Valve needle assembly and electronic expansion valve with same

Abstract

The utility model provides a valve needle assembly and an electronic expansion valve with the valve needle assembly, the valve needle assembly comprises a valve head, the valve head is provided with a first end and a second end which are oppositely arranged, the outer side of the valve head is sleeved with a connecting sleeve, an annular installation interval is arranged between the second end and the connecting sleeve, a sealing piece is arranged in the installation interval, and the sealing piece is used for blocking a valve port; the end face of the first end of the valve head and the end face of the end, away from the installation interval, of the connecting sleeve are coplanar to form a first abutting face, and the first end of the valve head is welded to the end, away from the installation interval, of the connecting sleeve. By means of the technical scheme, the problem that in the prior art, installation of a sealing piece is not stable can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of control valves, and in particular to a valve needle assembly and an electronic expansion valve having the same. Background Art

[0002] At present, electronic expansion valves are commonly used in air-conditioning systems to adjust the flow rate of refrigerant fluid. The electronic expansion valve includes a valve needle assembly and a valve seat. The valve seat has a valve port. A seal is usually provided at the valve head of the valve needle assembly to improve the sealing performance at the valve port when the electronic expansion valve is closed. In the prior art, the seal in the valve needle assembly is usually installed by press-fitting or riveting the valve head and the connecting sleeve tightly. However, the assembly method adopted in the prior art is difficult to ensure the stability of the assembly of the valve head and the seal. During the movement of the valve head, the seal is likely to fall off from the valve head, affecting the sealing performance of the electronic expansion valve. Summary of the Utility Model

[0003] The utility model provides a valve needle assembly and an electronic expansion valve having the same to solve the problem of unstable installation of the seal in the prior art.

[0004] According to one aspect of the utility model, a valve needle assembly is provided. The valve needle assembly includes: a valve head having a first end and a second end disposed opposite to each other. A connecting sleeve is sleeved outside the valve head. There is an annular installation interval between the second end and the connecting sleeve. A seal is disposed in the installation interval for blocking the valve port. Wherein, the end face of the first end of the valve head and the end face of the connecting sleeve away from the installation interval are coplanar to form a first abutting surface, and the first end of the valve head is welded to the end of the connecting sleeve away from the installation interval.

[0005] Applying the technical solution of the utility model, by providing a seal between the valve head and the connecting sleeve, when the electronic expansion valve is in the fully closed mode, a soft seal can be formed between the seal and the valve port, further improving the sealing performance of the valve head. In this application, by welding the first end of the valve head to the end of the connecting sleeve away from the installation interval, compared with the press-fitting or interference installation method in the traditional technical solution, the stability of the connection between the valve head and the connecting sleeve can be further improved, and thus the reliability of the installation of the seal can be further improved. By making the end face of the first end of the valve head and the end face of the connecting sleeve away from the installation interval coplanar, the size of the installation interval can be determined, avoiding excessive compression of the seal during the assembly process and preventing excessive deformation of the seal. At the same time, since the welding position is far from the seal, the influence of the heat generated during the welding process on the seal can be minimized, preventing the seal from deforming due to heat and ensuring the sealing performance of the seal.

[0006] Furthermore, the valve head has a first section and a second section connected to each other. One end of the second section away from the first section forms a first end. A stepped surface is formed between the first section and the second section. The outer diameter of the end of the first section close to the stepped surface is larger than that of the second section. An installation gap is formed between the end surface of the connecting sleeve away from the first end and the stepped surface. At least part of the seal is located in the installation gap. Through the above arrangement, the stability of the seal installation can be ensured, and the sealing effect of the seal can be improved.

[0007] Furthermore, the seal has a mating section located at the end away from the first end. The outer diameter of the mating section gradually increases from the second end to the first end. The outer wall surface of the mating section is used for sealing cooperation with the valve port. Through the above arrangement, the sealing area of the seal can be increased, and the sealing performance of the seal can be improved.

[0008] Furthermore, an angle α is formed between the outer wall surface and the axis of the valve head, and 10° ≤ α ≤ 30°. Through the above arrangement, a line seal is formed between the outer wall surface of the mating section and the fillet at the valve port, thereby further improving the sealing performance of the seal.

