JPH0624317Y2 - Wire holding mechanism for bicycle caliper brake - Google Patents

Description

[Detailed description of the device] [Industrial applications]

The present invention relates to a wire holding mechanism for a caliper brake for a bicycle mounted on a competition bicycle or an assembled bicycle. More specifically, it is possible to avoid the loss of parts, hold the wire securely, and improve the workability of assembling. The wire holding mechanism is improved so that

[Prior art]

A side-pull caliper brake is one of the brakes that is generally used for competitive bicycles and assembled bicycles. First, the basic structure will be described with reference to FIG. In the caliper brake C, a first brake arm 5 that curves so as to sandwich a tire 3 or a rim 4 of a wheel 2 from both sides with respect to a support shaft 1 attached to an appropriate portion of a vehicle body.
The second brake arm 6 is swingably supported. Brake shoes 7 and 8 are attached to the tip ends of the brake arms 5 and 6, respectively, and the both brake arms 5 and 6 are always elastically moved by a spring 9 in a direction in which the brake shoes 7 and 8 are separated from each other. Being energized. Further, the end portion of the inner wire w1 is fixed to the actuating arm portion 10 of the first brake arm 5 extending to the side opposite to the support shaft 1, while the second brake arm 6 is slanted upward from its proper portion. The outer wire w2 is fixed to the extended operation arm portion 11. At the time of brake operation, first, a brake operating lever (not shown) is operated in the braking side direction to index the inner wire w1 in the arrow P direction so that the first brake arm 5 and the second brake arm 6 are respectively moved in the arrow p direction. Rock. Then the brake shoes 7, 8
Will pinch the side surface of the rim, and braking will be performed. Next, when the brake operating lever is operated in the braking release side direction (when the operating force of the lever is relaxed), the both brake arms 5 and 6 are returned in the arrow q direction by the elastic force of the spring 9, and the inner wire w1 moves in the arrow direction. It is pulled out in the Q direction and the braking by the brake shoes 7 and 8 is released. By the way, the opening degree of the brake arms 5 and 6 in the normal state, that is, the distance between the brake shoes 7 and 8 is as large as possible between the brake shoes 7 and 8 and the side surface of the rim in order to enhance the braking response. It is set to be small. As a result, as shown in FIG. 6, the distance between the brake shoes 7 and 8 becomes smaller than the width of the tire. Therefore, at the time of tire replacement, the tire cannot be inserted / removed through the clearance between the brake shoes 7 and 8.
Therefore, there is provided a brake device having a mechanism configured to adjust the substantial length of the inner wire w1 or the outer wire w2 by a screw means to temporarily widen the gap between the brake shoes 7 and 8. However, in a bicycle used for competition, it is necessary that the distance between the brake shoes can be expanded and contracted more easily and quickly. Therefore, the braking device used in those bicycles is
A pair of brake arms 5 and 6 by one-touch operation of lever
Is configured to expand and contract. The structure will be described below with reference to FIGS. 6 and 7. A rotating body 14 which is rotated by operating a lever 13 is inserted into a boss portion 12 provided on the actuating arm portion 10 of the first brake arm 5, and the inner wire is eccentrically located from the rotation center of the rotating body 14. A wire holding mechanism 15 for fixing the end portion of w1 is provided. Then, by rotating the lever 13, the rotating body 1
4 is rotated to vertically move the fastening point of the inner wire w1 with respect to the operation arm portion 10. That is, the operating arm portion 1 of the inner wire w1
By moving the fastening point with respect to 0 up and down, the operating arm portions 10 and 11 of the pair of brake arms 5 and 6 are relatively oscillated, thereby expanding and contracting the interval between the brake shoes 7 and 8. ing. On the other hand, in the caliper brake C having the above-described structure, in order to maintain the braking performance constant, the inner wire w is always provided at a portion eccentric from the rotation center of the rotating body 14.
It is necessary to hold one end. Therefore, the wire holding mechanism 15 is an important constituent factor for maintaining constant braking performance. Hereinafter, the structure of the conventional wire holding mechanism 15 will be specifically described with reference to FIG. The wire holding mechanism 15 is provided for the rotating body 14 inserted into the boss portion 12 of the first brake arm side actuating arm portion 10 and has the threaded hole 16a.
6, a bolt 17 that is screwed into the screw hole 16a, and the projecting piece 16 through the screw hole 16a and the bolt 17.
And a nut 19 that is screwed onto the shaft portion 16b of the sandwiching projection piece 16. The sandwiching projection 16 includes a screw shaft portion 16b which is inserted into an eccentric hole 14b formed in the shaft portion 14a of the rotating body 14, and a flange portion 16c which is connected to one end of the screw shaft portion 16b. A fixing portion 16d connected to the collar portion 16c is further provided, and the screw hole 16a is formed in the fixing portion 16d. Further, a contact surface 16e is formed at one end of the fixed portion 16d. A through hole 18a is formed in the pressing body 18. Next, a method of assembling the above-described conventional wire holding mechanism 15 will be described. First, the pressing body 18 is externally fitted on the leg portion of the bolt 17. Next, the bolt 17 is screwed into the screw hole 16a in the holding projection 16. Then, the end portion of the inner wire w1 is inserted between the projecting piece 16 and the pressing body 18. Finally, by tightening the bolt 17, the pressing body 18 is crimped to the contact surface 16e of the sandwiching projection piece 16,
Complete the assembly. As a result, the end portion of the inner wire w1 is fixed to a predetermined portion of the operating arm portion 10.

