JPH01278894A - Speed changer for bicycle - Google Patents

Abstract

PURPOSE:To prevent any variation in rotational driving force from occurring by forming an input member of a bicycle speed changer, transmitting rotation of the input member as one body with a crankshaft to a freely decenterable ratchet wheel of an output member via a ratchet pawl, into both inner and outer rings in structure via a buffer member. CONSTITUTION:Rotation of a crankshaft rotated and driven by a pedal crank chain is transmitted to a hollow cylindrical member 12 as an input member. This hollow cylindrical member 12 is engaged with a ratchet pawl 45 as an output member, being energized by a spring, installing plural numbers of rockable ratchet pawls 36 and being free of decentering. A chain sprocket 52 is solidly attached to a ratchet wheel 45, transmitting motive power to a rear wheel via a chain 11, and an eccentric value of the ratchet wheel 45 is varied whereby a speed change takes place. The hollow cylindrical member 12 as an input member is constituted of an inner ring 13 and an outer ring 14 via a buffer member 17, and any impact at the time of operating a pedal is absorbed and simultaneously it aims at preventing any variation in turning effort at the time of driving from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a bicycle transmission device that is installed on a bicycle and is capable of steplessly changing 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. A ratchet, so-called pulsation, occurs in the transmission force due to causes such as a gap between the tips of the teeth due to the difference in speed between a plurality of ratchet pawls within the drive range.

For this reason, in order to reduce pulsation,
Publication No. 92 has been proposed.

This reduces the pulsation of the transmitted 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.

[Problems to be Solved by the Invention] In the above-mentioned conventional technology, since it is necessary to provide a plurality of sets of ratchet gears and ratchet pawls in parallel, the structure is large and complicated, resulting in problems in terms of handling and cost.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a bicycle transmission device that has a simplified configuration and can prevent the occurrence of pulsation in the transmission force.

[Means for Solving the Problems] The present invention includes an input side rotation member, an output side rotation member, and a plurality of rotation members arranged in the circumferential direction on one of the input and output side rotation members, and each base side is provided with one pivot portion. In the bicycle transmission device, the bicycle transmission is equipped with a rotatably provided ratchet pawl, and the input and output side rotating members are moved eccentrically relative to each other to change speed, wherein the input side rotating member connects an outer ring and an inner ring. In preparation, there is a Mf! between this outer ring and inner ring! It is constructed by arranging one member.

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

In Figures 1 to 10, 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 gauge 12
may be formed separately, and the hollow cylindrical gauge 12 may be fixed to the crankshaft 5 via the crank arm 6.

The hollow cylindrical gauge 12, which is the input-side rotating member, includes an outer ring 13 and an inner ring 14. On the inner peripheral surface of the outer ring 13, a large number of trapezoidal outer protrusions 15, which are engagement parts, are arranged at equal intervals. In addition, a large number of trapezoidal inner protrusions 16 serving as engagement receiving portions are integrally formed on the outer peripheral surface of the inner ring 14 at equal intervals. The inner ring 14 is disposed within the outer ring 13 such that an inner protrusion 16 is located at a distance between the outer protrusions 15, and the gap between the outer protrusion 15 and the inner protrusion 16 is filled with synthetic rubber or synthetic resin. A zigzag-shaped buffer ring 17, which is a buffer member made of an elastic material such as urethane rubber, is press-fitted.

Further, a ring-shaped outer plate 18 is integrally formed on the outer side of the inner ring 14, and a ring-shaped inner plate 1 is formed on the inner side.
9 is provided, and this inner plate 19 is screwed to the outer plate 18 by a plurality of screws 21 inserted through the outer tube 20.

Further, an outer plate 22 that is integral with the crankshaft 5 is provided on the outside of the outer ring 13 and the inner ring 14, and a ring-shaped inner plate 23 is provided on the inside.
3 is fixed to the outer ring 13 with a plurality of screws 24.

In addition, the width center of each outer projection 15 of the outer ring 13 and the inner ring 14
A groove 25 is formed in the center of the width of each inner protrusion 16, and a wire ring 26 serving as a countermeasure is fitted into the multi-groove 25, and a buffer ring 17 is disposed on each side of the wire ring 26. .

Further, an outer ring 1 is provided on each outer peripheral edge of the inner plate 23 and the outer plate 22.
3 is formed with a flange 27 that engages with the outer circumferential surface of the inner plate 3, and a circular protrusion 28 is formed on each inner surface at a position corresponding to the buffer ring 17. Circular projections 29 serving as perforations are formed at positions corresponding to the outer plate 18, respectively.

