Rack assembly of steering system
By designing a rack assembly that includes internal and external thread butt and fixing sleeves, the problem of the lack of uniform specifications of existing rack assembly is solved, standardized design and high-strength connection are achieved, and design and manufacturing complexity and cost are reduced.
Patent Information
- Application Number
- CN202411476574.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-11-20
- Filing Date
- 2024-10-22
- Publication Date
- 2025-05-20
AI Technical Summary
The lack of uniform specifications of existing rack assembly leads to the need for overall redevelopment of design manufacturers to meet the needs of different vehicle manufacturers, increasing the complexity and cost of design and manufacturing.
A rack assembly including the first rod member, the second rod member and the fixing sleeve is designed, and the connection strength is strengthened through the internal and external threads and the fixing sleeve is strengthened to avoid breaking the rack assembly, while allowing further fixation through welding, pin joints, etc.
The standardized design of rack assembly is realized, which reduces the adaptive development to the needs of different vehicle manufacturers, improves the efficiency and strength of design and manufacturing, and meets the requirements of the steering system for mechanical properties.
Smart Images
Figure CN120020042A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to a rack assembly for a steering system. Background Art
[0002] The rack is an important part in the steering system of a vehicle. Considering safety, most current racks adopt an integrally formed design. However, there is no unified specification for racks. For manufacturers designing racks, when cooperating with different vehicle manufacturers, the racks must be developed entirely anew to meet the requirements of different vehicle manufacturers. Summary of the Invention
[0003] In view of this, an object of this disclosure is to provide a rack assembly for a steering system of a vehicle to solve the above problems of the prior art.
[0004] To achieve the above object, according to some embodiments of this disclosure, a rack assembly of a steering system includes a first rod, a second rod, and a fixing sleeve. The first rod includes a first end, and a groove is formed on the first end. The groove has a first internal thread. The second rod includes a second end, the second end is inserted into the groove, and the second end has a first external thread, and the first external thread meshes with the first internal thread. The fixing sleeve is fixedly sleeved on the first end of the first rod and the second rod. One of the first rod and the second rod is a screw rod, and the other is a rack.
[0005] In one or more embodiments of this disclosure, the first end of the first rod has a second external thread, and the second external thread is disposed around the groove. The fixing sleeve has a second internal thread, the second internal thread meshes with the second external thread, and the fixing sleeve fixes the second rod through a fixing structure.
[0006] In one or more embodiments of this disclosure, the fixing structure includes solder, and the solder is disposed along the end face of the fixing sleeve and adheres to the end face of the fixing sleeve and the outer surface of the second rod.
[0007] In one or more embodiments of this disclosure, the groove has a non-threaded section and a threaded section. The threaded section has a first internal thread. The non-threaded section is located between the threaded section and the entrance of the groove, and the inner diameter of the non-threaded section is greater than the inner diameter of the threaded section.
[0008] In one or more embodiments of this disclosure, the second end has a first section and a second section. The first section has a first external thread. The second section is configured to be inserted into the non-threaded section of the groove, and the outer diameter of the second section is greater than the outer diameter of the first section.
[0009] In one or more embodiments of this disclosure, the fixing sleeve has a smooth inner peripheral surface. The inner peripheral surface of the fixing sleeve is in tight fit with the first end of the first rod and the second rod, and the fixing sleeve fixes the first rod and the second rod through at least one fixing structure.
[0010] In one or more embodiments of the present disclosure, the fixing sleeve has two opposite end surfaces. The fixing structure includes at least one solder, which is arranged along the two end surfaces of the fixing sleeve and attached to the two end surfaces of the fixing sleeve, the outer surface of the first rod, and the outer surface of the second rod.
[0011] In one or more embodiments of the present disclosure, the first rod and the second rod respectively include a first stop structure and a second stop structure, and the fixing sleeve is clamped between the first stop structure and the second stop structure.
[0012] In one or more embodiments of the present disclosure, the first rod further includes a first body, the first end portion is connected to the first body and is retracted relative to the first body to form a first stop structure. The second rod further includes a second body, the second body has two sections with different outer diameters and a step difference plane is formed between the two sections as a second stop structure.
[0013] In one or more embodiments of the present disclosure, the screw is a ball screw.
