JPH0524827Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a drum-in-disc brake.

Prior Art A rotating member having a hat shape and having a bottomed cylindrical portion and a disk portion protruding in the outer circumferential direction from the outer circumferential surface of the cylindrical portion, and the disk portion facing the opening side of the cylindrical portion. a bucking plate fixed to the non-rotating member on one side; and a bucking plate fixed to the non-rotating member together with the bucking plate on the opposite side of the bucking plate to the rotating member;
a support member that supports a caliper installed across the outer circumferential portion of the disc part, and the caliper applies braking by pressing pads on both sides of the disc part, while the inner peripheral surface of the cylindrical part A drum-in-disc brake is known that performs braking by pressing a brake shoe supported on the bucking plate. For example, the one described in Japanese Utility Model Application Publication No. 55-124639 is one example.

In such a drum-in disc brake,
The rotating member is usually installed with the one side of the disk portion exposed to the outside, so in order to prevent muddy water or foreign matter from adhering to the disk portion, the disk portion is A dust cover that covers the backing plate from one side is fixed to the outer peripheral side of the backing plate by welding or the like.

Problems to be Solved by the Invention However, such a drum-in-disc brake requires a large number of parts, requires separate molds for molding the bucking plate and the dust cover, and requires separate molds for molding the bucking plate and the dust cover. The work of positioning and fixing the dust cover to each other by welding, etc.
Usually, it is relatively troublesome and time-consuming, so there has been a problem that it is difficult to provide drum-in-disc brakes at low cost.

Further, like the drum-in-disc brake described in the above publication, a dust cover located on the outer circumferential side of the bucking plate support member is fixed, and a dust cover located on the outer circumferential side of the bucking plate support member is fixed. When the brake shoe is supported under pressure by the biasing force of the shoe hold down device on a flat surface (so-called registration surface) provided at a predetermined height position of the part, the dust cover is pressed against the bucking plate. When the brake shoe swings in a direction parallel to the axis of the brake shoe, there is a risk that the above-mentioned registration surface will tilt and the supporting position and attitude of the brake shoe on the bucking plate will change.

In contrast, by integrally molding the part corresponding to the dust cover with the bucking plate, and by making a part of the bucking plate with the part corresponding to the dust cover protrude in a direction parallel to the axis, the flatness can be improved. By providing a protrusion with a tip end surface and supporting the brake shoe on the tip end surface (ledge surface) of the protrusion, the number of parts and molds can be reduced, and the adhesion between the bucking plate and the dust cover can be reduced. It is thought that the drum-in-disc brake can be provided at a lower cost since the work is no longer required.

However, in this case, if the movement of the proximal end of the protrusion located on the outer circumferential side of the bucking plate in the direction parallel to the axis of the bucking plate is not regulated, the conventional case described in the above publication Similarly, there is a risk that the shaking of the dust cover may cause the recess surface to tilt, changing the support position or attitude of the brake shoe on the bucking plate.

Means for Solving the Problems The present invention was made against the background of the above circumstances, and its purpose is to solve the problem when integrally molding the part corresponding to the dust cover with the backing plate. A drum that can suitably prevent changes in the support position and posture of the brake shoe due to shaking of the part corresponding to the dust cover, and can suitably obtain the strength of the bucking plate in which the part corresponding to the dust cover is integrally molded. Our goal is to provide in-disc brakes. The gist of the present invention to achieve such an object is that, in the drum-in disc brake of the type described above, a cover part that covers the disc part from one side is integrally molded on the bucking plate. On the other hand, the bucking plate having the cover portion has a flat tip end surface projected in a direction parallel to the axis of the bucking plate at a position corresponding to the brake shoe; A protrusion is provided to support the brake shoe, and a proximal end of the protrusion located on the outer peripheral side of the bucking plate is brought into contact with a surface of the support member facing the bucking plate. .

Effects of operation and invention With this method, since the cover part that covers the disk part from the one side is integrally molded on the backing plate, the number of parts and molds etc. can be reduced compared to the conventional method, and the cover part can be formed integrally with the backing plate. When installing the parts, there is no need for conventional fixing work such as welding, and the drum-in-disc brake can be provided at a lower cost.

Moreover, since the base end of the outer peripheral side of the protrusion that supports the brake shoe is brought into contact with the surface of the support member that faces the bucking plate, the distal end surface of the protrusion is tilted due to shaking of the cover, and the brake shoe is The support position and posture on the bucking plate can be better prevented from changing, and when the cover part swings, compared to the case where the outer peripheral side base end of the protrusion part is not brought into contact with the support member. Since the fulcrum is located further toward the outer periphery, the strength in the direction parallel to the axis of the backing plate provided with the cover portion can be more preferably obtained.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.

FIG. 1 is a diagram showing the main parts of a drum-in-disc brake to which the present invention is applied, and 10 is a rotating member provided on the inner peripheral side of a wheel (not shown) and rotated together with the wheel. Rotating member 10
has a cylindrical portion 12, a bottom wall 14 provided at one end of the cylindrical portion 12, and a disk portion 16 protruding in the outer circumferential direction from the outer circumferential surface of the other end of the cylindrical portion 12, and has a substantially hat shape. It is fixed to the wheel at the bottom wall 14 by bolts (not shown). Cylindrical part 1
A bucking plate 18 having an overall disc shape is disposed on the opening side of the rotating member 10, facing the rotating member 10 and being close to it. It is fixed to a non-rotating member (not shown) with a bolt (not shown) together with a support member 20 provided on the opposite side.

