Electronic expansion valve

Abstract

The application provides an electronic expansion valve, which is optimized in structure of a core assembly, and comprises a body, a cylindrical part and a valve core; the cylindrical part comprises a lower end part, and the lower end part is provided with a flow-through channel; when the electronic expansion valve is in a small-flow adjusting state, the lower end part is not higher than an inlet end of a first connecting pipe; after the refrigerant enters a valve cavity from an inlet part, the refrigerant with less bubbles sinks into the inside of the core assembly through a gas-liquid separation and sedimentation effect, and the refrigerant with larger bubbles rises, so that the flow noise of the refrigerant generated by the electronic expansion valve in the small-flow adjusting state can be relatively improved.

Description

[Technical Field]

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

[0002] Electronic expansion valves are widely used in refrigeration systems as throttling elements to regulate refrigerant flow. They typically use a coil component to drive a rotor, which in turn drives a threaded transmission component to move a valve needle component axially up and down, thereby controlling the valve opening and regulating the refrigerant flow. An electronic expansion valve includes a valve core, a valve stem, and a valve body. The valve body has a large valve port, and the valve core has a small valve port. The valve stem and the small valve port constitute the small flow regulation mechanism of the electronic expansion valve. During the process of regulating the refrigerant flow in a small flow state, the electronic expansion valve generates refrigerant flow noise, which affects the user's comfort. [Summary of the Invention]

[0003] The purpose of this invention is to provide an electronic expansion valve that can relatively improve the flow noise generated by the refrigerant during small flow rate regulation.

[0004] An electronic expansion valve is characterized by having a valve cavity, and further comprising a valve body, a first connecting pipe, and a second connecting pipe. The valve body includes a first valve port, a first connecting interface, and a second connecting interface. The first connecting pipe is fixedly connected to the first connecting interface, and the second connecting pipe is fixedly connected to the second connecting interface. The first connecting pipe includes an inlet portion, and the inlet portion has an inlet end.

[0005] The electronic expansion valve also includes a core assembly and a lead screw. The core assembly includes a body, a cylindrical part, and a valve core. The body is fixedly connected to the cylindrical part and movably connected to the valve core. The lead screw is threadedly engaged with the body. The body includes a valve stem. The valve core is provided with a second valve port and also includes a flange. Through the threaded engagement, the valve core can approach or move away from the first valve port, and the valve stem can approach or move away from the second valve port.

[0006] The cylindrical portion includes a lower end, which is provided with a flow channel. When the valve core closes the first valve port, the lower end can abut against the flange to form a first limit position, and the lower end can move away from the flange to form a second limit position. The lower end can move between the first limit position and the second limit position, and the position of the lower end is not higher than the inlet end.

[0007] The electronic expansion valve provided by the present invention optimizes the core component structure, including a body, a cylindrical part and a valve core. The cylindrical part includes a lower end with a flow channel. When the valve core closes the first valve port, the lower end can abut against the flange to form a first limit position, and the lower end can move away from the flange to form a second limit position. The lower end can move between the first limit position and the second limit position, and the position of the lower end is not higher than the inlet end. This can relatively improve the flow noise of refrigerant generated during the small flow rate adjustment process of the electronic expansion valve. [Attached Image Description]

[0008] Figure 1 A cross-sectional view of the overall structure of the electronic expansion valve in the fully open state provided by the present invention;

[0009] Figure 2 A cross-sectional view of the overall structure of the electronic expansion valve in the fully closed state provided by the present invention;

[0010] Figure 3 A cross-sectional view of the overall structure of the electronic expansion valve provided by the present invention in the fully open small valve port state;

[0011] Figure 4 A cross-sectional view and a perspective view of the body portion of the core assembly of the electronic expansion valve provided by the present invention.

[0012] Figure 5 A schematic diagram of the first cylindrical section structure of the core assembly of the electronic expansion valve provided by the present invention;

[0013] Figure 6 A schematic diagram of a second cylindrical section structure for the core assembly of the electronic expansion valve provided by the present invention;

[0014] Figure 7 A schematic diagram of a third cylindrical section structure for the core assembly of the electronic expansion valve provided by the present invention;

[0015] Figure 8 A perspective view and a cross-sectional view of the valve core assembly of the electronic expansion valve provided by the present invention.

