JP3326192B2 - Bicycle front transmission system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an inner guide plate,
A front derailleur having an outer guide plate configured to be disposed outside of the inner guide plate with respect to the center line in the front-rear direction of the bicycle acts on the chain so that the chain is at least a small diameter, a medium diameter, and a large diameter front gear. The present invention relates to a front transmission system for a bicycle, comprising: a front transmission that changes between the transmissions; a manually operable transmission operation tool; and linking means that links the transmission operation tool and the front transmission.

[0002]

2. Description of the Related Art Conventionally, a speed change device has been linked to a speed change device that changes a chain to a plurality of gears by the action of a derailleur, and the chain has been changed to a target change gear by manually operating the speed change device. In the case of a front transmission in which a chain is changed to a plurality of front gears by a front derailleur in a bicycle transmission system that can shift gears by shifting, a shift operation is performed with a hand on a shift operation tool from the start to the end of the shift. It was like.
In other words, it is necessary to press the chain against the gear so that the chain lifts toward the tip of the large-diameter gear due to friction with the gear side surface. It was necessary to press more firmly so that the chain could switch regardless of the load.

[0003]

When performing a gear shift, it is necessary to continue the operation of the gear shift operation tool from the start to the completion of the gear shift, so that the time and effort required for the gear shift operation are increased. As a result, when fatigue becomes severe, for example, when running is continued for a long time, it has been difficult to perform a gear shifting operation properly. If the pedaling force of the chain was strong, the gear could not be shifted. SUMMARY OF THE INVENTION An object of the present invention is to provide a bicycle front transmission system that can easily change the speed of operation both in terms of operation force and operation time.

[0004]

In order to achieve the object, a bicycle front speed change system according to the present invention is characterized in that, in the system described at the outset, the operation of the front derailleur accompanying the manual operation of the speed change operation tool is achieved. Just by moving the chain to the larger-diameter destination front gear, a switching mechanism is provided for switching the chain to the destination front gear with the turning power of the destination front gear. When the changeover mechanism is provided on the inner guide plate of the front derailleur and projects in the direction of the outer guide plate, the changeover mechanism is provided at a position corresponding to the step on the side of the changeover destination front gear. The tooth side of the front gear to be changed,
The chain is configured with a changeover projection projecting in the direction of the changeover front gear on which the chain has been engaged, and the step portion has
A second pressing portion protruding in the direction of the outer guide plate with respect to a first pressing portion provided at a lower portion of the inner guide plate, and a second pressing portion protruding in the direction of the outer guide plate from the second pressing portion; It is characterized by having a third pressing portion disposed outside the large-diameter front gear when the switching to the large-diameter front gear is completed, as viewed in the direction of the rotation axis of the large-diameter front gear.

[0005]

[Function] By operating the shift operation tool, the front derailleur simply moves the chain toward the large-diameter gear, and the switching mechanism detects the movement of the chain and operates to change the chain by rotating the gear. Change to the target gear.

[0006]

According to the operation of the changeover mechanism, the gear can be shifted quickly and easily with a light operation force only by operating the operation tool sufficient to move the chain by the derailleur, and with a small amount of operation time. It is now easy to change chains easily. When the positioning mechanism is provided, it is not necessary to use a nerve for operating the speed change operation tool for positioning the derailleur at the desired shift position. Further, the operation speed is increased.

[0007]

As shown in FIGS. 1 and 2, a large-diameter front gear 1, a medium-diameter front gear 2, and a small-diameter front gear 3 are
The three front gears 1, 2, 3 are rotationally driven by the rotation operation of the crank 4 by being connected concentrically and integrally by the crank 4. A front gear device for a bicycle is configured so as to be transmitted to the wheel drive gear 6 to drive the rear wheels, and to be able to change the speed by changing the chain 5 to the front gears 1, 2, and 3. is there. The front derailleur 10 is used to enable the variable speed drive by the front gear device.
Is attached to the vehicle body frame F to form a front transmission A. The front transmission A and one of the transmission operating devices 20 are provided so as to be manually operated, and are attached to the handlebar H by the tightening band 21. The front speed change system is constituted by the speed change operation device B thus configured and the speed change wire 7 for linking the speed change operation tool 20 to the front speed change device A. Specifically, it is configured as follows.

