Electronic expansion valve

Abstract

The electronic expansion valve comprises a valve body and a coil component, the valve body comprises a valve seat, a valve needle, a vertical connecting pipe and a transverse connecting pipe, the valve seat is provided with a first inner hole and a second inner hole, a valve port is formed in the upper end of the second inner hole, the valve needle penetrates through the first inner hole to be matched with the valve port, and the coil component is arranged on the valve seat. The valve seat is provided with a first interface part and a second interface part, the vertical connecting pipe and the valve seat are welded and fixed at the first interface part, the transverse connecting pipe and the valve seat are welded and fixed at the second interface part, the valve seat and the valve needle are made of stainless steel materials, and the vertical connecting pipe and the transverse connecting pipe are made of copper materials; a first copper plating layer is arranged on the inner surface, used for being welded to the vertical connecting pipe, of the first connector part, and a second copper plating layer is arranged on the inner surface, used for being welded to the transverse connecting pipe, of the second connector part. The welding manufacturability and the sealing effect of the valve seat and the connecting pipe are improved, meanwhile, the economical efficiency of welding flux selection is improved, and the effect of improving the leakage performance of the valve body at low cost is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of valves, and particularly to an electronic expansion valve. Background Art

[0002] An electronic expansion valve is a device that adjusts the refrigerant flow through electronic control and belongs to an important component in a refrigeration system. Its main function is to control the refrigerant flow according to the changes in temperature and pressure to achieve automatic temperature regulation.

[0003] During operation, the electronic expansion valve detects temperature and pressure through sensors, feeds the information back to the controller, and then the controller electronically adjusts the opening degree of the electronic expansion valve according to the feedback information to ensure that the refrigerant can enter the evaporator at the optimal flow rate, thereby keeping the temperature within the set range.

[0004] According to different driving methods, electronic expansion valves can be divided into direct-acting electronic expansion valves and reduction-type electronic expansion valves. Taking the reduction-type electronic expansion valve as an example, it mainly includes a valve body for flow regulation and a coil component for driving. Among them, the valve body includes core components such as a valve seat, a valve stem, a valve needle, and a bellows. The coil component includes a permanent magnet stepper motor, a gear reduction mechanism with a reduction function, and a screw thread pair structure that converts the rotational motion of the motor into the vertical motion of the screw rod.

[0005] Reduction-type electronic expansion valves are mostly used in indoor units and have high requirements for internal leakage of the valve body. The total stroke of the valve needle moving up and down in this type of expansion valve is relatively short, only 0.7 mm from fully closed to fully open. Therefore, impurities are likely to accumulate at the valve port. When the valve body is in the fully closed state, the extrusion force of the valve needle on the valve port is greater than 300 N. Due to the poor weldability of brass and stainless steel, the solder at the welded seal part is likely to be unevenly distributed and have pores, resulting in an increase in internal leakage of the valve body. Moreover, since the valve seat made of brass and the valve port are integrally processed, the valve port is made of brass and the material is relatively soft, making it easy to accumulate impurities and be damaged by the stainless steel valve needle. Summary of the Invention

[0006] The purpose of the present invention is to provide an electronic expansion valve to solve the above technical problems.

[0007] To achieve the above-mentioned purpose, the present invention provides an electronic expansion valve, including a valve body and a coil component, the valve body including a valve seat, a valve needle, a vertical pipe and a transverse pipe, a guide chamber is provided inside the valve seat, a first inner hole is provided at the upper part of the guide chamber, a second inner hole is provided at the lower part of the guide chamber, a valve port is formed at the upper end of the second inner hole, the valve needle passes through the first inner hole and cooperates with the valve port, the valve seat is provided with a first interface part and a second interface part, the vertical pipe and the valve seat are welded and fixed at the first interface part, the transverse pipe and the valve seat are welded and fixed at the second interface part, the valve seat and the valve needle are made of stainless steel, and the vertical pipe and the transverse pipe are made of copper; the inner surface of the first interface part used for welding with the vertical pipe is provided with a first copper plating layer, and the inner surface of the second interface part used for welding with the transverse pipe is provided with a second copper plating layer.

[0008] Optionally, the first copper plating includes a first circumferential plating located on the inner wall of the first interface portion and a first annular plating located on the step surface of the first interface portion; the outer surface of the vertical pipe insertion end is welded to the first circumferential plating, and the end surface of the vertical pipe insertion end is welded to the first annular plating.

