JP2002145163A - Bicycle frame with suspension - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bicycle frame with a suspension capable of ensuring necessary stroke and spring constant within a limited space while reducing the weight. SOLUTION: This bicycle frame with suspension is equipped with a shock absorber. The shock absorber is formed of laminated rubber or resin-made columnar elastic members and a rigid plate inserted between the both, and the end surface sides of both the elastic member are mounted on the frame with the rigid plate between. 4: shock absorber support plate; 5. chain stay; 6. rotating support bolt; 7. mounting bolt; 11. elastic member; 12. elastic member; 13. rigid plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle frame with a suspension which is small and lightweight and which can easily obtain necessary strokes and spring constants.

[0002]

2. Description of the Related Art As a shock absorbing method for a bicycle, a method in which a shock absorber is attached to a saddle portion or a front fork on a front wheel side is widely known. Have been proposed. For example, actual Kaihei 5
In the device disclosed in Japanese Patent Publication No. 94087, as shown in FIG. 4, a chain stay 21 is rotatable concentrically with a crankshaft portion 22, and a coil spring 23 is incorporated into a shock absorber.

[0003]

However, the use of a metal spring as a shock absorber not only increases the weight but also makes it difficult to install the metal spring in a limited space of the frame to obtain the necessary stroke and spring constant. . On the other hand, if rubber or resin elastic members are used instead of metal springs, weight reduction can be achieved, but there remains a problem that it is difficult to obtain necessary stroke and spring constant in a limited space.

[0004] That is, when a shock absorber of a bicycle is constituted only by an elastic member made of rubber or resin, there is a problem that the elastic member becomes large and cannot be attached to the frame in order to obtain a necessary stroke and spring constant. If the size is set to such an extent that it can be mounted, the stroke becomes short, or the spring constant becomes small, which causes a problem that it cannot withstand practical use.

The present invention is an improvement of such a conventional bicycle frame with a suspension, which is capable of securing a necessary stroke and spring constant in a limited space while reducing the weight. It is intended to provide a frame.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and its gist is a bicycle frame provided with a shock absorbing device, wherein the shock absorbing device is: With a suspension in which a columnar elastic member made of rubber or resin is laminated, and a rigid plate is inserted between layers, with the rigid plate being in the middle and the end surfaces of the elastic members at both ends attached to a frame. The present invention relates to a bicycle frame. That is, an elastic member is divided by a rigid plate, a spring constant is increased by thinning each elastic member in a compression direction, and a stroke is secured by connecting the elastic members in series.

Preferably, the cross-sectional area of the elastic member at the both ends at the rigid plate side is larger than the cross-sectional area at the end face side, and in particular, for a bicycle with a suspension in which the ridge line of the elastic member is an octagon. It concerns the frame. That is, by forming a shape diverging toward the rigid plate side, stress concentration at the joint between the rigid plate and the elastic member is reduced.

[0008] More preferably, the shock absorber is provided with a through hole, a mounting bolt is inserted into the through hole, and the tip is fastened to the frame, whereby the shock absorber is attached to the frame. The present invention relates to a bicycle frame with a suspension in which the through-hole has the same diameter as the mounting bolt at the tip end side of the mounting bolt and expands so as not to contact the head side. That is, the contact between the through-holes and the mounting bolts during compression is avoided to prevent the generation of noise. Here, the phrase “the through hole has the same diameter as the mounting bolt” does not mean that the through hole has the same physical diameter as the mounting bolt. It means that

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The bicycle frame according to the present invention is provided with a shock absorbing device. The shock absorbing device can be attached to each part of the frame such as a rear portion, a front portion, a front fork portion and a saddle portion. . Since the shock absorber is formed by laminating columnar elastic members made of rubber or resin, it has an advantage that it is lighter in weight than one using a metal spring. Here, the rubber or resin constituting the elastic member is not particularly limited, but is easily bonded to a rigid plate and the like, and is a rubber capable of easily controlling the material hardness to obtain a target spring constant. ,
Further, considering the use environment, it is preferable to use a material having excellent weather resistance, bending resistance, and the like.

