Electronic expansion valve and its stop mechanism
By introducing a limiting mechanism into the electronic expansion valve, the movement of the valve needle is limited by the cooperation of the bushing and the stop ring, thus solving the problem of excessive valve needle movement and achieving higher operational accuracy and safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JOHNSON ELECTRIC (JIANGMEN) CO LTD
- Filing Date
- 2025-05-27
- Publication Date
- 2026-06-26
AI Technical Summary
The valve needle of existing electronic expansion valves has the risk of over-moving, affecting the accuracy of opening and closing and the safety of use.
A limiting mechanism is adopted, including a bushing, a guide spring and a stop ring. The movement of the valve needle is limited by the circumferential contact between the limiting groove and the stop ring, ensuring that the valve needle stays in the accurate position.
This improves the opening and closing accuracy and safety of the electronic expansion valve, and avoids wear and damage caused by excessive downward movement of the valve needle.
Smart Images
Figure CN224415440U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of valve technology, and in particular to an electronic expansion valve and its limiting mechanism. Background Technology
[0002] Valves are widely used in various pipelines to regulate the flow and / or pressure of fluids such as gas, water, and refrigerant. For example, in an automotive air conditioning system, an electronic expansion valve is installed in the inlet pipe of the evaporator to throttle and reduce the pressure of the medium-temperature, high-pressure refrigerant, ensuring that the amount of liquid refrigerant entering the evaporator is appropriate for the cooling load requirements.
[0003] An electronic expansion valve typically consists of a valve seat and a valve needle mounted within the valve seat. The movement of the valve needle relative to the valve seat connects or disconnects the corresponding valve ports, allowing the electronic expansion valve to switch between different states and regulate the flow and / or pressure of the refrigerant. However, existing electronic expansion valves have a risk of the valve needle over-moving during use, affecting the accuracy of opening and closing and operational safety, requiring further improvement. Utility Model Content
[0004] In view of this, the purpose of this utility model is to provide an electronic expansion valve and its limiting mechanism, which can limit the movement of the valve needle, so that the operation of the electronic expansion valve is more accurate and reliable.
[0005] On one hand, this utility model provides a limiting mechanism for use in an electronic expansion valve to limit the movement of its valve needle relative to the valve seat. The limiting mechanism includes a bushing, a guide spring sleeved on the bushing, and a stop ring screwed onto the guide spring. One end of the bushing protrudes radially outward to form a boss, and the end face of the boss facing the stop ring is recessed to form a limiting groove. The circumferential sidewall of the limiting groove serves as a first limiting part, and one end of the stop ring serves as a first stop part. When the first stop part abuts against the first limiting part, the valve needle can be limited to a first position.
[0006] On the other hand, this utility model provides an electronic expansion valve, including a valve seat, a valve needle movably disposed in the valve seat, a motor for driving the valve needle to move relative to the valve seat, and the aforementioned limiting mechanism. The motor includes a stator and a rotor rotatably disposed relative to the stator. The rotor includes a rotating shaft, which is drivenly connected to a stop ring of the limiting mechanism to drive the stop ring to slide along the guide spring.
[0007] Compared to existing technologies, the electronic expansion valve provided by this utility model has a limiting groove formed by the recess of the boss. The stop ring is housed in the limiting groove and abuts against its groove sidewall in the circumferential direction for positioning, thereby limiting the downward movement of the valve needle and ensuring the opening and closing accuracy and safety of the electronic expansion valve. Moreover, the setting of the limiting groove makes the stop ring less prone to displacement and accidental deformation. In this way, the stop ring and the groove sidewall of the boss can be stably matched to form an accurate and effective limit on the valve needle. Attached Figure Description
[0008] Figure 1 This is a schematic diagram of an embodiment of the electronic expansion valve of this utility model.
[0009] Figure 2 for Figure 1 The top view of the electronic expansion valve shown.
[0010] Figure 3 for Figure 2 A sectional view along line III-III.
[0011] Figure 4 for Figure 1 The exploded view of the electronic expansion valve is shown.
[0012] Figure 5 A further exploded view of the electronic expansion valve after the motor has been removed.
