JP3445853B2 - Bicycle transmission - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a chain changing member,
A gear shift operation tool and a gear shift operation tool including a connecting mechanism for reciprocally attaching the chain changing member to a bicycle vehicle body and a bicycle derailleur having a return spring for moving the chain changing member in one direction. The present invention relates to a bicycle transmission having a connecting mechanism for attaching an operating tool to a bicycle body so as to be reciprocally movable, and a shift operating device configured to operate the bicycle derailleur via an operation cable.

[0002]

2. Description of the Related Art In the above-described transmission, conventionally, an assist spring for urging a gear shift operation device in a direction opposite to a direction in which a return spring is urged is provided in the gear shift operation device, and the return spring operates in a direction for operating a derailleur. In some cases, when shifting gears in the opposite direction, an assist spring assists the gear shifting operation to allow a lighter gear shifting operation. In this type of transmission, conventionally, for example, in the case where the return spring biases the derailleur to the top side, the tension CT1 generated in the operation cable by the assist spring
And the tension CT2 generated in the operation cable by the return spring are as shown in FIG. 14 or FIG. 15, for example. That is, the cable tension CT2 by the return spring and the cable tension C by the assist spring
T1 is different in the entire range from the low position to the top position, or is different in a part of the range from the low position to the top position.

[0003]

In this type of transmission, when shifting to the low side, the force obtained by subtracting the cable tension from the assist spring from the cable tension from the return spring is added to the gearshift operation chain reaction force, and The force added with the frictional force of the operation cable is required as the operation force, and when shifting to the top side, the force obtained by adding the frictional force of the operation cable to the cable tension by the assist spring is required as the operation force. Then, while the spring force of the return spring increases as the gear shifts to the low side, the spring force of the assist spring decreases, and the spring force of the return spring decreases as the gear shifts to the top side. As a result, the spring force of the assist spring increases. Therefore, in the case of the transmission having the tension relationship shown in FIG. 14, there is a large difference between the operating force required for gear shifting operation on the low side and the operating force required for gear shifting operation on the top side. . Even in the case of the transmission having the tension relationship shown in FIG. 15, there is a small difference as compared with the transmission having the tension relationship shown in FIG. There was a difference in the operating force required for operation. SUMMARY OF THE INVENTION An object of the present invention is to provide a bicycle transmission device capable of shifting lightly and with a constant or nearly the same operating force regardless of whether the gear is shifted to the speed increasing or decelerating side and when switching to any gear. .

[0004]

Means for Solving the Problems For a bicycle according to claim 1.
The transmission is a chain that can be reciprocally moved on the bicycle body.
It has a change member and the chain change member is unidirectional
Bicycle derailleur having a return spring that biases against
And has a gear shift operation tool attached to the bicycle body.
Delay for bicycles via operation cable with speed control
And a gear shift operation device for operating the motor. And weird
The speed control device is equipped with a gear shift operation device with a return spring.
It has an assist spring that biases in the direction opposite to the biasing direction.
However, the return spring and assist spring must be chain-changed.
Shifting operation without changing chain reaction on the member
Operation by return spring in the entire operation area of the tool
Cable tension and operating cable tension with assist spring
Are provided to be balanced. In addition, the device
A base member that is connected to the vehicle body for rolling
And a support shaft member that swingably connects the speed operation tool,
Attach the gear shift operation tool to the bicycle body so that it can move back and forth.
Further equipped with a connecting mechanism, the gear shifting operation tool will
It is equipped with a connecting part that pulls linearly.

In carrying out the transmission according to the first aspect of the present invention, the cable tensions of the return spring and the assist spring change in accordance with the operation of the speed change operation tool, but the cable tension also changes and the entire operation area of the speed change operation tool is changed. May be configured to be balanced. However, adopting the configuration according to claim 2 is advantageous as follows.

In carrying out the speed change device according to the first or second aspect, even if a four-link type link mechanism for moving the speed change operation tool in parallel with the vehicle body is adopted as the connection mechanism for attaching the speed change operation tool to the vehicle body. Although good, adopting the configuration according to claim 3 is advantageous as follows.

