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 core sleeve, the valve core sleeve is installed on a valve seat, the valve core sleeve is provided with an installation groove, a nut is provided with an installation guide section, the nut is embedded in the installation groove through the installation guide section, the screw hole of the nut is coaxially arranged with the valve port of the valve core sleeve along a first reference axis, in addition, the valve core sleeve is provided with a guide channel, the valve needle part of a lead screw is gap-fitted with the guide channel to form a first guide structure, the nut is provided with a guide through hole, the light rod part of the lead screw is gap-fitted with the guide through hole to form a second guide structure, the axial movement of the lead screw is guided, and the opening degree of the valve port is adjusted, wherein the axis of the lead screw, the axis of the valve port, the axis of the guide channel and the axis of the guide through hole all coincide with the first reference axis; furthermore, the reference deviation caused by the welding of the nut and the valve seat during split assembly is eliminated, and the guide precision of the valve needle and the valve port is ensured.

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] Currently, electronic expansion valves use nuts for guidance, and the lead screw moves axially within the nut to control the opening of the valve port. The nut and valve seat are fixed by welding, which results in multiple assembly errors in the movement path of the valve needle. The perpendicularity accuracy between the nut and the valve seat directly affects the concentricity of the lead screw, valve needle, and valve port, causing poor alignment between the valve needle and valve port. This leads to friction and wear between the valve needle and valve port, resulting in a decrease in flow rate. 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 ensure that the axis of the nut hole, the guide channel and the valve port are forcibly kept to coincide with the first reference axis by guiding the nut onto the valve core sleeve through the mounting groove, thereby eliminating the reference offset caused by the separate assembly and ensuring the guiding accuracy of the valve needle and the valve port.

[0004] To achieve the above objectives, the present invention provides an electronic expansion valve comprising: A valve seat, wherein the valve seat has a pipe opening on its periphery and an installation port at its bottom; The valve core sleeve includes a valve port portion, a channel portion, and a connecting pipe portion: the valve port portion is located at the mounting port, and the valve port portion has a valve port centered on a first reference axis; The channel section is provided with a medium flow hole connecting the valve port and the pipe port; The connector is provided with an installation groove and a guide channel that extends from the installation groove through the medium flow hole. A nut is indirectly or directly fixedly connected to the valve core sleeve. The nut includes a mounting guide section and a guide through hole. The mounting guide section is interference-fitted with the mounting groove with the first reference axis as the center. A lead screw, through which the nut is movably inserted, comprises a valve needle portion and a smooth rod portion. The valve needle portion is clearance-fitted with the guide channel to form a first guide structure, and the smooth rod portion is clearance-fitted with the guide through hole to form a second guide structure; and A rotor assembly includes a rotor and a limiting plate disposed within the rotor, wherein the end of the lead screw is fixed to the limiting plate; The axes of the lead screw, the valve port, the guide channel, and the guide through hole are all aligned with the first reference axis; the valve needle can adjust the valve port opening by moving axially.

[0005] In one embodiment, the valve needle portion includes a needle valve portion and a needle rod portion that cooperate with the valve port, and the first guide structure is configured such that the needle rod portion and the guide channel are formed by a clearance fit.

[0006] In one embodiment, the nut includes an assembly section having a threaded hole and a guide hole located at the end of the assembly section with an inner diameter smaller than the threaded hole, the threaded hole extending to the mounting guide section; The lead screw also includes a threaded portion, and the end of the guide rod portion is fixed to the limiting plate; the threaded portion engages with a threaded hole.

[0007] In one embodiment, the installation guide section is provided with a lead screw through hole, the major diameter of the threaded hole is smaller than the inner diameter of the lead screw through hole, and a limiting step is formed between the lead screw through hole and the threaded hole; The outer diameter of the needle bar is larger than the minor diameter of the threaded part to form a limiting step. The limiting step abuts against the limiting step to limit the axial displacement of the lead screw. A limiting structure is provided between the limiting plate and the assembly section to restrict the circumferential rotation of the lead screw.

[0008] In one embodiment, the limiting structure is configured as a first limiting part and a second limiting part that abut against each other, the first limiting part being disposed on the limiting plate and facing the assembly section, and the second limiting part being disposed on the assembly section.

