Electronic expansion valve and assembly process

Abstract

The invention provides an electronic expansion valve and an assembling technology, the electronic expansion valve comprises a first connecting pipe, a silencing part, a valve seat part and a switching part, the valve seat part and the switching part are connected with each other, the switching part is connected with the valve seat part and the first connecting pipe, the switching part is provided with a containing cavity, and the silencing part is installed in the containing cavity in a limited mode. By the adoption of the scheme, the furnace welding object of the first connecting pipe is converted from the valve seat part to the switching part through the switching part, when the switching part and the first connecting pipe are subjected to furnace welding, the silencing part located in the containing cavity is separated from the first connecting pipe through the switching part, the first connecting pipe does not directly abut against the silencing part, welding flux generated during furnace welding cannot permeate into the silencing part, and the silencing effect is good. And the noise reduction effect of the noise reduction part and the flow capacity of the electronic expansion valve are ensured. And on the other hand, independent off-line installation of the switching part and the silencing part can be achieved, the production takt is reduced, part standardization is improved, the falling risk in the part turnover process is avoided, and the machining and installation efficiency of the electronic expansion valve is improved.

Description

TECHNICAL FIELD

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

[0002] Currently, the electronic expansion valve can be applied to the series reheating dehumidification field. Since the electronic expansion valve is arranged between two indoor side heat exchangers in this application, it is determined that the pressure drop of the electronic expansion valve at a large opening degree should be small enough to ensure the capacity of the air conditioning system under normal air conditioning conditions. In addition, since the electronic expansion valve is arranged indoors, the requirement for noise is also high. Therefore, a porous noise reduction part can be arranged at the valve port of the electronic expansion valve to reduce the noise of the refrigerant flow.

[0003] The electronic expansion valve usually directly press-fits the noise reduction part in the cavity of the valve seat part by using the first connecting pipe. One end of the first connecting pipe extends into the cavity of the valve seat and directly abuts against the noise reduction part in the cavity of the valve seat. Since the first connecting pipe is usually connected with the valve seat by furnace welding, the welding material is easy to penetrate from the gap between the inner wall of the cavity of the valve seat and the outer periphery of the first connecting pipe to the noise reduction part. The noise reduction part has a porous structure, and the welding material is easy to adhere to the noise reduction part after flowing to the noise reduction part, thereby causing partial blockage of the noise reduction part and affecting the noise reduction effect and flow capacity. Further, since the noise reduction part is usually press-fitted in the valve seat part, the valve seat part needs to be correspondingly machined to form a cavity for mounting the noise reduction part, which requires high machining and needs to consider many factors. On the other hand, the parts are also easy to fall off during the press-fitting process, thereby affecting the machining and installation efficiency. SUMMARY

[0004] The present application provides an electronic expansion valve and an assembling process to solve the problem that the noise reduction part is easy to be blocked by the furnace welding material and affect the noise reduction effect in the prior art and improve the machining and installation efficiency of the electronic expansion valve.

[0005] In order to solve the above problems, according to one aspect of the present application, an electronic expansion valve is provided, which comprises a first connecting pipe, a noise reduction part, and a valve seat part and an adapter part connected with each other. The adapter part is connected with the valve seat part and the first connecting pipe respectively. The adapter part has a containing cavity, and the noise reduction part is limitingly installed in the containing cavity.

[0006] Further, the noise reduction part is laser welded in the containing cavity, or the noise reduction part is riveted in the containing cavity, or the noise reduction part is press-fitted in the containing cavity.

[0007] Further, the valve seat part further has a limiting cavity, and the adapter part comprises a fitting section. At least part of the fitting section is arranged in the limiting cavity. The cavity inner wall of the fixing section and the cavity inner wall of the fitting section have an inner stepped surface, and the noise reduction part abuts against the inner stepped surface.

[0008] Further, the fitting section comprises a first fitting section and a second fitting section connected to each other, at least a part of the first fitting section extends into the limiting cavity, and at least a part of the second fitting section is located outside the limiting cavity for adapting the first connecting pipe, the outer diameter of the first fitting section is larger than that of the second fitting section, and the inner diameter of the first fitting section is larger than that of the second fitting section.

[0009] Further, an outer stepped surface is formed between the outer wall of the first fitting section and the outer wall of the second fitting section, the outer stepped surface protrudes out of the limiting cavity or is flush with the surface where the opening of the limiting cavity is located and forms a positioning reference surface.

[0010] Further, the adapting part has an annular stop protrusion, the annular stop protrusion is arranged between the first fitting section and the second fitting section and protrudes inward in the radial direction of the adapting part, the inner diameter of the annular stop protrusion is smaller than that of the second fitting section, an adapting opening is formed around the annular stop protrusion, and one end of the first connecting pipe is arranged in the second fitting section and is in stop cooperation with the annular stop protrusion, and the adapting opening is in communication with the opening of the first connecting pipe.

[0011] Further, the adapting opening is a straight opening section with a constant inner diameter along the axial direction of the electronic expansion valve, or the adapting opening is a first trumpet opening, or the adapting opening has a first trumpet opening on the side away from the first connecting pipe, the inner diameter of the first trumpet opening gradually increases along the direction of the first connecting pipe towards the adapting opening, the side with a smaller opening of the first trumpet opening is in communication with the first connecting pipe and the radial dimension is adapted to the inner diameter of the first connecting pipe, and the opening angle of the first trumpet opening is β, 20°≤β≤120°.

[0012] Further, the opening of the accommodating cavity has a riveting flange, and the adapting part is in riveting cooperation with the silencing part.

[0013] Further, the riveting flange is an annular flange, or the riveting flange is a plurality of riveting flanges, and the plurality of riveting flanges are distributed along the circumferential direction of the adapting part.

[0014] Further, the adapting part comprises a fixing section, and the accommodating cavity is formed around the fixing section, and in the axial direction of the fixing section, the part of the opening side of the fixing section protruding out of the silencing part forms the riveting flange.

[0015] Further, the valve seat part comprises a valve seat and a valve seat core, the valve seat has a mounting cavity, the valve seat core is arranged in the mounting cavity, the area of the mounting cavity for mounting the valve seat core forms a placing cavity, and the area of the mounting cavity for mounting the adapting part forms the limiting cavity.

[0016] Further, the valve seat core is separate from the valve seat and is arranged in the placing cavity of the valve seat, or the valve seat core and the valve seat are in an integrated structure.

[0017] Further, the valve seat portion has a valve port cavity located on the side of the accommodating cavity away from the adapter portion, the valve port cavity being in communication with the accommodating cavity, the valve port cavity comprising a valve port section, the valve port section being a variable-diameter flow regulating section, or the valve port section having a variable-diameter flow regulating section on the side away from the accommodating cavity.

[0018] Further, the flow regulating section is a second horn, the second horn having an opening angle of α, 1°≤α≤10°.

[0019] Further, the electronic expansion valve further comprises a valve needle assembly, the valve needle assembly comprising a valve head member cooperating with the inner wall of the flow regulating section to regulate the flow of the electronic expansion valve, one end of the valve head member extending into the valve port section in the full-closed state of the electronic expansion valve, a gap being present between the outer periphery of the valve head member and the inner wall of the valve port section.

[0020] Further, the electronic expansion valve further comprises a rotor assembly, the valve needle assembly further comprising a screw member drivingly connected with the rotor assembly, the inner wall of the valve port section having a first tapered section and a first straight section sequentially arranged and in communication with each other in the direction of the valve port cavity towards the first connecting pipe, the first tapered section being the flow regulating section, one end of the valve head member being located in the first tapered section in the full-closed state of the electronic expansion valve, a gap being present between the outer periphery of the valve head member and the inner wall of the first tapered section; the height of the first tapered section being H5, the distance between the end of the valve head member and the communication surface of the first tapered section and the first straight section being H9, the electronic expansion valve having a flow turning point with a flow rate slope change in the valve opening process; B*n*γ / 360+H9=H5; wherein B is the number of supply pulses required for the valve head member to open from the full-closed position to the flow turning point, n is the pitch of the screw member, and γ is the step angle of the rotor assembly.

[0021] Further, the electronic expansion valve further comprises a rotor assembly, the valve needle assembly further comprising a screw member drivingly connected with the rotor assembly, the inner wall of the valve port section having a first tapered section and a first straight section sequentially arranged and in communication with each other in the direction of the valve port cavity towards the first connecting pipe, the first tapered section being the flow regulating section, one end of the valve head member being located in the first tapered section in the full-closed state of the electronic expansion valve, a gap being present between the outer periphery of the valve head member and the inner wall of the first straight section; the height of the first tapered section being H5, the distance between the end of the valve head member and the communication surface of the first tapered section and the first straight section being H9, the electronic expansion valve having a flow turning point with a flow rate slope change in the valve opening process; B*n*γ / 360+H9=H5; wherein B is the number of supply pulses required for the valve head member to open from the full-closed position to the flow turning point, n is the pitch of the screw member, and γ is the step angle of the rotor assembly.

