Disc brake device for railway vehicle

Abstract

A disc brake device for railway vehicles is provided, which can suppress the warping of the brake disc. The disc brake device (1) includes a brake disc (2) and brake friction pads (4). The brake disc (2) is fastened to a wheel by a plurality of bolts (6) inserted into a plurality of bolt holes (21). The brake friction pads (4) include a plurality of sliding member groups (41). Each sliding member group (41) includes an inner peripheral sliding member (42i) and an outer peripheral sliding member (42o). When the projection areas (PA) of the inner peripheral sliding member (42i) and the outer peripheral sliding member (42o) formed on the sliding surface (22) of the brake disc (2) are divided into an inner peripheral projection area (PAi) and an outer peripheral projection area (PAo) by an imaginary circle (PC) passing through the center of each bolt hole (21), the area of ​​the outer peripheral projection area (PAo) is larger than the area of ​​the inner peripheral projection area (PAi).

Description

Technical Field

[0001] This disclosure relates to disc brake devices for railway vehicles. Background Technology

[0002] Disc brakes are widely used as braking devices for railway vehicles. A disc brake consists of a brake disc, a brake caliper, and brake friction pads. The brake disc is mounted on the wheel and rotates with it. The brake friction pads are supported by the brake caliper. When the brake caliper operates, the brake friction pads are pressed against the brake disc. Through the friction between the brake friction pads and the brake disc, the brake disc and the wheel are braked.

[0003] Typically, a brake disc is fastened to the wheel by multiple bolts. The brake disc has an annular shape, with the side opposite to the wheel's surface designated as the sliding surface. Meanwhile, the brake friction pads include multiple sliding components. These sliding components are mounted to the brake caliper via a mounting plate, facing the sliding surface of the brake disc. During braking, the sliding components are pressed against the sliding surface of the brake disc. At this time, friction between the sliding components and the sliding surface causes the temperature of the sliding surface to rise. Consequently, the sliding surface thermally expands within the brake disc, undergoing plastic deformation under various conditions. When such braking is repeated, warping occurs within the brake disc (e.g., Japanese Patent Application Publication No. 2007-205428 (Patent Document 1)).

[0004] Brake disc warping typically manifests as the outer periphery of the sliding surface becoming closer to the brake friction lining than the inner periphery. As brake disc warping increases, excessive load is generated on the bolts that fasten the brake disc to the wheel. Furthermore, with increased brake disc warping, the sliding surface becomes significantly tilted, resulting in uneven contact between the sliding components and the sliding surface during braking. Therefore, suppressing brake disc warping is desirable.

[0005] Prior art literature

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2007-205428 Summary of the Invention

[0008] The technical problem that the invention aims to solve

[0009] This disclosure is made in view of the above-mentioned circumstances. The purpose of this disclosure is to provide a disc brake device for railway vehicles that can suppress the warping of the brake disc.

[0010] Technical means for solving technical problems

[0011] The disc brake device for railway vehicles disclosed herein includes a brake disc, a brake caliper, and brake friction pads. The brake disc has an annular shape and a plurality of bolt holes are formed on its circumference surrounding the center of the brake disc. The brake disc is fastened to the wheel by a plurality of bolts inserted therein in a manner corresponding to the plurality of bolt holes. The brake friction pads are supported by the brake caliper. The brake friction pads include a mounting plate and a plurality of sliding component assemblies. The mounting plate is mounted on the brake caliper. One surface of the mounting plate faces the sliding surface of the brake disc. The plurality of sliding component assemblies are arranged circumferentially on the aforementioned surface of the mounting plate. Each plurality of sliding component assemblies includes an inner circumferential sliding component, an outer circumferential sliding component, a backing, an inner circumferential elastic component, an outer circumferential elastic component, an inner circumferential fastening component, and an outer circumferential fastening component. The inner and outer circumferential sliding components are arranged radially on the brake disc. The inner and outer circumferential sliding components are each pentagonal in plan view. The backing is fixed to the mounting plate side surfaces of both the inner and outer peripheral sliding components. An inner peripheral elastic component is positioned between the inner peripheral sliding component and the mounting plate. An outer peripheral elastic component is positioned between the outer peripheral sliding component and the mounting plate. An inner peripheral fastening component fastens the inner peripheral sliding component to the mounting plate. An outer peripheral fastening component fastens the outer peripheral sliding component to the mounting plate. In this disc brake system, when the projection areas formed on the sliding surface by projecting the inner and outer peripheral sliding components of all the multiple sliding component groups along the central axis of the brake disc are divided into inner peripheral projection areas and outer peripheral projection areas by an imaginary circle passing through the centers of the multiple bolt holes, the area of ​​the outer peripheral projection area is larger than the area of ​​the inner peripheral projection area.

[0012] Invention Effects

[0013] According to the disc brake device for railway vehicles disclosed herein, warping of the brake disc can be suppressed. Attached Figure Description

[0014] Figure 1 This is a top view of the disc brake device of this embodiment.

[0015] Figure 2 yes Figure 1 The cross-sectional view of the disc brake device shown at line II-II.

[0016] Figure 3 yes Figure 1 A cross-sectional view of the disc brake device shown at line III-III.

