Novel anti-falling structure of sliding pair of steering intermediate shaft

Abstract

The utility model relates to a novel steering intermediate shaft sliding pair anti -drop structure, including the steering pipe, the steering axle and the injection layer, the end of steering pipe and steering axle connection's end is the end for the light pipe, the inside extension of light pipe is the internal spline, the outside of one end of steering axle and steering pipe connection is equipped with the external spline, the external spline outer layer of steering axle is wrapped one layer injection layer, the free end light pipe of steering pipe is equipped with the baffle on the outer wall, the baffle one end and steering pipe integral structure, the other end and steering pipe main body are separated through cutting seam, the baffle and steering pipe through cutting line separation one end is arc shape. The baffle lower end of steering intermediate shaft sliding pair anti -drop structure is arc structure, in the telescopic sliding process of steering pipe and steering axle, will not break the injection layer, will not appear injection layer accumulation, prevents the intermediate axle limit position jamming phenomenon.

Description

Technical Field

[0001] This utility model relates to the field of automotive steering systems, specifically a novel anti-detachment structure for the sliding pair of the steering intermediate shaft. Background Technology

[0002] The steering intermediate shaft is mainly composed of a spline tube and a spline shaft. The spline shaft can slide and extend within the spline tube. After the spline shaft and spline tube are assembled, the spline tube is riveted to form rivets, thereby forming an anti-detachment structure to prevent the spline shaft from coming out of the spline tube and ensuring the stability and reliability of the steering intermediate shaft structure.

[0003] The existing riveting structure has two main defects: First, the normal surface shape of the riveting point should be a smooth transition, such as a hemispherical or flat arc. However, due to incorrect mold selection during riveting (e.g., the mold edge is too sharp or the mold does not match the component well), the riveting area is only locally deformed under pressure, failing to form a uniform, rounded protrusion, leaving a sharp edge underneath. Alternatively, uneven riveting force distribution may prevent the metal material from fully stretching, resulting in only slight surface compression forming a "sharp point" instead of overall plastic deformation, leading to a sharp point below the riveting point. During the sliding process of the spline tube and spline shaft, the sharp part below the riveting point may damage the injection-molded layer structure surrounding the spline of the steering tube. After the injection-molded layer is damaged, it accumulates, causing jamming during the sliding of the steering tube and steering shaft. Second, since the riveting point is formed by riveting with a riveting tool after the steering tube and steering shaft are assembled, improper selection of the riveting tool or improper operation process can lead to insufficient riveting force. This can prevent the riveting point from forming an effective "locking structure," easily causing the steering tube and steering shaft to detach. Excessive riveting force may also occur. Excessive riveting force can cause excessive compression and denting of the tube around the rivet point, leading to cracking of the base. Excessive riveting pressure can also cause the protruding part of the rivet point to be stretched and sharpened, or even break due to metal fatigue, easily tearing the injection molding layer and affecting the normal extension and contraction of the steering tube and steering shaft, resulting in jamming. To solve the above problems, it is necessary to invent a new type of anti-detachment structure for the steering intermediate shaft sliding pair. Utility Model Content

[0004] The purpose of this invention is to provide a novel anti-detachment structure for the sliding pair of the steering intermediate shaft to solve the above-mentioned problems.

[0005] The technical solution of this utility model:

[0006] A novel anti-detachment structure for a sliding pair of steering intermediate shafts includes a steering tube, a steering shaft, and an injection-molded layer. The end of the steering tube connected to the steering shaft is a smooth tube, which extends inward to form an internal spline. The outer side of the end of the steering shaft connected to the steering tube is provided with an external spline. The external spline of the steering shaft is wrapped with an injection-molded layer. A baffle is provided on the outer wall of the smooth tube at the free end of the steering tube. One end of the baffle is integral with the steering tube, and the other end is separated from the main body of the steering tube by a cutting seam. The end of the baffle separated from the steering tube by the cutting line is arc-shaped.

[0007] The beneficial effects of this utility model are:

[0008] 1. The lower end of the baffle of the anti-detachment structure of the steering intermediate shaft sliding pair in this application is an arc-shaped structure. During the extension and retraction sliding process of the steering tube and the steering shaft, the injection molding layer will not be torn, and the injection molding layer will not accumulate, thus preventing the intermediate shaft from getting stuck at the extreme position.

[0009] 2. The baffle of the anti-detachment structure of the steering intermediate shaft sliding pair in this application has a certain width and is in surface contact with the spline part of the steering shaft, which has better limiting performance, prevents the steering shaft from falling out of the steering tube, and significantly improves the connection stability and reliability.