[0022] According to another aspect of the present application, there is provided an assembling process for the electronic expansion valve, the assembling process comprising: welding one end of the second connecting pipe to the side of the valve seat part; welding the first connecting pipe to the end of the one end of the adapter part; installing the silencing part in the adapter part, and installing the part of the adapter part in the valve seat part, and welding the adapter part to the valve seat part.

[0023] Further, the silencing part comprises a first silencing block, a spacer block and a second silencing block abutting in sequence along the installation direction of the silencing part, and the process of installing the silencing part in the adapter part further comprises: installing the second silencing block, the spacer block and the first silencing block in the adapter part in sequence.

[0024] Further, the assembling process further comprises: the end of the one end of the adapter part is the end of the adapter part located outside the valve seat part, and the first connecting pipe is welded to the end of the one end of the adapter part located outside the valve seat part; or, the first connecting pipe is welded to the end of the one end of the adapter part located outside the valve seat part first, and then the silencing part is installed in the adapter part; or, the silencing part is installed in the adapter part first, and then the adapter part and the first connecting pipe are welded.

[0025] Further, the electronic expansion valve further comprises a nut assembly, a valve needle assembly and a guide sleeve, and the assembling process further comprises: sequentially installing the nut assembly and the valve needle assembly on the valve seat part; and before sequentially installing the nut assembly and the valve needle assembly on the valve seat part, the process of welding the one end of the second connecting pipe to the side of the valve seat part further comprises: press-fitting the guide sleeve in the valve seat part, integrally furnace welding the second connecting pipe, the valve seat part and the guide sleeve, or first furnace welding the second connecting pipe and the valve seat part, then press-fitting the guide sleeve in the valve seat part, and laser welding the guide sleeve and the valve seat part.

[0026] Further, the assembling process further comprises: laser welding the connecting position of the adapter part and the valve seat part; and pulsing the electronic expansion valve.

[0027] Further, the valve seat part comprises a split valve seat and a valve seat core, or the valve seat part comprises an integrated valve seat and a valve seat core, the part of the adapter part is installed in the valve seat, and the one end of the adapter part abuts against the valve seat core or the silencing part abuts against the valve seat core.

[0028] The technical scheme of the present application provides an electronic expansion valve, the electronic expansion valve comprising a first connecting pipe, a silencing part and a valve seat part and an adapter part connected to each other, the adapter part being connected to the valve seat part and the first connecting pipe respectively, the adapter part having a containing cavity, and the silencing part being limitingly installed in the containing cavity.

[0029] The scheme is adopted, the furnace welding object of the first connecting pipe is changed from the valve seat part to the adapter part through the adapter part, when the adapter part and the first connecting pipe are furnace welded, the sound attenuation part in the accommodating cavity is separated from the first connecting pipe through the adapter part, the first connecting pipe does not directly abut against the sound attenuation part, and the welding material generated during furnace welding will not penetrate to the sound attenuation part even if it penetrates, thereby avoiding the situation that the welding material easily penetrates from the gap between the first connecting pipe and the valve seat part to the sound attenuation part during furnace welding of the first connecting pipe and the valve seat part in the prior art, thereby affecting the noise reduction effect of the sound attenuation part and the flow capacity of the electronic expansion valve, and ensuring the noise reduction effect of the sound attenuation part and the flow capacity of the electronic expansion valve. On the other hand, the adapter part can realize independent off-line installation of the sound attenuation part, the operator only needs to adapt the valve seat part and the sound attenuation part when processing the adapter part, and then install the connected adapter part and sound attenuation part on the valve seat part, so that the production rhythm is reduced, the part standardization is improved, the risk of falling during the part turnover process is avoided, and the processing and installation efficiency of the electronic expansion valve is improved. BRIEF DESCRIPTION OF DRAWINGS

[0030] The drawings accompanying the specification of this application form a part thereof, serve to provide further understanding of the application, and together with the description of the application, explain the application. The embodiments of the application and its description are used to explain the application without forming an improper limitation on the application. In the drawings:

[0031] Figure 1 A structure schematic view of an electronic expansion valve provided by an embodiment of the application is shown;

[0032] Figure 2 A structure schematic view of Figure 1 is shown;

[0033] Figure 3 A structure schematic view of Figure 2 is shown;

[0034] Figure 4 A structure schematic view of Figure 2 is shown;

[0035] Figure 5 A structure schematic view of Figure 2 is shown;

[0036] Figure 6 A structure schematic view of Figure 2 is shown;

[0037] Figure 7 A structure schematic view of Figure 1 is shown;

[0038] Figure 8 A structure schematic view of Figure 7 is shown;

[0039] Figure 9 a flow schematic diagram of the electronic expansion valve according to the embodiment of the present application; Figure 7

[0040] Figure 10 a partial structural schematic diagram of a valve seat of the electronic expansion valve according to the second embodiment of the present application;

[0041] Figure 11 an assembly schematic diagram of a valve seat core, a sound-damping part and an adapter part of the electronic expansion valve according to the second embodiment of the present application;

[0042] Figure 12 a partial enlarged view of the electronic expansion valve according to the second embodiment of the present application;

[0043] Figure 13 a structural schematic diagram of the electronic expansion valve according to the third embodiment of the present application when the valve is closed;

[0044] Figure 14 an enlarged view of the D position in Figure 13

[0045] Figure 15 a flow schematic diagram of the electronic expansion valve according to the third embodiment of the present application. Figure 13

[0046] wherein the above-mentioned drawings include the following reference signs:

[0047] 1, annular groove;

[0048] 10, valve seat part; 101, mounting cavity; 1011, limiting cavity; 1012, placing cavity; 102, valve port cavity; 1021, valve port section; 10211, first tapered section; 10212, first straight-through section; 10213, second tapered section; 10214, second straight-through section; 1022, flared section; 11, valve seat; 12, valve seat core; 121, first loose-fitting section; 122, first tight-fitting section;

[0049] 20, adapter part; 201, containing cavity; 2011, first limiting cavity section; 2012, second limiting cavity section; 202, outer stepped surface; 203, adapter port; 204, inner stepped surface; 21, first fitting section; 22, second fitting section; 23, annular stop protrusion; 24, fixed section; 241, riveting flange;

[0050] 30, sound-damping part; 31, first sound-damping block; 32, cushion block; 33, second sound-damping block;

[0051] 41, first connecting pipe; 42, second connecting pipe;

[0052] 50, nut assembly;

[0053] 60, valve needle assembly; 61, valve head piece; 62, screw rod piece​​​

[0054] 70 guide sleeve; 71 first sleeve; 72 second sleeve; 73 limiting sleeve;

[0055] 80 rotor assembly. DETAILED DESCRIPTION

[0056] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0057] As shown in Figures 1 to 15 The embodiments of the present application provide an electronic expansion valve, which comprises a first connecting pipe, a sound attenuation part 30, and a valve seat part 10 and a switching part 20 connected with each other, the switching part 20 is connected with the valve seat part 10 and the first connecting pipe 41 respectively, the switching part 20 has a containing cavity 201, and the sound attenuation part 30 is limitedly installed in the containing cavity 201.

[0058] The sound attenuation part 30 can be laser welded in the containing cavity 201, or the sound attenuation part 30 is riveted in the containing cavity 201, or the sound attenuation part 30 is press-fitted in the containing cavity 201. The switching part 20 comprises a fixed section 24, and the containing cavity 201 is formed around the area surrounded by the fixed section 24.

[0059] In the embodiment, the adapter 20 is connected with the valve seat part 10 and the first connecting pipe 41 at two ends along the axial direction of the electronic expansion valve respectively. The adapter 20 changes the welding object of the first connecting pipe 41 from the valve seat part 10 to the adapter 20. When the adapter 20 and the first connecting pipe 41 are welded, the silencing part 30 in the accommodating cavity is separated from the first connecting pipe 41 by the adapter 20. The first connecting pipe 41 does not directly abut against the silencing part 30. The molten solder does not penetrate to the silencing part 30 during welding. The situation that the molten solder penetrates to the silencing part 30 from the gap between the first connecting pipe 41 and the valve seat part 10 during welding of the first connecting pipe 41 and the valve seat part 10, which affects the noise reduction effect of the silencing part 30 and the flow capacity of the electronic expansion valve, is avoided. The noise reduction effect of the silencing part 30 and the flow capacity of the electronic expansion valve are ensured. On the other hand, the adapter 20 can realize independent installation of the silencing part 30. The operator only needs to adapt the adapter 20 to the valve seat part 10 and the silencing part 30 during processing of the adapter 20. Then, the adapter 20 and the silencing part 30 are installed on the valve seat part 10. The setting is beneficial to reduce the production rhythm, improve the standardization of parts, avoid the risk of falling during the turnover of parts, and improve the processing and installation efficiency of the electronic expansion valve.

