JPH08239076A - Brake device for bicycle - Google Patents

Abstract

PURPOSE: To get enough braking force by enabling a link base to be kept in specified posture without shifting it even if a brake shoe abuts on the side of a rim and reaction force works on the brake shoe, by equipping this brake device with a posture maintenance means which maintains the mounting posture to a frame of the link base in specified posture. CONSTITUTION: When a rider operates a brake lever, an inner wire 10b is pulled, and brake arms 12a and 12b rotate each in the direction of their closing, and friction pads 47a and 47b of brake shoes 30a and 30b are pressed against the side 5a of a rim 5. At this time, shoe fixing links 32a and 32b shifts inward as they are in horizontal posture by the work of link mechanisms including auxiliary links 39a and 39b, respectively, and the friction pads 47a and 47b are pressed exactly against the rim 5. Moreover, even if reaction force works to the friction pads 47a and 47b, the link base 14 is kept in required posture by a lock pin 20a as a posture maintenance means, and it can exhibit enough braking force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to braking devices, and in particular to
The present invention relates to a brake device which is supported by a fixed pin extending from a pedestal provided on a frame of a bicycle and is driven by a brake wire to press a brake shoe against a rim of a wheel.

[0002]

2. Description of the Related Art For example, a bicycle capable of off-road running called a mountain bike (MTB) or an all-terrain bike (ATB) is generally equipped with a cantilever type brake device in order to obtain a strong braking force. .
A cantilever type brake device includes a brake arm rotatably and cantilevered by a front fork or a rear fork provided in front and rear of a frame of a bicycle, and a brake shoe fixed in the middle of the brake arm. . The brake arm has one end rotatably supported by the frame and the other end connected to the brake wire. Further, the brake shoes are arranged opposite to both side surfaces of the bicycle wheel rim in the middle of the brake arm.

In this cantilever type bicycle brake device, the brake wire is pulled by the brake lever to rotate the brake arm in the closing direction, and the brake shoe is pressed against the rim for braking. Such a cantilever type brake device has an advantage that it is not necessary to change the shape depending on the size of the bicycle unlike a caliper brake device, and the brake is hard to be applied one-sided and a uniform braking force can be obtained on the left and right.

However, in the cantilever type brake device, when the brake shoe rotates downward from the horizontal plane due to the rotation of the brake arm, the pressing force becomes small if the brake shoe comes into contact with the rim side surface without adjusting to the inclination. Therefore, it is necessary to accurately adjust the relative mounting positions of the rim side surface and the brake device, but this adjustment work is difficult.

As a conventional technique for solving this problem, there is a 4-link type brake device. This four-link type brake device includes a brake arm swingably supported by a fixed pin extending from a pedestal and an upper end of which is positioned outside the fixed pin, and an output that is rotatably supported in the middle of the brake arm and extends outward. The link, a driven link that extends downward and is rotatably connected to the output link, and a stationary link that is rotatably connected to the driven link and that extends inward and is non-rotatably connected to a fixed pin. ing. Moreover, a brake shoe is attached to the middle of the output link. In this brake device, when the brake arm is rotated upward by the brake wire, the driven link is rotated inward and the output link is moved horizontally or upward. As a result, the brake shoe comes into contact with the side surface of the rim horizontally or upward.

[0006]

SUMMARY OF THE INVENTION In the above conventional configuration,
The static link is non-rotatably connected to the fixed pin by utilizing the frictional force of a bolt screwed into the tip of the fixed pin. Therefore, when a strong braking force is applied to the brake shoe, the static link rotates due to the reaction force against friction,
The brake shoes may escape from the side surface of the rim and a sufficient braking force may not be obtained. Further, the stationary link may rotate due to looseness or rattling of the bolt, and a sufficient braking force may not be obtained.

An object of the present invention is to obtain a sufficient braking force in a bicycle brake device in which a brake shoe is pressed against a rim of a bicycle wheel.