[0007]

When the gear is shifted to one side of the acceleration / deceleration side, the shift operation tool is operated to the side where the operation cable is extended. Then, the return spring is elastically restored to move out the chain changing member for feeding the cable, and the chain changing member performs predetermined chain changing. When performing this gear shifting operation, the gear shifting operation tool is operated so that the balance between the cable tension of the return spring and the cable tension of the assist spring is disrupted in order to allow the operation cable to be extended, and
The shift operation tool is operated against the friction of the operation cable and the positioning mechanism of the shift operation tool. The derailleur is not attached to the vehicle body just by connecting the derailleur and the gear shift operation device to the vehicle body, or the chain is not wrapped around the chain changing member of the derailleur even if it is attached to the vehicle body, that is, the chain changing reaction force does not act on the derailleur. In this state, the tensions of the two cables are balanced even if the gear shift operation tool is located in any of the entire operation area of the gear shift operation tool. Since the return spring assists the operation force necessary to overcome the resistance by the assist spring, the gear shift operation can be performed even when switching to any gear by making the gear shift operation equal or almost the same in the entire operation area. The manipulative force required for is equal or almost equal. When shifting to the other of the acceleration / deceleration side, the shift operation tool is operated to the pull side of the operation cable. Then, the chain changing member is moved for pulling operation by the operation cable, and predetermined chain changing is performed. When this gear shifting operation is performed, the gear shifting operating tool is operated against the chain reengaging reaction force acting on the chain reengaging member, the return spring, the friction of the operation cable, and the positioning mechanism of the gear shifting operating tool. However,
When the chain change reaction force does not act on the derailleur, the tensions of the two cables are balanced even if the gear shift operation device is located in any of the entire operation region of the gear change operation device. Since the operation resistance of the positioning mechanism is equal or substantially equal in the entire operation area of the gear shift operation tool, the assist spring assists the operation force required to overcome the resistance of the return spring when switching to any gear. The shift operation can be performed, and moreover, the manual operation force required for the shift operation becomes equal or almost equal. In addition, here, the gear shift operating device is made compact.
It That is, the gear shift operation device is connected to the vehicle via the four-link mechanism.
Connect it to your body so that the outer end of the operating cable is
Inner quadruple link machine with fixed link of quadruple link mechanism
Move the gear shift operation device by connecting it to each swing link
If the operation cable can be operated by operating the
The tool moves all over the body
It is relatively difficult to reach, or the entire gear shifting operation device is relatively
It becomes large. On the other hand, if the gear shifting operation device is made swingable,
Both shifts so that the operation cable can be operated in a straight line.
When connected to the operation tool, hold the handlebar, for example.
If you can operate the gear shifting operation tool just by extending the fingers of your hand
Alternatively, the entire shift operating device becomes relatively compact.

If the construction according to claim 2 is adopted, the cable tension due to the return spring and the cable tension due to the assist spring remain balanced even if there is a slight change in the connection between the derailleur and the operation cable of the speed change device. . That is, if the cable tensions of the return spring and the assist spring are configured to be balanced while changing with the operation of the gear shift operation tool, if the derailleur and the gear shift operation device are misaligned, such as when the operation cable stretches. The shift position where the derailleur is located and the operation position where the shift operating tool is located do not correspond as designed. In other words, the degree of deformation of the return spring and the degree of deformation of the assist spring do not correspond as designed, and the cable tension of the return spring and the cable tension of the assist spring become unbalanced. Then, it is necessary to perform the connection adjustment so that the gear shift position of the derailleur and the gear shift operation tool operate in correspondence with each other as designed and the cable tensions of both springs are balanced. On the other hand, if the configuration according to claim 2 is adopted, a slight deviation occurs in the connection between the derailleur and the speed change operation device, and the degree of correspondence between the return spring deformation and the assist spring deformation is slightly different from the initial one. Even if it changes
No change occurs in the cable tension of the return spring and the cable tension of the assist spring, and the cable tensions of both springs remain balanced.

