Variable force solenoid armature push rod subassembly bearing structure

Abstract

The utility model provides a kind of variable force solenoid valve armature push rod subassembly bearing structure, including rubber base, bushing, push rod and armature;Rubber base is provided with the installation groove of top opening inside;The groove bottom of installation groove is provided with support table along the axial direction;The top surface of support table is provided with the coaxial distribution of stepped hole;Stepped hole includes the first hole in upper and the second hole in lower;Bushing is fixed on the first hole, push rod is movably connected in the second hole, and push rod is coaxially gap fit in bushing;Armature is coaxially fixed on push rod, and the upper end of push rod passes through armature, and makes armature suit on support table.The utility model's advantage this structure saves the bearing tube structure of higher unit price, increases hot melting bushing and combines with original pole piece bushing to form upper and lower double bushing bearing structure, structure is more simple and stable, further improve the response speed and control accuracy of solenoid valve, reduce solenoid valve material cost, improve market competitiveness.

Description

Technical Field

[0001] This utility model relates to the field of variable force solenoid valve technology, specifically to a bearing structure for an armature push rod assembly of a variable force solenoid valve. Background Technology

[0002] A variable force solenoid valve is an electromagnetic actuator used in engine fluid transmission systems to control pressure, volume, or flow direction. In a VCT system, the system controls the VFS pushrod stroke and thrust via a PWM signal from the ECU. The pushrod pushes a spool valve to control the inlet and outlet of the phaser, thereby changing the phase.

[0003] Common variable force solenoid valves have mature structural designs, but involve numerous sub-components and require high manufacturing precision. Among these, the bearing design of the armature actuator sub-assembly significantly impacts the solenoid valve's response and durability. Current armature actuator sub-assembly bearing designs often employ a structure on the actuator side, such as the solenoid valve bearing tube fixing structure disclosed in Chinese Utility Model Patent (Publication No. CN220891240U). In this design, the bearing pair directly relies on the armature's outer diameter and the bearing tube's inner diameter, resulting in direct sliding friction during solenoid valve operation. To improve durability, this design often requires surface hardening of the bearing tube. This hardening process demands high manufacturing precision, is complex, and is costly. Utility Model Content

[0004] This invention addresses the technical problems of existing variable force solenoid valves, which have numerous structural components, high manufacturing precision requirements, and high manufacturing costs. To overcome these shortcomings, this invention provides a solution that eliminates the high-cost bearing tube structure, adds a hot-melt bushing, and combines it with the original top electrode bushing to form an upper and lower double bushing bearing structure for the push rod. This results in a simpler and more stable structure, further improving the response speed and control precision of the solenoid valve, reducing the material cost of the solenoid valve, and enhancing its market competitiveness.

[0005] To achieve the purpose of this utility model, the following technical solution is adopted: A bearing structure for a variable force solenoid valve armature push rod assembly includes a rubber-coated base, a bushing, a push rod, and an armature. The rubber-coated base has a mounting groove with a top opening. A support platform is axially positioned at the bottom of the mounting groove. The top surface of the support platform has coaxially distributed stepped holes. Each stepped hole includes a first hole at the top and a second hole at the bottom, with the diameter of the first hole being larger than that of the second hole. The bushing is fixed to the first hole, and the push rod is movably connected to the second hole, with the push rod coaxially clearance-fitted within the bushing. The armature is coaxially fixed to the push rod, with the upper end of the push rod passing through the armature and fitting the armature onto the support platform. Based on electromagnetic functional characteristics analysis, this structure removes part of the armature core material to create a cavity to accommodate the support platform, making the internal space more rational. While ensuring the function of the solenoid valve, the high-priced bearing tube is eliminated. The push rod extends from the inner cavity of the armature and enters the bushing in the support platform, forming a double-shoulder bearing structure with the pole bushing originally inserted at the other end of the push rod. This makes the structure simpler and more stable, reduces the material cost of the solenoid valve, and improves market competitiveness. At the same time, changing the original outer diameter bearing surface of the armature to the outer diameter bearing surface of the push rod can greatly reduce the friction between the armature and the push rod sub-assembly in axial linear sliding and circumferential rotation, which is beneficial to improving the response speed and control accuracy of the solenoid valve.

[0006] Preferably, the bushing is fixedly installed in the first hole using a hot-melt press-fit process. This innovative hot-melt press-fit process, along with the design of the hot-melt bushing component, simplifies the assembly process, ensures a secure connection between the bushing and the support platform, prevents loosening, reduces manufacturing costs, and improves production efficiency.