[0009] In one embodiment, the needle valve portion has a gradually decreasing outer diameter, the needle valve portion has a closed state located within the valve port, and in the closed state, there is a preset gap between the needle valve portion and the inner wall of the valve port.

[0010] In one embodiment, the preset gap is d, where 0.01mm ≤ d ≤ 0.6mm.

[0011] In one embodiment, the length of the guide channel is L, where 3.3 mm ≤ L ≤ 3.8 mm.

[0012] In one embodiment, the outer diameter of the installation guide section is larger than the outer diameter of the assembly section to form a stop surface; the connecting pipe part is also provided with a riveting edge, which is riveted and fixed to the stop surface.

[0013] In one embodiment, the connecting pipe is provided with a stop portion, and the installation guide section is provided with a stop portion, the stop portion and the stop portion engaging in abutment.

[0014] In one embodiment, the abutting portion is configured as an abutting groove, and the stop portion is configured as a stop protrusion. The stop protrusion is inserted into the abutting groove from above and restricts the nut from rotating relative to the valve core sleeve in the circumferential direction with the abutting groove.

[0015] In one embodiment, the valve core is fitted inside the valve seat at a height of h, and the height of the valve seat from the bottom to the axial edge is H, where 1.6mm ≤ Hh ≤ 3.2mm.

[0016] In one embodiment, the connection between the limiting plate and the rotor is located axially near the middle of the rotor.

[0017] In one embodiment, the valve port, the channel, and the connecting pipe are integrally formed.

[0018] The present invention also proposes a refrigeration device, including the electronic expansion valve as described above.

[0019] The beneficial effects of the technical solution of the present invention are as follows: 1. High-precision concentricity between the lead screw and the valve port is guaranteed. The lead screw is redundantly guided by a two-stage guide structure consisting of the needle rod and the guide channel (first guide structure) and the smooth rod and the guide through hole (second guide structure), forming a long-stroke guide. The multi-stage coaxial guide structure offsets machining and assembly errors, avoids uneven wear between the valve needle and the valve port, reduces wear caused by friction, and maintains flow stability.

[0020] 2. The assembly process is simplified. The first reference axis is used as the assembly reference. By integrally molding the valve port, channel, and connecting pipe, it is ensured that the axis of the guide hole, guide channel, and valve port is forcibly kept to coincide with the first reference axis. Under the constraint of the reference axis, the fault tolerance of the component is improved. The nut and valve core sleeve are positioned by the mounting groove, and no additional calibration is required. Attached Figure Description

[0021] 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.

[0022] Figure 1 A schematic diagram of an embodiment of the electromagnetic expansion valve provided by the present invention; Figure 2 for Figure 1 A magnified view of a section at point A in the middle; Figure 3 for Figure 1 A magnified view of a section at point B in the middle; Figure 4 This is a schematic diagram of the structure of an embodiment of the valve core sleeve provided by the present invention; Figure 5 for Figure 4 A cross-sectional structural diagram of the Nakamoto valve core sleeve; Figure 6This is a schematic diagram of a nut according to an embodiment of the present invention; Figure 7 for Figure 6 A schematic diagram of the cross-sectional structure of the nut; Figure 8 This is a schematic diagram of a lead screw embodiment; Figure 9 This is a structural schematic diagram of one embodiment of the limiting plate.

[0023] Explanation of icon numbers: 1. Valve seat; 1a. Pipe port; 1b. Mounting port; 2. Valve core sleeve; 2a. Valve port portion; 2b. Channel portion; 2c. Pipe connection portion; 2c1. Riveting edge; 2c2. Stop portion; 2c3. Stop groove; 2d. Sleeve portion; 2e. Valve port; 2f. Medium flow hole; 2g. Mounting groove; 2h. Guide channel; 3. Nut; 3a. Mounting guide section; 3b. Assembly section; 3b1. Second limiting portion; 3a1. Stop surface; 3a2. Stop portion; 3 a3, Stop protrusion; 3c, Lead screw through hole; 3d, Threaded hole; 3e, Guide through hole; 3f, Limiting step; 4, Lead screw; 4a, Valve needle part; 4a1, Needle valve part; 4a2, Needle rod part; 4b, Threaded part; 4c, Smooth rod part; 4d, First guide structure; 4e, Second guide structure; 4f, Limiting step; 5, Rotor assembly; 5a, Rotor; 5b, Limiting plate; 5b1, First limiting part; 5c, Limiting structure; Q, First reference axis.