[0009]

[0010]

When shifting to one of the acceleration and deceleration sides, it is possible to shift gears while switching to any shift stage while the assist spring is prevented from becoming a resistance by the return spring, so that it is possible to resist the operation cable and the positioning mechanism. It is now possible to accurately shift to a desired speed by operating accurately so that there is no insufficient operation so that the shifting operation tool is not moved too much by an operation force that is light and constant or close to it. . When operating on the other side of the acceleration / deceleration side, the gear shift operation can be performed while the return spring does not become a resistance by the assist spring regardless of which gear position is changed. The gear shift operation tool is operated accurately with a proper operation so that the gear shift operation tool is not moved too much by an operation force of a light weight that is enough to operate against the positioning mechanism or a weight close to or equal to it. I was able to do it. In addition, here,
Is the tool easy to operate and compact?
, It is easy to operate by attaching it to the handlebar
In addition to being able to construct bicycles with high commercial value
It

When the construction according to claim 2 is adopted, the gear shift corresponding to the gear shift position of the derailleur is achieved even if the derailleur and the gear shift operating device are not connected and adjusted with high precision, or if the operation cable is slightly stretched. The cable tensions of both springs remain balanced by only a slight change in the operating position of the operating tool, and the operating state where the gear can be shifted can be maintained by an operating force of a constant or almost constant weight.

[0012]

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIG. 1, a bicycle rear derailleur 10 including a guide pulley 11 and a gear shift operating device 20 including a gear shift lever 21 constitute a bicycle gear shift device. In this bicycle transmission, the rear derailleur 10 is attached to the rear wheel fork 1 of the bicycle body as shown in FIG. 3, and the gear shift operation device 20 is attached to the handlebar 2 as shown in FIG. 4, and the rear derailleur 10 and the gear shift operation device are attached. 20 and the outer cable 3a
And the inner cable 3b are connected by an operation cable 3, and the shift lever 21 operates the rear derailleur 10 via the operation cable 3 to change the chain 4 to seven rear gears by the guide pulley 11. The details are configured as follows.

That is, as shown in FIGS. 1 and 3,
A pair of left and right swinging support bodies 14 having guide pulleys 11 and tension pulleys 12 attached via chain guides 13 and bracket bodies 15 configured to be bolted to the rear wheel fork 1 by a coupling plate portion 15a. While being connected by the links 16 and 17, the support body 14, the swing links 16 and 17, and the bracket body 15 are configured to form a parallel four-link mechanism R1. Of the pair of left and right swing links 16, 17, an operating arm portion 16a extending from the right swing link 16 toward the left swing link 17 and a support 14 are tension coil springs. A return spring RS is attached, and a first tension spring S1 made of a torsion coil spring is installed in a portion of the bracket body 15 where the connecting plate portion 15a is rotatably connected around the axis B, and a chain guide of the support body 14 is provided. A second tension spring S2, which is a torsion coil spring, is provided in a portion where 13 is rotatably connected about an axis P. An outer holder 18 for supporting the outer cable 3a of the operation cable 3 is provided on the bracket body 15, and an inner cable 3b of the operation cable 3 is fastened and connected to the operation arm portion 16a by a wire fixing screw 19. The rear derailleur 10 is provided with a cable connecting portion.

That is, the guide pulley 11 is attached to the derailleur attaching portion 1a extending from the fork end portion of the rear wheel fork 1 by the parallel four-link mechanism R1 so as to reciprocate in the lateral direction of the vehicle body. Then, as shown in FIG. 2, the guide pulley 11 has the lowest speed first gear position in which the chain 4 is hung on the largest outer diameter low gear of the seven rear gears located on the innermost side of the vehicle body and the most vehicle body as shown in FIG. The top gear with the smallest outer diameter is located on the outer side, and it reciprocates in the lateral direction of the vehicle from the highest speed position where the chain 4 is hung up to the seventh speed position. It is moved to the radial side to change the chain from the high speed side to the low speed side, and the elastic restoring force of the return spring RS moves the seven rear gears from the large diameter side to the small diameter side to move from the low speed side to the high speed side. Change the chain. One end of the first tension spring B1 is locked to the connecting plate portion 15a, and the other end thereof is locked to the bracket body 15 to move the bracket body 15 with respect to the rear wheel fork 1 around the axis B in the swinging direction BF. By urging the guide pulley 11 and the tension pulley 12,
Tension is applied to the chain 4 via. The second tension spring B2 has one end locked to the support 14 and the other end locked to the chain guide 13 to urge the chain guide 13 relative to the support 14 in the swinging direction PF around the axis P. As a result, tension is applied to the chain 4 via the guide pulley 11 and the tension pulley 12.

