Electronic expansion valve

Abstract

The application provides an electronic expansion valve, which comprises a valve seat, a sleeve, a valve rod assembly, a valve core assembly, a valve core seat, a rotor assembly, an inlet connector and an outlet connector; the valve core seat is fixed in a circumferential sealing mode at the bottom of the valve seat; the valve rod assembly is fixed with the upper end of the valve seat; the valve core assembly is arranged in the valve rod assembly and can move axially relative to the valve rod assembly; the rotor assembly is sleeved outside the upper part of the valve rod assembly and is threadedly connected with the valve rod assembly; the upper end of the valve core assembly is connected with the rotor assembly and is axially limited; the sleeve is sleeved outside the rotor assembly and is in clearance fit with the rotor assembly; the lower end of the sleeve is fixed with the valve seat and is circumferentially sealed; the inner cavity of the upper part of the valve core seat forms a tapered mouth part which is wide at the top and narrow at the bottom; the lower end of the valve core assembly forms a circular cylinder part which is coaxially inserted into the tapered mouth part; and the electronic expansion valve can more accurately regulate the flow of refrigerant.

Description

Technical Field

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

[0002] As people's demands for quality of life increase, their requirements for air conditioning noise control are also increasing, especially for indoor noise control. Therefore, solving the noise problem generated by electronic expansion valves during air conditioning operation is becoming increasingly important.

[0003] Currently, electronic expansion valves used in such scenarios mainly rely on coils to drive magnetic rings to open and close valve needles, thereby adjusting the valve core opening and thus regulating the refrigerant flow rate. High-temperature and high-pressure liquid refrigerant flows out from the condenser, and after passing through the throttling and pressure reduction effect of the electronic expansion valve, it flows out as a low-temperature and low-pressure gas-liquid two-phase flow.

[0004] Currently, Chinese Patent Publication No. CN224175388U discloses an electronic expansion valve and a refrigeration device. In the structure of this electronic expansion valve, since the outer edge of the lower end of the valve core assembly and the edge of the valve port are both flat, there will be uneven flow rate changes when the opening degree of the electronic expansion valve changes. That is, the flow rate curve of the electronic expansion valve is nonlinear or not smooth, which leads to the disadvantage of low flow rate regulation accuracy of the electronic expansion valve. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an electronic expansion valve that enables more precise regulation of refrigerant flow.

[0006] This invention provides an electronic expansion valve, comprising a valve seat, a sleeve, a valve stem assembly, a valve core assembly, a valve core seat, a rotor assembly, an inlet pipe, and an outlet pipe. The valve core seat is circumferentially sealed and fixed to the bottom of the valve seat. The inlet end of the outlet pipe is fixed to the outlet end of the valve core seat and circumferentially sealed. A valve cavity is formed inside the valve seat. The inlet pipe is circumferentially sealed and fixed to one side of the valve seat and communicates with the valve cavity. The valve stem assembly is fixed to the upper end of the valve seat. The valve core assembly passes through the valve stem assembly and is axially movable relative to the valve stem assembly. The rotor assembly is sleeved on the valve stem assembly. The outer side of the valve core assembly is threaded to the valve stem assembly. The upper end of the valve core assembly is connected to the rotor assembly and axially limited. The sleeve is fitted onto the outside of the rotor assembly and has a clearance fit with the rotor assembly. The lower end of the sleeve is fixed to the valve seat and circumferentially sealed. The inner cavity of the upper part of the valve core seat forms a tapered opening that is wider at the top and narrower at the bottom. The lower end of the valve core assembly forms a cylindrical part, which is coaxially inserted into the tapered opening. When the valve core assembly moves axially relative to the valve core seat, the cross-sectional area of ​​the annular gap between the cylindrical part and the tapered opening is changed to control the opening degree of the electronic expansion valve.

[0007] By adopting the above structure, the present invention forms a tapered opening that is wider at the top and narrower at the bottom in the inner cavity of the upper part of the valve core seat, and a cylindrical part at the lower end of the valve core assembly. As the cylindrical part moves vertically relative to the tapered opening to adjust the opening of the electronic expansion valve, the flow curve of the electronic expansion valve can be made more linear or smoother, that is, the electronic expansion valve can make the refrigerant flow regulation more precise.

