Double-valve-needle electronic expansion valve and refrigeration equipment

Abstract

The utility model discloses a double-valve-needle electronic expansion valve and refrigeration equipment, and relates to the technical field of electronic expansion valves. A connecting seat in the double-valve-needle electronic expansion valve is fixedly connected with a valve seat; the end of the lead screw is fixed to the limiting plate, the lead screw penetrates through the connecting base, and the lead screw is axially fixed and rotatably arranged on the connecting base. The nut penetrates through the connecting base, is in threaded fit with the lead screw and can move in the axial direction of the lead screw. The small valve needle is fixedly connected with the nut; the large valve needle is arranged in the valve seat and provided with a small valve port, and the small valve needle movably penetrates through the large valve needle; and the elastic reset piece is arranged in the valve seat. According to the scheme, through the design of axial fixation of the lead screw and movement transmission of the nut, the rotor only rotates around the shaft (without axial movement), the stator coil and the rotor are kept constant in the whole radial process, magnetic field distortion caused by vertical displacement of the rotor in a traditional scheme is eliminated, attenuation of electromagnetic driving force is improved, and it is ensured that stable driving force can still be output under the large stroke.

Description

Technical Field

[0001] This utility model relates to the field of electronic expansion valve technology, and in particular to a dual-valve needle electronic expansion valve and a refrigeration device. Background Technology

[0002] Traditional single-valve needle electronic expansion valves have gradually revealed their limitations when dealing with large flow regulation and precise control of small openings. Dual-valve needle electronic expansion valves have emerged to address this issue. Their core design concept is to decompose flow regulation into a two-stage control of "coarse adjustment + fine adjustment"—the outer valve needle is responsible for the main flow regulation under large stroke, while the inner valve needle compensates for the small opening range, thus taking into account both the wide flow range and the need for high-precision regulation.

[0003] The main structure of a dual-valve needle electronic expansion valve consists of an electromagnetic drive module (stator coil), a transmission mechanism, and a valve body assembly. In traditional designs, the rotor's rotational motion and axial displacement are highly coupled: when the electromagnetic force drives the rotor to rotate, the nut is fixed to the valve body, forcing the rotor to move up and down along the lead screw axis. This motion mode causes the radial clearance between the rotor and the stator coil to shift during dynamic operation, resulting in radial misalignment between the rotor and the stator coil. This reduces the electromagnetic drive force, especially for dual-valve needle valves requiring large strokes and large openings, easily leading to insufficient valve opening or closing drive capability, or even jamming and failure. Utility Model Content

[0004] The main purpose of this utility model is to propose a dual-valve needle electronic expansion valve and refrigeration equipment. It aims to eliminate the radial dynamic misalignment between the rotor and stator coil by fixing the lead screw and driving the nut to move axially, thereby ensuring the stability of the electromagnetic driving force throughout the entire process. This solves the problems of driving force attenuation, valve needle jamming, and excessive mechanical noise in traditional solutions under large stroke conditions.

[0005] To achieve the above objectives, the present invention proposes a dual-valve needle electronic expansion valve, comprising:

[0006] Valve seat with a large valve port;

[0007] The connecting seat is fixedly connected to the valve seat;

[0008] The rotor assembly includes a limiting plate and a lead screw, the end of which is fixed to the limiting plate, the lead screw passes through the connecting seat, and the lead screw is axially fixed and rotatably disposed on the connecting seat;

[0009] A nut is inserted through the connecting seat and threaded into the lead screw, and can move along the axial direction of the lead screw;

[0010] The small valve needle is fixedly connected to the nut.

[0011] A large valve needle is disposed within the valve seat and has a small valve port, and the small valve needle is movably inserted through the large valve needle;

[0012] A resilient reset element is disposed within the valve seat;

[0013] When the small valve needle seals the small valve port, the large valve needle seals the large valve port under the elastic force of the elastic reset member;

[0014] When the lead screw rotates, the nut moves along the axial direction of the lead screw and drives the small valve needle to disengage from the small valve port, and drives the large valve needle to disengage from the large valve port through the abutment structure.

[0015] In one embodiment, the lead screw and the connecting seat are connected by a bearing.

[0016] In one embodiment, the lead screw has a bearing limiting part, the bearing passes through the lead screw and abuts against the bearing limiting part, the limiting plate is welded to the end of the lead screw, and a bearing pressure plate is also provided between the bearing and the limiting plate.

[0017] In one embodiment, the connecting seat is provided with a first mounting groove and a riveting edge located at the edge of the first mounting groove. The bearing is located in the first mounting groove and is riveted and fixed by the riveting edge.

[0018] In one embodiment, the connecting seat has a nut guide section that has a clearance fit with the outer wall of the nut.

[0019] In one embodiment, the valve seat has a second mounting groove, the connecting seat is disposed in the second mounting groove, and the connecting seat is welded and fixed to the valve seat.

