JP3644814B2 - Manufacturing method of multi-tube bat for baseball or softball - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a baseball or softball bat (hereinafter simply referred to as a bat).
[0002]
[Prior art]
Conventionally, bats are made of various materials such as wood, metal such as titanium, titanium alloy and aluminum alloy, and fiber reinforced plastic made of carbon fiber and glass fiber. Yes. Also, in the conventional bat, while trying to improve the durability of the hitting portion of the bat and improve the rebound characteristics of the ball at the time of hitting, it is known that various structures are interposed inside the hitting portion of the bat. It has become. That is, it is an invention related to bats such as Japanese Patent Publication No. 50-7976, Japanese Utility Model Publication No. 51-13165, Japanese Utility Model Application Publication No. 56-93265, and Japanese Patent Application Laid-Open No. 5-57042.
[0003]
[Problems to be solved by the invention]
However, these conventionally known bats have the following problems. In other words, from the attempt to improve the durability of the hitting part of the bat and to improve the rebound characteristics of the ball at the time of hitting, various types of structures inserted into the hitting part of the bat have the following problems. Had. For example, in the bat of Japanese Patent Publication No. 50-7976, in order to make the grip as a suitable thickness around 3 mm as a bat, the thickness of an aluminum pipe having a diameter of 60 mm must be about 1.2 mm. Although this is lightweight as a bat, the hitting ball is a bat in which the pipe of the hitting surface is easily dented.
[0004]
Therefore, use an aluminum pipe with a suitable thickness as a bat, do not take into account the thickness of the striking surface, and have the purpose of strengthening the thinness of the hitting ball portion with the best grip thickness. A metal bat that is light and well-balanced, has a very high flying force, and withstands long-term use, with a metal ball that is either thick enough to withstand the ball when it is fitted or fitted inside the ball. Can provide. However, in the bat of Japanese Patent Publication No. 50-7976, a thick aluminum pipe having an appropriate weight is used as the bat, the wall thickness of the hitting surface is not taken into consideration, and the grip portion has the best thickness. Because the bat strengthens the wall thickness, weight balance was emphasized, so the design balance of the thickness of the outer pipe and the inner pipe was poor, and these pipes resonated at the time of hitting and the vibration of the bat resonated. He had the problem of being numb.
[0005]
In addition, regarding the bat of Japanese Utility Model Publication No. 51-13165, in order to remedy the defect that the vibration of the bat reverberates due to the resonance of the outer pipe and the inner pipe, which is a defect of the double pipe type bat. Also known are metal bats in which a striking ball layer in which a rubber or synthetic resin plate or a pipe thereof is inserted and bonded to an intermediate layer of these double pipes has a triple structure.
However, in the bat of Japanese Utility Model Publication No. 51-13165, the striking ball layer in which a rubber or synthetic resin plate or their pipe is inserted and bonded to the intermediate layer of the double pipe certainly has a triple structure. The problem that resonance can be prevented and vibration vibrates in the hand can be solved, but the hitting sound becomes dull and the rebound characteristics of the ball at the time of hitting are reduced. In addition to suppressing the flight distance, the hitting ball portion has a triple structure, and thus has a problem that the balance of the hitting ball portion of the bat becomes heavy.
[0006]
Further, regarding the bat of Japanese Utility Model Publication No. 56-93265, a composite layer structure in which an outer peripheral layer of a substrate having a cylindrical cross-sectional hollow structure is formed of an aluminum alloy and an inner peripheral layer thereof is formed of titanium or a titanium alloy. The bat is also known. However, in the bat of Japanese Utility Model Laid-Open No. 56-93265, a clad manufacturing method using dissimilar metals in which the outer peripheral layer is made of an aluminum alloy having a thickness of 2 to 3 mm and the inner peripheral layer is made of titanium or a titanium alloy having a thickness of 0.1 to 1 mm. However, in order to join aluminum alloy and titanium or titanium alloy as a clad manufacturing method, it is very difficult to fuse both of them, so the TIG welding method is mainly used. Since the joining method is an extremely time-consuming joining method, the manufacturing cost of the bat itself is increased, and the bat price is expensive.
