JP2607330Y2 - Bicycle chain gear - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle chain gear having a large number of teeth around it and rotating integrally with a crankshaft or a pair of left and right cranks.

[0002]

2. Description of the Related Art Conventionally, as a bicycle chain gear described above, for example, as disclosed in Japanese Patent Application Laid-Open No. 2-164684, the thickness of teeth is equal to or smaller than that of a chain gear body. .

[0003]

Conventionally, if the thickness of the teeth is increased to make it easy to adjust the disengagement and the difficulty of disengagement of the chain when the chain is switched, or if the teeth are formed to have excellent durability, the chain gear body is formed. The thickness of the part also became thick, and the entire chain gear became heavy. An object of the present invention is to obtain a bicycle light chain gear which is excellent in terms of speed change and durability and is relatively light.

[0004]

In order to achieve the object, in the bicycle chain gear according to the present invention, when a pair of right and left cranks is attached, the bicycle chain gear has the upper dead center and the lower dead center. at least six consecutive of the teeth located in the vicinity of the dead point, with some in the thick wall thick tooth thicknesses than Cheingiya body portion, the meat
Thick teeth are in the opposite direction to the off-chain direction for shifting
It has a thick tooth by having a protruding protrusion
Characterized in that that.

[0005]

When the gear is shifted near the top dead center or the bottom dead center of the chain gear, the chain tension becomes weaker than at other positions. . From this, when setting the vicinity of the top dead center or the bottom dead center as the shift position, at least six teeth continuously located in the vicinity of the top dead center or the bottom dead center are thick teeth. Of the teeth of the above, the teeth that should be the trigger teeth for the off-chain are formed into teeth with a thick tip and the chain is easy to climb up, and the teeth that should be the chain holding teeth to prevent the off-chain will have a chamfered area. Formed on teeth that are wide and the chain is hard to come off,
The teeth that are likely to be in contact with each other due to the chain being inclined at the time of shifting can be formed as teeth that can firmly drive the chain during normal rotation even if the chain is thick and slightly worn. That is, the teeth located near the top dead center and the bottom dead center, which are related to gear shifting, are chained regardless of the shape that is convenient for adjusting the chain change or the wear due to contact with the chain. It can be formed into a shape that easily secures the strength required for driving. In addition, since the thickness of the teeth is larger than the thickness of the chain gear body, the weight of the gear body becomes lighter than that of the conventional gear, which is the same as or thinner than the gear body.

[0006]

According to the present invention, the weight of the chain gear body is prevented from increasing due to the thickness difference between at least six teeth successively located near the top dead center and the bottom dead center and the chain gear body. Forming teeth related to gear shifting to teeth that are convenient for gear shifting or difficult to interfere with chain drive,
The gear can be shifted smoothly by operating the gear relatively lightly, and the vehicle can be driven firmly for a long period of time. In addition, it is relatively lightweight and can be used advantageously. Projections project in the opposite direction to the chain
Makes it easier to adjust the chain
No.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a right crank 4a is connected to three bicycle chain gears 1, 2 and 3 having different outer diameters so as to rotate together, and a crankshaft (see FIG. (Not shown) so as to be integrally rotated with the chain gears 1, 2, and 3, and is connected to the right crank 4a by 180 degrees.
The chain gears 1, 2, and 3 are rotationally driven by the left crank 4b arranged to have a phase difference of degrees, and the rotational power is transmitted to the rear wheel drive gear 6 for the bicycle by the chain 5. It is. The chain 5 is replaced with the chain gears 1, 2, 3 by the front derailleur 7 to change the drive speed of the rear wheel drive gear 6, thereby forming a front drive device for a bicycle capable of three-speed shifting. It is.