[0009] Optionally, the second copper plating includes a second circumferential plating located on the inner wall of the second interface portion and a second annular plating located on the step surface of the second interface portion; the outer surface of the transverse pipe insertion end is welded to the second circumferential plating, and the end surface of the transverse pipe insertion end is welded to the second annular plating.

[0010] Optionally, the thickness of the first copper plating layer and the second copper plating layer is 2 μm-3 μm.

[0011] Optionally, the valve needle is slidably matched with the inner wall of the first inner hole in the axial direction to guide the valve needle.

[0012] Optionally, it is a reduction-type electronic expansion valve, the coil component includes a permanent magnet stepping motor and a gear reduction mechanism, and the power output end of the gear reduction mechanism is drivingly connected to the valve needle to drive the valve needle to move up and down.

[0013] Optionally, the upper end of the valve needle is connected to a valve stem, and a bellows is sleeved on the outside of the valve stem.

[0014] Optionally, it is a direct-acting electronic expansion valve, and the coil component includes an excitation coil, a nut, a rotor component and a stopper.

[0015] Optionally, the vertical connecting pipe and the horizontal connecting pipe are made of red copper, and the first copper plating layer and the second copper plating layer are red copper plating layers.

[0016] Optionally, the vertical pipe and the horizontal pipe are made of brass, and the first copper plating layer and the second copper plating layer are brass plating layers.

[0017] For the electronic expansion valve provided by the present invention, its valve seat and valve core are of an integral structure, the valve port is directly formed inside the valve seat, and the valve seat and the valve needle are made of stainless steel, the vertical pipe and the horizontal pipe are made of copper, the vertical pipe is welded to the first copper plating layer of the first interface part, and the horizontal pipe is welded to the second copper plating layer of the second interface part. According to the characteristic that the closer the materials are, the better the weldability is, after the inner surface of the valve seat is copper-plated, the welding difficulty with the vertical pipe and the horizontal pipe can be reduced. In terms of solder selection, the solder with the silver content in the solder can be reduced or eliminated, so as to improve the welding economy between the valve seat and the pipe. In terms of welding effect, the solder filling of the entire welding surface is denser, the risk of leakage is reduced, and the sealing performance of the electronic expansion valve is optimized; moreover, the material of the valve port is stainless steel, which is matched with the valve needle of the same stainless steel material, the hardness resistance is improved, and the valve port is not easily damaged by the accumulation of impurities and the extrusion force of the valve needle. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of an electronic expansion valve provided by an embodiment of the present invention;

[0019] Figure 2 is a schematic structural diagram of the welding of the valve seat with the vertical pipe and the horizontal pipe;

[0020] Figure 3 is a schematic structural diagram of the valve seat shown in 2.

[0021] In the figure:

[0022] 100. Valve body 200. Coil component 110. Valve seat 111. First inner hole 112. Second inner hole 113. First interface part 114. Second interface part 115. First copper plating layer 1151. First circumferential plating layer 1152. First annular plating layer 116. Second copper plating layer 1161. Second circumferential plating layer 1162. Second annular plating layer 120. Valve rod 130. Valve needle 140. Bellows 150. Vertical pipe 160. Horizontal pipe DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] In order to enable those skilled in the art to better understand the solution of the present invention, the present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0024] In this text, terms such as "upper, lower, inner, outer" are established based on the positional relationships shown in the drawings. Depending on the different drawings, the corresponding positional relationships may also change accordingly. Therefore, they should not be construed as absolute limitations on the scope of protection. Moreover, relational terms such as "first" and "second" are only used to distinguish one component with the same name from another, and do not necessarily require or imply any such actual relationship or order between these components.

[0025] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of an electronic expansion valve provided by an embodiment of the present invention.

[0026] In a specific embodiment, the electronic expansion valve provided by the present invention is a speed-reducing electronic expansion valve, which can be widely applied to refrigeration and heating devices or equipment such as air conditioners, heat pump water heaters, chillers, vending machines, ice makers, supermarket freezers, and refrigerators.

[0027] This speed-reducing electronic expansion valve mainly consists of two major parts: a valve body 100 and a coil component 200. The valve body 100 is used to regulate the flow rate, and the coil component 200 is used to drive the valve body 100 to perform the action of regulating the flow rate. Among them, the valve body 100 has core components such as a valve seat 110, a valve stem 120, a valve needle 130, a bellows 140, a vertical connecting pipe 150, and a horizontal connecting pipe 160. The coil component 200 has a permanent magnet stepper motor, a gear reduction mechanism with a speed reduction function, and a screw pair structure that converts the rotational motion of the motor into the vertical motion of the lead screw.

