A noise muffling device for a vehicle

Abstract

The utility model discloses a kind of sound-attenuating devices of vehicle abnormal sound, belong to automobile structure noise reduction technical field;The device is formed on the surface texture layer on the matching working surface between wheel hub bearing and steering knuckle to realize the noise reduction function;Matching working surface is formed with the surface texture layer with set roughness by laser marking, for increasing the friction coefficient between matching surface, to inhibit the slight movement or peristalsis of two components under stress state, prevent structural abnormal sound generated by friction slip;The device has the advantages of simple process, accurate control, strong applicability, etc., can be popularized to other flange matching interface of vehicle and used, with the technical effects of improving NVH performance, prolonging the life of parts and improving assembly reliability.

Description

Technical Field

[0001] This utility model belongs to the field of noise elimination technology for mating flange surfaces, specifically relating to a noise reduction device for vehicles. Background Technology

[0002] Unusual noises from the front suspension system are common during vehicle operation, turning, or braking. Research has revealed that these noises primarily originate from the flange mating surface between the wheel hub bearing and the steering knuckle. In existing technology, this mating surface is typically formed using conventional machining processes, resulting in a low surface roughness. This makes it difficult to provide sufficient friction to suppress fretting or creeping movements of the two components under stress. This fretting friction generates periodic high-frequency vibrations, thus creating abnormal noises. This not only affects the driving experience but may also lead to localized wear of the mating surface, reduced locking force, and consequently, impacts structural stability and component lifespan.

[0003] To eliminate abnormal noise, some existing solutions attempt to increase surface roughness through multiple machining operations, but this approach has significant drawbacks: multiple machining operations significantly increase labor time and manufacturing costs, making it unsuitable for mass production; traditional machining is limited by tool precision and material properties, resulting in limited and inconsistent roughness improvement; unstable surface roughness control may lead to uneven stress distribution on the flange mating surfaces, thereby affecting the axial locking force of bolts and structural reliability. Utility Model Content

[0004] To solve the above problems, this utility model proposes a noise reduction device for vehicle noise. By changing the roughness of the mating surface between the wheel hub bearing and the steering knuckle flange, and by processing the mating surface with a laser engraving machine to increase the roughness, the noise of steering can be eliminated. In addition, it can be extended to increase the roughness by laser engraving the mating flange surfaces between other parts, which is also beneficial to the fit between the parts.

[0005] A noise reduction device for vehicle noise includes a mating working surface between two flange mating parts that cause the noise. The mating working surface is laser-engraved to form a surface texture layer with a set roughness. The surface texture layer is used to increase the friction coefficient between the mating surfaces and to suppress the micro-movement or creep of the two parts under stress.

[0006] Vehicles often produce abnormal noises when turning at low speeds or while stationary. These noises originate from fretting or creeping of the flange mating surfaces between the wheel hub bearing and the steering knuckle. Traditional machining of mating surfaces results in low surface roughness and insufficient friction coefficient, leading to periodic slippage of the two mating parts under load, thus generating high-frequency noise. Furthermore, attempting to solve the problem by increasing the locking force would cause assembly stress concentration, material fatigue, and increased manufacturing costs. Existing machining methods cannot significantly improve surface roughness while maintaining accuracy. Therefore, there is an urgent need for a new technology that can improve the friction performance of mating surfaces and suppress fretting noises without changing geometric accuracy.

[0007] The core of this technical solution lies in:

[0008] Using laser engraving technology, a surface texture layer with a micron-level texture structure is formed on the flange mating working surface of the wheel hub bearing and the steering knuckle by local ablation with laser energy, without affecting the original machining and subsequent assembly production process and tooling.

[0009] The formed surface texture layer achieves a preset roughness parameter Ra of 1.2μm to 5.0μm on the surface of the source of abnormal noise that may or needs to be eliminated, and is implemented according to the structural improvement required for the abnormal noise.

[0010] This solution is applicable not only to the wheel hub bearing and steering knuckle, but also to other flange-fitted components, such as caliper brackets and suspension connectors.

[0011] Laser engraving does not require tool contact and does not affect the overall geometric accuracy of the part. It can be used for secondary strengthening after heat treatment or coating.

[0012] The technical solution provided in this application also has the following technical features:

[0013] Preferably, in one embodiment of this application, the laser-etched surface texture is a grid shape.

[0014] Preferably, in one embodiment of this application, the laser-etched surface texture layer is a periodic or non-periodic microstructure with a surface roughness Ra of 1.2 μm to 5.0 μm.

[0015] Preferably, in one embodiment of this application, the laser marking is located on the end face of the wheel hub bearing, the flange face of the steering knuckle, or the mating surface of the caliper bracket.

[0016] Preferably, in one embodiment of this application, the wheel hub bearing and the steering knuckle are connected by fasteners.

