JPS6040375B2 - Manufacturing method for fiber reinforced plastic springs - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing various springs such as coil springs, spiral springs, circular springs, and shaped springs using fiber reinforced plastic as a spring material.

Fiber-reinforced plastics are made by impregnating reinforcing fibers such as carbon fibers, aramid fibers, and glass fibers with thermosetting resins such as unsaturated polyester resins and epoxy resins, or thermoplastic resins such as polyamide resins. In addition to having high strength and elastic modulus, it is resistant to acid and alkaline corrosion, has high fatigue strength, and has good vibration damping properties and electrical insulation properties, and is suitable for various spring materials. Although it has advantages, on the other hand, there are various difficulties when manufacturing it into springs, so it has not been put into practical use at present.

In some cases, a method is known in which prepreg tape or the like is wrapped around a core metal to create a semi-hardened FRP rod, then this FRP rod is wrapped around the core metal, coiled, and then molded and hardened. However, in this forming method, the FRP rod is pressurized only by the winding force, so it may not be possible to apply sufficient pressure to the FRP rod, and if the coiling core is male, Disadvantages include the machining of female molds or the combination of molds, and especially when manufacturing with a pair of upper and lower molds, machining of molds for molding products with free-form surfaces such as coils is extremely difficult. There is. Also,
Conventionally, a patent application has been filed for a wet method in which fibers are arranged into a machine or pipe shape and then impregnated with resin and coiled.
Because the RP rod is not press-formed but simply heat-formed, the cross-sectional shape of the FRP rod after coiling may no longer be a perfect circle, or the FRP may contain air bubbles.
There are drawbacks such as the possibility that This invention was made to improve the above-mentioned situation, and its purpose is to be able to reliably manufacture springs made of FRP, as well as to facilitate mold machining and to achieve highly efficient manufacturing. The present invention aims to provide a method for manufacturing fiber-reinforced plastic springs that enables the production of fiber-reinforced plastic springs.

The present invention will be explained below with reference to embodiments shown in the drawings.

Semi-cured state (not yet hardened and moldable)
A fiber-reinforced plastic rod (FRP rod) 1 is used as a core metal 2a having a smooth surface as shown in Fig. 1 or a core having a spiral R groove matching the diameter of an FRP rod 1 as shown in Fig. 2. While the metal 2b is rotated by a driving device 3 such as a lathe, the FRP rod 1 is spirally coiled around the outer peripheral surface of the core metal 2, and both ends of the rod are fixed to the core metal 2 in some form,
This FRP rod 1 is housed in a pressure vessel 4 together with a core metal 2. Then, a fluid medium (air, water, oil, etc.) is sealed in the pressure vessel 4, and the pressure of this fluid medium causes the FRP shield 1 to
The material is uniformly pressurized and molded, and the fluid medium is heated to harden and molded into a predetermined shape. In addition, as a pressurizing method, the first method is to use FR in a semi-cured state.
There is a method in which a fluid medium having a temperature necessary to harden the P rod 1 is filled around the coiled FRP rod 1 and then pressure is applied, and a second method is in which a low temperature fluid medium is sealed in the pressure vessel 4. This fluid medium may be heated later, and in this case, considering the expansion of the fluid due to heating, the pressure of the fluid at the time of sealing may be low.

Furthermore, the material for the FRP coil spring is not limited to one made from a semi-cured prepreg sheet as bamboo material, but may also be one made by the Midori method. In addition, if micro vibrations such as ultrasonic vibrations are applied during pressure molding, air bubbles, etc. can be easily removed, so a product with high strength can be molded using a uniform material with a small bubble rate.

As described in detail above, this invention involves storing a spring material made of fiber-reinforced plastic coiled around a core metal in a predetermined shape in a pressure vessel, and then enclosing a fluid medium in the container. This is characterized in that the spring material is pressed and molded using pressure.

Therefore, since the spring material is pressurized and molded by the pressure of the fluid medium, the spring material made of fiber-reinforced plastic can be reliably pressurized and molded, and the pressurizing force is not biased and acts uniformly, so that the spring material Fiber-reinforced plastic springs can be manufactured reliably and efficiently without uneven thickness or cross-sectional shape, and in particular, it is possible to reliably manufacture springs with complex free-form surfaces, which have been difficult in the past. can. Moreover, since only one core metal is required as the mold, the mold can be manufactured easily and can be manufactured very efficiently. Furthermore, by applying micro-vibration to the fluid medium, the porosity can be kept low, and a spring made of a uniform material with low porosity can be manufactured.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIGS. 1 and 2 are plan views of different core metals, and FIG. 3 shows FRP on the core metal.
A schematic view of a state in which a rod is coiled, and FIG. 4 is an explanatory diagram of a state in which a coiled FRP rod is pressurized and heated. 1...Fiber-reinforced plastic comb, 2, 2a, 2
b...Each core metal, 3...Drive device for lathe, etc., 4
・・・・・・Pressure vessel. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. After winding a spring material made of fiber-reinforced plastic into a desired cor spring shape and storing it in a pressure vessel,
A method for manufacturing a fiber-reinforced plastic spring, characterized in that a fluid medium is sealed in the container, and the spring material is pressurized and molded by the pressure of the fluid medium. 2. After a spring material made of fiber-reinforced plastic is coiled around a core metal in a predetermined shape and housed in a pressure vessel, a fluid medium is sealed in the container, and the spring material is pressurized by the pressure of the fluid medium. A method for manufacturing a fiber-reinforced plastic spring, characterized by adding microvibrations to the fluid medium during molding.