As shown in FIG. 12, the front derailleur 10 is configured to be fixed to the inner guide plate 11, the outer guide plate 12, and the vehicle body frame F provided with two holes S by the tightening band portion 13a. Swinging link mechanism 1 for movably supporting both guide plates 11 and 12 by the support member 13
4. Connect both guide plates 11 and 12 to front gear 1,
Each of the return springs (not shown) acting on the swing link mechanism 14 so as to move and bias toward the small-diameter front gear 3 located on the innermost side of the vehicle body among the gears 2 and 3; By swinging the link mechanism 14 by the swing operation of the operation arm 16 connected to one of the pair of swing links 14a, 14a constituting the mechanism 14, both the guide plates 11, 12 become front gears. It moves in the direction of the rotation axes 1, 2, and 3 to press the chain 5. As shown in FIG. 2, a plurality of chains as shown in FIGS. 3, 7, and 8 are provided on the side surface of the medium-diameter front gear 2 on the side of the small-diameter front gear 3 in the circumferential direction of the medium-diameter front gear 2. As shown in FIGS. 4 and 10, a plurality of replacement teeth 17 are provided on the side surface of the large-diameter front gear 1 on the side of the medium-diameter front gear 2 in the circumferential direction of the large-diameter front gear 1. Chain hooking spikes 18 are provided.
Have been. These chain replacement teeth 17 and chain
The latching spikes 18 are apparent from FIGS.
As you can see, each of the front gears
Protruding from the side surfaces 1a, 2a of the teeth provided on the periphery
Therefore, these are collectively referred to as transfer projections. This changeover projection
17 and 21 at the front end side on the inner surface side of the inner guide plate 11 when the inner guide plate 11 is press-formed.
The chain 5 can be changed from the small-diameter front gear 3 to the medium-diameter front gear 2 or can be changed from the medium-diameter front gear 2 by the step portion D provided so as to form the second pressing portion 11b and the third pressing portion 11c. At the time of up-shifting when changing to the large-diameter front gear 1, the chain 5
After the switch to the front derailleur 10 chain 5
, The chain of the chain is changed by the cooperation of the operation of the front derailleur 10 and the turning power of the front gears 1, 2, and 3, and the chain 5 is pressed by the front derailleur 10. A changeover mechanism E is configured to detect a movement toward the medium-diameter front gear 2 or the large-diameter front gear 1 and change the chain.

The speed change wire 7 has one end of the inner wire 7a connected to a wire winding body 22 provided in a state where the speed change operation device B is linked to the speed change operation tool 20, and the other end is connected to the operation arm. 16 so that the operation of the speed change operation tool 20 is transmitted to the operation arm 16 as a signal for starting the front transmission A.
0 and the front transmission A.

In the speed change operation device B, as will be described in detail later, the speed change operation tool 20 is swung downward from the original position N around the axis X by the pressing operation of the first operation portion 20a made of a resin cap. When the take-up body 22 is turned to the upshift position Y, the take-up body 22 is configured to take up and rotate the inner wire 7a by a predetermined length.
Is swung upward from the original position N about the axis X to the downshift position Z by pushing the second operation portion 20b made of the resin cap, whereby the winding body 22 is moved to the inner wire position. 7a, a rewinding rotation of a predetermined length is performed, so that only one-touch operation of operating the shift operation tool 20 from the original position N to the upshift position Y is performed, and the operation of the transfer mechanism E is performed. As a result, the contact between the chain 5 and the front derailleur 10 after the front transmission A is shifted to the front gears 1 and 2 is prevented, and the operation of the front derailleur 10 and the rotation of the front gears 1, 2, and 3 are prevented. It is configured to perform an upshift where the chain 5 is changed in cooperation with the power.