[0008]

A bicycle brake device according to a first aspect of the present invention is supported by a fixed pin extending from a pedestal provided on a frame of a bicycle and driven by a brake wire to press a brake shoe against a rim of a wheel. The device includes a pair of left and right brake arms, a pair of left and right link members, a pair of left and right shoe mounting members, a link base, a posture maintaining means, and a biasing member. The brake arm has a lower end rotatably supported by a fixed pin in a cantilever manner, and an upper end connected to a brake wire. The link member is provided in parallel with each of the pair of brake arms. The shoe mounting member is such that the upper end of the link member and the intermediate portion in the vertical direction of the brake arm are rotatably connected, and a brake shoe can be mounted. The link base is attached to the frame. The posture maintaining means is for maintaining the mounting posture of the link base on the frame in a predetermined posture. The urging member urges the pair of brake arms in a direction in which the upper ends thereof open.

In the bicycle brake device according to the second aspect of the present invention,
In the device according to the first aspect of the invention, the link members are arranged side by side inside the brake arm. A bicycle brake device according to a third aspect of the present invention is the bicycle brake device according to the first aspect, wherein the link members are arranged side by side outside the brake arm. Invention 4
The bicycle brake device according to any one of the first to third aspects of the present invention is further provided with a connecting member that abuts an outer wire of the brake wire, wherein the brake arm is convexly curved outward, and one of the brake arms is a brake. The wire is fixed to the tip of the inner wire, and the other is connected to the connecting member.

In the bicycle brake device according to the fifth aspect of the present invention,
In the device according to any one of the inventions 1 to 4, the pedestal has a plurality of holes arranged on the same circumference centered on the axis of the fixing pin, and the posture maintaining means includes the link base to the pedestal. Has a pin that projects toward and is locked in any one of the plurality of holes. A bicycle brake device according to a sixth aspect of the present invention is the bicycle brake device according to any one of the first to fifth aspects, wherein the shoe attachment member has a vertically elongated long hole for attaching the brake shoe, and the elongated hole has a spherical or semi-cylindrical shape. Further including a washer having a concave surface and a convex surface and further fastening means for fastening the brake shoe so as to be vertically tiltable.

[0011]

In the bicycle brake device according to the first aspect of the present invention, when the brake arm is rotated inward by the brake wire, the shoe attachment members rotatably connected to the middle of the brake arm are moved inward. An upper end of a link member provided in parallel with the brake arm is connected to the shoe attachment member. The lower end of the link member is connected to the link base mounted on the frame in a predetermined mounting posture by the posture maintaining means. Therefore, the shoe attachment member is regulated by the brake arm and the link member so as to be oriented horizontally or upward and moves inward, and the brake shoe comes into contact with the rim side surface of the wheel. Further, when the brake wire is loosened, the upper end of the brake arm is rotated in the opening direction by the biasing member, and the brake is released.

Here, even if the brake shoe comes into contact with the side surface of the rim and a reaction force acts on the brake shoe, the link base does not move while maintaining a predetermined posture, so that the brake shoe does not escape and it is sufficient. Braking force is obtained. In the bicycle brake device according to the second aspect of the invention, since the link member is arranged inside the brake arm, the dimension of the brake device in the width direction is compact.

In the bicycle brake device according to the invention 3,
Since the link member is arranged outside the brake arm, the gap between the rim and the brake arm becomes large,
Easy to change tires. A bicycle brake device according to a fourth aspect of the present invention further includes a connecting member that abuts an outer wire of the brake wire, wherein the brake arm is curved outwardly in a convex shape, one of which is fixed to an end of the inner wire of the brake wire and the other of which is It is connected to the connecting member. In this case, when the inner wire is pulled, the length of the inner wire exposed from the outer wire is shortened, so that the upper end of the brake arm is closed and pivoted inward. Here, the brake can be operated simply by fixing one inner wire to one brake arm. Further, the gap between the brake shoe and the rim side surface can be easily adjusted by adjusting the fixing position at the tip of the inner wire. Furthermore, since the tip of the outer wire of the brake wire can be arranged between both brake arms, the brake wire is unlikely to project outward.

