Electromagnet structure of variable valve timing system

Abstract

The invention belongs to the technical field of variable valve timing systems of engines, and discloses an electromagnet structure of a variable valve timing system. The magnetic core body (12) is of a cylindrical structure, a plurality of concave blind grooves (121) are formed in the periphery of the magnetic core body (12) along the circumference according to gaps, a shaft hole (123) is formed in the end face of the magnetic core body (12), an oil passing groove (122) is formed in the shaft hole (123), a cavity is formed in one end of a front yoke sleeve (22) of the front yoke sleeve sub-assembly (2), an opening cavity (221) is formed in the cavity, a plurality of oil passing holes (223) are formed in the end face of the front yoke sleeve (22), and the opening cavity (221) is communicated with the oil passing holes (223). A limiting boss (222) and a bearing hole (224) are arranged on the end face of the front yoke sleeve (22) in the axial direction, and the periphery of a cavity of the front yoke sleeve (22) is a conical surface (225). According to the electromagnet structure of the variable valve timing system, the problem of motion clamping stagnation of the magnetic core body can be effectively solved through an electromagnet guide-sleeve-free structure, magnetic circuit gaps are reduced, and weakening of generated electromagnetic force is reduced.

Description

Technical Field

[0001] This invention belongs to the technical field of variable valve timing systems for engines, and more specifically, relates to an electromagnet structure for a variable valve timing system. Background Technology

[0002] Variable Valve Timing (VVT) technology in engines primarily optimizes engine performance and fuel efficiency at different engine speeds by altering the opening and closing times of the intake and exhaust valves. The centrally located VVT design separates the electromagnet and valve body of the solenoid valve, integrating the valve body with the phaser. This offers advantages such as shortening the system oil passage, reducing oil leakage, and improving the phaser's response speed and control accuracy. Currently, the centrally located VVT design is widely used. In existing centrally located VVT electromagnet structures, guide sleeves are mostly used to guide the movement of the magnetic core. Because the guide sleeve has a multi-stage concave, thin-walled structure, it not only places high demands on manufacturing precision but is also prone to deformation of the inner wall during production, transportation, and assembly, potentially causing jamming of the magnetic core. Furthermore, the guide sleeve's placement between the magnetic core and the rear yoke increases the magnetic circuit gap, weakening the generated electromagnetic force. Therefore, there is still significant room for improvement in existing VVT electromagnet structures.

[0003] In the prior art, there is a technology entitled "A Centrally Positioned Variable Valve Timing System Proportional Solenoid Valve" with publication (announcement) number "CN107420616A". This technology provides a centrally positioned variable valve timing system proportional solenoid valve applied in the field of variable valve timing systems for automobile engines. The centrally positioned variable valve timing system proportional solenoid valve has an electromagnetic coil (4) installed inside the solenoid valve housing (1), and a magnetic core (5) inside the solenoid valve housing (1) is located at the center of the electromagnetic coil (4). 5) A push rod (6) is installed on the top. A core hole (16) is provided in the middle position of the core body (5) to penetrate the core body (5). A vent hole (7) is provided on the front yoke (2) to penetrate the front yoke (2). A circular hole (8) is provided on the rear yoke (3) to penetrate the rear yoke (3). The proportional solenoid valve of the centrally located variable valve timing system of the present invention has a simple structure, reduces the weight of the solenoid valve, reduces the air resistance when the core body is working, improves the characteristics of the electromagnet, optimizes the performance of the solenoid valve, and improves the overall quality.

[0004] However, this technology does not address the technical issues and solutions of this application. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an electromagnet structure for a variable valve timing system that can effectively solve the problem of magnetic core movement jamming, reduce magnetic circuit gap, and reduce the weakening of the generated electromagnetic force by using an electromagnet without a guide sleeve structure.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: This invention relates to an electromagnet structure for a variable valve timing system. The electromagnet's core assembly includes a core shaft, a core body, and a steel ball. The core body is a cylindrical structure with multiple recessed blind grooves spaced along its outer periphery. The end face of the core body has a shaft hole along the axial direction, and an oil passage groove is provided on the side of the shaft hole. The front yoke assembly includes a bearing and a front yoke sleeve. One end of the front yoke sleeve has a cavity with an open cavity inside. The end face of the front yoke sleeve has multiple oil passage holes, which are connected. The end face of the front yoke sleeve has a limiting boss and a bearing hole along the axial direction. The outer periphery of the cavity of the front yoke sleeve is conical.

