Electronic expansion valve

Abstract

The present application provides an electronic expansion valve, which comprises a screw rod, a rotor arranged outside the screw rod and threadedly matched with the screw rod to drive the screw rod to move along an axis, a valve seat assembly arranged below the rotor, the valve seat assembly being provided with a valve port, a valve needle assembly connected with a lower part of the screw rod, the screw rod being capable of driving the valve needle assembly to move along the axis to open and close the valve port, and a stop assembly arranged above the rotor, the stop assembly comprising a stopper, a spiral guide rail device and a sliding ring, the spiral guide rail device being fixed to an upper part of the screw rod, the spiral guide rail device being formed with a spiral guide rail on a side surface, the sliding ring having a ring body sleeved on the spiral guide rail and a ring handle extending outward from the ring body, the stopper being fixed to the rotor and rotating with the rotor, and the rotating stopper driving the sliding ring to rotate along the spiral guide rail through the ring handle of the sliding ring. Compared with the prior art, the present application is simple in assembly and adjustment operation, can not only be checked for positioning accuracy after assembly, but also saves time.

Description

[Technical Field]

[0001] This invention relates to the field of flow control valve technology, and in particular to an electronic expansion valve. [Background Technology]

[0002] Currently, electric valves driven by motors are widely used in refrigeration systems. Existing electric valves mainly consist of a valve body and a valve seat. The valve body houses a stator, rotor, transmission structure (e.g., a lead screw and nut structure), and a valve needle. The stator drives the rotor, and the transmission structure converts the rotor's rotational motion into linear motion, thereby causing the valve needle to engage or disengage relative to the valve seat. This adjusts the flow area of ​​the valve orifice, and consequently regulates the refrigerant flow into the evaporator. To ensure that the valve needle's upward and downward displacements are within a predetermined range, stop devices at upper and lower limit positions are typically provided.

[0003] Please refer to Figure 1 The diagram shows a longitudinal cross-section of a stop structure for an electronic expansion valve in the prior art. It includes a spiral guide rail 241, a slip ring 242, and a limiting sleeve 31. The spiral guide rail 241 is fixed to the top wall of the valve body. The slip ring 242 is fitted onto the outside of the spiral guide rail 241 and can rotate and slide along its track. Stop structures (such as protrusions at the end of the track) are provided at both ends of the track. The limiting sleeve 31 is fixedly connected to the rotor 27. When the rotor 27 rotates, the limiting sleeve 31, fixed to the rotor 27, drives the slip ring 242 to move up and down on the spiral guide rail 241. By limiting the stroke of the slip ring 242 on the spiral guide rail 241, the valve needle's up-and-down movement is stopped.

[0004] Figure 1 The assembly of the stop structure shown includes the following steps:

[0005] 1.1 First, rotate the rotor to bring the valve needle 29 to the closed position, and then continue to rotate the rotor at a predetermined angle to pre-tighten the valve needle;

[0006] 1.2 Install the limiting sleeve 31 onto the rotor and weld it in place;

[0007] 1.3 Position the slip ring 242 onto the spiral guide rail 241 and weld it to the valve body 21 to form a valve body with a stop component;

[0008] 1.4 Adjust the slip ring 242 to the lower dead center position (i.e., the stop position of the slip ring on the spiral guide rail 241 when the motor rotates to the predetermined valve closing position);

[0009] 1.5 Pass the portion of the slip ring 242 protruding in the radial direction of the limiting sleeve 31 through the groove on the limiting sleeve 31 (not shown in the figure), and move the valve body with the stop component downward along the axial direction of the limiting sleeve 31 to the welding position for welding and fixing.