The top chain gear 1 having the largest outer diameter among the chain gears 1, 2, 3 has a ring-shaped chain gear main body 1a shown in FIG. 2 and a plurality of ring gears provided around the inner periphery of the chain gear main body 1a. 8 mounting feet
And a number of teeth A, B, C, F, E, G, S which are provided around the outer periphery of the chain gear main body 1a. (Not shown), or by connecting the gear mounting portion of the right crank 4a via the middle chain gear 2, the cranks 4a and 4b are mounted so as to be integrally rotatable. . When the cranks 4a and 4b are mounted, by setting the positional relationship between the mounting foot 8 and the gear portions D1 and D2, the gear portions D1 and D2 are, as shown in FIG. It is located at a position overlapping with the axis X, and becomes the top dead center or the bottom dead center where the pedaling force when the chain gears 1 to 3 are rotationally driven by the rotational operation of the pedals 9 of the cranks 4a and 4b is minimized. Or

The top chain gear 1 includes a step of forming a gear base material having a shape close to a finished product by pressing a single plate-like body, and a step of grinding and processing details such as teeth of the gear base material. And cutting the gear base material into a finished product. That is, the entire chain gear 1 is formed by press working from one sheet. In the gear base material forming process, all the teeth A, B, C, F, E, G, and S are pressed so that a part of each of them swells as shown in FIGS. A, B, C, F, E, G,
Each of the swelling portions A protrudes in the direction opposite to the direction in which the chain 5 comes off the top chain gear 1 during shifting.
1 or B1 or C1 or F1 or E1 or G
1 or S1 is formed. That is, teeth A, B,
6 or 9 or 12 or 15 or 15 because the overall thickness of each of C, F, E, G, and S is due to the bulging portions A1, B1, C1, F1, E1, G1, and S1. 18, the thickness T1 is larger than the thickness T2 of the chain gear body 1a, so that all the teeth A, B, C, F, E, G, and S are thicker than the chain gear body 1a. It is formed with thick teeth.

In each of the teeth A, B, C, F, E, G, and S, as shown in FIGS.
Of the pair of side surfaces C, F, E, G, and S, chamfers A2, B2, and C are formed on the side surface on which the chain 5 is located in the direction opposite to the direction in which the chain 5 is disengaged from the top chain gear 1 for shifting.
2, F2, E2, G2, S2 and chamfers A2, B2, C2, F2, E2, G2, S2
Has one end on the bulging portion A1, B1, C1, F1, E1,
G1 and S1 are formed.

The height of the teeth B and C located near the top dead center D1 or D2 and the bottom dead center D2 or D1 is slightly lower than the height of the other teeth, and the chamfer C2 or F2 is set on the teeth C and F.
Therefore, when shifting the chain 5 from the top chain gear 1 to the middle chain gear 2 as shown in FIGS. 3A and 3B, the upper dead center D1 or D2 or the lower In the vicinity of the dead center D2 or D1, the teeth B and C become the trigger teeth of the chain being off, and the teeth C and F become the chain holding teeth and the chain 5 is switched. That is, in the case where the chain 5 is engaged with the top chain gear 1 when the space between the outer link plates coincides with the teeth A, FIG.
As shown in (a), the chain 5 is the inner plate 5
The rider gets on the tip of the tooth B at a and is disengaged from the tooth F and is switched to the middle chain gear 2. At this time, as shown in FIG. 9, the tip width W1 of the tooth B can be made as large as possible due to the thickness T1 of the tooth B being increased due to the bulging portion B1, so that the inner plate 5a It is easy to get on the tip of the tooth B, and the trigger for shifting by the tooth B can be obtained with high accuracy. Further, at this time, even if the next outer plate 5b rises from the bottom of the tooth C due to the inner plate 5a getting over the tooth B, the thickness T1 of the tooth C is increased due to the bulging portion C1 as shown in FIG. The outer plate 5b extends to the tip of the tooth C because the range W2 of the chamfer C2 is widened due to the fact that the chamfer C2 of the tooth C reaches the bulging portion C1. Is likely to only ride the chamfer C2 without getting on. Then, the outer plate 5b falls back to the bottom side of the tooth C due to the guiding action due to the inclination of the chamfer C2 and the tension of the chain 5, and the top chain gear is moved halfway until the chain 5 is securely engaged with the middle chain gear 2. The teeth C hold the chain 5 until the chain 5 is securely engaged with the middle chain gear 2 so as to prevent the shift shock from deviating from 1.