In the bicycle brake device according to the fifth aspect of the present invention,
The pedestal has a plurality of holes arranged on the same circumference centered on the axis of the fixing pin, and the link base is maintained in a predetermined mounting posture by the pin engaging with any one of the holes. ing. In this case, the mounting posture of the link base can be changed by using the hole for setting the restoring force of the normal cantilever-type brake device, and the bicycle having the cantilever-type brake device can be mounted on the bicycle later. A brake device can be attached. Further, by changing the mounting posture, the posture of the shoe mounting member can be changed. Therefore, depending on the shape and size of the rim, it becomes easy to adjust the brake shoe so as to always contact the side surface of the rim horizontally or upward.

In the bicycle brake device according to the sixth aspect of the present invention,
The shoe mounting member has a vertically elongated long hole, includes a washer having a spherical or semi-cylindrical concave surface and a convex surface, and further includes fastening means for fastening the brake shoe in a vertically tiltable manner. In this case, when the brake shoe is attached to the shoe attachment member, the vertical position of the attachment and the direction of the brake shoe can be adjusted arbitrarily or by limiting the direction. Therefore, the brake shoe can be attached to the rim at the optimum position and angle, and a stronger braking force can be obtained.

[0016]

1 and 2, a brake device 1 for a bicycle adopting an embodiment of the present invention is for a front wheel, for example, and is pressed against both side surfaces 5a of a rim 5 of the front wheel 2 for braking. To work. The brake device 1 is rotatably supported in the middle of the front fork 4 of the frame 3. Front fork 4
Is, for example, an air-oil type or elastomer type suspension fork, and can absorb a shock from the road surface. The front fork 4 has a pair of suspension portions 4a, a mounting portion 4b for mounting the pair of suspension portions 4a, and a brake arch 4c for reinforcing the suspension portion 4a. The brake arch 4c has a substantially bifurcated, inverted U-shape, and its lower end is fixed in the middle of the suspension portion 4a.

The brake device 1 is connected to an end portion of a brake wire 10 extending from a brake lever 7 provided on a handle 6. The braking device 1 is shown in FIGS.
The inner wire 10b of the brake wire 10 as shown in FIG.
Brake arm 12a fixed to the tip of the brake arm 1 and the brake arm 1 symmetrically arranged with the brake arm 12a
2b and. A connection arm 11 that is in contact with the outer wire 10a of the brake wire 10 and extends inward is rotatably connected to the upper end of the brake arm 12b. Both brake arms 12a and 12b have a long S-shape that is curved outwardly from the upper end to the lower end in a convex shape and a concave shape. As shown in FIG. 4, the lower ends of the brake arms 12a and 12b are rotatably supported by fixing pins 13a and 13b via link bases 14a and 14b (only 14a is shown).

Since the members described below including the fixing pins 13a and 13b are bilaterally symmetrical members, only the right member of FIG. 2 will be described in the following description, and the description of the left member of FIG. 2 will be omitted. . The fixing pin 13a is shown in FIGS.
As shown in, the stepped pin projects forward from the pedestal 15a provided inside the lower end of the brake arch 4c. As shown in FIG. 5, the fixing pin 1 is provided on the inner surface of the pedestal 15a.
Three holding holes 16 on the same circumference centered on the axis of 3a
a is formed vertically. The holding hole 16a is a hole for adjusting the strength of the return spring of a normal cantilever type brake device.

As shown in FIG. 4, the fixing pin 13a is provided with
The link base 14a is supported. Link base 1
4a is a cylindrical portion 17a arranged on the outer periphery of the fixed pin 13a and having a base end abutting on the stepped portion 13c of the fixed pin 13a.
And a locking portion 18a fitted and fixed to the outer circumference of the base end of the tubular portion 17a, and a raindrop-shaped arm portion 19a fitted and fixed to the outer circumference of the tip end. The brake arm 12a is rotatably supported by the tubular portion 17a. As shown in FIG. 5, the locking portion 18a is a substantially triangular member, and a locking pin 20a penetrating any one of the holding holes 16a is provided inside thereof. This locking pin 20a
By penetrating the holding hole 16a into the link base 14
The mounting posture of "a" is maintained in a predetermined posture.

