JP7720531B2 - Hitting part and bat using same - Google Patents

Description

The present invention relates to a hitting part having an elastic body and a bat for ball games that uses the same.

An example of a conventional bat is the one described in Patent Document 1. This bat has a cylindrical base member that serves as a core material, and a cylindrical elastic body that is integrated into the part of the base member that will serve as the ball-hitting portion.

In this conventional bat, the elastic body deforms when the ball is hit, suppressing deformation of the ball, and when the elastic body returns to its original shape, it applies a repulsive force to the ball, thereby improving the distance the ball travels.

However, because the elastic body of conventional bats is a viscoelastic material such as polyurethane foam, there is a large amount of energy loss in the elastic body, which limits the amount of repulsion force that can be generated. As a result, there is a limit to how far conventional bats can improve the distance a ball can travel.

Japanese Patent Application Laid-Open No. 2003-19236

The problem we were trying to solve was the large amount of energy loss at the hitting point, which limited the amount of repulsion force that could be generated.

The present invention provides a ball-hitting portion of a bat for ball games, which includes a core material positioned eccentrically to one radial side; a first elastic body having one radial side supported by the core material and the other radial side facing the core material with a space between them, the first elastic body having relatively small elastic hysteresis; and a second elastic body having relatively large elastic hysteresis, covering the radial outside of the other radial side of the first elastic body to form a ball-hitting surface.

The present invention also provides a bat equipped with the above-described ball-hitting portion.

By combining a first elastic body with a relatively small elastic hysteresis and a second elastic body with a relatively large elastic hysteresis, the present invention can reduce energy loss throughout the hitting area and improve repulsion force.

Furthermore, in this invention, the deformation stroke of the first elastic body is increased by the large space created by eccentrically positioning the core material, thereby increasing elastic energy and further improving repulsive force.

FIG. 1 is a perspective view showing a bat according to a first embodiment of the present invention. FIG. 2 is a longitudinal cross-sectional view of the bat of FIG. 3 is a cross-sectional view showing the ball-hitting portion of the bat taken along line III-III in FIG. 4 is a perspective view showing a portion of the core of the bat of FIG. 2. FIG. 5A and 5B are cross-sectional views showing the relationship between the bat and the ball when hitting the ball, with FIG. 5A showing an example and FIG. 5B showing a comparative example. FIG. 6 is a cross-sectional view showing the ball-hitting portion of a bat according to a modification of the first embodiment. FIG. 6 is a cross-sectional view showing the ball-hitting portion of a bat according to another modification of the first embodiment. FIG. 8 is a cross-sectional view showing a bat according to a second embodiment of the present invention. 9 is a perspective view showing a portion of the core of the bat of FIG. 8. FIG.

The goal of reducing energy loss in the hitting area and improving the generated repulsion force was achieved by eccentrically positioning the core material in the hitting area, which combines a first elastic body with relatively small elastic hysteresis and a second elastic body with relatively large elastic hysteresis.

As shown in Figures 1 to 9, the ball-hitting portion 5 of the ball game bat 1 of the present invention comprises a core material 7, a first elastic body 15, and a second elastic body 17.

The core material 7 is positioned eccentrically to one radial side. The first elastic body 15 has one radial side portion 19 supported by the core material 7 and another radial side portion 21 that faces the core material 7 in the radial direction with a space 23 between them, resulting in relatively small elastic hysteresis. The second elastic body 17 covers the radial outside of the other side portion 21 of the first elastic body 15 to form the ball-striking surface 5a, resulting in relatively large elastic hysteresis.

The second elastic body 17 may have any shape as long as it can form the ball-striking surface 5a, but it may also be cylindrical and contain the first elastic body 15 and core material 7.

The second elastic body 17 may also be bonded to the core material 7 on one radial side.

The first elastic body 15 may have any shape as long as it has one radial side portion 19 and the other radial side portion 21, but may also be annular and arranged alongside the core material 7. In this case, a circumferential portion of the first elastic body 15 may constitute the one radial side portion 19.

Instead of being arranged in parallel as described above, the first elastic body 15 may be a cantilevered plate member arranged along the axial direction, with one axial side connected to the core material 7. In this case, one axial side of the first elastic body 15 constitutes one side portion 19, and the other axial side of the first elastic body 15 constitutes the other side portion 21.