[0060] It should be noted that the adapter 20 can be a stretch part, a finished part, etc. In the embodiment, the adapter 20 needs to be processed with multiple steps and flow channels inside, and needs to be press-fitted into the valve seat part 10. Therefore, the size precision of the adapter 20 is required to be high. Therefore, the adapter 20 in the embodiment is preferably a finished part. It can be understood that the adapter 20 can be finished as a whole, or first stamped and then finished (the step part is finished), or first cold headed and then finished.

[0061] As shown in Figure 1 , Figure 2 , Figure 5 and Figure 6 , the opening of the accommodating cavity 201 has a riveting flange 241, and the adapter 20 is riveted with the silencing part 30. In this way, the silencing part 30 is riveted by the riveting flange 241, which is convenient to design and process and has reliable limiting effect, and is beneficial to improve the installation efficiency.

[0062] In the embodiment, the riveting flange 241 is an annular flange, or the riveting flange 241 is multiple, and the multiple riveting flanges 241 are distributed along the circumference of the adapter 20. In this way, the reliability and stability of the limiting installation of the silencing part 30 are ensured.

[0063] As shown in Figure 6As shown, the adapter 20 includes a fixed section 24, an accommodating cavity 201 is formed around the fixed section 24, and an opening side of the fixed section 24 in the axial direction of the fixed section 24 forms a riveting flange 241 of the sound attenuation portion 30. In this way, the accommodating cavity 201 and the riveting flange 241 are integrally formed, which facilitates processing and installation.

[0064] Preferably, the accommodating cavity 201 includes a first limiting cavity section 2011 and a second limiting cavity section 2012 that are in communication with each other, the second limiting cavity section 2012 is located on a side of the accommodating cavity 201 away from the first connecting pipe 41 along the axial direction of the electronic expansion valve, the first limiting cavity section 2011 is located on a side of the accommodating cavity 201 close to the first connecting pipe 41, and the radial dimension of the second limiting cavity section 2012 is smaller than the radial dimension of the first limiting cavity section 2011. Specifically, as shown in Figure 2 and Figure 5 As shown, the sound attenuation portion 30 includes a first sound attenuation block 31, a spacer 32, and a second sound attenuation block 33 that abut in sequence along the installation direction of the sound attenuation portion 30, the outer diameter of the first sound attenuation block 31 is adapted to the inner diameter of the first limiting cavity section 2011, the first sound attenuation block 31 is arranged in the first limiting cavity section 2011 and limited by the inner wall of the first limiting cavity section 2011, the outer diameter of the second sound attenuation block 33 is adapted to the inner diameter of the second limiting cavity section 2012, and the second sound attenuation block 33 is arranged in the second limiting cavity section 2012 and limited by the inner wall of the second limiting cavity section 2012. In this way, the first sound attenuation block 31 and the second sound attenuation block 33 can be distinguished, the installation sequence is prevented from being mistaken, the installation positions of the two sound attenuation blocks are prevented from being confused, and the installation efficiency of the sound attenuation portion 30 is improved. Preferably, the spacer 32 in the embodiment is in a ring structure.

[0065] It can be understood that the installation direction of the sound attenuation portion 30 is a direction parallel to the axial direction of the electronic expansion valve when the sound attenuation portion 30 is installed in the accommodating cavity 201, and the installation direction in the embodiment is the axial direction of the electronic expansion valve in which the first limiting cavity section 2011 faces the second limiting cavity section 2012.

[0066] The first sound attenuation block 31 and the second sound attenuation block 33 are provided with flow-through regions and decomposition regions, at least part of the flow-through regions provided on the first sound attenuation block 31 correspond to the decomposition regions provided on the second sound attenuation block 33, and at least part of the flow-through regions provided on the second sound attenuation block 33 correspond to the decomposition regions provided on the first sound attenuation block 31.

[0067] Preferably, in the axial direction of the electronic expansion valve, the height of the first silencing block 31 is H31, the height of the pad block 32 is H32, and the height of the second silencing block is H33. (H31+H32+H33) is the overall height of the silencing part 30 in the axial direction of the electronic expansion valve. The height of the first limiting cavity section 2011 is H62, and the height of the second limiting cavity section 2012 is H61. (H61+H62) is the overall height of the receiving cavity 201 in the axial direction of the electronic expansion valve. Wherein, H61≤H33, that is, along the axial direction of the electronic expansion valve, the second silencing block 33 is not lower than the opening of the second limiting cavity section 2012. Specifically, H61 < H33, meaning the second silencing block 33 protrudes from the opening of the second limiting cavity section 2012; or H61 = H33, meaning the second silencing block 33 is flush with the surface where the opening of the second limiting cavity section 2012 is located, to ensure the contact effect between the pad block 32 and the second silencing block 33. Preferably, H61 < H33, and preferably 0.01mm ≤ (H33 - H61) ≤ 0.7mm. On the other hand, (H31 + H32 + H33) < (H61 + H62) to ensure the forming of the riveting flange 241.

[0068] It is understood that (H61+H62) in this embodiment is the actual height of the fixed section 24 after the riveting flange 241 of the fixed section 24 is riveted to the silencing part 30, which is smaller than the initial height of the fixed section 24 before riveting.

[0069] In this embodiment, the valve seat portion 10 also has a limiting cavity 1011, and the transition portion 20 includes a fixed section 24 and a mating section connected to each other. The fixed section 24 and at least part of the mating section are disposed in the limiting cavity 1011. The inner diameter of the fixed section 24 is larger than the inner diameter of the mating section. There is an inner stepped surface 204 between the inner wall of the cavity of the fixed section 24 and the inner wall of the cavity of the mating section. The silencing portion 30 abuts against the inner stepped surface 204.

[0070] This configuration limits the installation depth of the muffler 30 through the inner stepped surface 204, thereby clamping both ends of the muffler 30 along the axial direction of the electronic expansion valve between the inner stepped surface 204 and the riveted flange 241. On the other hand, the limiting cavity 1011 facilitates the limiting installation of the adapter 20, ensuring the reliability of the installation of the adapter 20.

[0071] like Figures 1 to 15 As shown, the valve seat portion 10 includes a valve seat 11 and a valve seat core 12. The valve seat 11 has a mounting cavity 101, and the valve seat core 12 is disposed within the mounting cavity 101. Specifically, the valve seat core 12 is press-fitted into the mounting cavity. The area of ​​the mounting cavity 101 used for mounting the valve seat core 12 forms a placement cavity 1012, and the area of ​​the mounting cavity 101 used for mounting the adapter portion 20 forms a limiting cavity 1011. This arrangement facilitates the division of the limiting cavity 1011 and the installation of the valve seat core 12.

[0072] And in this embodiment, the valve seat 11 and the valve seat core 12 are provided separately, and the valve seat core 12 is press-fitted in the placement cavity 1012 of the valve seat 11; or in other embodiments not shown in the figure, the valve seat 11 and the valve seat core 12 can also be formed as an integrated structure to form the valve seat part 10.

[0073] The valve seat core 12 of the valve seat part 10 also has a valve port cavity 102, which is located on the side of the containing cavity 201 away from the adapter part 20, and the valve port cavity 102 communicates with the containing cavity 201. It should be noted that in a series reheating dehumidification system, the electronic expansion valve is arranged between two indoor side heat exchangers, which determines that the pressure drop of the electronic expansion valve at a large opening degree should be as small as possible in a normal air conditioning working condition to ensure the energy efficiency of the air conditioning system, and the noise requirement of the indoor side is relatively high. Therefore, a sound attenuation structure (corresponding to the sound attenuation part 30 in this embodiment) needs to be arranged at the valve port (corresponding to the valve port cavity 102 in this embodiment). In order to reduce the throttling of the porous sound attenuation structure, the area of the porous sound attenuation structure can be increased and a large-diameter electronic expansion valve can be used. In related technologies, the one end of the connecting pipe (corresponding to the first connecting pipe 41 in this embodiment) directly extends into the valve seat (corresponding to the valve seat 11 in this embodiment) and directly abuts against the sound attenuation part 30. The one end of the connecting pipe extending into the valve seat needs to have a relatively large outer diameter. In addition, in a series reheating dehumidification system, the electronic expansion valve is mainly used in 1-3P units, and the inner diameter of the corresponding indoor heat exchanger connecting pipeline is relatively small compared with that of a 3P or more unit. The other end of the electronic expansion valve connecting pipe is connected with the indoor heat exchanger connecting pipeline, which determines that the inner diameter of the other end of the connecting pipe is relatively small. The diameters of the two ends of the electronic expansion valve connecting pipe are inconsistent and the span is relatively large. The scheme of using the connecting pipe to abut against the sound attenuation mechanism makes the connecting pipe consist of three or more different pipe diameters. Such a connecting pipe is difficult to process and has a high cost.

