Electronic expansion valve and refrigeration apparatus

Abstract

The application discloses an electronic expansion valve and refrigeration equipment, and relates to the technical field of electronic expansion valves, wherein the electronic expansion valve comprises a valve seat, a nut for mounting the valve seat, a screw rod penetrating the nut, a stop mechanism and a rotor assembly, the outer wall of the nut is provided with a guide groove, the same limiting convex platform as the spiral direction of the spiral groove, a first stop convex platform and a second stop convex platform arranged at the axial two ends of the spiral groove respectively, the stop mechanism comprises a spiral ring arranged in the guide groove, the rotor assembly comprises a limiting plate fixed with the end of the screw rod and a guide rod arranged in the limiting plate, the guide rod is matched with the bent end of the end of the spiral ring, the screw rod has an opening station where the bent end is in contact with the second stop convex platform, and the limiting convex platform is inserted between the upper ring segment and the lower ring segment to form an interference fit so as to limit the axial movement of the screw rod downwards, thereby solving the problem that the valve port is closed due to the axial movement of the screw rod caused by vibration or external force during transportation or assembly.

Description

Technical Field

[0001] This invention relates to the field of electronic expansion valve technology, and particularly to an electronic expansion valve and a refrigeration device. Background Technology

[0002] The electronic expansion valve is a core throttling element in refrigeration / heat pump systems, achieving precise temperature control by regulating refrigerant flow. The electronic expansion valve consists of a valve body assembly and a coil assembly surrounding the valve body assembly. These components are transported separately, and the equipment experiences random vibrations during transport, which may cause the lead screw to shift and close the valve port. After reassembly, the valve port needs to be manually or electrically reopened, increasing operational complexity and time costs. Summary of the Invention

[0003] The main objective of this invention is to provide an electronic expansion valve and a refrigeration device, which aims to solve the problem that during transportation or assembly, due to vibration or external force, the lead screw may move axially, causing the valve port to close. After the valve port closes unexpectedly, it needs to be manually or electrically reopened after assembly, which increases the complexity of operation and time cost.

[0004] To achieve the above objectives, the electronic expansion valve proposed in this invention includes: Valve seat; The nut assembly includes a nut connected to the valve seat, the outer wall of the nut having an axially extending helical groove, a first stop protrusion at the lower end of the helical groove, a second stop protrusion at the upper end of the helical groove, and a limiting boss located below the second stop protrusion along the helical direction. A lead screw is movably inserted through the nut; The stop mechanism includes a spiral coil formed by helical winding; and The rotor assembly includes a limiting plate fixed to the end of the lead screw, the limiting plate having an axially extending guide rod that engages with the spiral ring; When the spiral ring contacts the second stop protrusion, the limiting boss inserts into the gap of the spiral ring to form an interference fit with the spiral ring.

[0005] In one embodiment, the spiral coil extends at both ends to form a stop end and a bend end, respectively, and the spiral coil includes an upper ring segment and a lower ring segment spaced apart from each other; The guide rod engages with the bent end; When the bent end contacts the second stop protrusion, the limiting boss is inserted between the upper ring segment and the lower ring segment.

[0006] In one embodiment, the maximum thickness of the limiting protrusion is L, and the effective spiral spacing between the upper ring segment and the lower ring segment in the free state is D, with the interference satisfying: 0.01mm≤LD≤0.2mm.

[0007] In one embodiment, the limiting protrusion is further provided with a wedge-shaped guide block at the end in the direction of insertion of the spiral ring.

[0008] In one embodiment, the wedge-shaped guide block includes two opposing guide ramps that form an angle θ in the extending direction, satisfying: 10°≤θ≤30°.

[0009] In one embodiment, the spiral groove extends in a spiral shape, and its spiral pitch P satisfies 1.0 mm ≤ P ≤ 3.0 mm.

[0010] In one embodiment, the valve seat is provided with a valve core seat, the valve core seat is provided with a valve port, and the lead screw includes a tapered valve needle that cooperates with the valve port. A preset gap between the tapered valve needle and the inner wall of the valve port forms a medium flow channel.

