Sealing structure of automobile steering system

Abstract

The utility model relates to the field of automobile steering systems, and discloses a sealing structure of an automobile steering system, which comprises a dash panel, a steering intermediate shaft, a sealing rubber sleeve and a nylon sleeve. A through hole is formed in the front wall plate, the sealing rubber sleeve is fixedly installed at the through hole, the nylon sleeve is embedded in an inner groove of the sealing rubber sleeve, and the steering middle shaft is arranged in an inner hole of the nylon sleeve in a penetrating mode. The inner hole of the nylon sleeve is of an R arc structure and is in linear contact with the steering intermediate shaft, so that the friction area is reduced, and abnormal sound during rotation is avoided; a single-side interference magnitude of 0.05-0.25 mm is arranged between the nylon sleeve and the steering intermediate shaft, so that the sealing performance is ensured; a Z-shaped opening extending in the axial direction is formed in the side wall of the nylon sleeve, the width of the opening ranges from 0.3 mm to 1 mm, and radial elasticity is provided to compensate the machining tolerance of the steering intermediate shaft. The sealing device is simple in structure, convenient to assemble, capable of improving sealing performance and avoiding rotation abnormal sound, and suitable for popularization and application in various automobile steering systems.

Description

Technical Field

[0001] This utility model relates to the field of automotive steering systems, and more specifically to a sealing structure for automotive steering systems. Background Technology

[0002] The steering system of a car is a key mechanism for ensuring safe driving and handling performance. Its basic function is to transmit the torque applied by the driver through the steering wheel to the wheels, thereby achieving vehicle steering control. The steering system typically consists of major components such as the steering wheel, steering column, steering intermediate shaft, and steering gear. The steering wheel and steering column are located in the driver's compartment, while the steering gear is generally installed in the engine compartment. The two are connected by the steering intermediate shaft. To achieve this connection, the steering intermediate shaft must pass through a through-hole in the front bulkhead of the vehicle.

[0003] Since the front bulkhead separates the engine compartment from the cab, this area must not only meet structural connection requirements but also possess excellent sealing performance. Inadequate sealing will allow engine compartment noise, dust, and airflow to enter the cab, affecting passenger comfort and the quality of the interior environment. Furthermore, during vehicle operation, the steering shaft is subject to frequent rotation and slight oscillation; the sealing structure must adapt to these dynamic conditions, ensuring sealing performance while preventing abnormal noises or accelerated wear due to improper friction.

[0004] In existing technologies, commonly used sealing structures generally employ rubber sleeves. These sleeves are fixed to the through-hole in the front bulkhead using screws or snap-fits, and achieve a seal through their fit with the steering intermediate shaft. Specifically, common fit types include clearance fits and interference fits. Clearance fits are convenient to assemble and have low rotational resistance, but due to the loose contact, they are prone to incomplete sealing, leading to noise and air leakage. Interference fits can improve sealing performance to some extent, but because a large surface area is formed between the steering intermediate shaft and the sealing sleeve, friction increases, making it prone to abnormal noise during rotation, and even causing accelerated rubber wear after long-term use.

[0005] Furthermore, traditional sealing sleeve structures often require pre-assembly of the steering intermediate shaft before the sleeve is fixed to the front bulkhead with screws. This assembly method involves numerous steps, is inefficient, and is not suitable for mass production in automotive manufacturing. Moreover, if the sealing sleeve ages or is damaged during use, multiple parts need to be disassembled for replacement, making maintenance difficult.

[0006] In summary, existing steering system sealing structures generally suffer from the following shortcomings:

[0007] First, it is difficult to balance sealing performance and smooth rotation. Clear fit is prone to air leakage, while interference fit is prone to abnormal noise.

[0008] Secondly, the assembly process is cumbersome and inefficient, which is not conducive to large-scale production.

[0009] Third, the structural reliability is limited, and the sealing effect is prone to decline under long-term use or in the presence of machining tolerances.

[0010] Therefore, it is necessary to propose a new sealing structure for automotive steering systems that, while maintaining ease of assembly, ensures sealing performance, prevents abnormal noises during rotation, and possesses strong adaptability and durability to meet the requirements of modern automobiles for safety, comfort, and production efficiency. Utility Model Content

[0011] This utility model provides a sealing structure for an automotive steering system. By setting a nylon sleeve inside the sealing rubber sleeve and adding an arc-shaped inner hole and opening to the structure of the nylon sleeve, the sealing effect is maintained while avoiding abnormal noise during rotation and improving the ease of assembly of the structure.

[0012] To achieve the above objectives, this utility model provides the following technical solution:

[0013] A sealing structure for an automotive steering system includes a front bulkhead, a steering intermediate shaft, a sealing sleeve, and a nylon sleeve, wherein:

[0014] The front bulkhead has a through hole, and the sealing sleeve is fixed at the through hole of the front bulkhead;

[0015] The nylon sleeve is embedded in the inner groove of the sealing sleeve;

[0016] The steering intermediate shaft passes through the inner hole of the nylon sleeve;

[0017] The inner hole has an R-shaped arc structure;

[0018] The nylon sleeve and the steering intermediate shaft are provided with a 1 / 2 interference fit of 0.05 to 0.25 mm;

[0019] The nylon sleeve has a Z-shaped opening on its side wall.

[0020] Preferably, the sealing sleeve is connected to the through hole of the front bulkhead by a snap-fit ​​method.

[0021] Preferably, the nylon sleeve is fixed by the limiting groove of the sealing sleeve.

[0022] Preferably, the radius of the inner hole is 0.5 to 2 mm.

[0023] Preferably, the width of the Z-shaped opening is 0.3 to 1 mm, and it extends along the axial direction of the nylon sleeve.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. By adding a nylon sleeve inside the sealing sleeve, the sealing environment of the steering intermediate shaft is improved, and the overall structure is more stable.