As shown in FIGS. 4 to 6, the handlebar 2
Attach the band 22a near the grip of the
A lever bracket 22 configured to attach the brake lever 5 to the handlebar 2 by tightening and fixing with a support shaft member 24 configured to tighten and fix with a mounting screw 23, and a lever bracket with the support shaft member 24. A claw holder 25 configured to be clamped and fixed to the unit 22 is attached. The shift lever 21 is supported by the support shaft member 24 so as to be rotatable around an axis 24a of the support shaft member 24, and a cover body 26 for covering the base portion 21a of the shift lever 21 is provided at the end of the support shaft member 24. It is constructed so as to be non-rotatably locked by spline engagement and fixed by a mounting screw 27. An assist spring AS, which is a torsion coil spring, is installed in the base portion 21a of the speed change lever 21, and the cover body 26 is provided.
Is provided with an outer holder 28 for supporting the outer cable 3a of the operation cable 3, and a cable connection configured to connect the inner cable 3b of the operation cable 3 by receiving and supporting the cable nipple 3c on the speed change lever 21. Comprises a part 21b,
Therefore, the shift operation device 20 is configured.

That is, the gear shift lever 21 has a support shaft member 24.
As a connecting mechanism for mounting the lever bracket 22 and the lever bracket 22, two finger contact operation portions provided on the handlebar 2 so as to be reciprocally swingable around the axis 24a and provided in a portion protruding from the cover body 26 of the speed change lever 21. 21A, 21B
Operate by either. That is, the shift lever 2
5 is operated in the swinging direction D shown in FIG. 5, the thumb is put on the finger-touching operation portion 21A, and the finger-touching operation portion 21A alone is used to operate over the entire stroke to move the shift lever 21 to the position shown in FIG. In the case of operating in the swinging direction U shown in, the index finger is applied to the finger contact operation section 21B, and only the finger contact operation section 21B is used for operation over the entire stroke. That is, in the shift lever 21, the positioning recessed portion located at the most one end side of the seven positioning recessed portions provided in the positioning portion 21 c of the shift lever 21 is a resin positioning claw attached to the claw holder 25. The lowest first speed position that matches the acting portion 29a of 29 and the positioning recessed portion that is located on the most other end side of the seven positioning recessed portions that matches the acting portion 29a of the positioning claw 29. It moves across the high speed 7th gear position. The cable connecting portion 21b pulls out the inner cable 3b from the outer cable 3a as the speed change lever 21 moves to the low speed side, and moves the inner cable 3b toward the outer cable 3a as the speed change lever 21 moves to the high speed side. The inner cable 3b pulled out from the outer cable 3a is linearly pulled without being wound up. One end of the assist spring AS is the lever bracket 22 of the claw holder 25.
It is locked to the lever bracket 22 by being locked to the mounting seat portion 25a, and the other end side is locked to the base portion 21a of the shift lever 21 to urge the shift lever 21 to the first speed position. That is, change the gearshift lever 21
The return spring RS of 0 urges in the direction opposite to the direction urged via the operation cable 3.

