JP7311332B2 - Brake pads for railway vehicles - Google Patents

Description

The present invention relates to brake pads for rail vehicles.

Railroad vehicle discs that perform braking operations on the wheelset of the railroad vehicle via brake discs (disc rotors) attached to the axle and a pair of brake discs arranged on both sides in the thickness direction of the wheel. A brake device is known (see Patent Literature 1, etc.).
This type of disc brake device for railway vehicles includes a caliper type brake device in which a piston, which is a drive mechanism, directly presses the brake pad, and a lever type brake device in which the drive mechanism presses the brake pad via a link mechanism or a wedge cam. It has a braking device.

Among them, the caliper-type brake device includes a brake caliper having a support frame fixed to the bogie of the vehicle and a caliper brake main body supported by the support frame. The caliper brake body includes a pair of arms that sandwich a brake disc attached to the wheelset of the vehicle. A brake pad having a lining is attached to the surface of the arm facing the brake disc. The brake pad is pressed against the brake disc by a hydraulically driven piston during braking.

Further, the caliper type brake device includes a floating type in which a pinton is arranged on one arm of a caliper brake body slidably supported on a support frame, and a caliper brake body fixed to the support frame. An opposed type is proposed in which a piston is arranged to face a pair of arms.

On the other hand, the lever-type brake device includes a brake caliper having a brake body supported by a bogie of a vehicle and a pair of arms whose intermediate portions are pivotally supported by the brake body. A brake pad having a lining is attached to each open end of the arm facing the brake disc. An output member of a driving mechanism for driving the base ends of the pair of arms in the expanding direction is connected to the base ends of the arms on the side opposite to the open ends.

In any of the types of disc brake devices for railway vehicles described above, when the brakes are applied, the drive mechanism is driven and the brake pads press the brake discs from both sides, so that the brake pads and the brake discs are pressed against each other. They press against each other to create a frictional force that stops the rotation of the brake disc, ie the wheelset.

JP 2017-198226 A

However, in the above-described conventional disc brake device for railway vehicles, the brake disc is mounted on the wheelset (axle or wheel) and the brake caliper is supported by the bogie of the vehicle, and the brake disc and the brake caliper are mounted on the same axis. not installed in Therefore, the brake pads attached to the brake caliper are displaced relative to the brake disc and move up and down due to changes in the weight and tilt of the vehicle. As a result, the friction surface of the brake disc, which has been worn by the lining friction of the brake pad, is unevenly worn such that the cross-sectional thickness decreases in a semi-parabolic shape from the center toward the outer diameter.
Then, when the lining of a new brake pad that has been replaced is pressed against the friction surface of the brake disc that is unevenly worn, there is a problem that burrs are generated on the inner peripheral side of the lining.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a railroad vehicle brake pad that can improve the contact with the brake disc and suppress the occurrence of burrs on the lining.

The above objects of the present invention are achieved by the following configurations.
(1) The brake caliper is rotatably supported by a pair of arms of the brake caliper, which is fixed to the bogie so as to straddle the brake disc mounted on the axle of the railway vehicle suspended on the bogie . A brake pad for a railway vehicle that is mounted via a caliper holder and pressed against the brake disc,
A relief portion is provided on the inner peripheral side of the lining of the brake pad, and is inclined toward the surface of the lining in a direction away from the center of rotation of the brake disc ,
The escape portion is a slope with an inclination angle in the range of 15° to 32°
A brake pad for a railway vehicle characterized by:

According to the railroad vehicle brake pad having the above configuration (1), when it is pressed against the friction surface of the unevenly worn brake disc, the inner peripheral side of the lining provided with the relief portion is the center side of the brake disc. contact with the inclined friction surface is weakened.
That is, when the lining of a new brake pad is pressed against a brake disc whose friction surface has been unevenly worn so that the cross-sectional thickness decreases in a semi-parabolic shape from the center toward the outer diameter, the inner peripheral side of the lining is applied to the brake. It hits the inclined friction surface on the center side of the disc first. At this time, the inner end of the lining surface provided with the relief portion on the inner peripheral side of the lining may come into contact with the inclined friction surface of the brake disc on the outer diameter side of the disc than the inner end of the lining surface without the relief portion. The less inclined the friction surface, the less the impact.
Therefore, burrs are less likely to occur on the inner peripheral side of the lining where the relief portion is provided to weaken the contact with the friction surface of the brake disc, thereby suppressing the occurrence of burrs on the lining.
Furthermore, according to the railroad vehicle brake pad having the above configuration (1), it is possible to suppress the occurrence of burrs on the lining while suppressing the decrease in the area of the lining surface and minimizing the deterioration of the friction characteristics.
That is, when the relief portion provided on the inner peripheral side of the lining is formed with an inclined surface having an inclination angle of more than 32°, the area of the lining surface is reduced compared to the conventional brake pad which is not provided with the relief portion, resulting in increased friction. characteristics deteriorate. Therefore, it becomes necessary to increase the driving force of the drive mechanism, which may lead to an increase in the cost and size of the disc brake device for railway vehicles.
In addition, if the relief portion provided on the inner peripheral side of the lining is formed by a slope with an inclination angle of less than 15°, the contact with the inclined friction surface on the center side of the brake disc cannot be sufficiently weakened, and the lining There is a possibility that the occurrence of burrs cannot be reliably suppressed.

