JP4677982B2 - Brake disc for railway vehicle and its fastening structure - Google Patents

Description

  The present invention is a brake disk that is mainly bolted on a sliding surface, and is excellent in strength reliability of the fastening bolt, and can reduce the impact load generated on a brake lining that contacts the sliding surface as much as possible, and can be used for a long time. The present invention relates to a brake disc for a railway vehicle that can withstand, and a fastening structure thereof.

  Block brakes, drum brakes, disk brakes, and the like are used as braking devices for land transportation machines such as railway vehicles, automobiles, and motorcycles. In recent years, disk brakes have been frequently used with the increase in speed and size of vehicles.

  A disc brake is a device that obtains a braking force by friction between a brake disc and a brake lining. Normally, a vehicle is obtained by applying a braking force by pressing a brake lining against a sliding surface of a donut-shaped disk-shaped disc attached to an axle via a wheel or a disc body with a bolt, and braking the rotation of the axle or the wheel. To control the speed. The disc-shaped disc having this sliding surface is called a brake disc.

  Among these brake discs, railcar brake discs include a side disc and a shaft mount disc. Among these, the side disc is a brake disc fastened to the side surface of the wheel, and the shaft mount disc is a brake disc fastened to the axle via a disc body. Hereinafter, in this specification, the term “brake disk” refers to both the side disk and the shaft mount disk.

  10A and 10B show a conventional rail car side disk, FIG. 10A is a radial-circumferential plan view showing a quarter of a brake disk, and FIG. 10B is a cross-sectional view taken along line AA in FIG. It is (radial direction-axial direction sectional drawing).

  As shown in FIG. 10, in general, the brake disc 1 includes a sliding portion 1b having a sliding surface 1ba on one (front surface) side and a fastening portion 1a having a fastening hole 1aa for fastening to a wheel. It is configured. A fin 1c is provided on the other side (back side) of the sliding surface 1ba of the brake disc 1.

FIG. 11 is a radial-axial cross-sectional view schematically showing a state in which a conventional railway vehicle brake disc is attached to a wheel.
As shown in FIG. 11, the brake disc 1 is attached to both side surfaces of the plate portion 2 a of the wheel 2 so as to be integrally rotatable by fastening bolts 3 and nuts 4. Moreover, the brake lining 5 is attached to the position facing these sliding surfaces 1ba, respectively so that the movement to a sliding surface direction is possible.

  At the time of braking, the brake lining 5 moves toward the brake disc 1 and is strongly pinched from both side surfaces of the wheel 2, and this frictional force brakes the rotation of the axle via the wheel 2 to stop the vehicle. In addition, 2b in FIG. 11 shows the fastening hole of the brake disc 1 provided in the plate part 2a of the wheel 2, and 6 shows a plain washer.

  By the way, in a high-speed railway vehicle such as the Shinkansen, the rotational speed and inertial force of the brake disk are very large, so that the temperature increase of the brake disk during braking is significantly increased. Therefore, there are problems such as thermal deformation of the brake disk and generation of significant stress on the fastening bolt.

Among these, as a technique for suppressing thermal deformation of the brake disc, Patent Literature 1 discloses a brake disc that is fastened to a wheel at a sliding portion.
JP 2001-311441 A

FIG. 12 is a radial-axial sectional view showing a fastening state with a wheel of a representative brake disc fastened with a wheel at a sliding portion disclosed in Patent Document 1.
As shown in FIG. 12, the brake disc 1 is fastened to the wheel 2 by inserting a fastening bolt 3 into a fastening hole 1bb provided in the sliding portion 1b. The deformation in the direction is suppressed, and thermal deformation can be reduced as compared with the conventional brake disc.

  However, in the fastening method disclosed in Patent Document 1, since the thermal expansion of the brake disk is directly applied to the fastening bolt, the stress fluctuation of the fastening bolt generated by one braking operation is larger than that of the conventional brake disk. Rather it gets bigger. Therefore, the fatigue life of the fastening bolt must be assumed to be short.

