JP2001120699A - Bat for baseball or softball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase significantly a flight. SOLUTION: Projections 2 are formed on the periphery 11a of a ball striking portion so as to strike a ball with the projections 2. The height of the projections 2 is between 1 cm and 3 cm, which are preferably formed symmetrically throughout the periphery 11a of the ball striking portion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved hitting portion of a baseball or softball bat.

[0002]

2. Description of the Related Art Conventionally, various types of bats have been used, such as wooden batts, metal battens such as titanium, titanium alloys and aluminum alloys, as well as fiber reinforced plastics (hereinafter referred to as FRP) made of carbon fiber, glass fiber and the like. Materials composed of raw materials are supplied to the market, and the shapes of the materials are generally circular in cross section perpendicular to the longitudinal direction, and the surface thereof is generally smooth. Therefore, the surface of the hitting part is roughened,
Japanese Patent Application Laid-Open No. 56-5560 and Japanese Utility Model Application Laid-Open No. 2-114073 disclose a device in which a concave streak is provided along the longitudinal direction to prevent the ball from slipping when hit. Also,
Japanese Utility Model Laid-Open No. 5-68570 discloses a device in which the cross-sectional shape of the hitting portion is substantially triangular and the curvature of the three hitting surfaces is changed to obtain different hitting effects. For the purpose of improving the resilience characteristics, Japanese Patent Application Laid-Open No. Hei 7-96055 discloses a bat in which an elastic insertion member is inserted and fixed inside the hitting portion, and a multi-tube bat in which a plurality of tubular insertion members are inserted and fixed in the hitting portion. No. 137,752.

[0003]

However, the known bat has the following problems. That is, Japanese Utility Model Laid-Open No. 56-5560 and Japanese Utility Model Laid-Open No. 2-114073.
The idea of the issue was to prevent the ball from slipping at the time of hitting the ball and to increase the ball's spin, thereby increasing the flight distance. However, a significant increase in the flight distance could not be expected. In addition, actual opening Hei 5-68
The invention of No. 570 is to change the impact contact area of the ball by changing the curvature of the three striking surfaces, thereby changing the directional stability and repulsion speed of the ball, but it is hoped that the flight distance will also be greatly increased. Absent. In the inventions of JP-A-7-96055 and JP-A-11-137752, resilience characteristics are improved by inserting and fixing a plurality of elastic insertion members or tubular insertion members inside the hitting portion, but the structure is complicated and the manufacturing cost is reduced. Will be higher.

[0004]

According to the present invention, a projection is formed on the outer peripheral surface of a hitting ball portion, and the projection hits the ball. By hitting the ball with the projection, the ball locally deforms at the time of hitting, reducing the overall deformation of the ball and minimizing the energy loss of the ball, the speed of the hitting ball due to the repulsion And the flight distance can be increased as compared with the conventional bat. But,
If the height of the projection is too low, the local deformation is small, and the effect is small. On the other hand, if the height of the projection is too high, the projection may be damaged or the direction of the hit ball may be unstable. Therefore, the height of the projection is desirably 1 cm or more and 3 cm or less. The shape of the projection is hemispherical, cylindrical, pyramidal, straight or curved with the tip of the projection being an arc, straight or curved with the tip of the projection being triangular, etc. From the point of the local deformation amount and the ease of hitting the ball with the protrusion, the protrusion is formed in the longitudinal direction of the hitting portion in the longitudinal direction or in the circumferential direction, or a plurality of protrusions formed in the protrusion or the ring are equally spaced. It is desirable to form them apart from each other. The number of the protrusions may be one hemispherical, cylindrical, pyramid-shaped, or one ridge or ring, but is preferably formed symmetrically over the entire outer peripheral surface of the hitting portion. However, by forming projections on the hitting part in this way, there is a surface that the direction of the hitting ball is not stable,
By coating a synthetic resin elastic body on the hitting part with projections and increasing the contact area between the ball and the bat at the time of hitting, even if the amount of local deformation of the ball slightly decreases, the directional stability is improved. can do. It is desirable that the projection is formed simultaneously with the bat body from the viewpoint of manufacturing cost. However, the projection may be formed separately from the bat and fixed to the hitting portion.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the principle that a projection provided on a hitting portion of the present invention improves the resilience characteristics of a bat will be described based on a rebound test conducted by the present inventors. FIG.
Figure 2 shows a schematic diagram of the repulsion test device. The experimental apparatus includes a pitching machine 20, a high-speed video camera 21, an image analyzer (not shown), an iron plate 22, and a projection model 23.
It was constituted by. In the experiment, a ball 24 launched from the pitching machine 20 was caused to collide with a fixed iron plate 22 and a projection model 23 attached to the iron plate 22, and the collision was photographed by a high-speed video camera 21 from the side, and the ball before and after the collision was hit. The coefficient of restitution was calculated from the speed of 24.

