JP2002079984A - Bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To compactly design a transmission mechanism of a bicycle to form neat design and thereby to improve its appearance, to compose a simple structure without providing a complicated mechanism for adjusting the tension of a chain to properly and smoothly change the speed, to effectively prevent the chain from coming off, to change the speed by driving a belt, and to change the speed even in a state of not pedaling. SOLUTION: This bicycle is provided with the transmission mechanism built in a sprocket 1 driven by a crank shaft 11. The bicycle is so structured that when the crankshaft 11 is rotated, the rotation of the crankshaft 11 is transmitted to the sprocket 1 through the transmission mechanism to drive the sprocket 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle having a speed change mechanism for changing a drive ratio of a sprocket for driving wheels.

[0002]

2. Description of the Related Art Bicycles having a transmission mechanism have already been developed. This bicycle can easily drive the wheels by switching the sprocket that drives the wheels according to the running state. For example, when climbing a hill or starting, the pedal can be lightened by reducing the rotation ratio. Also,
When the bicycle is accelerating and running at high speed, the rotation ratio can be increased to reduce the number of pedaling times.

FIG. 1 shows a bicycle having a conventional transmission mechanism. The bicycle speed change mechanism shown in FIG.
And a sprocket 28 connected to the
And a freewheel 2 driven by the chain 10 to rotate wheels.
9 and a rear derailleur 30 that changes the position of the chain 10 that is hung on the freewheel 29. In this transmission mechanism, five freewheels 29 are provided on the rear wheels, and the freewheel 29 on which the chain 10 is hung by the rear derailleur 30 is switched so that the rotation ratio of the wheels can be switched by five-speed shifting. Further, in this transmission mechanism, the crankshaft 11 is also provided with a two-stage sprocket 28, and the front derailleur 31
Is switched so that the rotation ratio of the wheels can be switched by two-step shifting. That is, this bicycle has 2 × 5 on the crankshaft side and the rear wheel side.
The gear can be shifted in 10 steps.

[0004]

A bicycle having this structure is
The driving ratio of the freewheel and the sprocket can be switched according to the driving condition, making traveling extremely convenient. However, this bicycle has a disadvantage that the chain is likely to come off during shifting. This is because the rear derailleur or the front derailleur forcibly shifts the position of the chain to the left or right, thereby changing the freewheel or sprocket on which the chain is hooked and shifting. In particular, when the chain is changed from a side having a larger outer diameter to a side having a smaller outer diameter, the chain is easily loosened because the chain is momentarily loosened. Therefore, in the bicycle of this structure, it is necessary to adjust the tension of the chain with the rear derailleur in order to prevent the chain from coming off easily, and the mechanism for this becomes complicated.

Further, in this bicycle, the chain is switched by a rear derailleur or a front derailleur.
There is also a disadvantage that the entire chain cannot be covered with the chain cover. For this reason, when pedaling, there is a drawback that the tip of the pants easily touches the chain or the chain ring, and the contact portion becomes dirty. Further, a bicycle having a rear derailleur or the like has a drawback that a clean design cannot be made and the appearance is deteriorated.

Further, this bicycle has a disadvantage that it cannot be used for a bicycle in which wheels are driven by belts instead of chains since the freewheel and sprocket are changed by forcibly shifting the position of the chain. Unlike bicycles using chains, bicycles driven by belts have been increasing in recent years because they are free of dirt such as oil and can be operated quietly. However, a bicycle driven by a belt has a disadvantage that the gear cannot be shifted.

Further, the conventional bicycle has a disadvantage that the gear cannot be shifted when the pedal is not pedaled, for example, when the bicycle is stopped. Because this bicycle forcibly shifts the position of the chain left and right and changes the freewheel and sprocket on which the chain is hung, it can only change the position of the chain while driving, that is, while driving It is. Therefore, when the bicycle is stopped from high-speed running, it is necessary to switch to a low-speed freewheel or sprocket in advance or to forcibly switch to a low-speed freewheel or sprocket when starting. As described above, if the speed is rapidly changed, the chain is more easily detached, and a load is applied to each part, which may cause a failure or breakage.

[0008] The present invention has been developed for the purpose of solving such disadvantages. An important object of the present invention is to provide a bicycle in which the speed change mechanism is designed to be compact and the appearance is improved as a neat design. Further, another important object of the present invention is to provide a bicycle which does not require a complicated mechanism for adjusting the tension of the chain, and which has a simple structure, can shift smoothly without difficulty, and can effectively prevent the chain from coming off. It is in. Another important object of the present invention is to provide a bicycle that can be driven by a belt to change gears. Still another important object of the present invention is to provide a bicycle that can change gears without pedaling.