That is, when the operation arm 16 is at the low speed position L shown in FIG.
At the position shown in FIG. 15A, the chain 5 is engaged with the small-diameter front gear 3, and the front transmission A is in a low-speed state. In this state, when the speed change operation tool 20 is rocked from the original position N to the upward shift position Y, the operation arm 16 is switched from the low speed position L to the middle speed position M shown in FIG. FIG. 15 through the position (b)
Move to position (c). As a result, as shown in FIG. 15 (b), the first pressing portion 11a formed at the end of the inner guide plate 11 is engaged with the chain 5 on the small-diameter front gear 3.
And presses the chain 5 toward the medium-diameter front gear 2 so that the chain 5 is obliquely shifted from the small-diameter front gear 3 toward the medium-diameter front gear 2. Then, as shown in FIG. 11A, the rotation of the middle diameter front gear 2 causes the gear 2 to rotate.
One of the plurality of chain replacement teeth 17 that rotates together with the chain enters the lower side of the chain 5 approaching the medium-diameter front gear 2 side, and as the medium-diameter front gear 2 further rotates, FIG. As shown in FIG. 5, the chain 5 and the chain replacement tooth 17 engage with each other in a state where the chain replacement tooth 17 enters between the outer link plates 5 a of the chain 5. As the middle diameter front gear 2 further rotates, as shown in FIG.
The chain 5 is lifted to the tip side of the medium-diameter front gear 2 due to the lifting action by the occlusal support, and at the same time, it is formed on the side of the chain replacement tooth 17 on the gear 2 side in FIG. The inclined guide surface 17a draws the chain 5 toward the medium-diameter front gear 2 by a cam action due to the inclination of the inclined guide surface 17a closer to the gear 2 closer to the tooth bottom side. In order for the outer link plate 5a to be inclined with respect to the medium-diameter front gear 2 by the action, the chain drive teeth 2a located behind the chain replacement teeth 17 of the medium-diameter front gear 2 in the drive rotation direction are provided. As the chain 5 is engaged and the medium-diameter front gear 2 further rotates, as shown in FIGS. 11 (C), 13 and 15 (C), the chain replacement tooth 17 and the chain 5 Over Kawari to the medium-diameter front gear second delay 5 with occlusion to release it is completed. The inner guide plate 11 is used to connect the chain 5 with the chain replacement tooth 17.
And the chain 5 engaged with the chain replacement tooth 17 is switched to the medium-diameter front gear 2 by the pulling action and the inclination guiding action of the chain replacement tooth 17, so that the The guide plate 11 does not come into contact with the chain 5 after being switched to the medium-diameter front gear 2 while being at the position shown in FIG.

In this state, when the shift operation tool 20 is operated from the original position N to the upward shift position Y, the operation arm 16 is moved.
Are switched from the medium speed position M to the high speed position T shown in FIG. 14, and the inner guide plate 11 is moved to the position shown in FIGS.
From the position shown in FIG. 16A through the position shown in FIG.
Move to position (c). As a result, as shown in FIG. 16B, the first pressing portion 11a comes into contact with the side surface of the chain 5 hanging on the medium-diameter front gear 2 and presses the chain 5 toward the large-diameter front gear 1, The chain 5 starts to lean obliquely from the medium-diameter front gear 2 to the large-diameter front gear 1 side.
At this time, the second pressing portion 11b does not yet press the chain 5. Then, as shown in FIG. 11A, one of the plurality of chain engaging spikes 18... That rotates together with the gear 1 is rotated toward the large-diameter front gear 1 to rotate the large-diameter front gear 1. As the large-diameter front gear 1 further rotates under the approaching chain 5 and the large-diameter front gear 1 further rotates, the chain hooking spike 18 does not bite the chain 5 as shown in FIGS. When the chain 5 starts to catch on the chain engaging spike 18, the second pressing portion 11b
Is projected toward the outer guide plate 12 side with respect to the first pressing portion 11a, so that the second pressing portion 11b does not come off the chain 5 from the chain hooking spike 18 as shown in FIG. As shown in FIG. 11 (b), the chain 5 is lifted by the chain hooking spikes 18 and supported by the support, so that the chain 5
To the tip side. As the chain 5 is lifted outward with respect to the large-diameter front gear 1 as viewed in the direction of the rotation axis of the large-diameter front gear 1, the third pressing portion 11c is moved in the rotation-axis direction of the large-diameter front gear 1 during this speed change operation. The third pressing portion 11c is configured to be positioned outside the large-diameter front gear 1 when viewed from the outside.
As shown in FIG. 16D, the third pressing portion 11c contacts the side surface of the chain 5 to move the chain 5 to the large-diameter front gear 1b. 1 side, chain 5 is large-diameter front gear 1
Is located above the tip of the tooth. As the large-diameter front gear 1 further rotates, the chain 5 begins to slightly engage with the large-diameter front gear 1 from the chain driving tooth 1a located on the rear side in the rotation direction of the gear 1 with respect to the chain engaging spike 18, and With the continued rotation of the front gear 1, FIGS.
As shown in FIG. 4 and FIG. 16E, the engagement between the chain 5 and the chain engaging spike 18 is released, and the switching of the chain 5 to the large-diameter front gear 1 is completed. When the chain 5 is switched to the large-diameter front gear 1 and completed, the chain 5 and the chain driving teeth 1a of the gear 1 are engaged, and a part of the chain 5 enters between the chain driving teeth, and the chain 5 becomes the third chain.
The position of the chain 5 with respect to the third pressing portion 11c is closer to the rotation axis of the large-diameter front gear 1 than when it is pressed by the pressing portion 11c and positioned outside the large-diameter front gear 1. The third pressing portion 11c is configured to be in a non-contact state with the chain 5 which has been switched to the large-diameter front gear 1 so that the inner guide plate 11 is configured such that the chain 5 is Even after being switched to the gear 1, the chain 5 does not come into contact with the chain 5 after being switched to the large-diameter front gear 1 while being at the position shown in FIG.