On the outer circumference of the link base 14a, a spring receiver 21a is provided between the brake arm 12a and the locking portion 18a. Spring receiver 21a
Has a groove 22a formed in the circumferential direction and an adjusting portion 23a (FIG. 5) arranged on the outer circumference. The base end of the return spring 24a is wound and fixed in the groove 22a. The tip end portion of the return spring 24a extends upward and is locked by a locking pin 25a (FIG. 3) projecting to the back side at the intermediate portion of the brake arm 12a. The return spring 24a is used for the brake arm 12
A is urged to rotate outward. Adjustment unit 23a
Includes a protrusion 26a formed on the outer periphery of the locking portion 18a.
The adjusting screw 27a that can come into contact with is screwed. The postures of the left and right brake arms 12a, 12b can be adjusted by adjusting the screwing amount of the adjusting screw 27a to adjust the clearance between the left and right brake shoes 30a, 30b (described later) and the rim side surface 5a.

A pair of lock nuts 28a and 29a (FIG. 4) are screwed between the brake arm 12a and the arm portion 19a on the outer periphery of the link base 14a. The lock nuts 28a and 29a are used for the brake arm 1.
The movement of 2a in the axial direction is restricted. Fixed pin 1
A mounting bolt 31a is fastened to the tip of 3a. The mounting bolt 31a suppresses the movement of the link base 14a in the axial direction.

As shown in FIGS. 2 and 3, a brake shoe 30 is provided at an intermediate portion in the vertical direction of the brake arm 12a.
A shoe fixing link 32a for attaching a to the rear portion of the apparatus 1 is attached substantially horizontally. The shoe fixing link 32a is rotatably connected to the brake arm 12a by a mounting pin 33a penetrating both. As shown in FIG. 6, the shoe fixing link 32a has an arm attachment portion 34a formed in a U shape so as to sandwich both sides of the brake arm 12a, and a shoe attachment portion 35a extending at a right angle from the arm attachment portion 34a. are doing. Arm attachment part 3
4a is provided with a mounting hole 36a for penetrating two U-shaped pieces for mounting the mounting pin 33a, and a fixing hole 37a for fixing the support pin 38a. The support pin 38a is for rotatably supporting an auxiliary link 39a described later. In this way, by connecting the shoe attachment portion 32a and the brake arm 12a so as to sandwich the brake arm 12a, the rigidity of the connecting portion can be increased and the escape of the brake shoes 30a and 30b can be suppressed. The shoe attachment portion 35a is formed with a shoe attachment elongated hole 40a that is long in the vertical direction (the depth direction of the paper surface of FIG. 6). As shown in FIG. 3, the shoe mounting elongated hole 40a is provided with the rear end of the brake shoe 30a and the fixing pin 1.
The distance L between the stepped portion 13c of 3a is 25 mm or more. When the shoe mounting elongated hole 40a is arranged at such a position, the braking center becomes closer to the center of the front fork 4, and the moment generated by the reaction force becomes smaller. Therefore, the force acting on the front fork 4 is weakened, and the rigidity of the brake device is increased.

The auxiliary link 39a, as shown in FIG.
It is a flat plate member, and its upper end is rotatably connected to the front surface of the arm attachment portion 34a of the shoe fixing link 32a by a support pin 38a. Further, as shown in FIGS. 2 and 4, the lower end portion is rotatably connected to the link base 14a by a support pin 41a attached to the tip of the arm portion 19a.

The distance from the axis of the fixed pin 13a to the axis of the support pin 41a is equal to the distance from the axis of the mounting pin 33a to the axis of the support pin 38a. In addition, the distance from the axis of the support pin 38a disposed at both ends of the auxiliary link 39a to the axis of the support pin 41a and the fixed pin 13
The distance from the axis of a to the axis of the mounting pin 33a is equal. That is, these four pins are arranged so as to form the vertices of a parallelogram, and a part of the brake arm 12a, the link base 14a, a part of the shoe fixing link 32a and the auxiliary link between these pins are arranged. A link mechanism is constituted by 39a. For this reason, the shoe fixing link 32a includes the shaft center of the fixing pin 13a and the support pin 41a.
Move parallel to the line connecting the axis of.