[Problems to be solved by the device]

By the way, in the wire holding mechanism 15 described above, by sandwiching the inner wire w1 between the sandwiching projecting piece 16 and the pressing body 18, screwing the bolt 17 into the screw hole 16a of the projecting piece 16, and tightening the bolt 17, Inner wire w1
Is designed to be fixed. In this case, as shown in FIG. 8, since the inner wire w1 is interposed between the projecting piece 16 and the pressing body 18, the pressing body 18 has the contact surface 1 thereof.
8b is placed in a state in which one end portion of 8b is separated from the protruding piece 16 by the thickness distance of the compressed inner wire w1, and only the other end portion of the contact surface 18b thereof is crimped to the contact surface 16e of the protruding piece 16. It will be placed in the state where it was. Therefore, when tightening the bolt, the screw shaft portion 17 of the bolt 17 is
A bending stress acts on a. Then, the bolt 17 having the bent shaft portion 17a is tightened, and the bolt 17 is repeatedly plastically deformed, so that the shaft portion 17a is broken. Further, due to the load concentration on the bolt bearing surface due to the tightening, stress concentrates on the connecting portion between the head portion 17b of the bolt 17 and the screw shaft portion 17a, and the head portion 17b can be damaged. Moreover, even if the head portion 17b of the bolt 17 is not damaged and the assembly is completed, there is a risk that the damage is caused by the external force applied during use. Therefore, there is a problem in that the wire is not reliably held and the safety is reduced. Further, since bending stress is applied to the screw shaft portion 17a, the bolt 17 in a bent state of the screw shaft portion 17a is tightened. Therefore, much labor is required as compared with tightening in the normal state. In addition, in the wire holding mechanism 15 having the above-described structure, when the head portion 17b of the bolt 17 is broken and missing, the bolt 17 remaining in the screw hole 16a of the pinching projection piece 16 remains.
It becomes difficult to take out the screw shaft portion 17a from the screw hole 16a. Therefore, there is also a problem that the assembly workability is reduced. In addition to the need for replacement parts due to the breakage of the bolts, it is disadvantageous in terms of manufacturing cost to machine and form a screw hole in a small device part such as the pinching projection piece 16 described above. Therefore, there is also a problem that the manufacturing cost becomes high. The present invention has been devised under the circumstances described above, and it is possible to avoid damage to the components, securely hold the wire, improve the workability of the assembly, and inexpensive. It is an object of the present invention to provide a wire holding mechanism for a bicycle caliper brake.

