A strong heat dissipation type drum brake

Abstract

The application discloses a strong heat dissipation type drum brake and relates to the technical field of brakes, which comprises a brake drum body, the brake drum body is in a whole cylinder shape, the cylinder wall of the brake drum body comprises a friction layer on the inner side and a heat conduction layer on the outer side; the inner surface of the friction layer is provided with a plurality of heat dissipation holes, and the heat dissipation holes are honeycomb blind holes. The honeycomb blind holes can increase the surface area and the turbulence effect, thereby improving the efficiency of air natural convection and accelerating heat dissipation. Meanwhile, the blind hole process is adopted instead of direct perforation, so that the heat dissipation efficiency is ensured, and the mechanical strength of the brake drum itself is also ensured, so that the brake drum has better durability.

Description

Technical Field

[0001] This invention relates to the field of brake technology, and more specifically, to a high-heat-dissipation drum brake. Background Technology

[0002] Drum brakes utilize a brake transmission mechanism to press the brake shoes against the brake friction pads inside the brake drum, thereby generating braking force. This allows the wheels to slow down or stop within the shortest distance as needed, ensuring driving safety and preventing the car from sliding automatically when parked.

[0003] The mainstream type of drum brake is the internally expanding type, where the brake pads are located inside the brake wheel. During braking, the brake pads expand outwards, rubbing against the inside of the brake wheel to achieve braking. Drum brakes have a large friction contact area, making them suitable for heavy vehicles and high-load scenarios. However, current drum brake technology has poor heat dissipation, which can easily lead to heat fade and brake failure. Summary of the Invention

[0004] The purpose of this invention is to provide a high-heat-dissipation drum brake with a novel structure, superior strength and heat dissipation performance, effectively solving the problem of poor heat dissipation in existing drum brakes.

[0005] The embodiments of the present invention are implemented as follows: A high-heat-dissipation drum brake includes a brake drum body, which is cylindrical in shape. The cylinder wall includes an inner friction layer and an outer heat-conducting layer. The inner surface of the friction layer is provided with multiple heat dissipation holes, which are honeycomb-shaped blind holes.

[0006] Furthermore, in other preferred embodiments of the present invention, the diameter of the heat dissipation hole is 3~5 mm, the depth is 3~5 mm, and the porosity of the inner surface of the friction layer is 10%~30%.

[0007] Furthermore, in other preferred embodiments of the present invention, the brake drum body includes an inlet end and an outlet end at both ends along its axial direction, and the porosity of the inner surface of the friction layer gradually decreases from the inlet end to the outlet end.

[0008] Furthermore, in other preferred embodiments of the present invention, the diameter of the heat dissipation hole gradually decreases from the inlet end to the outlet end.

[0009] Furthermore, in other preferred embodiments of the present invention, the edge roughness of the heat dissipation hole is Ra=1.6~3.2 μm.

[0010] Furthermore, in other preferred embodiments of the present invention, the friction layer is made of vermicular graphite cast iron with a thickness of 14~18mm; the thermally conductive layer is made of silicon carbide particle-reinforced aluminum matrix composite material with a thickness of 0.6~1 mm and a thermal conductivity ≥180W / m·K.

[0011] Furthermore, in other preferred embodiments of the present invention, a protective layer is also covered outside the thermally conductive layer. The protective layer is made of silicon nitride ceramic and has a thickness of 1.0~1.2 mm.

[0012] Furthermore, in other preferred embodiments of the present invention, the outer wall of the friction layer is provided with a plurality of storage holes, which are honeycomb-shaped blind holes and are positioned one-to-one with the heat dissipation holes, and the storage holes contain phase change material.

[0013] Furthermore, in other preferred embodiments of the present invention, the phase change material comprises, by weight parts: Paraffin wax 60-70 parts, fatty acid 10-15 parts, silicon carbide particles 15-20 parts, hydroxyethyl cellulose 5-8 parts; Phase change materials are encapsulated with polymethyl methacrylate to form microcapsule particles.

[0014] Furthermore, in other preferred embodiments of the present invention, the particle size of the microcapsule particles is 50~80 μm.

[0015] The beneficial effects of the embodiments of the present invention are: This invention provides a high-heat-dissipation drum brake, comprising a brake drum body, which is cylindrical in shape. The drum wall includes an inner friction layer and an outer heat-conducting layer. The inner surface of the friction layer has multiple heat dissipation holes, which are honeycomb-shaped blind holes. The honeycomb-shaped blind holes increase the surface area and turbulence effect, thereby improving the efficiency of natural air convection and accelerating heat dissipation. Furthermore, using a blind hole process instead of direct perforation ensures both heat dissipation efficiency and the mechanical strength of the brake drum itself, resulting in better durability. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the brake drum body of a high-heat-dissipation drum brake provided in an embodiment of the present invention; Figure 2A schematic diagram of the friction layer of a high-heat-dissipation drum brake provided in an embodiment of the present invention; Figure 3 This is a partial cross-sectional view of a high-heat-dissipation drum brake provided in an embodiment of the present invention.