  In the above brake disc that is fastened to the wheel at the sliding portion, as a technique for reducing the stress generated by the fastening bolt and ensuring safety against fatigue failure, the bearing surface of the large diameter portion 1bba of the fastening hole 1bb shown in FIG. It is conceivable that a disc spring is interposed between the head load bearing surfaces of the fastening bolt 3. The effect is that, when the object to be tightened is deformed, the dynamic load acting on the fastening bolt does not increase because the disc spring absorbs the deformation.

  However, when a disc spring is interposed, the size of the large-diameter portion of the fastening hole provided in the sliding portion must be larger than the outer diameter of the disc spring larger than the head of the fastening bolt. When a fastening hole (large diameter part) of such a size is provided, an impact load is generated when the brake lining that contacts the sliding surface passes over the fastening hole, and the brake lining is chipped or cracked. This causes a new problem that stable friction characteristics cannot be obtained.

In particular, as can be seen in Patent Document 2, this problem becomes important when the brake lining is formed of a large number of lining members.
Japanese National Patent Publication No. 10-507250

  To solve this problem, the size of the head of the fastening bolt and the disc spring must be reduced. However, reducing the size of the head of the fastening bolt and the disc spring reduces the screw diameter of the fastening bolt. Since it is made small, the load which arises in a fastening bolt increases and it becomes impossible to ensure the fatigue safety of a fastening bolt.

  The problem to be solved by the present invention is that, in a conventional brake disc that is bolted at a sliding portion, when a disc spring is used to reduce the stress fluctuation of the fastening bolt during braking, stable friction characteristics are obtained. If it is going to obtain, it is a point which cannot ensure the fatigue safety of a fastening bolt.

  The inventors have conducted numerical analysis assuming a braking load on a brake disk for railcars, in particular, a brake disk that is bolted at a sliding portion, and obtained the following knowledge as a result of repeated research.

(A) The stress generated in the brake lining due to the impact load when the brake lining passes through the fastening hole that opens in the sliding surface is generated when a part of the friction material block of the brake lining falls into the fastening hole. This sagging amount becomes smaller as the diameter of the fastening hole that opens in the sliding surface becomes smaller, thereby reducing the stress generated in the brake lining. Therefore, in order to suppress chipping and cracking of the brake lining and obtain stable friction characteristics, it is necessary to make the diameter of the fastening hole opened in the sliding surface as small as possible.

(B) In order to reduce the diameter of the fastening hole that opens in the sliding surface, if the head dimension of the fastening bolt or the outer diameter of the disc spring is reduced, the screw diameter of the fastening bolt naturally becomes smaller and is generated in the fastening bolt. Stress increases, and it becomes impossible to ensure the fatigue safety of the fastening bolt.

(C) If the diameter of the fastening hole that opens on the sliding surface is reduced without changing the screw diameter of the fastening bolt or the outside diameter of the disc spring, the disc spring, fastening bolt, and nut are inserted from the sliding surface. Can not be. For this reason, a hole with a minimum diameter necessary for fastening the fastening bolt is formed on the sliding surface, and the bolt seat provided on the fin surface side opposite to the sliding surface is connected to the plate from the fin surface side. The shape which provided the horizontal hole which can insert fastening components, such as a spring, a fastening bolt, and a nut, in the circumference direction of a brake disc was considered. With such a shape, the diameter of the fastening hole opened in the sliding surface can be greatly reduced without reducing the screw diameter of the fastening bolt.

  The brake disc for a railway vehicle according to the present invention is made based on the above knowledge obtained by the numerical analysis and research by the inventors. Particularly, the fastening bolt for the rail vehicle brake disc that is bolted at the sliding portion. The purpose is to obtain a stable friction characteristic by suppressing breakage and cracking of the brake lining while ensuring the reliability of the strength.

