JPH06115480A - Gearing device for bicycle - Google Patents

Abstract

PURPOSE:To surely release a chain from a specified position at a large diameter side gear when the chain is transferred to a small diameter side gear in a gearing device for a bicycle. CONSTITUTION:A specified position A at which position a chain 1 is to be transferred from a large diameter side gear G1 to a small diameter side gear G2, is provided at the large diameter side gear G1. When the chain 1 is tried to be transferred at a position other than the specified position A, a chain support body 21 acts on the portion of the chain 1 installed over the large diameter side gear G1 so as to support it, the portion of the chain is thereby restrained from being bent in such a way as to be expanded to the side opposite to the small diameter side gear G2 because of transfer operation force. The bending restraint thereby allows chain transfer resistance at the specified position A to be much less as compared with that at the other position, so that the chain can thereby be easily transferred at the specified position A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for changing a chain from a large-diameter gear to a small-diameter gear in a bicycle gear unit in which the chain is changed.

[0002]

2. Description of the Related Art Conventionally, in a bicycle gear device, if a derailleur operation is performed to shift a chain from a large diameter side gear to a small diameter side gear, the rotation phase of the gear at the time of the shifting operation is changed. Regardless, the chain was disengaged from the large-diameter gear at the timing of the shifting operation.

[0003]

SUMMARY OF THE INVENTION In a gear device, when a pair of adjacent gears are combined and a chain is disengaged from a specific tooth of one gear due to the number of teeth of the two gears and the positional relationship between the two gears, the other gear. However, if the gear is disengaged from a tooth other than the specific tooth, the gear may be occluded to the other gear and then occlude. It is difficult as a practical matter to artificially determine the rotational phase of the gear when shifting between the gears in such a combined state. Since it is difficult to shift gears in accordance with the gear shift, gear shift problems may occur, such as the chain coming off from an unfavorable position for gear chain change and it takes time to engage the chain change target gear. It was An object of the present invention is to provide a bicycle gear device that allows easy and smooth gear shifting regardless of the combination of gears.

[0004]

In the bicycle gear device according to the present invention, in order to achieve the object, when the chain is changed from the large diameter side gear to the small diameter side gear adjacent thereto, the small diameter side gear is used. It is characterized in that a bending restraining means for restraining bending of the large-diameter-side gear in the thickness direction is provided at a position where the chain that has been moved to the side is engaged with the large-diameter-side gear.

[0005]

[Function] When changing the chain from the large diameter gear to the small diameter gear, the derailleur presses the chain to move it toward the small diameter gear, so the portion of the chain that is still engaged with the large diameter gear is geared. A bending operation force for bending in the thickness direction of is generated. When the chain portion is allowed to flex freely with the generation of the bending operation force, the chain is relatively easily disengaged from the large diameter gear. On the other hand, if the chain part does not bend regardless of the generation of bending operation force, or if the bending is suppressed so that the bending is insufficient even if it is bent, the chain will not easily separate from the large diameter side gear. is there. Therefore, based on the meshing condition of the large diameter side gear with the small diameter side gear of the chain disengaged from this gear, identify a preferable location for chain separation, and when the chain tries to separate from this specific location, suppress bending. In order to prevent the means from acting on the chain, and when the chain tries to separate from the location other than the specific location, the bend restraining means acts on the chain. Set the shape properly. Then, even if the gear shift operation is performed and the gear change operation force is applied by the derailleur, if the gear is in a rotation phase that is not preferable for chain change, then the bending suppressing means acts on the chain and the chain is on the large diameter side. It will not come off easily from the gear. When the gear is in the preferred rotation phase for chain changing during gear shifting operation, or when the gear reaches the preferred rotation phase for chain changing by continuing derailleur operation, the chain bending suppressing means does not act on the chain. For some reason, the chain is switched to this non-operating state, and the chain is disengaged from the specific portion of the large diameter side gear and smoothly and quickly engages with the small diameter side gear.