[Means for Solving the Problems]

In order to solve the above problems, the present invention takes the following technical means. That is, the present invention includes a first brake arm and a second brake arm that are swingably supported by a support shaft attached to an appropriate portion of the vehicle body, and the operation is extended to the opposite side of the support shaft in the first brake arm. A rotating body is inserted into the boss portion of the arm portion, and a wire holding mechanism for holding the inner wire is provided at a portion eccentric from the center of rotation of the rotating body, and the inner wire is rotated by rotating the rotating body by lever operation. Is a bicycle caliper brake configured such that a fastening point with respect to the operating arm portion of the bicycle can be moved up and down, wherein the wire holding mechanism is provided for the rotating body and has a through hole, and has one side surface. A sandwiching protrusion having a wire guide groove at a portion distant from the through hole, and a screw shaft portion is inserted into the through hole of the protrusion from a side where the wire guide groove is provided. A bolt that is passed through and has a pinching head, and that is prevented from rotating when the screw shaft portion is inserted into the through hole; and a nut that is screwed into the screw shaft portion of the bolt, By tightening the nut, between the head for clamping the bolt and the projecting piece for clamping, the inner wire is configured to be clamped while being held in the wire groove. There is.

[Action]

In the conventional example, a threaded hole is formed in the wire-holding projecting piece, and a bolt is screwed into the threaded hole to press the pressing body against the joint surface of the projecting piece. On the other hand, in the present invention, a through hole is formed in the sandwiching projection, a bolt having a sandwiching head is inserted into the through hole, and a nut is screwed into this bolt, whereby the bolt is attached to the projection. The clamping head is crimped. Here, comparing the wire holding mechanism of the present invention with that of the conventional example, first, the pressing body in the conventional example is omitted by using a bolt having a clamping head. Then, a through hole is formed in the sandwiching protruding piece instead of the screw hole. Further, the bolt is inserted into the through hole of the projecting piece, and the nut is screwed onto the screw shaft portion of the bolt projecting to the outside of the projecting piece. That is, in the present invention, the wire is directly clamped between the bolt and the protrusion by inserting the bolt into the through hole of the clamping protrusion and screwing the nut. In the conventional example, the wire is sandwiched between the pressing body and the sandwiching projection piece, and the pressing body is sandwiched between the bolt and the projection piece. Therefore, when the pressing body is crimped by tightening the bolts, only the joint surface of the end portion of the pressing body on the side opposite to the wire clamping portion is crimped to the joint surface of the projecting piece. It will bend. Then, a bending moment acts on the shaft portion of the bolt due to the reaction force. The magnitude of this bending moment increases as the tightening force of the bolt increases. Therefore, when tightening the bolt, a bending moment proportional to the tensile force acts on the bolt shaft portion, and the bolt shaft portion is bent in the acting direction. When the bolt having the bent shaft portion is screwed, the bolt is screwed while repeatedly undergoing plastic deformation. Therefore, a large force is required to rotate the bolt due to the deformation resistance. Therefore, it takes a lot of labor to tighten the bolt until the wire can be fixed, and a sufficient wire clamping force cannot be obtained. Moreover, since the bolt repeatedly undergoes plastic deformation, it causes fatigue and breaks. Moreover, when the bolt is screwed, the internal thread portion on the screw hole side is damaged. In addition, if the bolt is screwed until the wire can be sufficiently clamped, an even greater force is required, so that excessive load concentration occurs on the bolt seat surface, and therefore, the connecting portion between the head and the shaft of the bolt. Stress concentration will occur at. If this stress value exceeds the allowable shear stress value of the bolt, the bolt head will be damaged and chipped. On the other hand, in this invention, the wire is directly clamped by the bolt clamping head and the projecting piece by tightening the nut. That is, instead of tightening the bolt as in the conventional example, the rotation of the bolt is blocked and the nut is rotated and tightened to fix the wire. Therefore, the work itself of tightening the bolt with the shaft portion bent as in the conventional example is omitted. In this case, by tightening the nut to crimp the clamping head onto the projecting piece, only the end surface of the bearing surface opposite to the wire clamping section is crimped to the joint surface of the projecting piece. As a result, the bolt head is bent. Then, a bending moment acts on the bolt shaft portion due to the reaction force. At this time, since the bolt shaft portion is screwed into the nut on the outside of the sandwiching projection piece, in other words, the bolt has the shaft portion loosely fitted in the through hole of the projection piece, and only the lower end portion of the shaft portion. Since it is screwed into the nut on the outside of the protrusion, even if a bending moment acts on the shaft, this bending force is buffered by the bending of the bolt shaft itself in the through hole on the protrusion side. Moreover, since the nut is screwed onto the screw shaft portion of the bolt projecting to the outside of the protruding piece, the force required for tightening the nut is smaller than that in the conventional example. Therefore, as described above, it becomes possible to complete the tightening of the bolt before a bending moment of a magnitude that causes the breakage of the bolt acts on the screw shaft portion. The damage of the female screw portion is avoided, and the concentration of load on the bolt seat surface is avoided. Therefore, it is possible to avoid breakage of the bolt head when the bolt is tightened or used in the conventional example.

