JPH0156029B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a reverse input permitting device for a continuously variable bicycle transmission installed on the crankshaft of a bicycle.

(Prior art) The applicant previously developed a continuously variable transmission device for bicycles (Showa
The proposed system was filed on May 21, 1959 (Japanese Patent Application No. 59-102404) (Japanese Patent Application Laid-open No. 60-248487), but this device requires a reverse input permitting device due to its structure.

(Purpose) The present invention has been made from the above-mentioned viewpoint, and an object of the present invention is to enable the practical use of the above-described planetary gear type continuously variable transmission by providing a reverse input permitting device. be.

(Structure) In order to achieve the above-mentioned object, in the present invention, a sun gear integrated with a chain gear is rotatably fitted to the crankshaft of a bicycle, a crank arm is fixed to the crankshaft, and a drive gear is fixed, A case enclosing the drive gear is fixed to the bicycle frame, an intermediate gear meshing with the drive gear is rotatably supported on the case, and a plate is pivotably supported by the pivot shaft. A circular hole is provided in the shaped shifter, and an annular carrier gear is rotatably provided in the shifter, having a stepped portion that fits into the circular hole, and a gear that meshes with the intermediate gear on the outer periphery. A plurality of carrier pins are provided protruding from the side surface, and a disk-shaped eccentric core having an eccentric hole is rotatably fitted into each of the carrier pins, and a planetary gear is connected to the outer periphery of each eccentric core via a one-way clutch. By fitting these planetary gears with springs so that they always mesh with the sun gear, and swinging the shifter about its pivot shaft, a continuously variable speed output is generated from the chain gear. In the continuously variable transmission device for a bicycle which can be taken out, a small gear having a smaller diameter than the intermediate gear is integrally formed with the intermediate gear, and a large gear that meshes with the small gear is connected to the shaft of the sun gear by a one-way clutch. A reverse input permitting device for a continuously variable bicycle transmission is configured by fitting the connector through the connector.

(Example) An example of the present invention will be described below with reference to the drawings. In the diagram, 1 is the main pipe of the bicycle frame, 2
A vertical pipe, 3 a chain stay, 4 a hanger lug, 5 a crankshaft, 6 a crank arm fitted onto the crankshaft 5, and 7 its lock nut.

In this embodiment, a sun gear 9 rotatably fitted to the crankshaft 5 via a needle roller bearing 8 is formed integrally with a chain gear 10, and a sun gear 9 is provided between the sun gear 9 and the chain gear 10. A step portion 11 having a larger diameter is formed, and a ring-shaped bearing fitting portion 12 is integrally formed on the outer periphery of the step portion 11 so as to protrude from the side surface of the chain gear 10. It is rotatably fitted onto the shaft 5.

Then, a plate-shaped case lid 14 is fitted to the outer periphery of the bearing fitting part 12 via a ball bearing 13, and a boss part 16a of a plate-shaped large gear 16 is fitted to the stepped part 11 via a one-way clutch 15. match.

This one-way clutch 15 may be of any type, for example as shown in FIGS.
The one-way clutch 15 is constructed by fitting a ring 15b having a pawl 15a onto the stepped portion 11, and forming a ratchet 15c on the inner periphery of the boss portion 16a of the large gear 16 to engage with the pawl 15a.

Further, the boss portion 20a of the driving gear 20 is inserted into the shaft hole 18a of the case body 18, which is connected to the case lid 14 by screws 17 (see FIG. 1) to form a case, via a ball bearing 19 (see FIG. 5).
The boss portion 6a of the crank arm 6 is fitted into the inner peripheral portion of the boss portion 20a via the serrations 6b, 20b (see FIG. 1).