[0017] Figure 4 This is a schematic diagram showing the arrangement of the inner peripheral sliding member and the outer peripheral sliding member relative to the brake disc in the disc brake device of this embodiment.

[0018] Figure 5 This is a cross-sectional view of the analysis model of the brake disc used in the FEM analysis of the embodiment.

[0019] Figure 6 This is a schematic diagram showing the heat distribution of Invention Examples 1 to 3.

[0020] Figure 7 This is a schematic diagram showing the heat distribution of Comparative Example 1.

[0021] Figure 8 This is a schematic diagram showing the heat distribution of Comparative Example 2.

[0022] Figure 9 This is a schematic diagram showing the heat distribution of Comparative Example 3.

[0023] Figure 10 This is a schematic diagram showing the heat distribution of Comparative Example 4.

[0024] Figure 11 This is a cross-sectional view showing an analytical model of a brake disc that warps due to heat input. Detailed Implementation

[0025] In order to achieve the above objectives, the inventors of this invention have conducted repeated and in-depth research and have obtained the following opinions.

[0026] To suppress brake disc warping, the temperature of the sliding surface should rise uniformly across the entire sliding surface region during sliding. This is because a uniform temperature rise across the entire sliding surface region can suppress localized thermal expansion. However, the temperature rise of the sliding surface is caused by the contact between the sliding component and the sliding surface. In practice, there are limitations in the configuration of the sliding component. Thus, it is practically difficult to ensure that the heat input from the sliding component to the sliding surface is uniform across the entire sliding surface region to achieve a uniform temperature rise.

[0027] Therefore, in the brake disc, the heat distribution that is less prone to warping was studied analytically using FEM, based on the distribution of heat input generated in the sliding surface. The results are shown below.

[0028] To secure the brake disc and wheel with multiple bolts, the brake disc has multiple bolt holes. Each bolt hole is formed on the circumference of the brake disc about its central axis. Specifically, the center of each bolt hole is positioned on an imaginary circle centered on the central axis of the brake disc. This imaginary circle is a reference circle associated with the arrangement of the bolt holes and is also referred to in design as the pitch circle of the bolt holes. Hereinafter, the imaginary circle associated with this arrangement of bolt holes is sometimes referred to as the pitch circle of the bolt holes.

[0029] In a brake disc, when the sliding surface is divided into an outer peripheral region and an inner peripheral region using the pitch circle of the bolt hole as the boundary, if the heat input in the outer peripheral region is greater than that in the inner peripheral region, warping can be suppressed to the same extent as with the same heat input, and excessive temperature rise can also be prevented. Furthermore, to increase the heat input in the outer peripheral region compared to the inner peripheral region, the sliding component can be positioned close to the outer peripheral side of the sliding surface of the brake disc.

[0030] The heat distribution and the configuration of the sliding components are determined by the contact state between the brake disc and the multiple sliding components. Specifically, to reproduce this heat distribution, the brake friction lining needs to be an isobaric structure where each sliding component makes equal contact with the brake disc. In an isobaric brake friction lining, an elastic component such as a spring is placed between each sliding component and the mounting plate. By introducing the elastic component, the entire surface area of ​​each sliding component on the brake disc side makes equal contact with the brake disc.

[0031] In contrast, for example, in the case of a rigid brake friction lining where each sliding component is fixed to a mounting plate, no elastic component is provided between the sliding components and the mounting plate. In this case, a portion of the sliding components does not contact the brake disc, or only a portion of the sliding components contacts the brake disc. This is due to the following reason: The mounting plate is connected to the brake caliper in a certain area, specifically in the central area of ​​the mounting plate. Therefore, the pressing force applied from the brake caliper to the mounting plate acts forcefully on the central area of ​​the mounting plate. Consequently, in a rigid brake friction lining, the portion of the sliding component that overlaps with the central area of ​​the mounting plate easily contacts the brake disc.

[0032] Furthermore, as a brake friction lining with a structure similar to the isobaric structure, there is also a structure in which multiple sliding parts are connected by a plate capable of elastic deformation, and the plate is fixed to a mounting plate. In this case, the pressing force can be easily transmitted to multiple sliding parts via the plate, but the pressing force is not transmitted equally to all sliding parts.

[0033] The disc brake device for railway vehicles disclosed herein is based on the above-described understanding. Embodiments of this disclosure will now be described. Furthermore, examples of embodiments of this disclosure will be given in the following description, but this disclosure is not limited to the examples described below. Specific numerical values ​​or specific materials may be illustrated in the following description, but this disclosure is not limited to these examples.

