Electronic expansion valve

Abstract

The application provides an electronic expansion valve, which comprises a shell, a sleeve and a valve seat connected with each other, and the valve seat is provided with a first mounting hole; a screw rod movably arranged in the shell; a nut assembly comprising a nut seat and a limiting piece, the screw rod is arranged in the nut seat, the nut seat comprises a threaded section and a guide section arranged in steps, the diameter of the threaded section is smaller than that of the guide section, the guide section is inserted into the first mounting hole, the limiting piece is in contact with the upper end surface of the guide section and is fixedly connected with the valve seat, the limiting piece is used for limiting the upper position of the nut seat, and a limiting structure is arranged between the lower end surface of the guide section and the inner wall of the valve seat, and the limiting structure is used for limiting the lower position of the nut seat. Through the technical scheme, the problem of poor coaxiality of the nut seat in the prior art can be solved.

Description

Technical Field

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

[0002] Currently, electronic expansion valves include a housing, a nut seat, a screw, and a valve needle, all of which are housed within the housing. The housing comprises a valve seat and a sleeve, with a valve port on the valve seat. Specifically, the nut seat is welded to the upper surface of the valve seat via a connecting piece. The screw is movably inserted into the nut seat, and the valve needle is located at the end of the screw near the valve port. The screw drives the valve needle to move, thus opening and closing the valve port.

[0003] However, in the prior art, the nut seat is located above the valve seat and is welded to the valve seat using a connecting piece. Under the stress generated during welding, the nut seat will move, making it impossible to guarantee the coaxiality of the nut seat and the valve seat. Therefore, the prior art has a problem with poor coaxiality of the nut seat. Summary of the Invention

[0004] This invention provides an electronic expansion valve to solve the problem of poor coaxiality of the nut seat in the prior art.

[0005] This invention provides an electronic expansion valve, comprising: a housing including a sleeve and a valve seat connected to each other, the valve seat having a first mounting hole; a screw movably disposed within the housing; and a nut assembly including a nut seat and a limiting member, the screw passing through the nut seat, the nut seat including a stepped threaded section and a guide section, the diameter of the threaded section being smaller than the diameter of the guide section, the guide section being inserted into the first mounting hole, the limiting member abutting against the upper end face of the guide section and fixedly connected to the valve seat, the limiting member being used to limit the nut seat to an upper position, and a limiting structure being provided between the lower end face of the guide section and the inner wall of the valve seat, the limiting structure being used to limit the nut seat to a lower position.

[0006] Furthermore, a limiting protrusion is provided on the inner wall of the valve seat, and the lower end face of the guide section abuts against the limiting protrusion, forming a limiting structure.

[0007] Furthermore, the first mounting hole has a first section and a second section that are connected to each other. The first section is located above the second section, and the inner diameter of the first section is larger than the inner diameter of the second section. A guide section is inserted into the first section, and the end face of the second section facing the first section forms a limiting protrusion.

[0008] Furthermore, an anti-rotation structure is provided between the limiting member and the nut seat to restrict the rotation of the nut seat relative to the valve seat.

[0009] Further, the limiting member comprises a limiting ring, the nut seat further comprises a rotation-stopping segment, one end of the rotation-stopping segment is connected with the threaded segment, the other end of the rotation-stopping segment is connected with the guide segment, the limiting ring is sleeved on the rotation-stopping segment, and the rotation-stopping structure is arranged between the rotation-stopping segment and the limiting ring.

[0010] Further, one of the rotation-stopping segment and the limiting ring is provided with a rotation-stopping convex part, the other of the rotation-stopping segment and the limiting ring is provided with a rotation-stopping concave groove, and the rotation-stopping convex part and the rotation-stopping concave groove cooperate to form the rotation-stopping structure.

[0011] Further, the nut seat is provided with a balance channel, the first mounting hole forms a valve cavity, the nut seat has a nut cavity, one end of the balance channel is communicated with the valve cavity, and the other end of the balance channel is communicated with the nut cavity.

[0012] Further, the balance channel comprises a first communication segment and a second communication segment which are communicated with each other, one end of the first communication segment is communicated with the nut cavity, one end of the second communication segment is communicated with the valve cavity, the first communication segment is arranged along the radial direction of the nut seat, and the second communication segment is arranged along the axial direction of the nut seat.

[0013] Further, the outer wall of the rotation-stopping segment is provided with a first notch, the first notch is provided with a first communication hole, and the first notch and the first communication hole cooperate to form the first communication segment.

[0014] Further, the rotation-stopping segment is provided with two rotation-stopping convex parts which are symmetrically arranged on the two sides of the rotation-stopping segment, and the opening direction of the first communication hole is perpendicular to the connecting line of the two rotation-stopping convex parts.

