JP2001311441A - brake disc - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the stress applied to a fastening hole portion and a fastening member of a disc during braking by suppressing the occurrence of the warpage of the disc due to the thermal stress of braking, and to improve the disc and fastening. Prolong the life of the member. Further, the concentration of stress that is repeatedly applied to the fastening hole and the fastening member of the disc due to the braking is suppressed, and the life of the disc and the fastening member is prolonged. A sliding portion having a sliding surface of a brake disk is provided with a fastening hole. In addition, a concave portion 11 that fits with the convex portion provided on the member to be fastened is provided on the fastening surface of the brake disc 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake disc for railway vehicles, and more particularly to a peripheral portion of a fastening hole such as a bolt hole (hereinafter, a peripheral portion of the fastening hole is also referred to as a fastening hole portion, and a peripheral portion of the bolt hole is a bolt). Brake disk that can withstand long-term use by reducing the stress acting on the fastening members such as holes) and bolts, thereby suppressing the fatigue failure from the fastening holes of the brake disk and the fatigue failure of the fastening members. About.

[0002]

2. Description of the Related Art Block brakes, drum brakes, disc brakes, and the like are used as mechanical braking devices for railway vehicles, automobiles, motorcycles, and the like. In recent years, disk brakes have come to be used heavily as vehicles have become faster and larger.

A disc brake is a device that obtains a braking force by friction between a brake disc and a brake lining. Usually, a brake is provided on a sliding surface of a donut-shaped disc-shaped disc attached to an axle or a wheel with bolts. By pressing the lining to obtain the braking force,
This device controls the speed of the vehicle by braking the rotation of the axle or wheels. The disc having the sliding surface is referred to as a brake disc.

[0004] Among them, the brake discs for railway vehicles include side discs and shaft mount discs. The side disc is a brake disc fastened to the side surface of the wheel, and the axle mount disc is a brake disc fastened to the axle. Hereinafter, the side disk and the shaft mount disk are referred to as a brake disk, or simply as a disk.

FIG. 1 shows the shape of a conventional brake disk for a railway vehicle. FIG. 1A is a partial plan view showing a quarter of the brake disk for a railway vehicle, and FIG.
FIG. 2 is a partial cross-sectional view showing the AA cross section of FIG.

[0006] As shown in FIG.
Generally comprises an outer peripheral portion 2 including a sliding surface 4 and an inner peripheral portion 3 having a peripheral portion of a bolt hole 5 which is a fastening hole for fastening to a wheel or the like.

FIG. 2 is a cross-sectional view schematically showing a state in which a conventional railway vehicle side brake disc is mounted on wheels. As shown in the figure, the brake discs 1 and 1 are fastened to both side surfaces of a wheel 6 by bolts 7 and nuts 8 as fastening members, and are mounted so as to integrally rotate. Brake linings (not shown) that are movable in the direction of the sliding surfaces are respectively attached to the positions of the brake disks 1 and 1 facing the sliding surfaces 4 and 4. When the brake is applied to stop the vehicle, the brake linings are used. Move to the disc side and press strongly from both sides of the wheel,
The frictional force brakes the rotation of the axle via the wheels to stop the vehicle.

[0008]

DISCLOSURE OF THE INVENTION In a high-speed railway vehicle such as a Shinkansen, the rotational speed of the disk and the inertia of the vehicle under a brake load are very large, so that the disk temperature rise is higher than that of other vehicles and motorcycles. And remarkably large. Therefore, in the outer peripheral portion including the sliding surface of the disk, an extremely large thermal expansion force is generated as the temperature rises. However, since it is constrained by the inner peripheral portion having a bolt hole portion and having a lower temperature than the outer peripheral portion, compressive stress is generated in the peripheral direction at the disk outer peripheral portion, and tensile stress is generated in the peripheral direction at the disk inner peripheral portion. . Since the tensile stress concentrates on the bolt hole in the inner peripheral portion of the disk, the bolt hole may be the most dangerous part in the entire disk. In addition, when the outer peripheral portion of the expanding disk is restricted by the inner peripheral portion, the outer peripheral portion of the disk may be deformed toward the sliding surface (hereinafter, also referred to as warpage).

FIG. 3 is a cross-sectional view schematically showing the state of the disk in which warpage has occurred. The broken line shows the state of the disk during non-braking, the solid line shows the state of the disk during braking, and arrows in the figure. Indicates the stress acting on the disc and bolt during braking.

[0010] As shown in FIG. 1, when warpage occurs in the outer peripheral portion of the disk, the contact between the brake lining and the disk becomes uneven at the time of braking, so that the frictional force becomes unstable and the intended braking is performed. Characteristics cannot be obtained. Also, since the outer periphery of the disc 1 is pressed against the wheel 6 during braking, tensile stress and bending stress are applied to the bolts 7 that fasten the disc 1 and the wheel 6, and local stress is applied to the bolt holes of the disc. Stress is applied. For this reason, by repeated braking (hereinafter also referred to as braking),
Local stress is repeatedly applied to the bolt holes of the disk, and fatigue fracture may occur from the bolt holes. Therefore, in actual use, the amount of warpage of the disk is periodically monitored, and replacement is performed when the value exceeds a predetermined value. Therefore, the occurrence of warping leads to shortening of the life of the disk, which is not preferable from the viewpoint of economy. Therefore, a technique for suppressing the occurrence of warping and extending the life of the disk is required.