That is, the brake disk for railway vehicles of the present invention is
A brake disc for a railway vehicle that is bolted at a sliding portion to a disc body attached to a wheel or an axle,
The fastening hole provided in the sliding part is
1) On the insertion side of the fastening bolt head,
A vertical hole provided in the sliding portion from the side opposite to the sliding surface of the sliding portion;
A horizontal hole provided to communicate with the vertical hole in the sliding portion;
The sliding surface side and the vertical hole are provided so as to pass through, and a fastening bolt tightening hole is configured.
The vertical hole is capable of penetrating the screw shaft portion of the fastening bolt and has an inner diameter that is impossible to penetrate the head,
Further, the lateral hole has a size that allows the head of the fastening bolt to be inserted and is open on the side opposite to the sliding surface.
2) On the nut insertion side,
A vertical hole provided in the sliding portion from the side opposite to the sliding surface of the sliding portion;
It is composed of this vertical hole and a horizontal hole provided so as to communicate within the sliding portion,
The vertical hole is capable of penetrating the screw shaft of the fastening bolt, and has an inner diameter that is impossible to penetrate the nut;
In addition, the lateral hole has a size into which the nut can be inserted and is open to the side opposite to the sliding surface, and a rotation blocking portion for blocking the rotation of the nut is formed.
The most important feature.

  Further, the fastening structure of the brake disc for a railway vehicle according to the present invention is a fastening bolt in such a manner that the disc disc attached to the wheel or the axle is sandwiched between the brake disc having the configuration 1) and the brake disc having the configuration 2). The main feature is that it is fastened with a nut.

  In the present invention, since the hole opening in the sliding surface can be made small without reducing the screw diameter of the fastening bolt, it is possible to suppress breakage and cracking of the brake lining while ensuring the strength reliability of the fastening bolt, and stable friction characteristics. There is an advantage that can be obtained.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to FIGS. 1 to 9 along with the progress from the idea of the present invention to the solution of the problem.

a) Regarding the stress generated in the brake lining when passing through the fastening hole that opens in the sliding surface The inventors have applied the brake to the fastening hole that opens in the sliding surface by the impact load when the brake lining passes through. In order to evaluate the stress generated in the lining, numerical analysis by a finite element method (FEM) was performed using the model shown in FIG.

  The model used is from a disk 10 having a plate material corresponding to a sliding portion provided with a chamfer 10b of 3 mm around a hole 10a having a diameter of 36 mm, and a columnar block 11 having a diameter of 40 mm corresponding to a friction material of a brake lining. It has become.

  The block 11 was pressed against the disk 10 with a load of 10 kN and slid in the horizontal direction with respect to the contact surface. FIG. 2A shows a change in stress acting on the base portion 11a of the block 11 in this case.

  From the results shown in FIG. 2A, it can be seen that a high stress is generated in the base portion 11a of the block 11 at the following two points, and then the stress decreases when slipping occurs.

The point immediately before the block 11 falls into the hole 10a of the disk 10 (FIG. 2 (b)) and begins to slide on the chamfer 10b of the hole 10a (between FIG. 2 (c) and FIG. 2 (d)).
A point immediately before riding on the sliding surface (immediately before FIG. 2 (e)).

  Therefore, it can be seen that in order to reduce the stress generated in the block 11, the inner diameter of the hole 10a including the chamfer 10b may be made smaller than the outer diameter of the block 11.

  However, even if the inner diameter of the hole 10a including the chamfer 10b is smaller than the outer diameter of the block 11, as shown in FIG. 3, due to the elastic deformation of the block 11, the front corner 11b of the block 11 is chamfered in the hole 10a. It may fall into 10b and stress may occur.

  Therefore, in order to reduce the stress generated in the block 11, it is effective to make the inner diameter of the hole 10a as small as possible and to reduce the amount of drop into the hole 10a due to elastic deformation of the block 11.

b) Relation between the screw diameter of the fastening bolt and the generated stress Based on the results of the study in a) above, the screw diameter of the fastening bolt and the outer diameter of the disc spring should be reduced in order to reduce the fastening hole provided in the sliding part. It was investigated.

