JPH0331635B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is mainly suitable for bicycle transmissions, which are capable of steplessly variable speed transmission by means of a pawl that engages with an internal ratchet. This relates to continuously variable transmissions.

(Prior Art) The present applicant previously filed Japanese Patent Application Nos. 77557, 77558 and 77559 for a continuously variable bicycle transmission.

(Problems to be Solved by the Invention) However, in the device of the prior application mentioned above, contact between the internal ratchet provided on the inner periphery of the drive rotating member and the pawl several times occurs even outside the transmission area. However, there was a problem in that noise was generated due to the sliding contact between the ratchet and the pawl.

In addition, the above device has a problem in that since the aforementioned engagement between the pawl and the internal tooth ratchet occurs even outside the transmission range during normal input, when a reverse input is applied, pulsations occur in the output of the reverse input. The point was hot.

(Means for Solving the Problems) In order to solve the above-mentioned problems, in the present invention, an internal toothed ratchet is provided on the inner periphery of the driving rotating member, and the base of the pawl that meshes with this internal toothed ratchet is connected to the driven rotating member. In a device in which the eccentricity of the driven rotary member can be freely adjusted with respect to the driving rotary member, and the rear wheel is driven by the driven rotary member, a protrusion branched from the tip of the pawl is provided. established,
After the pawl and the internal tooth ratchet are engaged in a transmission range, the protrusion comes into sliding contact with the driving rotation member to release the engaged state, thereby configuring the continuously variable transmission for a bicycle.

(Function) Since the device of the present invention is constructed as described above, after the pawl and the internal tooth ratchet are engaged in the transmission range, the protrusion provided on the pawl comes into sliding contact with the drive rotating member, so that the pawl and the internal tooth ratchet are engaged. It is possible to release the meshing state with.

Therefore, it is possible to eliminate noise caused by sliding contact between the pawl and the internal tooth ratchet, and to reduce output pulsation due to reverse input at the time of reverse input.

(Example) Hereinafter, an example of the continuously variable transmission device for a bicycle according to the present invention will be described with reference to the drawings.

In the diagram, 1 is the bicycle frame chain stay, 2
(See Figure 2) is a backhawk, 3 is a rear pawl, 4 is a rear wheel hub shaft fixed to the rear pawl 3 with a lock nut 5, 6 is a rear wheel hub rotatably fitted via a bearing 7, 8 is a spoke It is.

In this embodiment, a substantially hollow cylindrical driven rotating body 9 is fitted to the lower rear wheel hub shaft 4 in FIG.
0 so that they rotate together. 11
is a ring member that is integrally screwed together with the driven rotating body 9, and has a groove for supporting the ball bearing 12 formed therein. 13 is a ring plate fitted to the rear wheel hub shaft 4 on the lower side of the driven rotor 9 in FIG. 1, 14 is a ball bearing interposed between the ring plate 13 and the driven rotor 9, and 15 is a This is a disc-shaped cover inserted between the ring plate 13 and the lock nut 5.

Further, reference numeral 16 denotes a ball bearing 17 provided on the outer periphery of the ball bearing 12 and the driven rotating body 9.
18 is a hollow disk-shaped eccentric cam disc that is integrally connected to the shaft cylinder, and 18a is a cylinder formed by bending the outer circumference of the eccentric cam disc 18. As shown in FIG. 5, the outer circumferential edge 18a of the eccentric cam disk 18 is
It is eccentric by l _{1 such as O 2 with} respect to the center O ₁ of the rear wheel hub shaft 4.

Further, 19 is an outer peripheral edge 18a of the eccentric cam disk 18.
This eccentric cam ring 19 is a ring-shaped eccentric cam ring that is rotatably provided by fitting a part into the inner circumference of the eccentric cam ring 19.
As shown in FIG. 5, the center of the circle formed by the inner peripheral surface 19b of the bearing ring member 19a fitted on the inner peripheral surface of
It is eccentric by l ₂ like O ₃ with respect to O ₂ . Note that in this embodiment, l ₁ =l ₂ . Further, 19c is an annular groove provided on the outer peripheral surface of the eccentric cam ring 19, and 20 is engaged with this annular groove 19c.
9 is an engaging pin that prevents it from coming off, and the outer peripheral edge 1
It is screwed in from the outside of 8a. Further, 19d (see Figs. 1, 4, and 5) is an arc-shaped groove carved in the side surface of the eccentric cam ring 19 over a range of about 120°, and 21 is an eccentric cam disk so as to fit into this groove 19d. This is a stopper pin protruding from 18.