(2) A brake pad for railway vehicles according to (1) above,
It is pressed against the brake disc where the friction surface wears unevenly so that the cross-sectional thickness decreases in a semi-parabolic shape from the center toward the outer diameter as it is used.
A brake pad for a railway vehicle characterized by:

According to the railroad vehicle brake pad having the configuration (2) above, it is possible to suppress the occurrence of burrs on the lining in the same manner as in the above (1).

(3) A brake pad for railway vehicles according to (1) or (2) above,
A brake pad for a railway vehicle, wherein a corner portion between the surface of the relief portion and the surface of the lining is chamfered.

According to the railroad vehicle brake pad having the above configuration (3), chamfering such as 45° chamfering or rounding is provided at the corner between the surface of the relief portion and the surface of the lining. It is possible to reliably suppress the occurrence of burrs in the lining.

(4) A brake pad for railway vehicles according to any one of (1) to (3) above,
A brake pad for a railway vehicle, wherein the relief portion is provided up to a lining wear limit position of the brake pad.

According to the railway vehicle brake pad having the above configuration (4), even when the brake pad is used up to the lining wear limit, the relief portion remains on the inner peripheral side of the lining and the inclined friction surface on the center side of the brake disc. can be sufficiently weakened. Therefore, it is possible to reliably suppress the occurrence of burrs on the lining up to the use limit of the brake pad.

(5) A brake pad for railway vehicles according to any one of (1) to (4) above,
A brake pad for a railway vehicle, wherein the brake pad is composed of a plurality of divided pads.

According to the railroad vehicle brake pad having the above configuration (5), it is possible to reliably suppress the occurrence of burrs on the lining even in the brake pad that is configured by a plurality of divided pads.

(6) A brake pad for railway vehicles according to any one of (1) to (5) above,
A brake pad for a railway vehicle, wherein the lining of the brake pad is made of a synthetic resin-based friction material.

According to the railroad vehicle brake pad having the above configuration (6), it is possible to reliably suppress the occurrence of burrs in the lining even in a brake pad in which the lining is made of a synthetic resin-based friction material and is prone to burrs.

(7) A brake pad for railway vehicles according to any one of (1) to (6) above,
A brake pad for a railway vehicle, wherein chamfers are provided on a rotor turn-in side and a rotor turn-out side of a lining surface of the brake pad.

According to the railroad vehicle brake pad having the above configuration (7), even when the brake caliper is fixed to the steering bogie, the occurrence of burrs in the lining is suppressed, and when the wheelset is steered to follow a curve, In addition, it is possible to prevent the brake disc from strongly hitting the rotor turn-in side and the rotor turn-out side of the lining.

According to the brake pad for railway vehicle according to the present invention, contact with the brake disc can be improved, and burr generation of the lining can be suppressed.

The present invention has been briefly described above. Furthermore, the details of the present invention will be further clarified by reading the following detailed description of the invention (hereinafter referred to as "embodiment") with reference to the accompanying drawings. .