The speed change device B is constructed as shown in FIGS. 22 and 23. That is, the speed change operation tool 20
Has a first operating portion 20a and a second operating portion 20b formed of a resin lever cap, and is lowered from the original position N shown in FIG. 24 around the axis X by a pushing operation of the first operating portion 20a. It swings up and swings up around the axis X from the original position N by the pushing operation of the second operation portion 20b. As shown in FIG. 25, when the speed change operation tool 20 is moved downward from the original position N, the feed pawl 23 engages with one of the ratchet teeth 25 a of the positioning member 25 due to the urging action of the feed pawl spring 24. The first positioning claw 26 and the second positioning claw 26 by engaging the positioning member 25 with the boss of the winding body 22 so as to be integrally rotatable by meshing engagement. 27 is the ratchet teeth 25a
The operation of the operating tool operation in which the winding body 22 is transmitted via the feed claw 23 and the positioning member 25 by disengaging from the ratchet teeth 25a for the pushing action caused by the tooth shape of The inner wire 7a is rotated by the force to the winding side due to the force. When the speed change operation tool 20 swings by a predetermined angle to the upshift position Y, the wire winding stroke by the winding body 22 reaches the predetermined stroke, and the operation arm 16 of the front transmission A shifts to the position L or the position before the speed change operation. The position is switched from M to the shift target position M or T. At this time, the first positioning claw 2
6 automatically returns to a position in which it engages with any one of the ratchet teeth 25a due to the urging action of the claw spring 28, and acts as a stopper on the winding body 22 to apply an operating force to the speed change operation tool 20. Even if it is released, take-up body 2
Regardless of the biasing force of the rewinding spring 29 acting on the lever 2 and the self-restoring force of the return spring of the front transmission A, the operating arm 16 is maintained while maintaining a new rotational position after the winding body 22 is switched. It is maintained at the position M or T switched by the previous shift operation. Thereafter, when the application of the operating force to the gearshift operating tool 20 is released, the gearshift operating tool 20 is released.
Automatically return to the original position N due to the urging action of the return spring 30. As shown in FIG. 26, when the shift operation tool 20 is operated upward from the original position N, the feed claw 23 rides on the guide portion 31a of the guide member 31, comes off the ratchet teeth 25a, and rewinds the winding body 22. Rotation becomes possible. Further, the base of the feed claw 23 contacts the first arm portion 32a of the release member 32, and the release member 32
3 and the operation tool transmitted via the feed claw 23, the gear is rotated in the same direction as the swinging direction of the speed change operation tool 20, and the second arm 32 b of the release member 32 is moved to the arm of the first positioning claw 26. 26a and the arm 27 of the second positioning claw 27
a of the second arm portion 32b.
As shown in FIG. 27, the tip of the second positioning claw 25 enters between the ratchet teeth due to the swinging operation of the second positioning claw 27 by pressing on the 7a. At this time, the tip of the first positioning claw 26 contacts one of the ratchet teeth 25a and acts as a stopper on the winding body 22, and the winding body 22 does not yet rotate. From this state, when the speed change operation tool 20 further swings upward and reaches the down speed change position Z, the second arm portion 32b presses the arm portion 26a, and the tip of the first positioning claw 26 comes into contact with the tip first. Ratchet teeth 25a hit
And the winding body 22 is slightly rotated to the rewind side by the urging action of the rewind spring 29 and the wire pulling action by the front transmission A. At this time, as shown in FIG. 28, the ratchet teeth 25a that have come off from the first positioning claws 26 first come into contact with the toes of the second positioning claws 27, and the second
The positioning claw 27 acts to prevent the winding body 22 from rotating to the rewind side at once. Then, when the application of the operating force to the speed change operation tool 20 is released, the release member 32 is released.
24 returns to the standby position shown in FIG. 24 due to the urging action of the return spring 34, and the shift operation tool 20 automatically returns to the original position N due to the urging force of the return spring 34 acting via the release member 32. It returns. As the release member 32 returns to the standby position, the second arm 32b releases the pressing operation on the arm 27a. In this operation released state, the second positioning claw 27 is turned by the shape of the toe. When the moving take-up body 22 is disengaged from the ratchet teeth 25a by the pushing operation by the ratchet teeth 25a, the take-up body 22 rewinds and rotates, and the wire rewinding stroke by the take-up body 22 reaches a predetermined stroke. The arm 16 is switched to the low-speed position M or L by one step from before the gear shifting operation. At this time, the first
The ratchet tooth 2 whose toe of the positioning claw 26 is first disengaged from the first positioning claw 26 by the urging action of the claw spring 28
5a and the ratchet teeth 25a following the ratchet teeth 25a, and the ratchet teeth 25a contact the subsequent ratchet teeth 25a, so that the winding body 22 moves the operation arm 16 to a new position where the operation arm 16 has been switched by the previous shift operation. The rotation position for that is maintained so as to maintain M or L.