Reference numeral 22 denotes a hollow cylindrical driving rotation member, which is rotatably provided within the eccentric cam ring 19 via a ball bearing 23. Reference numeral 22a denotes a holding ring for the ball bearing 23, which is screwed onto the drive rotating member 22. A sprocket 24 is integrally fitted to the outer periphery of the portion protruding from the driving rotation member 22. 25 is the sprocket 24 and the sprocket provided on the front crankshaft (not shown)
This is the chain that was passed over.

Two rows of internally toothed ratchet rings 27 are fitted onto the inner circumference of the drive rotating member 22 via a one-way clutch 26. 26a (see FIG. 4) is a ball of the one-way clutch 26, and 26b is a spring. The one-way clutch 26 may be of other types.

27a is an internal tooth ratchet of the internal tooth ratchet ring 27, and 27b is an annular groove provided in the middle of the internal tooth ratchet 27a. This internal tooth ratchet 27
The bases of a plurality of pawls 28 (in this embodiment, three in each row) that engage with each other are pivotally supported on the driven rotary body 9 by pins 29 at positions alternately dividing the left and right circumferential positions. A spring 30 fitted to the pin 29 (see Fig. 3) ensures that each pawl 28 is always aligned with the internal tooth ratchet 2.
It is urged to rotate in the direction of meshing with 7a. In addition, as shown in FIGS. 3, 4, and 5, the claw 28
In addition to providing a protrusion 28a with a branched tip,
A roller 32 is rotatably provided at the tip of the protrusion 28a via a pin 31, and the transmission area between the pawl 28 and the internal toothed ratchet 27a ( In this embodiment, since there are a total of six pawls 28, the transmission range of each pawl 28 is approximately 60 degrees because 360 degrees ÷ 6 = 60 degrees.
2 comes into rolling contact with the annular groove 27b of the internal tooth ratchet ring 27, so that the pawl 28 and the internal tooth ratchet 2
It is configured to release the meshing state with 7a. That is, the pawl 28 meshes with the internal toothed ratchet 27a within the transmission range, but after that, the roller 32 comes into contact with the annular groove 27b, so that the pawl 28 engages with the internal toothed ratchet 27a.
8 is raised from the internal tooth ratchet 27a.

FIG. 7 shows another embodiment, in which the ring plate 34 is driven by a rotating member via a plurality of (six in this embodiment) rollers 33 on the side of the internally toothed ratchet ring 27. The protrusion 28a is provided rotatably relative to the ring plate 22, and the tip of the protrusion 28a without the roller 32 comes into direct contact with the inner circumferential surface 34a of the ring plate 34.

Furthermore, as shown in FIGS. 1, 3, and 6, a plurality of (five in this embodiment) rollers 35 are provided between the left and right internally toothed ratchet rings 27 in rolling contact with the inner periphery of the drive rotating member 22. A set of two advance rings 36
is provided rotatably. 37 is a shaft on which the advance ring 36 pivots around the roller 35.

The advance rings 36 are then frictionally joined to the internally toothed ratchet rings 27, respectively. To explain an example of the friction joining means, an annular step portion 27 is formed on the opposite side of the left and right internal toothed ratchet rings 27.
c, and a ring spring 38 is fitted into each of these stepped portions 27c, and one roller 35
The shaft 37 is extended and engaged with the ring spring 38.

Further, one end of a pair of connecting rings 39 is connected by a pin 40 between the two left and right advance rings 36 that sandwich the roller 35, and the base is inserted into an annular slit provided in the other driven rotating body 9. At the same time, an intermediate connecting fitting 4 is attached to the protrusion 41a of the connecting fitting 41 connected to the driven rotating body 9 by the pin 29.
2 is fixed by two screws 43, and the protrusion 42a of the intermediate connecting fitting 42 is inserted between the other ends of the two connecting rings 39 and connected by a pin 44, thereby constructing a forwarding mechanism. do.

FIG. 8 shows another embodiment of the advance mechanism, in which the advance ring 36 and the driven rotating body 9 are connected by a plurality of (six in this embodiment) coil springs 45. It is something. In the figure, 46 is a pin for connecting the inner end of the coil spring 45 to the driven rotating body 9, and 47 is a connecting rod for connecting the outer end of the coil spring 45 to the advance ring 36.

Further, in FIGS. 1 and 2, 48 is an annular cover fitted to the outer end of the drive rotating member 22, and 49 is an annular cover provided to seal the gap between the disc-shaped cover 15 and the annular cover 48. This is a seal ring made of elastic material.

