JP3290688B2 - Bicycle front derailleur - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention comprises an inner guide plate and an outer guide plate, and the inner guide plate and the outer guide plate press against the chain so that the chain has at least three large diameters different from each other. The present invention relates to a bicycle front derailleur that can be switched to a large-diameter front gear, a medium-diameter front gear, and a small-diameter front gear.

[0002]

2. Description of the Related Art Conventionally, in a bicycle front derailleur, for example, as shown in Japanese Utility Model Laid-Open Publication No. Sho 62-174994, among the chain pressing portions that press against the chain of the inner guide plate, medium to large diameter gears are used. The high-speed pressing portion that acts when the chain is switched to the small-diameter gear projects from the outer guide plate side to the medium-speed pressing portion that acts when the chain is switched from the small-diameter gear to the medium-diameter gear. Compared to shifting using a derailleur with the pressing part and the high-speed pressing part being in the same state, it is necessary to shift from a low speed where the chain engages the small diameter gear to a high speed where the chain engages the large diameter gear. In some cases, the shift operation can be performed while reducing the operation stroke of the derailleur.

[0003]

In the case of the conventional derailleur, when the chain is switched from the medium-diameter gear to the large-diameter gear, the chain is lifted to the tip side of the large-diameter gear, and then the chain is further moved onto the tooth tip. Since the derailleur operation for pressing by the high-speed pressing portion is required to be located, the reduction of the derailleur operation stroke required for shifting is not sufficient, and the shifting operation is still easy enough. I didn't. SUMMARY OF THE INVENTION It is an object of the present invention to provide a bicycle front derailleur that requires a sufficiently small operation stroke for shifting.

[0004]

In order to achieve the object, a bicycle front derailleur according to the present invention is characterized in that, in order to achieve the object, in the front derailleur described above, a small-diameter front gear of the front gears is shifted from a medium-diameter front gear. A first pressing portion that presses the chain toward the medium-diameter front gear when changing the chain; and changing the chain to the large diameter when changing the chain from the medium-diameter front gear to the large-diameter front gear of the front gear. A second pressing portion that presses against the diameter front gear side and protrudes toward the outer guide plate side with respect to the first pressing portion; Pressing the chain to the large-diameter front gear side, which is located radially outward of the large-diameter front gear when viewed in the rotation axis center direction of the large-diameter front gear,
And the inner guide with respect to the second pressing portion (11b).
The inner guide plate (11) is characterized in that the inner guide plate (11) is provided with a third pressing portion (11c) located on the front end side of the plate (11) and further protruding toward the outer guide plate (12). The operation and effect are as follows.

[0005]

[Function] In the case of a large-diameter front gear which is configured so that the chain is lifted to the tooth tip side of the gear when the chain is switched from the medium-diameter front gear to the large-diameter front gear by friction between the chain and the gear side surface. In the case of a large-diameter front gear that presses the chain against the gear side surface or lifts the chain with a locking part such as a chain-locking spike provided on the side of the large-diameter front gear, attach the chain to the hook. The second pressing portion presses the chain toward the large-diameter front gear side so as to be locked, and the second pressing portion projects toward the outer guide plate side with respect to the first pressing portion,
By performing the derailleur operation with a smaller operation stroke as compared with the case where the first pressing portion and the second pressing portion are flush with each other, it is possible to change the chain from the medium-diameter front gear to the large-diameter front gear. In addition, when the chain is lifted toward the tooth tip of the large-diameter front gear, the third pressing part further presses the chain and is positioned on the tooth tip of the large-diameter front gear, so that the second pressing part is engaged with the chain. The chain is switched to the large-diameter front gear without performing derailleur operation for further moving the inner guide plate, which has been operated to the position where the pressing action is performed, toward the large-diameter front side.

