Electronic expansion valve and assembly process

Abstract

The present application provides an electronic expansion valve and an assembly process. The electronic expansion valve comprises a first connecting pipe, a silencing portion, and a valve seat portion and an adapter portion which are connected to each other, wherein the valve seat portion is provided with an accommodating cavity, and the silencing portion is arranged in the accommodating cavity; and in the axial direction of the electronic expansion valve, one end of the adapter portion abuts against the silencing portion, and the other end of the adapter portion is connected to the first connecting pipe. By means of the adapter portion, a furnace brazing object of the first connecting pipe is converted from the valve seat portion to the adapter portion, the adapter portion and the first connecting pipe are furnace brazed, the silencing portion located in the accommodating cavity is separated from the first connecting pipe by the adapter portion, and solder generated during furnace brazing does not penetrate into the silencing portion, ensuring the noise reduction effect of the silencing portion and the flow capacity of the electronic expansion valve. In addition, in the present solution, the first connecting pipe does not directly abut against the silencing portion, but the silencing portion is press-fitted by means of the adapter portion. Compared with the press-fitting of the silencing portion by directly using the first connecting pipe, the press-fitting mode in the present solution is more stable and reliable, thereby ensuring mounting efficiency and mounting reliability.

Description

Electronic expansion valve and assembly process

[0001] The present application claims priority to the patent application No. 202410969538.7 filed on July 18, 2024 in the State Intellectual Property Office of China, with the title of "Electronic expansion valve and assembly process". TECHNICAL FIELD

[0002] The present application relates to the technical field of electronic expansion valves, in particular to an electronic expansion valve and an assembly process. BACKGROUND

[0003] Currently, electronic expansion valves can be used in the field of series reheating dehumidification. 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.

[0004] The electronic expansion valve usually directly press-fits the noise reduction part in the cavity of the valve seat by using a 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 located 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. SUMMARY

[0005] The present application provides an electronic expansion valve and an assembly process to solve the problem that the noise reduction part is easy to be blocked by the furnace welding material and thus affects the noise reduction effect in the prior art.

[0006] 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 valve seat part has a containing cavity, and the noise reduction part is arranged in the containing cavity. In the axial direction of the electronic expansion valve, one end of the adapter part abuts against the noise reduction part, and the other end of the adapter part is connected with the first connecting pipe.

[0007] Further, the inner side of the containing cavity away from the adapter part has a limiting structure for limiting the movement of the noise reduction part away from the adapter part.

[0008] Further, the limiting structure comprises a stop limiting surface. The noise reduction part has a first end and a second end arranged oppositely in the axial direction of the electronic expansion valve. The first end abuts against the stop limiting surface, and the second end abuts against the adapter part.

[0009] Further, the valve seat portion further has a valve port cavity, the valve port cavity is arranged on the side of the accommodating cavity away from the adapter portion, the valve port cavity is in communication with the accommodating cavity, and a stepped surface between the inner wall of the accommodating cavity and the inner wall of the valve port cavity forms a stop limiting surface, the second end protrudes from the opening of the accommodating cavity, or the second end is flush with the surface where the opening of the accommodating cavity away from the valve port cavity is located.

[0010] Further, the valve seat portion further has a valve port cavity and a limiting cavity, the valve port cavity, the accommodating cavity and the limiting cavity are sequentially communicated in the direction of the accommodating cavity towards the adapter portion, the adapter portion is at least partially arranged in the limiting cavity and abuts against the silencing portion located in the accommodating cavity.

[0011] Further, the valve seat portion includes 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 valve port cavity and the accommodating cavity are located in the valve seat core, the area of the mounting cavity for mounting the valve seat core forms a placing cavity, and the cavity area of the mounting cavity on the side of the placing cavity towards the adapter portion forms the limiting cavity.

[0012] Further, at least part of the outer wall of the valve seat core is in interference fit with the inner wall of the placing cavity, and at least part of the outer wall of the adapter portion protruding into the limiting cavity is in interference fit with the inner wall of the limiting cavity.

[0013] Further, the adapter portion includes a first fitting section and a second fitting section connected in sequence, at least part of the first fitting section is arranged in the limiting cavity and abuts against the silencing portion, at least part of the second fitting section is located outside the limiting cavity for adapting the first connecting pipe, and the radial dimension of the first fitting section is greater than the radial dimension of the second fitting section.

[0014] Further, there is an outer stepped surface 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 and forms a positioning reference surface, or the outer stepped surface is flush with the surface where the opening of the limiting cavity is located and forms a positioning reference surface.

[0015] Further, the adapter portion 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 adapter portion, the inner diameter of the annular stop protrusion is smaller than the inner diameter of the second fitting section, and the area surrounded by the annular stop protrusion forms an adapter port, one end of the first connecting pipe is arranged in the second fitting section and is in stop fit with the annular stop protrusion, and the adapter port is in communication with the opening of the first connecting pipe.

[0016] Further, the adapter port is a straight port section with constant inner diameter along the axial direction of the electronic expansion valve, or the adapter port is a first trumpet port, or the side of the adapter port away from the first connecting pipe has a first trumpet port, the inner diameter of the first trumpet port gradually increases in the direction of the first connecting pipe towards the valve port cavity, the side with smaller opening of the first trumpet port is in communication with the first connecting pipe and the radial dimension is adapted to the inner diameter of the first connecting pipe, the opening angle of the first trumpet port is β, and 20°≤β≤120°.

[0017] Further, the adapter and the valve seat are laser welded, and / or the adapter and the first connecting pipe are laser welded.

[0018] Further, the valve seat further has a valve port cavity, the valve port cavity is located on the side of the accommodating cavity away from the adapter, the valve port cavity is in communication with the accommodating cavity, the valve port cavity comprises a valve port section, the valve port section is a variable-diameter flow regulating section, or the side of the valve port section away from the accommodating cavity has a variable-diameter flow regulating section for regulating the flow of the electronic expansion valve.

[0019] Further, the flow regulating section is a second horn, the opening angle of the second horn is α, 1°≤α≤10°.

[0020] Further, the electronic expansion valve further comprises a valve needle assembly, the valve needle assembly comprises a valve head, the valve head 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 extends into the valve port section in the full-closed state of the electronic expansion valve, and a gap is formed between the outer periphery of the valve head and the inner wall of the valve port section.