[0011] In one embodiment, the conical valve needle includes a coaxially arranged cylindrical straight-wall section and a variable-diameter conical section. The outer diameter of the cylindrical straight-wall section is smaller than that of the valve stem portion and is connected to the valve stem portion by means of a transition slope. The cylindrical straight-wall section cooperates with the inner wall of the valve port to form the medium flow channel, and the transition slope guides the medium into the medium flow channel.

[0012] In one embodiment, the valve core seat is further provided with a horn-shaped guide cone at the valve inlet, the cone angle of the guide cone being greater than the cone angle of the transition slope, and the transition slope and the guide cone cooperate to form a gradually narrowing guide channel.

[0013] In one embodiment, the inner diameter of the medium flow channel is d, where 0.01 mm ≤ d ≤ 0.6 mm.

[0014] In one embodiment, the inner hole of the nut is formed from bottom to top with a first guide hole section, a threaded hole section and a second guide hole section, and the inner hole diameter decreases in a stepped manner; The lead screw also includes a valve stem portion that slides with the first guide hole section, a threaded portion that meshes with the threaded hole section, and a smooth rod portion extending from the top of the nut. The smooth rod portion includes a guide end that slides with the second guide hole section and a drive end located at the end of the smooth rod portion. The outer diameter of the drive end is smaller than the outer diameter of the guide end, forming a stop step that limits the positioning plate.

[0015] The present invention also proposes a refrigeration device, including the electronic expansion valve as described above.

[0016] The technical solution of this invention utilizes a limiting boss on the outer wall of the nut and a spiral ring design for the stop mechanism. In the open position, the limiting boss and the spiral ring form an interference fit to restrict the downward axial movement of the lead screw, thereby maintaining the valve port open. This solves the problem that during transportation or assembly, the lead screw may move axially due to vibration or external forces, causing the valve port to close. The structural design ensures the stability of the lead screw in the open position, preventing accidental valve closure and eliminating the need for repeated valve opening operations. The interference fit between the limiting boss and the spiral ring ensures the stability of the lead screw in the open position, improving the reliability and stability of the electronic expansion valve and reducing the risk of system failure. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 A schematic diagram of an embodiment of the electronic expansion valve provided by the present invention; Figure 2 for Figure 1 A schematic diagram of the structure when the middle spiral ring contacts the second stop protrusion; Figure 3 for Figure 2 A schematic diagram of the disassembled structure of the helical coil and nut; Figure 4 for Figure 1 Enlarged view of point A in the middle.

[0019] Explanation of icon numbers: 1. Valve seat; 12. Valve core seat; 12a. Valve port; 12a1. Trumpet-shaped guide cone surface; 2. Nut assembly; 21. Nut; 21a. First guide hole section; 21b. Threaded hole section; 21c. Second guide hole section; 22. Spiral groove; 23. Limiting boss; 23a. Wedge-shaped guide block; 23a1. Guide slope; 24a. First stop protrusion; 24b. Second stop protrusion; 3. Lead screw; 31. Conical valve needle; 31a. Cylindrical... 31b, Straight wall section; 31c, Variable diameter conical section; 31d, Valve stem section; 32, Transition slope; 33, Threaded section; 33, Smooth rod section; 33a, Guide end; 33b, Drive end; 33c, Stop step; 4, Stop mechanism; 41, Spiral ring; 41a, Stop end; 41b, Bent end; 42, Upper ring section; 43, Lower ring section; 5, Rotor assembly; 51, Limiting plate; 52, Guide rod; 6, Medium flow channel; 7, Gradually contracting guide channel.

[0020] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] It should be noted that if the embodiments of the present invention 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.

[0023] Furthermore, if the embodiments of this invention 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. Thus, 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 invention.

[0024] The electronic expansion valve is a core throttling element in refrigeration / heat pump systems, achieving precise temperature control by regulating refrigerant flow. The electronic expansion valve consists of a valve body assembly and a coil assembly surrounding the valve body assembly. These components are transported separately, and the equipment experiences random vibrations during transport, which may cause the lead screw to shift and close the valve port. After reassembly, the valve port needs to be manually or electrically reopened, increasing operational complexity and time costs.

[0025] Traditional designs rely on nut locking or spring retaining rings, but the locking force is easily attenuated under vibration. However, strengthening the locking structure sacrifices operational flexibility, leading to adjustment lag or jamming.

