JP6160014B2 - Bicycle transmission mechanism, bicycle transmission method, and transmission belt constituting the transmission - Google Patents

Description

  The present invention relates to a speed change mechanism for a bicycle constituted by an integrally formed speed change gear body and an L-shaped transmission belt that contacts and meshes with the speed change gear body.

  Conventionally, bicycle transmission mechanisms include an exterior transmission mechanism and an interior transmission mechanism.

  Many exterior-type transmission mechanisms incorporated in a narrow space between a frame and a wheel are constituted by a plurality of chain gears and a metal transmission chain (for example, Patent Document 1).

JP-A-8-40342

  The above-described exterior-type transmission mechanism is configured by laminating a plurality of chain gears from a small outer peripheral chain gear to a large outer peripheral chain gear and spanning a metal transmission chain on the outer periphery of the chain gear. In order to operate the mechanism smoothly, it is necessary to lubricate the transmission chain (because failure to lubricate may cause rusting). In addition, dust or the like adheres to the oil and causes oil stains. Therefore, regular maintenance work is necessary and troublesome.

  Moreover, since both the chain gear and the transmission chain are made of a metal material such as iron, the weight of the bicycle itself is increased.

  Accordingly, the problem to be solved by the present invention is to provide a bicycle speed change mechanism or its components (transmission gear body, transmission belt) that is lightweight and does not require lubrication.

  A problem to be solved by the present invention is to provide a bicycle shifting method suitable for the transmission mechanism.

In order to solve the above-mentioned problem, an integrally formed transmission gear body composed of a single member having an upside down shape that rises in a staircase pattern from the outer peripheral side toward the inner peripheral side, and the staircase of the transmission gear body A bicycle transmission mechanism comprising a rubber, resin, or fiber made of rubber, resin, or fiber that abuts and meshes with two adjacent vertical side surfaces of a vertically projecting vertical side surface , and a L-shaped transmission belt. To do.

  In order to solve the above-mentioned problem, by repeating the step of displacing the position of the transmission belt and the step of contacting and meshing the transmission belt with two adjacent vertical side surfaces of the transmission gear body, Provided is a bicycle speed change method suitable for the speed change mechanism.

Further, in order to solve the above-mentioned problem, the cross-sectional shape is made of rubber, resin, or fiber that comes into contact with and meshes with two adjacent vertical side surfaces among the vertical side surfaces that protrude in a stepped shape of the transmission gear body. An L-shaped transmission belt is provided.

  The bicycle speed change mechanism of the present invention is composed of a rubber, resin, or fiber transmission belt, so that it is lightweight and does not require lubrication. Further, since the transmission gear body is molded integrally, the manufacturing or assembly cost is reduced.

  In the bicycle speed change method according to the present invention, the corresponding portions of the transmission belt are brought into contact with and meshed with two adjacent vertical side surfaces of the transmission gear body, so that the shift between the transmission gear body and the transmission belt is suppressed. Can be executed reliably.

  Since the transmission gear body of the bicycle of the present invention is molded integrally, it is easy to manufacture or assemble. Further, the transmission gear body in which the transmission belt slip prevention means is added to the vertical side surface that rises like a staircase can further prevent the transmission belt from slipping.

  Since the material of the transmission belt of the present invention is made of rubber, resin, or fiber (nonmetal), it is lighter than a metal transmission chain. Further, the transmission belt to which the transmission gear body slip prevention means is added can further prevent the transmission gear body from slipping.

FIG. 1 is a front view showing the overall configuration of the speed change mechanism. FIG. 2 is a side view showing the overall configuration of the speed change mechanism. FIG. 3 is a plan view of the transmission gear body (metal press working) of the first embodiment. FIG. 4 is a front view of the transmission gear body (metal press working) of the first embodiment. FIG. 5 is a cross-sectional view of the transmission gear body (metal press working) of the first embodiment. FIG. 6 is a side view of the transmission belt according to the first embodiment. FIG. 7 is a plan view of the transmission belt according to the first embodiment. FIG. 8 is a front view of the transmission belt of the first embodiment. FIG. 9 is an image diagram showing a two-stage hold (first and second stage) state of the transmission belt of the first embodiment. FIG. 10 is an image diagram illustrating a two-stage hold (second stage and third stage) state of the transmission belt according to the first embodiment. FIG. 11 is a plan view of the transmission gear body (die casting process) of the second embodiment. FIG. 12 is a front view of the transmission gear body (die casting process) of the second embodiment. FIG. 13 is a cross-sectional view of the transmission gear body (die casting process) of the second embodiment. FIG. 14 is a side view of the power transmission belt according to the second embodiment. FIG. 15 is a plan view of the power transmission belt according to the second embodiment.

