Nut positioning structure of electronic expansion valve

Abstract

The utility model relates to the technical field of fluid control components, in particular to an electronic expansion valve nut positioning structure. According to the nut positioning structure of the electronic expansion valve, the nut is matched with the valve seat extending part at the upper end of the valve seat in a centering and vertical mode, the sleeve is matched with the step of the outer circle of the valve seat in a centering and vertical mode, the valve seat extending part at the upper end of the valve seat and the step of the outer circle of the valve seat can be machined through one-time clamping, and machining precision is high; therefore, the problem that due to the fact that the relative position deviation of the nut and the sleeve of the electronic expansion valve is large, the magnet rotates and interferes with the sleeve, and the magnet and the sleeve are stuck is solved. The valve port is prevented from extending into the valve seat to be matched with the nut, the length of the extending part of the valve port is reduced, and valve port production materials are saved; and the problem that the contact surfaces of the valve port and the valve seat extrude each other to generate scrap iron, so that stress is uneven, and finally the valve port is pressed to be deviated is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of fluid control components, in particular to a nut positioning structure for an electronic expansion valve. Background Art

[0002] Generally, in the prior art, the nut of the electronic expansion valve is positioned on the valve port, the valve seat is also positioned on the valve port, and the sleeve is positioned on the valve seat. However, the prior art nut positioning method for the electronic expansion valve has the following defects. First, due to the positioning of the nut and the valve port, the positioning of the valve port and the valve seat, and the fixing of the sleeve and the valve seat, the relative position deviation between the nut and the sleeve is relatively large, resulting in interference between the magnet and the sleeve, and jamming of the magnet rotor and the sleeve, thus affecting a large number of defective assemblies. Second, due to the relatively long protruding part of the valve port and the interference fit between the valve seat and the valve port during press-fitting, iron filings are generated during press-fitting, and finally the press-fitting is offset, thus affecting a large number of defective assemblies. Third, due to the relatively long protruding part of the valve port, the material and processing costs are relatively high. The prior art JP7369816B2 provides an electronic expansion valve, including: a valve seat assembly, the valve seat assembly includes a valve seat, the valve seat has a valve cavity and is provided with a valve port; a screw valve needle assembly, the screw valve needle assembly includes a screw, a valve needle and a sleeve part, and the screw and the valve needle are floatingly connected through the sleeve part; the valve needle cooperates with the valve port to adjust the flow rate of the electronic expansion valve; a nut assembly, the nut assembly includes a nut and a connecting piece, the nut is in threaded cooperation with the screw, and a nut guiding part is arranged at the lower part of the nut; a magnetic rotor assembly, the magnetic rotor assembly includes a magnetic rotor part and a connecting plate fixedly connected with the magnetic rotor part, and the connecting plate is fixedly connected with the screw; a housing assembly, the housing assembly includes a cover fixedly connected with the valve seat and a housing fixedly connected with the cover; a guiding part, the guiding part is fixedly connected with the valve seat and guides the sleeve part and the valve needle at the same time. In the prior art, the nut is positioned with the valve port, the valve port is positioned with the valve seat, and the sleeve is positioned with the valve seat. After the accumulation of multiple errors, the relative position deviation between the nut and the sleeve is relatively large, resulting in jamming of the magnet and the sleeve. The inventor believes that there is still a large room for improvement. Summary of the Utility Model