Next, the speed change operation mechanism of the device configured as described above will be explained. As shown in FIGS. 1 and 2, 50 is a reel support arm fastened to the rear wheel hub shaft 4 between the rear pawl 3 and the lock nut 5, and 51 is a reel support arm protruding from the middle of the reel support arm 50. Bracket 52
The reel is rotatably supported by a shaft 53. An annular groove 51a is formed in the reel 51.

18b is the outer peripheral edge 18 of the eccentric cam disk 18.
19e is an annular groove carved on the outer peripheral surface of the eccentric cam ring 19. A bolt 55 and a nut 5 are attached to a bracket 54 protruding from the chain stay 1 on the distal end side of the reel support arm 50.
A bracket 50a for attaching the operating wire is formed by bending the tip end of the outer wire 57.
Fix by b. 58 is an operating wire that slides inside the outer wire 57, and 59 is a wire guide that projects inside the reel support arm 50. As shown in FIG. 9, the operating wire 58 on the right side is first wound around the groove 19e of the eccentric cam ring 19 from bottom to top via the wire guide 59, and then wrapped around the groove 51a of the reel 51. The outer wire 57 (see FIG. ) is guided by.

Note that 60 is a set screw for fixing the operating wire 58 wound around the groove 19e, and 61 is the groove 18.
A presser piece 61 is used to fix the operating wire 58 wound around the engagement pin 2.
It is fastened to the eccentric cam disk 18 by a threaded portion of 0.0.

Next, the operation of the apparatus of the present invention constructed as described above will be explained. First, to explain the transmission order, the crank gear rotates via a crank pedal (not shown), and the rotation is transmitted to the sprocket 2 by the chain 25.
4 can be conveyed. Since the sprocket 24 is integrally connected to the drive rotating member 22, the rotation of the sprocket 24 is transmitted to the internal toothed ratchet ring 27 via the one-way clutch 26, and is further transmitted from the internal toothed ratchet 27a to the pawl 28 and the pin. It is transmitted to the driven rotating body 9 via 29. When the driven rotary body 9 rotates, the rear wheel hub 6 integrally connected to the driven rotary body 9 rotates, and the bicycle travels.

1, 2, 3, and 4 show a state in which the drive rotating member 22 is not eccentric with respect to the rear wheel hub axle 4, but when the drive rotating member 22 becomes concentric with the rear wheel hub axle 4, the inner Since the toothed ratchet ring 27 is also concentric with the rear wheel hub axle 4, when the sprocket 24, which is integral with the drive rotating member 22, rotates in the direction of arrow A in FIG. Since the internal ratchet ring 27, the pawl 28, and the driven rotating body 9 all rotate together, the gear ratio in this case is 1:1.

Further, from the above-mentioned concentric state, when the operating wire 58 is moved in the directions of arrows B and C as shown in FIG. 9 by operating the speed change operating lever (not shown), the eccentric cam ring 19 is moved in the direction of arrow D As a result of the rotation of the eccentric cam disc 18 in the direction of the arrow E, the stopper pin 21 moves from the position shown in FIG. 4 to the position shown in FIG.
2 changes from the concentric state shown in FIG. 4 with respect to the rear wheel hub shaft 4 to the maximum eccentric state shown in FIG. 5 (FIGS. 6, 7, and 8). And the center of the drive rotating member 22 in this case
The locus of O ₃ (see Figure 5) becomes a straight line along the vertical direction of the bicycle, as shown by arrow F in Figure 6.
For this reason, the distance between the front crank gear and the rear wheel sprocket 24 hardly changes, so the chain 25
There is no risk of the body becoming loose or becoming overly tense.

In the maximum eccentric state shown in FIGS. 5, 6, 7, and 8, when the sprocket 24 rotates in the direction of arrow A in FIG.
The rotation is transmitted to the internally toothed ratchet ring 27 through the pawl 28, and the ratchet ring 27 transmits the rotation to the driven rotating body 9 through the pawl 28.

If the drive rotating member 22 is eccentric, the transmission area G shown in FIG.
The angle is approximately 60° which is the sixth equal part of 360°. ) in pin 29
Since the speed increase rate due to the pawl 28 in which contacts the annular groove 27b and the pawl 28 and internal tooth ratchet 27
Release the mesh with a.

Then, when the pin 29 of the pawl 28 comes out of the transmission area G and the pin 29 of the next pawl 28 enters the transmission area G, it is then driven at an increased speed via that pawl 28, and the transmission is sequentially transmitted to the succeeding pawls. The claws are replaced.

The gear ratio (speed increase ratio) in this case is the rear wheel hub axle 4
The angle θ ₁ which is the transmission range with the center O ₁ as the base point,
This is the ratio to the angle θ ₂ which is the transmission range with the center O ₃ of the driven rotating body 9 as the base point.

