JP3039669U - Metal bat - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a strong metal bat having a metal structure in which the cross section of a hitting ball portion, a taper portion, and a grip portion is arranged in order in the longitudinal direction. [Structure] In a metal hollow bat 1 including a ball striking part 2, a taper part 3 and a grip part 4, the taper part 3 and the grip part 4 are made to have a uniform thickness, and the ball striking part 2, the taper part 3 and the grip are formed. A metal bat made of a metal structure whose cross section with the section 4 is arranged in order in the longitudinal direction is formed, and the wall thickness of the taper section and the grip section is made thinner than the residual deformation of the taper section and the grip section. It will be.

Description

[Detailed description of the invention]

[0001]

[Industrial applications]

 The present invention relates to a metal hollow bat including a hitting ball portion, a taper portion, and a grip portion. More specifically, the thickness of the taper portion and the grip portion is thin and uniform. The present invention relates to a metal bat having a strong strength and made of a metal structure in which the cross section of the grip portion and the grip portion are regularly arranged in the longitudinal direction.

[0002]

[Prior art]

 Conventional metal bats are made by swaging aluminum pipes into narrow squeezing shapes. However, if the straight pipe is shaped like a butt, the part where the dimensional deformation on the grip side is large becomes extremely thick, and such deformation causes cracks and wrinkles in the taper part and the grip part. There was a tendency for the particles to be generated or for the wall thickness to be thicker than the hit portion.

Further, in order to eliminate the drawback that the taper portion and the grip portion are thicker than the hitting portion, and to make the thickness of the taper portion and the grip portion equal to that of the hitting portion, a step drawing process is performed in advance. In some cases, a stepped tube with an outer diameter that was gradually reduced was manufactured and then swaged. However, since this is a method in which the aluminum pipe is once stepped and then processed into a smooth taper shape by swaging, there is a drawback that the thickness of each cross section is not always uniform. .

Further, in the conventional metal bat, the taper portion and the grip portion cannot obtain sufficient strength for their wall thickness. This was partly due to the fact that the final swaging process disturbed the cross-sectional structure of the aluminum extruded pipes that were once arranged in the longitudinal direction.

[0005]

[Problems to be solved by the device]

 In view of the above circumstances, the present invention is composed of a metal structure in which the thickness of the taper portion and the grip portion is thin and uniform, and the cross section of the hitting ball portion, the taper portion and the grip portion is arranged in an orderly manner in the longitudinal direction. The object is to provide a metal bat having a high strength.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention relates to a metal hollow bat comprising a hitting ball portion, a taper portion and a grip portion, and a metal structure in which the cross section of the hitting ball portion, the taper portion and the grip portion is arranged regularly in the longitudinal direction. And a thickness of the taper portion and the grip portion is smaller than the residual deformation of the taper portion and the grip portion.

[0007]

[Operation]

 Since the present invention is configured as described above, the strength of the bat is strong relative to the wall thickness due to the cross-sectional structure arranged in order in the longitudinal direction, and there is little variation in wall thickness and variation in the circumferential direction of the bat. It was possible to obtain a metal bat that does not exist.

[0008] Here, the cross-sectional structure arranged in order in the longitudinal direction means, for example, omitting the swaging process that disturbs the structure by repeated pressurization, and limiting the final stage to the drawing process, and Manufactured by pulling only.

[0009]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the drawings. This will be explained in comparison with the conventional comparative example. FIG. 1 is a side view showing an embodiment including a partially cutaway cross section of a metal bat of the present invention, and FIG. 2 shows a taper drawing method as one embodiment of manufacturing the metal bat of the present invention. It is a schematic sectional drawing which shows an outline. 3 (a), (b) and (c) are sectional views of the metal bat of the present invention of FIG. 1 cut at the positions of (a), (b) and (c) of FIG. It is sectional drawing which expanded 10 times with the microscope.

4A and 4B are schematic cross-sectional views showing an outline of a stepped drawing method and a swaging method showing a conventional example in comparison with FIG. Further, FIGS. 5A, 5B, and 5C are cross-sectional views in which the cross-sectional structure of the thick portion cut at the same position in the conventional example in comparison with FIG. 3 is magnified 10 times by an optical microscope.

The metal bat 1 of the present invention comprises a hitting portion 2 having a large diameter, a taper portion 3 and a grip portion 4 having a small diameter, and the inside thereof is a hollow 5. The metal bat 1 has a total length in the longitudinal direction L of about 850 mm. (A) shows the position where the flatness test, which is one of the certification standard confirmation tests for metal bats, is performed at a position about 140 mm from the tip 6, and (b) is the position 460 mm from the tip of the bat. The position where the wedge test is performed is shown, and (c) shows the position where the three-point bending test is also performed at a position of about 700 mm from the tip 6.

Although 7 is the thickness of the cross section, (a) is located at the hitting portion and a sufficient thickness is required, but (b) and (c) are of a thickness that can withstand a predetermined strength. It is thinner than the wall thickness at position (a).

As shown in FIG. 4 (A), the conventional method for manufacturing a metal bat is as follows. First, the ring 101 is attached to the outer circumference of the pipe, and hydraulically pulled in the longitudinal direction of the arrow 102 to form a step 103. 4B, and then, as shown in FIG. 4B, the stepped drawing product 104 is inserted between the jigs 106 and 106 that rotate 105, and the intermittent drawing in the drum 107 is performed. A roller (not shown) repeatedly applied pressure 108 to reduce the diameter to a predetermined shape.

