threaded sleeve further has a second portion that abuts against and connects to the valve seat; the valve seat includes a valve seat connecting portion, and the threaded sleeve can be connected to the valve seat connecting portion via the second portion in an interference fit or a transition fit manner; the valve seat assembly has a stepped portion that abuts against the end of the second portion assembled into the valve seat connecting portion facing the valve port, for limiting the assembly depth of the second portion on the valve seat connecting portion; the thickness of the stepped portion is defined as C, where 3mm ≥ C ≥ 0.1mm.

[0020] In one embodiment, in the axial direction of the electronic expansion valve, the first part extends toward the valve port relative to the second part, and the length of the extended part is defined as D, where 1mm < D < 4mm.

[0021] In one embodiment, a receiving groove is formed between the valve seat and the threaded sleeve, the receiving groove being able to receive burrs generated during the assembly of the threaded sleeve onto the valve seat connection portion.

[0022] In one embodiment, the second valve seat core is fitted onto the first valve seat core and connected to the first valve seat core, and a second connecting tube is fitted onto both the first valve seat core and the second valve seat core.

[0023] In one embodiment, at the location where the second connecting pipe is sleeved with the first valve seat core, the inner wall of the second connecting pipe is interference-fitted or transition-fitted with the outer wall of the first valve seat core; and / or, at the location where the first valve seat core is inserted into the mounting hole, the outer wall of the first valve seat core is clearance-fitted with the inner wall of the mounting hole.

[0024] In one embodiment, the second valve seat core includes a first connecting section and a second connecting section, which are disposed at both ends of the second valve seat core along the axial direction of the electronic expansion valve. The first connecting section is sleeved on the end of the first valve seat core away from the valve seat and is press-fitted or transition-fitted with the first valve seat core. The second connecting tube includes a first sleeve section and a second sleeve section. The first sleeve section is sleeved on the outer periphery of the first connecting section and is clearance-fitted with the first connecting section. The second sleeve section is sleeved on the outer periphery of the second connecting section and spaced apart from the outer wall of the second connecting section. The second valve seat core includes a first connecting section and a second connecting section, the first connecting section and the second connecting section being disposed at both ends of the second valve seat core along the axial direction of the electronic expansion valve, wherein the first connecting section is sleeved on the end of the first valve seat core away from the valve seat and is clearance-fitted with the first valve seat core; the second connecting tube includes a first sleeve section and a second sleeve section, the first sleeve section being sleeved on the outer periphery of the first connecting section and being clearance-fitted with the first connecting section, and the second sleeve section being sleeved on the outer periphery of the second connecting section and being interference-fitted or transition-fitted with the outer wall of the second connecting section.

[0025] In one embodiment, the second valve seat core further includes a plug-in guide section, which is located at one end of the second connecting section away from the first valve seat core to guide the second sleeve section; wherein the outer wall of the plug-in guide section is clearance-fitted with the inner wall of the second sleeve section; and / or, the outer peripheral wall of the upper portion of the second valve seat core fitted onto the first valve seat core is provided with an inclined surface, which is used to avoid the second connecting pipe.

[0026] In one embodiment, the valve seat assembly includes a valve seat, a first valve seat core, and a second valve seat core; the valve port is opened on the valve seat; the first valve seat core is disposed at the location of the valve port and connected to the valve seat, and a first refrigerant flow port is opened on the first valve seat core, which communicates with the valve port; the second valve seat core is connected to the first valve seat core, and a second refrigerant flow port is opened on the second valve seat core, which communicates with the first refrigerant flow port; the valve needle assembly is movably mounted on the valve seat and is used to control the refrigerant flow at the valve port and control the opening / closing of the electronic expansion valve; the center line of the valve port, the center line of the first refrigerant flow port, and the center line of the second refrigerant flow port are arranged on the same straight line, and along the axial direction of the electronic expansion valve, the valve port, the second refrigerant flow port, and the first refrigerant flow port are coaxially arranged and have the same channel diameter, wherein the valve seat, the first valve seat core, and the second valve seat core are an integral structure.

[0027] Details of one or more embodiments of this application are set forth in the following drawings and description. Other features, objects, and advantages of this application will become apparent from the specification, drawings, and claims. Attached Figure Description

[0028] To better describe and illustrate embodiments and / or examples of the inventions disclosed herein, reference may be made to one or more accompanying drawings. Additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed inventions, the currently described embodiments and / or examples, or the best mode of these inventions as currently understood.

[0029] Figure 1 is a schematic diagram of the structure of an electronic expansion valve provided in an embodiment of this application.

[0030] Figure 2 is a structural schematic diagram of an electronic expansion valve provided in one embodiment of this application from another perspective.

[0031] Figure 3 is a cross-sectional view of TT in Figure 2.

[0032] Figure 4 is an enlarged view of part P in Figure 3.

[0033] Figure 5 is a schematic diagram of the structure of a threaded sleeve provided in an embodiment of this application.

[0034] Figure 6 is a schematic diagram of the structure of a connecting plate provided in an embodiment of this application.

[0035] Figure 7 is an enlarged view of the Q part of one embodiment in Figure 3.

[0036] Figure 8 is an enlarged view of the Q part in another embodiment of Figure 3.

[0037] Figure 9 is a cross-sectional view of a portion of the structure of an electronic expansion valve provided in an embodiment of this application.

