Electronic expansion valve

Abstract

The application discloses an electronic expansion valve, which comprises a rotor component, a valve core component, a screw rod and a nut, the rotor component drives the screw rod to rotate, the screw rod is in threaded cooperation with the nut, and the screw rod can drive the valve core component to move along an axial direction to adjust the opening degree of a valve port of the electronic expansion valve; the electronic expansion valve further comprises a first elastic member and a second elastic member, the rigidity of the first elastic member is smaller than the rigidity of the second elastic member, and a valve closing process comprises a first state and a second state; in the first state, the first elastic member presses down the valve core component to close the valve port; and in the second state, the first elastic member and the second elastic member press down the valve core component to close the valve port. The valve closing force is generated by the first elastic member with smaller rigidity at the beginning of the valve port closing, so that noise can be reduced and the wear of the valve core component can be reduced; and after the valve core component contacts and abuts against the valve port, the second elastic member starts to compress and press against the valve core component, so that greater valve port closing force can be provided.

Description

Technical Field

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

[0002] Please refer to Figure 1 , Figure 1 This is a schematic diagram of an electronic expansion valve.

[0003] like Figure 1 As shown, the electronic expansion valve includes a valve seat component 1', a valve core component 2', a lead screw component 4', a rotor component 6', a housing component 7', a coil component 9', and a nut 3'. The valve seat component 1 forms the valve chamber and valve port 1a' of the electronic expansion valve. The valve seat component 1 is also provided with two connecting pipes for fluid to flow into or out of the valve chamber. The valve port 1a' controls the opening and closing of the two connecting pipes.

[0004] When the flow path is closed, the magnetic field generated by coil component 9' passes through housing component 7', driving rotor component 6 to rotate. Rotor component 6' drives lead screw component 4' to rotate. Lead screw component 4' is threadedly connected to nut 3', causing lead screw component 4' to move downward. When lead screw component 4' moves downward, it presses the top shaft 10' fixed on lead screw component 4' to move downward. Top shaft 10' presses the lower pressure spring 8' to move downward, and lower pressure spring 8' presses the valve core component 2' to move downward, thus closing valve port 1a'. Lower pressure spring 8' needs to provide the force to close valve port 1a', so the spring force of lower pressure spring 8' is relatively large. When closing the valve, it is easy to cause impact on valve port 1a' of valve seat component 1', thereby wearing valve port 1a' and generating noise. Summary of the Invention

[0005] This application provides an electronic expansion valve, including a rotor component, a valve core component, a lead screw, and a nut. The rotor component drives the lead screw to rotate, and the lead screw is threadedly engaged with the nut. When the lead screw rotates, it can drive the valve core component to move axially. The valve also includes a first elastic element and a second elastic element. The elasticity of the first elastic element is less than 1.5 times that of the second elastic element. The valve closing process includes a first state and a second state. In the first state, the first elastic element presses down on the valve core component to close the valve port. In the second state, the first elastic element and the second elastic element press down on the valve core component to close the valve port.

[0006] In one specific embodiment, the lead screw has an axial through hole, a portion of the valve core component is inserted into the axial through hole, and at least one of the first elastic element and the second elastic element is disposed within the axial through hole.

[0007] In one specific embodiment, the first elastic element and the second elastic element are disposed in the axial through hole and the other is disposed on the outside of the lead screw. The electronic expansion valve includes a force transmission part that penetrates the side wall of the lead screw. The first elastic element or the second elastic element located on the outside of the lead screw transmits elastic force to the valve core component through the force transmission part.

[0008] In one specific embodiment, the second elastic element is disposed on the outside of the lead screw, and the second elastic element is axially supported between the rotor component and the force transmission part; the force transmission part passes through and is supported by the lead screw, and when the valve core component contacts the valve port and the lead screw continues to move toward the valve port, the force transmission part axially disengages from the lead screw and is supported by the valve core component.

[0009] In one specific embodiment, the valve core component includes a valve stem and a bushing surrounding the valve stem, the bushing being integrally or separately disposed with the valve stem; the force transmission part is supported by the bushing of the valve core component.