A caliper 22 is supported by the supporting member 20 so as to be movable in a direction parallel to the axis of the rotating member 10 by a slide pin (not shown) or the like while straddling the disc portion 16 . A pair of pads 24 and 26 are provided inside the caliper 22 so as to face both sides of the disc portion 16, respectively. Braking by the service brake is performed by being pressed against both sides.

On the other hand, inside the cylindrical portion 12, a pair of brake shoes 28 (only one shown) is provided on the bucking plate 18 so as to be able to expand with respect to each other. are pressed against the inner circumferential surface of the cylindrical portion 12, thereby performing braking by the parking brake.

The bucking plate 18 is integrally formed from a single plate material by press working, and has a diameter that is approximately the same as the diameter of the cylindrical portion 12, as shown in FIGS. 1 and 2. The cylindrical part 12 of the lever
and a pair of brake shoes 2.
8, and the disk portion 16 located on the outer peripheral side of the support portion 32.
and a cover part 36 that covers from one surface 34 side exposed to the outside of the wheel. The support portion 32 has an annular protrusion 38 on its outer peripheral portion that protrudes to a position close to the open end of the cylindrical portion 12, and the cover portion 36 has an annular protrusion 38 that protrudes to a position close to the open end of the cylindrical portion 12.
4 and an inclined part 42 that is inclined from the outer peripheral edge of the opposed part 40 toward the outer peripheral side of the disk part 16. As a result, the brake shoe 28 is supported on the flat end surface 46 of the protruding part 38, while the cover part 36 prevents muddy water, foreign matter, etc. from adhering to the disk part 16, and the cover part 36 prevents muddy water, foreign matter, etc. The portion 36 and the protruding portion 38 remove muddy water, foreign matter, etc. from the cylindrical portion 1.
2 is prevented from entering. In addition, the brake shoe 12 is moved to the tip surface 46 of the protruding portion 38 according to the biasing force of a shoe hold down device (not shown).
The outer circumferential side proximal end 48 of the protrusion 38 located on the outer circumferential side of the bucking plate 18 and the inner circumferential side proximal end 50 located on the inner circumferential side of the bucking plate 18 are pressed against the support member 20. They are brought into contact with the surfaces facing the backing plate 18, respectively. Further, 44 is a notch for accommodating the caliper 22.

As described above, according to this embodiment, the cover part 3 covers the disc part 16 from the side of the surface 34 exposed to the outside of the wheel.
6 is formed integrally with the bucking plate 18, so compared to the conventional case where the bucking plate and the dust cover are molded separately, positioned relative to each other, and fixed together by welding or the like, it is easier to make the parts. The number of pieces, molds, etc. are reduced, and when installing the cover portion 36, the conventional fixing work such as welding, which is relatively troublesome and time-consuming, becomes unnecessary. As a result, a drum-in-disc brake can be provided at a lower cost than in the past.

Further, according to this embodiment, the brake shoe 28
Since the outer circumferential base end 48 of the protrusion 38 that supports is brought into contact with the surface of the support member 20 facing the bucking plate 18, the direction parallel to the axis of the bucking plate 18 of the cover 36 It is possible to suitably prevent the distal end surface 46 of the protrusion 38 from being tilted due to the shaking of the brake shoe 28 and the supporting position and posture of the brake shoe 28 on the bucking plate 18 to change. The cover portion 3
Since the fulcrum of the buckling plate 6 when swinging is located further toward the outer periphery, the strength in the direction parallel to the axis of the bucking plate 18 provided with the cover portion 36 can be more preferably obtained.

Although the present invention has been described above based on one embodiment of the present invention, various changes can be made to the present invention without departing from the spirit thereof.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the main parts of a drum-in-disc brake to which the present invention is applied. FIG. 2 is a view of the bucking plate of FIG. 1 viewed from the rotating member side. 10... Rotating member, 12... Cylindrical part, 16...
Disk portion, 18... Batting plate, 20...
Support member, 22... Caliper, 24, 26... Pad, 28... Brake shoe, 34... One side,
36...Cover part, 38...Protrusion part, 46...Distal end surface, 48...Outer peripheral side base end part.

Claims (1)

[Claims for Utility Model Registration] A rotating member having a hat shape and having a bottomed cylindrical portion and a disc portion protruding from the outer circumferential surface of the cylindrical portion in the outer circumferential direction; a bucking plate fixed to the non-rotating member on one side of the disc portion; and a bucking plate fixed to the non-rotating member together with the bucking plate on the opposite side of the bucking plate to the rotating member, and the disc a support member that supports a caliper installed across the outer periphery of the cylindrical portion, the caliper applies braking by pressing pads on both sides of the disc portion, and the backing member is provided with a support member that supports a caliper that is disposed astride the outer periphery of the cylindrical portion. In a drum-in-disc brake of the type that performs braking also by pressing a brake shoe supported on the plate, the bucking plate is provided with a cover portion integrally molded to cover the disk portion from the one surface side; The bucking plate having the cover has a flat tip surface that protrudes in a direction parallel to the axis of the bucking plate at a position corresponding to the brake shoe, and the brake shoe is attached to the tip surface on the tip surface. A protruding portion supporting the buckling plate is provided, and a proximal end portion of the protruding portion located on the outer peripheral side of the bucking plate is brought into contact with a surface of the supporting member facing the bucking plate. Drum-in disc brake.