Further, as described above, the tensile stress concentrates on the bolt holes in the inner peripheral portion of the disk that restrains the expansion of the outer peripheral portion of the disk, and the rotational stress is repeatedly received from the bolts during braking. May be a dangerous part where fatigue fracture is likely to occur. Accordingly, there is a need for a technique for reducing the stress applied to the bolt hole to extend the life of the disk.

On the other hand, in addition to the tensile stress always applied to fasten the disk and the wheel, the bolt has a bending stress in the rotating direction applied to restrain the rotation of the disk, and the bolt has an outer peripheral portion. The bending stress in the radial direction, which is applied when the inner peripheral portion receives the tensile stress toward the outer peripheral portion due to the thermal expansion, is repeatedly generated by the braking. Further, when the disk is warped, the tensile stress and the bending stress in the radial direction are repeatedly applied by the breaking as described above. Stresses averaged over these stresses and stresses that are repeatedly applied may cause fatigue fracture of the bolt. Therefore, in actual use, bolts should be regularly inspected in the same way as discs.
Exchanges are made before fatigue failure occurs. Therefore, there is a need for a technique for extending the life of a bolt by reducing the stress.

As an attempt to solve these problems,
Japanese Patent Application Laid-Open No. 10-318304 discloses a brake disc comprising an outer ring and an inner ring, wherein an inner peripheral surface of the outer ring and an outer peripheral surface of the inner ring are fitted with a margin in a radial direction to form a circle. A brake disc adapted to be fitted also in the circumferential direction has been proposed.

By applying the above-mentioned brake disc, the thermal stress generated in the outer ring having the sliding surface is absorbed by the gap provided between the outer ring and the inner ring. Stress concentration on the substrate can be reduced.

[0015] However, in order to fit the outer ring and the inner ring, it is necessary to provide a certain gap in the circumferential direction. However, the braking characteristics of the brake become unstable, which is not preferable. Further, since repeated stress due to braking acts on the fitting portion, there is a possibility that fatigue fracture may occur in the fitting portion. Further, when an excessive stress is applied to the fitting portion, the outer ring may come off from the inner ring, which may cause an unexpected accident.

As described above, especially in a disk for a railway vehicle, the disk and the bolt are repeatedly subjected to severe thermal stress, tensile stress and bending stress due to braking, so that the life of the disk and the bolt is longer than the current life. It was difficult.

In view of the above problems, the present invention optimizes the shape of an integrated disk to reduce the stress acting on a fastening hole such as a bolt hole of a disk and a fastening member such as a bolt by braking. Reduce the occurrence of fatigue fracture from the fastening hole and fatigue fracture of the fastening member,
An object of the present invention is to extend the life of a disk and a fastening member.

[0018]

Means for Solving the Problems The present inventors have studied the position of a fastening hole suitable for suppressing the generation of stress generated in a fastening hole such as a bolt hole of a disk. In addition, in order to disperse the stress concentration generated in the fastening hole, it was studied to restrain the disk by a portion other than the fastening hole. As a result, the following findings were obtained.

(A) By providing a fastening hole in the sliding portion, the disk is restrained by the sliding portion, and the outer peripheral portion, which has conventionally become high in temperature, has been restrained by the inner peripheral portion, which has a relatively low temperature. The warpage caused by the above can be suppressed. Further, it is possible to distribute the warp to the outer peripheral side and the inner peripheral side, and even when the disc is pressed against the wheel side by the brake lining during braking, the tensile stress and the tensile force acting on the fastening members such as the fastening holes and bolts are increased. Bending stress can be significantly reduced. Further, since a tensile stress in the circumferential direction for restraining other parts is not generated in the sliding portion, it is possible to suppress the concentration of the tensile stress in the fastening hole. Further, it is possible to omit the inner peripheral portion provided for securing the fastening hole portion in the related art, and it is possible to reduce the weight of the disc.

Here, the fastening hole portion is a peripheral portion of a fastening hole provided in a disc for fastening to a member to be fastened such as a wheel by a fastening member, and when the fastening member is a bolt, the bolt is used. It is a hole, and when the fastening member is a screw, it is a screw hole. The sliding portion is an annular portion of the disk surrounded by the inner and outer circumferences of the sliding surface. When the sliding surface is divided concentrically into a plurality of annular portions, the innermost portion is the innermost portion. It refers to an annular portion surrounded by the inner periphery of the annular sliding surface located at the periphery and the outer periphery of the sliding surface located at the outermost periphery. The sliding surface is a surface where the disc and the brake lining come into contact during braking.