[0009] Furthermore, the seal also has a cylindrical section connected to the end of the mating section close to the connecting sleeve. The diameter of the cylindrical section is larger than that of the mating section. Through the above arrangement, the sealing performance of the seal for the valve port can be ensured, and the internal leakage at the valve port can be reduced.

[0010] Furthermore, the first section has a flow regulation section for regulating the flow rate at the valve port. Through the above arrangement, the flow regulation section can change the flow area at the valve port, realizing the flow regulation function of the electronic expansion valve.

[0011] Furthermore, the flow regulation section is a conical section; or, the flow regulation section is a multi-segment continuous conical section; or, the flow regulation section is a combination of a conical section and a straight section. Through the above arrangement, the regulation of the flow curve in a stepped shape can be realized, meeting the use requirements of the electronic expansion valve in different situations.

[0012] Furthermore, the first section also includes a straight section arranged on the side of the flow regulation section close to the first end. The length of the straight section is L, and L ≤ 0.15 mm. Through the above arrangement, the processing at the periphery of the flow regulation section can be facilitated, preventing errors from occurring when the processing accuracy of the flow regulation section is low, and ensuring the matching effect between the valve head and the valve port.

[0013] Furthermore, the connecting sleeve has an interference section and a guiding section connected to each other. The interference section is arranged close to the first end. An interference fit is formed between the interference section and the valve head. A gap is formed between the inner wall of the guiding section and the outer wall of the valve head. Through the above arrangement, the interference section can ensure the connection effect between the valve head and the connecting sleeve, and the guiding section can guide the installation of the valve head and the connecting sleeve.

[0014] Further, a machining groove is provided on the end face of the second end of the valve head, and the bottom of the machining groove forms a second abutting surface. Through the above arrangement, the installation tool can abut against the second abutting surface to facilitate the press-fitting when the valve head is fitted with the connecting sleeve.

[0015] Further, the valve needle assembly further includes: a driving rod, one end of the driving rod is used for driving connection with the driving assembly, and the other end of the driving rod is connected to the valve head; a spring, the spring is arranged between the driving rod and the valve head, and the spring abuts against the first abutting surface.

[0016] According to another aspect of the present invention, an electronic expansion valve is provided, which includes: a sleeve, a valve seat, and the valve seat has a valve port; a valve body, the sleeve, the valve body and the valve seat cooperate to form a receiving cavity, and a valve needle assembly is arranged in the receiving cavity. The valve needle assembly is the above-mentioned valve needle assembly, the valve needle assembly is arranged corresponding to the valve port, and the first end of the valve needle assembly can move relative to the valve port to adjust the flow rate at the valve port. Through the above arrangement, a soft seal can be formed between the sealing member provided on the valve needle assembly and the valve port, ensuring the sealing performance at the valve head, reducing the internal leakage in the receiving cavity, and meeting the use requirements in the field of low internal leakage.

[0017] Further, the periphery of the valve port in cooperation with the sealing member has a fillet, and the radius of the fillet is between 0.05 - 0.5 mm. Through the above arrangement, the periphery of the valve port can be matched with the outer wall surface of the flow regulation section, increasing the sealing area between the sealing member and the valve port, and enhancing the sealing effect of the sealing member.

[0018] Further, the valve port has a first port and a second port arranged opposite to each other, and along the direction from the first port to the second port, the inner diameter of the valve port remains unchanged. Through the above arrangement, a straight flow passage section is formed between the first port and the second port of the valve port, so that the flow regulation function of the electronic expansion valve can be realized by the cooperation between the valve port and the flow regulation section.

[0019] Further, the valve port has a flow passage section and a diversion section connected in sequence. The port on the side of the flow passage section far from the diversion section is in sealed cooperation with the sealing member. The flow area of the flow passage section remains unchanged along the flow direction, and the flow area of the diversion section gradually increases along the direction away from the flow passage section. Through the above arrangement, the diversion section can release the pressure of the fluid and reduce the noise generated by fluid turbulence. Description of the Drawings

[0020] The schematic diagrams of the drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0021] Figure 1 The structural schematic diagram of the cooperation between the valve head and the connecting sleeve provided by the present invention is shown;

[0022] Figure 2 Shows a schematic structural diagram of the valve head provided by the present utility model;

[0023] Figure 3 Shows a schematic structural diagram of the electronic expansion valve provided by the present utility model;

[0024] Figure 4 Shows a schematic structural diagram of the valve seat provided by the first embodiment of the present utility model;

[0025] Figure 5 Shows a schematic structural diagram of the valve seat provided by the second embodiment of the present utility model;

[0026] Figure 6 Shows a schematic structural diagram of the valve seat provided by the third embodiment of the present utility model.

