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, the double-valve-needle electronic expansion valve comprises a large valve needle, the large valve needle comprises a valve needle base and a valve needle sleeve, and the valve needle base is axially sleeved with the valve needle sleeve; the large valve needle is provided with a balance channel, and the balance channel penetrates through the valve needle base and the valve needle sleeve. According to the technical scheme provided by the utility model, the balance channel is arranged on the large valve needle, so that the problems of difficulty in processing, high rejection rate and unsuitability for standardized production due to the fact that the traditional inner balance channel is designed on the small valve needle are solved.

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] Taking the valve needle assembly (large valve needle / small valve needle) as the research object, if there is a pressure difference between the upper and lower parts of the valve needle assembly, the resistance is very large, and the product is difficult to operate. Therefore, it is necessary to design a simple and reasonable pressure difference balancing channel to achieve the balance of the pressure difference between the upper and lower parts of the valve needle assembly. Utility Model Content

[0004] The main purpose of this invention is to propose a dual-valve needle electronic expansion valve and refrigeration equipment. It aims to solve the problems of difficult processing, high scrap rate and unsuitability for standardized production in traditional internal balance channel design on small valve needles by opening a balance channel on the large valve needle.

[0005] To achieve the above objectives, the present invention proposes a dual-valve needle electronic expansion valve, comprising: a large valve needle, wherein the large valve needle is provided with a balance channel, and the large valve needle includes:

[0006] Valve needle base; and

[0007] A valve needle sleeve is axially sleeved onto the valve needle base; wherein, the balance channel passes through the valve needle base and the valve needle sleeve.

[0008] In one embodiment, the valve needle base includes a base portion and a journal extending axially from the base portion. The outer diameter of the journal is smaller than the outer diameter of the base portion, forming a stepped surface on the base portion. The base portion has a vent hole penetrating the stepped surface. The valve needle sleeve is sleeved on the outside of the journal, with its bottom abutting against the stepped surface and forming a flow guide gap with the journal. The vent hole communicates with the flow guide gap. The valve needle sleeve has a flow guide hole communicating with the flow guide gap. The flow guide hole, the flow guide gap, and the vent hole constitute the balance channel.

[0009] In one embodiment, the stepped surface is annular.

[0010] In one embodiment, the guide hole is located at the top of the valve needle sleeve.

[0011] In one embodiment, multiple guide holes are provided at intervals along the stepped surface.

[0012] In one embodiment, the diameter of the guide hole is 0.8mm-2mm.

[0013] In one embodiment, the journal is provided with a longitudinal tangent plane corresponding to the guide hole along the axial direction.

[0014] In one embodiment, the inner wall of the valve needle sleeve is provided with a guide cone surface corresponding to the guide hole, and the guide cone surface extends obliquely from the bottom of the valve needle sleeve toward the guide gap.

[0015] In one embodiment, the guide cone surface is configured as an annular shape.

[0016] In one embodiment, the angle between the inclined direction of the guide cone surface and the stepped surface is 60°-70°.

[0017] In one embodiment, the dual-valve needle electronic expansion valve further includes:

[0018] Valve seat with a large valve port;

[0019] The connecting seat is fixedly connected to the valve seat;

[0020] A lead screw, which passes through the connecting seat, and is axially fixed and rotatably mounted on the connecting seat;

[0021] The rotor assembly includes a limiting plate, and the end of the lead screw is fixed to the limiting plate;

[0022] 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;

[0023] The small valve needle is fixedly connected to the nut.

[0024] A resilient reset element is disposed within the valve seat;

[0025] The large valve needle is also provided with a small valve port, and the small valve needle is movably inserted through the large valve needle; wherein, when the small valve needle seals the small valve port, the elastic reset member causes the large valve needle to seal the large valve port;

[0026] 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.

[0027] In one embodiment, the top of the valve needle base and the bottom of the valve needle sleeve form an installation cavity, the installation cavity is connected to the flow guide gap, and the abutment structure is disposed in the installation cavity.

[0028] In one embodiment, a first guide hole is provided through the center of the valve needle base, and a second guide hole is provided at the top of the valve needle sleeve, which is coaxially arranged with the first guide hole. The small valve needle passes through and is in clearance fit with the first guide hole and the second guide hole.