[0006]

According to the first, second and third pressing portions, an operation stroke for moving the chain from the medium-diameter front gear to the large-diameter front gear and lifting the chain to the tooth tip side of the large-diameter front gear. From the two sides of the operation stroke for pushing the chain over the tooth tip, the overall operation stroke required for shifting is small, and the operation is simple and quick with only a few strokes of operation Now you can.

[0007]

12. As shown in FIG. 12, a chain guide 10 formed by connecting an inner guide plate 11 and an outer guide plate 12 having two holes S, S and a support member 13 are connected to a pair of swing links 14a. , 14a, the chain guide 10 is configured to be movable with respect to the support member 13 by the action of the swing link mechanism 14 including the swing link 14a, and acts on the swing link mechanism 14. A return spring (not shown) is used for the chain guide 10.
Are biased toward one side to form a front derailleur for a bicycle. As shown in FIG. 1, this derailleur is attached to a vehicle body frame F through a mounting band 13a provided on a support member 13, and a speed change wire is connected to an operation arm 16 connected to one swing link 14a. (Not shown), and the swinging operation of the operation arm 16 by the pulling and loosening operation of the speed change wire allows the chain guide 10 to provide a pulling operation force of the speed change wire and an urging force of the return spring.
Have three different front gears with large, medium and small outside diameters.
3, the guide plates 11 and 12 are pressed against the chain 5, and the front gears 1, 2, 3
And the chain 5 is replaced.

As shown in FIGS. 17 to 21, a first pressing portion 11a and a second pressing portion 11
b, a third pressing portion 11c located closer to the front end side of the guide plate than the second pressing portion 11b is provided.
The pressing portion 11a is an end of the guide plate 11, and
The pressing portion 11b and the third pressing portion 11c are formed by a two-step-shaped step portion D which is simultaneously press-formed so as to swell toward the outer guide plate 12 when the inner guide plate 11 is press-formed. 11b protrudes toward the outer guide plate 12 with respect to the first pressing portion 11a,
The pressing portion 11c is configured to protrude toward the outer guide plate 12 with respect to the second pressing portion 11b. When the chain guide 10 is operated so as to change the chain from the medium-diameter front gear 2 to the large-diameter front gear 1, the position where the inner guide plate 11 is present and the step D are provided. Due to a certain shape, the third pressing portion 11c
Is located outside the large-diameter front gear 1 when viewed in the direction of the axis of rotation of the front gears 1, 2, and 3, and in this case, the chain 5 does not yet engage with the large-diameter front gear 1 but on the tooth tip. If it is located, it will be compared with after engaging with gear 1,
Since the part of the chain 5 that has not yet entered the space between the teeth of the gear 1 is located further away from the rotation axis of the gear 1 in the radial direction of the gear, the third pressing portion 11
Although c contacts the chain 5, the third pressing portion 11c is configured to be in a non-contact state with the chain 5 after the chain 5 engages with the gear 1, so that the operation stroke of the chain guide 10 Overshifting the inner guide plate 11 to position the chain 5 on the tooth tips of the front gears 2 and 3 while the chain 5 is shifted to the front gears 2 and 3. The shift operation can be performed without the need to return the inner guide plate 11 to avoid interference between the inner guide plate 11 and the inner guide plate 11.