[0006]

EFFECTS OF THE INVENTION By properly setting the bending restraining means in consideration of the specific portion for detaching the chain of the large diameter side gear, the chain is detached from the portion of the large diameter side gear which is preferable for chain changing. Quickly and smoothly engages the small diameter gear,
You can now smoothly shift gears by changing the chain from the large diameter gear to the small diameter gear.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a rear gear device including a first speed rear gear G1 to a seventh speed rear gear G7 having different outer diameters, a guide pulley 11 for a chain, a tension pulley 12, and both pulleys 11, 12 are guided. A support 14 that supports the plate 13 through the plate 13, and a swing link body 15 that supports the support 14.
The rear derailleur 10 including the bracket body 16 and the like that are supported by means of a rear rear derailleur for a bicycle capable of performing 7-speed shifting. That is, by attaching the rear gear device to the rear wheel hub for a bicycle and interlocking it with the front gear (not shown) via the chain 1, the rear gears G1 to G7 are driven in the rotational direction F by the front gears to be used for the rear bicycle. It is configured to drive wheels. When a gear shift lever (not shown) is connected to the operation portion of the rear derailleur via the gear shift wire 2 and the gear shift inner wire 2a is pulled by the gear shift lever, an artificial gear shift operation force transmitted through the gear shift inner wire 2a is transmitted. As a result, the swing link body 15 swings inwardly of the vehicle body with respect to the bracket body 16, the support body 14 moves in the same direction, and the guide pulley 11 moves to the large diameter side of the rear gears G1 to G7. 1 is configured to be switched from the small diameter side of the rear gears G1 to G7 to the large diameter side. When the gear shift inner wire 2a is loosened by the gear shift lever, the gear shift operation force due to the elastic restoration of the return spring 17 causes the swing link body 15 to swing to the outside of the vehicle body with respect to the bracket body 16, so that the support body 14 moves. In the same direction, the guide pulley 11 moves to the smaller diameter side of the rear gears G1 to G7 so that the chain 1 can be switched from the larger diameter side of the rear gears G1 to G7 to the smaller diameter side.