[0009]

The bicycle according to the present invention has a speed change mechanism, which is built in a sprocket 1 driven by a crankshaft 11. In this bicycle, when the crankshaft 11 is rotated, the rotation of the crankshaft 11 is transmitted to the sprocket 1 via the transmission mechanism, and drives the sprocket 1.

Further, the bicycle according to the second aspect of the present invention is characterized in that the speed change mechanism has all the following configurations. (A) The transmission mechanism is a sprocket 1 that drives a chain 10 or a belt, a rotating member 2 that is driven by a crankshaft 11 to rotate the sprocket 1, and a stopper mechanism that controls a rotation ratio between the sprocket 1 and the crankshaft 11. 3 is provided. (B) The sprocket 1 is ring-shaped, has an external gear 4 for driving a chain 10 or a belt on the outer peripheral edge, and has an internal gear 5 on the inner peripheral edge. (C) The rotating member 2 includes a first rotating plate 2A driven by the crankshaft 11 and a second rotating plate 2B whose forward rotation is prevented by the stopper mechanism 3, and the first rotating plate 2A and the second rotating plate 2B. Board 2
B is coaxially connected. (D) The first rotary plate 2 </ b> A connects the plurality of planetary gears 6 and the ratchet pins 8 via the connection pins 14, and arranges the plurality of planetary gears 6 at positions meshing with the internal gear 5. . (E) The second rotating plate 2B has the locking portion 9 and
A sun gear 7 is fixed at the center, and the sun gear 7 meshes with the plurality of planetary gears 6. (F) The ratchet pin 8 has its tip elastically pressed in the direction of the internal gear 5. (G) The ratchet pin 8 allows the sprocket 1 to rotate forward, but prevents the sprocket 1 from rotating in the reverse direction. (H) The stopper mechanism 3 is provided with a locking portion 9 of the second rotating plate 2B.
Bar 1 that abuts against the first rotation plate 2B to prevent forward rotation of second rotating plate 2B
5 is provided. (I) In the transmission mechanism, the second rotating plate 2 </ b> B
When the crankshaft 11 is rotated in a state where it is not locked, the first rotating plate 2A and the second rotating plate 2B rotate together, and the ratchet pin 8 of the rotating first rotating plate 2A locks the internal gear 5. In this state, the rotating member 2 and the sprocket 1 are rotated together to drive the sprocket 1 at a rotation ratio equal to that of the crankshaft 11, and the second rotating plate 2B is locked by the stopper mechanism 3 to prevent normal rotation. In this state, when the crankshaft 11 is rotated, the first rotary plate 2A rotates while sending out the internal gear 5 by the planetary gear 6 rolling along the sun gear 7 of the stopped second rotary plate 2B. By rotating the sprocket 1 more than the first rotating plate 2A,
The sprocket 1 is driven at a rotation ratio larger than the crankshaft 11. However, in this specification, the sprocket 1
Forward rotation means that the sprocket 1
Rotate, and the forward rotation of the second rotating plate 2B means the rotation of the sprocket 1 in the same direction as the forward rotation.

In the bicycle of the present invention, preferably, the number of teeth (z1) of the internal gear 5 of the sprocket 1 is 1.2 to 5 times the number of teeth (z2) of the sun gear 7. In this bicycle, (n2 / n1) which is the ratio of the rotation speed (n2) of the sprocket 1 to the rotation speed (n1) of the crankshaft 11 is calculated as 6/5 to 11
/ 6.

Further, the bicycle according to the present invention includes the first rotating plate 2.
The number of planetary gears 6 connected to A can be three to eight. Further, in the bicycle according to the present invention, the operating portion 16 for operating the locking bar 15 of the stopper mechanism 3 can be provided on the handle 27. The bicycle can be shifted in a convenient manner without releasing the hand from the steering wheel 27. Further, in the bicycle of the present invention, the ratchet pin 8 is preferably disposed so as to be inclined in the normal rotation direction of the sprocket 1 from the radial direction. The ratchet pin 8 has a very simple structure, and allows forward rotation of the sprocket 1 and prevents reverse rotation of the sprocket 1.

