Electronic expansion valve

Abstract

The invention relates to an electronic expansion valve which comprises a fixed seat assembly, a valve rod assembly, a valve rod assembly, a valve rod assembly, a valve rod assembly and a valve rod assembly, and the fixed seat assembly is provided with a valve cavity and a valve port communicating with the valve cavity; the transmission assembly comprises a screw rod and a nut, the screw rod is limited to the fixing seat assembly in the axial direction of the screw rod, and the screw rod can rotate around the axial direction of the screw rod; the nut sleeves the periphery of the screw and is in threaded fit with the screw, and the outer wall of the nut is limited to the fixed seat assembly in the circumferential direction of the nut; the valve element assembly is located in the valve cavity, the valve element assembly comprises a main element body and an elastic piece, a containing groove is formed in the main element body, the elastic piece is arranged in the containing groove, and the nut extends into the containing groove and is connected to the elastic piece in a pressed mode; the nut can push the main core body to move in the direction close to the valve port through the elastic piece and block the valve port. According to the electronic expansion valve, the problem that when the valve is closed, a refrigerant can still flow out of the valve port due to the fact that the valve port is not tightly blocked by the valve element is solved.

Description

Technical Field

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

[0002] The electronic expansion valve is installed in an air-conditioning system and is used to cut off or connect the refrigerant flow. The electronic expansion valve generally includes a valve seat assembly, a valve core, a screw rod, and a nut. Among them, the valve seat assembly has a valve cavity, and one end of the valve cavity is provided with a valve port. The motor drives the screw rod to rotate, and the nut is sleeved outside the screw rod and is in threaded cooperation with the screw rod, so as to convert the rotation of the screw rod into axial movement. The valve core is connected to the nut, so that the nut drives the valve core to move towards the valve port to block the valve port, or the nut drives the valve core to move away from the valve port to open the valve port.

[0003] However, when the valve core blocks the valve port, due to insufficient blocking, there is often a problem that the refrigerant still flows out through the valve port when closing the valve. Summary of the Invention

[0004] Based on this, it is necessary to provide an electronic expansion valve to solve the problem that the valve core blocks the valve port insufficiently, resulting in the refrigerant still flowing out of the valve port when closing the valve.

[0005] An electronic expansion valve includes: a fixed seat assembly having a valve cavity and a valve port; a transmission assembly including a screw rod and a nut, the screw rod is axially limited to the fixed seat assembly and can rotate around its own axis; the nut is sleeved on the outer periphery of the screw rod and is in threaded cooperation with the screw rod, and the outer wall of the nut is circumferentially limited to the fixed seat assembly; a valve core assembly located in the valve cavity, the valve core assembly includes a main core body and an elastic member, the main core body is provided with a receiving groove, the elastic member is installed in the receiving groove, the nut extends into the receiving groove and presses against the elastic member; wherein, the nut can push the main core body towards the direction close to the valve port through the elastic member to block the valve port.

[0006] In one embodiment, the valve core assembly further includes a pressing block, the opening of the receiving groove is arranged away from the valve port, the pressing block is located in the receiving groove and is fixedly connected to the opening of the receiving groove; a limiting convex block is arranged at the end of the nut close to the valve port, one end of the limiting convex block is used to press against the elastic member, and the other end is used to abut against the pressing block. It can be understood that, with such a setting, the nut can drive the main core body to move away from the valve port through the pressing block to open the valve port.

[0007] In one embodiment, the valve core assembly further includes a transmission block, and the transmission block stops between the limiting convex block and the elastic member. It can be understood that, with such a setting, the limiting convex block can press against the elastic member through the transmission block.

[0008] In one embodiment, a stop surface is formed in the accommodating groove and is arranged away from the valve port, the elastic member is located on a side of the stop surface close to the valve port, and at least a portion of the elastic member extends out of the stop surface so that an assembly gap can be formed between the transmission block and the stop surface. It can be understood that, in this arrangement, the valve opening idle stroke of the electronic expansion valve, that is, the clearance of the electronic expansion valve, can be set by setting the width of the assembly gap.

