JPH0689827B2 - Continuously variable transmission - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuously variable transmission, and particularly to an engagement for engaging both eccentric inner and outer wheels and transmitting rotational force from one of the two wheels to the other. By changing the engagement position and the disengagement position of the member by means of a guide, the gear ratio between the input and output wheels of a two-wheeled vehicle or the like is continuously changed.

[Conventional technology]

A conventional continuously variable transmission of this type is, for example, Japanese Patent Laid-Open No. 52-
There is one described in Japanese Patent No. 51640. In this conventional technique, a drive internal gear and a driven internal gear are coaxially arranged, and an intermediate rotor that is eccentrically movable with the both gears by a movable eccentric wheel is provided.
The intermediate rotor is provided with a plurality of driving clicks and driven clicks that mesh with the internal gear and transmit only rotation in one direction, and the movable eccentric wheel is rotated to change the eccentricity of the intermediate rotor. Thus, the gear ratio between the drive internal gear and the driven internal gear is changed.

[Problems to be solved by the invention]

However, in such a conventional continuously variable transmission, the gear ratio is changed by changing the amount of eccentricity, and the drive click and the follow click are provided between the drive internal gear and the driven internal gear. And the intermediate rotor, and the rotational force of the driving internal gear is to be transmitted to the driven internal gear through the driving click, the intermediate rotor, and the driven click in sequence, so the rotational force transmission path and the entire structure are In addition to the problem that the number of parts of the transmission increases and the size becomes large and complicated as a whole, the large number of parts of the rotational force transmission path leads to a loss of power due to friction at these connection parts, and this transmission When used on a bicycle, the problem is that pedaling becomes heavy.

The present invention has been made in view of the above-mentioned problems of the prior art, and simplifies the transmission path of the rotational force and simplifies the structure as a whole to reduce the size and cost of the transmission. The purpose is to reduce the

[Means for solving problems]

In the continuously variable transmission according to the present invention, the rotating inner and outer wheels are eccentric to each other, and the eccentric distance is fixed.
An engaging member is interposed between the two wheels, which engages while rotationally moving to transmit the rotational force from one of the two wheels to the other.

The engaging member is pivotally attached to one of the inner and outer wheels and is biased in a direction in which it rises toward the unevenness formed in the other ring, and is raised in an engaging posture in which it rises and engages with the unevenness. The attitude is variable between the disengagement attitude in which the interlocking operation is released by separating from the unevenness.

Further, a guide for changing the engagement member to the engagement posture at the engagement position and to the disengagement posture to disengage the engagement at the disengagement position on the movement locus of the engagement member is raised at the disengagement position of the engagement member. The guide rail is configured by an annular rail having a curved line that suppresses the rising restraint at the engaging position and releases the restraint of rising up at the engaging position, and rotatably supports both the inner and outer wheels in the circumferential direction while the guide is in sliding contact with each engaging member. The engagement and disengagement positions are made variable by.

[Action]

Since the distance between the inner and outer wheels that are eccentric to each other changes in a stepwise manner depending on the circumferential position, the circumferential speed ratio of the facing portions of the two wheels changes infinitely depending on the circumferential position. Therefore, the gear ratio between the inner and outer wheels can be determined by selecting the position in the circumferential direction and interlocking the inner and outer wheels with the engaging member only at the selected position of the inner and outer wheels. Further, the gear ratio is changed steplessly by changing the position in which both wheels are interlocked by the engaging member in the circumferential direction. A guide changes the position at which both wheels are interlocked with each other by the engagement member. The guide is rotated on the track of the engagement member by rotating it,
The posture of the engaging member is changed between an engaging posture in a state of engaging both wheels and a releasing posture in a disengaged state. The gear ratio between the two wheels can be changed steplessly by changing the position (separation position) in which the posture is taken in the circumferential direction. Thus, the gear shift in the present invention is performed only by the rotation of the guide.

[Principle of Invention]

First, the principle of the present invention will be described with reference to FIGS. 1 and 2.

The center 10a of the outer ring 10 and the center 11a of the inner ring 11 are eccentric by the distance shown. In FIG. 1, the outer wheel 10 is the driving wheel and the inner wheel 11 is
When the driven wheel is. In the figure, symbols 1 to 6 are attached to positions where the circumference of the outer ring 10 is divided into six equal parts, and a to f are assigned to the positions of the inner ring 11 that are equidistant from the respective positions.
Is attached. That is, line segments 1-a, 2-b ... 6
The lengths of −f are equal to each other. The arc between the position (g) of the inner ring 11 and the position a has a length obtained by dividing the inner ring 11 into six equal parts.