  First, an FEM analysis assuming a thermal load during braking was performed on the basic shape model shown in FIG. This model is the same as the model in which the brake disc 1 having a fastening hole 1bb penetrating the sliding portion 1b in the sliding portion 1b is modeled only for 15 ° in consideration of the symmetry. The plate 2a of the wheel 2 which is modeled only for 15 ° by 2, the fastening bolt 3 and the nut 4 are integrated, and only the axial direction 1/2 and the circumferential direction 1/2 are modeled, and a disc spring It consists of seven. At this time, the outer diameter of the thread portion of the fastening bolt 3 is assumed to be 18 mm, and the outer diameter of the disc spring 7 is 34 mm.

  Using the model shown in FIG. 4, FEM analysis was performed under conditions corresponding to a complete stop from the initial speed of 360 km / h. As a result, the values shown in Table 1 below were obtained as the stress generated in the fastening bolt 3.

  In Table 1, the stress described as the trunk is the maximum principal stress on the inner peripheral surface and the outer peripheral surface at the position corresponding to the center position in the plate thickness direction of the wheel in the trunk of the fastening bolt (in the case of this FEM analysis) The axial stress). The tensile stress is an average value on the inner peripheral side and the outer peripheral side, and indicates the fluctuation range during braking. On the other hand, the bending stress is half the stress difference between the inner peripheral side and the outer peripheral side, and shows the fluctuation range during braking as in the case of tensile stress.

  In addition, the stress described as the thread part is the tensile stress and bending stress for fine threads with an outer diameter of 18 mm, using the ratio of the effective cross-sectional area defined in JIS B 1082 and the section modulus obtained from this. Is obtained from the stress of the trunk.

  Next, the stress when the outer diameter of the screw was reduced was estimated. This estimation was made for fine screws with an outer diameter of 18 mm based on the tensile stress and bending stress of the trunk in Table 1, and using the same method as in Table 1, fine screws with an outer diameter of 16 mm, 14 mm, and 12 mm. The stress was calculated for. The results are shown in Table 2 below.

  It can be seen from Table 2 that, as a matter of course, when the outer diameter of the screw is reduced, the stress generated in the screw portion is significantly increased. The stress values listed in Table 2 were obtained on the premise that the shape of the disc spring does not change. The outer diameter of the screw is reduced and further reduced to the outer diameter of the disc spring to reduce the fastening hole. If it tries to do so, the spring rigidity of the disc spring will increase, and the stress generated in the fastening bolt is expected to be larger than the values listed in Table 2.

  From the above, if the screw outer diameter of the fastening bolt or the outer diameter of the disc spring is simply reduced in order to reduce the fastening hole, the stress generated in the fastening bolt increases and the fatigue safety of the fastening bolt can be ensured. I understand that I can't.

c) Shape for reducing the diameter of the fastening hole opened in the sliding surface As shown in FIG. 5, the fastening hole 3 opens to the sliding surface 1ba without changing the outer diameter of the screw or the disc spring 7. If the inner diameter d1 of the hole is reduced, the disc spring 7, the fastening bolt 3 and the nut 4 cannot be inserted and fastened from the sliding surface 1ba side.

  Therefore, as shown in FIG. 6, the screw shaft portion of the fastening bolt 3 can be penetrated into the sliding portion 1b from the fin surface 1ca opposite to the sliding surface 1ba of the sliding portion 1b. The head is provided with a vertical hole 1bbb whose diameter cannot be penetrated. In addition, when a hexagon socket head bolt is used as the minimum inner diameter d2 required for rotating the fastening bolt 3 so as to pass through the sliding surface 1ba and the vertical hole 1bbb, the maximum diameter of the hexagon socket is used. A tightening hole 1bbc with an inner diameter of is provided.

  A lateral hole 1bbd into which the disc spring 7 and the fastening bolt 3 can be inserted is provided in the circumferential direction of the brake disk 1 in the sliding portion 1b so as to communicate with the vertical hole 1bbb and open to the fin surface 1ca. Thought.