[0008] In one possible implementation, the valve core assembly includes a valve needle, a valve core sleeve, a valve core, and a spring. The valve needle passes through the valve stem assembly and is axially movable relative to the valve stem assembly. The upper end of the valve needle is connected to and axially limited by the rotor assembly. The lower end of the valve core axially moves through the lower end of the valve core sleeve and extends out of the valve core sleeve to form a cylindrical portion. An annular protrusion is provided on the outer peripheral wall of the upper end of the valve core, which abuts against the inner bottom of the valve core sleeve to prevent the valve core from detaching from the valve core sleeve. A flange is provided on the outer side wall of the lower part of the valve needle. The upper end of the valve core sleeve is welded and fixed to the lower end of the flange. The spring is located inside the valve core sleeve, and both ends of the spring abut against the upper end of the valve core and the lower end of the flange, respectively. With this valve core assembly, the lower end of the valve core axially moves through the lower end of the valve core sleeve and extends out of the valve core sleeve to form a cylindrical part. Therefore, when the rotor assembly rotates relative to the valve stem assembly and drives the valve core assembly to move axially relative to the valve core seat, the cross-sectional area of ​​the annular gap between the cylindrical part and the conical opening can be changed, thereby controlling the opening degree of the electronic expansion valve. In addition, since a spring is provided between the valve core and the valve needle, when the electronic expansion valve is closed, the cylindrical part can elastically press against the conical opening, which can avoid the cylindrical part and the conical opening from being hard pressed together, and thus avoid the cylindrical part and the conical opening from being squeezed and deformed against each other.

[0009] In one possible implementation, the upper end of the valve core is provided with a recess, the lower end of the valve needle is coaxially provided with a limiting post, the lower end of the spring is inserted into the recess, and the upper end of the spring is sleeved on the outside of the limiting post. By adopting this structure, radial limiting of the spring can be achieved, that is, the radial displacement of the spring can be avoided, so that the spring can reliably apply the elastic force to the valve core to drive the valve core to move downward.

[0010] In one possible implementation, the valve stem assembly includes a valve stem and a connecting plate; the inner edge of the connecting plate is embedded in the inner side of the lower part of the valve stem, and the outer edge of the connecting plate is welded and fixed to the upper end of the valve seat. The valve needle passes through the valve stem and can move axially relative to the valve stem; the valve core has a micro-hole coaxially arranged inside, and a notch is provided on the side wall of the flange to release the closed state of the inner cavity of the valve core sleeve. An annular diameter reduction part is provided on the outer side wall of the lower part of the valve needle, forming an annular gap between the annular diameter reduction part and the inner wall of the valve stem. A balance hole is provided on the side wall of the valve stem, the inner end of the balance hole communicating with the annular gap, and the outer end of the balance hole communicating with the cavity of the electronic expansion valve located above the connecting plate. With this valve stem assembly structure, the valve stem can be reliably fixed to the valve seat by the connecting plate. In addition, under the combined action of the micro-hole, the notch, the annular gap, and the balance hole, when the electronic expansion valve is in the closed state, the inner cavity of the valve core seat located below the valve core can communicate with the inner cavity of the valve core sleeve located above the connecting plate. The cavity of the electronic expansion valve above the connecting plate is connected, thus maintaining pressure balance at the two positions. This prevents opening difficulties when the electronic expansion valve is open (when the electronic expansion valve is closed, the micro-orifice, notch, annular gap, and balance hole allow a slight flow of refrigerant, which does not significantly affect the closed state of the electronic expansion valve; that is, the presence of this slight flow is permitted when the electronic expansion valve is closed). Furthermore, after the connecting plate is welded to the upper end of the valve seat, the connecting plate and the valve seat are not circumferentially sealed. Therefore, when the electronic expansion valve is closed, the refrigerant from the inlet pipe can sequentially enter the valve seat below the valve core through the gap between the connecting plate and the valve seat, the balance hole, the annular gap, the gap between the flange and the valve core sleeve, and the micro-orifice, thus maintaining pressure balance at the two positions and preventing opening difficulties when the electronic expansion valve is open.

[0011] In one possible implementation, the rotor assembly includes a rotor body and a magnetic ring; the rotor body is sleeved on the outer side of the upper part of the valve stem and threadedly connected to the valve stem; the magnetic ring is coaxially sleeved on the outer side of the rotor body and circumferentially and axially limited by the rotor body; an annular groove is provided on the outer side wall of the upper end of the valve needle, and an annular locking block is provided at the inner top of the rotor body, the annular locking block and the annular groove engaging to axially limit the valve needle and the rotor assembly; a torsion spring is coaxially sleeved on the upper end of the valve stem, the torsion spring circumferentially and axially limited by the valve stem, one free end of the torsion spring is connected to the valve stem, and the other free end of the torsion spring forms an abutment end; two stops are provided on the inner wall of the rotor body at intervals along the axial direction; when the rotor assembly rotates relative to the valve stem assembly and carries... When the valve core assembly moves axially to close the electronic expansion valve, the abutting end of the torsion spring abuts against one of the stops. When the rotor assembly rotates relative to the valve stem assembly and drives the valve core assembly to move axially to open the electronic expansion valve to its maximum degree, the abutting end of the torsion spring abuts against the other stop. By using this rotor assembly, when the electronic expansion valve is closed, the abutting end of the torsion spring can abut against one of the stops, and when the electronic expansion valve is at its maximum opening, the abutting end of the torsion spring can abut against the other stop. Thus, during the closing or opening of the electronic expansion valve, a flexible stop can be achieved between the valve stem assembly and the rotor assembly, effectively eliminating the noise generated by the collision between the rotor assembly and the valve stem assembly.