1(a) is a perspective view of a railroad vehicle brake pad according to a first embodiment of the present invention, and FIG. 1(b) is an exploded perspective view of the brake pad shown in FIG. FIG. 2 is a front view of the brake pad shown in FIG. 1(a); It is a perspective view of the back plate shown to (b) of FIG. (a) is a cross-sectional view taken along line AA in FIG. 2, and (b) is an enlarged cross-sectional view of a main part of (a). (a) is a perspective view of a disc brake pad assembly in the process of being attached to a caliper holder, and (b) is a perspective view of the disc brake pad assembly shown in (a) as seen from the lining side. (a) is an explanatory diagram showing the positional relationship between the railroad vehicle disc brake device and the brake disc according to the present invention, and (b) is a partial cross-sectional configuration showing the main part of the railroad vehicle disc brake device according to the present invention. It is a diagram. 1(a) is a partial cross-sectional view showing a railroad vehicle brake pad according to a first embodiment of the present invention for unevenly worn brake discs, and FIG. 1(b) shows a railroad vehicle brake pad according to a reference example; 4 is a cross-sectional view of a main part; FIG. (a) is a perspective view of a railroad vehicle brake pad according to a second embodiment of the present invention, (b) is a front view of a railroad vehicle brake pad according to a third embodiment of the present invention, and (c) is a It is a BB cross-sectional view in (b).

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments according to the present invention will be described with reference to the drawings.
FIG. 1(a) is a perspective view of a brake pad 10 for a railway vehicle according to a first embodiment of the present invention, and FIG. 1(b) is a view of the brake pad 10 shown in FIG. 1 is an exploded perspective view seen from above; FIG. FIG. 2 is a front view of the brake pad 10 shown in FIG. 1(a). FIG. 3 is a perspective view of the back plate shown in FIG. 1(b). 4(a) is a cross-sectional view taken along the line AA in FIG. 2, and FIG. 4(b) is an enlarged cross-sectional view of a main part of FIG. 4(a).

The railroad vehicle brake pad 10 according to the first embodiment can be suitably used by being attached to a brake caliper of various railroad vehicle disc brake devices such as a caliper type brake device and a lever type brake device.
The brake pad 10 of the first embodiment is composed of two divided pads 11 and 13, as shown in FIGS. The two divided pads 11 and 13 have a back plate 19, an anchor plate 25, a fixing portion 27, and a lining 17 formed in a bilaterally symmetrical shape with the abutment surface 43 as a boundary. Since the two divided pads 11 and 13 have the same configuration except that they are bilaterally symmetrical, the same constituent members are denoted by the same reference numerals in this specification.

Each of these split pads 11 and 13 is constructed by molding a lining 17 on a back plate 19 .
The back plate 19 is integrally formed by press working. As shown in FIG. 3 , the back plate 19 is formed by projecting a convex arc piece 51 from one of the pair of parallel long sides of the anchor plate 25 through the dovetail tenon base 37 . The back plate 19 is formed by projecting a recessed circular arc piece 53 from the other of the pair of parallel long sides of the anchor plate 25 via the dovetail tenon base 37 . A small piece portion 55 is formed to protrude from one short side portion of the anchor plate 25 opposite to the butted side. These convex arc piece 51, concave arc piece 53, and small piece 55 are embedded in the fixed lining 17 with only the anchor plate side surface exposed. As a result, the divided pads 11 and 13 with the lining 17 fixed to the back plate 19 are formed.

The lining 17 is, for example, a synthetic resin-based friction material obtained by mixing and polymerizing a synthetic resin with a friction material. Alternatively, the lining 17 may have a friction material such as metal powder sintered on the surface of the back plate 19 . The back plate 19 has a plurality of fixing holes 57 formed in the anchor plate 25 , the convex arcuate piece 51 , the concave arcuate piece 53 , and the small piece 55 . The fixing hole 57 is formed in a square shape, and a folded piece 59 to be embedded in the lining 17 is formed on each side. In the back plate 19, the lining 17 enters the fixing holes 57 and solidifies, thereby embedding the folded pieces 59 and increasing the fixing strength.

A brake pad 10 composed of two divided pads 11 and 13 is formed by a convex arc 14 projecting outward on the lining outer peripheral side 12 of a pair of parallel long sides, and a concave shape in which the lining inner peripheral side 16 is recessed inward. It is formed by an arc 18 .
The centers of these convex arcs 14 and concave arcs 18 coincide with the centers of the brake discs 80 (see FIG. 6) used in the railroad vehicle disc brake device 1 . Note that the outer shape of the brake pad 10 is not limited to this.

Further, the lining inner peripheral side 16 of the brake pad 10 is provided with a relief portion 20 that is inclined in a direction away from the rotation center of the brake disc 80 toward the lining surface 17a (leftward in FIG. 4).
As shown in FIG. 4(a), the escape portion 20 is desirably formed as a slope having an inclination angle θ in the range of 15° to 32°. Further, a corner portion 21 between the surface 20a of the relief portion 20 and the lining surface 17a is chamfered as a rounded surface, as shown in FIG. 4(b). Needless to say, the chamfer may be chamfered at 45°.

