Steel-aluminum composite brake disc with nanometer heat dissipation coating

Abstract

The utility model discloses a steel-aluminum composite brake disc with a nanometer heat dissipation coating, which comprises a brake disc main body made of stainless steel, metal heat dissipation pieces which are respectively attached to the left side and the right side of the brake disc main body and are made of aluminum alloy, and the nanometer heat dissipation coating coated on the surfaces of the metal heat dissipation pieces. And the metal heat dissipation piece is fixedly connected with the brake disc main body through a non-rigid riveting structure formed by riveting and matching flanged holes and salad holes. The utility model aims to provide a non-rigid riveting combination of stainless steel and aluminum alloy heterogeneous materials, so that the high-strength braking force of the stainless steel core is reserved, and the service life of the brake disc main body is prolonged. The friction heat is quickly conducted out through the aluminum alloy and the nanometer heat dissipation coating coated on the surface of the aluminum alloy, on the premise that the weight and the size are not obviously increased, heat exchange between internal airflow convection and the aluminum piece is facilitated, the transient heat dissipation speed is obviously increased, and the service life of the aluminum piece is prolonged. The super-strong structural stability and the excellent transient heat dissipation efficiency of the brake disc under the high-temperature and high-stress cycle conditions are achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of brake accessories, especially to a steel-aluminum composite brake disc with nano heat dissipation coating. BACKGROUND

[0002] With the development of the times, the brake technology of bicycles and motorcycles has gradually evolved from drum brakes and wheel rim brakes to the current mainstream disc brake system. As the core component to ensure the safety of cycling, the popularity of disc brakes is increasing. The existing brake discs are generally made of cast iron, stainless steel or single-layer aluminum alloy metal materials through integral casting or stamping forming process. During braking, the friction surface will quickly heat up due to high-speed friction, and the heat is mainly passively dissipated through the disc's own mass and surface vent channels. However, due to the uneven distribution of heat in the central area and the edge of the disc, the difference in radial (diameter direction) and thickness (thickness direction or axial) expansion caused by thermal expansion and contraction will form significant stress concentration inside the disc, especially under high-intensity working conditions such as long-time continuous braking, heavy braking or competitive cycling, which can easily cause the disc to warp, expand surface micro-cracks, or even structural cracking, resulting in a sharp decline in braking performance (i.e., thermal decay phenomenon), and in severe cases, it may cause brake failure.

[0003] To improve the heat dissipation performance and structural stability, various improvement schemes have been proposed in the industry: for example, designing spiral-shaped ventilation blades on the surface of the disc, increasing dense punching or slotting structure to enhance air exchange, or spraying traditional ceramic / metal-based heat dissipation coating on the surface of the disc. These schemes can improve the heat dissipation efficiency to some extent, but introduce new technical defects - the ventilation blades and dense punching weaken the overall structural strength of the disc, exacerbating the risk of stress concentration; the traditional heat dissipation coating has insufficient adhesion due to its large thickness (usually several microns), which can easily cause coating peeling, cracking or oxidation discoloration under repeated high-temperature thermal cycling, and the additional coating weight also offsets the lightweight advantage of the disc. On the other hand, simply upgrading the material (such as using higher thermal conductivity alloys or thickening the disc) can delay thermal decay, but the significantly increased unsprung mass will reduce the vehicle's handling flexibility. For motorcycles, competitive bicycles and other weight-sensitive vehicles, the conflict between the lightweight demand of the braking system and the improvement of heat dissipation performance has not been effectively balanced.

[0004] Therefore, the existing brake disc needs to be further optimized and improved. INVENTION CONTENTS

[0005] The utility model aims at providing a steel-aluminum composite brake disc with nano heat dissipation coating that can maintain structural stability under high temperature and high stress cycles, significantly improve transient braking heat dissipation efficiency without significantly increasing weight and volume.