[0009] In one embodiment, the fixing seat assembly includes a connecting sleeve and a guide sleeve connected by welding, the guide sleeve is arranged near the valve port; the screw rod is limitedly matched with the inner wall of the connecting sleeve along its own axial direction; the outer wall of the nut is limitedly matched with the inner wall of the connecting sleeve along its own circumferential direction. It can be understood that, in such an arrangement, the connecting sleeve and the guide sleeve can be processed separately, and then the connecting sleeve and the guide sleeve are welded to enclose and form a valve cavity.

[0010] In one embodiment, the guide sleeve is sleeved on the outer periphery of the connecting sleeve, and the inner wall of one end of the guide sleeve close to the connecting sleeve forms a limit surface, and the main core body can be stopped on the limit surface. It can be understood that in this arrangement, the limit surface is used to limit the main core body, thereby limiting the main core body from continuing to move in the direction away from the valve port.

[0011] In one embodiment, a limiting ring is provided at one end of the main core body close to the limiting surface, the limiting ring is used to abut the limiting surface, and the thickness of the limiting ring is h, and h≤1.5mm. It can be understood that such a setting can avoid the contact area between the limiting ring and the limiting surface being too large, so that the limiting ring and the limiting surface are easily adhered.

[0012] In one embodiment, the fixed seat assembly includes a connecting sleeve and a guide sleeve that are sleeved and connected to each other, the valve cavity is opened in the guide sleeve, the connecting sleeve is provided with a welding section, the welding section is attached to the guide sleeve, and a weld is formed between the connecting sleeve and the guide sleeve, at the end of the welding section away from the valve port, a welding groove is formed between the connecting sleeve and the guide sleeve, and the welding groove is connected to the weld; at the end of the welding section close to the valve port, a channel is formed between the connecting sleeve and the guide sleeve, and the channel is connected to the valve cavity and the weld. It can be understood that, in this arrangement, the channel can accommodate excess solder flowing out of the weld without causing this part of the solder to flow to the limiting surface.

[0013] In one embodiment, the fixed seat assembly also includes a valve seat, which is sleeved on the outer wall of the guide sleeve and encloses the guide sleeve to form a valve cavity; the guide sleeve includes a guide section and a connecting section, the guide section is arranged close to the connecting sleeve relative to the connecting section, the guide section and the inner wall of the valve seat are gap-matched, and along the direction from the connecting sleeve to the valve cavity, the outer diameter of the guide section tends to increase, and the connecting section and the inner wall of the valve seat are interference-fitted. It can be understood that with such a configuration, the guide section can play a guiding role, making it convenient for the valve seat to be sleeved on the outer side of the guide sleeve along the surface of the guide section. In addition, the interference fit between the connecting section and the inner wall of the valve seat makes the connection between the valve seat and the guide sleeve more secure.

[0014] In one embodiment, the electronic expansion valve further includes an inlet pipe, which is inserted into the side wall of the valve seat. Moreover, the inlet pipe, the valve seat, the connecting sleeve, and the guiding sleeve are integrally welded by furnace brazing. It can be understood that with such an arrangement, the processing cost can be reduced and the unilateral warping caused by laser welding can be avoided, thereby affecting the coaxiality among the connecting sleeve, the guiding sleeve, and the valve seat.

[0015] In one embodiment, the transmission assembly further includes a rotor and a connecting plate. The connecting plate is fixedly connected to the rotor. The connecting plate is provided with a mounting hole, and the screw rod is inserted into the mounting hole and is in interference fit with the inner wall of the mounting hole. The rotor drives the screw rod to rotate through the connecting plate. It can be understood that with such an arrangement, the problem of reduced coaxiality caused by welding the connecting plate and the screw rod can be avoided.