[0015] Further, the sleeve has a sleeve cavity, the outer wall of the guide segment is provided with a second notch, the second notch forms the second communication segment, the limiting ring is provided with a second communication hole, and the second communication hole is communicated with the second notch so as to communicate the sleeve cavity with the valve cavity.

[0016] Further, the outer wall of the guide segment is provided with a plurality of second notches which are symmetrically arranged along the circumferential direction of the guide segment, and at least one second notch is communicated with the first communication segment.

[0017] Further, the electronic expansion valve further comprises a valve seat core, the valve seat is provided with a second mounting hole, the valve seat core is arranged in the second mounting hole, the second mounting hole is a stepped hole, the outer wall of the valve seat core is provided with a stepped boss, and the shape and size of the stepped boss are matched with the shape and size of the stepped hole.

[0018] Further, the guide segment is in a cylindrical structure, the guide segment is provided with a first mounting boss which is coaxially arranged with the nut seat, the top of the valve seat core is provided with a second mounting boss which is coaxially arranged with the valve seat core, and the electronic expansion valve further comprises a guide sleeve, one end of the guide sleeve is sleeved on the first mounting boss, and the other end of the guide sleeve is sleeved on the second mounting boss.

[0019] Further, the nut seat further comprises a screw rod guiding section, the screw rod guiding section, the threaded section, the rotation-stopping section and the guiding section are sequentially connected from top to bottom, a first mounting boss coaxial with the nut seat is arranged in the guiding section, the nut seat has a through hole along the axial direction, the inner diameter of the screw rod guiding section, the inner diameter of the threaded section, the inner diameter of the rotation-stopping section and the inner diameter of the first mounting boss are sequentially reduced.

[0020] Further, the screw rod is movably arranged in the nut seat, the screw rod is threadedly connected with the threaded section, the screw rod guiding section is used for guiding the screw rod, the upper end of the screw rod is internally reduced in diameter to form an inner step, the electronic expansion valve further comprises: a valve needle, the valve needle is arranged in the nut seat and the screw rod, the first mounting boss has an inner hole for guiding the valve needle, the screw rod applies a downward driving force to the valve needle through the inner step; a positioning member, the valve needle has a third section and a fourth section connected with each other, the diameter of the third section is smaller than the diameter of the fourth section, the third section is located above the fourth section and extends out of the upper part of the screw rod, the positioning member is fixedly arranged at the end of the third section, the screw rod applies an upward driving force to the valve needle through the positioning member; a spring, the spring is sleeved on the third section and arranged between the fourth section and the inner step.

[0021] Further, the spring indirectly abuts against the end face of the fourth section and / or the inner step through the gasket.

[0022] By applying the technical scheme of the present application, the electronic expansion valve comprises a shell, a screw rod and a nut assembly, and the screw rod is movably arranged in the shell. Specifically, the shell comprises a sleeve and a valve seat connected with each other, the valve seat has a first mounting hole, the nut assembly comprises a nut seat and a limiting member, and the screw rod is arranged in the nut seat. The nut seat comprises a threaded section and a guiding section arranged in steps, and the diameter of the threaded section is smaller than the diameter of the guiding section. By inserting the guiding section into the first mounting hole, the limiting member is in abutment with the upper end face of the guiding section and is fixedly connected with the valve seat, the limiting member can be used to limit the upper position of the nut seat, so that the nut seat cannot be separated from the valve seat. Further, a limiting structure is arranged between the lower end face of the guiding section and the inner wall of the valve seat, and the limiting structure can be used to limit the lower position of the nut seat, so that the nut seat is fixed in the valve seat. By adopting the above structure, the guiding section can be used to guide the nut seat by inserting the guiding section into the first mounting hole, so as to ensure the coaxiality of the nut seat, and then the limiting member and the limiting structure are used to fix the nut seat, so that the assembly of the nut seat can be completed. BRIEF DESCRIPTION OF DRAWINGS

[0023] The accompanying drawings, which form a part of the present application, are used to provide further understanding of the present application, and serve as an implementation of the present application and its explanation, and do not constitute improper limitations to the present application. In the drawings:

[0024] Figure 1A sectional view of an electronic expansion valve according to an embodiment of the present application is shown;

[0025] Figure 2 A sectional view of an electronic expansion valve according to an embodiment of the present application is shown Figure 1 A partial enlarged view of A in FIG. 1 is shown;

[0026] Figure 3 A partial enlarged view of B in FIG. 1 is shown Figure 1 A partial enlarged view of B in FIG. 1 is shown

[0027] Figure 4 A partial enlarged view of B in FIG. 1 is shown Figure 1 A structural schematic view of a nut seat is shown;

[0028] Figure 5 A structural schematic view of a nut seat is shown; Figure 1 A structural schematic view of a nut seat is shown;

[0029] Figure 6 An assembly view of a nut assembly and a valve seat is shown Figure 1 An assembly view of a nut assembly and a valve seat is shown

[0030] Figure 7 A sectional view of a nut seat is shown Figure 1 A sectional view of a nut seat is shown

[0031] Figure 8 A sectional view of an electronic expansion valve according to an embodiment of the present application is shown.