[0010] In one specific embodiment, the inner wall of the axial through hole of the lead screw is provided with a step, and the bushing can abut against the step to press against the lead screw.

[0011] In one specific embodiment, the force transmission part includes two or more force transmission blocks and an annular block located in the axial through hole of the lead screw, the valve core component can pass through the annular block; the side wall of the lead screw is provided with circumferentially distributed through holes, the through holes correspond one-to-one with the force transmission blocks, the force transmission blocks pass through the through holes and are fixed to the annular blocks, and the annular blocks abut against the valve core component.

[0012] In one specific embodiment, the force transmission block is interference-fitted to the annular block or welded to the annular block.

[0013] In one specific embodiment, the side wall of the lead screw has an axially extending notch, and the portion between adjacent notches of the lead screw forms an insert. The force transmission part has an annular structure, and the force transmission part has two or more through holes distributed along its circumference. The through holes correspond one-to-one with the inserts, and the inserts are inserted into the through holes.

[0014] In one specific embodiment, a top shaft is provided in the axial through hole of the lead screw, and a bearing is provided between the top shaft and the inner wall of the axial through hole. The first elastic element and / or the second elastic element located in the axial through hole are located between the top shaft and the valve core component.

[0015] The present application provides a first elastic element and a second elastic element. When the valve port is initially closed, the first elastic element generates a closing force acting on the valve core component. At this time, the closing force is small, which can reduce noise and reduce wear on the valve core component. In the second state, the second elastic element presses against the valve core component to provide a larger valve port closing force and improve the sealing effect. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of an electronic expansion valve;

[0017] Figure 2 This is a schematic diagram of the electronic expansion valve provided in the first embodiment of this application. The valve core component has not yet sealed the valve port.

[0018] Figure 3 for Figure 2 Enlarged view of the location of the force transmission component;

[0019] Figure 4 for Figure 2 A schematic diagram of the valve core component of the electronic expansion valve when the valve port is closed;

[0020] Figure 5 for Figure 4 Enlarged view of the location of the force transmission component;

[0021] Figure 6 for Figure 4 A schematic diagram of the fit between the valve core component and the lead screw;

[0022] Figure 7 for Figure 6 A schematic diagram showing the connection between the lead screw and the force transmission part;

[0023] Figure 8 for Figure 7 A schematic diagram of the lead screw;

[0024] Figure 9 for Figure 6 Sectional view along line AA;

[0025] Figure 10 This is a schematic diagram showing the connection between the lead screw and the force transmission part in the electronic expansion valve provided in the second embodiment of this application;

[0026] Figure 11 for Figure 10 A schematic diagram of the lead screw;

[0027] Figure 12 for Figure 10 Sectional view along the BB direction. Detailed Implementation

[0028] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Example 1

[0030] Please refer to Figure 2-4 , Figure 2 This is a schematic diagram of the electronic expansion valve provided in the first embodiment of this application. The valve core component 2 has not yet sealed the valve port 1a. Figure 3 for Figure 2 Enlarged view of position 8 of the central force transmission unit;

[0031] Figure 4 for Figure 2 A schematic diagram of the valve core component 2 of the electronic expansion valve when the valve port 1a is closed; Figure 5 This is an enlarged view of the force transmission part 8 in Figure 4; Figure 6 for Figure 4 A schematic diagram of the engagement between the valve core component 2 and the lead screw 5.

[0032] like Figure 2 As shown, the electronic expansion valve in this embodiment includes a housing component 13, a coil component 10, a valve seat component 1, a rotor component, a valve core component 2, a lead screw 5, and a nut 3. The nut 3 is fixed to the valve seat component 1 and can be fixed to the valve seat component 1 through a connecting piece 4. The valve seat component 1 is provided with a valve cavity and a valve port 1a. The valve seat component 1 is externally connected to a first interface pipe 100 and a second interface pipe 100. The valve port 1a controls the opening and closing of the first interface pipe 100 and the second interface pipe 100. The valve core component 2 can move axially to adjust the opening degree of the valve port 1a.