[0038] Reference numerals: 100, Electronic expansion valve; 101, Valve seat assembly; 10, Valve seat; 1001, Valve cavity; 110, First connecting pipe; 111, Inner peripheral wall; 112, Open end; 120, Second connecting pipe; 121, Narrowing section; 122, First sleeve section; 123, Second sleeve section; 11, Valve seat connecting part; 12, Stepped part; 1201, First stepped surface; 13, Receiving groove; 14, Mounting hole; 20, Screw assembly; 21, Threaded sleeve; 210, Cavity; 211, First part; 2111, End face; 212, Second part; 2121, Lower end face; 213, Foolproof part; 2131, First boss; 2132, Second boss; 2133. Third boss; 214, connecting part; 22, screw; 221, bearing; 222, external thread section; 23, connecting plate; 231, foolproof mating part; 2311, first groove; 2312, second groove; 2313, third groove; 201, internal thread section; 202, guide section; 2021, upper guide section; 2022, lower guide section; 30, first valve seat core; 31, first refrigerant flow port; 32, valve port; 33, sleeve; 40, second valve seat core; 41, second refrigerant flow port; 42, outer peripheral wall; 421, inclined surface; 422, first connecting section; 423, second connecting section; 424, insertion guide section; 43, second stepped surface; 50, valve needle assembly. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] It should be noted that when a component is said to be "located on" another component, it can be directly located on the other component or may have an intervening component. When a component is considered to be "located on" another component, it can be directly located on the other component or may have an intervening component. When a component is considered to be "fixed to" another component, it can be directly fixed to the other component or may have an intervening component.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0042] As shown in Figures 3 and 4, an electronic expansion valve 100 provided in one embodiment of this application includes a valve seat assembly 101, a screw assembly 20, and a valve needle assembly 50. A valve port 32 is formed on the valve seat assembly 101, and a first connecting pipe 110 is connected to the valve seat assembly 101, communicating with the valve port 32. The screw assembly 20 includes a threaded sleeve 21, which is fixedly mounted on the valve seat assembly 101. The valve needle assembly 50 can control the opening / closing of the valve port 32 and / or the flow rate. The threaded sleeve 21 has a first part 211, which guides the movement of the valve needle assembly 50. Furthermore, along the axial direction of the threaded sleeve 21, the end face 2111 of the first part 211 facing the valve port 32 is not lower than the inner peripheral wall 111 of the first connecting pipe 110.

[0043] It should be noted that the first connecting pipe 110 has an inner peripheral wall 111 for refrigerant flow. The side of the inner peripheral wall 111 away from the valve port 32 along the axial direction of the threaded sleeve 21 is defined as the top wall, and the side closer to the valve port 32 is defined as the bottom wall. That is, the end face 2111 of the first part 211 facing the valve port 32 is not lower than the top wall of the inner peripheral wall 111 of the first connecting pipe 110. In other words, the electronic expansion valve 100 uses the threaded sleeve 21 to directly guide the movement of the valve needle assembly 50, achieving a guide sleeve-free design for the electronic expansion valve 100.

[0044] It is understandable that by omitting the guide sleeve structure in the electronic expansion valve 100, not only can costs be reduced, but the internal space of the valve seat assembly 101 can also be increased. This improves the flow capacity of the electronic expansion valve 100 and reduces the turbulent kinetic energy of the refrigerant flowing within the valve seat assembly 101, thus reducing noise. Furthermore, the positioning of the first part 211 and the first connecting pipe 110 ensures that the first part 211 does not obstruct the refrigerant introduced through the first connecting pipe 110. This prevents vortices from forming at the openings of the first part 211 and the first connecting pipe 110 when the refrigerant enters and exits, thereby improving the flow capacity of the electronic expansion valve 100 during operation and reducing its noise.

[0045] As shown in Figures 1 and 2, the electronic expansion valve 100 of this application is connected to and communicates with a second connecting pipe 120 at the valve port 32. The second connecting pipe 120 can be either a refrigerant inlet or a refrigerant outlet. When refrigerant flows in from the second connecting pipe 120, the refrigerant can pass through the valve port 32 into the valve seat assembly 101 and flow out from the first connecting pipe 110. When refrigerant needs to flow out from the second connecting pipe 120, the refrigerant can flow in from the first connecting pipe 110, flow through the valve seat assembly 101 and the valve port 32 in sequence, and finally flow out from the second connecting pipe 120.

[0046] The screw assembly 20 also includes a screw 22. During the refrigerant flow process, the screw 22 can drive the valve needle assembly 50 to move under the guidance of the threaded sleeve 21, so as to realize the on / off and / or flow control of the valve port 32, that is, to achieve the purpose of controlling the operation of the electronic expansion valve 100.

[0047] The structural composition of the valve needle assembly 50 and the working principle of how the screw 22 drives the valve needle assembly 50 to move under the guidance of the first part 211 on the threaded sleeve 21 can be described in the conventional way in related technologies, and will not be elaborated here.

[0048] As shown in Figure 3, the valve seat assembly 101 includes a valve seat 10. One end of the first connecting pipe 110 connected to the valve seat assembly 101 is defined as an open end 112, i.e., the end connected to the valve seat 10 is the open end 112. A preset gap is formed between the end face of the open end 112 and the outer wall of the first part 211 of the threaded sleeve 21 opposite it. The preset gap is defined as A, where 0.5mm ≤ A ≤ 2.5mm. That is, the first part 211 of the threaded sleeve 21 does not contact the portion of the first connecting pipe 110 inserted into the valve seat assembly 101. This prevents the heat generated during subsequent welding with the external pipeline from being directly transferred to the threaded sleeve 21 through the first connecting pipe 110, thus avoiding burns to the threaded sleeve 21 and improving its service life. In some embodiments, the threaded sleeve 21 can be a non-metallic part, specifically manufactured by injection molding.

[0049] In one embodiment, the preset gap A can be 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, etc. Of course, the preset gap A is not limited to this value and can be set according to actual needs.

[0050] As shown in Figures 3 and 4, the threaded sleeve 21 also has a second part 212, and the valve seat assembly 101 has a valve seat connecting part 11. The second part 212 is connected to the valve seat connecting part 11 by an interference fit. That is, the threaded sleeve 21 can be press-fitted onto the valve seat connecting part 11, achieving the assembly connection of the threaded sleeve 21 onto the valve seat assembly 101. This ensures the assembly accuracy of the threaded sleeve 21 when assembled onto the valve seat assembly 101. It should be noted that by directly assembling the threaded sleeve 21 onto the valve seat connecting part 11 of the valve seat assembly 101 through the second part 212, direct contact between the threaded sleeve 21 and the first connecting pipe 110 is avoided. This improves the machining accuracy of the first connecting pipe 110 and ensures that the insertion depth of the first connecting pipe 110 into the valve seat assembly 101 does not affect the assembly of the threaded sleeve 21 onto the valve seat assembly 101. It can be understood that the threaded sleeve can be a one-piece molded structure, which helps improve the assembly accuracy when assembling the threaded sleeve 21 and the valve seat assembly 101.

[0051] Furthermore, as shown in Figure 4, a first stepped surface 1201 is formed on the valve seat assembly 101. The first stepped surface 1201 can abut against the second part 212 pressed into the valve seat connection part 11, thereby limiting the pressing depth of the second part 212 on the valve seat connection part 11. This can limit the assembly position of the second part 212 on the valve seat connection part 11, making it easier to assemble the threaded sleeve 21 onto the valve seat assembly 101.