[0029] This utility model also proposes a refrigeration device, including the dual-valve needle electronic expansion valve as described above.

[0030] This invention solves the problems of difficult machining, high scrap rate, and unsuitability for standardized production associated with traditional internal balancing channel designs on small valve needles by creating a balancing channel on the large valve needle. By transferring the balancing channel from the small valve needle to the large valve needle, the machining of elongated holes on the small valve needle is avoided, thus reducing machining difficulty and scrap rate. By uniformly designing the balancing channel on the large valve needle, products of different specifications can share a similar large valve needle design, facilitating platform-based development. The valve needle base and sleeve can be machined with balancing channels separately, avoiding the complexity of machining both the inner hole and outer shape simultaneously in traditional integral large valve needles, which can affect the machining of the sealing surface of the valve needle base or cause deformation of the sealing surface. Attached Figure Description

[0031] 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.

[0032] Figure 1 A schematic diagram of an embodiment of the dual-valve needle electronic expansion valve provided by this utility model;

[0033] Figure 2 for Figure 1 A schematic diagram of an embodiment of the engagement between the large valve needle and the nut;

[0034] Figure 3 for Figure 2 A schematic diagram of the cross-sectional structure;

[0035] Figure 4 for Figure 2 Exploded view of the valve needle sleeve and valve needle base;

[0036] Figure 5 for Figure 4 A schematic diagram of the cross-sectional structure of the valve needle base;

[0037] Figure 6 for Figure 4 A schematic diagram of the cross-sectional structure of the valve needle sleeve.

[0038] Explanation of icon numbers:

[0039] 10. Valve seat; 11. Large valve port;

[0040] 20. Connecting seat;

[0041] 30. Rotor assembly; 31. Limiting plate; 32. Lead screw;

[0042] 33. Bearings;

[0043] 40. Nuts;

[0044] 50. Small valve needle;

[0045] 60. Large valve needle; 60a. Balance channel; 61. Small valve port; 62. Mounting cavity; 63. Valve needle base; 63a. Base part; 63b. Journal neck; 63b1. Longitudinal sectional plane; 63c. Stepped surface; 63c1. Air guide hole; 63d. Flow guide gap; 631. First guide hole; 64. Valve needle sleeve; 641. Second guide hole; 642. Flow guide hole; 643. Guide cone surface;

[0046] 70. Elastic reset component;

[0047] 80. Abutment structure.

[0048] 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

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] Taking the valve needle assembly (large valve needle / small valve needle) as the research object, if there is a pressure difference between the upper and lower parts of the valve needle assembly, the resistance is very large, and the product is difficult to operate. Therefore, it is necessary to design a simple and reasonable pressure difference balancing channel to achieve the balance of the pressure difference between the upper and lower parts of the valve needle assembly.

[0054] The traditional design of the internal balance channel in an electronic expansion valve consists of a through-flow hole at the center of the small valve needle and a lateral connecting hole at the upper end of the small valve needle, thus forming the internal balance channel. Considering that dual-valve-needle electronic expansion valves need to accommodate large-diameter, full-flow functions, the large valve port has a relatively large diameter. However, in the small-flow regulation range, precise flow control is required, resulting in a wide variety of small valve port diameters, generally between 1.3mm and 3.2mm. The optimal diameter for the internal balance hole is 1.6mm or larger. This makes it impossible to machine the internal balance hole in some small-diameter dual-valve-needle electronic expansion valves. For some slightly larger-diameter valve needles, machining a 1.6mm internal balance hole is extremely difficult, leading to a high valve needle scrap rate (drilling the center hole of the valve needle carries the risk of breaking through the outer wall).

[0055] In summary, the original internal balance design makes the product unsuitable for platform-based, standardized, and serialized development. Furthermore, the valve needle is very difficult to process, and it may be impossible to process slender holes, or the scrap rate is very high, which affects the overall cost of product components and thus the product's market competitiveness.

[0056] In addition, forced processing can also cause deformation of the conical seal of the small valve needle, affecting the seal between the small valve needle and the small valve port, leading to excessive internal leakage, failure, or even jamming.

[0057] Therefore, this utility model proposes a dual-valve needle electronic expansion valve.