[0032] In the above drawings, the following reference signs are used:

[0033] 10, housing; 11, sleeve; 111, sleeve cavity; 12, valve seat; 121, first mounting hole; 122, limiting protrusion; 123, second mounting hole;

[0034] 20, screw rod; 201, inner step;

[0035] 30, nut assembly; 31, nut seat; 311, threaded segment; 312, guide segment; 313, rotation-stopping segment; 314, first mounting boss; 315, screw rod guide segment; 32, limiting member; 321, second communication hole; 33, balance passage; 331, first communication segment; 3311, first notch; 3312, first communication hole; 332, second communication segment; 3321, second notch; 34, nut cavity;

[0036] 40, rotation-stopping structure; 41, rotation-stopping protrusion; 42, rotation-stopping groove;

[0037] 50, valve seat core; 51, second mounting boss;

[0038] 60, guide sleeve;

[0039] 70, valve needle; 71, third segment; 72, fourth segment;

[0040] 80. Positioning component; 90. Spring;

[0041] 100. Rotor assembly; 110. Rotor core; 120. Rotor connecting plate; 130. Fixing frame. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] like Figures 1 to 7 As shown, Embodiment 1 of the present invention provides an electronic expansion valve, which includes a housing 10, a screw 20, and a nut assembly 30. Both the screw 20 and the nut assembly 30 are disposed within the housing 10, and the screw 20 is movable within the housing 10. The housing 10 includes a sleeve 11 and a valve seat 12 connected to each other. The valve seat 12 has a first mounting hole 121. The nut assembly 30 includes a nut seat 31 and a limiting member 32. The screw 20 passes through the nut seat 31, and one end of the nut seat 31 passes through the first mounting hole 121. Specifically, the nut seat 31 includes a stepped threaded section 311 and a guide section 312. The diameter of the threaded section 311 is smaller than the diameter of the guide section 312, and the threaded section 311 is located above the guide section 312. By inserting the guide section 312 into the first mounting hole 121, the guide section 312 can guide the nut seat 31 to ensure the coaxiality of the nut seat 31. In this embodiment, the guide segment 312 is press-fitted into the first mounting hole 121. After the guide segment 312 is pressed into the first mounting hole 121, the limiting member 32 is attached to the upper end face of the guide segment 312 and fixedly connected to the valve seat 12. The limiting member 32 can be used to limit the nut seat 31 to prevent it from coming out of the first mounting hole 121. Furthermore, a limiting structure is provided between the lower end face of the guide segment 312 and the inner wall of the valve seat 12. The limiting structure can be used to limit the nut seat 31 to a lower position to fix the nut seat 31 and prevent it from being excessively pressed into the first mounting hole 121.

[0044] The electronic expansion valve provided in the embodiment can guide the nut seat 31 by the guide section 312 in cooperation with the first mounting hole 121, so that the coaxiality of the nut seat 31 can be ensured. In the assembly, the limiting structure can lower limit the nut seat 31, so that the nut seat 31 is prevented from being excessively inserted into the first mounting hole 121. When the nut seat 31 is assembled in place, the limiting piece 32 is attached to the upper end surface of the guide section 312 and the limiting piece 32 is fixedly connected with the valve seat 12, so that the assembly is facilitated and the assembly precision is improved, and thus the coaxiality of the nut seat 31 can be further improved.

[0045] In the embodiment, the limiting piece 32 is fixedly connected with the valve seat 12 by welding. Since the guide section 312 of the nut seat 31 is press-fitted in the first mounting hole 121, the nut seat 31 will not move when the limiting piece 32 is welded, so that the coaxiality of the nut seat 31 can be ensured. In the embodiment, the upper end surface of the guide section 312 is flush with the upper end surface of the valve seat 12.

[0046] The inner wall of the valve seat 12 is provided with a limiting protrusion 122, the lower end surface of the guide section 312 abuts against the limiting protrusion 122, and the limiting protrusion 122 forms the limiting structure. Specifically, the limiting protrusion 122 includes a limiting step and a limiting boss.