Further, the bicycle of the present invention has a crankshaft 1
One of the cranks 12 for driving the rotating member 1 has a driving plate 13 at a connection portion with the crankshaft 11, and the driving plate 13 is connected to the first rotating plate 2 </ b> A of the rotating member 2 to connect the crankshaft 11 to the rotating member It is connected to. Further, the drive plate 13 holds the sprocket 1 in a sandwiched state with the first rotary plate 2A. In the bicycle having this structure, the first rotary plate 2A can be directly driven by the crank 12, and the sprocket 1 can be simply and reliably arranged at a predetermined position. The drive plate 13 can be connected to the first rotary plate 2A, for example, via connection pins 14 that connect the plurality of planetary gears 6 and the ratchet pins 8 to the first rotary plate 2A.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. However, the embodiments described below exemplify a bicycle for embodying the technical idea of the present invention, and the present invention does not specify a bicycle as follows.

Further, in this specification, in order to make it easy to understand the claims, the numbers corresponding to the members shown in the embodiments will be referred to as “claims” and “ In the column of “means”. However, the members described in the claims are not limited to the members of the embodiments.

The bicycle of the present invention has a speed change mechanism, which is built in a sprocket driven by a crankshaft. The bicycle of the present invention has a unique structure of a transmission mechanism that transmits rotation of a crankshaft to drive a sprocket. Therefore, the structure other than the transmission mechanism is not specified. In the bicycle of the present invention, the structure other than the transmission mechanism may be any structure that has already been developed or that will be developed in the future. Hereinafter, the bicycle transmission mechanism of the present invention will be described in detail.

FIG. 2 shows the internal structure of the transmission mechanism of the bicycle according to the present invention, and FIG. The transmission mechanism shown in these figures includes a sprocket 1 for driving a chain 10,
A rotating member 2 driven by the crankshaft 11 to rotate the sprocket 1 and a stopper mechanism 3 for controlling a rotation ratio between the sprocket 1 and the crankshaft 11 are provided.

The sprocket 1 has a ring shape with a circular opening at the center. The sprocket 1 has an external gear 4 for driving the chain 10 on the outer peripheral edge, and has an internal gear 5 on the inner peripheral edge. The sprocket 1 shown in FIG.
Is driving the chain 10 of the edgeless track hung on
A freewheel (not shown) connected to the rear wheel is driven via the chain 10 to rotate the wheel.
Therefore, the external gear 4 is shaped so as to mesh with and drive the chain 10. However, the bicycle of the present invention may have a structure in which a belt on an edgeless track is hung on a sprocket to drive wheels. In this bicycle, the external gear of the sprocket has a shape capable of driving the belt. Further, although not shown, the bicycle of the present invention can cover the entire chain with a cover. This bicycle has features that it can improve the appearance and prevent the tip of the pants and the like from touching the chain or the like and becoming dirty.

The sprocket 1 shown in FIG. 3 comprises an outer ring 1A having an outer gear 4 on the outer peripheral edge and an inner ring 1B having an inner gear 5 on the inner peripheral edge connected in a stacked state to form an outer gear 4 and an inner gear 5 Are provided. Outer ring 1A and inner ring 1B
Has an external gear 4 and an internal gear 5 provided by processing a metal ring. The sprocket 1 has these rings coaxially laminated and fixed with fixing pins 17. In the sprocket 1 having this structure, the external gear 4 and the internal gear 5 can be easily provided. However, the sprocket can be constituted by one ring.

The rotating member 2 is formed by combining two disks so as to be rotatable with each other. The first rotating plate 2A driven by the crankshaft 11 and the first rotating plate 2A whose rotation is prevented by the stopper mechanism 3 are prevented. And two rotating plates 2B. The first rotary plate 2A and the second rotary plate 2B are coaxially stacked and connected.
The first rotary plate 2A and the second rotary plate 2B each have a circular opening at the center, and a central hole 18 into which the crankshaft 11 is inserted.
Is provided. The first rotary plate 2A and the second rotary plate 2B shown in FIG. 3 are connected via a cylindrical body 19 penetrating the center hole 18. The cylindrical body 19 has a flange at one end, and the other end is fixed to the second rotating plate 2B.
The first rotating plate 2A is connected with the rotating plate 2B and the flange so as to sandwich the first rotating plate 2A.

The first rotating plate 2A is connected to the crankshaft 11. The crankshaft 11 has a crank 12 fixed at both ends, and is driven by the crank 12 to rotate. The first rotating plate 2A is driven by the rotating crankshaft 11 and rotates in the same direction as the crankshaft 11. The crank 12 shown in FIG.
The drive plate 13 is connected to the first rotary plate 2A, and the crankshaft 11 is connected to the first rotary plate 2A. The first rotary plate 2 </ b> A and the crankshaft 11 are coaxially connected via a drive plate 13. Further, the sprocket 1 is disposed between the driving plate 13 and the first rotating plate 2A, and holds the sprocket 1 between the driving plate 13 and the first rotating plate 2A. The drive plate 13 is connected to the first rotary plate 2A via the connection pin 14.