[0052] As shown in Figures 3 and 4, the axial height of the second part 212 pressed into the valve seat connection part 11 in the axial direction of the threaded sleeve 21 is defined as B, where 5mm ≥ B ≥ 1.5mm.

[0053] In one embodiment, the value of B can be 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc. Of course, within the range of values ​​for B, the value of B is not limited to these, and it can be set according to actual needs.

[0054] Referring to Figures 3 and 4, the electronic expansion valve 100 also includes a connecting plate 23, which is fitted onto the threaded sleeve 21 and abuts against the second part 212. The connecting plate 23 is fixed to the valve seat connection part 11 by welding. In other words, the electronic expansion valve 100 uses the connecting plate 23 to limit the assembly of the threaded sleeve 21 on the valve seat connection part 11 of the valve seat assembly 101, allowing the electronic expansion valve 100 to disassemble the threaded sleeve 21 without damaging it. This enables the recycling and reuse of the threaded sleeve 21, reducing costs. Here, the connecting plate 23 is laser-welded to the valve seat connection part 11.

[0055] As shown in Figure 3, along the axial direction of the threaded sleeve 21, after the connecting plate 23 is fitted onto the threaded sleeve 21, the connecting plate 23 protrudes outward relative to the valve seat connecting portion 11. The thickness of the portion of the connecting plate 23 protruding from the valve seat connecting portion 11 is defined as E, where 0.8mm > E ≥ 0.1mm. In other words, when the connecting plate 23 limits the second part 212 pressed onto the valve seat connecting portion 11, a height difference is formed between the connecting plate 23 and the valve seat connecting portion 11. This facilitates focusing during laser welding between the connecting plate 23 and the valve seat connecting portion 11, thereby making it easier to weld the connecting plate 23 onto the valve seat connecting portion 11.

[0056] In one embodiment, the value of E can be 0.1mm, 0.3mm, 0.5mm, 0.6mm, 0.8mm, etc. Of course, within the range of values ​​for E, the value of E is not limited to these, and it can be set according to actual needs.

[0057] As shown in Figures 5 and 6, a foolproof part 213 is formed on the threaded sleeve 21, and a foolproof mating part 231 is formed on the connecting plate 23. The foolproof mating part 231 and the foolproof part 213 are mutually restrictive. This can, on the one hand, realize the foolproof function of the connecting plate 23 being pre-installed on the threaded sleeve 21, so as to facilitate the assembly of the connecting plate 23 on the threaded sleeve 21; on the other hand, it can also realize the circumferential restriction when the connecting plate 23 and the threaded sleeve 21 are assembled.

[0058] Furthermore, the foolproof part 213 is configured as three bosses formed on the threaded sleeve 21, defined as a first boss 2131, a second boss 2132, and a third boss 2133. These bosses are arranged sequentially at intervals along the circumferential direction of the threaded sleeve 21, with unequal dimensions. Correspondingly, the foolproof mating part 231 is configured as three grooves formed on the connecting plate 23, defined as a first groove 2311, a second groove 2312, and a third groove 2313. The first groove 2311 is connected to the first boss 2131, and the third groove 2313 is connected to the third boss 2133 by an interference fit to achieve a limiting function. The second groove 2312 is connected to the second boss 2132 by a clearance fit to achieve a limiting function. The foolproof part 213 and the foolproof mating part 231 are not limited to those shown in the figure. For those skilled in the art, the number of bosses in the foolproof part 213 can also be one, two or more, or the foolproof part 213 can be configured as a groove formed on the threaded sleeve 21, and the foolproof mating part 231 can be configured as a boss that matches the groove. This will not be elaborated here.

[0059] As shown in Figure 4, the threaded sleeve 21 also has a connecting portion 214, through which the first part 211 and the second part 212 on the threaded sleeve 21 are connected. The first part 211, the second part 212, and the connecting portion 214 together form a cavity 210, which communicates with the first connecting pipe 110. This reduces the amount of material required for manufacturing the threaded sleeve 21, thus lowering costs. Furthermore, it increases the internal space between the valve seat assembly 101 and the threaded sleeve 21, reducing noise. In this embodiment, the cavity 210 is configured as a ring structure. Moreover, the cavity 210 ensures uniform thickness of the first part 211, the second part 212, and the connecting portion 214, preventing injection molding defects such as whitening due to uneven thickness of these parts. Specifically, the thicknesses of the first part 211, the second part 212, and the connecting part 214 can be equal. In other embodiments, the wall thicknesses of the first part 211, the second part 212, and the connecting part 214 on the threaded sleeve 21 can also be set to be unequal, and their wall thicknesses can be approximated to make the wall thicknesses of the first part 211, the second part 212, and the connecting part 214 on the threaded sleeve 21 relatively uniform. In this way, the wall thicknesses of the first part 211, the second part 212, and the connecting part 214 are thicker than the wall thicknesses of the rest of the threaded sleeve 21, which can prevent the threaded sleeve 21 from having injection molding defects. Finally, the cavity 210 can also prevent the heat from the connecting plate 23 and the valve seat assembly 101 from being transferred to the first part 211 on the inner periphery of the threaded sleeve 21 during welding.

[0060] As shown in Figure 3, the screw 22 extends into the valve needle assembly 50. A bearing 221 is fitted onto the portion of the screw 22 that extends into the valve needle assembly 50. The inner ring of the bearing 221 is interference-fitted with the corresponding position of the screw 22. This arrangement allows the inner ring of the bearing 221 to rotate with the screw 22, while the outer ring remains stationary. This reduces the frictional resistance between the valve needle assembly 50 and the valve port 32 on the valve seat assembly 101 during the opening or closing of the electronic expansion valve. This reduces wear on the corresponding positions of the valve needle assembly 50 and the valve port 32, while also facilitating the movement of the valve needle assembly 50. In this embodiment, the axis of the threaded sleeve 21 is aligned with the axis of the valve port 32.

[0061] It should be noted that the axis of the electronic expansion valve 100 is coaxial with the axis of the threaded sleeve 21. In this application, the axial direction of the electronic expansion valve 100 and the axial direction of the threaded sleeve 21 are both the α direction marked in the figure.

[0062] Furthermore, when the electronic expansion valve is applied to and operates in a refrigeration cycle system, the compressor adjustment will affect the flow pulse of the refrigerant when it flows in the electronic expansion valve. The refrigerant will generate resonance excitation when it flows in the valve chamber of the electronic expansion valve, thereby generating abnormal noise. In addition, during the process of the refrigerant being throttled and depressurized at the valve port of the electronic expansion valve and discharged, the turbulent kinetic energy of the refrigerant is relatively large, which will generate a lot of noise during the process of the refrigerant being discharged from the valve seat, thereby reducing the product performance of the electronic expansion valve.

