JPH0639277B2 - Continuously variable transmission for bicycles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a continuously variable transmission for a bicycle, which is mounted on a bicycle and is capable of continuously shifting in accordance with the amount of eccentricity.

[Prior Art] Generally, a transmission of this type is configured to continuously transmit a speed change by a pawl feed that meshes with a ratchet gear. This is because when the ratchet pawl sequentially enters the drive range in an eccentric state, the load is increased. The rattling of the power transmission causes so-called pulsation due to a cause such as a gap between the tooth tips of the ratchet claws in the driving range due to the speed difference between the ratchet claws.

For this reason, in order to reduce the pulsation, there is a Japanese Patent Laid-Open No. 61-1841
No. 92 publication is proposed. This is to reduce the pulsation of power transmission by providing a plurality of sets of ratchet gears and ratchet pawls in parallel to greatly increase the number of ratchet pawls.

[Problems to be Solved by the Invention] In the above-mentioned conventional technique, a plurality of ratchet rings are provided on the input side rotating member via a one-way clutch, and a plurality of sets of ratchet pawls are provided on the output side rotating member. Therefore, the rotation of the input-side rotating member is transmitted from the one ratchet ring to the ratchet pawl of the one set via the one-way clutch, and from the ratchet pawl of the other set to the other ratchet ring. Therefore, the ratchet pawl of the other set comes to rotate by dragging the other ratchet ring via the one-way clutch, and the gear shifting operation is unstable. It is also possible to urge the ratchet pawl toward the ratchet ring to reduce unstable operation.
In this case, there is a problem that a metallic noise is likely to be generated when the engagement between the ratchet gear and the ratchet pawl is changed.

Therefore, an object of the present invention is to provide a continuously variable transmission for a bicycle capable of preventing pulsation of transmission power and metallic noise.

[Means for Solving the Problems] The present invention has a plurality of rows of ratchet pawls rotatably provided on the base side in the circumferential direction, and the ratchet pawls of the plurality of rows are arranged so that the ratchet pawls are staggered. And a plurality of ratchet gear main bodies corresponding to the plurality of sets of ratchet pawls are respectively provided via a one-way clutch, and the input, output, An eccentric moving portion that relatively eccentrically moves the side rotation member, and a regulation portion that regulates each ratchet pawl so that only the ratchet pawl within the drive range meshes with the output side rotation member when eccentric. It

Embodiments Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 to 9 show the first embodiment, and FIGS.
In the figure, 1 is a main pipe of a bicycle frame, 2 is a vertical pipe, 3 is a chain stay, 4 is a hanger rag formed integrally with the bicycle frame, 5 is a crank shaft, and 6 is fixed to the crank shaft 5 via a lock nut 7. Crank arm, 8 is rear wheel, 9 is rear wheel hub axle, 10 is rear wheel sprocket, and 11 is chain.

Reference numeral 12 denotes a hollow cylindrical case that is an input side rotating member. The hollow cylindrical case 12 has its center portion fixed to the crankshaft 5 by the lock nut 7, and the crank arm 6 is integrated with the hollow cylindrical case 12. Is formed in. In this case, the crank arm 6 and the hollow cylindrical case 12 may be formed separately, and the hollow cylindrical case 12 may be fixed to the crankshaft 5 via the crank arm 6. Reference numerals 13 and 13A denote ratchet pawls having a plurality of teeth 14, and a cylindrical portion 15 including the hollow cylindrical case 12 and a lid 12A of the case 12.
A set of six ratchet claws 13 are arranged in parallel in the inside in the circumferential direction at equal intervals, and a set of six ratchet claws 13A in the outside of the cylindrical portion 15 are arranged in the circumferential direction at equal intervals in the circumferential direction. The ratchet pawls 13 and 13A arranged in parallel are rotatably provided by a pivot 16 at the base end, and are biased toward the center of the hollow cylindrical case 12 by a spring 17 wound around the pivot 16. . Further, the two sets of ratchet pawls 13 and 13A are arranged alternately with each other. Further, at the base ends of the ratchet pawls 13 and 13A, there are extended restricting portions 19 which engage with the inner peripheral wall surface 18 of the cylindrical portion 15 to restrict and hold the ratchet pawls 13 and 13A at a constant angle. As a result, at the time of eccentricity, only the ratchet pawls 13 and 13A substantially within the driving range mesh with the output side rotating member described later, and the inner peripheral wall surface 18 of the cylindrical portion 15 and the restricting portion 19 are disengaged from each other. The ratchet pawls 13 and 13A outside the region are held at a constant angle by the engagement between the inner peripheral wall surface 18 and the regulating portion 19 in a state where the ratchet pawls 13 and 13A are separated from the output side rotating member.