[0017] Preferably, in one embodiment of this application, the laser-etched pattern is a dot matrix, grid, or concentric ring structure, and the pattern direction forms an angle of 30° to 90° with the flange load direction.

[0018] Preferably, in one embodiment of this application, the surface after laser etching is post-treated to form an oxide protective layer or a micro-bump oxide film.

[0019] Preferably, in one embodiment of this application, the laser-etched surface texture layer is composed of a combination of micropits, microgrooves and bumps with varying sizes.

[0020] Preferably, in one embodiment of this application, the pattern of the surface texture layer is distributed radially to form segments, and the texture directions of different segments are arranged alternately.

[0021] Preferably, in one embodiment of this application, a surface texture layer is provided on the mating surface of the caliper bracket.

[0022] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

[0023] This application provides a technical solution for forming a specific roughness on the flange mating surface of a wheel hub bearing and a steering knuckle using laser engraving. This method utilizes laser energy to generate a microscopic texture structure on the metal surface, precisely and controllably increasing the surface roughness, thereby significantly improving the friction coefficient of the mating surface, effectively suppressing relative slippage and creep between the two parts, and achieving the purpose of eliminating abnormal noise. Simultaneously, this method can optimize local surface characteristics without changing the geometric accuracy of the parts.

[0024] Compared with traditional machining methods, the technical solution of this application has achieved the following technical advancements:

[0025] 1. To solve the problem of abnormal noise generated on the mating surface between the wheel hub bearing and the steering knuckle flange during steering, a controllable roughness texture structure is formed on the mating surface by laser engraving. This overcomes the defects of insufficient surface roughness and low friction in traditional machining, and achieves the technical effect of effectively suppressing creep and eliminating abnormal noise. In addition, by laser engraving on the mating surface of the two parts, the torque between the two parts is increased, and the bolts used in the connecting parts are prevented from stripping, thus overcoming the technical problem of bolts not being tightened.

[0026] 2. In order to solve the problems of long processing time and high cost caused by conventional multiple machining processes, a single or multiple laser engraving forming process is adopted, which overcomes the defects of low processing efficiency and poor surface consistency, and achieves the technical effect of reducing manufacturing costs and improving production efficiency.

[0027] 3. In order to solve the problems of high locking force requirements and easy loosening of flange mating surfaces, laser engraving is used to increase the friction coefficient of mating surfaces. This overcomes the defects of strong dependence on bolt preload and easy slippage, and achieves the technical effect of improving connection reliability and extending the service life of components.

[0028] 4. In order to solve the problem of poor applicability of mating surface processes and limitation to specific parts, laser engraving is adopted to change the original roughness on various mating parts such as wheel hub bearings, steering knuckles, and caliper brackets, and eliminate abnormal noise. This overcomes the shortcomings of traditional machining, such as high cost and difficulty in maintaining consistent results, and achieves the technical effect of wide applicability and strong scalability.

[0029] 5. Laser engraving avoids the high cost and difficulty in precise control of machining, and overcomes the defects of large randomness and poor repeatability of surface roughness, achieving the technical effect of designable roughness and predictable friction performance. Attached Figure Description

[0030] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0031] Figure 1 This is a schematic diagram of the mating surface of a wheel hub bearing according to one embodiment;

[0032] Figure 2 This is a schematic diagram of the axial joint mating surface of one embodiment;

[0033] Figure 3 This is a schematic diagram of the mating surface of a caliper bracket according to one embodiment;

[0034] Figure 4 This is a perspective view of a wheel hub bearing, steering knuckle, and caliper bracket according to one embodiment.

[0035] Components in the diagram:

[0036] 1. Wheel hub bearing

[0037] 101. Wheel hub bearing mating surface

[0038] 2. Steering knuckle

[0039] 201. Steering knuckle mating surface

[0040] 3. Caliper bracket

[0041] 301. Caliper bracket mating surface. Detailed Implementation

[0042] The specific embodiments of this application will be further described in detail below with reference to the accompanying drawings. These embodiments are only for illustrating this application and are not intended to limit the scope of this utility model.

[0043] In the description of this utility model, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0045] Furthermore, in the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0046] like Figure 1-4 A noise reduction device for vehicle noise, wherein a mating working surface is provided between the two flange mating parts of the noise, such as between a wheel hub bearing and a steering knuckle, and the mating working surface is laser-engraved to form a surface texture layer with a set roughness; the surface texture layer is used to increase the friction coefficient between the mating surfaces and to suppress the micro-movement or creep of the two parts under stress.

