JP2000202080A - Bat made of frp for baseball and softball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a bat having an extremely large impact resilience and durability by interposing a weak boundary layer(WBL), as a bonding inhibiting layer, between layers of FRP material forming a pad body. SOLUTION: A weak boundary layer(WBL) 6 is interposed between FRP layers 5, 5 forming a bat 1 made of FRP. The layer 6 is preferably disposed at a ball hitting portion of the bat 1, but it can be extended as far as a shaft part. One WBL layer 6 is disposed; however, two or more layers may be arranged. The layer 6 is formed by stacking a releasable film material 6A made, for example, of polyethylene and the like. Thus, flat rigidity can be made smaller by using the layers 6 to enhance a trampoline effect, and hence impact resilience can be improved to send a ball far away to a distance. By satisfying SG reference value of the FRP bat, required strength can be ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fiber reinforced plastic (hereinafter simply referred to as FRP) such as glass fiber reinforced plastic (hereinafter simply referred to as GFRP) or carbon fiber reinforced plastic (hereinafter simply referred to as CFRP).
Is abbreviated. ) Inside the bat made of material,
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a baseball or softball bat made of an FRP bat which can provide excellent rebound performance so that a ball can be hit far when hit by providing a weak boundary layer (WBL) layer.

[0002]

2. Description of the Related Art Conventional FRP for baseball or softball
In the case of a bat, the G
The types and directions of the fibers of the FRP material such as FRP and CFRP, the directions of use, and the method of use have been complicatedly combined, or the aluminum alloy and the FRP material have been combined.

[0003]

In the conventional method of merely changing the type and combination of the FRP materials,
In order to improve the resilience performance, the flat stiffness of the hitting portion of the bat is softened, and the flat strength itself, which affects the durability of the bat, has a disadvantage that the flatness itself is significantly weakened. Therefore, in order to maintain durability, resilience performance must be sacrificed, and as a result, resilience performance superior to that of an aluminum alloy metal bat cannot be exhibited.

In the method of combining an aluminum alloy and a FRP material, an aluminum alloy and an FRP material are used.
There is a drawback that the production method is difficult because of poor adhesiveness and adhesion to the film. Furthermore, even if the manufacturing method can be solved, the resilience performance and durability cannot be improved more than the aluminum alloy metal bat.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention uses an adhesion inhibiting layer between the layers of the FRP material forming the bat body in order to achieve a high level of resilience performance and durability. A certain week boundary rare (WB
By providing the layer L) intentionally, a bat excellent in resilience performance and durability can be produced.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is to insert a material having releasability or a film having the same effect between specific layers inside an FRP material forming an FRP bat body, or to apply a release agent. As a result, by consciously providing a weak boundary layer (WBL) layer, the flat rigidity is reduced and the trampoline effect that enhances the resilience performance of the ball is increased as compared with the conventional FRP bat without the WBL layer. In addition, it is possible to provide a high-performance FRP bat excellent in durability by preventing a decrease in flat strength related to durability.

[0007] In order to improve the resilience performance, it is desirable to provide a WBL layer between the layers inside the FRP material of the entire hitting portion.

Further, if resilience performance is important, it is effective to provide a plurality of WBL layers between layers inside the FRP material of the entire hitting portion.

However, from the viewpoint of durability, WBL
It is realistic that one layer is formed between layers inside the FRP material of the entire hitting portion.

Next, as a method of forming a WBL layer,
Although it depends on the method of forming the bat, for example, after winding a sheet-shaped prepreg around a mandrel, the prepreg is placed in a mold, and pressure is applied from inside the cylindrical prepreg to form a desired bat shape. After winding about half of the prepreg forming the front FRP layer, a heat-resistant polypropylene, polyester, polyurethane, silicone, a synthetic resin film material appropriately selected from tetrafluorocarbon or the like is overlaid and wound or Alternatively, a cylindrical film made of these materials may be covered.

Further, a prepreg is wound thereon and then subjected to internal pressure molding, so that a WB is formed between the FRP layers.
An L layer is formed.

In addition, resin transfer molding in which a mandrel is covered with a braided (bag) -shaped reinforcing fiber and placed in a mold, and an epoxy resin or a polyester resin serving as a matrix resin is injected into the mold and cured. In the molding method (RTM molding method), one layer of a cylindrical silicon film is placed on top of an inner layer blade,
Further, by covering the outer layer with a blade, a WBL layer is formed in order for the silicon film to exhibit a releasing effect.

In addition to the above-mentioned molding method, the above-mentioned method is used in the filament winding molding method, the resin injection molding molding method (RIM molding method), or the like, or by applying the above-mentioned method,
It is possible to form a WBL layer inside the P layer.

As described above, the present invention can be implemented in various FRP molding methods. As a method of forming a WBL layer, two or more film-like materials are laminated and laminated between the FRP layers. Alternatively, the method of embedding is preferable because it is simple, the effect is reliable, and the cost is low.

Further, when viewed in cross section, the position of the WBL layer with respect to the entire FRP layer
It is preferable to form the layer at a substantially central portion of the thickness of the layer because the balance between resilience performance and durability is excellent.

Table 1 shows specific data obtained by comparing the FRP bat according to the present invention with a conventionally known FRP bat and a metal bat.

[0017]

[Table 1]

As shown in Table 1, the bat hitting portion has WBL
The formation of the layer suppresses the flat rigidity, increases the so-called trampoline effect, and greatly improves the resilience performance for hitting the ball far away.