[0074] To solve the above problems, in the embodiment, the adapter section includes a first adapter section 21 and a second adapter section 22 connected to each other, the first adapter section 21 is connected to the fixed section 24, at least part of the first adapter section 21 extends into the limiting cavity 1011, at least part of the second adapter section 22 is located outside the limiting cavity 1011 for connecting the first connecting pipe 41, the outer diameter of the first adapter section 21 and the outer diameter of the fixed section 24 are both greater than the outer diameter of the second adapter section 22, preferably, the outer diameter of the first adapter section 21 is equal to or slightly greater than the outer diameter of the fixed section 24; the inner diameter of the first adapter section 21 is greater than the inner diameter of the second adapter section 22. By limiting the size (inner diameter and outer diameter) of the first adapter section 21 and the second adapter section 22, the adapter section 20 can be adapted to valve seat sections 10 of different sizes, at the same time, the reduction of the radial size of the second adapter section 22 is equivalent to that the adapter section 20 itself forms a reduced opening, so the end of the first connecting pipe 41 connected to the adapter section 20 also does not need to be reduced in diameter to adapt to the valve seat section 10 with a large diameter, only the appropriate raw material needs to be selected according to the diameter of the electronic expansion valve to process the first connecting pipe 41, so as to reduce the processing difficulty of the first connecting pipe 41 and improve the processing efficiency.

[0075] It can be understood that the other end of the first connecting pipe 41 is connected to the system pipeline, the other end of the first connecting pipe 41 connected to the system pipeline is reduced in diameter, expanded in diameter or not processed according to the actual situation, compared with the case that the first connecting pipe 41 is directly connected to the valve seat section 10 in the prior art, the end of the first connecting pipe 41 connected to the electronic expansion valve saves at least one expanding process through the adapter section 20.

[0076] Preferably, at least part of the outer wall of the valve seat core 12 is in interference fit with the inner wall of the placing cavity 1012, and at least part of the outer wall of the adapter section 20 extending into the limiting cavity 1011 is in interference fit with the inner wall of the limiting cavity 1011.

[0077] Specifically, as shown in Figures 1 to 9In the shown first embodiment, the valve seat core 12 comprises a first loose fit section 121 and a first tight fit section 122 connected to each other. In this embodiment, the first tight fit section 122, the fixed section 24 and the first fit section 21 are straight cylinder sections. The outer diameter of the first loose fit section 121 gradually decreases in the direction of the first connecting pipe 41 towards the valve port cavity 102. At least part of the first tight fit section 122 and the inner wall of the placement cavity 1012 are in interference fit. The first fit section 21 extends into the limiting cavity 1011, and part or all of the outer wall of the first fit section 21 is in interference fit with the inner wall of the limiting cavity 1011. By providing the first loose fit section 121, the insertion of the valve seat core 12 during installation is facilitated, and the difficulty of press fitting caused by the excessive length of the tight fit interference section is avoided. Further, in this embodiment, the inner diameters of the placement cavity 1012 and the limiting cavity 1011 are the same, being D1. The outer diameters of the first tight fit section 122, the fixed section 24 and the first fit section 21 are the same, being D2. D2 = D1 or D2 is slightly larger than D1, so as to ensure the interference fit of the first tight fit section 122 in the installation cavity 101 and the coaxiality requirement during installation. Preferably, D2 is slightly larger than D1.

[0078] Preferably, as shown in the second embodiment of the present application, Figures 10 to 12 the electronic expansion valve is different from the first embodiment in that, as shown in the second embodiment of the present application, Figure 9 the inner diameter D11 of the placement cavity 1012 is smaller than the inner diameter D12 of the limiting cavity 1011, as shown in the second embodiment of the present application, Figure 11 the outer diameter of the first loose fit section 121 is D21, the outer diameter of the first tight fit section 122 is D22, the outer diameter of the fixed section 24 is D23, and the outer diameter of the first fit section 21 is D24. D21 is smaller than D11, D23 is smaller than D12, D22 is equal to D11 or slightly larger than D11, and D24 is equal to D12 or slightly larger than D12, so as to ensure the reliability of the interference fit and the coaxiality requirement during installation.

[0079] It can be understood that the interference length between the valve seat core 12 or the adapter 20 and the installation cavity 101 can be adjusted according to actual conditions.

[0080] In this embodiment, the bottom wall of the first fit section 21 is an outer stepped surface 202, which is located between the outer walls of the first fit section 21 and the second fit section 22. As shown in the second embodiment of the present application, Figure 12 the outer stepped surface 202 between the outer wall of the first fit section 21 and the outer wall of the second fit section 22 protrudes out of the limiting cavity 1011 and forms a positioning reference surface, or, as shown in the second embodiment of the present application, Figure 3As shown, the outer stepped surface 202 between the outer wall of the first fitting section 21 and the outer wall of the second fitting section 22 is flush with the surface where the opening of the limiting cavity 1011 is located and forms a positioning reference surface. By such arrangement, compared with the case where the valve seat part 10 is directly connected with the first connecting pipe 41 and the end surface of the valve seat part 10 opening towards the one end of the first connecting pipe 41 is used as the positioning reference surface, the area of the positioning reference surface is increased, and due to the arrangement of the adapter part 20, the placement position of the welding ring for furnace welding of the first connecting pipe 41 is far away from the positioning reference surface, and during furnace welding, the situation that the molten solder is laid on the positioning reference surface to cause insufficient positioning reference dimension and inaccurate positioning does not occur, the influence on the positioning reference is almost none, and the positioning during the subsequent assembly and welding is not affected.

[0081] The adapter part 20 and the valve seat part 10 and the adapter part 20 and the first connecting pipe 41 can be connected respectively by welding, specifically, the adapter part 20 and the valve seat part 10 can be connected by laser welding, and the adapter part 20 and the first connecting pipe 41 can be connected by furnace welding, brazing or other welding methods. In the embodiment, the adapter part 20 and the valve seat part 10 are connected by laser welding, and the adapter part 20 and the first connecting pipe 41 are connected by furnace welding, as shown in Figure 3 As shown in Figure 12 As shown, the bottom of the first fitting section 21 and the bottom of the valve seat 11 where the opening of the limiting cavity 1011 is located form an annular welding seam, and by such arrangement, the situation that the second connecting pipe 42 interferes with the welding when the laser welding position is formed on the side surface of the electronic expansion valve is avoided.

[0082] The bottom wall of the first fitting section 21 can be flush with the bottom wall of the valve seat 11; specifically, in Figures 1 to 9In the shown first embodiment, the sound attenuation part 30 is riveted in the fixing section 24, the valve seat core 12 is press-fitted on the bottom wall of the placing cavity 1012, the end of the fixing section 24 extending into the valve seat 11 abuts against the valve seat core 12, in the axial direction of the electronic expansion valve, the height of the installation cavity 101 is H1, the sum of the height of the valve seat core 12, the height of the first matching section 21 of the adapter part 20 and the height of the fixing section 24 of the adapter part 20 is H2 (wherein the height of the fixing section 24 is the actual height after the riveting flange 241 is riveted to the sound attenuation part 30, i.e. H61+H62), H1=H2, the bottom wall of the first matching section 21 is flush with the bottom wall of the valve seat 11, further, in order to avoid the case that the height of the laser welding trace after welding is too high, the bottom wall of the first matching section 21 and / or the bottom wall of the valve seat 11 has an annular groove 1 at the annular welding seam, the area in the annular groove 1 can be used as the annular welding seam, the laser welding trace after welding formed by welding will be all or most of located in the annular groove 1, realizing the hiding of the laser welding trace after welding, so that the laser welding trace after welding formed by laser welding will not protrude from the positioning reference surface or the part protruding from the positioning reference surface has little effect on the positioning reference effect of the positioning reference surface, and will not affect the positioning during the subsequent assembly and welding, so as to ensure the reliability of welding and the reliability of the positioning reference surface.

[0083] Preferably, the cross-sectional shape of the annular groove 1 can be adaptively adjusted according to actual conditions, and is not limited to the triangle of the embodiment.