The brake shoe 30a is inserted into the shoe attachment elongated hole 40a as shown in FIG. The brake shoe 30a includes a shoe fixing pin 45a, a shoe holder 46a fixed to the tip of the shoe fixing pin 45a,
It has an elastic friction pad 47a attached to the shoe holder 46a. The shoe fixing pin 45a is
A round head bolt with a hexagonal hole, and the round head and shoe mounting part 35
a and between the shoe holder 46a and the shoe mounting portion 35a
Between the convex washer 48a having a convex surface forming a part of a spherical surface and a concave washer 49 having a concave surface engaging with the convex surface.
a and are arranged. Here, by engaging the brake shoe 30a in the elongated hole 40a of the shoe attachment portion 35a with the convex washer 48a and the concave washer 49a interposed, the vertical position and inclination of the brake shoe 30a can be adjusted.
It can be freely adjusted according to the position and inclination of the side surface 5a.

Next, the operation of the above embodiment will be described. When the driver operates the brake lever 7, the inner wire 10b is pulled into the outer wire 10a, and the upper ends of the brake arms 12a and 12b are pulled inward. As a result, the brake arms 12a and 12b rotate in the closing direction, and the brake shoes 30a and 3b are rotated.
The friction pads 47a, 47b of 0b are brought into pressure contact with the side surface 5a of the rim 5 to perform a braking action. At this time, the shoe fixing links 32a and 32b are respectively connected to the auxiliary links 39a and
By the action of the link mechanism including 39b, it moves inward while maintaining a horizontal posture. This is shown in FIGS. 7 (A) and 7 (B). As a result, the friction pad 47 is surely attached to the rim 5.
The a and 47b come into contact with each other, and a strong braking force can be obtained. The auxiliary link 39a is provided on the brake arm 12a,
Since it is arranged inside 12b, the width dimension of the brake device 1 becomes compact. As a result, the brake device 1 does not project from the front fork 4 and does not hit the leg or the like during operation. Further, the friction pads 47a,
Even if a reaction force acts on 47b, link bases 14a, 14
Since b maintains its own posture by the locking pins 20a and 20b, a sufficient braking force can be obtained.

When the brake lever 7 is released, the brake wire 10 is loosened and the return spring 24a,
By 24b, the brake arms 12a, 12b are rotated in the opening direction, the tips of the friction pads 47a, 47b of the brake shoes 30a, 30b are separated from the side surface 5a of the rim, and the brake is released. Other Embodiments (a) Although the brake shoe 30a is arranged in the rear part of the brake device 1, it may be arranged in the front part. (B) In this embodiment, the auxiliary links 39a and 39b are arranged inside the brake arms 12a and 12b.
It may be arranged outside as shown in FIG. (C) In the above embodiment, the four pins are arranged at the vertices of the parallelogram, but these are not arranged at the vertices of the parallelogram, and the tips of the brake shoes 30a, 30b are along the side surface 5a of the rim 5. You may change each length like this. By changing the length in this way, for example, the shoe fixing links 32a and 32b can be moved in an upward or horizontal arbitrary posture at the time of contact. (D) The brake device 1 may be attached to the rear fork instead of the front fork. (E) As shown in FIG. 9, a structure may be used in which both sides of the shoe fixing link 32a are sandwiched by the brake arms 12a.

[0028]

With the bicycle brake device according to the first aspect of the present invention, the link base does not move in a predetermined posture even when the brake shoe comes into contact with the side surface of the rim and a reaction force acts on the brake shoe. Shoe does not escape and sufficient braking force is obtained.

In the bicycle brake device according to the second aspect of the present invention,
Since the link member is arranged inside the brake arm, the dimension of the brake device in the width direction is compact.
In the bicycle brake device according to the third aspect of the present invention, since the link member is arranged outside the brake arm, the gap between the rim and the brake arm becomes large, and tire replacement is easy.