Detailed Implementation Methods

[0016] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] Please refer to Figures 2-3 as well as Figure 5This is a schematic diagram of the structure of an electronic expansion valve according to the first embodiment of the present invention. It should be noted that the following description is based on a specific electronic expansion valve structure. This technical solution mainly focuses on improving the core component of the electronic expansion valve. Other components of the electronic expansion valve, such as the rotor screw assembly, connecting seat, and limiting seat, are not particularly limited. Those skilled in the art can apply the technical solution disclosed in this invention to other electronic expansion valve structures.

[0018] The electronic expansion valve includes a valve body 1 and a connecting seat 2, with the valve body 1 and connecting seat 2 fixedly connected. It also includes a housing 3, which is fixedly connected to the connecting seat 2. The valve body 1, connecting seat 2, and housing 3 together roughly define the valve cavity A of the electronic expansion valve. It should be noted that the valve cavity A referred to in this specification refers to the valve cavity A of the electronic expansion valve roughly formed by the fixed connection of the valve body 1, connecting seat 2, and housing 3, excluding cases where a first connecting pipe, a second connecting pipe, and other components located within the valve cavity A are already installed. The valve body 1 has a first connecting interface 12 on its side wall and a second connecting interface 13 at its lower end. The electronic expansion valve also includes a first connecting pipe 10 and a second connecting pipe 20. The first connecting pipe 10 is fixedly connected to the first connecting interface 12 and has an inlet portion 10a, which includes an inlet end 101a. The second connecting pipe 20 is fixedly connected to the second connecting interface 13. The first connecting pipe 10 extends into the valve cavity A through the first connecting interface, meaning the inlet portion 10a is located in the valve cavity A. The first connecting pipe 10 and the second connecting pipe 20 can be connected to the first connecting interface 13 by furnace welding. Interface 12 and the second connection interface 13 are fixedly connected. The valve body 1 is roughly cylindrical in shape and can be integrally formed by machining. The valve body 1 is also provided with a first valve port 11. The valve body 1 can be an integral structure or a split structure. When the valve body 1 is an integral structure, the first valve port 11 is directly set on the valve body 1; or the valve body 1 can also be a split structure, including the valve body body and the valve seat core. The valve body body and the valve seat core can be fixedly connected by welding or other means. The first valve port 11 is set on the valve seat core. When the valve body 1 is a split structure, the valve seat core is part of the valve body.The electronic expansion valve also includes a lead screw 43 and a core assembly 7. The core assembly 7 includes a body 71, a cylindrical portion 72, and a valve core 73. The cylindrical portion 72 is fixedly connected to the body 71, and the body 71 and the valve core 73 are movably and sealingly connected. The valve core 73 is provided with a second valve port 731. The body 71 includes a valve stem 711. Through the threaded engagement between the lead screw 43 and the body 71, the valve stem 711 can approach or move away from the second valve port 731 to regulate the refrigerant flow through the second valve port 731, forming a small flow rate regulating mechanism for the electronic expansion valve. The core assembly 7 as a whole performs axial lifting and lowering movement within the valve cavity A, and the valve core 73 can... The cylindrical portion 72 includes a lower end portion 722, which has a flow channel for refrigerant to flow through the first valve port 11. The refrigerant enters the core assembly 7 through the flow channel. When the valve core 73 closes the first valve port 11, the lower end portion 722 can abut against the flange portion 732 of the valve core 73 to form a first limit position A1. This first limit position is the maximum opening position of the small flow regulation mechanism of the electronic expansion valve. That is, when it is in the first limit position, the valve stem 711 is farthest from the second valve port 731. The valve core 73 closes the first valve port, and the lower end 722 can move away from the flange 732 to form a second limit position A2. This second limit position is the minimum opening of the small flow regulating mechanism of the electronic expansion valve. That is, when in the second limit position, the valve core 73 closes the first valve port 11 and the valve stem 711 abuts against the second valve port 731. The lower end 722 can move between the first and second limit positions, and the position of the lower end 722 is not higher than the inlet end 101a. Through the above design, when the refrigerant enters the valve chamber A through the first pipe 10, it further performs a noise reduction effect on the refrigerant through the gas-liquid separation gravity sedimentation principle. Larger air bubbles in the refrigerant rise in valve chamber A, while refrigerant containing smaller air bubbles sinks and enters the core assembly 7 through the flow channel, then flows out through the second valve port 731 and the second pipe 20. This relatively improves the flow noise generated by the refrigerant during the small flow rate adjustment process of the electronic expansion valve. If the lower end 722 is set above the inlet end 101a, at least some of the refrigerant entering from the inlet 10a cannot completely impact the cylindrical part 72, and at least some of the refrigerant containing larger air bubbles may directly enter the core assembly through the flow channel without undergoing gas-liquid separation and gravity settling, which is not conducive to the noise reduction effect.