[0034] The disc brake device for railway vehicles according to embodiments of this disclosure includes a brake disc, a brake caliper, and brake friction pads. The brake disc has an annular shape and a plurality of bolt holes are formed on its circumference surrounding a central axis. The brake disc is fastened to a wheel by a plurality of bolts inserted into the bolt holes in a corresponding manner. The brake friction pads are supported by the brake caliper. The brake friction pads include a mounting plate and a plurality of sliding member assemblies. The mounting plate is mounted on the brake caliper. One surface of the mounting plate faces the sliding surface of the brake disc. The plurality of sliding member assemblies are arranged circumferentially on the aforementioned surface of the mounting plate. Each plurality of sliding member assemblies includes an inner circumferential sliding member, an outer circumferential sliding member, a backing, an inner circumferential elastic member, an outer circumferential elastic member, an inner circumferential fastening member, and an outer circumferential fastening member. The inner and outer circumferential sliding members are arranged radially on the brake disc. The inner and outer circumferential sliding members are each pentagonal in plan view. The backing is fixed to the mounting plate side surfaces of both the inner and outer peripheral sliding components. An inner peripheral elastic component is disposed between the inner peripheral sliding component and the mounting plate. An outer peripheral elastic component is disposed between the outer peripheral sliding component and the mounting plate. An inner peripheral fastening component fastens the inner peripheral sliding component to the mounting plate. An outer peripheral fastening component fastens the outer peripheral sliding component to the mounting plate. In this disc brake device structure, when the inner and outer peripheral sliding components of all the multiple sliding component groups are projected onto the sliding surface along the central axis of the brake disc to form projection areas on the sliding surface, and when the projection area is divided into an inner peripheral projection area and an outer peripheral projection area by an imaginary circle passing through the centers of the multiple bolt holes, the area of ​​the outer peripheral projection area is larger than the area of ​​the inner peripheral projection area (first structure).

[0035] In the disc brake device of the first structure, the brake friction lining has multiple sliding member assemblies. In each sliding member assembly, an inner peripheral elastic member is disposed between the inner peripheral sliding member and the mounting plate, and the inner peripheral sliding member is fastened to the mounting plate by an inner peripheral fastening member. Furthermore, an outer peripheral elastic member is disposed between the outer peripheral sliding member and the mounting plate, and the outer peripheral sliding member is fastened to the mounting plate by an outer peripheral fastening member. At this time, the brake friction lining becomes a brake friction lining with an isobaric structure. Therefore, the entire surface area of ​​each sliding member on the brake disc side is in equal contact with the sliding surface of the brake disc. Furthermore, in the disc brake device of the first structure, when the projected areas of the inner and outer peripheral sliding members formed on the sliding surface of the brake disc are divided into an inner peripheral projection area and an outer peripheral projection area by an imaginary circle (the pitch circle of the bolt holes) passing through the center of each of the multiple bolt holes, the area of ​​the outer peripheral projection area is larger than the area of ​​the inner peripheral projection area. That is, the inner and outer peripheral sliding components in all the multiple sliding component groups are arranged as a whole on the outer peripheral side of the sliding surface of the brake disc. Therefore, when the sliding surface is divided into an outer peripheral region and an inner peripheral region in the brake disc with the pitch circle of the bolt hole as the boundary, the heat input to the outer peripheral region can be increased compared to the heat input to the inner peripheral region. Therefore, the disc brake device according to the first structure can suppress brake disc warping to the same extent as with the same heat input, and can also suppress excessive temperature rise of the brake disc.

[0036] In the first structure of the disc brake device, preferably, the ratio of the area of ​​the outer peripheral side projection region to the area of ​​the inner peripheral side projection region is 1.10 or more (second structure). In this case, the warping of the brake disc can be suppressed more effectively.

[0037] In the first or second structure of the disc brake device, preferably, during braking, when the inner and outer peripheral sliding members slide on the sliding surface of the brake disc, the heat input applied to the sliding surface, divided into inner peripheral heat input and outer peripheral heat input by the aforementioned imaginary circle, has a ratio of outer peripheral heat input to inner peripheral heat input of 1.10 or more (third structure). In this case, the heat input in the outer peripheral region is greater than the heat input in the inner peripheral region. Therefore, brake disc warping can be further effectively suppressed.

[0038] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In the drawings, the same or equivalent structures are labeled with the same reference numerals, and descriptions are not repeated.

[0039] Disc brake system

[0040] Figure 1 This is a top view of the disc brake device 1 according to this embodiment. The disc brake device 1 is used as a braking device for railway vehicles. (See reference...) Figure 1 The disc brake device 1 includes a brake disc 2, a brake caliper 3, and brake friction pads 4.

[0041] [Structure of the brake disc]

[0042] First, let's explain the structure of brake disc 2. For example... Figure 1 As shown, the brake disc 2 has an annular shape. The brake disc 2 is fastened to the wheel 5 by a plurality of bolts 6. For fastening the bolts 6, the brake disc 2 has a plurality of bolt holes 21. The bolt holes 21 are spaced apart along the circumference of the brake disc 2. Specifically, each bolt hole 21 is formed on the circumference surrounding the central axis of the brake disc 2. That is, the center of each bolt hole 21 is located on an imaginary circle PC centered on the central axis of the brake disc 2. In other words, the imaginary circle PC passes through the center of each bolt hole 21. This imaginary circle PC is the pitch circle of the bolt hole 21. Hereinafter, this imaginary circle PC is sometimes referred to as the pitch circle PC of the bolt hole 21.

[0043] Bolt 6 is inserted into bolt hole 21 to fasten brake disc 2 to wheel 5. Brake disc 2 and wheel 5 are substantially coaxially arranged. Brake disc 2 is disposed on both sides of wheel 5.

