JPH11270599A - Brake shoe structure of railway brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the partial wear, and to increase the service life by reducing the camber of a pad. SOLUTION: At least one slit 11 to split a pad into a plurality of parts in the longitudinal direction of a brake shoe 1 is provided. The slit 11 pierces the pad 2 from a face side to a back side leaving a part thereof, a wear detection groove 13 is provided on the extension of the slit 11 in a connection part 12 to connect the pads 2 on both sides left on one part of the slit 11, and the depth of the detection groove 13 corresponds to the wear limit from the surface of the pad 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake disc brake structure for railways, and more particularly to a measure against deformation of a brake pad due to heat.

[0002]

2. Description of the Related Art Conventionally, Japanese Unexamined Utility Model Publication No. 6-14571 discloses a brake disc brake for a railway train, for example, as shown in FIGS.

[0003] A pad 2 that comes into contact with the wheel is attached to a back plate 3 of a brake shoe 1 for holding a wheel (disk) from both sides during braking to generate a braking force. The pad 2 is divided into a plurality of, for example, three, and each pad 2 is firmly fixed to the back plate 3 by a rivet 4. A guide plate 6 is provided on the rear side of the back plate 3 to be attached to the brake shoe mounting portion on the caliper side.
Are integrally fixed, and are fitted in a fitting dovetail groove (not shown), whereby the brake shoe 1 is supported.

[0004] A wear detecting groove 5 having a constant depth for detecting the amount of wear of the pad 2 is formed substantially at the center of each pad 2, and the degree of wear of the pad 2 is determined from the depth of the wear detecting groove 5. For example, when the wear detection groove 5 is gone, the pad 2 is replaced.

[0005]

When the pad 2 comes into contact with the wheel during braking, frictional heat is generated. Usually, the pad 2 and the back plate 3 are made of a different material, for example, the pad 2 is a sintered alloy, and the back metal 3 is iron. The linear expansion coefficients are different from each other, and the thermal expansion difference may cause deformation of the brake shoe 1.

For example, the pad 2 and the back plate 3 fixed by the four rivets 4 are warped by the same principle as that of the bimetal, and the brake shoe 1 is deformed in the longitudinal direction. Increases as the value increases.

As a result, uneven contact between the brake shoe 1 and the disk occurs, causing uneven wear. Further, a strict force is applied to the rivet 4 for fixing the pad 2, and the rivet 4 is bent.
In some cases, the pad 2 may fall off, and further, the deformation of the brake shoe may cause problems such as difficulty in removing the brake shoe from the brake shoe mounting portion, such as during replacement.

The present invention aims to solve these problems.

[0009]

According to a first aspect of the present invention, in a brake brake shoe structure in which a pad is fixed to a back plate via a rivet, at least one of the pads is divided into a plurality of pieces in the longitudinal direction of the brake piece. A slit is provided, this slit penetrates from the front surface to the back surface of the pad except for a part, and a wear detecting groove is provided on the extension of the slit at a connecting portion connecting the pads on both sides left in a part of the slit. The depth of the detection groove is made to correspond to the wear limit from the pad surface.

According to a second aspect of the present invention, a step is provided on the pad along both sides of the slit, and the depth of the step from the pad surface is set to the same depth as the wear detection groove of the connecting part.

In the third invention, a gap is formed between the periphery of the rivet and the pad.

[0012]

According to the first aspect of the present invention, since the pad is completely divided at the slit portion, the substantial support interval connected to the back plate by rivets in the longitudinal direction of the brake shoe is reduced. Accordingly, the deformation due to frictional heat during braking based on the difference in the linear expansion coefficient between the pad and the back plate is reduced. For this reason, uneven wear of the pad is reduced, the life thereof is improved, and the brake shoe can be easily removed such as when replacing the pad.

In the second aspect of the present invention, since the step having the same depth as the wear detecting groove is provided on both sides of the slit, the wear state of the pad can be reduced by observing the depth of the step from the pad surface. It can be easily determined.

According to the third aspect of the present invention, since a gap is provided around the rivet, the stress applied to the rivet when the brake shoe is deformed can be reduced, the durability thereof can be increased, and the function of preventing the pad from falling off can be improved.