[0003] The design purpose of the present utility model is to solve the problems existing in the existing electronic expansion valve. Due to the positioning of the nut and the valve port, the valve port and the valve seat, and the sleeve and the valve seat, after the accumulation of multiple positioning errors, the relative position deviation between the nut and the sleeve is relatively large, ultimately resulting in interference between the magnet and the sleeve, jamming of the magnet and the sleeve, and a large number of defective assembly parts. To solve the problem that in the existing electronic expansion valve, because the protruding part of the valve port is relatively long, the fit between the valve seat and the valve port is an interference fit, iron filings appear on the contact surface between the two during the press-fitting process, the force is unbalanced, and finally it is pressed out of position, resulting in a large number of defective assembly parts. To solve the problem that in the existing electronic expansion valve, because the protruding part of the valve port is relatively long, more materials are used and the processing cost is relatively high, resulting in high material production and processing costs. The present utility model provides a nut positioning structure for an electronic expansion valve, which includes a valve seat, a nut, and a sleeve. The upper end of the valve seat is provided with a valve seat extension, the outer circle of the valve seat is provided with a step, the lower end of the nut is provided with a nut extension, and the valve seat extension cooperates with the nut extension for positioning, and the step is fixed to the lower end of the sleeve. The nut is vertically and concentrically matched with the valve seat extension at the upper end of the valve seat, and the sleeve is vertically and concentrically matched with the step on the outer circle of the valve seat. The valve seat extension at the upper end of the valve seat and the step on the outer circle of the valve seat can be machined by one-time clamping, and the machining accuracy is relatively high, thereby solving the problem that in the electronic expansion valve, due to the relatively large relative position deviation between the nut and the sleeve, ultimately the rotation of the magnet interferes with the sleeve, resulting in jamming of the magnet and the sleeve. Avoid the need for the valve port to extend into the valve seat for cooperation with the nut, reduce the length dimension of the protruding part of the valve port, and save the production materials of the valve port. In order to ensure the sealing performance inside the electronic expansion valve, the valve port and the valve seat need to be in an interference fit. With the above settings, it can be avoided that during the insertion process of the valve port, the contact surfaces of the valve port and the valve seat are squeezed against each other, generating metal debris, resulting in uneven force and ultimately the valve port being pressed out of position.

[0004] Preferably, the nut extension at the lower end of the nut is annular, and the valve seat extension of the valve seat is also annular. The inner circle of the nut extension cooperates with the valve seat extension for fixation. The nut extension at the lower end of the nut is in an interference fit with the valve seat extension, ensuring the sealing performance of the working environment of the screw rod and preventing the leakage of lubricating oil; ensuring that the nut is stationary relative to the sleeve, and the magnet will drive the screw rod to rotate according to the thread of the nut, realizing the up and down movement of the valve needle to control the opening and closing of the valve port.

[0005] Preferably, the electronic expansion valve further includes a valve port and a valve needle. The upper end of the valve port is provided with a valve port extension part, which is annular. The outer circle of the valve port extension part is fixed to the inner circle of the valve seat, and the length of the valve needle is matched with the length of the valve port extension part. Through the above settings, the outer circle of the valve port extension part and the inner circle of the valve seat can be fixed by welding, replacing the press-fitting fixation in the prior art where the valve port needs to be interference-fitted with the valve seat, avoiding inaccurate positioning of the valve seat and the valve port due to a small interference amount; avoiding the problem of uneven force caused by the generation of iron filings due to mutual friction between the contact surfaces during the press-fitting process of the valve port and the valve seat; the length of the valve port affects the length of the valve needle. Since the valve port extension part is shortened, the valve needle can also be shortened, reducing the material cost of the valve needle and the valve port and reducing the processing difficulty of the valve needle.

[0006] Preferably, the valve needle moves up and down within the inner circle of the valve port extension part, and a long pin is provided between the valve needle and the valve port. The long pin is fitted in the inner wall groove of the valve port extension part and the outer wall groove of the valve needle, so that the valve needle, the outer ring of the bearing, and the valve needle bushing will not rotate relative to the valve port, but the lead screw can realize the up and down movement of the valve needle through screw rotation.

[0007] Preferably, the electronic expansion valve further includes a slip ring and a brake rod. The nut is provided with an inner hole, the upper end of the nut is provided with an external thread, and the inner hole is provided with an internal thread. The slip ring is matched with the external thread at the upper end of the nut, and the brake rod is connected to the slip ring. The slip ring is fixed in the electronic expansion valve by the brake rod. When the magnet rotates and drives the lead screw to move vertically, the slip ring moves along the external thread at the upper end of the nut. The movement of the slip ring is restricted according to the external thread of the nut, and the total length of the external thread in the vertical direction restricts the vertical movement distance of the lead screw.