(B) By arranging the fastening holes so as to satisfy the following condition (a), the inner peripheral side and the outer peripheral side of the disk which is thermally expanded at the time of braking and is deformed toward the disk sliding surface side Can be restrained by the fastening member at a position close to both, so that the degree of warpage can be further suppressed. In addition, the warpage can be evenly distributed between the outer peripheral side and the inner peripheral side, and when the disc is pressed against the wheel side by the brake lining during braking, the tensile stress and the tensile stress acting on the fastening members such as the fastening holes and bolts are increased. Bending stress can be further reduced.

-0.12 ≦ r / R ≦ 0.20 (a) where, r: distance to the center of the fastening hole based on the center in the width direction of the sliding portion in the same radial direction of the brake disk ( Negative when the center of the fastening hole is located in the inner peripheral direction, and positive when it is located in the outer peripheral direction.) R: Width of the sliding portion.

Here, the width of the sliding portion is the width of the sliding portion in the radial direction of the disk, and the center in the width direction of the sliding portion is the center of the width of the sliding portion. FIG. 4 shows that r and R
(A) shows a case where r is positive, and FIG. (B) shows a case where r is negative. Also,
An alternate long and short dash line indicates an arc composed of a set of centers of the sliding portions in the width direction, and a broken line indicates an arc passing through the center of the fastening hole.

(C) After the disc and the member to be fastened are fastened in a recessed fastening mode, a lid constituting a sliding surface is attached to the fastening hole, so that the disc in the area where the bolt hole is drawn during rotation of the disc is removed. Since the sliding with the brake lining can be made continuous, the annular area drawn by the fastening hole when the disk rotates can also function sufficiently as a sliding surface, and the weight of the disk can be further reduced.

The same effect can be obtained even when the fastening member itself has the function of the lid. That is, for example, when the fastening member is a screw, the head of the screw may constitute a sliding surface when the disk and the member to be fastened are fastened.

Therefore, the lid is not limited to the lid independent of the fastening member, but is a concept that includes the fastening member when the fastening member also has a function as a lid. (D) By providing a concave portion or a convex portion that fits with the convex portion or the concave portion of the member to be fastened on the fastening surface of the disk, it is possible to disperse the stress concentration on the fastening hole portion, It is possible to suppress the occurrence of fatigue fracture and fatigue fracture of the fastening member.

Here, the member to be fastened is a member fastened to the disk by the fastening member, for example, a wheel in the case of a side disk fastened directly to a wheel, and a disk body in the case of a shaft mounted disk. When fastened through a disk, it is a disk body. However, when the fitting portion forming member is mounted on the wheel or the like and fitted with the disc, the wheel or the like includes the fitting portion forming member, and these are integrally referred to as a member to be fastened. The fastening surface is a surface facing the member to be fastened when the disk is fastened to the member to be fastened.

The present invention has been completed based on the above findings, and the gist thereof is as follows. (1) A brake disc having a fastening hole in a sliding portion defined as an annular portion of the brake disc.

(2) The brake disc according to item (1), wherein the position of the fastening hole satisfies the following condition (a). -0.12 ≦ r / R ≦ 0.20 (a) where, r: distance to the center of the fastening hole with respect to the center in the width direction of the sliding portion in the same radial direction of the brake disc (the Negative when the center is located in the inner peripheral direction, and positive when the center is located in the outer peripheral direction.) R: Width of the sliding portion.

(3) The brake disc according to the above mode (1) or (2), further comprising a lid attached to the fastening hole, wherein the lid forms a sliding surface. (4) A brake disc characterized by having a recess or a projection for fitting on a fastening surface of the brake disc.

(5) The brake disk has a concave or convex portion for fitting on the fastening surface of the brake disk.
The brake disc according to any one of the above items (3).

[0032]

FIG. 5 is a partial plan view showing a quarter of a brake disk according to an embodiment of the present invention.
In the figure, the dotted line indicates the shape of the fastening surface, reference numeral 11 indicates a concave portion that fits with the convex portion of the member to be fastened, and the same elements as those in FIG. 1 are denoted by the same reference numerals.

As shown in the drawing, a sliding portion having a sliding surface 4 is provided with a bolt hole 5 as a fastening hole. Also,
As shown by the dotted line, the fastening surface is provided with a concave portion 11 that fits with the convex portion of the member to be fastened.

FIG. 6 is a partial cross-sectional view schematically showing a cross section in a state where the brake disc shown in FIG. 5 is mounted on the wheel. FIG. 6A is a view corresponding to a cross section taken along the line BB in FIG. 5 (b) is a partial sectional view of a portion corresponding to a section taken along line CC of FIG.

As shown in FIG. 1A, the brake discs 1 and 1 are fastened to both side surfaces of the wheel 6 by bolts 7 and nuts 8 as fastening members, and are attached so as to integrally rotate together. I have. Also, as shown in FIG.
The brake discs 1 and 1 each have a concave portion 11 on a fastening surface to be fitted to the convex portion 10 of the pin 9 mounted on the wheel 6.