[0063] Therefore, referring to Figures 2 and 3, in one embodiment, the valve seat assembly 101 includes a valve seat 10, a first valve seat core 30, and a second valve seat core 40. The valve seat 10 has a mounting hole 14. The first valve seat core 30 is independently disposed relative to the valve seat 10, located at the mounting hole 14 and connected to the valve seat 10. The first valve seat core 30 has a first refrigerant flow port 31. The second valve seat core 40 is independently disposed relative to the first valve seat core 30 and connected to it. The second valve seat core 40 has a second refrigerant flow port 41, through which the second refrigerant flows... The inlet 41 is connected to the first refrigerant inlet 31; the valve needle assembly 50 is movable relative to the valve seat 10 along the axial direction of the electronic expansion valve 100, and is movably mounted on the valve seat 10 to control the opening / closing of the first refrigerant inlet 31 and the opening / closing of the electronic expansion valve 100; wherein, the center line of the first refrigerant inlet 31 and the center line of the second refrigerant inlet 41 are set on the same straight line, and along the axial direction of the electronic expansion valve 100, the channel diameter of the second refrigerant inlet 41 is consistent with and equal to the channel diameter of the first refrigerant inlet 31. A valve port 32 is provided on the first valve seat core 30, the valve port 32 is connected to the first refrigerant inlet 31, and the valve needle assembly 50 can act on the first valve seat core 30 and block the valve port 32.

[0064] It should be noted that "keeping in line" means that the first refrigerant inlet 31 and the second refrigerant inlet 41 are arranged coaxially along the axis of the electronic expansion valve 100. In this way, the positions of the two are relatively consistent, which can facilitate the refrigerant to pass through more normally and quickly.

[0065] The electronic expansion valve 100 of this application is a two-way valve. Specifically, the second connecting pipe 120 is fitted onto the outer circular wall of the first valve seat core 30 and the second valve seat core 40. The first connecting pipe 110 is connected to and communicates with one side of the valve seat 10. The valve seat 10 conducts refrigerant through the second connecting pipe 120 and the first connecting pipe 110.

[0066] Similarly, in this embodiment, the first connecting pipe 110 can be either a refrigerant inlet or a refrigerant outlet. When refrigerant flows in from the first connecting pipe 110, it enters the valve cavity 1001 formed in the valve seat 10, passes through the valve port 32, the first refrigerant flow port 31 of the first valve seat core 30, and the second refrigerant flow port 41 of the second valve seat core 40 in sequence, and flows out from the second connecting pipe 120. When refrigerant flows out from the first connecting pipe 110, it flows in from the second connecting pipe 120, passes through the second refrigerant flow port 41 of the second valve seat core 40 and the first refrigerant flow port 31 of the first valve seat core 30 in sequence, enters the valve cavity 1001 of the valve seat 10 from the valve port 32, and finally flows out from the first connecting pipe 110.

[0067] It is understood that, through the structural arrangement of the first valve seat core 30 and the second valve seat core 40, the first refrigerant flow port 31 and the second refrigerant flow port 41 together constitute the flow channel at the valve port 32 of the electronic expansion valve 100. Since the diameter of the channels between the first refrigerant flow port 31 and the second refrigerant flow port 41 along the axial direction of the electronic expansion valve 100 remains unchanged, and their diameters are equal, the diameter of the flow channel at the valve port 32 formed by their combination remains unchanged. If the first connecting pipe 110 is the refrigerant inlet, then after the refrigerant fluid is throttled and flows out through the valve port 32, since the diameter of the flow channel at the valve port 32 remains unchanged, As the refrigerant fluid passes through the first valve seat core 30 and the second valve seat core 40 in sequence, its pressure remains stable and does not change significantly. This prevents the bursting of air bubbles in the gas-liquid two-phase refrigerant fluid after throttling, which would otherwise generate noise. At the same time, the increased length of the flow channel at valve port 32 reduces the velocity gradient of the refrigerant fluid and lowers its pressure pulsation, thereby reducing noise. If the first connecting pipe 110 is the refrigerant outlet, the refrigerant first passes through the flow channel at valve port 32 and then through valve port 32. Therefore, the pressure change of the refrigerant fluid before valve port 32 can also be reduced, the velocity gradient can be decreased, and the pressure pulsation can be lowered, thereby reducing noise. Meanwhile, compared to the structure where two valve seat cores are integrated and a long flow channel is machined on the integrated valve seat core, setting the first valve seat core 30 independently from the valve seat 10 and the second valve seat core 40, and machining the first refrigerant flow port 31 on the first valve seat core 30 and the second refrigerant flow port 41 on the second valve seat core 40 respectively and then combining them to form the flow channel at the valve port 32, the operation is simpler and easier to produce and prepare the first valve seat core 30 and the second valve seat core 40 and to machine the longer flow channel at the valve port 32.

[0068] Specifically, the total length between the first refrigerant inlet 31 and the second refrigerant inlet 41 can be controlled between 2mm and 20mm.

[0069] As shown in Figures 1 to 3, the valve seat 10 is configured as an integral stamped part, which allows the valve seat 10 to be integrally stamped. This facilitates the production and processing of the valve seat 10, reducing costs compared to precision-machined parts. On the other hand, it also increases the volume of the valve cavity 1001 inside the valve seat 10, allowing the refrigerant introduced into the valve cavity 1001 to be released better, thereby reducing the turbulent kinetic energy of the refrigerant and further reducing noise. In addition, the structural characteristics of the stamped part can be used to make the cavity wall structure of the valve cavity 1001 on the valve seat 10 smoother, with fewer sharp edges inside the valve cavity 1001. This makes it less likely for the refrigerant to form vortices when flowing in the valve cavity 1001, which is also beneficial for noise reduction.

[0070] As shown in Figures 1 to 7, the second valve seat core 40 is fitted onto and connected to the first valve seat core 30. A second connecting pipe 120 is fitted onto the outer circular wall of both the first and second valve seat cores 30 and 40. Here, the second valve seat core 40 is press-fitted onto the first valve seat core 30 with an interference fit or a transition fit. Laser welding can also be used to increase the connection strength between the first and second valve seat cores 30 and 40. It should be noted that a welding ring can be provided between the first valve seat core 30 and the valve seat 10, and the valve seat 10, the first valve seat core 30, the second valve seat core 40, and the second connecting pipe 120 can be fixed together by a single furnace weld.