[0007]
In addition, in order to improve the resilience characteristics of the conventional double structure softball bat, it is necessary to reduce the thickness of the outer pipe, and the maximum outer diameter part other than the taper part and grip part is the same due to its manufacturing method. When the tip part is integrated by spinning, the thickness may be too thin to completely close the opening of the tip part, resulting in poor manufacturing process yield. I had the problem that I said. Therefore, as a workaround for these problems, the tip is bent by pressing or spinning after the inner pipe is inserted, and synthetic resin is injected into the opened portion without being completely integrated to form the tip and plug it A method such as a method and a method of fitting a cap made of synthetic resin to a bent portion of the tip portion has been taken.
[0008]
However, since the outer pipe is thin and the only strength factor of the tip is synthetic resin, it cannot withstand the compressive stress or impact force received from the ball or the ground, and the tip Deformation, cracking, etc. occurred early. In addition, when the thin tip part is closed by spinning, etc., it is not suitable for mass production because the strength is insufficient and the tip part is damaged due to insufficient strength and the tip part is deformed. there were. In addition, the bat itself has a thickened tip part and has been integrally molded, but in the case of a double structure or multiple structure bat, it is necessary to insert an inner pipe because of the structure. If the thickness of the outer pipe is increased, the inner diameter of the tip of the outer pipe is smaller than the outer diameter of the inner pipe, and insertion is impossible.
[0009]
[Means for Solving the Problems]
The present invention relates to a double-tube bat or a multi-tube bat in which a reinforcing inner pipe is installed inside an outer pipe corresponding to a hitting portion of a bat body, and a meat at the tip of the outer pipe. It relates to a manufacturing method of a bat characterized in that the thickness is formed to be thicker than the thickness of the hitting ball part, inside the outer pipe of the hitting ball part of the bat body, as a reinforcing inner pipe, iron, It is a bat in which an inner pipe for reinforcement selected from materials such as metal such as stainless steel, titanium, titanium alloy, aluminum alloy and fiber reinforced plastic is inserted and fixed, and the thickness of the tip of the outer pipe is a hitting part It is formed to be thick with respect to the wall thickness.
[0010]
Embodiment
The present invention relates to a method for manufacturing a double-tube bat or a multi-tube bat in which a reinforcing inner pipe is mounted inside an outer pipe corresponding to a hitting portion of a bat body. An outer pipe with a thick tip and a thin grip is formed by adjusting the thickness, and the outer pipe is pre-formed into a bat shape by swaging, and the pre-formed tip is After the thick outer pipe is expanded by pipe expansion, the inner pipe is inserted, and then the thickness of the tip of the outer pipe is formed thicker than the thickness of the hit ball by spinning. In addition, the present invention relates to a method for manufacturing a bat, wherein the tip of the outer pipe is narrowed down and integrally formed.
[0011]
【Example】
An embodiment of the bat according to the manufacturing method of the present invention will be described with reference to the drawings. That is, as shown in FIGS. 1 and 2, on the inner side 2F of the outer pipe 2 corresponding to the hitting portion 2B of the bat main body 1A, In the double tube type bat 1 equipped with the reinforcing inner pipe 3, the outer pipe 2 is made thicker by adjusting the thickness of the outer pipe 2 , and the outer pipe 2 is thinned by the grip 2D. The outer pipe 2 is formed into a bat shape by swaging, and the inner pipe 3 is expanded after the preformed distal end portion 2A is expanded by expanding the outer pipe 2. A bat in which the thickness of the distal end portion 2A of the outer pipe 2 is formed thicker than the thickness of the hitting ball portion 2B by spinning, and the distal end of the outer pipe is integrally formed. is there.