[0020] In one embodiment, the large valve needle has a mounting cavity and a valve needle channel with an inner diameter smaller than that of the mounting cavity, the small valve needle is movably inserted through the valve needle channel, and the abutment structure is provided on the nut and / or the small valve needle and is located within the mounting cavity.

[0021] In one embodiment, the abutment structure is configured as an abutment protrusion on the outer wall of the nut, the abutment protrusion abutting and limiting the position against the cavity wall of the mounting cavity of the large valve needle.

[0022] In one embodiment, the large valve needle includes an upper valve head and a lower valve head, the lower valve head being embedded in the upper valve head and defining the mounting cavity; the valve needle channel and the small valve port are located in the lower valve head.

[0023] In one embodiment, a limiting structure is provided between the large valve needle and the valve seat; or a limiting structure is provided between the large valve needle and the connecting seat to restrict the axial movement of the large valve needle.

[0024] In one embodiment, the valve seat has a valve cavity and a valve needle guide section communicating with the valve cavity, a first stop portion is formed between the valve needle guide section and the valve cavity, the upper valve head passes through the valve needle guide section, the valve needle guide section is clearance-fitted with the outer wall of the upper valve head, and a second stop portion is formed on the outer wall of the upper valve head near the lower valve head; the limiting structure is configured to abut against the first stop portion and the second stop portion.

[0025] In one embodiment, the outer wall of the large valve needle is provided with a first sealing element, and the large valve needle and the valve needle guide section are sealed by the first sealing element.

[0026] In one embodiment, the inner edge of the large valve port is provided with a first rounded corner, and the outer edge of the large valve needle is provided with a first conical surface, the first conical surface and the first rounded corner tangent surface are fitted together for sealing.

[0027] In one embodiment, the radius of the first fillet is 0.2mm-1.0mm, and the angle between the first conical surface and the horizontal plane containing the inner diameter of the large valve port is in the range of 60°-90°.

[0028] In one embodiment, the outer wall of the small valve needle is provided with a second sealing element, and the large valve needle and the small valve needle are sealed by the second sealing element.

[0029] In one embodiment, the inner edge of the small valve port is provided with a second rounded corner, and the outer edge of the small valve needle is provided with a second conical surface, the second conical surface and the second rounded corner tangent surface cooperate to seal.

[0030] In one embodiment, the radius of the second fillet is 0.2mm-1.0mm, and the angle between the second conical surface and the horizontal plane containing the inner diameter of the small valve port is in the range of 60°-90°.

[0031] In one embodiment, the nut includes a nut body and a metal connector embedded in the nut body and integrally injection molded with the nut body, and the small valve needle is fixedly connected to the metal connector.

[0032] In one embodiment, the nut body is made of polyphenylene sulfide containing 10%-30% carbon fiber or glass fiber.

[0033] This utility model also proposes a refrigeration device, including the dual-valve needle electronic expansion valve as described above.

[0034] This invention employs a screw-driven axial fixation and nut-driven transmission design, ensuring the rotor rotates only around its axis (without axial movement). The stator coils and rotor maintain a constant radial distance throughout the entire stroke, eliminating magnetic field distortion caused by rotor vertical displacement in traditional designs. This improves the attenuation of electromagnetic driving force, ensuring stable driving force output even with large strokes (e.g., 8-10mm). The rotor's rotation without axial displacement reduces the number of dynamic O-rings, simplifying components. Furthermore, the screw is directly fixed to the connecting seat, eliminating the need for precise rotor-screw coaxiality adjustment as in traditional designs, significantly reducing assembly time. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0036] Figure 1 A schematic diagram of an embodiment of the dual-valve needle electronic expansion valve provided by this utility model;

[0037] Figure 2 for Figure 1 A cross-sectional schematic diagram of the connection between the large valve needle, the small valve needle, and the nut.

[0038] Figure 3 for Figure 2 Schematic diagram of the connection structure between the large valve needle, the small valve needle, and the nut;

[0039] Figure 4 This is a schematic diagram of an embodiment of the small valve needle provided by this utility model.

[0040] Explanation of icon numbers:

[0041] 10. Valve seat; 11. Large valve port; 111. First fillet; 12. Second mounting groove; 13. Valve cavity;

[0042] 14. Valve needle guide section; 15. First stop section; 16. Second stop section; 17. First seal.

[0043] 20. Connecting seat; 21. First mounting groove; 22. Riveting edge; 23. Nut guide section;

[0044] 30. Rotor assembly; 31. Limiting plate; 32. Lead screw; 33. Bearing; 34. Bearing limiting part; 35. Bearing pressure plate;

[0045] 40. Nut; 41. Nut body; 42. Metal connector; 43. Abutting protrusion; 50. Small valve needle; 51. Second seal; 52. Second conical surface;

[0046] 60. Large valve needle; 61. Small valve port; 611. Second fillet; 62. Mounting cavity; 63. Valve needle channel; 64. Upper valve head; 65. Lower valve head; 651. First conical surface; 66. Limiting structure;

[0047] 70. Elastic reset component;

[0048] 80. Abutment structure.