  A connecting portion 1bbf for moving the screw shaft portion of the fastening bolt 3 so as to penetrate through the vertical hole 1bbb is provided from the opening portion 1bbe to the fin surface 1ca of the horizontal hole 1bbd to the vertical hole 1bbb.

  In the shape shown in FIG. 6, when a hexagon socket head bolt is used as the fastening bolt 3, as described above, the inner diameter d2 of the fastening hole 1bbc of the fastening bolt 3 that opens to the sliding surface 1ba is the maximum of the hexagon socket. The diameter can be reduced.

  Therefore, based on the basic shape of FIG. 4 examined in b) above, if the outer diameter of the fastening bolt 3 is 18 mm and the outer diameter of the disc spring 7 is 36 mm, a fastening hole 1bb having an inner diameter of 38 mm is conventionally provided. On the other hand, in the shape of the present invention, the inner diameter of the tightening hole 1bbc can be reduced to about 17 mm, which is slightly larger than the outer diameter (16.3 mm) of the hexagonal hole defined in JIS B 1176.

  Further, on the nut 4 side, as shown in FIG. 7D, the dimension L of the horizontal hole 1bbd is set to be approximately the same as the width of the opposite side portion of the nut 4, and the rotation of the nut 4 is prevented while the nut 4 is inserted. Like to do. In this way, when the fastening bolt 3 is rotated and tightened, there is no need to open a hole for inserting a jig for preventing the rotation of the nut 4 in the sliding surface 1ba. Furthermore, in the shape of the present invention, even if an unexpected excessive load is generated and the fastening bolt 3 is broken, the broken portion does not come off in the axial direction, so that there is an effect of suppressing the drop.

  In order to confirm the effect of the present invention, in order to compare the bolt generated stress of the present invention product with the analysis result of Table 2 which is the bolt generated stress of the conventional product performed previously, the shape of FIG. Based on this, a model shown in FIG. 8 was created.

  The model shown in FIG. 8 is the same as the model in which the brake disk 1 having the above-described fastening hole provided in the sliding portion 1b is modeled only for 30 ° in consideration of the symmetry thereof, and the axial direction 1/2. The plate portion 2a of the wheel 2 modeled only for 30 °, the fastening bolt 3 and the nut 4 are integrated to model only the axial direction 1/2 and the circumferential direction 1/2, and the disc spring 7 It is made up of.

  This is basically a shape obtained by doubling the conventional model of FIG. 4 in the circumferential direction, but the diameter of the tightening hole 1bbc opening in the sliding surface 1ba of the brake disc 1 is as small as 18.5 mm. A difference is that a bolt hole 1d provided on the opposite side of the sliding portion 1b is provided with a horizontal hole 1bbd into which the disc spring 7, the fastening bolt 3, and the nut 4 are inserted in the circumferential direction of the brake disc 1.

  Using the model shown in FIG. 8 which is the product of the present invention, FEM analysis was performed under the conditions corresponding to the time from the initial speed of 360 km / h to complete stop, as in the conventional product. As a result, the values shown in Table 3 below were obtained as the stress generated in the fastening bolt. The stress in Table 3 was obtained by the same method as that of the conventional product. However, since the product of the present invention is asymmetrical in the circumferential direction, it was obtained from the stress on the inner peripheral side and the outer peripheral side obtained by the conventional product. In addition to radial bending stress, circumferential bending stress is also generated. This is obtained as a half of the stress difference between both sides of the fastening bolt in the circumferential direction.

  Next, the results of the present invention product shown in Table 3 and the results of the conventional product shown in Table 2 are combined, and the stress value obtained by adding the tensile stress and bending stress, the screw outer diameter, and the inner diameter of the fastening hole are compared. It is shown in Table 4 below. Here, the bending stress used for calculation of the stress value of the product of the present invention was the larger bending stress in the circumferential direction.