[0084] The bottom wall of the first matching section 21 can protrude from the bottom wall of the valve seat 11, so that the bottom wall of the first matching section 21 and the bottom wall of the valve seat 11 have a spacing in the axial direction, facilitating the focusing of laser welding. Specifically, in the shown embodiment, the bottom wall of the first matching section 21 is flush with the bottom wall of the valve seat 11. Figures 10 to 12In the shown second embodiment, the silencing part 30 is riveted in the fixed section 24, the valve seat core 12 is press-fitted on the bottom wall of the placement cavity 1012, the end of the fixed section 24 extending into the valve seat 11 abuts against the valve seat core 12, and in the axial direction of the electronic expansion valve, the height of the installation cavity 101 is less than the sum of the heights of the valve seat core 12, the first fitting section 21 of the adapter part 20 and the fixed section 24 of the fixed section 24, i.e. the bottom wall of the first fitting section 21 protrudes from the bottom wall of the valve seat 11. Specifically, the height of the placement cavity 1012 is H11, the height of the limiting cavity 1011 is H12, the height of the installation cavity 101 is H1, H1 = H11 + H12, the sum of the heights of the valve seat core 12, the first fitting section 21 of the adapter part 20 and the fixed section 24 of the fixed section 24 is H2 (wherein the height of the fixed section 24 is the actual height after the riveting of the riveting flange 241 to the silencing part 30, i.e. H61 + H62), H1 < H2, and the bottom wall of the first fitting section 21 protrudes from the bottom wall of the valve seat 11. In this case, the positioning reference surface is spaced from the position of the weld, which facilitates the focusing of the laser welding at this position. Herein, the height of the bottom wall of the first fitting section 21 protruding from the bottom wall of the valve seat 11 is H8, H8 = H2 - H1, 0.1 mm < H8 < 1 mm. By limiting H8, the laser welding trace formed by the laser welding after welding will not protrude from the positioning reference surface or the protruding part will have little effect on the positioning reference effect of the positioning reference surface, which will not affect the positioning during the subsequent assembly and welding.

[0085] It can be understood that the fixing manner of the silencing part 30 in the adapter part 20 of the present application is not limited to riveting, and the silencing part 30 can be directly fixed in the adapter part 20 by laser welding or protruding from the first silencing block 31 of the silencing part 30, and the protruding part of the first silencing block 31 abuts against the valve seat part 10 along the end of the first connecting pipe 41 away from the electronic expansion valve in the axial direction.

[0086] As shown in Figure 1 , Figure 2 , Figure 5 and Figure 11 , the adapter part 20 has a ring-shaped stop protrusion 23, which is arranged between the first fitting section 21 and the second fitting section 22 and protrudes inward in the radial direction, the inner diameter of the ring-shaped stop protrusion 23 is less than the inner diameter of the second fitting section 22, the area surrounded by the ring-shaped stop protrusion 23 forms an adapter port 203, one end of the first connecting pipe 41 is arranged in the second fitting section 22 and abuts against the ring-shaped stop protrusion 23, and the adapter port 203 is in communication with the opening of the first connecting pipe 41. In this embodiment, one end of the first connecting pipe 41 penetrates into the second fitting section 22 and abuts against the ring-shaped stop protrusion 23, the penetration depth of the first connecting pipe 41 is limited by the ring-shaped stop protrusion 23, and the outer diameter of the first connecting pipe 41 is adapted to the inner diameter of the second fitting section 22.

[0087] In the embodiment, the inner diameter of the first connecting pipe 41 is adapted to the radial dimension of the adapter 203, facilitating the limited installation of the first connecting pipe 41 and the molding of the adapter 203, and at the same time, realizing the smooth transition of the refrigerant flowing through the adapter 203 and the first connecting pipe 41, and reducing the refrigerant flow noise.

[0088] The adapter 203 is a straight section with a constant inner diameter along the axis of the electronic expansion valve, or the adapter 203 is a first trumpet, or the adapter 203 has a first trumpet on the side away from the first connecting pipe 41, the inner diameter of the first trumpet gradually increases along the direction of the first connecting pipe 41 towards the valve port cavity 102, the side with a smaller opening of the first trumpet is in communication with the first connecting pipe 41 and the radial dimension is adapted to the inner diameter of the first connecting pipe 41, the opening angle of the first trumpet is β, and 20°≤β≤120°. Figure 5 and Figure 11 As shown in FIGS. 1, 2 and 3, the adapter 203 in the embodiment comprises a first trumpet and a straight section in communication with each other. By providing the first trumpet, on the one hand, it can be ensured that there is no burr (the adapter 20 is a finished product, and burrs are prone to occur when the straight section is formed); on the other hand, the side wall of the valve seat 11 of the electronic expansion valve is also connected with the second connecting pipe 42. In the case where the fluid flows from the first connecting pipe 41 to the second connecting pipe 42, since the inner diameter of the first trumpet gradually increases along the direction of the first connecting pipe 41 towards the valve port cavity 102, it provides a buffering effect for the fluid entering from the first connecting pipe 41, and vortex is not prone to occur, thereby realizing pressure gradient, reducing flow rate, reducing the impact of high-speed fluid on the filter screen, i.e., reducing the flow rate of the refrigerant entering the valve port position, reducing the turbulent kinetic energy and thus reducing the noise.

[0089] Preferably, the height of the first trumpet is H7, and 0.1mm≤H7≤3mm. The inner diameter of the small opening of the first trumpet close to the first connecting pipe 41 is as same as the inner diameter of the first connecting pipe 41 as possible, and the difference therebetween is not more than 5%.

[0090] Specifically, the flow curve of the electronic expansion valve provided in the embodiment is designed as a broken line type with an acute opening and a flow turning point. At a small opening degree, the flow is flat and the flow value is small, so as to meet the adjustment under the dehumidification working condition. At a large opening degree, the flow is large, so as to meet the flow capacity under the normal air conditioning working condition and reduce the pressure drop.

[0091] The valve cavity 102 includes a valve port section 1021 and a flared section 1022 that are interconnected. The valve port section 1021 has a flow regulating section, which is connected to the receiving cavity 201 through the flared section 1022. The electronic expansion valve also includes a valve needle assembly 60. The flow regulating section is located at one end of the valve port section 1021 near the valve needle assembly 60. The valve needle assembly 60 includes a valve head 61, which can move closer to or further away from the valve cavity 102 along the axial direction of the electronic expansion valve and cooperate with the flow regulating section to regulate the flow rate of the electronic expansion valve. It should be noted that the electronic expansion valve provided in this embodiment is a fully closed flow-line type. When the entire valve is in the fully closed state, there is a gap between the outer periphery of the valve head 61 and the inner wall of the valve port section 1021. The refrigerant can flow through the gap between the two connecting pipes (the first connecting pipe 41 and the second connecting pipe 42). At this time, the electronic expansion valve has a flow rate, and the flow rate value is greater than the internal leakage rate specified by the industry standard for the corresponding diameter. It is understandable that the flow rate when fully closed is achieved by moving the valve head 61 axially upward after finding the zero point with a fixed pulse, and the flow rate when fully closed is achieved through the gap between the valve head 61 and the valve port section 1021 when fully closed.

[0092] like Figures 6 to 9 In the first embodiment shown, the valve needle assembly 60 further includes a screw member 62, and the electronic expansion valve further includes a rotor assembly 80 for driving the screw member 62. The inner wall of the valve port section 1021 of this application has a first conical section 10211 and a first straight-through section 10212 that are interconnected and sequentially arranged along the direction from the valve mouth 102 toward the first connecting pipe 41. The first conical section 10211 is a flow regulating section, and the first straight-through section 10212 communicates with the flared section 1022. The valve head member 61 cooperates with the inner wall of the first conical section 10211 to regulate the flow rate of the electronic expansion valve. The height of the first conical section 10211 is H5. When the electronic expansion valve is fully closed, the valve… The distance H9 between the end of the head member 61 and the connecting surface of the first conical section 10211 and the first straight section 10212 is given by the electronic expansion valve. During the valve opening process, the electronic expansion valve has a flow inflection point where the flow slope changes. This flow inflection point is the point where the end of the valve head member 61 facing the valve cavity 102 just disengages from the first conical section 10211; B*n*γ / 360+H9=H5; where B is the number of supply pulses required for the valve head member 61 to move from the fully closed position away from the valve cavity 102 and open until it just disengages from the first conical section 10211 (flow inflection point), n is the pitch of the screw member 62, and γ is the step angle of the rotor assembly 80. For example... Figures 7 to 9As shown, in the present embodiment, the full-closing position is located on the first tapered section 10211, that is, when the electronic expansion valve is in the full-closing position, the end of the valve head piece 61 towards the one end of the valve port cavity 102 is located in the first tapered section 10211 and above the first straight-through section 10212, and there is a gap between the valve head piece 61 and the inner wall of the first tapered section 10211, and the flow curve has no flat section after 0 pulse, and directly has a slope upward from 0 pulse.