[0012] In one possible implementation, a support step is provided on the outer wall of the upper end of the valve stem, and a clamp is also fitted on the upper end of the valve stem. The two ends of the torsion spring in the axial direction abut against the lower end surfaces of the support step and the clamp, respectively. A limit groove is provided at the bottom of the support step, and one free end of the torsion spring engages with the limit groove. With this structure, since the two ends of the torsion spring in the axial direction abut against the lower end surfaces of the support step and the clamp, the axial limitation of the torsion spring and the valve stem can be reliably achieved to prevent the torsion spring from moving axially relative to the valve stem. Since one free end of the torsion spring engages with the limit groove, the circumferential limitation of the torsion spring and the valve stem can be reliably achieved to prevent the torsion spring from rotating circumferentially relative to the valve stem.

[0013] In one possible implementation, the rotor body includes two rotor halves, which are joined together radially to form the rotor body. An annular step is provided on the outer wall of the upper end of the rotor body, and an annular boss is provided on the inner wall of the upper end of the magnetic ring. The annular boss abuts against the annular step. A retaining ring is fitted onto the outer surface of the upper end of the rotor body, abutting against the outer top of the magnetic ring. Several positioning grooves are provided on the inner circumferential wall of the magnetic ring, and several positioning blocks are provided on the outer circumferential wall of the rotor body. Each positioning block vertically engages with a corresponding positioning groove to circumferentially limit the magnetic ring and the rotor body. By configuring the rotor body as two... After the rotor halves are assembled, when the rotor body and the upper end of the valve needle are assembled, the annular retaining block at the top of the rotor body can easily engage with the annular retaining groove on the outer wall of the upper end of the valve needle. Under the action of the annular boss and the annular step, and under the action of the retaining ring and the outer top of the magnetic ring abutting each other, the magnetic ring and the rotor body can reliably achieve axial positioning. Under the action of the positioning block and the positioning groove, the magnetic ring and the rotor body can reliably achieve circumferential positioning. Thus, when the magnetic ring is subjected to a magnetic field, it can reliably drive the rotor body to rotate synchronously, that is, it can reliably drive the rotor assembly to rotate synchronously.

[0014] In one possible implementation, a plurality of positioning posts arranged in an array are provided on the inner sidewall of one rotor half, and a plurality of positioning holes arranged in an array are provided on the inner sidewall of the other rotor half. Each positioning post is engaged with the positioning hole at a corresponding position to position the two rotor halves together. With this structure, when the two rotor halves are assembled, the positioning posts on one rotor half can be engaged with the positioning holes on the other rotor half one by one, thereby enabling the two rotor halves to be positioned together. This facilitates the assembly of the two rotor halves and improves the reliability of the assembled two rotor halves.

[0015] In one possible implementation, a connecting sleeve is coaxially welded to the upper end of the valve core seat. The connecting sleeve is coaxially sleeved on the outer side of the valve core sleeve and the valve core, and is clearance-fitted with the valve core sleeve and the valve core. Several through holes are evenly distributed on the side wall of the connecting sleeve, and each through hole radially penetrates the connecting sleeve. With this structure, when the refrigerant enters the valve cavity from the inlet pipe, the refrigerant can impact the outer wall of the connecting sleeve. After the refrigerant impacts the outer wall of the connecting sleeve, it can diffuse within the valve cavity. The refrigerant can also enter the inner side of the connecting sleeve through several circumferentially distributed through holes on the side wall of the connecting sleeve. This allows the refrigerant to enter the inner side of the connecting sleeve evenly along the circumferential direction, thereby maintaining a consistent pressure in the circumferential direction of the valve core assembly. This effectively prevents the valve core assembly from vibrating, thus eliminating the noise caused by the vibration of the valve core assembly and effectively suppressing the noise generated by the electronic expansion valve during operation.

[0016] In one possible implementation, the electronic expansion valve further includes a coil assembly and a support ring; the support ring is coaxially sleeved on the outside of the valve seat and the sleeve and welded and fixed at the joint of the valve seat and the sleeve; the coil assembly is sleeved on the outside of the sleeve and the upper end of the support ring, the outer wall of the upper end of the support ring is provided with an annular groove, and the inner circumferential wall of the lower end of the coil assembly is provided with an annular rib, which is fixedly embedded in the annular groove; the inner wall of the lower end of the coil assembly is provided with a plurality of slots circumferentially, and the outer wall of the upper end of the support ring is provided with a plurality of inserts, each insert vertically engaging with one of the slots to limit the circumferential positioning of the coil assembly and the support ring; by adopting this structure, the support ring can It reliably supports the coil assembly, and the annular ribs and annular grooves allow the coil assembly to be easily snapped together with the support ring, facilitating the assembly and fastening of the coil assembly. In addition, the slot and plug engagement allows the coil assembly and support ring to achieve circumferential positioning, improving the reliability of the assembly and ensuring that the coil assembly is assembled with the support ring at the required angle. Furthermore, since the support ring is coaxially sleeved on the outside of the valve seat and sleeve and welded to the joint of the valve seat and sleeve, the airtightness of the connection between the sleeve and the valve seat is further improved. Attached Figure Description