[0047] In the embodiment, the first mounting hole 121 has a first section and a second section connected with each other, the first section is located above the second section, the inner diameter of the first section is greater than that of the second section, and the connecting portion of the first section and the second section forms the limiting step. Specifically, the end surface of the second section facing the first section forms the limiting protrusion 122. After the guide section 312 is inserted into the first section, the end surface of the guide section 312 abuts against the end surface of the second section facing the first section, so as to lower limit the nut seat 31. In other embodiments, a plurality of limiting bosses can be arranged on the inner wall of the valve seat 12, the plurality of limiting bosses are arranged at intervals along the circumference of the valve seat 12, and the limiting bosses are used to lower limit the nut seat 31.

[0048] In the embodiment, a rotation stopping structure 40 is arranged between the limiting piece 32 and the nut seat 31, and the rotation stopping structure 40 is used to limit the rotation of the nut seat 31 relative to the valve seat 12. Specifically, a rotation stopping boss and a rotation stopping groove can be arranged on the limiting piece 32 and the nut seat 31, and the rotation stopping boss and the rotation stopping groove are used to stop rotation. Alternatively, the cross-sectional shape of the limiting piece 32 and the nut seat 31 can be non-circular structure to stop rotation.

[0049] Specifically, the nut seat 31 further comprises a rotation-stopping segment 313, one end of the rotation-stopping segment 313 is connected with the threaded segment 311, and the other end of the rotation-stopping segment 313 is connected with the guide segment 312. In the embodiment, the outer diameter of the rotation-stopping segment 313 is greater than the outer diameter of the threaded segment 311, and the outer diameter of the rotation-stopping segment 313 is less than the outer diameter of the guide segment 312. The limiting member 32 comprises a limiting ring, the limiting ring is sleeved on the rotation-stopping segment 313, and the rotation-stopping structure 40 is arranged between the rotation-stopping segment 313 and the limiting ring. Specifically, a rotation-stopping boss or a rotation-stopping groove can be arranged on the rotation-stopping segment 313, or the cross-sectional shape of the rotation-stopping segment 313 is a non-circular structure, and the structure and shape of the limiting ring are matched with the rotation-stopping segment 313.

[0050] Specifically, the rotation-stopping segment 313 and the limiting ring are matched with each other, one of the rotation-stopping segment 313 and the limiting ring is provided with a rotation-stopping convex part 41, and the other of the rotation-stopping segment 313 and the limiting ring is provided with a rotation-stopping groove 42, the rotation-stopping convex part 41 and the rotation-stopping groove 42 cooperatively form the rotation-stopping structure 40. In the embodiment, the rotation-stopping convex part 41 is arranged on the rotation-stopping segment 313, and the rotation-stopping groove 42 is arranged on the limiting ring, and the rotation-stopping convex part 41 extends along the radial direction of the rotation-stopping segment 313. In other embodiments, the rotation-stopping segment 313 can be arranged in a rectangular or triangular structure, and the inner hole of the limiting ring is matched with the cross-sectional shape of the rotation-stopping segment 313.

[0051] In order to facilitate the movement of the screw rod 20 in the nut seat 31, the nut seat 31 is provided with a balance channel 33, the first mounting hole 121 forms a valve cavity, the nut seat 31 has a nut cavity 34, one end of the balance channel 33 is communicated with the valve cavity, and the other end of the balance channel 33 is communicated with the nut cavity 34. Under the action of the balance channel 33, the nut cavity 34 and the valve cavity can quickly realize pressure balance, and the fluid in the nut cavity 34 will not hinder the movement of the screw rod 20.

[0052] Specifically, the balance channel 33 comprises a first communication segment 331 and a second communication segment 332 which are communicated with each other, one end of the first communication segment 331 is communicated with the nut cavity 34, one end of the second communication segment 332 is communicated with the valve cavity, the first communication segment 331 is arranged along the radial direction of the nut seat 31, and the second communication segment 332 is arranged along the axial direction of the nut seat 31. With the above structure, the nut cavity 34 can be communicated with the valve cavity through the first communication segment 331 and the second communication segment 332 in sequence.

[0053] Specifically, the outer wall of the rotation-stopping segment 313 is provided with a first gap 3311, the first gap 3311 is arranged along the radial direction of the nut seat 31, a first communication hole 3312 is arranged in the first gap 3311, and the first gap 3311 and the first communication hole 3312 cooperatively form a first communication segment 331. Since the limiting ring is arranged on the rotation-stopping segment 313, the first gap 3311 is arranged on the outer wall of the rotation-stopping segment 313, so that there is a gap between the limiting ring and the outer wall of the rotation-stopping segment 313, and thus the first communication segment 331 can be communicated with the second communication segment 332.

[0054] In the embodiment, two rotation-stopping protrusions 41 are arranged on the rotation-stopping segment 313 at intervals, the two rotation-stopping protrusions 41 are symmetrically arranged on the two sides of the rotation-stopping segment 313, and the opening direction of the first communication hole 3312 is perpendicular to the connecting line of the two rotation-stopping protrusions 41, so that the mold opening and processing are facilitated.