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

[0022] Further, the electronic expansion valve further comprises a rotor assembly, the valve needle assembly further comprises a screw rod in driving connection with the rotor assembly, the inner wall of the valve port section has a first tapered section and a first straight section in communication with each other and arranged in sequence in the direction of the valve port cavity towards the first connecting pipe, the first tapered section is the flow regulating section, one end of the valve head is located in the first straight section in the full-closed state of the electronic expansion valve, and a gap is formed between the outer periphery of the valve head and the inner wall of the first straight section; the height of the first tapered section is H5, the distance between the end of the valve head and the communication surface of the first tapered section and the first straight section is H9, the electronic expansion valve has a flow turning point with a flow rate slope change in the opening process; B*n*γ / 360+H9=H5; wherein B is the number of supply pulses required for the valve head to open from the full-closed position to the flow turning point, n is the pitch of the screw rod, and γ is the step angle of the rotor assembly.

[0023] According to another aspect of the present application, a mounting process is provided for the electronic expansion valve described above, the electronic expansion valve further comprising a second connecting pipe, the mounting 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 valve seat part, one end of the silencing part abutting against the valve seat part in the axial direction of the valve seat part; installing the part of the adapter part in the valve seat part and abutting against the other end of the silencing part, the adapter part being welded to the valve seat part; wherein the end of the one end of the adapter part is the end of the adapter part located outside the valve seat part.

[0024] Further, the valve seat part comprises a split valve seat and a valve seat core, the silencing part comprises a first silencing block, a spacer block and a second silencing block abutting against each other in the installation direction of the silencing part, the process of installing the silencing part in the valve seat part further comprising: installing the second silencing block and the spacer block in the valve seat core in sequence to form an assembly, and installing the assembly in the valve seat; or installing the second silencing block, the spacer block and the first silencing block in the valve seat core in sequence to form an assembly, and installing the assembly in the valve seat.

[0025] Further, the valve seat part comprises an integrated valve seat and a valve seat core, the silencing part comprises a first silencing block, a spacer block and a second silencing block abutting against each other in the installation direction of the silencing part, the process of installing the silencing part in the valve seat part comprising: installing the second silencing block, the spacer block and the first silencing block in the valve seat core in sequence.

[0026] Further, the electronic expansion valve further comprises a nut assembly, a valve needle assembly and a guide sleeve, the mounting process further comprising: 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 comprising: 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.

[0027] Further, the mounting process further comprising: laser welding the connection position of the adapter part and the valve seat part; and setting pulses for the electronic expansion valve.

[0028] According to the technical solution of the present application, an electronic expansion valve is provided, 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 valve seat part having a receiving cavity, the silencing part being arranged in the receiving cavity; in the axial direction of the electronic expansion valve, one end of the adapter part abutting against the silencing part to press-fit the silencing part in the receiving cavity, the other end of the adapter part being connected to the first connecting pipe.

[0029] The scheme is adopted, the first connecting pipe is changed from the valve seat part to the adapter part, the adapter part and the first connecting pipe are welded, the sound attenuation part in the accommodating cavity is separated from the first connecting pipe by the adapter part, and the welding material generated during welding will not penetrate the sound attenuation part, avoiding the welding material penetrating from the gap between the first connecting pipe and the valve seat part to the sound attenuation part, and further 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 first connecting pipe does not directly abut against the sound attenuation part, but realizes the press-fitting of the sound attenuation part through the adapter part, which is more stable and reliable than directly using the first connecting pipe to press-fit the sound attenuation part, and is beneficial to ensure the installation efficiency and reliability. BRIEF DESCRIPTION OF DRAWINGS

[0030] The drawings accompanying the specification of this application are used to provide further understanding of the application, the illustrative embodiments of the application and the description thereof are used to explain the application, and do not constitute improper limitation on the application. In the drawings:

[0031] Fig. 1 shows a structure schematic diagram of an electronic expansion valve provided by an embodiment of the application;

[0032] Fig. 2 shows an enlarged view of position A in Fig. 1;

[0033] Fig. 3 shows an enlarged view of position B in Fig. 2;

[0034] Fig. 4 shows a structure schematic diagram of a valve seat in Fig. 2;

[0035] Fig. 5 shows an assembly schematic diagram of a valve seat core, a sound attenuation part and an adapter part in Fig. 2;

[0036] Fig. 6 shows a structure schematic diagram of the valve seat core in Fig. 2;

[0037] Fig. 7 shows a structure schematic diagram of the electronic expansion valve in Fig. 1 when the valve is closed;

[0038] Fig. 8 shows an enlarged view of position C in Fig. 7;

[0039] Fig. 9 shows a flow schematic diagram of Fig. 7;

[0040] Fig. 10 shows a partial structure schematic diagram of a valve seat of an electronic expansion valve provided by an embodiment two of the application;

[0041] Fig. 11 shows an assembly schematic diagram of a valve seat core, a sound attenuation part and an adapter part of an electronic expansion valve provided by an embodiment two of the application;

[0042] Fig. 12 shows a partial enlarged view of an electronic expansion valve provided by an embodiment two of the application;

[0043] Fig. 13 shows a structural schematic diagram of the electronic expansion valve provided by the third embodiment of the present application when the valve is closed;

[0044] Fig. 14 shows an enlarged view of the D position in Fig. 13;

[0045] Fig. 15 shows a flow state diagram of Fig. 13.

[0046] wherein the above-mentioned figures include the following reference signs: 1, annular groove; 10, valve seat part; 101, accommodating cavity; 1011, stop limiting surface; 1012, first limiting cavity section; 1013, second limiting cavity section; 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; 103, mounting cavity; 1031, limiting cavity; 1032, placement cavity; 11, valve seat; 12, valve seat core; 121, first loose fit section; 122, first tight fit section; 20, adapter part; 201, outer stepped surface; 202, adapter port; 21, first fit section; 211, second loose fit section; 212, second tight fit section; 22, second fit section; 23, annular stop protrusion; 30, sound attenuation part; 301, first end; 302, second end; 31, first sound attenuation block; 32, spacer block; 33, second sound attenuation block; 41, first connecting pipe; 42, second connecting pipe; 50, nut assembly; 60, valve needle assembly; 61, valve head piece; 62, screw piece; 70, guide sleeve; 71, first sleeve; 72, second sleeve; 73, limiting sleeve; 80, rotor assembly. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present application will be clearly and completely described in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only 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 a person of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0048] As shown in Figs. 1 to 15, the embodiments of the present application provide an electronic expansion valve, which comprises a first connecting pipe 41, a sound attenuation part 30, and a valve seat part 10 and an adapter part 20 connected with each other, the valve seat part 10 has an accommodating cavity 101, and the sound attenuation part 30 is arranged in the accommodating cavity 101; in the axial direction of the electronic expansion valve, one end of the adapter part 20 abuts against the sound attenuation part 30 to press-fit the sound attenuation part 30 in the accommodating cavity 101, and the other end of the adapter part 20 is connected with the first connecting pipe 41.