In the rear gear device, as shown in FIG. 2, the first speed rear gear G1 is provided with a special tooth Id which is inclined as shown in FIGS. 4 and 6 and which is displaced to the side opposite to the second speed rear gear G2 side. At the same time, the inclined guide portion 20 as shown in FIG. 4 is provided on the tooth tip side of the special tooth Id,
A recessed portion 3 as shown in FIG. 3 is provided at a position on the side surface of the high-speed rear gear G1 opposite to the second-speed rear gear G2 and on the front side in the gear driving rotation direction F from the special tooth Id, and the first-speed rear gear G1 is provided. A chain support member 21 is provided on the lateral side opposite to the second speed rear gear G2 side of the first speed rear gear G1 and is specified for chain reshuffling between the special tooth Id of the first speed rear gear G1 and the tooth N1 adjacent thereto. From the first speed rear gear G1 to the second
When changing the chain to the high-speed rear gear G2, the special tooth I
d, inclined guide portion 20, recessed portion 3 and chain support 2
Due to the action of 1, the chain can be changed against a small change resistance as compared with the case of changing the chain at another place. The teeth Id may be arranged at the center in the thickness direction of the gear without being displaced laterally to one side of the rear gear to reduce the interchanging resistance at the specific location A. That is, as shown in FIG. 6, at the specific location A, as the chain 1 is pushed toward the second speed rear gear G2 side, the link plate portion 1a of the chain 1 enters the recess 3 and the second speed rear gear of the chain 1 is reached. The margin to G2 is larger than that of other parts, the chain 1 is less likely to be caught by the special tooth Id, and is easily disengaged from the first speed rear gear G1. The special tooth Id guides the chain 1 so that it can be easily disengaged from the first speed rear gear G1 by the eccentricity and inclination. The inclination guide portion 20 has a shape inclining toward the second gear rear gear G2 toward the tooth bottom side, and contacts the chain 1 operated by the rear derailleur 10 toward the second gear rear gear G2. Then, the chain 1 is pushed and guided toward the second speed rear gear G2 due to the inclined shape, so that the chain 1 is less likely to be caught by the special tooth Id and the first speed rear gear G2.
It becomes easy to leave from 1. The chain support 21 is shown in FIG.
As shown in, the rear wheel hub is provided with the boss portion 22 and the rear gear G.
1 to G7, which are configured to be attached so as to be integrally rotatable with the unit 1 to G7, and are located laterally to the specific location A.
Since the disc member is provided with the notch portion 23 such as 0, the lateral side surface of the chain 1 is supported only at the position deviating from the specific position A, and the chain 1 is switched at the specific position A. It is configured to be easier than other locations. That is, the chain 1 is connected to the first rear gear G1.
From the first shift rear gear G2 to the second shift rear gear G2 side, the shift operation force
The first rear gear G1 of the chain 1 is still engaged because it is supported by the tooth that the chain 1 of the high speed rear gear G1 is engaged with last (corresponding to the tooth N1 when the chain is changed over at the specific location A). In this portion, an operating force is generated to bend it in the thickness direction of the first speed rear gear G1 in a state of bulging it toward the side opposite to the second speed rear gear G2. If the chain portion can be sufficiently bent by the bending operation force, the chain 1 is easily disengaged from the first speed rear gear G1, and if the chain portion cannot be sufficiently bent by the bending operation force,
The actual situation is that the chain 1 is difficult to disengage from the first speed rear gear G1. When the chain 1 is tried to be re-interchanged at the specific position A, the chain support 21 does not work because of the notch 23, which facilitates the disengagement of the chain 1 from the first speed rear gear G1. If it is attempted to switch the chain 1 at the position, the chain support 21 acts on the side surface of the chain 1 to suppress the bending of the chain 1 to an insufficient amount, and it is difficult to disengage the chain 1 from the first rear gear G1. It is configured to As a result, the pressing operation force required for changing the chain 1 at the specific location A is lighter than at other locations. As shown in FIGS. 2 and 6, an intermediate portion O1 between the special tooth Id of the first speed rear gear G1 and a tooth E1 adjacent thereto and an intermediate point O2 of the second speed rear gear G2 and an tooth N2 adjacent thereto. By combining the rear gears G1 and G2 so that the point O2 and the point O2 are located on a straight line at an interval that is an integer multiple or about an integer multiple of the roller pitch of the chain 1, the chain 1 is the first speed rear gear at the specific position A. When the gear 1 is switched to the second speed rear gear G2, the chain 1 separated from the first speed rear gear G1 smoothly moves to the second speed rear gear G2 without riding on the tip of the second speed rear gear G2 as much as possible.
It is configured to bite into 2.

Second speed rear gear G2 to sixth speed rear gear G6
Also, a special tooth Id similar to the special tooth Id of the first speed rear gear G1 and a recessed portion 3 similar to the recessed portion 3 of the first speed rear gear G1 are provided. Further, as shown in FIG. 11, in order to form a chain support body 24 that exerts the same function as that of the chain support body 21 for the chain 1 which is about to be separated from the second speed rear gear G2 to the sixth speed rear gear G6. Is attached to the side surface of the first speed rear gear G1 to the sixth speed rear gear G6 on the small diameter side gear side, the chain reshuffling resistance is small compared to other locations, and the first speed rear gear The specific place A for replacement having a changing resistance having a value equal to or substantially equal to the changing resistance at the specific place A for changing G1 is formed. Also between the pair of gears adjacent to each other in the second speed rear gear G2 to the seventh speed rear gear G7, as in the case of the first speed rear gear G1 and the second speed rear gear G2, the large diameter side gear G2 or G3.
... The special tooth Id in G6 and the intermediate portion O1 of the tooth E1 adjacent thereto, the small-diameter gear G3 or G4 ... The tooth E2 in G7 and the intermediate portion O2 of the tooth N2 adjacent thereto have the inter-roller pitch of the chain 1. By combining the large-diameter side gear and the small-diameter side gear so that they are located on a straight line at intervals of an integer multiple or about an integral multiple, the chain 1 switches from the large-diameter gear to the small-diameter side gear at the specific location A. The chain 1 disengaged from the large-diameter gear is configured to smoothly mesh with the small-diameter gear without riding on the teeth of the small-diameter gear as much as possible. In addition, a rubber plate is attached to the chain supports 21 and 24, and the action surfaces of the chain supports 21 and 24 that come into contact with the chain 1 are used to generate noise and chain due to the contact between the chain supports 21 and 24 and the chain 1. If the elastic surface is formed so that abrasion can be easily avoided, it is advantageous that the shifting can be made quiet and the chain can be used for a long period of time.

