Valve needle assembly and electronic expansion valve

Abstract

A valve needle assembly and an electronic expansion valve, relating to the field of valve technology, include a first valve needle and a second valve needle. The first valve needle is provided with a first water channel and a second water channel communicating with each other; the second valve needle is slidably connected to the first valve needle, so that the second valve needle has a first operating state and a second operating state that can be switched between each other; in the first operating state, the second valve needle blocks the first water channel and the second water channel, and the second valve needle can slide relative to the first valve needle along a first direction; in the second operating state, the second valve needle opens the first water channel and the second water channel, and the second valve needle can drive the first valve needle to slide together along the first direction. It can accommodate both small-range and large-range flow regulation, and has a simple structure, is easy to disassemble and assemble, and can reduce manufacturing and maintenance costs.

Description

Technical Field

[0001] This invention relates to the field of valve technology, and more specifically, to a valve needle assembly and an electronic expansion valve. Background Technology

[0002] Electronic expansion valves utilize electrical signals generated by the regulated parameters to control the voltage or current applied to the expansion valve, thereby regulating the refrigerant supply. Variable capacity refrigeration systems require a wide range of refrigerant supply adjustment and rapid response, which traditional throttling devices (such as thermostatic expansion valves) struggle to handle effectively. Electronic expansion valves, however, meet these requirements well. They are typically driven by a motor, which rotates a lead screw. This screw, in turn, causes a nut to move a valve needle axially back and forth, controlling the opening and closing of the inlet and outlet. Depending on the operating environment, electronic expansion valves require high flow control precision, and the flow adjustment range of a single valve is limited, making it impossible to simultaneously achieve both small and large-range flow regulation. When simultaneous small and large-range regulation is needed, multiple electronic expansion valves are required, resulting in a complex structure. Summary of the Invention

[0003] The objectives of this invention include, for example, providing a valve needle assembly and an electronic expansion valve that can accommodate both small and large flow rate regulation, simplify the structure, and reduce costs.

[0004] The embodiments of the present invention can be implemented as follows: In a first aspect, the present invention provides a valve needle assembly, comprising: A first valve needle and a second valve needle, wherein the first valve needle is provided with a first water channel and a second water channel that are connected; the second valve needle is slidably connected to the first valve needle so that the second valve needle has a first working state and a second working state that can be switched between each other; in the first working state, the second valve needle blocks the first water channel and the second water channel, and the second valve needle can slide relative to the first valve needle in a first direction; in the second working state, the second valve needle opens the first water channel and the second water channel, and the second valve needle can drive the first valve needle to slide together in the first direction.

[0005] In an optional embodiment, the first valve needle is provided with a first limiting structure, the second valve needle is provided with a second limiting structure, the first limiting structure is located on the roadbed on which the second limiting structure slides along the first direction, and the first limiting structure is used to contact the second limiting structure.

[0006] In an optional embodiment, the first valve needle is provided with a guide hole, the guide hole having a first hole wall and a second hole wall spaced apart in a first direction, and at least a portion of the first hole wall is configured as the first limiting structure. The second valve needle is provided with a guide post, and part of the outer peripheral surface of the guide post is configured as the second limiting structure; the guide post passes through the guide hole and is located between the first hole wall and the second hole wall.

[0007] In an optional embodiment, the second valve needle and the first valve needle are fixed relative to each other in the circumferential direction of the second valve needle.

[0008] In an optional embodiment, the first valve needle is provided with a water pressure balancing chamber and an assembly hole, and the water pressure balancing chamber is connected to the second water channel through the assembly hole; The second valve needle is provided with a water pressure balance channel and an inner water pressure balance hole. One end of the water pressure balance channel is connected to the second water channel, and the other end is connected to the inner water pressure balance hole. The second valve needle is simultaneously inserted into the water pressure balance cavity and the assembly hole. The inner water pressure balance hole is connected to the water pressure balance cavity, and the second valve needle is sealed to the assembly hole.