[0010] The above solution has the following problems: ① When the valve body with the stop component moves downward along the axial direction of the limiting sleeve 31, it is easy to cause the position of the rotor or slip ring to change, resulting in the valve needle preload being too small or too large, which does not meet the process requirements. This is because too small a preload can easily cause leakage, while too large a preload can easily cause the valve needle to jam. For example, assuming that the valve port is closed when the rotor rotates counterclockwise, when the valve needle reaches the predetermined valve closing position, the slip ring is required to be located at the lower dead point of the spiral guide rail and cannot rotate further counterclockwise, thereby achieving the stop effect on the rotor and valve needle. Steps 1.1-1.5 are to achieve the above requirements. However, in practice, since step 1.5 needs to be performed manually, clockwise or counterclockwise deflection is inevitable when the valve body moves downward. If it deflects clockwise, it may drive the rotor to deflect, thus making the preload too small. If it deflects counterclockwise, it will cause the slip ring to deviate from the lower dead point position of the spiral guide rail, so that the rotor can rotate further after the motor is powered on, thus making the preload too large. ① The stop mechanism requires multiple manual assembly steps, and the welding and debugging process is complex and prone to errors. ② The spiral guide rail directly affects the rotor's rotation. If the spiral guide rail deviates from the valve body's central axis during the positioning welding process, it will affect the rotor's rotation. ③ Once the stop structure is fixed (here, the valve body is welded), it is sealed inside the valve body, making it impossible to check the accuracy of the stop structure's positioning.

[0011] Please refer to Figure 2 The diagram shows a longitudinal section of a stop structure for another electronic expansion valve in the prior art. It includes a limiting rod 42, a spiral guide rail 33, and a slip ring 34. The spiral guide rail 33 is fitted and fixed to a nut seat 32. The slip ring 34 rotates and slides along the spiral guide rail 33. Stop structures (such as bends at the end of the rail) are provided at both ends of the spiral guide rail 33. The limiting rod 42 is fixedly connected to a rotor 41. When the rotor 41 rotates, the limiting rod 42, fixed to the rotor 41, drives the slip ring 34 to move up and down on the spiral guide rail 33. By limiting the stroke of the slip ring 34 on the spiral guide rail 33, the valve needle's up-and-down movement is stopped.

[0012] Figure 2 The assembly of the stop structure shown includes the following steps:

[0013] 1.1 First rotate the lead screw to bring the valve needle to the closed position, then continue to rotate the lead screw by a predetermined angle to pre-tighten the valve needle;

[0014] 1.2 Fit the spiral guide rail 33 onto the nut seat 32 and fix it in place;

[0015] 1.3 Install the slip ring 34 onto the spiral guide rail 33 and adjust the slip ring 34 to the lower dead center position (i.e., the stop position of the slip ring on the spiral guide rail when the motor rotates to the predetermined valve closing position);

[0016] 1.4 Fix the limiting rod 42 to the rotor 41.

[0017] 1.5 Fit the rotor onto the lead screw, adjust the rotor so that the limiting rod 42 abuts against the protrusion of the slip ring 34, so that the rotor cannot rotate in the valve closing direction; weld the rotor and lead screw to fix them.

[0018] The above solution has the following problems: ① The slip ring 34 and the spiral guide rail 33 need to be manually installed in two separate steps, and the installation and adjustment work is located inside the valve body, making the operation difficult; ② In step 1.5, the rotor needs to be adjusted so that the limit rod 42 abuts against the protrusion of the slip ring 34, thus preventing the rotor from rotating in the valve closing direction. Since the limit rod and slip ring are obscured by the upper part of the rotor, this step cannot be visually observed. Therefore, the worker needs to rotate the rotor in the valve closing direction with a preset force to confirm whether the limit rod abuts against the slip ring. If the worker rotates the rotor with too much force, it will cause deformation of the slip ring and spiral guide rail. After the rotor is welded and fixed to the screw, the release of the deformation of the slip ring and spiral guide rail may cause the rotor to slightly deflect in the valve opening direction, resulting in a low valve closing preload. If no confirmation operation is performed, there will be a gap between the limit rod and the slip ring, meaning that the rotor can continue to rotate after reaching the predetermined valve closing position, resulting in a high valve closing preload. In short, the stop mechanism requires multiple manual assembly steps, and the welding and debugging process is complex and prone to errors. ③ Once the fixing work of the stop structure (here, the welding steps between the rotor and the lead screw) is completed, it is blocked by the rotor, making it impossible to check the positioning accuracy of the stop structure.