Here, while maintaining the length of the line segment 1-a (the line segment 1-a
Should be understood as a rigid body having the same length as this. ),
When the outer ring 10 is rotated in the direction of the arrow to move the position 1 to the position 2, the position a of the inner ring 11 moves to the position b. At this time, the line segment 1-a is of course the same length as the line segment 2-b. Then, the outer ring 10 is rotated by one sixth of 360 degrees, while the inner ring is rotated.
11 has been rotated by an angle larger than 1/6. Thus, the rotation of the inner ring 11 is accelerated between the positions 1 and 2 of the outer ring 10. Similarly, looking at FIG. 1, the inner ring 11 is accelerated between the position 6 and the position 3 of the outer ring 10, and conversely, the inner ring is decelerated between the position 3 and the position 6 of the outer ring 10. It can be understood that the speed ratio changes steplessly between the maximum value of the speed increasing ratio and the maximum value of the speed reducing ratio.

Therefore, according to the present invention, by appropriately selecting the speed-increasing and decelerating positions and the constant-velocity positions (regions) therebetween, the outer ring and the inner ring are interlocked only at the selected position, and at other positions, both wheels are linked. The gear ratio is selected with no gap between them, and the gear ratio is changed steplessly by changing the selected position.

FIG. 2 is an explanatory diagram when the inner wheel 11 is the driving wheel and the outer wheel 10 is the driven wheel. Here, the outer ring 10 can move from position 5 to position 6 on the circumference while the inner ring 11 rotates from position e to position f on the circumference by an angle of 1/6 of 360 degrees. I understand. At this time, position 5 on the circumference of outer ring 10
Since the distance from to the position corresponds to 1/6 of the circumference, the outer ring 10 is
It will be rotated at an angle of more than one-third to be accelerated.
Thus, even when the inner wheel 11 is the driving wheel and the outer wheel 10 is the driven wheel, it is possible to set the gear ratio and change the gear ratio depending on the position where both wheels are interlocked, as in the case of FIG.

In the present invention, the line segment 1
-A, 2-b ... 6-f are embodied as an engaging member, and a guide is used as a member for selecting and changing the position at which this engaging member engages with both wheels and interlocks both wheels. Is.

〔Example〕

FIGS. 3 and 4 show the case where the present invention is implemented as a continuously variable transmission for a bicycle. In particular, in this embodiment, the outer wheel 10 is a driving wheel and the inner wheel 11 is a driven wheel. Has been applied. However, it goes without saying that the inner wheel 11 can be used as the driving wheel and the outer wheel 10 can be used as the driven wheel by applying the principle of FIG.

In this embodiment, 12 shown is a boss forming a part of the body frame, through which the crankshaft 13 penetrates, and both ends of the crankshaft 13 (only one end is shown)
A crank arm 14 is fixed to the crank arm 14, and a pedal (not shown) is attached to the tip of the crank arm 14 so that a person can step on the pedal with a foot, as is known in the art.
It is designed to rotate 13.

An outer disk 15 concentric with the crankshaft 13 is fixed to the base of the crank arm 14, and the outer periphery of the disk 15 has the same center of rotation 10 as the axis of the crankshaft 13.
The outer ring 10 having a is integrally formed. Ratchet-shaped internal teeth 16 forming a part of the outer ring 10 are fixed to the inner side of the outer ring 10. In this embodiment, the outer ring 10 and the inner teeth 16 are fixed separately from each other for the convenience of manufacturing, but they are functionally integrated with each other. Of course, it may be integrally formed. Then, the rotation of the crankshaft 13 causes the internal teeth 16
The attached outer ring 10 is configured to rotate integrally.

Also, the crankshaft 13 has a collar that forms a slide bearing.
17, and the washers 18, 19 on both ends of the collar 17 are fitted,
The collar 17 is a transmission collar that transmits the shift operation force described later.
20 is rotatably fitted on the outside. At the end of the transmission collar 20 on the disc side, an internal disc 22 having an outer periphery formed with a guide 21 for gear shifting in the later operation is fixed so as to rotate integrally with the transmission collar 20. A handle 23 is fixed to the opposite end so as to rotate together with the transmission collar 20.

An eccentric collar 24 having a center 11a is externally fitted to the transmission collar 20, and an inner ring 11 having the center 11a as a rotation center is externally fitted to the outer periphery of the eccentric collar 24. Inner ring 11
On the drive side of the bicycle (generally two connected by chains)
The sprocket wheel 25, which forms the front side of the two sprocket wheels), is integrally formed. Similarly, this also has the center 11a as the center of rotation, and the inner ring 11 and the sprocket wheel 25 also integrally rotate about the center 11a as the center of rotation. It is configured to do.

Washers 26, 27 are provided on both end faces of the eccentric collar 24 and the inner ring 11.
The washer 26 and the eccentric collar 24 on one side are connected to the vehicle body (boss 1 through a fixing means 28 such as a screw and a fixing metal fitting 29).
It is fixed to 2) and stopped. Of the above parts, washers 18, 19, 26, 27 and eccentric collar 24
Is made of synthetic resin, and other parts are made of iron or other metal, but the material of each part can be changed appropriately according to the design conditions, and parts that are in sliding contact with other parts can be rolling bearings. Other bearings can be selected and used as appropriate. The nail 30 is carburized to increase its strength.