  The speed change mechanism according to the present invention is used by being attached to the rear wheel portion of the bicycle.

  The configuration of the speed change mechanism according to the first embodiment will be described with reference to FIGS.

  The transmission mechanism (1) includes an inverted saddle-shaped transmission gear body (10) that is raised stepwise at equal intervals from the outer peripheral side toward the inner peripheral side, and a vertical side surface that is raised like a step of the transmission gear body. And a transmission belt (20) that contacts and meshes with the belt. (FIGS. 1 and 2).

  For the eight vertical side surfaces of the transmission gear body (10), the vertical side surface located on the innermost periphery of the transmission gear body is referred to as a first-stage raised vertical side surface (11) (FIGS. 3 and 4).

  Further, the vertical side surface adjacent to the first-stage raised vertical side surface (11) is referred to as a second-stage raised vertical side surface (12), and sequentially toward the outer peripheral side, the third-stage raised vertical side surface (13), the fourth step The upright vertical side surface (14), the fifth-step raised vertical side surface (15), the sixth-step raised vertical side surface (16), and the seventh-step raised vertical side surface (17) are called the outermost vertical side surface in eight steps. Called the eye ridge vertical side (18) (FIGS. 3 and 4).

  A large number of small triangular protrusions are provided on the vertical side surfaces (11 to 18) of the transmission gear body as a transmission belt slip prevention means (FIG. 3).

  In the present embodiment, the number of steps of the transmission gear body (10) that rises in a staircase pattern is eight, but it can be increased or decreased as necessary (FIG. 4).

  As for the internal and external shapes of the transmission gear body (10), the inside is hollow, and the outside is an upside down shape like an upside down like a vessel (FIG. 5).

  The transmission gear body (10) of the present embodiment is integrally formed by a single metal pressing as punching (FIG. 5).

  The material of the transmission gear body (10) is made of non-ferrous metal in consideration of weight reduction, manufacturing cost, maintainability or durability. Preferably, it is reinforced aluminum (duralumin), titanium, or an incombustible magnesium alloy.

  The shape of the transmission belt (20) is L-shaped when viewed from the side (FIG. 6).

  This is because it is necessary to simultaneously abut and mesh with two adjacent vertical side surfaces (11 to 18) of the transmission gear body at the same time (hold two locations simultaneously). Since the transmission belt contacts and meshes simultaneously with two locations, transmission can be performed without slipping even if the contact width with each location is narrow. Therefore, a considerable number of steps can be incorporated even in a narrow space between the frame and the wheel.

  On the contact surface of the transmission belt (20) with the transmission gear body, as a transmission gear body slip prevention means for preventing the transmission gear body from slipping, the transmission gear body is perpendicular to the width direction in plan view. A large diameter side contact portion (21) that contacts the outer peripheral side (large diameter side) of the side surfaces, and a small diameter side contact portion (23) that contacts the inner peripheral side (small diameter side) of the vertical side surfaces of the transmission gear body. ) Are added (FIG. 7).

  The surface of the large diameter side contact portion (21) has many fine irregularities arranged (FIGS. 7 and 8).

  The surface of the small-diameter side contact portion (23) is arranged with a small interval between the irregularities as compared with the large-diameter side contact portion (21) (FIGS. 7 and 8).

  This is based on the assumption that the large-diameter side contact portion (21) always fits into the projections on the respective vertical side surfaces (11 to 18) that protrude in a stepped shape of the transmission gear body.

  As the transmission gear body slip prevention means, in this embodiment, irregularities are added to the surface of the large diameter side contact portion (21) and the surface of the small diameter side contact portion (23). Any other means may be used as long as it is a means for preventing slippage with each of the vertical side surfaces (11 to 18) protruding in a step shape.

  Regarding the material of the transmission belt (20), rubber, resin, fiber, or the like is used in consideration of weight reduction, maintainability, durability, and the like.

  Next, the shifting operation of the bicycle in which the transmission mechanism of the present application is attached to the rear wheel will be described with reference to FIGS.

  The small diameter side contact portion (23) of the transmission belt (20) contacts and meshes with the first-stage raised vertical side surface (11) which is the innermost periphery of the transmission gear body, and the large diameter side contact portion (21 of the transmission belt) ) Abuts and meshes with the second raised vertical side surface (12), and the transmission gear body (10) mounted on the free gear (50) rotates and the bicycle moves while holding the two positions simultaneously. (FIGS. 2 and 9).

  The rear derailleur (31) is actuated to displace the transmission belt (20) (FIG. 2).