[0006] To achieve the above object, the utility model discloses the following scheme: a steel-aluminum composite brake disc with nanometer heat dissipation coating, comprising: the brake disc body in the middle, a plurality of through holes are penetrated in brake disc body,

[0007] The metal heat dissipation piece is coaxial with the brake disc body and is connected together through the non-rigid riveting structure, and the diameter of the metal heat dissipation piece is less than the diameter of the brake disc body.

[0008] The outer surface of the metal heat dissipation piece is coated with nanometer heat dissipation coating.

[0009] The non-rigid riveting structure is formed by the hole flanging on one side of the metal heat dissipation piece, the through hole on the brake disc body and the salad hole on the other side of the metal heat dissipation piece.

[0010] The diameter of the hole flanging is less than the diameter of the through hole, so that the through hole of the brake disc body and the hole flanging of the metal heat dissipation piece form a thermal expansion buffer gap.

[0011] As a preferred scheme of the utility model, the brake disc body is made of stainless steel, which can provide excellent mechanical strength and wear resistance; the metal heat dissipation piece is made of aluminum alloy, and the thermal conductivity of the aluminum alloy is several times that of stainless steel, so that heat can be quickly transferred to the heat dissipation piece, and then the nanometer coating can accelerate heat radiation and convection. The combination of steel and aluminum can ensure braking force without significantly increasing weight, achieving the best balance between light weight and high heat dissipation.

[0012] The above scheme is based on the stainless steel brake disc body penetrating a plurality of through holes, and aluminum alloy heat dissipation pieces are symmetrically attached on the left and right sides and connected through non-rigid riveting. In this way, the high-strength braking force of the stainless steel core is retained, and the friction heat is quickly transferred to the edge of the disc by using aluminum alloy and the high-thermal-conductivity nanometer heat dissipation coating on the surface. Compared with simply upgrading the material, not only the unsprung mass is reduced, but also the internal airflow convection and heat exchange between the aluminum parts are improved, significantly accelerating the transient heat dissipation speed.

[0013] As a preferred scheme of the utility model, the diameter of the hole flanging is 3 mm to 5 mm, and the diameter of the salad hole is 4 mm to 6 mm.

[0014] As a preferred scheme of the utility model, the nanometer heat dissipation coating is a carbon-based two-dimensional nanometer coating coated on the surface of the metal heat dissipation piece, and the coating thickness is 0.1 μm to 1 μm. Under the premise of not increasing the weight and volume significantly, the heat radiation efficiency is improved by several times or more, and the heat conduction efficiency is greatly improved, solving the defects of "poor adhesion of traditional heat dissipation layer, large thickness leading to weight increase", and realizing ultra-thin, efficient and durable surface heat dissipation.

[0015] As the preferred aspect of the utility model, the thermal expansion buffer gap is between 0.1 mm and 0.3 mm, which can ensure riveting connection quality and guarantee sufficient thermal expansion gap.

[0016] The above scheme forms a thermal expansion buffer gap of 0.1 mm to 0.3 mm between the hole and the communication hole, allows different materials to freely expand and dislocate at high temperature, avoids high stress concentration caused by radial and thick expansion differences, completely solves the problem of warping deformation and micro cracks caused by thermal expansion and contraction of traditional discs, and reduces the transmission of thermal stress under the premise of ensuring coaxial force transmission, which is conducive to the structural stability of long-time continuous braking.

[0017] As a further aspect of the utility model, a plurality of heat dissipation grooves A are penetrated through the brake disc body around the center of the brake disc body, and a plurality of heat dissipation grooves B corresponding to the heat dissipation grooves A are penetrated through the metal heat dissipation member, and the corresponding heat dissipation grooves A and heat dissipation grooves B form a ventilation groove, which breaks the single path of solid heat conduction on one hand and strengthens the exchange of internal and external airflow on the other hand, effectively improves the steady-state and transient heat dissipation capacity, and the heat dissipation grooves are dispersed to the aluminum metal heat dissipation member and the stainless steel brake disc body, so that the stress distribution is more uniform, and the overall strength is not affected.

