JP3638295B2 - Bicycle hub brake - Google Patents

Description

[0001]
[Industrial application fields]
The present invention includes a brake drum that rotates integrally with a wheel hub and a brake member that presses against the brake drum, and holds the brake member and an operation member that presses the brake member against the brake drum. The present invention relates to a bicycle hub brake having a member.
[0002]
[Prior art]
In the above-described bicycle hub brake, conventionally, as shown in, for example, Japanese Utility Model Laid-Open No. 2-35897, the holding member is configured to rotate around the axis of the wheel hub and the brake operation is performed. When the braking reaction force acts on the holding member, the free end side of the holding member is received and supported by the wheel fork via a coil spring as an elastic body, thereby preventing the wheel from locking during braking operation. I was able to do it. That is, when the frictional force between the brake body and the brake drum increases with the brake operation, the holding member rotates in the wheel rotation direction while elastically deforming the coil spring due to this friction and the rotational force of the brake drum. As a result, since the operating member is also held by the holding member, it rotates around the hub axle together with the holding member, and the pulling operation force of the brake wire that pulls the operating member to the brake entry side is reduced and the brake is The power is automatically reduced.
[0003]
[Problems to be solved by the invention]
Conventionally, since the holding member is received and supported by a single coil spring, the length from the rotation center position of the holding member to the free end becomes longer, or the braking force by adjusting the operation of the brake lever It was difficult to adjust.
That is, as soon as the brake starts to act and the braking reaction force starts to act on the holding member, the coil spring starts to deform, so even if the operating member is operated to the stroke end, the braking force does not increase to a sufficient strength. After the braking force increases to a certain level, the coil spring needs to be deformed so that the braking force can be sufficiently obtained. For this purpose, the coil spring needs to be configured to receive and support the holding member without being deformed until the brake force is effective to some extent, and the brake force has just started to work and the brake force is not so strong. Since the braking reaction force acting on the operating member is strong even at times, it is necessary to create the coil spring as a solid spring. In this case, if the length from the rotation center position of the holding member to the free end is shortened so that the holding member is small, the distance from the rotation center position of the holding member to the position where the coil spring acts is shortened. Since the coil spring is difficult to deform, the stroke in which the holding member rotates to the stroke end while deforming the coil spring becomes small. Then, of the stroke that can be operated by the brake lever, the stroke portion where the coil spring deformation occurs becomes small, and it becomes difficult to adjust the braking force at this stroke portion, so the stroke portion where the coil spring deformation occurs becomes large. In order to easily adjust the braking force, it has been necessary to increase the length of the holding member from the rotation center position to the free end.
SUMMARY OF THE INVENTION An object of the present invention is to provide a bicycle hub brake that can prevent wheel lock due to automatic lowering of the braking force, is easy to adjust the braking force, and is compactly obtained.
[0004]
[Means for Solving the Problems]
In the bicycle hub brake according to the present invention, in order to achieve the object, in the one described at the beginning, an attachment portion for attaching the holding member near the tip of the wheel fork is connected to the holding member, and A holding member is provided so as to be rotatable around the axis of the wheel hub, and is configured to receive a reaction force at the time of brake operation with the wheel fork via the mounting portion, and between the holding member and the wheel fork. A plurality of elastic bodies are interposed, and the braking force is reduced by elastic deformation of the elastic bodies. In addition, the mounting portion that also serves as a spring case is connected to the end portion of the holding member that is located on the opposite side of the wheel hub, and the plurality of elastic bodies are connected to each other through the bellows type connecting member. It arrange | positions inside an edge part, a bellows type connection member, and an attaching part, It is characterized by the above-mentioned.
[0005]
[Action]
When a braking reaction is applied to the holding member by performing a braking operation, the holding member rotates around the hub axle while deforming a plurality of elastic bodies, and the operating member moves together. The force decreases and the braking force decreases automatically.
Since the holding member is received and supported by a plurality of elastic bodies, the overall elastic coefficient is finely adjusted and set by combining the plurality of elastic bodies, and the length from the rotation center position of the holding member to the free end is The braking reaction force when the elastic body starts to be deformed and the stroke that the holding member rotates after the elastic body starts to be deformed are shorter than the conventional one that employs a single elastic body, and the desired stroke. It can be adjusted and set so as to be a reaction force or stroke, or to be closer to a desired reaction force or stroke than before.