[0007] Preferably, the bushing has anti-detachment grooves on its outer peripheral wall; these grooves are distributed axially and are radially recessed. When molten plastic flows into the anti-detachment grooves and solidifies, it prevents the bushing from detaching under the friction of the push rod, thus enhancing the stability of the push rod's movement and improving the overall structural durability.

[0008] Preferably, the anti-detachment groove extends axially from the top surface of the bushing to the middle of the bushing. This further facilitates the retention of molten plastic within the anti-detachment groove, thereby enhancing the anti-detachment effect while avoiding weakening the overall structural strength of the bushing.

[0009] Preferably, there are two anti-detachment grooves, both with radially curved walls, and the two grooves are located on opposite sides of the bushing. The symmetrically arranged curved grooves evenly distribute stress, avoiding localized stress concentration, and the curved groove walls facilitate plastic flow and curing, further enhancing the reliability of the anti-detachment mechanism.

[0010] Preferably, the bushing has radially distributed vents on at least one end face, with one radial end of each vent connected to the outer wall of the bushing and the other radial end connected to the inner wall of the bushing. A vent groove is axially arranged on the outer peripheral wall of the bushing corresponding to each vent, and the vent groove is connected to the vent. The venting structure of the bushing can balance the gas pressure when the push rod moves inside the support platform, preventing pressure differences from hindering the push rod's movement and improving response smoothness and control accuracy.

[0011] Preferably, there are two exhaust ports, located on the same side end face and on opposite sides of the two exhaust port bushings. This symmetrical exhaust design improves exhaust efficiency, ensures pressure balance within the system, and further optimizes the pushrod's motion performance.

[0012] Preferably, the upper end face of the bushing is slightly higher than the upper end face of the support platform, and the lower end face of the bushing is in contact with the stepped surface of the first hole. During assembly, the bushing is heated and precisely pressed into the support platform. The upper end face of the bushing is slightly higher than the plastic surface to stop the armature, and the lower end face is in contact with the stepped surface of the first hole in the support platform to ensure axial positioning accuracy and improve overall assembly stability.

[0013] Preferably, the support platform is integrally formed on the rubber-coated base or fixedly installed on the rubber-coated base in the form of separate inserts. These two methods adapt to different manufacturing process requirements, ensuring the positioning of the push rod and the armature. The integrally formed structure has high strength and good sealing performance, making it suitable for high-pressure environments; the separate insert form facilitates maintenance and replacement, improving product maintainability.

[0014] The advantages of this invention are: it eliminates the need for the expensive bearing tube and forms a double-shoulder bearing structure by using a bushing and an electrode bushing; it changes the sliding friction surface from the outer diameter of the armature to the outer diameter of the push rod, significantly reducing friction in the direction of motion; it reduces frictional resistance and improves the response speed and control accuracy of the solenoid valve; it reduces the number of parts and processing requirements, thus reducing material and manufacturing costs; and the double-shoulder bearing structure improves the coaxiality and operational stability of the push rod and armature. Attached Figure Description

[0015] Figure 1 is a structural schematic diagram of the bearing structure of the variable force solenoid valve armature push rod assembly of this utility model. Figure 2 is a cross-sectional view of the bearing structure of the variable force solenoid valve armature push rod assembly of this utility model. Figure 3 is an exploded view of the bearing structure of the variable force solenoid valve armature push rod assembly of this utility model. Figure 4 is a structural schematic diagram of the bushing of this embodiment of the utility model. Figure 5 is a structural schematic diagram of the bushing of the alternative solution of this utility model.

[0016] Explanation of reference numerals in the attached figures: 1. Rubber-coated base; 11. Mounting slot; 12. Support platform; 13. First hole; 14. Second hole; 2. Bushing; 21. Anti-detachment slot; 22. Exhaust port; 23. Exhaust groove; 3. Push rod; 4. Armature; 41. Clearance slot; 5. Housing; 6. Magnetic tube; 7. Coil assembly; 8. Magnetic pole piece; 81. Positioning through hole; 9. Pole piece bushing. Detailed Implementation