[0007] The electromagnet includes a magnetic core assembly, a front yoke assembly, and a solenoid assembly.

[0008] The solenoid sub-assembly includes a housing, a coil sub-assembly, an integrated rear yoke, a bushing, and an injection-molded body.

[0009] The integrated rear yoke sleeve includes a cylindrical rear yoke sleeve and a flange plate. The rear yoke sleeve has a circular cavity in the middle, and the flange plate has multiple glue inlet holes and recessed positioning grooves.

[0010] When assembling the solenoid sub-assembly, the outer shell is flush with the flange plate of the integrated rear yoke sleeve, the coil sub-assembly is set inside the opening of the outer shell, and the center hole of the coil sub-assembly is fitted onto the rear yoke sleeve of the integrated rear yoke sleeve.

[0011] The positioning groove and positioning slot of the outer shell of the solenoid sub-assembly together position the setting direction of the coil sub-assembly.

[0012] The steel ball is movably disposed in the blind slot of the magnetic core. The length of the blind slot is greater than the diameter of the steel ball. The blind hole is a semi-circular blind slot. After the steel ball is installed in the blind slot, an external force is applied to narrow the semi-circular blind hole to prevent it from falling off. The magnetic core shaft is interference-fitted into the shaft hole of the magnetic core.

[0013] The bearing of the front yoke assembly is interference-fitted into the bearing hole of the front yoke assembly; the front yoke assembly is interference-fitted into the yoke hole of the solenoid assembly; and the magnetic core assembly is gapped into the circular cavity of the solenoid assembly.

[0014] The magnetic core shaft gap of the magnetic core sub-assembly is set in the bearing of the front yoke sub-assembly, forming a centrally located VVT electromagnet without a guide sleeve.

[0015] The solenoid sub-assembly has an O-ring on the outer ring of the injection molded body, and the wire harness connector of the injection molded body is provided with sealant. The outer shell and the insert are plastically encapsulated through the glue inlet hole of the integrated rear yoke sleeve.

[0016] The working principle and beneficial effects of the technical solution adopted in this invention are as follows: The electromagnet structure of the variable valve timing system described in this invention can effectively solve the problem of magnetic core movement jamming by using a non-conducting sleeve structure for the electromagnet, reducing the magnetic circuit gap and minimizing the weakening of the generated electromagnetic force. Attached Figure Description

[0017] The following is a brief explanation of the contents depicted in the accompanying drawings and the markings therein: Figure 1 This is a schematic diagram of the electromagnet structure of the variable valve timing system described in this invention; Figure 2 This is a schematic diagram of the electromagnet structure of the variable valve timing system described in this invention; Figure 3 This is a schematic diagram of the electromagnet structure of the variable valve timing system described in this invention; Figure 4 This is a schematic diagram of the electromagnet structure of the variable valve timing system described in this invention; Figure 5 This is a schematic diagram of the electromagnet structure of the variable valve timing system described in this invention; Figure 6 This is a schematic diagram of the electromagnet structure of the variable valve timing system described in this invention; Figure 7 This is a schematic diagram of the electromagnet structure of the variable valve timing system described in this invention; Figure 8 This is a schematic diagram of the electromagnet structure of the variable valve timing system described in this invention; Figure 9 This is a schematic diagram of the electromagnet structure of the variable valve timing system described in this invention; The labels in the attached diagram are as follows: 1. Magnetic core sub-assembly; 2. Front yoke sub-assembly; 3. Solenoid sub-assembly; 4. O-ring seal. Detailed Implementation