Further, an intermediate gear 21 meshing with the drive gear 20
is rotatably provided in the cases 18, 14 via a bearing 23 by a pivot shaft 22, and a boss portion 25a of a plate-shaped shifter 25 is fitted to a body portion 21a integral with the intermediate gear 21 via a bearing 24. match. As shown in FIG. 2, this shifter 25 is provided with a circular hole 25b and a cam hole 25c above the boss portion 25a. Further, a serration 21b having a smaller diameter than the body 21a is formed at the end of the body 21a of the intermediate gear 21, and a serration 26a having a small gear 26 formed on the inner periphery that meshes with the large gear 16 during assembly is formed. 21
b to integrally connect the intermediate gear 21 and the small gear 26. Note that the diameter of this small gear 26 is made smaller than the diameter of the intermediate gear 21.

It also has a stepped portion 28a that fits into the circular hole 25b of the shifter 25 via a large number of steel balls 27, and a gear 2 that meshes with the intermediate gear 21 on the outer periphery.
8b and a center hole 28c is fitted into the shifter 25 via the steel ball 27, and a hollow disk-shaped carrier plate 29 is applied to the end surface of the stepped portion 28a. Along with
Attach screw 30 (see Figure 2) to carrier plate 29.
The carrier gear 28 is rotatably attached to the shifter 25 by screwing it through the carrier gear 28.

In addition, a plurality of carrier pins 31 (in this embodiment, three on one side, six on both sides) protrude from each side of the carrier gear 28, and a coil spring is fitted and locked around each carrier pin 31. An annular groove 32 is provided. The carrier pin 31 on the carrier plate 29 side extends through the plate 29. 29a (see FIG. 2) is the through hole.

Further, a coil spring 33 as shown in FIG. 2 is inserted into the annular groove 32, and the spring 3
3 is locked to the carrier gear 28. Then, a disc-shaped eccentric core 34 having an eccentric hole 34a is fitted into each carrier pin 31, and the other end 33b of the spring 33 is locked to the eccentric core 34. A ring-shaped planetary gear 36 is fitted to the outer periphery of each eccentric core 34 via a one-way clutch 35, and during assembly, each planetary gear 36 is always connected to the sun gear 9 by the action of the coil spring 33. energize it so that it meshes with the

The one-way clutch 35 may be of any type, but for example, as shown in FIG.
A one-way clutch 35 is constructed by attaching a pawl 35a to the outer circumference of the planetary gear 36 via a ring-shaped spring 35b, and forming a ratchet 35c on the inner circumferential surface of the planetary gear 36 to engage with the pawl 35a.

Further, a pivot shaft 22 provided in the cases 18, 14
Above, a cam shaft 37 (see FIG. 1) is provided which passes through the cam hole 25c of the shifter 25 and has both ends of the shaft supported by the cases 18, 14, and an eccentric cam integrally formed with the wire reel 38. 39 is fitted into the cam hole 25c, and rotatably fitted onto the cam shaft 37 via the shaft hole 39a. Note that 40 is a spacer that fits on the camshaft 37, 41 is an inner wire for speed change operation wound around the wire reel 38, 42 is an outer wire, and 43 is an adjustment screw fixed to the end of the outer wire 42. 43 is case body 1
8 into the screw hole 18b provided at the upper edge. 4
4 is the lock nut.

The above-mentioned components are then assembled as shown in FIG. That is, as described above, the crank arm 6 connected to the case body 18 is fitted into the rectangular tube part of the crankshaft 5 and fixed with the lock nut 7, and the joint between the case body 18 and the case lid 14 is secured with the screw 17 (the first (see figure) to integrate the cases 18 and 14, and the cases 18 and 1
At the same time, connect the rear case lid 14 of 4 to the chain stay 3 of the bicycle frame, cover the chain stay 3 with the fixing metal fittings 45 as shown in FIG. ). 45a is the fixing metal fitting 4
5 is a screw insertion hole provided in the case lid 14, and 14a is a screw hole provided in the case lid 14. Further, 46 is a chain connected to the chain gear 10.