The rear derailleur 10 is provided with the speed change control mechanism 4, and the rear gears G1 to G7 are arranged such that a pair of adjacent large diameter side gears G1 or G2 ... G6 is connected to the small diameter side gear G2 or G3. In doing so, it is considered that the chain 1 is automatically interlocked at the specific portion A and smoothly meshes with the small diameter side gear by the action of the shift control mechanism 4. That is, as shown in FIG. 8, the shift restricting mechanism 4 includes a guide pulley mounting interchange provided between the guide pulley 11 and the guide plate 13 and a sensing spring 4a. The mounting flexibility allows the guide pulley 11 to slide with respect to the guide plate 13 in the direction of the rotation shaft cores of the rear gears G1 to G7 by a predetermined stroke, so that the guide plate 13 moves from a position directly below the large diameter rear gear to a small diameter. Even if the guide pulley 11 is moved to a position directly below the rear gear, the guide pulley 11 is still positioned immediately below or near the large rear gear, and the chain 1 is moved to the small gear, that is, the operation target position P. It's designed to allow you to do things that are far below. Spring 4a
If the chain reshuffling resistance acting on the guide pulley 11 is larger than the set resistance, the resistance causes the guide pulley 11 to elastically deform toward the compression side so that the guide pulley 11 does not reach the operation target position P. When the chain changing resistance that regulates the movement and acts on the guide pulley 11 is equal to or less than the set resistance, the guide pulley 11 slides to the operation target position P by elastically restoring to the extension side against the resistance. It is configured to operate. By setting the chain reshuffling resistance at the specific location A as the set resistance, the shift control mechanism 4 senses the chain reshuffling resistance at the rear gear, and the sensed chain reshuffling resistance is the chain reshuffling resistance at the specific location A. If the resistance is larger than the resistance, the guide pulley 11 is prevented from moving to the operation target position P by the gear shift operation force applied by the return spring 17, and the sensed chain changing resistance is equal to or lower than the chain changing resistance at the specific position A. In this case, the guide pulley 11 is moved to the operation target position P by the shift operation force applied by the return spring 17 or by the shift operation force accumulated by the sensing spring 4a provided by the return spring 17. I am doing it. That is, it operates as follows. 1st speed rear gear G1 to 2nd speed rear gear G
An example of changing the chain to 2 will be described with reference to FIG.
When the speed change lever L is operated to switch from the first speed position to the second speed position and the speed change inner wire 2a is operated to the loose side,
The operation force of the return spring 17 causes the guide plate 13 to move a predetermined stroke from the pre-shift operation position located immediately below the first speed rear gear G1 to the second speed gear G2 side as shown in FIG. (B) or as shown in FIG. 9 (c), the operation target position is located immediately below the second speed rear gear G2. As a result, the tension pulley 12 is
The position before the gear change operation in (a) is moved to the operation target position in (b) and (c) of FIG. 9. At this time, the rear gears G1, G2
Is in a rotation phase other than the predetermined rotation phase, and the chain changing resistance acting on the guide pulley 11 is larger than the chain changing resistance in the specific portion A, the shift lever L is set to a friction type or a ball type. By the position holding means of
Alternatively, by holding the gear in the second speed position by an artificial holding operation, as shown in FIG. 9B, due to the gear shifting operation force by the return spring 17 and the chain changing resistance acting on the guide pulley 11. The sensing spring 4a elastically deforms toward the shortened side to accumulate the shift operation force by the return spring 17, and the guide pulley 11 is attached to the guide plate 13 closer to the first speed rear gear G1 than directly below the second speed rear gear G2. It does not reach the operation target position P because it is located at the non-changing position. As a result, the guide pulley 11 does not press the chain 1 to the second speed rear gear G2,
It becomes impossible to switch the chain 1 to the second speed rear gear G2. After this, the chain 1 guided by the guide pulley 11
On the other hand, the rear gears G1 and G2 have a predetermined rotation phase,
When the position of the specific portion A with respect to the guide pulley 11 becomes a predetermined position and the chain changing resistance acting on the guide pulley 11 is reduced to the chain changing resistance at the specific portion A, as shown in FIG. In addition, the sensing spring 4a elastically restores to the extension side in order to reduce chain changing resistance, and the guide pulley 11 operates from the non-interchanging position of FIG. 9B by the shift operation force by the elastic restoring force of the sensing spring 4a. Move to the target position P. This causes the guide pulley 11 to move the chain 1 to the second speed rear gear G2.
To the second speed rear gear G2 of the chain 1
It becomes possible to switch to.

