JPH07137680A - Shaft drive type bicycle - Google Patents

Abstract

PURPOSE:To improve the comfortableness of a shaft drive type bicycle in a simple structure by supporting a rear wheel on the rear part of a power unit, and providing the front part of the power unit on a body frame so as to be rotatable centering around a crankshaft, and supporting the power unit on the body frame through a rear suspension. CONSTITUTION:When vibration from a road surface is transmitted from a rear wheel 58 to a power unit 100 during running, the rear part of the power unit 100 is supported by the seat tube 2 of the body frame 1 through a rear suspension 22. Since the front part of the power unit 100 rotates centering around a crankshaft 36 to vertically oscillate the power unit 100, the vibration is absorbed for improving comfortableness. In addition, in the case of absorbing the vibration by the rear suspension 22, since the front part of the power unit 100 rotates centering around a crankshaft 36, the rear wheel can be swung. Thus the comfortableness can be improved by a simple structure and a compact mechanism and moreover without extending wheel length.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft drive type bicycle in which the rotational force of a crankshaft is transmitted to a rear wheel through a transmission shaft.

[0002]

2. Description of the Related Art Conventionally, a shaft drive type bicycle has been known, and this shaft drive type bicycle has, for example, a drive gear device for transmitting the rotational force of a crankshaft to a rear wheel, a transmission shaft, Some include a power unit including a driven gear device. As such a shaft drive type bicycle, for example, JP-A-1-44385 and JP-A-1-70291 are known.

[0003]

In such a shaft drive type bicycle, since the front portion of the power unit is fixed to the vehicle body frame and the rear portion of the power unit is supported by the vehicle body frame via the back stay, the bicycle cannot be used during running. Vibration is transmitted from the rear wheels directly to the occupant via the power unit and the back stay, resulting in poor riding comfort.

For this reason, it is conceivable to swing the rear wheels by using, for example, a universal joint in a power transmission system for transmitting the rotational force of the crankshaft to the rear wheels through the transmission shaft. However, there is a problem that the wheel is complicated and the wheel length becomes longer accordingly.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a shaft drive type bicycle having a simple structure and improving the riding comfort.

[0006]

In order to solve the above-mentioned problems, the invention according to claim 1 incorporates a drive gear device, a transmission shaft, and a driven gear device for transmitting the rotational force of the crankshaft to the rear wheels. In a shaft drive type bicycle equipped with a power unit, the rear wheel is supported on the rear part of the power unit, and the front part of the power unit is provided on the vehicle body frame so as to be rotatable about a crankshaft.
The power unit is supported on the vehicle body frame via a rear suspension.

The invention according to claim 2 is a shaft drive type bicycle equipped with a power unit having a drive gear device for transmitting the rotational force of a crankshaft to a rear wheel, a transmission shaft and a driven gear device, The rear wheel is supported between the rear part of the power unit and the rear part of the rear arm, and the front part of the power unit and the rear arm are provided on the vehicle body frame so as to be rotatable around a crankshaft, and at least one of the power unit and the rear arm is provided. Is supported on the vehicle body frame via a rear suspension.

[0008]

According to the first and second aspects of the present invention, vibrations from the road surface are transmitted from the rear wheels to the vehicle body frame through the rear suspension during traveling, and at this time, the rear suspension absorbs the vibrations to improve the riding comfort. Get better.

According to the first aspect of the invention, when the rear suspension absorbs vibrations, the front portion of the power unit rotates about the crankshaft. Further, in the second aspect of the invention, the front portion of the power unit and the rear arm is rotated. Since the part rotates around the crank shaft, the rear wheel can be swung without using a universal joint or the like for the power transmission system, and has a simple structure and a compact mechanism without increasing the wheel length. Is.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a shaft drive type bicycle according to the present invention will be described below with reference to the drawings. 1 is a side view of a shaft drive type bicycle, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, FIG. 3 is a side view of a drive gear device portion, and FIG. 4 is FIG.
6 is a cross-sectional view taken along line IV-IV of FIG. 5, FIG.
7 is a side view of the driven gear unit, FIG. 7 is a sectional view taken along line VII-VII of FIG. 6, FIG. 8 is a sectional view taken along line VIII-VIII of FIG. 1, and FIG. 9 is taken along line IX-IX of FIG. FIG. 10 is a side view showing another embodiment of mounting the rear suspension.