[0026] The technical problem is characterized by its insidious nature. Firstly, valve closure issues typically only become apparent after transportation or assembly, rather than being directly exposed during the design or production stages. For example, the lead screw may slowly descend during transport due to bumps and jolting, but the critical condition might not have been triggered during factory testing. Secondly, the problem involves multiple coupled factors: vibration, temperature changes, material creep, and other factors work together, making it difficult to attribute to a single cause. For instance, low temperatures may exacerbate the shrinkage of the plastic spiral coil, leading to increased clearance.

[0027] Furthermore, it is easy to fall into preconceived notions and cognitive inertia. Traditional design assumes that "the structure is stable after static assembly," ignoring the cumulative displacement under dynamic conditions. For example, engineers' experience assumes that tightening the lock nut is sufficient to fix the lead screw. In typical installation scenarios, problems are often discovered on the front line, and due to the limitations of the job requirements of those skilled in the art, the problem is attributed to an "isolated case" rather than a systemic defect.

[0028] This invention proposes an electronic expansion valve to solve the problem that during transportation or assembly, the lead screw may move axially due to vibration or external force, causing the valve to close. After the valve closes unexpectedly, it needs to be manually or electrically reopened after assembly, which increases the complexity of operation and time cost.

[0029] Please see Figures 1 to 4 In one embodiment of the present invention, the electronic expansion valve includes a valve body assembly and a coil assembly, the coil assembly being disposed on the outer periphery of the valve body assembly.

[0030] The valve body assembly includes valve seat 1, nut assembly 2, lead screw 3, rotor assembly 5, housing, stop mechanism 4, etc.

[0031] The valve seat 1 has a medium port on its outer periphery and an axially extending mounting port at its bottom. A connecting pipe is embedded in the medium port and sealed by welding. A valve core seat 12 is embedded in the mounting port. The exposed end of the valve core seat 12 forms a sleeve, and its interior has a valve port 12a that communicates with the medium port. The connecting pipe is sleeved onto the sleeve of the valve core seat 12 and then sealed to the valve seat 1, such as by welding, to ensure sealing.

[0032] The valve port 12a of the valve core seat 12 cooperates with the conical valve needle 31 to control the refrigerant flow.

[0033] Nut 21 is fixedly connected to valve seat 1. An annular connector is sleeved and fixed to the top of nut 21 and connected as a whole, such as by injection molding. The edge of the annular connector abuts against the top edge of valve seat 1 and is welded and fixed.

[0034] To limit the axial movement of the lead screw 3 and ensure that the electronic expansion valve does not need to be repeatedly opened after assembly, this addresses the problem of the lead screw 3 easily moving axially during transportation and assembly, causing the valve port 12a to close.

[0035] Combination Figure 2 and Figure 3 The outer wall of the nut 21 is provided with an axially extending spiral groove 22, a limiting boss 23 with the same spiral direction as the spiral groove 22, and a first stop protrusion 24a and a second stop protrusion 24b respectively provided at both ends of the spiral groove 22. The second stop protrusion 24b is close to the upper end of the axial direction of the nut 21, and the limiting boss 23 is provided adjacent to the second stop protrusion 24b. The first stop protrusion 24a and the second stop protrusion 24b are used to limit the axial movement range of the lead screw 3.

[0036] The spiral groove 22 is arranged around the outer wall of the nut 21, that is, the outer wall.

[0037] The stop mechanism 4 includes a spiral coil 41 formed by spiral winding. The two ends of the spiral coil 41 extend to form a stop end 41a with a limiting function and a bent end 41b that is linked with the rotor. The spiral coil 41 includes an upper ring section 42 and a lower ring section 43 that are spaced apart. The lead screw 3 is coaxially inserted through the nut 21.

[0038] The lead screw 3 includes a tapered valve needle 31 that mates with the valve port 12a and a drive end 33b extending from the top of the nut 21; the rotor assembly 5 includes a limiting plate 51 fixed to the drive end 33b, the tapered valve needle 31 mates with the valve port 12a, and controls the opening and closing of the valve port 12a. The limiting plate 51 is provided with a guide rod 52 extending axially parallel to the nut 21; the guide rod 52 forms a motion coupling with the bent end 41b; wherein, the lead screw 3 has a closed position defined by the contact between the stop end 41a and the second stop protrusion 24b, and in the closed position, the limiting boss 23 is inserted between the upper ring section 42 and the lower ring section 43 to form a radial interference fit.