(Operation) Next, the operation of the apparatus of the present invention configured as described above will be explained. Figure 6 shows the cam hole 25 of the shifter 25.
This shows a concentric state in which the centers of the crankshaft 5 and the carrier gear 28 are completely aligned due to the action of the eccentric cam 39 fitted in the position c. From this state, when the operating wire 41 is operated in the direction of arrow A and the eccentric cam 39 is rotated as shown by arrow B, the shifter 25 moves from the case 18 to the case 18 as shown by arrow C in FIG. 14. As a result, the center O' of the carrier gear 28 is eccentric from the center O of the crankshaft 5 by l.

Furthermore, when the operating wire 41 is operated in the direction of arrow D from the state shown in FIG. 7 to rotate the eccentric cam 39 in the direction of arrow E, the shifter 25 is rotated in the direction of arrow F and concentric Return to state. That is, by arbitrarily operating the shifter 25 within the range shown in FIGS. 6 and 7, the amount of eccentricity of the carrier gear 28 with respect to the crankshaft 5 can be set steplessly to an arbitrary amount.

Next, the operation of the continuously variable transmission mechanism is shown in Figures 8 and 9.
The diagram will be explained.

FIG. 8 shows the sun gear 9 in the state shown in FIG. 6,
Drive gear 20, intermediate gear 21, and shifter 25
and a carrier gear 28 (concentric with the drive gear 20)
FIG. 3 is an explanatory diagram showing the relationship among the carrier pin 31, the planetary core 34, the planetary gear 36, and the eccentric cam 39.

In this state, when the drive gear 20 fixed to the crank arm 6 via the crank arm 6 rotates in the direction of arrow G, the intermediate gear 21 rotates as shown in FIG.
The carrier gear 28 rotates together with the crankshaft 5 via the carrier pin 31, and as a result, each eccentric core 34 and the planetary gear 36 also
It rotates with 8. However, in this case, since each of the carrier pins 31 protruding from the carrier gear 28 rotates on a circular trajectory H concentric with the shaft 5, the eccentric core 34 does not rotate with respect to the carrier gear 28 at all.

However, since each planetary gear 36 meshes with the sun gear 9 by the action of the coil spring 33, each planetary gear 36 moves clockwise in the direction of arrow I in FIG. 8 due to the load resistance of this sun gear 9. It attempts to rotate, but this rotation is prevented by the one-way clutch 35 consisting of a ratchet 35c and a pawl 35a.
This is prevented by the action of Therefore, the sun gear 9 rotates integrally with the crankshaft 5 in the same direction as the arrow J in FIG. 8 by the planetary gear 36 which rotates integrally with the carrier gear 28. Therefore, the gear ratio in this case is 1:1.

Next, when the shifter 25 is placed in the eccentric state shown in FIGS. 7 and 9 by the gear change operation, as the crank arm 6 rotates in the direction of the arrow G, the carrier gear 28 moves to the eccentric state shown in FIGS.
As a result, each eccentric core 34 also rotates together with the carrier pin 31, but in this case, the circular trajectory H of each carrier pin 31 coincides with the center O of the sun gear 9.
Since each planetary gear 36 is always biased to mesh with the sun gear 9 by the action of the coil spring 33, each eccentric core 34 is also eccentric to the carrier gear 28 from time to time. Rotate.

That is, in FIGS. 8 and 9, if the center of the sun gear 9 is O, the center of the carrier pin 31 in each phase is K, and the fixed point on the circumference of the planetary gear 36 is M, then θ, which is ∠OKM, is the 8th In the case of the figure, it is always constant, but in the case of Fig. 9, θ ₁ and
It changes like θ ₂ , θ ₃ , and θ ₄ . Then, a relationship of θ ₁ <θ ₂ <θ ₃ >θ ₄ >θ ₁ occurs between them.