In the figure, reference numeral 1 is a vehicle body frame formed by combining steel pipes, and the vehicle body frame 1 is composed of a seat tube 2, a down tube 3, and a head pipe 4. A front portion of the power unit 100 is rotatably provided on the body frame 1 about a crankshaft 36, and a rear portion of the power unit 100 is supported via a rear suspension 22.

The power unit 100 includes a shaft housing 5, a crank housing 6, and a rear housing 2.
1 and a drive gear device 51 for transmitting the rotational force of the crankshaft 36 incorporated therein to the rear wheel 58, a transmission shaft 50, a driven gear device 62, and the like.

Next, the structures of the body frame 1, the power unit 100 and the rear suspension 22 will be described in detail.

The front portion of the shaft housing 5 is provided in a crank housing 6, and the crank housing 6 is divided into two in the crankshaft direction. One of the divided housings 7 and the other of the divided housings 8 are joined and fastened with bolts 9. is doing.

A bottom bracket 11 is rotatably provided on the split housing 7 via a bearing 10, and a lower portion of the seat tube 2 and a rear portion of the down tube 3 are welded to the bottom bracket 11. In this way, the split housing 7 forming the crank housing 6 at the front of the power unit 100 is rotatable with respect to the seat tube 2 and the down tube 3 forming the vehicle body frame 1 by the bearing 10. This bearing 1
Instead of 0, an elastic body may be provided by, for example, rubber baking to rotate by a predetermined amount.

A saddle stay 12 is provided above the seat tube 2, and the saddle 1 is attached to the saddle stay 12.
3 is attached. A head pipe 4 is welded to the front portion of the down tube 3, and a front fork 14 is pivotally supported on the head pipe 4 and
The front wheel 15 is supported at the lower end of the front fork 14
A steering handle 16 is fixed to the upper end of the.

As shown in FIG. 9, the shaft housing 5 is made of, for example, an extruded material of aluminum and has a rectangular cross section. In this way, the shaft housing 5
By forming the cross-sectional shape into a rectangle and arranging it with the longitudinal direction being vertical, the rigidity of the shaft housing 5 is increased, and it is possible to cope with the load applied to the shaft housing 5.
Further, the shaft housing 5 can be arranged within a predetermined width in the vehicle width direction without widening the space between the pedal arms 39, 40 in the vehicle width direction.

Connection caps 17 and 18 are welded to the front and rear portions of the shaft housing 5, and the connection cap 17 is tightened and fixed to the mounting portion 8a of the split housing 8 with bolts 19, and the connection cap 18 is fixed to the bolts 20.
Is fastened and fixed to the mounting portion 21a of the rear housing 21.

The rear housing 21 is supported by the seat tube 2 via a rear suspension 22. The rear portion of the stay 23 of the rear suspension 22 is fixed to the bracket portion 21b of the rear housing 21 with bolts 24, and the cylinder 25 is fixed to the front portion of the stay 23.
A rod 27 having a piston 26 is slidably provided on the cylinder 25, and the rod 27 includes a bracket 28.
Is attached to. Plate 29 of bracket 28
31 between the plate and the plate 30 of the cylinder 25
Is provided, and the plate 29 is provided with a rubber damper 32 to prevent the cylinder 25 from coming into contact with the plate 29.

The bracket 28 is attached to the tightening fitting 34 of the seat tube 2 via the bolt 33, and the bolt 3
When the tightening handle 35 screwed to 3 is turned, the tightening metal fitting 34
Is tightened, the bracket 28 of the rear suspension 22
And the saddle stay 12 inserted in the seat tube 2 is fixed.

The stay 2 of the rear suspension 22
As shown in FIG. 10, the rear part of the shaft 3 has a shaft housing 5
It can be supported on the rear part of the back via the clamp 100.

Both ends of a crank shaft 36 are supported by the split housing 7 and the split housing 8 constituting the crank housing 6 via bearings 37 and 38. At both ends of the crankshaft 36, pedal arms 39, 40 are provided with nuts 41,
It is fixed at 42.