[0009] In an optional embodiment, the second valve needle includes a first cylinder, a second cylinder, and a third cylinder connected in sequence, with the outer diameters of the first cylinder, the second cylinder, and the third cylinder gradually decreasing. The first cylinder and the second cylinder are both located within the water pressure balance chamber. The first cylinder is slidably fitted with the inner circumferential surface of the water pressure balance chamber, and the second cylinder has a gap with the inner circumferential surface of the water pressure balance chamber to form an annular space. The inner water pressure balance hole communicates with the annular space. The third cylinder is slidably inserted into the assembly hole. When in the first working state, the outer circumferential surface of the third cylinder is sealed against the hole wall of the first water channel. The cavities of the first cylinder, the second cylinder, and the third cylinder are connected to form the water pressure balance channel.

[0010] In an optional embodiment, the first valve needle includes a body, a first pad, a second pad, and a sealing plate, and the water pressure balance chamber, the assembly hole, and the second water channel are all disposed on the body; The sealing plate includes an integral plate body and a boss. The boss is provided with a first through hole, which penetrates the plate body. The second pad is provided with a second through hole. The first pad and the second pad cooperate to clamp the plate body. The boss penetrates the first pad. The first through hole and the second through hole are connected and form the first water channel. The first pad and the second pad are both fixedly connected to the main body. When in the first working state, the outer peripheral surface of the third cylinder is in a sealing fit with the wall of the first through hole.

[0011] In a second aspect, the present invention provides an electronic expansion valve, the electronic expansion valve comprising: The valve assembly comprises a valve seat, a valve port, a drive assembly, an elastic element, and a valve needle assembly according to any one of the foregoing embodiments; one end of the valve seat is connected to the valve port, and the other end of the valve seat is connected to the drive assembly, which is connected to the second valve needle for driving the second valve needle to reciprocate in a first direction or a second direction opposite to the first direction; the first valve needle is slidably connected to the valve port; the elastic element is simultaneously connected to the valve seat and the first valve needle for giving the first valve needle a tendency to slide along the second direction; When in the first working state, the first valve needle closes the valve port under the action of the elastic element.

[0012] In an optional embodiment, the drive assembly includes a lead screw and a nut, the lead screw being rotatably engaged with the valve seat, the lead screw and the valve seat being fixed relative to each other in the axial direction of the lead screw; the nut being screwed to the lead screw, the nut being fixedly connected to the second valve needle; the valve needle assembly and the valve seat being fixed relative to each other in the circumferential direction of the first valve needle.

[0013] In an optional embodiment, the valve seat is provided with an anti-rotation groove, and the first valve needle is provided with an anti-rotation protrusion. The anti-rotation protrusion and the anti-rotation groove are slidably connected, and the two are relatively fixed in the circumferential direction of the first valve needle.

[0014] The beneficial effects of the embodiments of the present invention include, for example: In summary, the valve needle assembly provided in this embodiment, through the cooperation of a first valve needle and a second valve needle, initially operates with the first valve needle in a closed position and the second valve needle in a first working state that closes both the first and second water channels. When a small-range flow regulation is required, the second valve needle slides along a first direction, opening both water channels and achieving a small flow rate. When a large flow rate is required, force is applied to the second valve needle, causing it to move along the first direction to a second working state. In this state, the sliding of the second valve needle along the first direction drives the first valve needle, opening its valve and increasing the flow rate. Thus, by controlling the movement of the second valve needle, both small-range and large-range flow regulation can be achieved. This allows for flexible use in different scenarios, strong adaptability, and simplifies the structure and reduces costs by eliminating the need for multiple electronic regulating valves. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the valve needle assembly provided in this embodiment; Figure 2 This is a cross-sectional view of the valve needle assembly provided in this embodiment; Figure 3 This is an exploded view of the valve needle assembly provided in this embodiment; Figure 4 This is a cross-sectional view of the exploded structure of the valve needle assembly provided in this embodiment; Figure 5 This is a schematic diagram of the structure of the electronic expansion valve provided in this embodiment; Figure 6 This is a cross-sectional view of the electronic expansion valve provided in this embodiment.