Further, the first rotating plate 2A connects the plurality of planetary gears 6 and the ratchet pins 8 via connecting pins 14. The plurality of planetary gears 6 are rotatably connected to the surface of the first rotating plate 2A. The ratchet pin 8 is connected to the same plane as the planetary gear 6 so as to be tiltable in the same plane as the planetary gear 6. For example, as shown in FIG. 3, the planetary gear 6 and the ratchet pin 8 are connected to predetermined positions by connecting pins 14 that connect the driving plate 13 to the first rotating plate 2A.

The plurality of planetary gears 6 are arranged at equal intervals on the outer peripheral portion of the first rotating plate 2A, at positions where the inner gears 5 of the sprocket 1 mesh. First rotating plate 2A shown in FIG.
Has three planetary gears 6 arranged at equal intervals. However,
The first rotating plate may be provided with four or more planetary gears at equal intervals.

The ratchet pin 8 is disposed between the plurality of planet gears 6. The first rotating plate 2A shown in FIG.
Since three planetary gears 6 are provided, three ratchet pins 8
Are arranged at equal intervals. The same number of the ratchet pins 8 as the number of the planetary gears 6 are provided so that the ratchet pins 8 can be meshed with the internal gear 5 with a good balance. However, the number of the ratchet pins may be smaller or larger than that of the planetary gears.

The ratchet pin 8 is shaped such that its distal end is engaged with the internal gear 5 and elastically presses its distal end in the direction of the internal gear 5. The ratchet pin 8 is, for example,
It is urged by the elastic body 20 in a predetermined direction. The elastic body 20 shown in the figure is formed by bending a metal wire, and has one end fixed to the first rotating plate 2A and the other end elastically pressing the tip of the ratchet pin 8 toward the internal gear 5. I have. However, the elastic body may be a coil spring or a leaf spring.

Further, as shown in FIG. 2, the ratchet pin 8 is disposed so that its tip is inclined from the radial direction in the forward rotation direction of the sprocket 1 indicated by the arrow A. In this figure, the direction indicated by the arrow A indicates the forward rotation direction of the sprocket 1, that is, the rotation direction when the bicycle is advanced. Ratchet pin 8 arranged in this position
When the sprocket 1 is relatively rotated with respect to the first rotary plate 2A in the direction indicated by the arrow A, the sprocket 1 is lifted by the tip of the passing internal gear 5 to allow the sprocket 1 to rotate. On the other hand, when the sprocket 1 relatively rotates in the direction opposite to the direction indicated by the arrow A, the tip of the ratchet pin 8 locks the internal gear 5 to prevent the rotation.
That is, the ratchet pin 8 is disposed so as to allow the sprocket 1 to rotate in the normal rotation direction, but to prevent the rotation in the reverse rotation direction. The reason why the ratchet pin 8 is disposed in this state is that when the first rotating plate 2A is rotated forward, the sprocket 1 is driven by pressing the internal gear 5 with the ratchet pin 8 to be locked, and the pedal is moved in the reverse direction. This is because when rotating, the first rotating plate 2A idles.

The second rotating plate 2B has a sun gear 7 fixed at the center. The second rotating plate 2B shown in the figure has a sun gear 7 provided on the outer peripheral edge of a flange of a cylindrical body 19 fixed to a center hole 18. The sun gear 7 is disposed on the surface of the first rotary plate 2A, and includes three planetary gears 6 disposed on the first rotary plate 2A.
And are engaged.

The rotating member 2 shown in FIG. 3 includes a first rotating plate 2A.
A planetary gear 6, a ratchet pin 8, and a sun gear 7 are disposed on the surface of the first rotating plate 2A and the second rotating plate 2B, which are stacked on each other, on the surface opposite to the stacked surface. However,
The rotating member may be provided with a planetary gear, a ratchet pin, and a sun gear on opposing surfaces of the first rotating plate and the second rotating plate. The rotating member having this structure is, for example, provided with a flange or the like on a cylinder or a crankshaft that penetrates the center between the first rotating plate and the second rotating plate, and moves the first rotating plate and the second rotating plate at predetermined positions. Can be connected in a stacked state.