[0027] Among them, the above-mentioned drawings include the following reference numerals:

[0028] 100, the first abutting surface;

[0029] 10, the driving rod;

[0030] 20, the spring;

[0031] 30, the valve head;

[0032] 31, the first section; 311, the flow regulation section; 312, the straight section;

[0033] 32, the second section;

[0034] 33, the stepped surface;

[0035] 34, the machining groove; 341, the second abutting surface;

[0036] 40, the connecting sleeve; 41, the interference section; 42, the guiding section;

[0037] 50, the seal; 51, the mating section; 52, the cylindrical section;

[0038] 60, the valve seat;

[0039] 61, the valve port; 611, the first port; 612, the second port;

[0040] 601, the flow-through section; 602, the diversion section; 603, the flow-stabilizing section;

[0041] 70, the valve body;

[0042] 80, the sleeve. Specific embodiments

[0043] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0044] As Figures 1 to 3 shown, an embodiment of the present invention provides a valve needle assembly, and the valve needle assembly includes a valve head 30. The valve head 30 has a first end and a second end disposed opposite to each other. A connecting sleeve 40 is sleeved outside the valve head 30. There is an annular installation interval between the second end and the connecting sleeve 40, and a sealing member 50 is disposed in the installation interval. The sealing member is used to block a valve port 61. Among them, the end surface of the first end of the valve head 30 and the end surface of the connecting sleeve 40 away from the installation interval are coplanar to form a first abutting surface, and the first end of the valve head 30 is welded to the end of the connecting sleeve 40 away from the installation interval.

[0045] Applying the technical solution of the present invention, by providing the sealing member 50 between the valve head 30 and the connecting sleeve 40, when the electronic expansion valve is in the fully closed mode, a soft seal can be formed between the sealing member 50 and the valve port 61, further improving the sealing performance of the valve head 30. In this application, by welding the first end of the valve head 30 to the end of the connecting sleeve 40 away from the installation interval, compared with the press-fitting or interference installation methods in the traditional technical solutions, the connection stability between the valve head 30 and the connecting sleeve 40 can be further improved, and further the reliability of the installation of the sealing member 50 can be improved. By making the end surface of the first end of the valve head 30 and the end surface of the connecting sleeve 40 away from the installation interval coplanar, the size of the installation interval can be determined, avoiding excessive compression of the sealing member 50 during the assembly process and preventing excessive deformation of the sealing member 50. At the same time, since the welding position is far from the sealing member 50, the influence of the heat generated during the welding process on the sealing member 50 can be minimized, preventing the sealing member 50 from deforming due to heat and ensuring the sealing performance of the sealing member 50.

[0046] Specifically in this application, the valve head 30 and the connecting sleeve 40 can be connected by laser welding. The weld width formed by laser welding is relatively narrow, and the heat affected zone is relatively small, which can further reduce the influence of heat on the sealing member 50.

[0047] Specifically in this application, the sealing member 50 is made of a plastic material with relatively low rigidity, such as PEEK material or PTFE material, etc. In this way, a soft seal can be formed on the sealing surface between the sealing member 50 and the valve port 61, and the seal is more reliable, which can effectively improve the sealing performance of the electronic expansion valve.

[0048] In the present application, the valve needle assembly further includes a drive rod 10 and a spring 20. Among them, one end of the drive rod 10 is used for driving connection with a drive assembly, the spring 20 is arranged between the drive rod 10 and the valve head 30, and the spring 20 abuts against the first abutting surface 100. Through the above arrangement, the drive rod 10 can drive the valve head 30 to move relative to the valve port 61 to adjust the flow rate at the valve port 61. By arranging the spring 20 between the drive rod 10 and the valve head 30, when the electronic expansion valve is in the fully closed mode, the spring 20 can provide an elastic force in the direction towards the valve port 61 for the valve head 30 to improve the sealing performance of the seal 50.