[0008] Preferably, the electronic expansion valve further includes a lead screw. The upper part of the lead screw is provided with an external thread that is matched with the inner hole of the nut, and the lower end of the lead screw can be in direct contact with the valve needle. The external thread is provided on the upper part of the lead screw so that when the magnet drives the lead screw to rotate, the lead screw is matched with the inner hole of the nut to realize vertical movement, and finally control the opening and closing effect of the valve port; through the above settings, the length of the valve needle is shortened, the displacement of the lead screw inside the valve needle is shortened, and the shock-absorbing material between the lead screw and the valve needle can be reduced, reducing the manufacturing cost.

[0009] Preferably, a spring and a bearing are sleeved on the lower end of the lead screw. The valve needle is provided with an inner hole near the lead screw end. The inner ring of the bearing is matched with the lead screw, and the outer ring of the bearing is matched with the inner hole of the valve needle. The valve needle is provided with an inner hole, and the lead screw pushes the valve needle to move vertically through the inner hole. The inner hole improves the stability of the vertical movement of the lead screw; the lead screw realizes vertical movement through the thread, and there will also be relative rotation between the lead screw and the valve needle. A bearing is provided between the lead screw and the valve needle to reduce the wear during the relative rotation of the lead screw and the valve needle; the clearance between the outer ring of the bearing, the rotor, and the inner ring of the bearing can reduce the influence on the vertical movement of the lead screw pushing the valve needle caused by the coaxiality error between the lead screw and the inner hole of the valve needle, and reduce the wear during the vertical movement of the lead screw inside the valve needle.

[0010] Preferably, a valve needle bushing and a lead screw bushing are provided above the bearing. The valve needle bushing is fixed to the upper end of the valve needle, and the lead screw bushing is fixed to the lower end of the lead screw. The valve needle bushing fixes the outer ring of the bearing, and the lead screw bushing fixes the inner ring of the bearing.

[0011] The utility model has the following beneficial effects: solving the problem that in the existing electronic expansion valve, due to the positioning of the nut and the valve port, the valve port and the valve seat, and the sleeve and the valve seat, after the accumulation of multiple positioning errors, the relative position deviation between the nut and the sleeve is large, and finally the interference between the magnet and the sleeve occurs, resulting in the jamming of the magnet and the sleeve and a large number of defective assembly parts; solving the problem that in the existing electronic expansion valve, due to the relatively long protruding part of the valve port, the valve seat and the valve port are in an interference fit, and iron filings appear on the contact surface between the two during the press-fitting process, and the force is unbalanced, finally resulting in deviation, thus leading to a large number of defective assembly parts; solving the problem that in the existing electronic expansion valve, due to the relatively long protruding part of the valve port, more materials are used for the valve needle and the valve port and the processing cost is high, resulting in high material production and processing costs; a bearing is arranged between the lead screw and the valve needle to reduce the wear between the lead screw and the valve needle. Description of the Drawings

[0012] Figure 1 is a schematic structural diagram of the utility model;

[0013] Figure 2 is a partially enlarged view at A of the utility model;

[0014] Figure 3 is a partially enlarged view at B of the utility model.

[0015] Description of the reference numerals: 1 valve port; 2 long pin; 3 valve seat; 4 sealing ring; 5 spring; 6 lead screw; 7 nut; 8 magnet; 9 sleeve; 10 connecting plate; 11 brake rod; 12 slip ring; 13 slip ring extension; 14 nut extension; 15 valve seat extension; 16 valve needle sleeve; 17 sealing ring groove; 18 bearing; 19 lead screw bushing; 20 valve needle; 21 valve port extension. Detailed Embodiments

[0016] Next, the technical solutions in the embodiments of the utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only a part of the embodiments of the utility model, rather than all of the embodiments.