In the shift operating device 20, as shown in FIG. 8, when the shift lever 21 moves in the operating region from the first speed position to the seventh speed position, the cable connecting portion 21b serving as the connecting point of the inner cable 3b shifts. The lever 21 moves along an arcuate locus T around the swing axis 24a. When an assist operation force AF for swinging the shift lever 21 due to the assist spring AS is generated on the locus T,
The cable connecting portion 21b is used for the assist operation force AF.
Inner cable 3 that extends between the outer holder and the outer holder 28
A cable tension CT1 is generated at b. The ratio of the tension value of the cable tension CT1 to the assist operation force AF is
A straight line L passing through the swing axis 24a and the cable connecting portion 21b
By changing the inclination angle A of the inner cable 3b with respect to, the cable connecting portion 21b moves, and the assist operating force AF changes due to the change in the torsion of the assist spring AS.
If the inclination angle A is appropriately changed even if is changed, the cable tension CT1 does not change, or even if it changes, it does not change as much as the assist operation force AF. The inclination angle A is determined by the cable connecting portion 2 of the speed change lever 21.
1b and the outer holder 28 of the cover body 26 determine the positional relationship. Therefore, when the cable connection portion 21b and the outer holder 28 are arranged and set in an appropriate positional relationship, the cable tension CT1 generated in the inner cable 3b by the assist spring AS is at any speed position from the first speed position to the seventh speed position, and When operating between any speed position from the 1st speed position to the 7th speed position, such as between the 1st speed position and the 2nd speed position or between the 4th speed position and the 5th speed position, that is, to any position over the entire operation area. It becomes almost constant. Based on this, the torsion coil spring shown in FIG. 9 is adopted as the assist spring AS, and the cable connecting portion 21b
8 and the outer holder 28 are arranged and set in the positional relationship shown in FIG. 8, and a substantially constant cable tension CT1- shown in FIG.
1 and CT1-2 are generated. That is,
When the speed change lever 21 is operated to the 1st speed position, the shaft center of the inner cable 3b extending over the outer holder 28 and the cable connecting portion 21b is positioned at a distance D1 = about 25.9 mm from the swing shaft center 24a of the speed change lever 21. , When the gear shift lever 21 is operated to the 7th speed position, the outer holder 28
And inner cable 3 extending from the cable connecting portion 21b
The axis of b is a distance D7 = about 29 m from the swing axis 24a.
The cable connection 21b and the outer holder 28 are arranged and set so as to be located at the position m. Then, the gear shift lever 21 is operated so as not to act on the gear shift lever 21 by removing the positioning claw 29, and the tension generated on the inner cable 3b is measured by the outer holder 28.
1, CT1-2 were measured. That is, the cable tension CT1-1 is the cable tension in the case of increasing the speed of the speed change lever 21 from the 1st speed position to the 7th speed position.
It was a value of kgf. The cable tension CT1-2 is a cable tension of 2.72 to 2.68 kgf when the speed change lever 21 is decelerated from the seventh speed position to the first speed position. Cable tension C when increasing the speed of the speed change lever 21
T1-1 and cable tension CT1-2 during deceleration operation
Is slightly different from that due to friction or the like. That is, even if the gear shift lever 21 is operated to any position over the entire operation area thereof, the inner cable 3b has 2.68 to 3.4.
The tension CT1 of kgf is generated by the assist spring AS.

In the rear derailleur 10, as shown in FIG. 8, when the guide pulley 11 moves in the moving range from the first speed position to the seventh speed position, the cable fixing screw 19 as the connecting point of the inner cable 3b is swung right. The link 16 and the bracket body 15 move along an arc locus T around the connecting pin axis X as the connecting center. If a return operating force RF for swinging the right swing link 16 due to the return spring RS is generated on the locus T, the inner cable 3b extending from the connecting point 19 to the outer holder 18 due to the return operating force RF. Cable tension C
T2 occurs. The ratio of the tension value of the cable tension CT2 to the return operation force RT is the inner cable 3b with respect to the straight line L passing through the connecting pin axis X and the connecting point 19.
When the inclination angle A is appropriately changed even if the return operation force RF is changed due to the change of the length of the return spring RS by changing the inclination angle A of the connection point 19, The cable tension CT2 does not change, or even if it changes, it does not change as much as the return operation force RF. The inclination angle A is determined by setting the positional relationship between the cable connection point 19 of the right swing link 16 and the outer holder 18 of the bracket body 15. Therefore, by properly setting the positional relationship between the cable connection point 19 and the outer holder 18, the chain 4 is not wound around the guide pulley 11 and the tension pulley 12, and the chain pulley 4 is not wound around the guide pulley 11 so that the reaction force does not act. In this state, the tension CT2 generated in the inner cable 3b by the return spring RS is any speed position from the first speed position to the seventh speed position, between the first speed position and the second speed position, and between four speed positions.
It is constant or almost constant regardless of any speed position from the first speed position to the seventh speed position such as between the fifth speed position and the fifth speed position, that is, any position over the entire moving region.
Based on this, the cable connection point 19 of the right swing link 16
By arranging the outer holder 18 and the outer holder 18, the chain 4 is not hung on the guide pulley 11 and the tension pulley 12, and the chain 4 is not hung on the guide pulley 11 to prevent reaction force from acting on the inner cable 3b. The cable tension CT2 generated by the return spring RS has a value of 2.68 to 3.4 kgf regardless of the position of the guide pulley 11.