As shown in FIG. 12A, the projection model 23 is a triangular prism having a cross section of 8.5 cm at the base and an isosceles triangle having a height of 4 cm and a length of 6 cm. As shown in FIG. , A semicircle with a radius R of 3 cm or a radius R of 3.5 cm on one long side of a rectangle having a cross section of a long side 6 cm and a short side 3 cm
A columnar object having a length of 6 cm and a shape obtained by combining the arcs of a circle, as shown in FIG. 12 (3), a cross section of a rectangle having a long side of 6 cm and a short side of 1 cm, a short side of 2 cm, a long side Side 4cm
A rectangle with a radius r1 cm on one short side and a center line on the other short side, or a rectangle with a short side 1 cm and a long side 4.5 cm on one short side of a rectangle r0.5 cm
And a column having a length of 6 cm and a centerline of the other short side was made of wood. In addition, each protrusion model was attached to an iron plate by sticking a rectangular or square surface of a columnar object with a double-sided tape.

[0007] This experiment was conducted using a rubber-ball baseball. This is because when a rubber ball is hit in rubber-ball baseball or softball, the elastic deformation of the ball is large,
There is a problem that the resilience characteristics of the bat cannot be fully utilized, and there is no significant difference in the resilience characteristics of any bat. In order to confirm the shape, a rubber ball is used.

Next, the equation for calculating the coefficient of restitution e and the description of the code are shown in Equation 1, and the method of measuring data is shown below.

[0009]

E = V · BALL (OUT) / V · BALL (IN) e: coefficient of restitution V · BALL (IN): velocity of center of gravity of ball before collision (m
/ B) V · BALL (OUT): The velocity of the center of gravity of the ball after collision (m / s)

The velocity of the center of gravity of the ball in the above calculation formula was obtained by image-analyzing an image taken by a high-speed video camera with an image analyzer.

Next, the contents of the experiment and the coefficient of restitution are shown in Table 1.

[0012]

[Table 1] * Calculated value by linear approximation.

The iron plate of the collision object shown in Table 1 is a fixed iron plate having a flat surface. The triangular prism of the collision target is a projection model in which the bottom surface of an isosceles triangle shown in FIG. 11A is attached to an iron plate. 3.5 tip radius of the collision object
The cm and the tip radius of 3 cm are projection models in which the columnar object shown in (2) of FIG. 11 is adhered to an iron plate, and correspond to the hitting portion shape of a conventional bat. Tip radius of collision object 1
cm and a tip radius of 0.5 cm are projection models in which the columnar object shown in (3) of FIG. 11 is adhered to an iron plate.

As can be seen from the experimental results in Table 1, the coefficient of restitution is higher when colliding with a projection model than when colliding with a flat iron plate, and has a larger curvature than the curvature of the hitting portion of a conventional bat. This shows that the coefficient of restitution is higher when colliding with the projection model. Although the collision speed measured in the experiment is 10 m / s to 30 m / s, the relative speed between the ball and the bat at the time of an actual hit is approximately 200 km / h (5 km / h).
5 m / s), and was calculated from the graph of the measured data by external search using the least squares method. Comparing the calculated coefficients of restitution, the iron plate is 0.158 and the tip radius is 0.5 cm, which is 0.461, indicating that the difference between the two is more remarkable. Therefore, a clear difference appears in the flight distance when actually hitting.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A baseball or softball bat 1 according to the present invention will be described below with reference to the drawings. The bat shown in FIG. 1 is a hollow bat made of FRP, in which a protrusion 2 having a circular arc at the tip of the protrusion 2 is formed in the longitudinal direction of the hitting portion 11. As can be seen from the experimental results in Table 1 above, the smaller the radius r of the tip of the protrusion 2 is, the higher the resilience characteristic is, and the longer the ball 2 travels, but the worse the directionality is. Therefore, the radius r of the tip of the projection 2 is 0.5c
It is preferably about m to 1 cm. Also, the greater the height of the projections 2, the greater the bite into the ball, but the worse the directionality, and if too large, the hitting portion 11 is damaged by the impact at the time of hitting. Therefore, the height of the protrusion 2 is preferably 1 cm to 3 cm. The smaller the number of the projections 2, the more difficult it is to hit with the projections 2, and the larger the number, the smaller the effect of the projections 2. Therefore, it is desirable to form four to eight at equal intervals on the outer peripheral surface 11 a of the hitting portion. That is, for example, as shown in FIG. 1, four ridge projections 2 are formed every 90 ° with the center line in the longitudinal direction of the bat as an axis.
It is desirable to form eight lines every 45 °. Although not shown, the top of the projection 2 on the tip end side and the tapered portion side of the projection 2 may be gradually reduced, and the projection 2 may be extended to the tip end portion 10 and the tapered portion 12.