[0019] Therefore, it is necessary to propose a new technical solution to address the above problems. [Summary of the Invention]

[0020] One of the objectives of this invention is to provide an electronic expansion valve that is simple to assemble and adjust, and not only allows for positioning accuracy checks after assembly, but also saves time.

[0021] According to one aspect of the present invention, an electronic expansion valve is provided, comprising: a lead screw; a rotor disposed outside the lead screw and threadedly engaged with the lead screw to drive the lead screw to move along an axis; a valve seat assembly located below the rotor, the valve seat assembly having a valve port; a valve needle assembly connected to the lower part of the lead screw, the lead screw capable of driving the valve needle assembly to move along an axis to open and close the valve port; and a stop assembly located above the rotor, the stop assembly including a stop member, a helical guide rail device, and a slip ring, the helical guide rail device being fixed to the upper part of the lead screw, the side of the helical guide rail device forming a helical guide rail, the slip ring having a ring body sleeved on the helical guide rail and a ring shank extending outward from the ring body, the stop member being fixed to the rotor and rotating with the rotor, the rotating stop member driving the slip ring to rotate along the helical guide rail through the ring shank of the slip ring, thereby causing the slip ring to move helically up and down relative to the helical guide rail device along the axis of the lead screw.

[0022] Furthermore, the stop assembly also includes an upper limit member, which is fixed to the upper part of the spiral guide rail device to limit the highest position of the slip ring moving upward. The spiral guide rail device has a lower limit end face, which is used to limit the lowest position of the slip ring moving downward.

[0023] Furthermore, the upper limit member includes a limiting body fixed to the top of the spiral guide rail device and a limiting block extending outward from the limiting body, the limiting block extending onto the spiral guide rail.

[0024] Furthermore, the spiral guide rail device has a first through hole, and the lead screw passes through the first through hole of the spiral guide rail device and is fixed in the first through hole; the upper limit member has a second through hole located in the middle of the limiting body, and the lead screw passes through the second through hole of the upper limit member and is fixed in the second through hole.

[0025] Furthermore, the stop is a stop rod, which is placed along the axial direction of the lead screw.

[0026] Furthermore, the stop rod is an injection-molded rib of the rotor.

[0027] Furthermore, when the rotor rotates along the first direction, the rotating stop causes the slip ring to move spirally upward relative to the spiral guide device along the axis; when the rotor rotates along the second direction opposite to the first direction, the rotating stop causes the slip ring to move spirally downward relative to the spiral guide device along the axis.

[0028] Furthermore, the valve needle assembly includes an elastic component, which is connected to the lower part of the lead screw. After the top of the valve needle assembly contacts the valve port of the valve seat assembly, when the lead screw continues to move downward, the valve needle assembly and the lead screw undergo relative displacement along the axial direction, at which time the elastic component deforms.

[0029] Furthermore, the valve needle assembly also includes a valve needle, a gasket, and a pad. The valve needle includes a needle tip and a needle body. The needle body has a receiving cavity formed at the top. The elastic member is placed in the receiving cavity. The gasket is received at the top of the receiving cavity and is fixedly connected to the needle body. The gasket is also assembled with the lead screw. The pad is received in the receiving cavity and is located between the elastic member and the gasket. The pad is fixedly connected to the bottom end of the lead screw.

[0030] Furthermore, the bottom end of the lead screw is provided with a trapezoidal protrusion, and the washer cooperates with the trapezoidal protrusion of the lead screw; the pad is riveted to the bottom end of the lead screw; and the washer is riveted to the needle body of the valve needle.

