JPH08257187A - Metal bat - Google Patents

Abstract

PURPOSE: To make vibrations hard to transmit, improve the high-impact and instantaneous repulsion properties when a bat hits a ball, by a method wherein at least a part of the batting part is made of pure titanium or titanium alloy pipe, or austenite-ferrite stainless steel pipe and the other parts are made of aluminum alloy pipe. CONSTITUTION: A main barrel 1 of a bat consists of a head A1 and a batting part A2. The batting part A2 to be connected to a middle barrel B is made of titanium pipe, and the head A1 is made of aluminum alloy pipe. The middle barrel B and a grip C are integrally formed into one-piece of aluminum alloy pipe. A cap 2 molded of rigid resin is fitted in the top opening of the head A1 in the axial direction of the bat. A knob 3 made of the same material as the grip C is welded to the base end of the grip C in the axial direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow metal bat used for baseball, softball and the like.

[0002]

2. Description of the Related Art In this type of metal bat, it is required to increase the spring effect of the hitting portion of the bat body, that is, hardness, elastic restoring force, elastic restoring speed, etc., in order to increase the flight distance of the hitting ball. There is. Therefore, conventionally, in a portion corresponding to the hitting portion of a hollow bat body made of a single metal such as duralumin or an aluminum alloy, a metal or synthetic resin formed with an outer diameter slightly larger than the inner diameter of the portion. Those in which a core material is press-fitted (for example, Japanese Patent Publication No. 50-7976,
Or the outer shell of the hitting portion of the bat body is made of fiber reinforced plastic, and a synthetic resin is filled inside to form the core portion.
The grip part and the intermediate part from the grip part to the hitting part are made of a light alloy pipe (Jpn.
No. 4) has been proposed. Further, there is one in which the entire bat body is made of a titanium alloy tubular body.

[0003]

However, in the former case, since the bat body is made of a single metal, vibration at the time of hitting the ball easily propagates to the grip side. Moreover, in order to press-fit the core material in a predetermined position of the hitting portion corresponding to the hitting portion in the bat body in a state where the contact pressure with the inner peripheral surface of the bat body is constant in the circumferential direction and the bat axis direction, The inner peripheral surface of the bat body and the outer peripheral surface of the core must be machined with high precision, respectively, and the number of parts is increased, so that the manufacturing cost is likely to increase. In the case of the latter, since the portion corresponding to the hitting portion of the bat body is composed of the outer shell made of fiber reinforced plastic and the foam synthetic resin core material, it is lightweight and can attenuate the vibration at the time of hitting the ball. However, while the large impact at the time of hitting repeatedly acts, the fiber-reinforced plastic layers forming the outer shell,
Delamination may also occur between the fiber-reinforced plastic layer and the foam synthetic resin that constitutes the core material, and there is room for improvement in terms of life and flight distance. Also, if the entire bat body is composed of a titanium alloy tube, the spring effect of the hitting portion of the bat body can be increased, but titanium alloy has a higher material cost than duralumin and aluminum alloy, and titanium Processing the alloy tube into the shape of the bat body means that the titanium alloy has high hardness, tensile strength,
Since it has a proof stress as a characteristic, it is very difficult to perform, so that the processing cost also rises, resulting in an increase in manufacturing cost.

The present invention has been made in view of the above circumstances, and an object thereof is to prevent vibrations from being transmitted at the time of hitting a ball,
The point is to manufacture a product excellent in impact resistance and instantaneous repulsion, in terms of manufacturing cost.

[0005]

The first characteristic constitution of the present invention for achieving the above-mentioned object is that at least a part of the hitting portion of the bat body made of metal is made of pure titanium or titanium alloy, or In addition to being composed of an austenite-ferrite stainless steel tube, the other parts are made of an aluminum alloy tube.

A second characteristic configuration is that the tubular bodies are joined by friction-welding their end faces facing each other in the butt axis direction.

A third characteristic construction is such that the end portion of one pipe body joined by the friction pressure welding is internally rotatably fitted in the end portion of the other pipe body in a sliding contact state. The point is that the junction is formed.