[0039] The limiting boss 23 has the same spiral direction as the spiral groove 22 and is located near the second stop protrusion 24b. It is used to limit the further downward movement of the screw 3 by forming a radial interference fit between the upper and lower ring sections 43 of the inserted spiral ring 41 when the screw 3 reaches the opening position.

[0040] During the assembly of the electronic expansion valve, the lead screw 3 is coaxially inserted into the nut 21. The spiral ring 41 of the stop mechanism 4 is linked with the rotor through its bent end 41b, ensuring that the spiral ring 41 can move with the rotor when it rotates. When the lead screw 3 moves upward to the open position, its stop end 41a contacts the second stop protrusion 24b. At the same time, the limiting boss 23 is inserted between the upper and lower ring sections 43 of the spiral ring 41, which also plays an auxiliary limiting role. That is, the interference fit between the limiting boss 23 and the upper ring section 42 and the lower ring section 43 creates a friction force that is greater than the friction force when the lead screw 3 moves freely. This interference fit restricts the further downward movement of the lead screw 3, thereby ensuring that the valve port 12a remains in the open state and preventing the valve port 12a from being accidentally closed.

[0041] The design of the outer wall of nut 21, lead screw 3, and stop mechanism 4 effectively restricts the axial movement of lead screw 3, and the structure is compact, not occupying too much space. In the open position, the interference fit between the limiting boss 23 and the spiral ring 41 ensures the stability of lead screw 3 and effectively prevents accidental closure of valve port 12a. When lead screw 3 runs to the open position, "running lock" is achieved through the interference fit between limiting boss 23 and spiral ring 41, balancing transportation stability and operational flexibility.

[0042] The technical solution of this invention, through the design of the limiting boss 23 on the outer wall of the nut 21 and the spiral ring 41 of the stop mechanism 4, forms a radial interference fit in the open position, restricting the further downward movement of the lead screw 3, thereby keeping the valve port 12a open. This solves the problem that during transportation or assembly, the lead screw 3 may move axially due to vibration or external force, causing the valve port 12a to close. The structural design ensures the stability of the lead screw 3 in the open position, avoiding accidental closure of the valve port 12a, thus eliminating the need for repeated valve opening operations. The interference fit between the limiting boss 23 and the spiral ring 41 ensures the stability of the lead screw 3 in the open position, improving the reliability and stability of the electronic expansion valve and reducing the risk of system failure. Through the ingenious design of the outer wall of the nut 21, the lead screw 3, and the stop mechanism 4, the axial movement of the lead screw 3 is effectively restricted, and the structure is compact, not affecting the normal assembly process. Compared with the traditional solution of fitting a guide component on the outer wall of the nut 21, it also simplifies the assembly steps.

[0043] During assembly, first pre-assemble the lead screw 3 and nut 21, inserting the lead screw 3 coaxially into the nut 21, ensuring that the drive end 33b extends beyond the top of the nut 21. Then install the stop mechanism 4, fitting the spiral ring 41 onto the lead screw 3, so that its bent end 41b is linked with the rotor assembly 5. Adjust the position of the spiral ring 41 to ensure that the stop end 41a and the second stop protrusion 24b have a gap (for interference fit of the opening station). Then connect the rotor assembly 5 to the lead screw 3, fix the limiting plate 51 to the drive end 33b of the lead screw 3, and align the guide rod 52 parallel to the nut 21; verify that when the rotor rotates, the guide rod 52 can drive the lead screw 3 to move axially. Next, perform station debugging by manually rotating the rotor to move the lead screw 3 to the open position (where the stop end 41a contacts the second stop protrusion 24b). At this time, the limiting boss 23 should be precisely inserted between the upper ring section 42 and the lower ring section 43 of the spiral ring 41, forming a radial interference fit (the interference amount needs to be controlled according to the design tolerance, such as 0.05mm, 0.1mm, 0.15mm, etc.). For testing, apply a preset force to the lead screw 3 and check whether the lead screw 3 has shifted.