[0024] 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

[0025] 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.

[0026] 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.

[0027] 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.

[0028] Currently, electronic expansion valves use nuts for guidance, and the lead screw moves axially within the nut to control the opening of the valve port. The nut and valve seat are fixed by welding, which results in multiple assembly errors in the movement path of the valve needle. The perpendicularity accuracy between the nut and the valve seat directly affects the concentricity of the lead screw, valve needle, and valve port, causing poor alignment between the valve needle and valve port. This leads to friction and wear between the valve needle and valve port, resulting in a decrease in flow rate.

[0029] The aforementioned problems are difficult to detect. Accumulated errors causing valve needle misalignment typically manifest as a gradual decrease in flow control accuracy, easily misdiagnosed as sensor drift or software control algorithm defects rather than mechanical structural issues. Secondly, assembly errors in split-type valve core sleeves only become apparent after prolonged, high-frequency operation due to wear, making initial testing difficult to detect through static dimensional inspections. Furthermore, noise and vibration caused by lead screw misalignment are easily mixed with refrigerant flow noise and compressor vibration, making fault tracing difficult.

[0030] Therefore, the present invention aims to ensure that the nut hole, guide channel and valve port axis are forcibly kept to coincide with the first reference axis by integrally molding the valve port, channel and pipe part, and nut is guided and assembled on the valve core sleeve through the mounting groove. This eliminates the reference offset caused by separate assembly and ensures the guiding accuracy of valve needle and valve port.

[0031] Please see Figures 1 to 9 In one embodiment of the present invention, the electronic expansion valve includes a valve seat 1, a valve core sleeve 2, a nut 3, a lead screw 4, a rotor assembly 5, and a housing; the housing is connected to the valve seat 1, and the valve core sleeve 2, the lead screw 4, and the rotor assembly 5 are all covered by the housing, which provides protection.

[0032] Combination Figure 4 and Figure 5The valve seat 1 has a pipe port 1a on its periphery and an installation port 1b at its bottom. The pipe port 1a is for the first connecting pipe to be fitted and connected, and the installation port 1b is for the valve core sleeve 2 to be installed. The valve core sleeve 2 includes an integrally formed valve port portion 2a, a channel portion 2b, and a connecting pipe portion 2c. The valve port portion 2a is fitted into the installation port 1b, and its exposed portion forms a sleeve portion 2d. A positioning step is formed on the outer wall of the valve port portion 2a, abutting against the edge of the installation port 1b for positioning, and is fixed by welding. The sleeve portion 2d is fitted onto the second connecting pipe, and then the second connecting pipe is fixed to the valve seat 1 to form a sealing structure, preventing media leakage.

[0033] Reference Figure 1 The valve port 2a contains a valve port 2e centered on the first reference axis Q. In this embodiment, the valve port 2e is flared in a trumpet shape along the direction in which the lead screw closes the valve port 2e. The trumpet-shaped flare can change the flow path of the fluid, reduce turbulence, and lower the pressure drop. At the same time, during the valve needle closing process, the flared design helps guide the fluid, reduce the impact on the valve needle, and thus reduce wear.

[0034] In order for the fluid entering through the pipe port 1a to enter the valve core sleeve 2, the channel portion 2b of the valve core sleeve 2 is provided with a medium flow hole 2f that connects the valve port 2e and the pipe port 1a; the medium flow hole 2f penetrates the channel portion 2b radially (perpendicular to the first reference axis Q), and multiple medium flow holes 2f are formed in the circumference of the valve core sleeve 2, so that the fluid of the valve seat 1 can flow out through the medium flow hole 2f and then through the valve port 2e.