【effect】

As described above, according to the structure of the wire holding mechanism in the bicycle caliper brake of the present invention, since the rotation of the bolt is blocked, the head for pinching the bolt and the rotating body are not rotated. Since the inner wire can be directly pinched between the pin and the pinching protrusion, it is difficult to rotate the bolt due to the conventional bending of the bolt, early fatigue damage of the bolt, and damage to the head of the bolt. Besides the basic effect of being avoided,
Further, the following effects are achieved. That is, in the present invention, not only the inner wire is sandwiched between the sandwiching projection and the sandwiching head of the bolt, but a wire guide groove is provided in the sandwiching projection.
The inner wire is sandwiched in a state where the inner wire is held in the wire guide groove. By doing so, firstly, the workability of inserting the inner wire between the clamping head of the bolt and the clamping projection is significantly improved, and the inner wire is always placed at a uniform position on the clamping projection. I will be sandwiched,
Uniformity of the performance of the entire brake is ensured. Secondly, the inner wire is not crushed more than necessary, which extends the life of the inner wire, and even if the bolt clamping head is formed thin, the inner surface of the clamping head is Since it is possible to contact one side surface of the clamping projection over a wide range, a sufficient clamping force can be applied to the inner wire. This gives more freedom in designing the bolt head, for example:
As described above, by making the pinching head thin, or the like, the appearance of the entire wire holding mechanism can be made neat and organized. Further, the bolt of the present invention is configured to prevent rotation when inserted into the through hole of the sandwiching protrusion, so that the bolt does not rotate when the nut is rotated and tightened. It does not have to be held by a special tool. Therefore, the work of connecting the wires is very easy to perform.

[Explanation of Examples]