As described above, for example, in the conventional disk shown in FIG. 1, due to the thermal stress generated by the braking, a remarkable stress concentration occurs in the bolt holes on the inner peripheral portion of the disk, causing local plastic deformation. May occur. Further, when the disk is warped due to the thermal stress generated by the braking, it becomes difficult to obtain a stable braking characteristic, and remarkable stress is applied to the bolt holes and the bolts in the inner peripheral portion of the disk by the braking. Repeated action may lead to fatigue failure. At the time of braking, a remarkable bending stress acts on the bolt hole and the bolt in the rotation direction in order to restrain the displacement in the rotation direction.

On the other hand, in the disk of this embodiment,
As shown in FIG. 5 and FIG. 6, by providing a fastening hole in the sliding portion of the disk, it becomes possible to suppress the occurrence of warpage, so that a stable braking characteristic can be obtained at the time of braking. Fatigue failure can be suppressed by reducing the stress repeatedly applied to the fastening hole and the fastening member due to the warpage of the disk.

Here, it is desirable to arrange the fastening holes so as to satisfy the following condition (a). -0.12 ≦ r / R ≦ 0.20 (a) where, r: distance to the center of the fastening hole with respect to the center in the width direction of the sliding portion in the same radial direction of the brake disc (the Negative when the center is located in the inner peripheral direction, and positive when the center is located in the outer peripheral direction.) R: Width of the sliding portion.

By arranging the fastening holes so as to satisfy the above condition (a), both the inner circumferential side and the outer circumferential side of the disk, which are thermally expanded during braking and are likely to be deformed toward the disk sliding surface side, It can be restrained by the fastening member at a position close to both, and the degree of warpage can be further suppressed. In addition, the warpage can be evenly distributed between the outer peripheral side and the inner peripheral side, and when the disc is pressed against the wheel side by the brake lining during braking, the tensile stress and the tensile stress acting on the fastening members such as the fastening holes and bolts are increased. Bending stress can be further reduced.

Further, since the disc of the present embodiment has a concave portion 11 on the fastening surface which fits into the convex portion 10 of the pin 9 mounted on the wheel 6 as the member to be fastened, the disc can be displaced in the rotational direction during braking. Can be distributed to the periphery of the concave portion in the rotational direction, which is applied to restrain the rotation. Further, the stress applied to the fastening hole and the fastening member for restraining displacement in the radial direction due to thermal expansion can be dispersed to the periphery of the recess. As a result,
Stress concentration on the fastening hole and the fastening member can be suppressed, and fatigue fracture from the fastening hole and the fastening member can be suppressed.

FIGS. 7A and 7B show an example of a pin 9 mounted on a wheel or the like. FIG. 7A is a plan view, FIG. 7B is a front view, and FIG. 7C is a side view. FIG. 8 shows a fitting state of the pin 9 and the disk 1 shown in FIG. 7, and FIG. 8A is a sectional view of the fitting portion in the circumferential direction of the disk, and FIG.
FIG. 4 is a radial cross-sectional view of the disk with respect to the fitting portion.

The pin shown in FIGS. 5 and 8 has a disk-shaped base provided with a convex portion, and is mounted on the wheel 6 in a state where the disc 1 and the wheel 6 are fastened as shown in FIG. Convex portion 10 of pin 9 and concave portion 11 of the fastening surface of disk 1
Are fitted to each other.

Here, the height H of the convex portion of the pin and the depth D of the concave portion of the disk are preferably 5 to 25 mm when applied as a brake disk for a railway vehicle. If the height H of the protrusion of the pin or the depth D of the recess of the disc is less than 5 mm, the effect of restraining the displacement of the disc in the rotation direction when the disc warps may not be obtained. The height H of the convex portion of the pin or the depth D of the concave portion of the disk
If it exceeds 25 mm, the strength of the disc may decrease and become insufficient.

The width Wp of the convex portion of the pin and the width Wd of the concave portion of the disk are preferably set to 10 to 80 mm. If the width Wp of the convex portion of the pin or the width Wd of the concave portion of the disk is less than 10 mm, the strength of the convex portion may be insufficient, and it may not be possible to obtain a sufficient displacement restraining force. In addition, the convex portion width W of the pin
If p or the recess width Wd of the disc exceeds 80 mm, the strength of the disc may be insufficient.

The height H of the convex portion of the pin and the depth D of the concave portion of the disk are preferably the same. However, from the viewpoint of processing accuracy, a gap of 0.3 to 1.0 mm is formed at the time of fitting. It is good to The gap between the convex portion width Wp of the pin and the concave portion width Wd of the disk and the gap between the convex portion length Lp of the pin and the concave portion length Ld of the disk are determined from the viewpoint of machining accuracy, workability during fastening work, and suppression of image sticking. , 0.1-1.5
mm, more preferably 0.1 to 0.7 mm.