[0035] The valve core sleeve 2 has a mounting groove 2g and a guide channel 2h that extends from the mounting groove 2g through the medium flow hole 2f. The nut 3 includes a mounting guide section 3a and an assembly section 3b extending from the mounting guide section 3a. The mounting guide section 3a is fixed in the mounting groove 2g. On the one hand, the mounting groove 2g serves as the machining reference for the valve core sleeve 2. The fit between the mounting guide section 3a and the mounting groove 2g (such as H7 / h6 tolerance) can reduce the coaxiality error of the valve core sleeve 2, thereby reducing the concentricity error between the valve needle and the valve port 2e. On the other hand, the mounting guide section 3a being fixed in the mounting groove 2g allows for a longer guide channel 2h within the valve core sleeve 2 compared to the nut 3 being sleeved on the mounting groove 2c, thus ensuring the concentricity of the valve needle and the valve port 2e.

[0036] Combination Figure 6 and Figure 7The installation guide section 3a is provided with a lead screw through hole 3c, the inner diameter of which is larger than the inner diameter of the guide channel 2h. The assembly section 3b is also provided with a threaded hole 3d (the major diameter of the threaded hole) with an inner diameter smaller than that of the lead screw through hole 3c, and a guide through hole 3e located at the end of the assembly section 3b with an inner diameter smaller than that of the threaded hole 3d. The threaded hole 3d extends to the installation guide section 3a. A limiting step 3f is formed between the lead screw through hole 3c and the threaded hole 3d. The lead screw 4 includes a valve needle part 4a, a threaded part 4b, and a smooth rod part 4c. The threaded part 4b engages with the threaded hole 3d. A limiting step 4f is formed between the needle rod part 4a2 and the threaded part 4b. The limiting step 4f abuts against the limiting step 3f to limit the axial displacement of the lead screw 4.

[0037] Combination Figure 8 When the valve port 2e is open, the rotor assembly 5 drives the lead screw 4 to rotate. The lead screw 4 moves axially. The valve needle part 4a includes a needle valve part 4a1 and a needle rod part 4a2. The needle rod part 4a2 is clearance-fitted with the guide channel 2h to form a first guide structure 4d. The guide channel 2h guides the valve needle part 4a. The inner diameter of the lead screw through hole 3c is larger than the inner diameter of the guide channel 2h to avoid over-guiding of the valve needle part 4a and to absorb machining and assembly errors (if the inner diameter of the lead screw through hole 3c (the inner diameter of the end of the nut 3) is different from the guide channel 2h). Since the inner diameter of the guide channel 2h is the same, a double rigid guide will be formed, which will cause the lead screw through hole 3c and the guide channel 2h to apply radial constraints to the needle rod at the same time. If there is a slight coaxiality deviation between the two inner holes, it will aggravate wear. The valve needle part 4a will at least partially move into the lead screw through hole 3c. When the limiting step 4f abuts against the limiting step 3f, the axial movement of the lead screw 4 will be restricted. At this time, the valve port 2e opening is the largest. That is, when the limiting step 4f abuts against the limiting step 3f, it is the limit position of the valve port 2e opening.

[0038] The smooth rod portion 4c is clearance-fitted with the guide through hole 3e to form a second guide structure 4e. The guide through hole 3e is close to the upper end of the lead screw 4, and the guide channel 2h is close to the lower end of the nut 3, which can better ensure the coaxiality of the valve needle with respect to the valve port 2e during the movement of the valve. The rotor assembly 5 includes a rotor 5a and a limiting plate 5b disposed in the rotor 5a. The smooth rod portion 4c passes through and is fixed to the limiting plate 5b. A limiting structure 5c is provided between the limiting plate 5b and the assembly section 3b. The limiting structure 5c restricts the circumferential rotation of the lead screw 4. The needle valve portion 4a1 moves axially with the lead screw 4 to adjust the opening of the valve port 2e. That is, when the opening of the valve port 2e is reduced to the limit position, the limiting structure 5c takes effect. The axis of the valve port 2e, the axis of the guide channel 2h, and the axis of the lead screw through hole 3c all coincide with the first reference axis Q; the axis of the valve port 2e, the guide channel 2h, and the guide through hole 3e are all coaxial with the first reference axis Q, thus ensuring the high-precision concentricity of the valve needle and the valve port 2e.