Therefore, the rear derailleur 10 and the gear shift operating device 20 are not connected to the vehicle body only by connecting them with the operation cable 3, or even if they are attached to the vehicle body, the guide pulley 11 and the tension pulley 12 are not wound around the chain 4 but the guide pulley 11 When the gear shift lever 21 is operated in a state in which the change reaction force from the chain 4 does not act on the chain 4 and the positioning claw 9 does not act on the gear shift lever 21, the gear shift lever 21 moves at any speed position from the first speed position to the seventh speed position. Return between any speed position from the 1st speed position to the 7th speed position, such as between the speed position and the 2nd speed position or between the 4th speed position and the 5th speed position, that is, at any position over the entire operation area. The cable tension CT2 generated in the inner cable 3b by the spring RS and the inner cable 3b by the assist spring AS. Thus it has occurred cable tension C
It is configured to be in balance with T1.

In short, when shifting to the deceleration side, the shift lever 21 is operated in the swing direction D shown in FIGS. Then, the shift lever 21 pulls the inner cable 3b, and the inner cable 3b moves the guide pulley 11 inside the vehicle body together with the tension pulley 12 while elastically deforming the return spring RS. As a result, the guide pulley 11 switches the chain 4 from the small diameter side to the large diameter side of the rear gear, and the shift speed is switched from the high speed side to the low speed side. At this time, even when the gear is switched from the first speed to the seventh speed, the tension CT2 by the return spring RS of the inner cable 3b and the tension C by the assist spring AS
The assist spring AS assists the operating force having a strength necessary for elastically deforming the return spring RS in balance with T1. Therefore, the chain reshuffling resistance that acts on the guide pulley 11 and the outer cable 3a of the operation cable 3
Therefore, the transmission lever 21 is operated by an artificial operation force against the friction of the inner cable 3b and the operation resistance of the positioning claw 29. When shifting to the speed-increasing side, the shift lever 21 is operated in the swing direction U shown in FIGS. 2 and 5.
Then, the shift lever 21 operates the inner cable 3b to be unwound, and the return spring RS elastically restores to move the inner pulley 3b so that the guide pulley 11 and the tension pulley 12 act on the pulleys 11 and 12 together. Move to the outside of the body against the reaction force.
As a result, the guide pulley 11 switches the chain 4 from the large diameter side to the small diameter side of the rear gear, and the shift speed is switched from the low speed side to the high speed side. At this time, when the gear is switched from the 1st speed to the 7th speed, the tension CT2 of the return spring RS of the inner cable 3b and the tension CT1 of the assist spring AS are balanced, and the assist spring AS is elastically deformed. The return spring RS assists the operation force of the required strength. Therefore, the shift lever 21 is operated by an artificial operation force against the friction between the outer cable 3a and the inner cable 3b of the operation cable 3 and the operation resistance of the positioning claw 29.

As shown in FIG. 7, an arrow-shaped pointer mark 31 is provided on a peripheral surface portion 21d of the transmission lever 21 which is exposed from the cover body 26 and faces the rear of the vehicle body. The wall portion 26a, which corresponds to the surface portion 21d and faces rearward of the vehicle body, is provided with seven numeral-type gear position indicators 32 ,.
The d and the wall portion 26a constitute an indicator 30 for displaying the shift speed. That is, the shift lever 21
When the rocking operation is performed, the peripheral surface portion 21d moves with respect to the wall portion 26a, and when the speed change lever 21 reaches a desired operation position from the 1st speed position to the 7th speed position, the pointer mark 31 indicates the 7 speed stages. .., which corresponds to the operation position of the gear shift lever 21, and knows which gear position display 32 the pointer mark 31 indicates. It is possible to determine which gear stage the shift operation has been performed. The shift lever 21 is used as a pointer member and the cover body 26 is used as a display board member to simplify the structure and create an indicator.