[0031] Furthermore, the lead screw and the washer are provided with an anti-rotation mechanism, which ensures that the lead screw and the valve needle assembly can only move linearly along the axial direction of the lead screw.

[0032] Furthermore, a straight groove extending along the axial direction of the lead screw is provided on the outer wall of the bottom end of the lead screw; the gasket is an annular gasket with an inwardly extending protrusion on its inner wall; the protrusion in the gasket can only move linearly within the straight groove at the bottom end of the lead screw.

[0033] Compared with the prior art, in the electronic expansion valve provided by the present invention, the stop rod is fixed on the rotating rotor, the spiral guide rail device and the slip ring are set on the vertically moving lead screw, and the stop assembly is above the rotor, which makes the assembly and adjustment operation simple. It can not only check the positioning accuracy after assembly, but also save time. [Attached Image Description]

[0034] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0035] Figure 1 This is a schematic longitudinal section of the stop structure of an electronic expansion valve in the prior art.

[0036] Figure 2A longitudinal section schematic of the stop structure of another electronic expansion valve in the prior art;

[0037] Figure 3 This is a schematic front cross-sectional view of an electronic expansion valve in one embodiment of the present invention;

[0038] Figure 4 This is a partial rear cross-sectional view of the electronic expansion valve in one embodiment of the present invention;

[0039] Figure 5 For example, in one embodiment of the present invention Figure 3 and Figure 4 A three-dimensional schematic diagram of part of the stop structure of the stop assembly shown;

[0040] Figure 6 This is a perspective view of the upper limit member as shown in Figure 5 in one embodiment of the present invention;

[0041] Figure 7 For example, in one embodiment of the present invention Figure 3 and Figure 4 The diagram shows a three-dimensional representation of the assembled lead screw and valve needle assembly.

[0042] Figure 8 For example, in one embodiment of the present invention Figure 3 and Figure 4 The diagram shows a longitudinal section of the assembled lead screw and valve needle assembly.

[0043] Figure 9 As shown in one embodiment of the present invention Figure 8 A three-dimensional schematic diagram of the lead screw and washer shown;

[0044] Figure 10 As shown in one embodiment of the present invention Figure 3 and Figure 4 The diagram shows a three-dimensional cross-sectional view of the rotor assembly.

Detailed Implementation Methods

[0045] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] The term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the invention. The phrase "in one embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments. Unless otherwise specified, the terms "connected," "linked," and "connected" used herein to indicate electrical connection refer to direct or indirect electrical connection.

[0047] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. 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. Therefore, they should not be construed as limitations on this invention.

[0048] Please refer to Figure 3 The diagram shown is a front cross-sectional view of the electronic expansion valve in one embodiment of the present invention; please refer to... Figure 4 As shown, it is a partial rear cross-sectional schematic diagram of the electronic expansion valve in one embodiment of the present invention. Figure 3 and Figure 4 The electronic expansion valve shown includes a coil assembly 10, a valve body 20, a rotor assembly 30, a valve needle assembly 40, a valve seat assembly 50, a stop assembly 60, a base 70, and a lead screw 80.

[0049] The rotor 35 in the rotor assembly 30 is sleeved outside the lead screw 80 and threadedly engaged with the lead screw 80 to drive the lead screw 80 to move along the axis; the valve seat assembly 50 is located below the rotor 35 and is provided with a valve port 51; the valve needle assembly 40 is connected to the lower part of the lead screw 80, and the lead screw 80 can drive the valve needle assembly 40 to move along the axis to open and close the valve port 51.