Reference numeral 20 is a stop ring of a bearing 21 that rotatably supports the crankshaft 5 in the hanger rag 4, and this stop ring
A hanger stop nut 22 is screwed onto the 20. Reference numeral 23 is a disk-shaped fixed cam that is fixed by sandwiching it between the end of the hanger lug 4 and the hanger stop nut 22, and is an eccentric moving body along an annular flange 24 formed on the peripheral edge of the fixed cam 23. An eccentric cam 25 is rotatably arranged. A wire reel 26 provided on one end of the eccentric cam 25 via a cam retainer 26A is rotatably fitted to the annular flange portion 24. Further, the eccentric cam 25 is configured to rotate while being guided by the fixed cam 23 about a diagonally lower position rearward of the center A of the crankshaft 5 as a center B, and an arc centered on the point B. A center hole 28 having a surface 27 is formed in the eccentric cam 25, and the crankshaft 5 is inserted through the center hole 28. Reference numeral 29 denotes a ratchet gear serving as an output side rotating member rotatably provided on a circular cam surface 25A formed on the outer periphery of the eccentric cam 25 via a bearing 30. The ratchet gear 29 has a cam retainer 26A side. A sprocket 31 is screwed and fixed to the end portion. The ratchet gear 29 is rotatably provided via the sprocket 31 and a ratchet 29A provided on the outer peripheral surface of the annular body 29A via bearings 30A, 30B and one-way clutches 32A, 32B. It is composed of gear bodies 29B and 29C. In this case, one ratchet gear main body 29B is provided corresponding to one ratchet pawl 13 via the bearing 30A and one-way clutch 32A, and the bearing 30B and one-way clutch corresponding to the other set of ratchet pawls 13A. The other ratchet gear body 29C through 32B
Is provided. The one-way clutches 32A and 32B are composed of a tapered groove 32C formed on the outer peripheral surface of the annular body 29A, a ball 32D provided in the tapered groove 32C, and a push spring 32E.

Reference numeral 33 is a retaining ring of the bearing 30, and 34 is a collar interposed between the tooth portion 36 of the ratchet gear 29 and the sprocket 31. An eccentric amount adjusting mechanism 37 is connected to the cam retainer 26A. In this embodiment, in the eccentricity adjusting mechanism 37, a wire reel 40 having a manual operation lever 39 is rotatably supported by a disc-shaped receiver 38 fixed to the upper side of the main pipe 1, and the wire reel 40 A pair of wires 41, 42 up and down
Of the wires 41 and 42 are fixed to the upper and lower sides of the rear side of the wire reel 26 via pins 43A and 44A. These pins 43, 44, 43A, 44A are holes of the wire reels 26, 40 with the wires 41, 42 fixed.
It is fitted and fixed to 45.

Next, the operation of the apparatus of this embodiment configured as described above will be described. First, when the crank arm 6, the crankshaft 5 and the hollow cylindrical case 12 are integrally rotated via the crank pedal 46, the ratchet pawls 13 and 13A and the ratchet gear main bodies 29B and 29 mounted on the hollow cylindrical case 12 are rotated.
Rotate ratchet gear 29 via C to move ratchet gear 29
Sprocket 31 rotates together with this sprocket
The rotation of 31 is transmitted to the rear wheel 8 by the chain 11 via the rear wheel sprocket 10.

FIGS. 6A and 6B show the case where the ratchet gear 29 is located at the center of the hollow cylindrical case 12 and the eccentricity is o,
At this time, all ratchet pawls 13 and 13A are ratchet gear 29.
It is held at a constant inclination angle in the state of meshing with. As a result, the gear ratio between the crankshaft 5 and the sprocket 31 is 1: 1. When the lever 39 is manually moved forward from this state, the wire reel 40 is rotated clockwise through the disc-shaped receiver 38, and accordingly, the pair of wires 41 and 42 and the pin 4 are moved.
Wire reel 26 connected through 3,44,43A, 44A
Rotates clockwise along the annular flange 24 of the fixed cam 23. This causes the eccentric cam 25 to rotate integrally with the wire reel 26 about the point B, and as a result, the eccentric cam 25.
The ratchet gear 29 provided concentrically moves eccentrically with respect to the center of the hollow cylindrical case 12, that is, the crankshaft 5. In this case, the eccentric cam 25 is guided in a state where the arc surface 27 of the center hole 28 and the crankshaft 5 are in sliding contact with each other, and the movement locus of the center A of the crankshaft 5 virtually obtained by the rotation of the eccentric cam 25 is It is an arc C from point A to point A '.