[0018] As a further aspect of the utility model, a friction groove hole is penetrated through the brake disc body near the outer periphery and surrounds the periphery of the metal heat dissipation member, which can timely discharge water film and particles in rainy days or sandy environment, avoid the sliding of the friction surface, and make the heat quickly transfer in the outer edge area where heat is most likely to accumulate, further inhibit thermal decay, and meet the dual needs of chip removal and heat dissipation.

[0019] As the preferred aspect of the utility model, the center of the brake disc body is penetrated by a shaft hole, and bolt fixing holes are sequentially and spaced apart along the inner periphery of the shaft hole, the metal heat dissipation member has a clearance hole in the center, the diameter of the clearance hole is greater than the diameter of the shaft hole, so that the bolt fixing holes are exposed in the clearance hole, the installation is simple and convenient, the concentricity is high, the additional space of the clearance hole is used to avoid the direct jamming of the bolt and the coating or the aluminum part, the assembly stress caused by thermal expansion is eliminated, and the overall reliability is improved.

[0020] As the utility model discloses preferred place case, the hole end portion is in the state without riveting, in order to be followed through the corresponding intercommunication hole and the salad hole of the other side metal heat dissipation spare, and its top end extension part forms 0.3mm-0.4mm protruding height relative to the outer surface of the side metal heat dissipation spare.This protruding height guarantees that the rivet head has enough locking force and buffer space after riveting, and also will not form obvious local stress concentration point, thereby keeping the connection stable under high temperature thermal cycle, solve the traditional riveting connection loose or over-tightening two difficult problems.

[0021] In summary, the utility model has the advantages that: the utility model discloses high-strength stainless steel is prepared brake disc main part, and is assembled with aluminum alloy fin on both sides, through the combination of heterogeneous materials of stainless steel and aluminum alloy, while ensuring the shear strength of the brake surface, significantly reduce the unsprung mass, and the high thermal conductivity of aluminum alloy establishes efficient path for heat axial conduction and radial convection;The diameter of the metal heat dissipation piece made of aluminum alloy on both sides is slightly smaller than the main body, and is connected coaxially through the non-rigid riveting structure of the hole and the salad hole, wherein the outer wall of the hole is 0.1-0.3mm smaller than the diameter of the intercommunication hole, so that a thermal expansion buffer gap is formed between the aluminum piece and the main body, the gap design can accommodate the radial displacement of aluminum alloy and stainless steel due to the difference in thermal expansion coefficient, release the interface stress through micron-level slip, effectively inhibit the disc warping deformation and fatigue crack initiation;The outer surface of the aluminum heat dissipation piece is covered with a carbon-based two-dimensional nanometer heat dissipation coating, which realizes more than several times of heat radiation efficiency and significant improvement of heat conduction efficiency with single-atom thickness structure, and still maintains excellent adhesion under high temperature cycle, realizes the effective improvement of heat dissipation efficiency compared with traditional coating;At the same time, the heat dissipation grooves A distributed in the circumference of the main body and the heat dissipation grooves B of the aluminum alloy fin form a continuous flow channel, utilize the centrifugal force of disc rotation to drive airflow through heat exchange, enhance steady-state and transient heat exchange, and the friction groove hole design of the outer periphery can quickly remove the water film and particles in the wet and slippery or muddy environment, prevent the sliding of the friction surface.Finally, the center shaft hole and bolt fixing hole cooperate with the accommodation hole of the metal heat dissipation piece, ensure the installation concentricity and fastening reliability;And the 0.3-0.4mm riveting allowance reserved at the hole end forms a controllable pressing force through plastic deformation, which ensures the connection reliability and avoids stress concentration caused by over-constraint. The above-mentioned various optimized collaborative design makes the utility model realize the super strong structural stability and excellent transient heat dissipation efficiency of the brake disc under high temperature and high stress cycle conditions without significantly increasing the weight and volume. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is one of the utility model's three-dimensional structure views.

[0023] Figure 2 It is the second three-dimensional structure view of the utility model.

