JPH01195197A - Continuously variable transmission for bicycle - Google Patents

Abstract

PURPOSE:To prevent pulsation of a running load nicely and simply the structure concerned by arranging a plurality of sets each of which consists of a plurality of ratchet claw and forming said plurality of ratchet claw of each set with their teeth parts mutually shifted. CONSTITUTION:Two ratchet claws 13, 13A swingable around a privot 15 serving as one pivotal support part as a fulcrum are bounded in one set, and teeth 16, 16A are so constructed as being shifted from each other by a half pitch of one tooth. Owing to the above contrivance, pulsation of a running load can be improved and also a simplified structure and compactness of the transmission in the caption can be achieved because two ratchet claws 13, 13A with their teeth parts 16, 16A mutually shifted are bound in one set and six sets of ratchet claws 13, 13A are arranged similarly to the conventional case. Further, since the modules of teeth 16, 16A need not be reduced in their sizes, stable operation can be achieved without any anxiety of tooth skipping as well as the strength of teeth 16, 16A can be secured sufficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a continuously variable transmission device for a bicycle, which is installed on a bicycle and is configured to continuously change speed according to the amount of eccentricity.

[Prior Art] In general, this type of transmission is configured to continuously change speed transmission by feeding pawls that mesh with a ratchet gear. The transmission force rattling, so-called pulsation, occurs due to factors such as a gap between the fM and the customer due to the speed difference between a plurality of ratchet pawls within the drive range.

To explain this using FIGS. 14 to 18, the 14th
As shown in FIG. 15, six ratchet pawls B are provided on the circumference of a hollow cylindrical case A, which is an input-side rotating member that rotates integrally with a crank (not shown). In a transmission device in which a ratchet gear C, which is a rotating member, is engaged, the relationship between the ratchet pawl support shaft position and the gear ratio at maximum speed change is as shown in the graph of Fig. 16, and the ratchet pawl B is a hollow cylindrical gear. The rotation angle of A is 60 degrees, and the drive is performed while shifting sequentially, and the driving range is 60 degrees.

The graph in FIG. 16 uses the ratchet pawl support shaft position as a reference (0°) in the eccentric direction of the ratchet gear C from the center of the hollow cylindrical case A, and the direction of rotation relative to this (0°).
The figure shows the relationship between the ratchet pawl support shaft position and the gear ratio when (+) and the opposite are (-). Ratchet claw B
When the drive range is expressed by the ratchet pawl support shaft position, the relationship between the crank rotation angle and the gear ratio when the drive range is 120° to 40° is as shown in the graph in Figure 17. When the driving range is from 180° to -20°, the above relationship becomes as shown in the graph in Figure 18, and as the driving range moves toward the (10) side, the pulsation increases and becomes on the (-) side. The pulsation is small.

Conventional transmissions have a drive range of approximately 144° to 16°. This is from the position of the ratchet pawl Bl to the position of the ratchet pawl B in FIG.

In FIG. 15, the drive of the ratchet gear C is immediately after being transferred from the ratchet pawl B to the ratchet pawl B1, and at this time, the ratchet pawl B2 and the ratchet gear C that are to be engaged next
A gap t is created between the tips of the teeth. Ratchet claw B
In order to engage and drive ratchet gear B2 and ratchet gear C, there must be a gap t, but in the position shown in Fig. 15, ratchet gear C is closer to ratchet pawl B2, and the relative speed is lower. Because it is fast, the gap does not get smaller. However, as the crank rotates and ratchet pawl B2 rotates from the (-) side to the (+) side, the ratchet gear C
The difference in relative speed between and ratchet pawl B2 becomes smaller,
Finally, reverse the direction, close the gap t, and use the ratchet pawl B2.
When it reaches the position of the ratchet pawl B1, the gap t disappears, and it becomes in a driving state. Therefore, since there is a speed difference between the driving ratchet pawls Bl and B2, pulsation occurs.

The following measures can be considered to prevent such pulsations.

The first is to make the module of the teeth of each ratchet pawl smaller.
The gap t in Fig. 5 is made smaller and the drive range is set to the (-) side as much as possible. Second, the number of ratchet pawls is increased to narrow the driving range. However, in the case of the first measure, it is difficult to make the module smaller due to problems such as the strength of the teeth or the occurrence of tooth skipping, and in the case of the second measure, it is possible because the drive range is on the (+) side. It will not be effective unless additional ratchet pawls are added, and the device will become larger.

