JP2001253378A - Bicycle chain case and bicycle provided therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bicycle having a chain case allowing easy mounting operability and having a high degree of freedom of design. SOLUTION: The chain case 30 comprises an inner cover body 31 having therein a through hole 47 through which a crankshaft 22 is passed, the inner cover body being secured to the base frame of the bicycle for covering a drive sprocket 21 and at least the part of a chain 20 engaged with the drive sprocket; and an outer cover body 32 whose front portion 33 is attached to the inner cover body 31 and whose rear portion 34 extends along a chain stay 15. The outer cover body 32 is attached to the inner cover body 31 while being freely rotatable between a first position in which the rear portion 34 is tilted diagonally upwards from the chain stay 15 and a second position in which the rear portion 34 extends along the chain stay 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle, and more particularly to a structure of a chain case for covering a bicycle chain.

[0002]

2. Description of the Related Art There are various types of electric assist bicycles in which a driving force by human power is supplemented by a driving force by a motor. However, not only this type of electric assist bicycle but also a general bicycle is used as a chain case. And an integrally molded product.

[0003]

Therefore, the conventional chain case is long, and therefore, when the chain case is mounted on the body frame, workability is poor, and it is particularly difficult to mount the chain case in a narrow place. . In addition, the degree of freedom in design of the chain case was small.

SUMMARY OF THE INVENTION An object of the present invention is to provide a bicycle having a chain case which can be easily mounted and has a high degree of freedom in design.

[0005]

In order to achieve the above object, a bicycle according to the present invention has a through hole through which a crankshaft is inserted, and a drive sprocket and a chain at least in a portion engaged with the drive sprocket. An inner cover body to be fixed to the base frame of the bicycle, an outer cover body having a front part attached to the inner cover body and a rear part extending along the chain stay;
It has a chain case consisting of

According to the above configuration, the degree of freedom of design can be increased as compared with the conventional one by combining the inner cover and the outer cover made of different materials and colors.

[0007] Further, since the chain case is composed of two members, the length is shorter than that of the conventional chain case, so that the work of attaching the chain case is easy even in a narrow place.

Further, when a part of the chain case is damaged, it is conventionally necessary to discard the entire chain case. In the present invention, when one of the inner cover member and the outer cover member is damaged, only one of the inner cover member and the outer cover member is damaged. It may be replaced, and the repair cost can be reduced.

The present invention can be applied not only to an electric assisted bicycle but also to a normal non-electric bicycle.

Further, according to the present invention, the outer cover body is rotatable between a first position in which a rear portion is inclined obliquely upward from the chain stay and a second position in which the rear portion extends along the chain stay. It may be mounted on the inner cover body. With such a configuration, since there is room in the mounting dimensions, it is possible to absorb variations in the dimensions. Furthermore, it is possible to cope with bicycles having different sizes.

In the present invention, a locking projection may be formed on the inner surface of the outer cover body, and an arc-shaped locking hole through which the locking projection is inserted may be formed on the inner cover body. With this configuration, the outer cover body can be configured to be rotatable.

A plurality of locking holes are formed around the through hole, and the front side of the outer cover body has an insertion hole through which the crankshaft is inserted. A plurality of locking projections may be formed.

A mounting hole is formed in the inner cover body, and the mounting hole may be formed at a position where the mounting hole is covered by the outer cover body when the outer cover body rotates to the second position. . Thereby, since the mounting holes are not exposed to the outside, the appearance is improved.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. The present invention is not limited by the embodiment.

(Embodiment) FIG. 1 is a side view showing the entire structure of a bicycle according to the present invention, and FIG. 2 is an exploded perspective view showing the vicinity of a drive sprocket. This embodiment is an example in which the present invention is applied to a battery-assisted bicycle. First, a schematic configuration of the electric assisted bicycle will be described. An auxiliary power unit having a motor and the like is mounted on the body frame 10.
The body frame 10 is configured by integrally assembling a head pipe 11, a down tube 12, a seat tube 13, a seat stay 14, and a chain stay 15.
The lower end of the down tube 12, the lower end of the seat tube 13, and the front end of the chain stay 15 are connected, and a box-shaped casing 16 containing an auxiliary power unit is attached to the connected portion.

A drive sprocket 21 that engages with a chain 20 is attached to a crankshaft 22 near an outer surface on the right side (hereinafter, abbreviated as “right side”) of the casing 16 in the traveling direction. A crank 24 having a pedal 23 is attached to both ends of the crankshaft 22. An auxiliary power sprocket 25 to which a driving force from the auxiliary power unit is transmitted and an idler sprocket 26 for applying a constant tension to the chain 20 are arranged near the outer surface on the right side of the casing 16. A small-diameter wheel sprocket 28 is attached to a rear hub shaft (not shown) that rotatably supports the rear wheel 27. A chain 20 is wound around the wheel sprocket 28, the drive sprocket 21, the auxiliary power sprocket 25, and the idler sprocket 26, and the driving force from the drive sprocket 21 and the auxiliary driving force from the auxiliary power sprocket 25 And the rear wheel 27 is rotationally driven.