  By the operation of the rear derailleur (31), the small-diameter side contact portion (23) of the transmission belt (20) is in contact with the second-stage raised vertical side surface (12), and the large-diameter side contact of the transmission belt is achieved. The portion (21) abuts and meshes with the third-step raised vertical side surface (13), and the two positions are simultaneously held again to execute a speed change operation (FIGS. 2 and 10).

  In this state, the transmission gear body (10) rotates to move the bicycle.

  Note that the number of steps of the transmission gear body (10) that rises in a stepped manner is eight in this embodiment, but the transmission belt holds two portions at a time, so that it is used as a seven-stage transmission gear body.

  Further, although the operation of displacing the position of the transmission belt is performed by the rear derailleur, it may be performed by a front derailleur (not shown) or manually.

  Example 2 is a transmission mechanism using a transmission gear body formed by die casting (mold casting) of molten aluminum, and the configuration thereof is shown in FIGS. 1, 2, 11 to 15, Only parts different from the first embodiment will be described.

  The transmission mechanism (1) includes an inverted saddle-shaped transmission gear body (40) that is raised stepwise at equal intervals from the outer peripheral side toward the inner peripheral side, and a vertical side surface that is raised like a step of the transmission gear body. And a transmission belt (20) that contacts and meshes with the belt. (FIGS. 1 and 2).

  Of the eight vertical side surfaces of the transmission gear body (40) that protrude in a stepped manner, the vertical side surface located on the innermost periphery of the transmission gear body is referred to as a first-stage raised vertical side surface (41). Also, the vertical side surface adjacent to the first-stage raised vertical side surface is called a second-stage raised vertical side surface, and sequentially toward the outer peripheral side, the third-stage raised vertical side surface, the fourth-stage raised vertical side surface, and the fifth-stage raised vertical side surface The side surface, the sixth-stage raised vertical side surface, and the seventh-stage raised vertical side surface are referred to as the outermost vertical side surface and is referred to as the eighth-stage raised vertical side surface (48) (FIGS. 11 and 12).

  The transmission gear body (40) is provided with a bowl-shaped partition (49) between the steps (FIG. 12).

  The transmission gear body (40) is integrally formed by die casting (FIG. 13).

  About the shape of the said transmission belt (20), it is L shape in side view similarly to Example 1 (FIG. 14).

  The transmission gear body slip prevention means added to the transmission belt (20) is composed of a large diameter side contact portion (21) and a small diameter side contact portion (23) as in the first embodiment (FIG. 15). .

  A groove (25) is provided between the large-diameter side contact portion (21) and the small-diameter side contact portion (23) (FIGS. 14 and 15).

  This is in order to prevent misalignment in consideration of the fact that the transmission belt is hooked over two places of the transmission gear body.

  The bicycle transmission mechanism or the like according to the present invention is industrially applicable because it is a transmission mechanism that achieves weight reduction and is excellent in maintainability.

1 Transmission mechanism 10 Transmission gear body (metal press molding)
11 1st ridge vertical side surface (innermost circumference)
12 Second-stage raised vertical side surface 13 Third-stage raised vertical side surface 14 Fourth-stage raised vertical side surface 15 Fifth-stage raised vertical side surface 16 Sixth-stage raised vertical side surface 17 Seventh-stage raised vertical side surface 18 Eighth-stage raised vertical side surface ( Outermost)
20 Transmission belt 21 Large diameter side contact portion 22 Unevenness of large diameter side contact portion (transmission gear body slip prevention means)
23 Small diameter side contact portion 24 Concavity and convexity of the small diameter side contact portion (transmission gear body slip prevention means)
25 Groove 31 Rear derailleur 40 Transmission gear body (die cast molding)
41 1st step upright side (innermost circumference)
48 8th step upright side (outermost)
49 Samurai-shaped partition 50 Free gear

Claims (3)

An integrally molded transmission gear body made of a single member having an upside down shape that rises stepwise from the outer peripheral side toward the inner peripheral side;
A transmission belt made of rubber, resin, or fiber that comes into contact with and meshes with two adjacent vertical side surfaces among the vertical side surfaces that rise in a stepped shape of the transmission gear body; and a cross-sectional shape of the transmission belt,
Bicycle transmission mechanism consisting of   2. The transmission mechanism according to claim 1, wherein shifting is performed by repeating a step of displacing the position of the transmission belt and a step of contacting and meshing the transmission belt with two adjacent vertical side surfaces of the transmission gear body. Bicycle shifting method. 2. A cross-sectional shape made of rubber, resin, or fiber that contacts and meshes with two adjacent vertical side surfaces among the vertical side surfaces of the transmission gear body that form the stepped shape of the transmission gear body. Is an L-shaped transmission belt.