A second measure for preventing pulsation has been proposed in Japanese Patent Application Laid-Open No. 184192/1983.

This reduces the pulsation of the transmission force by arranging a plurality of sets of ratchet gears and ratchet pawl rows in parallel in the axial direction of the crankshaft to greatly increase the number of ratchet pawls.

[Issue to be solved by the invention w11 In the above-mentioned conventional technology, multiple sets of ratchet gears and ratchet pawls are arranged in parallel in the axial direction of the crankshaft, which makes the W4 structure large and complicated, resulting in problems in terms of handling and cost. I had a problem.

Therefore, the present invention focuses on the first measure, and makes it possible to shift the drive range as far as possible to the <-) side without reducing the module size of the three teeth of the ratchet pawl, thereby simplifying the configuration and reducing the transmission force. An object of the present invention is to provide a continuously variable transmission device for a bicycle that can prevent pulsation.

[Means for Solving the Problems] The present invention includes a plurality of ratchet pawls arranged in the circumferential direction of one side of an output side rotating member, each set of which is rotatable by one pivot, Also, the teeth of the plurality of ratchet pawls are shifted from each other.

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

In Figures 1 to 11, 1 is the main pipe of the bicycle frame, 2 is a vertical pipe, 3 is a chainstay, 4 is a hanger lug integrally formed with the bicycle frame, 5 is a crankshaft, and 6 is attached to the crankshaft 5. A crank arm is fixed via a lock nut 7, 8 is a rear wheel, 9 is a rear wheel hub shaft, 10 is a sprocket for the rear wheel, and 11 is a chain.

12 is a hollow cylindrical case which is an input side rotating member;
The center of the hollow cylindrical case 12 is fixed to the crankshaft 5 by the lock nut 7, and the crank arm 6 is integrally formed with the hollow cylindrical case 12. 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. 13 is a ratchet pawl, which is connected to the hollow cylindrical gauge 12.
and the beneficial body 12A of this gauge 12.
Six sets of two ratchet claws are arranged in parallel at equal intervals in the circumferential direction, and each set has two ratchet claws 13. The two ratchet pawls 13.13A of each set have a plurality of teeth 16.13, respectively.
16A are provided, and the tooth portions 16.16A are formed to be shifted from each other by 1/2 pitch of one tooth. In this case, the pivot 15 is fitted with cap-shaped receivers 15A at both ends, and the receivers 15A are fitted into holes 15B provided in the hollow cylindrical case 12 and the body 12A. Further, a washer 15C is interposed between the ratchet pawls 13 and 13A. Further, each ratchet pawl 13.13A is provided with a cushioning member 16B made of rubber or the like on the tooth portion 16.16A, and a ** member 15D on the pivot portion. In this case, one of the buffer members 16B is manufactured by the applicant in Japanese Patent Application No. 62-2160.
The structure is similar to that proposed in Japanese Patent Application No. 40, and the other W and surface member 15D are structured similarly to that proposed by the applicant in Japanese Patent Application No. 62-217434.

Further, a plate spring 17 is fixed to the cylindrical portion 14, and one spring piece 17A formed on the plate spring 17 causes one ratchet pawl 13 of each set, and the other spring piece 17B causes the other ratchet pawl 13A. are biased toward the center of the hollow cylindrical gauge 12, respectively. Further, an engaging portion 18 is formed at the base end of the ratchet pawl 13 and the ratchet pawl 13A, and this engaging portion 18 engages with the inner circumferential surface 19 of the hollow cylindrical case 12, so that each ratchet pawl 1
3.13A is configured to be guided while being locked at the same inclination angle.

20 is a retaining ring of a bearing 21 that rotatably supports the crankshaft 5 within the hanger lug 4, and a hanger retaining nut 22 is screwed onto this retaining ring 20. 2
Reference numeral 3 denotes a disk-shaped fixed cam that is integrally fixed with the retaining ring 20, and an eccentric cam 2, which is an eccentric moving body, moves along an annular flange portion 24 formed around the periphery of this fixed cam 23.
5 is arranged so that it can rotate.

Further, a wire reel 26 provided at one end of the eccentric cam 25 via a cam holder 26A is connected to the annular flange portion 2.
4 is rotatably fitted.

