CN117489727A - A parallel type carbon ceramic wheel mounted brake disc - Google Patents

Abstract

The invention discloses a parallel carbon ceramic wheel-mounted brake disc which comprises a friction disc and a plurality of heat dissipation ribs, wherein the heat dissipation ribs are uniformly distributed along the circumference of the friction disc, and are parallel heat dissipation ribs. The parallel heat dissipation rib comprises a main body part, a first extension part, a second extension part and a third extension part, wherein the first extension part is arranged on the inner side edge of the main body part and extends from the main body part to the inner side of the circumference of the friction disc, the second extension part is arranged on the outer side edge of the main body part and extends from the main body part to the outer side of the circumference of the friction disc, and the third extension part is arranged on the middle side edge of the main body part and extends from the main body part along the circumferential tangential direction of the friction disc. The parallel carbon ceramic wheel-mounted brake disc has the advantages that the limit maximum temperature can be effectively reduced by the adopted parallel heat dissipation ribs, the structural mass is obviously reduced, the light-weight design concept of reducing unsprung mass of a train is met, and the running stability of the train is improved. The fluid flow curve in the inner part is smoother, the heat transfer rate is greatly improved, and the temperature distribution of the disc surface is more uniform when the product is braked.

Description

A parallel type carbon ceramic wheel mounted brake disc

Technical field

The invention relates to the technical field of vehicle brake discs, and in particular to a double-type carbon ceramic wheel-mounted brake disc.

Background technique

High speed and lightweight are the development trends of high-speed trains in the world. Air braking technology is the last line of defense to ensure the safety and reliability of trains. The complex working environment and huge braking power have put forward new requirements for brake disc configuration and braking materials. High demand.

During pure air braking of a high-speed train running at a speed of 400 km per hour, the braking energy density endured by the brake disc is greater than 450J/mm2, and the instantaneous temperature on the surface of the brake disc is as high as 1000°C. The huge braking heat load causes a large temperature gradient in the brake disc. And this produces thermal stress. As shown in Figure 12, the cyclic effects of uneven temperature differences and thermal stress cause the brake disc to produce fine cracks. During repeated braking, the cracks continue to expand, and the brake disc will cause fatigue fracture. The existing brake disc structure is a cylindrical and straight rib structure as shown in Figure 13. In order to prevent fatigue fracture caused by thermal cracks, the brake disc must have good thermal crack resistance, wear resistance, thermal conductivity and friction braking performance. Existing wheel-mounted brake discs still need to be further structurally optimized in order to have better heat dissipation performance and temperature distribution gradient.

Contents of the invention

In view of this, the object of the present invention is to provide a parallel carbon ceramic wheel-mounted brake disc to achieve efficient ventilation and heat dissipation effects and uniform temperature distribution gradient.

The present invention solves the above problems through the following technical means:

A parallel type carbon ceramic wheel brake disc includes a friction disc and a plurality of heat dissipation ribs, each heat dissipation rib is evenly arranged along the circumference of the friction disc, and the heat dissipation ribs are double type heat dissipation ribs.

The heat generated during the braking process of the brake disc is mainly dissipated through heat conduction and heat convection, so the design of the heat dissipation ribs needs to take into account both the effects of heat conduction and heat convection. In the prior art, heat dissipation ribs are usually cylindrical and straight rib structures. In the present invention, a parallel structure of heat dissipation ribs is pioneered, which can effectively reduce the maximum maximum temperature of the brake disc and significantly reduce the structural quality with the same heat dissipation effect.