A recess 5 as shown in FIGS. 2 and 6 is provided at a position laterally of the tooth E1 on the side surface of each of the rear gears G1 to G6 on the small-diameter side, and the large-diameter gear G is formed.
1 or G2 ... G6 to small diameter side gear G2 or G3 ... G
When changing the chain to the chain 7, the chain 1 is partially inserted into the recess 5 so that the chain 1 and the gear on the large diameter side can be prevented from interfering with each other. The chain 1 to be engaged with the gear is smoothly engaged with the small diameter gear.

In the rear gears G1 to G7, as shown in FIGS. 2 and 6 as an example of the combination of the rear gears G1 and G2, from the inter-tooth center O3 with the small diameter side gear G2 or G3 ... G7 of a pair of mutually adjacent gears. On the tangent line drawn out, the center O between the teeth with the large diameter side gear G1 or G2 ... G6
The rear gears G1 to G7 are combined in a state in which 4 is positioned, and a distance between the inter-tooth centers O3 and O4 is an integer multiple or almost an integer multiple of the roller pitch of the chain 1. In the large-diameter gear, the tooth Iu facing the rear side of the center O4 of the gears in the gear drive rotation direction F is inclined as shown in FIGS. 5 and 7, and faces the front side of the center O4 of the gears in the gear drive rotation direction F. By forming the small-diameter side gear with respect to the tooth N so as to be displaced, the easy meshing teeth are formed so that the chain 1 that is switched from the small-diameter side gear can easily mesh. As shown in FIG. 2, all or some of the recessed portions 6, 7, 8, 9 are provided on the side surfaces of the rear gears G1 and G2 on the side of the small diameter gear. All or part of recessed portions (not shown) similar to the recessed portions 6, 7, 8 and 9 are provided also on the side surface of the rear gears G3 to G6 on the small diameter gear side and on the outer side surface of the rear gear G7. When changing the chain from the small diameter side gear to the large diameter side gear, a part of the chain enters one of the recessed portions 6 to 9 which is determined by the chain changing point, and the chain 1 interferes with the large diameter side gear. It is possible to avoid the above, and to make the shift margin of the chain 1 toward the large diameter side gear relatively large. In other words, when changing the chain from the small diameter side gear to the large diameter side gear,
The chain 1 is smoothly interlocked by the meshing action of the teeth Iu, the interference preventing action and the pulling action of the recessed portions 6 to 9. The recesses 5 and 6 are the same as those shown in FIGS.
As shown in, the first recessed portion 5a or 6a having the deeper recessed depth and the second recessed portion 5b or 6b having the shallower recessed depth are formed.

[Other Embodiments] In order to enable the bending of the chain 1 to be suppressed, the chain support members 21 and 24 are replaced with the chain support member shown in FIG.
As shown in FIG. 2, it is possible to employ a means for forming the tooth width of the gear tooth 25 located at a location where bending suppression is required to be larger than the tooth width of the tooth at the specific location A or in the vicinity thereof. That is, the teeth 25 are engaged with the chain 1 in a state where the teeth 1 mesh with each other in a relatively small amount, and the bending of the chain 1 is suppressed by the small amount of meshing. Further, like the chain support plates 21 and 24, the contact action portion for the chain 1 continuously exists in the circumferential direction of the rear gear, and the contact action portion for the chain 1 does not hinder the bending suppression of the chain 1. It may be implemented by adopting a configuration that exists intermittently in the circumferential direction of the rear gear in the state of performing. Further, in place of the chain support plate 24, it is also possible to adopt a means for bending the plate body forming the rear gear by pressing or integrally casting with the rear gear so that the side surface of the rear gear is provided in the form of a ridge or a protrusion. Therefore, these are bent suppressing means 21, 24,
Collectively referred to as 25.