Further, a stepped portion 30 is formed on each of the outer plate 22 and the inner plate 23, and the portion covering the inner ring 14 is expanded by the stepped portion 30.

Further, the outer protrusion 15 is formed at the end of the inner peripheral surface of the outer ring 13 with a slight interval 31, and the inner protrusion 16 is formed at the end of the inner circumferential surface of the outer ring 13.
4 with a slight interval 32 between them.

Reference numeral 33 denotes ratchet pawls, and six sets of two ratchet pawls are arranged in parallel at equal intervals in the circumferential direction within the cylindrical portion 34 consisting of the inner ring 14 and inner and outer plates 19° 18 of the hollow cylindrical case 12. arranged, each set has two ratchet pawls 33.3
3A are provided in the cylindrical portion 34 in an overlapping state so as to be rotatable by a common pivot 35 which is a pivot point at the base end, and each set of two ratchet pawls 33.33A has a plurality of teeth 36.3A, respectively. 36A is provided, and the teeth 36, 36A
are formed so as to be shifted from each other by 1/2 pitch of one tooth. In this case, the pivot 35 has cap-shaped receivers 35A on both ends.
In the fitted state, the receiver 35A is inserted into the hole 35B provided in the outer plate 19.18 of the hollow cylindrical case 12.
It is attached to. Further, a washer 35C is interposed between the ratchet pawls 33 and 33A. Further, each ratchet pawl 33.33A is provided with a member 36B made of rubber or the like on the tooth portion 36.36A. In this case, the buffer member 36B has a structure similar to that proposed by the applicant in Japanese Patent Application No. 62-216040.

Further, a plate spring 37 is fixed to the cylindrical portion 34, and one spring piece 37A formed on the plate spring 37 causes one ratchet pawl 33 of each set to be fixed, and the other spring piece 37B causes the other ratchet pawl 33A to are each urged toward the center of the hollow cylindrical case 12. Further, an engaging portion 38 is formed at the base end of the ratchet pawl 33 and the ratchet pawl 33A, and this engaging portion 38 engages with the inner circumferential surface 39 of the hollow cylindrical case 12, so that each ratchet pawl 3
3.33A is configured to be guided while being locked at the same inclination angle.

40 is a retaining ring of a bearing 41 that rotatably supports the crankshaft 5 within the hanger lug 4, and a hanger retaining nut 42 is screwed onto this retaining ring 40. 4
Reference numeral 3 denotes a disk-shaped fixed cam that is integrally fixed with the retaining ring 40, and an eccentric cam 4, which is an eccentric moving body, moves along an annular flange portion 44 formed around the periphery of this fixed cam 43.
5 is arranged so that it can rotate.

Further, a wire reel 46 provided at one end of the eccentric cam 45 via a cam retainer 46A is connected to the annular seven flange portion 4.
4 is rotatably fitted.

Further, the eccentric cam 45 is arranged around the fixed cam 43 with a center B at a diagonally lower position rearward from the center A of the crankshaft 5.
A center hole 48 having an arcuate surface 47 centered on the point B is formed in the eccentric cam 45, and the crankshaft 5 is inserted through the center hole 48. Reference numeral 49 denotes a ratchet gear serving as an output side rotating member rotatably provided on a circular cam surface 50 formed on the outer periphery of the eccentric cam 45 via a bearing 51, and the cam presser 46A side of this ratchet gear 49 A sprocket 52 is screwed and fixed to the end. 53 is a retaining ring of the bearing 51, and 54 is a ratchet gear 4.
A collar 56A interposed between the tooth portion 49A of No. 9 and the sprocket 52 is a dust intrusion prevention plate.

In addition, a (tM center quantifier mechanism 57) is connected to the cam presser 46A.In this embodiment, the eccentric amount adjusting mechanism 57
A wire reel 60 having a manual operation lever 59 is rotatably supported on a disc-shaped receiver 58 fixed to the upper side of the main vibrator 1, and one end of a pair of wires 61 and 62 is attached above and below the wire reel 60. are fixed via bins 63 and 64, and the other ends of the wires 61 and 62 are fixed to the upper and lower rear sides of the wire reel 46 via bins 63A and 64A. This bin 63, 64, 63A, 64A is the wire 61
, 62 are fitted and fixed in the hole 65 of the wire reel 46°60 in a fixed state.