[0014] In summary, the rack assembly of the steering system disclosed in the present invention includes a first rod and a second rod connected by internal and external threads, and includes a fixing sleeve, which is mounted on the first rod and the second rod and covers the joint between the first rod and the second rod. On the one hand, the fixing sleeve can help fix the first rod and the second rod, and on the other hand, it can also strengthen the strength of the rack assembly at the joint between the first rod and the second rod to prevent the rack assembly from breaking. In addition, the first rod / the second rod and the fixing sleeve can be fixed by welding, pinning, mortise and tenon joints, etc., so that the first rod, the second rod and the fixing sleeve are more firmly combined. Brief Description of the Figures
[0015] In order to make the above and other purposes, features, advantages and implementation methods of the present disclosure more obvious and easy to understand, the attached drawings are described as follows:
[0016] Figure 1 It is a top view of a rack assembly according to an embodiment of the present disclosure.
[0017] Figure 2 For illustration Figure 1 The partial enlarged cross-sectional view of the rack assembly along line segment 2-2' is shown.
[0018] Figure 3 For illustration Figure 2 A partial cross-sectional exploded view of the rack assembly is shown.
[0019] Figure 4 It is a partially enlarged cross-sectional view showing another embodiment of a rack assembly according to the present disclosure.
[0020] Figure 5 To illustrate Figure 4 a partial sectional exploded view of the shown rack assembly.
[0021] Reference numerals:
[0022] R A, R B: Rack assembly
[0023] 10, 10A: First rod
[0024] 11: First body
[0025] 12, 12A: First end
[0026] 13: Groove
[0027] 14: First internal thread
[0028] 15: Second external thread
[0029] 16: End face
[0030] 17: Non-threaded section
[0031] 18: Threaded section
[0032] 19: First stop structure
[0033] 20, 20A: Second rod
[0034] 21, 21A: Second body
[0035] 22: Second end
[0036] 24: First external thread
[0037] 26: Stop face
[0038] 27: Second section
[0039] 28: First section
[0040] 29: Second stop structure
[0041] 30, 30A: Fixed sleeve
[0042] 31, 32: End face
[0043] 35: Second internal thread
[0044] 36: Central through hole
[0045] 37: Inner peripheral surface
[0046] 91, 92: Fixing structure
[0047] T 1: Thread
[0048] T 2: Tooth body Detailed implementation manners
[0049] To make the description of the present disclosure more detailed and complete, reference may be made to the accompanying drawings and the various implementation manners described below. The components in the drawings are not drawn to scale and are provided only for illustrating the present disclosure. Many practical details are described below to provide a comprehensive understanding of the present disclosure. However, those skilled in the art should understand that the present disclosure can be implemented without one or more of these practical details. Therefore, these details should not be used to limit the present disclosure.
[0050] Please refer to Figure 1 。 Figure 1 To illustrate a top view of a rack assembly R A according to an implementation manner of the present disclosure. The rack assembly R A is a rack assembly of a steering system, which includes a first rod 10, a second rod 20, and a fixing sleeve 30. The first rod 10 is fixedly connected to the second rod 20. The fixing sleeve 30 is a hollow cylindrical structure, which is sleeved on the first rod 10 and the second rod 20 and covers the joint of the first rod 10 and the second rod 20. The rack assembly R A can be used in an electric power steering system. One of the first rod 10 and the second rod 20 is a screw rod, and the other is a rack. In the illustrated implementation manner, the first rod 10 and the second rod 20 are respectively a screw rod and a rack. The screw rod is, for example, a ball screw rod, which can be coupled to an electric motor of the electric power steering system, so that the electric motor can drive the rack assembly R A to move laterally. The rack is coupled to a steering wheel through a gear. The rack can be a solid rack or a hollow rack.
[0051] As Figure 1 shown, the first rod 10 includes a first body 11. In the implementation manner where the first rod 10 is a screw rod, the first body 11 is the part of the first rod 10 having a thread T1 for cooperating with the electric motor. The second rod 20 includes a second body 21. In the implementation manner where the second rod 20 is a rack, the second body 21 is the part of the second rod 20 having a plurality of tooth bodies T 2 for cooperating with the gear.