[0044] Combination Figure 3 Furthermore, the maximum thickness of the limiting protrusion is L, and the effective spiral spacing between the upper ring segment 42 and the lower ring segment 43 in the free state is D, with the interference satisfying: 0.01mm≤LD≤0.2mm.

[0045] Interference fit (LD): The amount of "extrusion" between the limiting protrusion and the spiral ring 41 when the limiting protrusion is inserted into the spiral ring 41. The minimum value (≥0.01mm) ensures that the limiting protrusion can "bite" the spiral ring 41, preventing the lead screw 3 from shifting downward due to vibration or external force. Just like when a key is inserted into a lock hole, the teeth must be slightly stuck, otherwise it will fall off with a slight wobbling. The maximum value (≤0.2mm) avoids excessive extrusion that could cause deformation or wear of the spiral ring 41, while ensuring that excessive external force is not required during assembly. Just like a key with too deep teeth will get stuck and cannot be pulled out, while one with too shallow teeth will not be able to lock.

[0046] When the lead screw 3 moves upward to the open position, the limiting protrusion is precisely inserted between the segments of the spiral ring 41, forming an interference fit. The interference causes the spiral ring 41 to be "spread out" and press tightly against the limiting protrusion, generating friction and preventing the lead screw 3 from moving downward. If it is necessary to close the valve port 12a, the lead screw 3 is rotated in the opposite direction, and the limiting protrusion exits from the spiral ring 41, restoring free sliding (the force required is greater than the preload of the interference fit). In this way, even if the equipment experiences severe bumps (such as truck transportation), the interference fit can keep the lead screw 3 in a stable position. It is convenient to implement and requires no special tools; the spiral ring 41 can be manually fitted onto the lead screw 3 to complete the interference fit.

[0047] Explanation of parameters L and D: L: Maximum thickness of the limiting protrusion (vertical distance of the protruding part on the outer wall of nut 21), starting point: outer wall plane of nut 21 (root of the limiting protrusion), ending point: highest point of the top of the limiting protrusion.

[0048] D: Effective helical spacing of helical ring 41 in free state (vertical distance between upper ring 42 and lower ring 43), starting point: the lowest point inside upper ring 42 of helical ring 41 (helical starting end), ending point: the lowest point inside lower ring 43 of helical ring 41 (adjacent helical starting end).

[0049] Specifically, a wedge-shaped guide block 23a is provided at the end of the limiting protrusion in the insertion direction of the spiral ring 41. The limiting protrusion and the second stop protrusion 24b are continuous along the rotational path of the outer wall of the nut 21 (the limiting protrusion and the second stop protrusion 24b can be connected together or disconnected, but they are on the same path), which can satisfy the requirement that the limiting protrusion 23 is inserted into the upper ring segment 42 and the lower ring segment 43 to form an interference fit in the open position. The wedge-shaped guide block 23a is located at the end of the limiting protrusion in the insertion direction of the spiral ring 41 (i.e., the front end of the limiting protrusion that contacts the spiral ring 41).

[0050] Combination Figure 3Specifically, the wedge-shaped guide block 23a includes two opposing guide ramps 23a1, which form an angle θ in the extending direction, satisfying 10°≤θ≤30°, to guide the spiral coil 41 to be inserted smoothly and avoid excessively large angles (such as 60°), which may cause the spiral coil 41 to "jump" or be mispositioned during insertion. When the spiral coil 41 is inserted, the wedge-shaped ramps decompose the radial compressive force into axial guiding force, reducing the risk of jamming.

[0051] Furthermore, the spiral groove 22 extends in a spiral shape, and its spiral pitch P satisfies 1.0mm≤P≤3.0mm. The spiral groove 22 extends in a spiral shape and cooperates with the spiral ring segment of the spiral ring 41 to guide the spiral ring 41 to move axially, while restricting its radial displacement, thus ensuring the synchronous movement of the lead screw 3 and the spiral ring 41.