[0050] The stop assembly 60 is located above the rotor 35, and includes a stop member 64, a spiral guide device 61, and a slip ring 62. Please refer to [reference needed]. Figure 5 As shown, this is one embodiment of the present invention. Figure 3 and Figure 4 A three-dimensional schematic diagram of part of the stopping structure of the stopping assembly 60 shown. (See diagram below.) Figure 3 , Figure 4 and Figure 5As shown, the spiral guide rail device 61 is fixed to the upper part of the lead screw 80 and located above the rotor 35. The side of the spiral guide rail device 61 forms a guide structure in the form of a spiral guide rail. The slip ring 62 has a ring body (unmarked) sleeved on the spiral guide rail and a ring handle (unmarked) extending outward from the ring body. The stop member 64 is fixed to the rotor 35 and rotates with the rotor 35. The rotating stop member 64 drives the slip ring 62 to rotate along the spiral guide rail by abutting against the ring handle of the slip ring 62, thereby causing the slip ring 62 to move spirally up and down relative to the spiral guide rail device 61 along the axis of the lead screw 80. When the rotor 35 rotates in the first direction, the rotating stop member 64 drives the slip ring 62 to move spirally upward relative to the spiral guide rail device 61 along the axis; when the rotor 35 rotates in the second direction opposite to the first direction, the rotating stop member 64 drives the slip ring 62 to move spirally downward relative to the spiral guide rail device 61 along the axis.

[0051] exist Figure 5 In the specific embodiment shown, the stop assembly 60 further includes an upper stop point and a lower stop point. The upper stop point is used to limit the highest position of the upward movement of the slip ring 62, and the lower stop point is used to limit the lowest position of the downward movement of the slip ring 62. Specifically, the upper stop point can be an upper limit member 63, which is fixed to the upper part of the spiral guide rail device 61. The upper limit member 63 is used to limit the highest position of the upward movement of the slip ring 62. The lower stop point is a lower limit end face on the spiral guide rail device 61, which is used to limit the lowest position of the downward movement of the slip ring 62.

[0052] Please refer to Figure 6 As shown, this is a perspective view of the upper limit member as illustrated in embodiment 5 of the present invention. Figure 5 and Figure 6 In the embodiment shown, the upper limit member 63 includes a limiting body 631 fixed to the top of the spiral guide rail device 61 and a limiting block 632 extending outward from the limiting body 631, with the limiting block 632 extending onto the spiral guide rail of the spiral guide rail device 61.

[0053] exist Figures 3-6 In the specific embodiment shown, the spiral guide device 61 has a first through hole (not labeled), and the lead screw 80 passes through and is fixed within the first through hole of the spiral guide device 61; the upper limit member 63 has a second through hole 633 located in the middle of the limiting body 631, and the lead screw 80 passes through and is fixed within the second through hole 633 of the upper limit member 63. In one embodiment, the spiral guide device 61 and the upper limit ring 63 are injection molded into a single structure using non-metallic material.

[0054] exist Figure 3 and Figure 4In the specific embodiment shown, the stop 64 is a stop rod, which is positioned along the axial direction of the lead screw 80. In a preferred embodiment, the stop rod 64 can be replaced by a molded rib inside the rotor 35; that is, the stop rod 64 is a molded rib of the rotor 35. Please refer to [link to details]. Figure 10 As shown, this is an embodiment of the present invention. Figure 3 and Figure 4 The diagram shows a cross-sectional perspective view of the rotor assembly 30. Figure 10 In the implementation shown, the injection-molded rib inside the rotor assembly 30 is used as a stop rod 64.

[0055] Please refer to Figure 7 As shown, this is one embodiment of the present invention. Figure 3 and Figure 4 The diagram shown is a three-dimensional representation of the assembled lead screw 80 and valve needle assembly 40; please refer to it. Figure 8 As shown, this is one embodiment of the present invention. Figure 3 and Figure 4 The diagram shows a longitudinal section of the lead screw 80 and valve needle assembly 40 assembled together. Figure 7 and Figure 8 In the embodiment shown, the valve needle assembly 40 includes an elastic component (e.g., a spring) 46. The valve needle assembly 40 is connected to the lower part of the lead screw 80 through the elastic component 46. After the top of the valve needle assembly 40 contacts the valve port 51 of the valve seat assembly 50, when the lead screw 80 continues to move downward, the valve seat assembly 50 and the lead screw 80 undergo relative displacement along the axial direction, at which time the elastic component 46 deforms.