FIGS. 10 (A) and (B) show the case where the eccentric amount of the hollow cylindrical case 12 with respect to the ratchet gear 29 is in the maximum eccentric state, and at this time, the eccentric cam 25 has a center hole 28 centered at the point B.
Ratchet gear 29 that rotates clockwise to the position where the left end of the contact with the crankshaft 5 and moves integrally with the eccentric cam 25
Pushes ratchet pawls 13DR and 13ADR in drive range D. As a result, the ratchet pawls 13DR and 13ADR are spring-loaded.
The ratchet gear 29 is meshed with the biasing force of 17, and the other ratchet pawl 13 is held at a constant inclination angle in a state of being separated from the ratchet gear 29 by the engagement of the restricting portion 19 and the inner peripheral wall surface 18.

The ratchet gear 29 has the ratchet pawl 13DR or the ratchet pawl 13A that has the maximum speedup rate due to the ratchet pawl 13DR or the ratchet pawl 13ADR in the drive range D.
The ratchet claws 13 and 13A are rotated by DR to increase the speed.
Disengages from ratchet gear 29. Also ratchet claws
The ratchet pawls 13DR and 13ADR, which are sequentially accelerated so that 13DR and 13ADR move out of the drive range D and the adjacent ratchet pawls 13 and 13A enter into the drive range D to drive the ratchet gear 29 to speed up, are replaced. . in this case,
In the axial direction, one set of ratchet pawls 13 and the other set of ratchet pawls 13A are arranged alternately with each other, so that the ratchet pawls have twice as many ratchet pawls as those having only one set of ratchet pawls. In the drive range D, the drive ratchet pawls are accelerated so that the ratchet pawls 13DR and the ratchet pawls 13ADR alternate with each other. Therefore, the speed difference between the plurality of ratchet pawls 13DR and 13ADR in the drive range D becomes small and pulsation is suppressed. Further, when the ratchet pawl 13DR becomes a drive ratchet pawl, the rotational force is transmitted from the ratchet pawl 13DR to the ratchet gear main body 29B, and the ratchet gear main body 29B is further used as a one-way clutch.
The ring member 29A rotates through the ring member 32A, and the sprocket 31 rotates integrally with the ring member 29A. On the other hand, the rotation of the ring body 29A is faster than that of the ratchet gear body 29C, so that the one-way clutch 32B is rotated.
Is in a disconnected state, and the ratchet pawl 13ADR and the ratchet gear main body 29C idle in a meshed state via the bearing 30B. On the contrary, when the ratchet pawl 13ADR becomes the drive ratchet pawl, the ratchet gear main body 29C rotational force is transmitted from the ratchet pawl 13DR, and the ring body 29A rotates from the ratchet gear main body 29C via the one-way clutch 32B. The sprocket 31 rotates integrally with the ring body 29A. On the other hand, since the rotation of the ring body 29A is faster than that of the ratchet gear body 29B, the one-way clutch 32A is in a disengaged state, and the ratchet pawl 13DR and the ratchet gear body 29B are idling through the bearing 30A in a meshed state.

In this way, when one of the ratchet pawls 13DR and 13ADR is driven, the other becomes idle, so that the meshing does not change, the gear shifting operation is reliable, and pulsation is prevented.
On the other hand, in the conventional one, a plurality of ratchet rings are provided on the input side rotation member via a one-way clutch,
Since the output side rotating member is provided with multiple sets of ratchet pawls, when one set of ratchet pawls is driven,
The other set of ratchet pawls slides the other ratchet ring through the one-way clutch to rotate the ratchet pawl, and the gear shifting operation is unstable. Further, in this conventional example, when the ratchet pawl is biased toward the ratchet ring side, a metallic sound is likely to be generated when the engagement of the ratchet gear and the ratchet pawl is changed, but in the embodiment of the present invention, the ratchet is substantially within the driving range D. Since only the pawls 13DR and 13ADR mesh with the ratchet gear 29 and the ratchet pawl that is not on the drive side runs idle, it is possible to prevent the generation of the metallic noise.