The merged structure is a microstructural configuration obtained by designing heat transfer materials through topology optimization to achieve better thermal conductivity of the structure. When heat is transferred from high temperature to low temperature, there is heat transfer potential capacity dissipation. The merged structure design is based on The overall heat transfer potential capacity is minimized and is designed for optimization objectives. The heat during the braking process comes from the friction surface. The friction layer transfers the surface temperature to the low temperature part in the thickness direction, and then transfers it to the parallel heat dissipation rib structure. The structural design of the parallel heat dissipation rib material extending to all sides forms a high thermal conductivity channel. , compared to exchanging heat through air, solid materials ensure efficient heat conduction, and the shape has sufficient convection heat transfer area, which can fully dissipate the heat transferred to the surface of the structure through the convection effect of the surrounding air, efficient heat conduction It works together with heat convection to achieve rapid cooling of the brake disc, ensuring the temperature uniformity of the brake disc. Further, the parallel heat dissipation ribs include a main body, a first extension, a second extension and a third extension. The first extension is provided on the inner side of the main body and extends from the main body to the inner side of the friction plate circumference. The second extension part is provided on the outer side of the main body part and extends from the main body part to the outer circumference of the friction disk. The third extension part is provided on the side of the middle part of the main body part and extends tangentially from the main body part along the circumference of the friction disk. By arranging extension parts in multiple directions on the main body, the present invention can fully guide the flow of gas, make the flow curve more aligned with the air inlet, increase the air mass flow rate, and greatly improve the heat transfer rate.

Furthermore, the parallel heat dissipation ribs are provided with two first extension parts, each first extension part extends in a direction away from the axis of the main body and the angle between the first extension part and the radial direction of the circumference of the friction disk is 15° to 25°, preferably 20°. °.

Furthermore, the parallel heat dissipation ribs are provided with two third extensions, each of the third extensions extends in a direction away from the axis of the main body and has an included angle with the circumferential radial direction of the friction disk of 0° to 35°, preferably 30°. °.

Further, the first extension extends to the inner circular line of the friction disk, and the distance between the first extensions of two adjacent parallel heat dissipation ribs is 18 mm to 20 mm, preferably 19 mm.

Further, the third extension portion extends to the outer circular line of the friction disk, and the distance between the third extension portions of two adjacent parallel heat dissipation ribs is 6 mm to 8 mm, preferably 7 mm.

Further, both the first extension part and the third extension part are provided with first guide grooves extending tangentially along the circumference of the friction disk.

Furthermore, the main part of some parallel heat dissipation ribs is provided with a second guide groove extending tangentially along the circumference of the friction plate, and the other part of the main body part of the heat dissipation rib without the second guide groove is provided with bolt holes. Parallel heat dissipation ribs are arranged on the friction plate at intervals.

Further, the friction disc includes a friction surface layer and a friction middle layer, wherein parallel heat dissipation ribs are provided in the friction middle layer.

Further, the friction surface layer is made of ceramic material, the friction middle layer is made of carbon-ceramic composite material, and the thickness ratio of the friction surface layer to the friction middle layer is 0.15 to 0.16.

Furthermore, the thickness of the parallel heat dissipation ribs is 24 mm to 25 mm, preferably 24.5 mm.

Further, the thickness of the friction disc is 21 mm to 23 mm, preferably 22 mm.

Furthermore, the parallel heat dissipation ribs are provided with four second extension parts, and two second extension parts are each arranged symmetrically along the axis of the main body.

Furthermore, the parallel heat dissipation ribs are made of carbon-ceramic composite material and are integrally formed with the friction disc.

Furthermore, the ends of the first extension part, the second extension part and the third extension part are all provided with rounded corners with a radius of 5 mm to 7 mm, preferably 6 mm rounded corners.

Beneficial effects of the present invention:

1. The double-type carbon ceramic wheel-mounted brake disc of the present invention uses a double-type heat dissipation rib structure to make the material form a divergent branch shape on the friction disc, thereby effectively reducing the maximum maximum temperature of the brake disc and achieving the same heat dissipation effect. It significantly reduces the structural weight, meets the lightweight design concept of reducing the unsprung mass of the train, and is conducive to improving the smoothness of train operation.

2. The structure of the extension part and the guide groove is adopted to take into account the rotation of the brake disc and the air flow of the train moving forward. The guide groove makes the fluid flow curve inside the brake disc smoother. The angle setting of the extension makes the air flow curve more aligned with the air inlet, increases the air mass flow rate, greatly improves the heat transfer rate, and also provides When realizing product braking, a more uniform temperature distribution on the disk provides the necessary conditions.