[0049] Specifically, the drive assembly includes a rotor and a nut. The rotor is in driving connection with the drive rod 10, the nut is fixedly arranged inside the electronic expansion valve, and there is a threaded structure between the side wall of the drive rod 10 and the nut. The rotor drives the drive rod 10 to rotate, and through the nut, the circumferential rotation can be converted into axial movement to adjust the distance between the drive rod 10 and the valve head 30 relative to the valve port 61.

[0050] Reference Figure 1 and Figure 2 As shown, the valve head 30 has a first section 31 and a second section 32 which are connected to each other. One end of the second section 32 far from the first section 31 forms a first end. A stepped surface 33 is formed between the first section 31 and the second section 32. The outer diameter of one end of the first section 31 close to the stepped surface 33 is larger than the outer diameter of the second section 32. An installation interval is formed between the end surface of the connecting sleeve 40 far from the first end and the stepped surface 33. At least part of the seal 50 is located in the installation interval. Through the above arrangement, after the valve head 30 is installed, the stepped surface 33 and the end surface of the connecting sleeve 40 far from the first end can limit the seal 50 axially to improve the installation stability of the seal 50. When the seal 50 seals the valve port 61 axially, the installation interval can apply a certain pressure to the seal 50 axially to improve the sealing effect of the seal 50.

[0051] Furthermore, the seal 50 has a mating section 51. The mating section 51 is located at one end far from the first end. The outer diameter of the mating section 51 gradually increases from the second end to the first end direction. The outer wall surface of the mating section 51 is used for sealing cooperation with the valve port 61. Through the above arrangement, when the outer wall surface of the mating section 51 is in cooperation with the port of the valve port 61, the outer wall surface of the mating section 51 can generate a certain elastic deformation, thereby improving the sealing performance of the seal 50 and preventing internal leakage inside the electronic expansion valve.

[0052] Specifically, an included angle α is formed between the outer wall surface and the axis of the valve head 30, where 10° ≤ α ≤ 30°. When α is less than 10°, the included angle α formed between the outer wall surface of the mating section 51 and the axis of the valve head 30 is too small, and the deformation generated when the outer wall surface of the mating section 51 is in sealing fit with the valve port 61 is small, which cannot effectively improve the sealing effect on the valve port 61. When α is greater than 30°, the included angle α formed between the outer wall surface of the mating section 51 and the axis of the valve head 30 is too large. When the valve head 30 seals the valve port 61, the length of the seal 50 entering the valve port 61 will be reduced, affecting the sealing effect of the seal 50. In this application, by setting 10° ≤ α ≤ 30°, the sealing effect of the seal 50 can be effectively improved. Specifically, α can be set to 10°, 20° or 30°.

[0053] Furthermore, the seal 50 further has a cylindrical section 52. The cylindrical section 52 is connected to one end of the mating section 51 close to the connecting sleeve 40, and the diameter of the cylindrical section 52 is greater than the diameter of the mating section 51. Through the above settings, the overall radial dimension of the seal 50 is larger, and compared with the seal 50 whose outer diameter is smaller than the outer diameter of the first section 31, the sealing effect is better.

[0054] In an embodiment of the present application, the first section 31 has a flow regulating section 311 for regulating the flow rate at the valve port 61. Through the above settings, when the valve port 61 moves, the distance between the side wall of the first section 31 and the inner wall of the valve port 61 can change with the movement of the valve head 30, thereby changing the flow area at the valve port 61 and realizing the flow regulating function of the electronic expansion valve.

[0055] In this application, the first section 31 has a flow regulating section 311 for regulating the flow rate at the valve port 61. Through the above settings, when the valve port 61 moves, the distance between the side wall of the first section 31 and the inner wall of the valve port 61 can change with the movement of the valve head 30, thereby changing the flow area at the valve port 61 and realizing the flow regulating function of the electronic expansion valve.

[0056] In a specific embodiment of the present application, the flow regulating section 311 is a tapered section, and the outer diameter of the tapered section gradually increases or gradually decreases from the first section 31 to the second section 32. Through the above settings, it is convenient to determine the current distance between the flow regulating section 311 and the inner wall of the valve port 61, and thus convenient to regulate the flow rate at the valve port 61.

[0057] In another specific embodiment of the present application, the flow regulating section 311 includes a plurality of continuous tapered sections. Through the above settings, it can meet the flow curve types such as parabola, broken line or three-segment type, meet the use requirements of the electronic expansion valve in different situations, and improve the applicability of the electronic expansion valve.