FIG. 10 and FIG. 11 show a second embodiment of the present invention. Explaining the same parts as those in the above embodiment, 51 is a chain stay of a bicycle frame, and a rear wheel hub 52 is a receiving plate.
It is fixed by a lock nut 53 via 51A, and a rear wheel hub 54 is mounted on a rear wheel hub shaft 52 via a bearing (not shown).
Are rotatably fitted and spokes 55 are connected to the rear wheel hub 54. Reference numeral 56 denotes an arm whose one end is rotatably connected to the inside of one of the chain stays 51 by a pivoting portion 57, and a plurality of discs 58 are fixed to the inner surface of the arm 56 by screws 59. Reference numeral 60 denotes a hollow cylindrical case that is an input side rotating member rotatably provided on the outer periphery of the disk 58 via a bearing 61, and the sprocket 62 is concentrically integrated with the outer periphery of the hollow cylindrical case 60. Is screwed to.
The arm 56 and the disk 58 are respectively provided with elongated holes 63 extending from the center of the disk 58 to the vicinity of the lower end, and the rear wheel hub shaft 52 is inserted into the elongated holes 63, and the arm 56 and the chain stay 51 is connected by a tension spring 64, and the arm 56 is biased upward so that the hub shaft 52 side is held in a state of being locked to the upper end of the elongated hole 63. In this case, the lower end of the long hole 63 is held at the maximum eccentric position by engagement with the rear wheel hub shaft 52 side, and the upper end of the long hole 63 is held at the position of eccentricity o by the engagement with the rear wheel hub shaft 52 side. is doing. Reference numeral 65 is a ratchet pawl having a plurality of tooth portions 66, and six ratchet pawls 65 are arranged as a set in parallel in the circumferential direction inside the cylindrical portion 60A of the hollow cylindrical case 60, and Six ratchet pawls 65A are arranged on the outside as another set in parallel at equal intervals in the circumferential direction, and each ratchet pawl 65, 65A is rotatably provided by a pivot shaft 67 at the base end and a collar 67A mounted on the pivot shaft 67. The
A spring 68 wound around a pivot 67 is biased toward the center of the hollow cylindrical case 60. Further, the two sets of ratchet pawls 65, 65A are arranged alternately with each other. Further, at the base end of each ratchet pawl 65, 65A, a restricting portion 70 that engages with the inner peripheral wall surface 69 of the cylindrical portion 60A and restricts and holds each ratchet pawl 65, 65A at a constant angle is extended.

On the outside of the chain stay 51, the receiving plate 51A is screw 71.
And an outer cylinder 72 that externally covers the hub axle 52 is integrally formed on the inner surface side of the receiving plate 51A.
73 is provided.

74 is a ratchet gear that is an output side rotating member that is screwed to one of a pair of male screws 75 formed in the rear wheel hub 54 and is located inside the hollow cylindrical case 60. A ring 74A screwed to the male screw 75, and this ring
A ratchet gear body 74B provided on the outer peripheral surface of 74A corresponding to the set of ratchet pawls 65 via a bearing 76A and a one-way clutch 77A, and the other set of ratchet on the outer peripheral surface of the ring body 74A. It is composed of a bearing 76B and a ratchet gear body 74C provided via a one-way clutch 77B corresponding to the pawl 65A.