[0047] When implementing this application, the key points are as follows:

[0048] Process selection and machining location determination: In contact areas prone to fretting, such as the outer flange face of the wheel hub bearing and the connecting flange face of the steering knuckle, determine the mating working surfaces that need to form a textured layer;

[0049] Laser engraving parameters are set by selecting appropriate laser power, pulse frequency, scanning speed and engraving spacing according to material properties and design requirements, so that the mating working surface forms a surface texture layer with a set roughness Ra of 1.2 to 5 μm;

[0050] Texture design: The texture can be circular, grid, or radial. The arrangement angle of the texture can be adjusted according to the direction of force to enhance shear friction performance.

[0051] After assembly and inspection, maintain the geometric fit accuracy of the parts, assemble using standard bolt torque, and test the friction coefficient and flange surface contact state to ensure that the textured layer plays an effective damping role.

[0052] With the expansion of compatibility, in addition to wheel hub bearings and steering knuckles, this method can be applied to mating interfaces such as steering tie rods and brake caliper brackets;

[0053] like Figure 1 The hub bearing 1 is formed by laser engraving on the hub bearing 1 to form the hub bearing mating surface 101;

[0054] like Figure 2 The steering knuckle mating surface 201 is formed on the steering knuckle 2 by laser engraving;

[0055] like Figure 3 The caliper bracket mating surface 301 is formed on the caliper bracket 3 by laser engraving;

[0056] The working principle or process of this application is as follows: When the vehicle is in a steering or low-speed vibration condition, the wheel hub bearing and the steering knuckle flange surface will produce relatively small slippage under the action of force; the friction coefficient of traditional smooth mating surfaces is low, resulting in fretting friction and periodic creep, which causes abnormal metal friction noise;

[0057] In this scheme, the surface texture layer formed by laser etching forms several micro-protrusion peak structures at the microscale, so that the two mating surfaces produce a "mechanical interlocking-micro-damping" effect when they come into contact: on the one hand, a stable frictional contact is formed between the micro-protrusion peaks, which increases the friction coefficient of the contact interface; on the other hand, the grooves between the textures store trace amounts of oxides and wear debris, preventing the accumulation of local slippage.

[0058] When the external load changes, the surface texture layer absorbs some of the energy from the micro-motion, forming energy dissipation and suppressing high-frequency vibrations in the hard metal contact; as a whole, it maintains a stable contact state between the wheel hub bearing and the steering knuckle, thereby effectively eliminating structural noises caused by micro-motion and creep.

[0059] Specifically, in one embodiment of this application, the laser-etched surface texture is a grid shape;

[0060] The surface texture layer etched by laser is a periodic or non-periodic microstructure with a surface roughness Ra of 1.2–5 μm;

[0061] Laser engraving is applied to the end face of the wheel hub bearing, the flange face of the steering knuckle, or the mating surface of the caliper bracket.

[0062] The wheel hub bearing is connected to the steering knuckle by fasteners;

[0063] This embodiment addresses the issues of fretting, creep, and structural noise caused by insufficient friction coefficient between flange mating surfaces. It employs laser precision etching to create a surface texture layer with a specific geometric shape. This allows the microscopic uneven structure of the local surface to create a micro-interlocking effect under stress, increasing the friction coefficient and homogenizing the contact stress distribution. This overcomes the shortcomings of traditional machining methods that struggle to balance roughness and precision, achieving significant technical effects in suppressing noise, improving connection stability, and extending assembly life. In actual processing, the energy density and pattern period of laser etching can be adjusted according to the part size and stress characteristics to achieve different roughness levels. Alternatively, equivalent micro-texture layers can be formed using laser etching, plasma spraying, or micro-milling processes to achieve the same friction-enhancing and noise-reducing effects.

[0064] Specifically, in one embodiment of this application, the laser-etched pattern is a dot matrix, grid, or concentric ring structure, and the pattern direction forms an angle of 30° to 90° with the flange load direction; the surface after laser etching is post-processed to form an oxide protective layer or a micro-bump oxide film; the surface texture layer of the laser-etched pattern is composed of a combination of micro-pits, micro-grooves, and bumps with different sizes; the pattern of the surface texture layer is distributed radially to form segments, and the texture directions of different segments are arranged alternately; a surface texture layer is provided on the mating surface of the caliper bracket;

[0065] The technical solution of this embodiment has the following technical features: To further solve the problem of local stress concentration and frictional attenuation at the mating interface under complex loads, a composite microstructure texture arranged in multiple directions and segments is adopted to make the contact characteristics of each region complementary, thereby maintaining a stable friction coefficient and preventing local slippage; by controlling the angle between the pattern and the load direction, the shear stress transmission path is optimized to improve the anti-fretting ability; the protective layer formed after oxidation can reduce the risk of corrosion and improve the surface hardness, overcoming the defects of traditional untreated metal mating surfaces that are prone to oxidation and wear; this solution achieves long-term noise reduction and fatigue resistance improvement under multiple load conditions; similar microstructures and protective layers can also be formed by using chemical etching, laser cladding or shot peening to achieve the same technical effect.

