JPH04164467A - Core material for ski board - Google Patents

Abstract

PURPOSE:To provide an optimum torsional rigidity while the weight of a core for ski board is suppressed, by constructing a fiber-reinforced plastic plate with a size and thickness sufficient for a ski reinforcing material. CONSTITUTION:A fiber-reinforced plastic plate 4 is used, which has as core a three-dimensional textile 3 consisting of a plate-shaped fabric 2 and a fabric 1 having undulate section or an X-parallel row section. If a lightweight plastics 6 is arranged in the cavity 5 of the core, or if fiber-reinforced plastic sheets 7 are arranged over and under the core, the torsional rigidity is still more enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a core material for skis made of a fiber-reinforced plastics composite using wavy and X-parallel fabrics.

[Conventional technology]

In general, methods for increasing the torsional rigidity of skis include: -Structural considerations such as making the core material a so-called sandwich structure or box structure.

■The core material is made of glass fiber, carbon fiber, duralumin, and other materials.

■When the core material is made of fibers, consideration should be given to improving the fiber orientation by making the orientation direction of the fibers biased, etc.

etc. are possible.

To illustrate this diagrammatically, for example, various experiments have been repeated to obtain appropriate torsional rigidity based on these known facts, and various core materials 21 for skis have been proposed.

[Problem to be solved by the invention]

(a) For example, in the case of the ski core material 21 made of wood or foamed urethane, although it provides high rigidity in the length direction of the ski, it cannot provide high rigidity in the width direction.

Therefore, a ski constructed of these core materials 21 has the disadvantage that even if it can obtain the desired bending rigidity, it cannot obtain the desired torsional rigidity.

In other words, skis with a certain degree of hardness can be obtained, but
On the other hand, the skis tend to twist easily.

(b) In addition, in order to compensate for the drawbacks shown in (a), skis that have achieved the desired torsional rigidity by placing sheets of duralumin or fiber-reinforced plastics above and below the core material are The mass becomes heavy, which not only impairs the glide performance during one turn when skiing, but also increases the cost due to the increase in the number of constituent materials.

(C) As shown in FIGS. 28 and 29, other skis include skis whose core material 21 is made of aluminum honeycomb material 22 or paper honeycomb material filled with foamed urethane 23; 26.27 As shown in Fig. 27, the ski core material 21 is made of foamed urethane 23 with glass fibers 24 arranged in the thickness direction, but the effect of preventing crushing is low considering the thickness during molding. However, there is a problem in that sufficient torsional rigidity cannot be obtained, so the method shown in (b) above is used to compensate for the lack of torsional rigidity.

-The reason that sufficient torsional rigidity cannot be obtained is that the wood 1 urethane foam does not have a fiber reinforced layer that contributes to torsional rigidity (for example, a fiber reinforced layer arranged diagonally, horizontally, or in the thickness direction). This is due to

To increase torsional rigidity, for example, duralumin is used, which generally increases the weight of the ski, but the present invention achieves optimal torsional rigidity while suppressing the weight of the ski core material. The technical problem is to provide a core material for skis that can be used in various ways.

[Means to solve the problem]

The present invention will now be described in detail with reference to the accompanying drawings.

A fiber-reinforced plastic plate 4 is formed using a three-dimensional woven fabric 3 consisting of a woven fabric 1 whose longitudinal cross-section in the longitudinal direction is wavy or X-parallel and a plate-shaped woven fabric 2 as a core material. This invention relates to a core material for a ski board characterized in that the base board 4 has the size and thickness as a ski reinforcing material.

Foamed urethane is used in the cavity 5 of the core material according to claim 1.

This relates to a core material for skis, which is characterized in that a lightweight plastic 6 such as foamed epoxy is integrally attached thereto.

A core material for a ski according to claim 1, characterized in that a fiber-reinforced plastic sheet 7 is disposed on the outside of the fiber-reinforced plastic board 4.

The ski core according to claim 1, characterized in that the thickness in the longitudinal direction of the fiber-reinforced plastic plate 4 is adapted to the change in the thickness in the longitudinal direction of the ski 8, so that it is formed thinner toward both ends. It is related to materials.

[For production]

The core material for skis according to the present invention can achieve optimal torsional rigidity compared to conventional core materials made of wood or urethane foam because the woven fabric 1 with a wavy or X-parallel cross-sectional shape and the plate-shaped woven fabric This is because a fiber-reinforced plastic board 4 is used with a three-dimensional woven fabric 3 consisting of 2 and 3 as a core material, and lightweight plastics 6 are placed in the void 5 of the core material, and fiber-reinforced plastics 6 are placed above and below the core material. When the plastic sheet 7 is provided, the torsional rigidity is further improved.