[0071] Specifically, at the point where the second connecting pipe 120 is sleeved with the first valve seat core 30, the inner wall of the second connecting pipe 120 and the outer wall of the first valve seat core 30 are press-fitted or transition-fitted to improve the connection strength between the second connecting pipe 120 and the first valve seat core 30, and to ensure the coaxiality of the two through the press-fit or transition.

[0072] Specifically, at the point where the first valve seat core 30 inserts into the mounting hole 14, the outer wall of the first valve seat core 30 and the inner wall of the mounting hole 14 are fitted with a clearance fit. This reduces the assembly difficulty of the first valve seat core 30. To ensure the reliability of the relative position between the first valve seat core 30 and the valve seat 10, their positions can be pre-fixed by spot welding. Then, the valve seat 10, the first valve seat core 30, the second valve seat core 40, and the second connecting pipe 120 are simultaneously brazed, thereby improving welding strength and welding convenience.

[0073] As shown in Figure 7, a sleeve 33 is formed on the first valve seat core 30. The sleeve 33 can be inserted into the second valve seat core 40 along the axial direction of the electronic expansion valve 100 until the sleeve 33 abuts against the second stepped surface 43 of the second valve seat core 40, thereby achieving assembly limiting between the first valve seat core 30 and the second valve seat core 40. Here, the outer diameters of the portions on the first valve seat core 30 and the second valve seat core 40 used for insertion and mating with the second connecting pipe 120 are the same, which simplifies the structure of the portion on the second connecting pipe 120 used for mating with the first valve seat core 30 and the second valve seat core 40.

[0074] As shown in Figures 7 and 8, the second valve seat core 40 includes a first connecting section 422 and a second connecting section 423, which are disposed at both ends of the second valve seat core 40 along the axial direction of the electronic expansion valve 100. The second connecting pipe 120 includes a first sleeve section 122 and a second sleeve section 123.

[0075] In one embodiment, as shown in FIG7, the first connecting segment 422 is sleeved on the end of the first valve seat core 30 away from the valve seat 10, and is either interference-fitted or transition-fitted with the first valve seat core 30. In this case, the first sleeve segment 122 is sleeved on the outer periphery of the first connecting segment 422 and is clearance-fitted with the first connecting segment 422. The second sleeve segment 123 is sleeved on the outer periphery of the second connecting segment 423 and is spaced apart from the outer wall of the second connecting segment 423. Thus, the second valve seat core 40 ensures a reliable connection with the insert 33 on the first valve seat core 30 through interference or transition fitting. Therefore, the axial ends of the second valve seat core 40 can be respectively configured to be clearance-fitted with the second connecting pipe 120 and spaced apart, reducing the difficulty of sleeved connection of the second connecting pipe 120 to the second valve seat core 40 and improving overall assembly efficiency.

[0076] In another embodiment, as shown in FIG8, the first connecting segment 422 is sleeved on the end of the first valve seat core 30 away from the valve seat 10 and is clearance-fitted with the first valve seat core 30. At this time, the first sleeve segment 122 is sleeved on the outer periphery of the first connecting segment 422 and is clearance-fitted with the first connecting segment 422, and the second sleeve segment 123 is sleeved on the outer periphery of the second connecting segment 423 and is interference-fitted or transition-fitted with the outer wall of the second connecting segment 423. That is, in this embodiment, the inner wall of the first connecting segment 422 and the outer wall of the insert 33 are clearance-fitted. This can reduce the difficulty of the two fitting together and improve the assembly efficiency. However, the clearance fit can also easily lead to unstable connection between the two, causing the second valve seat core 40 to wobble, thereby affecting the coaxiality of the internal channel. At this time, through the interference or transition fit between the second connecting pipe 120 and the first valve seat core 30, and simultaneously through the interference or transition fit between the second sleeve section 123 on the second connecting pipe 120 and the second connecting section 423 on the second valve seat core 40, the second valve seat core 40 can be stably confined within the second connecting pipe 120, ensuring the reliability of the overall connection between the first valve seat core 30, the second valve seat core 40, and the second connecting pipe 120.

[0077] To facilitate the press-fitting of the second valve seat core 40 into the second connecting pipe 120, as shown in Figure 8, the second valve seat core 40 further includes an insertion guide section 424. The insertion guide section 424 is located at the end of the second connecting section 423 furthest from the first valve seat core 30, guiding the second sleeve section 123. The outer wall of the insertion guide section 424 and the inner wall of the second sleeve section 123 have a clearance fit. Thus, during the insertion process of the second connecting pipe 120, when the second sleeve section 123 on the second connecting pipe 120 moves to the insertion guide section 424, it can smoothly move to the second connecting section 423 under the guidance of the insertion guide section 424, reducing insertion difficulty and facilitating an interference or transition fit between the inner wall of the second sleeve section 123 and the outer wall of the second connecting section 423. Here, the insertion guide section 424 can be configured as a guide slope.

[0078] As shown in Figure 7, the second valve seat core 40 has an inclined surface 421 on the outer peripheral wall 42 of the portion fitted onto the first valve seat core 30. This inclined surface is used to avoid the second connecting pipe 120 and prevent the outer peripheral wall 42 of the second valve seat core 40 from interfering with the second connecting pipe 120. Specifically, this facilitates the smooth movement of the first sleeve section 122 on the second connecting pipe 120 to the outer wall of the first valve seat core 30, so as to achieve an interference fit or transition fit with the outer wall of the first valve seat core 30.

[0079] Specifically, in different system pipelines, a constriction 121 can be provided on the second connecting pipe 120 according to the actual situation. The inclined surface 421 can be used to avoid the constriction 121 on the second connecting pipe 120 to prevent interference between the second connecting pipe 120 and the second valve seat core 40 during the assembly process. This allows the electronic expansion valve 100 to be assembled with different types of second connecting pipes 120 to meet the usage requirements of different working conditions. Of course, the constriction 121 may not be provided on the second connecting pipe 120.