[0058] In another specific embodiment of the present application, the flow regulating section 311 is a combination of a tapered section and a straight section. Specifically, the tapered section can adjust the flow area at the valve port 61, and the straight section can keep the flow area at the valve port 61 unchanged, thereby meeting the regulation needs of various flow curves.

[0059] Furthermore, the first section 31 also includes a straight section 312, which is arranged on one side of the flow regulating section 311 close to the first end, and the length of the straight section 312 is L, L≤0.15mm. Through the above arrangement, the straight section 312 can avoid interference between the periphery of the flow regulating section 311 and the valve port 61, ensure the matching effect between the valve head 30 and the valve port 61, and ensure that when the valve is closed, the matching section 51 of the sealing member 50 can abut against the valve port 61 to form a soft seal; at the same time, burrs can be removed to facilitate the processing of the valve head 30.

[0060] Furthermore, the connecting sleeve 40 has an interference section 41 and a guide section 42 that are connected to each other. The interference section 41 is arranged near the first end. The interference section 41 and the valve head 30 are in interference fit. There is a gap between the inner wall of the guide section 42 and the outer wall of the valve head 30. By providing the interference section 41, the assembly effect between the connecting sleeve 40 and the valve head 30 can be ensured, and the stability of the installation of the connecting sleeve 40 can be improved. By providing a gap between the inner wall of the guide section 42 and the outer wall of the valve head 30, during the installation of the connecting sleeve 40, the guide section 42 can guide the movement of the second section 32 of the valve head 30 in the connecting sleeve 40, thereby preventing the valve head 30 from being deformed during the press-fitting process and ensuring the assembly effect.

[0061] In some feasible embodiments of the present application, a machining groove 34 is provided on the end surface of the second end of the valve head 30, and the bottom of the machining groove 34 forms a second abutting surface 341. Through the above arrangement, the machining groove 34 can provide a working space for the installation tool, and during installation, the installation tool can abut against the second abutting surface 341, so as to facilitate the press-fitting of the valve head 30 and the connecting sleeve 40, and avoid damaging the outer wall surface and end surface of the valve head 30 during press-fitting.

[0062] like Figure 3 As shown, according to the embodiment of the present application, an electronic expansion valve is also provided, which includes a sleeve 80, a valve seat 60 and a valve body 70. Among them, the valve seat 60 has a valve port 61, and the sleeve 80, the valve body 70 cooperate with the valve seat 60 to form a receiving chamber, and a valve needle assembly is arranged in the receiving chamber, and the valve needle assembly is the above-mentioned valve needle assembly, and the valve needle assembly is arranged corresponding to the valve port 61, and the valve needle assembly can move relative to the valve port 61 to adjust the flow at the valve port 61. Through the above-mentioned arrangement, a soft seal can be formed with the valve port 61 through the sealing member 50 arranged on the valve needle assembly, thereby ensuring the sealing performance of the valve head 30, reducing the internal leakage in the receiving chamber, and meeting the use requirements of the low internal leakage field.

[0063] Specifically, the periphery where the valve port 61 mates with the seal 50 has a rounded corner, and the radius of the rounded corner is between 0.05 - 0.5 mm. By setting the periphery where the valve port 61 mates with the seal 50 to have a rounded corner, a line seal fit can be formed between the rounded corner of the valve port 61 and the outer wall surface of the mating section 51 of the seal 50, further reducing the internal leakage of the electronic expansion valve and ensuring the sealing effect of the seal 50. When the radius of the rounded corner is less than 0.05 mm, the radius of the rounded corner is too small, and the periphery where the valve port 61 mates with the seal 50 is too sharp, which will affect the service life of the seal 50; when the radius of the rounded corner is greater than 0.5 mm, the radius of the rounded corner is too large, and when the seal 50 mates with the valve port 61, the deformation generated cannot adapt to the rounded corner, which may affect the mating effect between the seal 50 and the valve port 61. In this application, by setting the radius of the rounded corner between 0.05 - 0.5 mm, the sealing effect of the seal 50 can be effectively improved. Specifically, the radius of the rounded corner can be set to 0.05 mm, 0.25 mm, or 0.5 mm.