[0013] Figure 6 A further exploded view of the limiting mechanism of the electronic expansion valve.
[0014] Figure 7 This is a cross-sectional view of the electronic expansion valve of this utility model in another state.
[0015] Figure 8 for Figure 7 A three-dimensional schematic diagram of the electronic expansion valve in the indicated state.
[0016] Figure 9 This is a three-dimensional schematic diagram of the electronic expansion valve in another state. Detailed Implementation
[0017] To facilitate understanding of this utility model, a more comprehensive description will be provided below with reference to the accompanying drawings. One or more embodiments of this utility model are exemplarily shown in the drawings to enable a more accurate and thorough understanding of the disclosed technical solutions. However, it should be understood that this utility model can be implemented in many different forms and is not limited to the embodiments described below.
[0018] This invention provides an electronic expansion valve for regulating the flow rate, pressure, etc. of fluids in pipelines. Figure 1-5The figure shows a specific embodiment of the electronic expansion valve of the present invention. The electronic expansion valve 100 includes a valve seat 20, a valve needle 30 movably disposed in the valve seat 20, a motor 40 for driving the valve needle 30 to move relative to the valve seat 20, and a limiting mechanism 50 for limiting the movement of the valve needle 30.
[0019] like Figure 3 , Figure 5 As shown, the valve seat 20 is provided with a first valve port 22 and a second valve port 24. The first valve port 22 serves as the fluid inlet of the electronic expansion valve 100, and the second valve port 24 serves as the fluid outlet of the electronic expansion valve 100. In this embodiment, the valve seat 20 is generally tubular. The first valve ports 22 are disposed on the circumferential sidewall of the valve seat 20. Preferably, there are multiple first valve ports 22, which are spaced apart circumferentially along the valve seat 20, thus enabling simultaneous connection of multiple input pipes (not shown). The second valve port 24 is disposed on the axial outer end of the valve seat 20 (e.g., ...). Figure 3 The lower end shown is preferably a gradually expanding structure for the second valve port 24. As the fluid flows through the second valve port 24 to the output pipe (not shown), its flow rate and pressure gradually decrease, forming a throttling and pressure reduction effect.
[0020] The valve needle 30 is generally a slender rod-shaped structure, one end of which (e.g.) Figure 3 The lower end shown serves as the actuating end 32, housed within the valve seat 20; the other end (as shown) Figure 3 The upper end (as shown) extends beyond the valve seat 20 as a connecting end 34 and connects to the motor 40. Driven by the motor 40, the valve needle 30 moves axially along the valve seat 20. Figure 3 As shown, when the valve needle 30 moves downward relative to the valve seat 20 to the first position P1, its actuating end 32 seals against the second valve port 24, closing the electronic expansion valve 100; Figure 7 As shown, when the valve needle 30 moves upward relative to the valve seat 20 away from the first position P1, its actuating end 32 is in clearance fit with the second valve port 24 to open the electronic expansion valve 100. At this time, the fluid that enters the electronic expansion valve 100 through the first valve port 22 can flow out through the second valve port 24.
[0021] like Figure 3 , Figure 4As shown, the motor 40 includes a stator 42 and a rotor 44 rotatably disposed at the center of the stator 42. A rotating shaft 46 is disposed at the center of the rotor 44, and the end of the rotating shaft 46 extends outward for connecting the valve needle 30. In this embodiment, the valve needle 30 is connected to the rotating shaft 46 via a needle sleeve 60. Specifically, the end of the rotating shaft 46 and the connecting end 34 of the valve needle 30 extend into the needle sleeve 60 from the upper and lower ends, respectively, and are axially aligned and spaced a certain distance apart. An elastic element 62, such as a spring or sheet, is housed in the needle sleeve 60 and abuts against the rotating shaft 46 and the valve needle 30. Preferably, the end of the needle sleeve 60 facing the rotating shaft 46 (i.e., Figure 3 The top end (shown) is equipped with a bearing 64, and the end of the rotating shaft 46 passes through the bearing 64 and extends into the needle sleeve 60, abutting against the elastic element 62.
