JPH01233101A - Disc wheel for bicycle - Google Patents

Abstract

PURPOSE:To improve the traveling performance, strength, etc. by installing a hub at the center part of a disc-shaped honeycomb core and fitting a rim which is shaped into an annular form by the plastic resin for fitting a tire, onto the outer peripheral part of a wheel body having surface plates on the both outer surfaces. CONSTITUTION:A disc wheel 1 consists of a wheel body 2 and a rim 6. In the wheel body 2, a hub 4 is installed at the center part of a disc-shaped honeycomb core 3 which forms a core member, and a disc-shaped surface plate 5 made of carbon fiber or others is installed onto each of the both outer surfaces of the honeycomb core 3. While, the rim 6 is formed into an annular form from the plastic resin material. In the rim 6, a tire installation part 7a which coincides with the sectional shape of a tire T is formed over the whole peripheral of the outer peripheral part. Further, in the inner peripheral part, an engaging projection part 7b which is engaged with a gap part 8 formed between the honeycomb core 3 and the both surface plates 5 is formed at the center part, and a pair of nipping pieces 7c which are opposed, keeping the interval equal to the thickness of the wheel body 2 are erected on the both sides of the engaging projection part 7b.

Description

[Detailed description of the invention] "Industrial application field" The present invention relates to a disc wheel for a bicycle.

More specifically, the present invention relates to a bicycle disc wheel having a disc-shaped wheel body mainly used for competitions.

``Prior art'', ``Problem to be solved by the invention'' Disc wheels for bicycles, especially competition bicycles, are designed to reduce air resistance during riding, reduce weight, etc. As shown in FIG. 4, a honeycomb core 33 is used as a core material instead of the conventional spoke, and the honeycomb core 33 and rim 36 are bonded together, and a surface plate 35 is attached to cover both outer surfaces. A disc wheel 31 made of the following has become quite popular in recent years.

However, the rim 36 of such a disc wheel 31 is generally made of a pipe material made of a light metal such as an aluminum alloy that is processed and formed into an annular shape for reasons such as strength.

Although such a rim 36 can achieve the purpose of reducing the weight of the disc wheel 31, the following problems have been pointed out.

In other words, the rim 36 made of pipe material such as aluminum alloy has poor workability and is almost impossible to form into a perfect circle with no errors. Therefore, the defect rate of the product is low. is high, and the cost l- becomes high. Further, even if the error is within the allowable range, the disc wheel 31 may not be able to move easily when the rim 36 is used.
It has been pointed out that rolling resistance is likely to occur, and as a result, rolling resistance is increased and running stability is also deteriorated, resulting in a reduction in running performance.

Secondly, due to poor workability, the corner portion 36a on the side where the honeycomb core 33 is attached is not a right angle but a curved surface, and there is a gap between the rim 36, the honeycomb core 33, and the surface plate 35. The space 37 was likely to occur. Therefore, due to the existence of this space 37, the adhesion area between the rim 36 and the top plate 35 is reduced, and the top plate 35 is easily bent at this portion when attached, and deformation of the recess 38 etc. often occurs. Ta. In the case of a disc wheel 31 in which the surface plate 35 in such a portion is deformed, stress will be concentrated on this portion of the surface plate 35 when subjected to an impact load, causing problems in terms of strength such as local damage. At the same time, it has been pointed out that the surface plate 35 has poor planar accuracy, which increases the air resistance of the disc wheel 31 during running.

In addition, some disc wheels are available that use rims that are not processed or molded from balsa wood, but although such rims can easily produce rims with excellent roundness, Even machetes had concerns about their strength, and it was pointed out that if they absorbed moisture, they would further reduce their strength and increase their weight.

Therefore, in order to eliminate the drawbacks of the conventional rims made of light metal pipe materials such as aluminum alloy or processed and molded balsa wood, foamed plastic materials, especially those with a high resin content, are used, as shown in Figure 5. A rim made of a so-called high-density urethane foam material has been provided.

In the disc wheel 41 using the foamed plastic material 46, by finishing the outer periphery by machining, for example, the disc wheel 41 with excellent roundness accuracy can be obtained. During driving, increases in rolling resistance caused by vibration are eliminated.

In addition, since the corner portion 46a on the attachment side to the honeycomb core 33 can be easily formed into a right-angled shape, no space is created between the rim 46, the honeycomb core 33, and the surface plate 35. Therefore, there will be no deformation such as a recess in the surface plate 35 in this area, and the disk wheel 41 can be easily formed due to its excellent planar accuracy. This does not occur, and it is excellent in terms of strength, and does not cause problems such as increased air resistance during running.

Furthermore, since the foamed plastic material does not have hygroscopic properties, problems such as a decrease in strength and an increase in weight due to moisture absorption do not occur.