[0058] Please see Figures 1 to 6 In one embodiment of the present invention, the dual-valve needle electronic expansion valve includes a large valve needle 60, the large valve needle 60 includes a valve needle base 63 and a valve needle sleeve 64 axially sleeved on the valve needle base 63; the large valve needle 60 is provided with a balance channel 60a, the balance channel 60a passing through the valve needle base 63 and the valve needle sleeve 64.

[0059] This invention solves the problems of difficult machining, high scrap rate, and unsuitability for standardized production associated with traditional internal balance channel 60a designs on small valve needles 50 by creating a balance channel 60a on the large valve needle 60. By transferring the balance channel 60a from the small valve needle 50 to the large valve needle 60, the machining of elongated holes on the small valve needle 50 is avoided, thus reducing machining difficulty and scrap rate. By uniformly designing the balance channel 60a on the large valve needle 60, products of different specifications can share a similar large valve needle 60 design, facilitating platform-based development. The balance channel 60a can be machined separately on the valve needle base 63 and the sleeve, avoiding the complexity of simultaneously machining the inner hole and outer shape of the traditional integral large valve needle 60, which could affect the machining of the sealing surface of the valve needle base 63 or cause deformation of the sealing surface.

[0060] In this way, the processing challenges of the small valve needle 50 can be transferred to the large valve needle 60. By leveraging the split design of the large valve needle 60 and its structural advantages of having more ample wall thickness and stronger resistance to deformation, the manufacturing process can be reduced in cost. At the same time, the bottleneck of platform development can be solved through modularization and standardization, ultimately achieving synergistic optimization of "high-precision control - high reliability - low-cost manufacturing". This will clear technical obstacles for the large-scale application of dual-valve needle electronic expansion valves in scenarios such as variable frequency air conditioners and thermal management of new energy vehicles.

[0061] The main structure of the dual-valve needle electronic expansion valve consists of an electromagnetic drive module (stator coil), a transmission mechanism, and a valve body assembly.

[0062] In one embodiment, the large valve needle 60 of this solution is used in a dual-valve needle electronic expansion valve scheme where the lead screw 32 moves axially and the nut 40 is fixed. Specifically, the nut 40 is fixed to the valve seat 10, the lead screw 32 is threadedly connected to the nut 40, and it rotates under the electromagnetic force of the stator coil and moves up and down axially. The lead screw 32 is connected to the large valve needle 60, and the small valve needle 50 is closed by the action of a spring; or the lead screw 32 is connected to the small valve needle 50, and the large valve needle 60 is closed by the action of a spring. The structure of the slip ring and the ring rail realizes the upper and lower stops to achieve the opening and closing limit of the valve needle.

[0063] Reference Figure 1 In one embodiment, in order to avoid the radial gap between the rotor and the stator coil shifting during dynamic processes, which would cause radial misalignment between the rotor and the stator coil (not shown in the figure) and thus reduce the electromagnetic driving force, the large valve needle 60 of this solution is used in a double valve needle electronic expansion valve solution where the lead screw 32 fixes the rotation and the nut 40 moves axially.

[0064] The transmission mechanism includes a lead screw 32 (connected to the rotor), a nut 40 (linked with the valve needle), and a limiting structure, which are responsible for converting rotational motion into axial displacement.

[0065] Lead screw 32: The rigid shaft of the transmission mechanism, coaxially connected to the rotor.

[0066] 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.

[0067] Large / small valve needles (60, 50): The actuators of the valve body assembly, responsible for main flow regulation and fine-tuning compensation, respectively.

[0068] 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.

[0069] The valve seat 10 has a medium inflow pipe interface on its side wall. 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.

[0070] The stator coil is installed on the outer side 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.

[0071] The screw 32 is axially fixed and the nut 40 is movable. The rotor only rotates around the shaft (without axial movement). The stator coil and 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 traditional solutions, improves the attenuation of electromagnetic driving force, and ensures that stable driving force can still be output even with a large stroke (such as 8-10mm).

[0072] The top of the valve needle base 63 and the bottom of the valve needle sleeve 64 form an installation cavity 62. The installation cavity 62 is connected to the flow guide gap 63d, and the abutment structure 80 is provided in the installation cavity 62.

[0073] 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.