Also, the escape portion 20 is provided up to a lining wear limit position 23 of the brake pad 10 . That is, the inclined surface of the escape portion 20 is formed up to the lining wear limit position 23 where the remaining amount of the lining 17 in the brake pad 10 is the use limit, and the lining 17 of the brake pad 10 is used up to the lining wear limit position 23. Even in this case, the escape portion 20 remains on the inner peripheral side 16 of the lining. For example, the depth of the groove 17b formed in the lining surface 17a of the lining 17 is up to the lining wear limit position 23. As shown in FIG. Then, the brake pad 10 can know the remaining amount of the lining 17 by checking the depth of the groove 17b.

5(a) is a perspective view of the disc brake pad assembly 15 in the process of being attached to the caliper holder 47, and FIG. 5(b) is a lining of the disc brake pad assembly 15 shown in FIG. 5(a). Fig. 3 is a perspective view seen from the side;

As shown in FIG. 5A, the brake pad 10, which is composed of a set of split pads 11 and 13, has shims 30 on the back plate for the purpose of preventing squeal during braking, uneven wear of the lining, or heat insulation. It is attached to the 19 side and constitutes a disk brake pad assembly 15 . As the material of the shim 30, for example, a general thin SUS material is used.

The disc brake pad assembly 15 is assembled by inserting one of the two continuous fixing portions 27 into a holding portion 49 of a caliper holder 47 formed in a dovetail groove shape. One shim 30 is attached by being sandwiched between the two split pads 11 and 13 and the caliper holder 47 by engaging the fixing portions 27 of the two split pads 11 and 13 with the holding portion 49 .

FIG. 6(a) is an explanatory view showing the positional relationship between a railroad vehicle disc brake device 1 and a brake disc 80 according to the present invention, and FIG. 6(b) is a railroad vehicle disc brake device 1 according to the present invention. It is a partial cross-sectional configuration diagram showing the main part of.

The disk brake pad assembly 15 attached to the caliper holder 47 is attached to the brake caliper 75 of the railway vehicle disk brake device 1 as shown in FIGS. 6(a) and 6(b).
A railroad vehicle disc brake device 1 includes a brake caliper 75 having a brake body 73 supported by a bogie 71 of a vehicle and a pair of arms 77 , 77 pivotally supported by the brake body 73 at intermediate portions thereof. A brake pad 10 is attached via a caliper holder 47 to each open end of the arm 77 facing the friction surface 81 of the brake disc 80 . An output member (not shown) of a drive mechanism for driving the base ends of the pair of arms 77 in the opening direction is connected to the base ends of the arms 77 opposite to the open ends.

That is, the brake caliper 75 is fixed to the bogie 71 side so as to straddle the brake disc 80 mounted on the wheelset 100 for the railway vehicle. The brake pad 10 attached to the brake caliper 75 via the caliper holder 47 is pressed against the brake disc 80 by the drive mechanism.

As shown in FIGS. 6A and 6B, the railroad vehicle disc brake device 1 has a brake disc 80 mounted on an axle 95 of a wheel set 100 and a brake caliper 75 supported by a bogie 71 of the vehicle. , and the brake disc 80 and the brake caliper 75 are not mounted on the same axis. Therefore, the brake pad 10 attached to the brake caliper 75 is displaced relative to the brake disc 80 and moves up and down due to the weight change and tilt of the vehicle.

Next, the operation of the brake pad 10 according to the first embodiment will be described.
FIG. 7(a) is a cross-sectional view of the main part showing the railroad vehicle brake pad 10 according to the first embodiment of the present invention against the unevenly worn brake disc 80, and FIG. 7(b) is a reference example. FIG. 5 is a cross-sectional view of a main part showing a brake pad 510 for railway vehicles;

As shown in (a) of FIG. 7 , according to the brake pad 10 according to the first embodiment, the escape portion 20 is provided when the brake disc 80 is pressed against the friction surface 81 of the unevenly worn brake disc 80 . The inner peripheral side 16 of the lining weakens contact with the inclined friction surface 81a on the center side of the brake disc 80 .