[0039] Combination Figure 6 and Figure 9 The aforementioned limiting structure 5c may have a first limiting part 5b1 facing the assembly section (3b) of the limiting plate 5b, and a second limiting part 3b1 of the assembly section 3b, with the first limiting part 5b1 and the second limiting part 3b1 abutting against each other. The first limiting part 5b1 is configured as a lower stop, the second limiting part is configured as an upper stop, and the nut 3 is provided with upper stop limiting.

[0040] The limiting structure 5c can also be a limiting plate 5b with a guide rod, and the nut 3 with a guide groove and a stop ring. The guide rod cooperates with the stop ring, and the stop ring moves up and down in the guide groove of the nut 3. Stop blocks are set at the upper and lower ends of the guide groove to abut and limit the movement.

[0041] The beneficial effects of the technical solution of the present invention are as follows: 1. High-precision concentricity between lead screw 4 and valve port 2e is ensured. Lead screw 4 forms a long-stroke guide through the double clearance fit between needle rod part 4a2 and guide channel 2h (first guide structure 4d) and smooth rod part 4c and guide through hole 3e (second guide structure 4e). The multi-stage coaxial guide structure offsets machining and assembly errors, avoids uneven wear between valve needle and valve port 2e, reduces wear caused by friction, and maintains flow stability.

[0042] 2. Dual axial and circumferential limiting design: In the axial direction, the limiting step 4f (lead screw 4) abuts against the limiting step 3f (nut 3), restricting the displacement of the lead screw 4; in the circumferential direction, the limiting structure 5c between the limiting plate 5b and the assembly section 3b prevents the lead screw 4 from rotating with the rotor 5a. The lead screw 4 moves only along the axial direction, resulting in more linear valve needle opening adjustment; it also prevents the lead screw 4 from deviating due to vibration or refrigerant impact, providing high anti-interference performance.

[0043] 3. The assembly process is simplified. The first reference axis Q is used as the assembly reference. The guide channel 2h, the lead screw through hole 3c, and the valve port 2e are pre-machined coaxially. Under the constraint of the reference axis, the fault tolerance of the components is improved. The nut 3 and the valve core sleeve 2 are positioned through the mounting groove 2g, without the need for additional calibration.

[0044] To ensure that the electronic expansion valve has a small flow rate when closed, such as to prevent excessive system pressure or maintain a certain level of lubrication to meet usage requirements, the needle valve part 4a1 has a gradually decreasing outer diameter. The needle valve part 4a1 is located within the valve port 2e in a closed state, and in the closed state, there is a preset gap between the needle valve part 4a1 and the inner wall of the valve port 2e. The gradually decreasing needle valve part 4a1 can also improve flow accuracy. The preset gap can reduce manufacturing difficulty, allow for certain tolerances, and still maintain functionality. It can also shorten the response time of the valve from closed to fully open and improve the response speed.

[0045] Combination Figure 2Specifically, the preset gap is d, which is 0.01mm≤d≤0.6mm, and can also be limited to the range of 0.02mm-0.4mm as needed, such as 0.05mm, 0.10mm, 0.15mm, 0.2mm, 0.3mm, 0.4mm, etc.

[0046] Combination Figure 3 Specifically, to achieve better concentricity between the valve port 2e and the valve needle, the length of the guide channel 2h is L, where 3.3 mm ≤ L ≤ 3.8 mm. If the guide channel 2h is too short (e.g., L < 3.3 mm), the contact between the needle rod 4a2 and the guide channel 2h will be insufficient, and the offset will increase. If the guide channel 2h is too long (e.g., L > 3.8 mm), the contact area is proportional to the frictional resistance, the frictional power consumption between the needle rod 4a2 and the guide channel 2h will increase dramatically, and thermal expansion interference is likely to occur.

[0047] If the diameter D of the needle bar 4a2 is such that the diameter and guide length satisfy L / D=1.65-1.9, this ratio can balance the axial stiffness and suppress resonance under high frequency vibration, thereby satisfying the high-precision concentric design of the lead screw 4 and the valve port 2e, and also satisfying the design requirements of the valve port 2e for larger flow rates, such as the 3.2mm valve port flow rate design requirement.