That is, when the operating arm 16 is at the low speed position L shown in FIG.
The chain 5 is engaged with the small-diameter front gear 3 at the position shown in FIG. When the operation arm 16 is switched from the low speed position L to the middle speed position M shown in FIG. 13, the inner guide plate 11 moves to the position shown in FIG. 15C via the position shown in FIG. As a result, FIG.
As shown in (b), the chain 5 in which the first pressing portion 11a of the inner guide plate 11 is hooked on the small-diameter front gear 3 is used.
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. 11 (a), a plurality of chain replacement teeth as shown in FIGS. 2, 7 and 8 provided on the side of the middle diameter front gear 2 in the circumferential direction of the gear 2. One of 17... Enters into the lower side of the chain 5 which is close to the medium-diameter front gear 2 for integral rotation with the medium-diameter front gear 2, and the medium-diameter front gear 2 further rotates. Accordingly, as shown in FIGS. 3 and 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 5a and 5a of the chain 5. As the medium-diameter front gear 2 further rotates, as shown in FIG. 11 (b), the chain 5 shifts its teeth with respect to the medium-diameter front gear 2 due to the lifting action by the occlusal support of the chain replacement teeth 17. It is lifted to the front side, and at the same time, the inclined guide surface 17a as shown in FIG.
However, in order to draw the chain 5 toward the medium-diameter front gear 2 by the cam action due to the inclination closer to the gear 2 toward the gear root side, the inclined guide surface 17a is further guided by the inclined link to the outer link plate. In order to set 5a to be inclined with respect to the medium-diameter front gear 2, the chain 5 is applied to the chain drive teeth 2a located on the rear side in the drive rotation direction from the chain replacement teeth 17 of the medium-diameter front gear 2, As the medium-diameter front gear 2 further rotates, as shown in FIGS. 11 (C), 13 and 15 (C),
The engagement between the chain switching teeth 17 and the chain 5 is released, and the switching of the chain 5 to the medium-diameter front gear 2 is completed. The inner guide plate 11 is pressed only to hang the chain 5 on the chain replacement tooth 17, and the chain 5 hooked on the chain replacement tooth 17 is attracted by the chain replacement tooth 17 and inclinedly guided. By changing over to the medium-diameter front gear 2 by the above, the inner guide plate 11 keeps the inner guide plate 11 even after the chain 5 is changed over to the medium-diameter front gear 2 as shown in FIG.
Is not in contact with the chain 5 after being switched to the medium-diameter front gear 2.

When the operation arm 16 is switched from the middle speed position M to the high speed position T shown in FIG. 14, the inner guide plate 11 is moved from the position shown in FIGS.
It moves to the position shown in FIG. 16C via the position shown in FIG. As a result, as shown in FIG. 16B, the first pressing portion 11b of the inner guide plate 11 comes into contact with the side surface of the chain 5 hanging on the medium-diameter front gear 2, and the chain 5 is moved to the large-diameter front gear 1. Side, and the chain 5 starts to move 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, a plurality of chain engaging spikes 1 shown in FIGS. 2 and 10 provided on the side surface of the large-diameter front gear 1 in a circumferential direction of the gear 1 are provided.
8 enters into the lower side of the chain 5 which is close to the large-diameter front gear 1 for the integral rotation with the large-diameter front gear 1, and the large-diameter front gear 1 is further rotated. Accordingly, as shown in FIG. 4 and FIG.
When the chain 8 does not bite the chain 5 but acts on the outer link plate 5a of the chain 5 and the chain 5 starts to be hooked on the chain hooking spike 18, FIG.
As shown in FIG. 11, the second pressing portion 11b presses the chain 5 so as not to come off the chain hooking spike 18, and
As shown in (b), the chain 5 is lifted toward the tooth tip side of the large-diameter front gear 1 due to the lifting action by the receiving support of the chain hooking spike 18. Chain 5
Is raised outward with respect to the large-diameter front gear 1 as viewed in the direction of the axis of rotation of the gear 1, and the third pressing portion 11 c of the inner guide plate 11 is moved to the side of the chain 5 as shown in FIG. And presses the chain 5 toward the large-diameter front gear 1, and the chain 5 is positioned above the tooth tip of the large-diameter front gear 1. 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. 6E, the engagement between the chain 5 and the chain engaging spike 18 is released, and the engagement of the chain 5 with the large-diameter front gear 1 is completed. When the chain 5 is switched to the large-diameter front gear 1 and completed, the third pressing portion 11c is switched to the large-diameter front gear 1 and is brought into a non-contact state with the chain 5 which has been completed.
Even after the chain 5 is engaged with the large-diameter front gear 1, the inner guide plate 11 does not come into contact with the chain 5 after being engaged with the large-diameter front gear 1 while being at the position shown in FIG.

