JP2002282405A - Wooden bat and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wooden bat for which breakage is prevented, durability is improved and a natural environment is taken into consideration and to provide the manufacturing method of the wooden bat efficiently manufacturing it at a low cost. SOLUTION: The wooden bat is compressed by the pressurization of a hydrostatic pressure. The wooden bat is manufactured through the process of cutting out a bat base material from raw wood, the process of putting a coating member on the bat base material, the process of heating the bat base material on which the coating member is put inside a pressure-resistant container and softening it, the process of compressing the softened bat base material by the pressurization of the hydrostatic pressure, the process of cooling the bat base material in a pressurized state as it is and the process of taking out the bat base material from the pressure-resistant container and removing the coating member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wooden bat used for baseball and softball, and a method for manufacturing the same.

[0002]

2. Description of the Related Art In a wooden bat, repeated hitting causes peeling or cracking from a grain or the like during use, resulting in loss or breakage. Conventionally, in order to solve such a problem, a so-called compression bat that injects a resin into the wood of a wooden bat and cures the resin, and a so-called compression bat that compresses with a mold after injection of the resin and heat-cures the resin. And is known.

[0003]

However, in the former resin injection bat, there is a problem that the mass of the bat increases and the manufacturing cost increases due to the resin injection. Furthermore, in recent years, there has been a demand for the development of products that take the natural environment into consideration. Had the same problem as a general plastic product that did not return to nature.

Further, in the latter compression bat, since it is necessary to apply pressure mechanically, it is necessary to manufacture a compression mold and a jig, which requires labor and cost. There was a problem. Furthermore, since the pressure is applied mechanically by a mold formed in a desired shape and compressed, the wood structure may be destroyed.In addition, depending on the direction and position where the pressure is applied, the compressed state is applied to the entire wood. It was difficult to obtain a uniform. further,
The conventional compression bat also has a similar problem based on the above-described resin because the resin is impregnated with resin for the purpose of fixing the compressed shape.

In view of the above-mentioned conventional problems, the present invention provides a wooden bat which is uniformly pressurized and compressed to prevent breakage, improve durability, and further consider the natural environment. An object of the present invention is to provide a bat and further provide a method for manufacturing a wooden bat that can be efficiently manufactured at low cost.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the invention of claim 1 is a wooden bat which is compressed by hydrostatic pressure.

According to a second aspect of the present invention, there is provided the wooden bat according to the first aspect, wherein the wooden bat has irregularities formed on an outer peripheral surface thereof.

According to a third aspect of the present invention, there is provided the wooden bat according to the first aspect, wherein an outer peripheral surface of the wooden bat is smooth.

According to a fourth aspect of the present invention, there is provided a method for shaving a bat base material from a log, a step of covering the bat base material with a covering member, and heating the bat base material covered with the covering member in a pressure vessel. Softening the bat base material, compressing the softened bat base material by applying a hydrostatic pressure, cooling the bat base material in a pressurized state, and compressing the bat base material with the pressure resistance. Removing the covering member from the container and removing the covering member.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below.

The wooden bat of this embodiment has a configuration in which the wooden bat is subjected to compression processing by applying a hydrostatic pressure. Normally, wood has an early wood part and a late wood part according to the growth stage, and the surface hardness is not uniform at each part.
On the other hand, in pressurization by hydrostatic pressure, as in Pascal's theorem, the same pressure is applied to all parts in water, so the same pressure is applied to the outer surface of an object in water. Is an addition. Therefore, in the wooden bat of this embodiment, by the hydrostatic pressure,
Since the entire outer surface of the wooden bat is uniformly pressurized, conduits and other voids in the wood are uniformly compressed, and as a result, the hardness of the outer surface of the wooden bat is substantially uniform. . Therefore, the dent caused by the impact is eliminated, and the durability is improved. In addition, uniform pressurization by hydrostatic pressure on the outer surface, which originally has uneven hardness, mainly compresses soft parts preferentially. Therefore, breakage due to repeated impact can be prevented. In addition, as a result of the above-described operation, irregularities are formed on the outer surface.