[0093] The flow regulating section as a whole is a second trumpet mouth, and the side with a larger opening of the second trumpet mouth is arranged away from the first connecting pipe 41. In the present embodiment, the first tapered section 10211 is the second trumpet mouth, and the opening angle of the second trumpet mouth is a, and 1°≤a≤10°. The slope of the broken line before and after the flow turning point is different, the flow curve before the flow turning point is gentle, the slope of the broken line after the flow turning point is larger, the corresponding flow is large, and the flow resistance is small when the electronic expansion valve is fully opened. The flow requirement is small under the dehumidification condition, and the angle is too large to cause the flow to be too large at a small opening, which cannot meet the requirement of the whole machine under the dehumidification condition, and the angle is too small to interfere with the outer diameter of the valve head piece 61. By limiting the angle a, the flow value and stability of the electronic expansion valve at a small opening can be ensured. Preferably, 1°≤a≤6°, and the required supply pulse number of the valve head piece 61 from the full-closing position to the flow turning point can be realized by setting the height H5 of the first tapered section 10211, and H5 can be customized according to the requirement of the whole machine of the customer (to ensure that the turning point of the flow curve is between 300P-400P under normal conditions). Specifically, 2.5mm≤H5≤7mm.

[0094] Wherein, the unit of B is pulse or step, and the value of B can be customized according to the requirement of the customer, and the height H5 of the corresponding first tapered section 10211 can be determined after the value of B is determined; it can be understood that, as Figure 7 As shown in the embodiment I, the maximum diameter of the first tapered section 10211 is D41, the minimum diameter of the first tapered section 10211 is the same as the diameter of the first straight-through section 10212 and is D2, and a or H5 can be calculated by tan a / 2 = [(D41-D42) / 2] / H5, and the unit of n is mm; γ is related to the number of magnetic poles of the valve body, 1-2 phase excitation, rotor 10 against magnetic pole, step angle γ = 4.5°; 1-2 phase excitation, rotor 12 against magnetic pole, step angle γ = 3.75°; 2-2 phase excitation, rotor 10 against magnetic pole, step angle γ = 9°; 2-2 phase excitation, rotor 12 against magnetic pole, step angle γ = 7.5°; and γ / 360 is the number of pulses required for the valve head to rotate one circle.

[0095] As shown in the embodiment I, the maximum diameter of the first tapered section 10211 is D41, the minimum diameter of the first tapered section 10211 is the same as the diameter of the first straight-through section 10212 and is D2, and a or H5 can be calculated by tan a / 2 = [(D41-D42) / 2] / H5, and the unit of n is mm; γ is related to the number of magnetic poles of the valve body, 1-2 phase excitation, rotor 10 against magnetic pole, step angle γ = 4.5°; 1-2 phase excitation, rotor 12 against magnetic pole, step angle γ = 3.75°; 2-2 phase excitation, rotor 10 against magnetic pole, step angle γ = 9°; 2-2 phase excitation, rotor 12 against magnetic pole, step angle γ = 7.5°; and γ / 360 is the number of pulses required for the valve head to rotate one circle. Figures 13 to 15As shown, the third embodiment of the present application provides an electronic expansion valve, which is different from the first embodiment in that the inner wall of the valve port section 1021 has sequentially connected first tapered section 10211, first straight section 10212, second tapered section 10213 and second straight section 10214 in the direction of the valve port cavity 102 towards the first connecting pipe 41.

[0096] In this embodiment, when the electronic expansion valve is in the full-closed state, the end of the valve head piece 61 is located in the first straight section 10212, and there is a gap between the outer periphery of the valve head piece 61 and the first straight section 10212, at this time, the first tapered section 10211 functions as the flow rate regulating section, and the following second tapered section 10213 does not function as the flow rate regulating section. Specifically, the first tapered section 10211 is the flow rate regulating section, and in the full-closed position, the end of the valve head piece 61 towards the one end of the valve port cavity 102 is located in the first straight section 10212, the height of the first tapered section 10211 is H5, the depth of the valve head piece 61 extending into the first straight section 10212 is H9, and then B*n*γ / 360-H9=H5. As shown in the figure, the flow rate curve has a flat section after 0 pulse, and then starts to have a slope upwards after the flat section. Figures 13 to 15 As shown, in this embodiment, the full-closed flow rate is achieved through the gap between the valve head piece 61 and the first straight section 10212, and the full-closed position is located in the first straight section 10212. Since in this embodiment, the outer wall of the part of the valve head piece 61 extending into the valve port cavity 102 is a straight section, the size of the gap between the outer wall of the valve head piece 61 and the inner wall of the first straight section 10212 does not change during the movement of the valve head piece 61 from the full-closed position to the direction away from the valve port cavity 102, and therefore, the flow rate curve has a flat section after 0 pulse, and then starts to have a slope upwards after the flat section. Since the full-closed position is located in the first straight section 10212, the gap between the valve head piece 61 and the straight section can be controlled to be smaller in the full-closed state, and the risk of the valve head piece 61 and the valve port section 1021 being stuck is smaller, so as to achieve the regulation of smaller flow rate in the dehumidification working condition. In this embodiment, the second tapered section 10213 is used for the pulse setting of the electronic expansion valve, that is, during the installation of the electronic expansion valve, the valve head piece 61 and the second tapered section 10213 are first abutted, and then the valve head piece 61 is moved axially by a certain distance, so that the end surface of the valve head piece 61 towards the one end of the valve port cavity 102 enters the first straight section 10212.

[0097] As shown, in this embodiment, the full-closed flow rate is achieved through the gap between the valve head piece 61 and the first straight section 10212, and the full-closed position is located in the first straight section 10212. Since in this embodiment, the outer wall of the part of the valve head piece 61 extending into the valve port cavity 102 is a straight section, the size of the gap between the outer wall of the valve head piece 61 and the inner wall of the first straight section 10212 does not change during the movement of the valve head piece 61 from the full-closed position to the direction away from the valve port cavity 102, and therefore, the flow rate curve has a flat section after 0 pulse, and then starts to have a slope upwards after the flat section. Since the full-closed position is located in the first straight section 10212, the gap between the valve head piece 61 and the straight section can be controlled to be smaller in the full-closed state, and the risk of the valve head piece 61 and the valve port section 1021 being stuck is smaller, so as to achieve the regulation of smaller flow rate in the dehumidification working condition. In this embodiment, the second tapered section 10213 is used for the pulse setting of the electronic expansion valve, that is, during the installation of the electronic expansion valve, the valve head piece 61 and the second tapered section 10213 are first abutbed, and then the valve head piece 61 is moved axially by a certain distance, so that the end surface of the valve head piece 61 towards the one end of the valve port cavity 102 enters the first straight section 10212. Figure 14 and Figure 15 As shown, in this embodiment, the full-closed flow rate is achieved through the gap between the valve head piece 61 and the first straight section 10212, and the full-closed position is located in the first straight section 10212. Since in this embodiment, the outer wall of the part of the valve head piece 61 extending into the valve port cavity 102 is a straight section, the size of the gap between the outer wall of the valve head piece 61 and the inner wall of the first straight section 10212 does not change during the movement of the valve head piece 61 from the full-closed position to the direction away from the valve port cavity 102, and therefore, the flow rate curve has a flat section after 0 pulse, and then starts to have a slope upwards after the flat section. Since the full-closed position is located in the first straight section 10212, the gap between the valve head piece 61 and the straight section can be controlled to be smaller in the full-closed state, and the risk of the valve head piece 61 and the valve port section 1021 being stuck is smaller, so as to achieve the regulation of smaller flow rate in the dehumidification working condition. In this embodiment, the second tapered section 10213 is used for the pulse setting of the electronic expansion valve, that is, during the installation of the electronic expansion valve, the valve head piece 61 and the second tapered section 10213 are first abutbed, and then the valve head piece 61 is moved axially by a certain distance, so that the end surface of the valve head piece 61 towards the one end of the valve port cavity 102 enters the first straight section 10212.

[0098] Of course, in other embodiments of the application not shown in the drawings, the valve seat core 12 and the valve seat 11 can also be formed as an integrated valve seat portion 10, and the valve port cavity 102 is located in the integrated valve seat portion 10, and the valve port cavity 102 has the aforementioned valve port section 1021. In this embodiment, in addition to the valve seat core 12 and the valve seat 11 being integrally arranged, the other full-flow implementation and flow curve are the same as the aforementioned embodiment, and will not be described again here.

[0099] It can be understood that, according to the position of the end of the valve head piece 61 when the valve is closed (including but not limited to the first tapered section 10211, the first straight section 10212, the second tapered section 10213, and the second straight section 10214 in the present embodiment), the formula of tan a / 2 and the formula between H5 and H9 can be correspondingly adjusted adaptively, and examples will not be given one by one here.

[0100] Specifically, when the electronic expansion valve is in the full open mode, the flow coefficient Cv≥1, wherein, V is the maximum flow of the electronic expansion valve, G is the specific gravity of the medium flowing in the electronic expansion valve, P1 is the pressure on the inflow side of the electronic expansion valve, and P2 is the pressure on the outflow side of the electronic expansion valve. The Cv value is the flow coefficient of the electronic expansion valve, which represents the flow capacity of the electronic expansion valve provided by the application when it is fully open. When the Cv value is less than 1, it will affect the flow capacity of the fluid, i.e. the electronic expansion valve will still throttle the fluid flowing through it when it is fully open, which means that the flow capacity of the electronic expansion valve in the fully open state is not enough, affecting the fluid flow between the indoor side heat exchangers and thus affecting the overall performance. By setting Cv≥1 in the present application, the flow capacity of the electronic expansion valve can be guaranteed to ensure that the valve meets the overall performance requirements when used in normal working conditions of the air conditioner.