[0017] Embodiment 1

[0018] As Figure 1As shown, an electronic expansion valve nut 7 positioning structure includes a valve port 1, a long pin 2, a valve seat 3, a sealing ring 4, a spring 5, a lead screw 6, a nut 7, a magnet 8, a sleeve 9, a connecting plate 10, a brake rod 11, a slip ring 12, a slip ring extension 13, a nut extension 14, a valve seat extension 15, a valve needle sleeve 16, a sealing ring groove 17, a bearing 18, a lead screw bushing 19, and a valve needle 20. As Figure 2 As shown, a valve seat extension 15 is provided at the upper end of the valve seat 3, a step is provided on the outer circle of the valve seat 3, a nut extension 14 is provided at the lower end of the nut 7, and the valve seat extension 15 at the upper end of the valve seat 3 cooperates with the nut extension 14 for positioning, and the step is fixed to the lower end of the sleeve 9. The nut extension 14 at the lower end of the nut 7 is annular, and the valve seat extension 15 of the valve seat 3 is also annular, and the inner circle of the nut extension 14 is circumferentially fixed to the outer circle of the valve seat extension 15.

[0019] With the above settings, the nut 7 is centered and vertically matched with the valve seat extension 15 at the upper end of the valve seat 3, and the sleeve 9 is centered and vertically matched with the step on the outer circle of the valve seat 3. The valve seat extension 15 at the upper end of the valve seat 3 and the step on the outer circle of the valve seat 3 can be machined by one clamping, and the machining accuracy is relatively high, thus solving the problem that the relative position deviation between the nut 7 and the sleeve 9 of the electronic expansion valve is relatively large, which ultimately leads to interference between the rotation of the magnet 8 and the sleeve 9 and jamming of the magnet 8 and the sleeve 9; avoiding the need for the valve port 1 to extend into the valve seat 3 for cooperation with the nut 7, reducing the length dimension of the valve port extension 21, and saving the production material of the valve port 1; in order to ensure the internal sealing of the electronic expansion valve, the valve port 1 and the valve seat 3 need to be in interference fit. With the above settings, it can be avoided that during the insertion process of the valve port 1, the contact surfaces of the valve port 1 and the valve seat 3 are squeezed against each other, generating iron chips, resulting in uneven force and ultimately causing the valve port 1 to be pressed out of alignment; the nut extension 14 at the lower end of the nut 7 is in interference fit with the valve seat extension 15 to ensure the sealing of the working environment of the lead screw 6 and prevent lubricating oil leakage; ensuring that the nut 7 is stationary relative to the sleeve 9, and the magnet 8 will drive the lead screw 6 to rotate according to the thread of the nut 7, realizing the up and down movement of the valve needle 20 to control the opening and closing of the valve port 1.

[0020] Combined with Figure 1 and Figure 3As shown in the figure, the electronic expansion valve further includes a valve port 1 and a valve needle 20. The upper end of the valve port 1 is provided with a valve port extension 21. The valve port extension 21 is annular, and the valve seat 3 is also annular. The outer ring of the valve port extension 21 is fixedly connected to the inner ring of the valve seat 3. The length of the valve needle 20 is matched with the length of the valve port extension 21. Through the above settings, the outer ring of the valve port extension 21 and the inner ring of the valve seat 3 can be fixedly connected by welding, replacing the press-fitting fixation in the prior art where the valve port 1 needs to be press-fitted with the valve seat 3 with interference fit, avoiding the problem that the valve seat 3 and the valve port 1 are misaligned due to a small interference amount; avoiding the problem that during the press-fitting process of the valve port 1 and the valve seat 3, iron filings are generated due to mutual friction of the contact surfaces, resulting in uneven force and press deviation; the length of the valve port 1 affects the length of the valve needle 20. Since the elongation of the valve port 1 is shortened, the valve needle 20 can also be shortened, reducing the material cost of the valve needle 20 and the valve port 1 and reducing processing losses.