[0018] The following description, with reference to the accompanying drawings, provides a more detailed explanation of the specific embodiments of the present invention, including the shape and structure of each component, the relative positions and connections between the parts, the functions and working principles of each part: As attached Figure 1 - Appendix Figure 9As shown, the present invention is an electromagnet structure for a variable valve timing system, wherein the electromagnet includes a magnetic core sub-assembly 1, a front yoke sub-assembly 2, and a solenoid sub-assembly 3. The electromagnet's core assembly 1 includes a core shaft 11, a core body 12, and steel balls 13. The core body 12 has a cylindrical structure, with multiple recessed blind grooves 121 spaced apart along its outer periphery. The end face of the core body 12 has a shaft hole 123 along its axial direction, and an oil passage groove 122 is provided on the side of the shaft hole 123. The front yoke assembly 2 includes a bearing 21 and a front yoke 22. One end of the front yoke 22 has a cavity with an open cavity 221 inside. The end face of the front yoke 22 has multiple oil passage holes 223, which are connected. A limiting boss 222 and a bearing hole 224 are provided axially on the end face of the front yoke 22. The outer periphery of the cavity of the front yoke 22 is a conical surface 225. To address the shortcomings of the prior art, an improved technical solution is proposed. In the structural setup, the magnetic core sub-assembly 1, the front yoke sub-assembly 2, the solenoid sub-assembly 3, and the sealing ring 4 are fabricated separately. These components are then assembled to form an electromagnet. When the electromagnet operates, the coil sub-assembly 32 generates an electromagnetic field. Under the magnetization of this field, the magnetic core sub-assembly 1 generates an electromagnetic force and moves within the opening 221 of the front yoke 22. The limiting boss 222 at the bottom of the opening 221 restricts the displacement of the magnetic core sub-assembly 1, preventing the magnetic core 12 and the front yoke 22 from having an excessively large contact surface. Adjusting the angle of the conical surface 225 changes the magnitude of the generated electromagnetic force. During the movement of the magnetic core assembly 1, engine oil can enter the electromagnet's inner cavity through the oil passage 223 of the front yoke sleeve 22. The oil passage 122 enables oil exchange between the opening 221 and the opening 311, achieving lubrication for the movement of the magnetic core assembly 1. Simultaneously, the bearing 21 and the steel ball 13 jointly support and guide the movement of the magnetic core assembly 1. This support structure not only has low friction but also allows the steel ball to directly contact the inner wall of the rear yoke sleeve 331, reducing the magnetic circuit gap and positively impacting the electromagnetic force. The electromagnet's oil circuit is sealed: the O-ring seal 4 provides external sealing for the VVT ​​electromagnet, and the sealant 36 provides internal sealing, satisfying the electromagnet's operating performance. The variable valve timing system electromagnet structure described in this invention effectively solves the problem of magnetic core movement jamming through the electromagnet's guide sleeve-less structure, reducing the magnetic circuit gap and minimizing the weakening of the generated electromagnetic force.

[0019] The solenoid sub-assembly 3 includes a housing 31, a coil sub-assembly 32, an integrated rear yoke sleeve 33, an insert 34, and an injection-molded body 35. The integrated rear yoke sleeve 33 includes a cylindrical rear yoke sleeve 331 and a flange plate 332. The rear yoke sleeve 331 has a circular cavity 333 in the middle, and the flange plate 332 has multiple glue inlet holes 334 and a recessed positioning groove 335. During assembly, the housing 31 is flush with the flange plate 332 of the integrated rear yoke sleeve 33, and the coil sub-assembly 32 is positioned within the opening 311 of the housing 31. The center hole of the coil sub-assembly 32 is fitted onto the rear yoke sleeve 331 of the integrated rear yoke sleeve 33. The positioning groove 313 and the positioning groove 335 of the housing 31 of the solenoid sub-assembly 3 together position the coil sub-assembly 32. This structure forms a solenoid sub-assembly 3 that meets the requirements of actual use.

[0020] The steel ball 13 is movably disposed within the blind slot 121 of the magnetic core 12. The length of the blind slot 121 is greater than the diameter of the steel ball 13. The blind hole 121 is a semi-circular blind slot. After the steel ball 13 is installed into the blind slot 121, an external force is applied to narrow the semi-circular blind hole 121 to prevent it from detaching. The magnetic core shaft 11 is interference-fitted into the shaft hole 123 of the magnetic core 12. The above structure forms the magnetic core sub-assembly 1.