[0056] exist Figure 8 In the illustrated embodiment, the valve needle assembly 40 includes a valve needle 41, a gasket 43, and a pad 44, in addition to the elastic member 46. The valve needle 41 includes a needle tip 411 and a needle body 412. The needle body 412 has a receiving cavity (not labeled) formed at the top, in which the elastic member 46 is placed. The gasket 43 is received at the top of the receiving cavity and is fixedly connected to the needle body 412, and the gasket 43 is assembled with the lead screw 80. The pad 44 is received in the receiving cavity and is located between the elastic member 46 and the gasket 43, and the pad 44 is fixedly connected to the bottom end of the lead screw 80.

[0057] exist Figure 8In the specific embodiment shown, the bottom end of the lead screw 80 has a trapezoidal protrusion, the washer 43 engages with the trapezoidal protrusion of the lead screw 80, the pad 44 is riveted to the bottom end of the lead screw 80, and the washer 43 is riveted to the needle body 412 of the valve needle 41, thereby controlling the engagement stroke between the lead screw 80 and the valve needle assembly 40. The pad 44 interacts with the elastic component 46 within the valve needle assembly 40, so that when the valve is closed, the pad 44 fixed to the lead screw 80 is subjected to an upward spring force, preventing the valve needle 41 from seizing with the valve port 51 due to thread jamming.

[0058] Please refer to Figure 9 As shown, this is an embodiment of the present invention. Figure 8 A three-dimensional schematic diagram of the lead screw 80 and washer 43 is shown. Figure 9 In the embodiment shown, the lead screw 80 and the gasket 43 are provided with an anti-rotation mechanism, so that the lead screw 80 and the valve needle assembly 40 can only move linearly along the axial direction of the lead screw 80.

[0059] exist Figure 9 In the specific embodiment shown, a linear groove 81 extending axially along the outer wall of the bottom end of the lead screw 80 is provided; the gasket 43 is an annular gasket, and an inwardly extending protrusion 431 is provided on its inner wall; the protrusion 431 in the gasket 43 can only move linearly within the linear groove 81 at the bottom end of the lead screw 80.

[0060] Please continue to refer to this. Figure 3 and Figure 4 As shown, the valve seat assembly 50 and the base 70 are assembled together; the sleeve 90 installed in the valve body 20 is directly or indirectly fixed to the valve seat assembly 50. The sleeve 90 has a cavity (not labeled) that opens toward the valve seat assembly 50. The rotor assembly 30, the valve needle assembly 40, the stop assembly 60 and the lead screw 80 are located or partially located in the cavity; the coil assembly 10 is located outside the sleeve 90. When energized, the coil assembly 10 drives the rotor 35 in the rotor assembly 30 to rotate.

[0061] The working principle of the electronic expansion valve provided by the present invention is as follows: the electronic expansion valve provides a power source for the rotor assembly 30 inside the valve body 20 by energizing the coil assembly 10; the rotor assembly 30 is threadedly engaged with the lead screw 80, so that when the rotor assembly 30 rotates, it drives the lead screw 80 and the valve needle assembly 40 to move up and down; the valve needle 41 in the valve needle assembly 40 is engaged with the valve port 51 inside the valve seat assembly 50, so that the valve needle 41 adjusts the opening size of the valve port (51) of the base during the up and down movement, thereby realizing the flow rate regulation.