Next, the operation of the apparatus of this embodiment configured as described above will be explained. First, when the crank arm 6, crankshaft 5, and hollow cylindrical case 12 rotate integrally via the crank pedal 66, the ratchet gear 4 is rotated via the ratchet pawl 33.33A attached to the hollow cylindrical case 12.
9 rotates, the sprocket 52 rotates integrally with the ratchet gear 49, and the rotation of the sprocket 52 is transmitted to the rear wheel 8 by the chain 11 via the rear wheel sprocket 10. In this case, the rotational force is transmitted from the crankshaft 5 and crank arm 6 to the outer ring 13 of the hollow cylindrical case 12, and from the outer ring 13 to the inner ring 14 via the vibrator ring 17.

6(A) and 6(B) show a case where the ratchet gear 49 is located at the center of the hollow cylindrical gauge 12 and the eccentricity is 0. At this time, the ratchet gear 49 and the ratchet pawl 33.
3A is held at a constant angle of inclination by sliding contact between the engaging portion 38 of the ratchet pawl 33.33A and the inner peripheral surface 39 of the hollow cylindrical case 12 while meshing with the ratchet gear 49 . As a result, the gear ratio between the crankshaft 5 and the sprocket 52 is 1:1.

When the lever 59 is manually moved forward from this state, the wire reel 60 rotates clockwise via the disk-shaped receiver 58, and the pair of wires 61.62 and the bin 63.84.63A are rotated accordingly. , 64A, the wire reel 46 rotates clockwise along the annular flange portion 44 of the fixed cam 43. As a result, the eccentric cam 45 rotates around point B integrally with the wire reel 46, and as a result, the ratchet gear 49, which is provided concentrically with the eccentric cam 45, moves to the center of the hollow cylindrical gauge 12, that is, the crankshaft. Move eccentrically with respect to 5. In this case, the centering cam 45 is guided with the circular arc surface 47 of the center hole 48 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 45 is This is an arc C from point A to point A'.

7(A) and 7(B) show the case where the eccentricity of the hollow cylindrical case 12 with respect to the ratchet gear 49 is at its maximum eccentricity, and at this time the eccentric cam 45 is positioned at the left end of the center hole 48 with point B as the center. The ratchet gear 49 rotates clockwise to a position where it contacts the crankshaft 5, and moves integrally with the eccentric cam 45.
Push R, 33ADR. As a result, the ratchet pawls 33DR, 33ADR are engaged with the ratchet gear 49 by the biasing force of the spring 37, and the other ratchet pawls 33, 33
A is guided in a state separated from the ratchet gear 49 by sliding contact between the engaging portion 38 and the inner circumferential surface 39.

And the ratchet pawls 33DR, 33 within the drive range.
Since the speed increase rate by ADR is the maximum, ratchet gear 4
9 is ratchet pawl 33D R.

33ADH, the other ratchet pawls 33 are disengaged from the ratchet gear 49.

In addition, the ratchet pawls 33DR, 33AD sequentially drive at an increased speed, such that when the ratchet pawls 33DR, 33ADR move out of the driving range, the adjacent ratchet pawl 33 enters the driving range and drives the ratchet gear 49 at an increased speed.
R takes turns.

That is, a gear is virtually formed in the hollow cylindrical case 12 by the ratchet pawls 33DR and 33ADR within the drive range, and the diameter of this gear changes as the faith cam 45 rotates by operating the lever 59. Ratchet pawl 33D R.

33ADR, and the speed ratio (speed increase ratio) of the ratchet gear 49 changes steplessly.

During eccentric operation as shown in FIG. 7, the ratchet pawl 33DR within the drive range.

33ADR receives a meshing load between it and the ratchet gear 49, thereby causing the ratchet pawl 33DR.

The meshing load applied to 33A D R is the ratchet pawl 33D.
Ft, 33
compresses the M streeting 17 interposed between the outer protrusion 15 and the outer protrusion 15. As the hollow cylindrical gauge 12 rotates, the ratchet pawls 33DR and 33ADR within the drive range are sequentially replaced, but when the ratchet pawls 33DR and 33ADR enter the drive range and engage with the ratchet gear 49 for the first time, the meshing load is instantaneous. This is transmitted to the inner ring 14, but this is absorbed by the Mfll ring 17, thereby effectively preventing pulsations in the transmitted force and suppressing the transmission to the outer ring 13 and crank arm 6111. Further, due to the speed difference between the plurality of ratchet pawls 33DR and 33ADR within the drive range, a gap is created between the tips of the teeth, which causes a shock during rotation, but the shock can be absorbed by the [1 ring 17].