A chain case 30 that covers a part of the chain 20 is disposed on the right side of the drive sprocket 21 in the traveling direction. The chain case 30 includes a synthetic resin inner cover body 3 fixed to the casing 16.
1 and an outer cover body 32 made of synthetic resin which is attached to the inner cover body 31 so as to be rotatable about a horizontal axis.

FIG. 3 is a plan view of the inner cover body 31, FIG. 4 is a side view as viewed from the arrow A side in FIG.
FIG. 6 is a cross-sectional view taken along the line BB of FIG. 3, and FIG.
7 is a plan view of the outer cover body 32, FIG. 8 is a perspective view of the outer cover body 32 seen from the back side, and FIG. 9 is a cross-sectional view of FIG. FIG. Referring to FIGS. 3 to 9 and 2, chain case 3
The specific structure of 0 will be described. The outer cover body 32 has a front part 33 attached to the inner cover body 31, and a longitudinal rear part 34 connected to the front part 33 and extending rearward along the chain stay 15 above the chain stay 15. . The rear portion 34 also has a role of covering the upper chain 20. A circular insertion hole 35 through which the crankshaft 22 is inserted is formed in the front portion 33. A ring-shaped convex portion 36 concentric with the insertion hole 35 is provided on a left side surface (a surface facing the inner cover body 31 and corresponding to the inner side surface of the front portion 33) in the traveling direction of the front portion 33. Is formed. This convex part 3
A plurality of (three in the present embodiment) locking projections 37 are formed at equal intervals in the circumferential direction. Locking projection 3
7 has an L-shaped cross section, and includes a shaft portion 37a and a shaft portion 3a.
A holding portion 37b extends from an end of the insertion hole 7a toward the center of the insertion hole 35. An insertion hole 39 is provided at the rear end of the rear portion 34.
The through hole 39 is screwed into the through hole 39 and screwed into a fixing bracket (not shown) attached to the chain stay 15 to fix the rear portion 34.

The inner cover body 31 has a substantially circular main body 4.
5 and a protrusion 46 protruding rearward. The main body 45 mainly covers the drive sprocket 21, and the projection 46 mainly covers the auxiliary power sprocket 25 and the idler sprocket 26. A circular through hole 47 is formed substantially at the center of the main body portion 45.
7 and the through-hole 35 of the outer cover body 32
Is inserted. A through hole 47 is formed on the right side surface (the surface facing the outer cover body 32) in the traveling direction of the main body 45.
A ring-shaped convex portion 48 protruding toward the outer cover body 32 is formed at a peripheral edge of the outer cover body 32, and a concave portion 49 concaved toward the casing 16 is formed at an outer circumferential portion of the convex portion 48. ing. A locking hole 50 is formed in the recess 49 to lock the locking projection 37 of the outer cover body 32. The locking hole 50 is formed in an arc shape extending along a virtual circle concentric with the through hole 47. The plurality of (three in this embodiment) locking holes 50 are formed at equal intervals in the circumferential direction on the imaginary circumference concentric with the through hole 47 corresponding to the locking projections 37. The locking hole 50 includes a first locking hole portion 50a,
The second locking hole portion 50b is connected to the first locking hole portion 50a and has a smaller hole width than the first locking hole portion 50a. First
The locking hole portion 50a has a hole width through which the holding portion 37b of the locking protrusion 37 can be inserted. On the other hand, the second locking hole portion 50
b has a hole width through which the shaft portion 37a of the locking projection 37 can be inserted but the holding portion 37b cannot be inserted. Therefore,
After the locking projection 37 is inserted into the first locking hole portion 50a,
The rotation of the outer cover body 32 causes the shaft portion 3 of the locking projection 37 to move.
As the 7a moves to the second locking hole portion 50b, the holding portion 37b comes into contact with the peripheral portion of the second locking hole portion 50b and is locked. Thus, the outer cover body 32
Is rotatable between a first position where the rear portion 34 is inclined obliquely upward from the chain stay 15 and a horizontal second position where the rear portion 34 extends along the chain stay.

The casing 1 is provided on the inner cover body 31.
A boss 60 (see FIGS. 2 and 4) protruding toward the sixth side is formed, and a mounting hole 61 extending in the axial direction is formed in the boss 60. One end of the mounting hole 61 is on the inner cover body side 3
1 is open. The mounting hole 61 is formed in the outer cover body 3.
2 is formed at a position where it is covered by the outer cover body 32 when rotated to the second position.