[0101] Another embodiment of the present application provides an assembling process applied to the electronic expansion valve described above, the electronic expansion valve further comprising a second connecting pipe 42, a nut assembly 50, a valve needle assembly 60 and a guide sleeve 70, the assembling process comprising: welding one end of the second connecting pipe 42 to a side of the valve seat part 10; welding the first connecting pipe 41 to an end of one end of the adapter part 20; installing the silencing part 30 in the adapter part 20, installing a part of the adapter part 20 in the valve seat part 10, welding the adapter part 20 to the valve seat part 10, sequentially installing the nut assembly 50 and the valve needle assembly 60 on the valve seat part 10; and before sequentially installing the nut assembly 50 and the valve needle assembly 60 on the valve seat part 10, the process of welding one end of the second connecting pipe 42 to the side of the valve seat part 10 further comprises: first press-fitting the guide sleeve 70 in the valve seat part 10, integrally furnace welding the second connecting pipe 42, the valve seat part 10 and the guide sleeve 70, or first furnace welding the second connecting pipe 42 and the valve seat part 10, then press-fitting the guide sleeve 70 in the valve seat part 10, laser welding the guide sleeve 70 and the valve seat part 10, and pulsing the electronic expansion valve. In this way, the independent out-of-line installation of the adapter part 20 and the silencing part 30 can be realized, which is conducive to reducing the production rhythm, improving the standardization of parts, avoiding the risk of falling during the turnover of parts, facilitating the assembly of the electronic expansion valve, and being conducive to improving the assembly efficiency.

[0102] Preferably, the end of one end of the adapter part 20 is an end of the adapter part 20 located outside the valve seat part 10, and the first connecting pipe 41 is welded to the end of the adapter part 20 located outside the valve seat part 10.

[0103] Preferably, the order of the step of welding one end of the second connecting pipe 42 to the side of the valve seat part 10, the step of welding the first connecting pipe 41 to the end of one end of the adapter part 20, and the step of installing the silencing part 30 in the adapter part 20 is not limited.

[0104] Specifically, the silencing part 30 comprises a first silencing block 31, a spacer 32 and a second silencing block 33 abutting in sequence along the installation direction of the silencing part 30, and the process of installing the silencing part 30 in the adapter part 20 further comprises: sequentially installing the second silencing block 33, the spacer 32 and the first silencing block 31 in the adapter part 20.

[0105] Similarly, the first connecting pipe 41 is also welded to the end of the adapter part 20 located outside the valve seat part 10 first, and then the silencing part 30 is installed in the adapter part 20; or, the silencing part 30 is installed in the adapter part 20 first, and then the adapter part 20 and the first connecting pipe 41 are welded.

[0106] Further, in the present embodiment, the valve seat part 10 comprises a split valve seat 11 and a valve seat core 12, and the assembling process further comprises the step of arranging the valve seat core 12 in the valve seat 11, and the end of the adapter part 20 extending into the valve seat 11 abuts against the valve seat core 12.

[0107] It can be understood that in another embodiment of the other not shown figure, the valve seat part 10 comprises an integrated valve seat 11 and valve seat core 12, at which time there is no need to include the installation step of the valve seat core 12. Or in another embodiment of the other not shown figure, the valve seat part 10 comprises a split valve seat 11 and valve seat core 12, and the silencer part 30 abuts against the valve seat core 12.

[0108] In the embodiment, the adapter part 20 and the valve seat part 10 are laser welded.

[0109] Preferably, the guide sleeve 70 in the embodiment is small at the top and large at the bottom, the nut assembly 50 comprises a nut part, the guide sleeve 70 comprises a first sleeve 71, a limiting sleeve 73 and a second sleeve 72 connected in sequence, the limiting sleeve 73 is used to limit the position of the guide sleeve 70 in the valve seat 11, the outer diameters of the first sleeve 71, the second sleeve 72 and the limiting sleeve 73 increase in sequence, the inner diameters of the first sleeve 71 and the limiting sleeve 73 are the same and larger than the inner diameter of the second sleeve 72, the outer periphery of the second sleeve 72 is in interference fit with the inner hole of the nut part to ensure the coaxiality of the two, the inner cavity of the first sleeve 71 is used to pass through the valve head part 61 and is in clearance fit with the outer periphery of the valve head part 61, and the clearance amount is 0.01mm-0.1mm.

[0110] Since the outer diameter of the current mainstream household 3P split cabinet machine indoor heat exchanger connecting main pipe is mostly Φ9.0 or Φ8.0, taking the outer diameter Φ9.0 as an example, the wall thickness is mostly 0.75mm, that is, the inner diameter is Φ7.5, so the valve port must be >Φ7.5mm to ensure that there is no excessive pressure drop when the valve is fully open, thereby ensuring the performance of the whole machine; preferably, 7mm≤the minimum diameter of the valve port cavity 102≤9.5mm.

[0111] It is to be understood that the terms used herein are for the purpose of describing specific embodiments and are not intended to limit exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise, and it will be further understood that the terms "comprise" and / or "include" when used in this specification, specify the presence of features, steps, operations, devices, components and / or combinations thereof.

[0112] The foregoing is considered as illustrative only of the principles of the application. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the application to the exact construction and practice described. Accordingly, all such variations are intended to be included within the scope of the present application as defined in the following claims, along with full equivalents thereof.

[0113] In the description of the present application, it is to be understood that the orientation or positional relationships indicated by terms such as "front", "back", "up", "down", "left", "right", "lateral", "vertical", "horizontal", "top", "bottom", and the like are generally based on the orientation or positional relationships shown in the drawings, and are merely intended to facilitate the description of the present application and simplify the description, and do not indicate or imply that the device or element must have a particular orientation or be constructed and operated in a particular orientation, and therefore should not be construed as limiting the scope of protection of the present application. The orientation terms "inner", "outer" refer to the inner and outer relative to the contour of the components themselves.

[0114] For the convenience of description, spatial relative terms such as "above", "upper", "top", "up", "lower", "bottom", and the like can be used herein to describe the spatial position relationship of one device or feature with respect to other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device as described in the drawings. For example, if the device in the drawings is inverted, the device described as "above" or "on" other devices or structures will be positioned "below" or "under" the other devices or structures. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0115] In addition, it should be noted that the use of the terms "first", "second", and the like do not have a special meaning, and are used only to facilitate the distinction between corresponding parts, and therefore should not be construed as limiting the scope of protection of the present application.

[0116] The above merely provides the preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. An electronic expansion valve characterized by, The electronic expansion valve comprises a first connecting pipe (41), a sound damping part (30), and a valve seat part (10) and a switching part (20) connected with each other, the switching part (20) is connected with the valve seat part (10) and the first connecting pipe (41) respectively, the switching part (20) has a containing cavity (201), and the sound damping part (30) is limitingly installed in the containing cavity (201).

2. The electronic expansion valve according to claim 1, characterized in that The sound damping part (30) is laser welded in the containing cavity (201), or the sound damping part (30) is riveted in the containing cavity (201), or the sound damping part (30) is press-fitted in the containing cavity (201).

3. The electronic expansion valve according to claim 1, wherein The valve seat part (10) has a limiting cavity (1011), the switching part (20) comprises a matching section, at least part of the matching section is arranged in the limiting cavity (1011), an inner stepped surface (204) is arranged between the cavity inner wall of the containing cavity (201) and the cavity inner wall of the matching section, and the sound damping part (30) abuts against the inner stepped surface (204).

4. The electronic expansion valve according to claim 3, wherein The matching section comprises a first matching section (21) and a second matching section (22) connected with each other, at least part of the first matching section (21) extends into the limiting cavity (1011), at least part of the second matching section (22) is arranged outside the limiting cavity (1011) and is used for switching the first connecting pipe (41), the outer diameter of the first matching section (21) is greater than the outer diameter of the second matching section (22), and the inner diameter of the first matching section (21) is greater than the inner diameter of the second matching section (22).

5. The electronic expansion valve according to claim 4, wherein An outer stepped surface (202) is arranged between the outer wall of the first matching section (21) and the outer wall of the second matching section (22), the outer stepped surface (202) protrudes out of the limiting cavity (1011) or is flush with the surface where the opening of the limiting cavity (1011) is arranged and forms a positioning reference surface.

