CN117157472A

CN117157472A - Brake disc

Info

Publication number: CN117157472A
Application number: CN202280026227.6A
Authority: CN
Inventors: 冈本充弘; 野上裕; 藤本隆裕; 市川雄基; 宫部成央; 加藤孝宪
Original assignee: Nippon Steel and Sumitomo Metal Corp
Current assignee: Nippon Steel Corp
Priority date: 2021-04-01
Filing date: 2022-03-30
Publication date: 2023-12-01

Abstract

A brake disc (100) includes a disc main body (10) and a plurality of heat radiating fins (20). The plurality of fins (20) are arranged on one surface (12) of the disk body (10) such that the fins (20) extend from the inner peripheral side to the outer peripheral side of the disk body (10). The heat sink (20) includes 2 side surfaces (221, 222) and a top surface (21), respectively. More than 1 heat sink (20) of the plurality of heat sinks (20) comprises a plurality of protruding strip parts (25). The plurality of protruding strip parts (25) are arranged along the radial direction of the disk main body (10) on at least one side surface of the 2 side surfaces (221, 222) of the radiating fin (20). Each of the protruding strip portions (25) extends between the disk main body (10) and the top surface (21) of the heat sink (20).

Description

Brake disc

Technical Field

The present disclosure relates to a brake disc for a railway vehicle.

Background

As a brake device for a railway vehicle, a disc brake device is widely used. The disc brake device comprises a brake disc and a brake lining. The brake disc is fastened to the wheel, for example, and rotates together with the wheel. The brake pads are pressed against the brake disc. The railway vehicle is braked by friction of the brake linings with the brake disc.

The brake disc includes, for example, a disc body having a circular annular plate shape, and a plurality of fins. The plurality of fins are radially arranged on one surface of the disk main body. By means of these cooling fins, the cooling performance of the brake disc is ensured. More specifically, since the brake disc is fastened to the wheel with the heat radiating fins facing the wheel, the air passage is formed by the wheel, the disc main body, and the adjacent heat radiating fins. The ventilation passage allows air to pass from the inner peripheral side to the outer peripheral side of the disc main body when the brake disc rotates together with the wheel. Thereby, the brake disc is cooled.

In this way, air flows through the ventilation passage defined by the wheel, the disc main body, and the adjacent fin, and the brake disc can be cooled. However, aerodynamic noise is generated due to air flowing in the ventilation path. In particular, when a railway vehicle runs at a high speed, the ventilation amount in the ventilation path increases, and a large aerodynamic noise is generated. In addition to ensuring cooling performance, it is also necessary to reduce aerodynamic noise for brake discs for railway vehicles.

For example, patent document 1 discloses a brake disc for reducing aerodynamic noise during high-speed running and improving cooling performance at the time of braking. In the brake disc of patent document 1, a fastening hole for inserting a fastening member is provided in a part of the fin. In these fins, grooves along the circumferential direction of the disk main body are formed on the outer peripheral side and/or the inner peripheral side of the fastening hole. According to patent document 1, the corners and wall surfaces of the groove cause pressure loss in the air flowing through the ventilation passage defined by the wheel, the disk main body, and the fin. Accordingly, the ventilation amount in the ventilation passage is reduced, and as a result, aerodynamic noise during high-speed running can be reduced. Further, according to patent document 1, since the grooves of the fin and the pressure loss portion where the heat transfer rate with the air becomes high are widely formed in the brake disc, the cooling performance at the time of braking can be improved.

Prior art literature

Patent literature

Patent document 1: international publication No. 2014/038621

Disclosure of Invention

Technical problem to be solved by the invention

However, as described in patent document 1, in a brake disc for a railway vehicle, there is a strong correlation between the ventilation amount in a ventilation passage and the level of aerodynamic noise. That is, when the ventilation amount in the ventilation path increases, the aerodynamic noise also increases, and when the ventilation amount in the ventilation path decreases, the aerodynamic noise also decreases. In order to reduce aerodynamic noise generated during running of the railway vehicle, the ventilation amount in the ventilation passage may be limited. However, when the air flow rate is limited to reduce the aerodynamic noise, the cooling performance of the brake disc is generally reduced.

The present disclosure provides a brake disc for a railway vehicle capable of reducing aerodynamic noise while securing cooling performance.

Means for solving the technical problems

The brake disc of the present disclosure is a brake disc for a railway vehicle. The brake disc includes a disc body and a plurality of cooling fins. The disk main body has a circular ring plate shape. The plurality of heat sinks are arranged on one face of the disk main body in the following manner: the heat sinks extend from the inner peripheral side to the outer peripheral side of the disk main body, respectively. The plurality of fins each include 2 side surfaces arranged in the circumferential direction of the disk main body, and a top surface connecting the 2 side surfaces. More than 1 of the plurality of fins includes a plurality of protruding portions. The plurality of protruding strip portions are arranged along the radial direction of the disk main body on at least one of the 2 side surfaces of the heat sink. Each of the protruding strip portions extends between the disk main body and the top surface of the heat sink.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the brake disc for a railway vehicle of the present disclosure, aerodynamic noise can be reduced while securing cooling performance.

Drawings

Fig. 1 is a rear view of a brake disc for a railway vehicle according to embodiment 1.

Fig. 2 is a partial perspective view of the brake disc shown in fig. 1.

Fig. 3 is a III-III cross-sectional view of the brake disc shown in fig. 1.

Fig. 4 is an IV-IV cross-sectional view of the brake disc shown in fig. 1.

Fig. 5 is a rear view of a brake disc for a railway vehicle according to embodiment 2.

Fig. 6 is a rear view of a brake disc for a railway vehicle according to embodiment 3.

Fig. 7 is a rear view of a brake disc for a railway vehicle according to embodiment 4.

Fig. 8 is a rear view of a brake disc for a railway vehicle according to embodiment 5.

Fig. 9 is a rear view of a brake disc for a railway vehicle according to embodiment 6.

Fig. 10 is a rear view of a brake disc for a railway vehicle according to embodiment 7.

Fig. 11 is a rear view of a brake disc for a railway vehicle according to embodiment 8.

Fig. 12 is a partial perspective view of the brake disc shown in fig. 11.

Fig. 13 is an enlarged view of a portion of the back surface of the brake disc shown in fig. 11.

Fig. 14 is a graph showing evaluation results of analysis of brake discs of examples and comparative examples.

Fig. 15 is a graph showing the results of a rotation test using a model of a brake disc of examples and comparative examples.

Detailed Description

The brake disc according to the embodiment is a brake disc for a railway vehicle. The brake disc includes a disc body and a plurality of cooling fins. The disk main body has a circular ring plate shape. The plurality of heat sinks are arranged on one face of the disk main body in the following manner: the heat sinks extend from the inner peripheral side to the outer peripheral side of the disk main body, respectively. The plurality of fins each include 2 side surfaces arranged in the circumferential direction of the disk main body, and a top surface connecting the 2 side surfaces. More than 1 of the plurality of fins includes a plurality of protruding portions. The plurality of protruding strip portions are arranged along the radial direction of the disk main body on at least one of the 2 side surfaces of the heat sink. Each of the protruding portions extends between the disk main body and the top surface of the heat sink (1 st configuration).

In the brake disc of the 1 st configuration, a plurality of projecting portions are provided on the side surface of 1 or more of the plurality of fins arranged on one surface of the disc main body. The protruding portions can reduce the cross-sectional area of the ventilation passage in the circumferential direction of the disk main body when the brake disk is attached to the rotating member such as a wheel and the ventilation passage is formed by the rotating member, the disk main body, and the adjacent heat radiating fins. This can limit the amount of air (ventilation amount) passing through the ventilation passage during running of the railway vehicle. Thus, aerodynamic noise can be reduced.

In the brake disc of the 1 st configuration, the plurality of projecting portions provided on the side surfaces of the heat sink can also enlarge the surface area of the brake disc. In addition, since the air flowing into the ventilation passage from the inner peripheral side of the disc main body flows along the side surfaces of the heat radiation fins during running of the railway vehicle, the heat transfer rate between the brake disc and the air can be improved by providing the plurality of protruding portions on the side surfaces of the heat radiation fins. As a result, the cooling performance of the brake disc at the time of braking can be improved. Therefore, according to the brake disc of the 1 st configuration, the ventilation amount in the ventilation passage can be efficiently restricted while securing the cooling performance, thereby reducing the aerodynamic noise.

In the brake disc according to the embodiment, each of the plurality of fins may further include an inner peripheral surface. The inner peripheral surface of each fin is connected to the top surface and the radially inner end portions of the 2-sided disk main body. Preferably, the plurality of protruding portions are arranged outside the inner peripheral surface of each fin in the radial direction of the disk main body (configuration 2).