[0016] Compared with the prior art, for the electronic expansion valve provided by the present application, since the screw rod is axially limited in the fixed seat assembly and the screw rod can rotate around its own axis; that is, the screw rod can only rotate relative to the fixed seat assembly and will not axially move relative to the fixed seat assembly. Further, since the nut is sleeved on the outer periphery of the screw rod and is in threaded cooperation with the screw rod, and the outer wall of the nut is circumferentially limited in the fixed seat assembly; therefore, the rotation of the screw rod can be converted into the axial movement of the nut. Furthermore, by providing a receiving groove in the main core body, the elastic member is installed in the receiving groove, the nut extends into the receiving groove and presses against the spring. In this way, the nut can push the main core body to move towards the direction close to the valve port through the elastic member. And when the main core body abuts against the valve port, the nut can further press down the elastic member, so that the elastic member exerts a sufficient elastic force on the main core body to tightly press the main core body, which is beneficial to more firmly block the valve port to avoid internal leakage of the valve port. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to these drawings.

[0018] Figure 1 It is a cross-sectional view of the electronic expansion valve in the valve-opening state according to an embodiment provided by the present application;

[0019] Figure 2 is Figure 1 an enlarged schematic view at A;

[0020] Figure 3 It is a cross-sectional view of the electronic expansion valve in the valve-closing state according to an embodiment provided by the present application;

[0021] Figure 4 is Figure 3 an enlarged schematic view at B;

[0022] Figure 5 is Figure 3 an enlarged schematic view at C;

[0023] Figure 6 is a cross-sectional view of the main core body of an embodiment provided by the present application.

[0024] Reference numerals: 10, fixed seat assembly; 11, valve cavity; 12, valve port; 13, limiting surface; 15, assembly gap; 16, connecting sleeve; 161, welding section; 162, welding groove; 163, channel; 164, weld seam; 17, guide sleeve; 171, guiding section; 172, connecting section; 18, valve seat; 20, transmission assembly; 21, screw; 22, nut; 23, rotor; 24, connecting plate; 241, mounting hole; 221, limiting projection; 30, valve core assembly; 31, main core body; 311, accommodating groove; 311a, first groove section; 311b, second groove section; 311c, stopping surface; 32, pressing block; 321, small-diameter section; 322, large-diameter section; 33, elastic member; 34, transmission block; 341, abutting section; 342, connecting section; 35, limiting ring; 40, inlet pipe. Detailed Description of the Embodiment

[0025] In order to make the above objects, features, and advantages of the present application more obvious and understandable, the following detailed description of the specific embodiments of the present application will be made with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0026] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it can be directly on the other component or there can also be an intermediate component. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be an intermediate component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the specification of the present application are only for the purpose of illustration and do not represent the only implementation manner.

[0027] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of this application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0028] In this application, unless otherwise clearly specified and defined, the first feature may be in direct contact with the second feature "on" or "under" the second feature, or the first feature and the second feature may be in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or only indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or only indicates that the first feature has a lower horizontal height than the second feature.

[0029] Unless otherwise defined, all technical and scientific terms used in the description of this application have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used in the description of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in the description of this application includes any and all combinations of one or more of the related listed items.

[0030] Please refer to Figures 1-3 , this application provides an electronic expansion valve, which includes: a fixed seat assembly 10 having a valve cavity 11 and a valve port 12 communicating with the valve cavity 11; a transmission assembly 20 including a screw 21 and a nut 22, the screw 21 is axially limited in the fixed seat assembly 10 and can rotate circumferentially around its own axis; the nut 22 is sleeved on the outer periphery of the screw 21 and is in threaded cooperation with the screw 21, and the outer wall of the nut 22 is circumferentially limited in the fixed seat assembly 10; a valve core assembly 30 located in the valve cavity 11, the valve core assembly includes a main core body 31 and an elastic member 33, the main core body 31 is provided with a receiving groove 311, the elastic member is installed in the receiving groove 311, the lower end of the nut 22 extends into the receiving groove 311 and presses against the elastic member 33, and the upper end of the nut 22 is used to abut against the groove wall of the receiving groove 311. Wherein, the nut 22 can drive the main core body 31 to move towards the direction close to the valve port 12 through the elastic member 33 and block the valve port 12; or, the nut 22 can drive the main core body 31 to move towards the direction away from the valve port 12 through abutting and cooperating with the groove wall of the receiving groove 311 to open the valve port 12.