[0006]
【The invention's effect】
Even if the brake is operated to the operation limit, the brake force automatically decreases during the operation and the brake does not work so effectively that the brake can be advantageously operated so that the wheel lock does not occur. Furthermore, when setting the elasticity of the elastic body, the elastic body starts to deform at an appropriate timing and the maximum braking force does not decrease too much. It is set appropriately so that it can be secured, and it is possible to easily adjust the braking force to a desired strength in an operation range in which a relatively strong braking force is generated after the elastic body starts to be deformed. In this way, it became possible to operate the brake force to a relatively strong maximum, and from this aspect, it became possible to operate the brake advantageously.
In addition, the holding member is formed in a small size having a relatively short length from the rotation center position to the free end, and can be assembled so as to be inconspicuous as much as possible to constitute a vehicle body with high commercial value.
[0007]
【Example】
As shown in FIGS. 1 and 2, a holding member 4 having a notch hole 4a on one end side of a front wheel hub 3 configured to be attached to a fork 1 for a front wheel of a bicycle via a hub shaft 2, an operation member 5. A hub brake B provided with decorative caps 6, 7 and the like is attached, the inner wire 8a of the brake wire 8 is connected to the wire connector 5a provided in the operation member 5, and the inner wire 8a is operated by pulling or loosening. When the member 8a is swung around the axis of the hub shaft 2 and the operation member 8a is swung, the hub brake B brakes the front wheel hub 3 or releases the braking operation. This is a hub with a brake for a bicycle front wheel.
[0008]
The hub brake B is configured as follows.
That is, as shown in FIGS. 5 and 6, the brake drum 9 is integrally formed on one end side of the front wheel hub 3 so as to rotate integrally with the front wheel hub 3. Are provided with three brake bodies 10 dispersed in the circumferential direction of the brake drum 9, six rollers 11..., And a roller case 12. It is. When the operating member 5 is at the cutting position OFF shown in FIG. 6, the operating cam portion 5 b of the operating member 5 is positioned as shown in the figure with respect to the roller 11, and the braking body presser that presses and biases the braking body 10 against the roller 11. Due to the diameter-reducing force of the spring 13, the roller 11 enters the recessed portion of the operation cam portion 5 b and the brake body 10 is separated from the inner peripheral surface of the brake drum 9, and the brake is cut off. When the inner wire 8a is pulled from this brake cut state, the operation member 5 swings from the cut position OFF to the ON direction, and the operation cam portion 5b of the operation member 5 rotates in the direction a as shown in FIG. And the cam surface 5c of the operation cam portion 5b presses and moves the roller 11 toward the brake drum 9, so that the roller 11 presses the braking body 10 against the inner peripheral surface of the brake drum 9, and the braking body 10 The drum 9 is braked so as to apply a friction brake. When the inner wire 8a is loosened from this braked state, the operating member 5 returns to the cut position OFF due to the return spring 14 acting on the wire connector 5a, and the brake for the brake body pressing spring 13 is braked. The body 10 leaves the brake drum 9 and returns to brake breaking.
[0009]
As shown in FIG. 5, the case fixing pin 15 extends from the roller case 12, and the extended end side of the case fixing pin 15 enters the through hole 4 b as shown in FIG. 4 of the holding member 4 and is engaged with the holding member 4. By stopping, the case fixing pin 15 is configured to prevent rotation of the roller case 12 with respect to the holding member 4. Further, as clearly shown in FIG. 6, the roller case 12 accommodates the roller 11 and prevents the roller 11 from rotating and revolving, and the roller 11 enters the recessed portion 10 a of the braking body 10 to cause braking. The holding member 4 engages the brake body 10 via the case fixing pin 15, the roller case 12, and the roller 11 by engaging the brake body 10 so as to prevent the body 10 from rotating together with the brake drum 9. When the brake body 10 is applied to the brake drum 9 by braking, the braking reaction force is applied to the holding member 4. That is, during forward travel, the brake drum 9 rotates in the direction b shown in FIG. 1, and a rotating operation force by the brake drum 9 that rotates in the direction b acts on the holding member 4.