[0008]

According to the structure of claim 1, at least a part of the hitting portion of the bat body is made of pure titanium or titanium alloy or austenite-ferrite stainless steel tube. Therefore, by utilizing the high hardness, tensile strength, and proof stress, which are the characteristics of pure titanium or titanium alloy, or austenite / ferrite stainless steel, the impact resistance of the hitting part is improved and the weight is reduced due to thinning, and instantaneous repulsion is achieved. You can increase your strength. However, the parts other than pure titanium or titanium alloy or austenite-ferrite stainless steel tubes are made by using the ductility, which is a characteristic of aluminum alloys, in the pipe shrinking process (swaging) in the manufacturing process of metal bats. Processing, tapering processing and spinning processing) can be easily performed. Moreover, since the tubular bodies made of different metals are joined together, the vibration at the time of hitting can be attenuated by the change in the vibration characteristics at the joined portion.

According to the structure of claim 2, one tube is rotated at a high speed around the bat axis while the two tube ends are opposed to each other in the butt axis direction, and one of these ends is rotated at a high speed. After being melted by frictional heat and then cooled and solidified, both pipes are joined together. During this friction welding, impurities such as thin oil films, oxides, and dirt attached to each of the end faces of both pipes are destroyed in the process of frictional heat generation and are extruded as burrs from the molten metal part. It is possible to suppress a decrease in bonding accuracy due to impurities existing in the joint portion, as compared with a case where the end faces are joined together via an adhesive or a case where they are welded together via a molten metal.

According to the third aspect of the present invention, both pipes are friction-welded between their joint end faces, and at the same time, the other pipe of the fitting portion formed at the end of one pipe is formed. Since they are fitted and joined to each other by internal fitting to the ends, when an impact force, such as when hitting a ball, acts on the joint portion of both pipes, this impact force is applied not only to the friction welding portion but also to the wide joint portion. It can be distributed and received on the mating surface.

[0011]

According to the metal bat of the first aspect of the present invention, since the tubes made of different metals are simply joined together, the number of parts and the number of manufacturing steps are reduced and the processing accuracy is improved as compared with the conventional case. In addition to facilitating processing, the problem of strength reduction due to delamination does not occur, but the characteristics of pure titanium or titanium alloy, or austenite-ferrite stainless steel and aluminum alloy Since the characteristics can be effectively used, the synergistic effect of these characteristics makes it possible to manufacture a vibration-resistant ball that is hard to be transmitted to the hand and is excellent in impact resistance and instantaneous repulsion in terms of manufacturing cost.

The metal bat according to claim 2 is one in which the end faces of both pipes are joined together with an adhesive, or
It is possible to increase the joint strength of the joint portion while facilitating the production, as compared with the case of welding through molten metal.

In the metal bat according to claim 3, the joint strength of the joint portion can be further improved.

[0014]

【Example】

[First Embodiment] The metal bat shown in FIG. 1 includes a ball hitting portion A, an intermediate portion B, and a grip C that constitute the bat body 1.
The hitting portion A comprises a head portion A1 formed of a cylindrical tube body having substantially the same outer diameter along the bat axis direction and a hitting portion formed of a cylindrical tube body having substantially the same outer diameter along the bat axis direction. Of the head part A1 and the hitting part A2, the hitting part A2 is joined to the intermediate part B.
Is formed of a titanium alloy tube, the head portion A1 is formed of an aluminum alloy tube, and the intermediate portion B and the grip portion C are integrally formed of an aluminum alloy tube. Has been done. Further, a cap 2 formed of a hard resin is fitted and fixed to the opening of the head portion A1 at the tip end side in the butt shaft center direction, and the grip portion C is provided at the base end side in the butt shaft center direction of the grip portion C.
An aluminum alloy grip end 3 made of the same material as the above is welded and fixed, and a non-slip tape 4 is wound around the grip portion of the grip portion B. The intermediate portion B and the grip portion C are formed into a trumpet-shaped tubular body having a smaller outer diameter on the grip end 3 side. The diameter of the outer peripheral surface from the hitting portion A to the tip portion of the intermediate portion B is about 56 mm.

As shown in FIG. 3, the head portion A1
Is an example of an aluminum alloy having a wall thickness of about 2.3 mm, and has a tensile strength of 265 N / mm ² or more,
An extruded tube made of a 6061 alloy (JIS name) having mechanical properties with a proof stress of 245 N / mm ² or more and an elongation of 8% or more was cut into a predetermined length, and the end of the cut cylindrical body was surrounded by one end. An annular engaged portion a for preventing the cap 2 from slipping out by engaging with an annular engaging portion 2a formed in the fitting portion 2A of the cap 2 is integrally formed.