[0026] 2. The inner hole of the nylon sleeve adopts an arc-shaped design, which can form a line contact with the steering intermediate shaft, significantly reducing the friction area and avoiding abnormal noise during rotation.

[0027] 3. The interference fit between the nylon sleeve and the steering intermediate shaft is reasonably designed, which not only ensures the sealing effect but also reduces assembly resistance.

[0028] 4. The open structure on the nylon sleeve gives it radial elasticity, effectively compensating for dimensional deviations in the steering intermediate shaft and further improving the reliability of the seal.

[0029] 5. This utility model has a simple structure and easy assembly steps. It is more efficient than the traditional screw connection method and is convenient for later maintenance and replacement. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0031] Figure 1 This is an overall schematic diagram of the sealing structure of the automotive steering system of this utility model;

[0032] Figure 2 for Figure 1 A magnified view of a section at point A in the middle;

[0033] Figure 3 This is a three-dimensional structural diagram of the nylon sleeve;

[0034] Figure 4 This is a front view of the nylon sleeve structure;

[0035] Figure 5 This is a structural cross-sectional view of the nylon sleeve;

[0036] In the attached diagram: 1-Steering intermediate shaft, 2-Nylon sleeve, 201-Z-type opening, 202-R-arc inner hole, 3-Sealing sleeve, 4-Front panel. Detailed Implementation

[0037] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0038] Example 1

[0039] like Figure 1 As shown, this embodiment provides a sealing structure for an automotive steering system. The sealing structure includes a front bulkhead 4, a steering intermediate shaft 1, a sealing sleeve 3, and a nylon sleeve 2. A through hole is provided on the front bulkhead 4, through which the steering intermediate shaft 1 passes and connects to the steering gear. The sealing sleeve 3 is fixed at the through hole of the front bulkhead 4, and its outer edge forms a snap-fit ​​with the front bulkhead 4, thereby ensuring the stability and reliability of the sealing sleeve 3 during long-term use.

[0040] like Figure 2 As shown, the nylon sleeve 2 is embedded in the inner groove of the sealing sleeve 3. The outer diameter of the nylon sleeve 2 and the inner groove of the sealing sleeve 3 are interference-fitted, ensuring that the nylon sleeve 2 is firmly fixed after assembly and will not come off under vehicle vibration or impact. The steering intermediate shaft 1 passes through the inner hole 202 of the nylon sleeve 2, forming a sealed fit. The inner hole 202 of the nylon sleeve 2 adopts an R-arc structure design, forming line contact with the steering intermediate shaft 1, thereby effectively reducing the contact area and avoiding the frictional noise problem generated during rotation of traditional surface contact structures.

[0041] like Figures 3 to 5 As shown, the nylon sleeve 2 has an axially extending Z-shaped opening 201 on its side wall, with a width of 0.3 to 1 mm. The Z-shaped opening 201 design gives the nylon sleeve 2 radial elasticity, which can compensate for the tolerance of the steering intermediate shaft 1 diameter during processing, thereby ensuring that the overall structure maintains a stable sealing effect under different dimensional conditions. A 0.05 to 0.25 mm interference fit is provided between the nylon sleeve 2 and the steering intermediate shaft 1 on one side, ensuring a good sealing effect without causing excessive resistance, allowing the steering intermediate shaft 1 to rotate smoothly.

[0042] During the assembly process, the nylon sleeve 2 is first installed into the inner groove of the sealing sleeve 3, so that the nylon sleeve 2 is fixed by the groove limit; then the steering intermediate shaft 1 is passed through the nylon sleeve 2 and the sealing sleeve 3 in sequence; finally, the outer edge of the sealing sleeve 3 is pressed into the through hole of the front bulkhead 4, thereby completing the assembly of the sealing structure.

[0043] In terms of materials, the front bulkhead 4 is typically made of stamped steel plate with an electrophoretic coating, the sealing sleeve 3 is made of high-temperature and aging-resistant rubber, and the nylon sleeve 2 is made of reinforced nylon. A polytetrafluoroethylene coating can be added to the surface of the inner hole 202 to further reduce the coefficient of friction. Through the above structural design, the sealing structure of this embodiment can operate stably in environments ranging from -40℃ to 120℃. Bench tests have verified that no significant sealing failure or abnormal noise occurred under simulated 100,000 km of use, demonstrating significantly better reliability than traditional solutions.

[0044] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A sealing structure for an automotive steering system, comprising a front bulkhead (4), a steering intermediate shaft (1), a sealing sleeve (3), and a nylon sleeve (2), characterized in that: The front panel (4) is provided with a through hole, and the sealing sleeve (3) is fixed at the through hole of the front panel (4); The nylon sleeve (2) is embedded in the inner groove of the sealing sleeve (3); The steering intermediate shaft (1) passes through the inner hole (202) of the nylon sleeve (2); The inner hole (202) has an R-shaped arc structure; The nylon sleeve (2) and the steering intermediate shaft (1) are provided with a unilateral interference of 0.05 to 0.25 mm; The nylon sleeve (2) has a Z-shaped opening (201) on its side wall.

2. The sealing structure according to claim 1, characterized in that: The sealing sleeve (3) is connected to the through hole of the front panel (4) by a snap-fit ​​method.

3. The sealing structure according to claim 1, characterized in that: The nylon sleeve (2) is fixed by the limiting groove of the sealing sleeve (3).

4. The sealing structure according to claim 1, characterized in that: The radius of the arc of the inner hole (202) is 0.5 to 2 mm.

5. The sealing structure according to claim 1, characterized in that: The width of the Z-shaped opening (201) is 0.3 to 1 mm and extends along the axial direction of the nylon sleeve (2).

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