3. By arranging the second extension part, the air between the adjacent parallel heat dissipation ribs can be disturbed, so as to strengthen the local heat exchange and improve the heat exchange effect. The second extension can also increase the density of the heat dissipation ribs of the support layer and increase the heat capacity of the brake disc without increasing the pump air power consumption at the inlet and outlet of the support layer.

4. The friction disc is divided into a friction surface layer and a friction middle layer. The friction surface layer is made of ceramic material, which has the characteristics of high temperature resistance, wear resistance and oxidation resistance. The friction middle layer is made of carbon ceramic composite material, which has large specific heat capacity, thermal shock resistance and Lightweight and high temperature resistant, the friction disc structure formed combines the advantages of carbon fiber composite materials and ceramic materials.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and examples.

Figure 1 is a schematic structural diagram from a first perspective of a preferred embodiment of the present invention;

Figure 2 is a schematic structural diagram from a second perspective of a preferred embodiment of the present invention;

Figure 3 is an enlarged view of the parallel heat dissipation ribs (the guide groove is not shown);

Figure 4 is a schematic diagram of the diversion groove of the parallel heat dissipation rib;

Figure 5 is a schematic angle view of the first extension part and the third extension part (the guide groove is not shown);

Figure 6 is a graph showing the influence of the angle change of the first extension part and the third extension part on the temperature change;

Figure 7 is a detailed view of the parallel heat dissipation rib area;

Figure 8 is a top view of the preferred embodiment;

Figure 9 is a comparison chart of the maximum average temperature of the emergency brake brake disc;

Figure 10 is a comparison chart of temperature uniformity between the present invention and the prior art;

Figure 11 is a schematic diagram of air flow inside the brake disc of the present invention and the prior art;

Figure 12 is a schematic diagram of thermal cracking in an existing brake disc;

Figure 13 is a schematic diagram of the existing cylindrical and straight rib structure of the brake disc.

Reference signs: 1. Friction disc; 101. Friction surface layer; 102. Friction middle layer; 2. Parallel heat dissipation ribs; 201. Main body; 202. First extension; 203. Second extension; 204. Third extension part; 205, the first guide groove; 206, the second guide groove.

Detailed ways

The present invention will be further described in detail below through the drawings and examples. Through these descriptions, the features and advantages of the present invention will become more apparent. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all of the embodiments.

The terms “first” and “second” are used for descriptive purposes only and shall not be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Therefore, features defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, "plurality" means two or more than two, unless otherwise explicitly and specifically limited.

As shown in Figures 1-8, the present invention discloses a parallel type carbon ceramic wheel brake disc, which includes a friction disc 1 and a plurality of heat dissipation ribs. Each heat dissipation rib is evenly arranged along the circumference of the friction disc 1. The heat dissipation ribs It is a parallel heat dissipation rib 2. The double-shaped heat dissipation rib 2 includes a main body part 201, a first extension part 202, a second extension part 203 and a third extension part 204. The first extension part 202 is provided on the inner side of the main body part 201 and is connected by the main body part 201. Extending toward the inner circumference of the friction plate 1, the second extension portion 203 is provided on the outer side of the main body 201 and extends from the main body 201 to the outer circumference of the friction plate 1. The third extension portion 204 is provided on the middle side of the main body 201. The side extends tangentially from the main body 201 along the circumference of the friction plate 1 .

More specifically, with reference to Figures 1, 5 and 6, the parallel heat dissipation rib 2 is provided with two first extension portions 202. Each first extension portion 202 extends in an axial direction away from the main body portion 201 and is in contact with the circumference of the friction plate 1. The radial angle is 15°~25°. Considering the uniformity of the temperature distribution of the plate and the fluid disturbance inside the heat dissipation ribs, the above included angle is selected to be 20° in this embodiment. It should be noted that the axial direction of the main body portion 201 refers to the central axis that is the same as the radial direction of the friction plate 1 and symmetrically divides the main body portion 201 .

The parallel heat dissipation rib 2 is provided with two third extension portions 204. Each third extension portion 204 extends in an axial direction away from the main body 201 and forms an angle between 0° and 35° in the radial direction of the circumference of the friction plate 1. As shown in Figure 6, the change in the angle of the third extension part 204 has a greater impact on the temperature. It is determined through experiments that the maximum average temperature is the lowest when the angle is 30°. Therefore, in this embodiment, the angle is selected to be 30° to allow the air to dissipate heat. The rib impact is enhanced, thereby strengthening local heat transfer and improving cooling performance.