The bearing 37 is held between the convex portion 36a of the crankshaft 36 and the cap 43 so that the movement in the axial direction is restricted, the cap 43 is screwed to the split housing 7, and the lock ring 44 is attached to the cap 43. The cap 43 is screwed through the washer 45 so that the cap 43 is prevented from coming off.

The bearing 38 is press-fitted into the split housing 8,
A driving bevel gear 46 is serration-fitted on the right side of the crankshaft 36 so as to be integrally rotatable. Crankshaft 36
Is loosely fitted in the cap 43, and its convex shape 36b
Is loosely fitted in the insertion hole 7b of the mounting portion 7a of the split housing 7. By tightening the cap 43, the bearing 37
The convex 36a of the crankshaft 36 is pushed through the crankshaft 36, whereby the crankshaft 36 moves in the axial direction, and the convex 36b presses the drive bevel gear 46 against the bearing 38, and the position in the thrust direction is determined. .

A bearing 48 is press-fitted into a driven bevel gear 47 meshing with the drive bevel gear 46. The bearing 48 is press-fitted into the mounting portion 8a of the split housing 8 to drive the driven bevel gear 4
7 is rotatably arranged in the mounting portion 8a of the split housing 8 via a bearing 48. A spacer 49 is further inserted into the mounting portion 8a of the split housing 8 and the connection cap 17 is tightened and fixed with bolts 19. The bearing 48 and the spacer 49 position the driven bevel gear 47 in the thrust direction. Be done. The driven bevel gear 47 has a front end of a transmission shaft 50 arranged in the shaft housing 5 which is serrated to be integrally rotatable.
The drive bevel gear 46 and the drive bevel gear 46 constitute a drive gear device 51.

A drive bevel gear 5 is provided at the rear end of the transmission shaft 50.
The two are fitted with serrations so that they can rotate together.
A bearing 53 is press-fitted into the drive bevel gear 52, and the bearing 53 is supported by the mounting portion 21 a of the rear housing 21 via a ring 54.

The one end 55a of the rear axle 55 is inserted into the support portion 21c of the rear housing 21, and the nuts 56 and 57 are tightened to prevent the rear axle 55 from coming off.
It is cantilevered at 1. The support portion 21c of the rear housing 21 is formed in a space 80 formed by the mounting of the drive bevel gear 52, and is mounted for supporting the rear axle 55 in a cantilever manner without projecting the rear housing 21 outward in the vehicle width direction. The width D is sufficiently secured.

A hub 59 of a rear wheel 58 is inserted into the rear axle 55 in advance, and the hub 59 is rotatably provided via bearings 81 and 82. When the cap 83 is tightened, the hub 59 is attached via the bearing 82. When pushed, this hub 59 pushes against the cap 84 via the bearing 81, and positioning in the thrust direction is performed. A nut 57 is screwed to the rear axle 55 to form a unit, and one end portion 5 of the rear axle 55 in this unit state.
5a is inserted through the washer 85 into the support portion 21c of the rear housing 21, and the nut 56 is inserted through the washer 86.
Is screwed on and cantilevered in a locked state.

A driven bevel gear 61 is fixed to the cantilever support side of the hub 59 of the rear wheel 58, and a driven bevel gear 52 is meshed with the driven bevel gear 61.
The driven bevel gear 52 constitutes a driven gear device 62.

An unillustrated planetary gear type transmission is built in the hub 59 of the rear wheel 58, and a rim 64 is provided on the outer peripheral flange portion 59a via a spoke 63, and a tire 65 is attached to the rim 64. Is installed.

A brake drum 66 of a band brake is fixed to the rear wheel 58 on the cantilever support side of the hub 59, and the brake drum 66 rotates integrally with the rear wheel 58. A brake cover 67 is inserted into the rear housing 21 so as to cover the brake drum 66, and a mounting portion 67a of the brake cover 67 is fixed to the shaft housing 5 with screws 90. One end portion 68a of the band brake shoe 68 that brakes the brake drum 66 is fixed to the brake cover 67, and the other end portion 68b is linked to the link 70 via the connecting pin 69.
Are linked to. The link 70 is supported by the brake cover 67 via the support pin 71, and the brake wire 72 is connected to the link 70.