[0028] During operation, a high-pulse-frequency current is used to drive the stepper motor to rotate, directly driving the gear reducer, and through the transmission of the screw pair and the bellows, the valve needle 130 is raised or lowered, thereby changing the opening degree of the valve port to automatically regulate the flow rate of the refrigerant and keep the refrigerant circuit system in an optimal state at all times.

[0029] Please then refer to Figure 2 , Figure 3 , Figure 2 which is a schematic structural diagram of the welding of the valve seat to the vertical connecting pipe and the horizontal connecting pipe; Figure 3 which is a schematic structural diagram of the valve seat shown in 2.

[0030] The valve seat 110 is made of stainless steel. A flow guiding cavity is provided inside it. A first inner hole 111 is provided in the upper part of the flow guiding cavity, and a second inner hole 112 is provided in the lower part of the flow guiding cavity. The first inner hole 111 and the second inner hole 112 are located on the same axis. The upper end of the second inner hole 112 forms a valve port. The valve needle 130 is made of stainless steel. It passes through the first inner hole 111 from top to bottom and can slide axially along the inner wall of the first inner hole 111 to guide the valve needle 130. The valve needle 130 realizes the flow regulation function by cooperating with the valve port.

[0031] When the valve needle 130 moves downward, the valve port gradually decreases until it is closed. When the valve needle 130 moves upward, the valve port component increases until it is fully open.

[0032] The valve seat 110 is provided with a first interface part 113 and a second interface part 114. The inner surface of the first interface part 113 for welding with the vertical pipe 150 is provided with a first copper coating 115. The inner surface of the second interface part 114 for welding with the horizontal pipe 160 is provided with a second copper coating 116.

[0033] Both the vertical pipe 150 and the horizontal pipe 160 can be made of red copper. The upper end of the vertical pipe 150 is inserted into the first interface part 113 of the valve seat 110 and is welded and connected with the first copper coating 115. One end of the horizontal pipe 160 is inserted into the second interface part 114 of the valve seat 110 and is welded and connected with the second copper coating 116.

[0034] Specifically, the first copper coating 115 is divided into a first circumferential coating 1151 and a first annular coating 1152. The first circumferential coating 1151 is located on the inner wall of the first interface part 113, and the first annular coating 1152 is located on the step surface of the first interface part 113. The outer surface of the inserted end of the vertical pipe 150 is welded and connected with the first circumferential coating 1151, and the end surface of the inserted end of the vertical pipe 150 is welded and connected with the first annular coating 1152.

[0035] The second copper coating 116 is divided into a second circumferential coating 1161 and a second annular coating 1162. The second circumferential coating 1161 is located on the inner wall of the second interface part 114, and the second annular coating 1162 is located on the step surface of the second interface part 114. The outer surface of the inserted end of the horizontal pipe 160 is welded and connected with the second circumferential coating 1161, and the end surface of the inserted end of the horizontal pipe 160 is welded and connected with the second annular coating 1162.

[0036] Copper plating of the valve seat 110 can be carried out by electroplating or electroless plating and other methods. Before copper plating, surface treatment work of the steel body needs to be carried out, including removing oil stains and oxide scales, etc. After the valve seat 110, the vertical pipe 150, and the horizontal pipe 160 are assembled, tunnel furnace or flame brazing is carried out.

[0037] According to the characteristic that the closer the materials are, the relatively better the weldability is, after the inner surface of the valve seat 110 is copper-plated, the welding difficulty with the vertical pipe 150 and the horizontal pipe 160 can be reduced. In terms of solder selection, a solder that can reduce or eliminate the silver content in the solder can be used, thereby improving the welding economy between the valve seat 110 and the pipe. In terms of welding effect, the solder filling of the entire welding surface is made denser, reducing the risk of leakage and optimizing the sealing performance of the electronic expansion valve. Moreover, the material of the valve port is stainless steel, which is matched with the valve needle 130 of the same stainless steel material, improving the hardness resistance and making the valve port not easily damaged by impurity accumulation and the extrusion force of the valve needle 130.

[0038] The above embodiments are only the preferred solutions of the present invention, and are not specifically limited thereto. On this basis, targeted adjustments can be made according to actual needs to obtain different implementation manners.