[0049] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0050] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0051] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0052] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0053] Traditional single-valve needle electronic expansion valves have gradually revealed their limitations when dealing with large flow regulation and precise control of small openings. Dual-valve needle electronic expansion valves have emerged to address this issue. Their core design concept is to decompose flow regulation into a two-stage control of "coarse adjustment + fine adjustment"—the outer valve needle is responsible for the main flow regulation under large stroke, while the inner valve needle compensates for the small opening range, thus taking into account both the wide flow range and the need for high-precision regulation.

[0054] The main structure of a dual-valve needle electronic expansion valve consists of an electromagnetic drive module (stator coil), a transmission mechanism, and a valve body assembly. In traditional designs, the rotor's rotational motion and axial displacement are highly coupled: when the electromagnetic force drives the rotor to rotate, the nut is fixed to the valve body, forcing the rotor to move up and down along the lead screw axis. This motion mode causes the radial clearance between the rotor and the stator coil to shift during dynamic operation, resulting in radial misalignment between the rotor and the stator coil. This reduces the electromagnetic drive force, especially for dual-valve needle valves requiring large strokes and large openings, easily leading to insufficient valve opening or closing drive capability, or even jamming and failure.

[0055] Secondly, most dual-valve needle valves currently rely on slip rings and ring rails to achieve upper and lower stops, which results in high noise levels and negatively impacts the customer experience.

[0056] Secondly, the current dual-valve needle electronic expansion valve has a complex structure with many parts, resulting in high design and manufacturing costs, which is not conducive to improving market competitiveness.

[0057] This utility model proposes a dual-valve needle electronic expansion valve.

[0058] Please see Figures 1 to 4 In one embodiment of this utility model, the main structure of the dual-valve needle electronic expansion valve consists of an electromagnetic drive module (with a stator coil), a transmission mechanism, and a valve body assembly. The electromagnetic drive module is sleeved outside the valve body assembly, and the transmission mechanism is located inside the valve body assembly. After the stator coil is energized, it generates a rotating magnetic field, which drives the internal permanent magnet rotor to rotate.

[0059] The valve body assembly includes valve seat 10, large valve needle 60, small valve needle 50, sealing assembly, etc.

[0060] The transmission mechanism includes a lead screw 32 (connected to the rotor), a nut 40 (linked with the valve needle), and a limiting structure 66, which are responsible for converting rotational motion into axial displacement.

[0061] Lead screw 32: The rigid shaft of the transmission mechanism, coaxially connected to the rotor.

[0062] Nut 40: A motion conversion component of the transmission mechanism, which moves axially along the lead screw 32 and drives the small valve needle 50.

[0063] Large / small valve needle 50: The actuator of the valve body assembly, responsible for main flow regulation and fine-tuning compensation respectively.

[0064] Specifically, the valve seat 10 has a large valve port 11, and the connecting seat 20 is fixedly connected to the valve seat 10; the rotor assembly 30 includes a limiting plate 31 and a lead screw 32, the end of the lead screw 32 is fixed to the limiting plate 31, the lead screw 32 passes through the connecting seat 20, and the lead screw 32 is axially fixed and rotatably mounted on the connecting seat 20; the nut 40 passes through the connecting seat 20 and is threadedly engaged with the lead screw 32, and can move axially along the lead screw 32; the small valve needle 50 is fixedly connected to the nut 40; the large valve needle 60 is provided with... The valve seat 10 is located and has a small valve port 61. A small valve needle 50 is movably inserted through a large valve needle 60. An elastic reset member 70 is disposed within the valve seat 10. When the small valve needle 50 seals the small valve port 61, the large valve needle 60 seals the large valve port 11 under the elastic force of the elastic reset member 70. When the lead screw 32 rotates, the nut 40 moves axially along the lead screw 32 and drives the small valve needle 50 to disengage from the small valve port 61, and drives the large valve needle 60 to disengage from the large valve port 11 through the abutment structure 80.

[0065] Please refer to Figure 1 The valve seat 10 has a medium inflow pipe interface on its side wall. Figure 1 The valve seat 10 has a circumferential opening. The large valve needle 60 passes through the valve seat 10 and the connecting seat 20. In order to fix the axial coaxiality, there is a guide section with clearance fit between the outer wall of the large valve needle 60 and the valve seat 10 to ensure that the axial movement of the large valve needle 60 is free from wobble. The guide section is an inner hole provided in the valve seat 10 in the axial direction that has clearance fit with the outer wall of the large valve needle 60.

[0066] The stator coil (not shown in the figure) is installed on the outside of the housing above the valve seat 10. The stator coil corresponds to the rotor in the rotor assembly 30, eliminating rotor radial offset, stabilizing electromagnetic efficiency, and solving the problem of insufficient driving force of traditional double valve needles under large stroke.

[0067] In order to achieve the axial fixation and rotatable arrangement of the lead screw 32 on the connecting seat 20, in this embodiment, the lead screw 32 and the connecting seat 20 are connected by a bearing 33.

