Tubular fiber structure and fiber reinforced composite material

Abstract

A tubular fiber structure, which includes a tubular section and a flange section that is on at least one end of the tubular section and which is formed by shaping a wound fabric base material.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is a National Stage of International Application No. PCT / JP2013 / 078764, filed Oct. 24, 2013, claiming priority based on Japanese Patent Application No. 2012-261056, filed Nov. 29, 2012, the contents of all of which are incorporated herein by reference in their entirety.FIELD OF THE INVENTION[0002]The technology of the present disclosure relates to a tubular fiber structure and a fiber reinforced composite material that uses the tubular fiber structure as a reinforcement.BACKGROUND OF THE INVENTION[0003]A typical automobile includes bumpers secured to the front and rear of the vehicle body to absorb impact energy of a collision and protect the vehicle body and the vehicle occupants during a collision. A bumper needs to absorb, in an irreversible manner, the energy of the load that is produced when the automobile collides with an obstacle. There are structures that support the bumper with a substantially tubular energy abso...

AI Technical Summary

Benefits of technology

[0009]When applying the structure of patent document 1 to an energy absorption member, the coupling of the energy absorption member to the bumper beam 81 and the frame body 83 at the flanges simplifies the coupling structure. However, in the structure of patent document 1, the slits are cut into the two ends of the tube, which is formed by a three-axis braid texture, and the cut ends are bent to form the flanges. Thus, when using the structure of patent document 1 as a reinforcement for fiber-reinforced plastic to form the energy absorption member, cracks may form from the slits and lower the energy absorption efficiency. Further, when increasing the amount of the axial threads to counter compression in the three-axis braid texture, undulations (crimps) increase in the radial threads. This lowers the strength.

[0013]In this structure, the tubular fiber structure includes the flange that is shaped at the region of the end of the rolled fabric base material. Thus, the formation of cracks from the boundary of the flange and the tube is limited when forming a composite material. This differs from when cutting slits into the region at the end of a tubular braid texture. Further, the tubular fiber structure is entirely formed by a fabric base material. Thus, compared to when threads serving as reinforcement fibers of a tube are free, the threads may be laid out in an orderly manner when manufacturing a composite material. Accordingly, when the tubular fiber structure, which includes the flange, is used as a reinforcement for a tubular fiber reinforced composite material that can easily be coupled to another member, the necessary strength may be ensured.

Problems solved by technology

Thus, when using the structure of patent document 1 as a reinforcement for fiber-reinforced plastic to form the energy absorption member, cracks may form from the slits and lower the energy absorption efficiency.

This lowers the strength.

This results in a complicated manufacturing process.

Thus, when manufacturing a composite material, it is difficult to lay out the threads, and it is difficult to increase the strength.

Images