The bat shown in FIG. 2 is a hollow bat made of FRP, in which the tip of the projection 2 has a triangular projection 2 formed in the longitudinal direction of the hitting portion 11. The smaller the angle of the tip of the projection 2 is, the greater the bite into the ball is. However, if the angle is too small, the ball may be damaged or the projection 2 may be damaged. Therefore, the angle of the tip is preferably 20 ° to 100 °. Also,
The height of the projection 2 is desirably 1 cm to 3 cm for the above reasons.

The bat shown in FIG. 3 is a hollow bat made of FRP, in which the tip of the projection 2 is formed in the circumferential direction of the striking ball portion 11 with a circular arc-shaped projection 2. The size of the protrusion 2 is
It is the same as that formed in the longitudinal direction of the hitting portion 11, but the number of the protrusions 2 is preferably 4 to 5 cm from the balance between resilience and directional stability.

The bat shown in FIG. 4 is a hollow bat made of FRP, in which the protrusion 2 has a triangular ring-shaped protrusion 2 in the circumferential direction of the hitting portion 11. The size of the projection 2 is the same as that formed in the longitudinal direction of the hitting portion 11, but the number of the projections 2 is 4 to 4 from the balance between resilience and directional stability. 5 cm is desirable.

The bat shown in FIG. 5 has a plurality of protrusions 2 formed on the ridge in the longitudinal direction of the hitting portion 11 and separated from each other. The size of the projection 2 is the same as that formed in the longitudinal direction of the hitting portion 11 in FIG. 1, but the length of the projection 2 is determined from the balance between the formability of the projection 2 and the resilience and directional stability. Is preferably 4 to 5 cm, and the interval between the projections 2 is preferably 3 to 4 cm. It is to be noted that the protrusion 2 having a triangular tip can be similarly formed to be spaced apart.

In the bat shown in FIG. 6, odd-numbered projections 2 counted from the tip 10 of the bat shown in FIG. 5 are formed at positions rotated by 90 ° about the longitudinal center line of the bat as an axis.
An even number of projections 2 counted from the tip 10 is formed at a position rotated by 45 ° about the longitudinal center line of the bat as an axis. In addition, the protrusion 2 to be rotated and the rotation angle are arbitrary, but it is desirable to form the protrusion 2 uniformly over the entire hitting portion 11 from the viewpoint of directional stability. Also, protrusion 2
Can be formed in a similar manner.

The bat shown in FIG. 7 has a plurality of projections formed on the hoop in the circumferential direction of the hitting ball portion 11 and separated from each other. The size of the projections 2 is the same as that formed in the circumferential direction of the hitting portion 11 in FIG. 3 described above. However, from the balance between the moldability of the projections 2 and the resilience and directional stability, 4 to 8 positions are used. Uniform formation is desirable from the viewpoint of directional stability. Above all, it is desirable that the center of the cross section of the hitting portion 11 is formed at four places in the direction orthogonal to each other, the length of the projection 2 is 1.5 to 2.5 cm, and the interval between the projections 2 is 2 to 4 cm. In addition,
Similarly, the protrusion 2 having a triangular tip can be separated.