Further, the eccentric cam 25 is arranged around the fixed cam 23 with a center B at a diagonally lower position rearward from the center A of the crankshaft 5.
A center hole 28 having a circular arc surface 27 centered on the point B 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 via a bearing 31 on a circular cam surface 30 formed on the outer periphery of the eccentric cam 25, and the cam holder 26A side of this ratchet gear 29 A sprocket 32 is screwed and fixed to the end. 33 is a retaining ring of the bearing 31, and 34 is a ratchet gear 2.
A collar 36.36A interposed between the m portion 29A of 9 and the subroket 32 is a dust intrusion prevention plate provided on the hollow cylindrical case 12 side and the sprocket 32.

Further, an eccentricity adjustment mechanism 37 is connected to the cam presser 26A. In this embodiment, in the face center amount adjustment mechanism 37, a wire reel 40 having a manual operation lever 39 is rotatably supported on a disc-shaped receiver 38 fixed to the upper side of the main pipe 1. One end of a pair of wires 41.42 is fixed to the top and bottom of the wire reel 26 via pins 43.44, and the other ends of the wires 41.42 are fixed to the top and bottom of the rear side of the wire reel 26 via pins 43A, 44A. These pins 43, 44, 43A, 44A are wires 41, 4
2 is fixed, wire reel 26° 40 hole 45
The mating is fixed.

Next, the operation of the device of this embodiment configured as described above will be explained.6 First, when the crank arm 6, crankshaft 5, and hollow cylindrical case 12 are rotated together via the crank pedal 46, the hollow cylindrical case 12 is rotated. The ratchet gear 2 is attached to the cylindrical case 12 through the ratchet pawl 13.13A.
9 rotates, the sprocket 32 rotates integrally with the ratchet gear 29, and the rotation of this sprocket 32 is transmitted to the rear wheel 8 by the chain 11 via the rear wheel sprocket 10.

6(A) and 6(B) show a case where the ratchet gear 29 is located at the center of the hollow cylindrical gauge 12 and the amount of steel core is 0. At this time, the ratchet pawl A.29 and the ratchet pawl 13.
13A is engaged with the ratchet gear 29, and the ratchet pawl 13.13A slides into contact with the engaging portion 18 of the 13A and the inner circumferential surface 19 of the hollow cylindrical case 12, so that one side of the ratchet claw 13A has a constant inclination angle of one angle. Retained. As a result, the gear ratio between the crankshaft 5 and the sprocket 32 is 1:1.

When the lever 39 is manually moved forward from this state, the wire reel 40 rotates clockwise via the disc-shaped receiver 38, and the pair of wires 41.42 and pins 43, 44, 43A are rotated accordingly. , 44A, the wire reel 26 is connected to the annular flange portion 24 of the fixed cam 23.
Rotate clockwise along. As a result, the eccentric cam 25 rotates around point B integrally with the wire reel 26, and as a result, the ratchet gear 29, which is provided concentrically with the eccentric cam 25, rotates at the center of the hollow cylindrical case 12, that is, the crankshaft. Move the mind to 1 for 5. In this case, the eccentric cam 25 is guided with the circular arc surface 27 of the center hole 28 and the crankshaft 5 in sliding contact, and the movement trajectory of the center A of the crankshaft 5 virtually obtained by the rotation of the eccentric cam 25 is A
This is an arc C from the point to the A° point.

FIG. 7 (A>(B) shows the case where the steel core amount of the hollow cylindrical case 12 with respect to the ratchet gear 29 is at its maximum eccentricity, and at this time, the eccentric cam 25 is centered on the center hole 28 with respect to the point B. The ratchet gear 29, which rotates clockwise until the left end contacts the crankshaft 5 and moves integrally with the eccentric cam 25, has two sets of ratchet pawls 13D within the drive range.
Push R, 13ADR. As a result, the ratchet pawls 13DR and 13ADR are engaged with the ratchet gear 29 by the urging force of the spring 17, and the other ratchet pawls 13.13
A is guided in a state separated from the ratchet gear 29 by sliding contact between the engaging portion 18 and the inner circumferential surface 19.

Then, the ratchet pawls 13DR, 13 within the drive range
Since the speed increase rate due to ADR is the highest, ratchet gear 2
9 is ratchet pawl 13DR.

13ADR, the other ratchet pawls 13 are separated from the ratchet gear 29.

Also, the ratchet pawls 13DR, 13ADH are sequentially driven at increased speeds such that when the ratchet pawls 13DR, 13ADH move out of the driving range, the adjacent ratchet pawl 13 enters the driving range to drive the ratchet gear 29 at increased speed.
R takes turns.