[0017] First, those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the embodiments of this application and are not intended to limit the scope of protection of the embodiments of this application. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0018] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0019] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0020] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0021] like Figures 1 to 5As shown, a bearing structure for a variable force solenoid valve armature push rod assembly includes a rubber-coated base 1, a bushing 2, a push rod 3, an armature 4, and a housing 5. The rubber-coated base 1 has a top-opening mounting groove 11. A support platform 12 protrudes axially from the center of the bottom of the mounting groove 11. The support platform 12 is integrally formed on the rubber-coated base 1 or fixedly installed on the rubber-coated base 1 as a separate insert. These two methods adapt to different manufacturing process requirements, ensuring the positioning of the push rod 3 and the armature. The integrally formed structure has high strength and good sealing performance, suitable for high-pressure environments; the separate insert form facilitates maintenance and replacement, improving product maintainability. In this embodiment, the support platform 12 is integrally formed and set at the bottom of the mounting groove 11. The top surface of the support platform 12 has downward-opening, coaxially distributed stepped holes; the stepped holes include a first hole 13 located at the top and a second hole 14 located at the bottom, with the diameter of the first hole 13 being larger than the diameter of the second hole 14. Bushing 2 is fixed to the first hole 13. Push rod 3 slides axially and rotates circumferentially within the second hole 14, and is coaxially fitted with clearance within bushing 2. Armature 4 is coaxially fixed and press-fitted onto push rod 3, and is press-fitted with push rod 3. The upper end of push rod 3 passes through armature 4, allowing armature 4 to be fitted onto support platform 12. Based on electromagnetic functional characteristics analysis, this structure removes part of the core material of armature 4 to form a cavity to accommodate support platform 12, making the internal space more rational. When the variable force solenoid valve is energized, it generates electromagnetic force to push armature 4 and push rod 3 to move. Push rod 3 touches the central bolt slide valve until the spring force is balanced. The outer casing 5 is coaxially mounted on top of the rubber-coated base 1, forming an installation space between them. A magnetic tube 6 and a coil assembly 7 are coaxially mounted within this space. The magnetic tube 6 is fitted around the armature 4 and fixed to the outer casing 5, with an interference fit between the magnetic tube 6 and the outer casing 5. The inner diameter of the magnetic tube 6 is clearance-fitted with the outer diameter of the armature 4. The coil assembly 7 is fitted around the magnetic tube 6 and fixed to the outer casing 5, with an interference fit between the coil assembly 7 and the outer casing 5. The coil assembly 7 includes a hollow cylindrical frame and copper wire wound around the frame. A magnetic pole piece 8 is coaxially positioned in the center of the top surface of the outer casing 5, and the magnetic pole piece 8 is fixed to the outer casing 5 by rubber injection molding. A positioning through hole 81 is coaxially and penetratingly provided on the magnetic pole piece 8. A pole piece bushing 9 is press-fitted into the positioning through hole 81, with an interference fit between the pole piece bushing 9 and the magnetic pole piece 8. The upper end of the push rod 3 passes through the electrode bushing 9, and the push rod 3 and the electrode bushing 9 are in clearance fit. The top surface of the armature 4 is provided with a relief groove 41 that matches the bottom of the electrode bushing 9 to avoid mechanical interference between the armature 4 and the electrode bushing 9, ensure smooth movement of the push rod 3, improve assembly tolerance, reduce manufacturing precision requirements, and reduce costs.

[0022] This structure forms a double-shoulder bearing structure through the cooperation of the electrode bushing 9 and the bushing 2. While ensuring the function of the solenoid valve, it eliminates the need for the slightly more expensive bearing tube, reducing costs, optimizing the magnetic circuit structure, improving electromagnetic efficiency, and enhancing response speed and control accuracy. The push rod 3 extends from the inner cavity of the armature 4 into the bushing 2 in the support platform 12, forming a double-shoulder bearing structure with the electrode bushing 9 originally inserted at the other end of the push rod 3. This structure is simpler and more stable, reducing the material cost of the solenoid valve and improving market competitiveness. At the same time, replacing the original outer diameter bearing surface of the armature 4 with the outer diameter bearing surface of the push rod 3 can greatly reduce the friction between the armature 4 and the push rod 3 subassemblies in axial linear sliding and circumferential rotation, which is beneficial to improving the response speed and control accuracy of the solenoid valve.

[0023] In this embodiment, the bushing 2 is fixedly installed in the first hole 13 by a hot-melt press-fit process. This is the first time that a hot-melt press-fit process has been introduced into the solenoid valve manufacturing process. A hot-melt bushing part has been designed to simplify the assembly process and ensure a firm connection between the bushing 2 and the support platform 12, preventing loosening. At the same time, it reduces manufacturing costs and improves production efficiency.