[0019] The first connecting pipe 10 extends into the valve cavity A through the first connecting interface 12, that is, the inlet 10a is located in the valve cavity A. The end face of the inlet 10a in the axial direction is separated from the inner wall surface of the valve body 1 by a distance L1. Assuming that the pipe wall thickness of the first connecting pipe 10 is represented by d, then L1≥2d is satisfied. The first connecting pipe 10, that is, the inlet connecting pipe, is relatively close to the cylindrical part 72, so the refrigerant can impact the cylindrical part 72 from the positive direction and more fully, thereby dispersing the refrigerant that originally carried large air bubbles.

[0020] The following is combined with Figure 5 The structure of the cylindrical part 72 is described in detail. The cylindrical part 72 includes a cylindrical body 721 and a lower end 722. The cylindrical body 721 is fixedly connected to the body 71. The lower end 722 is a generally hollow annular end plate structure. The lower end 722 is provided with a through hole 7224 to fit with the valve core 72. The lower end extends radially inward from the cylindrical body 721. Through the threaded engagement of the lead screw 43 and the body 71, the lower end 722 can approach or move away from the valve core 73 and abut against the flange 732 of the valve core 73, and lift the valve core 73 axially upward to move away from the first valve port 11. The lower end 722 includes a wall edge 7221 and a flow channel for refrigerant flow. A recessed hole 7222 is formed inwardly along the circumference of the wall edge 7221. The 7222 is roughly semi-circular in shape, with several recessed holes distributed circumferentially along the wall edge 7221 to allow refrigerant flow. There is a partition 7223 between two adjacent recessed holes. The recessed holes 7222 form the flow channel of the lower end 722. After the refrigerant settles through the principle of gas-liquid separation and gravity settling, the settled refrigerant enters the core assembly 7 through the recessed holes. The recessed holes further disperse the refrigerant. The present invention provides an electronic expansion valve that, through the improvement of the cylindrical part 72, disperses the large annular flow channel into multiple small channels, and there are partitions between each small channel. This further disperses and reduces the noise of the refrigerant, which still carries a lot of air bubbles after gravity settling, through the flow channel. This relatively improves the flow noise of the refrigerant generated by the electronic expansion valve when adjusting the flow rate at small flow rates.