In the 2 nd configuration, the plurality of protruding portions are located outside the inner peripheral surface of the heat sink in the radial direction of the disk main body. Therefore, the corners between the inner peripheral surface and the both side surfaces can be ensured in the plurality of fins, respectively. By this corner portion, air can be efficiently scooped into the ventilation passage formed between the adjacent fins, and the local heat transfer rate in this region can be maintained high. Therefore, the cooling performance of the brake disc can be ensured.

In the brake disc according to the embodiment, a plurality of protruding portions (3 rd configuration) may be provided on each of 2 side surfaces of 1 or more of the plurality of fins.

According to the 3 rd configuration, a plurality of protruding portions are provided on both side surfaces of the fin. In this case, the effects of reducing aerodynamic noise and improving cooling performance can be further improved.

In the brake disc according to the embodiment, the plurality of fins may include a plurality of projecting portions (configuration 4).

According to the 4 th configuration, a plurality of protruding portions are provided on the side surfaces of all the fins. In this case, the effects of reducing aerodynamic noise and improving cooling performance can be further improved.

The plurality of protruding portions may include 1 or more 1 st protruding portions and 1 or more 2 nd protruding portions. The 2 nd protrusion is disposed at a position different from the 1 st protrusion in the radial direction of the disk main body. The length of the 1 st projection in the circumferential direction of the disk main body is larger than the length of the 2 nd projection in the circumferential direction (5 th configuration).

According to the 5 th configuration, the 1 st projection and the 2 nd projection are provided on the side surface of the fin. The 1 st projection has a length greater than that of the 2 nd projection in the circumferential direction of the disk main body. In this case, the cross-sectional area of the ventilation passage can be reduced particularly at the position of the 1 st ridge portion, and the ventilation amount in the ventilation passage can be effectively restricted. Therefore, aerodynamic noise can be further reduced.

Further, by providing the 1 st ridge portion having a relatively large length in the circumferential direction of the disc main body on the side surface of the heat sink, the surface area of the brake disc can be further increased. Therefore, the cooling performance of the brake disc at the time of braking can be improved. Therefore, the ventilation amount in the ventilation passage can be efficiently and well restricted while ensuring cooling performance.

The plurality of fins may be adjacent to each other in the circumferential direction of the disk main body, and each of the plurality of fins may include a 1 st projection portion and a 2 nd projection portion. In this case, the 1 st ridge portion in one of the adjacent fins is opposed to the 1 st ridge portion in the other of the adjacent fins in the circumferential direction (the 6 th configuration).

The 1 st projection may be disposed on the outer peripheral side of the disk main body (the 7 th configuration). The 1 st projection may be disposed on the inner peripheral side of the disk main body (8 th configuration). The 1 st projection may be arranged at the center (9 th configuration) of the disk main body in the radial direction.

In the brake disc according to the embodiment, each of the plurality of fins adjacent to each other in the circumferential direction of the disc main body may include a plurality of protruding portions. The plurality of tabs can include at least 1 st tab. The 1 st ridge portion in one of the adjacent fins may be configured to: the 1 st ridge portion in the other of the adjacent fins is displaced in the radial direction (10 th configuration) so that the ventilation passage formed between the adjacent fins is curved.

In the 10 th configuration, a plurality of protruding portions are provided on each side surface of adjacent fins among the plurality of fins arranged on one surface of the disk main body. The protruding portions can reduce the cross-sectional area of the ventilation passage in the circumferential direction of the disk main body when the brake disk is attached to the rotating member such as a wheel and the ventilation passage is formed by the rotating member, the disk main body, and the adjacent heat radiating fins. Therefore, the amount of air (ventilation amount) passing through the ventilation passage during running of the railway vehicle can be limited. Further, the plurality of protruding strip portions includes a 1 st protruding strip portion. Since the positions of the 1 st projecting portions of the adjacent fins are shifted in the radial direction of the disk main body, the ventilation paths formed between the adjacent fins are curved. By bending the ventilation passage in this manner, the flow resistance against the air passing through the ventilation passage can be increased. Therefore, aerodynamic noise can be effectively reduced.

In the 10 th configuration, the plurality of protruding portions provided on the side surface of the fin can also enlarge the surface area of the brake disc. In addition, since the air flowing into the ventilation passage from the inner peripheral side of the disc main body is intended to flow along the side surfaces of the fins during running of the railway vehicle, the ventilation passage can be curved by providing the 1 st ridge portion on the side surfaces of the fins, and the passage length can be made longer, whereby the air flowing in the ventilation passage is sufficiently brought into contact with the back surface of the disc main body and the side surfaces of the fins. Further, the bent portion of the ventilation passage abruptly changes the flow direction of the air, so that the heat transfer rate between the brake disc and the bent portion of the air can be improved. As a result, the cooling performance of the brake disc at the time of braking can be improved. Therefore, the ventilation amount in the ventilation passage can be efficiently restricted while ensuring cooling performance, thereby reducing aerodynamic noise.

In the brake disc of the 10 th configuration, the plurality of projecting portions may further include a 2 nd projecting portion. The 2 nd protrusion is disposed at a position different from the 1 st protrusion in the radial direction of the disk main body. The length of the 1 st projection in the circumferential direction of the disk main body is larger than the length of the 2 nd projection in the circumferential direction (11 th configuration).

The 1 st ridge portion of one of the adjacent fins may be opposed to the 2 nd ridge portion of the other of the adjacent fins with a gap therebetween in the circumferential direction of the disk main body. The 2 nd ridge portion of one of the adjacent fins may be opposed to the 1 st ridge portion of the other of the adjacent fins with a gap therebetween in the circumferential direction of the disk main body (12 th configuration).

According to the 12 th configuration, the 1 st ridge portion having a relatively large length in the circumferential direction of the disk main body is opposed to the 2 nd ridge portion having a relatively small length in the circumferential direction of the disk main body with a gap. In this case, the cross-sectional area of the ventilation passage can be reduced particularly at the position where the 1 st projection and the 2 nd projection face each other, and the ventilation amount in the ventilation passage can be effectively restricted. Therefore, aerodynamic noise can be efficiently reduced.

In the brake disc according to the embodiment, 1 or more of the plurality of fins may include grooves (13 th configuration) intersecting the fins.

According to the 13 th configuration, 1 or more fins include grooves intersecting themselves. The groove reduces the ventilation amount in the ventilation passage by causing pressure loss in the air flowing through the ventilation passage, and increases the heat transfer rate between the brake disc and the air. In addition, by providing the grooves in the heat sink, the surface area of the heat sink can be enlarged. Therefore, according to the 13 th configuration, aerodynamic noise can be further reduced, and cooling performance can be further improved.

In the brake disc of the embodiment, 1 or more of the plurality of fins may include a fastening hole for inserting a fastening member. The groove may be disposed in at least one of a portion outside and a portion inside the fastening hole in the radial direction of the disk main body in the fin including the fastening hole (the 14 th configuration). Preferably, the grooves are disposed in a portion of the heat sink including the fastening hole, the portion being located outside and the portion being located inside the fastening hole in the radial direction of the disk main body (structure 15).

According to the 14 th or 15 th configuration, by forming the groove in the fin provided with the fastening hole, thermal expansion and contraction in the radial direction of the disk main body can be allowed for the fin. Therefore, during braking of the railway vehicle, the restraint of the heat radiating fin against thermal expansion is relaxed, and deformation accompanying thermal expansion of the brake disc is reduced. As a result, the stress load on the fastening member and the brake disc inserted into the fastening hole can be reduced, and the durability of the brake disc can be improved.

Hereinafter, a brake disc according to an embodiment of the present disclosure will be described with reference to the drawings. In the drawings, the same or corresponding components are denoted by the same reference numerals, and the same description is not repeated. Each of the drawings is a schematic view for explaining a main structure of the brake disc according to the embodiment. Therefore, the shape, the dimensional proportion, and the like of the details of the brake disc shown in each figure may be different from those of an actual brake disc.

Embodiment 1

[ construction of brake disc ]

Fig. 1 is a rear view of a brake disc 100 for a railway vehicle according to embodiment 1. Fig. 2 is a partial perspective view of the brake disc 100 shown in fig. 1. The brake disc 100 is fastened to a rotating member (not shown) of the railway vehicle. The rotating member is an annular disk, and is fixed to and rotates together with an axle of the railway vehicle. The rotating member is, for example, a wheel. Brake disc 100 is typically steel, and can be formed, for example, by forging.

Referring to fig. 1 and 2, a brake disc 100 includes a disc main body 10 and a plurality of heat radiating fins 20.

The disk main body 10 has a substantially annular plate shape. The disk body 10 includes a front surface 11 and a back surface 12. The surface 11 includes a sliding surface against which a brake pad (not shown) is pressed. The back surface 12 is a surface facing opposite to the front surface 11. When the brake disc 100 is fastened to the rotating member, the back face 12 is opposite the rotating member. Hereinafter, for convenience of explanation, the radial direction and the circumferential direction of the disk main body 10 may be simply referred to as the radial direction and the circumferential direction. The direction of the central axis of the disk main body 10 is referred to as the thickness direction.

