JPH06182010A - Frp bat - Google Patents

Abstract

PURPOSE:To improve an FRP bat (bat made of a fiber reinforced plastic) used in baseball and softball by preventing the peculiar numbness and clatter of hands generated in hitting a ball with the FRP bat. CONSTITUTION:To prevent the numbness and clatter of hands in hitting a ball with the FRP-made bat 1, the bending rigidity of a grip part 3 in a position spaced by about 30cm from a grip end 2 of the FRP-made bat 1 is set to at least 10X10<5>Kg/cm<2>. For that end, the thickness of the FRP layer 6 in the grip part 3 is formed thicker than the thickness of the part extending from a shaft part 4 to a ball hitting part 5 or the FRP layer 6 is formed with a reinforcing part 9 having a cross-like shape, straight line-shape, multifillet-like shape or the like in the FRP made bat.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a fiber reinforced plastic bat (hereinafter referred to simply as "F") used for baseball and softball.
It is abbreviated as RP bat).

[0002]

BACKGROUND ART Conventionally, wooden bats, metal bats, FRPs have been used as bats for baseball and softball.
Bat and the like are known. Currently, metal bats are predominant in amateur baseball and softball, but as a recent trend, there is a movement to globally approve FRP bats. As the FRP bat, a metal mandrel, a foam synthetic resin core material or a low melting point alloy mandrel is used as a core material at the time of molding, and is made of glass fiber or carbon fiber impregnated with a matrix resin. Filament made of glass fiber or carbon fiber, which is obtained by winding a filament, cloth, sleeve, etc., and heating and curing with a mold, or by using a tube or the like and impregnating it with a matrix resin. Or a cloth, a sleeve, etc. are wound, and the tube is expanded in a mold and heated under pressure to be cured, or a mandrel or core material is wrapped with a filament, cloth, sleeve, etc. made of glass fiber, carbon fiber, etc. A reaction that puts it on the mold and injects and cures the matrix resin.
Injection molding (RIM molding) and the like are known.

[0003]

These conventionally known FRP bats have the following problems. That is, as compared with metal bats, FRP bats currently on the market have many complaints that the hand is numb or hits the hand when hit.

Then, the present inventors investigated the numbness of the hands when hitting each bat by a sensory test, and found that numbness was present in the order of metal <FRP <wood. That is, when the ball is hit, the natural frequency of the bat is 1st vibration, 2nd vibration, 3rd vibration ...
From the next on, high-order vibrations will overlap and start to vibrate,
It affects the numbness and sound of the hands. Among them, the present inventors have found that numbness and reverberation of the hand and the primary vibration have the highest correlation. That is, it was found that the higher the natural frequency of the primary vibration is and the lower the vibration level is, the less numbness and reverberation of the hand. As a specific example, the natural frequency of the primary vibration of each bat is shown in Table 1, and the data of the vibration level measured by a fast Fourier transformer (FFT analyzer) are shown in FIG. 1 as the transfer function of each bat.

[Table 1] 65 cm from the grip end, as is clear from FIG.
The sweet spot corresponding to the position of indicates that the transfer function is small, while 50c from the grip end.
In the part corresponding to the position of m, the transfer function is large and the hand resonates and the hand is easily numbed. As is clear from Table 1, when viewed from the natural frequencies of the primary vibrations of various bats, the order is FRP>metal> wood, while the graph of the transfer function in FIG. 1 shows that FRP>wood> metal. However, these numerical values are intricately intertwined with each other, and from the actual sensory test, the result is that the hands are less likely to get numb in the order of metal <FRP <wood as described above.

[0005]

SUMMARY OF THE INVENTION In view of these drawbacks of the prior art, the present invention is intended to increase the primary natural frequency of the bat and lower the vibration level thereof in order to suppress numbness and vibration of the hand. In order to perform the most efficient design, modal analysis and sensitivity analysis were performed on the FRP bat to collect data. The results are shown in FIGS. 2 (A) and 2 (B). From this result, it was found that the rigidity of the grip portion from the grip end to about 30 cm greatly affects the numbness and sound of the hand. Therefore, by focusing on the fact that by increasing the rigidity of this part, the primary natural frequency can be efficiently increased and the vibration level can be lowered to prevent numbness and reverberation of the hand when hit. is there.

That is, in the FRP bat of the present invention, in order to prevent numbness and reverberation of the hand at the time of hitting, the bending rigidity of the grip portion corresponding to the position up to about 30 cm from the grip end is intentionally made substantially. 10 × 10 ⁵ Kg / cm ²
The FRP bat is characterized by being set as described above. In order to increase the rigidity of the portion approximately 30 cm from the grip end, there are a method of increasing the bending elastic modulus of the material used for that portion and a method of increasing the second moment of area of that portion. As a means for that, the F of the present invention is used.
In the RP bat, the bending rigidity of the grip part is increased by forming the FRP layer of the grip part corresponding to the position up to about 30 cm from the grip end to be thicker than the thickness of the part continuous from the hitting part to the shaft part. , Approximately 10 × 10 ⁵
It is set so as to be Kg / cm ² or more.