A plurality of claws 30 of the same size are pivotally attached to the inner ring 11 by pins 31 at equal intervals in the circumferential direction. The claws 30 serve as an engaging member used in the present invention, and transmit the rotation of the outer ring 10 to the inner ring 11. Six claws are used here, but other numbers are used. Of course, it is also good.
The claw 30 is urged by a spring 32 in the direction in which the tip of the claw 30 separates from the inner ring 11 (the direction in which it engages with the inner teeth 16 of the outer ring 10). Therefore, if it is left as it is, all the claws 30 will be engaged with the inner teeth 16, and the guide 21 for gear shifting controls this.

The speed-changing guide 21 is a guide rail integrally formed on the outer periphery of the internal disk 22 as described above, and has the claw 30 and the outer ring.
Engagement position 21 in an engagement position for engaging the internal teeth 16 of the 10
A and a disengagement position 21b in a disengagement position for disengaging the claw 10 from the inner tooth 16 are formed. That is, in this embodiment, the guide 21 is a continuous endless rail, the engagement position 21a and the disengagement position 21b form an arc centered on the center 10a, and the radius of the disengagement position 21b is the engagement position. The radius is smaller than 21a, and the portion where both positions 21a and 21b are continuous is continuous with a smooth curve.

A protrusion 30a protruding from the side surface of the pawl 30 is slidably contacted with the inner periphery of the guide 21 to control the pawl 30 between an engaging posture and a releasing posture. With the protrusion 30a and the guide 21 in contact with each other,
The release position 21b of the guide 21 has a radius such that the tip of the claw 30 separates from the inner tooth 16, and the tip of the claw 30 engages with the inner tooth 16 regardless of whether or not the protrusion 30a and the guide 21 contact each other. This is the engagement position 21a.

In particular, in this embodiment, as described above, the claw 30 is a spring.
Since the guide 21 in this embodiment has a main function to disengage this engagement, since it is biased in the direction in which it is constantly engaged with the inner teeth 16 by 32, at least in this embodiment, Only the disengagement position 21b of the guide 21 needs to be formed (this results in
It also serves to identify the engagement position 21a. ) In this case, release position 21b
The both ends of the claw 30 have smooth curves so that the claw 30 can be smoothly undulated.

Then, the guide 21 includes an internal disc 22, a transmission collar 20.
Since it is possible to rotate around the crankshaft 13 with the handle 23 via the
When the guide 21 is rotated by operating a gear shift lever or the like via a wire rope or the like (not shown), the guide 21 is rotated about the center 10a by a predetermined angle, whereby the position of the engagement position 21a can be changed.

In the present invention, the position (engagement position) on the circumference where the engaging member (the claw 30) is engaged between the two wheels to interlock the two wheels is selected.
Since the principle is to continuously change the speed by changing it, the claw 30 may be pivotally attached to the outer ring 10 or may be attached to the third component. Therefore, contrary to this embodiment, the claw 30 of the inner ring 11 may be biased by a spring (not shown) so as to fall toward the inner ring 11. In this case, contrary to the above, it is necessary to guide the engaging position 21a used to raise the claw 30 and positively engage the internal tooth 16. Further, it is possible to reversely pivot the pawl 30 to the outer ring 10 and employ means for forming outer teeth engaging with the outer ring 10 on the inner ring 11, or to pivotally attach the pawl 30 to both the wheels 10 and 11. Without attaching to other parts,
It is also possible to install a guide for engaging the claw 30 between the two wheels at a.

Further, although this embodiment applies the principle of FIG. 1, it is also possible to apply the principle of FIG. 2 to use the inner wheel 11 as a driving wheel and the outer wheel 10 as a driven wheel. Is an embodiment of. Furthermore, the present invention can be applied to the sprocket wheel portion on the rear wheel side of the bicycle, and can also be applied to a power transmission mechanism other than the bicycle.

Next, the operation of this embodiment will be described.

First, the shift position of the shift guide 21 is selected and set. This is done by rotating the handle 23 with a gear shift lever or the like and thereby rotating the guide 21 to a predetermined position. Here, an index for reading the gear ratio is attached to the gear shift lever or the like or the vicinity thereof, which serves as a guide for the gear shift operation.