A plurality of heat sinks 20 are provided on the back surface 12, the back surface 12 being one surface of the disk main body 10. More specifically, the plurality of heat sinks 20 are arranged on the back surface 12 of the disk main body 10 in the following manner: each fin 20 disk extends from the inner peripheral side to the outer peripheral side of the main body 10. Each heat sink 20 includes a top surface 21 and 2 side surfaces 221, 222. In each fin 20, the side surfaces 221, 222 are substantially arranged in the circumferential direction. Top surface 21 connects side surfaces 221 and 222. The top surface 21 contacts the rotating member when the brake disc 100 is fastened to the rotating member. Thereby, a space is formed between the rotating member, the disk main body 10, and the adjacent heat sink 20. This space becomes a ventilation passage through which air passes when the brake disc 100 rotates together with the rotating member.

More than 1 fin 20 of the plurality of fins 20 includes fastening holes 23. In the present embodiment, 2 or more fins 20 each include a fastening hole 23. A fastening member such as a bolt is inserted into the fastening hole 23 when the brake disc 100 is fastened to the rotating member. The fastening hole 23 penetrates the heat sink 20 and the disk main body 10 in which the fastening hole 23 is provided in the thickness direction. The fastening hole 23 is disposed at the center of the annular sliding surface 11 (fig. 2) in the radial direction. Therefore, the brake disc 100 is fastened to a rotating member such as a wheel by a fastening member at a position of the center portion in the radial direction of the sliding surface 11.

In the example of the present embodiment, the heat sink 20 including the fastening holes 23 includes grooves 241 and 242, respectively. In the example of the present embodiment, the heat sink 20 having no fastening hole 23 also includes grooves 241 and 242. The grooves 241, 242 have a concave shape from the top surface 21 of the heat sink 20 toward the disk main body 10 side. Grooves 241, 242 extend substantially circumferentially across fin 20. One groove 241 is disposed in each fin 20 at a portion radially outside the fastening hole 23. The other groove 242 is disposed in a portion of each fin 20 radially inward of the fastening hole 23. Accordingly, in the heat sink 20 having the fastening holes 23, the fastening holes 23 may be positioned between the grooves 241 and 242.

The shape of the grooves 241, 242 is not particularly limited. For example, the wall surfaces and the bottom surfaces of the grooves 241 and 242 may be flat surfaces, convex curved surfaces, or concave curved surfaces, respectively. The wall surfaces and the bottom surfaces of the grooves 241 and 242 may be formed by a combination of 2 or more surfaces.

In the present embodiment, each fin 20 includes a plurality of protruding portions 25 provided on both side surfaces 221 and 222 thereof. The plurality of protruding portions 25 are arranged substantially in the radial direction (the longitudinal direction of the side surface 221) on the one side surface 221 of each fin 20. The plurality of protruding portions 25 are also arranged substantially in the radial direction (the longitudinal direction of the side surface 222) on the other side surface 222 of each fin 20. The ridge portion 25 is provided in a corrugated shape on each of the side surfaces 221 and 222. The ridge 25 is integrally formed with the side surfaces 221, 222.

Fig. 3 is a III-III cross-sectional view of the brake disc 100 shown in fig. 1. Fig. 4 is an IV-IV cross-sectional view of the brake disc 100 shown in fig. 1. Hereinafter, the protruding portion 25 will be described in further detail with reference to fig. 3 and 4.

As shown in fig. 3, in one side 221 of the heat sink 20, the protruding strip portions 25 extend between the disk main body 10 and the top surface 21 of the heat sink 20, respectively. Also, as shown in fig. 4, in the other side face 222 of the heat sink 20, the protruding portions 25 extend between the disk main body 10 and the top face 21 of the heat sink 20, respectively. In the example of the present embodiment, each of the protruding portions 25 extends substantially in the thickness direction of the disk main body 10, as viewed from the side surface 221 side and the side surface 222 side of the fin 20. However, at least a part of the ridge portion 25 may be inclined with respect to the thickness direction as viewed from the side surface 221 and the side surface 222 of the fin 20.

One end of each of the protruding strip portions 25 is in contact with the back surface 12 of the disk main body 10. In the example shown in fig. 3 and 4, the other end of each of the protruding portions 25 reaches the top surface 21 of the heat sink 20. However, the other end of each of the protruding portions 25 may not necessarily reach the top surface 21 of the heat sink 20. That is, the length L (length in the thickness direction) of each of the protruding portions 25 can be equal to or less than the height (length in the thickness direction) of the heat sink 20 protruding from the rear surface 12 of the disk main body 10. The respective protruding portions 25 may extend from the back surface 12 of the disk main body 10 to the vicinity of the top surface 21 of the heat sink 20, without reaching the top surface 21.

In the present embodiment, as shown in fig. 3, the protruding portions 25 are disposed at substantially equal intervals over the entire one side surface 221 of the fin 20. As shown in fig. 4, the protruding portions 25 are disposed at substantially equal intervals on the other side surface 222 of the fin 20. However, the method of disposing the protruding portions 25 in the side surfaces 221, 222 of the heat sink 20 is not limited thereto. For example, the plurality of protruding portions 25 may be arranged at unequal intervals in at least one of the side surfaces 221, 222 of the heat sink 20. At least one of the side surfaces 221 and 222 of the fin 20 may be provided with a region where the protruding portion 25 is arranged and a region where the protruding portion 25 is not arranged. The number of the protruding portions 25 in each of the side surfaces 221 and 222 may be 2 or more, and may be appropriately determined. However, it is preferable that 3 or more protruding portions 25 are provided on each of the side surfaces 221 and 222.

In the present embodiment, the region in which the protruding portion 25 is arranged in the one side surface 221 of the heat sink 20 corresponds to the region in which the protruding portion 25 is arranged in the other side surface 222 of the heat sink 20. That is, the position of each of the projecting portions 25 provided on one side surface 221 substantially coincides with the position of each of the projecting portions 25 provided on the other side surface 222 in the longitudinal direction (radial direction) of each of the fins 20. However, the region in which the protruding portion 25 is arranged on the one side surface 221 of the heat sink 20 may not necessarily correspond to the region in which the protruding portion 25 is arranged on the other side surface 222 of the heat sink 20. For example, the protruding portion 25 may be provided in one of the side surfaces 221 and 222 in a region on the inner peripheral side than the center of the fastening hole 23 (fig. 1 and 2), and the protruding portion 25 may be provided in the other of the side surfaces 221 and 222 in a region on the outer peripheral side than the center of the fastening hole 23.

Each of the protruding portions 25 protrudes substantially in the circumferential direction from the side surface 221 or the side surface 222. In the present embodiment, the protruding amounts are substantially the same for all the protruding portions 25 provided on the one side surface 221 of the fin 20. In the present embodiment, the protruding amounts of all the protruding portions 25 provided on the other side surface 222 of the fin 20 are substantially the same. The protruding amount of the protruding portion 25 refers to the length of the protruding portion 25 in the circumferential direction of the disk main body 10.

In each of the side surfaces 221, 222 of the heat sink 20, the protruding amount of each of the protruding portions 25 can be appropriately determined. However, the protruding amount of each of the protruding portions 25 is set to a size such that the protruding portions 25 of the fins 20 adjacent in the circumferential direction do not interfere with each other. The protruding amount of the protruding portion 25 can be determined based on the wall thickness of the fin 20, for example. The thickness of each fin 20 is the length of the fin 20 in a direction substantially perpendicular to the longitudinal direction (radial direction of the disc body 10) and the height direction (thickness direction of the disc body 10) of the fin 20. For example, when the wall thickness of the heat sink 20 having the smallest wall thickness among the plurality of heat sinks 20 provided in the disk main body 10 is denoted by T, the protruding amount of each of the protruding portions 25 may be 1/3×t or more.

In the example of the present embodiment, in each of the side surfaces 221, 222 of the heat sink 20, all the protruding portions 25 have the same protruding amount. However, the one side surface 221 of the fin 20 may be divided into a plurality of regions in the radial direction, and the protruding amount of the protruding portion 25 may be changed for each region. For example, in the region adjacent to the fastening hole 23 (fig. 1 and 2) in the side surface 221 of the fin 20, the protruding amount of the protruding portion 25 may be made relatively small, and in the regions inside and outside the region in the radial direction, the protruding amount of the protruding portion 25 may be made relatively large. Alternatively, in contrast, in the region adjacent to the fastening hole 23 in the side surface 221 of the fin 20, the protruding amount of the protruding portion 25 may be relatively large, and in the regions inside and outside the region in the radial direction, the protruding amount of the protruding portion 25 may be relatively small.

Similarly, the other side surface 222 of the fin 20 may be divided into a plurality of regions in the radial direction, and the protruding amount of the protruding portion 25 may be changed for each region. For example, in the region adjacent to the fastening hole 23 in the side surface 222 of the fin 20, the protruding amount of the protruding portion 25 may be made relatively small, and in the regions inside and outside the region in the radial direction, the protruding amount of the protruding portion 25 may be made relatively large. Alternatively, in contrast, the protruding amount of the protruding portion 25 may be relatively large in a region adjacent to the fastening hole 23 in the side surface 222 of the fin 20, and the protruding amount of the protruding portion 25 may be relatively small in regions inside and outside the region in the radial direction.