[0068] Specifically, the lead screw 32 has a bearing limiting part 34, the bearing 33 passes through the lead screw 32 and abuts against the bearing limiting part 34, the limiting plate 31 is welded to the end of the lead screw 32, and a bearing pressure plate 35 is also provided between the bearing 33 and the limiting plate 31, which allows the lead screw 32 to rotate freely but restricts axial movement.

[0069] In other solutions, two sets of angular contact ball bearings (back-to-back installation) can be embedded in the connecting seat 20, with the lead screw 32 passing through the inner ring of the bearings and pre-tightened by a lock nut to achieve bidirectional axial positioning. Alternatively, a self-lubricating copper alloy bushing can be installed between the lead screw 32 and the connecting seat 20, with the end of the lead screw 32 axially locked by a shoulder and a retaining ring (such as an E-type retaining circlip), allowing the lead screw 32 to rotate freely but restricting axial movement. Alternatively, a ball spline lead screw 32 can be used, with the spline shaft engaging with the spline groove inside the connecting seat 20, achieving pure rotational motion of the lead screw 32 (without axial displacement) through ball circulation.

[0070] The technical solution of this utility model uses a design that fixes the lead screw 32 axially and moves the nut 40 to transmit power. The rotor only rotates around the axis (without axial movement). The stator coil and the rotor remain constant in the radial direction throughout the entire process. This eliminates the magnetic field distortion caused by the vertical displacement of the rotor in the traditional solution, improves the attenuation of electromagnetic driving force, and ensures that a stable driving force can still be output even with a large stroke (such as 8-10mm).

[0071] By eliminating the traditional slip ring-rail assembly and replacing it with a stepped abutment boss consisting of a nut 40 and a large valve needle 60, the number of parts is reduced (eliminating components such as slip rings, rails, and limit screws). In addition, since the rotor only rotates without axial displacement, the number of dynamic seal O-rings can be reduced, thus simplifying the components.

[0072] Furthermore, since the lead screw 32 is directly fixed to the connecting seat 20, there is no need for the precision adjustment of the coaxiality of the rotor and lead screw 32 in the traditional solution, which greatly shortens the assembly time.

[0073] Specifically, in order to solve the problems of axial movement and assembly complexity, the connecting seat 20 is provided with a first mounting groove 21 and a riveting edge 22 with the edge of the first mounting groove 21. The bearing 33 is located in the first mounting groove 21 and is riveted and fixed by the riveting edge 22.

[0074] The combination of bearing limiting part 34 and bearing pressure plate 35 can be used to precisely control the axial position of lead screw 32, avoiding magnetic field deviation caused by rotor movement in traditional solutions. The limiting plate 31 is welded to lead screw 32, and the bearing 33 is fixed by riveting edge 22, which improves the overall rigidity and stability of the assembly, reduces the risk of component loosening or displacement, and the restriction of axial movement directly improves the stability of electromagnetic drive force, because the rotor no longer needs to move up and down, reducing the fluctuation of magnetic field coupling efficiency.

[0075] Please refer to Figure 1The first mounting groove 21 and riveting edge 22 of the connecting seat 20 simplify the assembly process because the bearing 33 is precisely installed in the groove and fixed by riveting. The bearing 33, pressure plate, limiting plate 31 and lead screw 32 can be pre-assembled into independent units and then pressed into the connecting seat 20 at once by riveting edge 22. The assembly steps are reduced, reducing the need for precision adjustment in traditional assembly. The fixing method of bearing 33 improves the durability of the system, reduces wear, thereby extending the service life, reducing production costs, and improving product consistency and reliability.

[0076] In addition, by fixing the lead screw 32 and optimizing the installation of the bearing 33, problems such as insufficient driving force, noise and complex structure are solved. For example, reducing axial movement can reduce mechanical noise, and simplifying the structure can reduce the number of parts, thereby reducing costs.

[0077] To ensure the coaxiality of the large valve needle 60 and the small valve needle 50, the connecting seat 20 has a nut guide section 23 that is clearance-fitted with the outer wall of the nut 40, the large valve needle 60 has a first guide section that is clearance-fitted with the outer wall of the small valve needle 50, and the valve seat 10 has a second guide section that is clearance-fitted with the outer wall of the large valve needle 60.

[0078] Please refer to Figure 1 The nut guide section 23 guides the nut 40 to move along the lead screw 32. The first guide section guides the small valve needle 50 within the large valve needle 60, and the second guide section guides the large valve needle 60 within the valve seat 10. Clearance fit implies a certain clearance, but it must also ensure motion accuracy. The guide structure can solve problems such as valve needle misalignment, high frictional resistance, and poor sealing, thereby improving motion coaxiality, reducing friction and wear, improving sealing performance, and extending service life.

[0079] The nut guide section 23 can reduce the shaking of the nut 40 during movement and improve transmission efficiency; the first guide section ensures that the small valve needle 50 is accurately aligned with the small valve port 61 to avoid jamming; the second guide section ensures the alignment of the large valve needle 60 with the valve seat 10, improves sealing performance, and achieves the three-stage guide synergy. The three-stage guide structure ensures the coaxiality of the large and small valve needles 50 with the corresponding valve ports.