[0039] For example, the above structure is not only applicable to the throttling electronic expansion valve, but also applicable to the direct-acting electronic expansion valve. If it is a direct-acting electronic expansion valve, the coil component has an exciting coil, a nut, a rotor component, a stopper, etc.

[0040] Since there are many possible implementation manners, they will not be enumerated one by one here.

[0041] The present invention improves the welding processability and sealing effect between the valve seat 110 and the vertical pipe 150 and the horizontal pipe 160 by the process method of plating a copper layer on the surface of the valve seat 110 for cooperating with the vertical pipe 150 and the horizontal pipe 160, and at the same time improves the economy of solder selection, achieving the effect of improving the leakage performance of the valve body at low cost.

[0042] The above has introduced the electronic expansion valve provided by the present invention in detail. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the core idea of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. Electronic expansion valve, comprising a valve body (100) and a coil component (200), wherein the valve body (100) includes a valve seat (110), a valve needle (130), a vertical connecting pipe (150) and a horizontal connecting pipe (160). A flow guiding cavity is provided inside the valve seat (110). A first inner hole (111) is provided at the upper part of the flow guiding cavity, and a second inner hole (112) is provided at the lower part of the flow guiding cavity. The upper end of the second inner hole (112) forms a valve port. The valve needle (130) passes through the first inner hole (111) and cooperates with the valve port. The valve seat (110) is provided with a first interface portion (113) and a second interface portion (114). The vertical connecting pipe (150) is fixedly welded to the valve seat (110) at the first interface portion (113), and the horizontal connecting pipe (160) is fixedly welded to the valve seat (110) at the second interface portion (114), characterized in that, The valve seat (110) and the valve needle (130) are made of stainless steel, and the vertical pipe (150) and the transverse pipe (160) are made of copper; the inner surface of the first interface portion (113) used for welding with the vertical pipe (150) is provided with a first copper coating (115), and the inner surface of the second interface portion (114) used for welding with the transverse pipe (160) is provided with a second copper coating (116).

2. The electronic expansion valve according to claim 1, wherein The first copper plating layer (115) comprises a first circumferential plating layer (1151) located on the inner wall of the first interface portion (113) and a first annular plating layer (1152) located on the step surface of the first interface portion (113); the outer surface of the insertion end of the vertical pipe (150) is welded to the first circumferential plating layer (1151), and the end surface of the insertion end of the vertical pipe (150) is welded to the first annular plating layer (1152).

3. The electronic expansion valve according to claim 2, characterized in that, The second copper plating (116) comprises a second circumferential plating (1161) located on the inner wall of the second interface portion (114) and a second annular plating (1162) located on the step surface of the second interface portion (114); the outer surface of the insertion end of the transverse pipe (160) is welded to the second circumferential plating (1161), and the end surface of the insertion end of the transverse pipe (160) is welded to the second annular plating (1162).

4. The electronic expansion valve according to claim 3, characterized in that, The thickness of the first copper plating layer (115) and the second copper plating layer (116) is 2 μm-3 μm.

5. The electronic expansion valve according to claim 1, characterized in that, The valve needle (130) is slidably matched with the inner wall of the first inner hole (111) in the axial direction to guide the valve needle (130).

6. The electronic expansion valve according to claim 1, wherein, The invention is a deceleration type electronic expansion valve, wherein the coil component comprises a permanent magnet stepping motor and a gear reduction mechanism, and the power output end of the gear reduction mechanism is drivingly connected to the valve needle (130) to drive the valve needle (130) to move up and down.

7. The electronic expansion valve according to claim 6, wherein, The upper end of the valve needle (130) is connected to the valve stem (120), and a bellows (140) is sleeved on the outside of the valve stem (120).

8. The electronic expansion valve according to claim 1, wherein The invention is a direct-acting electronic expansion valve, wherein the coil component comprises an excitation coil, a nut, a rotor component and a stopper.

9. The electronic expansion valve according to any one of claims 1 to 8, characterized in that, The vertical pipe (150) and the horizontal pipe (160) are made of red copper, and the first copper plating layer (115) and the second copper plating layer (116) are red copper plating layers.

10. The electronic expansion valve according to any one of claims 1 to 8, characterized in that, The vertical pipe (150) and the horizontal pipe (160) are made of brass, and the first copper plating layer (115) and the second copper plating layer (116) are brass plating layers.

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