Valve needle assembly and electronic expansion valve having same

Abstract

Disclosed are a valve needle assembly and an electronic expansion valve having same. The valve needle assembly comprises: a valve head (30) having a first end and a second end arranged opposite to each other; the outer side of the valve head is sleeved with a connecting sleeve (40), an annular mounting interval is provided between the second end and the connecting sleeve, a sealing member (50) is provided in the mounting interval, and the sealing member is used for blocking a valve port (61); the end surface of the first end of the valve head and the end surface of the connecting sleeve away from the mounting interval are coplanar to form a first abutting surface (100), and the first end of the valve head is welded and connected to the end of the connecting sleeve away from the mounting interval. The electronic expansion valve can solve the problem in the prior art of unstable installation of sealing members.

Description

Valve needle assembly and electronic expansion valve having it

[0001] This application claims priority to the patent application filed on April 22, 2024, with application number 202420841089.3, entitled "Valve needle assembly and electronic expansion valve having the same". Technical Field

[0002] This application relates to the field of control valve technology, and more specifically, to a valve needle assembly and an electronic expansion valve having therein. Background Technology

[0003] Currently, electronic expansion valves are commonly used in air conditioning systems to regulate the flow rate of refrigerant. An electronic expansion valve includes a valve needle assembly and a valve seat. The valve seat has a valve port, and the valve head of the valve needle assembly typically has a seal. This seal engages with the valve port to improve the sealing performance at the valve port when the electronic expansion valve is closed. In existing technologies, the seal is usually installed in the valve needle assembly through press-fitting or riveting between the valve head and the connecting sleeve. However, the assembly methods used in existing technologies make it difficult to guarantee the stability of the valve head and seal assembly. During valve head operation, the seal can easily detach from the valve head, affecting the sealing performance of the electronic expansion valve. Summary of the Invention

[0004] This application provides a valve needle assembly and an electronic expansion valve having the same, to solve the problem of unstable seal installation in the prior art.

[0005] According to one aspect of this application, a valve needle assembly is provided, comprising: a valve head having a first end and a second end disposed opposite to each other, a connecting sleeve being sleeved on the outer side of the valve head, and an annular mounting gap being provided between the second end and the connecting sleeve, a sealing element being disposed within the mounting gap for sealing the valve port; wherein, the end face of the first end of the valve head is coplanar with the end face of the connecting sleeve away from the mounting gap, and the first end of the valve head is welded to the end of the connecting sleeve away from the mounting gap.

[0006] By applying the technical solution of this application, a sealing element is provided 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 sealing element 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 furthest from the installation interval, compared with the press-fit or interference fit method in the traditional technical solution, the stability of the connection between the valve head and the connecting sleeve can be further improved, thereby further improving the reliability of the sealing element installation. By making the end face of the first end of the valve head coplanar with the end face of the connecting sleeve furthest from the installation interval, the size of the installation interval can be determined, avoiding excessive compression of the sealing element during assembly and preventing excessive deformation of the sealing element. At the same time, because the welding position is far from the sealing element, the impact of the heat generated during welding on the sealing element can be minimized, preventing the sealing element from deforming due to heat and ensuring the sealing performance of the sealing element.

[0007] Furthermore, the valve head has a first section and a second section connected to each other. The end of the second section away from the first section forms the first end. A stepped surface is formed between the first and second sections. The outer diameter of the end of the first section closest to the stepped surface is larger than the outer diameter of the second section. An installation gap is formed between the end face of the connecting sleeve away from the first end and the stepped surface, and at least part of the seal is located within the installation gap. This configuration ensures the stability of the seal installation and improves the sealing effect.

[0008] Furthermore, the seal has a mating section located at the end furthest from the first end. The outer diameter of the mating section gradually increases from the second end towards the first end, and the outer wall surface of the mating section is used for sealing mating with the valve port. This configuration increases the sealing area of ​​the seal and improves its sealing performance.

[0009] Furthermore, an angle α is formed between the outer wall surface and the axis of the valve head, where 10°≤α≤30°. Through this configuration, the rounded corners at the valve port and the mating section form a line seal, thereby further improving the sealing performance of the seal.