[0080] Please refer to Figure 1Specifically, the valve seat 10 has a second mounting groove 12, and the connecting seat 20 is disposed within the second mounting groove 12. The connecting seat 20 is welded to the valve seat 10. Embedding the connecting seat 20 into the second mounting groove 12 of the valve seat 10 and welding it provides higher structural rigidity and sealing performance. Welding typically provides a stronger connection, reducing the risk of loosening between components. Welding the connecting seat 20 into the second mounting groove 12 of the valve seat 10 ensures precise alignment of the connecting seat 20 and the valve seat 10 during the welding process, resulting in better positional stability between them and reducing errors caused by loose mechanical fasteners. This design improves product consistency and reliability, especially in mass production, where the assembly quality of each component is easier to control. Of course, in some alternative solutions, the connecting seat 20 and the valve seat 10 may also be fixed using threaded connections, riveting, or gluing.

[0081] Please refer to Figure 1 The lead screw 32 is fixed to the connecting seat 20 by the bearing 33. The lead screw 32 can rotate circumferentially relative to the connecting seat 20, but there is no axial movement. The lead screw 32 is located inside the connecting seat 20. The nut 40 is threadedly engaged with the lead screw 32. Part of the nut 40 extends beyond the connecting seat 20. The end of the nut 40 that extends beyond the connecting seat 20 is connected to the small valve needle 50, such as by threaded connection, riveting, welding, etc.

[0082] To prevent the small valve needle 50 from rotating with the nut 40, in one solution, the connecting seat 20 and the nut 40 are provided with irregularly shaped holes, such as a square fit between the outer wall of the nut 40 and the through hole of the connecting seat 20, which restricts the circumferential rotation of the nut 40 but does not affect the axial movement of the nut 40. In another solution, the nut 40 and the small valve needle 50 are connected by a bearing 33, reducing the possibility that the small valve needle 50 will move with the nut 40.

[0083] Specifically, when the lead screw 32 rotates, the nut 40 moves axially along the lead screw 32 and drives the small valve needle 50 to disengage from the small valve port 61, and drives the large valve needle 60 to disengage from the large valve port 11 through the abutment structure 80.

[0084] The dual-valve needle design is typically used to resolve the conflict between high flow rates and fine-tuning. The smaller valve needle 50 actuates first, and when its stroke reaches a certain position, it triggers the larger valve needle 60 to actuate. This allows for staged flow control, improving accuracy. Staged control reduces the force required to simultaneously drive both valve needles, resulting in greater precision at low flow rates and higher efficiency at high flow rates. Furthermore, it can lead to a more compact structure, reducing the number of components and lowering costs.

[0085] Please refer to Figures 1 to 3The large valve needle 60 has a mounting cavity 62 and a valve needle channel 63 with an inner diameter smaller than that of the mounting cavity 62. The small valve needle 50 is movably inserted through the valve needle channel 63. The abutment structure 80 is provided on the nut 40 and / or the small valve needle 50 and is located inside the mounting cavity 62.

[0086] In one embodiment, the tail of the large valve needle 60 is hinged to the nut 40 via a compression spring. When the nut 40 drives the small valve needle 50 to move, the spring preload gradually accumulates until it overcomes the sealing force of the large valve needle 60 and opens synchronously.

[0087] Please refer to Figure 1 and Figure 2 In this embodiment, the abutment structure 80 is configured as an abutment protrusion 43 on the outer wall of the nut 40, which abuts and limits the movement of the abutment protrusion 43 against the cavity wall of the mounting cavity 62 of the large valve needle 60. The abutment structure 80 is a stepped boss machined at the end of the nut 40. When the nut 40 moves to the set stroke, the boss presses against the annular shoulder at the tail end of the large valve needle 60, forcing the large valve needle 60 to move synchronously. The small valve needle 50 first disengages from the small valve port 61, and then the boss triggers the large valve needle 60 to open the large valve port 11, achieving a smooth transition from "fine adjustment" to "coarse adjustment" of the flow rate.

[0088] The large valve needle 60 has a mounting cavity 62 and a valve needle channel 63 with an inner diameter smaller than that of the mounting cavity 62. The small valve needle 50 is movably inserted through the valve needle channel 63. The abutment structure 80 is provided on the nut 40 and / or the small valve needle 50 and is located within the mounting cavity 62. The abutment structure 80 being located within the mounting cavity 62 reduces the number of external components, simplifies the overall structure, brings assembly advantages, reduces the number of parts, and lowers costs.

[0089] The abutment structure 80 is integrated into the mounting cavity 62 of the large valve needle 60. By utilizing the stepped inner diameter difference between the mounting cavity 62 and the valve needle channel 63 (the first guide section mentioned above), a natural limiting space is formed to create a compact embedded abutment (the traditional external abutment structure 80 requires an additional extension of the valve needle length).