[Other Embodiments] FIGS. 22 to 25 show another embodiment 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.

[0012] As in the above embodiment, the chain replacement tooth 17
When the chain is used for shifting the front gears 1 and 2 including the chain engaging spikes 17, the overshift operation of the chain guide becomes unnecessary even when the chain is switched from the small-diameter front gear 1 to the medium-diameter front gear 2. As compared with the case where the chain 5 is pressed against the side surface of the medium-diameter front gear 2 or the large-diameter front gear 1 and the chain 5 is lifted to the gear tooth side by friction with the gears 2 and 1, the required speed change This is advantageous in that the operating force is light. But,
When used for shifting in a front gear that does not have the chain replacement tooth 17 or the chain engaging spike 17, that is, a front gear configured so that the chain is lifted to the tooth tip side of the gear due to friction between the chain and the gear side surface. Also, the derailleur according to the present invention can be applied. Also in this case, the operation stroke required for shifting is reduced, and
The effect of eliminating the need for the overshift operation and the return operation at the time of shifting from a medium speed to a high speed is similarly obtained.

If the third pressing portion 11c is configured not to come into contact with the chain 5 after the shifting of the chain 5 to the large-diameter front gear 1 is completed, the chain between the chain 5 and the inner guide plate 11 after the shift is completed. Advantageously, there is no generation of noise due to contact, but it may be configured and implemented so as to remain in contact.

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 applicable to a front derailleur in which a gear having a larger diameter than the large-diameter front gear 1 is arranged outside the vehicle body of the group, and four, five, or more front gears are chained. Applicable.

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 accompanying drawings.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a bicycle front transmission.

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 front view of a chain guide of another front derailleur.

FIG. 23 is a rear view of a chain guide of another front derailleur.

FIG. 24 is a plan view of a chain guide of another front derailleur.

FIG. 25 is a bottom view of a chain guide of another front derailleur.

[Explanation of symbols]

 1, 2, 3 Front gear 5 Chain 11 Inner guide plate 11a First pressing portion 11b Second pressing portion 11c Third pressing portion 12 Outer guide plate

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

Claims (3)

(57) [Claims] 1. An inner guide plate (1) comprising an inner guide plate (11) and an outer guide plate (12).
1) and the outer guide plate (12) presses against the chain (5) to cause the chain (5) to have at least three large-diameter front gears (1) and medium-diameter front gears (2) having different outer diameters. A bicycle front derailleur for changing over to the small diameter front gear (3), wherein when the chain is changed from the small diameter front gear (3) to the medium diameter front gear (2), the chain (5) is changed to the medium diameter. The first pressing portion (11) pressing against the front gear (2) side
a) when the chain is changed from the medium-diameter front gear (2) to the large-diameter front gear (1), the chain (5) is pressed toward the large-diameter front gear (1); A second pressing portion (11b) protruding toward the outer guide plate (12) with respect to one pressing portion (11a), when changing the chain from the medium-diameter front gear (2) to the large-diameter front gear (1); The large-diameter front gear (1) as viewed in the direction of the rotation axis of the large-diameter front gear (1).
And presses the chain (5) toward the large-diameter front gear (1) at a position radially outward of the inner guide plate (11) against the second pressing portion (11b).
And the outer guide plate (1
2) A bicycle front derailleur provided with a third pressing portion (11c) further protruding toward the side on the inner guide plate (11). 2. The apparatus according to claim 2, wherein said second pressing portion (11b) is provided on said rotating shaft.
After the front end of the outer guide plate (12) when viewed in the core direction
The bicycle front according to claim 1, wherein the bicycle front is formed on a side.
Derailleur. 3. The third pressing part (11c) is provided with the second pressing part.
The first pressing portion (11a) without the pressure portion (11b).
3. The CFC for bicycle according to claim 1 or 2, which is connected.
Todelera.