[0010] Furthermore, the seal also has a cylindrical section that connects to the end of the mating section near the connecting sleeve, and the diameter of the cylindrical section is larger than the diameter of the mating section. This design ensures the sealing performance of the seal at the valve port and reduces internal leakage at the valve port.

[0011] Furthermore, the first section includes a flow regulation section, which is used to regulate the flow rate at the valve port. Through this configuration, the flow regulation section can change the flow area at the valve port, thereby achieving the flow regulation function of the electronic expansion valve.

[0012] Furthermore, the flow regulation section is a conical section; or, the flow regulation section is multiple continuous conical sections; or, the flow regulation section is a combination of conical and straight sections. Through these settings, a broken-line flow curve can be achieved, meeting the usage requirements of the electronic expansion valve under different conditions.

[0013] Furthermore, the first segment also includes a straight section, which is located on the side of the flow regulating section near the first end. The length of the straight section is L, where L ≤ 0.15 mm. This arrangement facilitates the machining of the periphery of the flow regulating section, prevents errors when the machining accuracy of the flow regulating section is low, and ensures the proper fit between the valve head and the valve port.

[0014] Furthermore, the connecting sleeve has an interference section and a guide section that are interconnected. The interference section is located near the first end and has an interference fit with the valve head. There is a gap between the inner wall of the guide section and the outer wall of the valve head. Through the above configuration, the interference section can ensure the connection effect between the valve head and the connecting sleeve, and the guide section can guide the installation of the valve head and the connecting sleeve.

[0015] Furthermore, 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 abutment surface. With the above configuration, the installation tool can abut against the second abutment surface to facilitate press-fitting when the valve head mates with the connecting sleeve.

[0016] Furthermore, 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. The valve needle assembly also includes: a drive rod, one end of which is used for driving connection with the drive assembly, and the other end of which is connected to the valve head; and a spring, which is disposed between the drive rod and the valve head, and abuts against the first abutting surface.

[0017] According to another aspect of this application, an electronic expansion valve is provided, comprising: a sleeve, a valve seat having a valve port; and a valve body, wherein the sleeve, valve body, and valve seat cooperate to form a receiving cavity, and a valve needle assembly is disposed within the receiving cavity. The valve needle assembly is the aforementioned valve needle assembly, and the valve needle assembly is disposed corresponding to the valve port. The first end of the valve needle assembly is movable 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 element disposed on the valve needle assembly and the valve port, ensuring the sealing performance at the valve head, reducing internal leakage within the receiving cavity, and meeting the requirements for use in low-internal-leakage applications.

[0018] Furthermore, the periphery where the valve port mates with the seal has a rounded corner, with a radius between 0.05mm and 0.5mm. This design allows the periphery of the valve port to mate with the outer wall of the flow regulating section, increasing the sealing area between the seal and the valve port and improving the sealing effect of the seal.

[0019] Furthermore, the valve port has a first port and a second port arranged opposite to each other, and the inner diameter of the valve port remains unchanged along the direction from the first port to the second port. With the above arrangement, a straight flow 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 cooperating between the valve port and the flow regulation section.

[0020] Furthermore, the valve port has a flow section and a guide section connected in sequence. The port of the flow section away from the guide section is sealed with a sealing element. The flow area of ​​the flow section remains constant along the flow direction, while the flow area of ​​the guide section gradually increases in the direction away from the flow section. Through the above arrangement, the guide section can release the pressure of the fluid and reduce the noise caused by fluid turbulence.

[0021] Furthermore, the valve port also has a flow stabilizing section, which is located on the side of the guide section away from the flow section, and the flow area of ​​the flow stabilizing section remains constant along the flow direction. Through the above configuration, the flow stabilizing section can ensure the stability of fluid flow and reduce the noise of the electronic expansion valve. Attached Figure Description

[0022] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0023] Figure 1 shows a schematic diagram of the valve head and connecting sleeve provided in this application;

[0024] Figure 2 shows a schematic diagram of the valve head provided in this application;

[0025] Figure 3 shows a schematic diagram of the electronic expansion valve provided in this application;

[0026] Figure 4 shows a schematic diagram of the valve seat provided in the first embodiment of this application;

[0027] Figure 5 shows a schematic diagram of the valve seat provided in the second embodiment of this application;

[0028] Figure 6 shows a schematic diagram of the valve seat provided in the third embodiment of this application.