  The fastening hole inner diameter of the conventional product was calculated on the assumption that the ratio of the screw outer diameter of 18 mm and the fastening hole inner diameter of 36 mm in the shape shown in FIG. FIG. 9 shows the relationship between the stress generated in the threaded portion of the fastening bolt described in Table 4 below and the inside diameter of the fastening hole. From this, it can be seen that the fastening hole can be made smaller in the product of the present invention without increasing the stress generated in the threaded portion of the fastening bolt as compared with the conventional product.

  From the above, it was concluded that by adopting the shape of the present invention, the strength reliability of the fastening bolt 3 was ensured, and the chipping and cracking of the brake lining were suppressed, and a stable friction characteristic was obtained.

  The brake disc shape shown in FIGS. 6 and 7 is based on the technique of the present invention obtained from the above examination results. In the shape shown in FIGS. 6 and 7, a lateral hole 1 bbd into which the fastening bolt 3, the disc spring 7, and the nut 4 are inserted is provided in the circumferential direction of the brake disc 1. However, the direction of the horizontal hole 1bbd does not necessarily have to be the circumferential direction, and the lateral hole 1bbd may be inclined to the inner circumferential side or the outer circumferential side of the brake disc 1 with respect to the circumferential direction.

  Further, the brake disc shown in FIG. 6 and the brake disc shown in FIG. 7 are fastened by using the fastening bolt 3 and the nut 4 in a manner of sandwiching the wheel 2, for example, as shown in FIG. It is the fastening structure of the brake disk for railway vehicles of this invention.

  The present invention is not limited to the above example, and it goes without saying that the embodiments may be changed as appropriate within the scope of the technical idea described in each claim.

  For example, the technology of the present invention has been confirmed to be effective by FEM analysis assuming that the brake disc is a steel material, but the same effect can be obtained even if the brake disc is made of other materials such as aluminum other than the steel material. .

  Moreover, the effectiveness was confirmed by FEM analysis when a disc spring was used as a fastening part. However, even when there is no disc spring or when a component having an alternative function of the disc spring is used, the technique of the present invention is used. By using the same, relatively similar effects can be obtained.

  Furthermore, the technology of the present invention attaches not only the wheel-side disc type in which two brake discs are attached to both sides of the wheel plate portion shown in FIG. 6, but also two discs to the disc body press-fitted into the axle. It can also be applied to shaft mount type brake discs.

  Further, if the inner diameter of the vertical hole is smaller than the head of the fastening bolt and has a horizontal hole communicating with the vertical hole in the sliding portion, the head has a normal hexagonal shape instead of the hexagon socket head bolt. Bolts may be used. At this time, the diameter of the tightening hole that opens to the sliding surface side only needs to be able to fasten the head of the fastening bolt, and may be smaller than the hexagonal hole diameter when a hexagon socket head bolt is used, for example. A plurality of holes may be provided.

  The present invention described above is not limited to a brake disk for a railway vehicle, but can be applied to a brake disk for an automobile, a motorcycle, or the like.