The width W of each of the protruding portions 25 (the length in the longitudinal direction of the side 221 or the side 222 of the fin 20) can also be appropriately determined. In one side 221 of the 2 sides 221, 222 of the heat sink 20, all the protruding portions 25 may have the same width, or the protruding portions 25 having different widths may be mixed. Similarly, in the other side surface 222, all the protruding portions 25 may have the same width, or protruding portions 25 having different widths may be mixed.

Each of the protruding strip portions 25 can have various cross-sectional shapes. Each of the protruding portions 25 may have a cross section of a polygonal shape such as a semicircular shape, a semi-elliptical trajectory shape, a triangle, or a quadrangle, for example. In one side 221 of the 2 sides 221, 222 of the fin 20, all the protruding portions 25 may have the same cross-sectional shape, or the protruding portions 25 having different cross-sectional shapes may be mixed. Also, in the other side face 222, all the protruding portions 25 may have the same cross-sectional shape, or protruding portions 25 having different cross-sectional shapes may be mixed. The cross section of the ridge portion 25 is a cross section when the ridge portion 25 is cut in a plane substantially perpendicular to the extending direction thereof.

Referring to fig. 3 and 4, in the brake disc 100 of the present embodiment, the sliding surface (the surface 11 of the disc main body 10) on which the brake lining is pressed is provided only on one side in the thickness direction. In each of the side surfaces 221 and 222 of the fin 20, the plurality of protruding portions 25 are arranged between the inner peripheral end and the outer peripheral end (within the range of the sliding width) of the annular sliding surface 11. Preferably, the plurality of protruding portions 25 are arranged within the range of the top surface 21 of the fin 20 in the radial direction. The plurality of protruding portions 25 are arranged radially outward of the inner peripheral surface 27 of the fin 20. The plurality of protruding portions 25 are disposed radially inward of the outer peripheral surface 28 of the fin 20. In each fin 20, the inner peripheral surface 27 is connected to the inner end portion of the top surface 21 and the side surfaces 221 and 222, among the two end portions in the radial direction. In each fin 20, the outer peripheral surface 28 is connected to the outer end portion of the top surface 21 and the side surfaces 221 and 222, which are both radially outer end portions. In the present embodiment, the outer peripheral surface 28 is inclined with respect to the thickness direction of the disk main body 10 in the following manner: the height of the fin 20 is reduced as it goes radially outward. The inner peripheral surface 27 may be inclined with respect to the thickness direction of the disk main body 10 as follows: the height of the fin 20 increases as going radially outward. The height of the fin 20 is substantially constant in the range of the top surface 21 between the inner peripheral surface 27 and the outer peripheral surface 28.

[ Effect ]

According to the brake disc 100 of the present embodiment, the plurality of fins 20 are provided with the plurality of projecting portions 25, respectively, and the plurality of fins 20 are arranged on the rear surface 12 of the disc main body 10. The plurality of protruding portions 25 are provided on the side surfaces 221 and 222 of each fin 20. When the brake disc 100 is fastened to the rotating member of the railway vehicle and the ventilation passage is formed by the rotating member, the disc main body 10, and the side surfaces 221, 222 of the adjacent heat radiating fins 20, the cross-sectional area of the ventilation passage can be reduced in the circumferential direction by the protruding portions 25. This can limit the amount of air (ventilation amount) passing through the ventilation passage during running of the railway vehicle. Thus, aerodynamic noise can be reduced.

On the other hand, the protruding portions 25 provided on the side surfaces 221 and 222 of the respective heat radiating fins 20 can also enlarge the surface area of the brake disc 100. In addition, during running of the railway vehicle, the air flowing into the ventilation passage from the inner peripheral side of the disc main body 10 flows along the side surfaces 221, 222 of each fin 20, and therefore, the heat transfer rate between the brake disc 100 and the air can be improved by the ridge portions 25 provided on the side surfaces 221, 222 of each fin 20. As a result, the cooling performance of the brake disc 100 at the time of braking can be improved. Therefore, according to the brake disc 100 of the present embodiment, the ventilation amount in the ventilation passage can be efficiently restricted while securing the cooling performance, thereby reducing the aerodynamic noise.

In the brake disc 100 of the present embodiment, fastening holes 23 are provided in 2 or more heat radiating fins 20, and the fastening holes 23 are used for inserting fastening members. The heat sink 20 having the fastening holes 23 includes grooves 241, 242, respectively, intersecting itself. Further, the heat sink 20 having no fastening hole 23 also includes grooves 241 and 242, respectively. These grooves 241 and 242 reduce the ventilation amount in the ventilation passage by causing pressure loss in the air flowing through the ventilation passage, and increase the heat transfer rate between the brake disc 100 and the air. Further, the grooves 241 and 242 can enlarge the surface area of each fin 20. Therefore, by providing the grooves 241 and 242 in each fin 20, aerodynamic noise can be further reduced, and cooling performance can be further improved.

Further, since the grooves 241 and 242 are formed in the heat sink 20 including the fastening holes 23, thermal expansion and contraction in the radial direction can be allowed for the heat sink 20. Therefore, during braking of the railway vehicle, the restraint of the heat sink 20 against thermal expansion is relaxed, and the deformation accompanying the thermal expansion of the brake disc 100 is reduced. As a result, the stress load on the fastening member inserted into the fastening hole 23 and the brake disc 100 can be reduced, and the durability of the brake disc 100 can be improved.

In the brake disc 100 of the present embodiment, the plurality of protruding portions 25 are arranged radially outward of the inner peripheral surface 27 of the fin 20. In this case, the corners formed between the inner peripheral surface 27 and the side surfaces 221 and 222 can be ensured in each fin 20. By this corner portion, air can be efficiently scooped into the ventilation passage formed between the adjacent fins 20, and the local heat transfer rate in this region can be maintained high. Therefore, the cooling performance of the brake disc 100 can be well maintained.

In the brake disc 100 of the present embodiment, the outer peripheral surface 28 of each fin 20 is inclined with respect to the thickness direction of the disc main body 10 in the following manner: the height of the fin 20 is reduced as it goes radially outward. The plurality of protruding portions 25 are arranged radially inward of the outer peripheral surface 28. As a result, when the brake disc 100 is deformed into an arch shape protruding toward the brake lining side by frictional heat generated between the brake lining and the sliding surface 11 of the disc main body 10 during braking of the brake disc 100, the outer peripheral side of the heat sink 20 and the protruding strip portion 25 can be made less likely to interfere with a rotating member such as a wheel.

< embodiment 2 >

Fig. 5 is a rear view of a brake disc 100A for a railway vehicle according to embodiment 2. In fig. 5, a portion of a brake disc 100A is shown. The brake disc 100A of the present embodiment is different from the brake disc 100 of embodiment 1 in the structure of the protruding portion 26.

Referring to fig. 5, the plurality of fins 20 include a plurality of protruding portions 26, respectively. A plurality of protruding portions 26 are provided on both side surfaces 221 and 222 of each fin 20. The plurality of protruding portions 26 include 1 st protruding portion 261 and 1 nd protruding portion 262 in each of the side surfaces 221 and 222. In the present embodiment, a plurality of 1 st projecting portions 261 and a plurality of 2 nd projecting portions 262 are provided on each of the side surfaces 221 and 222. Preferably, the number of the protruding portions 261, 262 is 3 or more in total in each of the side surfaces 221, 222.

The 1 st projection 261 is disposed on the inner peripheral side and the outer peripheral side of the disk main body 10, respectively. That is, the 1 st ridge 261 is provided on the inner side and the outer side of the fastening hole 23 in the radial direction of the disk main body 10. The 2 nd ridge 262 is arranged at a position different from the 1 st ridge 261 in the radial direction. In the example of the present embodiment, a plurality of 2 nd protruding portions 262 are arranged between the 1 st protruding portion 261 on the inner peripheral side of the disk main body 10 and the 1 st protruding portion 261 on the outer peripheral side of the disk main body 10. The 2 nd protrusions 262 are arranged in the radial direction.

The protruding portions 261 and 262 extend between the disk main body 10 and the top surface 21 of the heat sink 20, respectively, similarly to the protruding portion 25 in embodiment 1. The protruding portions 261 and 262 protrude substantially in the circumferential direction of the disk main body 10 from the side surface 221 or the side surface 222 of the heat sink 20. The protrusion amount P1 of the 1 st protrusion 261 is larger than the protrusion amount P2 of the 2 nd protrusion 262. The protruding amounts P1, P2 are lengths of the protruding portions 261, 262 in the circumferential direction, respectively. In each of the side surfaces 221 and 222 of the fin 20, the protrusion amount P1 of the 1 st protrusion 261 can be 2.0 times or more the protrusion amount P2 of the 2 nd protrusion 262, for example. The thickness of the fin 20 having the smallest thickness among the plurality of fins 20 is denoted by T, and the protrusion amount P2 of the 2 nd protrusion 262 can be 1/3×t or more, similarly to the protrusion 25 in embodiment 1.