[0055] Specifically, the sleeve 11 has a sleeve cavity 111, the outer wall of the guide segment 312 is provided with a second gap 3321, the second gap 3321 forms a second communication segment 332, the second communication hole 321 is arranged on the limiting ring to communicate with the second gap 3321, so that the sleeve cavity 111 can be communicated with the valve cavity, and the pressure of the sleeve cavity 111 and the valve cavity can be quickly balanced. In other embodiments, a communication groove can be arranged on the inner wall of the valve seat 12 to form the second communication segment 332.

[0056] In the embodiment, a plurality of second gaps 3321 are arranged on the outer wall of the guide segment 312 at intervals, the plurality of second gaps 3321 are symmetrically arranged along the circumferential direction of the guide segment 312, and at least one second gap 3321 is communicated with the first communication segment 331. By adopting the above structure, when the nut seat 31 is press-fitted into the first mounting hole 121, the plurality of second gaps 3321 can play a role in assisting deformation, and the press-fitting of the nut seat 31 is facilitated. Specifically, two second gaps 3321 are arranged on the outer wall of the guide segment 312.

[0057] Specifically, the second gap 3321 is used to balance the pressure of the sleeve cavity 111 and the valve cavity on one hand, and is used to ensure the reliability of the installation of the nut seat 31 on the other hand. The nut seat 31 is in interference fit with the inner wall of the valve seat 12, and the nut seat 31 needs to be pressed into the valve seat 12 during assembly. In order to prevent damage to the nut seat 31, the second gap 3321 serves as a contraction joint and allows a certain deformation. In order to ensure the uniformity of deformation, the second gap 3321 is symmetrically arranged to ensure the perpendicularity and coaxiality of the nut seat 31.

[0058] The electronic expansion valve further comprises a valve seat core 50, and the bottom of the valve seat 12 is provided with a second mounting hole 123, and the valve seat core 50 is arranged in the second mounting hole 123. Specifically, the second mounting hole 123 is a stepped hole, and a stepped boss is arranged on the outer wall of the valve seat core 50, and the shape and size of the stepped boss are matched with the shape and size of the stepped hole, so that the coaxiality of the valve seat core 50 can be ensured. The valve port is arranged on the valve seat core 50. In the embodiment, the first mounting hole 121 and the second mounting hole 123 are machined by one-time clamping machining of a lathe, so that the coaxiality of the first mounting hole 121 and the second mounting hole 123 can be ensured, the nut seat 31 is positioned based on the first mounting hole 121, and the valve seat core 50 is positioned based on the second mounting hole 123, so that the coaxiality of the inner hole of the nut seat and the valve port of the valve seat core can be ensured.

[0059] Specifically, the guide section 312 is in a cylindrical structure, the top surface of the guide section 312 is provided with a first mounting boss 314, the first mounting boss 314 is coaxially arranged with the nut seat 31, the first mounting boss 314 extends towards the valve seat core 50, and the top of the valve seat core 50 is provided with a second mounting boss 51, the second mounting boss 51 is coaxially arranged with the valve seat core 50. In the embodiment, the nut seat 31 is made of plastic material.

[0060] In the embodiment, the nut seat 31 further comprises a screw rod guide section 315, and the screw rod guide section 315, the threaded section 311, the rotation-stopping section 313 and the guide section 312 are sequentially connected from top to bottom. The guide section 312 is provided with the first mounting boss 314 coaxial with the nut seat 31, and the nut seat 31 has a through hole in the axial direction. Specifically, the inner diameter of the screw rod guide section 315, the inner diameter of the threaded section 311, the inner diameter of the rotation-stopping section 313 and the inner diameter of the first mounting boss 314 gradually decrease. The screw rod guide section 315, the threaded section 311 and the rotation-stopping section 313 are all located outside the valve seat 12, and only the guide section 312 is located inside the valve seat 12, so that the space of the electronic expansion valve can be fully utilized, the volume of the electronic expansion valve can be reduced, and the integration degree can be improved.

[0061] In the embodiment, the screw rod 20 is movably arranged in the nut seat 31, the screw rod 20 is threadedly connected with the threaded section 311, and the screw rod 20 can rotate relative to the nut seat 31. The screw rod guide section 315 is used for guiding the screw rod 20, and the screw rod guide section 315 can guide the screw rod 20 during the movement of the screw rod 20. The upper end of the screw rod 20 is internally reduced in diameter to form an inner step 201.