In short, the chain 5 is a small-diameter front gear 3
When the transmission arm 20 is engaged, the operating arm 16 is moved from the low-speed position L to the medium-speed position M by the one-touch operation of operating the shift operation tool 20 from the original position N to the upward shift position Y. And the front transmission A starts, and the first pressing portion 1 of the front derailleur 10
The chain 5 is switched from the small-diameter front gear 3 to the medium-diameter front gear 2 in cooperation with the pressing action on the chain 5 by 1a, the turning power of the medium-diameter front gear 2, and the operation of the chain-changing teeth 17. In addition, after the chain is changed, the inner guide plate 11 is brought into a non-contact state with the chain 5. When the chain 5 is engaged with the medium-diameter front gear 2, only one-touch operation of the shift operation tool 20 to operate from the original position N to the upward shift position Y is performed, and the operation arm 16 is actuated by the operation force of the shift operation tool 20. The front transmission A is started by switching from the middle speed position M to the high speed position T, and the second depressor 11b and the third depressor 11c of the front derailleur 10 press the chain 5 against the chain 5,
Rotating power of large-diameter front gear 2 and chain hook spike 1
The chain 5 is switched from the medium-diameter front gear 2 to the large-diameter front gear 1 in cooperation with the operation of FIG. In addition, after the chain is changed, the inner guide plate 11 is brought into a non-contact state with the chain 5.

When the transmission A is constructed, the front derailleur 10 and the chain 5 are brought into a non-contact state after the chain 5 is switched to the medium-diameter front gear 2 or the large-diameter front gear 1. Although it is advantageous that no noise is generated after the shift is completed, a configuration in which the front derailleur 10 and the chain 5 remain in contact may be employed.