In this embodiment, the parallel heat dissipation rib 2 is provided with four second extension portions 203 , and two second extension portions 203 are each arranged symmetrically along the axis of the main body 201 . The second extension part 203 can disturb the air inside the heat dissipation rib, thereby strengthening local heat exchange and improving the heat exchange effect. This circumferentially distributed second extension part 203 structure can also increase the support layer heat dissipation rib plate. The density increases the heat capacity of the brake disc. And it does not increase the pump air power consumption at the inlet and outlet of the support layer.

Referring to Figures 1 and 7, the first extension portion 202 extends to the inner circular line of the friction plate 1. The distance between the first extension portions 202 of two adjacent parallel heat dissipation ribs 2 is 18mm~20mm. In this example In the embodiment, 19mm is selected. The third extension portion 204 extends to the outer circular line of the friction plate 1. The distance between the third extension portions 204 of two adjacent parallel heat dissipation ribs 2 is 6 mm to 8 mm, and is selected to be 7 mm in this embodiment.

Referring to FIGS. 1 and 7 , both the first extension part 202 and the third extension part 204 are provided with first guide grooves 205 extending tangentially along the circumference of the friction plate 1 . The main body 201 of some parallel heat dissipation ribs 2 is provided with a second guide groove 206 extending tangentially along the circumference of the friction plate 1. The other part of the main body 201 of the heat dissipation rib without the second guide groove 206 is provided with bolts. holes, and two types of parallel heat dissipation ribs 2 are arranged on the friction plate 1 at intervals. The flow guide groove makes the gas flow curve inside the heat dissipation rib smoother and improves the heat transfer rate. Bolt holes are used to securely connect the brake disc to external equipment. Bolt holes are only provided in areas where the second guide groove 206 is not provided to ensure the depth of the bolt holes. At the same time, the heat dissipation ribs with bolt holes and without bolt holes are evenly spaced to make subsequent bolt connections more stable.

Referring to FIG. 2 , the friction disc 1 includes a friction surface layer 101 and a friction middle layer 102 , in which parallel heat dissipation ribs 2 are provided in the friction middle layer 102 . The friction surface layer 101 structure is designed to be a coating material with high temperature resistance, wear resistance, and oxidation resistance, such as ceramic materials, which can be realized by laser cladding of ceramic materials on the surface of the friction middle layer 102 structure using surface modification technology. The friction middle layer 102 structure adopts carbon ceramic composite material with large specific heat capacity, thermal shock resistance, light weight and high temperature resistance. The density of carbon ceramic composite material is 2300kg/m3, and it has thermal conductivity anisotropy. Compared with metal materials such as cast steel, its quality is much higher. Reduced, but the heat capacity is also reduced accordingly. Carbon fiber toughened ceramic materials combine the advantages of carbon fiber composite materials and ceramic materials, and have the advantages of high temperature resistance, oxidation resistance and wear resistance.

The thickness of the friction disc directly affects the distribution of the temperature field during the braking process. Since the emergency braking time is relatively short, the kinetic energy of the train will be converted into the heat generated by braking in a short time, and it will be concentrated on the friction between the brake disc and the brake pad. Contact surfaces. If the thickness of the brake disc friction ring is insufficient and the heat capacity is small, the temperature of the brake disc will rise rapidly, leaving the brake disc in a high temperature state with low strength and hardness, reducing the reliability of the brake disc. However, since the heat of braking is concentrated on the friction surface, the conduction of heat in the material requires a certain process. Unlimited increase in the thickness of the brake disc friction ring will not continuously reduce the braking temperature, but will also increase the material cost. The increase in the unsprung weight of the train is not conducive to the economy and the stability of the train operation. Unlimited increase in the thickness of the brake disc friction ring is also not conducive to the convection heat dissipation of the brake disc. Therefore, the thickness of the parallel heat dissipation ribs is 24mm~25mm, and the thickness of the friction disc is 21mm~23mm. In this embodiment, the thickness of the parallel heat dissipation ribs is preferably 24.5 mm, and the thickness of the friction disk is 22 mm. By adjusting the thickness ratio of the friction surface layer and the friction middle layer, on the one hand, the extreme temperature can be reduced and the brake disc can be prevented from warping due to excessive disc surface temperature. On the other hand, it can also be increased to ensure that the disc body has sufficient strength. In the present invention, the thickness ratio of the friction surface layer and the friction middle layer is 0.15 to 0.16. Based on surface modification technology and brake wear requirements, the designed friction surface thickness is 3mm and the friction middle layer thickness is 19mm.