[0017] Figure 1 A three-dimensional structural diagram of an electronic expansion valve after the coil assembly has been removed; Figure 2 A cross-sectional view of the electronic expansion valve after the coil assembly has been removed. Figure 3 for Figure 2 A magnified structural diagram of point A in the middle; Figure 4 A partial exploded 3D structural diagram of an electronic expansion valve after the coil assembly has been removed; Figure 5 A three-dimensional exploded view of the first part of the electronic expansion valve after removing some of its structure. Figure 6 A three-dimensional exploded view of the second part of the electronic expansion valve after removing some of its structure. Figure 7 This is a three-dimensional structural diagram of an electronic expansion valve; Figure 8 This is a cross-sectional view of an electronic expansion valve. Detailed Implementation

[0018] First, those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the embodiments of this application and are not intended to limit the scope of protection of the embodiments of this application. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0019] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0020] In the embodiments of this application, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can be interpreted as the first feature being directly above or diagonally above the second feature, or simply indicating that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean the first feature being directly below or diagonally below the second feature, or simply indicating that the first feature is at a lower horizontal level than the second feature.

[0021] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0022] See Figures 1-8As shown in the figure, this application discloses an electronic expansion valve, including a valve seat 1, a sleeve 2, a valve stem assembly 3, a valve core assembly 4, a valve core seat 5, a rotor assembly 6, an inlet pipe 7, and an outlet pipe 8. The valve core seat 5 is circumferentially sealed and fixed to the bottom of the valve seat 1. The inlet end of the outlet pipe 8 is fixed to the outlet end of the valve core seat 5 and circumferentially sealed. A valve cavity 11 is formed on the inner side of the valve seat 1. The inlet pipe 7 is circumferentially sealed and fixed to one side of the valve seat 1 and communicates with the valve cavity 11. The valve stem assembly 3 is fixed to the upper end of the valve seat 1. The valve core assembly 4 passes through the valve stem assembly 3 and can move axially relative to the valve stem assembly 3. The rotor assembly 6 is sleeved on the valve stem. The outer side of the upper part of component 3 is threadedly connected to the valve stem component 3. The upper end of the valve core component 4 is connected to the rotor component 6 and axially limited. The sleeve 2 is sleeved on the outside of the rotor component 6 and has a clearance fit with the rotor component 6. The lower end of the sleeve 2 is fixed to the valve seat 1 and circumferentially sealed. The inner cavity of the upper part of the valve core seat 5 forms a tapered opening 51 that is wider at the top and narrower at the bottom. The lower end of the valve core component 4 forms a cylindrical part 41, which is coaxially inserted into the tapered opening 51. When the valve core component 4 moves axially relative to the valve core seat 5, the cross-sectional area of ​​the annular gap between the cylindrical part 41 and the tapered opening 51 is changed to control the opening degree of the electronic expansion valve.

[0023] The valve core assembly 4 includes a valve needle 42, a valve core sleeve 43, a valve core 44, and a spring 45. The valve needle 42 passes through the valve stem assembly 3 and can move axially relative to the valve stem assembly 3. The upper end of the valve needle 42 is connected to the rotor assembly 6 and is axially limited. The lower end of the valve core 44 moves axially through the lower end of the valve core sleeve 43 and extends out of the valve core sleeve 43 to form a cylindrical part 41. An annular protrusion 441 is provided on the outer peripheral wall of the upper end of the valve core 44. The annular protrusion 441 is used to abut against the inner bottom of the valve core sleeve 43 to prevent the valve core 44 from disengaging from the valve core sleeve 43. A flange 421 is provided on the outer side wall of the lower part of the valve needle 42. The upper end of the valve core sleeve 43 is welded and fixed to the lower end of the flange 421. The spring 45 is located inside the valve core sleeve 43, and the two ends of the spring 45 are respectively connected to the valve core. The upper end of 44 and the lower end of flange 421 abut against each other. By adopting this valve core assembly, since the lower end of the valve core moves axially through the lower end of the valve core sleeve and extends out of the valve core sleeve to form a cylindrical part, when the rotor assembly rotates relative to the valve stem assembly and drives the valve core assembly to move axially relative to the valve core seat, the cross-sectional area of ​​the annular gap between the cylindrical part and the conical opening can be changed, thereby controlling the opening degree of the electronic expansion valve. In addition, since a spring is provided between the valve core and the valve needle, when the electronic expansion valve is closed, the cylindrical part can be elastically pressed against the conical opening, which can avoid the situation of hard pressing between the cylindrical part and the conical opening, and thus avoid the situation of mutual compression and deformation between the cylindrical part and the conical opening.