6. The electronic expansion valve according to claim 4, wherein The switching part (20) has an annular stop protrusion (23) arranged between the first matching section (21) and the second matching section (22) and protruding inward in the radial direction of the switching part (20), the inner diameter of the annular stop protrusion (23) is smaller than the inner diameter of the second matching section (22), an switching interface (203) is formed around the annular stop protrusion (23), one end of the first connecting pipe (41) is arranged in the second matching section (22) and is in stop cooperation with the annular stop protrusion (23), and the switching interface (203) is in communication with the opening of the first connecting pipe (41).

7. The electronic expansion valve according to claim 6, characterized in that The adapter (203) is a straight section with a constant inner diameter along the axial direction of the electronic expansion valve, or the adapter (203) is a first trumpet, or the adapter (203) has a first trumpet on the side away from the first connecting pipe (41), the inner diameter of the first trumpet gradually increases in the direction of the first connecting pipe (41) towards the adapter (203), the side with a smaller opening of the first trumpet is in communication with the first connecting pipe (41) and the radial dimension is adapted to the inner diameter of the first connecting pipe (41), the opening angle of the first trumpet is β, 20°≤β≤120°.

8. The electronic expansion valve according to claim 1, wherein The opening of the accommodating cavity (201) has a riveted flange (241), and the adapter (20) is riveted with the sound reduction part (30).

9. The electronic expansion valve according to claim 8, characterized in that The riveted flange (241) is an annular flange, or the riveted flange (241) is a plurality of riveted flanges (241) distributed along the circumference of the adapter (20).

10. The electronic expansion valve according to claim 8, wherein The adapter (20) includes a fixed section (24), and the area surrounded by the fixed section (24) forms the accommodating cavity (201); in the axial direction of the fixed section (24), the opening side of the fixed section (24) protrudes from the part of the sound reduction part (30) to form the riveted flange (241).

11. The electronic expansion valve according to claim 1, wherein The valve seat part (10) includes a valve seat (11) and a valve seat core (12), the valve seat (11) has a mounting cavity (101), the valve seat core (12) is arranged in the mounting cavity (101), the area of the mounting cavity (101) for mounting the valve seat core (12) forms a placement cavity (1012), and the area of the mounting cavity (101) for mounting the adapter (20) forms a limiting cavity (1011).

12. The electronic expansion valve according to claim 11, wherein The valve seat core (12) is separate from the valve seat (11), and the valve seat core (12) is arranged in the placement cavity (1012) of the valve seat (11); or the valve seat core (12) and the valve seat (11) are an integral structure.

13. The electronic expansion valve of claim 1, wherein, The valve seat part (10) has a valve port cavity (102) on the side away from the adapter (20) of the accommodating cavity (201), the valve port cavity (102) is in communication with the accommodating cavity (201), and the valve port cavity (102) includes a valve port section (1021), the valve port section (1021) is a variable-diameter flow regulating section, or the side away from the accommodating cavity (201) of the valve port section (1021) has a variable-diameter flow regulating section for regulating the flow of the electronic expansion valve.

14. The electronic expansion valve according to claim 13, wherein The flow regulating section is a second trumpet, and the opening angle of the second trumpet is α, 1°≤α≤10°.

15. The electronic expansion valve of claim 13, wherein, The electronic expansion valve further comprises a valve needle assembly (60), the valve needle assembly (60) comprises a valve head piece (61), the valve head piece (61) cooperates with the inner wall of the flow regulating section to regulate the flow of the electronic expansion valve, one end of the valve head piece (61) extends into the valve port section (1021) in the full closing state of the electronic expansion valve, and there is a gap between the outer periphery of the valve head piece (61) and the inner wall of the valve port section (1021).

16. The electronic expansion valve according to claim 15, wherein The electronic expansion valve further comprises a rotor assembly (80), the valve needle assembly (60) further comprises a screw rod piece (62) in driving connection with the rotor assembly (80), the inner wall of the valve port section (1021) has a first tapered section (10211) and a first straight-through section (10212) arranged in sequence and communicated with each other in the direction of the valve port cavity (102) towards the first connecting pipe (41), the first tapered section (10211) is the flow regulating section, one end of the valve head piece (61) is located in the first tapered section (10211) in the full closing state of the electronic expansion valve, and there is a gap between the outer periphery of the valve head piece (61) and the inner wall of the first tapered section (10211); the height of the first tapered section (10211) is H5, the distance between the end of the valve head piece (61) and the communication surface of the first tapered section (10211) and the first straight-through section (10212) is H9, and the electronic expansion valve has a flow turning point with a flow rate slope change in the valve opening process; B*n*γ / 360+H9=H5; Wherein, B is the number of supply pulses required for the valve head piece (61) to open from the full closing position to the flow turning point, n is the pitch of the screw rod piece (62), and γ is the step angle of the rotor assembly (80).

17. The electronic expansion valve of claim 15, wherein, The electronic expansion valve further comprises a rotor assembly (80), the valve needle assembly (60) further comprises a screw rod piece (62) in driving connection with the rotor assembly (80), the inner wall of the valve port section (1021) has a first tapered section (10211) and a first straight-through section (10212) arranged in sequence and communicated with each other in the direction of the valve port cavity (102) towards the first connecting pipe (41), the first tapered section (10211) is the flow regulating section, one end of the valve head piece (61) is located in the first tapered section (10211) in the full closing state of the electronic expansion valve, and there is a gap between the outer periphery of the valve head piece (61) and the inner wall of the first straight-through section (10212); the height of the first tapered section (10211) is H5, the distance between the end of the valve head piece (61) and the communication surface of the first tapered section (10211) and the first straight-through section (10212) is H9, and the electronic expansion valve has a flow turning point with a flow rate slope change in the valve opening process; B*n*γ / 360+H9=H5; Wherein, B is the number of supply pulses required for the valve head piece (61) to open from the full closing position to the flow turning point, n is the pitch of the screw rod piece (62), and γ is the step angle of the rotor assembly (80). Wherein, B is the number of supply pulses required for the valve head piece (61) to open the valve from the full closed position to the flow turning point, n is the pitch of the screw piece (62), and γ is the step angle of the rotor assembly (80).

18. An assembly process characterized by, The assembly process is applied to the electronic expansion valve of any one of claims 1 to 17, the electronic expansion valve further comprising a second connecting pipe (42), the assembly process comprising: welding one end of the second connecting pipe (42) to the side of the valve seat part (10); welding the first connecting pipe (41) to the end of the one end of the adapter part (20); installing the sound reduction part (30) in the adapter part (20), and installing part of the adapter part (20) in the valve seat part (10), and welding the adapter part (20) to the valve seat part (10).

19. The assembly process of claim 18, wherein, The sound reduction part (30) comprises a first sound reduction block (31), a spacer (32) and a second sound reduction block (33) which abut in sequence along the installation direction of the sound reduction part (30), and the process of installing the sound reduction part (30) in the adapter part (20) further comprises: installing the second sound reduction block (33), the spacer (32) and the first sound reduction block (31) in the adapter part (20) in sequence.

20. The assembly process of claim 18, wherein, The assembly process further comprises: the end of the one end of the adapter part (20) is the end of the adapter part (20) located outside the valve seat part (10), and the first connecting pipe (41) is welded to the end of the one end of the adapter part (20) located outside the valve seat part (10); first, the first connecting pipe (41) is welded to the end of the one end of the adapter part (20) located outside the valve seat part (10), and then the sound reduction part (30) is installed in the adapter part (20); or, first, the sound reduction part (30) is installed in the adapter part (20), and then the adapter part (20) and the first connecting pipe (41) are welded.

21. The assembly process of claim 18, wherein, The electronic expansion valve further comprises a nut assembly (50), a valve needle assembly (60) and a guide sleeve (70), The assembly process further comprises sequentially installing the nut assembly (50) and the valve needle assembly (60) on the valve seat part (10); and before sequentially installing the nut assembly (50) and the valve needle assembly (60) on the valve seat part (10), the process of welding one end of the second connecting pipe (42) to the side of the valve seat part (10) further comprises: press-fitting the guide sleeve (70) in the valve seat part (10), integrally furnace welding the second connecting pipe (42), the valve seat part (10) and the guide sleeve (70), or first furnace welding the second connecting pipe (42) and the valve seat part (10), and then press-fitting the guide sleeve (70) in the valve seat part (10), and laser welding the guide sleeve (70) and the valve seat part (10).

22. The assembly process of claim 18, wherein, The assembly process further comprises: laser welding the connection position of the adapter part (20) and the valve seat part (10); defining the pulse of the electronic expansion valve. The assembly process further comprises: laser welding the connection position of the adapter part (20) and the valve seat part (10); defining the pulse of the electronic expansion valve.

23. The assembly process of claim 18, wherein, The valve seat part (10) comprises a split valve seat (11) and a valve seat core (12), or the valve seat part (10) comprises an integrated valve seat (11) and a valve seat core (12), part of the adapter part (20) is mounted in the valve seat (11), one end of the adapter part (20) abuts the valve seat core (12) or the sound attenuation part (30) abuts the valve seat core (12).

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