[0033] Specifically, the rotor component includes a cylindrical rotor 72 and an annular connecting portion 71 located on the upper part of the rotor 72. The outer edge of the connecting portion 71 is inserted into the inner peripheral wall of the rotor 72 and fixed to the rotor 72. The connecting portion 71 serves as the top of the rotor component. The inner peripheral wall of the connecting portion 71 is fixed to the outer peripheral wall of the lead screw 5, that is, the lead screw 5 is inserted into the inner hole of the connecting portion 71. The middle part of the connecting portion 71 can be... Figure 2 As shown by the upward protrusion, it can be seen that the rotor 72 and the connecting part 71 can also be integrally set.

[0034] In addition, this embodiment also includes a first elastic member and a second elastic member, which are respectively Figure 2 The first spring 9 and the second spring 14 shown herein, the first elastic component and the second elastic component are both in a pre-compressed state in the initial state and have initial elastic force. This initial state can be found in [reference needed]. Figure 2 Understandably, when valve port 1a is open, neither the first elastic component nor the second elastic component is further compressed. In this embodiment, the initial elastic force of the first elastic component is less than 1.5 times the initial elastic force of the second elastic component, and the multiple can specifically be 1.5, 1.2, 1, 0.8, 0.5, or 0.3, etc.

[0035] In this embodiment, the lead screw 5 has an axial through hole 5b (shown in...). Figure 6 The first spring 9 is disposed within the axial through hole 5b, while the second spring 14 is disposed outside the lead screw 5 and can be disposed outside the lead screw 5. The valve core component 2 includes a valve stem 21 and a valve needle 22 located at the end of the valve stem 21. The valve needle 22 is tapered and is used to cooperate in sealing the valve port 1a. The valve stem 21 may be provided with an annular stop 15 surrounding the valve stem 21. Figure 2 The annular baffle 15 is fixed separately from the valve stem 21, but it can also be integrally installed with the valve stem 21. The first spring 9 is positioned between the annular baffle 15 and the top shaft 12 located at the end of the lead screw 5, providing axial restraint for the top shaft 12 and the lead screw 5. Figure 2 The top shaft 12 is located above the axial through hole 5b of the lead screw 5, and the two are connected by a bearing 11. In this way, when the lead screw 5 rotates, the top shaft 12 will not rotate with it, thus preventing the first spring 9 from generating torque. Of course, the top shaft 12 and the lead screw 5 can also be fixedly connected, or the top shaft 12 can be integrally set with the lead screw 5 and form the top of the lead screw 5.

[0036] exist Figure 2 Based on the structure, when the valve port 1a is closed, the magnetic field generated by the energized coil component 10 passes through the housing component 13 and drives the rotor 72 of the rotor component to rotate. The connecting part 71 of the rotor component correspondingly drives the lead screw 5 to rotate. Since the lead screw 5 and the nut 3 are threadedly engaged, the rotation is converted into axial movement; that is, the rotor component and the lead screw 5 can move together axially to approach the valve port 1a. Figure 2 From the perspective of moving downwards, the valve stem 21 of the valve core component 2 is inserted into the axial through hole 5b of the lead screw 5. At this time, the top shaft 12 will move axially with the lead screw 4 and press down the first spring 9. The first spring 9 presses down the annular stop 15, which in turn drives the valve core component 2 to move downwards to perform the valve closing operation.

[0037] It can be seen that the annular baffle 15 is used to transmit the elastic force of the first spring 9 to the valve core component 2. Obviously, the way the first spring 9 drives the valve core component 2 to move is not limited to this. For example, the valve stem 21 of the valve core component 2 can be directly opened as a spring seat at the end facing the top shaft 12. Regardless of the structural form adopted, as long as the first spring 9 is positioned axially between the rotor component and the valve core component 2 and can press against the valve core component, it is acceptable.