As shown in FIG. 2, a head portion A1 and an intermediate portion B are provided at both ends of the striking portion A2 in the axial direction of the bat.
And a fitting portion b which is fitted in the head portion A1 and the intermediate portion B such that the head portion A1 and the intermediate portion B are relatively rotatably fitted in the sliding contact state. The striking portion A2 including b is an example of a titanium alloy, has a tensile strength of 890 N / mm ² or more and a proof stress of 825 N / mm.
It is composed of a tube body made of α-10β type Ti-6Al-4V alloy having a mechanical property of ² or more and an elongation of 10% or more, and the hitting portion A2 is formed to have a wall thickness of about 1.5 mm. The outer diameter of the fitting portion b is about 4.
It is formed as small as about 5 mm and has a wall thickness of about 0.5 mm.

As shown in FIGS. 1 and 2, the intermediate portion B and the grip portion C are made of the same material as that of the head portion A1,
That is, the thickness of 6061 is approximately 2.3 mm.
An extruded pipe made of an alloy is cut into a predetermined length, and the cut cylindrical body is swaged into a trumpet shape having an outer diameter smaller toward the grip end 3 side (an example of a pipe shrinking process).

Next, the head portion A1 and the hitting portion A
2, and the joining method of the hitting portion A2 and the intermediate portion B and the steps thereof will be specifically described. First, one fitting portion b of the striking portion A2 is fitted inward from the butt shaft center direction at the end portion of the head portion A1 opposite to the side where the cap 2 is attached,
The end portions 5 and 6 of the head portion A1 and the striking portion A2, which face each other in the butt axis direction, are butted against each other in a pressed state, and one of the head portion A1 and the striking portion A2 is fixed and the other is fixed. When the bat shaft is rotated at high speed, the end faces 5 and 6 are melted by frictional heat. After the melted metal molecules forming the head portion A1 and the metal molecules forming the striking portion A2 are fused, the melted portion is cooled and solidified, so that the head portion A
The end face 5 of No. 1 and the end face 6 of the striking portion A2 are joined by friction welding. Next, the other fitting portion b of the striking portion A2 of the striking portion A, which is formed by joining the head portion A1 and the striking portion A2 by friction welding to the end portion on the tip side of the intermediate portion B, is arranged in the bat axial direction. End surfaces 7 and 8 of the striking portion A2 and the intermediate portion B that face each other in the bat axis direction.
Are abutted in a pressed state, and when one of the hitting portion A and the intermediate portion B is fixed and the other is rotated at high speed around the bat axis, these end faces 7 and 8 are melted by frictional heat. It Then, after the molten metal molecules forming the striking portion A2 and the metal molecules forming the intermediate portion B are bonded, the molten portion is cooled and solidified, so that the end surface 7 of the striking portion A2 and the intermediate portion B are The butt body 1 is formed in a state where it is joined to the end surface 8 by friction welding.
Further, both the joining parts joined by friction welding have a frictional heat generation process even if thin oil films, oxides or impurities such as dirt adhere to the respective end surfaces 5, 6, 7, 8 before joining. Since it is destroyed and extruded as a flash from the molten metal part, impurities existing in the bonded part after bonding do not reduce the bonding accuracy of metal molecules, and it is possible to secure high bonding strength and its reliability. Is also high.
The flash is scraped off during the final processing of the bat body 1.

As shown in FIG. 2, the annular end surfaces 6 and 7 located on both sides of the striking portion A2 in the bat axis direction project toward the head portion A1 side and the intermediate portion B side in the diametrically outward direction. Each of the annular end surface 5 of the head portion A1 and the annular end surface 8 of the intermediate portion B which are formed in such a wedge-shaped concave surface and face the both end surfaces 6 and 7 are hitting portions toward the inner side in the diametrical direction. The striking portion A protruding toward the A2 side
2 is formed into a wedge-shaped convex surface that comes into contact with both end surfaces 6 and 7,
It is joined in a so-called scarf shape. The both fitting parts b are
It is also configured as a guide member for smoothly abutting the end surfaces of the head portion A1 and the striking portion A2 and the end surfaces of the striking portion A2 and the intermediate portion B during friction welding. The joining step is not limited to the above-mentioned steps, but after the intermediate portion B is joined to the striking portion A2 by friction pressure welding, the head portion A1 is joined to the striking portion A2 by friction welding. 1 may be formed.