Therefore, when the brake is operated, the brake wire 7
2 is pulled in the direction of the arrow in FIG.
The band brake shoe 68 is pulled by rotating about 1 as a fulcrum. As a result, the band brake shoe 68 contacts the brake drum 66 and brakes. Brake wire 72
9 is fitted into a recess 5a formed in the lower portion of the shaft housing 5 in the axial direction so as not to hit obstacles such as pebbles and the like, and the appearance is improved because it cannot be seen from the outside. .

When the bicycle is driven by this shaft drive type bicycle, when the driver pedals the pedal arms 39 and 40 with his / her feet, the rotational force of the pedal gears 39 and 40 is transmitted from the crankshaft 36 to the drive gear device 51 and the transmission shaft incorporated in the power unit 100. 50 is transmitted to the hub 59 of the rear wheel 58 via the driven gear device 62, whereby the rear wheel 58 rotates and travels.

When vibrations from the road surface are transmitted from the rear wheels 58 to the power unit 100 during this traveling, the rear portion of the power unit 100 is supported by the seat tube 2 of the vehicle body frame 1 via the rear suspension 22, and the front portion is crankshaft. The power unit 100 rotates about 36.
Swings up and down, which absorbs vibrations and improves ride comfort.

When the rear suspension 22 absorbs vibrations, the front portion of the power unit 100 rotates about the crankshaft 36 to swing the rear wheels without using, for example, a universal joint in the power transmission system. It is possible to improve the riding comfort with a simple structure and a compact mechanism without increasing the wheel length.

FIG. 11 is a sectional view showing another embodiment of the shaft drive type bicycle. In this embodiment, members designated by the same reference numerals as those in the embodiment shown in FIGS. 1 to 9 have the same structure and will not be described.

In this embodiment, the axial direction L1 of the shaft housing 5 and the transmission shaft 50 is parallel to the vehicle body center line L2.

Therefore, when the rear wheel 58 is produced by changing the size, the crank housing 6, the rear housing 21, and the drive shaft can be changed by simply changing the shaft housing 5 and the transmission shaft 50 to which the connection caps 17 and 18 are welded. Since it is not necessary to change the gear device 51 and the driven gear device 62, the size of the rear wheel 58 can be easily changed, which is effective for mass production.

A brake drum 200 of a drum brake is provided on the rear housing 21 side of the hub 59 of the rear wheel 58, and spokes 63 are attached to the brake drum 200. A brake shoe 201 is arranged in the brake drum 200, and the brake shoe 201 is supported by the rear housing 21. Brake shoe 20
1 is opened by an operating shaft 202, and this operating shaft 202 is supported by the rear housing 21. The actuating shaft 202 is moved by the brake wire 203, whereby the brake shoe 201 is opened and pressed against the brake drum 200 for braking.

FIG. 12 is a sectional view showing still another embodiment of the shaft drive type bicycle. In this embodiment, the members designated by the same reference numerals as those in the embodiments shown in FIGS. 1 to 9 and 11 have the same structure, and therefore the description thereof will be omitted.

In this embodiment, the axial direction L1 of the shaft housing 5 of the power unit 100 and the transmission shaft 50 is parallel to the vehicle body center line L2.

Further, the bracket 300 is inserted into the split housing 7 of the crank housing 6 constituting the power unit 100 while being prevented from rotating by spline engagement or the like, and the bracket 300 is tightened and fixed by the nut 44.
The front part 301a of the rear arm 301 is attached to the bracket 300.
Are attached by bolts 302, and this rear arm 3
In the rear portion 301b of 01, a support groove 303 having an open rear is formed.

Rear housing 2 of power unit 100
1, one end of a rear axle 55 is supported via a collar 304, and is fixed by tightening nuts 305 and 306.
The other end of 5 is inserted into the support groove 303 of the rear arm 300 and is fixed by tightening with a nut 307.

Rear arm 301 of hub 59 of rear axle 55
A brake drum 308 of a band brake is integrally rotatably provided on the side, and a brake cover 309 covering the brake drum 308 is fixed to the rear axle 55. A brake shoe 310 of a band brake is arranged in the brake cover 309, and the brake drum 310 is braked by the brake shoe 310.