It is preferable that the corners of the convex portion of the pin and the concave portion of the disk are chamfered by 0.3 to 2.0 mm. Further, it is preferable that the concave portions of the disk are uniformly arranged in the circumferential direction of the disk, and the number thereof is 3 to 16.
Further, as shown in FIG. 5, it is preferable that the fastening holes and the concave portions are alternately arranged in the circumferential direction of the disk.

When fitting the pin mounted on the wheel and the disk as in this embodiment, the shape of the base of the pin can be appropriately determined. If the base is a disk,
The diameter of the base is preferably between 20 and 80 mm. 20mm
If it is less than 80 mm, the strength of the pin may be small, and if it is more than 80 mm, the strength of the wheel may be small. In the case of other shapes, it is preferable to have the same size.

FIG. 9 shows an embodiment in which a lid constituting a sliding surface is attached to a fastening hole provided in the sliding portion, and FIG.
Is a sectional view showing a state in which a lid that constitutes a sliding surface is mounted after fastening with a bolt and nut in an embedded fastening mode, and FIG. FIG. 4C is a cross-sectional view showing a state in which a lid constituting a moving surface is mounted, and FIG. 4C is a cross-sectional view showing a state in which the head is fastened with a screw having a function of a lid constituting a sliding surface.

In the example shown in FIG.
Are bolts 7 and nuts 8 as fastening members on both sides of the wheel 6.
, And a lid 12 having one surface constituting the sliding surface 4 is mounted in a fastening hole of both disks.

As shown in the figure, after the discs 1 and 1 are fastened in a recessed fastening mode, a lid 12 constituting the sliding surface 4 is attached to the fastening hole, so that a bolt hole is drawn when the disc is rotated. Since the sliding between the disc and the brake lining in the area can be continuous, the annular area drawn by the fastening hole when the disc rotates can also function sufficiently as a sliding surface. It is possible to suppress an increase in weight for securing the disk and reduce the weight of the disk.

In the example shown in FIG.
Are fixed to both sides of the wheel 6 by screws 13 serving as a fastening member in an embedded fastening manner.
Is attached to the fastening hole of one of the disks.

As shown in the drawing, after the disks 1 and 1 are fastened by screws 13 in a recessed fastening manner, a lid 12 constituting the sliding surface 4 is attached to the fastening hole.
In addition to the above-mentioned effects, the fastening operation is simplified and the workability is improved.

In the example shown in FIG.
Are fastened to both sides of the wheel 6 by screws 13 serving as fastening members, and the heads of the screws 13 constitute the sliding surface 4.

As shown in the figure, by fastening the disks 1 and 1 with the screws 13 whose heads constitute the sliding surface 4, the fastening operation is further simplified and the workability is improved. In the present embodiment, a concave portion is provided on the fastening surface of the sliding portion for a conventional disc having no portion corresponding to the inner peripheral portion. However, the present invention is not limited to this, and FIG. In a conventional disk as shown, a concave portion may be provided on the fastening surface of the inner peripheral portion, or may be provided over both the outer peripheral portion and the inner peripheral portion or independently of each other.

Further, in this embodiment, the concave portion for fitting to the convex portion of the member to be fastened is provided on the fastening surface of the disk. However, the concave portion is provided for the member to be fastened, and the convex portion for fitting to the concave portion is provided for the disk. It may be provided on the fastening surface.

In this embodiment, the projection of the pin mounted on the wheel and the recess of the fastening surface of the disk are fitted. However, the projection or recess is provided on the wheel itself, and the projection or recess is fitted to the wheel. Recesses or projections that fit together may be provided on the fastening surface of the disc. Alternatively, a key groove may be provided in the disk and the wheel, and the key groove, which is a concave portion of the disk, may be fitted to a key fitted in the key groove of the wheel.

Further, in this embodiment, the concave portion which fits into the convex portion of the member to be fastened is provided on the fastening surface of the disk so as to restrain the rotational and radial displacement of the disk. Only one of the displacement in the rotation direction and the radius direction may be restricted. It is preferable to restrict the displacement in the rotation direction and the radial direction of the disk as in the present embodiment, since the stress concentration on the fastening holes and the fastening members can be more dispersed.

Further, in this embodiment, only the fastening holes and the recesses of the fastening surfaces of the disc are increased in thickness, but the entire disc may be made uniform in thickness. It is preferable to increase the thickness of only the fastening holes and the recesses of the fastening surface as in the present embodiment, because the disk can be further reduced in weight.

Further, in this embodiment, a disk having a fastening hole in the sliding portion of the disk and a concave portion for fitting in the fastening surface of the disk has been described as an example. It may be. As in this embodiment,
Having a fastening hole in the sliding portion of the disk, and having a recess or projection for fitting on the fastening surface suppresses the generation of stress acting on the fastening hole and the fastening member, and This is preferable because stress concentration on the portion and the fastening member can be dispersed.