[0066] Specifically, in one embodiment of this application, a noise reduction device for vehicle noise eliminates steering noise by changing the roughness of the mating surface between the wheel hub bearing and the steering knuckle flange, and by processing the mating surface with a laser engraving machine to increase the roughness.

[0067] Furthermore, it can be extended to laser engraving the mating flange surfaces between other parts, thereby increasing the roughness and improving the fit between the parts;

[0068] This application addresses the aforementioned shortcomings by optimizing conventional machining methods to meet the high surface roughness requirements. It employs laser engraving to increase surface roughness, thereby resolving issues such as abnormal steering noise and reduced axial locking force of bolts between mating parts.

[0069] Laser engraving can improve the surface roughness of machined parts, solving problems such as steering noise and reducing the requirement for axial tightening force of bolts. Laser engraving can be used to increase the roughness of machined surfaces. Laser engraving can be done on steering knuckles, wheel bearings, calipers, brackets, or other machined surfaces that fit together.

[0070] This application solves the problem of abnormal steering noise caused by creep between the contact surfaces of the steering knuckle and the wheel hub bearing, and solves the problem of radial slippage caused by insufficient friction between the machined mating surfaces;

[0071] A solution for improving the surface roughness of machined parts using laser engraving involves repeatedly laser-engraving the mating surfaces of wheel hub bearings and steering knuckles to increase roughness. This increased roughness can be achieved by laser engraving on the steering knuckle, on the mating end face of the bearing, or on the caliper bracket or other mating machined surfaces.

[0072] For example, the surface roughness achieved by machining is Ra8.37-Ra12.15μm, while this embodiment uses different numbers of laser printing: 1 laser print: Ra1.2647μm; 2 laser prints: Ra3.8139μm; 10 laser prints: Ra4.3107μm; all of these can achieve the effect of changing the original abnormal noise and reducing the abnormal noise.

[0073] In summary, this utility model aims to solve the problem of abnormal noise caused by fretting or creep between the mating surfaces of the wheel hub bearing and the steering knuckle flange during vehicle steering or vibration. By using laser engraving technology to form a surface texture layer with a set roughness on the mating working surface, the friction coefficient of the mating surface is controllable and significantly improved, thereby suppressing fretting slippage and frictional vibration. This solution not only effectively eliminates steering noise but also delays wear and loosening of the mating surfaces, improving the reliability and service life of the structural connection. This technical solution has a simple structure, controllable processing, and is applicable to wheel hub bearings, steering knuckles, and other automotive parts with flange mating surfaces, possessing strong versatility and engineering application value.

[0074] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. A noise reduction device for vehicle noise, characterized in that, The mating parts of the flange that make abnormal noise are provided with mating working surfaces. The mating working surfaces are laser-engraved to form a surface texture layer with a set roughness. The surface texture layer is used to increase the friction coefficient between the mating surfaces and to suppress the micro-movement or creep of the two parts under stress.

2. The noise reduction device for vehicle abnormal noise as described in claim 1, characterized in that, The surface texture obtained by laser engraving is a grid shape.

3. The noise reduction device for vehicle abnormal noise as described in claim 1, characterized in that, The surface texture layer etched by laser is a periodic or non-periodic microstructure with a surface roughness Ra of 1.2 μm to 5.0 μm.

4. A noise reduction device for vehicle abnormal noise as described in claim 1, characterized in that, Laser engraving is applied to the end face of the wheel hub bearing, the flange face of the steering knuckle, or the mating surface of the caliper bracket.

5. A noise reduction device for vehicle abnormal noise as described in claim 1, characterized in that, The wheel hub bearing is connected to the steering knuckle by fasteners.

6. A noise reduction device for vehicle abnormal noise as described in claim 1, characterized in that, The laser-engraved pattern is a dot matrix, grid, or concentric ring structure, and the pattern direction is at an angle of 30° to 90° with the flange load direction.

7. A noise reduction device for vehicle abnormal noise as described in claim 1, characterized in that, After laser engraving, the surface is post-processed to form an oxide protective layer or a micro-bump oxide film.

8. A noise reduction device for vehicle abnormal noise as described in claim 1, characterized in that, The surface texture layer formed by laser engraving consists of a combination of micro-pits, micro-grooves and bumps with varying sizes.

9. A noise reduction device for vehicle abnormal noise as described in claim 1, characterized in that, The surface texture layer has a pattern distributed radially to form segments, with different segments having alternating texture directions.

10. A noise reduction device for vehicle abnormal noise as described in any one of claims 1-9, characterized in that, The mating surface of the caliper bracket has a surface texture layer.

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