Next, the operation of the advance ring 36 shown in FIGS. 1, 3, 6, and 8 will be explained.

In the embodiment shown in FIGS. 1, 3, and 6, the driven rotary body 9 and the advance ring 36 are connected to a link type connecting member 4.
1, 42, 39, and in the embodiment shown in FIG. When the member 22 and the driven rotary member 9 are concentric, the driven rotary member 9 rotates at the same speed as the drive rotary member 22 as described above, so the advance ring 36 also rotates with the drive rotary member 22 and the internally toothed ratchet ring. 27 and rotates at a constant speed.
That is, in this case, the advance ring 36 is not advanced with respect to the internal tooth ratchet 27a, but when this amount of eccentricity is zero, all the pawls 28 remain engaged with the internal tooth ratchet 27a, so there is no need for advance.

When the driven rotary member 9 is shifted eccentrically with respect to the driving rotary member 22 (speed increase), the driven rotor 9 is driven to increase its speed as described above, so that the advance ring 36 connected thereto also has a higher speed than the internal toothed ratchet 27a. Rotates at increased speed. Since the advance ring 36 is frictionally connected to each of the internal toothed ratchet rings 27 via the roller 35 and the ring spring 38, the internal toothed ratchet that is engaged with either one of the left and right pawls 28 and transmits power. The ratchet ring on either side of the rings 27 is in a differential state with the advance ring 36, but the internally toothed ratchet ring 27 which is idle is further advanced by the friction engagement of the advance ring 36. Therefore, even if there is a gap between the tooth tips of the ratchet 27a and the pawl 28 when transmitting the pawl 28, the advance ring 36
By advancing the internal toothed ratchet ring 27 due to the accelerated rotation, the ratchet 27a immediately catches up with the pawl 28, eliminating the gap between the tooth tips.

Note that while the ratchet 27a and the pawl 28 are fully engaged and driven, the ring spring 38 appropriately slips on each member to absorb speed differences between the members.

In addition, the above explanation has been made for the case of zero eccentricity and the case of maximum eccentricity, but since this eccentricity can be freely set between zero and maximum,
Needless to say, this device is capable of continuously variable speed.

(Effect of the invention) Since the device of the present invention is constructed as described above, the claw 2
8 and the internal tooth ratchet 27a in the transmission range, the protrusion 28 provided on the pawl 28
The pawl 28 is brought into sliding contact with the annular groove 27b of the internally toothed ratchet ring 27 that rotates through the roller 32 or directly with the drive rotating member 22.
The meshing state between the internal tooth ratchet 27a and the internal tooth ratchet 27a can be released. That is, the engagement between the pawl 28 and the internal tooth ratchet 27a can be made within a more limited range than in the conventional case.

Therefore, according to the present invention, noise caused by sliding contact between the pawl 28 and the internal tooth ratchet 27a is eliminated, and
An excellent effect can be obtained in that the output pulsation of the reverse input at the time of reverse input can be reduced.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional plan view of the device of the present invention, Fig. 2 is a side view of Fig. 1, Fig. 3 is a side view showing a part of Fig. 2 in section, and Fig. 4 shows the arrangement of the claws. 5 is a partial sectional view showing the maximum eccentricity state, FIG. 6 is a partial sectional view showing the advance mechanism in the maximum eccentricity state, and FIGS. 7 and 8 are parts showing other embodiments. The sectional view and FIG. 9 are perspective views showing how to hang the operating wire. 4... Rear wheel hub axle, 6... Rear wheel hub, 9... Driven rotating body, 18... Eccentric cam disc, 18a... Outer peripheral edge portion, 19... Eccentric cam ring, 22... Drive rotating member, 24... Sprocket, 25... Chain, 26... One-way clutch, 27... Internal tooth ratchet ring, 27a... Internal tooth ratchet, 28
...Claw, 28a...Protrusion, 32...Roller, 36
... Advance ring, 50 ... Reel support arm, 51
... Reel, 57 ... Outer wire, 58 ...
operating wire.

Claims (1)

[Claims] 1. An internal toothed ratchet is provided on the inner periphery of the driving rotating member, and the base of the pawl that engages with this internal toothed ratchet is pivotally supported on a driven rotating body, so that the amount of eccentricity of this driven rotating body with respect to the driving rotating member can be adjusted freely. In addition, in the device in which the rear wheel is driven by the driven rotary body, a protrusion branched from the tip of the pawl is provided,
A continuously variable transmission device for a bicycle, characterized in that, after the pawl and the internal tooth ratchet are engaged in a transmission range, the engagement state is released by the protrusion slidingly contacting the driving rotation member. .