[Bat structure]
Fig. 1 is a perspective view showing a bat according to a first embodiment of the present invention. Fig. 2 is a longitudinal cross-sectional view showing the bat of Fig. 1. Fig. 3 is a transverse cross-sectional view showing the ball-hitting portion of the bat along line III-III of Fig. 2. Fig. 4 is a perspective view showing a portion of the core material of the bat of Fig. 2.

The bat 1 of this embodiment is used for ball games such as baseball and softball, and includes a grip portion 3 and a hitting portion 5.

The grip portion 3 is the part that the batter holds and is made up of part of the core material 7.

The core material 7 is a hollow rod-shaped body. This core material 7 has a circular cross-sectional shape and a constant wall thickness. However, the wall thickness of the core material 7 can be made thinner or thicker in parts. Also, while the cross-sectional shape of the core material 7 is constant from the tip to the base end, it can also be made different in parts by changing the diameter, etc. Furthermore, the cross-sectional shape of the core material 7 is not limited to a circle, and other shapes such as an ellipse can be used, and it can also be solid.

The material used for the core material 7 is fiber-reinforced plastic (FRP), and in this embodiment, carbon fiber-reinforced plastic (CFRP). However, the material for the core material 7 is not limited to FRP, and metal, wood, etc. can also be used.

The core 7 integrally comprises the grip portion 3, the hitting area 9, and the head portion 11 from the base end to the tip end in the axial direction. However, one, two, or all of the grip portion 3, the hitting area 9, and the head portion 11 may be constructed as separate components, and the core 7 may be formed by integrally joining these separate components together. The axial direction is the direction along the axis of the bat 1, and also includes a direction slightly oblique to the axis.

The grip portion 3 is a cylindrical portion that is gripped by the batter. In this embodiment, the grip portion 3 is formed into a hollow rod with a circular cross section that corresponds to the shape of the core material 7. Grip tape 3a is wrapped around the grip portion 3. A grip end 3b that protrudes radially is provided at the base end of the grip portion 3. A ball-hitting area 9 is integrally provided at the tip of the grip portion 3. The radial direction refers to the direction along the diameter of the bat 1, but also includes a direction slightly oblique to the diameter.

The hitting area 9 is part of the core material 7 that, together with the elastic member 13, constitutes the hitting area 5, and is formed as a hollow rod with a circular cross-sectional shape. The cross-sectional shape of the hitting area 9 is not limited to a circular shape, and other shapes are also possible. For example, the cross-sectional shape of the hitting area 9 may be asymmetrical between one radial side and the other, or may be elliptical.

This hitting area 9 is positioned eccentrically to one side in the radial direction. In other words, the center O2 of the hitting area 9 (core material 7) is positioned radially offset from the center O1 of the hitting area 5.

The eccentricity of the hitting area 9 is gradual from the base end toward the tip end, and the amount of eccentricity is constant where the outer diameter of the hitting area 5 is approximately constant. This constant amount of eccentricity is set according to the amount of deformation of the other side portion 21 of the first elastic body 15, which will be described later. The eccentricity of the hitting area 9 may also be crank-shaped.

A head portion 11 is integrally formed at the tip of the hitting area 9. The head portion 11 is formed in a disk shape. The head portion 11 bulges radially from the hitting area 9. The outer diameter of the head portion 11 is approximately the same as the outer diameter R of the hitting area 5.

The hitting portion 5 is configured by attaching an elastic member 13 to the hitting portion region 9 of the core material 7. The elastic member 13 deforms when hitting the ball B, suppressing deformation of the ball B and applying a repulsive force to the ball B. Note that the ball B is a rubber ball. In this embodiment, the elastic member 13 includes a first elastic body 15 and a second elastic body 17.

The first elastic body 15 is a member with relatively small elastic hysteresis, and when hit with a ball, it elastically deforms to generate a repulsive force with little energy loss.

Elastic hysteresis refers to the energy loss that occurs when a load and unload cycle forms a loop within the elastic range of the stress-strain relationship. This elastic hysteresis can be set appropriately by adjusting the material and shape of the first elastic body 15.

In this embodiment, the material of the first elastic body 15 is CFRP, the same material as the core material 7. However, the first elastic body 15 can also be formed from a different material than the core material 7.

The first elastic body 15 is formed in a ring shape and arranged in parallel in the hitting area 9. In this embodiment, the first elastic body 15 is preferably arranged in the axial direction in an area that includes at least the center of impact of the hitting area 5, the so-called sweet spot. In this embodiment, the first elastic body 15 is formed in a cylindrical shape that extends axially from the front to the rear of the sweet spot.