[0022] like Figure 3 , Figure 5-6 As shown, the limiting mechanism 50 includes a bushing 52, a guide spring 54 mounted on the bushing 52, and a stop ring 56 movably screwed into the guide spring 54. The bushing 52 is fixedly disposed in the electronic expansion valve 100, such as being fixedly connected to the valve seat 20. The bushing 52 is provided with a first limiting part. The stop ring 56 is sleeved on the bushing 52 and can rotate and move relative to the bushing 52 along the guide spring 54. The stop ring 56 forms a first stop part. Through the cooperation of the first limiting part and the first stop ring 56, the valve needle 30 is restricted to the first position P1 and cannot continue to move downward. This avoids the valve needle 30 moving downward excessively and causing unnecessary interference with the valve seat 20, which could lead to wear or even damage to the electronic expansion valve 100, affecting the opening and closing accuracy and safety of the electronic expansion valve 100.
[0023] Specifically, the bushing 32 is generally a hollow cylindrical shape, and the rotating shaft 46 of the motor rotor 44 passes through the bushing 32. In this embodiment, the outer wall surface of the rotating shaft 46 is formed with an external thread, and the inner wall surface of the bushing 32 is formed with an internal thread that mates with it. By fixing the engagement between the bushing 32 and the rotating shaft 46, the rotating shaft 46 can move axially while rotating, thereby driving the valve needle 30 connected to it to move up and down.
[0024] The end of the bushing 32 facing the valve needle 30 protrudes radially outward to form a boss 521. The outer diameter of the upper end of the boss 521 is not less than the outer diameter of the guide spring 54. The guide spring 54 has a helical structure and is looped around the bushing 32. Its lower end rests on the upper end face of the boss 521, so that the boss 521 can provide axial support and positioning for the guide spring 54. In this embodiment, the boss 521 is a truncated cone, and its outer diameter gradually increases in the direction away from the guide spring 54.
[0025] like Figure 6As shown, the upper part of the boss 521 facing the guide spring 54 is recessed to form a limiting groove 523. The limiting groove 523 has an axial bottom wall 525 and a circumferential side wall 527. In this embodiment, the side wall 527 is the first limiting part of the bushing 52.
[0026] When the valve needle 30 moves to the first position P1, as Figure 5-6 As shown, the stop ring 56 slides to the bottom of the guide spring 54, and its tail end 561 is accommodated in the limiting groove 523 and abuts against the side wall 527 of the groove in the circumferential direction. In this embodiment, the tail end 561 of the stop ring 56 is the first stop part.
[0027] Thus, by limiting the first stop, the stop ring 56 cannot continue to rotate, which in turn prevents the motor rotor 44 from continuing to rotate, ultimately causing the valve needle 30 to stop at the first position P1 and not to move further down. This effectively avoids the problem of excessive downward movement of the valve needle 30 caused by rotational inertia, making the operation of the electronic expansion valve 100 more accurate and reliable.
[0028] In the electronic expansion valve 100 provided by this utility model, a limiting groove 523 is formed by the recess of the boss 521. The side wall 527 of the limiting groove 523 serves as the first limiting part of the bushing 52, and abuts against the first stop part formed by the tail end 561 of the stop ring 56 in the circumferential direction for positioning. This restricts the downward movement of the valve needle 30, allowing it to be held in the first position and closing the second valve port 24 of the valve seat 20. Compared with setting an additional mechanism on the outer wall of the boss 521 to restrict the movement of the stop ring 56, this method is not only simpler in structure, but also reduces the material cost and weight of the bushing 52 to a certain extent.
[0029] Preferably, the axial depth of the limiting groove 523 of the bushing 52 gradually changes in the circumferential direction, making the bottom wall 525 of the groove inclined, which is compatible with the shape of the spirally extending stop ring. When the stop ring 56 slides to the bottom of the guide spring 54, most of it is accommodated in the limiting groove 523 and abuts against the bottom wall 525 of the groove. Compared with supporting the stop ring 56 by a plane (such as the outer end face of the boss 521), the stop ring 56 can be stably and effectively supported at all positions. In this way, the stop ring 56 will not be suspended and easily deformed, making the fit between the stop ring 56 and the bushing 52 more stable.