Further, as the FRP bat of the present invention,
The bending rigidity of the grip portion is approximately 10 × 10 ⁵ Kg / by forming a reinforcing portion having a cross shape, a single letter shape, a multi-fillet shape, or the like on the FRP layer of the grip portion 3 corresponding to a position up to about 30 cm from the grip end. The setting is made to be not less than cm ² . In addition, as the FRP bat of the present invention, approximately 30c from the grip end
By forming a highly elastic composite material in the FRP layer of the grip portion corresponding to the position up to m, the bending rigidity of the grip portion is set to about 10 × 10 ⁵ Kg / cm ² or more.

Further, in the FRP bat of the present invention, the bending rigidity of the grip portion is improved by joining and integrating a rigid body to the inner periphery of the FRP layer of the grip portion corresponding to a position up to about 30 cm from the grip end. Approximately 10 × 10 ⁵ Kg /
It is set to cm ² or more. Further, the FRP of the present invention
As a bat for manufacturing, a bending rigidity of the grip portion is about 10 × 10 ⁵ Kg / cm ² or more by joining and integrating a rigid body to the outer periphery of the FRP layer of the grip portion corresponding to a position up to about 30 cm from the grip end. To be set to.

[0009]

With the above structure, the FRP of the present invention
In a bat made by bending, the bending rigidity of the grip portion corresponding to the position from the grip end to about 30 cm is about 10 × 1.
Since it can be set to 0 ⁵ Kg / cm ² or more, FR when hit
Since it is possible to increase the primary natural frequency of the P-made bat and lower the vibration level, it is possible to reduce numbness and vibration of the hand.

[0010]

EXAMPLE An example of the present invention will be described with reference to the drawings. As shown in FIGS. 3 to 4, in an FRP bat 1, in order to prevent numbness and reverberation of the hand when hitting a ball,
The bending rigidity of the grip part 3 corresponding to the position from the grip end 2 of the RP bat 1 to about 30 cm is about 10 × 1.
It is an FRP bat characterized in that it is set to be not less than 0 ⁵ Kg / cm ² . Other examples include:
In the FRP bat 1, the FRP of the grip portion 3 corresponding to the position from the grip end 2 to about 30 cm.
The FRP bat is characterized in that the thickness of the layer 6 is formed to be thicker than the thickness of the portion connecting the shaft portion 4 to the hitting portion 5. Although the inside of the FRP layer has a hollow structure in FIG. 4, it may have a solid structure in terms of design.

As another embodiment, as shown in FIGS. 5 to 7, in the FRP bat 1, the FRP layer 6 of the grip portion 3 corresponding to the position from the grip end 2 to about 30 cm is cross-shaped, The FRP bat is characterized in that reinforcing portions 7, 8, 9 having a one-letter shape, a multi-fillet shape or the like are formed. In addition, these cross-shaped, single-character, and multi-fillet-shaped reinforcements 7,
8 and 9 can be formed in a continuous shape from the grip end 2 to a position of approximately 30 cm, or can be formed in a discontinuous rib shape.

As another embodiment, as shown in FIG. 8, in the FRP butt 1, a grip portion 3 corresponding to a position from the grip end 2 to about 30 cm is provided.
The FRP bat is characterized in that the high elastic composite material 10 is interposed in the FRP layer 5. For example, conventional F
In addition to the specifications of RP bats and these conventional FRP bats, a sleeve made of carbon fiber (96 striking × 3 K, tensile elastic modulus of carbon fiber 2,350,000 Kg / cm 2) is added to the grip end 5-45 cm. It is used for a half amount of the carbon fiber mating angle of 0 ° from the grip end to the middle part of the bat.
A FRP bat having a tensile modulus of 3,000,000 kg / cm2 replaced with a carbon fiber of 50,000 kg / cm2 was subjected to a three-point bending test (span 400 m
When the flexural rigidity was measured by m), a value of 8.6 × 10 kg / cm 2 to 13.3 kg / cm 2 was obtained at a position 30 cm from the grip end, and a rigidity of about 1.54 times was obtained.

