JPS5953287A - Front fork pipe for two-wheel barrow - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a front fork pipe for two-wheeled vehicles, and particularly to a front fork pipe made of carbon fiber reinforced plastic (hereinafter referred to as CFRP).

(b) Prior Art The front fork of a two-wheeled vehicle consists of a fork pipe and a bottom case into which the fork pipe is slidably inserted, and conventionally, both of these have been made of steel.

On the other hand, CFRP, which is made by hardening and molding carbon fiber with thermosetting resin such as epoxy resin or polyester resin, has features such as high strength and elastic modulus, good vibration damping properties, and is lightweight. It is a material that is attracting attention as a component.

Therefore, although it has been put into practical use in the aircraft sector, where weight reduction has been a particular focus, it has not yet been put into practical use in vehicles, particularly passenger cars.

However, in recent years, there has been an increasing need to reduce the weight of passenger cars from the viewpoint of saving energy, and the application of CFRP as a lightweight structural member for automobiles is being considered.

(c) Problems to be solved by the invention Since conventional front fork pipes for two-wheeled vehicles are made of steel as described above, surface finishing such as machining, plating, and puff finishing can be easily performed. Although a product with good finishing accuracy can be produced, it has the disadvantage of being heavy due to the material it is made of.

Therefore, an object of the present invention is to provide a fork pipe made of CFRP that has rigidity, strength, and finishing accuracy equivalent to or higher than that of a steel fork pipe, and is also lightweight.

) Means for solving the above problems In order to solve the above problems and achieve the purpose of the invention,
In this invention, the fork pipe is made of CFRP, and a metal layer is provided on all or part of the outer surface of the fork pipe.

(e) Embodiment FIG. 1 shows a front fork in which a fork pipe 1 is coaxially fitted to a bottom case 2. The fork pipe 1 is fixed to the front part of the vehicle body, and the bottom case 2 is fixed to the axle of the front wheel. 1. Inside the front fork, a vehicle suspension spring 3, a piston 4, etc. are housed, and 2. buffering oil is sealed.

''-The fork pipe 1 is a pipe 5 made of CFRP with a metal layer 6 provided on the outer surface thereof. The CFRP that forms the above-mentioned pipe 5 is set to contain 80% or more of carbon fibers with a winding angle of 0 to 20 degrees with respect to the pipe axis direction, and has a high longitudinal elastic modulus (axial elastic modulus). There is.

Further, the metal layer 6 can be formed by a wet method such as a spray method or a wet plating method, or a dry method such as a metal spraying method, a vacuum evaporation method, a sputtering method, an ion blasting method, or a method of bonding a thin metal pipe. It is formed on all or part of the outer surface of the pipe 5 by, for example, the outer surface of the pipe 5.

(f) Experimental results By winding carbon fiber impregnated with epoxy resin so that the ratio of 15° helical winding to 90° winding (cylindrical winding) was 9:1, and hardening it, the inner diameter was 30°.
A CFRP pipe with an outer diameter of 41grn was manufactured. After that, the outer surface was machined and subjected to wet plating surface treatment, and then chrome plating was applied to the surface to form a metal layer, and a puff finish was applied to produce a fork pipe.

This fork pipe was about 50% lighter than a steel pipe with equivalent bending rigidity, and was also high in strength.

(g) Effects As described in ``2'', this invention makes fork pipes made of CFRP.
By making the fork pipe made of steel, it is possible to provide a fork pipe that has rigidity and strength equivalent to or greater than steel fork pipes, and is significantly lighter than steel fork pipes. It is also suitable for mass production because it can be made in large numbers from a long pipe.

Furthermore, by providing a metal layer on the outer surface, good finishing accuracy can be obtained, so that it can exhibit the same effects as those made of steel in sliding properties and oil sealing properties.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the front fork, and FIG. 2 is a partially enlarged sectional view of the fork pipe. 1...Fork pipe, 3...Bottom case, 5.
...CFRP pipe, 6...Metal layer Patent applicant Honda Motor Co., Ltd. Sumitomo Electric Industries Co., Ltd. Meisha Co., Ltd. Agent
Sickle 1) Letter 2 Figure 1 3-゛Figure 2

Claims (1)

[Claims] A front fork pipe for a two-wheeled vehicle comprising a carbon fiber reinforced plastic pipe with a metal layer provided on all or part of the outer surface.