JPH0778286B2 - Lightweight helmet cap manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to impact resistance and light weight for protecting the safety of a driver of a high-speed body such as a motorcycle, an automobile, an aircraft, and a high-speed boat and passengers in the event of an accident. About excellent Helmet.

(Prior Art) A helmet is a simple helmet with low impact resistance, which is used for a vehicle that has a relatively low impact and a small impact during an accident, and a vehicle that moves at a high speed has a very large impact during an accident. There are helmets having a high impact resistance used for various purposes, and there are also those used for various purposes such as sports, military, and construction and earthworks.

The present invention mainly relates to a light weight and high impact resistance helmet that protects the head of a person riding a vehicle moving at high speed.

Conventionally, the Hermet used for this purpose mainly uses an unsaturated polyester resin as a matrix, and uses a mat in which glass fibers are laminated in the outermost layer and the innermost layer, and several roving cloths composed of high modulus fibers are laminated in the intermediate layer. It is generally made by pressing and heat curing. The finished product, which is made by applying this method, is coated with cushion material, fittings, etc.
It weighs more than g, and there has been a strong demand for weight reduction due to the problem of physical fatigue during long-term use.

(Problems to be Solved by the Invention) In order to achieve this weight reduction, it is indispensable to reduce the weight of the cap body, and various studies such as reduction of the amount of reinforcing material or resin and change of material have been made. However, the decrease in the amount of roving cloth and the amount of resin causes performance deterioration such as drop impact resistance and penetrating weight, and in order to prevent performance deterioration, it is necessary to make the roving cloth material significantly stronger and more modular. Since it is a large cost up, it cannot be a realistic improvement measure, which has been a long-standing problem in the industry.

The present invention provides a fundamental improvement to a conventional manufacturing method using a roving cloth to achieve satisfactory performance and cost, and to achieve an epoch-making weight reduction.

(Means for Solving the Problem) The present inventor has conducted a research on the relationship between the reinforcing material structure of the FRP plate and the falling ball impact property, and found a very interesting phenomenon. That is, when an FRP plate with the same thickness is made, a roving cloth of the same weight, the same area made with fibers of the same type, the same thickness, and the same performance as the structure of the reinforcing material, and the monofilament uniformly dispersed laminated mat ( FRP with non-woven mats)
Comparing the performance of the plates, the roving cloth reinforced FRP plate shows higher values in bending strength and bending rigidity, but the non-woven mat reinforced FRP plate shows much higher values in bending fracture deformation amount and falling ball impact resistance. Found out to show. This phenomenon can be effectively utilized in various fields of use of FRP (Japanese Patent Application No. 62-213838).

The present inventor has conducted research to apply this knowledge to hermet.

The method of the present invention is generally applied to a bag molding method. For the molding, a lower hemispherical, medium-thick cylindrical outer shell mold in which the crown of the Helmet is the lowermost part of the molding mold and the neck is the uppermost part is used, and the uppermost part of the mold that hits the neck hits the head. The press die on the inner shell side cannot be inserted because the cross section is narrower than the center of the die. Therefore, the pressing from the inner shell side is performed by the expansion of the balloon inserted from the top. A glass mat is placed on the entire inner surface of the outer shell mold, a roving cloth made of organic synthetic fiber is placed in the middle layer, and the glass mat is placed in the innermost layer, and then a required amount of resin is poured. Next, the bag in the deflated state is inserted from the opening corresponding to the neck of the Hermet neck at the top of the mold, and air is forced into the bag to expand (pressure 3 to 6 kg / cm ² ). The resin liquid accumulated at the bottom of the mold is pressed by the expanding bag and penetrates into the reinforcing material layer, and is further pushed up to penetrate into the entire surface of the hermetic reinforcing material layer. In this state, the mold is heated (100-150 ℃ x 10-20 minutes),
The resin is cured by the curing agent added to the resin in advance. When the curing is completed, the bag is deflated and pulled out from the mold, the outer shell mold is removed, and the hermet cap body is taken out.

The present inventor has made a hermet with a non-woven mat having various thicknesses and densities in which the roving cloth of the intermediate layer has been changed in various ways, such as weight, drop impact resistance, and drop weight penetration. We have conducted experiments on Hermet's performance and molding processability to pursue the possibility of weight reduction and performance improvement of Hermet, and provide Hermet with sufficient performance for amazing weight reduction that was considered impossible in the industry. I succeeded in doing so.

That is, the present invention, impregnating a curable resin in the fiber reinforcement,
When producing a Hermet cap body by molding and curing, a thickness of 1 to 30 denier as at least a part of the reinforcing material, a weight per unit area of 50 to 500 g / m ² and an organic synthetic single fiber of 100 g / denier or more, and a density of 0.015 A method for producing a lightweight hermetic cap body, which comprises using non-woven mats of up to 0.08 g / cm ^{3 in} a single layer or in multiple layers.

The monofilament referred to in the present invention means a state in which the fibers are not bundled and are substantially separated as individual fibers to form a non-woven mat.