[0010]
A portion of the holding member 4 located on the hub side is rotatably fitted to the hub shaft 2 by a boss portion 4c provided at this location, and an end portion 4d located on the opposite side of the hub side is provided at this location. Are attached to the spring case connected to the front end of the front wheel fork 1 near the front end of the fork 1 for the front wheel. As shown in FIGS. 3 and 4, by arranging the four coil springs 18, 19 inside the end portion 4 d of the holding member 4, the bellows type connecting member 16, and the mounting portion 17, the coil spring 18, When 19 is located between the holding member 4 and the front wheel fork 1 and a braking reaction force acts on the holding member 4, the front wheel fork 1 applies a braking reaction force via the coil springs 18, 19 and the mounting portion 17. It is configured so as to be received, and as the pressing force of the braking body 10 against the brake drum 9 increases and the braking reaction force acting on the holding member 4 increases, the rotational operation force by the rotating brake drum 9 increases. Therefore, the holding member 4 is configured to rotate in the b direction together with the brake drum 9 around the axis of the front wheel hub 3 while elastically deforming the coil springs 18 and 19.
4 acts on the case fixing pin 15 to position the roller case 12 with respect to the holding member 4. The spring 15a shown in FIG.
[0011]
Since the operation cam portion 5b of the operation member 5 and the roller 11 are in pressure contact with each other, the holding member 4 holds the operation member 5 in a state of rotating integrally, and the holding member 4 holds the coil springs 18 and 19 together. When rotating around the hub axis while being elastically deformed, the operation member 5 also rotates together with the holding member 4. When the operation member 5 rotates in this way, the inner wire 8a that is pulling the operation member 5 in the ON direction, that is, the brake application direction is operated to the slack side, and the pulling operation force of the inner wire 8a is reduced. The brake force actually acting on the brake drum 9 is configured to be lower than the brake force acting when the pulling force of the inner wire 8a does not decrease due to the rotation of the holding member 4. Then, by configuring the holding member 4 to be received and supported by the plurality of coil springs 18 and 19, the elasticity of the whole spring is appropriately and delicately adjusted by combining the plurality of coil springs 18 and 19. As the brake lever (not shown) connected to the brake wire 8 is gripped and operated from the non-operation position to the stroke end, the brake force exerted by the hub brake B changes as shown in FIG. It is.
[0012]
That is, the horizontal axis indicates the brake lever operation stroke S, and the vertical axis indicates the brake force P of the hub brake B. When the brake operation is finished, the brake body 10 starts to come into contact with the brake drum 9 when the brake lever finishes operating the play stroke S1, and thereafter, as the operation stroke S of the brake lever increases, The braking force P increases along the solid line L1. When the operation stroke S of the brake lever reaches the stroke S2, the hub brake B exerts a braking force P1, and this braking force P1 is a ground braking force exerted by the tire when braking on a 26 inch tire. When converted to the tire tangential force F, it is 58 to 62 pounds. That is, around 60 pounds. This value is the braking force that effectively brakes the maximum braking force P2 obtained by operating the brake during traveling, while preventing deformation of the front wheel fork 1 and preventing wheel lock. It is an appropriate value to set. From this time, the coil springs 18 and 19 start to be elastically deformed, and the brake force is automatically reduced. As the brake lever operating stroke S further increases, the brake force P of the hub brake B reaches the solid line L2. Increase along. That is, when the coil springs 18 and 19 are not elastically deformed, the brake force P of the hub brake B is along the broken line L3 corresponding to the extension line of the solid line L1 as the operation stroke S of the brake lever increases. However, as compared with this case, even if the operation stroke S of the brake lever is the same, a low braking force is exhibited. Further, when the vehicle body is traveling forward, if a brake operation is performed, the rotational operation force by the rotating brake drum 9 acts on the holding member 4 and the coil springs 18 and 19 are elastically deformed, but the vehicle body stops. In this case, even if the brake is operated, the brake drum 9 is not rotated. Therefore, the rotation operation force does not act on the holding member 4 and the coil springs 18 and 19 are not elastically deformed. As a result, the brake lever can be operated only up to the operation stroke S3 when traveling is stopped, while the brake lever can be operated up to an operation stroke S4 larger than the operation stroke S3 during travel. Thus, during traveling, when the brake lever is operated to the stroke end, the hub brake B exhibits the maximum braking force P2. The relationship between the stroke portion W1 where the brake lever operates from the non-operation position to the start of elastic deformation of the coil springs 18 and 19, and the stroke portion W2 where the brake lever operates from the start of elastic deformation of the coil springs 18 and 19 to the stroke end. Is set to W1: W2 = 9: 8.