[0031] Since the screw rod 21 is axially limited in the fixed seat assembly 10 along its own axis, and the screw rod 21 can rotate around its own axis; that is, the screw rod 21 can only rotate relative to the fixed seat assembly 10 and will not axially move relative to the fixed seat assembly 10. Further, since the nut 22 is sleeved on the outer periphery of the screw rod 21 and is in threaded cooperation with the screw rod 21, and the outer wall of the nut 22 is circumferentially limited in the fixed seat assembly 10 along its own circumference; therefore, the rotation of the screw rod 21 can be converted into the axial movement of the nut 22. Further still, by providing a receiving groove 311 in the main core body 31, the elastic member is installed in the receiving groove 311, the nut 22 extends into the receiving groove 311 and is pressed against the spring. Thus, the nut 22 can push the main core body 31 to move in the direction close to the valve port 12 through the elastic member 33. And when the main core body 31 abuts against the valve port 12, the nut 22 can further press down the elastic member 33, so that the elastic member applies a sufficient elastic force to the main core body 31 to tightly press the main core body 31, which is beneficial to more firmly block the valve port 12 to avoid internal leakage of the valve port 12.

[0032] Wherein, the elastic member 33 can be configured as a spring. The transmission assembly 20 further includes a coil, a rotor 23 and a connecting plate 24. The connecting plate 24 is fixedly connected to the rotor 23. The connecting plate 24 is provided with a mounting hole 241. The screw rod 21 is inserted into the mounting hole 241 and is in interference fit with the inner wall of the mounting hole 241. The coil is used to drive the rotor 23 to rotate, and the rotor 23 drives the screw rod 21 to rotate through the connecting plate 24.

[0033] In the related art, the screw rod 21 and the connecting plate 24 are often fixedly connected by welding. However, the heat of welding is uneven or the welding quality at the welding part is uneven, resulting in a large difference in coaxiality after the screw rod 21 and the connecting plate 24 are welded. By providing an interference fit between the screw rod 21 and the mounting hole 241, the problem of reduced coaxiality caused by welding can be avoided.

[0034] Further, the valve core assembly 30 further includes a pressing block 32. The opening of the receiving groove 311 is arranged away from the valve port 12. The pressing block 32 is located in the receiving groove 311 and is fixedly connected to the opening of the receiving groove 311. A limiting convex block 221 is provided at the end of the nut 22 close to the valve port 12. One end of the limiting convex block 221 along its own axis is used to press against the elastic member 33, and the other end is used to abut against the pressing block 32.

[0035] By providing the limiting convex block 221 and the pressing block 32, when the nut 22 moves in the direction away from the valve port 12, the limiting convex block 221 abuts against the pressing block 32, so that a supporting force in the direction away from the valve port 12 can be applied to the pressing block 32, and then the main core body 31 is driven to move in the direction away from the valve port 12 through the pressing block 32 to open the valve port 12.

[0036] Specifically, the briquette 32 is annular, and the briquette 32 is welded to the inner wall of the receiving groove 311. The limiting convex block 221 is also annular, and the limiting convex block 221 protrudes from the outer peripheral wall of the nut 22. The nut 22 and the limiting convex block 221 are integrally formed.

[0037] In this way, the contact area between the limiting convex block 221 and the briquette 32 can be increased, so as to facilitate the limiting convex block 221 to drive the briquette 32 to move.

[0038] When assembling the nut 22, the main core body 31 and the briquette 32, the limiting convex block 221 can be first inserted into the receiving groove 311, and then the briquette 32 can be welded to the opening of the receiving groove 311.

[0039] Furthermore, as Figure 1 shown, the briquette 32 includes a small-diameter section 321 and a large-diameter section 322. The small-diameter section 321 is welded to the inner wall of the receiving groove 311, and the large-diameter section 322 abuts against and is welded to the outer periphery of the opening of the receiving groove 311.

[0040] In this way, it is beneficial to increase the welding area between the briquette 32 and the receiving groove 311, thereby being beneficial to improving the connection firmness between the briquette 32 and the main core body 31.