[0012]
An embodiment of the multi-tube bat according to the manufacturing method of the present invention will be described with reference to the drawings . As shown in FIG. 3, the inner side 2F of the outer pipe 2 corresponding to the hitting portion 2B of the bat main body 1A. In addition, in the multi-tube bat 1 in which a plurality of reinforcing inner pipes 3, 3 ′, 3 ″ are mounted, the outer pipe 2 is thickened by adjusting the thickness of the outer pipe 2 and the grip 2D is thin. The outer pipe 2 is formed, and the outer pipe 2 is pre-formed into a bat shape by swaging, and the pre-molded tip portion 2A is expanded by expanding the thick outer pipe 2 After that, the inner pipes 3 , 3 ′ , 3 ″ are inserted, and then the thickness of the tip part 2 A of the outer pipe 2 is formed thicker than the thickness of the hit ball part 2 B by spinning. This is a bat in which the tip of the outer pipe is integrally formed.
[0013]
Next, with reference to FIG. 4 , an example of a method for manufacturing a double tube bat that is one of the embodiments of the present invention will be described . The inner side of the outer pipe 2 corresponding to the hitting portion 2 </ b> B of the bat main body 1 </ b> A. In the manufacturing method of the double tube type bat 1 in which the reinforcing inner pipe 3 is attached to 2F, first, the tip 2A is changed to the thick part 2G and the grip part 2D is thinned by the thickness adjustment processing. A tube pipe 2-1 is formed, and the outer tube pipe 2-1 is swaged to form an outer tube pipe 2-2 that is preformed into a bat shape, and then the preformed tip portion 2A is a thick wall portion. After the 2G outer pipe 2-2 is expanded by pipe expansion processing to form the outer pipe 2-3, the inner pipe 3 is inserted, and then the tip 2A by head spinning processing (squeezing with a spatula 7). refine the thick portion 2G of integrally formed a tip thick portion 2H It is intended to produce a bat 1 as the leading end portion 2A of the outer tube pipe 2 turned into. Although not shown in the drawings, the manufacturing method of the multi-tube bat is the same manufacturing method.
[0014]
Further, the manufacturing process of the outer tube 2 of the bat according to the present invention will be described in more detail . First, as shown in FIG. 4 (a) , a thick portion 2G is formed at the tip portion 2A by thickness adjustment processing. In addition, the inner cross-sectional shape is tapered, and the grip portion 2D forms an outer pipe 2-1 that is a thin portion 2I . Next, as shown in FIG. As shown in FIG. 4C , a mandrel 6 is inserted into the thick portion 2G of the distal end portion 2A, and the inserted portion is placed outside. extends, and an inner diameter performs pipe expanding to be larger than the outer diameter of the inner tube pipe 3 to be inserted, as shown in FIG. 4 (d), by inserting the inner tube pipe 3 which is molded separately, 4 As shown in (e), the tip is removed by head spinning (squeezing the spatula 7). It is completely closed and integrated.
[0015]
The feature of this process is that the thickness distribution can be easily set by adjusting the thickness, and the thickness is thicker than that required for the hit ball portion (approximately 1.75 to 1.85 mm or 1.85 mm). (Thickness of 2.00 mm or less) can be produced. In addition, swaging is performed using a straight uncoated pipe having an outer diameter of about 57 mm and a wall thickness of about 1.3 mm to 1.5 mm as the outer pipe of the bat, and the head spinning process (squeezing the spatula) Even if the tip portion 2A is squeezed and integrally molded by processing), it is difficult to produce a thick-walled tip portion because of poor yield as described above. Therefore, in the bat 1 of the present invention, the thickness of the distal end thick portion 2H of the distal end portion 2A of the outer tube pipe 2-2 is set to about 1.80 ± 0.05 mm, and the hitting portion 2B of the outer tube pipe 2 is set. It is desirable to set the thickness of the portion corresponding to 1 to about 1.25 ± 0.05 mm.