[0090] Specifically, an elastic reset element 70 is provided inside the valve seat 10. The elastic reset element 70 is located between the connecting seat 20 and the large valve needle 60. In the natural state (when the small valve needle 50 closes the small valve port 61, that is, when the nut 40 or the small valve needle 50 does not exert force on the large valve needle 60), the large valve needle 60 seals the large valve port 11 under the elastic force of the elastic reset element 70. The elastic reset element 70 can be a helical spring, a disc spring, a wave spring, a rubber elastomer, etc.

[0091] Please refer to Figures 1 to 3Specifically, the large valve needle 60 includes an upper valve head 64 and a lower valve head 65. The lower valve head 65 is embedded in the upper valve head 64 and defines a mounting cavity 62. A valve needle channel 63 and a small valve port 61 are located in the lower valve head 65. Traditionally, large valve needles 60 are usually integrally molded. A split design optimizes the manufacturing and assembly process. Specifically, separating the upper and lower valve heads 65 makes them easier to process, especially since the lower valve head 65 has a more complex internal structure, such as the valve needle channel 63 and the small valve port 61. Furthermore, the split design allows for the use of different materials; for example, the upper valve head 64 can be made of a high-strength material, while the lower valve head 65 can be made of a wear-resistant or corrosion-resistant material, thereby improving overall durability.

[0092] The lower valve head 65 is inserted into the upper valve head 64 with an interference fit and is fixed by laser welding, resulting in minimal overall coaxiality error. The lower valve head 65 defines a mounting cavity 62, providing installation space for the abutment protrusion 43 on the outer wall of the nut 40. The abutment protrusion 43 is placed within the mounting cavity 62. When the nut 40 moves along the lead screw 32, the abutment protrusion 43 contacts the structure within the large valve needle 60, thereby moving the large valve needle 60. The elastic reset member 70 is located within the valve seat 10, with its two ends contacting the large valve needle 60 and the connecting seat 20 respectively, providing a reset force to ensure that the large valve needle 60 can seal the large valve port 11 when there is no driving force. The mounting cavity 62 is integrated within the large valve needle 60, reducing external components, making the overall structure more compact, and saving space. The abutment protrusion 43 acts directly on the mounting cavity 62, transmitting driving force more directly, reducing energy loss, and improving response speed.

[0093] Please refer to Figures 1 to 3 Furthermore, a limiting structure 66 is provided between the large valve needle 60 and the valve seat 10; or a limiting structure 66 is provided between the large valve needle 60 and the connecting seat 20, in order to limit the axial movement of the large valve needle 60.

[0094] Specifically, the valve seat 10 has a valve cavity 13 and a valve needle guide section 14 communicating with the valve cavity 13. A first stop portion 15 is formed between the valve needle guide section 14 and the valve cavity 13. The upper valve head 64 passes through the valve needle guide section 14 (the second guide section mentioned above). The valve needle guide section 14 is clearance-fitted with the outer wall of the upper valve head 64. A second stop portion 16 is formed on the outer wall of the upper valve head 64 near the lower valve head 65, or a second stop portion 16 is formed between the lower valve head 65 and the upper valve head 64. The limiting structure 66 is configured to abut against the first stop portion 15 and the second stop portion 16.

[0095] In other embodiments, an annular groove is machined on the inner wall of the valve needle guide section 14, and an open elastic retaining ring is embedded therein. When the large valve needle 60 moves, the retaining ring contacts and limits the movement of the valve needle's outer wall boss. Alternatively, a threaded hole is provided at the end of the valve seat 10, and an adjustable limiting screw is screwed in. The stroke of the large valve needle 60 is controlled by adjusting the extension length of the screw. Alternatively, a permanent magnet is embedded at the end of the large valve needle 60, and a magnetic ring of the same pole is provided at a corresponding position on the valve seat 10, using magnetic repulsion to achieve non-contact limiting.

[0096] Furthermore, the outer wall of the large valve needle 60 is provided with a first sealing element 17, which seals the large valve needle 60 and the valve needle guide section 14. The first sealing element 17 can be an O-ring, a PTFE sealing ring, etc. Specifically, the outer wall of the upper valve head 64 is provided with a first sealing groove, and the first sealing element 17 is a sealing ring installed in the first sealing groove to achieve sealing between the inner wall of the upper valve head 64 and the valve needle guide section 14.

[0097] Furthermore, the inner edge of the large valve port 11 is provided with a first rounded corner 111, and the outer edge of the large valve needle 60 is provided with a first conical surface 651. The first conical surface 651 and the first rounded corner 111 are tangentially fitted together for sealing. The design of the first rounded corner 111 and the first conical surface 651 is a line contact. The fit between the rounded corner and the conical surface forms a line contact, reducing the contact area, thereby increasing the contact pressure under the same pressure and enhancing the sealing effect. Specifically, the tangential fit between the conical surface and the rounded corner can form a better self-centering effect, that is, during the movement of the valve needle, the conical surface can automatically adjust its position to ensure tight contact of the sealing surface, reducing leakage caused by installation errors or deviations during movement. Moreover, the fit between the conical surface and the rounded corner can generate greater sealing force under high pressure, preventing media leakage. At the same time, the rounded corner may reduce stress concentration, improve the durability of the valve port and the valve needle, and extend the service life.