[0041] In an embodiment, as Figure 1 and Figure 3 shown, the valve core assembly 30 further includes a transmission block 34, and the transmission block 34 abuts between the limiting convex block 221 and the elastic member 33.

[0042] That is to say, in this embodiment, the limiting convex block 221 presses against the elastic member 33 through the transmission block 34.

[0043] The volume of the transmission block 34 is relatively small compared with the nut 22. Therefore, when it is necessary to increase the contact area with the elastic member 33, the transmission block 34 can be customized according to requirements without changing the nut 22, which is beneficial to reducing the processing difficulty.

[0044] In an embodiment, as Figure 3 and Figure 6 shown, the receiving groove 311 is formed with a stop surface 311c facing away from the valve port 12. The elastic member 33 is located on the side of the stop surface 311c close to the valve port 12, and at least part of the elastic member 33 extends out of the stop surface 311c, so that an assembly gap 15 can be formed between the transmission block 34 and the stop surface 311c.

[0045] Since the transmission block 34 abuts between the limiting convex block 221 and the elastic member 33, by setting at least part of the elastic member 33 to extend out of the stop surface 311c, an assembly gap 15 can be formed between the transmission block 34 and the stop surface 311c.

[0046] When the electronic expansion valve closes, the stroke of the nut 22 is divided into two sections. The first valve closing stroke is as follows: The nut 22, through the transmission block 34 and the elastic member 33, pushes the main core body 31 towards the valve port 12 and stops the main core body 31 against the valve port 12. Then, the nut 22 enters the second valve closing stroke: The nut 22 further compresses the elastic member 33 through the transmission block 34, so that the transmission block 34 further moves a distance towards the direction close to the valve port 12 until the transmission block 34 stops against the stop surface 311c. The second stroke of the nut 22 is equal to the width of the assembly gap 15. Among them, the second stroke of the nut 22 enables the elastic member to apply sufficient elastic force to the main core body 31 to press the main core body 31 tightly, thereby facilitating more firmly blocking the valve port 12 to avoid internal leakage of the valve port 12.

[0047] When the electronic expansion valve opens, the stroke of the nut 22 is also divided into two sections. Among them, the first valve opening stroke is as follows: The nut 22 moves towards the direction away from the valve port 12 until the limit lug 221 abuts against the pressure block 32. At this time, the spring pushes the transmission block 34 and the stop surface 311c to form the assembly gap 15 again. Then, the nut 22 enters the second valve opening stroke, and the limit lug 221 drives the main core body 31 to move away from the valve port 12 through the pressure block 32 to open the valve port. Among them, the first valve opening stroke of the nut 22 is the valve opening empty stroke of the nut 22, and the main core body 31 still blocks the valve port 12, that is, the valve port 12 is still in the closed state, and the elastic member 33 is in the compressed state, so that the elastic member 33 can apply an elastic force towards the valve port 12 to the main core body 31. In this way, it can ensure that the valve port 12 has good sealing performance before being fully opened.

[0048] In this embodiment, the valve opening empty stroke of the electronic expansion valve, that is, the passing capacity of the electronic expansion valve, can be set by setting the width of the assembly gap 15.

[0049] Further, in one embodiment, as Figure 3 and Figure 6 shown, the accommodation groove 311 includes a first groove section 311a and a second groove section 311b that are connected and communicated. The first groove section 311a is arranged close to the valve port 12, and the inner diameter of the first groove section 311a is smaller than the inner diameter of the second groove section 311b to form a stop surface 311c on the bottom wall of the second groove section 311b. The elastic member 33 is located in the first groove section 311a, and the transmission block 34 is located in the second groove section 311b. The transmission block 34 includes an abutting section 341 and a connecting section 342. The abutting section 341 is used for abutting and cooperating with the limit lug 221, and the connecting section 342 is used for sleeving the elastic member 33. Among them, the outer diameter of the abutting section 341 is larger than the outer diameter of the connecting section 342, so that the connecting section 342 can extend into the first groove section 311a.