[0062] The electronic expansion valve provided by this invention stops the valve closing process by means of the reverse motion achieved by the screw rotation of the rotor 35 and the lead screw 80. This causes the stop rod 64 on the rotor 35 to interact with the slip ring 62 during rotation, driving the slip ring 62 to move on the spiral guide rail device 61. When the slip ring 62 contacts the lower limit end face of the spiral guide rail device 61, the lower limit end face of the spiral guide rail device 61 will restrict the slip ring 62 from continuing to move, thereby achieving the effect of stopping the rotor 35. This effectively solves the problem of the valve needle 41 of the valve needle assembly 40 and the valve port 51 of the valve seat assembly 50 getting stuck.

[0063] The electronic expansion valve provided by this invention stops the valve opening process by means of the reverse motion achieved by the screw rotation of the rotor 35 and the lead screw 80. This causes the stop rod 64 on the rotor 35 to interact with the slip ring 62 during rotation, driving the slip ring 62 to move on the spiral guide rail device 61. When the slip ring 62 contacts the upper limit ring 63, the upper limit ring 63 will restrict the slip ring 62 from continuing to move, thereby achieving the effect of stopping the rotor 35. This effectively solves the problem of the sleeve 90 getting stuck due to contact with the lead screw 80 caused by the interaction between the lead screw 80 and the sleeve 90.

[0064] The installation steps of the electronic expansion valve provided by this invention are as follows:

[0065] 1.1 First, rotate the rotor assembly 30 to bring the valve needle 41 to the closed position, and then continue to rotate the lead screw 80 by a predetermined angle to pre-tighten the valve needle 41;

[0066] 1.2 Pre-assemble the slip ring 62 and the spiral guide rail device 61 externally (if the upper / lower stop points are not integrally formed, they are assembled / fixed together in this step), and pre-rotate the slip ring 62 to the lower stop point (e.g., the lower limit end face of the spiral guide rail device 61). Place the assembled guide rail assembly onto the lead screw 80, and adjust the guide rail assembly so that the stop rod 64 abuts against the protrusion of the slip ring 62, thereby preventing the rotor 35 from rotating in the valve closing direction. Since the stop rod 64 is injection molded and fixed to the rotor assembly 30, or is set as an injection-molded rib within the rotor assembly 30 as the stop rod 64, the stop rod 64 is pre-fixed during the production process of the rotor assembly 30. Therefore, it does not need to be fixed again during assembly.

[0067] 1.3 Weld and fix the spiral guide rail device 61 to the lead screw 80.

[0068] The electronic expansion valve provided by this invention has the following advantages in assembly:

[0069] ① The slip ring 62 and the spiral guide rail device 61 can be pre-assembled and adjusted externally, making operation easy and saving time;

[0070] ②Since the spiral guide device 61 is directly fixed to the lead screw 80, there is no risk of the spiral guide device 61 being misaligned with the central axis of the valve body 20;

[0071] ③Since it can be visually observed, the worker can stop the operation after visually confirming that the stop rod 64 has reached the slip ring 62 during installation. The position of the rotor 35 / slip ring 62 will not be deflected, so there will be no problem of the valve closing preload being too high / too low.

[0072] ④ After assembly and fixing are completed, further visual inspection can be performed to confirm that the product meets the requirements.

[0073] In summary, the electronic expansion valve provided by the present invention adopts a brand-new stop mechanism design, wherein the stop rod 64 is fixed on the rotating rotor 35, the spiral guide rail device 61 and the slip ring 62 are set on the vertically moving lead screw 80, and the stop assembly 60 is above the rotor 35. The BOM cost is lower than the existing solution, the number of parts is reduced, and the assembly process is simple.

[0074] It should be noted that any modifications made by those skilled in the art to the specific embodiments of the present invention do not depart from the scope of the claims. Accordingly, the scope of the claims is not limited to the foregoing specific embodiments.