[0024] Figure 3 is a sectional view of the utility model, and an enlarged view of a local area in the figure.

[0025] Figure 4 is Figure 3 is an enlarged view of position A in the figure.

[0026] Figure 5 is an overall exploded view of the utility model.

[0027] Figure 6 is a sectional view of the utility model in which the metal heat dissipation member with a hole punched on one side is inserted into the hole punched on the other side, and the hole punched on one side has not yet passed through the corresponding communication hole.

[0028] Figure 7 is a sectional view of the utility model in which the metal heat dissipation member with a hole punched on one side has passed through the corresponding communication hole, and is inserted into the hole punched on the other side, and has not yet been riveted.

[0029] Figure 8 is a sectional view of the utility model in which the metal heat dissipation member with a hole punched on one side has passed through the corresponding communication hole, and is inserted into the hole punched on the other side, and has been riveted.

[0030] BRIEF DESCRIPTION OF DRAWINGS 1. Brake disc main body; 2. Metal heat dissipation member; 3. Non-rigid riveting structure; 4. Thermal expansion buffer gap; 10. Ventilation channel; 11. Communication hole; 12. Heat dissipation groove A; 13. Friction groove hole; 14. Shaft hole; 15. Bolt fixing hole; 21. Hole punched; 22. Hole punched; 23. Heat dissipation groove B; 24. Letting hole. DETAILED DESCRIPTION

[0031] The following detailed implementation provides a plurality of different embodiments or examples for implementing the utility model. Of course, these are only examples and are not intended to be limiting. In addition, repeated reference numbers may be used in different embodiments, such as repeated numbers and / or letters. These repetitions are for the purpose of simply and clearly describing the present application, and do not represent a specific relationship between the different embodiments and / or structures being discussed.

[0032] Moreover, spatially relative terms, such as "beneath", "below", "lower", "above", "upper", and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. The devices can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly, depending on the particular orientation being referred to. The terms "first", "second", etc., are used herein only to describe one element or feature versus another, and are not intended to denote relative importance or significance. Thus, a feature defined with "first" or "second" can implicitly or explicitly include one or more of either feature.

[0033] The utility model will be further described below in combination with the description of the drawings and specific embodiments: as Figures 1 to 8 As shown in the utility model discloses a kind of steel-aluminum composite brake disc with nanometer heat dissipation coating, including the brake disc main body 1 made of stainless steel material with yield strength ≥205 MPa, Rockwell hardness HRC50-55 and the metal heat dissipation piece 2 made of aluminum alloy material respectively pasted in the left and right sides of the brake disc main body 1 with slightly smaller diameter than the diameter of brake disc main body 1. The shaft hole 14 is passed through the center of brake disc main body 1, and the metal heat dissipation piece 2 is annular, and the coaxial alignment of the two is connected by non-rigid riveting structure 3. Specifically, on the brake disc main body 1, multiple groups of communication holes 11 with diameter of 3.1 mm~5.3mm are evenly set on its disc surface by stamping or laser cutting process, wherein the left metal heat dissipation piece 2 is punched with a flange hole 21 with diameter of 3 mm~5 mm at the position corresponding to the communication hole 11, and the right metal heat dissipation piece 2 is punched with a salad hole 22 with diameter of 4 mm~6 mm, the chamfer angle is 90°, and the depth is 0.8 mm. The outer wall diameter of flange hole 21 is smaller than the diameter of communication hole 11. Insert the flange hole 21 of left aluminum alloy heat dissipation fin into the communication hole 11 of brake disc main body, and form a thermal expansion buffer gap 4 of 0.1 mm~0.3 mm between the outer wall of flange hole 21 and the inner wall of communication hole 11; the thermal expansion buffer gap 4 can freely adjust the difference between thermal expansion and cold shrinkage of the material under high temperature working condition, avoid radial and thick stress concentration and structural deformation. Then pass the end of flange hole 21 through the salad hole 22 on the opposite side, and the top end of flange hole 21 protrudes 0.3 mm~0.4 mm relative to the outer surface of the metal heat dissipation piece 2 before riveting, which is converted into sufficient locking force and thermal expansion buffer space after riveting, to prevent loosening or excessive extrusion at the connection. Use pneumatic riveting machine to apply 15 kN pressure, make the plastic deformation of flange hole 21 top end extension fill the chamfer space of salad hole 22, form mushroom head locking structure, which not only ensures the coaxial consistency of transmission power, but also retains the function of thermal expansion buffer gap 4.