In this embodiment, the cross-sectional shape of the first elastic body 15 is formed into an arc shape with a C-shaped channel. The arc shape of the first elastic body 15 has an outer diameter larger than the hitting area 9 of the core material 7 and a constant thickness. The center O3 of the first elastic body 15 is radially offset from the center O1 of the hitting area 5 and the center O2 of the hitting area 9.

However, the center O3 of the first elastic body 15 may coincide with the center O1 of the ball-hitting area 5. Furthermore, the thickness of the first elastic body 15 may vary in either or both the circumferential and axial directions.

One radial side 19 of the first elastic body 15 is a discontinuous end of a C-shaped channel and is integrally connected to the hitting area 9 of the core material 7. This gives the first elastic body 15 a closed ring shape. As a result, one radial side 19 of the first elastic body 15 is supported by the hitting area 9 of the core material 7, and the other radial side 21 of the first elastic body 15 faces the hitting area 9 of the core material 7 in the radial direction, with a space 23 between them.

The one side portion 19 is a portion of the first elastic body 15 located on one radial side, and the other side portion 21 is a portion of the first elastic body 15 located on the other radial side. When the first elastic body 15 is annular, as in this embodiment, the one side portion 19 is made up of a portion in the circumferential direction, and the other side portion 21 is made up of a portion in the circumferential direction located on the opposite side of the one side portion 19 in the radial direction.

The support of the one side portion 19 against the core material 7 is sufficient if the one side portion 19 can be supported by the core material 7 in the radial direction and radial movement of the first elastic body 15 can be suppressed. For this reason, the one side portion 19 does not have to be integral with the core material 7; for example, it can be formed separately from the core material 7 and either joined or abutted against it without being joined.

In addition, the support position (bonding position) of one side portion 19 of the core material 7 in this embodiment is a position slightly offset to one side from the radial center O2 of the ball-hitting area 9. However, this bonding position can be changed as appropriate depending on the elasticity of the first elastic body 15, the size of the space 23, etc.

The other side portion 21 of the first elastic body 15 is part or all of the arc-shaped portion in the range radially facing the ball-hitting area 9 of the core material 7. This other side portion 21 can be displaced radially toward the core material 7 within the space 23 due to elastic deformation of the first elastic body 15.

In this embodiment, the eccentricity of the hitting area 9 of the core material 7 allows for a large space 23, which increases the amount of deformation of the other side portion 21 of the first elastic body 15 until it reaches the core material 7. In other words, the first elastic body 15 can be made flexible according to the amount of eccentricity of the core material 7, making it possible to actively elastically deform the first elastic body 15.

In addition, in this embodiment, the first elastic body 15 is annular and arranged in parallel with the core material 7 along the axial direction, and a portion of the circumferential direction forms one side portion 19, making it easy to ensure a space 23 and to easily support one side portion 19 of the first elastic body 15 on the core material 7.

The second elastic body 17 covers the radially outer side of the other side portion 21 of the first elastic body 15 to form the ball-striking surface 5a, and is a member with relatively large elastic hysteresis. This second elastic body 17 suppresses deformation of the ball B by compressive deformation and bending when hitting the ball. The ball-striking surface 5a refers to the surface of the ball-striking section 5 that is intended to be hit. The elastic hysteresis of the second elastic body 17 can be set as appropriate depending on the material, shape, etc. of the second elastic body 17.

In this embodiment, the second elastic body 17 is cylindrical and encloses the first elastic body 15 and the hitting area 9 of the core material 7. As a result, the second elastic body 17 is provided around the entire circumference of the hitting area 5, forming a hitting surface 5a around the entire circumference of the hitting area 5. Therefore, in this embodiment, it is possible to hit the ball B around the entire circumference of the hitting area 5.

However, the second elastic body 17 may also be an arc-shaped plate or the like provided on a portion of the circumference of the ball-hitting portion 5. In this case, it is positioned at least on the other side portion 21 of the first elastic body 15 to form the ball-hitting surface 5a.

The outer diameter of the second elastic body 17 gradually increases from the base end toward the tip end in the axial direction, remaining approximately constant at the tip end. The axial tip of this second elastic body 17 abuts against the head portion 11 of the core material 7 in the axial direction, and the base end is prevented from coming off in the axial direction by a collar 25. In this state, the inner surface of the second elastic body 17 is fixed to the first elastic body 15 and the core material 7 by an appropriate fixing means such as adhesive.