[0021] The structure of the core assembly 7 is described in detail below, including a body 71, a cylindrical portion 72, and a valve core 73. The body 71 includes a valve stem 711 and an extension 712. The valve stem 711 is fixedly connected to the body 71 or is an integral structure. The extension 712 is generally a sleeve extending downward from the body 71. The extension 712 is movably and sealingly connected to the valve core 73. Figure 7The valve core 73 shown has a sealing ring 733 at its upper end. The extension 712 achieves a sealed connection with the valve core 73 by cooperating with the sealing ring 733. The extension 712 can move axially up and down along the peripheral wall of the upper end. The upper end of the body 71 also has an opening. The wall of the opening has an internal thread 713. The lower end of the lead screw 43 has an external thread 432. The internal thread 713 and the external thread 432 are screwed together. The valve core 73 also includes a flange 732. The extension 712 can approach or move away from the flange 732. An internal flow channel S1 for refrigerant is generally formed between the cylindrical body 721 and the extension 712. The extension 712 has a flow hole 7121. The refrigerant enters the core assembly through the flow channel. After passing through the flow channel S1, the refrigerant enters the space C formed between the body 71 and the valve core 73 through the flow hole 7121 and then flows out through the second valve port 731. In order to achieve better noise reduction, a spring 74 can also be provided in the internal flow channel S1. The spring 74 is sleeved on the outer periphery of the extension 712, with one end abutting against the body 71 and the other end abutting against the flange 732. When the refrigerant enters the flow channel S1 through the flow channel, it can be further disturbed by the action of the spring 74 to reduce noise. In addition, when the electronic expansion valve is in the fully closed state or the small flow regulation state, the action of the spring 74 can press the valve core 73 against the first valve port 11 to prevent the valve core 73 from being dislodged from the first valve port 11 by the refrigerant pressure. The valve core 73 also includes a valve core receiving cavity B. Furthermore, to achieve better noise reduction, the electronic expansion valve may also include a silencing device, including a first silencing component 81, a second silencing component 82, and a third silencing component 83. The first silencing component 81 can be fixedly connected to the lower end 722 of the cylindrical portion 72 by spot welding or other methods. When the refrigerant enters the valve cavity, it is silenced by the first silencing component 81 and then enters the core assembly 7 through the flow channel. The second silencing component 82 can be fixedly connected to the body 71 by interference fit with the valve stem 711 or the extension 712. When the refrigerant enters the space C through the flow hole 7121... After being silenced by the second silencer 82, the refrigerant flows outward from the second valve port 731. The third silencer is located in the valve core receiving cavity B. The valve core 73 also includes a retaining ring 734, which confines the third silencer 83 in the valve core receiving cavity B. After entering the valve core receiving cavity B, the refrigerant flows out of the second pipe 20 after being silenced by the third silencer 83. It should be noted that the electronic expansion valve provided by the present invention does not impose any limitations on the specific matching method between the silencer device and the components. In addition to the connection method described above, the connection between each silencer device and component can be achieved by other methods such as bonding or limiting.

[0022] The following is combined with Figure 1 and Figure 2A brief explanation of the operating principle of the core assembly 7: When the electronic expansion valve is fully closed, the valve core 73 closes the first valve port 11, the valve stem 711 closes the second valve port 731, the lower end 722 is relatively far away from the flange portion 732 of the valve core 73, and the extension portion 712 is relatively close to the flange portion 732. At this time, the space C between the body 71 and the valve core 73 reaches its relative minimum value. When a small flow rate adjustment is required, through the threaded engagement between the lead screw 43 and the body 71, the body 71 moves axially upward, the extension portion 712 gradually moves away from the flange portion 732, and the valve stem 71... As valve stem 711 gradually moves away from the second valve port 731, the space C gradually increases. When valve stem 711 fully opens the second valve port 731 and is far away from the second valve port 731, valve core 73 remains closed by the force of spring 74. Then, due to the threaded engagement of lead screw 43 and body 71, core assembly 7 continues to rise. The lower end 722 of cylindrical part 72 gradually approaches flange part 732 until the two abut. The lower end 722 can carry valve core 73 to continue to rise so that valve core 73 opens the first valve port 11. At this time, the large flow rate regulating mechanism is activated.