[0044] Figure 2 yes Figure 1 A cross-sectional view of the disc brake device 1 shown at line II-II. Figure 2 In the diagram, the brake discs 2 are installed on both sides of the wheel 5; only one is shown, and the other is omitted.

[0045] Reference Figure 2 The brake disc 2 has a surface 22 and a back surface 23. Surface 22 is the outward-facing surface in the thickness direction of the brake disc 2. Surface 22 is the sliding surface pressed by the brake friction pads (not shown). Hereinafter, the surface 22 of the brake disc 2 is sometimes referred to as the sliding surface 22. The back surface 23 is opposite to the side of the wheel 5. In the case where the brake disc 2 has a plurality of radially extending longitudinal vanes, the back surface 23 is the top surface of the longitudinal vanes.

[0046] Each bolt hole 21 passes through the brake disc 2. Each bolt hole 21 includes a large diameter portion 211 and a small diameter portion 212. The diameter of the large diameter portion 211 is larger than the diameter of the small diameter portion 212. The large diameter portion 211 and the small diameter portion 212 are arranged in this order from the surface (sliding surface) 22 of the brake disc 2 toward the back surface 23.

[0047] The wheel 5 has multiple through holes 51. The multiple through holes 51 are formed on the wheel 5 corresponding to the multiple bolt holes 21 of the brake disc 2. The brake disc 2 is mounted on both sides of the wheel 5. Therefore, the bolt holes 21 of one brake disc 2, the through holes 51 of the wheel 5, and the bolt holes of the other brake disc (not shown) are arranged in sequence.

[0048] Bolts 6 are inserted into bolt holes 21 of one brake disc 2, through holes 51 of the wheel 5, and bolt holes of the other brake disc. The head 61 of the bolt 6 is placed in the large-diameter portion 211 of the bolt hole 21 of one brake disc 2, and a nut (not shown) is placed in the large-diameter portion of the bolt hole of the other brake disc. The brake disc 2 is fastened to the wheel 5 by the engagement of the threaded portion of the bolt 6 with the threaded portion of the nut. Figure 2 In the example shown, in the large-diameter portion 211 of the bolt hole 21 of a brake disc 2, an elastic member 7 is disposed between the head 61 and the small-diameter portion 212 of the bolt 6. This elastic member 7 is, for example, obtained by stacking disc springs. Similarly, in the large-diameter portion of the bolt hole of another brake disc, an elastic member is disposed between the nut and the small-diameter portion.

[0049] [Structure of brake friction pads]

[0050] return Figure 1 This explains the composition of the brake friction lining 4. For example... Figure 1 As shown, the brake friction pad 4 includes a mounting plate 40 and a plurality of sliding component assemblies 41. The brake friction pad 4 is supported by the brake caliper 3. Specifically, the mounting plate 40 has a generally rectangular shape in frontal view. The mounting plate 40 is configured to overlap a portion of the circumferential direction of the brake disc 2. The mounting plate 40 is mounted to the brake caliper 3. The mounting plate 40 is connected to the brake caliper 3 in the central region of the mounting plate 40.

[0051] Multiple sliding component groups 41 are arranged at intervals in the circumferential direction of the brake disc 2. The multiple sliding component groups 41 do not necessarily need to be arranged exactly along the circumferential direction of the brake disc 2, as long as they are substantially arranged in the circumferential direction of the brake disc 2. In this embodiment, six sliding component groups 41 are arranged in the circumferential direction of the brake disc 2. Each sliding component group 41 includes an inner circumferential sliding component 42i and an outer circumferential sliding component 42o as sliding components. The inner circumferential sliding component 42i is disposed on the inner circumferential side of the brake disc 2. The outer circumferential sliding component 42o is disposed on the outer circumferential side of the brake disc 2. The inner circumferential sliding component 42i and the outer circumferential sliding component 42o are arranged at intervals in the radial direction of the brake disc 2.

[0052] Both the inner circumferential sliding member 42i and the outer circumferential sliding member 42o are plate-shaped and pentagonal when viewed from above. One side of the inner circumferential sliding member 42i is adjacent to the outer circumferential sliding member 42o, and this side extends circumferentially on the brake disc 2. One side of the outer circumferential sliding member 42o is adjacent to the inner circumferential sliding member 42i, and this side extends circumferentially on the brake disc 2. One of the five vertices of the inner circumferential sliding member 42i is located on the opposite side of the outer circumferential sliding member 42o, and the corner containing this point protrudes radially inward on the brake disc 2. One of the five vertices of the outer circumferential sliding member 42o is located on the opposite side of the inner circumferential sliding member 42i, and the corner containing this point protrudes radially outward on the brake disc 2.