[0049] In the application, the furnace welding object of the first connecting pipe 41 is changed from the valve seat part 10 to the adapter part 20, the adapter part 20 and the first connecting pipe 41 are furnace welded, the sound attenuation part 30 located in the accommodating cavity 101 is separated from the first connecting pipe 41 through the adapter part 20, and the molten solder during furnace welding cannot penetrate to the sound attenuation part 30, thereby avoiding the situation that the molten solder easily penetrates from the gap between the first connecting pipe 41 and the valve seat part 10 to the sound attenuation part 30 when the first connecting pipe 41 is furnace welded with the valve seat part 10, and further affecting the noise reduction effect of the sound attenuation part 30 and the flow capacity of the electronic expansion valve, and ensuring the noise reduction effect of the sound attenuation part 30 and the flow capacity of the electronic expansion valve. On the other hand, in the application, the first connecting pipe 41 does not directly abut against the sound attenuation part 30, but realizes the press-fitting of the sound attenuation part 30 through the adapter part 20, which is more stable and reliable than directly using the first connecting pipe 41 to press-fit the sound attenuation part 30, and is beneficial to ensure the installation efficiency and the reliability of installation.

[0050] It should be noted that it can be understood that the adapter part 20 can be a stretch part, a finished part, etc. In the application, since multiple steps and flow channels need to be machined inside the adapter part 20, and the adapter part 20 needs to be press-fitted into the valve seat part 10, the dimensional accuracy of the adapter part 20 has a higher requirement, so the adapter part 20 in the application preferably adopts finishing. It can be understood that the adapter part 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.

[0051] Among them, the side of the accommodating cavity 101 inside away from the adapter part 20 has a limiting structure, and the limiting structure is used to limit the movement of the sound attenuation part 30 away from the adapter part 20. In this way, the limiting structure is used to limit the installation depth of the sound attenuation part 30 in the accommodating cavity 101, thereby avoiding the situation that the sound attenuation part 30 is over-installed or cannot be press-fitted.

[0052] Specifically, the limiting structure includes a stop limiting surface 1011. In the axial direction of the electronic expansion valve, the sound attenuation part 30 has a first end 301 and a second end 302 arranged oppositely, the first end 301 is located at one end of the sound attenuation part 30 away from the first connecting pipe 41, the second end 302 is located at one end of the sound attenuation part 30 close to the first connecting pipe 41, the first end 301 abuts against the stop limiting surface 1011, and the adapter part 20 abuts against the second end 302. In this way, the sound attenuation part 30 is limited between the adapter part 20 and the stop limiting surface 1011, thereby ensuring the reliability and stability of the press-fitting of the sound attenuation part 30.

[0053] In the embodiment one shown in Fig. 6, the valve seat part 10 further has a valve port cavity 102, which is arranged at the side of the accommodating cavity 101 away from the adapter part 20, and which communicates with the accommodating cavity 101. The stepped surface between the inner wall of the accommodating cavity 101 and the inner wall of the valve port cavity 102 forms a stop limiting surface 1011. The second end 302 protrudes out of the opening of the accommodating cavity 101, or the second end 302 is flush with the surface where the opening of the accommodating cavity 101 away from the valve port cavity 102 is located.

[0054] In the present application, the stop limiting surface 1011 can also be understood as the bottom wall of the side of the accommodating cavity 101 facing the valve port cavity 102. In the embodiment one shown in Figs. 2 and 5, the second end 302 protrudes out of the opening of the accommodating cavity 101, which can ensure the reliability of the abutment between the adapter part 20 and the second end 302, i.e., the adapter part 20 directly abuts against the second end 302 of the sound attenuation part 30, avoiding the situation that the second end 302 and the adapter part 20 are not tightly abutted against each other, which can cause the sound attenuation part 30 to move easily in the accommodating cavity 101, and ensuring the reliability and stability of the press fitting of the sound attenuation part 30.

[0055] The accommodating cavity 101 comprises a first limiting cavity section 1012 and a second limiting cavity section 1013, which communicate with each other. In the axial direction of the electronic expansion valve, the second limiting cavity section 1013 is located at the side of the accommodating cavity 101 away from the first connecting pipe 41, and the first limiting cavity section 1012 is located at the side of the accommodating cavity 101 close to the first connecting pipe 41. The radial dimension of the second limiting cavity section 1013 is smaller than that of the first limiting cavity section 1012 (as shown in Fig. 6, the inner diameter of the first limiting cavity section 2011 is D31, and the inner diameter of the second limiting cavity section 2012 is D32, D31>D32). The second limiting cavity section 1013 communicates with the valve port cavity 102, and the bottom wall of the second limiting cavity section 1013 forms the stop limiting surface 1011. Specifically, in the embodiment one shown in Figs. 2 and 5, the sound attenuation part 30 comprises a first sound attenuation block 31, a spacer 32 and a second sound attenuation block 33, which abut against each other in sequence in the mounting direction of the sound attenuation part 30. The outer diameter of the first sound attenuation block 31 is adapted to the inner diameter of the first limiting cavity section 1012, the first sound attenuation block 31 is arranged in the first limiting cavity section 1012 and limited by the inner wall of the first limiting cavity section 1012, and the outer diameter of the second sound attenuation block 33 is adapted to the inner diameter of the second limiting cavity section 1013, the second sound attenuation block 33 is arranged in the second limiting cavity section 1013 and limited by the inner wall of the second limiting cavity section 1013. Such arrangement can facilitate the differentiation between the first sound attenuation block 31 and the second sound attenuation block 33, avoid the wrong installation sequence, prevent the installation positions of the two sound attenuation blocks from being confused, and be beneficial to improving the installation efficiency of the sound attenuation part 30. The spacer 32 in the present application has a ring structure.

[0056] It can be understood that the installation direction of the sound attenuation part 30 is the direction parallel to the axial direction of the electronic expansion valve when the sound attenuation part 30 is installed in the accommodating cavity 101. In this application, the installation direction is the axial direction of the electronic expansion valve with the first limiting cavity section 1012 facing the second limiting cavity section 1013.