The position of the 1 st ridge 261 in the radial direction of the disk main body 10 is substantially the same in all the fins 20. Therefore, the 1 st ridge 261 in one fin 20 of the adjacent fins 20 is opposed to the 1 st ridge 261 in the other fin 20 in the circumferential direction. The 1 st ridge 261 of the adjacent heat sink 20 does not interfere with each other. That is, a gap S1 exists between the 1 st ridge 261 with respect to the circumferential direction. The thickness of the fin 20 having the smallest thickness among the plurality of fins 20 is denoted by T, and the size of the gap S1 in the circumferential direction may be 0.7×t or more and 5.0×t or less.

In the present embodiment, the 1 st projecting portion 261 and the 2 nd projecting portion 262 are provided on the side surfaces 221, 222 of each fin 20, and the projecting amount P1 of the 1 st projecting portion 261 is larger than the projecting amount P2 of the 2 nd projecting portion 262. In particular, the cross-sectional area of the ventilation passage can be reduced at the position of the 1 st projection 261, and the ventilation amount in the ventilation passage can be effectively restricted. Therefore, aerodynamic noise can be further reduced.

In the present embodiment, the 1 st projecting portion 261 having a relatively large projecting amount P1 is provided on the side surfaces 221 and 222 of each fin 20. This can further expand the surface area of the brake disc 100A. Therefore, the cooling performance of the brake disc 100A at the time of braking can be improved.

Therefore, the brake disc 100A of the present embodiment can efficiently restrict the ventilation amount in the ventilation passage while securing cooling performance, as in embodiment 1, thereby reducing aerodynamic noise.

Embodiment 3

Fig. 6 is a rear view of a brake disc 100B for a railway vehicle according to embodiment 3. In fig. 6, a part of a brake disc 100B is shown. In the brake disc 100B of the present embodiment, each fin 20 includes the same ridge portion 26 as in embodiment 2 on both side surfaces 221 and 222 thereof. That is, the side surfaces 221 and 222 of the fins 20 are provided with: a 1 st projection 261 having a relatively large projection amount P1; and a 2 nd projection 262 having a relatively small projection amount P2.

However, in the present embodiment, the 1 st ridge 261 is disposed only on the outer peripheral side of the disk main body 10. That is, the 1 st ridge 261 is provided only on the outer side of the fastening hole 23 in the radial direction of the disk main body 10. In the example shown in fig. 6, the 1 st ridge 261 is located at the outermost side in the radial direction among the 1 st ridge 261 and the plurality of 2 nd ridge 262 provided on the side surface 221 or the side surface 222 of each fin 20.

Even with the structure of the brake disc 100B according to the present embodiment, the ventilation amount in the ventilation passage can be efficiently restricted while securing the cooling performance, as in the above embodiments, so that the aerodynamic noise can be reduced.

Embodiment 4

Fig. 7 is a rear view of a brake disc 100C for a railway vehicle according to embodiment 4. Fig. 7 shows a part of a brake disc 100C. In the brake disc 100C of the present embodiment, each fin 20 includes the same ridge portion 26 as in embodiment 2 on both side surfaces 221 and 222 thereof. That is, the side surfaces 221 and 222 of the fins 20 are provided with: a 1 st projection 261 having a relatively large projection amount P1; and a 2 nd projection 262 having a relatively small projection amount P2.

However, in the present embodiment, the 1 st ridge 261 is disposed only on the inner peripheral side of the disk main body 10. That is, the 1 st ridge 261 is provided only on the inner side of the fastening hole 23 in the radial direction of the disk main body 10. In the example shown in fig. 7, the 1 st ridge 261 is located radially innermost among the 1 st ridge 261 and the plurality of 2 nd ridge 262 provided on the side surface 221 or the side surface 222 of each fin 20.

Even with the structure of the brake disc 100C according to the present embodiment, the ventilation amount in the ventilation passage can be efficiently restricted while securing the cooling performance, as in the above embodiments, so that the aerodynamic noise can be reduced.

In the present embodiment, the 1 st projection 261 is disposed on the inner peripheral side of the disk main body 10. In this case, compared with the case where the 1 st ridge 261 is arranged on the outer peripheral side of the disk main body 10, when there is a jam such as refuse between the 1 st ridge 261 facing in the circumferential direction of the disk main body 10, maintenance thereof becomes easy. Further, the arrangement of the 1 st ridge 261 on the inner peripheral side of the disc body 10 is also advantageous in terms of formability of the brake disc 100C by forging.

Embodiment 5

Fig. 8 is a rear view of a brake disc 100D for a railway vehicle according to embodiment 5. In fig. 8, a part of a brake disc 100D is shown. In the brake disc 100D of the present embodiment, each fin 20 includes the same ridge portion 26 as in embodiment 2 on both side surfaces 221 and 222 thereof. That is, the side surfaces 221 and 222 of the fins 20 are provided with: a 1 st projection 261 having a relatively large projection amount P1; and a 2 nd projection 262 having a relatively small projection amount P2.

However, in the present embodiment, the 1 st ridge 261 is disposed at the center portion in the radial direction of the disk main body 10. The 1 st projection 261 is disposed at substantially or substantially the same position as the fastening hole 23 in the radial direction of the disk main body 10, for example. The 2 nd ridge 262 is disposed radially inward and outward of the 1 st ridge 261. In the example shown in fig. 8, a plurality of 2 nd ridge portions 262 are provided on each of the side surfaces 221, 222 of the fin 20 on the inner side in the radial direction than the 1 st ridge portion 261. Further, in each of the side surfaces 221, 222 of the fin 20, a plurality of 2 nd ridge portions 262 are provided on the outer side in the radial direction than the 1 st ridge portion 261.

Even with the structure of the brake disc 100D according to the present embodiment, the ventilation amount in the ventilation passage can be efficiently restricted while securing the cooling performance, as in the above embodiments, so that the aerodynamic noise can be reduced.

< embodiment 6 >

Fig. 9 is a rear view of a brake disc 100E for a railway vehicle according to embodiment 6. Fig. 9 shows a part of a brake disc 100E. In the brake disc 100E of the present embodiment, each fin 20 includes the same ridge portion 26 as in embodiment 2 on both side surfaces 221 and 222 thereof. That is, the side surfaces 221 and 222 of the fins 20 are provided with: a 1 st projection 261 having a relatively large projection amount P1; and a 2 nd projection 262 having a relatively small projection amount P2.

In this embodiment, as in embodiment 4, the 1 st ridge 261 is disposed on the inner peripheral side of the disk main body 10. In this embodiment, similarly to embodiment 5, the 1 st ridge 261 is disposed at the center in the radial direction of the disk main body 10. In the example shown in fig. 9, 1 2 nd ridge portions 262 are arranged between 21 st ridge portions 261 in each of the side surfaces 221, 222 of the fin 20. In each of the side surfaces 221, 222 of the fin 20, a 2 nd ridge 262 is also provided at the outer side in the radial direction with respect to the 1 st ridge 261.

Even with the structure of the brake disc 100E according to the present embodiment, the ventilation amount in the ventilation passage can be efficiently restricted while securing the cooling performance, as in the above embodiments, so that the aerodynamic noise can be reduced.

In the present embodiment, the 1 st ridge 261 is disposed on the inner peripheral side and the radial direction center of the disk main body 10 in the side surfaces 221 and 222 of each fin 20. However, the 1 st ridge 261 may be disposed on the outer peripheral side and the radial direction center of the disk main body 10 in the side surfaces 221 and 222 of each fin 20.

Embodiment 7

Fig. 10 is a rear view of a brake disc 100F for a railway vehicle according to embodiment 7. Fig. 10 shows a part of a brake disc 100F. In the brake disc 100F of the present embodiment, a plurality of 1 st projecting portions 261 are provided on both side surfaces 221 and 222 of each fin 20. In the present embodiment, the 2 nd projecting portions 262 are not provided on both side surfaces 221 and 222 of each fin 20. Only the 1 st projection 261 having a relatively large projection amount P1 is arranged along the radial direction of the disk main body 10 on the side surfaces 221, 222 of each fin 20.

Even with the brake disc 100F according to the present embodiment, the ventilation amount in the ventilation passage can be efficiently restricted while securing the cooling performance, as in the above embodiments, so that the aerodynamic noise can be reduced.

< embodiment 8 >

Fig. 11 is a rear view of a brake disc 100G for a railway vehicle according to embodiment 8. Fig. 12 is a partial perspective view of the brake disc 100G shown in fig. 11. As shown in fig. 11 and 12, a brake disc 100G of the present embodiment has substantially the same structure as the brake disc 100 (fig. 1 and 2) of embodiment 1. However, the brake disc 100G of the present embodiment is different from the brake disc 100 of embodiment 1 in the structure of the protruding portion 29.