At this time, the buffer ring 17 has the effect of expanding in the width direction during this deformation, but the above-mentioned spacing of 31.32 places allows smooth deformation in the width direction without applying external pressure to the M street ring 17.

In addition, in this embodiment, at the time of eccentricity shown in FIG.
Two ratchet pawls 33.33A that can be rotated around the pivot 35, which is a pivot point, are combined as a set, and the tooth portions 36.36A are shifted by 1/2 pitch of each tooth. As shown in FIGS. 8 and 9, one of the two sets of ratchet pawls 33DR and 33ADH within the drive range is such that the tooth portion 36 of the ratchet pawl 33D R and the tooth portion 49A of the ratchet gear 49 are connected to each other. When the drive meshes normally, the other pair to be driven next is the ratchet pawl 33.
Tooth portion 36A of ADR and tooth portion 4 of ratchet gear 49
The gap with 9A is t/2. Therefore, the driving range is from the center of the hollow cylindrical case 12 to the ratchet gear 4.
The eccentric direction of 9 is used as the reference (0°), and when the direction of rotation is set as (+) and the opposite is set as (-), the drive range is -53° from the conventional 20''~40°. The angle shifts to the (-) side up to about 7 degrees, and the pulsation is improved accordingly.

FIG. 11 shows a second embodiment of the present invention, and in this example, between the outer protrusion 15 of the outer ring 13 on the rotational direction side of the outer ring 13 and the inner protrusion 16 of the inner ring 14, there is formed a lug made of synthetic rubber or synthetic resin. A buffer piece 67 as a member is interposed therebetween, and the meshing load and shock applied to the ratchet claws 33DR and 33ADH can be absorbed by the Mff1 piece 67.

12 and 13 show a third embodiment of the present invention,
To explain without omitting the explanation of the same parts as the above example, 7
Reference numeral 1 designates a chainstay of a bicycle frame, in which a rear wheel hub shaft 72 is fixed with a lock nut 73 via a receiving plate 71A, and a rear wheel hub 74 is rotatable on the rear wheel hub shaft 72 through a bearing (not shown). Spokes 75 are connected to the rear wheel hub 74.

Reference numeral 76 denotes an arm whose one end is rotatably connected to the inside of one chainstay 71 by a pivot joint 77, and a plurality of discs 78 are fixed to the inner surface of this arm 76 with screws 79. 80 is a bearing 81 on the outer periphery of the disk 78
A sprocket 82 is concentrically and integrally screwed onto the outer periphery of the hollow cylindrical case 80. The arm 76 and the disc 78 are each provided with a long hole 83 extending from the center of the disc 78 to near the lower end, and the rear wheel hub axle 72 is inserted into the long hole 83, and the arm 76 and the chain stay 71 are connected by a tension spring 84, the arm 76 is urged upward, and the hub shaft 72 side is held in a locked state at the upper end of the elongated hole 83. In this case, the lower end of the elongated hole 83 and the rear wheel hub shaft 72
The engagement between the upper end of the elongated hole 83 and the rear wheel hub shaft 72 maintains the eccentricity at the maximum eccentric position.

85 is a ratchet pawl having a plurality of teeth 86; 85A is a ratchet pawl having a plurality of teeth 86A that are shifted by 1/2 pitch from the tooth 86; these two ratchet pawls 85.85A are A plurality of sets of ratchet pawls 85.85A are connected to the cylindrical portion 80 of the hollow cylindrical gauge 80.
Each set of ratchet pawls 85.
85A is rotatably provided by a pivot 87 at the base end and a collar 87A mounted on the pivot 87, and is biased toward the center of the hollow cylindrical gauge 80 by a spring 88 wound around the pivot 87.

The receiving plate 71A is fixed to the outside of the chainstay 71 with screws 91, and an outer cylinder 92 for housing the rear wheel hub axle 72 is integrally formed on the inner side of the receiving plate 71A. is provided with an inner cylinder 93. Further, the hollow cylindrical case 80 has an outer ring 95 having an outer protrusion 94 and an inner ring 97 having an inner protrusion 96.
An M cylinder member 98 is interposed therebetween.