[0080] In other embodiments, as shown in FIG9, the valve seat 10, the first valve seat core 30, and the second valve seat core 40 can also be configured as an integral structure. The valve seat 10 has a valve port 32, and the valve needle assembly 50 cooperates with the valve port 32 to control the flow rate at the valve port 32. The valve port 32 is sequentially connected to the first refrigerant flow port 31 on the first valve seat core 30 and the second refrigerant flow port 41 on the second valve seat core 40. The center lines of the valve port 32, the first refrigerant flow port 31, and the second refrigerant flow port 41 are all aligned on the same straight line. Furthermore, along the axial direction of the electronic expansion valve 100, the channel diameters of the valve port 32, the second refrigerant flow port 41, and the first refrigerant flow port 31 are consistent and equal. It should be noted that "keeping in line" means that the valve port 32, the first refrigerant flow port 31 and the second refrigerant flow port 41 are arranged coaxially along the axis of the electronic expansion valve 100. In this way, the positions of the three are relatively consistent, which can facilitate the refrigerant to pass through more normally and quickly.

[0081] It is understandable that designing the valve seat 10, the first valve seat core 30, and the second valve seat core 40 as a single integrated structure can also extend the length of the flow channel corresponding to the valve port 32, thereby stabilizing the pressure of the refrigerant fluid flowing through the channel, preventing noise caused by the bursting of air bubbles in the gas-liquid two-phase refrigerant fluid after throttling, and also reducing the velocity change gradient of the refrigerant fluid, reducing pressure pulsation, and thus further reducing noise. Here, the total length between the valve port 32, the first refrigerant flow port 31, and the second refrigerant flow port 41 can also be controlled within 2mm-20mm. As shown in Figures 3 and 4, the threaded sleeve 21 is fixedly mounted on the valve seat 10, and the valve needle assembly 50 is partially disposed within the threaded sleeve 21. The threaded sleeve 21 includes an internal thread section 201, and the screw 22 has an external thread section 222. The internal thread section 201 and the external thread section 222 on the screw 22 are threadedly engaged. A bearing 221 is fitted on the portion of the screw 22 that extends into the valve needle assembly 50, and the screw 22 and the inner ring of the bearing 221 are interference-fitted. Thus, the threaded sleeve 21, through the threaded engagement of the internal thread section 201 and the external thread section of the screw 22, and with the synergistic effect of the bearing 221, can convert the circumferential rotation of the valve needle assembly 50 into movement along the axial direction of the electronic expansion valve 100.

[0082] As shown in Figure 3, the threaded sleeve 21 also includes a guide section 202, which is clearance-fitted with part of the valve needle assembly 50 to guide the axial movement of the valve needle assembly 50. In other words, the electronic expansion valve 100 uses the threaded sleeve 21 to directly guide the axial movement of the valve needle assembly 50, which eliminates the need for a guide sleeve (not shown) compared to electronic expansion valves in related technologies. This reduces production costs and further increases the volume of the valve cavity 1001 inside the valve seat 10, thus further reducing noise.

[0083] As shown in Figure 3, the guide section 202 of the threaded sleeve 21 includes an upper guide section 2021 and a lower guide section 2022. The upper guide section 2021 and the lower guide section 2022 are arranged on both sides of the internal thread section 201 along the axial direction of the electronic expansion valve 100, which can improve the guiding effect of the threaded sleeve 21 on the screw 22. The upper guide section 2021 and the lower guide section 2022 are partially clearance-fitted to both sides of the external thread section 222 of the screw 22. The lower guide section 2022 guides the outer periphery of the valve needle assembly 50 near the valve port 32 during the movement of the valve needle assembly 50 along the axial direction of the electronic expansion valve 100, and the lower guide section 2022 is clearance-fitted with the valve needle assembly 50.

[0084] It is understandable that this application uses a threaded sleeve 21 to guide both the screw 22 and the valve needle assembly 50 from both the upper and lower sides. Compared to a structure where the screw is guided by a threaded sleeve at the upper position and the valve needle assembly is guided by a guide sleeve at the lower position, the coaxiality of the parts is better guaranteed. It is also understandable that, compared to the method where the threaded sleeve and guide sleeve guide separately at the upper and lower sides, using an integral threaded sleeve 21 to directly guide the axial movement of both the screw 22 and the valve needle assembly 50 simultaneously can effectively avoid assembly errors of the guide sleeve, thereby ensuring the coaxiality of the valve needle assembly 50.

[0085] As shown in Figure 4, the threaded sleeve 21 has a first part 211 and a second part 212. The second part 212 abuts against and connects to the valve seat 10 to assemble the threaded sleeve 21 onto the valve seat 10. The first part 211 is part of the lower guide section 2022 of the threaded sleeve 21, and the first part 211 has a clearance fit with the valve needle assembly 50, which can guide the valve needle assembly 50. That is to say, the threaded sleeve 21 can be assembled with the valve seat 10 through the second part 212, and the threaded sleeve 21 can be assembled and connected on the valve seat 10; the threaded sleeve 21 can guide the valve needle assembly 50 through the first part 211. Here, the outer wall of the second part 212 on the threaded sleeve 21 can be press-fitted with the corresponding inner wall on the valve seat 10, so that the threaded sleeve 21 can be assembled on the valve seat 10 by pressing the second part 212 directly to the bottom. It should be noted that the outer wall of the second part 212 of the threaded sleeve 21 can be a complete circle.

[0086] As shown in Figures 1, 3 and 4, in the axial direction of the electronic expansion valve 100 (i.e., the α direction in the figure), the first part 211 extends relative to the second part 212 toward the first valve seat core 30. This extends the effective length of the threaded sleeve 21 in guiding the valve needle assembly 50, thereby ensuring that the threaded sleeve 21 can guide the reciprocating motion of the valve needle assembly 50 and improving the coaxiality between the valve needle assembly 50 and the threaded sleeve 21.

[0087] Furthermore, in the axial direction of the electronic expansion valve 100, the first part 211 extends towards the valve port 32 relative to the second part 212, and the length of the extended portion is defined as D. In other words, the length of the portion of the first part 211 extending towards the first valve seat core 30 in the axial direction of the valve seat 10 relative to the second part 212 is defined as D. Wherein, 1mm < D < 4mm. In this way, the concentricity of the assembly between the second part 212 and the valve seat connecting part 11 can be ensured, thereby ensuring the assembly accuracy of the threaded sleeve 21 when it is assembled on the valve seat assembly 101, and ensuring the guiding effect of the first part 211 on the valve needle assembly 50.

[0088] The threaded sleeve 21 is also provided with a balance hole (not shown in the figure) to balance the pressure on the inner and outer sides of the threaded sleeve 21, thereby reducing the valve opening resistance of the valve needle assembly 50. It should be noted that the position of the balance hole on the threaded sleeve 21 and the working principle of balancing the pressure difference on the inner and outer sides of the threaded sleeve 21 can be achieved by conventional methods, which will not be elaborated here.