[0018] Icons: 100-Brake drum body; 110-Friction layer; 1101-Inlet end; 1102-Outlet end; 111-Heat dissipation hole; 112-Material storage hole; 113-Phase change material; 120-Heat conductive layer; 130-Protective layer. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and 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. Therefore, they should not be construed as limitations on this invention.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0023] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature. Example

[0024] This embodiment provides a high-heat-dissipation drum brake, see reference. Figure 1 As shown, it includes a brake drum body 100, which is cylindrical in shape, and its cylindrical wall includes an inner friction layer 110 and an outer heat-conducting layer 120.

[0025] like Figure 1 and Figure 2 As shown, the inner surface of the friction layer 110 is provided with multiple heat dissipation holes 111, which are honeycomb-shaped blind holes. The honeycomb-shaped blind holes increase the surface area and turbulence effect, thereby improving the efficiency of natural air convection and accelerating heat dissipation. Compared to the traditional solid structure, its convection efficiency can be improved by about 40%. At the same time, using a blind hole process instead of direct perforation ensures both heat dissipation efficiency and the mechanical strength of the brake drum itself, giving it better durability.

[0026] It should be noted that the honeycomb structure, which mimics the shape of a honeycomb, can be fabricated using additive manufacturing, specifically by layering materials on the inner wall surface through 3D printing technologies such as laser fused deposition modeling (LDM) and selective laser sintering (SLS) to directly form the honeycomb-shaped heat dissipation holes 111. Alternatively, it can be fabricated by drilling holes in the inner wall surface to form the heat dissipation holes 111.

[0027] Furthermore, such as Figure 2 and Figure 3As shown, the diameter of the heat dissipation hole 111 is 3~5 mm, the depth is 3~5 mm, and the porosity of the inner surface of the friction layer 110 is 10%~30%. Within the above parameter range, a balance between heat dissipation efficiency and mechanical performance can be achieved. If the hole diameter is too small and the porosity is too low, the heat dissipation effect will not be achieved, while if the hole diameter is too large and the porosity is too high, the contact area between the inner wall and the brake shoe will be significantly reduced, affecting the braking effect. It should be noted that the hole diameter here refers to the diameter of the circle inscribed in the hexagon.

[0028] The brake drum body 100 includes an inlet end 1101 and an outlet end 1102 at both ends along its axial direction. The porosity of the inner surface of the friction layer 110 gradually decreases from the inlet end 1101 to the outlet end 1102. The inlet end 1101 is the end of the brake drum closest to the outer side of the wheel. When the vehicle moves forward, this is the first area to come into contact with the outside airflow and is a high-heat flow area. More heat dissipation holes 111 are distributed here to enhance heat dissipation efficiency. The outlet end 1102 refers to the end closest to the inner side of the wheel, which is the main area for heat and airflow to be discharged. The number of heat dissipation holes 111 is reduced here to increase the friction area and provide better braking performance. In addition, the diameter of the heat dissipation holes 111 can be gradually reduced from the inlet end 1101 to the outlet end 1102 to achieve the same effect. It should be noted that... Figure 1 and Figure 2 The diagram shows a uniform distribution of porosity and pore size, without showing gradient changes.

[0029] The edge roughness of the heat dissipation hole 111 is Ra=1.6~3.2 μm. The surface roughness can be achieved by laser micromachining. Improving the edge roughness can compensate for the friction loss caused by the reduction of friction area after the hole is opened, and maintain the stability of friction.

[0030] Furthermore, the friction layer 110 is made of vermicular graphite cast iron (such as RuT450) with a thickness of 14-18 mm. Compared to traditional gray cast iron, it exhibits better thermal fatigue performance and an approximately 15% increase in thermal conductivity. The thermally conductive layer 120 is made of silicon carbide particle-reinforced aluminum matrix composite material with a thickness of 0.6-1 mm and a thermal conductivity ≥180 W / m·K. Its thermal diffusion rate can reach 2.5 times that of traditional cast iron, and its coefficient of thermal expansion matches that of the friction layer 110, reducing interfacial thermal stress.

[0031] In addition, a protective layer 130 is also covered outside the heat-conducting layer 120. The protective layer 130 is made of silicon nitride ceramic and has a thickness of 1.0~1.2 mm. Silicon nitride ceramic has a temperature resistance of ≥800℃, a surface hardness of ≥1500 HV, and a 30% improvement in wear resistance, providing better protection for the brake drum.