As in the above embodiments, each fin 20 includes a plurality of protruding portions 29. More specifically, a plurality of protruding portions 29 are provided on one side surface 221 of each fin 20. The plurality of protruding portions 29 are arranged substantially in the radial direction (longitudinal direction of the side surface 221) on the side surface 221 of each fin 20. A plurality of protruding portions 29 are also provided on the other side surface 222 of each fin 20. The plurality of protruding portions 29 are arranged substantially in the radial direction (longitudinal direction of the side surface 222) on the side surface 222 of each fin 20. The ridge 29 is provided in a fold shape on each of the side surfaces 221 and 222. The ridge 29 is integrally formed with the side surfaces 221, 222.

The plurality of protruding strip portions 29 include a plurality of protruding strip portions 29L and a plurality of protruding strip portions 29S. The protruding portions 29L and 29S protrude substantially in the circumferential direction from the side surface 221 or the side surface 222 of the fin 20, respectively. However, in each fin 20, the protruding amount of the protruding portion 29L is larger than the protruding amount of the protruding portion 29S. In each fin 20, the projecting portion 29L having a relatively large projecting amount and the projecting portion 29S having a relatively small projecting amount are mixed. The protruding amounts of the protruding portions 29L, 29S refer to the lengths of the protruding portions 29L, 29S in the circumferential direction of the disk main body 10.

In the example of the present embodiment, the protruding portions 29L having a relatively large protruding amount and the protruding portions 29S having a relatively small protruding amount are alternately arranged in each of the side surfaces 221, 222 of the fin 20. The protruding portions 29L and 29S are disposed at equal intervals on the side surfaces 221 and 222 of the entire fin 20, for example. However, the protruding portions 29L, 29S may be disposed at unequal intervals in at least one of the side surfaces 221, 222 of the heat sink 20.

The protruding portions 29L, 29S extend between the disk main body 10 and the top surface 21 of the heat sink 20, respectively. The protruding portions 29L, 29S extend substantially in the thickness direction of the disk main body 10, for example. However, the protruding portions 29L, 29S may be inclined with respect to the thickness direction in a side view of the fin 20.

In each of the heat sinks 20, one ends of the protruding portions 29L, 29S are in contact with the back surface 12 of the disk main body 10. The other ends of the protruding portions 29L, 29S may reach the top surface 21 of the heat sink 20 or may not reach the top surface 21 of the heat sink 20. That is, the lengths of the protruding portions 29L, 29S in the thickness direction of the disk main body 10 can be set to be equal to or less than the distance from the back surface 12 of the disk main body 10 to the top surface 21 of the heat sink 20.

Fig. 13 is a partially enlarged view of the back surface of the brake disc 100G. Hereinafter, the protruding portions 29L and 29S will be described in more detail with reference to fig. 13.

Referring to fig. 13, when the adjacent 2 fins 20 among the plurality of fins 20 are referred to as fins 20a, 20b, the positions in the radial direction of the protruding portions 29L having a relatively large protruding amount are different between the fins 20a and the fins 20 b. The protruding portions 29L of the fins 20a are arranged so as to be displaced from the protruding portions 29L of the fins 20b in the radial direction, so that the ventilation path formed between the fins 20a, 20b is curved. That is, the protruding portion 29L protruding from the side surface 222 of one heat sink 20a is not opposed to the protruding portion 29L protruding from the side surface 221 of the other heat sink 20b in the circumferential direction. As a result, as indicated by the arrow of the two-dot chain line in fig. 13, a zigzag-shaped ventilation passage is formed between the adjacent fins 20a, 20 b. The ventilation path has more than 1 position for bending the flow of air. Preferably, there are a plurality of locations in the ventilation path that bend the flow of air. In order to reliably bend the flow of air, it is preferable that the ventilation path has a shape such that the outflow port side is not visible from the inflow port side of the air.

A gap S1 is formed between the protruding portion 29L of the fin 20a and the fin 20 b. More specifically, the protruding portions 29L of the heat sink 20a are opposed to the protruding portions 29S of the heat sink 20b with a gap S1 therebetween in the circumferential direction. Similarly, a gap S2 is formed between the fin 20a and the ridge portion 29L of the fin 20 b. More specifically, the protruding portions 29S of the heat sink 20a are opposed to the protruding portions 29L of the heat sink 20b with a gap S2 therebetween in the circumferential direction. The position of the gap S1 between the ridge portion 29L of the fin 20a and the fin 20b is shifted from the position of the gap S2 between the ridge portion 29L of the fin 20b and the fin 20a in the circumferential direction.

The size of the gaps S1 and S2 in the circumferential direction can be determined based on the thickness of the fin 20, for example. The thickness of the heat sink 20 is the length of the heat sink 20 in a direction substantially perpendicular to the radial direction and the thickness direction of the disk main body 10. The thickness of the heat sink 20 having the smallest thickness among the plurality of heat sinks 20 provided in the disk main body 10 is denoted by T, and the gaps S1 and S2 in the circumferential direction can be 0.7×t or more and 5.0×t or less. The size of the gap S1 is substantially equal to the size of the gap S2, for example. However, the size of the gap S1 may be different from the size of the gap S2.

The protruding strip parts 29L and 29S have a protruding amount A _L 、A _S . The protruding amounts AL, AS may be determined based on the wall thickness of the fin 20, for example. Let the wall thickness of the fin 20 having the smallest wall thickness among the plurality of fins 20 be T, the protruding amount A of the protruding portion 29L _L For example, the temperature is 1.0×t or higher. Protrusion amount a of the protrusion portion 29L _L The protruding portion 29S is set to a size that does not interfere with the circumferential direction. In each heat sink 20Protrusion amount a of the protruding portion 29S _S For example, the protruding amount A of the protruding strip portion 29L _L Is less than 0.85 times of the total weight of the composition.

The protruding end portions of the protruding portions 29L, 29S have, for example, a semicircular cross section. However, the protruding end portions of the protruding portions 29L, 29S may have a polygonal cross section such as a semi-elliptical shape, a triangle shape, or a quadrangle shape. In each of the side surfaces 221 and 222 of the fin 20, the protruding end portions of the plurality of protruding portions 29L and 29S may have the same cross-sectional shape, or the protruding portions 29L and 29S having protruding end portions of different cross-sectional shapes may be mixed. The cross section here refers to a cross section when the protruding portions 29L and 29S are cut in a plane substantially perpendicular to the thickness direction of the disk main body 10.

The width of each of the protruding portions 29L, 29S (the length in the longitudinal direction of the side surfaces 221, 222 of the fin 20) can be appropriately determined. In each of the side surfaces 221 and 222 of the fin 20, all of the plurality of protruding portions 29L and 29S may have the same width, or the protruding portions 29L and 29S having different widths may be mixed.

According to the brake disc 100G of the present embodiment, the plurality of projecting portions 29 are provided on the plurality of fins 20 arranged on the back surface 12 of the disc main body 10, respectively. The plurality of protruding portions 29 are provided on the side surfaces 221 and 222 of each fin 20. When the brake disc 100G is fastened to the rotating member of the railway vehicle and the ventilation passage is formed by the rotating member, the disc main body 10 and the adjacent fin 20, the cross-sectional area of the ventilation passage can be reduced in the circumferential direction by the protruding portions 29. This can limit the amount of air (ventilation amount) passing through the ventilation passage during running of the railway vehicle. Further, in the present embodiment, the plurality of protruding portions 29 include protruding portions 29L, 29S. With a relatively large projection A _L The positions of the protruding portions 29L of the adjacent fins 20 are shifted in the radial direction of the disk main body 10. As a result, the ventilation paths formed between the adjacent fins 20 are curved, and therefore, the flow resistance against the air passing through the ventilation paths can be increased. Thus, aerodynamic noise can be reduced.

In the brake disc 100G of the present embodiment, the surface area of the brake disc 100G can be enlarged by the protruding portions 29L and 29S provided on the side surfaces 221 and 222 of the heat sink 20. In addition, since the air flowing into the ventilation passage from the inner peripheral side of the disc main body 10 flows along the side surfaces 221 and 222 of each fin 20 during running of the railway vehicle, the ventilation passage can be curved by the ridge portions 29L of the side surfaces 221 and 222 to lengthen the passage length, and the air flowing in the ventilation passage can be brought into sufficient contact with the back surface 12 of the disc main body 10 and the side surfaces 221 and 222 of each fin 20. Further, since the bent portion of the ventilation passage abruptly changes the flow direction of the air, the heat transfer rate between the brake disc 100G and the bent portion of the air can be improved. As a result, the cooling performance of the brake disc 100G at the time of braking can be improved. Therefore, according to the brake disc 100G of the present embodiment, the ventilation amount in the ventilation passage can be efficiently restricted while securing the cooling performance, thereby reducing the aerodynamic noise.