Further, the second rotating plate 2B has a locking portion 9 as shown in the rear view of FIG. The second rotating plate 2B is
When the locking bar 15 of the stopper mechanism 3 comes into contact with and locks the locking portion 9, normal rotation is prevented. In the second rotating plate 2B shown in FIG. 4, three engaging portions are provided at equal intervals on the outer peripheral edge to form the locking portion 9. The locking portion 9 which is a concave portion
The outer peripheral edge of the rotating plate 2B can be cut and provided in a predetermined shape having a lock surface 9A for locking the tip of the locking bar 15. However, as shown in FIG. 5, the second rotating plate 2 </ b> B may be provided with a protrusion protruding in the radial direction from the outer peripheral edge to serve as the locking portion 9, or not shown, but provided with a protrusion protruding from the surface. It can also be a locking part. Although the second rotating plate 2B shown in these figures is provided with three locking portions 9, the number of locking portions may be two or less or four or more.

The rotating member 2 is located at the center opening of the sprocket 1 and is arranged coaxially with the sprocket 1. As shown in FIG. 2, the rotating member 2 is connected such that the plurality of planetary gears 6 mesh with the internal gear 5 of the sprocket 1.

The stopper mechanism 3 controls the rotation ratio of the sprocket 1 and the crankshaft 11 by changing the rotation state of the rotating member 2. The stopper mechanism 3 is in contact with the locking portion 9 of the second rotating plate 2B to prevent the rotation of the second rotating plate 2B in the forward direction, and the operating portion 1 for operating the locking bar 15
6 is provided.

The locking bar 15 is connected to the bicycle via a connecting member 21 so as to be tiltable in a vertical plane. The connector 21 is fixed to the bicycle tube, and has the locking bar 15 at a predetermined position. The locking bar 15 shown in FIG.
And a lock portion 15A at the front end which comes into contact with the locking portion 9 of the second rotary plate 2B, and the operating portion 1 at the rear end.
One end of a wire 23 operated by 6 is connected. Further, an elastic body 24 is connected to the locking bar 15.
The elastic body 24 urges the lock portion 15A at the tip of the locking bar 15 in a direction of pressing the lock portion 15A toward the second rotating plate 2B. The elastic body 24 shown in the drawing has a coil spring having one end connected to the rear end of the locking bar 15 and the other end contacting a pressing plate 25 protruding from the connecting tool 21 and extending. The pressing plate 25 has one end fixed to the connector 21 and the other end bent vertically to provide a pressing surface 25 </ b> A with which one end of the elastic body 24 abuts. Further, a wire 23 for operating the locking bar 15 is inserted through the elastic body 24 which is a coil spring, and the leading end of the wire 23 is connected to the rear end of the locking bar 15. The rear end of the wire 23 is extended and connected to the operation unit 16.

Further, the locking bar 15 is disposed in such a manner that its tip is inclined in a direction opposite to the normal rotation direction of the sprocket 1 shown by an arrow A in FIG. When the second rotating plate 2B rotates in the direction shown by the arrow A in a state where the locking portion 15A is pressed toward the locking portion 9, the locking bar 15A disposed in this posture is The second rotating plate 2B is held in a locked state by contacting
The rotation of the rotating plate 2B is prevented. Further, the locking bar 15
When the second rotating plate 2B rotates in the direction opposite to the direction indicated by the arrow A, the second rotating plate 2B is lifted up by the locking portion 9 passing therethrough without being locked, and the second rotating plate 2B is rotated in the reverse direction. Tolerate. The reason that the second rotating plate can be reversed is
This is to allow the rotating member 2 to idle when the pedal is rotated in the reverse direction. The locking bar 15 shown in the figure has a portion where the locking portion 9 comes into contact when the second rotating plate 2B rotates reversely, as an inclined surface 15B, so that the second rotating plate 2B can smoothly rotate reversely. However, the second rotating plate 2B is
The shape shown in FIG. 5 or FIG. 6 can be used to smoothly reverse the second rotating plate 2B. The locking portion 9 shown in these figures has a locking surface 9 at a position where the locking portion 15A of the locking bar 15 is locked when the second rotating plate 2B rotates forward.
A and when the second rotating plate 2B rotates in the reverse direction,
Inclined surface 9B through which lock portion 15A of locking bar 15 passes
Having.

The operating section 16 operates the locking bar 15 via the wire 23. As shown in FIG. 7, the other end of the wire 23 having one end connected to the locking bar 15 is connected to the operation unit 16. The operation unit 16 shown in FIG.
Is provided adjacent to the grip 26. The operation unit 16 includes a rotating unit 16 </ b> A disposed coaxially with the grip 26.
The wire 23 is pulled or loosened by rotating the rotating portion 16A to operate the locking bar 15. The rotating part 16A is arranged so as to be able to rotate in a moderate state, and can hold the wire 23 in a pulled state and a loosened state. Thus, the operation unit 1 disposed adjacent to the grip 26
6 is characterized in that the gear can be shifted without releasing the hand from the handle 27.