[0048] Specifically, the outer diameter of the installation guide section 3a is larger than the outer diameter of the assembly section 3b to form a stop surface 3a1; the connecting pipe 2c is also provided with a riveting edge 2c1, which is riveted and fixed to the stop surface 3a1. The installation guide section 3a is riveted and fixed in the installation groove 2g, that is, the valve core sleeve 2 and the nut 3 are riveted and fixed. Compared with welding, this can avoid coaxiality misalignment caused by thermal stress, thereby ensuring the concentricity of the valve needle and the valve port 2e.

[0049] Specifically, the connecting pipe 2c is provided with a stop 2c2, and the installation guide section 3a is provided with a stop 3a2, and the stop 2c2 and the stop 3a2 abut against each other.

[0050] In one embodiment, the abutting part 2c2 is configured as an abutting groove 2c3, and the stop part 3a2 is configured as a stop protrusion 3a3. The stop protrusion 3a3 is inserted into the abutting groove 2c3 from above and restricts the nut 3 from rotating relative to the valve core sleeve 2 in the circumferential direction with the abutting groove 2c3.

[0051] In one embodiment, the abutment portion 2c2 is configured as a stop protrusion 3a3, and the stop portion 3a2 is configured as an abutment groove 2c3; alternatively, both the abutment portion 2c2 and the stop portion 3a2 may be protrusions.

[0052] Specifically, in this embodiment, the stop groove 2c3 is provided in the connecting part 2c of the valve core sleeve 2. The stop groove 2c3 is a U-shaped groove that passes through the edge of the mounting groove 2g. The stop protrusion 3a3 is provided on the outer wall of the mounting guide section 3a of the nut 3. During installation, the mounting guide section 3a is inserted into the mounting groove 2g from top to bottom, and the stop protrusion 3a3 is inserted into the stop groove 2c3 to form a bidirectional positioning installation. Then, the valve core sleeve 2 and the nut 3 are riveted and fixed.

[0053] Reference Figure 1 Specifically, the height of the valve core sleeve 2 within the valve seat 1 is h, and the height of the valve seat 1 from its bottom to its axial edge is H, where 1.6mm ≤ Hh ≤ 3.2mm. The valve core sleeve 2 is installed inside the valve seat 1, and the height difference Hh refers to the height H of the inner cavity of the valve seat 1 minus the height h of the valve core sleeve 2 portion inside the valve seat 1. When the portion of the valve core sleeve 2 extends beyond the valve seat 1, it may form a cantilever structure, which is prone to bending deformation when subjected to lateral forces (such as fluid pressure or vibration), affecting concentricity. Furthermore, an excessively large height difference increases the difficulty of processing and assembly, and accumulated errors may further affect the coaxiality of the overall structure.

[0054] The height H of valve seat 1 is measured from the bottom of the inner cavity of valve seat 1 as the starting point and the edge of valve seat 1 as the ending point, and the vertical distance between the two points is measured; the height h of valve core sleeve 2 is measured in the same way.

[0055] Reference Figure 1 Furthermore, the connection between the limiting plate 5b and the rotor 5a is located axially near the middle of the rotor 5a. Understandably, the limiting plate 5b is fixed to the axial middle of the rotor 5a by an interference fit or a snap-fit ​​structure, and is integrally formed with the magnetic rotor 5a through a mold. The limiting plate 5b is welded to the lead screw 4 or fixed by threaded adhesive to avoid deformation of the lead screw 4 caused by the heat-affected zone of welding. The rotor 5a drives the limiting plate 5b to rotate, which in turn drives the lead screw 4 to rotate. The limiting plate 5b is located in the middle of the rotor 5a. Compared with the end of the rotor 5a, it can reduce the offset during rotation, so as to balance the torque and ensure the concentricity of the lead screw 4 and the valve port 2e.

[0056] In addition, when the limiting step 4f abuts against the limiting ladder 3f, the needle valve part 4a1 disengages from the valve port 2e so that the valve port 2e is configured to be fully open.

[0057] This invention also proposes a refrigeration device including an electronic expansion valve. The specific structure of the 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 possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated further here. The electronic expansion valve can be used in household and commercial air conditioning systems, automotive air conditioning systems, etc.