[0010] 3. The steering tube and the baffle on the steering tube of the anti-detachment structure of the steering intermediate shaft sliding pair in this application are manufactured uniformly. From raw material selection and processing technology to finished product inspection, uniform standards are followed to achieve consistent product dimensions. The length of the baffle can be designed according to the size of the steering shaft, and the shape and size are standardized. Therefore, the problems of insufficient riveting force and excessive riveting force in the prior art do not exist. Attached Figure Description

[0011] 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.

[0012] Figure 1 This is a cross-sectional view of the anti-detachment structure of the sliding pair of the novel steering intermediate shaft in this application.

[0013] Figure 2 This is a transverse cross-sectional view of the anti-detachment structure of the novel steering intermediate shaft sliding pair of this application.

[0014] Figure 3 This is a top view of the anti-detachment structure of the novel steering intermediate shaft sliding pair of this application.

[0015] Figure 4 This is a schematic diagram of the steering tube structure of the novel steering intermediate shaft sliding pair anti-detachment structure of this application.

[0016] Figure label:

[0017] Steering tube 1; Steering shaft 2; Injection layer 3; Smooth tube 11; Internal spline 12; Baffle 13; Cutting seam 14; External spline 21. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be noted that in the description of this application, terms such as "inner", "outer", "upper", and "lower" that indicate direction or positional relationship are based on the direction or positional relationship shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or element 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.

[0020] In order to solve the problems in the background art, this application presents a novel anti-detachment structure for the steering intermediate shaft sliding pair, which replaces the rivet structure in the prior art and better prevents the steering tube and steering shaft from separating.

[0021] A novel anti-detachment structure for a steering intermediate shaft sliding pair includes a steering tube 1, a steering shaft 2, and an injection-molded layer 3. The end of the steering tube 1 connected to the steering shaft is a smooth tube 11, extending inwards as an internal spline 12. The outer side of the end of the steering shaft 2 connected to the steering tube 1 is provided with an external spline 21, and the external spline 21 of the steering shaft 2 is wrapped with an injection-molded layer 3. A baffle 13 is provided at the free end of the steering tube 1 at the smooth tube 11. The baffle 13 is integrally formed with the steering tube 1, with one end integrally formed with the steering tube 1, and the other end separated from the main body of the steering tube 1 by a cutting seam 14. In use, the end of the baffle separated from the steering tube can be pressed inwards using a riveting tool, causing the baffle to bend inwards, forming a limiting structure that prevents the steering shaft from detaching from the steering tube.

[0022] The end of the baffle 13 that separates from the steering tube 1 via the cutting line 14 is arc-shaped. This arc-shaped design prevents damage to the injection molding layer outside the outer spline of the steering shaft, avoiding damage and buildup of the injection molding layer that could cause jamming between the steering tube and the steering shaft. Two or more baffles are used, evenly distributed on the sidewall of the steering tube. Preferably, there are two baffles 13, symmetrically arranged with the center of the steering tube 1 as the center. This symmetrical arrangement of the two baffles around the center of the steering tube results in a more even distribution of the limiting force on the steering shaft.

[0023] The baffle, integrally connected to the steering tube, is 3-5mm (can be 3, 4, or 5mm) from the end of the steering tube. The baffle is 2-4mm (can be 2, 3, or 4mm) long and 4-6mm (can be 4, 5, or 6mm) wide. The baffle in this application's steering intermediate shaft sliding pair anti-detachment structure has a certain width, forming a surface contact limit with the outer spline portion of the steering shaft's injection-molded layer. This increases the contact area, making the limiting performance more stable and preventing the spline tube and spline shaft from separating during vehicle assembly and normal driving. This avoids the steering system malfunction and potential driver injury caused by the steering tube and steering shaft separating, improving the overall performance and safety of the steering system.

[0024] After the steering tube 1 and steering shaft 2 are assembled, the baffle 13 is bent inward by a tool, and the distance between the end of the baffle 13 facing the steering shaft 2 and the steering shaft 2 is 0.5-1mm. Throughout the entire production process of the steering tube and internal spline, standardized processes, high-precision tooling positioning, and online dimensional inspection ensure that the external dimensions and key parameters of the internal spline of all finished products conform to the unified technical standards of the design drawings. The baffle is then cut out at the smooth part of the steering tube using a cutting machine, ensuring uniform size and position. After the steering tube and steering shaft are assembled, the two rivet heads of a double-sided riveting tool are simultaneously applied along the same axis, making the distance between the two baffles bent inward and the steering shaft the same. Furthermore, the inward bending dimension of the baffles in each steering tube is essentially the same, with minimal error, avoiding the problem of insufficient riveting force or excessive riveting force found in existing technologies.