[0062] In the embodiment, the electronic expansion valve further comprises a valve needle 70, a positioning member 80 and a spring 90. Specifically, the valve needle 70 is arranged in the nut seat 31 and the screw rod 20, the valve needle 70 is arranged corresponding to the valve port, the first mounting boss 314 has an inner hole for guiding the valve needle 70, and the screw rod 20 applies a downward driving force to the valve needle 70 through the inner step 201 to drive the valve needle 70 to move close to the valve port, so as to realize the closing of the valve port. Specifically, the valve needle 70 has a third section 71 and a fourth section 72 connected with each other, the diameter of the third section 71 is smaller than that of the fourth section 72, the third section 71 is located above the fourth section 72 and extends out of the upper part of the screw rod 20, and the positioning member 80 is fixedly arranged at the end of the third section 71. By arranging the positioning member 80 at the end of the third section 71, the position of the valve needle 70 relative to the screw rod 20 can be limited by the positioning member 80, so as to avoid the valve needle 70 from falling off. In the embodiment, the screw rod 20 applies an upward driving force to the valve needle 70 through the positioning member 80 to drive the valve needle 70 to move away from the valve port, so as to realize the opening of the valve port. Specifically, the spring 90 is sleeved on the third section 71 and arranged between the fourth section 72 and the inner step 201, the spring 90 can provide a pre-tightening force, can improve the precision of the device, and the spring 90 can also play a buffering role.

[0063] In the embodiment, the spring 90 indirectly abuts against the end face of the fourth section 72 and / or the inner step 201 through a gasket, the gasket is preferably made of a wear-resistant metal material, so as to avoid the metal spring 90 from being worn after being in contact with the inner wall of the valve needle 70 or the screw rod 20, thus increasing the service life of the product. In the embodiment, gaskets are arranged at both ends of the spring 90, and the spring 90 indirectly abuts against the end face of the fourth section 72 and the inner step 201 through the gaskets.

[0064] In the embodiment, the electronic expansion valve further comprises a rotor assembly 100, the rotor assembly 100 is rotatably arranged in the housing 10, and the rotor assembly 100 is drivingly connected with the screw rod 20. The rotor assembly 100 comprises a rotor core 110 and a rotor connecting plate 120.

[0065] In the embodiment, the sleeve 11 and the valve seat 12 are both made by using a stretching process, only a flat end face is needed, the amount of cutting in metal processing can be reduced, and the efficiency can be improved.

[0066] In addition, the electronic expansion valve further comprises a fixing frame 130, the fixing frame 130 is arranged on the outer wall of the valve seat 12, the fixing frame 130 uses a fan-shaped structure, the use of materials can be reduced to the greatest extent, and the cost can be reduced.

[0067] As Figure 8As shown, the second embodiment of the present application provides an electronic expansion valve, and the electronic expansion valve provided by the second embodiment is different from the first embodiment in that, in the second embodiment, the electronic expansion valve further comprises a guide sleeve 60, one end of the guide sleeve 60 is sleeved on the first mounting boss 314 in a manner of interference fit or transition fit, and the other end of the guide sleeve 60 is sleeved on the second mounting boss 51 in a manner of interference fit, so that the guide sleeve 60 can guide the nut seat 31 and the valve seat core 50 again, and the coaxiality of the device can be further improved.

[0068] In the present embodiment, the assembly steps of the electronic expansion valve are as follows:

[0069] (1) The valve seat 12 and the valve seat core 50 are fixed by using furnace brazing;

[0070] (2) The guide sleeve 60 and the nut seat 31 are assembled together and then pressed into the first mounting hole 121 of the valve seat 12 in a manner of interference fit, so that the lower end surface of the nut seat 31 abuts against the limiting protrusion 122;

[0071] (3) The limiting piece 32 is loaded and fixed by laser welding;

[0072] (4) The valve needle 70 and the spring 90 are sequentially placed, and then the screw rod 20 is screwed to the initial position;

[0073] (5) The rotor assembly 100 is placed and screwed clockwise to the lower stop position and kept stationary, and the rotor connecting plate 120 and the screw rod 20 are fixed by laser welding;

[0074] (6) The positioning piece 80 is loaded, and then the rotor assembly 100 is rotated counterclockwise by an angle θ (the angle size can be customized according to the adjustment characteristics, and generally between 90-235 degrees), and kept stationary, and the positioning piece 80 and the valve needle 70 are fixed by laser welding;

[0075] (7) Finally, the sleeve 11 is pressed in and welded, and then the fixing frame 130 is placed and welded, and the assembly is completed.

[0076] Through the device provided by the present embodiment, by setting the nut seat 31 as a guide section 312 with a skirt structure, and by pressing the guide section 312 into the valve seat 12, the coaxiality of the nut seat 31 and the valve seat 12 can be ensured, and the upper end surface and the lower end surface of the guide section 312 are respectively limited by the limiting piece 32 and the limiting structure, so that the assembly and fixation of the nut seat 31 can be completed.