[0050] In this way, it is convenient to accommodate the elastic member 33, and the bottom wall of the second groove section 311b can form a stop surface 311c, thus facilitating the machining of the stop surface 311c.

[0051] In one embodiment, as Figure 3 shown, the fixed seat assembly 10 includes a connecting sleeve 16 and a guide sleeve 17 connected by welding. The guide sleeve 17 is disposed close to the valve port 12, and the valve cavity 11 is formed in the guide sleeve 17. The screw rod 21 is in limit fit with the inner wall of the connecting sleeve 16 along its own axial direction; the outer wall of the nut 22 is in limit fit with the inner wall of the connecting sleeve 16 along its own circumferential direction to prevent the circumferential rotation of the nut 22.

[0052] In this way, the connecting sleeve 16 and the guide sleeve 17 can be machined separately, and then the connecting sleeve 16 and the guide sleeve 17 are welded to enclose and form the valve cavity 11.

[0053] Specifically, a bearing is fixedly installed on the inner wall of the connecting sleeve 16. The screw rod 21 passes through the bearing, and limit convex rings are respectively formed at both ends of the screw rod 21 on the bearing to prevent the axial movement of the screw rod 21 and realize the circumferential rotation of the screw rod 21.

[0054] Further, in one embodiment, the guide sleeve 17 is sleeved on the outer periphery of the connecting sleeve 16, and a limiting surface 13 is formed on the inner wall of one end of the guide sleeve 17 close to the connecting sleeve 16. The main core body 31 can be stopped at the limiting surface 13.

[0055] The limiting surface 13 is used to limit the main core body 31, thereby restricting the further movement of the main core body 31 in the direction away from the valve port 12. After the main core body fully opens the valve, it abuts against the limiting surface 13, and the stroke of the main core body 31 depends on the distance between the limiting surface 13 and the valve port 12. In this application, since the screw rod 21 and the rotor 23 do not move axially, when the overall height of the electronic expansion valve remains unchanged, the height of the cavity where the rotor is located can be set smaller, and the distance between the limiting surface 13 and the valve port 12 can be set larger, thereby increasing the stroke of the main core body 31 and the distance between the main core body 31 and the valve port 12 after the main core body fully opens the valve, which is beneficial to increasing the maximum flow rate of the electronic expansion valve.

[0056] Even further, in one embodiment, as Figure 3 and Figure 6 shown, a limiting ring 35 is provided at one end of the main core body 31 close to the limiting surface 13. The limiting ring 35 is used to abut against the limiting surface 13. The thickness of the limiting ring 35 is h, and h ≤ 1.5 mm.

[0057] Since the limiting ring 35 is used to abut against the limiting surface 13, if the cross-sectional area of the limiting ring 35 is too large, the contact area between the limiting ring 35 and the limiting surface 13 will be too large. And since the viscosity of the refrigerant is relatively high, the too large contact area between the limiting ring 35 and the limiting surface 13 will cause the limiting ring 35 and the limiting surface 13 to easily adhere to each other, thereby reducing the flexibility of the movement of the main core 31. By setting h ≤ 1.5 mm, the limiting ring 35 and the limiting surface 13 have an appropriate contact area, which is conducive to improving the flexibility of the movement of the main core 31. For example, the value of h can be 1.5 mm, 1.4 mm, 1.3 mm, etc., and can be specifically set according to the actual situation, which will not be listed one by one here.

[0058] In one embodiment, as Figure 3 and Figure 4 shown, the connecting sleeve 16 is provided with a welding section 161. The welding section 161 is attached to the guide sleeve 17, and a weld 164 is formed between the welding section 161 and the guide sleeve 17. At one end of the welding section 161 away from the valve port 12, a welding groove 162 is formed between the connecting sleeve 16 and the guide sleeve 17, and the welding groove 162 communicates with the weld 164; at one end of the welding section 161 close to the valve port 12, a channel 163 is formed between the connecting sleeve 16 and the guide sleeve 17, and the channel 163 communicates with the valve cavity 11 and the weld 164.