Further, in this embodiment, a brake disc for a railway vehicle has been described as an example. However, the present invention is not limited to this, and is also applicable to a mechanical braking device such as an automobile and a motorcycle.

[0061]

EXAMPLES (Example 1) In order to confirm the effects of the present invention,
Using forged steel materials currently used for Shinkansen, five types of discs with different shapes were manufactured and brake tests were performed.

Table 1 shows the shapes of the disks subjected to the test. The test materials 1 to 3 also show the shapes of the pins that form the projections that fit into the recesses on the fastening surface of the disk when the disk is fastened to the wheel.

[0063]

[Table 1]

Test materials 1 to 3 are disks having the shape shown in FIG. 5, and test material 4 is a disk having the conventional shape shown in FIG. The test material 5 is disclosed in Japanese Unexamined Patent Publication No. 10-31830.
No. 4 discloses a disk comprising an outer ring and an inner ring, and the inner diameter of the outer ring was 450 mm. The mass of the test materials 1 to 3 was about 45 kg, and the mass of the test materials 4 and 5 was about 60 kg.

The pins have the shape shown in FIG.
The diameter of the base disk was 50 mm. For the five types of discs shown in Table 1, using a wheel tester modeled on a bogie of the JR Shinkansen, a set of two discs was mounted on both sides of the wheel with the sliding surface outside, and a brake test was performed. . As the brake lining material, a copper-based sintered alloy is used, and the initial speed is 100 km / h to 2.5 km / (h ·
This was performed under the condition of constant deceleration in s). At this time, the temperature of the test materials 1 to 3 rose to about 110 ° C., and the test materials 4 and 5
Increased to about 100 ° C. Thereafter, the disk was allowed to cool, and when the disk temperature dropped to 60 ° C., the wheels were driven again, and the brake test was performed again under the above conditions. This step was repeated 100 times.

Table 2 shows the friction coefficient in the 90th to 100th brakes, the stress applied to each fastening bolt (hereinafter also referred to as bolt load stress), and the amount of warpage after the brake test. Here, the amount of warpage means the maximum distance between the sliding surface after the brake test and the reference surface, when the sliding surface of the disk before the brake test is used as the reference surface.

[0067]

[Table 2]

Here, the fluctuation range of the friction coefficient is the fluctuation range of the friction coefficient during braking, and the smaller this value is, the more stable braking characteristics can be obtained and the more excellent the braking performance is. . In addition, the fluctuation range of the bolt load stress is the fluctuation range of the stress applied to the bolt during braking, and the smaller the value is, the smaller the repeated stress applied to the fastening hole and the fastening member is, and the fatigue fracture resistance is reduced. Means better.

As shown in Table 2, in Test Material 4, warping was caused by thermal stress due to braking, so that the range of fluctuation in bolt load stress was large. Further, in the test material 5, since the outer ring and the inner ring are fitted with a margin in the radial direction of the disk, the thermal stress generated in the outer ring is absorbed by the fitting portion, and the test material 4 No large warpage was observed. However, since the outer ring and the inner ring are fitted, the fluctuation range of the friction coefficient and the fluctuation range of the bolt load stress are large. Further, although the average value of the bolt load stress could be slightly reduced, it was not much different from that of the test material 4 which was a disk having a conventional shape.

On the other hand, since the test materials 1 to 3 were fastened to the wheels at the sliding portions, the degree of warpage was smaller than that of the test material 5 and was good. Further, since the concave portion of the fastening surface of the disc and the convex portion of the pin mounted on the wheel are fitted to restrain the displacement in the rotation direction and the radial direction, the number of bolts is half that of the test materials 4 and 5. However, the fluctuation value of the bolt load stress was smaller than that of the test materials 4 and 5 and was good.

(Example 2) Next, a brake test was carried out using the test materials 1 to 3 at an initial speed of 300 km / h. The brake test conditions were equivalent to those of an emergency brake. The temperature of the test material after braking was 600 ° C.

Table 3 shows the friction coefficient and the bolt load stress in the 90th to 100th brakes.

[0073]

[Table 3]

As shown in Table 3, the friction characteristics of the test materials 1 to 3 were almost the same, but the width of the concave portion of the test material 2 was 10 m.
m, the strength of the protrusion of the pin was low, and the deformation of the protrusion reduced the binding force of the disk.
The variation width of the bolt load stress of the test material 1 was larger.
Further, in the test material 3, the depth of the concave portion was as small as less than 5 mm, and the disc binding force by the fitting portion was small.
Was larger than the fluctuation range of the bolt load stress of Test material 1
Since the shape of the fitting portion was within the suitable range, the fluctuation width of the bolt load stress was small and a more preferable value.