[0024] like Figures 2 to 4 As shown, anti-detachment grooves 21 are provided on the outer peripheral wall of the bushing 2; the anti-detachment grooves 21 are distributed axially and are radially recessed. When molten plastic flows into the anti-detachment grooves 21 and solidifies, it can prevent the bushing 2 from detaching under the frictional force of the push rod 3, enhancing the stability of the push rod 3's movement and improving the overall structural durability. In this embodiment, the anti-detachment grooves 21 extend axially from the top surface of the bushing 2 to the middle of the bushing 2. This further facilitates the retention of molten plastic within the anti-detachment grooves 21, thereby enhancing the anti-detachment effect while avoiding weakening the overall structural strength of the bushing. Furthermore, there are two anti-detachment grooves 21, both with radially curved walls, and the two grooves 21 are located on opposite sides of the bushing 2. The symmetrically arranged curved grooves evenly distribute stress, avoiding localized stress concentration. The curved groove walls facilitate plastic flow and solidification, further enhancing the reliability of the anti-detachment mechanism. The structure of the anti-detachment grooves 21 can also be as follows... Figure 5 As shown, there are also two anti-detachment grooves 21, and the structure is similar to that of this embodiment. The difference is that the anti-detachment groove 21 runs longitudinally through the entire outer peripheral wall of the bushing 2. The anti-detachment effect is not as good as that of this embodiment, which extends to the middle of the bushing 2. This embodiment is more conducive to the better accumulation of molten plastic.

[0025] like Figures 2 to 4As shown, the bushing 2 has radially distributed exhaust ports 22 on at least one end face. In this embodiment, the exhaust ports 22 are located on the lower end face of the bushing 2, and one radial end of the exhaust port 22 connects to the outer wall of the bushing 2, while the other radial end of the exhaust port 22 connects to the inner wall of the bushing 2. The exhaust ports 22 are rectangular. Corresponding to each exhaust port 22, an axial exhaust groove 23 is provided on the outer peripheral wall of the bushing 2. The exhaust groove 23 is rectangular and connected to the exhaust port 22, forming a right-angled exhaust distribution. The exhaust structure of the bushing 2 can balance the gas pressure when the push rod 3 moves inside the support platform 12 (the pressure should be oil pressure during machine operation), avoiding pressure differences that hinder the movement of the push rod 3, and improving response stability and control accuracy. In this embodiment, there are two exhaust ports 22, located on the same end face, on opposite sides of the bushing 2, and forming a cross distribution with the anti-detachment groove 21, located at the quarter points of the bushing. A symmetrical exhaust design improves exhaust efficiency, ensures pressure balance within the system, and further optimizes the motion performance of pushrod 3. The exhaust port 22 structure can also be configured as follows: Figure 5 As shown, the exhaust port 22 is not only located on the lower end face of the bushing 2, but also on the upper end face of the bushing 2, and the two exhaust ports 22 are symmetrically arranged to form a U-shaped exhaust distribution. In actual use, the exhaust port 22 is only located on the lower end face of the bushing 2, as adopted in this embodiment, which has a better effect.

[0026] like Figure 2 As shown, the upper end face of bushing 2 is slightly higher than the upper end face of support platform 12, and the lower end face of bushing 2 is in contact with the stepped surface of the first hole 13. During assembly, bushing 2 is heated and precisely pressed into support platform 12. The upper end face of bushing 2 is slightly higher than the plastic surface to stop armature 4, and the lower end face is in contact with the stepped surface of the first hole 13 in support platform 12 to ensure axial positioning accuracy and improve overall assembly stability.

[0027] When the coil assembly 7 is energized, a magnetic field is generated, and the magnetic circuit forms a loop through the magnetic tube 6, the magnetic pole piece 8, and the air gap (between the armature 4 and the magnetic pole piece 8). The electromagnetic force generated by the magnetic field attracts the armature 4, causing the push rod 3 to move upward and rotate with the central bolt. Guided by the bushing 2 and the pole piece bushing 9, the push rod 3 moves and rotates smoothly, pushing the external slide valve to change the oil circuit. When the coil current changes, the electromagnetic force changes accordingly, thereby achieving precise control of the stroke and output force of the push rod 3. Because the friction area between the push rod 3 and the two bushings is small, and the armature 4 is well positioned by the support platform 12, this structure is responsive, precise in control, runs smoothly, and is durable.

[0028] In summary, the advantages of this utility model are: Simplified structure and reduced cost: By eliminating the traditional bearing tube structure, the plastic support platform 12 is accommodated within the armature 4 cavity, and a bushing 2 is installed within the support platform 12, forming a double-shoulder bearing structure with the pole bushing 9 at the other end of the push rod 3. This structure eliminates the need for the expensive bearing tube and its surface hardening treatment process, significantly reducing material and processing costs.