That is, a gear is virtually formed in the hollow cylindrical case 12 by the ratchet pawls 13DR and 13ADR within the drive range, and the diameter of this gear changes as the eccentric cam 25 rotates by operating the lever 39. Ratchet claw 13DR.

13ADR, and the speed ratio (speed increasing ratio) of the ratchet gear 29 changes steplessly.

At the time of eccentricity as shown in FIG.
．． 13A is one set, and the tooth portions 16 and 16A are shifted by 1/2 pitch of each tooth, so the two sets within the drive range as shown in Figs. 8 and 9. One set of the ratchet pawls 13DR and 13ADR is the tooth portion 16 of the ratchet pawl 13D R and the tooth portion 2 of the ratchet gear 29.
9A, the other pair to be driven next is the tooth portion 1 of the ratchet pawl 13A D R.
Gap t/2 between 6A and tooth portion 29A of ratchet gear 29
It becomes.

For this reason, the drive range has changed from the conventional 120° to 40° to 153°.
The drive range shifts to the (-) side up to about 7 degrees, and the pulsation is improved accordingly.

In this way, in the above embodiment, instead of multiple sets of ratchet gears and circumferential ratchet pawl rows being arranged side by side in the axial direction of the crankshaft as in the conventional case, two ratchets with the tooth portions 16 and 16A shifted from each other are used. With pawls 13.13A as one set, for example, six sets of ratchet pawls 1 are arranged in the circumferential direction as in the past.
Since the 3.13A is arranged, the structure is simplified and compact, and there is no need to make the module of the tooth 16°16A small, so the strength of the tooth 16.16A can be obtained sufficiently.There is no need to worry about tooth skipping. Stable operation can be obtained without any problems.

12 and 13 show a second embodiment of the present invention,
To explain without omitting the explanation of the same parts as in the above example, 5
Reference numeral 1 designates a chainstay of a bicycle frame, in which a rear wheel hub shaft 52 is fixed with a lock nut 53 via a receiving plate 51A, and a rear wheel hub 54 is rotatable on the rear wheel hub shaft 52 through a bearing (not shown). 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 chainstays 51 by a pivot joint 57, and a plurality of discs 58 are fixed to the inner surface of this arm 56 with screws 59. 60 is a bearing 61 on the outer periphery of the disc 58
This is a hollow cylindrical case which is an input-side rotating member rotatably provided through the hollow cylindrical case 60, and a sprocket 62 is concentrically and integrally screwed onto the outer periphery of the hollow cylindrical case 60. The arm 56 and the disc 58 are each provided with a long hole 63 extending from the center of the disc 58 to near the lower end, and the rear wheel hub axle 52 is inserted into the long hole 63, and the arm 56 and the chain stay 51 are connected by a tension spring 64, the arm 56 is urged upward, and the hub shaft 52 side is held in a locked state at the upper end of the elongated hole 63. In this case, the lower end of the elongated hole 63 and the rear wheel hub shaft 52
It is held at the maximum eccentric position by engagement with the side, and held at the eccentric position by engagement between the upper end of the elongated hole 63 and the rear wheel hub shaft 52 side.

65 is a ratchet pawl having a plurality of teeth 66; 65A is a ratchet pawl having a plurality of teeth 66A that are shifted by 1/2 pitch from the tooth 66; these two ratchet pawls 65.65A are A plurality of sets of ratchet pawls 65.65A are connected to the cylindrical portion 60 of the hollow cylindrical gauge 60.
Each set of ratchet pawls 65.
65A is rotatably provided by a pivot 67 at the base end and a collar 67A mounted on the pivot 67, and is biased toward the center of the hollow cylindrical case 60 by a spring 68 wound around the pivot 67.

The receiving plate 51A is fixed to the outside of the chainstay 51 with screws 71, and an outer cylinder 72 for housing the rear wheel hub axle 52 is integrally formed on the inner side of the receiving plate 51A. is provided with an inner cylinder 73.

Next, the operation of the apparatus of this embodiment configured as described above will be explained. First, as shown in FIG.
The crank gear 75 rotates through the chain 76, and the rotation of the crank gear 75 is transmitted to the sprocket 62 by the chain 76. The sprocket 62 rotates integrally with the hollow cylindrical case 60 via the bearing 61, rotates the ratchet gear 77 via the ratchet claw 65.65A attached to the hollow cylindrical case 60, and from the ratchet gear 77 rear wheel hub 54. rotation is transmitted to.