That is, the new brake disc 80 has a friction surface 81 that is unevenly worn such that the cross-sectional thickness decreases in a semi-parabolic shape from the center toward the outer diameter (from left to right in FIG. 7). When the lining 17 of the pad 10 is pressed, the inner peripheral side 16 of the lining first contacts the inclined friction surface 81a on the central side of the brake disc 80 . At this time, the inner end E1 of the lining surface 17a of the brake pad 10 provided with the relief portion 20 on the inner peripheral side 16 of the lining is the same as the brake of the reference example without the relief portion 20 shown in FIG. It is thought that the lining surface 17a of the pad 510 can come into contact with the inclined friction surface 81a of the brake disc 80 at a position closer to the disc outer diameter than the inner end E2 of the lining surface 17a, and the contact is weakened as much as the inclination of the friction surface 81a becomes gentler. .

Therefore, even when the brake pad 10 according to the first embodiment is used for the brake disc 80 whose friction surface 81 is unevenly worn, the escape portion 20 is provided so that the friction surface 81 of the brake disc 80 does not come into contact with the brake pad 10 . The inner peripheral side 16 of the lining where the tension is weakened is less likely to have burrs, and the occurrence of burrs on the lining 17 can be suppressed.

Further, it is desirable that the relief portion 20 of the brake pad 10 according to the first embodiment is formed as a slope having an inclination angle θ in the range of 15° to 32°. In this case, it is possible to prevent burrs from occurring on the lining 17 while minimizing the deterioration of the friction characteristics by suppressing the decrease in the area of the lining surface 17a.
That is, when the relief portion 20 provided on the inner peripheral side 16 of the lining is formed with an inclined surface having an inclination angle θ greater than 32°, the lining surface 17a is reduced compared to the conventional brake pad in which the relief portion 20 is not provided. The area is reduced and the frictional characteristics are deteriorated. Therefore, it becomes necessary to increase the driving force of the drive mechanism, which may lead to an increase in cost and size of the railroad vehicle disc brake device 1 .
Further, when the relief portion 20 provided on the inner peripheral side 16 of the lining is formed with a slope having an inclination angle θ of less than 15°, the contact with the inclined friction surface 81a on the center side of the brake disc 80 should be sufficiently weakened. burr formation on the lining 17 cannot be reliably suppressed.

Further, in the brake pad 10 according to the first embodiment, the corner 21 between the surface 20a of the relief portion 20 and the lining surface 17a is chamfered with a rounded surface. Therefore, it is possible to reliably suppress the occurrence of burrs on the lining 17 particularly at the initial stage of pad replacement.

Further, the relief portion 20 of the brake pad 10 according to the first embodiment is provided up to the lining wear limit position 23 of the brake pad 10 . Therefore, even when the brake pad 10 is used up to the lining wear limit position 23, the relief portion 20 remains on the inner peripheral side 16 of the lining to sufficiently weaken the contact with the inclined friction surface 81a on the center side of the brake disc 80. can be done. Therefore, it is possible to reliably suppress the occurrence of burrs on the lining 17 up to the use limit of the brake pad 10 .

(a) of FIG. 8 is a perspective view of a brake pad 10A for a railway vehicle according to a second embodiment of the present invention, and (b) of FIG. 8 is a brake pad 10B for a railway vehicle according to a third embodiment of the present invention. , and FIG. 8(c) is a cross-sectional view taken along line BB in FIG. 8(b).

As shown in (a) of FIG. 8, the brake pad 10A for railway vehicles according to the second embodiment is divided into two parts, similar to the brake pad 10 for railway vehicles according to the first embodiment. divided pads 11A and 13A.
In the brake pad 10A for a railway vehicle according to the second embodiment, in addition to the relief portion 20 provided on the inner peripheral side 16 of the lining, chamfers are provided on the rotor turn-in side 41 and the rotor turn-out side 42 of the lining surface 17a. 50 are provided.

According to the railroad vehicle brake pad 10A according to the second embodiment, even when the brake caliper 75 is fixed to the steering bogie, burrs are prevented from occurring in the lining 17, and the wheel set 100 is adjusted so as to follow a curve. It is possible to prevent the brake disc 80 from strongly hitting the rotor entry side 41 and the rotor exit side 42 of the lining 17 when the vehicle is steered.

As shown in FIGS. 8B and 8C, the railroad vehicle brake pad 10B according to the third embodiment includes two brake pads like the railroad vehicle brake pad 10 according to the first embodiment. It is not composed of the split pads 11 and 13 split into two.
A railroad vehicle brake pad 10B according to the third embodiment has three linings 17B fixed to the surface of one back plate 19B.