[0038] It is worth noting that in this embodiment, when the valve core component 2 moves down to the point where it begins to abut against the valve port 1a, that is, when the valve needle 22 just touches the valve port 1a, the second spring 14 will begin to be compressed and press against the valve core component 2. The specific implementation method is as follows:

[0039] Since the second spring 14 is located on the outside of the lead screw 5, and the valve core component 2 is located inside the axial through hole 5b of the lead screw 5, the second spring 14 pressing against the valve core component 2 needs to be achieved through the force transmission part 8, such as... Figure 2, 3 As shown, the force transmission part 8 penetrates the side wall of the lead screw 5, that is, it is inserted from the outside of the side wall of the lead screw 5 and extends to the inside of the side wall of the lead screw 5. The second spring 14 is axially disposed between the connecting part 71 of the rotor component and the portion of the force transmission part 8 located on the outside of the lead screw 5. The portion of the force transmission part 8 located on the inside of the lead screw 5 is located on the bushing 6 of the valve core component 2. Before the valve core component 2 moves down but before it contacts the valve port 1a, the force transmission part 8 penetrates and is supported by the lead screw 5, as shown. Figure 3 As shown, in this state, the distance between the force transmission part 8 and the connecting part 71 of the rotor component remains unchanged. At this time, the second spring 14 is compressed and has an initial elastic force. Additionally, as... Figure 2 As shown, the wall of the axial through hole 5b of the lead screw 5 is provided with a step 52. When the bushing 6 of the valve core component 2 is pressed down, it abuts against the step 52, which also provides the force for the lead screw 5 to be pressed down, which is beneficial to the downward movement of the lead screw 5.

[0040] See again Figure 4 , 5 Comparable Figure 3 , 5 Understanding the valve closing process involves two states. In the first state, the first spring 9 presses down on the valve core component 2 to contact the valve port 1a. As the valve core component 2 moves down to the position contacting the valve port 1a and continues to move towards it, the rotor component and the lead screw 5 continue to rotate and move axially towards the valve port 1a. However, since the valve core component 2 has already contacted the valve port 1a, the bushing 6, which is integrally or separately fixed to the valve core component 2, cannot continue to move down. Consequently, the position of the bushing 6 relative to the lead screw 5 is raised. Figure 4 As shown, due to the relative downward movement of the lead screw 5, the bushing 6 is relatively raised, creating a gap between it and the step 52. Looking further... Figure 5 At this time, the force transmission part 8 is disengaged from the support of the lead screw 5 and is supported by the bushing 6. The height of the force transmission part 8 and the bushing 6 will remain unchanged. When the rotor component continues to move down, the distance between the connecting part 71 of the rotor component and the force transmission part 8 will decrease, thereby starting to compress the second spring 14 and entering the second state of valve closure. The first spring 9 and the second spring 14 jointly press down the valve core component 2 until the rotor component and the lead screw 5 move to the lower limit position.

[0041] The second spring 14 can be designed to have a stiffness greater than that of the first spring 9. In this way, the compressed second spring 14 can provide a larger pressure to the bushing 6, so that the valve core component 2 is subjected to a greater axial pressure, thereby pressing the valve port 1a and achieving a better seal of the valve port 1a.

[0042] As can be seen, in this embodiment, during the valve closing process, both before and when the valve core component 2 contacts the valve port 1a, the first elastic element generates a force that presses the valve core component 2 closer to the valve port 1a. The elastic force provided by the first elastic element is relatively small, which can prevent the valve core component 2 from being subjected to excessive pressure in the initial stage of valve port 1a closure, thereby reducing the wear and impact noise of the valve needle 22 of the valve core component 2. After the valve core component 2 contacts the valve port 1a, the second elastic element generates a force that presses the valve core component 2, which can increase the force on the valve core component 2 and improve the sealing effect. Since the second elastic element applies force after the valve core component 2 contacts the valve port 1a, it will not generate impact noise or increase the wear of the valve needle 22.

[0043] Please continue to refer to this. Figure 7-9 , Figure 7 for Figure 6 A schematic diagram showing the connection between the lead screw 5 and the force transmission part 8; Figure 8 for Figure 7 Schematic diagram of lead screw 5; Figure 9 for Figure 6 Sectional view along line AA.