[0029] Reduced friction and improved performance: The original friction between the outer diameter of the armature 4 and the inner diameter of the bearing tube is replaced by friction between the outer diameter of the push rod 3 and the inner diameter of the bushing 2. Since the diameter of the push rod 3 is much smaller than the outer diameter of the armature 4, the contact area of ​​the friction pair is greatly reduced, thereby significantly reducing the kinetic friction force, which is beneficial to improving the response speed, control accuracy and durability of the solenoid valve.

[0030] High stability and good reliability: The support platform 12 provides radial positioning and support for the armature 4. Combined with the double bushing bearing guide design, the movement of the armature 4 and the push rod 3 sub-assembly is more stable and the centering is better, reducing the risk of uneven wear and jamming, and improving the product's working reliability and service life.

[0031] Good processability and easy to produce: The bushing 2 adopts hot melt press fitting and other processes, and the connection is firm; the anti-detachment groove 21, vent 22 and vent groove 23 and other structures further improve the reliability of press fitting and working stability. At the same time, these structures are easy to process and implement, and are suitable for large-scale mass production.

[0032] In the description of the embodiments of this application, it should be noted that the terms "inner" and "outer" and other terms indicating direction or positional relationship are based on the direction or positional relationship shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this application.

[0033] In the description of this application, the references to terms such as "an embodiment," "some embodiments," "in this embodiment," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0034] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A variable force solenoid armature push rod sub-assembly bearing structure, characterized by, The device includes a rubber-coated base (1), a bushing (2), a push rod (3), and an armature (4). The rubber-coated base (1) has a mounting groove (11) with an open top. A support platform (12) is provided at the bottom of the mounting groove (11) along the axial direction. The top surface of the support platform (12) has stepped holes distributed coaxially. The stepped holes include a first hole (13) located above and a second hole (14) located below, and the diameter of the first hole (13) is larger than the diameter of the second hole (14). The bushing (2) is fixed on the first hole (13), and the push rod (3) is movably connected in the second hole (14), and the push rod (3) is coaxially clearance fitted in the bushing (2). The armature (4) is coaxially fixed on the push rod (3), and the upper end of the push rod (3) passes through the armature (4), and the armature (4) is fitted on the support platform (12).

2. The variable force solenoid armature push rod sub-assembly bearing structure of claim 1 wherein, The bushing (2) is fixedly installed in the first hole (13) by hot melt pressing process.

3. The variable force solenoid armature push rod sub-assembly bearing structure of claim 1 wherein, The bushing (2) has an anti-detachment groove (21) on its outer peripheral wall; the anti-detachment groove (21) is distributed along the axial direction and is radially recessed.

4. The variable force solenoid armature push rod sub-assembly bearing structure of claim 3, wherein, The anti-detachment groove (21) extends axially from the top surface of the bushing (2) to the middle of the bushing (2).

5. The variable force solenoid armature push rod sub-assembly bearing structure of claim 3 or 4, wherein, The number of anti-detachment grooves (21) is two, and the radial groove walls of the two anti-detachment grooves (21) are both arc-shaped, and the two anti-detachment grooves (21) are located on opposite sides of the bushing (2).

6. The variable force solenoid armature push rod sub-assembly bearing structure of claim 1 wherein, The bushing (2) has radially distributed exhaust ports (22) on at least one side end face, and one radial end of the exhaust port (22) is connected to the outer wall of the bushing (2), and the other radial end of the exhaust port (22) is connected to the inner wall of the bushing (2); an exhaust groove (23) is provided on the outer peripheral wall of the bushing (2) for each exhaust port (22) along the axial direction, and the exhaust groove (23) is connected to the exhaust port (22).

7. The variable force solenoid armature push rod sub-assembly bearing structure of claim 6 wherein, There are two exhaust ports (22), which are located on the same side end face and on opposite sides of the bushing (2).

8. The bearing structure of the variable force solenoid valve armature push rod assembly according to claim 1, characterized in that, The upper end face of the bushing (2) is slightly higher than the upper end face of the support platform (12), and the lower end face of the bushing (2) is in contact with the stepped surface of the first hole (13).

9. The variable force solenoid armature push rod sub-assembly bearing structure of claim 1 wherein, The support platform (12) is integrally formed on the rubber-coated base (1) or fixedly installed on the rubber-coated base (1) by means of separate inserts.

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