Next, a method of fixing the above-structured chain case 30 to the vehicle body frame will be described. First,
The inner cover body 31 is fixed to the casing 16. Specifically, the inner cover body 3 is inserted so that the crankshaft 22 is inserted into the through hole 47 and the boss 60 corresponds to the mounting hole 70 (see FIG. 2) formed in the casing 16.
1 is arranged outside the casing 16. Next, the mounting holes 72 of the fixing bracket 71 (see FIG. 2) previously fixed to the casing 16 correspond to the mounting holes 73 (see FIG. 3) formed on the side surface of the inner cover body 31, and are fixed with screws. . At the same time, a tapping screw is inserted into the mounting hole 62 of the boss 61, and the tapping screw is tightened. Thereby, the inner cover body 31 is fixed to the casing 16.

Next, the outer cover body 32 is attached to the inner cover body 31. Specifically, as shown in FIG. 10A, the locking projection 37 is inserted into the first locking hole portion 50a.
At this time, the outer cover body 32 is in a state in which the rear portion 34 is inclined obliquely upward as shown by the solid line in FIG. This state is the first position. Next, the outer cover body 32 is
Is rotated to the second position indicated by the virtual line. At this time, the shaft portion 37a of the locking projection 37 moves from the first locking hole portion 50a to the second locking hole portion 50b. As a result, FIG.
As shown in (a), the holding portion 37b of the locking projection 37 contacts the peripheral portion of the second locking hole portion 50b, and the outer cover body 3
2 is locked to the inner cover body 31. In this state, the rear end of the outer cover body is
5, the outer cover body 32 is fixed at the second position. Thus, the chain case 3
0 can be fixed to the body frame.

It should be noted that even a normal non-electric bicycle can be directly fixed to the vehicle body frame using the same fixing bracket as described above.

(1) In the above embodiment, the electric assisted bicycle has been described. However, the present invention is applicable not only to the electric assisted bicycle but also to a non-electrically powered bicycle.

(2) In the above embodiment, both the inner cover 31 and the outer cover 32 are made of synthetic resin. However, both or one of the inner cover 31 and the outer cover 32 may be made of metal. Good.

(3) In the above embodiment, the boss 60 is formed on the inner cover body 31, but may be formed on the casing 16.

(4) In the above embodiment, the locking projection 37
Is directed to the center side of the insertion hole 35, but may be directed to the opposite outside. Further, the locking projection 37 is not limited to the L shape, and may be a T shape.

[0028]

As described above, according to the present invention, the following effects can be obtained.

(1) The inner cover body and the outer cover body are
Smaller than conventional chain cases. Therefore, the work of attaching the chain case becomes easy. Also, at the transportation stage, many components (the inner cover body and the outer cover body) can be packed in a small box, and the transportation cost can be reduced.

(2) If a plurality of types of inner and outer cover members having different materials, colors, and shapes are prepared, by appropriately selecting and combining them, the degree of freedom in design can be increased as compared with the conventional case. Can be expensive.

(3) When the size of the bicycle is different, only the outer cover needs to be changed, and the inner cover can be shared. Further, since the outer cover body is rotatably mounted on the inner cover body, if the fixed state of the outer cover body is slightly inclined, the outer cover body can be shared by changing the fixing bracket. It becomes possible.

(4) If a part of the chain case is damaged, it is conventionally necessary to replace the entire chain case. In the present invention, if one of the inner cover and the outer cover is damaged, only one of the inner cover and the outer cover is damaged. The replacement can be performed, and the cost can be reduced.

(5) Even if the inner cover body has a mounting hole,
It can be covered with the outer cover body. Therefore, the mounting hole is not exposed to the outside, and the appearance is improved.

[Brief description of the drawings]

FIG. 1 is a side view showing the overall configuration of a bicycle according to the present invention.

FIG. 2 is an exploded perspective view of the vicinity of a drive sprocket.

FIG. 3 is a plan view of the inner cover body 31;

FIG. 4 is a side view as viewed from an arrow A side in FIG. 3;

FIG. 5 is a sectional view taken along the line BB of FIG. 3;

FIG. 6 is a sectional view taken along the line CC of FIG. 3;

7 is a plan view of the outer cover body 32. FIG.

FIG. 8 is a perspective view of the outer cover body 32 as viewed from the back side.

9 is a cross-sectional view taken along the line DD in FIG. 7;

FIG. 10 is a cross-sectional view showing a state in which a locking projection 37 is fitted into a locking hole 50.

FIG. 11 is a view showing a rotating state of the outer cover body 32.