[0052] Please refer to Figure 2 and Figure 3 。 Figure 2 To illustrate Figure 1 a partial enlarged sectional view of the rack assembly R A shown along the line 2-2’, and Figure 3 to illustrate Figure 2Partial sectional exploded view of the rack assembly RA shown. The first rod member 10 further includes a first end portion 12 connecting to the first body 11. The first end portion 12 is provided at one end of the first body 11, and a groove 13 is formed on the first end portion 12. The second rod member 20 further includes a second end portion 22 connecting to the second body 21. The second end portion 22 is provided at one end of the second body 21, and the second end portion 22 is configured to be inserted into the groove 13 of the first rod member 10. The groove 13 of the first rod member 10 has a first internal thread 14, and the first internal thread 14 is provided on the inner wall of the groove 13. The second end portion 22 of the second rod member 20 has a first external thread 24, and the first external thread 24 is provided on the outer surface of the second end portion 22 and meshes with the first internal thread 14 of the groove 13. In some embodiments, the number of threads of the first internal thread 14 and the first external thread 24 is at least four to ensure that the first rod member 10 and the second rod member 20 can be firmly combined.
[0053] As Figure 2 With Figure 3 shown, the fixing sleeve 30 is fixedly sleeved on the first end portion 12 of the first rod member 10 and the second rod member 20. In this embodiment, the fixing sleeve 30 is fixed to the first end portion 12 of the first rod member 10 by threads. Specifically, the first end portion 12 of the first rod member 10 has a second external thread 15, and the second external thread 15 is provided on the outer surface of the first end portion 12 and surrounds the groove 13. The fixing sleeve 30 has a second internal thread 35, and the second internal thread 35 is provided on the inner circumferential surface of the central through hole 36 of the fixing sleeve 30 and meshes with the second external thread 15 of the first rod member 10.
[0054] As Figure 2 With Figure 3 shown, the fixing sleeve 30 partially extends beyond the end face 16 of the first end portion 12 of the first rod member 10 and is in tight fit with the second body 21 of the second rod member 20. In addition, the fixing sleeve 30 can further fix the second rod member 20 through a fixing structure 92. In this embodiment, the fixing structure 92 includes solder (represented by a black triangle in the figure), and the solder is provided along one end face 32 of the fixing sleeve 30 and adheres to the end face 32 of the fixing sleeve 30 and the outer surface of the second body 21 of the second rod member 20. In other words, the solder is distributed at the junction of the end face 32 of the fixing sleeve 30 and the outer surface of the second body 21 of the second rod member 20.
[0055] In some embodiments, the manufacturing method of the rack assembly RA includes the following steps in sequence: (1) using a suitable metal processing method to form the first rod 10, the second rod 20 and the fixing sleeve 30; (2) screwing the first rod 10 into the fixing sleeve 30 (through the cooperation of the second external thread 15 of the first rod 10 and the second internal thread 35 of the fixing sleeve 30), but not tightening it temporarily; (3) screwing the second rod 20 into the groove 13 of the first rod 10 (through the cooperation of the first internal thread 14 of the first rod 10 and the first external thread 35 of the second rod 20). 24), until the end face 16 of the first rod 10 abuts against the stop face 26 of the second rod 20 (the stop face 26 is formed by the second end 22 being retracted relative to the second body 21. In other words, the maximum outer diameter of the second end 22 is smaller than the maximum outer diameter of the second body 21, so that a difference plane is formed between the two); (4) tighten the fixing sleeve 30 with a predetermined torque; (5) perform welding (full circumference welding or partial welding) at the junction of the end face 32 of the fixing sleeve 30 and the outer surface of the second body 21 of the second rod 20.
[0056] In some embodiments, the aforementioned welding step can be replaced by pinning, mortise and tenoning or other fixing means (in other words, the fixing sleeve 30 can be fixed to the second rod 20 by means of a pin, a tenon or other fixing structure). In addition, welding and pinning, mortise and tenoning or other fixing means can also be implemented simultaneously to enhance the fixing effect.
[0057] If Figure 2 and Figure 3 As shown in FIG. 1 , in some embodiments, the groove 13 of the first rod 10 has a non-threaded section 17 and a threaded section 18. The threaded section 18 has a first internal thread 14. The non-threaded section 17 is located between the threaded section 18 and the entrance of the groove 13, and the inner diameter of the non-threaded section 17 is greater than the inner diameter of the threaded section 18. The non-threaded section 17 defines a substantially cylindrical first space, and the threaded section 18 defines a substantially cylindrical second space. The central axis of the first space and the central axis of the second space are substantially collinear, so as to facilitate guiding the second end 22 of the second rod 20 to enter the groove 13 and screw with the first internal thread 14. In some embodiments, the second end 22 of the second rod 20 has a first section 28 and a second section 27. The first section 28 has a first external thread 24 for engaging with the first internal thread 14. The second section 27 is configured to be inserted into the non-threaded section 17 of the groove 13, and the outer diameter of the second section 27 is greater than the outer diameter of the first section 28. The outer diameter of the second section 27 is substantially the same as the inner diameter of the non-threaded section 17. Through the cooperation between the second section 27 and the non-threaded section 17, the first section 28 with the first external thread 24 can be guided to be accurately screwed into the threaded section 18 of the groove 13.