However, the operating portion may be structured so as to pull or loosen the wire with a tilting lever, without having a rotating portion disposed coaxially with the grip. The operating part of this structure can be arranged adjacent to the grip, but can also be arranged at a place other than the handle, for example, at a down tube or a handle post.

As described above, when the operating mechanism 16 is operated to loosen the wire 23, the stopper mechanism 3
Is tilted by being pressed by the elastic body 24, and the locking portion 15 at the distal end is tilted.
A comes into contact with the locking portion 9 of the second rotating plate 2B,
B is locked to prevent normal rotation. When the operation part 16 is operated in the opposite direction and the wire 23 is pulled, the locking bar 15
Is released from the locking portion 9 of the second rotating plate 2B to release the locked state of the second rotating plate 2B.

In the bicycle having the above structure, the transmission mechanism operates as follows to rotate the wheels at different drive ratios. [During Normal Travel] The locking bar 15 is located at a position away from the locking portion 9 of the second rotating plate 2B, and the second rotating plate 2B is in an unlocked state. When the pedal is driven to rotate the drive plate 13 fixed to the crankshaft 11, the drive plate 13 rotates the first rotary plate 2A via the connecting pin 14. Since the second rotating plate 2B is in the free state, the planetary gear 6 connected to the first rotating plate 2A and the sun gear 7 connected to the second rotating plate 2B do not rotate with respect to each other, but perform the first rotation. The plate 2A and the second rotating plate 2B rotate together as a unit. The first rotating plate 2 </ b> A that rotates is engaged with the tip of the ratchet pin 8 in engagement with the internal gear 5 of the sprocket 1 and presses it. When the internal gear 5 is pressed by the ratchet pin 8, the sprocket 1 rotates. At this time, the sprocket 1 rotates together with the first rotating plate 2A. That is, the sprocket 1 rotates at the same rotation speed as the crankshaft 11 (rotation ratio = 1: 1).

[During High-Speed Running] The operating portion 16 is operated to bring the locking bar 15 into contact with the locking portion 9 to lock the second rotary plate 2B. When the pedal is driven to rotate the drive plate 13 fixed to the crankshaft 11, the drive plate 13 rotates the first rotary plate 2A via the connecting pin 14. Since the second rotating plate 2B is in the locked state, the forward rotation of the second rotating plate 2B is prevented, and only the first rotating plate 2A rotates. Planetary gear 6 connected to rotating first rotating plate 2A
Rotates around the connecting pin 14 while revolving around the sun gear 7 connected to the second rotating plate 2B. Since the planetary gear 6 rolling along the sun gear 7 is meshed with the internal gear 5 on the outer peripheral side of the first rotary plate 2A, the planetary gear 6 rotates while sending out the internal gear 5 to rotate the sprocket 1 to the first rotary plate 2A. Rotate more than. That is, the sprocket 1 is rotated at a rotation ratio larger than that of the crankshaft 11.

The rotation ratio of the sprocket 1 to the crankshaft 11 is determined by the number of teeth (z1) of the internal gear 5 of the sprocket 1.
And the number of teeth (z2) of the sun gear 7. Sun gear 7
The planetary gear 6 rolling around the internal gear 5 rotates by rotation.
Orbiting while sending out. Therefore, the number of rotations of the sprocket 1 with respect to the first rotating plate 2 </ b> A increases by the number of teeth fed by the planetary gear 6. While the planetary gear 6 revolves once, the number of the internal gears 5 sent out by the planetary gear 6 is equal to the number of teeth (z2) of the sun gear 7, and if the rotation speed of the crankshaft 11 is (n1), The increasing number of rotations is n1 × (z2 / z1). Therefore, the rotation speed (n2) of the sprocket 1 is represented by the following expression: n2 = n1 * (1 + z2 / z1). That is, the rotation ratio of the sprocket 1 to the crankshaft 11 (n2 / n1) is (z1 + z
2) It becomes / z1.

In the transmission mechanism shown in FIG. 2, the number of teeth (z1) of the internal gear 5 of the sprocket 1 is 36, and the number of teeth (z
2) is set to 12. Therefore, this transmission mechanism
Rotation ratio of sprocket 1 to crankshaft 11 (n
2 / n1) becomes 4/3. However, the bicycle of the present invention does not specify the number of teeth (z1) of the internal gear 5, the number of teeth (z2) of the sun gear 7, and the rotation ratio (n2 / n1). In the present invention, the number of teeth (z1) of the internal gear 5 is changed to the number of teeth (z2) of the sun gear 7.
1.1 to 10 times, preferably 1.2 to 5 times. The transmission mechanism in which the number of teeth (z1) of the internal gear 5 is 1.2 to 5 times the number of teeth (z2) of the sun gear 7 has a rotation ratio (n2 / n1) of the sprocket 1 with respect to the crankshaft 11.
From 6/5 to 11/6.