[0089] As shown in Figure 4, the valve seat 10 includes a valve seat connection part 11, and the threaded sleeve 21 can be press-fitted onto the valve seat connection part 11 by means of interference fit or transition fit through the second part 212.

[0090] The threaded sleeve 21 is press-fitted to the valve seat connection portion 11 of the valve seat 10. A receiving groove 13 is formed between the valve seat 10 and the threaded sleeve 21. The receiving groove 13 can receive the burrs generated when the threaded sleeve 21 is press-fitted onto the valve seat connection portion 11. This can prevent burrs from falling between the threaded sleeve 21 and the valve seat 10, thereby ensuring the flatness of the threaded sleeve 21 and the valve seat connection portion 11 during assembly.

[0091] Specifically, the valve seat 10 also includes a stepped portion 12, which can abut against or be spaced apart from the lower end face 2121 of the second part 212. When the stepped portion 12 abuts against the lower end face 2121 of the second part 212, a receiving groove 13 can be provided on the inner circumferential surface of the valve seat connecting portion 11 and / or the outer circumferential surface of the second part 212 of the threaded sleeve 21 on the corresponding press-fit section. This can prevent burrs from falling into the lower end face 2121 of the second part 212 of the threaded sleeve 21 and the end face of the valve seat connecting portion 11 away from the valve port 32, that is, the position where it abuts against the first stepped surface 1201 of the stepped portion 12, thus ensuring the flatness of the threaded sleeve 21 and the valve seat connecting portion 11 during assembly.

[0092] For example, the receiving groove 13 is provided on the second part of the threaded sleeve 21. When the receiving groove 13 is provided on the outer peripheral surface of the second part 212 of the threaded sleeve 21, it can be formed directly during the injection molding process of the threaded sleeve 21. For example, the receiving groove 13 can be directly injection molded on the outer peripheral surface of the threaded sleeve 21 during injection molding. Of course, a step-like structure can also be injection molded at the junction of the lower end face 2121 of the second part 212 and the outer peripheral surface of the threaded sleeve 21, and after press fitting, it can be used together with the valve seat connection part 11, the step part 12 or other structures to form the receiving groove 13.

[0093] Specifically, in this embodiment, the receiving groove 13 is disposed on the press-fit section corresponding to the inner circumferential surface of the valve seat connection portion 11, wherein the cross-section of the receiving groove 13 can be set as trapezoidal, rectangular or conical, etc.

[0094] When the step portion 12 and the lower end face 2121 of the second portion 212 are spaced apart, the lower end face 2121 of the second portion 212 on the threaded sleeve 21, the inner circumferential surface of the valve seat connection portion 11 and the first step surface 1201 of the step portion 12 can form a receiving groove 13, thereby receiving the burrs generated when the threaded sleeve 21 is pressed on the valve seat connection portion 11.

[0095] The receiving groove 13 can be configured as an annular structure, so that it can receive burrs generated during the press-fitting of the threaded sleeve 21 at the valve seat connection 11 in a 360° full-coverage manner, thus ensuring that all burrs can be received by the receiving groove 13. Of course, those skilled in the art can also set the receiving groove 13 as multiple spaced arc-shaped grooves, and the projections of the multiple arc-shaped grooves in the axial direction of the valve seat 10 can be combined to form an annular structure.

[0096] As shown in Figure 3, the stepped portion 12 can abut against the second portion 212 of the threaded sleeve 21 pressed into the valve seat connection portion 11, facing the first valve seat core 30, to limit the pressing depth of the second portion 212 when pressed into the valve seat connection portion 11. Here, the thickness of the stepped portion 12 is defined as C, where 3mm ≥ C ≥ 0.1mm.

[0097] In summary, the electronic expansion valve 100 of this application can reduce the noise generated during operation and improve the performance of the electronic expansion valve 100 product.

[0098] 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.

[0099] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An electronic expansion valve, characterized in that, The electronic expansion valve includes: A valve seat assembly, wherein the valve seat assembly is provided with a valve port, and the valve seat assembly is connected to a first connecting pipe, the first connecting pipe communicating with the valve port; Screw assembly, the screw assembly including a threaded sleeve fixedly mounted to the valve seat assembly; and Valve needle assembly; The threaded sleeve has a first part that is guided and engaged with the valve needle assembly; and, along the axial direction of the threaded sleeve, the end face of the first part facing the valve port is not lower than the inner circumferential wall of the first connecting pipe.

2. The electronic expansion valve according to claim 1, wherein, The end of the first connecting pipe used to connect with the valve seat assembly is defined as the open end. There is a preset gap between the end face of the open end and the outer wall of the first part opposite to the open end. The preset gap is defined as A, where 0.5mm≤A≤2.5mm.

3. The electronic expansion valve according to claim 1, wherein, The threaded sleeve also has a second part, and the valve seat assembly has a valve seat connection part, wherein the second part is connected to the valve seat connection part by means of interference fit or transition fit.

4. The electronic expansion valve according to claim 3, wherein, The valve seat assembly is provided with a first stepped surface, which can abut against the second part pressed into the valve seat connection portion, thereby limiting the pressing depth of the second part on the valve seat connection portion; in the axial direction of the threaded sleeve, the axial height of the second part pressed into the valve seat connection portion is defined as B, where 5mm≥B≥1.5mm.

5. The electronic expansion valve according to claim 3, wherein, The electronic expansion valve further includes a connecting plate, which is fitted onto the threaded sleeve and abuts against the second part; wherein the connecting plate is welded to the valve seat connection part.

6. The electronic expansion valve according to claim 5, wherein, In the axial direction of the threaded sleeve, the connecting plate protrudes outward relative to the valve seat connecting portion, and the thickness of the portion of the connecting plate protruding from the valve seat connecting portion is defined as E, where 0.8mm > E ≥ 0.1mm; and / or, The threaded sleeve has a foolproof part, and the connecting plate has a foolproof mating part, which can be limited to fit with the foolproof part.

7. The electronic expansion valve according to claim 1, wherein, The threaded sleeve also has a second part and a connecting part. The threaded sleeve can be fixedly connected to the valve seat assembly through the second part, and the connecting part is disposed between the second part and the first part. The first part, the second part, and the connecting part together form a cavity, which is connected to the first connecting pipe.