[0057] The first sound attenuation block 31 and the second sound attenuation block 33 are both provided with flow-through regions and decomposition regions. At least part of the flow-through region provided on the first sound attenuation block 31 is correspondingly provided with the decomposition region provided on the second sound attenuation block 33, and at least part of the flow-through region provided on the second sound attenuation block 33 is correspondingly provided with the decomposition region provided on the first sound attenuation block 31.

[0058] In the axial direction of the electronic expansion valve, the height of the first sound attenuation block 31 is H31, the height of the cushion block 32 is H32, the height of the second sound attenuation block is H33, (H31+H32+H33) is the overall height of the sound attenuation part 30 in the axial direction of the electronic expansion valve (which can also be understood as the distance between the first end 301 and the second end 302 of the sound attenuation part 30), the height of the first limiting cavity section 1012 is H62, the height of the second limiting cavity section 1013 is H61, and (H61+H62) is the overall height of the accommodating cavity 101 in the axial direction of the electronic expansion valve, wherein H61≤H33. Specifically, H61

[0059] In the first embodiment shown in FIG. 4 and the second embodiment shown in FIG. 10, the valve seat part 10 further has a limiting cavity 1031. The valve port cavity 102, the accommodating cavity 101, and the limiting cavity 1031 are sequentially communicated in the direction in which the accommodating cavity 101 faces the adapter part 20. The adapter part 20 is at least partially arranged in the limiting cavity 1031 and abuts against the sound attenuation part 30 arranged in the accommodating cavity 101. In this way, the limiting cavity 1031 facilitates the limiting installation of the adapter part 20.

[0060] The valve seat part 10 comprises a valve seat 11 and a valve seat core 12, the valve seat 11 has a mounting cavity 103, the valve seat core 12 is arranged in the mounting cavity 103, specifically, the valve seat core 12 in the application is press-fitted in the mounting cavity, the valve port cavity 102 and the containing cavity 101 are located in the valve seat core 12, the area of the mounting cavity 103 for mounting the valve seat core 12 forms a placing cavity 1032, and the cavity area of the mounting cavity 103 located on the side of the placing cavity 1032 towards the adapter part 20 forms a limiting cavity 1031. In this way, the limiting cavity 1031 is divided and the valve seat core 12 is mounted.

[0061] It should be noted that, in the series reheating dehumidification system, the electronic expansion valve is arranged between the two indoor side heat exchangers, which determines that, in the normal air conditioning working condition, the pressure drop of the electronic expansion valve at a large opening degree is as small as possible to ensure the energy efficiency of the air conditioning system, and the requirement of the indoor side for noise is relatively high, therefore, the sound attenuation structure (corresponding to the sound attenuation part 30 in the application) needs to be arranged at the valve port position (corresponding to the valve port cavity 102 in the application), 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 is adopted, in the related technology, one end of the connecting pipe (corresponding to the first connecting pipe 41 in the application) directly extends into the valve seat and directly abuts against the sound attenuation structure, the connecting pipe extending into the valve seat (corresponding to the valve seat 11 in the application) needs to have a relatively large outer diameter; and in the series reheating dehumidification system, the electronic expansion valve is mainly used in 1-3P units, and the inner diameter of the indoor heat exchanger connecting pipeline corresponding to the electronic expansion valve is relatively small compared with the 3P and above units, 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, and the scheme of abutting the connecting pipe 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.

[0062] To solve the above problems, in the application, the adapter 20 comprises a first fitting section 21 and a second fitting section 22 connected with each other, at least part of the first fitting section 21 is arranged in the limiting cavity 1031 and abuts against the sound attenuation part 30, at least part of the second fitting section 22 is located outside the limiting cavity 1031 for adapting the first connecting pipe 41, the radial dimension (outer diameter and inner diameter) of the first fitting section 21 is larger than the radial dimension (outer diameter and inner diameter) of the second fitting section 22. The outer wall of the first fitting section 21 is limitedly fitted with the inner wall of the limiting cavity 1031, by limiting the size (inner diameter and outer diameter) of the first fitting section 21 and the second fitting section 22, the adapter 20 can be adapted to valve seat parts 10 of different sizes, at the same time, the reduction of the radial dimension of the second fitting section 22 is equivalent to that the adapter 20 itself forms a reduced opening, therefore, the end of the first connecting pipe 41 connected with the adapter 20 also does not need to be reduced in diameter for adapting the valve seat part 10 of large diameter, only needs to select appropriate raw materials to process the first connecting pipe 41 according to the diameter of the electronic expansion valve, so as to reduce the processing difficulty of the first connecting pipe 41 and improve the processing efficiency.

[0063] It can be understood that the other end of the first connecting pipe 41 is connected with the system pipeline, the reduced opening processing, the flared processing or no processing of the other end of the first connecting pipe 41 connected with the system pipeline are determined according to the actual situation, compared with the case that the first connecting pipe 41 directly communicates with the valve seat part 10, the end of the first connecting pipe 41 connected with the electronic expansion valve saves at least one flaring process through the adapter 20.

[0064] At least part of the outer wall of the valve seat core 12 is interference-fitted with the inner wall of the placing cavity 1032, and at least part of the outer wall of the adapter 20 extending into the limiting cavity 1031 is interference-fitted with the inner wall of the limiting cavity 1031. As shown in FIG. 5, the valve seat core 12 comprises a first loose fitting section 121 and a first tight fitting section 122 connected with each other, the first fitting section 21 of the adapter 20 extending into the limiting cavity 1031 comprises a second loose fitting section 211 and a second tight fitting section 212 connected with each other, at least part of the first tight fitting section 122 is interference-fitted with the inner wall of the placing cavity 1032, and at least part of the second tight fitting section 212 is interference-fitted with the inner wall of the limiting cavity 1031, by arranging the first loose fitting section 121 and the second loose fitting section 211, the extension direction of the valve seat core 12 and the adapter 20 during installation is facilitated, and the high pressing difficulty caused by the too long tight interference section is avoided.

[0065] Specifically, in the first embodiment as shown in FIGS. 1-9, the first and second tight fitting sections 122 and 212 are straight sections, and the first and second loose fitting sections 121 and 211 are circular truncated cone sections with inclined outer walls, the outer diameter of the first and second loose fitting sections 121 and 211 gradually decreases in the direction of the first connecting pipe 41 towards the valve cavity 102, the inner diameters of the placement cavity 1032 and the limiting cavity 1031 are the same, D1, the outer diameters of the first and second tight fitting sections 122 and 212 are the same, D2, D2=D1 or D2 is slightly larger than D1, to ensure the interference fit and the coaxiality requirement of the first and second tight fitting sections 122 and 212 in the installation cavity 103, and preferably D2 is slightly larger than D1.