[0029] The above-mentioned figures include the following reference numerals: 100, first contact surface; 10, drive rod; 20, spring; 30, valve head; 31, first section; 311, flow regulating section; 312, straight section; 32, second section; 33, stepped surface; 34, machined groove; 341, second contact surface; 40, connecting sleeve; 41, interference fit section; 42, guide section; 50, seal; 51, mating section; 52, cylindrical section; 60, valve seat; 61, valve port; 611, first port; 612, second port; 601, flow section; 602, flow guiding section; 603, flow stabilizing section; 70, valve body; 80, sleeve. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0031] As shown in Figures 1 to 3, this application provides a valve needle assembly, which 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 fitted onto the outer side of the valve head 30. An annular mounting gap is formed between the second end and the connecting sleeve 40, and a sealing element 50 is disposed within the mounting gap to seal the valve port 61. The end face of the first end of the valve head 30 is coplanar with the end face of the connecting sleeve 40 away from the mounting gap, and the first end of the valve head 30 is welded to the end of the connecting sleeve 40 away from the mounting gap.

[0032] By applying the technical solution of this application, a sealing element 50 is provided 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 element 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 furthest from the installation interval, compared with the press-fit or interference fit method in the traditional technical solution, the stability of the connection between the valve head 30 and the connecting sleeve 40 can be further improved, thereby further improving the reliability of the installation of the sealing element 50. By making the end face of the first end of the valve head 30 coplanar with the end face of the connecting sleeve 40 furthest from the installation interval, the size of the installation interval can be determined, avoiding excessive compression of the sealing element 50 during assembly and preventing excessive deformation of the sealing element 50. At the same time, because the welding position is far from the sealing element 50, the impact of the heat generated during the welding process on the sealing element 50 can be minimized, preventing the sealing element 50 from deforming due to heat and ensuring the sealing performance of the sealing element 50.

[0033] 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 narrow and the heat-affected zone is small, which can further reduce the impact of heat on the sealing element 50.

[0034] Specifically, in this application, the sealing element 50 is made of a plastic material with low rigidity, such as PEEK or PTFE. This allows the sealing surface between the sealing element 50 and the valve port 61 to form a soft seal, making the seal more reliable and effectively improving the sealing performance of the electronic expansion valve.

[0035] In this application, the end face of the first end of the valve head 30 and the end face of the connecting sleeve 40 away from the installation interval form a first abutment surface 100. The valve needle assembly also includes a drive rod 10 and a spring 20. One end of the drive rod 10 is used for drive connection with the drive assembly, and the spring 20 is disposed between the drive rod 10 and the valve head 30, abutting against the first abutment surface 100. With 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 providing 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 to the valve head 30 in the direction of the valve port 61, thereby improving the sealing performance of the seal 50.

[0036] Specifically, the drive assembly includes a rotor and a nut. The rotor is driven to connect with the drive rod 10, and the nut is fixedly installed inside the electronic expansion valve. The side wall of the drive rod 10 and the nut have a threaded structure. The rotor drives the drive rod 10 to rotate. The nut can convert the circumferential rotation of the valve needle assembly into axial movement to adjust the distance between the drive rod 10 and the valve head 30 relative to the valve port 61.

[0037] Referring to Figures 1 and 2, the valve head 30 has a first segment 31 and a second segment 32 connected to each other. The end of the second segment 32 away from the first segment 31 forms the first end. The outer diameter of the end of the first segment 31 near the stepped surface 33 is larger than the outer diameter of the second segment 32. A stepped surface 33 is formed between the first segment 31 and the second segment 32. An installation gap is formed between the end face of the connecting sleeve 40 away from the first end and the stepped surface 33. At least part of the seal 50 is located within the installation gap. With the above arrangement, after the valve head 30 is installed, the stepped surface 33 and the end face of the connecting sleeve 40 away from the first end can limit the seal 50 in the axial direction, improving the stability of the seal 50 installation. When the seal 50 blocks the valve port 61 in the axial direction, the installation gap can apply a certain pressure to the seal 50 in the axial direction, improving the sealing effect of the seal 50.