[0030] It should be noted that the direction in which the depth of the limiting groove 523 gradually increases is consistent with the direction of rotation of the motor rotor 44 when the valve needle 30 moves toward the first position P1. Figure 5-6As shown, the axial depth of the limiting groove 523 gradually increases in the clockwise direction, reaching its maximum axial depth near the groove sidewall 527. That is, when the motor rotor 44 rotates clockwise, it drives the valve needle 30 to move downward toward the first position P1. At the same time, the stop ring 56 slides downward along the guide spring 54 as the motor rotor 44 rotates clockwise, until the tail end 561 of the stop ring 56 abuts against the groove sidewall 527 of the limiting groove 523.
[0031] Preferably, the axial depth of the limiting groove 523 gradually increases radially from the outside to the inside, so that the bottom wall 525 of the groove is higher on the outside and lower on the inside, which helps to limit the stop ring 56 in the limiting groove 523.
[0032] Preferably, the sidewall 527 of the limiting groove 523 is inclined relative to the bottom wall 525 of the groove, and the included angle between the two is an acute angle slightly less than 90 degrees. In this way, the bottom wall 525 can generate an axial upward and downward component force on the tail end 561 of the stop ring 56 that abuts against it, further enhancing the stability of the fit between the tail end 561 (i.e., the first stop part) and the bottom wall 525 (i.e., the first limiting part).
[0033] like Figure 5-6 As shown, the upper end of the guide spring 54 forms a second limiting portion, and correspondingly, the upper end of the stop ring 56 forms a second stop portion. The displacement of the valve needle 30 when it moves upward is controlled by the cooperation of the second stop portion and the second limiting portion. In this embodiment, the upper end of the guide spring 54 extends axially outward to form a first protrusion 541, which serves as the second limiting portion; the upper end of the stop ring 56 extends radially outward to form a second protrusion 563, which serves as the second stop portion.
[0034] When the motor rotor 44 rotates in the reverse direction (e.g., counterclockwise), it drives the valve needle 30 at the first position P1 to move upward. Simultaneously, the stop ring 56, as the motor rotor 44 rotates counterclockwise, slides upward along the guide spring 54 to its top, until the radial protrusion 563 of the stop ring 56 abuts against the axial protrusion 541 of the guide spring 54. Figure 9 As shown. At this time, the valve needle 30 moves upward to the second position P2, and the second valve port 24 has the largest effective flow area. The cooperation between the second protrusion 563 and the first protrusion 541 also ensures that the stop ring 56 will not automatically disengage from the guide spring 54 when sliding upward.
[0035] In the electronic expansion valve 100 shown, by providing a limiting mechanism 50, the valve needle 30 can be restricted to move between the first position P1 and the second position P2. As the valve needle 30 moves from the first position P1 to the second position P2, its actuating end 32 gradually withdraws from the second valve port 24, and the effective flow area of the second valve port 24 gradually increases; conversely, as the valve needle 30 moves from the second position P2 to the first position P1, the depth to which its actuating end 32 inserts into the second valve port 24 gradually increases, and the effective flow area of the second valve port 24 gradually decreases.
[0036] During the movement of the valve needle 30 between the first position P1 and the second position P2, it can stop at any intermediate position as needed. For example... Figure 7-8 As shown, the actuating end 32 is partially located inside the second valve port 24 and forms a blockage, and the effective flow area of the second valve port 24 is small; the stop ring 56 slides to the middle of the guide spring 54, and its tail end 561 separates from the side wall 527 of the bushing 52, and the second protrusion 563 at the upper end separates from the first protrusion 541 at the upper end of the guide spring 54.
[0037] In this embodiment, the bottom end of the guide spring 54 is bent downward along the outer wall of the boss 521 to form a first fixing part 543, and the end of the first fixing part 543 is bent and extended to form a second fixing part 545. The first fixing part 543 and the second fixing part 545 together constitute a hook 547. The bottom end of the boss 521, that is, the end opposite to the guide spring 54, protrudes further outward in the radial direction to form two lugs 529. A groove 528 is formed between the two lugs 529. The first fixing part 543 of the hook 547 passes through the groove 528, and the second fixing part 545 hooks onto the bottom surface of one of the lugs 529, fixing the guide spring 54 to the bushing 52.