Claims

1. An electronic expansion valve, characterized in that, It includes: Lead screw; A rotor is disposed outside the lead screw and threadedly engaged with the lead screw to drive the lead screw to move along the axis; A valve seat assembly located below the rotor, the valve seat assembly being provided with a valve port; A valve needle assembly is connected to the lower part of the lead screw, which can drive the valve needle assembly to move along the axis to open and close the valve port; A stop assembly is located above the rotor. The stop assembly includes a stop member, a helical guide rail device, and a slip ring. The helical guide rail device is fixed to the upper part of the lead screw, and a helical guide rail is formed on the side of the helical guide rail device. The slip ring has a ring body sleeved on the helical guide rail and a ring shank extending outward from the ring body. The stop member is fixed to the rotor and rotates with the rotor. The rotating stop member drives the slip ring to rotate along the helical guide rail through the ring shank of the slip ring, thereby causing the slip ring to move up and down helically along the axis of the lead screw relative to the helical guide rail device.

2. The electronic expansion valve according to claim 1, characterized in that, The stop assembly also includes an upper limit member, which is fixed to the upper part of the spiral guide rail device to limit the highest position of the slip ring's upward movement. The spiral guide rail device has a lower limit end face, which is used to limit the slip ring to the lowest position of downward movement.

3. The electronic expansion valve according to claim 2, characterized in that, The upper limit component includes a limiting body fixed to the top of the spiral guide rail device and a limiting block extending outward from the limiting body, the limiting block extending onto the spiral guide rail.

4. The electronic expansion valve according to claim 3, characterized in that, The spiral guide rail device has a first through hole, and the lead screw passes through the first through hole of the spiral guide rail device and is fixed in the first through hole; The upper limit positioner has a second through hole located in the middle of the limiting body, and the lead screw passes through the second through hole of the upper limit positioner and is fixed in the second through hole.

5. The electronic expansion valve according to claim 1, characterized in that, The stop is a stop rod, which is placed along the axial direction of the lead screw.

6. The electronic expansion valve according to claim 5, characterized in that, The stop rod is the injection-molded rib of the rotor.

7. The electronic expansion valve according to claim 1, characterized in that, When the rotor rotates in the first direction, the rotating stop causes the slip ring to move spirally upward relative to the spiral guide rail device along the axis. When the rotor rotates in a second direction opposite to the first direction, the rotating stop causes the slip ring to move spirally downward relative to the spiral guide device along the axis.

8. The electronic expansion valve according to claim 1, characterized in that, The valve needle assembly includes an elastic component, and the valve needle assembly is connected to the lower part of the lead screw via the elastic component. After the top of the valve needle assembly contacts the valve port of the valve seat assembly, as the lead screw continues to move downward, the valve needle assembly and the lead screw undergo relative displacement along the axial direction, at which time the elastic component deforms.

9. The electronic expansion valve according to claim 8, characterized in that, The valve needle assembly also includes a valve needle, a gasket, and a pad. The valve needle includes a needle tip and a needle body, the needle body having a receiving cavity formed at the top, and the elastic member being placed within the receiving cavity. The gasket is housed at the top of the receiving cavity and is fixedly connected to the needle body, and the gasket is assembled with the lead screw; The pad is housed within the receiving cavity and located between the elastic member and the gasket, and the pad is fixedly connected to the bottom end of the lead screw.

10. The electronic expansion valve according to claim 9, characterized in that, The bottom end of the lead screw is provided with a trapezoidal protrusion, and the washer cooperates with the trapezoidal protrusion of the lead screw; The pad is riveted to the bottom end of the lead screw; The gasket is riveted to the body of the valve needle.

11. The electronic expansion valve according to claim 9, characterized in that, The lead screw and gasket are equipped with an anti-rotation mechanism, which ensures that the lead screw and the valve needle assembly can only move linearly along the axial direction of the lead screw.

12. The electronic expansion valve according to claim 11, characterized in that, A straight groove extending along the axial direction of the lead screw is provided on the outer wall of the bottom end of the lead screw. The gasket is an annular gasket with inwardly extending protrusions on its inner wall; The protrusions within the gasket can only move linearly within the linear groove at the bottom end of the lead screw.

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