[0024] The upper end of the valve core 44 is provided with a recess 442, and the lower end of the valve needle 42 is coaxially provided with a limiting post 422. The lower end of the spring 45 is inserted into the recess 442, and the upper end of the spring 45 is sleeved on the outside of the limiting post 422. By adopting this structure, the radial limiting of the spring can be achieved, that is, the radial displacement of the spring can be avoided, so that the spring can reliably apply the elastic force to the valve core to drive the valve core to move downward.

[0025] The valve stem assembly 3 includes a valve stem 31 and a connecting plate 32; the inner edge of the connecting plate 32 is embedded in the inner side of the lower part of the valve stem 31, and the outer edge of the connecting plate 32 is welded and fixed to the upper end of the valve seat 1. The valve needle 42 passes through the valve stem 31 and can move axially relative to the valve stem 31; the valve core 44 has a micro-hole 443 coaxially arranged inside, and a notch 423 is provided on the side wall of the flange 421. The notch 423 is used to release the closed state of the inner cavity of the valve core sleeve 43, and an annular diameter reduction portion 42 is provided on the outer side wall of the lower part of the valve needle 42. 4. An annular gap 425 is formed between the annular reduced diameter portion 424 and the inner wall of the valve stem 31. A balance hole 311 is provided on the side wall of the valve stem 31. The inner end of the balance hole 311 communicates with the annular gap 425, and the outer end of the balance hole 311 communicates with the cavity of the electronic expansion valve located above the connecting plate 32. With this valve stem assembly structure, the valve stem can be reliably fixed to the valve seat by the connecting plate. In addition, under the combined action of the micro-hole, notch, annular gap and balance hole, when the electronic expansion valve is in the position of When closed, the inner cavity of the valve core seat located below the valve core can communicate with the cavity of the electronic expansion valve located above the connecting plate, thereby maintaining pressure balance at the two positions. This prevents opening difficulties when the electronic expansion valve is opened (when the electronic expansion valve is closed, the micro-orifice, notch, annular gap, and balance hole allow a slight flow of refrigerant, which does not significantly affect the closed state of the electronic expansion valve itself; that is, the presence of this slight flow is permitted when the electronic expansion valve is closed). Furthermore, after the connecting plate is welded and fixed to the upper end of the valve seat, the connecting plate and the valve seat are not in a circumferentially sealed state. Therefore, when the electronic expansion valve is closed, the refrigerant from the inlet pipe can sequentially enter the valve core seat located below the valve core through the gap between the connecting plate and the valve seat, the balance hole, the annular gap, the gap between the flange and the valve core sleeve, and the micro-orifice, thereby maintaining pressure balance at the two positions and preventing opening difficulties when the electronic expansion valve is opened.

[0026] The rotor assembly 6 includes a rotor body 61 and a magnetic ring 62. The rotor body 61 is sleeved on the outer side of the upper part of the valve stem 31 and threadedly connected to the valve stem 31. The magnetic ring 62 is coaxially sleeved on the outside of the rotor body 61 and is circumferentially and axially limited by the rotor body 61. An annular groove 426 is provided on the outer wall of the upper end of the valve needle 42, and an annular block 611 is provided at the inner top of the rotor body 61. The annular block 611 and the annular groove 426 are engaged to lock the valve needle 42 axially and limit the valve assembly 6. A torsion spring 33 is coaxially sleeved on the upper end of the valve stem 31. The torsion spring 33 is circumferentially and axially limited by the valve stem 31. One free end of the torsion spring 33 is connected to the valve stem 31, and the other free end of the torsion spring 33 forms an abutment end 331. Two stops 612 are provided on the inner wall of the rotor body 61 at intervals along the axial direction. When the rotor... When component 6 rotates relative to valve stem assembly 3 and drives valve core assembly 4 to move axially to close the electronic expansion valve, the abutting end 331 of torsion spring 33 abuts against one of the stops 612. When rotor assembly 6 rotates relative to valve stem assembly 3 and drives valve core assembly 4 to move axially to open the electronic expansion valve to its maximum degree, the abutting end 331 of torsion spring 33 abuts against the other stop 612. By adopting this rotor assembly, when the electronic expansion valve is closed, the abutting end of the torsion spring can abut against one of the stops, and when the electronic expansion valve is at its maximum opening, the abutting end of the torsion spring can abut against the other stop. Thus, during the closing or opening of the electronic expansion valve, flexible stopping can be achieved between the valve stem assembly and the rotor assembly to effectively eliminate the noise generated by the collision between the rotor assembly and the valve stem assembly.