[0017] icon: 100-First valve needle; 101-First water channel; 102-Second water channel; 103-Water pressure balance chamber; 104-Assembly hole; 105-Water collection chamber; 106-Mounting hole; 110-Body; 111-Anti-rotation protrusion; 112-Guide hole; 113-Lower shell; 114-Top cover; 120-First pad; 130-Second pad; 131-Second through hole; 140-Third pad; 150-Sealing ring; 160-Sealing plate; 161-Plate body; 162-Boss; 1621-First through hole; 200-Second valve needle; 201-Water pressure balance channel; 210-First cylinder; 211-Guide post; 220-Second cylinder; 221-Inner water pressure balance hole; 230-Third cylinder; 001-Valve seat; 011-Positioning hole; 012-Anti-rotation groove; 002-Valve port; 021-Third water channel; 022-Fourth water channel; 003-Drive assembly; 031-Lead screw; 032-Nut; 004-Elastic element. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0021] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and 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 of this invention.

[0022] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0023] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0024] Please refer to Figures 1-4 This embodiment provides a valve needle assembly, which includes a first valve needle 100 and a second valve needle 200. The first valve needle 100 is provided with a first channel 101 and a second channel 102 that communicate with each other; the second valve needle 200 is slidably connected to the first valve needle 100 so that the second valve needle 200 has a first working state and a second working state that can be switched between each other; when in the first working state, the second valve needle 200 blocks the first channel 101 and the second channel 102, and the second valve needle 200 can slide relative to the first valve needle 100 along a first direction; when in the second working state, the second valve needle 200 opens the first channel 101 and the second channel 102, and the second valve needle 200 can drive the first valve needle 100 to slide together along the first direction.

[0025] As described above, the working principle of the valve needle assembly provided in this embodiment is as follows: It should be understood that the valve needle assembly can be used in conjunction with other components of the electronic expansion valve. For example, the valve needle assembly can be used with valve port 002. By adjusting the position of the first valve needle 100, the first valve needle 100 can open or close valve port 002. That is, in the initial state, the first valve needle 100 is in the position where valve port 002 is closed, and the second valve needle 200 is in the first working state where the first water channel 101 and the second water channel 102 are closed. When a small-range flow regulation is required, the second valve needle 200 is slid along a first direction, and the second valve needle 200 opens the first water channel 101 and the second water channel 102. The first water channel 101 and the second inlet hole are connected to valve port 002. Fluid enters from the inlet of valve port 002, passes through the first water channel 101 and the second water channel 102, and is discharged from the outlet of valve port 002, thereby achieving a small flow rate. When a large flow rate is required, force is continued to be applied to the second valve needle 200, causing it to move along the first direction to the second working state. At this time, as the second valve needle 200 slides along the first direction, it not only increases the flow rate of the first waterway 101 and the second waterway 102, but also drives the first valve needle 100 to open the valve port 002. This allows the flow rate to not only be discharged through the first waterway 101 and the second waterway 102, but also to flow directly from the inlet to the outlet of the valve port 002, thereby increasing the flow rate. In this way, the valve needle assembly of this embodiment can achieve both small-range and large-range flow rate regulation by controlling the movement of the second valve needle 200. It can be used flexibly in different scenarios, has strong adaptability, eliminates the need for multiple electronic regulating valves, simplifies the structure, and reduces costs.

[0026] The following embodiments illustrate the details of the valve needle assembly of this application by way of example.

[0027] Please refer to Figures 1-4 In this embodiment, optionally, the valve needle assembly includes a first valve needle 100 and a second valve needle 200. The first valve needle 100 is sleeved on the outside of the second valve needle 200, and the second valve needle 200 can slide relative to the first valve needle 100. After sliding to a set position, it can drive the first valve needle 100 to slide, thereby realizing the adjustment of small flow range and large flow range.

[0028] The first valve needle 100 includes a body 110, a first pad 120, a second pad 130, a third pad 140, a sealing ring 150, and a sealing plate 160. The body 110 has a first end and a second end opposite each other in a first direction. The first end is provided with an anti-rotation protrusion 111, which protrudes radially outward from the outer peripheral surface of the first end. Simultaneously, the outer peripheral wall of the body 110 is provided with a guide hole 112 and a second water channel 102. The guide hole 112 is a strip-shaped hole, extending in the first direction. The guide hole 112 has a first hole wall and a second hole wall in the first direction. The first hole wall is closer to the first end, and correspondingly, the second hole wall is closer to the second end. At least a portion of the first hole wall is configured as a first limiting structure; for example, the entire surface of the first hole wall can be a first limiting structure. There can be multiple second water channels 102. The inner ends of multiple second water channels 102 converge to form a water collection cavity 105, and the outer ends are all located on the outer circumferential surface of the main body 110. The multiple second water channels 102 are evenly spaced in the circumferential direction of the main body 110. The second water channels 102 also serve as external water pressure balancing holes to balance water pressure.