[0021] The bearing 21 of the front yoke assembly 2 is interference-fitted into the bearing hole 224 of the front yoke 22; the front yoke assembly 2 is interference-fitted into the yoke hole 312 of the solenoid assembly 3, and the magnetic core assembly 1 is loosely positioned within the circular cavity 333 of the solenoid assembly 3. The magnetic core shaft 11 of the magnetic core assembly 1 is loosely positioned within the bearing 21 of the front yoke assembly 2, forming a centrally located VVT electromagnet without a guide sleeve.

[0022] The solenoid sub-assembly 3 has an O-ring 4 on the outer ring of its injection-molded body 35. Sealant 36 is applied to the wire harness connector of the injection-molded body 35, and the outer shell 31 and the insert 34 are encapsulated through the glue inlet 334 of the integrated rear yoke sleeve 33. With this structure, the electromagnet is installed via the injection-molded body 35, while the O-ring 4 provides an external seal.

[0023] The connection relationships of the relevant components of the electromagnet structure of the variable valve timing system described in this invention are as follows: (see attached diagram) Figure 1 - Appendix Figure 8As shown, the steel ball 13 is spaced within the semi-circular blind groove 121 of the magnetic core 12. External force is used to narrow the blind groove 121, preventing the steel ball 13 from detaching. The steel ball 13 can only slide within the long groove defined by the blind groove 12 and will not detach from it. The magnetic core shaft 11 is interference-fitted into the shaft hole 123 of the magnetic core 12 for fixed installation. These components form the magnetic core sub-assembly 1. The bearing 21 is interference-fitted into the bearing hole 224 of the front yoke sleeve 22 for fixed installation, forming the front yoke sleeve sub-assembly 2. The outer shell 31 is flush with the flange plate 332 of the integrated rear yoke sleeve 33. The coil sub-assembly 32 is located within the opening 311 of the outer shell 31. The center hole of the coil sub-assembly 32 is fitted onto the rear yoke sleeve 331 of the integrated rear yoke sleeve 33. Positioning grooves 313 and 335 jointly position the coil sub-assembly 32. The wire harness connector of the injection molded body 35 is provided with sealant 36, and the outer shell 31 and the insert 34 are coated and cured through the glue inlet 334 of the integrated rear yoke 33. The above components form a solenoid sub-assembly 3. The front yoke sub-assembly 2 is interference-fitted in the yoke hole 312 of the solenoid sub-assembly 3. The magnetic core sub-assembly 1 is gapped in the circular cavity 333 of the solenoid sub-assembly 3, and the magnetic core shaft 11 of the magnetic core sub-assembly 1 is gapped in the bearing 21 of the front yoke sub-assembly 2. The O-ring seal 4 is sleeved on the injection molded body 35 to form an electromagnet.

[0024] The working principle of the electromagnet structure of the variable valve timing system described in this invention is as follows: When the coil sub-assembly 32 is energized, an electromagnetic field is formed. Under the magnetization effect of this electromagnetic field, the magnetic core sub-assembly 1 generates an electromagnetic force and moves within the opening 221 of the front yoke sleeve 22. The limiting boss 222 at the bottom of the opening 221 can limit the displacement of the magnetic core sub-assembly 1, preventing the magnetic core 12 and the front yoke sleeve 22 from having an excessively large contact surface. Adjusting the angle of the conical surface 225 can change the magnitude of the generated electromagnetic force. During the movement of the magnetic core sub-assembly 1, engine oil enters the electromagnet cavity through the oil passage 223 of the front yoke sleeve 22. The oil passage 122 enables oil exchange between the opening 221 and the opening 311, thereby achieving lubrication of the magnetic core sub-assembly 1. The oil circuit of the electromagnet is sealed as follows: Figure 9 As shown, the O-ring 4 provides external sealing for the VVT ​​electromagnet, and the sealant 36 provides internal sealing for the VVT ​​electromagnet, thus satisfying the working performance requirements of the electromagnet.

[0025] The key improvement of this invention is that it proposes a centrally located VVT electromagnet without a guide sleeve, which uses bearings and steel balls to support and guide the movement of the magnetic core assembly. This structure has low friction, which can effectively solve the problem of magnetic core movement jamming. At the same time, the steel balls can directly contact the inner wall of the rear yoke sleeve, which can reduce the magnetic circuit gap and has a positive effect on improving the electromagnetic force.