However, the above-mentioned type of disc wheel 31.
41, the tire T is attached to the rim 36.46 by adhering the tire T to the rim 36.46 using adhesive A. Because the focus is on weight reduction, they are more prone to punctures than regular bicycle tires. Therefore, especially for road competition bicycles, it may be necessary to replace the tires T fairly frequently during competitions.

However, although foamed plastic materials are excellent in lightness and workability, they are brittle, so in the case of a disc wheel 41 using a rim 46 molded from a foamed plastic material, it is difficult to replace the tire T. At this time, the foamed plastic material near the tire mounting surface was easily peeled off along with the adhesive A, and the tire mounting surface was easily damaged, resulting in a problem with the durability of the rim 46. Moreover, since the mounting structure of the rim 46 is bonded to the inner circumferential surface of the rim 46 or to the honeycomb core 33 serving as the core material, and both sides of the rim 46 are bonded to the surface plate 35 together with the outer surface of the honeycomb core 33, the rim 46 can be easily attached to the rim. It is not possible to replace only the rim 46, so when the rim 46 is damaged, if the damage is minor, it is repaired with putty or the like. However, if repairs are made with putty or the like, the roundness of the rim 46 is likely to be damaged, and the center of gravity of the disc wheel 11 is biased, resulting in a loss of smooth rotation. The problem was still pointed out that if the disc cannot be repaired, it must be replaced every 6 = beer 41, which is expensive, which is extremely uneconomical.

The present invention was made in view of the above-mentioned circumstances, and its purpose is to provide a product with excellent strength such as impact resistance, excellent durability, and excellent circular accuracy and flatness accuracy. The purpose of the present invention is to propose a disc wheel that is easy to mold and has an annular rim molded from a plastic resin material that allows only the rim to be replaced. be.

"Means for Solving the Problems" The present invention has been made to achieve the above object, and the technical solution thereof is as follows. This bicycle disc wheel consists of a wheel body consisting of a disk-shaped honeycomb core as a core material, a hub attached to the center of this honeycomb core, and a surface plate that covers both outer surfaces of this honeycomb core. A rim formed into an annular shape made of plastic resin material for mounting a tire is fitted onto the outer periphery of the tire.

1. Effect” Since the rotating disc wheel according to the present invention is comprised of the above-mentioned means, it functions as follows. In other words, since this disc wheel uses a rim formed into an annular shape from a plastic resin material, the rim has excellent strength such as impact resistance, and is also excellent in durability. Since it is possible to easily mold a disc wheel with excellent roundness accuracy without requiring any processing, there is no need to mold the disc wheel by integral molding as in the conventional example, and it is possible to mold the wheel body separately. Therefore, it becomes easy to form a wheel body having excellent circular accuracy and flatness accuracy.

Furthermore, since the rim can be easily attached to the wheel body, the assembly of the disc wheel is also easy, and the assembled disc wheel has excellent roundness and flatness accuracy, so it is easy to install and is easy to assemble. Increases in air resistance due to poor flatness of the surface plate, etc., are completely prevented, resulting in excellent running stability and strength. Furthermore, only the rim can be easily replaced.

“Example j The present invention will be described below based on embodiments shown in the drawings.

First, an overview of bicycles will be explained.

FIG. 3 is a partially cutaway side view showing an example of a bicycle equipped with a disc wheel according to the present invention.

11 is a substantially inverted triangular frame;
A fork 12 is attached to the front part of the fork 1 so as to be freely rotatable in the horizontal direction, and a generally V-shaped stay 13 is fixed to the rear part. At the lower ends of these forks 12 and stays 13, disk wheels constituting front wheels and rear wheels, which will be described later, are respectively supported via hubs 4, and at the upper ends of the forks 12, handle posts 1
A bundle 15 is fixedly attached via 4.

A saddle 16 is attached to the upper rear end of the frame 11, and a gear crank 17 is pivotally supported at the lower end of the frame 11. And gear crank 17
A pedal 19 is attached to the tip of the crank 18, and a large-diameter gear plate 20 on the gear crank 17 and a small-diameter gear plate 21 fixed on the hub 4 of the disc wheel 1 constituting the rear wheel. An endless chain 22 that meshes with these gear plates 20 and 21 is installed between them.

In addition, T is the tire attached to disc wheel 1, 2
3 is an air valve.

The bicycle generally looks like this.

Next, the disc wheel 1 will be explained.

Figure 1 is a partially cutaway side view of the disc wheel showing the state in which tires are mounted, and Figure 2 is a side view of the disc wheel shown in Figure 1.
■It is a sectional view taken along the line.

The disc wheel 1 consists of a wheel body 2 and a rim 6. The wheel body 2 is a sandwich type as shown below. That is, 3 is a disk-shaped honeycomb core formed with a slightly smaller diameter than a surface plate 5 which will be described later and constitutes a core material, and a hub 4 is located in the center of this honeycomb core 3.
are attached to both outer surfaces of the honeycomb core 3, for example, a surface plate 5 formed into a disc shape of a predetermined diameter using carbon fiber or other composite material, or an adhesive (not shown) is attached to both outer surfaces of the honeycomb core 3. They are attached to each other via.