[0074] Combination Figure 3 The abutment structure 80 is integrated into the mounting cavity 62 of the large valve needle 60. The valve needle base 63 has a first guide hole 631 through the center. The valve needle sleeve 64 has a second guide hole 641 arranged coaxially with the guide hole at the top. The small valve needle 50 passes through and is clearance-fitted with the first guide hole 631 and the second guide hole 641.

[0075] By utilizing the stepped inner diameter difference between the top of the valve needle base 63 and the valve needle sleeve 64, 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).

[0076] Reference Figure 1 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.

[0077] 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.

[0078] Specifically, the lead screw 32 has a bearing limiting part, the bearing 33 passes through the lead screw 32 and abuts against the bearing limiting part, the limiting plate 31 is welded to the end of the lead screw 32, and a bearing 33 pressure plate 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.

[0079] In other solutions, two sets of angular contact ball bearings 33 (back-to-back installation) can be embedded in the connecting seat 20, with the lead screw 32 passing through the inner ring of the bearing 33 and pre-tightened by the lock nut 40 to achieve bidirectional axial positioning. Alternatively, a self-lubricating copper alloy bushing can be provided 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 in the connecting seat 20, achieving pure rotational motion of the lead screw 32 (without axial displacement) through ball circulation.

[0080] Reference Figures 2 to 6 Specifically, the large valve needle 60 includes a valve needle sleeve 64 and a valve needle base 63. The valve needle base 63 is embedded in the valve needle sleeve 64 and defines a mounting cavity 62. The valve needle channel and the small valve port 61 are located in the valve needle base 63. Traditionally, the large valve needle 60 is usually integrally molded. By using a split design, the manufacturing and assembly process can be optimized. Specifically, the split design allows the use of different materials. For example, the valve needle sleeve 64 can be made of a high-strength material, and the valve needle base 63 can be made of a wear-resistant or corrosion-resistant material, thereby improving overall durability.

[0081] The valve needle base 63 is inserted into the valve needle sleeve 64 with an interference fit and fixed by laser welding, resulting in minimal overall coaxiality error. The valve needle base 63 defines a mounting cavity 62, providing installation space for the abutment protrusion on the outer wall of the nut 40. The abutment protrusion on the outer wall of the nut 40 is placed within the mounting cavity 62. When the nut 40 moves along the lead screw 32, the abutment protrusion 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 acts directly on the mounting cavity 62, transmitting driving force more directly, reducing energy loss, and improving response speed.

[0082] Furthermore, a limiting structure is provided between the large valve needle 60 and the valve seat 10; or a limiting structure is provided between the large valve needle 60 and the connecting seat 20, to restrict the axial movement of the large valve needle 60. In this embodiment, the limiting structure is an abutment protrusion formed on the outer edge of the bottom of the valve needle sleeve 64, combined with... Figure 1 After the abutting protrusion moves upward in the axial direction, it will abut against the edge of the channel of the valve seat 10 for the large valve needle 60 to move, thereby restricting the axial movement of the large valve needle 60.

[0083] Combination Figures 3 to 6Specifically, the valve needle base 63 includes a base portion 63a and a journal 63b extending axially from the base portion 63a. The outer diameter of the journal 63b is smaller than the outer diameter of the base portion 63a, thus forming a stepped surface 63c in the base portion 63a. The base portion 63a is provided with a vent hole 63c1 that penetrates the stepped surface 63c. The valve needle sleeve 64 is sleeved on the outside of the journal 63b, with its bottom abutting against the stepped surface 63c, and forming a flow guide gap 63d between it and the journal 63b. The vent hole 63c1 communicates with the flow guide gap 63d. The valve needle sleeve 64 is provided with a flow guide hole 642 that communicates with the flow guide gap 63d. The flow guide hole 642, the flow guide gap 63d, and the vent hole 63c1 constitute a balance channel 60a.

[0084] Reference Figure 4 The valve needle base 63 is divided into a base portion 63a and a journal portion 63b. The journal portion 63b has a smaller outer diameter, forming a stepped surface 63c. The base portion 63a has a vent hole 63c1 (corresponding to the large valve port 11). The sleeve is fitted onto the outside of the journal portion 63b, with its bottom abutting against the stepped surface 63c, forming a flow guide gap 63d. The vent hole 63c1, the flow guide gap 63d, and the flow guide hole 642 on the sleeve together constitute a balance channel 60a.