The natural frequency of the FRP bat itself is also 2
The frequency changed from 35 Hz to 313 Hz, and the vibration level when hitting 100 mm from the sweet spot on the hand side was about 1/5 of the conventional level. In addition, as another embodiment of the FRP bat of the present invention, as shown in FIG. 9, in the FRP bat 1, on the inner circumference of the FRP layer 6 of the grip portion 3 corresponding to the position from the grip end 2 to about 30 cm. It is also possible to join and integrate the rigid body 11. When the rigid body 11 is integrally joined to the inner circumference of the FRP layer 6 of the grip portion 3, the rigid body 11 is made of stainless steel, aluminum alloy, or other metal, or CFRP (carbon fiber reinforced plastic) or other materials. It can be formed of fiber reinforced plastic or synthetic resin. Further, the shape at that time may be a pipe-like hollow shape, a solid shape, or, as described above, a cross shape, a single character shape, or a multi-fillet shape.

Further, as another embodiment of the FRP bat according to the present invention, as shown in FIG.
At the outer periphery of the FRP layer 6 of the grip portion 3 corresponding to a position from the grip end 2 to about 30 cm, the rigid body 1
It is also possible to join and integrate the two. When the rigid body 12 is integrally bonded to the outer circumference of the FRP layer 6, the rigid body 12 is made of stainless steel, an aluminum alloy, or other metal, or is made of CFRP or other fiber-reinforced plastic, or is made of synthetic material. It can be formed of resin or the like.

[0015]

As described above, in the FRP bat according to the present invention, the primary natural frequency at the time of impact is the same as that of the conventional F.
Since it is set higher than the RP bat and the vibration level is lowered, it has the effect of being less numb than the metal bat without touching the hand. Further, since the numbness of the hand at the time of hitting is reduced, even if the sweet spot is removed, there is an effect that the hitting can be performed without losing the numbness and sound of the hand.

[Brief description of drawings]

FIG. 1 is a graph showing transfer functions of various bats.

FIG. 2 is a graph showing the results of rigidity sensitivity analysis of FRP bats.

FIG. 3 is a plan view showing an FRP bat according to the present invention.

FIG. 4 is a half cross-sectional view of an essential part showing a grip part of an FRP bat according to the present invention.

FIG. 5 is an F of the grip portion of the FRP bat according to the present invention.
It is an important section sectional view in which an RP layer shows a cross shape.

FIG. 6 is an F of the grip portion of the FRP bat according to the present invention.
It is a principal part sectional view in which an RP layer shows a single letter shape.

FIG. 7 is an F of the grip portion of the FRP bat according to the present invention.
FIG. 4 is a cross-sectional view of a main part showing an RP layer having a multi-fillet shape.

FIG. 8 is an F of the grip portion of the FRP bat according to the present invention.
It is a principal part sectional view which shows the structure which interposed the highly elastic composite material in the RP layer.

FIG. 9 is an F of the grip portion of the FRP bat according to the present invention.
It is a principal part sectional view which shows the structure which joined and integrated the rigid body to the inner periphery of RP layer.

FIG. 10 is a cross-sectional view of essential parts showing a configuration in which a rigid body is joined and integrated to the outer periphery of the FRP layer of the grip portion of the FRP bat according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 FRP butt 2 Grip end 3 Grip part 4 Shaft part 5 Hitting part 6 FRP layer 7 Cross-shaped reinforcing part 8 One-character reinforcing part 9 Multifillet-shaped reinforcing part 10 High elastic composite material 11 Rigid body 12 Rigid body

Claims (6)

[Claims] 1. In an FRP bat, in order to prevent numbness and reverberation of the hand when hitting a ball, approximately 30 from the grip end.
The bending rigidity of the grip corresponding to the position up to cm is about 1
An FRP bat characterized by being set to 0 × 10 ⁵ Kg / cm ² or more. 2. In the FRP bat, a thickness of an FRP layer of a grip portion corresponding to a position from a grip end to about 30 cm is formed thicker than a thickness of a portion connecting the hitting portion to the shaft portion. And F of claim 1
RP bat. 3. In the FRP bat, a reinforcing portion having a cross shape, a single character shape, a multi-fillet shape, or the like is formed on the FRP layer of the grip portion corresponding to a position up to about 30 cm from the grip end. Item 1 FRP bat. 4. The FRP bat according to claim 1, wherein in the FRP bat, a high elastic composite material is interposed in the FRP layer of the grip portion corresponding to a position up to about 30 cm from the grip end. 5. The FRP bat according to claim 1, wherein in the FRP bat, a rigid body is integrally joined to the inner circumference of the FRP layer of the grip portion corresponding to a position up to about 30 cm from the grip end. . 6. The FRP bat according to claim 1, wherein in the FRP bat, a rigid body is integrally joined and interposed on the outer periphery of the FRP layer of the grip portion corresponding to a position up to about 30 cm from the grip end. Made bat.