[0026] The present invention has been described above with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. An electromagnet structure for a variable valve timing system, characterized in that: The electromagnet's core assembly (1) includes a core shaft (11), a core body (12), and a steel ball (13). The core body (12) has a cylindrical structure. Multiple recessed blind grooves (121) are spaced along the outer periphery of the core body (12). A shaft hole (123) is provided on the end face of the core body (12) along the axial direction. An oil passage groove (122) is provided on the side of the shaft hole (123). The front yoke assembly (2) includes... Includes a bearing (21) and a front yoke sleeve (22). One end of the front yoke sleeve (22) is provided with a cavity, the inside of which is an open cavity (221). The end face of the front yoke sleeve (22) is provided with multiple oil passage holes (223). The open cavity (221) and the oil passage holes (223) are connected. The end face of the front yoke sleeve (22) is provided with a limiting boss (222) and a bearing hole (224) along the axial direction. The outer periphery of the cavity of the front yoke sleeve (22) is a conical surface (225).

2. The electromagnet structure for the variable valve timing system according to claim 1, characterized in that: The electromagnet includes a magnetic core assembly (1), a front yoke assembly (2), and a solenoid assembly (3).

3. The electromagnet structure for the variable valve timing system according to claim 1 or 2, characterized in that: The solenoid sub-assembly (3) includes a housing (31), a coil sub-assembly (32), an integrated rear yoke sleeve (33), a bushing (34), and an injection-molded body (35).

4. The electromagnet structure for the variable valve timing system according to claim 3, characterized in that: The integrated rear yoke sleeve (33) includes a cylindrical rear yoke sleeve (331) and a flange plate (332). The rear yoke sleeve (331) has a circular cavity (333) in the middle, and the flange plate (332) has multiple glue inlet holes (334) and recessed positioning grooves (335).

5. The electromagnet structure for the variable valve timing system according to claim 4, characterized in that: When the solenoid sub-assembly (3) is assembled, the outer shell (31) is flush with the flange plate (332) of the integrated rear yoke sleeve (33), the coil sub-assembly (32) is set in the opening (311) of the outer shell (31), and the center hole of the coil sub-assembly (32) is sleeved on the rear yoke sleeve (331) of the integrated rear yoke sleeve (33).

6. The electromagnet structure for the variable valve timing system according to claim 5, characterized in that: The positioning groove (313) and positioning slot (335) of the outer shell (31) of the solenoid sub-assembly (3) together position the setting direction of the coil sub-assembly (32).

7. The electromagnet structure for the variable valve timing system according to claim 1 or 2, characterized in that: The steel ball (13) is movably disposed in the blind slot (121) of the magnetic core (12). The length of the blind slot (121) is greater than the diameter of the steel ball (13). The blind hole (121) is a semi-circular blind slot. After the steel ball (13) is installed in the blind slot (121), the semi-circular blind hole (121) is narrowed by applying external force to prevent it from falling off. The magnetic core shaft (11) is interference-fitted into the shaft hole (123) of the magnetic core (12).

8. The electromagnet structure for the variable valve timing system according to claim 1 or 2, characterized in that: The bearing (21) of the front yoke assembly (2) is interference-fitted into the bearing hole (224) of the front yoke (22); the front yoke assembly (2) is interference-fitted into the yoke hole (312) of the solenoid assembly (3); and the magnetic core assembly (1) is gapped into the circular cavity (333) of the solenoid assembly (3).

9. The electromagnet structure for a variable valve timing system according to claim 1 or 2, characterized in that: The magnetic core shaft (11) of the magnetic core sub-assembly (1) is positioned within the bearing (21) of the front yoke sub-assembly (2) to form a centrally located VVT electromagnet without a guide sleeve.

10. The electromagnet structure for the variable valve timing system according to claim 3, characterized in that: The outer ring of the injection-molded body (35) of the solenoid sub-assembly (3) is provided with an O-ring (4), the wire harness connector of the injection-molded body (35) is provided with sealant (36), and the outer shell (31) and the insert (34) are plastic-coated through the glue inlet (334) of the integrated rear yoke sleeve (33).

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