Although unsaturated polyester resin is most suitable as the thermosetting resin, resins such as epoxy resin, phenol resin, melamine resin and urea resin may be used.

The non-woven mat used for the reinforcing material is composed of single fibers of organic synthetic fibers, and has a structure in which the fibers are uniformly dispersed / laminated mainly in a state of short fibers or long fibers. Further, the individual fibers may be combined to form a sheet by a method of entwining fibers such as needle punching or hydroentanglement, or by a suitable resin, and these are also included in the non-woven mat referred to in the present invention. It is what is done.

The non-woven mat is produced by a card web, a uniform shake in the width direction (method used for producing SMC), a suction laminating method (fibers are dispersed in air and suction laminated on a moving succession net). Any method may be used as long as it is a method of uniformly dispersing / stacking monofilaments in a plane, such as a method) and a wet papermaking method. Also, mats in which the monofilaments are not bonded to each other may be used. Among them, a non-woven mat obtained by needle punching a card web in which monofilaments are uniformly dispersed and sheet elongation is appropriate is excellent in handleability during production, resin impregnation property and the like.

The fibers used for the non-woven mat are polyvinyl alcohol fiber, polyethylene terephthalate fiber, polyamide fiber, polyacrylonitrile fiber, polypropylene fiber, polyethylene fiber, aramid fiber, polyarylate fiber, ultra high strength polyethylene. It has a performance of 100 g / denier or more of a module selected from organic synthetic fibers such as fibers, and a thickness of 1 to 30 denier that is not substantially affected by strength deterioration due to the temperature (100 to 150 ° C) during Hermet molding. Fibers are suitable. In particular, polyvinyl alcohol fiber (vinylon) is very suitable in terms of specific modulus, cost per unit, resin affinity, heat resistance and the like.

When the modulus of the fiber is 100 g / denier or less, the reinforcing effect is small and the drop impact resistance as a helmet is low, so the reinforcing layer becomes thick and the weight cannot be reduced. Desirably 150g /
You need a module more than denier. Fiber thickness is 1.
If the fiber has a denier of 0 denier or less, the fiber surface area is large and the amount of liquid retained by the resin is very large, resulting in a large weight of the hermet. Further, if fibers having a denier of 30 denier or more are used, it is very difficult to handle at the time of molding because the thickness and bending hardness of the non-woven mat become large unless the amount of fibers is sufficient to obtain sufficient drop impact resistance.

As the structure of the non-woven mat, when the basis weight is 50 g / m ² or less, the amount of fibers is small and the influence of the basis weight is large, and the number of laminated layers is very large, which is troublesome in manufacturing. If the density is 500 g / m ² or more, the thickness will be extremely large if a proper density is adopted, and the amount of resin impregnated will be large, which will increase the weight of the hermet and be difficult to handle.

If the density of the non-woven mat is 0.015 g / cm ³ or less, the amount of resin absorbed is large, and even if the bag is pressed, the resin does not fill the whole area, and the resin is not impregnated on the upper part of the mold, resulting in a "blurred" portion and poor appearance. . In order to prevent "blurring", it is necessary to increase the amount of resin, which causes a significant increase in the weight of the helmet. When the density is 0.08 g / cm ³ or more, the liquid retention is small and the appearance is good, but the drop impact resistance and drop weight penetration resistance are poor, and if the number of laminated nonwoven mats is increased to improve, The weight increases.

The density of the non-woven mat is the average weight of 10 samples of 30 cm × 30 cm and the average value of the thickness of 5 points in one sample, and the average value of 10 sheets is calculated to obtain the average weight (g / g cm ² ) /
The average thickness (cm) is the average density (g / cm ³ ).

The thickness is measured by using a 6 cm × 6 cm compressor under a pressure of 5 g / cm ² by using a Pekotko thickness gauge.

In the Hermet of the present invention, it goes without saying that the non-woven mat may be used as a reinforcing layer by itself, but the non-woven mat made of fibers having a modulus of 100 to 400 g / denier, and 400 g / denier or higher. A non-woven mat or woven cloth (roving cloth) made of modular fibers may be laminated and used. In particular, the outermost layer of the helmet is polished during the finishing process, so that the glass fiber, which breaks the fiber, is finished more beautifully.

Example Using the reinforcing material shown in Table 1, the resin shown in Table 1 was used as the matrix resin, and a hermetic hat body was manufactured by the bag molding method. The performance of the obtained cap body was measured.
The results are shown in Table 1.

As is clear from this result, it is understood that the Hermet obtained by the method of the present invention can be remarkably reduced in weight as compared with the conventional one and can greatly contribute to the industry.

Claims (1)

[Claims] 1. When manufacturing a hermet cap body by impregnating a fiber-reinforced material with a thermosetting resin and molding and hardening it, at least a part of the reinforcing material has a thickness of 1 to 30 denier and a modular 100 g / denier. A method for producing a lightweight hermet hat body characterized by using a non-woven mat having a basis weight of 50 to 500 g / m ² and a density of 0.015 to 0.08 g / cm ^{3 made} of the above organic synthetic single fibers in a single layer or a plurality of layers. .