[0016]
In addition, as a raw material used for the outer pipe 2 or the inner pipe 3 of the bat 1 according to the present invention, in the case of an aluminum alloy, a JIS6000 series or JIS7000 series aluminum alloy can be used. In particular, among the materials used for the outer pipe 2 and the inner pipes 3, 3 ′, 3 ″ of the bat 1 according to the present invention, JIS7001, JIS7046, JIS7050, JIS7101, JIS7478, and JIS6061 are used as the aluminum alloy. It is desirable.
[0017]
In addition, as a material used for the outer pipe 2 and the inner pipes 3, 3 ′, 3 ″ of the bat 1 according to the present invention, it is desirable to use JIS 7001 or JIS 7101 which is excellent in resilience if it is an aluminum alloy, for example. When the material used for the inner pipes 3, 3 ′, 3 ″ is a bat made of fiber reinforced plastic (made of FRP), carbon fiber, glass fiber, aramid fiber or other reinforcing fiber can be used. Is. The orientation angle of these reinforcing fibers can be a combination of 0 ° to 45 ° to 90 ° with respect to the longitudinal direction of the bat. The combination of the types of reinforcing fibers and the orientation angles of the reinforcing fibers depends on the strength of the bat. It is determined by the required characteristics as a bat. As the matrix resin, epoxy resin or other thermosetting synthetic resin, polyurethane resin or other thermoplastic synthetic resin can be used.
[0018]
Further, as a material used for the outer pipe 2 and the inner pipes 3, 3 ′, 3 ″ of the bat 1 according to the present invention, titanium alloy or pure titanium can be used. For example, β type or α + β is used as an example. Type titanium alloy can be used. Particularly, as the titanium alloy of the outer pipe 2 and the inner pipe 3, 3 ', 3 " of the bat according to the present invention, Ti-15V-3Cr which is a β-type titanium alloy It is preferable to use Ti-6Al-2Sn-4Zr-2Mo, which is −3Sn-3Al or α + β type titanium alloy, for plastic working by a swaging machine.
[0019]
【The invention's effect】
As described above, in the bat manufacturing method of the present invention, by forming a thick portion at the tip of the outer pipe, the outer pipe is inserted into the double pipe bat or the multi pipe bat into which the inner pipe is inserted. It is easy to integrally mold the tip part, and the tip part can be reliably closed, so the strength of the tip part is significantly improved compared to conventional bats, so there is no risk of cracking, breakage, or dents. The sound can be prevented and the durability can be improved. In addition, the manufacturing method of the present invention can be produced with the same tip processing equipment as a general single-layer bat, compared to the casting injection method of the synthetic resin at the tip portion used in the conventional bat. There is no need for new capital investment, and the production cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a side view showing a bat according to a manufacturing method of the present invention.
FIG. 2 is an enlarged cross-sectional view of a main part of a bat according to the manufacturing method of the present invention.
FIG. 3 is an enlarged cross-sectional view of a main part showing another embodiment of the bat according to the manufacturing method of the present invention.
FIG. 4 is an explanatory view showing the steps of a bat manufacturing method according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Butt 1A Butt body 2 Outer pipe 2A Tip part 2B Hitting part 2C Shaft part 2D Grip part 2E Grip end 2F Inner 2G Thick part 2H Thick part 2I Thin part 2-1 Outer pipe 2-2 Outer pipe 2-3 Outer pipe 3 Inner pipe 3 'Inner pipe
3 " inner pipe 6 mandrel 7 spatula

Claims (1)

Thickness adjustment processing of the outer pipe in the manufacturing method of the double pipe type bat or multi-tube type bat in which the inner pipe for reinforcement is installed inside the outer pipe corresponding to the hitting part of the bat body To form an outer pipe with a thicker tip and a thinner grip, and pre-molding the outer pipe into a bat shape by swaging, and the preformed tip is thick After the pipe pipe is expanded by pipe expansion processing, the inner pipe pipe is inserted, and then by spinning, the thickness of the tip portion of the outer pipe pipe is formed thicker than the thickness of the hitting ball portion, and the outer pipe A method of manufacturing a multi-tube bat for baseball or softball, wherein the tip of the pipe is squeezed and integrally formed.

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