[0038] In this embodiment, the bushing 52 and the valve seat 20 are respectively fixed to both sides of the mounting base 70. An axially penetrating assembly hole 72 is formed in the center of the mounting base 70, and the needle sleeve 60 is fixedly disposed in the assembly hole 72. The housing 74 covers and seals the mounting base 70, separating the valve needle 30, motor rotor 44, limiting mechanism 50, etc., from the motor stator 42 to prevent fluid from affecting electrical safety. For simplified illustration, only... Figure 3 The stator 42 of the motor is shown in the dashed line. Its specific structure can be referred to the drive motor of the existing electronic expansion valve, and will not be described in detail here.
[0039] The electronic expansion valve 100 provided by this invention can be applied to air conditioning systems. The fluid flowing through the electronic expansion valve 100 can be a refrigerant used for heat exchange in the air conditioning system, such as R410A. Specifically, the electronic expansion valve 100 can be installed at the inlet of the evaporator in the air conditioning system, serving as a boundary element between the high-pressure and low-pressure sides. It throttles and reduces the pressure of the high-pressure liquid refrigerant, thereby regulating and controlling the amount of liquid refrigerant entering the evaporator, ensuring that the amount of liquid refrigerant meets the requirements of the external cooling load. Of course, the electronic expansion valve 100 provided by this invention can be applied to any piping system that requires throttling and pressure reduction, and is not limited to use in air conditioning systems.
[0040] It should be noted that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the present invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, such as combining different features in various embodiments, and these should all fall within the protection scope of the present invention.
Claims
1. A limiting mechanism, used in an electronic expansion valve to limit the movement of its valve needle relative to a valve seat, the limiting mechanism comprising a bushing fixed relative to the valve seat, a guide spring sleeved on the bushing, and a stop ring screwed onto the guide spring, characterized in that, One end of the bushing protrudes radially outward to form a boss, and the end face of the boss facing the stop ring is recessed to form a limiting groove. The circumferential sidewall of the limiting groove serves as a first limiting part, and one end of the stop ring serves as a first stopping part. When the first stopping part abuts against the first limiting part, the valve needle can be restricted to a first position.
2. The limiting mechanism as described in claim 1, characterized in that, The bottom wall of the limiting groove extends in a spiral shape along its axial direction, which is adapted to the shape of the stop ring.
3. The limiting mechanism as described in claim 2, characterized in that, The axial depth of the limiting groove gradually decreases in the circumferential direction away from the sidewall of the groove.
4. The limiting mechanism as described in claim 3, characterized in that, The axial depth of the limiting groove gradually increases radially from the outside to the inside.
5. The limiting mechanism as described in claim 2, characterized in that, The angle between the side wall and the bottom wall of the limiting groove is an acute angle.
6. The limiting mechanism as described in claim 1, characterized in that, The other end of the stop ring forms a second stop portion, and the end of the guide spring away from the boss forms a second limiting portion. When the second stop portion abuts against the second limiting portion, the valve needle can be restricted to a second position.
7. The limiting mechanism as described in claim 6, characterized in that, The second limiting part is a first protrusion extending axially from the guide spring, and the second stop part is a second protrusion extending radially outward from the stop ring.
8. The limiting mechanism as described in any one of claims 1-7, characterized in that, The guide spring has a hook at one end near the boss, and the boss has a lug extending radially outward, with the hook engaging the lug.
9. The limiting mechanism as described in any one of claims 1-7, characterized in that, The inner wall surface of the bushing is threaded.
10. An electronic expansion valve, comprising a valve seat, a valve needle movably disposed in the valve seat, and a motor for driving the valve needle to move relative to the valve seat, characterized in that, It also includes the limiting mechanism according to any one of claims 1-9, wherein the motor includes a stator and a rotor rotatably configured relative to the stator, the rotor including a shaft passing through the bushing and threadedly engaging with the bushing, the rotor being drivenly connected to a stop ring of the limiting mechanism to drive the stop ring to slide along the guide spring.