[0027] A support step 312 is provided on the outer wall of the upper end of the valve stem 31. A clamp 34 is also clamped on the upper end of the valve stem 31. The two ends of the torsion spring 33 in the axial direction abut against the lower end surfaces of the support step 312 and the clamp 34, respectively. A limit groove 313 is provided at the bottom of the support step 312. One free end of the torsion spring 33 is engaged with the limit groove 313. With this structure, since the two ends of the torsion spring in the axial direction abut against the lower end surfaces of the support step and the clamp, the axial limit of the torsion spring and the valve stem can be reliably achieved to prevent the torsion spring from moving axially relative to the valve stem. Since one free end of the torsion spring is engaged with the limit groove, the circumferential limit of the torsion spring and the valve stem can be reliably achieved to prevent the torsion spring from rotating circumferentially relative to the valve stem.

[0028] The rotor body 61 includes two rotor halves 613, which are spliced ​​together along the radial direction of the rotor assembly 6 to form the rotor body 61. An annular step 614 is provided on the outer wall of the upper end of the rotor body 61, and an annular boss 621 is provided on the inner wall of the upper end of the magnetic ring 62. The annular boss 621 abuts against the annular step 614. A retaining ring 615 is fitted onto the outer surface of the upper end of the rotor body 61, abutting against the outer top of the magnetic ring 62. Several positioning grooves 622 are provided on the inner peripheral wall of the magnetic ring 62, and several positioning blocks 616 are provided on the outer peripheral wall of the rotor body 61. Each positioning block 616 is vertically engaged with the corresponding positioning groove 622 to allow the magnetic ring 62 to... The rotor body 61 is circumferentially limited; by setting the rotor body as two rotor halves, when assembling the rotor body and the upper end of the valve needle, the annular locking block at the top of the rotor body can easily engage with the annular locking groove on the outer wall of the upper end of the valve needle; under the action of the annular boss and the annular step, and under the action of the locking ring and the outer top of the magnetic ring abutting each other, the magnetic ring and the rotor body can reliably achieve the purpose of axial limitation; under the action of the positioning block and the positioning groove, the magnetic ring and the rotor body can reliably achieve the purpose of circumferential limitation, so that when the magnetic ring is subjected to the magnetic field, it can reliably drive the rotor body to rotate synchronously, that is, it can reliably drive the rotor assembly to rotate synchronously.

[0029] One rotor half 613 has several positioning posts 6131 arranged in an array on its inner wall, and the other rotor half 613 has several positioning holes 6132 arranged in an array on its inner wall. Each positioning post 6131 is engaged with the corresponding positioning hole 6132 to position the two rotor halves 613. With this structure, when assembling the two rotor halves, the positioning posts on one rotor half can be engaged with the positioning holes on the other rotor half one by one, thereby enabling the two rotor halves to be positioned. This facilitates the assembly of the two rotor halves and improves the reliability of the assembled rotor halves.

[0030] A connecting sleeve 9 is coaxially welded to the upper end of the valve core seat 5. The connecting sleeve 9 is coaxially sleeved on the outside of the valve core sleeve 43 and the valve core 44 and is clearance-fitted with the valve core sleeve 43 and the valve core 44. Several through holes 91 are evenly distributed on the side wall of the connecting sleeve 9, and each through hole 91 radially penetrates the connecting sleeve 9. With this structure, when the refrigerant enters the valve cavity from the inlet pipe, the refrigerant can impact the outer wall of the connecting sleeve. After the refrigerant impacts the outer wall of the connecting sleeve, it can diffuse in the valve cavity. The refrigerant can also enter the inner side of the connecting sleeve through several circumferentially distributed through holes on the side wall of the connecting sleeve. This allows the refrigerant to enter the inner side of the connecting sleeve evenly along the circumferential direction, thereby keeping the pressure of the valve core assembly in the circumferential direction consistent. This effectively avoids the valve core assembly from shaking, thus eliminating the noise caused by the valve core assembly shaking and effectively suppressing the noise generated by the electronic expansion valve during operation.