[0053] The top view of the two sliding components 42i and 42o should essentially be pentagonal. Specifically, the five sides of the two sliding components 42i and 42o can be straight lines or curves. For example, among the five sides of the inner peripheral sliding component 42i, the two sides extending radially from the brake disc 2 can be curved in a bulging manner. Among the five sides of the outer peripheral sliding component 42o, the two sides extending radially from the brake disc 2 can also be curved in a bulging manner. Figure 1 In the example shown, the outer peripheral sliding members 42o of each of the four sliding member groups 41 located at the center, and the inner peripheral sliding members 42i of each of the two sliding member groups 41 located at both ends, have curved sides. Furthermore, the corners of the inner peripheral sliding members 42i, each containing five vertices, can be rounded. Similarly, the corners of the outer peripheral sliding members 42o, each containing five vertices, can also be rounded. Moreover, the top-view shape of each sliding member 42i, 42o can be, for example, a circle, or a polygon such as a quadrilateral or hexagon.

[0054] Each sliding component group 41 includes an inner peripheral sliding component 42i and an outer peripheral sliding component 42o, and is mounted on one surface of the mounting plate 40. This one surface is opposite to the sliding surface 22 of the brake disc 2. Furthermore, the number of sliding component groups 41 is not particularly limited, even if it is a plurality. In the sliding component group 41, the size of the outer peripheral sliding component 42o in plan view may be the same as or different from that of the inner peripheral sliding component 42i. Furthermore, among the sliding component groups 41, the sizes of the inner peripheral sliding components 42i in plan view may be the same as or different from each other, and the sizes of the outer peripheral sliding components 42o in plan view may also be the same as or different from each other. Figure 1In the example shown, the outer peripheral sliding members 42o of each of the four sliding member groups 41 disposed on the central side, and the inner peripheral sliding members 42i of each of the two sliding member groups 41 disposed at both ends are of the same size. The inner peripheral sliding members 42i of each of the four sliding member groups 41 disposed on the central side, and the outer peripheral sliding members 42o of each of the two sliding member groups 41 disposed at both ends are of the same size. Furthermore, for example, in the four sliding member groups 41 disposed on the central side, the size of the outer peripheral sliding member 42o is larger than that of the inner peripheral sliding member 42i.

[0055] The brake friction pad 4 in this embodiment has an equal pressure structure. Hereinafter, refer to... Figure 3 The brake friction lining 4 with an isobaric structure will be explained.

[0056] Figure 3 yes Figure 1 A cross-sectional view of the disc brake device 1 shown at line III-III. (See attached image.) Figure 3 As shown, the sliding component group 41 constituting the brake friction lining 4 includes, in addition to the inner peripheral sliding component 42i and the outer peripheral sliding component 42o, a backing 43, an inner peripheral elastic component 44i, an outer peripheral elastic component 44o, an inner peripheral fastening component 45i, and an outer peripheral fastening component 45o.

[0057] A backing 43 is fixed on the side (back side) of the mounting plate 40 of both the inner peripheral sliding member 42i and the outer peripheral sliding member 42o. Specifically, a set of inner peripheral sliding members 42i and outer peripheral sliding members 42o are connected via a single backing 43.

[0058] An inner peripheral elastic member 44i is disposed between the inner peripheral sliding member 42i and the mounting plate 40. Specifically, the inner peripheral elastic member 44i is disposed behind the corresponding inner peripheral sliding member 42i, between the backing 43 fixed to the inner peripheral sliding member 42i and the mounting plate 40. An outer peripheral elastic member 44o is disposed between the outer peripheral sliding member 42o and the mounting plate 40. Specifically, the outer peripheral elastic member 44o is disposed behind the corresponding outer peripheral sliding member 42o, between the backing 43 fixed to the outer peripheral sliding member 42o and the mounting plate 40. The two elastic members 44i and 44o are, for example, disc springs. However, the two elastic members 44i and 44o can be leaf springs or coil springs, etc.

[0059] The inner peripheral fastening member 45i fastens the inner peripheral sliding member 42i to the mounting plate 40. Specifically, the inner peripheral fastening member 45i is positioned at the center of gravity of the corresponding inner peripheral sliding member 42i. The outer peripheral fastening member 45o fastens the outer peripheral sliding member 42o to the mounting plate 40. Specifically, the outer peripheral fastening member 45o is positioned at the center of gravity of the corresponding outer peripheral sliding member 42o. The two fastening members 45i and 45o are, for example, rivets. The inner peripheral sliding member 42i, the backing 43, and the inner peripheral elastic member 44i are mounted to the mounting plate 40 by the inner peripheral fastening member 45i. The outer peripheral sliding member 42o, the backing 43, and the outer peripheral elastic member 44o are mounted to the mounting plate 40 by the outer peripheral fastening member 45o.

[0060] Thus, the brake friction pad 4 has multiple sliding member assemblies 41. In each sliding member assembly 41, an inner peripheral elastic member 44i is disposed between the inner peripheral sliding member 42i and the mounting plate 40, and the inner peripheral sliding member 42i is fastened to the mounting plate 40 by an inner peripheral fastening member 45i. Furthermore, an outer peripheral elastic member 44o is disposed between the outer peripheral sliding member 42o and the mounting plate 40, and the outer peripheral sliding member 42o is fastened to the mounting plate 40 by an outer peripheral fastening member 45o. In this case, the brake friction pad 4 has an equal pressure structure. Therefore, during braking, if the brake friction pad 4 moves towards the brake disc 2 through the operation of the brake caliper, the entire surface area of ​​each sliding member 42i, 42o on the brake disc 2 side will contact the sliding surface 22 of the brake disc 2 equally.