By the way, α-10β type Ti-6Al-4V
The hitting portion A2 composed of an alloy tube is 6061
Compared with the case where the striking part A2 is composed of an alloy extruded tube,
The spring effect in the hitting portion A2, that is, the elastic restoring force and the elastic restoring speed necessary for extending the flight distance of the hit ball are high, and thus the momentary repulsion force is high, and the flight distance of the hit ball can be effectively extended. it can.

[Second Embodiment] In the first embodiment, the cap 2 made of hard resin is fitted and fixed to the opening of the head portion A1 at the tip end side in the butt axis direction. As described above, the opening on the tip end side in the butt shaft center direction of the head portion A1 may be squeezed and closed by spinning.
In this case, it is not necessary to provide the cap 2. The other structure is similar to that of the first embodiment.

[Third Embodiment] In the first embodiment, the hitting portion A is formed by friction-welding a head portion A1 made of aluminum alloy and a hitting portion A2 made of titanium alloy. As shown, the head portion A1 and the hitting portion A2 forming the hitting portion A may be integrally formed of a titanium alloy. In this case, one end portion of the hitting portion A on the side of the intermediate portion B is relatively rotated in a sliding contact state with the hitting portion A and the intermediate portion B in a state where the hitting portion A and the intermediate portion B are joined. A fitting portion b that freely fits inside is integrally formed, and the hitting ball portion A including this fitting portion b is an example of a titanium alloy, and has a tensile strength of 890 N / mm ² or more and a proof stress of 825 N / mm
It is formed of a tube body made of α-10β type Ti-6Al-4V alloy having a mechanical property of ² or more and an elongation of 10% or more. Furthermore, an annular cover for preventing the cap 2 from slipping out is engaged with the annular engaging portion 2a formed in the fitting portion 2A of the cap 2 on the peripheral edge of the hitting ball portion A in the butt shaft center direction. The engaging portion a is integrally formed.
The other structure is similar to that of the first embodiment.

[Other Examples] The joint shape of the joint portion between the tubular bodies made of different metals and
Then, as shown in FIG. 6, at two locations in the bat axis direction.
You may fit in the step shape which can be friction-welded. This place
The bat body 1 including the joint portion
Can be formed uniformly in any direction. Furthermore, as shown in FIG.
The step-like mating part with a thicker wall,
The combined strength may be improved. The hitting portion A2 of the first embodiment or the second actual
The hit ball portion A of the example is replaced with a titanium alloy, and an industrial pure titanium
Tube or austenite / ferrite type
You may comprise from a stainless steel pipe. In addition,
Tensile strength for knight-ferrite stainless steel
Is 620 N / mm²Above, the yield strength is 450 N / mm²that's all
SUS329J2LTP (JIS
And the tensile strength is 590 N / m.
m²Above, yield strength is 390N / mm ²The mechanical properties above
Even with SUS329J1TP (JIS name) provided
Good. As the aluminum alloy, the 6061 alloy
However, it is not limited to
Among the alloys, the tensile strength is 550N / mm²Above, proof stress
Is 490 N / mm²Above, machines with growth of 7% or more
It may be a 7075 alloy with mechanical properties.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a front view of a metal bat according to a first embodiment.

FIG. 2 is an enlarged sectional view of a main part.

FIG. 3 is an enlarged cross-sectional view showing a cap attached state.

FIG. 4 is a front view of a metal bat according to a second embodiment.

FIG. 5 is a front view of a metal bat according to a third embodiment.

FIG. 6 is an enlarged sectional view showing another embodiment of the friction welding portion.

FIG. 7 is an enlarged cross-sectional view showing another embodiment of the friction welding portion.

[Explanation of symbols]

 1 Bat body 5 End face 6 End face 7 End face 8 End face A Hitting part A1 Tubular body A2 Tubular body B Tubular body C Tubular body b Fitting part

Claims (3)

[Claims] 1. A bat body (1) of a metal bat body (1), at least a part of which is made of pure titanium or a titanium alloy, or an austenite-ferrite stainless steel tubular body (A2). In addition, a metal bat having the other parts made of aluminum alloy tubes (A1, B, C). 2. The pipe bodies (A1, A2, B) are joined together by friction-welding end faces (5, 6, 7, 8) facing each other in the bat axis direction. Metal bat. 3. The end portion of the one pipe body (A2) joined by the friction welding is relatively rotatably inside the end portion of the other pipe body (A1, B) in a sliding contact state. Fitting part to fit (b)
The metal bat according to claim 2, wherein the metal bat is formed.