Next, the operation of the apparatus of this embodiment configured as described above will be described. First, as shown in FIG. 11, the crank gear 82 rotates via the crank pedal 81, and the rotation of the crank gear 82 is transmitted to the sprocket 62 by the chain 83. The sprocket 62 has a hollow cylindrical case 60 via a bearing 61.
And ratchet claws 65, 65A mounted on the hollow cylindrical case 60 to rotate the ratchet gear 74,
Rotation is transmitted from the ratchet gear 74 to the rear wheel hub 54.
Then, at the time of starting, climbing uphill or running on a rough road, a large force is naturally applied to the pedal, the tension of the chain 83 becomes strong, and a large load is applied to the ratchet pawls 65DR and 65ADR that propel the ratchet gear 74. Ratchet pawl 65DR, 65ADR is pivoted 67 depending on the size of the load.
With the fulcrum as the fulcrum, bite in toward the ratchet gear 74 side,
This causes the ratchet pawls 65DR and 65ADR to stand up, and this action causes the arm 56 to move downward against the force of the spring 64 with the pivotal attachment portion 57 as a fulcrum, and in this embodiment, the inner cylinder on the hub shaft 52 side. The ratchet gear 74 and the hollow cylindrical case are made by engaging 73 with the upper end of the slot 63.
The eccentricity that is concentric with 60 is automatically maintained in the state of o, and the rotation ratio of the sprocket 62 and the wheel 84 becomes 1: 1.
Next, when the force applied to the pedal is reduced, the tension of the chain 83 gradually weakens and the arm 56 moves upward with the pivoting portion 57 as the fulcrum by the restoring force of the spring 64, so that it is a hollow cylinder with respect to the ratchet gear 74. The cylindrical case 60 gradually shifts to an eccentric state for speed change (acceleration), and the inner cylinder 73 on the hub shaft 52 side engages with the lower end of the long hole 63, whereby the hollow cylindrical case 60
The maximum eccentricity state is set, and the gear is automatically changed at the maximum gear ratio (speed increase ratio).

Also in this embodiment, one set of ratchet pawls 65 and the other set of ratchet pawls 65A are arranged in a staggered manner in the axial direction. It has a double ratchet pawl, and the drive ratchet pawl in the drive range D is the ratchet pawl 65 and the ratchet pawl.
The speed is increased in such a manner that 65A are alternately exchanged, and when one group speeds up, the other group idles. Therefore, as in the above embodiment, a plurality of ratchet pawls 65DR, 65A within the driving range are provided.
The speed difference between DR becomes small and pulsation is prevented. Also, the generation of metallic noise is prevented.

The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the present invention. For example, the transmission is adaptable to various types with ratchet pawls. Further, the ratchet pawl and the ratchet gear body may be provided in three or more sets in the axial direction.

[Advantages of the Invention] The present invention has a plurality of rows of ratchet pawls rotatably provided on the base side in the circumferential direction, and the plurality of rows of ratchet pawls are axially arranged so that the ratchet pawls are staggered. A pair of input side rotating members, an output side rotating member provided with a plurality of ratchet gear bodies corresponding to the plurality of sets of ratchet pawls via a one-way clutch, and the input and output side rotating members are relatively arranged. An eccentric moving part for eccentric movement, and a restricting part for restricting each ratchet pawl so that only the ratchet pawl within the drive range meshes with the output side rotating member when eccentric. A continuously variable transmission for a bicycle that can prevent noise can be provided.

[Brief description of drawings]

1 to 9 show a first embodiment of the present invention, in which FIG. 1 is an overall longitudinal sectional view, FIG. 2 is a perspective view, FIG. 3 is an exploded perspective view, and FIG. 4 and FIG. Partially cutaway perspective views showing the guide state of the ratchet pawls, FIGS. 6 (A) and (B) and FIGS. 7 (A) and (B) are sectional views showing changes in eccentricity, and FIG. 8 is an eccentricity adjusting mechanism. FIG. 9 is a perspective view showing the state of use, FIG.
FIG. 11 and FIG. 11 show a second embodiment of the present invention, FIG. 10 is a longitudinal sectional view and FIG. 11 is a use state diagram. 12, 60 …… Input side rotating member 13, 13A, 65, 65A …… Ratchet claw 29, 74 …… Output side rotating member 29B, 29C, 74B, 74C …… Ratchet gear body 32A, 32B, 77A, 77B …… One-way clutch 37 …… Eccentric movement part 19,70 …… Regulation part

Claims (1)

[Claims] 1. A plurality of rows of ratchet pawls rotatably provided on the base side are arranged in the circumferential direction, and a plurality of sets of the ratchet pawls of the plurality of rows are arranged side by side in the axial direction so that the ratchet pawls are staggered. An input side rotating member, and an output side rotating member provided with a plurality of ratchet gear bodies corresponding to the plurality of sets of ratchet pawls respectively through a one-way clutch,
An eccentric moving part for relatively eccentrically moving the input / output side rotating member, and a restricting part for restricting each ratchet claw so that only the ratchet claw substantially within the driving range meshes with the output side rotating member when eccentric. A continuously variable transmission for a bicycle, characterized in that