[0061] [Configuration of sliding components]

[0062] Figure 4 This is a schematic diagram showing the arrangement relationship between the inner peripheral sliding member 42i and the outer peripheral sliding member 42o relative to the brake disc 2 in the disc brake device 1 of this embodiment. Figure 4 The image shows a top view of brake disc 2. (See image below.) Figure 4 As shown, in the brake disc 2, the pitch circle PC of the bolt hole 21 is used as the boundary to divide the sliding surface 22 into an outer peripheral region 22o and an inner peripheral region 22i. Further, the inner peripheral sliding components 42i and the outer peripheral sliding components 42o of all the multiple sliding component groups 41 are projected onto the sliding surface 22 along the central axis of the brake disc 2, forming projection areas PA of the inner peripheral sliding components 42i and the outer peripheral sliding components 42o in the sliding surface 22. Then, using the pitch circle PC of the bolt hole 21 as the boundary, the projection area PA is divided into an inner peripheral projection area PAi and an outer peripheral projection area PAo.

[0063] In the disc brake device 1 of this embodiment, the inner peripheral sliding member 42i and the outer peripheral sliding member 42o in all the plurality of sliding member groups 41 are arranged such that the area of ​​the outer peripheral projection region PAo is larger than the area of ​​the inner peripheral projection region PAi. That is, the inner peripheral sliding member 42i and the outer peripheral sliding member 42o in all the plurality of sliding member groups 41 are arranged as a whole on the outer peripheral side of the sliding surface 22 of the brake disc 2. In this case, when braking, each sliding member 42i, 42o slides on the sliding surface 22, and when heat is input from each sliding member 42i, 42o to the sliding surface 22, the heat input from the outer peripheral region 22o is greater than the heat input from the inner peripheral region 22i.

[0064] [Effect]

[0065] In the disc brake device 1 of this embodiment, the brake friction pad 4 is a brake friction pad with an isobaric structure. Therefore, the entire surface area of ​​each sliding member 42i, 42o on the brake disc 2 side is in equal contact with the sliding surface 22 of the brake disc 2. Furthermore, the inner peripheral sliding member 42i and the outer peripheral sliding member 42o of all the multiple sliding member groups 41 are arranged as a whole on the outer peripheral side of the sliding surface 22 of the brake disc 2. Therefore, in the brake disc 2, the heat input to the outer peripheral side region 22o can be increased compared to the heat input to the inner peripheral side region 22i. Therefore, as described above, the warping of the brake disc 2 can be suppressed to the same extent as with the same heat input, and the excessive temperature rise of the brake disc 2 can also be suppressed.

[0066] In the disc brake device 1 of this embodiment, a plurality of sliding member assemblies 41 are arranged circumferentially on the brake disc 2. Each sliding member assembly 41 includes, as a sliding member, an inner circumferential sliding member 42i and an outer circumferential sliding member 42o arranged radially on the brake disc 2. Therefore, each sliding member 42i, 42o is of appropriate size and can effectively withstand the elastic force from each elastic member 44i, 44o. Furthermore, the inner circumferential sliding member 42i and the outer circumferential sliding member 42o are connected by a backing 43, thus preventing them from falling off or spinning freely.

[0067] In this embodiment, in each sliding member group 41, the inner peripheral sliding member 42i and the outer peripheral sliding member 42o are each pentagonal when viewed from above. In this case, the inner peripheral sliding member 42i and the outer peripheral sliding member 42o can be arranged to fill the entire area. Therefore, the contact area of ​​each sliding member 42i, 42o with the sliding surface 22 of the brake disc 2 can be sufficiently ensured.

[0068] [Preferred Solution]

[0069] Regarding the brake friction lining 4, preferably, the inner peripheral sliding member 42i and the outer peripheral sliding member 42o are configured such that the ratio of the area of ​​the outer peripheral projection area PAo to the area of ​​the inner peripheral projection area PAi is 1.10 or more. If the area ratio of the outer peripheral projection area PAo to the inner peripheral projection area PAi is 1.10 or more, the warping of the brake disc 2 can be suppressed more effectively. This area ratio is preferably 1.20 or more, and more preferably 1.25 or more. The upper limit of this area ratio is not particularly limited. However, if the area ratio is very large, the temperature of the brake disc will locally rise, resulting in uneven wear. Therefore, the area ratio is preferably 1.80 or less.