[0032] like Figure 2 and Figure 3As shown, the outer wall of the friction layer 110 is provided with multiple storage holes 112. The storage holes 112 are honeycomb-shaped blind holes, and their positions correspond one-to-one with the heat dissipation holes 111. The storage holes 112 store phase change material 113. When the friction temperature exceeds the critical value, the phase change material 113 can absorb heat and undergo a phase change, absorbing instantaneous frictional heat, thereby reducing the peak temperature of a single braking action. This, combined with the heat dissipation holes 111, accelerates air convection, achieving a dual-layer heat dissipation mechanism. The processing method of the storage holes 112 and the heat dissipation holes 111 is similar. After the phase change material 113 is filled, a thermally conductive layer 120 is applied, and then the layers are sealed by laser welding.

[0033] Optionally, the phase change material 113 comprises, by weight parts: Paraffin wax 60-70 parts, fatty acids 10-15 parts, silicon carbide particles 15-20 parts, hydroxyethyl cellulose 5-8 parts.

[0034] This phase change material 113 uses paraffin wax as the main material, with a phase change temperature of 150~200℃ and a latent heat ≥220J / g. Silicon carbide particles are used as a thermal conductivity enhancer, and hydroxyethyl cellulose is used as a stabilizer. This phase change material 113 uses polymethyl methacrylate as the wall material and is encapsulated into microcapsules via electrostatic spraying. The particle size of the microcapsules is 50~80 μm. Using this formulation, the peak temperature of phase change material 113 can be reduced by 40~50℃.

[0035] In summary, this invention provides a high-heat-dissipation drum brake, comprising a brake drum body 100, which is cylindrical in shape. The cylinder wall includes an inner friction layer 110 and an outer heat-conducting layer 120. The inner surface of the friction layer 110 is provided with multiple heat dissipation holes 111, which are honeycomb-shaped blind holes. The honeycomb-shaped blind holes increase the surface area and turbulence effect, thereby improving the efficiency of natural air convection and accelerating heat dissipation. Furthermore, the use of blind holes instead of direct perforation ensures both heat dissipation efficiency and the mechanical strength of the brake drum itself, resulting in better durability.

[0036] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-heat-dissipation drum brake, characterized in that, The device includes a brake drum body, which is cylindrical in shape. The cylinder wall includes an inner friction layer and an outer heat-conducting layer. The inner surface of the friction layer is provided with a plurality of heat dissipation holes, which are honeycomb-shaped blind holes.

2. The high-heat-dissipation drum brake according to claim 1, characterized in that, The diameter of the heat dissipation holes is 3~5 mm, the depth is 3~5 mm, and the porosity of the inner surface of the friction layer is 10%~30%.

3. The high-heat-dissipation drum brake according to claim 2, characterized in that, The brake drum body includes an inlet end and an outlet end at both ends along its axial direction, and the porosity of the inner surface of the friction layer gradually decreases from the inlet end to the outlet end.

4. The high-heat-dissipation drum brake according to claim 3, characterized in that, The diameter of the heat dissipation hole gradually decreases from the inlet end to the outlet end.

5. The high-heat-dissipation drum brake according to claim 4, characterized in that, The edge roughness of the heat dissipation hole is Ra=1.6~3.2 μm.

6. The high-heat-dissipation drum brake according to claim 5, characterized in that, The friction layer is made of vermicular graphite cast iron with a thickness of 14~18 mm; the thermally conductive layer is made of silicon carbide particle-reinforced aluminum matrix composite material with a thickness of 0.6~1 mm and a thermal conductivity ≥180W / m·K.

7. The high-heat-dissipation drum brake according to claim 6, characterized in that, The thermally conductive layer is also covered by a protective layer, which is made of silicon nitride ceramic and has a thickness of 1.0~1.2 mm.

8. The high-heat-dissipation drum brake according to claim 7, characterized in that, The outer wall of the friction layer is provided with a plurality of storage holes, which are honeycomb-shaped blind holes and are positioned one-to-one with the heat dissipation holes. The storage holes contain phase change material.

9. The high-heat-dissipation drum brake according to claim 8, characterized in that, The phase change material comprises, by weight parts: Paraffin wax 60-70 parts, fatty acid 10-15 parts, silicon carbide particles 15-20 parts, hydroxyethyl cellulose 5-8 parts; The phase change material is encapsulated with polymethyl methacrylate to form microcapsule particles.

10. The high-heat-dissipation drum brake according to claim 9, characterized in that, The microcapsule particles have a particle size of 50~80 μm.

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