[0077] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, devices, components and / or combinations thereof, but do not preclude the presence or addition of one or more other features, steps, operations, devices, components and / or combinations thereof.

[0078] The relative arrangement of components and steps, numerical expressions, and numerical values set forth in the examples are not intended to limit the scope of the application unless otherwise specifically stated. It is to be understood that the drawings are not necessarily to scale of the various parts shown in the drawings. Techniques, methods, and apparatus known to those of ordinary skill are not discussed in detail because they would be understood that such techniques, methods, and apparatus are considered part of the art. In all examples shown and discussed herein, any specific values are to be interpreted as merely exemplary and not limiting. Thus, other examples of the example embodiments can have different values. It is noted that like numbers and letters on the figures identify like parts throughout the several views, and thus, once an item is defined in one figure, it is not necessary to discuss it further in connection with other figures where it is understood that the item will be present.

[0079] In the description of the present application, it is to be understood that the orientation or positional relationships indicated by orientation words such as "front, back, upper, lower, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are generally based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Without the opposite indication, these orientation words do not indicate and imply that the indicated device or element must have a particular orientation or be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the scope of protection of the present application. The orientation words "inner, outer" refer to the inner and outer relative to the contour of each component.

[0080] For purposes of the description hereinafter, the orientations in the various drawings will be described as shown in the drawings. However, it will be understood that the device can assume different orientations, e.g. viewed from the bottom, based on the application. Accordingly, the illustrative terms such as "above", "below", "upper", "lower", and the like are used as a shorthand notations to convey the relative positions of an object or feature as shown in the figures. It will be further appreciated that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if the device described is turned over, then a depiction that was previously described as "above" other parts or steps would then be oriented "below" other parts or steps. Thus, the exemplary term "above" can encompass both an "above" and "below" position depending on the particular orientation being referred to. Similarly, the terms "above" and "below" can include vertical orientations of the device as well as horizontal orientations of the device. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0081] In addition, it should be pointed out that the use of the terms "first", "second" and the like does not indicate any special meaning, but is merely intended to distinguish one part from another, and is not intended to limit the scope of the present application.

[0082] The preferred embodiments of the present application have been described above with the aid of drawing figures, and are not limited to those embodiments per se, but can be modified in various ways. It will be apparent to persons skilled in the art that, where parts or steps are interchangeable, they have been described as a single part or step. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall fall within the scope of the present application.

Claims

1. An electronic expansion valve characterized by, The electronic expansion valve comprises: A shell (10) comprising a sleeve (11) and a valve seat (12) connected to each other, the valve seat (12) having a first mounting hole (121); A screw rod (20) movably arranged in the shell (10); A nut assembly (30) comprising a nut seat (31) and a limiting piece (32), the screw rod (20) being arranged in the nut seat (31), the nut seat (31) comprising a threaded section (311) and a guide section (312) arranged in steps, the guide section (312) being a cylindrical structure, the diameter of the threaded section (311) being smaller than that of the guide section (312), the guide section (312) being inserted into the first mounting hole (121), the limiting piece (32) being in contact with the upper end surface of the guide section (312) and being fixedly connected to the valve seat (12), the limiting piece (32) being used for limiting the upper position of the nut seat (31), a limiting structure being arranged between the lower end surface of the guide section (312) and the inner wall of the valve seat (12), the limiting structure being used for limiting the lower position of the nut seat (31), a first mounting boss (314) being arranged in the guide section (312); A valve needle (70) arranged in the nut seat (31) and the screw rod (20), the first mounting boss (314) having an inner hole for guiding the valve needle (70); The guide section (312) and the first mounting boss (314) form an accommodation space in communication with the first mounting hole (121); The nut seat (31) is provided with a balance channel (33), the first mounting hole (121) forms a valve cavity, the nut seat (31) has a nut cavity (34), one end of the balance channel (33) is in communication with the valve cavity, and the other end of the balance channel (33) is in communication with the nut cavity (34); The balance channel (33) comprises a first communication section (331) and a second communication section (332) in communication with each other, one end of the first communication section (331) is in communication with the nut cavity (34), and one end of the second communication section (332) is in communication with the valve cavity; The sleeve (11) has a sleeve cavity (111), the outer wall of the guide section (312) is provided with a second notch (3321), the second notch (3321) penetrates the inner wall and the outer wall of the guide section (312), the second notch (3321) forms the second communication section (332), the limiting piece (32) is provided with a second communication hole (321), the second communication hole (321) is in communication with the second notch (3321), so that the sleeve cavity (111) is in communication with the valve cavity.

2. The electronic expansion valve according to claim 1, characterized in that The inner wall of the valve seat (12) is provided with a limiting protrusion (122), the lower end surface of the guide section (312) abuts against the limiting protrusion (122), and the limiting protrusion (122) forms the limiting structure.