[0070] Regarding the brake disc 2, preferably, during braking, when the inner peripheral sliding member 42i and the outer peripheral sliding member 42o slide against the sliding surface 22 of the brake disc 2, the heat input applied to the sliding surface 22 due to the sliding of the inner peripheral sliding member 42i and the outer peripheral sliding member 42o against the brake disc 2 is divided into inner peripheral heat input and outer peripheral heat input with the pitch circle PC of the bolt hole 21 as the boundary, the ratio of the outer peripheral heat input to the inner peripheral heat input is 1.10 or more. That is, preferably, the ratio of the heat input of the outer peripheral region 22o to the heat input of the inner peripheral region 22i is 1.10 or more. If the ratio of the heat input of the outer peripheral region 22o to the inner peripheral region 22i is 1.10 or more, then the heat input of the outer peripheral region 22o is greater than that of the inner peripheral region 22i. Therefore, the warping of the brake disc 2 can be further effectively suppressed. This heat input ratio is preferably 1.20 or more, and more preferably 1.25 or more. The upper limit of this heat input ratio is not particularly limited. However, if the heat input ratio is very high, the brake disc temperature will rise locally, resulting in uneven wear. Therefore, the heat input ratio is preferably below 1.80.

[0071] [Example]

[0072] Next, in order to confirm the effect of the disc brake device 1 in this embodiment, FEM analysis will be performed. Figure 5 This is a cross-sectional view of the analysis model of brake disc 2 used in the FEM analysis of the embodiment. Figure 5 The analysis model shown is a simulation. Figure 1 The disc brake device 1 shown is... Figure 5 The cross section shown is equivalent to Figure 2 The cross-section shown is illustrated. The analysis model consists of a brake disc 2, bolts 6, elastic components 7, and a wheel 5. Furthermore, considering axisymmetry, the analysis model adopts a configuration where the axial direction of the wheel with the brake disc is set to 1 / 2, and the circumferential direction of the brake disc is set to 1 / 12.

[0073] The brake disc 2 is designed as an elasto-plastic material to reproduce thermal deformation. Other components (bolt 6, elastic component 7, and wheel 5) are designed as elastic or elasto-plastic materials. The element type of each component is set as a linear hexahedral element. The element size of the brake disc 2 and other components is set to a minimum of 0.5 mm. However, the minimum element size of other components can be larger.

[0074] For the analysis model, it is assumed that braking energy equivalent to the specified braking conditions will be applied three times. The braking conditions are set as a stop caused by emergency braking from a speed of 360 km / h. The initial axial force of bolt 6 is determined by the actual brake disc 2.

[0075] Furthermore, in the analysis model of brake disc 2, a heat input distribution Q is applied to the entire region of sliding surface 22. The heat input distribution Q is set with 7 conditions. Among these 7 conditions, the total amount of heat input is set to be the same. Figure 6 , Figure 7 , Figure 8 , Figure 9 and Figure 10 The figure shows the heat distribution Q under seven conditions. Figure 6 This is a schematic diagram showing the heat distribution Q in Examples 1 to 3 of the invention. Figure 7 This is a schematic diagram showing the heat distribution Q of Comparative Example 1. Figure 8 This is a schematic diagram showing the heat distribution Q of Comparative Example 2. Figure 9 This is a schematic diagram showing the heat distribution Q of Comparative Example 3. Figure 10 This is a schematic diagram showing the heat distribution Q of Comparative Example 4.

[0076] Reference Figure 6 In Invention Examples 1-3, the heat input to the outer peripheral region 22o is increased compared to the inner peripheral region 22i. In this case, the area of ​​the outer peripheral projected region PAo is larger than that of the inner peripheral projected region PAi. (Refer to...) Figure 7 In Comparative Example 1, the input heat was set to be the same. (Refer to...) Figure 8 and Figure 9 In Comparative Examples 2 and 3, the heat input to the outer peripheral region 22o is set to be the same as the heat input to the inner peripheral region 22i. Wherein, as Figure 8 As shown, in Comparative Example 2, the heat input on the pitch circle PC of the bolt hole 21 is reduced, and a W-shaped heat input is applied as a whole. Figure 9 As shown, in Comparative Example 3, the heat input on the pitch circle PC of the bolt hole 21 is increased, and a V-shaped heat input is applied as a whole. In the cases of Comparative Examples 1 to 3, the area of ​​the outer peripheral projection region PAo is the same as the area of ​​the inner peripheral projection region PAi. (Refer to...) Figure 10In Comparative Example 4, the heat input to the outer peripheral region 22o is reduced compared to the inner peripheral region 22i. Therefore, the area of ​​the outer peripheral projected region PAo is smaller than that of the inner peripheral projected region PAi.

[0077] More specifically, in Invention Examples 1-3, the heat input ratio of the outer peripheral region 22o to the inner peripheral region 22i is greater than 1.00. In Invention Example 1, the heat input ratio is 1.70. In this case, the area ratio of the outer peripheral projected region PAo to the inner peripheral projected region PAi is 1.70. In Invention Example 2, the heat input ratio is 1.40. In this case, the area ratio is 1.40. In Invention Example 3, the heat input ratio is 1.20. In this case, the area ratio is 1.20. In Comparative Examples 1-3, the heat input ratio of the outer peripheral region 22o to the inner peripheral region 22i is 1.00. In this case, the area ratio of the outer peripheral projected region PAo to the inner peripheral projected region PAi is 1.00. In Comparative Example 4, the heat input ratio of the outer peripheral region 22o to the inner peripheral region 22i is less than 1.00. The heat input ratio of Comparative Example 4 is 0.60. At this point, the area ratio of the outer peripheral projection region PAo to the inner peripheral projection region PAI is 0.60.