[0029] The main body 110 is also provided with a water pressure balancing cavity 103, an assembly hole 104, a water collection cavity 105, and a mounting hole 106 arranged sequentially and connected in a first direction. The port of the water pressure balancing cavity 103 away from the assembly hole 104 is located at the first end, and correspondingly, the port of the mounting hole 106 away from the water collection cavity 105 is located at the second end. Both the assembly hole 104 and the mounting hole 106 are stepped holes. The diameter of the smaller end of the assembly hole 104 is smaller than the diameter of the water pressure balancing cavity 103 and is connected to the water pressure balancing cavity 103. The diameter of the smaller end of the mounting hole 106 is smaller than the diameter of the water collection cavity 105 and is connected to the water collection cavity 105. The first pad 120 and the second pad 130 cooperate to clamp the sealing plate 160, and all three are fixed within the mounting hole 106. The third gasket 140 and the sealing ring 150 are located inside the assembly hole 104. The third gasket 140 and the wall of the assembly hole 104 cooperate to clamp the sealing ring 150, preventing the sealing ring 150 from coming out of the assembly hole 104. During assembly, the sealing ring 150 can be installed first, followed by the third gasket, and then the first gasket 120, the sealing plate 160, and the second gasket 130 can be installed in sequence. Assembly is convenient and quick, with low processing and manufacturing costs, and it is also conducive to maintenance and replacement.

[0030] Furthermore, the sealing plate 160 includes an integral plate body 161 and a boss 162. The boss 162 is provided with a first through hole 1621, which penetrates the plate body 161. The second pad 130 is provided with a second through hole 131. When the first pad 120 and the second pad 130 cooperate to clamp the plate body 161, the boss 162 penetrates the first pad 120, and the first through hole 1621 and the second through hole 131 are connected to form a second water channel 102. Both the first pad 120 and the second pad 130 are fixedly connected to the body 110.

[0031] It should be understood that the first water channel 101 can be a water inlet, and the corresponding second water channel 102 can be a water outlet, or the first water channel 101 can be a water outlet, and the corresponding second water channel 102 can be a water inlet.

[0032] Furthermore, the body 110 can be a split structure, which facilitates processing and also makes it easier to install the second valve needle 200 inside the body 110. For example, the body 110 includes a lower shell 113 and a top cover 114. The top cover 114 is fixed to the top of the lower shell 113, and the top cover 114 and the lower shell 113 cooperate to form a guide hole 112. During installation, the top cover 114 is opened first, then the second valve needle 200 is inserted into the lower shell 113, and then the top cover 114 is fixed to the lower shell 113. This can prevent the second valve needle 200 from sliding away from the end where the top cover 114 is located from the lower shell 113.

[0033] Optionally, the second valve needle 200 includes a first cylinder 210, a second cylinder 220, and a third cylinder 230 that are coaxial and connected in sequence. The first cylinder 210, the second cylinder 220, and the third cylinder 230 are connected in sequence, and the outer diameters of the first cylinder 210, the second cylinder 220, and the third cylinder 230 gradually decrease. The first cylinder 210 is provided with a guide post 211, which protrudes outward from the outer circumferential surface of the first cylinder 210 along the radial direction. The guide post 211 can be inserted into the guide hole 112. The guide post 211 and the guide hole 112 are slidably engaged in a first direction, and the guide post 211 and the guide hole 112 are relatively fixed relative to each other in the circumferential direction of the first valve needle 100, that is, the guide post 211 and the guide hole 112 will not rotate relative to each other. The outer circumferential surface of the second cylinder 220 is provided with an internal water pressure balancing hole 221 for balancing water pressure. Meanwhile, the cavities of the first cylinder 210, the second cylinder 220 and the third cylinder 230 are connected in sequence to form a water pressure balance channel 201.

[0034] It should be understood that there can be multiple guide posts 211 and guide holes 112, and the two can be equal in number and correspond one-to-one to improve sliding stability.