[0038] Furthermore, the seal 50 has a mating section 51 located at the end furthest from the first end. The outer diameter of the mating section 51 gradually increases from the second end towards the first end, and the outer wall surface of the mating section 51 is used for sealing mating with the valve port 61. Through this arrangement, when the outer wall surface of the mating section 51 mates with the valve port 61, it can undergo a certain elastic deformation, thereby improving the sealing performance of the seal 50 and preventing internal leakage inside the electronic expansion valve.

[0039] Specifically, the angle α formed between the outer wall surface and the axis of the valve head 30 is 10°≤α≤30°. When α is less than 10°, the angle α between the outer wall surface of the mating section 51 and the axis of the valve head 30 is too small, resulting in less deformation when the outer wall surface of the mating section 51 seals with the valve port 61, which cannot effectively improve the sealing effect of the valve port 61. When α is greater than 30°, the angle α between the outer wall surface of the mating section 51 and the axis of the valve head 30 is too large, and when the valve head 30 blocks the valve port 61, the length of the sealing element 50 entering the valve port 61 will be reduced, affecting the sealing effect of the sealing element 50. In this application, by setting 10°≤α≤30°, the sealing effect of the sealing element 50 can be effectively improved. Specifically, α can be set to 10°, 20°, or 30°.

[0040] Furthermore, the seal 50 also has a cylindrical section 52, which is connected to the end of the mating section 51 near the connecting sleeve 40. The diameter of the cylindrical section 52 is larger than the diameter of the mating section 51. With the above arrangement, the overall radial dimension of the seal 50 is larger, resulting in a better sealing effect compared to a seal 50 with an outer diameter smaller than that of the first section 31.

[0041] In one embodiment of this application, the first segment 31 has a flow regulating segment 311, which is used to regulate the flow rate at the valve port 61. With the above configuration, when the valve port 61 moves, the distance between the side wall of the first segment 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 regulation function of the electronic expansion valve.

[0042] In this application, the first segment 31 has a flow regulating section 311, which is used to regulate the flow at the valve port 61. With the above configuration, when the valve port 61 moves, the distance between the side wall of the first segment 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.

[0043] In one specific embodiment of this application, the flow regulating section 311 is a conical section, and the outer diameter of the conical section gradually increases or decreases from the first section 31 to the second section 32. This configuration facilitates the determination of the distance between the current flow regulating section 311 and the inner wall of the valve port 61, thereby simplifying the adjustment of the flow rate at the valve port 61.

[0044] In another specific embodiment of this application, the flow regulating section 311 includes multiple continuous conical sections. This configuration allows for flow curve types such as parabolic, broken line, or three-segment flow, meeting the usage requirements of the electronic expansion valve under different conditions and improving its applicability.

[0045] In another specific embodiment of this application, the flow regulating section 311 is a combination of a conical section and a straight section. Specifically, the conical section can adjust the flow area at the valve port 61, while the straight section can keep the flow area at the valve port 61 constant, thereby meeting the adjustment needs of various flow curves.

[0046] Furthermore, the first segment 31 also includes a straight segment 312, which is located on the side of the flow regulating segment 311 near the first end. The length of the straight segment 312 is L, where L ≤ 0.15 mm. Through this arrangement, the straight segment 312 can prevent interference between the periphery of the flow regulating segment 311 and the valve port 61, ensuring the proper fit between the valve head 30 and the valve port 61. This ensures that when the valve is closed, the mating section 51 of the sealing element 50 can abut against the valve port 61 to form a soft seal. Simultaneously, it deburrs the valve head 30, facilitating its machining.

[0047] Furthermore, the connecting sleeve 40 has an interference fit section 41 and a guide section 42 connected to each other. The interference fit section 41 is located near the first end and is interference-fitted with the valve head 30. There is a gap between the inner wall of the guide section 42 and the outer wall of the valve head 30. By setting the interference fit section 41, the assembly effect between the connecting sleeve 40 and the valve head 30 can be guaranteed, and the installation stability of the connecting sleeve 40 can be improved. By setting the gap between the inner wall of the guide section 42 and the outer wall of the valve head 30, the guide section 42 can guide the movement of the second section 32 of the valve head 30 within the connecting sleeve 40 during the installation of the connecting sleeve 40, preventing the valve head 30 from deforming during the press-fitting process and ensuring the assembly effect.

