JPH08299513A - Metallic bat - Google Patents

Abstract

PURPOSE: To buffer the impact waves of a metallic bat consisting of a hollow cylindrical body while maintaining the clear sound of metal and to improve its pressure resistance strength so as to lessen the crack and breakage thereof by packing a foamed aluminum body into this hollow cylindrical body. CONSTITUTION: The metallic bat 1 is formed of an aluminum alloy and is composed of a head part 2, a large-diameter hitting part 3, a tapered part 4 and a small-diameter grip part 5 and the inside thereof is formed as the hollow cylindrical body 6. The honeycomb-like foamed aluminum material 7 is packed into the hitting part 3 of the hollow cylindrical body 6. The production thereof is executed by adding and mixing particles which generate gasses at about 700 deg.C near the m.p. of molten aluminum increased in viscosity to and with this molten aluminum and storing the generated gases as closed cells into the molten metal. The foamed aluminum body 7 is thereafter immersed into an aq. caustic soda soln., etc., and is rested, by which the thin films of the closed cells connected to each other are removed and the stable honeycomb-like foamed aluminum body 7 of open cells is molded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal bat, and more particularly to a metal bat that buffers shock waves.

[0002]

2. Description of the Related Art Conventionally, a metal bat made of a hollow cylindrical body made of an aluminum alloy material has a case in which a shock wave at the time of hitting a ball directly propagates to a grip, so that the hand is numb and the elbow is hurt.

Therefore, it has been attempted to fill the hollow cylindrical body with a cushioning material made of an elastic body. However, in the case of an elastic body, the pleasant sound made of metal tends to be dull.

[0004]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a metal bat that maintains a pleasant sound of metal, buffers shock waves, increases pressure resistance, and reduces breakage damage. It is intended.

[0005]

In order to achieve the above-mentioned object, the present invention relates to a metal bat made of a hollow cylinder, the hollow cylinder being filled with an aluminum foam body.

[0006]

[Operation] Since the metal bat of the present invention is constructed as described above and filled with the honeycomb foam aluminum body, the pleasant sound made of metal is maintained and the shock wave is buffered.

In the metal bat of the present invention, since the cushioning material is a foamed aluminum body made of metal open cells, the hitting sound is silenced and the flight distance is not reduced.

In the metal bat of the present invention, since the hollow cylindrical body is filled with the foamed aluminum body, the pressure resistance is remarkably improved and the breakage is reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a side view including a partially cut-away cross section showing an embodiment of the metal bat of the present invention, and FIG. 2 shows an embodiment of the foamed aluminum body filled in the metal bat of FIG. It is a perspective view.

The metal bat 1 is made of aluminum alloy, and has a head portion 2, a large-diameter striking portion 3, and a taper portion 4.
And a small-diameter grip portion 5, but the inside is a hollow cylindrical body 6. The hitting portion 3 in the hollow cylindrical body 6 is filled with a honeycomb-shaped aluminum foam body 7.

The foamed aluminum body is a porous body in which continuous cells are dispersed in a honeycomb shape, and is a lightweight metal composite material excellent in lightness and shock absorption. Means for producing a foamed aluminum body include, for example, alloying, oxidation of molten metal,
Particles such as hydrides and natural minerals that generate gas at around 700 ° C near their melting point are added as a foaming agent to molten aluminum whose viscosity has been increased by a method such as dispersing ceramic particles, and the generated gas is melted. Keep as closed bubbles inside. Next, a method of immersing the foamed aluminum body in a 20 wt% caustic soda aqueous solution and leaving it for 8 hours to remove the thin films of the closed cells to form a stable honeycomb-shaped open-celled foamed aluminum body can be exemplified. it can.

Further, the viscosity of molten aluminum is increased under atmospheric pressure and hydrogen, nitrogen, oxygen or a mixed gas thereof is blown into the thickened molten aluminum, or hydrides, nitrides, oxides, hydrous minerals, etc. After the gas is dissolved in the thickened molten aluminum plate by stirring and mixing particles that generate gas by thermal decomposition, -4
It is also possible to exemplify a method of foaming molten aluminum by setting a reduced pressure atmosphere in the range of 00 to -760 mmHg. The apparent specific gravity obtained by such a method is 0.1 to 0.5, and the porosity is about 65 to 78%.

The foamed aluminum body 7 of this embodiment is a cylindrical processed product obtained by hollowing out the foamed aluminum plate material into a cylindrical shape and forming a hollow hole 8 at the center in the axial direction. However, the foamed aluminum body 7 is not limited to such a cylindrical processed product, and if necessary, about four hollow holes may be provided in the axial direction, and the specific gravity is as described above. Since it is small, it may be used in a cylindrical shape without a hollow hole.