[0035] In this embodiment, the assembly structure and working principle of the valve needle assembly are as follows: The second valve needle 200 passes through the first valve needle 100. Specifically, both the first cylinder 210 and the second cylinder 220 are located within the water pressure balance chamber 103. The first cylinder 210 slides within the inner circumferential surface of the water pressure balance chamber 103, and the second cylinder 220 has a gap with the inner circumferential surface of the water pressure balance chamber 103 to form an annular space. The inner water pressure balance hole 221 communicates with the annular space. The guide post 211 on the first cylinder 210 passes through the corresponding guide hole 112. The third cylinder 230 passes through the sealing ring 150 and the water collection chamber 105 in sequence and can extend into the second water channel 102. The outer circumferential surface of the third cylinder 230 can make sealing contact with the hole wall of the first through hole 1621, thereby blocking the first water channel 101 and the second water channel 102. At this time, the valve needle assembly is in the first working state, and the first water channel 101 and the second water channel 102 are blocked, preventing fluid flow. When the second valve needle 200 slides along the first direction, that is, when... Figure 4 With a mid-range viewing angle as a reference, when the second valve needle 200 slides upward, the third cylinder 230 gradually moves away from the first through hole 1621, thereby opening the first water channel 101 and connecting the first water channel 101 and the second water channel 102. As the second valve needle 200 slides upward, the guide post 211 slides within the guide hole 112. After the guide post 211 contacts the first hole wall of the guide hole 112, the second valve needle 200 can continue to move upward, driving the first valve needle 100 to open the flow channel on the valve port 002, increasing the flow rate. When it is necessary to close the valve, the second valve needle 200 slides in a second direction opposite to the first direction, closing the second water channel 102. Simultaneously, the first valve needle 100 can slide downward under the action of the elastic element 004, closing the valve port 002.

[0036] It should be understood that when the second valve needle 200 opens the first water channel 101, the second water channel 102, the water pressure balance channel 201, the inner water pressure balance hole 221 and the water pressure balance chamber 103 are connected in sequence, so that the pressure difference between the inside and outside of the valve needle assembly is small, which is conducive to opening the valve.

[0037] Please combine Figures 1-6 This embodiment also provides an electronic expansion valve, which includes: The system comprises a valve seat 001, a valve port 002, a drive assembly 003, an elastic element 004, and a valve needle assembly as described in the above embodiment. One end of the valve seat 001 is connected to the valve port 002, and the other end of the valve seat 001 is connected to the drive assembly 003. The drive assembly 003 is connected to a second valve needle 200 and is used to drive the second valve needle 200 to reciprocate in a first direction or a second direction opposite to the first direction. A first valve needle 100 is slidably connected to the valve port 002. The elastic element 004 is connected to both the valve seat 001 and the first valve needle 100, and is used to give the first valve needle 100 a tendency to slide along the second direction. In the first working state, the first valve needle 100 closes the valve port 002 under the action of the elastic element 004.

[0038] It should be understood that when the drive assembly 003 drives the first valve needle 100 and the second valve needle 200 to slide together in the first direction, the drive assembly 003 needs to overcome the elastic force of the elastic element 004, and the elastic element 004 is further compressed. When the drive assembly 003 drives the second valve needle 200 to slide in the second direction, under the action of the elastic force of the elastic element 004, the first valve needle 100 can move downward, and can close the first water channel 101 and the second water channel 102 through the second valve needle 200, and close the valve port 002 through the first valve needle 100, ultimately closing the valve.

[0039] Optionally, the valve seat 001 is provided with a positioning hole 011, and an anti-rotation groove 012 extending in a first direction is provided on the wall of the positioning hole 011. The anti-rotation protrusion 111 slidably engages with the anti-rotation groove 012, thereby restricting the rotation of the first valve needle 100 and the second valve needle 200 relative to the valve seat 001. The elastic element 004 is located in the positioning hole 011, with its upper end contacting the stepped hole wall of the positioning hole 011 and its lower end contacting the upper end of the first valve needle 100, and is in a compressed state. That is, the elastic element 004 can be a compression spring, etc.

[0040] It should be understood that in other embodiments, the anti-rotation protrusion 111 may also be provided on the valve seat 001, and correspondingly, the anti-rotation groove is provided on the first valve needle 100.