[0058] Please refer to Figure 4 and Figure 5 .Figure 4 FIG. Figure 4 is a partial enlarged sectional view of a rack assembly RB according to another embodiment of the present disclosure, and Figure 5 FIG. Figure 5 is for showing Figure 4 a partially exploded sectional view of the rack assembly RB shown in FIG. Figure 4 . The difference between this embodiment and the foregoing embodiment is that the fixing sleeve 30A of the rack assembly RB of this embodiment has a smooth inner peripheral surface 37 (specifically, the inner peripheral surface 37 of the central through hole 36 of the fixing sleeve 30A is smooth as a whole and does not have threads), and correspondingly, the outer peripheral surface of the first end portion 12A of the first rod member 10A is also smooth and does not have threads. The inner peripheral surface 37 of the fixing sleeve 30A is in tight fit with the outer peripheral surface of the first end portion 12A of the first rod member 10A, and the fixing sleeve 30A is fixed to the first rod member 10A by at least one fixing structure 91. In addition, as in the foregoing embodiment, the inner peripheral surface of the fixing sleeve 30A is in tight fit with the outer surface of the second body 21A of the second rod member 20A, and the fixing sleeve 30A is fixed to the second rod member 20A by at least one fixing structure 92.
[0059] As Figure 4 shown in FIG. Figure 4 and FIG. Figure 5 , the fixing sleeve 30A has another end surface 31 opposite to the end surface 32, and the two end surfaces 31, 32 of the fixing sleeve 30A are located on opposite sides of the fixing sleeve 30A. In the embodiment shown, the fixing structure 91 includes at least one solder (represented by a black triangle in the figure), and the solder is disposed along the end surface 31 of the fixing sleeve 30A and adheres to the end surface 31 of the fixing sleeve 30A and the outer surface of the first rod member 10A. In other words, the solder (i.e., the fixing structure 91) is distributed at the junction of the end surface 31 of the fixing sleeve 30A and the outer surface of the first rod member 10A. In other embodiments, the fixing structure 91 may also be a pin, a tenon or other suitable fixing structure.
[0060] As Figure 4 shown in FIG. Figure 4 and FIG. Figure 5 , in some embodiments, the first rod member 10A and the second rod member 20A respectively include a first stop structure 19 and a second stop structure 29, and the fixing sleeve 30A is clamped between the first stop structure 19 and the second stop structure 29. In some embodiments, the first end portion 12A of the first rod member 10A is retracted relative to the first body 11 to form the first stop structure 19 (in other words, the maximum outer diameter of the first end portion 12A is smaller than the maximum outer diameter of the first body 11, so that a step plane is formed therebetween), and the second body 21A of the second rod member 20A has two sections with different outer diameters, and a step plane is formed between the two sections as the second stop structure 29.
[0061] In some embodiments, the manufacturing method of the rack assembly RB includes the following steps in sequence: (1) using a suitable metal processing method to form the first rod 10A, the second rod 20A and the fixing sleeve 30A; (2) sleeve the fixing sleeve 30A on the first end 12A of the first rod 10A; (3) screw the second rod 20A into the groove 13 of the first rod 10A (through the cooperation of the first internal thread 14 of the first rod 10A and the first external thread 24 of the second rod 20A) until the end surface 16A of the first rod 10A is fixed. Abutting against the stop surface 26 of the second rod 20A, the fixing sleeve 30A is clamped between the first stop structure 19 of the first rod 10A and the second stop structure 29 of the second rod 20A; (4) Welding is performed at the junction of the end surface 31 of the fixing sleeve 30A and the outer surface of the first rod 10A (for example, the position of the first stop structure 19), and welding is performed at the junction of the end surface 32 of the fixing sleeve 30A and the outer surface of the second body 21A of the second rod 20A (for example, the position of the second stop structure 29).