[Alternative Embodiment] FIGS. 29 to 32 show an alternative embodiment structure of the front derailleur 10 and the inner guide put 11.
A first pressing portion 11a on the inner surface side of the second pressing portion 11a, and a second pressing portion 11 protruding from the first pressing portion 11a to the outer guide plate 12 side.
b, is different from the front derailleur 10 in that it has a third pressing portion 11c protruding from the second pressing portion 11b toward the outer guide plate 12, but the connection angle of the guide plates 11 and 12 to the link 14a is slightly different. Differently, the configuration is such that the mounting posture with respect to the body frame is slightly different. Due to this difference in mounting posture, the shapes of the second pressing portion 11b and the third pressing portion 11c are slightly different.

FIG. 33 shows another embodiment of the front transmission system, in which the inner guide plate 11 of the front derailleur 10 has a chain pressing portion 1 having no stepped portion D as shown in FIG.
1d, the front derailleur 10 is provided with the electric motor 35, and the speed change operation tool 20 is provided with three operation positions of the low speed position L1, the medium speed position M1, and the high speed position T1. Is different from the shift system shown in FIG. 1 in detail. That is, to configure the front derailleur 10,
The operation arm 16 for moving the guide plates 11 and 12 is formed with a sector gear, and the output gear 35a of the electric motor 35 is engaged with the sector gear to drive the electric motor 35. By
The operation of moving the inner guide plate 11 and the outer guide plate 12 with respect to the front gears 1, 2, 3 is performed. The changeover mechanism E is constituted by an electric motor 35 and a control circuit or a shift control means 37 constituted by a microcomputer linked to a drive circuit 36 of the electric motor 35. The detection switch 38 is connected to the speed change operation device B.
Is provided so as to detect the operating position where the shift operation tool 20 is located, and the detection switch 38 and the shift control means 37 are connected by an electric wire 39 so that the shift operation tool 20 and the front transmission A are connected. It is configured to be linked. That is, when the shift operation tool 20 is switched to the low-speed position L1 by the swing operation, the shift control means 37 automatically outputs a signal to the drive circuit 36 based on the information from the detection switch 38, so that the motor 35 By operating the plates 11 and 12 to the position shown in FIG. 34A, the chain 5 is engaged with the small-diameter front gear 3. Speed change gear 2
When 0 is switched from the low speed position L1 to the middle speed position M1, the shift control means 37 automatically outputs a signal to the drive circuit 36 based on the information from the detection switch 38, so that the motor 35 In FIG. 34 (b)
As shown by a solid line, the inner guide plate 11 moves the chain 5 toward the side of the medium-diameter front gear 2 by the inner guide plate 11 acting as a pressing portion 11d. Chain 5 is used for friction with the side surface of middle diameter front gear 2 and rotation of middle diameter front gear 2.
Is raised to the tip side of the medium-diameter front gear 2. Along with this lifting, the motor 35 further moves the inner guide plate 11 toward the middle-diameter front gear 2 as shown by a virtual line in FIG.
Makes the pressing portion 11 d further press the chain 5 toward the medium-diameter front gear 2 so that the chain 5 is positioned on the tooth tip of the medium-diameter front gear 2. Thereafter, as the middle-diameter front gear 2 further rotates, the chain 5 meshes with the chain driving teeth of the middle-diameter front gear 2, and the switching to the middle-diameter front gear 2 of the chain 5 is completed. Upon completion of the switching, the shift control means 37 automatically outputs a signal to the drive circuit 36 so as to operate the motor 35 in the reverse rotation direction, and the motor 35 moves the inner guide plate 11 to the position shown in FIG. The operation is returned to the position indicated by the solid line in (b) or in the vicinity thereof so that the middle diameter front gear 2 and the inner guide plate 11 do not come into contact with each other. When the shift operation tool 20 is switched from the middle speed position M1 to the high speed position T1, the shift control means 3
7 is a drive circuit 36 based on information from the detection switch 38.
34, the motor 35 moves the inner guide plate 11 toward the large-diameter front gear 1 as shown by the solid line in FIG. 34C, and the inner guide plate 11 pushes the pressing portion 11d. Then, the chain 5 is pressed against the side surface of the large-diameter front gear 2, and the friction between the chain 5 and the side surface of the large-diameter front gear 1 due to the pressing operation and the rotation of the large-diameter front gear 1 cause the chain 5 to move. Large diameter front gear 1
So that it can be lifted to the tip side. With this lifting, the motor 35 moves the inner guide plate 11 as shown in FIG.
As shown by an imaginary line, the inner guide plate 11 further moves the chain 5 toward the large-diameter front gear 1 by pressing the inner guide plate 11 to the pressing portion 11d. The gear 2 is located on the tooth tip. Thereafter, as the large-diameter front gear 1 further rotates, the chain 5 meshes with the chain driving teeth of the large-diameter front gear 1, and the switching of the chain 5 to the large-diameter front gear 1 is completed. Upon completion of the switching, the shift control means 37 automatically outputs a signal to the drive circuit 36 so as to operate the motor 35 in the reverse rotation direction, and the motor 35 moves the inner guide plate 11 to the position shown in FIG. Returning to or near the position indicated by the solid line in FIG.
And the inner guide plate 11 do not come into contact with each other.