(Example 3) Next, using the disk of the test material 1 as a fin formed on the wheel with a convex portion that fits into the concave portion of the fastening surface of the disk, and a sliding surface in the bolt hole Brake tests were performed for the case where the constituent lid was attached. The brake test conditions were the same as in Example 2. The shape of the fin was the same as the shape of the projection of the pin. After the lid is made of the same material as the disk and fastened with bolts and nuts, the lid is screwed into the bolt holes so that it is at the same level as the sliding surface of the disk, as shown in FIG. It was a form.

Table 4 shows the friction coefficient and the bolt load stress in the 90th to 100th brakes, and the presence or absence of the protrusion forming member and the lid.

[0077]

[Table 4]

As shown in Table 4, in Test No. B, since the fins formed directly on the wheel fit into the recesses on the fastening surface of the disk, the fluctuation range of the bolt load stress was smaller than in Test No. A. . In test number C,
By attaching the lid that constitutes the sliding surface to the bolt hole,
The disc and the brake lining slide continuously in the area where the bolt hole is drawn when the disc is rotating, and the annular area where the fastening hole is drawn when the disc is rotated is made to function sufficiently as a sliding surface. The average value of the friction coefficient was large, and the fluctuation range of the friction coefficient was small.

(Example 4) Next, three types of disks having different shapes were manufactured by sand casting using an Al-based composite material, and a brake test was performed.

Table 5 shows the shapes of the disks subjected to the test. As for the test material 6, the shape of a pin forming a convex portion that fits into a concave portion of the fastening surface of the disk when the disk is fastened to the wheel is also shown.

[0081]

[Table 5]

The test material 6 is a disk having the shape shown in FIG. 5, and the test material 7 is a disk having the conventional shape shown in FIG. The test material 8 was a disk having an outer ring and an inner ring described in JP-A-10-318304, and the inner diameter of the outer ring was 450 mm. In the test material 8, an Al-based composite material was used only for the outer ring, and a forged steel material was used for the inner ring.

The pins have the shape shown in FIG.
The diameter of the base disk was 50 mm. The brake test conditions were the same as those in Example 2, and if a crack occurred from the bolt hole during the test, the test was stopped there.

Table 6 shows the friction coefficient and the bolt load stress in the 90th to 100th brakes.

[0085]

[Table 6]

As shown in Table 6, since the test material 7 does not have a bolt hole in the sliding portion, stress concentrates on the bolt hole, and a crack occurs from the bolt hole at the fourth brake load. did.

In the test material 8, since the outer ring and the inner ring are fitted with a margin in the radial direction of the disk, the thermal stress generated in the outer ring is absorbed by the fitting portion, No large warpage was observed in No. 4, and no crack was generated from the bolt hole even after 100 times of braking load. However, since the outer ring and the inner ring are fitted, the fluctuation range of the friction coefficient and the fluctuation range of the bolt load stress are large.

Since the test material 6 is fastened to the wheel at the sliding portion, the large warpage observed in the test material 4 does not occur, and
No crack was generated from the bolt hole even when the brake load was applied 0 times. Further, since the concave portion of the fastening surface of the disc and the convex portion of the pin mounted on the wheel are fitted to restrain the displacement in the rotation direction and the radial direction, the number of bolts is half of the test material 8, The variation width of the coefficient of friction and the variation width of the bolt load stress were smaller and better than those of the test material 8.

Example 5 Next, the relationship between the position of the bolt hole and the amount of warpage was determined by FEM analysis. FIG.
It is explanatory drawing which shows the finite element division method performed in M analysis.

As shown in the figure, in the FEM analysis of the present example, it is assumed that a brake is applied to a disk fastened with 12 bolts evenly in the circumferential direction, and the symmetry of the disk is taken into consideration. 1/2 from the position passing through the center of the bolt hole to the intermediate position between the bolt hole and the adjacent bolt hole.
A finite element division was performed on a portion of 4 (a range of 15 ° as a central angle). Here, the points A and B correspond to the inner peripheral portion and the outer peripheral portion in the radial direction passing through the center of the bolt hole, respectively. The points C and D correspond to the inner and outer peripheral portions in the radial direction passing through the center of the bolt hole and forming a central angle of 15 ° with the radial direction, respectively.

Assuming that the sliding surface width is 134 mm and the braking conditions are equivalent to the emergency braking from 300 km / h, points A to D after cooling to room temperature by repeatedly applying the brake three times (see FIG. 10) The amount of warpage of each part was determined. Here, the amount of warpage of each part indicates a distance from the sliding surface of the disk before the brake load as a reference surface to points A to D after the brake load, with the sliding surface side being positive.
Under the brake conditions of this example, the disc stopped 90 seconds after the brake load. The maximum temperature of the disk in this example was about 630 ° C. For each finite element, the material constant of a forged steel material currently used for Shinkansen was used.

FIG. 11 is a graph showing the relationship between the amount of warpage of each part determined by FEM analysis and the position of a bolt hole.
As shown in the figure, when the position of the bolt hole is located on the inner peripheral side of the center position of the sliding surface width, the amount of warp at points C and D, which are the outer peripheral portions, increases, and the position of the bolt hole is increased. Is located on the outer peripheral side of the center position of the sliding surface width, the amount of warpage at points A and B, which are the inner peripheral parts, tends to increase.

