JPH0958558A - Brake device for bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the generation of squeal noise during braking of a brake device for an automobile, to improve effectiveness and durability of a brake, and to reduce a cost. SOLUTION: In an inner spread type drum brake comprising a brake drum 3 fixed at the hub of a wheel; and cylindrical two-division brake shoes 5 and 6 arranged along the inner periphery of the brake drum 3, a lining 18 is fixed on the inner peripheral surface of the brake drum 3, and slide surfaces 5a and 6a making slide contact with the lining 18 are arranged on the outer peripheral surfaces of the brake shoes 5 and 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inner expansion type drum brake for a rear wheel of a bicycle.

[0002]

2. Description of the Related Art A conventional in-expansion type drum brake device has a lining fixed to the brake shoe side with an adhesive or a pin, and this brake is applied to the inner peripheral surface of a drum rotating integrally with a rear wheel. The shoes were brought into contact with each other, a pressing force was applied, and the friction was used to brake.

[0003]

The conventional bicycle brake device described above has the following problems. (1) Since the lining is adhered to the shoe or pinned, the lining may be damaged and fall off due to the shearing force between the lining and the shoe during braking. In this case, the brake will not work and it is dangerous. Is. (2) Since it is necessary to grind the contact surfaces of the outer peripheral surface of the lining and the inner peripheral surface of the drum, the processing time becomes long and the cost increases. (3) The contact area between the lining and the inner peripheral surface of the drum is about half as much as the contact surface of the lining is twisted together with the twist on the side of the brake shoe holding the lining, so braking stability is improved. Lack.

[0004]

SUMMARY OF THE INVENTION In order to solve the above problems, in the present invention, a brake drum fixed to a hub of a wheel, and an arc-shaped two-divided brake shoe provided along the inner circumference of the drum. In an inner expansion type drum brake device including: a lining is fixed to an inner peripheral surface of the brake drum, and a sliding surface that comes into contact with the lining is provided on an outer surface of the brake shoe to form a bicycle braking device. To do.

Further, in the present invention, the inner peripheral surface of the brake drum for fixing the lining may be subjected to uneven processing for stabilizing the fixing of the lining, and this uneven processing may be knurling.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In the figure, 1 is a rear axle of a bicycle, 2 (see FIG. 2) is a hub for rear wheels, 3 is a brake drum fixed to this hub 2, 4 is fitted to the rear axle 1, and its front end portion is a bicycle frame ( A base plate fixed to (not shown), 4a is an operation wire attachment portion, and 4b is an attachment hole.

Further, 5 is the first of the two-divided brake shoes.
Brake shoes, 6 is a second brake shoe, 7 is a pin that connects the first brake shoe 5 and the second brake shoe 6, 8 is an anchor pin that pivotally supports the end of the second brake shoe 6 on the base plate 4, 9 Is a lever having an intermediate portion pivotally supported on the base plate 4 by a pin 10, and 11 is a connecting fitting for connecting the end portion of the lever 9 and the end portion of the first brake shoe 5.

Further, 12 is a bracket projecting outward from the second brake shoe 6, 13 is a brake shoe adjusting screw screwed to the base plate 4 so as to face the bracket 12, and 14 is fitted to the screw 13. It is a coil spring. Further, 15 covers the outside of the base plate 4 and the outer periphery of the brake drum 3, so that the nut 16 is attached to the rear axle 1.
The cover is fixed by (see FIG. 2). 17
Is a nut of the pin 10.

In this embodiment, as shown in detail in FIGS. 3 and 4, a lining 18 is applied to the inner peripheral surface of the brake drum 3 and several (6 in this embodiment) rivets 19 are applied. 1 and 2, sliding surfaces 5a and 6a that come into contact with the lining 18 are provided on the outer peripheral surfaces of the brake shoes 5 and 6, respectively.

Further, in order to stabilize the fixing of the lining 18, the inner peripheral surface 3a of the brake drum 3 for fixing the lining 18 may be subjected to uneven processing as shown in FIG. Knurling is suitable for this uneven processing. The unevenness of the inner peripheral surface 3a in FIG. 5 shows this knurling example.

The shape of the lining 18 described above is preferably a belt-shaped one that is rolled along the inner peripheral surface 3a of the brake drum 3, but a cylindrical molded product may also be used. Further, the fixing of the lining 18 to the drum inner peripheral surface 3a is shown by the rivet 19 in the present embodiment, but the fixing method may be an adhesive method using an adhesive. If the lining 18 is a mold type cylindrical molded product, it can be fixed by press fitting. Further, when the lining 18 is fixed, if the inner peripheral surface 3a of the drum is subjected to uneven processing such as knurling as described above, the non-slip effect enables more stable fixing.

[0012]

According to the above construction, the present invention has the following actions and effects. (1) Since the weight on the side of the brake drum is increased, the squeaking noise during braking can be suppressed by the damping effect in the high frequency range. (2) A large amount of friction heat is transmitted not only to the brake drum side but also to the brake body side, so the heat dissipation effect is improved,
The braking effectiveness and durability are improved, and the squeaking noise during braking can be suppressed. (3) The fixing of the lining is more stable than before, but even if the lining is damaged and falls off, the inner surface of the drum and the sliding surface of the brake shoe come into contact with each other, so that the braking force remains and the safety is improved. . (4) Since it becomes easy to grind the contact surface of the lining with the brake shoe, the processing time can be shortened and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a front view of the device of the present invention.

FIG. 2 is a bottom view showing the device of FIG. 1 in a partial cross-section.

FIG. 3 is a front view of a brake drum of the device of the present invention.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a partially enlarged view showing an example of processing unevenness on the inner peripheral surface of the drum of FIG.

[Description of symbols] 1 rear axle 2 rear wheel hub 3 brake drum 3a inner peripheral surface 4 base plate 4a operating wire mounting portion 4b mounting hole 5 first brake shoe 5a sliding surface 6 second brake shoe 6a sliding surface 7 pin 8 Anchor pin 9 Lever 10 pin 11 Connecting bracket 12 Bracket 13 Brake shoe adjusting screw 14 Coil spring 15 Cover 16,17 Nut 18 Lining 19 Rivet

Claims (3)

[Claims] 1. An inner expansion type drum brake device comprising: a brake drum fixed to a wheel hub; and an arc-shaped two-divided brake shoe provided along an inner circumference of the drum. A braking device for a bicycle, wherein a lining is fixed to a peripheral surface, and a sliding surface which comes into contact with the lining is provided on an outer peripheral surface of the brake shoe. 2. A bicycle braking device according to claim 1, wherein an inner peripheral surface of a brake drum for fixing the lining of the bicycle braking device according to claim 1 is provided with a concavo-convex process for stabilizing the fixing of the lining. 3. The bicycle braking device according to claim 2, wherein the inner peripheral surface of the brake drum of the bicycle braking device according to claim 2 is formed by knurling to make unevenness for stabilizing the fixing of the lining.