In the case where the shift operation tool and the front derailleur are configured in a mechanically linked manner so as to be linked by a shift wire, when implementing a shifting mechanism, the chain engaging spike attached to the large-diameter front gear 1 is used. Instead of 18, a chain replacement tooth similar to the chain replacement tooth 17 attached to the middle diameter front gear 2 may be employed.

In the speed change operation device B, the speed change operation tool 20 is configured to be positioned by the positioning claws 26 and 27 at an operation position to be operated and positioned for shifting. Instead of this gearshift operating device, the gearshift operating tool side,
A ball and a concave portion, or a groove and a convex portion may be provided on the side of the fixing member. Further, the speed change operation tool may be provided with a medium speed position, and the front derailleur may be provided with a stopper for positioning the high speed position and the low speed position, so that all operation positions may be positioned. Alternatively, the speed change operation tool may be a friction type that does not include positioning and that is provided only on the front derailleur. In short, the means for positioning only on the side of the gearshift operating device, the means for positioning only on the side of the front derailleur, or the means for positioning on the side of the gearshift operating tool and the positioning on the side of the front derailleur The positioning mechanism may be constituted by a combination of means for performing the positioning.

Further, when the transmission operation tool and the front derailleur are configured to be electrically linked so as to be electrically connected to each other, as shown in the above-described embodiment, a lever-type transmission operation tool is employed. A switch may be employed as the operation tool. When the shift operation switch is employed, either a single switch type in which a plurality of gears are shifted by the same switch or a multiple switch type in which the number of switches equal to the number of gears may be adopted.

The large, medium and small diameter front gears 1, 2, 3
A gear with a smaller diameter than the small-diameter front gear 3 may be arranged inside the vehicle body of the group, or large, medium, and small-diameter front gears 1, 2, 3
The present invention is also applied to a transmission system in which a gear having a larger diameter than the large-diameter front gear 1 is arranged outside the group of vehicle bodies, and four, five, or more front gears are chained. it can.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a bicycle front shifting system.

FIG. 2 is a side view of a bicycle front gear.

FIG. 3 is a side view of the operation state of the chain replacement tooth.

FIG. 4 is a side view of an operation state of a chain hooking spike.

FIG. 5 is a plan view showing an operation state of the chain replacement tooth;

FIG. 6 is a plan view showing an operation state of a chain hooking spike.

FIG. 7 is a side view of the chain replacement tooth.

FIG. 8 is a plan view of a chain replacement tooth.

FIG. 9 is a front view of the chain replacement tooth.

FIG. 10 is a sectional view of a chain hooking spike.

FIG. 11 is an explanatory view showing the operation of a chain replacement tooth and a chain hooking spike.

FIG. 12 is a side view of the front derailleur in a low-speed state.

FIG. 13 is a side view of the front derailleur in a middle speed state.

FIG. 14 is a side view of the front derailleur in a high-speed state.

FIG. 15 is an explanatory view showing an operation state of the inner guide plate.

FIG. 16 is an explanatory view showing an operation state of an inner guide plate.

FIG. 17 is a front view of a chain guide.

FIG. 18 is a rear view of the chain guide.

FIG. 19 is a plan view of a chain guide.

FIG. 20 is a bottom view of the chain guide.

FIG. 21 is a sectional view of an inner guide plate.

FIG. 22 is a longitudinal sectional plan view of a speed change operation device.

FIG. 23 is a longitudinal sectional side view of the speed change operation device.