[0013]
As shown in FIGS. 2 to 4, the spring 18 having the larger coil diameter and the spring 19 having the smaller coil diameter among the coil springs 18 and 19 are arranged in a double spring, and a pair of double springs are arranged. The spring is juxtaposed to the holding member 4 so as to be arranged in the longitudinal direction of the front wheel fork 1 in a state where the holding member 4 is attached to the front wheel fork 1. In other words, when a plurality of coil springs 18 and 19 are employed, the space required for the arrangement is reduced and the length protruding from the front wheel fork 1 to the inside of the vehicle body or the outside of the vehicle body is suppressed. I am thinking so that I can do it.
[0014]
[Another Example]
Instead of the coil springs 18 and 19, rubber may be employed, or rubber and coil springs may be used in combination, and these are collectively referred to as elastic bodies 18 and 19. Further, a conical or pinched spring may be employed to adjust the change characteristic of the braking force.
[0015]
When applied to the front wheel as in the above embodiment, it is advantageous in that it prevents the lock of the wheel and the deformation of the fork for the front wheel due to excessive braking, but the present invention is not limited to the front wheel, and the hub brake for the rear wheel. It can also be applied to. In addition to the brake in which the brake drum is integrally formed with the hub, the brake drum is formed as a separate part from the hub, and the brake is configured to be connected to the hub so as to be integrally rotatable by a spline or the like. Is applicable. Furthermore, the present invention can also be applied to a brake configured as a band type in addition to a roller configured as in the above-described embodiment, or an internally expanded brake including a pair of braking bodies in an openable / closable manner.
[0016]
In addition, although the code | symbol is written in order to make contrast with drawing convenient for the term of a claim, this invention is not limited to the structure of an accompanying drawing by this entry.
[Brief description of the drawings]
FIG. 1 is a side view of the entire front wheel hub brake. FIG. 2 is a rear view of the entire front wheel hub brake. FIG. 3 is a sectional view of a coil spring mounting portion. FIG. 5 is a cross-sectional view of the front wheel hub brake. FIG. 6 is a side view of the brake body arrangement portion when the brake is off. FIG. 7 is a side view of the brake body arrangement portion when the brake is applied. Explanatory diagram showing the relationship between lever operating stroke and braking force [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Wheel fork 3 Wheel hub 4 Holding member 5 Operation member 9 Brake drum 10 Brake body 17 Attachment part 18, 19 Elastic body F Tire tangential force

Claims (3)

A brake drum (9) that rotates integrally with the wheel hub (3) and a brake body (10) that presses against the brake drum (9) are provided. The brake body (10) and the brake body (10) A bicycle hub brake having a holding member (4) for holding an operation member (5) for pressure-contacting the brake drum (9)
An attachment portion (17) for attaching the holding member (4) near the tip of the wheel fork (1) is connected to the holding member (4), and
The holding member (4) is provided so as to be rotatable around the axis of the wheel hub (3), and is configured to receive a reaction force at the time of brake operation by the wheel fork (1) via the mounting portion (17). And
A plurality of elastic bodies (18), (19) are interposed between the holding member (4) and the wheel fork (1), and the elastic bodies (18), (19) are elastically deformed. To reduce the braking force ,
The attachment portion (17), which also serves as a spring case, is connected to an end portion (4d) located on the opposite side of the wheel hub (3) of the holding member (4) via a bellows type connecting member (16). Are connected,
The plurality of elastic bodies (18), (19) are disposed inside the end portion (4d), the bellows type connecting member (16), and the attachment portion (17).
Bicycle hub brake. When the holding member (4) is attached to a wheel fork (1), the plurality of elastic bodies (18), (19) are arranged in the longitudinal direction of the fork (1). The bicycle wheel hub brake according to claim 1, wherein the hub brake is arranged side by side. The wheel hub (3) is a front wheel hub, and the plurality of elastic bodies (18), (19) have a tire tangential force (F) of around 60 pounds in terms of a 26-inch tire. 3. The bicycle hub brake according to claim 1, wherein the bicycle hub brake is set so as to be elastically deformed to reduce a braking force.

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