[0041]

The bicycle according to the present invention has the features that the speed can be shifted smoothly and easily and the chain can be effectively prevented from coming off. That is, the bicycle of the present invention
This is because the transmission mechanism is incorporated in a sprocket driven by the crankshaft. A bicycle having this structure can shift gears without forcibly shifting the position of the chain and changing a sprocket for hanging the chain, unlike a conventional bicycle. For this reason, if the tension of the chain is kept constant, in other words, the speed can be changed smoothly and smoothly without requiring a complicated mechanism for adjusting the tension of the chain, and the chain can be effectively prevented from coming off.

Further, the bicycle of the present invention can realize the feature that the speed can be changed by driving with a belt. That is, since the bicycle of the present invention incorporates the speed change mechanism in the sprocket driven by the crankshaft, the tension of the belt stretched to drive the wheels is kept constant, and these positions are forcibly set. This is because the rotation ratio between the crankshaft and the sprocket can be changed without shifting. As described above, the bicycle which can be shifted by driving with a belt has features that it is free from dirt such as oil and can be operated quietly.

Further, the bicycle of the present invention has a feature that the transmission mechanism is designed to be compact and the appearance is improved as a neat design. That is, the bicycle of the present invention effectively utilizes the space inside the large sprocket and arranges a transmission mechanism here, and transmits the rotation of the crankshaft to the sprocket via the built-in transmission mechanism. This is because the sprocket is driven. In addition, the bicycle of the present invention can be improved in appearance in that the speed can be shifted without using a multi-stage freewheel or sprocket and without disposing a rear derailleur or a front derailleur, unlike the conventional bicycle. In addition, bicycles without a rear derailleur can cover the entire chain with a cover, so by providing a cover, etc., it is possible to prevent the tip of the trousers from touching the chain or sprocket when pedaling and getting dirty. You can also.

Further, in the bicycle according to the second aspect of the present invention, the characteristic that the gear can be shifted more smoothly and without difficulty is realized by the transmission mechanism having a unique structure. This is because the bicycle of the present invention changes the rotation ratio between the sprocket and the crankshaft by controlling the rotation state of the rotating member that drives the sprocket with the stopper mechanism.
Moreover, this bicycle has a feature that various members such as a planetary gear, a sun gear, and a ratchet pin, which are provided on a rotating member, can be provided inside the sprocket, so that the appearance can be improved as a neat design.

Further, the bicycle according to the second aspect of the present invention has a feature that the gear can be shifted even when the pedal is not pedaled. The reason is that this bicycle changes the rotation ratio by changing the rotation state of the rotating member with the stopper mechanism without changing the position of the chain forcibly and changing the sprocket on which the chain is hooked as in the past. It is. This bicycle can be shifted irrespective of the drive state of the chain, so that the bicycle can be freely shifted without limitation during traveling and can be driven extremely conveniently. Further, since the speed can be changed without difficulty, the burden on each part can be reduced, and failure or damage can be prevented.

[Brief description of the drawings]

FIG. 1 is a side view showing a conventional bicycle transmission mechanism.

FIG. 2 is a front view showing the internal structure of the transmission mechanism of the bicycle according to the embodiment of the present invention.

FIG. 3 is an exploded sectional view of the transmission mechanism shown in FIG. 2;

FIG. 4 is a rear view of the transmission mechanism shown in FIG. 2;

FIG. 5 is a rear view showing another example of the locking portion provided on the second rotating plate.

FIG. 6 is a rear view showing another example of the locking portion provided on the second rotating plate.

FIG. 7 is a perspective view showing an operation unit of the stopper mechanism of the bicycle according to the embodiment of the present invention.