[0085] Specifically, the stepped surface 63c is annular. On the one hand, the annular stepped surface 63c can provide a uniform support surface, making the sleeve more evenly distributed when subjected to axial force; and the annular feature can be efficiently completed by conventional processes such as turning, reducing complex procedures. On the other hand, considering the flow of fluid in the guide gap 63d, the annular stepped surface 63c may help the fluid to be evenly distributed, avoiding turbulence or local high-pressure areas, thereby improving the efficiency of the balance channel 60a; and the annular feature has self-centering properties, requiring no complex adjustment during assembly, and the sleeve and base 63a can be pressed into place in one step by axial pressing, improving assembly efficiency.

[0086] Specifically, to improve pressure balancing efficiency, a flow guide hole 642 is located at the top of the valve needle sleeve 64. This top-mounted flow guide hole 642 more effectively guides refrigerant flow. When the valve needle moves, the refrigerant enters the balancing channel 60a through the flow guide hole 642, thereby balancing the upstream and downstream pressures. The top position allows for rapid pressure balancing at the initial stage of valve opening, reducing flow fluctuations. Furthermore, considering ease of processing and assembly, the top position makes drilling easier, reducing processing difficulty and improving yield. Simultaneously, this design may result in a more compact structure, reducing the number of parts and lowering costs.

[0087] Combined with reference Figure 5 and Figure 6Specifically, multiple guide holes 642 are provided at intervals along the step surface 63c. The specifications (number / diameter) of the guide holes 642 can be adjusted according to the outer diameter of the sleeve. For example, 1, 2, 3 or more guide holes 642 are provided on the step surface 63c.

[0088] Specifically, the diameter of the guide hole 642 is 0.8mm-2mm. Specifically, the guide hole 642 is located at the top of the valve needle sleeve 64 and is used for pressure balancing and flow control. The size of the hole directly affects the flow characteristics of the fluid, such as flow rate, pressure drop and the accuracy of flow regulation.

[0089] Different applications require different balancing effects. For example, under high pressure or high flow conditions, a larger orifice diameter may be needed to quickly balance the pressure, while a smaller orifice diameter may be more suitable for scenarios requiring precise control. Setting this orifice diameter range is to ensure sufficient pressure balancing capability while avoiding structural strength problems caused by an excessively large orifice diameter, or the risk of clogging caused by an excessively small orifice diameter. Furthermore, the orifice diameter also affects the manufacturing difficulty, so a balance must be struck between machinability and performance; and the multiple guide holes 642, compared to setting a guide hole axially in the small valve needle 50, can also quickly balance the pressure.

[0090] Reference Figure 4 Specifically, the journal 63b has a longitudinal cutting plane 63b1 along its axial direction corresponding to the guide hole 642. The longitudinal cutting plane 63b1 refers to the planar structure cut along the axial direction of the journal 63b. In order to optimize the fluid channel to match the position of the guide hole 642 and ensure the effective flow area of ​​the guide hole 642, the longitudinal cutting plane 63b1 can form a guide groove in the journal 63b, guiding the fluid to pass through the guide hole 642 more effectively and reducing the generation of eddies. In addition, when the journal 63b is provided with the longitudinal cutting plane 63b1, the longitudinal cutting plane 63b1 serves as a reference plane to ensure the positioning accuracy when the guide hole 642 is laser-drilled.

[0091] Reference Figure 3 and Figure 6 Furthermore, the inner wall of the valve needle sleeve 64 is provided with a guide cone surface 643 corresponding to the guide hole 642. The guide cone surface 643 extends obliquely from the bottom of the valve needle sleeve 64 towards the guide gap 63d. The guide cone surface 643 can be used to guide fluid flow and reduce turbulence or pressure drop. The oblique extension helps the refrigerant enter the guide gap 63d more smoothly, avoiding sudden changes in flow direction that could cause eddies or increased resistance. In addition, corresponding to the position of the guide hole 642, the guide cone surface 643 can help the fluid accurately enter the through hole, improving efficiency.

[0092] Specifically, the guide cone 643 is configured as an annular shape, that is, a conical chamfer is provided on the inner wall of the valve needle sleeve 64. The annular structure can usually provide a uniform force distribution and reduce local stress concentration. In addition, the annular cone may help guide the fluid to flow uniformly, avoid turbulence, and reduce pressure drop.