[0034] The outer surface of the metal heat sink 2 is entirely sprayed with a carbon-based two-dimensional nanometer heat dissipation coating, the thickness of which is controlled within the range of 0.1 μm to 1 μm. The carbon-based two-dimensional nanometer heat dissipation coating is uniformly sprayed on the surface of the metal heat sink 2 by first performing sand blasting treatment on the surface of the metal heat sink 2 and then performing alcohol ultrasonic cleaning, and then uniformly dispersing the carbon-based two-dimensional nanometer material in water-based resin to prepare water-based paint, or the carbon-based two-dimensional nanometer heat dissipation coating can be deposited by chemical vapor deposition (CVD) at 300°C or coated by dipping, scraping, brushing, rolling and other processes. The thickness of the carbon-based two-dimensional nanometer heat dissipation coating in this embodiment is preferably 0.5 μm, which can increase the heat radiation efficiency by more than 10 times and achieve excellent performance of increasing the heat conduction efficiency by 70% to 80%; and the adhesion can remain at level 0, without falling off, discoloration or cracking under the cold and hot impact environment of -20 °C to 150 °C and the high temperature cycle environment of 400 °C. The carbon-based two-dimensional nanometer heat dissipation coating cooperates with the metal heat sink 2 to form a heat conduction path through the communication hole 11 between the disc body 1 and the combination of the hole 21 and the salad hole 22, which significantly improves the transient braking heat dissipation efficiency.

[0035] As shown in Figures 1 to 8 , to further enhance the air exchange and chip and water drainage functions, a plurality of heat dissipation grooves A12 are arranged around the shaft hole 14 outside the central shaft hole 14 of the brake disc body 1, and the metal heat sink 2 is provided with heat dissipation grooves B23 corresponding to the heat dissipation grooves A12, and the heat dissipation grooves A12 and the heat dissipation grooves B23 corresponding to each other form a through ventilation groove 10. This design not only reduces the unsprung mass, but also provides a heat dissipation channel for air convection and heat conduction between the metal heat sink 2 and the brake disc body 1. The through ventilation groove 10 allows heat to be conducted along the metal solid and quickly carried away by the hot air flow through the ventilation groove 10, achieving the synergistic optimization of steady-state and transient-state heat dissipation; the friction groove hole 13 is also provided around the outer periphery of the metal heat sink 2 at the position close to the outer periphery of the brake disc body 1, which can timely drain the water film and particles in rainy or muddy environments to avoid the sliding of the friction surface.

[0036] In addition, as shown in Figures 1 to 3 and Figures 5 to 8 , the bolt fixing holes 15 for fixing the 6 M6 bolts for installation with the frame spline shaft are arranged at equal intervals along the inner periphery of the shaft hole 14, and the center hole diameter of the bolt fixing hole 15 is 22 mm; the metal heat sink 2 has a clearance hole 24 with a diameter larger than that of the shaft hole 14, so that the bolt fixing hole 15 can protrude into the clearance hole 24, which not only ensures the concentricity of the fixing bolts, but also avoids the direct contact of the bolts with the nanometer coating or the metal heat sink 2 to prevent the assembly stress caused by jamming.

[0037] The embodiment realizes multiple optimizations of stainless steel and aluminum alloy combination, nano coating synergism, ventilation channel cooperation and non-rigid riveting thermal expansion buffering under the premise of not significantly increasing weight and volume, so that the brake disc has excellent transient and steady-state heat dissipation capacity under high temperature and high stress cycle conditions, and meanwhile, excellent structural stability and installation reliability are maintained.