[0066] As shown in FIGS. 10-12, the second embodiment of the present application provides an electronic expansion valve, which is different from the first embodiment in that the first and second loose fitting sections 121 and 211, the first and second tight fitting sections 122 and 212 are straight sections, the first and second loose fitting sections 121 and 211 are connected by a transition chamfer between the first and second tight fitting sections 122 and 212. As shown in FIG. 10, the inner diameter D11 of the placement cavity 1032 is smaller than the inner diameter D12 of the limiting cavity 1031, as shown in FIG. 11, the outer diameter of the first loose fitting section 121 is D21, the outer diameter of the first tight fitting section 122 is D22, the outer diameter of the second loose fitting section 211 is D23, and the outer diameter of the second tight fitting section 212 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, to ensure the reliability of the interference fit and the coaxiality requirement.

[0067] It can be understood that the interference length between the valve seat core 12 or the adapter 20 and the installation cavity 103 can be adjusted according to actual conditions.

[0068] In the present application, the bottom wall of the first fitting section 21 is an outer stepped surface 201, which is located between the outer wall of the first fitting section 21 and the outer wall of the second fitting section 22. In the second embodiment as shown in FIG. 12, the outer wall of the first fitting section 21 and the outer wall of the second fitting section 22 have the outer stepped surface 201, which protrudes from the limiting cavity 1031 and forms a positioning reference surface, or, in the first embodiment as shown in FIG. 3, the outer stepped surface 201 is flush with the surface where the opening of the limiting cavity 1031 is located and forms a positioning reference surface. In this way, 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 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, so that during furnace welding, the molten solder will not be laid on the positioning reference surface, which will not cause the positioning reference surface to be insufficient in size and the positioning to be inaccurate, and the influence on the positioning reference surface is almost none, which will not affect the positioning during the subsequent assembly and welding.

[0069] As shown in FIG. 1, FIG. 2, FIG. 5 and FIG. 11, the adapter part 20 in the present application 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 smaller than the inner diameter of the second fitting section 22, and the area surrounded by the ring-shaped stop protrusion 23 forms an adapter interface 202, one end of the first connecting pipe 41 is arranged in the second fitting section 22 and stop-fitted with the ring-shaped stop protrusion 23, and the adapter interface 202 is in communication with the opening of the first connecting pipe 41. In the present application, 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.

[0070] In the present application, the inner diameter of the first connecting pipe 41 is adapted to the radial dimension of the adapter interface 202, which facilitates the limiting installation of the first connecting pipe 41 and the forming of the adapter interface 202, and at the same time, realizes the smooth transition of the refrigerant flowing through the adapter interface 202 and the first connecting pipe 41, and reduces the refrigerant flow noise.

[0071] The adapter 202 is a straight section with a constant inner diameter along the axis of the electronic expansion valve, or the adapter 202 is a first trumpet, or the adapter 202 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, 20°≤β≤120°. Specifically, in the first embodiment shown in FIG. 5 and the second embodiment shown in FIG. 11, the adapter 202 includes a first trumpet and a straight section in communication with each other. By providing the first trumpet, on the one hand, it can ensure that there is no burr (the adapter 20 is a finished part, and burrs are easy to occur when the straight channel 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 of fluid flowing 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 buffer effect for the fluid entering from the first connecting pipe 41, and it is not easy to form vortex, realizes pressure gradient, reduces flow rate, reduces the impact of high-speed fluid on the filter screen, that is, reduces the flow rate of the refrigerant entering the valve port position, reduces the turbulent kinetic energy and thus reduces the noise.

[0072] The height of the first trumpet is H7, 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 between them cannot exceed 5%.

[0073] The adapter 20 and the valve seat part 10 and the adapter 20 and the first connecting pipe 41 can be connected by welding respectively, specifically, the adapter 20 and the valve seat part 10 can be connected by laser welding, and the adapter 20 and the first connecting pipe 41 can be connected by furnace welding, brazing or other welding methods. In this application, the adapter 20 and the valve seat part 10 are laser welded, and the adapter 20 and the first connecting pipe 41 are furnace welded, in the first embodiment shown in FIG. 3 and the second embodiment shown in FIG. 12, the bottom of the first fitting section 21 and the bottom of the valve seat 11 where the opening of the limiting cavity 1031 is formed form an annular weld, which is set to avoid the case that the laser welding position is formed on the side surface of the electronic expansion valve, and the second connecting pipe 42 will interfere with the welding.

[0074] In the first embodiment shown in FIGS. 1-9, the bottom wall of the first fitting section 21 is flush with the bottom wall of the valve seat 11. Specifically, in some embodiments, the valve seat core 12 is press-fitted on the bottom wall of the placement cavity 1032, the sound-damping part 30 is press-fitted in the accommodating cavity 101 of the valve seat core 12 and protrudes out of the opening of the accommodating cavity 101 away from the valve port cavity 102, and the end of the first fitting section 21 extending into the valve seat 11 abuts against the end of the sound-damping part 30 protruding out of the opening of the accommodating cavity 101, wherein, in the axial direction of the electronic expansion valve, the height of the sound-damping part 30 protruding out of the opening of the accommodating cavity 101 is x, x is the difference between (H31+H32+H33) and (H61+H62), the height of the mounting cavity 103 is H1, the sum of the height H6 of the valve seat core 12, the height H4 of the first fitting section 21 of the adapter 20, and the height x of the sound-damping part 30 protruding out of the opening of the accommodating cavity 101 is H2 (H2=H4+H6+x), H1=H2, the bottom wall of the first fitting section 21 is flush with the bottom wall of the valve seat 11, and further, in order to avoid the situation that the height of the welding bead is too high after welding, the bottom wall of the first fitting 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 welding bead formed by welding is all or mostly located in the annular groove 1, the welding bead is hidden, the welding bead formed by laser welding does not protrude out of the positioning reference surface or the protruding part has little effect on the positioning reference effect of the positioning reference surface, does not affect the positioning during the subsequent assembly and welding, and ensures the reliability of the welding and the reliability of the positioning reference surface.