[0015]

1 to 5 show an embodiment of the present invention.

As shown in the figure, the back plate 3 of the brake shoe 1 is formed in a longitudinal shape extending in the circumferential direction of the wheel.
One pad 2 is fixed at each of its four corners by rivets 4. Each of the pads 2 has a slit 11 located substantially at the center thereof and extending radially toward the center of wheel rotation.

The slit 11 penetrates from the front surface to the rear surface of the pad 2, and a part thereof is formed on the sliding inner peripheral side of the pad 2 in the connecting portion 12 which connects the pads 2 on both sides. The connecting portion 12 is provided with a wear detecting groove 13 whose depth matches the wear limit from the surface of the pad 2 on the extension of the slit.

A predetermined gap 14 is formed between the pad 2 and the rivet 4 for fixing the pad 2 to the back plate 3.

The pad 2 configured as described above and fixed to the back plate 3 by the rivets 4 is substantially divided into two parts in the circumferential direction by the slits 11 at the center. Therefore, the frictional heat generated at the time of braking tends to warp like a bimetal due to the difference in the linear thermal expansion coefficient between the back plate 3 and the pad 2.
, The substantial support length of the pad 2 with respect to the longitudinal direction is reduced, and the amount of deformation is correspondingly reduced accordingly.

As a result, the overall deformation of the brake shoe 1 is small, the uneven contact of the pad 2 is eliminated, the uneven wear of the pad 2 is prevented, and the life of the pad 2 is extended. In addition, brake shoe 1
Deformation of the guide plate 6 makes it difficult for the guide plate 6 to come off from the fitting surface, such as at the time of replacement, but such a problem is also solved.

Since a gap 14 is formed between the pad 2 and the rivet 4 for fixing the pad 2 to the back plate 3, even if stress is generated in the direction of the joint surface between the pad 2 and the back plate 3. Does not directly act as the shearing force of the rivet 4, so that the rivet 4 can be prevented from bending and the pad 2 can be prevented from falling off.

The amount of wear of the pad 2 can be easily determined by determining the depth of the wear detecting groove 13 provided in the connecting portion 12 on the inner peripheral side of the slide. Note that the pad 2 is not completely divided due to the presence of the connecting portion 12, and therefore, the pad 2 can be easily handled at the time of replacement or the like.

Next, another embodiment will be described with reference to FIGS.

In this embodiment, a step 15 having the same depth as the wear detecting groove 13 is formed along both sides of the slit 11 of the pad 2. When the step portion 15 is formed in this way, the depth of the step portion 15 can be increased not only from the wear detecting groove 13 of the connecting portion 12 on the inner peripheral side of the slide but also from the opposite outer peripheral side of the slide, that is, from the outside of the wheel. Can be determined, and the wear amount of the pad 2 can be easily grasped.

[Brief description of the drawings]

FIG. 1 is a front view of a brake shoe showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

FIG. 4 is a diagram also shown in the direction of arrow C.

FIG. 5 is a perspective view of a main part.

FIG. 6 is a view corresponding to the arrow C direction diagram of the second embodiment.

FIG. 7 is a perspective view of a main part.

FIG. 8 is a front view of a conventional example.

FIG. 9 is a view showing the same in the C-direction.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 brake shoe 2 pad 3 back plate 4 rivet 11 slit 12 connecting part 13 wear detection groove 15 step

Claims (3)

[Claims] 1. A railway brake structure in which a pad is fixed to a back plate via a rivet, wherein at least one slit for dividing the pad into a plurality of parts in the longitudinal direction of the brake is provided, and at least one slit is provided. A wear detection groove is provided on the extension of the slit at the connecting portion connecting the pads on both sides left in a part of the slit while penetrating from the front surface to the back surface of the pad while leaving the depth of the pad surface. A brake shoe structure for railroad brakes, which is adapted to the wear limit of the railway. 2. The railway according to claim 1, wherein a step is provided on the pad along both sides of the slit, and the depth of the step from the surface of the pad is set to the same depth as the wear detection groove of the connecting part. Brake structure for vehicle. 3. The brake shoe brake structure according to claim 1, wherein a gap is formed between the periphery of the rivet and the pad.