When the position of the bolt hole is within the range satisfying the following (a), the warpage at each of the points A to D is less than 0.012 mm, and the occurrence of warpage can be effectively suppressed. Was confirmed.

-0.12 ≦ r / R ≦ 0.20 (a)

[0095]

According to the present invention, it is possible to reduce the stress applied to the fastening holes and the fastening members of the disc by suppressing the occurrence of the warpage of the disc due to the thermal stress caused by the braking. Therefore, the life of the disk and the fastening member can be extended.

Also, by restricting the displacement of the disk at a portion other than the fastening portion, it is possible to disperse the stress applied to the fastening hole portion and the fastening member of the disk. Fatigue failure of the member can be suppressed, and the life of the disk and the fastening member can be extended.

[Brief description of the drawings]

FIG. 1 is a view showing a shape of a conventional railway vehicle brake disc, FIG. 1 (a) is a partial plan view showing a quarter of a railway vehicle brake disk, and FIG. ,
FIG. 2 is a partial sectional view showing an AA section in FIG.

FIG. 2 is a cross-sectional view schematically showing a state in which a conventional railway vehicle side brake disc is mounted on wheels.

FIG. 3 is a cross-sectional view schematically illustrating a state of a disk in which warpage has occurred, in which a broken line indicates a state of the disk when no brake is applied;
The solid line shows the state of the disc during braking.

FIG. 4 is an explanatory diagram showing definitions of r and R, and FIG.
4A shows a case where r is positive, and FIG. 4B shows a case where r is negative.

FIG. 5 is a partial plan view showing a quarter of a brake disk according to an embodiment of the present invention.

6 is a partial cross-sectional view schematically showing a cross section in a state where the brake disc shown in FIG. 5 is attached to a wheel.
FIG. 6A is a partial cross-sectional view of a portion corresponding to a BB cross section in FIG. 5, and FIG. 6B is a partial cross-sectional view of a portion corresponding to a CC cross section in FIG.

FIG. 7 is a diagram showing an example of a pin mounted on a wheel or the like;
7A is a plan view, FIG. 7B is a front view, and FIG.
Is a side view.

8 is a sectional view showing a fitting state between the pin and the disk shown in FIG. 7, FIG. 8 (a) is a circumferential sectional view of the disk about a fitting portion, and FIG. 8 (b) is FIG. 4 is a radial cross-sectional view of the disc with respect to the fitting portion.

FIG. 9 is a cross-sectional view showing an embodiment in which a lid constituting a sliding surface is attached to a fastening hole provided in a sliding portion, and FIG.
FIG. 9B is a cross-sectional view showing a state in which a lid constituting a sliding surface is attached after fastening with a bolt and nut in an embedded fastening mode, and FIG. FIG. 9C is a cross-sectional view illustrating a state in which a lid that forms a moving surface is mounted, and FIG. 9C is a cross-sectional view illustrating a state in which the head is fastened with a screw that also has a function of a lid that forms a sliding surface.

FIG. 10 is an explanatory diagram showing a finite element division method performed in FEM analysis.

FIG. 11 is a graph showing the relationship between the amount of warpage of each part determined by FEM analysis and the position of a bolt hole.

[Explanation of symbols]

 1: brake disc 2: outer peripheral part 3: inner peripheral part 4: sliding surface 5: bolt hole 6: wheel 7: bolt 8: nut 9: pin 10: convex part 11: concave part 12: lid 13: screw

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuhisa Misawa 5-1-1109 Shimaya, Konohana-ku, Osaka-shi, Osaka Sumitomo Metal Industries, Ltd. Kansai Works Steelmaking Products Office (72) Inventor Taizo Makino, Osaka-shi, Osaka 4-5-33 Kitahama, Chuo-ku Sumitomo Metal Industries Co., Ltd. F-term (reference) 3J058 AA44 AA47 AA53 AA58 BA32 CB12 CB14 CB22 CB24 CB27 FA21

Claims (5)

[Claims] 1. A brake disc having a fastening hole in a sliding portion defined as an annular portion of the brake disc. 2. The brake disc according to claim 1, wherein the position of the fastening hole satisfies the following condition (a). -0.12 ≦ r / R ≦ 0.20 (a) where, r: distance to the center of the fastening hole with respect to the center in the width direction of the sliding portion in the same radial direction of the brake disc (the Negative when the center is located in the inner peripheral direction, and positive when the center is located in the outer peripheral direction.) R: Width of the sliding portion. 3. The brake disc according to claim 1, further comprising a lid attached to the fastening hole, wherein the lid forms a sliding surface. 4. A brake disc having a recess or a projection for fitting on a fastening surface of the brake disc. 5. The brake disk according to claim 1, further comprising a concave portion or a convex portion for fitting on a fastening surface of the brake disk.