[0048] In some feasible embodiments of this application, a machining groove 34 is provided on the end face of the second end of the valve head 30, and the bottom of the machining groove 34 forms a second abutment surface 341. With the above arrangement, the machining groove 34 can provide a working space for the installation tool. During installation, the installation tool can abut against the second abutment surface 341 to facilitate the press-fitting of the valve head 30 with the connecting sleeve 40, and avoid damage to the outer wall surface and end face of the valve head 30 during press-fitting.

[0049] As shown in Figure 3, an electronic expansion valve is also provided according to an embodiment of this application, which includes a sleeve 80, a valve seat 60, and a valve body 70. The valve seat 60 has a valve port 61. The sleeve 80, valve body 70, and valve seat 60 cooperate to form a receiving cavity. A valve needle assembly is disposed within the receiving cavity. The valve needle assembly is the aforementioned valve needle assembly, positioned corresponding to the valve port 61. The valve needle assembly can move relative to the valve port 61 to adjust the flow rate at the valve port 61. Through this arrangement, a soft seal can be formed between the sealing element 50 on the valve needle assembly and the valve port 61, ensuring the sealing performance of the valve head 30, reducing internal leakage within the receiving cavity, and meeting the requirements for low internal leakage applications.

[0050] Specifically, the periphery where the valve port 61 mates with the seal 50 has a rounded corner, with a radius between 0.05mm and 0.5mm. By setting the periphery of the valve port 61 mates with the seal 50 to a rounded corner, a line seal 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 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 0.05mm, the radius is too small, and the periphery of 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 0.5mm, the radius is too large, and the deformation generated when the seal 50 mates with the valve port 61 cannot be adapted 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 0.05-0.5mm, the sealing effect of the seal 50 can be effectively improved. Specifically, the radius of the fillet can be set to 0.05mm, 0.25mm, or 0.5mm.

[0051] As shown in Figure 4, in the first embodiment of this application, the valve port 61 has a first port 611 and a second port 612 disposed opposite to each other, and the inner diameter of the valve port 61 remains unchanged along the direction from the first port 611 to the second port 612. With the above arrangement, the valve port 61 forms a straight flow section between the first port 611 and the second port 612, so that the valve port 61 and the flow regulating section 311 can cooperate to realize the flow regulating function of the electronic expansion valve.

[0052] As shown in Figure 5, in the second embodiment of this application, the valve port 61 has a flow section 601 and a guide section 602 connected sequentially. The port of the flow section 601 away from the guide section 602 is sealed with the sealing element 50. The flow area of ​​the flow section 601 remains constant along the flow direction, while the flow area of ​​the guide section 602 gradually increases in the direction away from the flow section 601. With the above configuration, the flow section 601 can cooperate with the flow regulating section 311 to realize the flow regulation function of the electronic expansion valve. Compared with the flow section 601, the flow area of ​​the guide 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 of the fluid flowing through the valve port 61 and improving the user experience.

[0053] As shown in Figure 6, in the third embodiment of this application, the valve port 61 further has a flow stabilizing section 603. The flow stabilizing section 603 is disposed on the side of the guide section 602 away from the flow section 601. 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 this application, after the fluid flows out of the guide section 602, the flow stabilizing section 603 can further stabilize the fluid and reduce the noise of the fluid when it flows through the electronic expansion valve.