An embodiment of the present invention will be specifically described below with reference to the drawings. As shown in FIGS. 1 to 3, the wire holding mechanism 20 in this embodiment includes a support shaft 1 attached to an appropriate portion of the vehicle body.
It is provided on a bicycle caliper brake C including a first brake arm 5 and a second brake arm 6 which are swingably supported. The rotating body 14 is inserted into the boss portion 12 of the operation arm portion 10 of the first brake arm 5 that extends to the side opposite to the support shaft 1. The wire holding mechanism 20 is attached to a portion eccentric from the center of rotation of the rotating body 14, and the caliper brake C fixes the inner wire w1 to the operating arm portion 10 by rotating the rotating body 14 by operating a lever. The dots are configured to move up and down. As shown in FIGS. 1 and 2, the wire holding mechanism 20 is provided in the rotating body 14 and has a through hole 21.
and a through-hole 21a of this projecting piece 21.
A bolt 22 having a screw shaft portion 22a inserted therein and having a holding head portion 22b, and a hexagon socket nut 23 screwed to the screw shaft portion 22a of the bolt 22 are provided.
By tightening the inner wire w between the pinching head 22b of the bolt 22 and the pinching protrusion 21.
1 is sandwiched. The sandwiching projection 21 is provided on the shaft portion 1 of the rotating body 14.
Shaft portion 21b inserted into eccentric hole 14b formed in 4a
And a collar portion 21c coupled to one end of the shaft portion 21b,
The fixed portion 2 which has a substantially U-shaped outline and is connected to the collar portion 21c.
1d and the through hole 21 in the fixed portion 21d.
a is opened. Further, the shaft portion 21b is provided with a screw hole 21e in the axial direction thereof, and further the fixing portion 21
A wire guide groove 21g is formed at the end of the contact surface 21f of d on the flange side. The sandwiching projection 21 is fixed to the rotating body 14 when the set screw 24 is screwed into the screw hole 21e during assembly. The screw shaft portion 22a of the bolt 22 is a holding head portion 22b.
And the above-mentioned clamping projection 21 when assembled.
The fitting portion 22c that fits into the through hole 21a of the
2c and has a screw portion 22d that is screwed to the nut 23. Further, the pinching head 22b of the bolt 22 has a substantially U-shaped contour corresponding to the fixing portion 21d of the pinching protrusion 21, and prevents the bolt 22 from rotating during assembly. , Its lower end surface 22
e is the flange portion 21 of the protrusion 21 in the assembled state.
It is formed so as not to rotate so as to be superposed on the upper side surface 21h of c. Also, the bearing surface 22f of the bolt 22 is
Has been knurled to prevent the wire from slipping. A first tooth row 25 in the shape of a chrysanthemum is formed on one end of the boss portion 12 of the operation arm portion 10, while the collar portion 14 connected to the shaft portion 14a of the rotating body 14 is formed.
The c-shaped second tooth row 2 corresponding to the first tooth row 25 is shown in c.
6 is formed. Further, a contact surface 14d is formed at the lower end of the rotating body 14, and the axial dimension L of the shaft portion 14a of the rotating body 14 is the operating arm portion 1.
The contact surface 14d is larger than the axial dimension B of the boss portion 12 of 0.
The length is set to be longer by the axial length m. Therefore, the lever 13 fitted onto the rotating body 14 in the assembled state is movable within the range of the axial length m. Further, the operating arm portion 10 and the lever 13 are
A corrugated plate-shaped urging spring 27 for urging the rotating body-side second tooth row 26 in the direction of the operating arm portion-side first tooth row 25 is interposed between and. Then, the rotating body 14 is rotated stepwise through the both tooth rows 25 and 26 by rotating the lever 13. Therefore, the inner wire w1
It is possible to move the fastening point of the up and down stepwise between the top dead center and the bottom dead center. Next, a method of assembling the above-described mechanism to be provided on the rotating body 14 in the operating arm unit 10 will be described. First, so that the first tooth row 25 of the boss portion 12 and the second tooth row 26 of the rotating body 14 of the operating arm portion 10 correspond to each other,
The rotating body 14 is inserted into the boss portion 12. Next, the biasing spring 27 and the lever 13 are externally fitted to the shaft portion 14a of the rotating body 14. Then, the holding projection piece 21 is inserted into the eccentric hole 14b of the rotating body 14, the set screw 24 is screwed into the screw hole 21e, and the set piece 24 is tightened to connect the protruding piece 21 to the rotating body 14. To do. Further, the bolt 22 is inserted into the through hole 21a of the sandwiching projection 21, and the nut 23 is screwed into the screw portion 22d of the screw shaft portion 22a. Finally, the end portion of the inner wire w1 is inserted along the wire guide groove 21g in the fixing portion 21d of the holding projection piece 21 between the fixing portion 21d of the projection piece 21 and the holding head portion 22b of the bolt 22. Then, the assembly work is completed by tightening the nut 23. Next, the operation of assembling the above-mentioned mechanism will be described with reference to FIGS. 4 and 5. FIG. 4 shows a state where the nut 23 is simply screwed into the bolt 22 (a state before the nut 23 is tightened).
At this time, the bolt 22 still has a tightening force (pulling force).
Does not work, and therefore, the bolt seat surface 22f is not in contact with the contact surface 21f of the pinching projection piece 21. Next, when the nut 23 is tightened from this state, a tensile force is applied to the bolt 22, so that as shown in FIG.
The bolt seat surface 22f is pressed against the contact surface 21f of the projecting piece 21. At this time, the bolt seat surface 2 on the side of the collar portion 21c
The inner wire w1 is clamped between the 2f and the clamping projection side contact surface 21f. When the nut 23 is further tightened with a very strong force, only the end of the bolt seat surface 22e on the side opposite to the wire holding portion comes into close contact with the contact surface 21f. Therefore, the bolt head portion 22b is bent, and the reaction force thereof causes a bending moment in the direction of arrow A in the figure to act on the bolt screw shaft portion 22a. The size increases as the tightening force of the nut increases. At this time, in the screw shaft portion 22a of the bolt 22, only the screw portion 22d at the lower end thereof is screwed into the nut 23, and the portion other than the screw portion (fitting portion 22c) is simply the clamping projection 21.
It is placed in a state of being loosely fitted in the through hole 21a. Therefore, when a bending moment acts, the fitting portion 22c of the bolt 22 can bend in the direction of arrow A in the figure.
Therefore, the bolt bending force accompanying the tightening of the nut 23 is sufficiently buffered by the bending of the fitting portion 22c of the screw shaft portion 22a, and the bolt seat surface 2 as in the conventional example.
Stress concentration on 2f is avoided. As described above, the wire holding mechanism 20 in this embodiment
According to this, the damage of the bolt 22 can be avoided and the assembling work becomes easy. Of course, the scope of the present invention is not limited to the above embodiment. In particular, regardless of the type of caliper brake, it may be a caliper brake configured to perform braking operation by expanding and contracting a pair of brake arms or an operating arm portion integrated with these by relative movement of the inner wire and the outer wire. For example, the mechanism characterized by the present invention can be incorporated in the inner wire fastening portion. Further, the rotating means for rotating the rotating body 14 may have a structure other than the above-mentioned embodiment. It should be noted that the fitting portion 22c of the bolt 22 is not particularly required, and a bolt having only a screw portion can sufficiently withstand its use. Further, the type of the nut 23 is not limited, as long as it can be screwed into the screw shaft portion of the bolt 22.