On the other hand, when the chain 5 is engaged with the top chain gear 1 with the gap between the inner link plates and the teeth A coincident with each other, as shown in FIG. 3B, the chain 5 is brought into contact with the teeth C by the inner plate 5a. After getting up, the tooth E is disengaged from the tooth E and is switched to the middle chain gear 2. At this time, FIG.
As shown in the figure, the tooth plate width W1 of the tooth C can be made as large as possible due to the thickness T1 of the tooth C being thickened due to the bulging portion C1, so that the inner plate 5a It is easy to get on, and the trigger for shifting by the teeth C can be obtained with high accuracy. Further, at this time, the next outer plate 5b is moved to get over the tooth C of the inner plate 5a.
15, the thickness T1 of the tooth F is increased due to the bulging portion F1 and the chamfer F2 of the tooth F reaches the bulging portion F1 as shown in FIG. As a result, the range W2 of the chamfer F2 is widened, so that the outer plate 5b tends to ride on the chamfer F2 without climbing up to the tip of the tooth F. Then
The outer plate 5b falls back to the bottom side of the tooth F due to the guiding action due to the inclination of the chamfer F2 and the tension of the chain 5, and the top chain gear 1 moves from the top chain gear 1 halfway until the chain 5 is securely engaged with the middle chain gear 2. The teeth F hold the chain 5 until the chain 5 is securely engaged with the middle chain gear 2 so as to prevent the shift shock from occurring.

During shifting, as shown in FIGS. 3 (a) and 3 (b), the chain 5 is inclined with respect to the top chain gear 1, so that the teeth A, B, C, F, E, G are particularly used. And the teeth A, B, C, F, E, and G are likely to be worn by contact with the chain 5. However, tooth A,
Each of B, C, F, E, and G is a bulge A1, B1,
Since the thickness T1 is increased due to C1, F1, E1, and G1, the strength necessary for rotationally driving the chain 5 is maintained even if the wheel is slightly worn, and a strong traveling drive can be performed for a long time. Over time.

Of the teeth A, B, C, F, E, G, S, the teeth A, B, C, F, E, located near the top dead center D1 or D2 and the bottom dead center D2 or D1. The teeth S except G are shown in FIG.
As shown in the figure, a strong pedaling force is applied by being located between the vicinity of the top dead center and the vicinity of the bottom dead center, and the teeth A, B, C, F,
Strong chain tension is more likely to act than E and G. However, since the thickness T1 is increased due to the bulging portion S1, high strength is maintained, and the chain 5 can be strongly driven against strong tension. Also in this tooth S, as shown in FIG. 18, the range W2 of the chamfer S2 is widened by the chamfer S2 reaching the bulging portion S1, and the meshing flexibility when the chain 5 engages the tooth S is increased. Despite its smallness due to the thickness T1, when the chain 5 engages the teeth S, the chain 5 and the teeth S smoothly mesh with each other due to the effective guiding action of the wide range W2 of the chamfer S2.

In short, the teeth A, B, C, F, E, G, S
Among the top dead center D1 or D2 and the bottom dead center D2 or D1
, Six teeth A, B, C, F,
E and G are the teeth related to the shift, so that the bulging portion A
Thick thickness T for 1, B1, C1, F1, E1, G1
By equip 1, it is formed on the tooth to secure or formed on the tooth to adjust the hanging Kawari of chain 5, the strongly performing intensity chain drive regardless of wear due to contact with the chain 5. The teeth S other than the teeth A, B, C, F, E, and G are located between the vicinity of the top dead center and the vicinity of the bottom dead center, and a strong pedaling force is likely to act on the teeth S. For this reason, by providing a thicker thickness T1, the chain 5 is formed on a tooth that maintains a high strength that can be driven firmly even in a high tension state.

Incidentally, the middle chain gear 2 and the low chain gear 3 are configured similarly to the top chain gear.

[Another embodiment] Tooth A, B, C, F, E, G, S bulges A1, B1, C
In forming 1, F1, E1, G1, and S1, it may be formed as shown in FIG. That is, by performing a press working so that a part of the chain gear main body 1a is swelled together with a part of the teeth, the swelling parts A1 and B of the teeth are formed.
1, C1, F1, E1, G1, S1
Roots A3, B3, C3, F3, E3, G3
It is formed in a bulging portion extending beyond S3. in this case,
The bulging portions A1, B1, C1, F1, E1, G1, and S1 serve as reinforcing ribs to increase the strength of the chain gear body 1a, and the strength of the entire chain gear also improves from this surface.