[Explanation of symbols]

 Reference Signs List 20: Chain 21: Drive sprocket 22: Crankshaft 30: Chain case 31: Inner cover body 32: Outer cover body 37: Locking protrusion 37a: Shaft portion of locking protrusion 37b: Nipping portion of locking protrusion 50: Locking Hole 50a: First locking hole portion 50b: Second locking hole portion

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[Procedure amendment]

[Submission date] April 17, 2000 (2004.1.
7)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Name of invention

[Correction method] Change

[Correction contents]

Patent application title: Bicycle chain case and bicycle with the same

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction contents]

[0001]

The present invention relates to a bicycle chain.
The present invention relates to a case and a bicycle provided with the case .

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction contents]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a bicycle which can be easily mounted and has a high degree of design freedom.
It is an object to provide a chain case for use and a bicycle provided with the same.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

[0005]

In order to achieve the above object, a bicycle chain case according to the present invention has a through hole through which a crankshaft is inserted, is fixed to a bicycle base frame, and includes a drive sprocket and at least the drive. an inner cover for covering the chain portion engaging the sprocket, with the front is attached to the inner cover body, the rear part Ru outer cover Toka Rana extending along the chain stay. Also, such a bicycle chain
Bicycles with cases are also included in the spirit of the present invention.
You.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction contents]

[0018] Figure 3 is a planar surface view of an inner cover body 31,
4 is a side view as viewed from the arrow A side in FIG. 3, FIG. 5 is a cross-sectional view taken along the line BB in FIG. 3, and FIG. 6 is a cross-sectional view taken along the line CC in FIG. Figure 7 is a planar surface view of the outer cover member 32, FIG. 8 is a perspective view from the back side of the outer cover member 32, FIG. 9 is a D-D arrow sectional view of Fig. The specific structure of the chain case 30 will be described with reference to FIGS. 3 to 9 and FIG. The outer cover body 32 has a front part 33 attached to the inner cover body 31, and a longitudinal rear part 34 connected to the front part 33 and extending rearward along the chain stay 15 above the chain stay 15. . The rear portion 34 also has a role of covering the upper chain 20.
A circular insertion hole 35 through which the crankshaft 22 is inserted is formed in the front portion 33. The left side surface in the traveling direction of the front part 33 (the surface on the side facing the inner cover body 31,
A ring-shaped convex portion 36 concentric with the insertion hole 35 is formed on the inner surface of the front portion 33). A plurality of the protrusions 36 are provided at equal intervals in the circumferential direction (3 in this embodiment).
) Are formed. The cross section of the locking projection 37 is L-shaped, and includes a shaft portion 37a and the shaft portion 37a.
Holding portion 3 extending from the end of the hole toward the center of insertion hole 35
7b. An insertion hole 39 is formed in the rear end of the rear portion 34, and a fixing bracket (not shown) in which the screw 40 is inserted through the insertion hole 39 and attached to the chain stay 15.
And the rear part 34 is fixed.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] Figure 3

[Correction method] Change

[Correction contents]

3 is a planar surface view of an inner cover body 31.

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] Fig. 7

[Correction method] Change

[Correction contents]

7 is a planar surface view of the outer cover 32.

Claims (5)

[Claims] An inner cover body having a through hole through which a crankshaft is inserted, the inner cover body being fixed to a base frame of a bicycle and covering a drive sprocket and at least a chain of a portion engaged with the drive sprocket; And a chain case comprising: an outer cover body attached to the inner cover body and having a rear portion extending along the chain stay; 2. The outer cover body according to claim 1, wherein the rear portion is rotatable between a first position in which the rear portion is inclined obliquely upward from the chain stay and a second position in which the rear portion extends along the chain stay. The bicycle according to claim 1, wherein the bicycle is mounted on an inner cover body. 3. An inner surface of a front portion of the outer cover body,
A locking projection having a shaft portion and a holding portion provided at a tip of the shaft portion is formed, and a first locking hole portion having a hole width through which the holding portion can be inserted is provided on the inner cover body. An arc-shaped locking hole formed of a second locking hole having a hole width which is continuous with the first locking hole and has a hole width through which the shaft portion can be inserted but the pinching portion cannot be inserted; At the first position, the locking projection is located at the first locking hole portion, and at the second position, the locking projection is located at the second locking hole portion, and a holding portion of the locking projection is provided. 3. The bicycle according to claim 2, wherein the bicycle is locked in the second locking hole. 4. A plurality of locking holes are formed around the through hole, a front portion of the outer cover body has an insertion hole through which the crankshaft is inserted, and the plurality of engagement holes are formed around the insertion hole. The bicycle according to claim 3, wherein a plurality of locking projections are formed corresponding to the stop holes. 5. A mounting hole is formed in the inner cover body, and the mounting hole is formed at a position where the mounting hole is covered by the outer cover body when the outer cover body rotates to the second position. The bicycle according to claim 2, wherein