Then, the outer ring 10 rotates about the center 10a via the crank arm 14, the crank shaft 13, and the external disk 15 which rotate by the depression of the pedal. At this time, the claw 30 is provided only at the engagement position 21a set by the guide 21.
Is engaged with the inner teeth 16 of the outer ring 10, the outer ring 10 is rotated by the claw 30
Is transmitted to the inner ring 11 via a certain gear ratio. Outer ring
When the inner ring 11 rotates in conjunction with the rotation of 10, the plurality of claws 30 successively reach the engagement position 21a of the guide 21 according to the rotation, and the springs 32 raise the claws 30 to the engagement position. Engages with the inner teeth 16 of the outer ring 10 to apply the rotational force of the outer ring 10 to the inner ring 11.
Communicate to. When the engaging position 21a is exceeded and the disengagement position 21b is reached, the guide 21 moves the pawl 30 into the disengagement posture and the internal teeth 16
Get away from. A certain claw 30 leaves the engagement position 21a and is released from the engagement position 2
When it reaches 1b, it reaches the subsequent claw 30 engagement position 21a, and the rotational force of the outer ring 10 is always transmitted to the inner ring 11. Thus, the rotational force is transmitted from the outer wheel 10 to the inner wheel 11 by the gear ratio set by the engagement position 21a of the guide 21. Therefore, the sprocket wheel 25 also rotates at the gear ratio integrated with the inner ring 11.

Further, when changing the gear ratio, the handle 23 may be rotated by the gear shift lever or the like to rotate the guide 21 by a predetermined angle about the center 10a. The gear ratio can be continuously changed according to this angle. Then, the engagement position 21a of the guide 21 moves according to the rotation and is set to a new position, so that the gear ratio corresponding to this position can be obtained. As described in the principle in FIG. 1, the maximum acceleration position and the maximum deceleration position between the two wheels 10 and 11 are on the opposite side of the two rotation centers 10a and 11a and on a straight line passing through the two centers. Since there is a rotation angle of about 180 degrees between the two positions in the vicinity, the guide 21 has a rotation angle of about 18 degrees so that the engagement position 21a can be moved between the maximum increase side position and the maximum deceleration position.
If the rotation of about 0 degree is possible, the range of the gear ratio can be maximized. However, if the width of the gear ratio is small, the angle may be smaller than 180 degrees.

In order to automate the operation of changing the gear ratio by the rotation of the guide 21, the handle 23 is configured to be rotated by a drive source that uses fluid pressure, electromagnetic force, etc. It is also possible to connect to a device for detecting the speed change ratio so that the gear ratio can be changed in proportion to the running load amount. Then, when traveling uphill, the gear ratio can be automatically changed to the deceleration side, and the gear ratio can be made proportional to the climbing angle.

〔The invention's effect〕

As described above, in the continuously variable transmission of the present invention, the engaging position of the engaging member that interlocks the two wheels is selected by the guide for speed change between the eccentric wheels to change the two wheels. The gear ratio between the two wheels can be continuously changed without changing the eccentric distance. Therefore, since the power transmission member between the outer ring and the inner ring can be only the engagement member, not only can the size, weight and cost be reduced by reducing the number of parts, but also the power transmission path can be achieved. Since the number of frictional points is also reduced, the power loss can be reduced as much as possible.

Particularly, in the present invention, the operation for changing the gear ratio is simply rotating the guide constituted by the annular rail, so that the structure for changing the gear ratio is simplified and the frictional resistance to the changing operation is also reduced. Since it is reduced, there is also an effect that the operation of changing the gear ratio becomes easy.

[Brief description of drawings]

1 and 2 are explanatory views showing the principle of the present invention, and FIG. 3 is a sectional view showing an embodiment of the present invention.
The drawing is a sectional view taken along the line IV-IV in FIG. 10 …… outer ring, 10a …… outer ring rotation center, 11 …… inner ring, 11a …… inner ring rotation center, 16 …… internal teeth, 21 …… guide, 21a …… engaging position, 21b ……
Disengagement position, 24 ... Eccentric washer, 25 ... Sprocket wheel, 30 ... Claw (engaging member).

Claims (1)

[Claims] Claims: 1. Engagement in which both rotating inner and outer wheels are eccentric to each other and the eccentric distance is fixed, and while rotating, they are engaged with both wheels to transmit rotational force from one of the two wheels to the other. The member is pivotally attached to one of the inner and outer wheels and is biased in a direction in which it rises toward the unevenness formed on the other ring, so that the member rises up and engages with the unevenness, and an engaging posture to lie down from the unevenness. The posture is variable between the disengagement posture and the disengagement posture in which the engagement member is disengaged and the interlocking is released. Further, the engagement member is changed to the engagement posture at the engagement position on the movement locus of the engagement member, and the engagement member is moved at the disengagement position. The guide for changing to the disengagement posture that separates the engagement is composed of an annular rail having a curve that suppresses the rising at the distance position of the engaging member and releases the suppression of the rising at the engaging position. Inside and outside with sliding contact with the member CVT, characterized in that positioned the engagement and disengagement position variable by rotatably supporting the circumferential direction of the wheel.