[Brief description of drawings]

1 and 2 are perspective views of the wire holding mechanism of the present invention in an exploded state, and FIG. 3 is a perspective view of its assembled state,
4 and 5 are explanatory views of the operation, FIG. 6 is a front view of a conventional caliper brake having a wire holding mechanism, and FIG.
FIG. 8 is an exploded perspective view of a conventional example, and FIG. 8 is an operation explanatory view thereof. 1 ... Support shaft, 5 ... First brake arm, 6 ... Second brake arm, 10 ... Actuating arm portion, 12 ... Boss portion, 14 ... Rotating body, 20 ... Wire holding mechanism, 21 ...
... pinching projection, 21a ... through hole, 21g ... wire guide groove, 22 ... bolt, 22a ... (bolt) screw shaft part, 22b ... (bolt) head part, 23 ... nut, C
...... Caliper brake, w1 ...... Inner wire.

Claims (1)

[Scope of utility model registration request] 1. An actuating arm comprising a first brake arm and a second brake arm, which are swingably supported by a support shaft attached to an appropriate portion of a vehicle body, and which extends on the opposite side of the support shaft in the first brake arm. A rotator is inserted into the boss portion of the portion, a wire holding mechanism for holding the inner wire is provided at a portion eccentric from the center of rotation of the rotator, and the rotor is rotated by a lever operation to rotate the inner wire. A bicycle caliper brake configured such that a fastening point with respect to an actuating arm can be moved up and down, wherein the wire holding mechanism is provided for the rotating body and has a through hole, and the wire holding mechanism is provided on one side of the wire holding mechanism. A sandwiching projection piece having a wire guide groove at a portion distant from the through hole, and a screw shaft portion is inserted into the through hole of the projection piece from the side where the wire guide groove is provided, And a bolt having a pinching head, rotation of which is prevented when the screw shaft portion is inserted into the through hole, and a nut screwed to the screw shaft portion of the bolt. A bicycle, characterized in that the inner wire is clamped between the clamping head of the bolt and the clamping projection by being tightened in a state of being retained in the wire groove. Holding mechanism in the caliper brake for car.