[0041] Optionally, the drive assembly 003 includes a lead screw 031 and a nut 032. The lead screw 031 can be rotatably engaged with the valve seat 001 through multiple bearings, improving the rotational stability of the lead screw 031. Simultaneously, the lead screw 031 and the valve seat 001 are relatively fixed relative to each other in the axial direction of the lead screw 031. The nut 032 is screwed onto the outside of the lead screw 031 and is embedded and fixed within the first cylinder 210 of the second valve needle 200. The lead screw 031 can be connected to a motor rotor. When the motor rotor rotates, it drives the lead screw 031 to rotate, causing the nut 032 to drive the second valve needle 200 to slide linearly along a first direction or a second direction, thereby regulating the valve flow rate and opening / closing.

[0042] It should be understood that the valve port 002 is provided with a third channel 021 and a fourth channel 022. The third channel 021 is located on the end face of the valve port 002 away from the valve seat 001, and the fourth channel 022 is located on the outer circumferential surface of the valve port 002. There can be multiple fourth channels 022, evenly spaced around the axis of the valve port 002. The inner ends of multiple fourth channels 022 converge and communicate with each other. After the valve port 002 and valve seat 001 are installed, the first valve needle 100 is slidably installed in the valve port 002. The first channel 101 communicates with the third channel 021, and the second channel 102 communicates with the fourth channel 022. The lower end of the first valve needle 100 can close the third channel 021, thereby blocking both the third channel 021 and the fourth channel 022. Simultaneously, the diameter of the third channel 021 is larger than the diameter of the first channel 101.

[0043] The working principle of the electronic expansion valve provided in this embodiment is as follows: In the initial state, that is, when the valve needle assembly is in the first working state, the second valve needle 200 closes the first water channel 101 and the first valve needle 100 closes the third water channel 021. At this time, the first water channel 101, the second water channel 102, the third water channel 021, and the fourth water channel 022 are blocked, and the fluid cannot flow. When the drive assembly 003 is started, it can drive the second valve needle 200 to move in the first direction. Before the guide post 211 contacts the first hole wall, only the second valve needle 200 moves in the first direction. The second valve needle 200 opens the first water channel 101. At this time, the third water channel 021 is connected to the fourth water channel 022 in sequence through the first water channel 101 and the second water channel 102, which can realize a small flow rate. As the guide post 211 contacts the first hole wall, the second valve needle 200 continues to slide along the first direction, which can drive the second valve needle 200 to slide along the first direction, thereby opening the third water channel 021. The third water channel 021 is directly connected to the fourth water channel 022, realizing large flow and flexible flow regulation.

[0044] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A valve needle assembly, characterized in that, include: A first valve needle (100) and a second valve needle (200). The first valve needle (100) is provided with a first water channel (101) and a second water channel (102) that are connected. The second valve needle (200) is slidably connected to the first valve needle (100) so that the second valve needle (200) has a first working state and a second working state that can be switched between each other. When in the first working state, the second valve needle (200) blocks the first water channel (101) and the second water channel (102), and the second valve needle (200) can slide relative to the first valve needle (100) along a first direction. When in the second working state, the second valve needle (200) opens the first water channel (101) and the second water channel (102), and the second valve needle (200) can drive the first valve needle (100) to slide together along the first direction.

2. The valve needle assembly according to claim 1, characterized in that: The first valve needle (100) is provided with a first limiting structure, and the second valve needle (200) is provided with a second limiting structure. The first limiting structure is located on the roadbed on which the second limiting structure slides along the first direction, and the first limiting structure is used to contact the second limiting structure.

3. The valve needle assembly according to claim 2, characterized in that: The first valve needle (100) is provided with a guide hole (112), the guide hole (112) has a first hole wall and a second hole wall arranged at intervals in a first direction, and at least a portion of the first hole wall is configured as the first limiting structure; The second valve needle (200) is provided with a guide post (211), and part of the outer peripheral surface of the guide post (211) is configured as the second limiting structure; the guide post (211) passes through the guide hole (112) and is located between the first hole wall and the second hole wall.

4. The valve needle assembly according to claim 1, characterized in that: The second valve needle (200) and the first valve needle (100) are fixed relative to each other in the circumferential direction of the second valve needle (200).