In this way, the rear wheel 58 has the power unit 1
The power unit 100 and the front part of the rear arm 301 are supported between the rear part of the rear arm 00 and the rear part of the rear arm 301 so that the power unit 100 and the front part of the rear arm 301 can rotate about the crankshaft 36.

In this embodiment, the rear portion of the power unit 100 is supported by the vehicle body frame 1 via the rear suspension, but the rear portion of the rear arm 301 may be supported by the vehicle body frame 1 via the rear suspension. Further, by using two rear suspensions, the rear portion of the power unit 100 may be supported on the vehicle body frame 1 via the rear suspension, and the rear portion of the rear arm 301 may be supported on the vehicle body frame 1 via the rear suspension. Further, the front portion of the power unit 100 and the front portion of the rear arm 301 may be connected by a cross pipe or the like, and the cross pipe or the like may be supported by the vehicle body frame 1 via the rear suspension.

In this embodiment, when the rear wheel 58 is produced by changing the size, the shaft housing 5 and the transmission shaft 50 to which the connection caps 17 and 18 are welded are changed, and the rear arm 301 is changed. Since it is not necessary to change the crank housing 6, the rear housing 21, the drive gear device 51, and the driven gear device 62, the size of the rear wheel 58 can be easily changed, which is effective for mass production.

When the tires and tubes are replaced, the nut 307 is removed from the rear axle 55 and the rear arm 3
The bolt 302 for fastening and fixing the front portion 301a of 01 is removed, and the rear arm 301 is removed.

When the rear wheel 58 is serviced, the rear arm 301 is removed as described above, the nut 305 of the rear axle 55 supported by the rear housing 21 is removed, and the rear axle 55, the rear wheel 58, and the band are removed. The brakes can be removed for easy servicing.

[0050]

As described above, according to the first and second aspects of the present invention, vibrations from the road surface are transmitted from the rear wheels to the vehicle body frame through the rear suspension during traveling,
At this time, vibration is absorbed by the rear suspension,
The riding comfort of a shaft drive type bicycle is improved.

According to the first aspect of the invention, when the rear suspension absorbs vibrations, the front portion of the power unit rotates about the crankshaft. Further, in the second aspect of the invention, the front portion of the power unit and the rear arm is rotated. Since the part rotates around the crank shaft, the rear wheel can be swung without using a universal joint or the like for the power transmission system, and has a simple structure and a compact mechanism without increasing the wheel length. Can improve the ride comfort.

[Brief description of drawings]

FIG. 1 is a side view of a shaft drive type bicycle.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a side view of a drive gear unit portion.

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

5 is a view on arrow A in FIG. 4. FIG.

FIG. 6 is a side view of a driven gear device portion.

7 is a sectional view taken along line VII-VII of FIG.

8 is a cross-sectional view taken along the line VIII-VIII of FIG.

9 is a sectional view taken along line IX-IX in FIG.

FIG. 10 is a side view showing another embodiment of mounting the rear cushion.

FIG. 11 is a sectional view showing another embodiment of the shaft drive type bicycle.

FIG. 12 is a sectional view showing still another embodiment of the shaft drive type bicycle.

[Explanation of symbols]

 1 Body Frame 22 Rear Suspension 36 Crank Shaft 50 Transmission Shaft 51 Drive Gear Device 58 Rear Wheel 59 Hub 62 Driven Gear Device 100 Power Unit

Claims (2)

[Claims] 1. A shaft drive type bicycle including a power unit having a drive gear device for transmitting a rotational force of a crankshaft to a rear wheel, a transmission shaft, and a driven gear device, wherein the rear wheel is a rear portion of the power unit. A shaft drive type bicycle characterized in that a front portion of the power unit is rotatably provided on a vehicle body frame about a crankshaft, and the power unit is supported on the vehicle body frame via a rear suspension. 2. A shaft drive type bicycle including a power unit having a drive gear device for transmitting a rotational force of a crankshaft to a rear wheel, a transmission shaft, and a driven gear device, wherein the rear wheel is a rear portion of the power unit. And a rear part of the rear arm, the power unit and the front part of the rear arm are rotatably provided on the body frame about a crankshaft, and at least one of the power unit and the rear arm is provided via a rear suspension. A shaft drive type bicycle characterized by being supported by a frame.