3. The electronic expansion valve according to claim 2, characterized in that The first mounting hole (121) has a first section and a second section connected with each other, the first section is located above the second section, an inner diameter of the first section is larger than an inner diameter of the second section, the guide section (312) is inserted into the first section, and an end face of the second section towards the first section forms the limiting protrusion (122).

4. The electronic expansion valve according to claim 1, wherein The stop structure (40) is arranged between the limiting piece (32) and the nut seat (31), and is used for limiting rotation of the nut seat (31) relative to the valve seat (12).

5. The electronic expansion valve according to claim 4, wherein The limiting piece (32) comprises a limiting ring, the nut seat (31) further comprises a rotation-stopping section (313), one end of the rotation-stopping section (313) is connected with the threaded section (311), the other end of the rotation-stopping section (313) is connected with the guide section (312), the limiting ring is sleeved on the rotation-stopping section (313), and the stop structure (40) is arranged between the rotation-stopping section (313) and the limiting ring.

6. The electronic expansion valve according to claim 5, wherein One of the rotation-stopping section (313) and the limiting ring is provided with a rotation-stopping protrusion (41), the other of the rotation-stopping section (313) and the limiting ring is provided with a rotation-stopping groove (42), and the rotation-stopping protrusion (41) and the rotation-stopping groove (42) cooperate to form the stop structure (40).

7. The electronic expansion valve according to claim 5, wherein The first communication section (331) is arranged in a radial direction of the nut seat (31), and the second communication section (332) is arranged in an axial direction of the nut seat (31).

8. The electronic expansion valve according to claim 7, characterized in that A first communication hole (3312) is arranged in a first notch (3311) in an outer wall of the rotation-stopping section (313), and the first notch (3311) and the first communication hole (3312) cooperate to form the first communication section (331).

9. The electronic expansion valve according to claim 8, wherein Two rotation-stopping protrusions (41) are arranged on the rotation-stopping section (313) at intervals, the two rotation-stopping protrusions (41) are symmetrically arranged on two sides of the rotation-stopping section (313), and an opening direction of the first communication hole (3312) is perpendicular to a connecting line of the two rotation-stopping protrusions (41).

10. The electronic expansion valve according to claim 7, wherein A plurality of second notches (3321) are arranged on an outer wall of the guide section (312) at intervals, the plurality of second notches (3321) are symmetrically arranged in a circumferential direction of the guide section (312), and at least one second notch (3321) is in communication with the first communication section (331).

11. The electronic expansion valve according to claim 1, wherein The electronic expansion valve further comprises a valve seat core (50), a second mounting hole (123) is arranged on the valve seat (12), the valve seat core (50) is arranged in the second mounting hole (123), the second mounting hole (123) is a stepped hole, a stepped boss is arranged on an outer wall of the valve seat core (50), and the stepped boss is matched with the stepped hole in shape and size.

12. The electronic expansion valve according to claim 11, wherein The first mounting boss (314) is coaxially arranged with the nut seat (31), the top of the valve seat core (50) is provided with a second mounting boss (51), the second mounting boss (51) is coaxially arranged with the valve seat core (50), and the electronic expansion valve further comprises a guide sleeve (60), one end of the guide sleeve (60) is sleeved on the first mounting boss (314), and the other end of the guide sleeve (60) is sleeved on the second mounting boss (51).

13. The electronic expansion valve according to claim 5, wherein The nut seat (31) further comprises a screw rod guide section (315), the screw rod guide section (315), the threaded section (311), the rotation-stopping section (313) and the guide section (312) are sequentially connected from top to bottom, the guide section (312) is provided with a first mounting boss (314) coaxial with the nut seat (31), the nut seat (31) has a through hole in the axial direction, and the inner diameters of the screw rod guide section (315), the threaded section (311), the rotation-stopping section (313) and the first mounting boss (314) gradually decrease.

14. The electronic expansion valve according to claim 13, wherein The electronic expansion valve further comprises: a positioning member (80), the valve needle (70) has a third section (71) and a fourth section (72) connected with each other, the diameter of the third section (71) is smaller than that of the fourth section (72), the third section (71) is located above the fourth section (72), the positioning member (80) is arranged at the end of the third section (71), and the positioning member (80) is used for limiting the position of the valve needle (70) relative to the screw rod (20); a spring (90) arranged between the valve needle (70) and the screw rod (20), the spring (90) is sleeved on the third section (71), one end of the spring (90) abuts against the end face of the fourth section (72), and the other end of the spring (90) abuts against the screw rod (20); wherein the screw rod (20) is movably arranged in the nut seat (31), the screw rod (20) is threadedly connected with the threaded section (311), and the screw rod guide section (315) is used for guiding the screw rod (20).

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