The back plate 19B is a metal plate having a convex arc piece 51B formed on one of a pair of parallel long sides and a concave arc piece 53B formed on the other of the pair of parallel long sides. is.
The lining 17B is, for example, a synthetic resin-based friction material obtained by mixing and polymerizing a synthetic resin with a friction material. In addition, in the lining 17B, a friction material such as metal powder may be sintered on the surface of the back plate 19B.

A brake pad 10B having three linings 17B has an outer lining side 12B of each lining 17B formed by a convex arc 14B protruding outward, and an inner lining side 16B of each lining 17B formed by a concave arc 18B concave inward.
The centers of the convex arc 14B and concave arc 18B coincide with the center of the brake disc 80. As shown in FIG. In addition, the outer shape of each lining 17B is not limited to this.

In addition, on the lining inner peripheral side 16B of each lining 17B in the brake pad 10B, a relief portion inclined in a direction away from the rotation center of the brake disc 80 toward the lining surface 17a (rightward in FIG. 8(c)). 20B is provided.
Like the relief portion 20 of the railroad vehicle brake pad 10 according to the first embodiment, the relief portion 20B preferably has an inclination angle θ in the range of 15° to 32°. Further, the corner 21 between the surface 20a of the relief portion 20B and the lining surface 17a is chamfered with a rounded surface.

Therefore, according to the railroad vehicle brake pad 10B according to the third embodiment, similar to the railroad vehicle brake pad 10 according to the first embodiment, the friction surface 81 is applied to the brake disc 80 with uneven wear. Even in the case of being used as a lining 17B, burrs are less likely to occur on the inner peripheral side 16B of the lining, which is provided with the escape portion 20B to weaken the contact with the friction surface 81 of the brake disc 80, and burrs can be suppressed from occurring on the lining 17B.

As described above, according to the railway vehicle brake pads 10, 10A, 10B according to the first to third embodiments, contact with the brake disc 80 can be improved, and burr generation on the linings 17, 17B can be suppressed.

It should be noted that the present invention is not limited to the above-described embodiments, and can be modified, improved, etc. as appropriate. In addition, the material, shape, size, number, location, etc. of each component in the above-described embodiment are arbitrary and not limited as long as the present invention can be achieved.
For example, in the above embodiment, the brake disc 80 is configured as a disc rotor mounted on the axle 95 of the wheelset 100. It can also consist of a pair of brake discs arranged in plane position.

Here, the characteristics of the embodiment of the brake pad for railway vehicles according to the present invention described above are briefly summarized and listed below.
[1] It is mounted on a brake caliper (75) fixed to a bogie (71) side so as to straddle a brake disc (80) mounted on a wheelset (100) for a railway vehicle, and is pressed against the brake disc (80). A brake pad (10, 10A, 10B) for a railway vehicle,
On the lining inner peripheral side (16, 16B) of the brake pad (10, 10A, 10B), a relief portion (20) inclined in a direction away from the rotation center of the brake disc (80) toward the lining surface (17a). , 20B) for a railway vehicle.
[2] A brake pad (10, 10A, 10B) for a railway vehicle according to [1] above,
A brake pad (10, 10A, 10B) for a railway vehicle, wherein the relief portion (20, 20B) is a slope having an inclination angle (θ) in the range of 15° to 32°.
[3] A brake pad (10, 10A) for a railway vehicle according to [1] or [2] above,
A brake pad (10, 10A) for a railway vehicle, characterized in that a corner (21) between a surface (20a) of the relief portion (20) and the lining surface (17a) is chamfered. .
[4] A brake pad (10, 10A, 10B) for a railway vehicle according to any one of [1] to [3] above,
A brake pad (10, 10A, 10B) for a railway vehicle, characterized in that the relief portion (20, 20B) is provided up to a lining wear limit position (23) of the brake pad (10, 10A, 10B). ).
[5] A brake pad (10, 10A) for a railway vehicle according to any one of [1] to [4] above,
A brake pad (10, 10A) for a railway vehicle, wherein the brake pad (10, 10A) is composed of a plurality of divided pads (11; 11A, 13; 13A).
[6] A brake pad (10, 10A, 10B) for a railway vehicle according to any one of [1] to [5] above,
A brake pad (10, 10A, 10B) for a railway vehicle, wherein a lining (17, 17B) of the brake pad (10, 10A, 10B) is made of a synthetic resin friction material.
[7] A brake pad (10A) for a railway vehicle according to any one of [1] to [6] above,
A brake for railway vehicles, wherein a chamfer (50) is provided on a rotor turn-in side (41) and a rotor turn-out side (42) of a lining surface (17a) of the brake pad (10A). Pad (10A).