FIG. 24 is an explanatory diagram showing the operation of the speed change operation device.

FIG. 25 is an explanatory diagram showing an upshift operation state of the shift operation device.

FIG. 26 is an explanatory diagram showing a downshift operation state of the shift operation device.

FIG. 27 is an explanatory view showing an operation of a positioning claw of the speed change operation device.

FIG. 28 is an explanatory diagram showing an operation of a positioning claw of the speed change operation device.

FIG. 29 is a front view of a chain guide of another front derailleur.

FIG. 30 is a rear view of a chain guide of another front derailleur.

FIG. 31 is a plan view of a chain guide of another front derailleur.

FIG. 32 is a bottom view of a chain guide of another front derailleur.

FIG. 33 is a schematic view of another embodiment of the front transmission system.

FIG. 34 is an explanatory view showing an operation state of a chain guide in another embodiment of the front transmission system.

[Explanation of symbols]

 1, 2, 3 Front gear 5 Chain 7, 39 Linking means 10 Front derailleur 11 Inner guide pute 17 Chain changing teeth 18 Chain engaging spikes 20 Shifting operation tool 35 Electric motor 39 Control means A Front transmission E Changing mechanism D Step T1, M1, L1 Operation position

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B62M 9/12 B62M 9/00 B62M 25/04 B62M 25/08

Claims (6)

(57) [Claims] 1. A front derailleur (10) comprising an inner guide plate (11) and an outer guide plate (12) arranged outside of the inner guide plate (11) with respect to the center line in the bicycle longitudinal direction. ) Is acted on the chain (5) to convert the chain (5) into at least a small diameter, a medium diameter, and a large diameter front.
A front transmission (A) for shifting between the gears (3), (2) and (1), and a shift operation tool (20) that can be manually operated
And a linkage means (7), (39) for linking the speed change operation tool (20) with the front transmission (A), wherein the speed change operation tool (20) With the operation of the front derailleur (10) accompanying the manual operation of the above, the chain (5) is merely moved to the larger-diameter destination front gears (1) and (2) , so that the destination front is changed. Gear (1)
And (2), a changeover mechanism (E) for changing the chain (5) to the changeover destination front gears (1) and (2 ) is provided, and the changeover mechanism (E) is provided. , Provided on the inner guide plate (11) of the front derailleur (10),
When it protrudes in the direction of the outer guide plate (12), the stepped portion (D) and
A front gear provided at a corresponding position,
(1), with respect to the tooth sides of (2), said chain (5) is multiplied換突out section projecting in the direction of the hanging recombinant original front gear which has been applied (17), is composed of (18), wherein Step (D) is below the inner guide plate (11)
The outer pressing member against a first pressing portion (11a) provided on the
The second pressing portion (1) protruding in the direction of the
1b) and the outer guide from the second pressing portion (11b).
Projecting in the direction of the plate (12),
When the shift to the large-diameter front gear (1) is completed,
The large-diameter front gear (1) has a large diameter
A third pressing portion (11) disposed outside the front gear (1)
A front transmission system for a bicycle, comprising: c) . 2. The bicycle front transmission system according to claim 1, wherein the changeover projections (17) and (18) are chain hooking spikes (18) provided on the side of the changeover destination front gear. . Wherein the chain hook spike (18) is pre-Symbol small <br/> diameter, middle diameter, large diameter front gear (3), (2), of the (1), large-diameter front gear ( The bicycle front transmission system according to claim 2, which is provided in ( 1 ). 4. The bicycle front transmission system according to claim 1, wherein the changeover projections (17) and (18) are chain changeover teeth (17) provided on the side of the changeover destination front gear. . Wherein said chain hooking recombinant teeth (17), before Symbol small <br/> diameter, middle diameter, large diameter front gear (3), of the (2), (1), middle diameter front gear The bicycle front transmission system according to claim 4, which is provided in (2). 6. The front derailleur (10) is provided with a positioning mechanism, and the front derailleur (10) has the same number of operation positions (T1) as the number of front gears (1), (2) and (3) to be chained. The bicycle front transmission system according to any one of claims 1 to 5, wherein the positioning mechanism is configured to position each of (M1), (M1), and (L1) by the positioning mechanism.