[0059] The welding groove 162 is used to accommodate the solder. The width of the weld 164 is small, and the solder is more likely to penetrate into the weld 164 under capillary action, so that the connecting sleeve 16 is welded to the guide sleeve 17 at the welding section 161. Among them, capillary action refers to the process of liquid flowing in a narrow space.

[0060] In order to prevent the solder from flowing along the weld 164 to the limiting surface 13 and accumulating on the limiting surface 13, thereby affecting the abutting fit between the limiting ring 35 and the limiting surface, in this embodiment, by providing a channel 163 with a relatively large cross-sectional area, the solder is not likely to undergo capillary phenomenon in the channel 163, that is, the solder is not likely to spread along the surface of the channel 163. Therefore, the channel 163 can accommodate the excess solder flowing out of the weld 164 without allowing this part of the solder to flow to the limiting surface 13.

[0061] In one embodiment, as Figure 3 and Figure 5 shown, the fixed seat assembly 10 further includes a valve seat 18. The valve seat 18 is sleeved on the outer wall of the guide sleeve 17, and a valve cavity 11 is formed by surrounding between the valve seat 18 and the guide sleeve 17. The guide sleeve 17 includes a guide section 171 and a connecting section 172. The guide section 171 is relatively closer to the connecting sleeve 16 than the connecting section 172. The guide section 171 is in clearance fit with the inner wall of the valve seat 18, and, along the direction from the connecting sleeve 16 to the valve cavity 11, the outer diameter of the guide section 171 shows an increasing trend, and the connecting section 172 is in interference fit with the inner wall of the valve seat 18.

[0062] Among them, the valve seat 18 is used to connect the inlet pipe 40. The inlet pipe 40 is inserted into the side wall of the valve seat 18 and communicates with the valve cavity 11. The refrigerant enters the valve cavity 11 through the inlet pipe 40. During the assembly process of the valve seat and the guide sleeve 17, the guiding section 171 can play a guiding role, facilitating the valve seat 18 to be sleeved on the outside of the guide sleeve 17 along the surface of the guiding section 171. Moreover, the connecting section 172 is in interference fit with the inner wall of the valve seat 18, making the connection between the valve seat 18 and the guide sleeve 17 more firm.

[0063] Furthermore, the connecting sleeve 16, the guide sleeve 17, the valve seat 18 and the inlet pipe 40 are integrally welded by furnace brazing.

[0064] Compared with laser welding, furnace brazing makes it not easy for the connecting sleeve 16, the guide sleeve 17, the valve seat 18 and the inlet pipe 40 to have unilateral warping, which is beneficial to improving the coaxiality of the connecting sleeve 16, the guide sleeve 17 and the valve seat 18.

[0065] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0066] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. An electronic expansion valve, characterized in that, the electronic expansion valve includes: a fixed seat assembly (10), the fixed seat assembly (10) having a valve cavity (11) and a valve port (12); a transmission assembly (20), the transmission assembly (20) including a screw rod (21) and a nut (22), the screw rod (21) being axially limited in the fixed seat assembly (10) and capable of rotating circumferentially about its own axis; the nut (22) being sleeved on the outer periphery of the screw rod (21) and threadedly engaged with the screw rod (21), and the outer wall of the nut (22) being circumferentially limited in the fixed seat assembly (10); a valve core assembly (30), located in the valve cavity (11), the valve core assembly (30) including a main core body (31) and an elastic member (33), the main core body (31) having a receiving groove (311), the elastic member (33) being installed in the receiving groove (311), the nut (22) extending into the receiving groove (311) and pressing against the elastic member (33); wherein, the nut (22) can push the main core body (31) in the direction towards the valve port (12) through the elastic member (33) and block the valve port (12).

2. The electronic expansion valve according to claim 1, characterized in that, the valve core assembly (30) further includes a pressing block (32), the opening of the receiving groove (311) being arranged away from the valve port (12), the pressing block (32) being located in the receiving groove (311) and fixedly connected to the opening of the receiving groove (311); a limiting convex block (221) is provided at the end of the nut (22) close to the valve port (12), one end of the limiting convex block (221) being used for pressing against the elastic member (33) and the other end being used for abutting against the pressing block (32).