[0058] 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: A valve seat, wherein the valve seat has a pipe opening on its periphery and an installation port at its bottom; A valve core sleeve includes a valve port portion, a channel portion, and a connecting pipe portion: the valve port portion is located at the mounting port, and the valve port portion has a valve port centered on a first reference axis; The channel section is provided with a medium flow hole connecting the valve port and the pipe port; The connector is provided with an installation groove and a guide channel that extends from the installation groove through the medium flow hole. A nut is indirectly or directly fixedly connected to the valve core sleeve. The nut includes a mounting guide section and a guide hole. The mounting guide section is interference-fitted with the mounting groove with the first reference axis as the center. A lead screw, through which the nut is movably inserted, comprises a valve needle portion and a smooth rod portion. The valve needle portion is clearance-fitted with the guide channel to form a first guide structure, and the smooth rod portion is clearance-fitted with the guide through hole to form a second guide structure; and A rotor assembly includes a rotor and a limiting plate disposed within the rotor, wherein the end of the lead screw is fixed to the limiting plate; The axes of the lead screw, the valve port, the guide channel, and the guide through hole are all coincident with the first reference axis; the valve needle can adjust the valve port opening by moving axially.

2. The electronic expansion valve as described in claim 1, characterized in that, The valve needle portion includes a needle valve portion and a needle rod portion that cooperate with the valve port, and the first guide structure is configured such that the needle rod portion and the guide channel are formed by a clearance fit.

3. The electronic expansion valve as described in claim 2, characterized in that, The nut includes an assembly section, the assembly section having a threaded hole and a guide hole located at the end of the assembly section with an inner diameter smaller than the threaded hole, the threaded hole extending to the mounting guide section; The lead screw also includes a threaded portion, and the end of the guide rod portion is fixed to the limiting plate; the threaded portion engages with a threaded hole.

4. The electronic expansion valve as described in claim 3, characterized in that, The installation guide section is provided with a lead screw through hole, the major diameter of the threaded hole is smaller than the inner diameter of the lead screw through hole, and a limiting step is formed between the lead screw through hole and the threaded hole; The outer diameter of the needle bar is larger than the minor diameter of the threaded part to form a limiting step. The limiting step abuts against the limiting step to limit the axial displacement of the lead screw. A limiting structure is provided between the limiting plate and the assembly section to restrict the circumferential rotation of the lead screw.

5. The electronic expansion valve as described in claim 4, characterized in that, The limiting structure is configured as a first limiting part and a second limiting part that abut against each other. The first limiting part is disposed on the limiting plate and faces the assembly section, and the second limiting part is disposed on the assembly section.

6. The electronic expansion valve as described in claim 2, characterized in that, The needle valve part has a gradually decreasing outer diameter and a closed state located inside the valve port. In the closed state, there is a preset gap between the needle valve part and the inner wall of the valve port.

7. The electronic expansion valve as described in claim 6, characterized in that, The preset gap is d, where 0.01mm ≤ d ≤ 0.6mm.

8. The electronic expansion valve as described in claim 1, characterized in that, The length of the guide channel is L, 3.3mm≤L≤3.8mm.

9. The electronic expansion valve as described in claim 1, characterized in that, The outer diameter of the installation guide section is larger than the outer diameter of the assembly section to form a stop surface; the connecting pipe part is also provided with a riveting edge, which is riveted and fixed to the stop surface.

10. The electronic expansion valve as described in claim 9, characterized in that, The connecting section is provided with a stop part, and the installation guide section is provided with a stop part, and the stop part and the stop part abut against each other.

11. The electronic expansion valve as described in claim 10, characterized in that, The abutting part is configured as an abutting groove, and the stop part is configured as a stop protrusion. The stop protrusion is inserted into the abutting groove from above and restricts the nut from rotating relative to the valve core sleeve in the circumferential direction with the abutting groove.

12. The electronic expansion valve as claimed in claim 1, characterized in that, The valve core is fitted inside the valve seat at a height of h, and the valve seat is at a height of H from the bottom to the axial edge, where 1.6mm ≤ Hh ≤ 3.2mm.

13. The electronic expansion valve as described in claim 1, characterized in that, The connection between the limiting plate and the rotor is located axially near the middle of the rotor; and / or, the valve port, the channel, and the connecting pipe are integrally formed.

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

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