Next, the operation of the apparatus of this embodiment configured as described above will be explained. First, as shown in FIG.
The crank gear 100 rotates through the chain 101, and the rotation of the crank gear 100 is caused by the chain 101
2 can be conveyed. The sprocket 82 rotates integrally with the hollow cylindrical gauge 80 via the bearing 81, rotates the ratchet gear 102 via the ratchet claw 85° 85A attached to the hollow cylindrical gauge 80, and rotates the ratchet gear 102.
Rotation is transmitted from 02 to the rear wheel hub 74. When starting, going uphill, or driving on rough roads, a large force is naturally applied to the pedals, increasing the tension of the chain 101, and applying a large load to the ratchet pawl 85.85A that propels the ratchet gear 102. Depending on the magnitude of the load, the ratchet pawl 85.85A digs in toward the ratchet gear 1021m using the pivot shaft 87 as a fulcrum, thereby causing the ratchet pawl 85.85A to stand up, and this action causes the arm 76 to pivot using the pivot portion 77 as a fulcrum. The inner cylinder 93 of the hub shaft 72rfIJ moves downward against the force of the spring 84, and in this embodiment, the inner cylinder 93 of the hub shaft 72rfIJ is inserted into the elongated hole 83.
By engaging with the upper end, the amount of eccentricity in which the ratchet gear 102 and the hollow cylindrical gate 80 are concentric is automatically maintained at 0, and the rotation ratio between the sprocket 82 and the wheel 103 becomes 1=1. Next, when the force applied to the pedal is reduced, the tension on the chain 101 gradually weakens and the arm 76 moves upward using the pivot portion 77 as a fulcrum due to the restoring force of the spring 84. The shaped gauge 80 gradually becomes eccentric and the speed is changed and increased, and the inner cylinder 93 of the hub shaft 721FI is inserted into the elongated hole 83.
By engaging with the lower end of the hollow cylindrical gate 80, the hollow cylindrical gate 80 is brought into the maximum eccentric state, and the speed is automatically changed at the maximum gear ratio (speed increase ratio).

In this embodiment as well, the inner ring 9 of the hollow cylindrical gauge 80
The meshing load and shock transmitted to 7 are absorbed by the buffer member 98 and pulsation is prevented.

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.6 For example, the material of the cushioning member may be appropriately selected to have a cushioning function, or the material may be made of a continuous material. The shape or division shape, etc. may be freely selected, and the buffer member should be provided at least at the engagement location on the rotational direction side of the outer ring. The dimensions etc. may be selected as appropriate, and it goes without saying that the transmission can be applied to various types equipped with ratchet pawls, such as those mounted on the crankshaft or rear wheel side, or automatic or manual transmission types. It is. Further, although the description has been made assuming that one set of ratchet pawls is two, one set of ratchet pawls may be formed of one or three or more ratchet pawls.

[Effects of the Invention] The present invention has a structure in which pulsation can be effectively prevented by configuring the input side rotating member to include an outer ring, an inner ring, and a Mi11 member disposed between the outer ring and the inner ring. It is possible to provide a bicycle transmission device that is simplified.

[Brief explanation of the drawing]

1 to 10 show a first embodiment of the present invention.
The figure is an overall longitudinal sectional view, Figure 2 is a perspective view, Figure 3 is an exploded perspective view, Figure 4 is a partially cutaway perspective view, Figure 5 is a perspective view of the ratchet pawl, and Figures 6 (A) (B). ) and Figure 7(A)(B)
8 is a front view showing the engagement state of the ratchet pawl and the ratchet gear, FIG. 9 is a perspective view showing the eccentricity adjustment mechanism, FIG. 10 is a usage state diagram, and FIG.
FIG. 1 is a sectional view showing a second embodiment of the present invention, FIGS. 12 and 13 are a third embodiment of the invention, FIG. 12 is a longitudinal sectional view, and FIG. 13 is a usage state diagram. . 13, 95... Outer ring 14, 97... Inner ring 12, 80... Input side rotating member 17, 67.98・M Town member 33, 33A, 85.85A... Ratchet pawl 49
, 102... Output side rotating member Fig. 2

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. 1. A bicycle transmission device for shifting gears, wherein the input side rotating member includes an outer ring and an inner ring, and a buffer member is disposed between the outer ring and the inner ring.