[0023] The electronic expansion valve provided by this invention also includes a rotor screw assembly 4, a limiting seat 5, and a bearing 6, all three located in valve cavity A. The rotor screw assembly 4 includes a rotor 41, a rotor seat 42, and a screw 43. The rotor and rotor seat are integrally formed by injection molding. The rotor seat 42 has a guide portion 421 that provides guidance for the screw 43. The screw 43 and the guide portion 421 are fixedly connected by laser welding or interference fit. Through coil excitation, the rotor 41, rotor seat 42, and screw 43 rotate together. Part of the limiting seat 5 is located in the inner cavity of the rotor 41. The limiting seat 5 is fixedly connected to the connecting seat 2 and has a roughly cap-shaped structure with a smaller diameter at the top and a larger diameter at the bottom. It includes an upper cover and a lower cover. The lower cover has a limiting groove 53, and the upper cover has a through hole 52. The screw 43 extends downward through the through hole 52 into the opening and is threaded into the body 71. The upper cover also has The receiving part 51 is in which the bearing 6 is located. The bearing 6 includes an inner ring 61, an outer ring 62, and a rolling element 63. The rolling element 63 is located between the inner ring and the outer ring. The inner ring 61 is fixedly connected to the lead screw 43, and the outer ring 62 is fixedly connected to the upper cover. The lead screw 43 and the inner ring 61 can rotate together relative to the outer ring 62. The lead screw 43 also includes a lead screw step 431, which abuts against the inner ring 61 to prevent the lead screw 43 from moving in the axial direction. Through the threaded engagement between the lead screw 43 and the body 71, the core assembly 7 can move axially up and down in the valve cavity A. The body 71 can move axially up and down along the limiting groove 53. When the body 71 is relatively close to or abuts against the limiting surface 54 of the lower cover, the electronic expansion valve is in a fully open state. When the body 71 is relatively far away from the limiting surface 54, the electronic expansion valve is in a fully closed state.

[0024] The following is combined with Figure 1 Figure 2 as well as Figure 6 This invention introduces a second embodiment of the electronic expansion valve, which differs from the first embodiment in the structure of the cylindrical portion 72. The cylindrical portion 72 includes a cylindrical body 721 and a lower end portion 722. The lower end portion 722 is generally a hollow annular end plate structure. The lower end portion 722 is provided with a through hole 7224 to fit with the valve core 72. The lower end portion extends radially inward from the cylindrical body 721, and a plurality of through holes 7222' are provided along the circumferential direction of the lower end portion 722. A partition portion 7223' is provided between two adjacent through holes 7222'. The through holes 7222' form a flow channel at the lower end for the refrigerant to flow into the core assembly 7. When the refrigerant flows... After entering the valve chamber A through the first connector 10, the refrigerant settles through the principle of gas-liquid separation and gravity settling. The refrigerant containing more bubbles rises, while the refrigerant containing fewer bubbles sinks. The settled refrigerant enters the core assembly 7 through the through hole 7222'. The through holes distributed circumferentially along the lower end 722 form a flow channel for the refrigerant to flow, further dispersing the refrigerant and dispersing the larger annular flow channel into multiple smaller channels. Each smaller channel has a partition, thereby further dispersing and reducing noise of the refrigerant that still carries more bubbles after gravity settling through the flow channel. This relatively improves the flow noise generated by the refrigerant in the electronic expansion valve when adjusting the flow rate at small flow rates.

[0025] The following is combined Figure 1 Figure 2 as well as Figure 7 The present invention introduces a third embodiment of the electronic expansion valve. The cylindrical portion 72 includes a cylindrical body 721 and a lower end portion 722. The lower end portion 722 is generally a hollow annular end plate structure. The lower end portion 722 is provided with a through hole 7224 to be adapted to the valve core 72. The lower end portion extends radially inward from the cylindrical body 721. The lower end portion 722 includes a wall edge 7221. A plurality of strip-shaped through grooves 7222a are provided circumferentially along the wall edge 7221 toward the cylindrical body 721. The plurality of strip-shaped through grooves 7222a are arranged circumferentially along the lower end portion 722 and are generally radial in structure. A partition portion 7223a is provided between two adjacent through grooves 7222a. The through grooves 7222a form a flow channel for refrigerant to flow through the lower end portion 722. The relevant technical effects have been described in detail in the first and second embodiments of the present invention, and will not be repeated here.

[0026] The electronic expansion valve provided by this invention optimizes the structure of the core assembly. When the valve core closes the first valve port, the lower end can move between the first and second limit positions, and the position of the lower end is not higher than the inlet end. When the refrigerant enters the valve chamber A from the inlet, it can be fully subjected to the gravity settling effect of gas-liquid separation, so that the refrigerant containing larger bubbles rises and the refrigerant containing smaller bubbles sinks. After settling, the refrigerant containing fewer bubbles enters the core assembly through the flow channel at the lower end and flows out through the second valve port. This can relatively improve the flow noise of the refrigerant generated by the electronic expansion valve when adjusting the flow rate at small flow rates.