[0075] In another aspect, in the second embodiment shown in Figs. 10-12, the bottom wall of the first fitting section 21 protrudes from the bottom wall of the valve seat 11. Specifically, in some embodiments, the valve seat core 12 is press-fitted on the bottom wall of the placement cavity 1032, the sound-damping part 30 is press-fitted in the receiving cavity 101 of the valve seat core 12 and protrudes from the opening of the receiving cavity 101 away from the valve port cavity 102, and the end of the first fitting section 21 extending into the valve seat 11 abuts the end of the sound-damping part 30 protruding from the opening of the receiving cavity 101, wherein, in the axial direction of the electronic expansion valve, the height of the sound-damping part 30 protruding from the opening of the receiving cavity 101 is x, x is the difference between (H31+H32+H33) and (H61+H62), and the height of the mounting cavity 103 is less than the sum of the heights of the valve seat core 12, the first fitting section 21 of the adapter 20, and the sound-damping part 30 protruding from the opening of the receiving cavity 101, 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 1032 is H11, the height of the limiting cavity 1031 is H12, the height of the mounting cavity 103 is H1, H1=H11+H12, the sum of the height H6 of the valve seat core 12, the height H4 of the first fitting section 21 of the adapter 20, and the height x of the sound-damping part 30 protruding from the opening of the receiving cavity 101 is H2 (H2=H4+H6+x), H1

[0076] Specifically, the electronic expansion valve provided in the present application has a flow curve designed as a broken line type with a sharp opening and a flow turning point, a gentle flow and a small flow value at a small opening degree to meet the adjustment in dehumidification conditions, and a large flow at a large opening degree to meet the flow capacity in normal air conditioning conditions, thereby reducing the pressure drop.

[0077] The valve port cavity 102 comprises a valve port section 1021 and a flared section 1022 which are in communication with each other, the valve port section 1021 has a flow regulating section, the flow regulating section is in communication with the containing cavity 101 through the flared section 1022, the electronic expansion valve further comprises a valve needle assembly 60, the flow regulating section is located at one end of the valve port section 1021 away from the valve needle assembly 60, the valve needle assembly 60 comprises a valve head piece 61, the valve head piece 61 can move towards or away from the valve port cavity 102 along the axial direction of the electronic expansion valve, and cooperate with the flow regulating section to regulate the flow of the electronic expansion valve. It should be noted that the electronic expansion valve provided in the present application is a full-closed flow fold line type, and the outer periphery of the valve head piece 61 has a gap with the inner wall of the valve port section 1021 in the full-closed state, and the refrigerant can flow between the two connecting pipes (the first connecting pipe 41 and the second connecting pipe 42) through the gap, at this time the electronic expansion valve has a flow, and the flow value is greater than the internal leakage amount specified in the corresponding caliber industry standard. It can be understood that the full-closed flow is specifically realized by moving the valve head piece 61 axially after finding the zero point by a fixed pulse, and the full-closed flow is realized by the gap between the valve head piece 61 and the valve port section 1021 in the full-closed state.

[0078] In the embodiment I shown in FIGS. 6-9, the valve needle assembly 60 further comprises a screw piece 62, and the electronic expansion valve further comprises a rotor assembly 80 for driving the screw piece 62. The inner wall of the valve port section 1021 of the present application has a first tapered section 10211 and a first straight-through section 10212 which are in communication and arranged in sequence in the direction of the valve port cavity 102 towards the first connecting pipe 41, wherein the first tapered section 10211 is the flow regulating section, the first straight-through section 10212 is in communication with the flared section 1022, the valve head piece 61 cooperates with the inner wall of the first tapered section 10211 to regulate the flow of the electronic expansion valve, the height of the first tapered section 10211 is H5, and the distance between the end of the valve head piece 61 and the surface where the first tapered section 10211 and the first straight-through section 10212 communicate is H9 when the electronic expansion valve is in the full-closed state. The electronic expansion valve has a flow turning point with a flow slope change during the opening process, and the flow turning point here is the point when the end of the valve head piece 61 towards the one end of the valve port cavity 102 just leaves the first tapered section 10211; B*n*γ / 360+H9=H5; wherein B is the number of supply pulses required for the valve head piece 61 to move from the full-closed position towards the direction away from the valve port cavity 102, open to just leave the first tapered section 10211 (flow turning point), n is the pitch of the screw piece 62, and γ is the step angle of the rotor assembly 80. As shown in FIGS. 7-9, in the embodiment I, the full-closed position is located on the first tapered section 10211, that is, when the electronic expansion valve is 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 within 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 pulses, and directly has a slope upwards from 0 pulses.

[0079] The flow regulation section as a whole is a second horn, or the flow regulation section has a second horn on the side facing away from the first connecting pipe 41, and the side with a larger opening of the second horn is arranged to face away from the first connecting pipe 41. In this application, the first tapered section 10211 is a second horn, and the opening angle of the second horn is α, 1°≤α≤10°. The slope of the fold line before and after the flow turning point is different, the fold line before the flow turning point is gentle, the slope of the fold line after the flow turning point is larger, the corresponding flow is large, and the electronic expansion valve has small flow resistance when fully open. The flow requirement is small in dehumidification condition, and the angle is too large, which leads to too large flow at small opening, and cannot meet the requirement of the whole machine in dehumidification condition, and the angle is too small, which will interfere with the outer diameter of the valve head piece 61. By limiting the angle α, the flow value and stability of the electronic expansion valve at small opening can be ensured. 1°≤α≤6°, the number of supply pulses required for the valve head piece 61 from the full-closed 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 (ensure that the turning point of the flow curve is between 300P-400P under normal conditions). Specifically, 2.5mm≤H5≤7mm.

[0080] Wherein, the unit of B is pulse or step, the value of B can be customized according to customer requirements, and the value of B can be determined after the value of B is determined; it can be understood that in the first embodiment as shown in FIG. 7, 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 section 10212 and is D42, and α or H5 can be calculated by tanα / 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°; γ / 360 is the number of pulses required for the valve head to rotate one circle.

[0081] As shown in FIGS. 13 and 15, 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 of the third embodiment has a first tapered section 10211, a first straight section 10212, a second tapered section 10213, and a second straight section 10214 connected in sequence in the direction of the valve port cavity 102 towards the first connecting pipe 41. As shown in FIG. 13, the maximum diameter of the first tapered section 10211 is D43, the minimum diameter of the first tapered section 10211 is the same as the diameter of the first straight section 10212 and is D44, and the minimum diameter of the valve port section 1021, i.e. the minimum diameter of the second tapered section 10213, is also the minimum diameter of the second straight section 10214, which is D45.