When the entire chain gear is formed by press working from a plate-like body, a difference in thickness between the teeth and the chain gear body can be formed by bulging due to the press working of the teeth.
Although relatively inexpensive and advantageous, the entire chain gear is made by forging, etc.
A means for forming a thickness difference between the teeth and the chain gear main body portion by this buildup may be employed. In addition, or bulges in the direction opposite to the direction out of the chain bulging and padding, to form to that rise, Ru advantageous der to facilitate the adjustment of the chain of off-condition. Therefore, the bulging part A
The projections A1, B1, C1, F1, E1, and G1 are collectively referred to as 1, B1, C1, F1, E1, G1, and the overlay.

The teeth located between the vicinity of the top dead center and the vicinity of the bottom dead center may be formed as teeth having the same thickness as the thickness of the chain gear body instead of the thick teeth. In addition, if the number of teeth related to shifting increases near the top dead center and the bottom dead center due to a reason such as a large outer diameter of the chain gear, the number of teeth formed in the thick teeth is accordingly adjusted. It is preferable that the number of sheets is six or more such as seven or eight.

In the claims of the utility model registration, reference numerals are written for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the attached drawings by the entry.

[Brief description of the drawings]

FIG. 1 is a schematic side view of the entire front drive device for a bicycle.

FIG. 2 is a side view of the entire top chain gear.

FIG. 3 is an explanatory diagram showing chain switching.

FIG. 4 is a side view of a tooth A.

FIG. 5 is a plan view of a tooth A.

FIG. 6 is a sectional view of an arrangement portion of a tooth A.

FIG. 7 is a side view of a tooth B.

FIG. 8 is a plan view of a tooth B;

FIG. 9 is a sectional view of an arrangement portion of a tooth B.

FIG. 10 is a side view of a tooth C.

FIG. 11 is a plan view of a tooth C.

FIG. 12 is a sectional view of an arrangement portion of a tooth C.

FIG. 13 is a side view of a tooth F.

FIG. 14 is a plan view of a tooth F.

FIG. 15 is a sectional view of an arrangement portion of a tooth F.

FIG. 16 is a side view of teeth E, G, and S.

FIG. 17 is a plan view of teeth E, G, and S.

FIG. 18 is a sectional view of an arrangement portion of teeth E, G, and S;

FIG. 19 is a side view of a part of another embodiment gear;

[Explanation of symbols]

1 chain gears 4a, 4b cranks A, B, C, F, E, G, S teeth A1, B1, C1, F1, E1, G1, S1 projecting portions A2, B2, C2, F2, E2, G2, S2 chamfering A3 , B3, C3, F3, E3, G3, S3 root D1, D2 top dead center,
Bottom dead center T1 Thickness

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B62M 9/10 B62M 9/00

Claims (5)

(57) [Scope of request for utility model registration] 1. A bicycle chain gear having a large number of teeth on its periphery and rotating integrally with a crankshaft and a pair of left and right cranks (4a) and (4b). Crank (4
a) When (4b) is attached, at least six of the teeth located near the top dead center (D1 or D2) and the bottom dead center (D2 or D1) of the chain gear (1) are continuously connected. And the thickness (T) from the chain gear body (1a).
1) The thick teeth are made thick, and the thick teeth are
Protrudes in the direction opposite to the direction of chain disengagement for shifting
Projection (A1, B1, C1, F1, E1, G1, S1)
A chain gear for bicycles that has thick teeth by being provided . 2. The bicycle chain gear according to claim 1, wherein all the teeth (A, B, C, F, E, G, S) around the chain gear (1) are the thick teeth. 3. The thick tooth is provided outside a chain for shifting.
In the direction opposite to the direction of
(A1, B1, C1, F1, E1, G1, S1)
Chamfer (A2, B2, C2, F2, E2, G2, S
The bicycle chain gear according to claim 1, further comprising (2) . 4. The whole of the chain gear (1) is a plate-like body.
Formed by press working from the
(A1, B1, C1, F1, E1, G1, S1)
Claim 1 which is formed by swelling due to less processing
Or the chain gear for bicycle according to 3 . 5. The projection (A1, B1, B1 ) of the thick tooth.
C1, F1, E1, G1, S1) are chain gears
The tooth bottom (A3, B3, C3, F3, E
5. The bicycle chain gear according to claim 4 , wherein the chain gear extends beyond (3, G3, S3) .