On the other hand, in the metal bat of the present invention, for example, as shown in FIG. 2, a taper ring 8 is attached to the outer circumference of the pipe, and is pulled by hydraulic pressure in the longitudinal direction of the arrow 10. It is manufactured by the method.

The metal bat finally subjected to the pulling process by such a method has a structure in which the cross section is orderly arranged in the longitudinal direction. As shown in FIG. 3, the metal bat of the present invention is not limited to the position of the striking part in (a), and the entire cross section including the position of the taper part in (b) and the position of the grip part in (c) is It is composed of tissues 11a, 11b, 11c arranged in order in the longitudinal direction La, Lb, Lc.

On the other hand, when the conventional product is compared at the same positions (a), (b), and (c), the position of the striking part in (a) is composed of the tissues 110 arranged in order in the longitudinal direction 109 as shown in FIG. However, the position of the caper portion in (b) is composed of a plaque-like tissue 111 in cross section, and the position of the grip portion in (c) is also composed of a satin-like tissue 112 in cross section, both of which are regularly arranged in the longitudinal direction. It is not an organized organization.

The table below shows the test results comparing the present invention product and the conventional comparative product. ┌────┬─────────┬─────────┬─────────┐ │ │ Flat test (mm) │ Wedge test (mm) │ 3-point bending test (mm) │ ├────┼────┬────┼────┬────┼────┬────┤ │ │ Residual deformation │ average Wall thickness │ Residual deformation │ Average wall thickness │ Residual deformation │ Average wall thickness │ ├────┼────┼────┼────┼────┼────┼── ──┤ │This product│0.55│3.15│0.61│1.99│0.27│2.36│ ├────┼────┼────┼── ──┼────┼────┼────┤ │ Comparative product │0.48│3.12│0.59│2.07│0.25│2.45│ └─── ─┴────┴────┴────┴────┴────┴────┘

In Table 1, in the flatness test, a load of 6,700 N (670 kgf), for example, in the case of a hardball baseball bat (general purpose), was applied to a test piece having a length of 50 mm collected from the hitting portion. After that, the residual deformation amount (mm) when unloading is shown. In the wedge test, a load of 5,500N (550kgf) was applied by a wedge to the part where the outer diameter of the bat was 45mm, and then the unloading was performed. The amount of residual deformation (mm) at that time is shown. In the three-point bending test, a load of 6,700 N (670 kgf) is applied at a position of about 400 mm from the tip of the bat, for example, for a hardball baseball bat (general purpose). The amount of residual deformation (mm) after unloading is shown.

As shown in Table 1, in the flatness test at the position (a), there is not much difference between the product of the present invention and the comparative product, but at the taper portion at the position of (b), the product of the present invention has a residual deformation compared with the comparative product. It is possible to reduce the wall thickness at the same level, and even in the grip part at the same position (c), the product of the present invention can reduce the average wall thickness at the same level of residual deformation as compared with the comparative product, and It became strong.

[0020]

[Effect of the invention]

 In the metal bat of the present invention, the wall thickness of the taper portion and the grip portion is equal to that of the hitting portion, and the wall thickness of the taper portion and the grip portion is higher than the residual deformation of the taper portion and the grip portion. It became thinner, and the entire cross-section including the taper and grip was made of a metallographic structure arranged in the longitudinal direction in order to improve the strength. In addition, by increasing its strength, it became a light and strong metal bat.

The metal bat of the present invention can be provided at a lower cost because the steps can be omitted.

[Brief description of the drawings]

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

FIG. 2 is a schematic cross-sectional view showing the outline of a taper drawing method as an embodiment for manufacturing the metal bat of the present invention.

[Fig. 3] (a) shows the metal bat of the present invention about 1 from the tip.
It is sectional drawing which expanded the cross-section structure of the thick part cut | disconnected at the position of 40 mm 10 times with the optical microscope. (B) is a cross-sectional view in which the cross-sectional structure of a thick portion obtained by cutting the metal bat of the present invention at a position of 460 mm from the tip is magnified 10 times with an optical microscope. FIG. 3C is a cross-sectional view in which the cross-sectional structure of a thick portion obtained by cutting the metal bat of the present invention at a position of about 700 mm from the tip is magnified 10 times with an optical microscope.

FIG. 4A is a schematic cross-sectional view showing an outline of a conventional stepped drawing method compared with FIG. FIG. 2B is a schematic sectional view showing an outline of a conventional swaging method compared with FIG. 2.

5A is a cross-sectional view in which a cross-sectional structure of a thick portion cut at the same position in the conventional example compared with FIG. 3 is magnified 10 times with an optical microscope. FIG. 3B is an enlarged cross-sectional view showing a cross-sectional structure of a thick portion cut at the same position in the conventional example as compared with FIG. FIG. 3C is an enlarged cross-sectional view showing the cross-sectional structure of the thick portion cut at the same position in the conventional example as compared with FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal bat 2 Hitting ball part 3 Tapered part 4 Grip part 5 Hollow part 7 Wall thickness 11a Tissues arranged in order in the longitudinal direction 11b Tissues arranged in order in the longitudinal direction 11c Tissues arranged in order in the longitudinal direction L Longitudinal direction La Longitudinal direction Lb Longitudinal direction Lc Longitudinal direction

Claims (1)

[Utility model registration claims] 1. A metal hollow bat comprising a hitting ball portion, a taper portion and a grip portion, wherein a cross section of the hitting ball portion, the taper portion and the grip portion is made of a metallographic structure in which the taper portion and the grip portion are arranged orderly in the longitudinal direction. A metal bat characterized in that the thickness of the bat is thinner than the residual deformation of the taper and the grip.