In the present embodiment, the adjacent fins 20 have a relatively large protruding amount a _L The projection 29L and the relatively small projection A _S The projecting portions 29S of (a) are opposed to each other with gaps S1 and S2 therebetween. In this case, the cross-sectional area of the ventilation passage can be reduced particularly at the position where the ridge portion 29L faces the ridge portion 29S, and the flow resistance against the air passing through the ventilation passage can be further increased. Therefore, the ventilation amount in the ventilation passage can be effectively limited, and the aerodynamic noise can be reduced.

In the present embodiment, similarly, the protruding portions 29L and 29S are arranged between the inner peripheral end and the outer peripheral end (within the range of the sliding width) of the annular sliding surface 11 in each of the side surfaces 221 and 222 of the fin 20. As in the above embodiments, the protruding portions 29L and 29S are preferably arranged within the range of the top surface 21 of the fin 20 in the radial direction. The protruding portions 29L, 29S are disposed, for example, radially outward of the inner peripheral surface 27 of the fin 20. Therefore, as in the above embodiments, air can be efficiently scooped into the ventilation passage formed between the adjacent fins 20, and the local heat transfer rate in this region can be maintained high. Therefore, the cooling performance of the brake disc 100G can be maintained well. The protruding portions 29L and 29S are disposed radially outward of the outer peripheral surface 28 of the fin 20. Therefore, as in the above embodiments, the outer peripheral side of the fin 20 and the protruding portions 29L and 29S can be made less likely to interfere with the rotating member such as the wheel at the time of braking of the brake disc 100G.

The embodiments of the present disclosure have been described above, but the present disclosure is not limited to the above embodiments, and various modifications can be made without departing from the gist thereof.

For example, in the brake discs 100, 100A to 100F of the above-described embodiments 1 to 7, all the fins 20 arranged on the back surface 12 of the disc main body 10 include the plurality of projecting portions 25 or the plurality of projecting portions 26, respectively. However, among the plurality of fins 20 arranged on the back surface 12 of the disk main body 10, the plurality of protrusions 25 or the protrusions 26 may be formed only on a part of the fins 20. That is, 1 or more of the plurality of fins 20 may include the protruding portion 25 or the protruding portion 26. However, in order to reduce aerodynamic noise and improve cooling performance, it is preferable that 2 or more of the plurality of fins 20 include the protruding portions 25 or the protruding portions 26, and it is more preferable that all of the fins 20 include the protruding portions 25 or the protruding portions 26, in order to obtain higher effects.

In the brake discs 100, 100A to 100F according to the above-described embodiments 1 to 7, the projecting portions 25 and 26 are provided on both side surfaces 221 and 222 of each fin 20. However, in each fin 20, a plurality of the protruding portions 25 or a plurality of the protruding portions 26 may be formed only on one of the 2 side surfaces 221, 222. In the brake discs 100, 100A to 100F, 2 or more of the heat sink 20 including the ridge portion 25 or the ridge portion 26 provided on the both side surfaces 221, 222, the heat sink 20 including the ridge portion 25 or the ridge portion 26 provided on only one of the side surfaces 221, 222, and the heat sink 20 including no ridge portion 25, 26 may be mixed.

In embodiment 8, the side surfaces 221 and 222 of the fins 20 are provided with a relatively large protruding amount a _L The projection portion 29L of (2) has a relatively small projection amount A _S Is provided with a protruding strip portion 29S. However, each fin 20 may not have the protruding portion 29S. For example, it may be that,only the projecting portions 29L are provided on the adjacent fins 20. Alternatively, one of the adjacent fins 20 may be provided with the protruding portions 29L and 29S, and the other of the adjacent fins 20 may be provided with only the protruding portion 29L. In this case as well, as in embodiment 8, the positions of the protruding portions 29L in the adjacent fins 20 are shifted in the radial direction of the disk main body 10, so that the ventilation paths between the adjacent fins 20 can be curved. In the case where the side 221 or the side 222 of the fin 20 does not have the protruding portion 29S, 2 or more protruding portions 29L, more preferably 3 or more protruding portions 29L, are provided on the side 221 or the side 222.

In embodiment 8 described above, all the heat sinks 20 disposed on the back surface 12 of the disk main body 10 include the plurality of protruding portions 29. However, among the plurality of fins 20 arranged on the back surface 12 of the disk main body 10, the plurality of protruding portions 29 may be formed only on a part of the fins 20. That is, a plurality of protruding portions 29 including the protruding portions 29L may be formed on at least 2 adjacent fins 20 among the plurality of fins 20. However, in order to reduce aerodynamic noise and improve cooling performance, it is preferable that 3 or more of the plurality of fins 20 include the protruding portions 29, and more preferable that all of the fins 20 include the protruding portions 29, in order to obtain a higher effect.

In embodiment 8, the protruding portion 29L is disposed substantially over the entire side surfaces 221 and 222 of the fin 20, and the protruding portion 29L has a relatively large protruding amount a _L . However, a region where the protruding portion 29L is not disposed may be provided on the side surface 221 and/or the side surface 222. For example, in the adjacent fin 20, the protruding portion 29L may be provided only in the inner peripheral side of the center of the fastening hole 23, and the ventilation passage may be bent by the protruding portion 29L only in the inner peripheral side of the center of the fastening hole 23. For example, in the adjacent fin 20, the protruding portion 29L may be provided only in the outer peripheral side of the center of the fastening hole 23, and the ventilation passage may be bent by the protruding portion 29L only in the outer peripheral side of the center of the fastening hole 23. Alternatively, the adjacent fins 20 may be formed only in the vicinity of the fastening holes 23The domain is provided with a ridge portion 29L, and the ventilation channel is bent by the ridge portion 29L only at the central portion in the radial direction. In each fin 20, the protruding portion 29S may or may not be provided in the region where the protruding portion 29L is present and the region where the protruding portion 29L is not present, and the protruding portion 29S has a relatively small protruding amount a _S . Preferably, when both the protruding portions 29L and 29S are present in each fin 20, the number of protruding portions 29L and 29S is 3 or more in total.

In the brake discs 100, 100A to 100G of the above embodiments, each fin 20 includes the grooves 241, 242. However, each fin 20 may include only one of the grooves 241, 242. Alternatively, each fin 20 may not include any of the grooves 241 and 242. In the brake discs 100, 100A to 100G, the heat sink 20 including at least one of the grooves 241, 242 and the heat sink 20 not including the grooves 241, 242 may be mixed. For example, among the plurality of fins 20 arranged on the back surface 12 of the disk main body 10, at least one of the grooves 241, 242 may be provided only on the fin 20 including the fastening hole 23, and the grooves 241, 242 may not be provided on the other fin 20. Alternatively, the heat sink 20 including the fastening hole 23 may not be provided with the grooves 241 and 242, and at least one of the grooves 241 and 242 may be provided with the other heat sink 20. The grooves 241 and 242 may not be provided in all the heat sinks 20 disposed on the back surface 12 of the disk main body 10. When at least one of the grooves 241 and 242 is provided in the fin 20 including no fastening hole 23, the groove 241 and/or the groove 242 may be disposed at a free position in the fin 20 in the radial direction without being restricted by the fastening hole 23.

Examples

The present disclosure is described in further detail below by way of examples. However, the present disclosure is not limited to the following examples.

[ example 1 ]

In order to verify the effect of the present disclosure, as example 1, a three-dimensional thermal fluid analysis was performed on a brake disc having the same shape as the brake disc 100 (fig. 1 and 2) of embodiment 1 described above, using general-purpose thermal fluid analysis software (product name: ANSYS Fluent, ANSYS corporation), assuming that a railway vehicle was stably driven at 330 km/h. Further, as examples 2 to 7, the same analyses as described above were performed for the brake discs 100A to 100F (fig. 5 to 10) of the above-described 2 nd to 7 th embodiments, respectively. As a comparative example, the same analysis as described above was performed on a brake disc in which the side surface protrusions of the fin were removed from the brake disc of example 1. The brake discs of each example and comparative example have 33 fins.

The brake discs of each example and comparative example were evaluated for the level of aerodynamic noise and cooling performance. As an evaluation index indicating the level of aerodynamic noise, the ventilation amount [ kg/s ] obtained by the isothermal flow analysis of gas was used. The ventilation amount is the ventilation amount between the brake disc and the rotating member (wheel) in every 1 brake disc. As described above, in the brake disc for a railway vehicle, there is a strong correlation between the ventilation amount in the ventilation passage and the level of aerodynamic noise. Therefore, it can be said that the greater the ventilation amount, the greater the level of aerodynamic noise.

As an evaluation index indicating the cooling performance of the brake disc, a heat dissipation index [ W/K ] obtained by gas non-isothermal flow analysis was used. The heat dissipation index is an integral of the average heat transfer rate of the disc surface and the disc surface area per 1 brake disc. The higher the heat dissipation index, the higher the cooling performance of the brake disc.