The inventors focused on the following points and arrived at the present invention.

b) Torsional rigidity is expressed by the following equation (1).

G X p = α XGXIp fist ・ ・
(1) Here, Ip = βxwxh' GIp: Torsional rigidity [kg/mmt1 α, β, γ: Constant G: Torsional modulus of material [kg/am”] (mechanical parameter of material) Ip: Cross section 2 of the material Subpolar moment [■4] (Shape parameter of material) W: Width of the material [-■koh: Height of the material [l-] From equation (1), in order to increase the torsional rigidity, the following It turns out that the points are important.

■Use highly rigid materials.

■Increase the range of materials.

■Increase the thickness of the material.

■Use light materials.

To be more specific, the torsional rigidity can be increased by providing a fiber-reinforced layer in the core material.

c) Torsional rigidity can also be increased by appropriately arranging the fibers used in the fiber-reinforced layer due to the anisotropy of the fiber-reinforced layer provided in the core material.

2) In addition, in a state where two fiber-reinforced layers arranged in the core material are arranged at a constant interval, that is, a so-called sandwich structure, the torsional rigidity increases as the interval increases.

e) Gliding properties when skiing When considering one-turn performance, the relationship between torsional rigidity and weight is also an important factor.

Within the somewhat limited volume of ski core material, the weight is determined by the density of the material. Furthermore, here,
Define a weight reduction parameter related to torsion called specific torsional stiffness.

Gvr=GIl)/ρ where Gwr: specific torsional stiffness ρ: greater than or equal to the density of the material It is possible to obtain a core material for skis that has a structure and configuration that brings out the characteristics of the fibers most effectively, and has the desired torsional rigidity.

Adding knowledge 2) to this, we find that ``ski core materials have fiber-reinforced layers on the top and bottom.
The larger the distance, the more the torsional rigidity improves. "That's what it means.

On the other hand, from the knowledge in e), ``If the core material for skis has the same torsional rigidity, a ski with a smaller density can provide a ski with better glide and one-turn performance.''

As shown in the prior art, in order to improve the torsional rigidity of the ski 8, a method is used in which sheets of fiber-reinforced plastic are placed above and below the core material. It will be distributed to This makes use of the characteristics of 口) and iii) shown above.

The present invention was previously shown by forming a three-dimensional woven fabric 3 consisting of a woven fabric l having a wavy or X-parallel cross-sectional shape and a plate-like woven fabric 2 into a three-dimensional shape with a height suitable for a core material. b)1
By utilizing the characteristics of (1) and (3), and placing lightweight plastics 6 in the void 5 of the core material, and placing fiber-reinforced plastic sheets 7 above and below the core material, it is possible to ), ha).

Utilizing the second characteristic, it is possible to obtain a ski with optimal torsional rigidity compared to conventional products.

Furthermore, while taking advantage of these features, we reduced the density by lowering the density to less than that of conventional products, and by utilizing the characteristics of The result was a ski with optimal rigidity, light weight, and excellent maneuverability.

That is, although the present invention has a sandwich structure, it is possible to obtain torsional rigidity comparable to that of a BOX structure.

〔Example〕

The drawings illustrate embodiments of the invention and will be described below.

Figures 1.2, 3, and 4.5 show the upper and lower sides of a woven fabric 1 (preferably made of inorganic fibers such as glass fiber or carbon fiber) having a wavy longitudinal section in the longitudinal direction of a ski 8. Woven fabric 2 (
It is desirable to use inorganic fibers such as glass fibers and carbon fibers. ) is woven to form a core material, and this core material is impregnated with a reinforcing resin to form a fiber reinforced plastics board 4.

In this case, other materials that can be used as the core material include the types shown in Figures 6 to 10, and other types that can be used as the fiber reinforced plastic board 4 include those shown in Figures 11 to 24
3.14.17.18, 20, 23.24 Figures show a type in which a fiber-reinforced plastic sheet 7 is laminated on a plate-like woven fabric 2).

15 to 24 show the case where the void 5 is filled with foamed urethane as the lightweight plastic 6.

In the figure, reference numeral 9 is an ABS) flat sheet, 10 is an edge-to-edge sheet (fiber-reinforced resin sheet such as glass fiber), 11 is a top edge, 12 is a bottom edge, and 1
3 is an ABS side seat, and code I4 is a sliding seat.

The higher the torsional rigidity of skis is required of skis for advanced skiers. If the desired torsional rigidity cannot be obtained even in the above embodiments, the edge-to-edge sheet 10 disposed outside the core material may be a bias fiber-reinforced plastic sheet with fibers disposed in the bias direction.

