JPH039771A - Metallic bat - Google Patents

Abstract

PURPOSE:To reduce the batting sound at a low cost with a simple mean by filling air bag sheets inside a bat made of hollow aluminum material. CONSTITUTION:An hollow aluminum material is formed into a main body 1, and air bag sheets 7 are filled inside a barrel 4 of the main body 1. After the air bag sheets 7 are filled, soft type one-component adhesive 8 is injected into the main body to fix the ends of the air bag sheets 7 to the main body 1. After the air bag sheets 7 are filled in and fixed to the main body 1, a grip end 2 is welded to the main body 1. The vibration waves generated by batting is prevented from dispersing inside the barrel 4 of a bat by filling the air bag sheets 7, and the phase of the secondary sound, which is generated a while after batting, is prevented from coinciding with that of the first sound which is generated immediately after batting.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a metal bat used in baseball.

[Conventional technology]

When the metal bat is made of aluminum material, the main body portion 1 is formed of a hollow aluminum material as shown in FIG.
Similarly, a grip end 2 made of aluminum is often attached by welding.

The main body part 1 has a closed end as a head part 3, a striking part 4 having approximately the same diameter in the vicinity thereof, and a grip part 6 having a small diameter located through a tapered part 5.

[Problem to be solved by the invention]

Such metal bats have a higher impact sound than wooden bats, and in particular, when hitting a hardball baseball, the audible sound of a wooden bat is a bright ``click'', whereas an aluminum metal bat has a ``knock'' sound. ” It was an extremely loud sound with a long tail.

The impact sound of a metal bat generally consists of two types of sounds: the sound that occurs immediately after the impact (the first sound) and the sound that occurs after a while (the second sound).The first sound is caused by the impact and the resulting sound. This is thought to be due to the vibration caused.

In addition, the second sound is a wave of vibration caused by a hit that is diffused inside the bat, reflected at both ends of the head part 3 and grip end 2, and while moving inside the bat, the phases match and become large vibrations. It emits a sound.

Incidentally, according to measurement using a sound level meter, the audible sound near the batter is 90 to 91 dB for a wooden bat, but 109 to 111 dB for an aluminum metal bat.

Continuously listening to such high-level hitting sounds from an aluminum metal bat may cause hearing loss for players and referees. Furthermore, it may cause noise pollution to the surrounding environment.

SUMMARY OF THE INVENTION An object of the present invention is to provide a metal bat that eliminates the disadvantages of the conventional example and can easily and inexpensively suppress the sound of hitting.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a bat made of a hollow aluminum material, in which the inside of the hitting portion of the bat is filled with an airbag sheet.

[Function] According to the present invention, by filling the inside of the hitting part of the bat with an airbag sheet, it is possible to suppress the vibration waves generated by the bat from diffusing within the bat, and prevent vibrations generated immediately after the hitting. This can prevent the first sound generated and the second sound generated after a while from matching in phase.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a partially cutaway side view showing one embodiment of the aluminum metal bat of the present invention, and the bat has a main body 1 made of a hollow aluminum material as explained in FIG. Grip end 2 also made of aluminum material
It is used for welding.

These main body part 1 and grip end 2 are formed from a 7000 series aluminum alloy material according to a conventional method.
As for the main body part, the drawn tube is swaged to form the taper part and the grip part, and then the head part is closed integrally by spinning process, and then heat treated to give the required strength. The grip end is formed from a plate material by drawing.

In the present invention, an airbag sheet 7 as shown in FIGS. 2 and 3 is filled inside the striking part 4 of the main body part 1. The airbag sheet 7 is a well-known material (used as a cushioning material for packaging fragile items), and is made by laminating two synthetic resin films such as polyethylene films and sealing air between them into hemispherical particles 7a. are formed at appropriate intervals.

- As an example, the airbag sheet 7 has a sheet thickness: 0.
03~0.10mm, grain size: φ6~φ14mm, grain pitch: 8~15mm, width 15~30mm, length 500~
Many rectangular pieces of about 1200M are used.

As shown in FIG. 4, before welding the grip end 2 to the main body part I, an airbag sheet 7 is inserted into the interior through the opening at the end of the grip part 6 of the main body part 1, and is filled inside the striking part 4. . Further, after inserting the airbag sheet 7, a one-component soft adhesive 8 made of soft epoxy resin or the like was injected from the same opening to fix the end of the airbag sheet 7 to the main body l. Although not shown in the drawings, the adhesive 8 can be filled only in the necessary areas by being extruded from a cartridge having a tubular spouting part inserted through the opening.

The insertion weight of the airbag sheet 7 is 5 to 20g 1 adhesive 8
The zero weight is 4 to 10 g, which is extremely small compared to the weight of the entire bat.

After filling and fixing the airbag sheet 7 into the main body part 1 in this manner, the grip end 2 is welded to the main body part 1, the surface is polished, etc., and the product is completed and inspected.

Next, the results of an experiment to test the effects of the metal bat of the present invention are shown in Table 1 below.

Table 1 (Note 1) Tribute test pitching machine (initial velocity of ball 110 law/Hr
s) Batter: Baseball player The time waveform of the sound is as shown in FIG.

As can be seen from Table 1 and FIG. 5, a sound reduction effect comparable to that of a wooden bat was observed, and the impact sound was at a level that was not bothersome even when listened to continuously.

This is due to the synergistic effect of the presence of the airbag sheet 7, which reduces the impact sound itself and eliminates the second sound that occurs a while after the first sound that occurs immediately after the impact.

〔Effect of the invention〕

As described above, the metal bat of the present invention is a bat formed from a hollow aluminum material, and the audible impact sound is a bright "kang" sound, which does not cause discomfort, and the impact sound itself can be reduced.

In addition, it is extremely easy to manufacture as there is no need to make any changes to the current production line, and the manufacturing cost is low.The airbag sheet has a long lifespan, resulting in a sustained effect, and the airbag sheet is lightweight. Therefore, weight adjustment is easy.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway side view showing one embodiment of the metal bat of the present invention, Fig. 2 is a front view of the airbag sheet to be filled, Fig. 3 is a longitudinal cross-sectional side view of the same, and Fig. 4 is the manufactured one. FIG. 5 is a perspective view showing the process, FIG. 5 is a waveform diagram showing the time waveform of sound, and FIG. 6 is a side view showing a conventional example. 1...Body part 2...Grip end 3
...Head part 4...Blowing part 5...Taper part 6...Grip part 7...Airbag sheet 7a...Grain 8...Adhesive Fig. 4

Claims (1)

[Claims] 1. A metal bat made of a hollow aluminum material, characterized in that the inside of the hitting part of the bat is filled with an airbag sheet.