[0078] Figure 11 This is a cross-sectional view of the analytical model of the brake disc 2, which warps due to heat input. In the FEM analysis, the amount of warpage d generated in the brake disc 2 is evaluated. The warpage amount d is defined as the displacement in the thickness direction of the outer periphery of the sliding surface 22. Using Comparative Example 1, which has the same amount of heat input, as a benchmark, if the warpage amount is equal to that of Comparative Example 1, or within 15% of the warpage amount of Comparative Example 1, it is judged as good (OK). Furthermore, the highest temperature from the sliding surface 22 to 6 mm inside is evaluated. If the highest temperature does not exceed the 700°C specified in the design of the brake disc 2, it is judged as good (OK).

[0079] The analysis results are shown in Table 1.

[0080] [Table 1]

[0081]

[0082] Based on the results in Table 1, the following findings are presented. As in Examples 1-3, if the heat input to the outer peripheral region 22o is greater than that to the inner peripheral region 22i, warping is suppressed, and excessive temperature rise of the brake disc 2 is also suppressed. As in Comparative Example 2, the heat input to the outer peripheral region 22o is the same as that to the inner peripheral region 22i, and the heat input to the pitch circle PC of the bolt hole 21 is small, so warping suppression is not confirmed. As in Comparative Example 3, even if the heat input to the outer peripheral region 22o is the same as that to the inner peripheral region 22i, if the heat input to the pitch circle PC of the bolt hole 21 is large, warping is suppressed. However, in the case of Comparative Example 3, excessive temperature rise of the brake disc 2 is confirmed. As in Comparative Example 4, the heat input to the outer peripheral region 22o is smaller than that to the inner peripheral region 22i, so warping suppression is not confirmed.

[0083] Based on the above results, the effectiveness of the disc brake device 1 in this embodiment has been confirmed.

[0084] The embodiments of this disclosure have been described above. However, the above embodiments are merely illustrative for implementing this disclosure. Therefore, this disclosure is not limited to the above embodiments, and the above embodiments can be appropriately modified and implemented without departing from its spirit.

[0085] Explanation of reference numerals in the attached figures

[0086] 1: Disc brake device

[0087] 2: Brake disc

[0088] 3: Brake calipers

[0089] 4: Brake friction pads

[0090] 5: Wheels

[0091] 6: Bolts

[0092] 21: Bolt hole

[0093] PC: Imaginary circle (joint circle)

[0094] 22: Surface (sliding surface)

[0095] 22o: Peripheral region

[0096] 22i: Peripheral region

[0097] 40: Mounting plate

[0098] 41: Sliding component assembly

[0099] 42i: Inner peripheral sliding component

[0100] 42o: Outer peripheral sliding component

[0101] PA: Projection area

[0102] PAi: Inner peripheral projection area

[0103] PAo: Peripheral projection area

[0104] 43: Backing

[0105] 44i: Inner peripheral elastic component

[0106] 44o: Peripheral elastic component

[0107] 45i: Inner peripheral fastening component

[0108] 45°: Outer peripheral fastening components

Claims

1. A disc brake device, used on railway vehicles, comprising: A brake disc having an annular shape has a plurality of bolt holes formed on the circumference of the brake disc around its central axis, and is fastened to the wheel by a plurality of bolts inserted therein in a manner corresponding to the plurality of bolt holes respectively; Brake calipers; as well as A brake friction lining, supported by the brake caliper, includes a mounting plate and a plurality of sliding component assemblies. The mounting plate is mounted to the brake caliper, with one face facing the sliding surface of the brake disc. The plurality of sliding component assemblies are arranged circumferentially on the one face of the mounting plate of the brake disc. Each of the plurality of sliding component groups includes: The inner and outer peripheral sliding components are arranged radially on the brake disc and each has a pentagonal shape when viewed from above. A backing is fixed to the mounting plate side of both the inner peripheral sliding component and the outer peripheral sliding component; An inner peripheral elastic member is disposed between the inner peripheral sliding member and the mounting plate; An outer peripheral elastic member is disposed between the outer peripheral sliding member and the mounting plate; An inner peripheral fastening component that fastens the inner peripheral sliding component to the mounting plate; and The peripheral fastening component secures the peripheral sliding component to the mounting plate. For the projection area formed on the sliding surface by projecting the inner and outer peripheral sliding components of all the plurality of sliding component groups along the central axis of the brake disc onto the sliding surface, when dividing the area into an inner peripheral projection area and an outer peripheral projection area by an imaginary circle passing through the center of each of the plurality of bolt holes, the area of ​​the outer peripheral projection area is greater than the area of ​​the inner peripheral projection area.

2. The disc brake device according to claim 1, The ratio of the area of ​​the outer peripheral projection region to the area of ​​the inner peripheral projection region is 1.10 or more.

3. The disc brake device according to claim 1 or 2, During braking, the heat applied to the sliding surface of the brake disc by the sliding of the inner and outer peripheral sliding components is such that, when the imaginary circle is used as a boundary to divide the heat into inner and outer peripheral heat, the ratio of the outer peripheral heat to the inner peripheral heat is 1.10 or more.

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