In this embodiment, the parallel heat dissipation ribs 2 are made of carbon-ceramic composite material and are integrally formed with the friction disc 1. This is taking into account the carbon-ceramic composite material molding process to prevent smaller-sized heat dissipation ribs from falling off.

Referring to FIG. 7 , the ends of the first extension part 202 , the second extension part 203 and the third extension part 204 are all provided with rounded corners with a radius of 5 mm to 7 mm. In this embodiment, the rounded corners are preferably 6 mm.

As shown in Figure 9 and Table 1 below, it is a comparison of the maximum average temperature under emergency braking of the double-type carbon ceramic wheel brake disc of this embodiment and the 350km/h cast steel brake disc. As can be seen from the figure, Whether it is the heat dissipation effect of the brake disc when it is stationary in the air or the ventilation characteristics when rotating, parallel wheel-mounted brake discs have obvious advantages compared to 350km/h cast steel brake discs. Parallel-type wheel-mounted brake discs when stationary Compared with the cast steel brake disc, the maximum temperature is 11.80℃ lower. When rotating, the parallel wheel mounted brake disc has a maximum temperature that is 32.26℃ lower than the cast steel brake disc. It can be seen that the double-shaped carbon ceramic wheel-mounted brake disc of the present invention has better heat dissipation effect.

structure 350km/h stationary 350km/h rotation parallel static Parallel rotation Maximum temperature/℃ 785.31 820.12 773.51 787.86

Table 1

As shown in Figure 10, Figure 10(a) is a parallel brake disc of the present invention, and Figure 10(b) is a 350km/h brake disc in the prior art. It can be seen that the high temperature area of the brake disc is concentrated on the surface of the disc body. The temperature distribution of the parallel structure and the brake disc at 350km/h can be compared. The surface temperature distribution of the parallel brake disc is uniform, and the high temperature area is at the edge of the disc body. The distribution range is small, with the highest average temperature being 785°C. The temperature distribution on the 350km/h brake disc surface has a large gradient. There are high temperature areas in the middle and outer edge of the disc body, while the middle temperature is lower and the temperature gradient is large.

As shown in Figure 11, Figure 11(a) is a parallel brake disc of the present invention, and Figure 11(b) is a 350km/h brake disc in the prior art. It can be seen that compared with the 350km/h brake disc, the air around the parallel brake disc heat dissipation rib structure forms a vortex, the air flow speed at the design of the heat dissipation rib extension is larger, and the heat taken away by the air is relatively more , the flow velocity of the 350km/h brake disc is larger on the windward side, but the flow velocity is lower in the middle of the heat dissipation rib and the leeward side. It can be seen that the brake disc with parallel heat dissipation ribs has greater advantages in uniform heat dissipation than the 350km/h brake disc during long-term braking.

Unless otherwise stated in any of the technical solutions disclosed above, if a numerical range is disclosed, then the disclosed numerical range is a preferred numerical range. Any person skilled in the art should understand that the preferred numerical range is only Among the many implementable values, the technical effect is more obvious or representative. Since there are too many numerical values to be exhaustive, the present invention only discloses some numerical values to illustrate the technical solution of the present invention. Furthermore, the numerical values listed above should not constitute a limitation on the scope of the invention.

In addition, unless otherwise stated, terms used to express positional relationships or shapes used in any of the technical solutions disclosed in the present invention include their meanings include states or shapes that are similar, similar or close to them. Any component provided by the present invention can be assembled from multiple individual components, or it can be an individual component manufactured by an integrated forming process.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified. Modifications or equivalent substitutions without departing from the spirit and scope of the technical solution of the present invention shall be included in the scope of the claims of the present invention.