In the bicycle brake device according to the invention 4,
The brake can be operated simply by fixing one inner wire to one brake arm. Further, the gap between the brake shoe and the rim side surface can be easily adjusted by adjusting the fixing position at the tip of the inner wire. Furthermore, since the tip of the outer wire of the brake wire can be arranged between both brake arms, the brake wire is unlikely to project outward.

In the bicycle brake device according to the fifth aspect of the present invention,
The mounting posture of the link base can be changed by using the hole for setting the restoring force of the normal cantilever type brake device, and the brake device of the present invention can be attached later to the bicycle to which the cantilever type brake device is attached. .
Further, by changing the mounting posture, the posture of the shoe mounting member can be changed. Therefore, depending on the shape and size of the rim, it becomes easy to adjust the brake shoe so as to always contact the side surface of the rim horizontally or upward.

In the bicycle brake device according to the invention 6,
When attaching the brake shoe to the shoe attachment member, the vertical position of the attachment and the direction of the brake shoe can be adjusted arbitrarily or by limiting the direction. Therefore, the brake shoe can be attached to the rim at the optimum position and angle, and a stronger braking force can be obtained.

[Brief description of drawings]

FIG. 1 is a front side view of a bicycle that employs an embodiment of the present invention.

FIG. 2 is a front view of a brake device.

FIG. 3 is a side view of the brake device.

4 is a sectional view taken along line IV-IV in FIG.

5 is a cross-sectional view taken along line VV of FIG.

6 is a sectional view taken along line VI-VI in FIG.

FIG. 7 is a schematic diagram showing an operating state of a brake.

FIG. 8 is a diagram corresponding to FIG. 2 of another embodiment.

FIG. 9 is a view corresponding to FIG. 6 of still another embodiment.

[Explanation of symbols]

 1 Brake device 4 Front fork 10 Brake wire 10a Outer wire 10b Inner wire 11 Connecting arm 12a, 12b Brake arm 13a, 13b Fixing pin 14a, 14b Link base 15a, 15b Pedestal 16a, 16b Holding hole 19a, 19b Brake shoe 20a, 20b Locking pin 24a, 24b Return spring 30a, 30b Brake shoe 32a, 32b Shoe fixing link 39a, 39b Auxiliary link

Claims (6)

[Claims] 1. A brake device which is supported by a fixing pin extending from a pedestal provided on a frame of a bicycle and is driven by a brake wire to press a brake shoe against a rim of a wheel, the lower end portion of which is fixed to the fixing pin. A pair of left and right brake arms which are movably supported in a cantilever manner and whose upper ends are connected to the brake wires; a pair of left and right link members provided in parallel with each of the pair of brake arms; Upper and lower end portions of the brake arm are rotatably connected to each other, and a pair of left and right shoe mounting members on which the brake shoes can be mounted and a lower end portion of the link member are rotatably attached. A link base connected and attached to the frame, and for maintaining the attachment posture of the link base to the frame in a predetermined posture. A position maintaining means, a biasing member for biasing the pair of brake arm in the direction of opening its upper part, bicycle brake apparatus having a. 2. The bicycle brake device according to claim 1, wherein the link members are juxtaposed inside the brake arm. 3. The bicycle brake device according to claim 1, wherein the link members are arranged side by side outside the brake arm. 4. A connecting member that abuts an outer wire of the brake wire, wherein the brake arm is curved outwardly in a convex shape, one of which is fixed to a tip of an inner wire of the brake wire, and the other of which is fixed. The bicycle brake device according to any one of claims 1 to 3, which is connected to the connecting member. 5. The pedestal has a plurality of holes arranged on the same circumference centered on the axis of the fixing pin, and the posture maintaining means directs from the link base to the pedestal. The bicycle brake device according to any one of claims 1 to 4, further comprising a pin that protrudes and is locked in any one of the plurality of holes. 6. The shoe mounting member has a vertically elongated long hole for mounting the brake shoe, and in the elongated hole, a washer having a spherical or semi-cylindrical concave surface and a convex surface is included, and the brake shoe is tilted up and down. The bicycle brake device according to any one of claims 1 to 5, further comprising a fastening unit that is fastened.