[0064] Specifically, as Figure 4 shown, in the first embodiment of this application, the valve port 61 has a first port 611 and a second port 612 that are oppositely arranged. Along the direction from the first port 611 to the second port 612, the inner diameter of the valve port 61 remains unchanged. Through the above setting, a straight flow section is formed between the first port 611 and the second port 612 of the valve port 61. In this way, the flow regulation function of the electronic expansion valve can be realized by the cooperation between the valve port 61 and the flow regulation section 311.

[0065] Specifically, as Figure 5 shown, in the second embodiment of this application, the valve port 61 has a flow section 601 and a diversion section 602 that are sequentially connected. The port of the flow section 601 away from the diversion section 602 is sealingly mated with the seal 50. The flow area of the flow section 601 remains unchanged along the flow direction, and the flow area of the diversion section 602 gradually increases along the direction away from the flow section 601. Through the above setting, the flow section 601 can cooperate with the flow regulation section 311 to realize the flow regulation function of the electronic expansion valve. Compared with the flow section 601, the flow area of the diversion section 602 gradually increases, which can release the pressure of the fluid to a certain extent, reduce the turbulence of the fluid at the valve port 61, thereby reducing the noise when the fluid flows through the valve port 61 and improving the user experience.

[0066] Specifically, as Figure 6As shown in the figure, in the third embodiment of the present application, the valve port 61 further has a flow stabilizing section 603. The flow stabilizing section 603 is arranged on the side of the diversion section 602 away from the flow through section 601, and the flow area of the flow stabilizing section 603 remains unchanged. Compared with the second embodiment, according to the flow stabilizing section 603 in the third embodiment of the present application, after the fluid flows out of the diversion section 602, the flow stabilizing section 603 can further stabilize the fluid and reduce the noise of the fluid when flowing through the electronic expansion valve.

[0067] In the traditional technical solution, the valve head as a whole is usually set as a straight section, and the position where the valve port cooperates with the valve head for flow regulation is set as a conical flow through section. At the bottom hole of the valve seat, that is, at the end of the conical flow through section away from the valve head, a straight section is provided. This straight section is the standard diameter, and the diameters of this straight section of electronic expansion valves of different model calibers are the same, resulting in that when the staff makes a visual identification, they cannot intuitively see the model of the valve seat 60. During the assembly process, along the axial direction of the valve seat 60, whether looking down or up, what is observed by the naked eye is the inner diameter of the straight section at the bottom hole of the valve seat 60; while in the valve port 61 provided in the present application, the position where it cooperates with the valve head 30 for flow regulation is set as a straight section. Therefore, during the assembly process, whether looking down or up in the axial direction of the valve seat 60, the model of the valve seat 60 can be judged through the inner diameter of the straight section of the valve port 61, which is convenient for anti-mixing during the production process; and, compared with the structure in the traditional technical solution where the valve seat 60 and the valve body 70 are integrally processed and formed, the electronic expansion valve provided in the present application can facilitate the replacement and identification of the valve seat 60.

[0068] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0069] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the description. In all the examples shown and discussed here, any specific values should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0070] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by orientation terms such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom" are generally based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description. Without contrary description, these orientation terms do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus should not be construed as limiting the protection scope of the present invention; the orientation terms "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0071] For the convenience of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "above" can be used here to describe the spatial positional relationships of one device or feature shown in the drawings with other devices or features. It should be understood that the spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation shown in the drawings of the device. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations should be made for the spatial relative descriptions used here.

[0072] In addition, it should be noted that the use of words such as "first", "second" to limit components is only for the convenience of distinguishing the corresponding components. Without otherwise stating, the above words have no special meanings, and thus should not be construed as limiting the protection scope of the present invention.

[0073] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. For those skilled in the art, the present utility model may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A valve needle assembly, characterized in that: The valve needle assembly comprises: A valve head (30) having a first end and a second end arranged opposite to each other, a connecting sleeve (40) being sleeved on the outer side of the valve head (30), an annular mounting gap being provided between the second end and the connecting sleeve (40), a sealing member (50) being provided in the mounting gap, and the sealing member (50) being used for blocking the valve port (61); The end surface of the first end of the valve head (30) and the end surface of the connecting sleeve (40) away from the installation interval are coplanar to form a first abutment surface (100), and the first end of the valve head (30) is welded to the end of the connecting sleeve (40) away from the installation interval.