[0052] The helical pitch is the axial distance between two adjacent turns of the helix, similar to the tooth pitch of a gear. Too large a pitch causes jamming, while too small a pitch increases friction. A suitable pitch ensures that the helical ring 41 experiences uniform force during axial movement, reducing vibration and noise. Furthermore, the helical pitch matches the inter-ring spacing D of the helical ring 41 to prevent radial offset. The pitch affects the axial displacement of the lead screw 3 per revolution, indirectly controlling the opening speed of the valve port 12a.

[0053] Furthermore, a preset gap between the conical valve needle 31 and the inner wall of the valve port 12a forms a medium flow channel 6. The preset gap is also the minimum radial distance between the valve needle and the inner wall of the valve port 12a, forming a channel for medium flow.

[0054] Combination Figure 4 Specifically, the inner diameter of the medium flow channel 6 is d, where 0.01mm ≤ d ≤ 0.6mm. The clearance size directly affects the flow regulation accuracy and response speed; optimizing the inner diameter design can significantly improve the regulation performance of the electronic expansion valve.

[0055] Furthermore, the conical valve needle 31 includes a coaxially arranged cylindrical straight wall section 31a and a variable diameter conical section 31b. The outer diameter of the cylindrical straight wall section 31a is smaller than that of the valve stem portion 31c and is connected to the valve stem portion 31c by means of a transition slope 31d. The cylindrical straight wall section 31a cooperates with the inner wall of the valve port 12a to form a medium flow channel 6, and the transition slope 31d guides the medium into the medium flow channel 6.

[0056] The outer diameter of the cylindrical straight-wall section 31a is smaller than that of the valve stem section 31c, forming a stepped structure. This structure, along with the inner wall of the valve port 12a, forms an annular media flow channel 6 to control the flow rate. The variable-diameter conical section 31b is located below the cylindrical straight-wall section 31a, with its tip facing the valve port 12a. The cone angle is typically 30° to 60° (adjustable according to flow regulation requirements). The transition slope 31d connects the cylindrical straight-wall section 31a and the valve stem section 31c, with an inclination angle of 15° to 45° (optimizing the media flow direction) to guide the media smoothly from the valve stem section 31c into the media flow channel 6, reducing eddy current losses.

[0057] The smaller the gap in the medium flow channel 6, the higher the flow regulation accuracy, but the lower the anti-clogging ability. The gap d = the difference between the outer diameter of the cylindrical straight wall section 31a and the inner diameter of the valve port 12a / 2. For example, if the outer diameter of the cylindrical straight wall section 31a = 2.0mm and the inner diameter of the valve port 12a = 2.2mm, d = 0.1mm, which is suitable for precision adjustment.

[0058] Furthermore, the valve core seat 12 also has a horn-shaped guide cone 12a1 at the inlet of the valve port 12a. The cone angle of the guide cone is greater than the cone angle of the transition slope 31d. The transition slope 31d and the guide cone cooperate to form a tapered guide channel 7. The guide cone guides the medium to smoothly transition from the valve stem portion 31c to the medium flow channel 6, reducing flow resistance and eddy current losses. The guide channel is formed by the transition slope 31d and the guide cone. The channel shape is a tapered structure with a large inlet and a small outlet, which can accelerate the medium flow rate and improve the flow regulation response speed.

[0059] Combination Figure 1 Furthermore, the inner hole of the nut is formed sequentially from bottom to top with a first guide hole section 21a, a threaded hole section 21b, and a second guide hole section 21c, with the inner hole diameter decreasing in a stepped manner; this guides the lead screw 3 step by step, reducing stress concentration and wear. It solves the problem in traditional designs where the clearance between the lead screw 3 and the nut 21 is too large or the guide structure is too simple, resulting in low axial positioning accuracy and inability to meet the requirements of precision flow regulation. It also solves the problem that the lead screw 3 is prone to uneven loading during movement due to installation deviations or external loads, leading to stress concentration, accelerated thread wear, and even breakage.

[0060] The lead screw 3 also includes a valve stem portion 31c that slides with the first guide hole section 21a, a threaded portion 32 that meshes with the threaded hole section 21b, and a smooth rod portion 33 that extends out of the top of the nut 21. The smooth rod portion 33 includes a guide end 33a that slides with the second guide hole section 21c and a drive end 33b located at the end of the smooth rod portion 33. The outer diameter of the drive end 33b is smaller than the outer diameter of the guide end 33a, forming a stop step 33c that limits the positioning plate 51, ensuring that the positioning plate 51 is reliably positioned and preventing the lead screw 3 from coming out.