With such a structure and configuration, it is possible to achieve desired torsional rigidity.

The desired optimum twist can be achieved by variously setting the height of the woven fabric l of the core material, the interval between waves or Of course, a core material having rigidity can be obtained.

Further, the height of the wavy or X-parallel woven fabric l may be designed to vary depending on the thickness distribution with respect to the length of the ski core material. Section 1.2.3.

Figure 4.5 shows the case where this type is adopted, and Figure 25 shows the case where the height of the woven fabric l is kept constant without changing.

Incidentally, FIG. 30 shows comparison data between an example of the present invention (the core material shown in FIG. 1) and a conventional core material.

From FIG. 30, it can be clearly seen that the flexural modulus in the width direction of the ski core material according to the example is significantly higher than that of the conventional product.

〔Effect of the invention〕

Since the core material for skis according to the present invention is constructed as described above, it is possible to impart optimum torsional rigidity to skis compared to conventional core materials for skis, and it is also possible to provide skis with optimal torsional rigidity, and also to be made of lightweight plastics. By disposing the fiber-reinforced plastic sheet, it is possible to further improve the torsional rigidity and also to substantially reduce the weight, thereby making it possible to manufacture skis with excellent glide and rotation performance.

[Brief explanation of drawings]

Figure 1 is an explanatory cross-sectional view of a ski using the core material of the present invention, Figure 2 is an enlarged cross-sectional view of the main part in Figure 1, Figure 3 is a cross-sectional view taken along the line A-A in Figure 1, and Figure 4 is an explanatory cross-sectional view of a ski using the core material of the present invention. .6.7, III
, 9.10 is an explanatory diagram of three-dimensional woven fabric, 5゜11.12
,13,14,15.1B,17.1B,19,20,
Figures 21, 22, 23, and 24 are explanatory diagrams of the fiber-reinforced plastics board, Figure 25 is an explanatory side view of the core material falling sideways, and Figure 26 is an explanatory diagram of the fiber-reinforced plastic board.
．． 27 is an explanatory side view and an explanatory plan view of the conventional example, and No. 28
．． Figure 29 is an explanatory side view and an explanatory plan view of another conventional example, the third
FIG. 0 is a table showing comparative data between the present invention and the conventional example. 1... Woven fabric, 2... Plate woven fabric, 3... Three-dimensional woven fabric, 4
...Fiber-reinforced plastics plate, 5...Void portion, 6
...Lightweight plastics, 7.Fiber-reinforced plastic sheets, 8.Skis. October 27, 1990 Applicant: Ario Seisakusho Co., Ltd. Inventor: 1) Hirotoshi Naka, Masuo Aoyama, Agent, Akira Yoshii, Eipu b! 717 fake f sa15 7θ- ”N'2fstsu-7/6/ri3 ゛me7.a ”l)It)m puIIIJIJ tsuku seat it' ・puz6necessary 2? 7 boar i z? Su27n112θ4wa, l Da Procedural Amendment (Method) February 20, 1991 l Display of Case 1990 Patent Application No. 289084 2 Name of Invention Ski core material 3 Person making the amendment Case and Relationship Patent applicant Co., Ltd. Arisawa Seisakusho 4 Agent 5 Date of amendment order January 28, 1991 6 Subject of amendment Patent application in the "Brief explanation of drawings" column in the specification
No. 2-289084 Procedural Amendment Regarding the present application, the following portions of the specification are amended. Note 1, page 14, lines 1 to 2, 1, 2 is an enlarged cross-sectional view of the main part in Fig. 1,'' replaced with ``Fig. 2 is an enlarged cross-sectional view of the main part in Fig. 1,'' ” he corrected. February 20, 1991 Applicant Arisawa Seisakusho Co., Ltd. Agent Akie Yoshii

Claims (1)

[Scope of Claims] 1. A fiber-reinforced plastic board is formed using a three-dimensional woven fabric as a core material, which is composed of a woven fabric whose vertical cross section in the longitudinal direction of the ski is wavy or X-parallel, and a plate-like woven fabric, and this fiber A core material for skis characterized by a reinforced plastic board having the size and thickness required as a ski reinforcing material. 2. A core material for skis, characterized in that a lightweight plastic such as foamed urethane or foamed epoxy is integrally attached to the void portion of the core material according to claim 1. 3. The core material for a ski according to claim 1, further comprising a fiber-reinforced plastic sheet disposed on the outside of the fiber-reinforced plastic board. 4. A core material for a ski according to claim 1, wherein the thickness of the fiber-reinforced plastic plate in the longitudinal direction is made thinner toward both ends so as to adapt to changes in the thickness of the ski in the longitudinal direction. .