The shift operating device of the type attached to the handlebar is configured to be supported by the lever bracket 22 and attached to the handlebar 2 together with the brake lever 5, and also has a dedicated attaching member different from the lever bracket 22. Alternatively, the brake lever 5 may be separately attached to the handlebar 2 for implementation. Therefore, the lever bracket 22 is called a base member.

[Other Embodiment] By adopting the speed change device 40 configured as shown in FIG. 11 as the speed change operation device, the cable tension C generated in the inner cable 3b by the assist spring AS is adopted.
The T1 may be constant or almost constant regardless of the deformation of the assist spring AS. That is, the base 41 configured to be fixed to the handlebar 2 and the speed change lever 42 including the operation arm portion 42a are connected by the pair of swing links 43 and 44, and the base member 41 and the swing link 43, 44 and shift lever 42
Is configured to form a parallel quadruple link mechanism R2, and one swing link 4 of the pair of swing links 43, 44 is formed.
4 is attached to the arm portion 44a extending from 4 and the base member 41, an assist spring AS formed of a tension coil spring is attached, and the shift lever 42 is provided with an outer holder 18 for supporting the outer cable 3a of the operation cable 3. The portion 44a is provided with a cable connecting portion configured to connect the inner cable 3b of the operation cable 3 with the cable fixing screw 19. The base member 41 is a fixed link of the parallel quadruple link mechanism R2, and the shift lever 42 is a movable link of the parallel quadruple link mechanism R2, enabling the shift lever 42 to be moved with respect to the handlebar 2. There is. That is, the parallel quadruple link mechanism R2 serves as a connecting mechanism for attaching the speed change lever, and connects the speed change lever 42 to the handlebar 2 so as to be movable. Then, when the shift lever 42 is moved, the swing link 43 and the shift lever 42 relatively swing, so that the inner cable 3b of the operation cable 3 can be extended or pulled. Further, when the shift lever 42 moves, the swing link 44 and the base member 41 relatively swing so that the distance between the assist spring connecting portion of the swing link 44 and the assist spring connecting portion of the base member 41 changes. Assist spring AS
It is possible to deform with the gear shifting operation. In the case of the link type gear shift operation device 40, as shown in FIG. 12, the cable fixing screw 19 as the connecting point of the inner cable 3b is used.
Moves along an arcuate locus T around a connecting pin axis X as a connecting center between the swing link 44 and the mounting member 41. When an assist operation force AF for swinging the swing link 44 due to the assist spring AS is generated on the locus T, the inner cable 3b extending between the cable connection point 19 and the outer holder 18 is generated due to the assist operation force AF. A cable tension CT1 is generated at. The ratio of the tension value of the cable tension CT1 to the assisting operation force AF changes depending on the inclination angle A of the inner cable 3b with respect to the straight line L passing through the connecting pin axis X and the cable connecting point 19, so that the cable connecting point 19 is changed. Even if the assist operation force AF changes due to a change in the length of the assist spring AS, the cable tension CT1 does not change or the assist operation does not change if the inclination angle A changes appropriately. It does not change as much as force AF.
The inclination angle A is determined by setting the positional relationship between the cable connection point 19 of the swing link 44 and the outer holder 18 of the speed change lever 42. Therefore, by appropriately setting the positional relationship between the cable connecting point 19 and the outer holder 18, the cable tension CT1 by the assist spring AS becomes constant or almost constant regardless of the change in the operating position of the shift lever 42. Further, in the case of this gear shift operating device, the specifications of the parallel quadruple link mechanism R2 are formed to be the same as the specifications of the parallel quadruple link mechanism R1 of the derailleur 10, and the tension of the inner cable 3b by the assist spring AS in the gear shift operating device 40 is set. CT1 and tension C of the inner cable 3b due to the return spring RS of the derailleur 10
T2 can be the same and balanced.

The present invention can be applied to a front transmission as well as a rear transmission. Therefore, the guide pulley 11 and the chain changing guide plate of the front derailleur are collectively referred to as a chain changing member 11, and the parallel four-link mechanism R1 is a connecting mechanism for attaching the chain changing member 11 to a bicycle body. Collectively referred to as R1.