That is, since the planetary gear 36 between θ ₁ and _{θ 3} rotates in the direction of arrow N shown in FIG. 9,
This rotation in the direction of arrow N and the revolution of the planetary gear 36 in the direction of arrow G due to the rotation of the carrier gear 28 cause the sun gear 9 that meshes with the planetary gear 36 to move to the direction indicated by the arrow P in FIG.
The crankshaft 5 is rotated at an increased speed as shown in . In this case, in this embodiment, the planetary gear 36 is 6
Since there are six planetary gears 36, the speed of the gear 36 that is not in the speed increasing range is not increased, but by the action of the one-way clutch 35, one planetary gear 36 that is in the highest speed increasing range at that time. Only the gear 36 is the sun gear 9
The remaining five planetary gears 36 are then rotated by the sun gear 9. That is, at this time, the ratchet 3 of the gear 36
5c will slide and rotate with respect to the claw 35a.

FIG. 10 shows the speed increasing characteristics of the device of the present invention, with the speed increasing gear ratio plotted on the ordinate and the rotation angle of the crankshaft 5 plotted on the abscissa.

As can be seen from this, in order to minimize variations in the speed ratio, it is preferable to use a large number of planetary gears 36. Since six planetary gears 36 are used in this embodiment, the angular range Q (60 degrees) shown in FIG. 9 is the driving range of each planetary gear 36 with respect to the sun gear 9. Therefore, it can be seen from FIG. 10 that in this embodiment, a rotational driving force with almost no pulsation is obtained even during speed increase.

Furthermore, in the above explanation, the case of the speed increase ratio of 1:1 and the case of the maximum speed increase ratio have been explained, but the rotational operation amount of the shifter 25 can be set to an arbitrary amount between the values shown in FIGS. 6 and 7. Particularly, according to the device according to the invention,
It is obvious that any speed ratio can be obtained steplessly.

The above is an explanation of the operation of the continuously variable transmission device according to the present invention when the bicycle is running (normal rotation). When a bicycle equipped with this continuously variable transmission device stops, for example, in the middle of a slope, it is affected by the action of gravity. If you turn around and move backwards, the rear wheels will rotate in the opposite direction and the chain 46 will rotate.
A reverse input in the direction indicated by arrow R in FIG. 8 acts on the sun gear 9 of this continuously variable transmission via the chain gear 10.

When this reverse input is applied, the continuously variable transmission becomes mechanically self-locked and cannot be reversed, and unreasonable force is applied to each part of the device. Therefore, in order to put this continuously variable transmission into practical use, A reverse input permissive device is required during this reverse rotation.

The small gear 26 and the large gear 16 mentioned above are for allowing this reverse input, and their functions will be explained below.

That is, in FIG. 8, when a rotational force in the direction of the arrow R acts on the sun gear 9 as described above, each planetary gear 36 meshing with the sun gear 9 rotates in the direction of the arrow I in FIG. However, since this rotation is blocked by the one-way clutch 35, it is impossible to rotate.

However, as described above, the small gear 26 and the large gear 16 are incorporated in this continuously variable transmission, thereby allowing reverse input.

That is, as shown in FIG. 3, when the crank arm 6 rotates normally in the direction of arrow S, the intermediate gear 21 rotates in the direction of arrow T via the drive gear 20, and this rotation is transmitted to the large gear 16 via the small gear 26. transmits a decelerated rotation in the direction of arrow U to . However, during normal rotation, the rotation of the sun gear 9 is the same as the rotation of the drive gear 20 or is rotated at an increased speed. It is clear that it is faster in the same direction than the large gear 16 shown in the figure. Therefore, during normal rotation, the large gear 16 rotates in the direction of arrow U, but the ring 15b rotates in the same direction at a faster speed, so that the one-way clutch 15 is in a slipping state. Therefore, no excessive force is applied to the device.