[Explanation of symbols]

1 ... sprocket 1A ... outer ring 1
B: inner ring 2: rotating member 2A: first rotating plate 2
B: Second rotating plate 3: Stopper mechanism 4: External gear 5: Internal gear 6: Planetary gear 7: Sun gear 8: Ratchet pin 9: Locking portion 9A: Lock surface 9
B: Inclined surface 10: Chain 11: Crank shaft 12: Crank 13: Driving plate 14: Connection pin 15: Locking bar 15A: Lock part 1
5B: Inclined surface 16: Operation unit 16A: Rotating unit 17: Fixing pin 18: Center hole 19: Cylindrical body 20: Elastic body 21: Connecting tool 22: Rotating shaft 23: Wire 24: Elastic body 25: Press plate 25A: Press Surface 26 ... Grip 27 ... Handle 28 ... Sprocket 29 ... Freewheel 30 ... Rear derailleur 31 ... Front derailleur

Claims (8)

[Claims] A bicycle equipped with a speed change mechanism, wherein the speed change mechanism is built in a sprocket (1) driven by a crankshaft (11), and rotation of the crankshaft (11) is transmitted through the speed change mechanism to the sprocket (1). 1) A bicycle characterized by being driven. 2. The bicycle according to claim 1, wherein the speed change mechanism has all of the following configurations. (A) The transmission mechanism includes a sprocket (1) for driving a chain (10) or a belt, a rotating member (2) driven by a crankshaft (11) to rotate the sprocket (1), and a sprocket (1). And a stopper mechanism (3) for controlling the rotation ratio of the crankshaft (11). (B) The sprocket (1) is ring-shaped and has an external gear (4) for driving a chain (10) or a belt on the outer peripheral edge,
The inner peripheral edge has an internal gear (5). (C) The rotating member (2) includes a first rotating plate (2A) driven by the crankshaft (11) and a second rotating plate (2B) whose forward rotation is prevented by the stopper mechanism (3). , The first rotary plate (2A) and the second rotary plate (2B) are coaxially connected. (D) The first rotating plate (2A) connects the plurality of planetary gears (6) and the ratchet pin (8) via the connecting pin (14), and connects the plurality of planetary gears (6) to the internal gear. It is arranged at the position where it meshes with (5). (E) The second rotating plate (2B) has a locking portion (9) and has a sun gear (7) fixed at the center, and the sun gear (7) meshes with a plurality of planetary gears (6). ing. (F) The tip of the ratchet pin (8) is elastically pressed in the direction of the internal gear (5). (G) The ratchet pin (8) allows forward rotation of the sprocket (1), but stops and prevents reverse rotation of the sprocket (1). (H) The stopper mechanism (3) is a locking portion of the second rotating plate (2B).
An engaging bar (15) is provided to abut the (9) to prevent the second rotating plate (2B) from rotating forward. (I) In the transmission mechanism, the second rotating plate (2B) is a stopper mechanism.
When the crankshaft (11) is rotated in a state where it is not locked in (3), the first rotating plate (2A) and the second rotating plate (2B) rotate together, and the rotating first rotating plate (2A) Ratchet pin
(8) is pressed while the internal gear (5) is locked to rotate the rotating member (2).
And sprocket (1), rotate the crankshaft (1
The sprocket (1) is driven at a rotation ratio equal to
When the crankshaft (11) is rotated in a state where the rotating plate (2B) is locked by the stopper mechanism (3) and the forward rotation is blocked, the sun gear (7) of the stopped second rotating plate (2B) is stopped. The first rotating plate (2A) rotates while sending out the internal gear (5) with the planetary gear (6) rolling along with the sprocket (1) more than the first rotating plate (2A). The sprocket (1) is driven at a higher rotation ratio than the crankshaft (11). 3. The number of teeth (z) of the internal gear (5) of the sprocket (1)
1) is 1.2 to 5 times the number of teeth (z2) of the sun gear (7),
Sprocket for rotation speed (n1) of crankshaft (11)
(N2 / n1), which is the ratio of the number of revolutions (n2) in (1), is 6/5
The bicycle according to claim 2, wherein the number of the bicycles is about 11/6. 4. A planetary gear connected to the first rotating plate (2A)
The bicycle according to claim 2, wherein (6) is 3 to 8 pieces. 5. The bicycle according to claim 2, wherein the stopper mechanism (3) has an operating part (16) for operating the locking bar (15) on the handle (27). 6. The bicycle according to claim 2, wherein the ratchet pin (8) is disposed so as to be inclined from a radial direction in a forward rotation direction of the sprocket (1). 7. A crank (12) for driving a crankshaft (11)
Has a drive plate (13) at the connection with the crankshaft (11), and connects the drive plate (13) to the first rotary plate (2A) of the rotary member (2) to connect the crankshaft (11 ) Is connected to the rotating member (2), and the drive plate (13) and the first rotating plate (2A)
The bicycle according to claim 2, wherein the bicycle is held in a sandwiched state. 8. A plurality of planet gears (6) and a ratchet pin (8).
Via a connecting pin (14) connecting the first rotating plate (2A) to
The bicycle according to claim 7, wherein the drive plate (13) is connected to the first rotating plate (2A).