[0021] As Figure 3 shown in the figure, the valve needle 20 moves up and down within the inner ring of the valve port extension 21. A long pin 2 is provided between the valve needle 20 and the valve port 1. The long pin 2 is fitted in the inner wall groove of the valve port extension 21 and the outer wall groove of the valve needle 20, so that the valve needle 20, the outer ring of the bearing 18, and the bushing of the valve needle 20 will not rotate relative to the valve port 1, but the lead screw 6 can move the valve needle 20 up and down through screw rotation.

[0022] As Figure 1 shown in the figure, the electronic expansion valve further includes a slip ring 12 and a brake lever 11. The nut 7 is provided with an inner hole. The upper end of the nut 7 is provided with an external thread, and the inner hole is provided with an internal thread. The slip ring 12 is matched with the external thread at the upper end of the nut 7. The brake lever 11 is connected to the slip ring 12, and the slip ring 12 is fixed in the electronic expansion valve by the brake lever 11. The electronic expansion valve further includes a lead screw 6. The upper part of the lead screw 6 is provided with an external thread that is matched with the inner hole of the nut 7, and the lower end of the lead screw 6 can directly contact the valve needle 20.

[0023] Through the above settings, when the magnet 8 rotates and drives the lead screw 6 to move vertically, the slip ring 12 moves along the external thread at the upper end of the nut 7. According to the external thread of the nut 7, the movement of the slip ring 12 is restricted, and the total length of the external thread in the vertical direction restricts the vertical movement distance of the lead screw 6. The upper part of the lead screw 6 is provided with an external thread to enable the lead screw 6 to be matched with the inner hole of the nut 7 when the magnet 8 drives the lead screw 6 to rotate, realizing vertical movement and finally controlling the opening and closing effect of the valve port 1; through the above settings, the length of the valve needle 20 is shortened, the relative displacement between the lead screw 6 and the valve needle 20 is shortened, and the shock-absorbing material between the lead screw 6 and the valve needle 20 can be reduced, reducing the manufacturing cost.

[0024] As Figure 3As shown in the figure, a spring 5 and a bearing 18 are sleeved on the lower end of the lead screw 6. An inner hole is provided at one end of the valve needle 20 close to the lead screw 6. The inner ring of the bearing 18 is fitted with the lead screw 6, and the outer ring of the bearing 18 is fitted with the inner hole of the valve needle 20. The valve needle 20 is provided with an inner hole, and the lead screw 6 pushes the valve needle 20 to move vertically through the inner hole, and the inner hole improves the stability of the vertical movement of the lead screw 6; the lead screw 6 realizes vertical movement through threads, and at the same time, relative rotation will also occur between the lead screw 6 and the valve needle 20. The bearing 18 is arranged between the lead screw 6 and the valve needle 20 to reduce the friction between the lead screw 6 and the valve needle 20; the clearance between the outer ring of the bearing 18, the rotor and the inner ring of the bearing 18 can reduce the coaxiality error between the lead screw 6 and the inner hole of the valve needle 20, the influence on the vertical movement of the lead screw 6 pushing the valve needle 20, and reduce the wear between the lead screw 6 and the valve needle 20.

[0025] As Figure 3 shown in the figure, a valve needle bushing and a lead screw bushing 19 are provided above the bearing 18. The valve needle bushing is fixed to the upper end of the valve needle 20, and the lead screw bushing 19 is fixed to the lower end of the lead screw 6. The valve needle bushing fixes the outer ring of the bearing 18, and the lead screw bushing 19 fixes the inner ring of the bearing 18.