2. The valve needle assembly according to claim 1, characterized in that: The valve head (30) comprises a first section (31) and a second section (32) which are connected to each other; an end of the second section (32) away from the first section (31) forms the first end; a step surface (33) is formed between the first section (31) and the second section (32); an outer diameter of an end of the first section (31) close to the step surface (33) is greater than an outer diameter of the second section (32); an installation gap is formed between an end surface of the connecting sleeve (40) away from the first end and the step surface (33); and at least a portion of the sealing member (50) is located within the installation gap.

3. The valve needle assembly according to claim 1, characterized in that: The sealing member (50) comprises a mating section (51), wherein the mating section (51) is located at an end away from the first end, and the outer diameter of the mating section (51) gradually increases from the second end toward the first end, and the outer wall surface of the mating section (51) is used for sealingly mating with the valve port (61).

4. The valve needle assembly according to claim 3, characterized in that: An included angle α is formed between the outer wall surface and the axis of the valve head (30), and the angle is 10°≤α≤30°.

5. The valve needle assembly according to claim 3, characterized in that: The sealing member (50) further comprises a cylindrical section (52), wherein the cylindrical section (52) is connected to an end of the fitting section (51) close to the connecting sleeve (40), and the diameter of the cylindrical section (52) is greater than the diameter of the fitting section (51).

6. The valve needle assembly according to claim 2, characterized in that: The first section (31) has a flow regulating section (311), and the flow regulating section (311) is used to regulate the flow at the valve port (61).

7. The valve needle assembly according to claim 6, characterized in that: The flow regulating section (311) is a conical section; Or, the flow regulating section (311) is a plurality of continuous conical sections; Alternatively, the flow regulating section (311) is a combination of a tapered section and a straight section.

8. The valve needle assembly according to claim 6, characterized in that: The first section (31) further comprises a straight section (312), and the straight section (312) is arranged on a side of the flow regulating section (311) close to the first end.

9. The valve needle assembly according to claim 8, characterized in that: The length of the straight line segment (312) is L, and L≤0.15 mm.

10. The valve needle assembly according to claim 1, characterized in that: The connecting sleeve (40) comprises an interference section (41) and a guide section (42) which are connected to each other. The interference section (41) is arranged close to the first end. The interference section (41) and the valve head (30) are in interference fit. There is a gap between the inner wall of the guide section (42) and the outer wall of the valve head (30).

11. The valve needle assembly according to claim 1, characterized in that: A machining groove (34) is provided on the end surface of the second end of the valve head (30), and the bottom of the machining groove (34) forms a second abutting surface (341).

12. The valve needle assembly according to claim 1, characterized in that: The valve needle assembly also includes: A driving rod (10), one end of the driving rod (10) being used for driving connection with the driving assembly, and the other end of the driving rod (10) being connected with the valve head (30); A spring (20), wherein the spring (20) is arranged between the driving rod (10) and the valve head (30), and the spring (20) abuts against the first abutting surface (100).

13. An electronic expansion valve, characterized in that: The electronic expansion valve comprises: Casing (80); A valve seat (60), wherein the valve seat (60) has a valve port (61); The valve body (70), the sleeve (80), the valve body (70) and the valve seat (60) cooperate to form a accommodating cavity, a valve needle assembly is arranged in the accommodating cavity, the valve needle assembly is the valve needle assembly described in any one of claims 1 to 12, the valve needle assembly is arranged corresponding to the valve port (61), and the valve needle assembly can move relative to the valve port (61) to adjust the flow at the valve port (61).

14. The electronic expansion valve according to claim 13, characterized in that: The periphery of the valve port (61) and the sealing member (50) where they cooperate has a rounded corner, and the radius of the rounded corner is between 0.05-0.5 mm.

15. The electronic expansion valve according to claim 13, characterized in that: The valve port (61) comprises a first port (611) and a second port (612) which are arranged opposite to each other, and along the direction from the first port (611) to the second port (612), the inner diameter of the valve port (61) remains unchanged.

16. The electronic expansion valve according to claim 13, characterized in that: The valve port (61) comprises a flow section (601) and a guide section (602) which are connected in sequence, and a port of the flow section (601) on a side away from the guide section (602) is sealed with the sealing member (50), and a flow area of ​​the flow section (601) remains unchanged along the flow direction, while a flow area of ​​the guide section (602) gradually increases in a direction away from the flow section (601).

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