In the bat shown in FIG. 8, odd-numbered projections 2 counted from the tip 10 of the bat shown in FIG. 7 are formed at positions rotated by 90 ° about the longitudinal center line of the bat.
An even number of projections 2 counted from the tip 10 is formed at a position rotated by 45 ° about the longitudinal center line of the bat as an axis. In addition, the protrusion 2 to be rotated and the rotation angle are arbitrary, but it is desirable to form the protrusion 2 uniformly over the entire hitting portion 11 from the viewpoint of directional stability. Also, protrusion 2
Can be formed in a similar manner.

The bat shown in FIG. 9 is obtained by covering the hitting portion 11 having the projection 2 of the bat shown in FIG. 1 with a synthetic resin elastic body 3. With such a configuration, it is possible to further improve the directional stability while maintaining the effect of improving the resilience by the projections 2. The synthetic resin elastic body 3 is JIS A
By coating such a synthetic resin elastic body 3 with a sheet or tube of an ionomer, butadiene rubber, or the like having physical properties of a hardness of 40 to 90, spin is applied to the ball due to friction with the ball, and the flight distance is also measured from this point. Is improved. When using an elastic tube, the hitting portion 11
By covering the protrusion 2 with a size slightly smaller than the diameter of the outer periphery or covering the distal end portion 10 to the tapered portion 12, it is possible to make the tube hard to come off. In addition, a heat-shrinkable tube made of ethylene propylene is used for the synthetic resin elastic body 3,
Using a polyolefin-based heat-shrinkable tube, a silicone heat-shrinkable tube, a fluororesin heat-shrinkable tube, or the like, cover the hitting portion 11 with a slightly larger diameter than the outer circumference of the projection 2 and heat-shrink to adhere to the surface of the projection 2 It can also be installed as follows.

The baseball or softball bat 1 according to the present invention can be formed of wood, metal, or FRP. In the case of wooden, it is formed by machining to the above-mentioned external shape. In the case of metal, once formed into a normal shape, only the hitting portion 11 is formed by pressing and polishing using a die. Therefore, it is desirable to use an aluminum alloy which is relatively easy to mold and has an ASTM number of 6000 or 7000. In case of FRP,
Carbon fiber, glass fiber or aramid fiber is used as the reinforcing fiber, and epoxy resin or other thermosetting synthetic resin, polyurethane resin or other thermoplastic synthetic resin is used as the matrix resin. Also, as a manufacturing method, a projection is formed on the hitting portion of the mold, and the RI is formed.
The bat having the projection 2 on the hitting portion 11 can be formed without increasing the number of steps by molding by the M manufacturing method or the internal pressure manufacturing method.

When the projections 2 are formed separately, the projections 2 formed separately from the same material as the bat or separately from the bats may be adhered and attached to the hitting portion 11, or as shown in FIG. It is also possible to use a different material to externally search and glue the projection part 14 having the inner diameter slightly larger than the outer diameter of the hitting part 11 and the protrusion 2 formed on the surface of the pipe having the length of the hitting part 11 to the hitting part 11. it can. Alternatively, the projections 2 may be formed on the surface of the heat-shrinkable tube itself, coated on the hitting portion 11 on which the projections 2 are not formed, and then heat-shrinked to form the projections 2.

[0026]

As described above, according to the present invention, by forming a projection which is not provided in the conventional bat on the hitting portion, the ball is locally deformed at the time of hitting and the overall deformation of the ball is reduced. Energy loss can be minimized, the speed of the hit ball due to the rebound increases, and the flight distance can be greatly increased as compared with the conventional bat. In particular, even when hitting a soft ball such as a rubber-ball baseball or a rubber softball, the resilience characteristics of the bat can be increased.

Further, since the bat of the present invention can be formed by using a conventionally used material and a manufacturing method, the bat is superior in resilience characteristics to the conventional bat without a large increase in material costs and a great increase in man-hours. It can be a bat.

[Brief description of the drawings]

FIG. 1 (1) A baseball or softball bat in which a projection of an arc-shaped ridge is formed in the longitudinal direction of a hitting portion, (2) AA sectional view

FIG. 2 (1) A baseball or softball bat in which a protrusion with a triangular ridge having a triangular tip formed in the longitudinal direction of the hitting portion, (2) AA sectional view

FIG. 3 (1) A baseball or softball bat in which a projection of an arc-shaped rim is formed in a circumferential direction of a hitting portion, (2) a longitudinal sectional view of an A portion

FIG. 4 (1) A baseball or softball bat in which a projection of a triangular ring is formed in a circumferential direction of a hitting portion, and (2) a longitudinal sectional view of a portion A.