[0098] Specifically, the radius of the first fillet 111 is 0.2mm-1.0mm, and the angle between the first conical surface 651 and the horizontal plane containing the inner diameter of the large valve port 11 ranges from 60° to 90°. The fillet radius and conical surface angle affect sealing performance, contact pressure, and durability in the sealing design. First, a smaller fillet radius increases contact pressure but also leads to stress concentration and accelerated wear. A larger radius helps to disperse pressure and reduce wear, but the contact pressure may be insufficient, leading to a risk of leakage. The conical surface angle is between 60° and 90°. A larger angle (close to 90°) may form a seal closer to line contact, increasing contact pressure, but it is more sensitive to assembly errors. A smaller angle (such as 60° or 70°) may provide better self-alignment capability, but the contact area may increase, reducing the pressure per unit area and affecting the sealing effect. Considering the ease of machining the fillet radius and angle, as well as the sealing effect, the above ranges apply.

[0099] Please refer to Figures 1 to 4 Furthermore, the outer wall of the small valve needle 50 is provided on the second sealing member 51, and the large valve needle 60 and the small valve needle 50 are sealed by the second sealing member 51.

[0100] Specifically, the inner edge of the small valve port 61 is provided with a second rounded corner 611, and the outer edge of the small valve needle 50 is provided with a second conical surface 52. The second conical surface 52 and the tangential surface of the second rounded corner 611 are fitted together for sealing. The design of the second rounded corner 611 and the second conical surface 52 is a line contact. The fit between the rounded corner and the conical surface forms a line contact, reducing the contact area and thus increasing the contact pressure under the same pressure, enhancing the sealing effect. Specifically, the tangential fit between the conical surface and the rounded corner can form a better self-centering effect, that is, during the movement of the valve needle, the conical surface can automatically adjust its position to ensure tight contact of the sealing surface, reducing leakage caused by installation errors or deviations during movement. Moreover, the fit between the conical surface and the rounded corner can generate greater sealing force under high pressure, preventing media leakage. At the same time, the rounded corner may reduce stress concentration, improve the durability of the valve port and the valve needle, and extend the service life.

[0101] Specifically, the radius of the second fillet 611 is 0.2mm-1.0mm, and the angle between the second conical surface 52 and the horizontal plane containing the inner diameter of the small valve port 61 is 60°-90°.

[0102] Furthermore, the nut 40 includes a nut body 41 and a metal connector 42 embedded in and integrally injection-molded with the nut body 41. The small valve needle 50 is fixedly connected to the connector. Embedding the metal connector 42 into the nut body 41 improves structural strength and simplifies the manufacturing process. The fixed connection between the metal connector 42 and the small valve needle 50 enhances transmission efficiency and load capacity. The integrated injection molding process reduces the number of parts, lowers costs, and improves reliability.

[0103] Specifically, the nut body 41 is made of polyphenylene sulfide containing 10%-30% carbon fiber or glass fiber. The nut body 41 is made of PPS reinforced with carbon fiber or glass fiber. PPS itself is a high-performance engineering plastic with high temperature resistance, chemical corrosion resistance, and good mechanical properties. Adding carbon fiber or glass fiber can improve its strength and stiffness.

[0104] Traditional dual-valve needle valves rely on slip rings and ring rails for up-and-down stopping, resulting in high noise levels and negatively impacting the customer experience. This solution, however, features an electromagnetic coil and rotor assembly 30 aligned directly. During valve opening and closing, the rotor and lead screw 32 rotate without vertical movement, ensuring consistent positioning and maximizing driving power while mitigating defects during these processes. The nut 40 abuts against the large valve needle 60, and the large valve needle 60 abuts against the valve seat 10, replacing the traditional slip ring and rail stopping structure and eliminating stopping noise, further enhancing customer comfort.

[0105] This utility model also proposes a compressor, which includes the above-mentioned dual-valve needle electronic expansion valve (the specific structure is described in the above embodiments). Since this compressor adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0106] This utility model also proposes a refrigeration device, which includes the above-mentioned compressor or dual-valve needle electronic expansion valve (the specific structure is described in the above embodiments). Since the refrigeration device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0107] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A dual-valve needle electronic expansion valve, characterized in that, include: Valve seat with a large valve port; The connecting seat is fixedly connected to the valve seat; The rotor assembly includes a limiting plate and a lead screw, the end of which is fixed to the limiting plate, the lead screw passes through the connecting seat, and the lead screw is axially fixed and rotatably disposed on the connecting seat; A nut is inserted through the connecting seat and threaded into the lead screw, and can move along the axial direction of the lead screw; The small valve needle is fixedly connected to the nut. A large valve needle is disposed within the valve seat and has a small valve port, and the small valve needle is movably inserted through the large valve needle; as well as A resilient reset element is disposed within the valve seat; When the small valve needle seals the small valve port, the large valve needle seals the large valve port under the elastic force of the elastic reset member; When the lead screw rotates, the nut moves along the axial direction of the lead screw and drives the small valve needle to disengage from the small valve port, and through the abutment structure, drives the large valve needle to disengage from the large valve port.