The rear derailleur shown in FIGS. 13 and 14 is provided with a gear shift restricting mechanism 4 having a different structure.
That is, the sensing spring 4a acting on the guide pulley 11 is a leaf spring, and is attached over the guide pulley support portion and the tension pulley support portion of the guide plate 13. Then, the support 14 is moved to the smaller diameter side of the rear gears G1 to G7 by the shift operation force of the return spring 17, and the chain changing resistance acts on the guide pulley 11 so that the guide pulley 11 moves relative to the pulley support shaft 13a. The guide pulley 11 presses the guide pulley side end portion of the sensing spring 4a as it slides away from the support body 14, and the guide pulley side end portion of the sensing spring 4a slides on the pulley support shaft 13a. Due to the movable fitting, the sensing spring 4a is elastically deformed into a state of swinging around a portion supported by the tension pulley side of the guide plate 13 as a swing center, and the return spring 1
The gear shift operation force given by 7 is accumulated, and
The guide pulley 11 is configured to be biased to move in the same direction as the moving direction of the support body 14 with respect to the bracket body 16.

Further, in carrying out the present invention, the following modifications may be carried out. (A) The gear shift restricting mechanism 4 may be omitted, and the shift may be performed by artificially sensing a change in the switching resistance. (B) Two or more locations may be set as the locations for changing the chain from the large diameter rear gear to the small diameter rear gear. (C) The number of rear gears constituting the rear gear device may be 6 or less, or 8 or more. In other words, the present invention can be applied to a rear gear device that employs two or more gears and implements gear shifting in two or more stages. (D) Only by providing only the bending suppressing means 21, 24, 25, or any one or two of the special tooth Id, the inclined guide portion 20, and the recessed portion 3, and the bending suppressing means 21, By combining 24 and 25, the chain changing resistance difference between the specific location A and other locations may be configured to be realized. (E) A place convenient for chain switching from the large diameter side gear to the small diameter side gear, that is, if the specific place exists in two or more places in the circumferential direction of the gear, any of the specific places Also in this case, it is preferable that the bending suppressing means does not act. (F) The recessed portions 6 to 9 may be omitted. (G) The present invention can be applied to a front gear. Therefore, the rear gears G1 to G7 are simply referred to as gears G1 to G7.

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

[Brief description of drawings]

FIG. 1 is a front view of a bicycle rear transmission.

FIG. 2 is a front view of a first speed rear gear and a second speed rear gear.

FIG. 3 is a side view of the teeth of the rear gear.

FIG. 4 is a side view of the special teeth of the rear gear.

FIG. 5 is a side view of the teeth of the rear gear.

FIG. 6 is an explanatory view of switching from a large diameter rear gear to a small diameter rear gear of the chain.

FIG. 7 is an explanatory diagram of switching from a small diameter rear gear to a large diameter rear gear of the chain.

FIG. 8 is a front view of a shift control mechanism.

FIG. 9 is an explanatory diagram of an operating state of the shift control mechanism.

FIG. 10 is a perspective view of a chain bending prevention support.

FIG. 11 is a sectional view of a rear gear device.

FIG. 12 is a plan view of a chain bending preventing tooth.

FIG. 13 is a front view of a gear shift restricting mechanism of another embodiment rear derailleur.

FIG. 14 is a side view of a gear shift restricting mechanism of another embodiment rear derailleur.

[Explanation of symbols]

 1 chains G1 to G7 gears 21, 24, 25 bending suppressing means

Claims (1)

[Claims] 1. A bicycle gear device in which a chain (1) is re-operated, the chain re-transfer from a large diameter side gear (G1 to G6) to a small diameter side gear (G2 to G7) adjacent thereto. At this time, the chain (1) operated to move toward the small diameter side gears (G2 to G7) is engaged with the large diameter side gears (G1 to G6) at a position where the large diameter side gears (G1 to G6) are engaged. A bicycle gear device comprising bending suppressing means (21, 24, 25) for suppressing bending in the thickness direction.