FIG. 3 is an exploded side view mainly showing a notched cross section showing an embodiment in the manufacturing process of the metal bat of the present invention. 9 is an aluminum hollow shell after the extrusion process, 6 is its hollow cylindrical body, and the striking part, the taper part and the grip part are already formed, but the tip part 10 of the head part is , Still open.

Reference numeral 11 in this embodiment is a plug, which has a conical shape made of a cushion material obtained by hardening soft polyurethane scraps with an adhesive. The outer diameter of this conical shape is equal to the size reduced from the inner diameter 12a of the striking portion to the inner diameter 13 of the taper portion, and this plug 11 is bonded to one end 14 of the foamed aluminum 7. In addition, the other end 1 of the foamed aluminum body 7
A cylindrical plug 16 having the same outer diameter as the inner diameter 12b of the striking portion made of the same material is adhered to the column 5. The bonding can be performed by using soldering such as vacuum brazing together.

The foamed aluminum 7 in which the conical plug 11 and the cylindrical plug 16 are bonded and integrated at both ends has an outer diameter equal to the inner diameters 12a-12b of the striking portion. Therefore, when this integrated body 17 is inserted into the hollow cylindrical body 6 from the tip portion 10 of the bat, the portion of the foamed aluminum body 7 enters the inside diameters 12a to 12b of the striking portion of the same size, but the size is reduced. Stop before the inner diameter 13 of the taper. At this time, the outer diameter of the conical plug 11 is the inner diameter 1 of the striking portion.
2a has a cone-shaped equivalent size that is reduced to the inner diameter 13 of the taper portion, so that the integrated product 17 is the hollow cylindrical body 6
It is filled in a fixed position inside.

The present embodiment shows an example in which the foamed aluminum 7 is filled in the inner diameters 12a to 12b of the striking portion 3. However, the aluminum foam 7 can be filled over the head portion 2 and the taper portion 4 or separately. For example, if the entire head portion 2 is filled, it will not move even if it receives an impact. If the taper portion 4 is also filled, it can contribute to the prevention of breakage of the bat.

In order to fix the position, an adhesive is applied to the outer diameter surface of the integrated body 17 at the time of insertion so that it is sufficiently bonded to the inner surface of the hollow cylindrical body 6. Adhesives are foamable or fibrous because the adhesives are metallic.
It is also desirable to consider so as to fill the gap, and in particular, it is necessary to make a strong bond that does not come off even when subjected to repeated impacts.

Next, the tip portion 10 of the hollow shell 9 is applied to the inlet of a female mold (not shown) and cold pressed in the direction of the arrow. By this drawing process, the tip of the hollow shell 1
0 is bent inward and is automatically and firmly inserted into the annular recess 19 of the tip cap 18, and the tip portion 10 of the metal bat which has been opened is closed by the tip cap 18.

The above manufacturing method is merely an example, and the metal bat of the present invention can be manufactured by other methods. For example, instead of the foamed aluminum body, a metal having a high melting point such as copper, iron or titanium can be similarly foamed to obtain a porous sintered body.

[0021]

As described above, the metal bat of the present invention manufactured as described above can absorb a shock wave at the time of hitting a ball while maintaining a pleasant sound made of metal. Therefore, it was possible to eliminate the conventional drawback that the hand is numb and the elbow is damaged by the impact at the time of hitting the ball.

The metal bat of the present invention has a sound absorbing effect due to the communicating bubbles, and can contribute to the muffling of the hitting sound.

The metal bat of the present invention has a drawback of breakage of the bat because the pressure resistance strength is remarkably improved by the foamed aluminum body filled in the cavity even when the wall thickness is reduced without reducing the flight distance at all. Could be resolved.

Since the metal bat of the present invention is made of a foam having a light specific gravity, the weight control is performed depending on the volume used.
Now you can do it easily.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of a metal bat of the present invention including a partially cutaway cross section.

2 is a perspective view showing an embodiment of aluminum foam filled in the metal bat of FIG. 1. FIG.

FIG. 3 is an exploded side view mainly showing a notched cross section showing one embodiment in the process of manufacturing the metal bat of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal bat 6 Hollow cylinder 7 Foamed aluminum body 9 Hollow shell 17 Integrated aluminum foam to be filled

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshihiro Hosokawa 2840 Ikedashitamachi, Izumi City, Osaka Prefecture Hosokawa Manufacturing Co., Ltd.

Claims (2)

[Claims] 1. A metal bat made of a hollow cylinder, wherein the hollow cylinder is filled with a honeycomb-shaped aluminum foam body. 2. A foamed aluminum body is obtained by mixing a molten aluminum alloy with a foaming agent capable of foaming at around 700 ° C. near the melting point, retaining the generated gas as independent bubbles in the molten aluminum, and then immersing it in an alkaline aqueous solution. The metal bat according to claim 1, which is manufactured by removing the thin films of the independent cells to form honeycomb-shaped continuous cells.