8. The electronic expansion valve according to claim 7, wherein, The difference between the thickness of the first part, the thickness of the second part, and the thickness of any two of the connecting parts is less than or equal to 1 mm.

9. The electronic expansion valve according to claim 1, wherein, The screw assembly further includes a screw, a portion of which extends into the valve needle assembly. A bearing is fitted onto the portion of the screw extending into the valve needle assembly, and the screw is interference-fitted with the inner ring of the bearing; and / or, The axis of the threaded sleeve is aligned with the axis of the valve port.

10. The electronic expansion valve according to claim 1, wherein, The valve seat assembly includes a valve seat, a first valve seat core, and a second valve seat core; The valve seat is provided with a mounting hole; The first valve seat core is independently disposed relative to the valve seat, the first valve seat core is disposed in the mounting hole and connected to the valve seat, and the first valve seat core has a first refrigerant flow port. The second valve seat core is independently disposed relative to the first valve seat core and connected to the first valve seat core. The second valve seat core has a second refrigerant flow port, which is connected to the first refrigerant flow port. The valve needle assembly is movably mounted on the valve seat and is capable of controlling the opening / closing of the first refrigerant inlet; The centerline of the first refrigerant inlet and the centerline of the second refrigerant inlet are located on the same straight line. Furthermore, along the axial direction of the electronic expansion valve, the second refrigerant inlet and the first refrigerant inlet are coaxially arranged and have the same channel diameter.

11. The electronic expansion valve according to claim 10, wherein, The threaded sleeve is fixedly mounted on the valve seat; the threaded sleeve includes an internal thread section and a guide section; the screw assembly also includes a screw, a portion of which extends into the valve needle assembly, a bearing is fitted on the portion of the screw extending into the valve needle assembly, and the screw is interference-fitted with the inner ring of the bearing; the screw has an external thread section, which is threadedly engaged with the internal thread section of the threaded sleeve; The valve needle assembly is partially disposed within the threaded sleeve, and the guide section is in clearance fit with at least a portion of the valve needle assembly to guide the valve needle assembly.

12. The electronic expansion valve according to claim 11, wherein, The guide section includes an upper guide section and a lower guide section, which are arranged on both sides of the internal thread section along the axial direction of the electronic expansion valve.

13. The electronic expansion valve according to claim 10, wherein, The threaded sleeve also has a second part, which abuts against and is connected to the valve seat; the valve seat includes a valve seat connection part, and the threaded sleeve can be connected to the valve seat connection part by the second part in an interference fit or a transition fit manner. The valve seat assembly is provided with a stepped portion, which abuts against the end of the second portion assembled into the valve seat connection portion facing the valve port, thereby limiting the assembly depth of the second portion on the valve seat connection portion; The thickness of the stepped portion is defined as C, where 3mm ≥ C ≥ 0.1mm.

14. The electronic expansion valve according to claim 13, wherein, In the axial direction of the electronic expansion valve, the first part extends toward the valve port relative to the second part, and the length of the extended part is defined as D, where 1mm < D < 4mm.

15. The electronic expansion valve according to claim 13, wherein, A receiving groove is formed between the valve seat and the threaded sleeve, which can accommodate burrs generated when the threaded sleeve is assembled on the valve seat connection.

16. The electronic expansion valve according to claim 10, wherein, The second valve seat core is fitted onto the first valve seat core and connected to the first valve seat core, and a second connecting tube is fitted onto both the first valve seat core and the second valve seat core.

17. The electronic expansion valve according to claim 16, wherein, At the point where the second connecting pipe is sleeved with the first valve seat core, the inner wall of the second connecting pipe is either interference-fitted or transition-fitted with the outer wall of the first valve seat core. And / or, at the location where the first valve seat core is inserted into the mounting hole, the outer wall of the first valve seat core and the inner wall of the mounting hole are in clearance fit.

18. The electronic expansion valve according to claim 17, wherein, The second valve seat core includes a first connecting section and a second connecting section. The first connecting section and the second connecting section are disposed at both ends of the second valve seat core along the axial direction of the electronic expansion valve. The first connecting section is sleeved on the end of the first valve seat core away from the valve seat and is interference-fitted or transition-fitted with the first valve seat core. The second connecting pipe includes a first sleeve section and a second sleeve section, wherein the first sleeve section is sleeved on the outer periphery of the first connecting section and has a clearance fit with the first connecting section, and the second sleeve section is sleeved on the outer periphery of the second connecting section and is spaced apart from the outer wall of the second connecting section; and / or, The second valve seat core includes a first connecting section and a second connecting section. The first connecting section and the second connecting section are disposed at both ends of the second valve seat core along the axial direction of the electronic expansion valve. The first connecting section is sleeved on the end of the first valve seat core away from the valve seat and is in clearance fit with the first valve seat core. The second connecting pipe includes a first sleeve section and a second sleeve section. The first sleeve section is sleeved on the outer periphery of the first connecting section and has a clearance fit with the first connecting section. The second sleeve section is sleeved on the outer periphery of the second connecting section and has an interference fit or transition fit with the outer wall of the second connecting section.

19. The electronic expansion valve according to claim 18, wherein, The second valve seat core further includes an insertion guide section, which is located at the end of the second connecting section away from the first valve seat core, to guide the second socket section; Wherein, the outer wall of the insertion guide section is clearance-fitted with the inner wall of the second socket section; and / or, The outer peripheral wall of the upper part of the second valve seat core, which is fitted onto the first valve seat core, is provided with an inclined surface, which is used to avoid the second connecting pipe.

20. The electronic expansion valve according to claim 1, wherein, The valve seat assembly includes a valve seat, a first valve seat core, and a second valve seat core; The valve port is located on the valve seat; The first valve seat core is disposed at the position of the valve port and connected to the valve seat. The first valve seat core is provided with a first refrigerant flow port, which is connected to the valve port. The second valve seat core is connected to the first valve seat core, and the second valve seat core has a second refrigerant flow port, which is connected to the first refrigerant flow port. The valve needle assembly is movably mounted on the valve seat and is used to control the refrigerant flow at the valve port and to control the opening / closing of the electronic expansion valve; The centerline of the valve port, the centerline of the first refrigerant inlet, and the centerline of the second refrigerant inlet are all located on the same straight line. Furthermore, along the axial direction of the electronic expansion valve, the valve port, the second refrigerant inlet, and the first refrigerant inlet are coaxially arranged and have the same channel diameter. The valve seat, the first valve seat core, and the second valve seat core are an integral structure.

Images