[0038] The basic principle and main features of the utility model and the advantages of the utility model are shown and described above, and the person skilled in the art should understand that the utility model is not limited by the above embodiments, and the above embodiments and the description in the specification are only to illustrate the principle of the utility model, and various changes and improvements of the utility model can be made without departing from the spirit and scope of the utility model, and these changes and improvements all fall within the scope of the utility model claimed for protection. The protection scope of the utility model is defined by the appended claims and equivalents thereof.

Claims

1. A steel-aluminum composite brake disc with nano heat dissipation coating, characterized in that, The utility model relates to a brake disc body (1) is penetrated with a plurality of communication holes (11), metal heat radiating parts (2) are respectively attached to the left and right sides of the brake disc body (1), the metal heat radiating parts (2) are coaxially connected with the brake disc body (1) through a non-rigid riveting structure (3), and the diameter of the metal heat radiating parts (2) is less than the diameter of the brake disc body (1), the outer surface of the metal heat radiating parts (2) is coated with a nano heat radiating coating, the non-rigid riveting structure (3) is formed by the cooperation of a punch hole (21) on one of the metal heat radiating parts (2), a communication hole (11) on the brake disc body (1) and a salad hole (22) on the other metal heat radiating part (2), the diameter of the punch hole (21) is less than the diameter of the communication hole (11), so that a thermal expansion buffer gap (4) is formed between the communication hole (11) of the brake disc body (1) and the punch hole (21) of the metal heat radiating part (2). The brake disc body (1) is made of stainless steel, and the metal heat radiating parts (2) are made of aluminum alloy. The diameter of the punch hole (21) is 3-5 mm, and the diameter of the salad hole (22) is 4-6 mm. The nano heat radiating coating is a carbon-based two-dimensional nano coating coated on the surface of the metal heat radiating part (2), and the coating thickness is 0.1-1 microns. The thermal expansion buffer gap (4) is 0.1-0.3 mm. A plurality of heat radiating grooves A (12) are penetrated through the brake disc body (1) around the center of the brake disc body (1), and a plurality of heat radiating grooves B (23) corresponding to the heat radiating grooves A (12) are penetrated through the metal heat radiating parts (2).

2. The steel-aluminum composite brake disc with nano heat dissipation coating according to claim 1, characterized in that, A friction groove hole (13) is penetrated through the brake disc body (1) around the periphery of the metal heat radiating parts (2) near the outer periphery of the brake disc body (1).

3. The steel-aluminum composite brake disc with nano heat dissipation coating according to claim 1 or 2, characterized in that, An axle hole (14) is penetrated through the center of the brake disc body (1), and bolt fixing holes (15) are sequentially and spacedly arranged along the inner periphery of the axle hole (14), the metal heat radiating parts (2) have clearance holes (24) in the center, the diameter of the clearance holes (24) is greater than the diameter of the axle hole (14), so that the bolt fixing holes (15) are exposed in the clearance holes (24).

4. The steel-aluminum composite brake disc with nano heat dissipation coating according to claim 1, characterized in that, In the state of not being riveted, the end of the punch hole (21) sequentially penetrates through the corresponding communication hole (11) and the salad hole (22) of the other metal heat radiating part (2), and the top end extension part forms a protruding height of 0.3-0.4 mm relative to the outer surface of the metal heat radiating part (2).

5. The steel-aluminum composite brake disc with nano heat dissipation coating according to claim 1, characterized in that, ​ 6. The steel-aluminum composite brake disc with nano heat dissipation coating according to claim 1, characterized in that, ​ 7. The steel-aluminum composite brake disc with nano heat dissipation coating according to claim 6, characterized in that, ​ 8. The steel-aluminum composite brake disc with nano heat dissipation coating according to claim 1, characterized in that, ​ 9. The steel-aluminum composite brake disc with nano heat dissipation coating according to claim 3, characterized in that, ​

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