5. The valve needle assembly according to claim 1, characterized in that: The first valve needle (100) is provided with a water pressure balance chamber (103) and an assembly hole (104), and the water pressure balance chamber (103) is connected to the second water channel (102) through the assembly hole (104). The second valve needle (200) is provided with a water pressure balance channel (201) and an inner water pressure balance hole (221). One end of the water pressure balance channel (201) is connected to the second water channel (102), and the other end is connected to the inner water pressure balance hole (221). The second valve needle (200) is simultaneously inserted into the water pressure balance cavity (103) and the assembly hole (104). The inner water pressure balance hole (221) is connected to the water pressure balance cavity (103), and the second valve needle (200) is sealed to the assembly hole (104).

6. The valve needle assembly according to claim 5, characterized in that: The second valve needle (200) includes a first cylinder (210), a second cylinder (220), and a third cylinder (230) connected in sequence. The outer diameters of the first cylinder (210), the second cylinder (220), and the third cylinder (230) gradually decrease. The first cylinder (210) and the second cylinder (220) are both located inside the water pressure balance chamber (103). The first cylinder (210) slides with the inner circumferential surface of the water pressure balance chamber (103). The second cylinder (220) has a gap with the inner circumferential surface of the water pressure balance chamber (103) to form an annular space. The inner water pressure balance hole (221) communicates with the annular space. The third cylinder (230) is slidably inserted into the assembly hole (104). When in the first working state, the outer circumferential surface of the third cylinder (230) is sealed with the hole wall of the first water channel (101). The cavities of the first cylinder (210), the second cylinder (220) and the third cylinder (230) are connected to form the water pressure balance channel (201).

7. The valve needle assembly according to claim 6, characterized in that: The first valve needle (100) includes a body (110), a first pad (120), a second pad (130), and a sealing plate (160). The water pressure balance chamber (103), the assembly hole (104), and the second water channel (102) are all disposed on the body (110). The sealing plate (160) includes an integral plate body (161) and a boss (162). The boss (162) is provided with a first through hole (1621) that penetrates the plate body (161). The second pad (130) is provided with a second through hole (131). The first pad (120) and the second pad (130) cooperate to clamp the plate body (161). The boss (162) penetrates the first pad (120). The first through hole (1621) and the second through hole (131) are connected and form the first water channel (101). The first pad (120) and the second pad (130) are both fixedly connected to the body (110). When in the first working state, the outer peripheral surface of the third cylinder (230) is sealed to the hole wall of the first through hole (1621).

8. An electronic expansion valve, characterized in that, The electronic expansion valve includes: A valve seat (001), a valve port (002), a drive assembly (003), an elastic element (004), and a valve needle assembly according to any one of claims 1-7; one end of the valve seat (001) is connected to the valve port (002), and the other end of the valve seat (001) is connected to the drive assembly (003), the drive assembly (003) is connected to the second valve needle (200), for driving the second valve needle (200) to reciprocate in the first direction or in a second direction opposite to the first direction; the first valve needle (100) is slidably connected to the valve port (002); the elastic element (004) is simultaneously connected to the valve seat (001) and the first valve needle (100), for giving the first valve needle (100) a tendency to slide along the second direction; When in the first working state, the first valve needle (100) closes the valve port (002) under the action of the elastic member (004).

9. The electronic expansion valve according to claim 8, characterized in that: The drive assembly (003) includes a lead screw (031) and a nut (032). The lead screw (031) is rotatably engaged with the valve seat (001), and the lead screw (031) and the valve seat (001) are fixed relative to each other in the axial direction of the lead screw (031). The nut (032) is screwed to the lead screw (031), and the nut (032) is fixedly connected to the second valve needle (200). The valve needle assembly and the valve seat (001) are fixed relative to each other in the circumferential direction of the first valve needle (100).

10. The electronic expansion valve according to claim 9, characterized in that: The valve seat (001) is provided with an anti-rotation groove (012), and the first valve needle (100) is provided with an anti-rotation protrusion (111). The anti-rotation protrusion (111) and the anti-rotation groove (012) are slidably connected, and the two are relatively fixed in the circumferential direction of the first valve needle (100).

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