This fixation allows the second elastic body 17 to be connected to the core material 7 on one radial side. The connection of the second elastic body 17 to the core material 7 can be ensured by the eccentricity of the core material 7. By being connected to the core material 7 on one radial side in this manner, the second elastic body 17 can be reliably compressed and bent to suppress deformation of the ball B when it collides with the other radial side.

In this embodiment, the second elastic body 17 has a cylindrical cross section with a substantially uniform thickness in the circumferential direction. However, the thickness of the second elastic body 17 may vary in the circumferential direction. The thickness refers to the radial dimension between the inner and outer peripheries of the second elastic body 17.

The material of the second elastic body 17 is a viscoelastic body such as foamed polyurethane resin. However, the material of the second elastic body 17 may be any material that can suppress deformation relative to the ball B, and may be selected appropriately in relation to the ball B, etc.

The surface of the second elastic body 17 is covered with a skin material 27. The skin material 27 improves durability against impact with the ball B. In this embodiment, the skin material 27 is formed in the shape of a cylindrical film made of a thermoplastic resin such as polyurethane film. Note that the skin material 27 can be omitted.

[Bat Action]
5A and 5B are cross-sectional views showing the relationship between the bat and the ball when hitting the ball, with FIG. 5A showing the present embodiment and FIG. 5B showing a comparative example.

In the comparative example shown in Figure 5(B), a circular first elastic body 15 is embedded within a second elastic body 17, and the core material 7, first elastic body 15, and second elastic body 17 are arranged concentrically.

In this embodiment, when the hitting portion 5 collides with the ball B, part of the kinetic energy of the ball B is converted into deformation energy of the hitting portion 5. This deformation energy is the sum of the deformation energy of the second elastic body 17, which has high viscous damping, and the deformation energy of the first elastic body 15, which has low damping.

As the conversion of ball B's kinetic energy into deformation energy progresses, ball B decelerates, and the deformation energy stored in the first elastic body 15 and second elastic body 17 of the hitting area 5 is converted back into kinetic energy of ball B as ball B stops.

Specifically, as shown in Figure 5(A), when ball B collides with the other radial side of the hitting area 5, the other radial side of the second elastic body 17, where the ball B collides, is initially pressed by the ball B and undergoes primarily compressive deformation. This compressive deformation suppresses deformation of ball B when it collides with the hitting area 5.

At this time, the second elastic body 17 is connected to and supported by the core material 7 on one radial side, allowing it to reliably undergo compressive deformation on the other radial side in response to the impact of the ball B.

When the second elastic body 17 is compressed between the ball B and the first elastic body 15, the pressing force of the ball B is transmitted to the other side portion 21 of the first elastic body 15 via the compressed portion. This pressing force elastically deforms the first elastic body 15, and the other side portion 21 is displaced radially to one side so as to narrow the space portion 23.

At this time, due to the eccentricity of the hitting area 9 of the core material 7, a large space 23 is secured, allowing for a large amount of elastic deformation of the other side portion 21 of the first elastic body 15 until it reaches the core material 7. This in turn reduces the amount of compressive deformation of the second elastic body 17.

As a result, in this embodiment, viscous damping due to compressive deformation of the second elastic body 17 is suppressed, and energy loss when the deformation energy stored in the ball-hitting area 5 is converted into the kinetic energy of the ball B is reduced. As a result, the bat 1 of this embodiment has a good resilience characteristic value in the ball-hitting area 5, and can improve the flight distance of the ball B.

Furthermore, with the bat 1 of this embodiment, by using one radial side of the ball-hitting portion 5, it is possible to deform only the second elastic body 17 and obtain a different hit than with the other radial side.

In the comparative example, when the ball B hits the ball-hitting area 5 on the other radial side, the other radial side of the second elastic body 17, where the ball B hits, is initially pressed by the ball B and undergoes compressive deformation, just as in the example.

When the second elastic body 17 is compressed between the ball B and the first elastic body 15, the pressing force of the ball B is transmitted to the other side portion 21 of the first elastic body 15 via the compressed portion. At this time, in the comparative example, the first elastic body 15 moves as a whole to the other radial side and undergoes almost no elastic deformation. As a result, the ball B deforms or the amount of compression of the second elastic body 17 increases.