[0082] In the third 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-through section 10212, and there is a gap between the outer periphery of the valve head piece 61 and the first straight-through section 10212, at this time, the first tapered section 10211 functions as the flow regulating section, and the second tapered section 10213 below does not function as the flow regulating section. Specifically, the first tapered section 10211 is the flow regulating section, and in the full-closed position, the end of the valve head piece 61 toward the one end of the valve port cavity 102 is located in the first straight-through 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-through section 10212 is H9, and B*n*γ / 360-H9=H5. In the third embodiment shown in FIGS. 13 to 15, the full-closed flow is achieved through the gap between the valve head piece 61 and the first straight-through section 10212, and the full-closed position is located on the first straight-through section 10212. Since in the third 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-through 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 curve has a flat section after 0 pulse, and after the end of the valve head piece 61 toward the one end of the valve port cavity 102 exits the first straight-through section 10212 and enters the first tapered section 10211, the flow curve starts to have a slope upward again after the flat section. Since the full-closed position is located on the first straight-through section 10212, the gap between the valve head piece 61 and the straight section in the full-closed state can be controlled to be smaller, 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 in the dehumidification working condition. In the third 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 toward the one end of the valve port cavity 102 enters the first straight-through section 10212.

[0083] As shown in FIGS. 14 and 15, in the third embodiment, the full-closed flow is achieved through the gap between the valve head piece 61 and the first straight-through section 10212, the full-closed position is located on the first straight-through section 10212, and the flow curve has a flat section after 0 pulse, and after the flat section, the flow curve starts to have a slope upward again.

[0084] 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 part 10, the valve seat core 12 is integrally formed in the placement cavity 1032, the valve port cavity 102 is located in the integrated valve seat part 10, and the valve port cavity has the aforementioned valve port section 1021. In this embodiment, except that the valve seat core 12 and the valve seat 11 are integrally arranged, the other full-closed flow achieving modes and the flow curve are the same as those in the aforementioned embodiments, and will not be described herein again.

[0085] 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-through section 10212, the second tapered section 10213, and the second straight-through section 10214 in the present application), the formula of tanα / 2 and the formula between H5 and H9 can be correspondingly adjusted adaptively, which will not be exemplified one by one here.

[0086] 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 when it is fully open. When the Cv value is less than 1, the flow capacity of the fluid will be throttled when the electronic expansion valve is fully open, that is, the flow capacity of the electronic expansion valve in the fully open state is not enough, which affects the fluid flow between the indoor side heat exchangers and thus affects the overall performance. In the present application, by setting Cv≥1, the flow capacity of the electronic expansion valve can be ensured to meet the overall performance requirements when the valve is used in normal working conditions of the air conditioner.

[0087] Another embodiment of the present application provides an assembly 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 assembly process comprises: 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 one end of the adapter part 20; installing the sound attenuation part 30 in the valve seat part 10, with one end of the sound attenuation part 30 abutting against the valve seat part 10 along the axial direction of the valve seat part 10; installing part of the adapter part 20 in the valve seat part 10 and abutting against the other end of the sound attenuation part 30, and 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: 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, and laser welding the guide sleeve 70 and the valve seat part 10; and welding the adapter part 20 to the valve seat part 10 to pulse the electronic expansion valve. The end of one end of the adapter part 20 is the end of the adapter part 20 located outside the valve seat part 10. In this way, the assembly of the electronic expansion valve is facilitated, and the assembly efficiency is improved.

[0088] In the present application, the sound attenuation portion 30 includes a first sound attenuation block 31, a spacer block 32, and a second sound attenuation block 33 abutting in sequence along the mounting direction of the sound attenuation portion 30, the valve seat portion 10 comprises a split valve seat 11 and a valve seat core 12, and the process of mounting the sound attenuation portion 30 in the valve seat portion 10 further comprises: mounting the second sound attenuation block 33 and the spacer block 32 in sequence in the valve seat core 12 to form an assembly, and mounting the assembly in the valve seat 11; or mounting the second sound attenuation block 33, the spacer block 32, and the first sound attenuation block 31 in sequence in the valve seat core 12 to form an assembly, and mounting the assembly in the valve seat 11.

[0089] It can be understood that in some embodiments not shown in the drawings, the valve seat portion 10 comprises an integrated valve seat 11 and a valve seat core 12, and the process of mounting the sound attenuation portion 30 in the valve seat portion 10 further comprises: mounting the second sound attenuation block 33, the spacer block 32, and the first sound attenuation block 31 in sequence in the valve seat core 12.

[0090] Specifically, the guide sleeve 70 is mounted in the valve seat 11, and the adapter portion 20 and the valve seat portion 10 are laser welded.

[0091] The guide sleeve 70 in the present application is large at the bottom and small at the top, the nut assembly 50 comprises a nut member, and 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 member to ensure the coaxiality of the two, and the inner cavity of the first sleeve 71 is used to pass through the valve head member 61 and is in clearance fit with the outer periphery of the valve head member 61, and the clearance is 0.01mm-0.1mm.

[0092] Since the outer diameter of the main indoor heat exchanger connecting pipe of the current mainstream household 3P split cabinet machine is 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; 7mm≤the minimum diameter of the valve port cavity 102≤9.5mm.

[0093] The above only describes optional embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection 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 attenuation part (30), and a valve seat part (10) and a switching part (20) connected with each other, the valve seat part (10) has a containing cavity (101), the sound attenuation part (30) is arranged in the containing cavity (101); in the axial direction of the electronic expansion valve, one end of the switching part (20) abuts against the sound attenuation part (30), and the other end of the switching part (20) is connected with the first connecting pipe (41).

2. The electronic expansion valve according to claim 1, characterized in that The side of the containing cavity (101) inside away from the switching part (20) has a limiting structure for limiting the movement of the sound attenuation part (30) in the direction away from the switching part (20).

3. The electronic expansion valve according to claim 2, wherein The limiting structure comprises a stop limiting surface (1011), the sound attenuation part (30) has a first end (301) and a second end (302) arranged oppositely in the axial direction of the electronic expansion valve, the first end (301) abuts against the stop limiting surface (1011), and the switching part (20) abuts against the second end (302).

4. The electronic expansion valve according to claim 3, wherein The valve seat part (10) further has a valve port cavity (102) arranged on the side of the containing cavity (101) away from the switching part (20), the valve port cavity (102) is communicated with the containing cavity (101), and the step surface between the inner wall of the containing cavity (101) and the inner wall of the valve port cavity (102) forms the stop limiting surface (1011), the second end (302) protrudes from the opening of the containing cavity (101), or the second end (302) is flush with the surface of the opening of the containing cavity (101) away from the valve port cavity (102).