[0027] It should be noted that the ordinal numbers such as "first" and "second" or directional terms such as "upper" and "lower" mentioned in this specification are introduced for ease of description based on the accompanying drawings and do not impose any restrictions on order or direction. Furthermore, specific examples are used in this document for illustration, and the descriptions of the above embodiments are merely for the purpose of helping to understand the method and core ideas of the present invention. It should be pointed out that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. An electronic expansion valve, characterized in that... It has a valve cavity and also includes a valve body, a first connecting pipe and a second connecting pipe. The valve body includes a first valve port, a first connecting interface and a second connecting interface. The first connecting pipe is fixedly connected to the first connecting interface, and the second connecting pipe is fixedly connected to the second connecting interface. The first connecting pipe includes an inlet portion and the inlet portion has an inlet end. The electronic expansion valve also includes a core assembly and a lead screw. The core assembly includes a body, a cylindrical part, and a valve core. The body is fixedly connected to the cylindrical part and movably connected to the valve core. The lead screw is threadedly engaged with the body. The body includes a valve stem. The valve core is provided with a second valve port and also includes a flange. Through the threaded engagement, the valve core can approach or move away from the first valve port, and the valve stem can approach or move away from the second valve port. The cylindrical portion includes a lower end, which is provided with a flow channel. When the valve core closes the first valve port, the lower end can abut against the flange to form a first limit position, and the lower end can move away from the flange to form a second limit position. The lower end can move between the first limit position and the second limit position, and the position of the lower end is not higher than the inlet end. The first connecting pipe extends into the valve cavity through the first connection interface, and the end face of the inlet in the axial direction is spaced from the inner wall surface of the valve body; The cylindrical part includes a cylindrical body, which is fixedly connected to the body. The lower end extends radially inward from the cylindrical body. The lower end is generally a hollow annular end plate structure. The lower end is provided with a through hole, which is adapted to the valve core. The flow channel is for refrigerant to flow and is arranged circumferentially along the lower end. There is a partition between two adjacent flow channels. The body also includes an extension, on which a flow hole is provided, through which refrigerant enters between the body and the valve core via a flow channel.

2. The electronic expansion valve according to claim 1, characterized in that, The value of the spacing is greater than or equal to twice the pipe wall thickness of the first pipe.

3. The electronic expansion valve according to claim 1, characterized in that, The lower end includes a wall edge, and an inwardly recessed hole is formed along the circumference of the wall edge. The recessed hole is generally semi-circular in structure, and a plurality of the recessed holes are distributed along the circumference of the wall edge. The partition portion is provided between two adjacent recessed holes.

4. The electronic expansion valve according to claim 1, characterized in that, A plurality of through holes are provided along the circumferential direction of the lower end, and a partition is provided between two adjacent through holes.

5. The electronic expansion valve according to claim 1, characterized in that, The lower end includes a wall edge, and a plurality of strip-shaped through grooves are provided along the circumference of the wall edge toward the cylindrical body. The through grooves are arranged circumferentially along the lower end and have a radial structure. The partition is provided between two adjacent through grooves.

6. The electronic expansion valve according to any one of claims 1-5, characterized in that, It also includes a silencing device, which includes a first silencing component, a second silencing component, and a third silencing component. The first silencing component is fixedly connected to the lower end, the second silencing component is fixedly connected to the valve stem or the extension, the valve core has a valve core receiving cavity, the third silencing component is located in the valve core receiving cavity, the valve core also includes a retaining ring, and the third silencing component is limited to the valve core receiving cavity by the retaining ring.

7. The electronic expansion valve according to any one of claims 1-5, characterized in that, The body includes an extension portion that is movably connected to the valve core. An internal flow channel is provided between the cylindrical portion and the extension portion. The core assembly also includes a spring that is located in the internal flow channel and is sleeved on the outer periphery of the extension portion, with one end abutting against the body and the other end abutting against the flange portion of the valve core.

8. The electronic expansion valve according to claim 7, characterized in that, The upper end of the valve core is provided with a sealing ring, and the extension can move axially up and down along the peripheral wall of the upper end, and the extension is connected to the valve core in a movable sealing manner through the sealing ring.

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