[0031] The electronic expansion valve also includes a coil assembly 10 and a support ring 20. The support ring 20 is coaxially sleeved on the outside of the valve seat 1 and the sleeve 2 and welded and fixed at the joint of the valve seat 1 and the sleeve 2. The coil assembly 10 is sleeved on the outside of the sleeve 2 and the upper end of the support ring 20. An annular groove 201 is provided on the outer wall of the upper end of the support ring 20, and an annular rib 101 is provided on the inner circumferential wall of the lower end of the coil assembly 10. The annular rib 101 is embedded in the annular groove 201. Several slots 102 are provided circumferentially on the inner wall of the lower end of the coil assembly 10, and several inserts 202 are provided on the outer wall of the upper end of the support ring 20. Each insert 202 is vertically engaged with one of the slots 102 to make the coil assembly 10 and the support ring 20 fit together. 0. Circumferential limiting: By adopting this structure, the support ring can reliably support the coil assembly, and the coil assembly can be easily snapped together with the support ring by the action of the annular rib and the annular groove, which facilitates the assembly and fastening of the coil assembly. In addition, the cooperation of the slot and the plug can achieve circumferential limiting between the coil assembly and the support ring, thereby improving the reliability of the coil assembly and the support ring after assembly, and ensuring that the coil assembly is assembled with the support ring at the required angle. Furthermore, since the support ring is coaxially sleeved on the outside of the valve seat and the sleeve and welded to the joint of the valve seat and the sleeve, the airtightness of the connection between the sleeve and the valve seat can be further improved.

[0032] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An electronic expansion valve, comprising a valve seat (1), a sleeve (2), a valve stem assembly (3), a valve core assembly (4), a valve core seat (5), a rotor assembly (6), an inlet pipe (7), and an outlet pipe (8); the valve core seat (5) is circumferentially sealed and fixed to the bottom of the valve seat (1), the inlet end of the outlet pipe (8) is fixed to the outlet end of the valve core seat (5) and circumferentially sealed, a valve cavity (11) is formed on the inner side of the valve seat (1), and the inlet pipe (7) is circumferentially sealed and fixed to one side of the valve seat (1) and communicates with the valve cavity (11). The valve stem assembly (3) is fixed to the upper end of the valve seat (1), the valve core assembly (4) passes through the valve stem assembly (3) and can move axially relative to the valve stem assembly (3), the rotor assembly (6) is sleeved on the outer side of the upper part of the valve stem assembly (3) and threadedly connected to the valve stem assembly (3), the upper end of the valve core assembly (4) is connected to the rotor assembly (6) and axially limited, the sleeve (2) is sleeved on the outside of the rotor assembly (6) and clearance-fitted with the rotor assembly (6), the lower end of the sleeve (2) is fixed to the valve seat (1) and circumferentially sealed; characterized in that: The upper cavity of the valve core seat (5) forms a tapered opening (51) that is wider at the top and narrower at the bottom. The lower end of the valve core assembly (4) forms a cylindrical part (41). The cylindrical part (41) is coaxially inserted into the tapered opening (51). When the valve core assembly (4) moves axially relative to the valve core seat (5), the cross-sectional area of ​​the annular gap between the cylindrical part (41) and the tapered opening (51) is changed to control the opening degree of the electronic expansion valve.

2. The electronic expansion valve according to claim 1, characterized in that: The valve core assembly (4) includes a valve needle (42), a valve core sleeve (43), a valve core (44), and a spring (45). The valve needle (42) passes through the valve stem assembly (3) and can move axially relative to the valve stem assembly (3). The upper end of the valve needle (42) is connected to the rotor assembly (6) and is axially limited. The lower end of the valve core (44) axially moves through the lower end of the valve core sleeve (43) and extends out of the valve core sleeve (43) to form the circular cylindrical part (41). The outer peripheral wall of the upper end of the valve core (44) is provided with The valve core sleeve (43) has an annular protrusion (441) which abuts against the inner bottom of the valve core sleeve (43) to prevent the valve core (44) from detaching from the valve core sleeve (43). A flange (421) is provided on the outer side wall of the lower part of the valve needle (42). The upper end of the valve core sleeve (43) is welded and fixed to the lower end of the flange (421). The spring (45) is located inside the valve core sleeve (43), and the two ends of the spring (45) abut against the upper end of the valve core (44) and the lower end of the flange (421), respectively.

3. The electronic expansion valve according to claim 2, characterized in that: The upper end of the valve core (44) is provided with a recess (442), the lower end of the valve needle (42) is coaxially provided with a limit post (422), the lower end of the spring (45) is inserted into the recess (442), and the upper end of the spring (45) is sleeved on the outside of the limit post (422).

4. The electronic expansion valve according to claim 2 or 3, characterized in that: The valve stem assembly (3) includes a valve stem (31) and a connecting plate (32); the inner edge of the connecting plate (32) is embedded in the inner side of the lower part of the valve stem (31), and the outer edge of the connecting plate (32) is welded and fixed to the upper end of the valve seat (1). The valve needle (42) passes through the valve stem (31) and can move axially relative to the valve stem (31); the valve core (44) has a micro-hole (443) coaxially arranged inside, and a notch (423) is provided on the side wall of the flange (421). The valve needle (42) is used to release the closed state of the inner cavity of the valve core sleeve (43). An annular reduced diameter part (424) is provided on the outer wall of the lower part of the valve needle (42). An annular gap (425) is formed between the annular reduced diameter part (424) and the inner wall of the valve stem (31). A balance hole (311) is provided on the side wall of the valve stem (31). The inner end of the balance hole (311) is connected to the annular gap (425). The outer end of the balance hole (311) is connected to the cavity of the electronic expansion valve located above the connecting plate (32).