3. The electronic expansion valve according to claim 2, characterized in that, the valve core assembly (30) further includes a transmission block (34), the transmission block (34) being stopped between the limiting convex block (221) and the elastic member (33).

4. The electronic expansion valve according to claim 3, characterized in that, a stop surface (311c) arranged away from the valve port is formed in the receiving groove (311), the elastic member (33) being located on the side of the stop surface (311c) close to the valve port (12), and at least a part of the elastic member (33) extending out of the stop surface (311c) so that an assembly gap (15) can be formed between the transmission block (34) and the stop surface (311c).

5. The electronic expansion valve according to claim 1, characterized in that, the fixed seat assembly (10) includes a connecting sleeve (16) and a guiding sleeve (17) connected by welding, the guiding sleeve (17) being arranged close to the valve port (12); the screw rod (21) is axially limited and engaged with the inner wall of the connecting sleeve (16); the outer wall of the nut (22) is circumferentially limited and engaged with the inner wall of the connecting sleeve (16).

6. The electronic expansion valve according to claim 5, characterized in that, the guide sleeve (17) is sleeved on the outer periphery of the connecting sleeve (16), and a limiting surface (13) is formed on the inner wall of one end of the guide sleeve (17) close to the connecting sleeve (16), and the main core body (31) can be stopped against the limiting surface (13).

7. The electronic expansion valve according to claim 6, characterized in that, a limiting ring (35) is arranged at one end of the main core body (31) close to the limiting surface (13), the limiting ring (35) is used for abutting against the limiting surface (13), the thickness of the limiting ring (35) is h, and h≤1.5 mm.

8. The electronic expansion valve according to claim 1, characterized in that, the fixed seat assembly (10) includes a connecting sleeve (16) and a guide sleeve (17) which are sleeved and connected with each other, and the valve cavity (11) is opened in the guide sleeve (17); the connecting sleeve (16) is provided with a welding section (161), the welding section (161) is attached to the guide sleeve (17), and a weld seam (164) is formed between the connecting sleeve (16) and the guide sleeve (17); at one end of the welding section (161) far from the valve port (12), a welding groove (162) is formed between the connecting sleeve (16) and the guide sleeve (17), and the welding groove (162) communicates with the weld seam (164); at one end of the welding section (161) close to the valve port (12), a channel (163) is formed between the connecting sleeve (16) and the guide sleeve (17), and the channel (163) communicates with the valve cavity (11) and the weld seam (164).

9. The electronic expansion valve according to claim 8, characterized in that, the fixed seat assembly (10) further includes a valve seat (18), the valve seat (18) is sleeved on the outer wall of the guide sleeve (17), and the valve cavity (11) is formed by surrounding between the valve seat (18) and the guide sleeve (17); the guide sleeve (17) includes a guide section (171) and a connecting section (172), the guide section (171) is arranged closer to the connecting sleeve (16) than the connecting section (172), the guide section (171) is in clearance fit with the inner wall of the valve seat (18), and along the direction from the connecting sleeve (16) to the valve cavity (11), the outer diameter of the guide section (171) shows an increasing trend, and the connecting section (172) is in interference fit with the inner wall of the valve seat (18).

10. The electronic expansion valve according to claim 9, characterized in that, the electronic expansion valve further includes an inlet pipe (40), the inlet pipe (40) is inserted into the side wall of the valve seat (18) and communicates with the valve cavity (11), and the inlet pipe (40), the valve seat (18), the connecting sleeve (16) and the guide sleeve (17) are integrally welded by furnace welding.

11. The electronic expansion valve according to claim 1, characterized in that, The transmission assembly (20) further includes a rotor (23) and a connecting plate (24). The connecting plate (24) is fixedly connected to the rotor (23). The connecting plate (24) is provided with a mounting hole (241). The screw (21) is inserted into the mounting hole (241) and is in interference fit with the inner wall of the mounting hole (241). The rotor (23) drives the screw (21) to rotate through the connecting plate (24).

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