FIG. 5 (1) A baseball or softball bat in which a plurality of protrusions each having a projection with a circular arc at the tip of the protrusion are formed in the longitudinal direction of the hitting portion, and (2) AA cross-sectional view.

FIG. 6 (1) An even number of projections counted from the tip of the bat in FIG.
Baseball or softball bat formed at a 45 ° rotated position, (2) AA cross-sectional view

FIG. 7 (1) A baseball or softball bat in which a plurality of protrusions of an arc-shaped protrusion having a circular tip are formed in a circumferential direction of a hitting portion, and (2) AA sectional view

(1) An even number of projections counted from the tip of the bat in FIG. 7 are formed by using a center line in the longitudinal direction of the bat as an axis.
Baseball or softball bat formed at a 45 ° rotated position, (2) AA cross-sectional view

FIG. 9 (1) A baseball or softball bat in which an elastic sheet or an elastic tube is coated on a hitting portion on which a projection of the bat of FIG. 1 is formed, (2) AA cross-sectional view

FIG. 10 (1) A baseball or softball bat in which a protruding part is extrapolated to a hitting portion of the bat, and (2) AA sectional view.

FIG. 11 (1) Schematic side view of a repulsion test device, (2)
Schematic top view of repulsion test device

12 (1) is a perspective view of a projection model having a projection with a triangular tip, (2) a perspective view of a projection model with a large arc at the tip of the projection, and (3) a perspective view of a projection model having a small arc at the tip of the projection.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Baseball or softball bat 2 Projection 3 Synthetic resin elastic body 10 Tip part 11 Hitting part 11a Outer peripheral surface of hitting part 12 Taper part 13 Grip part 14 Projection part 20 Pitching machine 21 High-speed video camera 22 Iron plate 23 Projection model 24 ball

Claims (10)

[Claims] 1. A baseball or softball bat (1) comprising a tip portion (10), a hitting portion (11), a taper portion (12), and a grip portion (13), and an outer peripheral surface (11a) of the hitting portion. A baseball or softball bat (1), characterized in that a projection (2) is formed thereon. 2. The height of the projection (2) is not less than 1 cm and not more than 3 cm.
The bat (1) for baseball or softball according to claim 1, wherein the bat is formed to have a diameter of not more than 1 cm. 3. The baseball or softball bat (1) according to claim 1, wherein the projection (2) is formed as a ridge in a longitudinal direction of the hitting portion (11). . 4. The baseball or softball bat (1) according to claim 1 or 2, wherein the projection (2) is formed in a loop in the circumferential direction of the hitting portion (11). ). 5. The baseball or softball bat (1) according to claim 3, wherein a plurality of protrusions (2) formed in a ridge in a longitudinal direction of the hitting portion (11) are formed apart from each other. ). 6. An odd-numbered projection (2) counted from the tip (10) is formed at a position rotated by 90 ° about a longitudinal center line of a baseball or softball bat (1). An even numbered projection (2) counting from the tip (10)
6. The baseball or softball bat (1) according to claim 5, wherein the baseball or softball bat (1) is formed at a position rotated by 45 [deg.] Around the longitudinal center line of the baseball or softball bat. . 7. A baseball or softball bat according to claim 4, wherein a plurality of projections (2) formed on the hoop in the circumferential direction of the hitting portion (11) are formed apart from each other. 1). 8. An odd-numbered projection (2) counted from the tip (10) is formed at a position rotated by 90 ° about the longitudinal center line of the baseball or softball bat (1). An even numbered projection (2) counting from the tip (10)
8. The baseball or softball bat (1) according to claim 7, wherein the baseball or the softball bat (1) is formed at a position rotated by 45 degrees about a longitudinal center line of the baseball or softball bat. . 9. A hitting portion (1) having the projection (2) formed thereon.
The baseball or softball bat (1) according to any one of claims 1 to 8, wherein 1) is covered with a synthetic resin elastic body (3). 10. The baseball or softball according to claim 1, wherein the projection (2) is formed separately and fixed to the hitting portion (11). Bat (1).