In place of the speed change levers 21 and 42, a rotary operation body is adopted which is rotatably fitted onto the handlebar to form a grip portion of the handlebar and which operates a derailleur via an operation cable. The present invention can also be applied to a case where the shift operating device is configured by using the above. Therefore, these gear shift levers and rotary operation bodies are collectively referred to as gear shift operation tools 21 and 42.

The present invention is applicable not only to the transmission in which the return spring is configured to operate the chain changing member to the low speed side, but also to the transmission in which the return spring is configured to operate the chain changing member to the high speed side. Can be provided. Therefore, the return spring is referred to as a spring for operating the chain changing member in one direction.

The cable tensions of the return spring and the assist spring are balanced and maintained while maintaining a constant or substantially constant value regardless of the deformation of both springs, and both springs are deformed as shown in FIG. The present invention can also be applied to a case in which the cable tensions CT1 and CT2 are changed and the cable tensions CT1 and CT2 are balanced so that the cable tensions CT1 and CT2 are changed.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a schematic diagram of the entire transmission in a 7-speed state.

FIG. 2 is a schematic diagram of the entire transmission in a first speed state.

[Figure 3] Side view of the entire rear derailleur

FIG. 4 is a plan view of the entire shift operating device.

FIG. 5 is a cross-sectional view of a shift operating device.

FIG. 6 is a sectional view of a gearshift lever mounting portion of the gearshift operating device.

FIG. 7 is an explanatory diagram of an indicator of the gear shift operating device.

FIG. 8 is an explanatory diagram of cable tension.

FIG. 9 is an explanatory diagram of an assist spring.

FIG. 10 is an explanatory diagram of cable tension.

FIG. 11 is a schematic view of a shift operating device according to another embodiment.

FIG. 12 is an explanatory diagram of cable tension.

FIG. 13 is an explanatory view of cable tension of another embodiment.

FIG. 14 is an explanatory diagram of conventional cable tension.

FIG. 15 is an explanatory diagram of conventional cable tension.

[Explanation of symbols]

3 operation cable 10 derailleur 11 Chain changing member 20, 40 gear shift operation device 21, 42 gear shifting operation tool 21b Connection part 22,24, R2 connection mechanism R1 connection mechanism RS return spring AS Assist spring CT1 Cable tension by assist spring CT2 Return spring cable tension

Claims (3)

(57) [Claims] 1. A bicycle derailleur having a chain reshuffling member (11) reciprocally movable on a bicycle body and a return spring (RS) for urging the chain reshuffling member (11) in one direction. 10), and a gear shift operation tool (21, 42) attached to the bicycle body
And the operation cable (3) by the gear shift operation tool (21, 42)
And a gear shift operating device (20, 40) for operating the bicycle derailleur (10) via the gear shift operating device (20, 40), wherein the gear shift operating device (21, 42)
A return spring (RS) has an assist spring (AS) that is biased in a direction opposite to the direction biased by the return spring (RS), and the return spring (RS) and the assist spring (AS) are the chain changing members. In the entire operation area of the speed change operation tool (21, 42) without the chain changing reaction force acting on (11), the operation cable tension (CT
2) and the operation cable tension (CT
1) and is provided with so balanced, the base member with the base portion connected to the body for the bicycle
A spindle that swingably connects the speed change operation tool (21) to a member
And a member for moving the speed change operation tool (21) to the bicycle body.
Further equipped with a connecting mechanism (22, 24) that can be freely moved back and forth
The gear shift operation tool (21) pulls the operation cable (3) in a straight line.
A bicycle transmission including a connecting portion (21b) for tensioning . 2. The tension (CT1, CT2) generated in the operation cable (3) by the return spring (RS) and the assist spring (AS) is the speed change operation tool (21, 4).
The bicycle transmission according to claim 1, wherein the entire operation area of 2) is constant or substantially constant. 3. A pre-Symbol Assisted spring (AS) is Ru torsion coil Banedea attached over said base member and said speed change operation member (21), bicycle speed change device 請 Motomeko 1 or 2 wherein.