[0054] In traditional technical solutions, the valve head is typically designed as a straight section, while the valve port, which cooperates with the valve head for flow regulation, is designed as a tapered flow section. A straight section is located at the bottom hole of the valve seat, at the end of the tapered flow section furthest from the valve head. This straight section has a standard diameter, and its diameter is consistent across different models and calibers of electronic expansion valves. This makes it impossible for operators to visually identify the valve seat model (60). During assembly, along the axis of the valve seat (60), whether viewed from above or below, what is visible to the naked eye is the valve seat itself. The inner diameter of the straight section at the bottom hole 60; and the position of the valve port 61 that cooperates with the valve head 30 for flow regulation provided in this application is set as a straight section. Therefore, during the assembly process, whether viewed from above or below in the axial direction of the valve seat 60, the model of the valve seat 60 can be determined by the inner diameter of the straight section of the valve port 61, which is convenient for preventing confusion 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 machined, the electronic expansion valve provided in this application can facilitate the replacement and identification of the valve seat 60.

[0055] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0056] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0057] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0058] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0059] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this application.

[0060] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A valve needle assembly, characterized in that, The valve needle assembly includes: A valve head (30) has a first end and a second end that are arranged opposite to each other. A connecting sleeve (40) is sleeved on the outside of the valve head (30). There is an annular installation gap between the second end and the connecting sleeve (40). A sealing element (50) is provided in the installation gap. The sealing element (50) is used to block the valve port (61). Wherein, the end face of the first end of the valve head (30) is coplanar with the end face of the connecting sleeve (40) away from the installation interval, 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) has a first segment (31) and a second segment (32) connected to each other. The end of the second segment (32) away from the first segment (31) forms the first end. A stepped surface (33) is formed between the first segment (31) and the second segment (32). The outer diameter of the end of the first segment (31) near the stepped surface (33) is larger than the outer diameter of the second segment (32). The end face of the connecting sleeve (40) away from the first end forms the installation gap with the stepped surface (33). At least a portion of the seal (50) is located within the installation gap.

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

4. The valve needle assembly according to claim 3, characterized in that, The outer wall surface forms an angle α with the axis of the valve head (30), where 10°≤α≤30°.

5. The valve needle assembly according to claim 3, characterized in that, The seal (50) also has a cylindrical section (52) connected to one end of the mating section (51) near the connecting sleeve (40), the diameter of the cylindrical section (52) being larger than the diameter of the mating section (51).

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

7. The valve needle assembly according to claim 6, characterized in that, The flow regulation section (311) is a conical section; Alternatively, the flow regulation section (311) may be a series of continuous conical sections; Alternatively, the flow regulation section (311) may be a combination of a conical section and a straight section.

8. The valve needle assembly according to claim 6, characterized in that, The first segment (31) further includes a straight segment (312), which is disposed on the side of the flow regulating segment (311) near the first end.

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

10. The valve needle assembly according to claim 1, characterized in that, The connecting sleeve (40) has an interference section (41) and a guide section (42) connected to each other. The interference section (41) is located near the first end and is interference-fitted with the valve head (30). 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 face of the second end of the valve head (30), and the bottom of the machining groove (34) forms a second abutment surface (341).

12. The valve needle assembly according to claim 1, characterized in that, The end face of the first end of the valve head (30) and the end face of the connecting sleeve (40) away from the mounting interval form a first abutment surface (100). The valve needle assembly further includes: A drive rod (10), one end of which is used to drive the drive assembly, and the other end of which is connected to the valve head (30); A spring (20) is disposed between the drive rod (10) and the valve head (30), and the spring (20) abuts against the first contact surface (100).

13. An electronic expansion valve, characterized in that, The electronic expansion valve includes: Sleeve (80); A valve seat (60) having a valve port (61); The valve body (70), the sleeve (80), the valve body (70) and the valve seat (60) cooperate to form a receiving cavity. A valve needle assembly is provided in the receiving cavity. The valve needle assembly is the valve needle assembly according to any one of claims 1 to 12. The valve needle assembly is provided corresponding to the valve port (61). The valve needle assembly can move relative to the valve port (61) to adjust the flow rate at the valve port (61).

14. The electronic expansion valve according to claim 13, characterized in that, The valve port (61) has a rounded corner around its periphery where it mates with the seal (50), and the radius of the rounded corner is between 0.05 mm and 0.5 mm.

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

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

17. The electronic expansion valve according to claim 16, characterized in that, The valve port (61) also has a flow stabilizing section (603), which is located on the side of the flow guide section (602) away from the flow section (601), and the flow area of ​​the flow stabilizing section (603) remains unchanged along the flow direction.

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