[0062] In some embodiments, the aforementioned welding step can be replaced by pinning, mortise and tenoning or other fixing means (in other words, the fixing sleeve 30A can be fixed to the first rod 10A and the second rod 20A by means of a pin, a tenon or other fixing structure). In addition, welding and pinning, mortise and tenoning or other fixing means can also be implemented simultaneously to enhance the fixing effect.
[0063] In summary, the rack assembly of the steering system disclosed in the present invention includes a first rod and a second rod connected by internal and external threads, and includes a fixing sleeve, which is mounted on the first rod and the second rod and covers the joint between the first rod and the second rod. On the one hand, the fixing sleeve can help fix the first rod and the second rod, and on the other hand, it can also strengthen the strength of the rack assembly at the joint between the first rod and the second rod to prevent the rack assembly from breaking. In addition, the first rod / the second rod and the fixing sleeve can be fixed by welding, pinning, mortise and tenon joints, etc., so that the first rod, the second rod and the fixing sleeve are more firmly combined. The rack assembly of the steering system disclosed in the present invention can solve the problem that the one-piece rack on the market must be redeveloped as a whole to meet the different needs of different vehicle manufacturers. By separating the rack part from the screw part, the screw part can be made into a standard product, and the rack part can be designed according to the needs of the vehicle manufacturer and then combined with the screw part. In this way, the troubles in design and manufacturing can be reduced. At the same time, through the aforementioned structural design, the various components of the rack assembly disclosed in the present invention are tightly combined and have high strength as a whole, which can meet the requirements of the steering system for mechanical properties.
[0064] Although the present disclosure has been disclosed above in embodiments, it is not intended to limit the present disclosure. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to that defined by the claims.
Claims
1. A rack assembly of a steering system, characterized in that: Include: A first rod member comprises a first end portion, a groove is formed on the first end portion, and the groove has a first internal thread; A second rod member, comprising a second end portion, the second end portion is inserted into the groove, and the second end portion has a first external thread, the first external thread is engaged with the first internal thread; and A fixed sleeve, fixedly sleeved on the first end of the first rod and the second rod; One of the first rod and the second rod is a screw rod, and the other is a rack.
2. The rack assembly of the steering system according to claim 1, characterized in that: The first end of the first rod has a second external thread, the second external thread is arranged around the groove, the fixing sleeve has a second internal thread, the second internal thread is meshed with the second external thread, and the fixing sleeve is fixed to the second rod through a fixing structure.
3. The rack assembly of the steering system according to claim 2, characterized in that: The fixing structure comprises solder, which is arranged along an end surface of the fixing sleeve and attached to the end surface of the fixing sleeve and the outer surface of the second rod.
4. The rack assembly of the steering system according to claim 1, characterized in that: The groove has a non-threaded section and a threaded section, the threaded section has the first internal thread, the non-threaded section is located between the threaded section and the entrance of the groove, and the inner diameter of the non-threaded section is greater than the inner diameter of the threaded section.
5. The rack assembly of the steering system according to claim 4, characterized in that: The second end has a first section and a second section. The first section has the first external thread. The second section is configured to be inserted into the non-threaded section of the groove. The outer diameter of the second section is greater than the outer diameter of the first section.
6. The rack assembly of the steering system according to claim 1, characterized in that: The fixing sleeve has a smooth inner circumference, the inner circumference is tightly matched with the first end of the first rod and the second rod, and the fixing sleeve is fixedly connected to the first rod and the second rod through at least one fixing structure.
7. The rack assembly of the steering system according to claim 6, characterized in that: The fixing sleeve has two opposite end surfaces. The at least one fixing structure includes at least one solder. The at least one solder is arranged along the two end surfaces of the fixing sleeve and attached to the two end surfaces of the fixing sleeve, the outer surface of the first rod and the outer surface of the second rod.
8. The rack assembly of the steering system according to claim 6, characterized in that: The first rod and the second rod respectively include a first stop structure and a second stop structure, and the fixing sleeve is clamped between the first stop structure and the second stop structure.
9. The rack assembly of the steering system according to claim 8, characterized in that: The first rod member also includes a first body, the first end portion is connected to the first body and is retracted relative to the first body to form the first stop structure, and the second rod member also includes a second body, the second body has two sections with different outer diameters and a difference plane is formed between the two sections as the second stop structure.
10. The rack assembly of the steering system according to claim 1, characterized in that: The screw is a ball screw.