The most significant feature of the present invention is that a rigid plate is inserted between the layers of the laminated elastic members, and the end surfaces of the elastic members at both ends are attached to the frame with the rigid plate being in the middle. That is, first, a columnar elastic member is divided by a rigid plate, and the length of each elastic member in the compression direction is shortened. Therefore, the spring constant can be increased by the shorter length. For example, when applied to a rear suspension, a high spring constant suitable for the rear suspension can be obtained with a size that can be attached to the chain stay near the crankshaft. Can be.

Further, when the length of each elastic member in the compression direction is shortened, the spring constant can be increased.
The stroke becomes small. Therefore, a second feature of the present invention is that the elastic members are arranged in series by laminating,
The required stroke can be secured.
Therefore, the stroke can be increased while increasing the spring constant. For example, when applied to a rear suspension,
It is large enough to be attached to the chain stay near the crankshaft, and can provide a sufficient stroke for the rear suspension.

The number of layers of the elastic members is not particularly limited, and may be a multilayer structure including not only two elastic members (one rigid plate) but also three elastic members (two rigid plates). It can also be determined appropriately according to the mounting position of the shock absorber. However, in consideration of productivity and economy, it is preferable to use two layers. Also, the mounting direction of the shock absorber is not particularly limited, and the shock absorber is arranged in a necessary direction in the frame, such as a vertical direction, a horizontal direction, or the like. However,
In either direction, the end faces of the elastic members at both ends are mounted on a frame with the rigid plate being in the middle, so that the elastic members are connected in series in the displacement direction via the rigid plates.

Here, the shape of the elastic member is not particularly limited as long as it has a columnar cross section and a vertical cross section. In the case of the elastic members at both ends, the cross-sectional area of the rigid plate side is reduced by the end surface side. It is preferable that the shape is larger than the cross-sectional area (the longitudinal section is substantially trapezoidal). With such a shape, the repulsive load becomes 2 as the elastic member is compressed.
This is because it increases in the shape of the following curve, and preferable characteristics as a shock absorber can be obtained. In particular, if the ridgeline of the elastic member is formed in an eight-letter shape, the angle of the fixed portion with the rigid plate becomes small, so that even if the ridgeline expands due to compression, stress concentration does not occur at the fixed portion and peeling can be prevented.

In the case where three or more layers are laminated, the ridge line of the elastic member at the intermediate portion of the rigid plate is preferably formed so that the angle between the rigid plate fixing portions on both sides becomes small. Is preferably circular rather than square, because if there is a corner, stress concentration occurs at that part.

Next, a method of mounting the shock absorber will be described.
As long as it does not fall off or shift, for example,
A through hole can be provided in the shock absorber, and a mounting bolt can be inserted into the through hole to fasten the end to the frame for mounting. That is, the head of the mounting bolt prevents the shock absorber from coming off, but the elastic member is made compressible.

In this case, when the through hole of the elastic member expands inward due to the compression and is rubbed with the mounting bolt, abnormal noise is generated on the mounting bolt head side where displacement is large. In particular, when the present invention is applied to a rear suspension in which a chain stay rotates around the crankshaft portion, an angle difference is generated between the center axis of the through hole and the center axis of the mounting bolt due to compression, and the mounting bolt head is The through holes and the mounting bolts are additionally rubbed on the part side, and become a noise source.

Therefore, the diameter of the mounting bolt at the tip end side is substantially the same as that of the mounting bolt, but it is preferable to enlarge the through hole so as not to make contact at the head side. That is, the tip side of the mounting bolt having a small displacement is brought into contact with the mounting bolt to prevent displacement of the shock absorber, and the head side of the mounting bolt having a large displacement is not brought into contact with the mounting bolt to prevent generation of abnormal noise. It is.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing an example of a bicycle frame with a suspension according to the present invention, which is applied to a rear suspension. That is, the main pipe 1
Has a head pipe 2 welded to one end and a vertical pipe 3 welded to the other end. A shock absorber support plate 4 is welded on an extension of the main pipe 1, and a chain stay 5 is rotatably attached to a lower portion of the vertical pipe 3 by a rotation support bolt 6.