Therefore, in the comparative example, viscous damping due to deformation of the ball B or compressive deformation of the second elastic body 17 increases, resulting in greater energy loss when deformation energy is accumulated in the hitting area 5 and converted into kinetic energy of the ball B.

[Modification]
FIG. 6 is a cross-sectional view showing the ball-hitting portion 5 of the bat 1 according to a modified example.

In the modified example shown in Figure 6, the cross-sectional shape of the first elastic body 15 is annular, and the core material 7 is bonded to the inner surface of one side portion 19.

Figure 7 is a cross-sectional view showing the ball-hitting portion 5 of a bat 1 according to another modification.

In the modified example shown in Figure 7, the cross-sectional shape of the first elastic body 15 is semicircular, and the core material 7 is bonded to the outer surface of one side portion 19. The first elastic body 15 may also be circular. In this modified example, the other side portion 21 of the first elastic body 15 faces the hitting area 9 of the core material 7 with a space 23 interposed between the one side portion 19.

In this way, the other side portion 21 only needs to face the core material 7 with the space 23 between them, and the form of facing can be direct facing with no intervening member, or indirect facing with an intervening member.

These modified examples shown in Figures 6 and 7 can also achieve the same effects as those of Example 1.

Figure 8 is a cross-sectional view of a bat according to Example 2 of the present invention. Figure 9 is a perspective view of a portion of the core material of the bat in Figure 8. Note that Example 2 shares the same basic configuration as Example 1, so corresponding components are designated by the same reference numerals and redundant explanations will be omitted.

In Example 2, the first elastic body 15 is formed from a cantilevered plate material. Furthermore, in this example, the collar 25 is integrally formed with the core material 7. Other aspects are the same as in Example 1. Note that the collar 25 may also be formed separately from the core material 7, as in Example 1.

The first elastic body 15 is disposed along the axial direction, with one axial side connected to the core material 7. One axial side of this first elastic body 15 forms one radial side portion 19, and the other axial side forms the other radial side portion 21. Note that while one axial side of the first elastic body 15 is the base end side of the bat 1, it may also be the tip end side. In this case, the other axial side of the first elastic body 15 is the base end side of the bat 1.

In this embodiment, the side portion 19 is integrally connected to the collar 25 and is an inclined plate portion that gradually transitions radially outward toward the tip. The side portion 19 can also be provided along the core material 7.

The other side portion 21 is a plate portion that extends along the core material 7 as a whole. In cross section, this other side portion 21 is formed in an arc shape that curves along the inner circumferential surface of the second elastic body 17. The other side portion 21 may also be a flat plate, a wavy plate, or a collection of multiple rod-shaped or linear bodies.

In this embodiment, when the second elastic body 17 is compressed on the other radial side upon collision between the hitting area 5 and the ball B, the first elastic body 15 elastically deforms with one side portion 19 as a fulcrum, displacing the other side portion 21 so as to narrow the space 23 between the hitting area 9 of the core material 7 in the radial direction.

As a result, this embodiment can achieve the same effects as Example 1.

1 Bat 5 Ball-hitting portion 5a Ball-hitting surface 7 Core material 15 First elastic body 17 Second elastic body 19 One side portion 21 Other side portion 23 Space portion

Claims (6)

A hitting portion of a bat for a ball game,
a core material disposed eccentrically on one side in the radial direction;
a first elastic body having one radial side supported by the core material and another radial side facing the core material with a space therebetween, the first elastic body having a relatively small elastic hysteresis;
a second elastic body that covers the radially outer side of the other side portion of the first elastic body to form a ball striking surface and has a relatively large elastic hysteresis;
A hitting area equipped with The ball hitting portion of claim 1,
the second elastic body is tubular and contains the first elastic body and the core material;
Hitting club. The ball hitting portion of claim 2,
The second elastic body is coupled to the core material at one side in the radial direction.
Hitting club. The ball hitting portion of any one of claims 1 to 3,
The first elastic body is annular and arranged in parallel with the core material, and a part of the first elastic body in the circumferential direction constitutes the one side portion.
Hitting club. The ball hitting portion of any one of claims 1 to 3,
the first elastic body is a cantilevered plate member provided along the axial direction and connected to the core member at one side in the axial direction, the one side in the axial direction constituting the one side portion and the other side in the axial direction constituting the other side portion,
Hitting club. A bat having the ball-hitting portion of any one of claims 1 to 5.