[0025] Specific embodiments of the novel anti-derailment structure for the sliding pair of the steering intermediate shaft in this application:

[0026] Applicable models: Chery Automobile

[0027] Materials used: Steering tube is made of No. 20 high-quality carbon steel, steering shaft is made of No. 20 high-quality carbon steel, and injection molding layer is made of PA11 (core resin) + GF8 (reinforcing filler) mixture.

[0028] Process parameters:

[0029] The steering tube is 235mm long and 24mm in diameter; the plain tube is 15mm long.

[0030] The length of the internal spline is 157mm.

[0031] The steering shaft is 175mm long and 17mm in diameter.

[0032] The external spline is 44.5mm long.

[0033] The injection layer length is 44.5mm.

[0034] The end of the baffle that connects to the steering tube is 4mm from the end of the steering end.

[0035] The baffle is 3mm long and 5mm wide.

[0036] The installation process of the novel steering intermediate shaft sliding pair anti-detachment structure of this application is as follows:

[0037] Machining the steering tube: The steering tube with internal splines is machined using a rotary forging process. The steering tube is then positioned and a baffle is precisely machined using a wire EDM machine. One end of the baffle is integrated with the steering tube, and the other end is cut into an arc shape.

[0038] Steering tube and steering shaft assembly: Align the end of the steering shaft with the external spline with the port of the steering tube with the internal spline, ensuring that the spline teeth and spline grooves correspond one-to-one, and achieve quick centering; slowly push the steering shaft to enter the steering tube; push the steering shaft to its limit position.

[0039] Inward bending of the baffles: The steering tube is positioned, and a double-sided riveting tool is used. Two rivet heads simultaneously apply pressure to the two baffles. One end of the baffle, integral with the steering tube, remains fixed, while the other end, separate from the steering tube, bends inward. Because the two rivet heads of the double-sided riveting tool apply the same force to the two baffles, and the two baffles have the same dimensions and thickness, the gaps between the two baffles and the steering shaft are identical. Furthermore, each steering tube and baffle has uniform dimensions and consistent manufacturing processes, so the gap between the baffle of each steering tube and the steering shaft after inward bending is essentially consistent with minimal error, thus solving the problem of excessive or insufficient riveting force in existing technologies. Simultaneously, the inward-curving end of the baffle will not scratch the injection molding layer, avoiding the problem of sharp lower ends at the rivets found in existing technologies.

[0040] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art, inspired by this description, design similar structures and implementations to the above embodiments without departing from the technical essence of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A novel anti-detachment structure for a steering intermediate shaft sliding pair, characterized in that: It includes a steering tube, a steering shaft, and an injection-molded layer. The end of the steering tube connected to the steering shaft is a smooth tube, which extends inward to form an internal spline. The outer side of the end of the steering shaft connected to the steering tube is provided with an external spline. The external spline of the steering shaft is wrapped with an injection-molded layer. A baffle is provided on the outer wall of the smooth tube at the free end of the steering tube. One end of the baffle is integral with the steering tube, and the other end is separated from the main body of the steering tube by a cutting seam. The end of the baffle separated from the steering tube by the cutting line is arc-shaped.

2. The novel anti-detachment structure for the sliding pair of the steering intermediate shaft according to claim 1, characterized in that: There are two or more baffles, which are evenly distributed on the side wall of the steering tube.

3. The novel anti-detachment structure for the sliding pair of the steering intermediate shaft according to claim 1, characterized in that: There are two baffles, which are symmetrically arranged with the center of the steering tube as the center.

4. The novel anti-detachment structure for the sliding pair of the steering intermediate shaft according to claim 1, characterized in that: The distance between the end of the baffle, which is integrally connected to the steering tube, and the end of the steering tube is 3-5mm. The length of the baffle is 2-4mm and the width is 4-6mm.

5. The novel anti-detachment structure for the sliding pair of the steering intermediate shaft according to claim 1, characterized in that: After the steering tube and steering shaft are assembled, the baffle is bent inward, and the distance between the end of the baffle facing the steering shaft and the steering shaft is 0.5-1mm.

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