JPS6121433A - Torsion bar - Google Patents

Abstract

PURPOSE:To prevent separation of a core material from a FRP layer to use a torsion bar repeatedly by disposing a FRP layer on the outer periphery of the core material to form a torsional portion body, providing metal fixing members on the end portions of the body, and specifying shearing stress of the core material. CONSTITUTION:A torsional portion body 1 is formed by winding a FRP layer 3 on the outside of a solid core material 2. Metal fixing members 5 fixed to both end portions of the above body 1 comprise an inner cylinder portion 5a and an outer cylinder portion 5b, where the end portion 3a of the FRP layer 3 is clamped between both portions 5a, 5b. In this case, the quality and shape of the core material 2 are set in such a manner that the shearing stress of the adhesive surface of the core material 2 that contacts the FRP layer 3 does not exceed 10kgf/mm.<2> under use conditions of a torsion bar. In this arrangement, even if the core material 2 and the fixing member 5 are not directly coupled to each other, separation at the interface between the core material 2 and the FRP layer 5 caused by repeated use can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a 1-1 section bar using FRP for the torsion part body.

[Technical background of the invention and its problems]

Torsion bars used in vehicle suspension systems, cab suspensions, springs for biasing trunk lids in trunk rooms, etc. are desired to be as light as possible from the perspective of reducing vehicle weight. Therefore, some attempts have been made to use FRP (fiber reinforced synthetic resin) for torsion bars. In the prior art by the present inventors, there are two methods: wrapping reinforcing fibers impregnated with matrix resin around the outer periphery of a metal core material, and removing the core material after molding to make the product, and another method leaving the core material as is and making the product. A method is being considered.

However, it is difficult to remove the core material after molding if the torsion bar is long or the shaft is not in a straight line. In addition, if the core material is left, the weight will increase, and the torsional rigidity (determined by the lateral rigidity and shape) of the metal core material is generally large (ζ), so it is difficult to attach it to one end of the torsion bar. If the core material and the core material are not integrated, peeling may occur at the interface between the core material and the FRP layer during repeated use, resulting in problems such as a decrease in the spring constant or wear of the FRP due to friction with the core material. It turned out that.

[Purpose of the invention]

The present invention was made based on the above circumstances, and its purpose is to provide a lightweight torsion bar that can withstand repeated use without causing peeling at the interface between the core material and the FRP layer. .

[Summary of the invention]

The gist of the present invention is to provide a torsion part main body which is formed by providing an FRP layer on the outer periphery of a core material and bonding the core material and the FRP layer using the resin of this FRP, and a structure in which the torsion part main body is constructed separately. and a metal attachment member fixed to the end of the torsion part main body, and the material and shape of the core material are such that the shear stress of the adhesive surface of the core material in contact with the FRP layer is such that the torsion bar is used. The torsion bar is characterized in that the torsion bar does not exceed 10Kgf/mm2 under certain conditions.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In FIG. 1, reference numeral 1 indicates the main body of the twisted portion. This twisted part main body 1 is made by wrapping an FRP layer 3 around the outside of a solid core material 2 and bonding them together. Furthermore, metal attachment members 5.5 are attached to both ends of the torsion section main body 1. Each mounting member 5, 5 has an inner cylinder part 5a and an outer cylinder part 5b, and these inner cylinder parts 5a
The end portion 3a of the FRP layer is sandwiched between the outer cylindrical portion 5b and the outer cylindrical portion 5b, and fixed by, for example, adhesive.

Note that fixing tools such as bolts and rivets may be used in combination to increase the fixing strength. Furthermore, for attachment, parts of the members 5, 5 may be made solid.

For the above-mentioned attachment, the member 5.5 is integrally formed with rotation preventing portions 6, 6 such as serrations or hexagonal holes. Then, one side of the rotation stopper 6.6 is placed on the torque transmission side.
In addition, the other is attached to the non-transmission side for use.

The above FRP layer 3 is made by hardening reinforcing fibers with a well-known matrix resin, and is attached to the core material 2 in an adhesive, uncured state.
Wrap it around and then harden it. Therefore, core material 2 and FRP layer 3
The matrix resin acts as an adhesive and is fixed to each other. The core material 2 may be made of a polymeric material such as hard urethane, or a suitable amount of filler for molding purposes.
Composite materials made of 7-trix polymer materials reinforced with fibers, etc., are suitable. The material, shape, etc. of the core material 2 are selected so that the shear stress τ on the outer surface of the core material 2 does not exceed 10 Kgf/mm<2> under the usage conditions of the product. According to experiments conducted by the present inventors, FR
When the resin component of P acts as an adhesive to bond the core material 2, the shear stress τ on the outer surface of the core material 2 is 10 K, regardless of the material of the core material 2! It has been found that when it exceeds i f /mm2, peeling occurs at the interface between the core material 2 and the FRP layer 3.

In general, regarding a solid core material: Rigidity against torsion (constant 4a) T: Torque φ: Torsion angle d: Outer diameter of the core material 2: Length of the core material G: Transverse elastic modulus τ: Cloth surface shear stress Then, k=T/φ=πda TG/321 and τ
-dGφ/22 holds true.

In the above equation, in order to reduce τ, d and G should be reduced and 2
However, since d and 2 are values that are rather influenced by the FRP layer 3, they cannot be determined solely by the core material 2. Further, the twist angle φ is determined by the usage conditions of the product. Therefore, what can be determined by the core material alone is G (transverse modulus of elasticity). In consideration of the above, the transverse elastic modulus and shape of the core material 2 shall be determined so that the shear stress τ under the usage conditions of the torsion bar does not exceed 1 (19 f/mm2).

Thus, according to this embodiment, even if the core material 2 and the mounting members 5, 5 are not directly connected to each other as shown in FIG. Therefore, problems such as a decrease in the spring constant and wear of the FRP layer 3 due to friction with the core material 2 can be prevented. In addition, since it can be used without removing the core material, there is no problem even if the torsion bar is long or the shaft is not in a straight line. It has sufficient strength against the member to which the bar is attached (usually metal) and can withstand wear and tear caused by repeated use. The torsion part main body 1 is made up of an FRP layer 3 and a core material 2 made of a polymeric material, and since both are made of materials with low specific gravity, it can be made sufficiently lightweight compared to a general metal torsion bar. Note that aluminum or other light metals may be used as the material of the core material 2.

Note that FIG. 3 shows an example in which the core material 2 is hollow, and FIG. 4 shows an example in which a hollow metal core frame 10 is embedded in the center of the core material 2.

〔Effect of the invention〕

As described above, according to the present invention, peeling at the interface between the core material and the FRP layer is prevented, allowing repeated use with the core material remaining.

[Brief explanation of the drawing]

FIG. 1 shows a torsion bar showing an embodiment of the present invention.
FIG. 2 is a sectional view of one end of the torsion bar in the same embodiment, and FIGS. 3 and 4 are sectional views showing other embodiments of the present invention. 1... Twisted part body, 2... Core material, 3... F R
P.H. 5...Installation is by parts.

Claims (1)

[Claims] A twisted part main body, which is formed by providing an FRP layer on the outer periphery of a core material and bonding the core material and the FRP layer using the resin of this FRP, and an end part of the twisted part main body, which is constructed separately from the twisted part main body. and a metal mounting member fixed to the
Further, the material and shape of the core material are such that the shear stress of the adhesive surface between the core material and the FRP layer in contact with the FRP layer does not exceed 10 Kgf/mm^2 under the usage conditions of the torsion bar. torsion bar.