5. The electronic expansion valve according to claim 4, characterized in that: The rotor assembly (6) includes a rotor body (61) and a magnetic ring (62); the rotor body (61) is sleeved on the outer side of the upper part of the valve stem (31) and threadedly connected to the valve stem (31); the magnetic ring (62) is coaxially sleeved on the outside of the rotor body (61) and is circumferentially and axially limited by the rotor body (61); an annular groove (426) is provided on the outer side wall of the upper end of the valve needle (42); an annular block (611) is provided at the inner top of the rotor body (61); the annular block (611) and the annular groove (426) are engaged to make the valve needle (42) axially limited by the rotor assembly (6); a torsion spring (33) is coaxially sleeved on the upper end of the valve stem (31); the torsion spring (33) is circumferentially and axially limited by the valve stem (31). One of the free ends of the torsion spring (33) is connected to the valve stem (31), and the other free end of the torsion spring (33) forms an abutment end (331). Two stops (612) are provided on the inner wall of the rotor body (61) and are spaced apart along the axial direction. When the rotor assembly (6) rotates relative to the valve stem assembly (3) and drives the valve core assembly (4) to move axially so that the electronic expansion valve is in the closed state, the abutment end (331) of the torsion spring (33) is used to abut against one of the stops (612). When the rotor assembly (6) rotates relative to the valve stem assembly (3) and drives the valve core assembly (4) to move axially so that the electronic expansion valve is in the maximum opening state, the abutment end (331) of the torsion spring (33) is used to abut against the other stop (612).

6. The electronic expansion valve according to claim 5, characterized in that: A support step (312) is provided on the outer wall of the upper end of the valve stem (31). A clamp (34) is also installed on the upper end of the valve stem (31). The two ends of the torsion spring (33) in the axial direction respectively abut against the lower end surface of the support step (312) and the clamp (34). A limit groove (313) is provided at the bottom of the support step (312). One of the free ends of the torsion spring (33) is engaged with the limit groove (313).

7. The electronic expansion valve according to claim 5, characterized in that: The rotor body (61) includes two rotor halves (613), which are spliced ​​together along the radial direction of the rotor assembly (6) to form the rotor body (61); an annular step (614) is provided on the outer wall of the upper end of the rotor body (61), and an annular boss (621) is provided on the inner wall of the upper end of the magnetic ring (62). The annular boss (621) abuts against the annular step (614). A retaining ring (615) is fitted on the outer side of the upper end of the rotor body (61), and the retaining ring (615) abuts against the outer top of the magnetic ring (62); a plurality of positioning grooves (622) are provided on the inner peripheral wall of the magnetic ring (62), and a plurality of positioning blocks (616) are provided on the outer peripheral wall of the rotor body (61). Each positioning block (616) is vertically engaged with the positioning groove (622) at the corresponding position to limit the circumferential positioning of the magnetic ring (62) and the rotor body (61).

8. The electronic expansion valve according to claim 7, characterized in that: One rotor half (613) has a number of positioning posts (6131) arranged in an array on its inner sidewall, and the other rotor half (613) has a number of positioning holes (6132) arranged in an array on its inner sidewall. Each positioning post (6131) is engaged with the corresponding positioning hole (6132) to make the two rotor half (613) cooperate and be positioned.

9. The electronic expansion valve according to claim 1, characterized in that: The upper end of the valve core seat (5) is coaxially welded and fixed with a connecting sleeve (9). The connecting sleeve (9) is coaxially sleeved on the outside of the valve core sleeve (43) and the valve core (44) and is clearance-fitted with the valve core sleeve (43) and the valve core (44). Several through holes (91) are evenly distributed on the side wall of the connecting sleeve (9), and each through hole (91) radially penetrates the connecting sleeve (9).

10. The electronic expansion valve according to claim 1, characterized in that: The electronic expansion valve also includes a coil assembly (10) and a support ring (20); the support ring (20) is coaxially sleeved on the outside of the valve seat (1) and the sleeve (2) and welded and fixed at the joint of the valve seat (1) and the sleeve (2); the coil assembly (10) is sleeved on the outside of the sleeve (2) and the upper end of the support ring (20), and an annular groove (201) is provided on the outer wall of the upper end of the support ring (20), and an annular groove (201) is provided on the inner circumferential wall of the lower end of the coil assembly (10). The coil assembly (10) is provided with an annular rib (101) which is fixed to the annular groove (201); the inner wall of the lower end of the coil assembly (10) is provided with a plurality of slots (102) circumferentially, and the outer wall of the upper end of the support ring (20) is provided with a plurality of inserts (202), each insert (202) being vertically engaged with one of the slots (102) to limit the coil assembly (10) and the support ring (20) circumferentially.

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