EXAMPLES The present invention will be specifically described below with reference to examples. However, the present invention is not limited only to these examples.
In order to confirm the burr suppressing effect of the railroad vehicle brake pad according to the present invention, a brake pad lining wear test was conducted on unevenly worn brake discs using a disc brake tester (manufactured by Tokyo Koki Co., Ltd.). The contents of the test are shown below.

[Brake pad wear test]
(Test method)
1. A brake disc with uneven wear on the friction surface so that the cross-sectional thickness decreases in a semi-parabolic shape from the center toward the outer diameter (see FIG. 7), and brake pads of samples 1 to 5 with different inclination angles θ of the relief portion ( 5 pieces of each sample) are used to perform a brake pad wear test under the following test conditions.
2. Check the presence or absence of burrs and the presence or absence of chipping on the inner peripheral side of the lining of each of the 5 samples of each of the collected materials 1 to 5.
3. Table 1 below shows the determination results of the above brake pad wear test.
Judgment Criteria ○: No "burrs" or "edges" in each of the 5 samples △: "Borders" in each of the 5 samples ×: "Burrs" and "edges" in each of the 5 samples " is all there

(Test condition)
Test speed: 40km/h (brake disc diameter 610mm equivalent)
Pad pressing force: 20kN x 2
Flywheel moment of inertia: 1226kg・m ²
Braking times: 200 times

(lining)
Material: Synthetic disc lining Perimeter R: 296mm
Inner circumference R: 212mm
Inclination angle θ of relief portion 20: 0°, 9°, 15°, 18°, 23°

From Table 1 above, it can be confirmed that the railroad vehicle brake pad according to the present invention can suppress the occurrence of burrs on the lining. In particular, by setting the inclination angle θ of the relief portion to 15° or more, it is possible to reliably suppress the occurrence of burrs and edge chipping of the lining.
In addition, if the inclination angle θ of the relief portion is greater than 32°, the area of the lining surface is reduced by 10% or more compared to a brake pad without the relief portion, and the friction characteristics exceed the allowable range. so undesirable.

DESCRIPTION OF SYMBOLS 10... Brake pad for railcars 16... Lining inner peripheral side 17... Lining 17a... Lining surface 20... Relief part 71... Bogie 75... Brake caliper 80... Brake disk 100... Wheelset

Claims (7)

A caliper holder rotatably supported by a pair of arms of a brake caliper fixed to a bogie so as to straddle a brake disc mounted on a wheelset for a railway vehicle suspended from the bogie . A brake pad for a railway vehicle that is mounted through and pressed against the brake disc,
A relief portion is provided on the inner peripheral side of the lining of the brake pad, and is inclined toward the surface of the lining in a direction away from the center of rotation of the brake disc ,
The escape portion is a slope with an inclination angle in the range of 15° to 32°
A brake pad for a railway vehicle characterized by: A brake pad for a railway vehicle according to claim 1,
The friction surface is pressed against the brake disc, which wears unevenly, so that the cross-sectional thickness decreases in a semi-parabolic shape from the center toward the outer diameter as it is used.
A brake pad for a railway vehicle characterized by: A brake pad for railway vehicles according to claim 1 or 2,
A brake pad for a railway vehicle, wherein a corner portion between the surface of the relief portion and the surface of the lining is chamfered. A brake pad for railway vehicles according to any one of claims 1 to 3,
A brake pad for a railway vehicle, wherein the relief portion is provided up to a lining wear limit position of the brake pad. A brake pad for a railway vehicle according to any one of claims 1 to 4,
A brake pad for a railway vehicle, wherein the brake pad is composed of a plurality of divided pads. A brake pad for railway vehicles according to any one of claims 1 to 5,
A brake pad for a railway vehicle, wherein a lining of the brake pad is made of a synthetic resin friction material. A brake pad for a railway vehicle according to any one of claims 1 to 6,
A brake pad for a railway vehicle, wherein chamfers are provided on a rotor turn-in side and a rotor turn-out side of a lining surface of the brake pad.

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