[0026] The utility model has the following beneficial effects: it solves the problem that in the existing electronic expansion valve, due to the positioning of the nut 7 and the valve port 1, the valve port 1 and the valve seat 3, and the sleeve 9 and the valve seat 3, after the accumulation of multiple positioning errors, the relative position deviation between the nut 7 and the sleeve 9 is relatively large, and finally the interference between the magnet 8 and the sleeve 9 occurs, resulting in the jamming of the magnet 8 and the sleeve 9 and a large number of defective assembly parts; it solves the problem that in the existing electronic expansion valve, due to the relatively long protruding part of the valve port 1, the valve seat 3 and the valve port 1 are in an interference fit, and iron filings appear on the contact surface between the two during the press-fitting process, and the force is unbalanced, and finally it is pressed out of position, resulting in a large number of defective assembly parts; it solves the problem that in the existing electronic expansion valve, due to the relatively long protruding part of the valve port 1, the valve needle 20 and the valve port 1 use more materials and the processing cost is relatively high, resulting in high material production and processing costs; a bearing 18 is arranged between the lead screw 6 and the valve needle 20 to reduce the wear between the lead screw 6 and the valve needle 20.

[0027] In this article, specific examples are used to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application. The above is only the preferred implementation manner of the present application. It should be noted that due to the limited nature of written expression and the objectively infinite specific structures, for those of ordinary skill in the art in this technical field, without departing from the principle of the present application, several improvements, refinements or changes can also be made, or the above technical features can be combined in an appropriate manner; these improvements, refinements, changes or combinations, or the direct application of the inventive concept and technical solution of the utility model to other occasions without improvement, should all be regarded as the protection scope of the present application.

Claims

1. An electronic expansion valve nut positioning structure, comprising a valve seat (3), a nut (7) and a sleeve (9), characterized in that: The upper end of the valve seat (3) is provided with a valve seat extension (15), the outer circle of the valve seat (3) is provided with a step, the lower end of the nut (7) is provided with a nut extension (14), the valve seat extension (15) and the nut extension (14) are matched for positioning, and the step is fixed to the lower end of the sleeve (9).

2. The electronic expansion valve nut positioning structure according to claim 1, characterized in that: The nut extension portion (14) at the lower end of the nut (7) is annular, and the inner ring of the nut extension portion (14) is matched and fixed with the valve seat extension portion (15).

3. The electronic expansion valve nut positioning structure according to claim 1, characterized in that: The electronic expansion valve further comprises a valve port (1) and a valve needle (20); a valve port extension portion (21) is provided at the upper end of the valve port (1); the valve port extension portion (21) is annular; an outer ring of the valve port extension portion (21) is fixed to an inner ring of the valve seat (3); and a length of the valve needle (20) matches a length of the valve port extension portion (21).

4. The electronic expansion valve nut positioning structure according to claim 3, characterized in that: The valve needle (20) is capable of moving up and down within the inner circle of the valve port extension (21), and a long pin (2) is provided between the valve needle (20) and the valve port (1).

5. The electronic expansion valve nut positioning structure according to claim 3, characterized in that: The electronic expansion valve further comprises a slip ring (12) and a brake rod (11); the nut (7) is provided with an inner hole; the upper end of the nut (7) is provided with an outer thread; the inner hole is provided with an inner thread; the slip ring (12) and the outer thread at the upper end of the nut (7) match; the brake rod (11) is connected to the slip ring (12); and the slip ring (12) is fixed in the electronic expansion valve by means of the brake rod (11).

6. The electronic expansion valve nut positioning structure according to claim 5, characterized in that: The electronic expansion valve further comprises a screw rod (6), the upper portion of the screw rod (6) being provided with an external thread which matches the inner hole of the nut (7), and the lower end of the screw rod (6) being able to directly contact the valve needle (20).

7. The electronic expansion valve nut positioning structure according to claim 6, characterized in that: The lower end of the screw rod (6) is sleeved with a spring (5) and a bearing (18); the valve needle (20) is provided with an inner hole at one end close to the screw rod (6); the inner ring of the bearing (18) cooperates with the screw rod (6); and the outer ring of the bearing (18) cooperates with the inner hole of the valve needle (20).

8. The electronic expansion valve nut positioning structure according to claim 7, characterized in that: A valve needle (20) bushing and a screw bushing (19) are provided above the bearing (18); the valve needle (20) bushing is fixed to the upper end of the valve needle (20), and the screw bushing (19) is fixed to the lower end of the screw (6).

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