Claims (10)

1. A parallel type carbon ceramic wheel brake disc, including a friction disc (1) and a plurality of heat dissipation ribs, each heat dissipation rib is evenly arranged along the circumference of the friction disc (1), characterized in that: the heat dissipation ribs are parallel type Cooling ribs(2); The parallel heat dissipation rib (2) includes a main body (201), a first extension (202), a second extension (203) and a third extension (204). The first extension (202) is The second extension part (203) is provided on the inner side of the main body part (201) and extends from the main body part (201) to the inner circumference of the friction plate (1). The second extension part (203) is provided on the outer side of the main body part (201) and extends from the main body part (201). 201) extends toward the outside of the circumference of the friction disc (1), and the third extension portion (204) is provided on the middle side of the main body portion (201) and extends tangentially from the main body portion (201) along the circumference of the friction disc (1). 2. The double-type carbon ceramic wheel brake disc according to claim 1, characterized in that: the double-type heat dissipation rib (2) is provided with two first extension parts (202), each first extension part (202). 202) all extend in the direction away from the axis of the main body (201) and the angle between the radial direction of the circumference of the friction disk (1) is 15° to 25°; The parallel heat dissipation ribs (2) are provided with two third extension parts (204). Each third extension part (204) extends in an axial direction away from the main body part (201) and is radially connected to the circumference of the friction disk (1). The included angle is 0°~35°. 3. The double-shaped carbon ceramic wheel brake disc according to claim 1, characterized in that: the first extension part (202) extends to the inner circular line of the friction disc (1), and two adjacent ones The spacing between the first extension parts (202) of the parallel heat dissipation ribs (2) is 18 mm to 20 mm. 4. The double-shaped carbon ceramic wheel-mounted brake disc according to claim 1, characterized in that: the third extension portion (204) extends to the outer circular line of the friction disc (1), and two adjacent ones The spacing between the third extension parts (204) of the parallel heat dissipation ribs (2) is 6 mm to 8 mm. 5. The double-type carbon ceramic wheel-mounted brake disc according to claim 4, characterized in that: both the first extension part (202) and the third extension part (204) are provided along the circumference of the friction disc (1). A tangentially extending first guide groove (205). 6. The double-type carbon ceramic wheel brake disc according to claim 4, characterized in that: the main body (201) of the partial double-type heat dissipation rib (2) is provided with a tangential extension along the circumference of the friction disc (1). The second guide groove (206) is provided with bolt holes in the main part (201) of the other part of the heat dissipation rib that does not have the second guide groove (206). Two parallel heat dissipation ribs (2) are arranged at intervals on the friction On the plate (1). 7. The double-shaped carbon ceramic wheel brake disc according to claim 4, characterized in that: the friction disc (1) includes a friction surface layer (101) and a friction middle layer (102), wherein the double-shaped heat dissipation ribs (2 ) is located in the friction middle layer (102). 8. The combined type carbon ceramic wheel brake disc according to claim 5, characterized in that: the friction surface layer (101) is a ceramic material, the friction middle layer (102) is a carbon ceramic composite material, and the friction surface layer (101) is a ceramic material. The thickness ratio between the surface layer (101) and the friction middle layer (102) is 0.15 to 0.16. 9. The double-shaped carbon ceramic wheel brake disc according to claim 1, characterized in that: The thickness of the parallel heat dissipation ribs (2) is 24mm~25mm; The thickness of the friction disc (1) is 21 mm to 23 mm. 10. The double-shaped carbon ceramic wheel brake disc according to claim 1, characterized in that: the double-shaped heat dissipation rib (2) is provided with four second extension parts (203) along the main body part (201) Two second extension parts (203) are arranged symmetrically along the axis; The parallel heat dissipation ribs (2) are made of carbon-ceramic composite material and are integrally formed with the friction disc (1). The ends of the first extension part (202), the second extension part (203) and the third extension part (204) are all provided with rounded corners with a radius of 5 mm to 7 mm.