[0093] Specifically, the angle between the inclined direction of the guide cone surface 643 and the step surface 63c is 60°-70°. If the angle is too small, it may cause poor fluid flow, while if it is too large, it may affect the structural strength or sealing performance. In addition, considering the manufacturing process, such as the difficulty of machining the cone chamfer, the precision control of the angle, and the impact of the ring structure on assembly, the angle is set within the above-mentioned range.

[0094] This utility model also proposes a compressor, which includes a dual-valve needle electronic expansion valve. The specific structure of the dual-valve needle electronic expansion valve is as 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.

[0095] This utility model also proposes a refrigeration device, which includes the above-mentioned compressor or a dual-valve needle electronic expansion valve. The specific structure of the dual-valve needle electronic expansion valve is as described in the above embodiments. Since this 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.

[0096] 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: A large valve needle, wherein a balance channel is provided on the large valve needle; the large valve needle includes: Valve needle base; and A valve needle sleeve is axially sleeved onto the valve needle base; wherein, the balance channel passes through the valve needle base and the valve needle sleeve.

2. The dual-valve needle electronic expansion valve as described in claim 1, characterized in that, The valve needle base includes a base portion and a journal extending axially from the base portion. The outer diameter of the journal is smaller than the outer diameter of the base portion, thus forming a stepped surface on the base portion. The base portion is provided with a vent hole penetrating the stepped surface. The valve needle sleeve is sleeved on the outside of the journal, with its bottom abutting against the stepped surface and forming a flow guide gap with the journal; the air guide hole communicates with the flow guide gap, and the valve needle sleeve is provided with a flow guide hole communicating with the flow guide gap. The flow guide hole, the flow guide gap and the air guide hole constitute the balance channel.

3. The dual-valve needle electronic expansion valve as described in claim 2, characterized in that, The stepped surface is annular.

4. The dual-valve needle electronic expansion valve as described in claim 2, characterized in that, The guide hole is located at the top of the valve needle sleeve.

5. The dual-valve needle electronic expansion valve as described in claim 2, characterized in that, Multiple guide holes are provided at intervals along the stepped surface.

6. The dual-valve needle electronic expansion valve as described in claim 2, characterized in that, The diameter of the guide hole is 0.8mm-2mm.

7. The dual-valve needle electronic expansion valve as described in claim 2, characterized in that, The journal is provided with a longitudinal cutting plane corresponding to the guide hole along the axial direction.

8. The dual-valve needle electronic expansion valve as described in claim 2, characterized in that, The inner wall of the valve needle sleeve is provided with a guide cone surface corresponding to the guide hole, and the guide cone surface extends obliquely from the bottom of the valve needle sleeve toward the guide gap.

9. The dual-valve needle electronic expansion valve as described in claim 8, characterized in that, The guide cone surface is configured as an annular shape; and / or, the angle between the tilt direction of the guide cone surface and the step surface is 60°-70°.

10. The dual-valve needle electronic expansion valve as described in claim 2, characterized in that, The dual-valve needle electronic expansion valve also includes: Valve seat with large valve port The connecting seat is fixedly connected to the valve seat; A lead screw, which passes through the connecting seat, and is axially fixed and rotatably mounted on the connecting seat; The rotor assembly includes a limiting plate, and the end of the lead screw is fixed to the limiting plate; 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 resilient reset element is disposed within the valve seat; The large valve needle is also provided with a small valve port, and the small valve needle is movably inserted through the large valve needle; wherein, when the small valve needle seals the small valve port, the elastic reset member causes the large valve needle to seal the large valve port; 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.

11. The dual-valve needle electronic expansion valve as described in claim 10, characterized in that, The top of the valve needle base and the bottom of the valve needle sleeve form an installation cavity, the installation cavity is connected to the flow guide gap, and the abutment structure is disposed in the installation cavity.

12. The dual-valve needle electronic expansion valve as described in claim 10, characterized in that, The valve needle base has a first guide hole through the center, and the top of the valve needle sleeve has a second guide hole arranged coaxially with the first guide hole. The small valve needle passes through and is clearance-fitted with the first guide hole and the second guide hole.

13. A refrigeration device, characterized in that, Includes the dual-valve needle electronic expansion valve as described in any one of claims 1 to 12.

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