When starting, going uphill, or driving on rough roads, a large force is naturally applied to the pedals, increasing the tension of the chain 76, and applying a large load to the ratchet pawl 65.65A that propels the ratchet gear 77. Depending on the magnitude of the load, the ratchet pawl 65.65A digs in toward the ratchet gear 77 using the pivot 67 as a fulcrum.
This causes the ratchet pawl 65.65A to rise, and this action causes the arm 56 to move downward against the force of the spring 64 using the pivot portion 57 as a fulcrum.
In this embodiment, the inner cylinder 73 on the side of the hub shaft 52 engages with the upper end of the elongated hole 63, so that the eccentricity of the concentricity of the ratchet gear 77 and the hollow cylindrical case 60 is automatically maintained at zero. When the rotation ratio of the sprocket 62 and the wheel 78 is 1:1, and the force applied to the pedal is reduced, the tension of the chain 76 gradually weakens, and the arm 56 moves the pivot portion 57 due to the restoring force of the spring 64. In order to move upward as a fulcrum, the hollow cylindrical case 60 gradually becomes eccentric with respect to the ratchet gear 77 to change speed (speed up), and the inner cylinder 73 on the hub shaft 52 side engages with the lower end of the elongated hole 63. This brings the hollow cylindrical case 60 into the maximum eccentric state, and the speed is automatically changed at the maximum gear ratio (speed increase ratio).

In this embodiment, the ratchet pawls 65 and 65A have tooth portions 66° and 66A that are shifted from each other as in the above embodiment, so that the drive range shifts to the (-) side and pulsation is prevented accordingly. It has the same effect as the example.

Note that the present invention is not limited to the above-mentioned embodiments, and various modifications can be made within the scope of the gist of the present invention. For example, it goes without saying that the present invention can be applied to various types of transmissions equipped with ratchet pawls, such as crankshaft side or rear wheel side, automatic transmission or manual transmission, etc. In addition, although the description has been made assuming that there are two ratchet pawls in one set, three or more pawls may be used. In that case, the gap t shown in FIG. 6 [Effects of the Invention] The present invention can effectively prevent pulsation by arranging a plurality of ratchet pawls in a plurality of sets and shifting the teeth of a plurality of ratchet pawls in each set, thereby simplifying the structure. It is possible to provide a continuously variable transmission device for a bicycle.

[Brief explanation of the drawing]

1 to 11 show a first embodiment of the present invention.
Is the diagram all M? ! 2 is a perspective view, 3 is an exploded perspective view, 4 is a partially cutaway perspective view, 5 is a perspective view of the ratchet pawl, and 6 (A>(B) and 7 Figure (A) (
B) is a sectional view showing no change in the amount of eccentricity, FIGS. 8 and 9 are front views showing the mating state of the ratchet pawl and the ratchet gear, FIG. 10 is a perspective view showing the eccentricity adjustment mechanism, and FIG.
1 is a usage state diagram, 12th and 13th diagrams show a second embodiment of the present invention, and FIG. 12 is an IM! Jfr side view, FIG. 13 is a usage state diagram, FIGS. 14 to 18 show a conventional example, FIGS. 14 and 15 are front views showing the meshing state of the ratchet pawl and ratchet gear, and FIG. 16 is a A graph showing the relationship between the ratchet pawl support shaft position and the gear ratio, and FIGS. 17 and 18 are graphs showing the relationship between the rotation angle of the crank and the gear ratio. 12, 60... Input side rotating member 13, 13A, 65.65A... Ratchet pawl 16
, 16A, 66, 66A... Tooth i5.67...
Pivotal section (axis) 29, 77... Output side rotating member permission Applicant Nippon Seiki Co., Ltd. Attorney Patent attorney Godo Ushiki Patent attorney Usui 1
) Length 4 Part 813 Figure 14/1 Figure 15

Claims (1)

[Claims] (1) An input side rotating member, an output side rotating member, and the above-mentioned input side,
A plurality of ratchet pawls are provided on one side of the output rotating member in the circumferential direction, and each base side is rotatably provided by one pivot portion, and the ratchet pawls are provided to relatively eccentrically move the input and output side rotating members. In the continuously variable bicycle transmission device, each of the ratchet pawls is rotatably provided as a set on one of the input and output side rotating members by the one pivot portion; A continuously variable transmission device for a bicycle, characterized in that the teeth of each ratchet pawl are formed to be shifted from each other.