As for the strength related to durability, W
Despite the formation of the BL layer, it satisfies the SG reference value (the breaking load value of the FRP bat: 400 kgf),
Since there is no particular problem in terms of strength, it is possible to realize a bat which satisfies the strength standard and exhibits a rebound performance that is remarkably higher than that of the conventional product.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, an embodiment of the present invention will be described with reference to FIG.
A baseball or softball baseball or softball comprising a baseball or softball bat 1 made of an FRP material such as P, wherein a weak boundary layer (WBL) layer 6 is provided between the FRP layers 5. FRP bat 1 for use.

As shown in FIG. 2, it is desirable to provide a weak boundary layer (WBL) layer 6 on the hitting portion 2, but it is also possible to extend it to around the shaft portion 3.

Further, as shown in FIG. 3, only one weak boundary layer (WBL) layer 6 can be provided, and as shown in FIG. 4, two or more layers can be provided.

The weak boundary layer of the present invention (W
BL) As a material having a release effect on the layer 6, for example, a release film-like material 6A made of polyethylene, polypropylene, silicon, tetrafluorocarbon, or the like is laminated, wound, or covered with a cylindrical material. It can be formed by:

As another embodiment, the weak boundary layer (WBL) layer 6 can be formed by applying or spraying a silicone resin-based or fluorine resin-based release agent.

Referring to the drawings, an embodiment of the present invention will be described. In FIG.
An example in which the BL layer 6 is formed is shown. FIG. 3 shows an example in which the WBL layer 6 is formed at a position corresponding to substantially the center of the thickness of the FRP layer 5 in the bat cross-sectional view.

FIG. 4 shows an embodiment in which the WBL layer 6 is formed by stacking two releasable film-like materials 6A and interposing them in the FRP layer 5, as shown in FIG.

In the present invention, the structure of the fiber reinforced plastic material such as glass fiber reinforced plastic or carbon fiber reinforced plastic constituting the bat body is as follows.
Although various combinations are possible, Table 2 shows an example of lamination of the hitting portion in the FRP bat of the present invention.

[0028]

[Table 2] In addition, the symbol GF marked on the fiber type which is the item in the table
Represents glass fiber, CF represents carbon fiber, PP
The film indicates a polypropylene film.

In the present invention, the bat body may be constituted by an FRP bat having a hollow portion as described above, or not shown, but a core made of polyurethane, polyacrylonitrile or other foamed synthetic resin is used. May be an FRP bat having a solid portion interposed therebetween.

[0030]

The present invention is embodied in the form described above and has the following effects. W on bat hitting part
Since the flat layer rigidity is reduced by the formation of the BL layer, the so-called trampoline effect increases,
The resilience performance for flying the ball farther is greatly improved.

As for the strength related to durability, W
Despite the formation of the BL layer, it satisfies the SG reference value (the breaking load value of the FRP bat: 400 kgf),
Since there is no particular problem in strength, it is possible to realize a bat which satisfies the strength standard and exhibits a remarkably high resilience performance as compared with the conventional product.

[Brief description of the drawings]

FIG. 1 is a sectional perspective view of a main part of an FRP bat according to the present invention.

FIG. 2 is an explanatory view showing an intervening portion of a WBL layer in a hitting portion of an FRP bat according to the present invention.

FIG. 3 is an essential part cross-sectional view showing a cross section of an AA section, a BB section, and a CC section of FIG. 2 of the FRP bat according to the present invention.

FIG. 4 is an essential part cross-sectional view showing a cross section of an AA part, a BB part, and a CC part of FIG. 2 of the FRP bat in another embodiment according to the present invention;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 FRP bat 2 Hitting part 3 Shaft part 4 Grip part 5 FRP layer 6 WBL layer 6A Releasable film material 7 Hollow part

 ──────────────────────────────────────────────────の Continued on the front page F term (reference) 4F100 AD11A AD11C AG00A AG00C AK04 AK07 AK17B AK18 AK52B BA03 BA04 BA05 BA06 BA07 BA10A BA10C BA13 DA11 DG01A DG01C DH02A DH02C EH46 EH51 GB87 JK20B JL00

Claims (7)

[Claims] In a FRP bat for baseball or softball, wherein a bat body is made of a fiber reinforced plastic material such as glass fiber reinforced plastic or carbon fiber reinforced plastic, a weak boundary is formed between layers of the fiber reinforced plastic material. FR for baseball or softball, characterized by having a layer (WBL) layer
P bat. 2. The weak boundary layer (WB)
2. The layer (L) is provided on the hitting portion.
An FRP bat for baseball or softball as described. 3. The weak boundary layer (WB)
3. The FRP bat for baseball or softball according to claim 1, wherein only one layer is provided between the layers of the fiber reinforced plastic material. 4. The weak boundary layer (WB)
3. The baseball or softball FRP bat according to claim 1, wherein two or more layers L) are provided between layers of the fiber reinforced plastic material. 5. The weak boundary layer (WB)
5. The FRP bat for baseball or softball according to claim 1, wherein the layer (L) is made of a material having a releasing effect. 6. The weak boundary layer (WB)
The baseball or softball FRP bat according to claim 5, wherein the layer (L) is formed by laminating a film-like material. 7. The weak boundary layer (WB)
The FRP bat for baseball or softball according to claim 5, wherein the layer (L) is formed of a silicone resin-based or fluorine resin-based release agent.