5. The electronic expansion valve according to claim 1, wherein The valve seat part (10) further has a valve port cavity (102) and a limiting cavity (1031), the valve port cavity (102), the containing cavity (101) and the limiting cavity (1031) are sequentially communicated in the direction of the containing cavity (101) towards the switching part (20), and the switching part (20) is at least partially arranged in the limiting cavity (1031) and abuts against the sound attenuation part (30) arranged in the containing cavity (101).

6. The electronic expansion valve according to claim 5, wherein The valve seat part (10) comprises a valve seat (11) and a valve seat core (12), the valve seat (11) has a mounting cavity (103), the valve seat core (12) is arranged in the mounting cavity (103), the valve port cavity (102) and the containing cavity (101) are located in the valve seat core (12), the area of the mounting cavity (103) for mounting the valve seat core (12) forms a placing cavity (1032), and the cavity area of the mounting cavity (103) located on the side of the placing cavity (1032) towards the switching part (20) forms the limiting cavity (1031).

7. The electronic expansion valve according to claim 6, characterized in that The outer wall of at least part of the valve seat core (12) is in interference fit with the inner wall of the placing cavity (1032), and the outer wall of the switching part (20) at least partially extending into the limiting cavity (1031) is in interference fit with the inner wall of the limiting cavity (1031).

8. The electronic expansion valve according to claim 5, wherein The adapter (20) comprises a first fitting section (21) and a second fitting section (22) connected in sequence, at least part of the first fitting section (21) is arranged in the limiting cavity (1031) and abuts against the silencing portion (30), at least part of the second fitting section (22) is located outside the limiting cavity (1031) for adapting the first connecting pipe (41), the radial dimension of the first fitting section (21) is greater than the radial dimension of the second fitting section (22).

9. The electronic expansion valve according to claim 8, characterized in that An outer stepped surface (201) is formed between the outer wall of the first fitting section (21) and the outer wall of the second fitting section (22), the outer stepped surface (201) protrudes out of the limiting cavity (1031) and forms a positioning reference surface, or the outer stepped surface (201) is flush with the surface where the opening of the limiting cavity (1031) is located and forms a positioning reference surface.

10. The electronic expansion valve according to claim 8, wherein The adapter (20) has an annular stop protrusion (23) therein, the annular stop protrusion (23) is arranged between the first fitting section (21) and the second fitting section (22) and protrudes inward in the radial direction of the adapter (20), the inner diameter of the annular stop protrusion (23) is smaller than the inner diameter of the second fitting section (22), an adapter port (202) is formed around the annular stop protrusion (23), one end of the first connecting pipe (41) is arranged in the second fitting section (22) and stop-fitted with the annular stop protrusion (23), the adapter port (202) is in communication with the opening of the first connecting pipe (41).

11. The electronic expansion valve according to claim 10, wherein The adapter port (202) is a straight port section with constant inner diameter along the axial direction of the electronic expansion valve, or the adapter port (202) is a first trumpet port, or the adapter port (202) has a first trumpet port on the side away from the first connecting pipe (41), the inner diameter of the first trumpet port gradually increases along the direction of the first connecting pipe (41) towards the valve port cavity (102), the smaller opening side of the first trumpet port is in communication with the first connecting pipe (41) and the radial dimension thereof is adapted to the inner diameter of the first connecting pipe (41), the opening angle of the first trumpet port is β, 20°≤β≤120°.

12. The electronic expansion valve according to claim 1, wherein The adapter (20) and the valve seat portion (10) are laser-welded, and / or the adapter (20) and the first connecting pipe (41) are furnace-welded.

13. The electronic expansion valve of claim 1, wherein, The valve seat portion (10) further has a valve port cavity (102) located on the side away from the adapter (20) of the containing cavity (101), the valve port cavity (102) is in communication with the containing cavity (101), the valve port cavity (102) comprises a valve port section (1021), the valve port section (1021) is a variable-diameter flow regulating section, or the side away from the containing cavity (101) 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 port, the opening angle of the second trumpet port 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 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) which are sequentially arranged and communicated 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 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 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) which are sequentially arranged and communicated 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 straight-through section (10212) 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 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), and the assembly process comprises: 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 one end of the adapter part (20); mounting the sound attenuation part (30) in the valve seat part (10), and abutting one end of the sound attenuation part (30) to the valve seat part (10) along the axial direction of the valve seat part (10); mounting part of the adapter part (20) in the valve seat part (10) and abutting the other end of the sound attenuation part (30), and welding the adapter part (20) to the valve seat part (10); wherein the end of one end of the adapter part (20) is the end of the adapter part (20) located outside the valve seat part (10).

19. The assembly process of claim 18, wherein, The valve seat part (10) comprises a split valve seat (11) and a valve seat core (12), the sound attenuation part (30) comprises a first sound attenuation block (31), a spacer block (32) and a second sound attenuation block (33) abutting in sequence along the mounting direction of the sound attenuation part (30), and the process of mounting the sound attenuation part (30) in the valve seat part (10) comprises: sequentially mounting the second sound attenuation block (33) and the spacer block (32) in the valve seat core (12) to form an assembly, and mounting the assembly in the valve seat (11); or, sequentially mounting the second sound attenuation block (33), the spacer block (32) and the first sound attenuation block (31) in the valve seat core (12) to form an assembly, and mounting the assembly in the valve seat (11).

20. The assembly process of claim 18, wherein, The valve seat part (10) comprises an integrated valve seat (11) and a valve seat core (12), the sound attenuation part (30) comprises a first sound attenuation block (31), a spacer block (32) and a second sound attenuation block (33) abutting in sequence along the mounting direction of the sound attenuation part (30), and the process of mounting the sound attenuation part (30) in the valve seat part (10) further comprises: sequentially mounting the second sound attenuation block (33), the spacer block (32) and the first sound attenuation block (31) in the valve seat core (12).

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 mounting the nut assembly (50) and the valve needle assembly (60) on the valve seat part (10); And before the nut assembly (50) and the valve needle assembly (60) are sequentially installed on the valve seat part (10), the process that one end of the second connecting pipe (42) is welded with the side of the valve seat part (10) further comprises: the guide sleeve (70) is pressed into the valve seat part (10), the second connecting pipe (42), the valve seat part (10) and the guide sleeve (70) are integrally furnace welded, or the second connecting pipe (42) and the valve seat part (10) are furnace welded first, then the guide sleeve (70) is pressed into the valve seat part (10), and the guide sleeve (70) and the valve seat part (10) are laser welded.

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

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