[0044] As mentioned earlier, the force transmission part 8 needs to pass through the side wall of the lead screw 5 to transmit the elastic force of the second spring 14 on the outside of the lead screw 5 to the valve core component 2 located inside the lead screw 5. The specific method is as follows: Figure 8 As shown, the side wall of the lead screw 5 is provided with multiple circumferentially distributed through holes 5a, and the force transmission part 8 includes two or more force transmission blocks 81. Figure 9 Three force transmission blocks 81 are provided in the middle, and the through holes 5a on the side wall of the lead screw 5 correspond one-to-one with the multiple force transmission blocks 81. The force transmission part 8 also includes an annular block 82, which is disposed in the axial through hole 5b of the lead screw 5, and the valve stem 21 of the valve core component 2 can pass through the through hole of the annular block 82.

[0045] During installation, the force transmission block 81 located outside the lead screw 5 is inserted into the through hole 5a and fixed to the annular block 82 located inside the lead screw 5. For example... Figure 9 As shown, the force transmission block 81 includes a main body 811 and a protrusion 812 protruding from the main body 811. The protrusion 812 is inserted into the through hole 5a and into the annular block 82. It can be fixed by interlocking with the annular block 82 and by interference fit. Alternatively, it can be inserted and then welded. Alternatively, the protrusion 812 can pass through the through hole 5a without being inserted into the annular block 82, but can still contact the annular block 82 and be welded. Of course, it can also be fixed to the annular block 82 in other ways. This embodiment does not impose specific limitations.

[0046] It should be noted that the height of the perforation 5a should be greater than the height of the part of the force transmission part 8 located inside the perforation 5a. In this way, when the valve core component 2 contacts the valve port 1a and the lead screw 5 continues to move downward, the force transmission part 8 can disengage from the support of the lead screw 5 and be supported by the bushing 6.

[0047] In this embodiment, multiple force transmission blocks 81 can be connected by plugging, bonding, or fasteners. Of course, multiple force transmission blocks 81 can also be unconnected.

[0048] The above method simply realizes the transmission of the force of the second spring 14 to the valve core component 2 by the force transmission part 8. It can be seen that the arrangement of the force transmission part 8 is not limited to this, and can be understood by referring to the following embodiment 2.

[0049] Example 2

[0050] Please refer to Figure 10-12 , Figure 10 This is a schematic diagram showing the connection between the lead screw 5 and the force transmission part 8 in the electronic expansion valve provided in the second embodiment of this application; Figure 11 for Figure 10 Schematic diagram of lead screw 5; Figure 12 This is a cross-sectional view along the BB direction in Figure 10.

[0051] This embodiment has a basically the same electronic expansion valve structure as the first embodiment, except that the assembly method of the force transmission part 8 and the lead screw 5 is different in this embodiment.

[0052] In the second embodiment, the force transmission part 8 is not a separate unit, but a complete annular structure, and the force transmission part 8 has two or more through holes 8a distributed along its circumference. The side wall of the lead screw 5 has an axially extending notch 5c, which extends away from the valve port 1a. Figure 10 From the perspective of notch 5c extending upwards. Figure 10 A notch 5c is provided on the upper part of the lead screw 5. At this time, the portion between adjacent notches 5c of the lead screw 5 forms an insert 51 located on the upper part of the lead screw 5. The insert 51 corresponds one-to-one with the through hole 8a of the force transmission part 8. In this way, the force transmission part 8 can be inserted into the lead screw 5 axially, and the portion between the through holes 8a of the force transmission part 8 can pass through the notch 5c of the lead screw 5, thereby establishing that the second spring 14 on the outside of the lead screw 5 presses against the bushing 6 of the valve core component 2 on the inside of the lead screw 5.

[0053] This application aims to achieve the following: initially, when valve port 1a is closed, the first spring 9 with lower stiffness presses down on valve core component 2, while the second spring 14 does not exert pressure on valve core component 2. Only after valve core component 2 contacts and abuts against valve port 1a, and the rotor component and lead screw 5 continue to move downwards, does the second spring 14 begin to compress and press down on valve core component 2, providing a greater closing force for valve port 1a and improving the sealing effect. To achieve this objective, the above embodiment uses the example of the second spring 14 being located on the outside of the lead screw 5 and the first spring 9 being located on the inside of the lead screw 5, i.e., within the axial through hole 5b of the lead screw 5, but it is clearly not limited to this.