[0061] The present invention also proposes a refrigeration device, which includes an electronic expansion valve. The specific structure of the electronic expansion valve is as 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.

[0062] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. An electronic expansion valve, characterized in that, include: Valve seat; The nut assembly includes a nut connected to the valve seat, the outer wall of the nut having an axially extending helical groove, a first stop protrusion at the lower end of the helical groove, a second stop protrusion at the upper end of the helical groove, and a limiting boss located below the second stop protrusion along the helical direction. A lead screw is movably inserted through the nut; The stop mechanism includes a spiral coil formed by helical winding; and The rotor assembly includes a limiting plate fixed to the end of the lead screw, the limiting plate having an axially extending guide rod that engages with the spiral ring; When the spiral ring contacts the second stop protrusion, the limiting boss inserts into the gap of the spiral ring to form an interference fit with the spiral ring.

2. The electronic expansion valve as described in claim 1, characterized in that, The spiral coil extends to form a stop end and a bend end at both ends, and the spiral coil includes an upper ring segment and a lower ring segment spaced apart from each other; The guide rod engages with the bent end; When the bent end contacts the second stop protrusion, the limiting boss is inserted between the upper ring segment and the lower ring segment.

3. The electronic expansion valve as described in claim 2, characterized in that, The maximum thickness of the limiting boss is L, and the effective helical spacing between the upper ring segment and the lower ring segment in the free state is D, with the interference satisfying: 0.01mm≤LD≤0.2mm.

4. The electronic expansion valve as described in claim 1, characterized in that, The end of the limiting boss is provided with a wedge-shaped guide block.

5. The electronic expansion valve as described in claim 4, characterized in that, The wedge-shaped guide block includes two opposing guide ramps, the extension directions of the two guide ramps form an included angle θ, and satisfy: 10°≤θ≤30°.

6. The electronic expansion valve as described in claim 1, characterized in that, The spiral groove extends in a spiral shape, and its spiral pitch P satisfies: 1.0mm≤P≤3.0mm.

7. The electronic expansion valve as described in claim 1, characterized in that, The valve seat contains a valve core seat, and the valve core seat has a valve port. The lead screw includes a tapered valve needle that cooperates with the valve port. A preset gap between the tapered valve needle and the inner wall of the valve port forms a medium flow channel.

8. The electronic expansion valve as described in claim 7, characterized in that, The conical valve needle includes a coaxially arranged cylindrical straight-wall section and a variable-diameter conical section. The outer diameter of the cylindrical straight-wall section is smaller than that of the valve stem and is connected to the valve stem by means of a transition slope. The cylindrical straight-wall section cooperates with the inner wall of the valve port to form the medium flow channel. The transition slope guides the medium into the medium flow channel.

9. The electronic expansion valve as described in claim 8, characterized in that, The valve core seat also has a horn-shaped guide cone surface at the valve inlet. The cone angle of the guide cone surface is greater than the cone angle of the transition slope. The transition slope and the guide cone surface cooperate to form a gradually narrowing guide channel.

10. The electronic expansion valve as described in claim 7, characterized in that, The inner diameter of the medium flow channel is d, where 0.01mm ≤ d ≤ 0.6mm.

11. The electronic expansion valve as claimed in claim 1, characterized in that, The inner hole of the nut is formed from bottom to top with a first guide hole section, a threaded hole section and a second guide hole section, and the inner hole diameter decreases in a stepped manner. The lead screw also includes a valve stem portion that slides with the first guide hole section, a threaded portion that meshes with the threaded hole section, and a smooth rod portion extending from the top of the nut. The smooth rod portion includes a guide end that slides with the second guide hole section and a drive end located at the end of the smooth rod portion. The drive end is fixed to the limiting plate, and the outer diameter of the drive end is smaller than the outer diameter of the guide end to form a stop step that limits the limiting plate.

12. A refrigeration device, characterized in that, Includes the electronic expansion valve as described in any one of claims 1 to 11.

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