Furthermore, when the rotational force in the direction of arrow V in FIG. Rotate in the direction of. Therefore, the drive gear 20 rotates in the direction of the arrow X through the small gear 26 and the intermediate gear 21 at a higher speed than the large gear 16. Therefore, since the carrier gear 28 also rotates integrally with the drive gear 20 at a higher speed than the large gear 16 in the direction of arrow Y in FIG. 8, the gears 16, 26, 21,
If the speed increase ratio by 28 is set larger than the speed increase ratio by the eccentric core 34, the planetary gear 36 will rotate in the direction of arrow Z in FIG. 8 with respect to the eccentric core 34 even during reverse rotation. No lock phenomenon occurs. Therefore, according to the device of the present invention, no lock phenomenon occurs in the continuously variable transmission even during reverse rotation, and there is no fear that unreasonable force will be applied to each part of the device.

(Effects) Next, the effects of the device of the present invention will be explained. Since the reverse input permitting device of the continuously variable transmission for a bicycle according to the present invention is as described above, the above-described continuously variable transmission can be put into practical use for the first time. In addition, this reverse input permitting device only requires adding the small gear 26 and the large gear 16 to the continuously variable transmission, and since this device is completely sealed inside the case, its operation is reliable. Moreover, the overall device can be made lighter and smaller, and the appearance can also be improved.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of a continuously variable bicycle transmission having a device of the present invention, Fig. 2 is an exploded perspective view of the main parts thereof, Figs. 3 and 4 are front views showing the partially assembled state, and Figs. Fig. 5 is a cross-sectional plan view of a continuously variable transmission for a bicycle having a device of the present invention, Figs. 6 and 7 are explanatory diagrams of the operation of the eccentric operation device, and Figs. 8 and 9 are gear changes of the continuously variable transmission. FIG. 10 is a graph showing speed increase characteristics of the continuously variable transmission. 5... Crank shaft, 6... Crank arm, 9... Sun gear, 10... Chain gear, 14... Case lid (case), 15... One-way clutch, 16... Large gear,
18... Case body (case), 20... Drive gear,
21... Intermediate gear, 22... Pivot shaft, 25... Shifter, 26... Small gear, 27... Steel ball, 28... Carrier gear, 29... Carrier plate, 31... Carrier pin, 32... Annular groove, 33... Coil spring (spring) ), 34... Eccentric nucleus, 35... One-way clutch,
36... Planetary gear, 37... Camshaft, 38... Wire reel, 36... Eccentric cam, 41... Inner wire, 42... Outer wire, 45... Fixing metal fittings,
46...Chien.

Claims (1)

[Claims] 1 A sun gear 9 integrated with a chain gear 10 is rotatably fitted to the crankshaft 5 of a bicycle, a crank arm 6 is fixed to the crankshaft 5, and a drive gear 20 is fixed, and a case 18 encloses the drive gear 20. , 14 fixed to the bicycle frame,
The intermediate gear 21 that meshes with the drive gear 20 is shown in case 1.
A circular hole 25b is provided in a plate-shaped shifter 25 which is rotatably supported on the shafts 8 and 14 and swingably supported by the pivot shaft 22, and a stepped portion 28a that fits into the circular hole 25b is provided. It also has an intermediate gear 2 on the outer periphery.
An annular carrier gear 28 formed with a gear 28b that meshes with the shifter 25 is rotatably provided on the shifter 25,
A plurality of carrier pins 31 are protruded from the side surface of the carrier gear 28, and each carrier pin 31 has a disk-shaped eccentric core 34 having an eccentric hole 34a.
A planetary gear 36 is fitted to the outer periphery of each eccentric core 34 via a one-way clutch 35, and a spring 33 is fitted so that each planetary gear 36 always meshes with the sun gear 9. In the continuously variable bicycle transmission device, a continuously variable transmission is output from the chain gear 10 by energizing the shifter 25 using its pivot shaft 22 as a fulcrum. Small gear 26
is formed integrally with the intermediate gear 21, and this small gear 26
This reverse input permitting device for a continuously variable bicycle transmission is characterized in that a large gear 16 meshing with the sun gear 9 is fitted onto the shaft of a sun gear 9 via a one-way clutch 15.