It is a figure which shows the analytical model for evaluating the generated stress when a brake lining passes on the fastening hole opened to a sliding surface, (a) is sectional drawing seen from the side, (b) was seen from the plane FIG. (A) is the figure which showed the generated stress analysis result when a brake lining passes on the fastening hole opened to a sliding surface, (b)-(e) is the schematic diagram which shows the deformation | transformation behavior later on. is there. It is a schematic diagram which shows the amount of depression when a brake lining passes on the fastening hole opened to a sliding surface. It is a schematic diagram showing an analysis model of a basic shape of a brake disc that is fastened to a wheel at a sliding portion, (a) is a view seen from the sliding surface side, (b) is a cross-sectional view taken along line AA in FIG. (C) is a perspective view seen from the sliding surface side of the brake disc, (d) is a perspective view seen from the fin side of the brake disc, and (e) is a perspective view seen from the anti-bolt fastening side of FIG. It is. FIG. 2 is a diagram showing a brake disc shape and a fastening structure in which the diameter of a fastening hole opened in a sliding surface is reduced without changing the screw diameter of a fastening bolt and the outer diameter of a disc spring, and FIG. (B) is an AA sectional view of (a) figure, (c) is an enlarged view of B section in (a) figure, (d) is a CC sectional view of (c) figure, (e) (C) It is DD sectional drawing of a figure. (A)-(e) is a figure similar to FIG. 5 explaining the brake disc of this invention, and its fastening structure. (A)-(e) is the same figure as FIG. 5 explaining the brake disc of the nut side which does not provide the fastening hole opened to a sliding surface, and its fastening structure. (A) (b) is a schematic diagram similar to FIG. 4 showing an analysis model of the brake disc shape and its fastening structure of the present invention, (c) is a cross-sectional view taken along the line BB in FIG. (F) is the schematic diagram similar to FIG.4 (c)-(e). It is a figure which shows the relationship between the analysis result of bolt generation stress, and a fastening hole diameter. 1 shows a conventional rail car side disk, where (a) is a radial-circumferential plan view showing a quarter of a brake disk, and (b) is a cross-sectional view taken along line AA (radial direction-axis) of FIG. Direction sectional view). It is a radial direction-axial direction sectional view showing typically the state where the conventional brake disk for rail vehicles was attached to the wheel. FIG. 6 is a radial direction-axial direction sectional view showing a fastening state with a wheel of a representative brake disc fastened with a wheel at a sliding portion disclosed in Patent Document 1;

Explanation of symbols

1 Brake disc 1b Sliding part 1ba Sliding surface 1bb Fastening hole 1bbb Vertical hole 1bbc Tightening hole 1bbd Lateral hole 1bbe Opening part 1bbf Connection part 2 Wheel 3 Fastening bolt 4 Nut 5 Brake lining 7 Disc spring

Claims (6)

A brake disc for a railway vehicle that is bolted at a sliding portion to a disc body attached to a wheel or an axle,
The fastening hole provided in the sliding part is
A vertical hole provided in the sliding portion from the side opposite to the sliding surface of the sliding portion;
A horizontal hole provided to communicate with the vertical hole in the sliding portion;
The sliding surface side and the vertical hole are provided so as to pass through, and a fastening bolt tightening hole is configured.
The vertical hole is capable of penetrating the screw shaft portion of the fastening bolt and has an inner diameter that is impossible to penetrate the head,
In addition, the lateral hole has a size in which a head of a fastening bolt can be inserted, and is open on the opposite side to the sliding surface. The opening that opens to the side opposite to the sliding surface of the sliding portion of the horizontal hole has a connecting portion that connects to the vertical hole,
2. The brake disk for a railway vehicle according to claim 1, wherein the connecting portion has a width that allows the threaded shaft portion of the fastening bolt to pass therethrough and cannot penetrate the head portion. A brake disc for a railway vehicle that is bolted at a sliding portion to a disc body attached to a wheel or an axle,
The fastening hole provided in the sliding part is
A vertical hole provided in the sliding portion from the side opposite to the sliding surface of the sliding portion;
It is composed of this vertical hole and a horizontal hole provided so as to communicate within the sliding portion,
The vertical hole is capable of penetrating the screw shaft of the fastening bolt, and has an inner diameter that is impossible to penetrate the nut;
In addition, the lateral hole has a size into which a nut can be inserted, is open on the side opposite to the sliding surface, and is formed with a rotation blocking portion that blocks rotation of the nut. brake disc. The opening of the horizontal hole that opens on the opposite side of the sliding surface of the sliding portion has a connecting portion that is connected to the vertical hole,
4. The brake disk for a railway vehicle according to claim 3, wherein the connecting portion has a width that allows the screw shaft portion of the fastening bolt to pass therethrough and cannot allow the nut to pass therethrough.   The brake disc according to claim 1 or 2 and the brake disc according to claim 3 or 4 are fastened by using a fastening bolt and a nut in a mode of sandwiching a disc body attached to a wheel or an axle. Fastening structure for brake discs for railway vehicles.   The fastening structure for a brake disk for a railway vehicle according to claim 5, wherein the fastening bolt is a hexagon socket head cap screw.

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