2. The dual-valve needle electronic expansion valve as described in claim 1, characterized in that, The lead screw is connected to the connecting seat via a bearing.

3. The dual-valve needle electronic expansion valve as described in claim 2, characterized in that, The lead screw has a bearing limiting part, the bearing passes through the lead screw and abuts against the bearing limiting part, the limiting plate is welded to the end of the lead screw, and a bearing pressure plate is also provided between the bearing and the limiting plate.

4. The dual-valve needle electronic expansion valve as described in claim 2, characterized in that, The connecting seat has a first mounting groove and a riveting edge located at the edge of the first mounting groove. The bearing is disposed within the first mounting groove and is riveted and fixed by the riveting edge; and / or, The connecting seat has a nut guide section that clearance-fits the outer wall of the nut; and / or, The valve seat has a second mounting groove, and the connecting seat is disposed in the second mounting groove. The connecting seat is welded and fixed to the valve seat.

5. The dual-valve needle electronic expansion valve as described in claim 1, characterized in that, The large valve needle has a mounting cavity and a valve needle channel with an inner diameter smaller than that of the mounting cavity. The small valve needle is movably inserted through the valve needle channel. The abutment structure is provided on the nut and / or the small valve needle and is located within the mounting cavity.

6. The dual-valve needle electronic expansion valve as described in claim 5, characterized in that, The abutment structure is configured as an abutment protrusion on the outer wall of the nut, and the abutment protrusion abuts and limits the movement against the cavity wall of the mounting cavity of the large valve needle.

7. The dual-valve needle electronic expansion valve as described in claim 5, characterized in that, The large valve needle includes an upper valve head and a lower valve head, the lower valve head is embedded in the upper valve head and defines the mounting cavity; the valve needle channel and the small valve port are located in the lower valve head.

8. The dual-valve needle electronic expansion valve as described in claim 7, characterized in that, A limiting structure is provided between the large valve needle and the valve seat; or a limiting structure is provided between the large valve needle and the connecting seat to restrict the axial movement of the large valve needle.

9. The dual-valve needle electronic expansion valve as described in claim 8, characterized in that, The valve seat has a valve cavity and a valve needle guide section communicating with the valve cavity. A first stop portion is formed between the valve needle guide section and the valve cavity. The upper valve head passes through the valve needle guide section. The valve needle guide section is clearance-fitted with the outer wall of the upper valve head. A second stop portion is formed on the outer wall of the upper valve head near the lower valve head. The limiting structure is configured to abut against the first stop portion and the second stop portion.

10. The dual-valve needle electronic expansion valve as described in claim 9, characterized in that, The outer wall of the large valve needle is provided with a first sealing element, and the large valve needle and the valve needle guide section are sealed by the first sealing element.

11. The dual-valve needle electronic expansion valve as described in claim 1, characterized in that, The inner edge of the large valve port is provided with a first rounded corner, and the outer edge of the large valve needle is provided with a first conical surface. The first conical surface and the first rounded corner tangent are fitted together for sealing.

12. The dual-valve needle electronic expansion valve as described in claim 11, characterized in that, The radius of the first fillet is 0.2mm-1.0mm, and the angle between the first conical surface and the horizontal plane containing the inner diameter of the large valve port is 60°-90°.

13. The dual-valve needle electronic expansion valve as described in claim 1, characterized in that, The outer wall of the small valve needle is provided with a second sealing element, and the large valve needle and the small valve needle are sealed by the second sealing element.

14. The dual-valve needle electronic expansion valve as described in claim 13, characterized in that, The inner edge of the small valve port is provided with a second rounded corner, and the outer edge of the small valve needle is provided with a second conical surface. The second conical surface and the second rounded corner tangent are fitted together for sealing.

15. The dual-valve needle electronic expansion valve as described in claim 14, characterized in that, The radius of the second fillet is 0.2mm-1.0mm, and the angle between the second conical surface and the horizontal plane containing the inner diameter of the small valve port is 60°-90°.

16. The dual-valve needle electronic expansion valve as described in claim 1, characterized in that, The nut includes a nut body and a metal connector embedded in the nut body and integrally injection molded with the nut body. The small valve needle is fixedly connected to the metal connector.

17. The dual-valve needle electronic expansion valve as described in claim 16, characterized in that, The nut body is made of polyphenylene sulfide containing 10%-30% carbon fiber or glass fiber.

18. A refrigeration device, characterized in that, Includes the dual-valve needle electronic expansion valve as described in any one of claims 1 to 17.

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