The rim 6 has an annular shape, and is provided with concave tire mounting portions 7a that match the cross-sectional shape of the tire T along the width direction of the entire outer periphery, and has tire mounting portions 7a formed on the inner periphery. is an engaging convex portion 7b that engages with a gap 8 formed between both surface plates 5 and the outer periphery of the honeycomb core 3 at the outer periphery of the wheel main body 2 along its width direction over its entire circumference. is formed in the center, and a pair of opposing clamping pieces 7C are erected on both sides of the engaging convex portion 7b at an interval equal to the thickness of the wheel body 2.

This rim 6 is formed by, for example, press-fitting a molten plastic resin into a mold, and in the embodiment, the annular rim 6 is divided into two parts, and two rim members each having a semicircular shape are formed. 7 constitutes a rim 6.

= 11- Then, the rim 6 is assembled to the wheel body 2 by placing the two rim members 7 in opposing positions and engaging the respective engagement protrusions 7b in the gap 8 of the wheel body 2. , the outer periphery of the wheel body 2 is held between a pair of clamping pieces 7C, and the clamping pieces 7C, the surface plate 5, and each other's rim member 7
It is fitted into the wheel body 2 by adhering the abutting end surfaces (seam portions) of the two through an adhesive (not shown).

Once this is done, attachment of the rim 6 to the wheel body 2 is extremely easy.

To attach the tire T to the disc wheel 1 that has been assembled in this way, the tire 'F fitted on the tire attachment part 7a of the rim 6 is attached to the tire attachment part 7a with adhesive A applied in advance to the tire attachment part 7a. It is attached by gluing.

The disc wheel 1 constituting the front wheel and the rear wheel configured as described above is connected to the shaft 4a of each hub 4 through the
They are rotatably attached to a fork 12 and a stay 13, respectively.

Regarding the plastic resin used to mold the rim 6,
For example, when using ABSW resin, ABS resin has excellent moldability, so it is possible to create a highly precise rim 6 with stable dimensions.
It is extremely easy to mold.

In addition, the rim 6 has the characteristic that there is no sudden change in strength such as impact resistance particularly in a wide temperature range from low to high temperatures, so that a strong rim 6 can be obtained.

The disc wheel 1 is like this.

Disc wheel 1 according to the present invention configured as described above
Since the rim 6 is formed by press-fitting a molten plastic resin such as ABS resin into a mold, the rim 6 has excellent strength and durability such as impact resistance. Furthermore, since the rim 6 is composed of two semicircular rim members 7 obtained by dividing the annular rim 6 into two, it is easy to obtain a rim member 7 with excellent roundness accuracy.
Since it is easy to attach to the wheel body 2, like the conventional example,
Since it is not necessary to integrally mold the disc wheel 1 and the wheel body 2 can be molded separately, it is easy to mold the wheel body 2 with excellent circular accuracy and planar accuracy.

Therefore, it is easy to assemble the disc wheel 1, and the assembled disc wheel 1 has excellent roundness and flatness accuracy. The increase in air resistance caused by poor performance is completely prevented, and it has excellent running stability and strength.

Furthermore, if the rim 6 is damaged, only the rim 6 can be replaced.

"Effects of the Invention" As detailed above, according to the bicycle disc wheel according to the present invention, the rim is molded into an annular shape from a plastic resin material and fitted into the wheel body, so the rim itself has impact resistance, etc. Not only does it have excellent strength and durability, but it is also easy to form disc wheels with excellent roundness and flatness, so it is low cost and has excellent running performance and strength. An excellent disc wheel with = 14 - is obtained. Furthermore, since only the rim can be replaced, it is highly economical, and the drawbacks of conventional disc wheels of this type are eliminated, and its effects are significant.

[Brief explanation of the drawing]

1 to 3 show embodiments of the present invention.
The figure is a partially cutaway side view of a disc wheel showing a state in which a tire is mounted, Figure 2 is a sectional view taken along the line ■-■ in Figure 1, and Figure 3 is a disc wheel according to the present invention. 1 is a partially cutaway side view showing an example of a bicycle equipped with a bicycle. FIGS. 4 and 5 are longitudinal sectional views of essential parts of a conventional disc wheel, respectively. 1... Disc wheel, 2... Wheel body, 3
...Honeycomb core, 4...Hub, 5...Surface plate,
6... Rim, 7... Rim member, 7a... Tire mounting portion, 7b... Engaging convex portion, 7c... Clamping piece, T...
·tire.

Claims (1)

[Claims] A plastic resin material for mounting a tire on the outer periphery of a wheel body that has a hub in the center of a honeycomb core that is a disk-shaped core material and has surface plates attached to both outer surfaces of the honeycomb core. A bicycle disc wheel characterized by being fitted with a ring-shaped rim.