As shown in FIG. 2 in an enlarged manner, a shock absorber 10 is attached to the shock absorber support plate 4 by mounting bolts 7 and serves as a cushion against the vertical movement of the chain stay 5. In addition, the mounting position of the shock absorber 10 is set such that the distance from the center axis of the rotation supporting bolt 6 which is the center of rotation of the chain stay 5 to the center axis of the rear wheel is L1, taking into consideration the space and moderate cushioning property. The distance from the center axis of the bolt 6 to the center axis of the shock absorber 10 is represented by L2.
It is preferable that L1: L2 = 4: 1. Further, since the positional relationship between the head of the mounting bolt 7 and the chain stay 5 changes as the chain stay 5 moves up and down, the chain stay 5 is provided with a long hole 5A so as not to interfere with each other.

FIG. 3 is a view showing a shock absorber used for the bicycle frame of the example shown in FIG. 1, wherein FIG. 3 (A) is a side view and FIG. 3 (B) is a partial sectional view. As shown in FIG. 3, the shock absorber is configured by stacking columnar elastic members 11 and 12 and inserting a rigid plate (aluminum plate) 13 between the layers. Here, the ridgeline of the elastic member 11 changes from an end face 11A to a bonding portion with the rigid plate 13 in an octagonal shape. In addition, R is attached at the bonding portion with the rigid plate 13 in order to prevent peeling.

The elastic members 12 also have the same shape, and are arranged vertically symmetrically with the rigid plate 13 in between. Therefore, the overall height of the shock absorber is approximately twice that of the elastic member. In addition, since the ridgeline changes in an eight-character shape, the rebound load increases in a quadratic curve with the compression.

Further, a through hole 14 for inserting a mounting bolt is provided in the shock absorber. The diameter of this through hole 14 is
The elastic member 11 has substantially the same diameter as the mounting bolt on the end face 11A side, and is positioned when mounted on the frame. On the other hand, the diameter of the elastic member 12 is large, and a gap is formed between the elastic member 12 and the mounting bolt in the initial state.
Therefore, even if an angle difference occurs between the central axis of the through hole and the central axis of the mounting bolt due to the compression, it is possible to avoid the rubbing of the elastic member 12 near the end surface 12A, and to generate abnormal noise. Will not occur.

[0023]

According to the present invention, the shock absorber of the bicycle frame is formed by laminating a columnar elastic member made of rubber or resin and inserting a rigid plate between layers.
The required stroke and spring constant can be ensured in a limited space while reducing the weight. In addition, if the elastic member is formed to have a shape diverging toward the rigid plate, stress concentration at the bonding portion between the elastic member and the rigid plate can be reduced. Furthermore, if the through holes for inserting the mounting bolts are enlarged so as not to come into contact with the mounting bolts, generation of abnormal noise due to rubbing with the elastic member can be prevented.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of a bicycle frame with a suspension according to the present invention.

FIG. 2 is an enlarged side view showing a periphery of a shock absorber.

FIG. 3 is a view showing a shock absorber used for the bicycle frame of the example shown in FIG. 1;

FIG. 4 is a side view showing a conventional bicycle frame with suspension.

[Explanation of symbols]

 Reference Signs List 1 1 Main pipe 2 Head pipe 3 Vertical pipe 4 Shock absorber support plate 5 Chain stay 5 A Slot 6 Rotation support bolt 7 Mounting bolt 10 Shock absorber 11 Elastic member 11 A End face 12 Elastic member 12 A ‥ End face 13 ‥ Rigid plate 14 ‥ Through hole 21 ‥ Chain stay 22 ‥ Crankshaft 23 ‥ Coil spring

Claims (4)

[Claims] 1. A bicycle frame provided with a shock absorbing device, wherein the shock absorbing device is formed by laminating a columnar elastic member made of rubber or resin and inserting a rigid plate between layers. A bicycle frame with a suspension, wherein the end faces of the elastic members at both ends are attached to the frame with the rigid plate in between. 2. The bicycle frame with a suspension according to claim 1, wherein the cross-sectional area of the elastic member at the both ends at the rigid plate side is larger than the cross-sectional area at the end face side. 3. A ridge line of an elastic member at both ends,
The bicycle frame with a suspension according to claim 2, wherein the bicycle frame is shaped like an octagon. 4. A bicycle frame in which a shock absorber is attached to a frame by providing a through hole in the shock absorber, inserting a mounting bolt into the through hole, and fastening a tip to the frame. The bicycle with a suspension according to any one of claims 1 to 3, wherein the bicycle has the same diameter as the mounting bolt at the tip end side of the mounting bolt and is enlarged so as not to contact the head side. For frames.