[0054] For example, both the first spring 9 and the second spring 14 can be installed within the axial through hole 5b of the lead screw 5. One end of the second spring 14 is connected to the annular stop 15 and has a certain distance from the top shaft 12. When the top shaft 12 moves down a certain distance and the valve core component 2 just contacts and abuts against the valve port 1a, the second spring 14 begins to contact the top shaft 12. If the top shaft 12 continues to press down, it can also compress the second spring 14 to generate greater pressure to seal the valve port 1a. Alternatively, it is also feasible to install the first spring 9 on the outside of the lead screw 5 and the second spring 14 inside the lead screw 5.

[0055] As can be seen, in the first and second embodiments of this application, the second spring 14 is disposed on the outside of the lead screw 5, which can make full use of the space inside the rotor 72, making the structure more compact. Moreover, the two springs are disposed on the inside and outside of the lead screw 5 respectively, which also makes them less likely to interfere with each other. In addition, the first elastic element and the second elastic element are not limited to springs; any component that can be compressed to generate elastic force can be used.

[0056] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. An electronic expansion valve, comprising a rotor assembly, a valve core assembly, a lead screw, and a nut, wherein the rotor assembly drives the lead screw to rotate, the lead screw is threadedly engaged with the nut, and the rotation of the lead screw enables the valve core assembly to move axially, characterized in that, It also includes a first elastic element and a second elastic element. The initial elastic force of the first elastic element is less than 1.5 times the initial elastic force of the second elastic element. The valve closing process includes a first state and a second state. Before and when the valve core component contacts the valve port, it is in the first state. In the first state, the first elastic element presses down on the valve core component to close the valve port. In the second state, the first elastic element and the second elastic element press down on the valve core component to close the valve port. The lead screw has an axial through hole, a portion of the valve core component is inserted into the axial through hole, and at least one of the first elastic element and the second elastic element is disposed within the axial through hole; The first elastic element and the second elastic element are respectively disposed in the axial through hole and the other is disposed on the outside of the lead screw. The electronic expansion valve includes a force transmission part, which penetrates the side wall of the lead screw. The first elastic element or the second elastic element located on the outside of the lead screw transmits elastic force to the valve core component through the force transmission part. The second elastic element is disposed on the outside of the lead screw, and the second elastic element is axially supported between the rotor component and the force transmission part; the force transmission part passes through and is supported by the lead screw, and when the valve core component contacts the valve port and the lead screw continues to move toward the valve port, the force transmission part axially disengages from the lead screw and is supported by the valve core component.

2. The electronic expansion valve according to claim 1, characterized in that, The valve core component includes a valve stem and a bushing surrounding the valve stem, wherein the bushing is integrally or separately disposed from the valve stem; the force transmission part is supported by the bushing of the valve core component.

3. The electronic expansion valve according to claim 2, characterized in that, The inner wall of the axial through hole of the lead screw is provided with a step, and the bushing can abut against the step to press against the lead screw.

4. The electronic expansion valve according to claim 2, characterized in that, The force transmission part includes two or more force transmission blocks and an annular block located in the axial through hole of the lead screw. The side wall of the lead screw is provided with circumferentially distributed through holes, which correspond one-to-one with the force transmission blocks. The force transmission blocks pass through the through holes and are fixed to the annular blocks. In the second state, the annular blocks abut against the valve core component axially.

5. The electronic expansion valve according to claim 4, characterized in that, The force transmission block is interference-fitted to the annular block or welded to the annular block.

6. The electronic expansion valve according to claim 1, characterized in that, The lead screw has an axially extending notch on its side wall. The portion between adjacent notches of the lead screw forms an insert. The force transmission part has a ring structure and two or more through holes are distributed along its circumference. The through holes correspond one-to-one with the inserts, and the inserts are inserted into the through holes.

7. The electronic expansion valve according to any one of claims 1-6, characterized in that, A top shaft is provided in the axial through hole of the lead screw, and a bearing is provided between the top shaft and the inner wall of the axial through hole. The first elastic element and / or the second elastic element located in the axial through hole are located between the top shaft and the valve core component.

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