As an evaluation index indicating the efficiency of reducing aerodynamic noise, heat dissipation efficiency was used. The heat dissipation efficiency is a value obtained by dividing the heat dissipation index by the ventilation amount. The higher the heat radiation efficiency, the more the ventilation amount can be limited without impairing the cooling performance of the brake disc, that is, the aerodynamic noise is efficiently reduced.

The evaluation results of the brake discs of the examples and comparative examples are shown in table 1 and fig. 14.

TABLE 1

As shown in table 1 and fig. 14, it can be seen that: in the comparative example, the heat dissipation index was high, and excellent cooling performance was obtained. On the other hand, it can be seen that: in example 1, the comparative example and the heat dissipation index were the same level, and excellent cooling performance was obtained. In example 1, the ventilation rate was reduced as compared with the comparative example. That is, in example 1, the level of aerodynamic noise can be reduced while maintaining excellent cooling performance equivalent to that of the comparative example. Even if the comparison is made in terms of heat dissipation efficiency, embodiment 1 is significantly larger than the comparative example. Therefore, it can be said that in example 1, aerodynamic noise is efficiently reduced while ensuring cooling performance of the brake disc, as compared with the comparative example.

In examples 2 to 7 in which the projecting portions having a relatively large projecting amount were provided on both side surfaces of each fin, the ventilation amount was reduced and the level of aerodynamic noise was lowered as compared with the comparative example. On the other hand, regarding the heat dissipation index, only example 3 was higher than comparative example, and examples 2 and 4 to 7 were slightly lower than comparative example. However, in each of examples 2 to 7, the heat dissipation efficiency was significantly improved as compared with the comparative example. Therefore, it can be said that even in examples 2 to 7, aerodynamic noise is reduced with high efficiency while ensuring cooling performance of the brake disc.

Through this analysis, it was confirmed; by providing a plurality of protruding portions on the side surfaces of the heat sink, aerodynamic noise can be reduced while securing cooling performance for the brake disc for a railway vehicle.

[ example 2 ]

In order to verify the effect of the present disclosure, as example 8, the same three-dimensional thermal fluid analysis as that of example 1 was performed for a brake disc having the same shape as the brake disc 100G (fig. 11 to 13) of embodiment 8 described above. Table 2 shows the evaluation results of the brake discs of example 8 and comparative example. The comparative example is the same as that in example 1.

TABLE 2

As shown in table 2, in example 8, the ventilation amount was significantly reduced as compared with the comparative example. On the other hand, in example 8, the heat dissipation index was lowered somewhat as compared with the comparative example. However, in example 8, the heat dissipation efficiency was significantly larger than that of the comparative example. Therefore, it can be said that in embodiment 8, although the aerodynamic noise is significantly reduced, the reduction in the cooling performance of the brake disc is suppressed.

By this analysis, it was confirmed that: by providing a plurality of protruding portions in each of the adjacent fins and bending the ventilation passage between the adjacent fins by the protruding portions, aerodynamic noise can be efficiently reduced while securing cooling performance for the brake disc for a railway vehicle.

[ example 3 ]

Models (disc test bodies) of the brake discs of examples 1 to 8 were prepared, and rotation tests using the respective models were performed. In this test, the disc test bodies of examples 1 to 8 were each mounted on a model of a wheel (wheel test body) and rotated at a predetermined rotational speed, and the sound pressure level was measured by a noise meter provided at a distance of 70cm from the surface of each disc test body. For comparison, the same rotation test was also performed on a wheel test body to which no disc test body was attached, and a model (disc test body) of the brake disc of the above comparative example. The results of the rotation test are shown in fig. 15. Fig. 15 shows the ventilation amounts obtained in the analyses of the above 1 st and 2 nd embodiments, in addition to the sound pressure level measured in the rotation test (the sum of noise components at frequencies 2700Hz to 3300Hz estimated to originate from the peak of the tester does not exist).

As shown in fig. 15, in examples 1 to 8 in which the protruding portions were provided on the respective heat radiating fins, the sound pressure level was lowered as compared with the comparative example in which the protruding portions were not provided on the wheel test body and the respective heat radiating fins. In example 8 in which the ventilation path between the adjacent fins is curved, the sound pressure level becomes small in particular. The tendency of the sound pressure level obtained in the present rotation test corresponds to the tendency of the ventilation amount obtained in the analysis of the above-described 1 st and 2 nd embodiments. That is, it can be said that the magnitude relation of the ventilation amount in the analysis corresponds to the magnitude relation of the sound pressure level, and the evaluation of the aerodynamic noise reduction effect in the analysis is accurate.

From this rotation test, it was confirmed that: by providing a plurality of projecting portions on the side surfaces of the heat sink, the sound pressure level (aerodynamic noise) is actually reduced for the brake disc for a railway vehicle. Aerodynamic noise is particularly reduced in cases where the ventilation paths between adjacent fins are bent by the ridge portions.

Description of the reference numerals

100. 100A to 100G: brake disc

10: disk main body

20. 20a, 20b: heat sink

21: top surface

221. 222: side surface

27: an inner peripheral surface

23: fastening hole

241. 242: groove(s)

25. 26, 261, 262, 29L, 29S: protruding strip part

S1, S2: gap of

Claims

1. A brake disc for a railway vehicle, comprising:

a disk main body having a circular ring plate shape, and

a plurality of heat sinks each disposed on one surface of the disk main body so as to extend from an inner peripheral side to an outer peripheral side of the disk main body, and each including 2 side surfaces arranged in a circumferential direction of the disk main body, and a top surface connecting the 2 side surfaces;

more than 1 of the plurality of fins includes a plurality of protruding portions arranged in a radial direction of the disk main body on at least one of the 2 side surfaces and extending between the disk main body and the top surface, respectively.

2. The brake disk according to claim 1, wherein,

the plurality of fins further include inner peripheral surfaces connected to ends of the top surface and the 2 side surfaces on the inner side in the radial direction, respectively;

the plurality of protruding strip portions are arranged outside the inner peripheral surface in the radial direction.

3. The brake disc according to claim 1 or 2, wherein,

the plurality of projecting portions are provided on the 2 side surfaces, respectively, in 1 or more of the plurality of fins.

4. A brake disc according to claim 1 to 3, wherein,

The plurality of fins respectively include the plurality of protruding strip portions.

5. The brake disc according to claim 1 to 4, wherein,

the plurality of tabs includes: 1 or more 1 st ridge portions and 1 or more 2 nd ridge portions, the 1 or more 2 nd ridge portions being arranged at positions different from the 1 st ridge portions in the radial direction;

the length of the 1 st ridge portion in the circumferential direction is greater than the length of the 2 nd ridge portion in the circumferential direction.

6. The brake disk according to claim 5, wherein,

the fins adjacent to the circumferential direction in the plurality of fins respectively include the 1 st protruding portion and the 2 nd protruding portion;

the 1 st ridge portion in one of the adjacent fins is opposed to the 1 st ridge portion in the other of the adjacent fins in the circumferential direction.

7. The brake disc of claim 5 or 6, wherein,

the 1 st ridge portion is disposed on the outer peripheral side of the disk main body.

8. The brake disc according to any one of claims 5 to 7, wherein,

the 1 st ridge portion is disposed on the inner peripheral side of the disk main body.

9. The brake disc according to any one of claims 5 to 8, wherein,

The 1 st ridge portion is disposed at a center portion of the disk main body in the radial direction.

10. The brake disc according to claim 1 to 4, wherein,

the plurality of fins adjacent in the circumferential direction include the plurality of protruding strip portions, respectively;

the plurality of tabs comprises at least 1 st tab;

the 1 st ridge portion in one of the adjacent fins is arranged so as to be offset from the 1 st ridge portion in the other of the adjacent fins in the radial direction so as to bend a ventilation passage formed between the adjacent fins.

11. The brake disk of claim 10, wherein,

the plurality of protruding strip parts further include a 2 nd protruding strip part, and the 2 nd protruding strip part is configured at a position different from the 1 st protruding strip part in the radial direction;

12. The brake disk of claim 11, wherein,

the 1 st ridge portion in one of the adjacent fins and the 2 nd ridge portion in the other of the adjacent fins are opposed to each other with a spacing in the circumferential direction;

The 2 nd ridge portion in one of the adjacent fins is opposed to the 1 st ridge portion in the other of the adjacent fins with a spacing in the circumferential direction.

13. The brake disc according to any one of claims 1 to 12, wherein,

more than 1 of the plurality of fins includes a slot traversing the fin.

14. The brake disk of claim 13, wherein,

more than 1 of the plurality of fins includes a fastening hole for inserting a fastening member;

the groove is disposed in at least one of a portion outside and a portion inside the fastening hole in the radial direction in the fin including the fastening hole.

15. The brake disk of claim 14, wherein,

the groove is disposed in each of a portion outside and a portion inside the fastening hole in the radial direction in the fin including the fastening hole.