As an apparatus for manufacturing the wooden bat of the present invention, a compression molding apparatus 10 as shown in FIG. 2 is used. The compression molding device 10 includes a pressure-resistant container 11, a heater 1
4, an air vent valve 16, a relief valve 17, a drain valve 18, a water tank 12, and a pump 13.
The pressure-resistant container 11 has an internal volume such that the wooden bat can be arranged with a margin, and allows the wooden bat to be taken in and out.
It has a lid 15 for hermetic sealing during manufacturing operations. The heater 14 controls the atmospheric temperature in the pressure-resistant container 11,
This is for heating the water filled in the pressure-resistant container 11 to a predetermined temperature, and is provided at a lower part in the pressure-resistant container 11. The pump 13 causes water to flow from the water tank 12 into the pressure-resistant container 11. The air bleed valve 16 is for bleeding air from the pressure vessel 11 when water is flowed into the pressure vessel 11 by the pump 13. The relief valve 17 adjusts the drainage speed of the water filled in the pressure-resistant container 11,
This is for adjusting the water pressure in the pressure vessel 11. The drain valve 18 is for draining water from the inside of the pressure-resistant container 11 finally.

Next, an embodiment of a method for manufacturing a wooden bat of the present invention using the above-described apparatus will be described with reference to the drawings. As shown in FIG. 1, the manufacturing process of the wooden bat according to the present embodiment is performed through the steps of shaving, covering, softening, compressing, cooling, and taking out in order.

First, the shaving step is a step of shaving the bat base material 2 from a log using a lathe or the like. Prepare a log, if the log is a hard tree species, process the log into the same size as the desired bat shape, if a soft tree species, process it into a shape larger than the desired bat shape, A bat substrate 2 is obtained. The hard tree species are tree species such as Aodamo, yachidamo, avian cat, and white ash conventionally used for wooden bats, and the soft tree species are, for example, tree species such as oak, maple, beech, pine, and cedar. can give.

In the next coating step, after covering the bat base material 2 with the covering member 3 formed in a bag shape, air in the covering member 3 is discharged from the opening 4 of the covering member 3 by a vacuum pump. Then, the inside of the covering member 3 is evacuated. Thereafter, the opening 4 is sealed so that air does not enter. As a material of the covering member 3, a temperature generated in a softening step described later, and
A film-like material that can withstand the water pressure generated in the compression step and has flexibility that can follow the shape of the bat substrate 2 is preferable.

In the subsequent softening step, after placing the bat base material 2 covered with the covering member 3 in the pressure-resistant container 11,
5 is closed, and the inside of the pressure-resistant container 11 is closed. afterwards,
By heating the atmosphere in the pressure-resistant container 11 to a temperature at which the wood is softened by the heater 14, the bat substrate 2 is heated.
Softens. Wood is usually heated
It has the property of softening when it reaches a certain temperature. The temperature at the time of softening is generally about 100 ° C., though there is some variation depending on the water content of the wood.
Preferably it is in the range of 90 to 120 ° C. Therefore, by heating the wood to this temperature, the wood can be changed to a state in which it is easily deformed.

In the next compression step, water is flowed into the pressure-resistant container 11 by the pump 13 with the air-release valve 16 opened, and the entire pressure-resistant container 11 is filled with water. close. Further, after that, the inflow is continued by the pump 13 to increase the water pressure to a predetermined pressure. Therefore, the cell wall inside the wood in the bat substrate 2 is deformed, and the void portion such as the conduit portion is pressed, so that the bat substrate 2 is compressed. In addition, the inflowing water may be heated to an appropriate temperature. Further, the water pressure referred to here is a water pressure generated in still water, and is called hydrostatic pressure. Since the hydrostatic pressure produces the same pressure in all directions, the bat base 2 is uniformly pressed and compressed at all parts of its outer surface. Therefore, the early wood portion, which is relatively low in density and easily deforms, is preferentially compressed and deformed compared to the originally high density late wood portion, so that the entire wood is homogenized.

In the subsequent cooling step, the heating by the heater 14 is stopped, cold water flows in by the pump 13, and the cold water inflow and the discharge by the relief valve 17 are kept the same to keep the water pressure constant. By circulating the water in the pressure vessel 11, the water temperature is lowered, and the bat base 2 is cooled. The compressed state can be fixed by cooling the bat substrate 2 to the softening temperature or lower while maintaining the pressure.

In the last removal step, the water in the pressure-resistant container 11 is discharged from the drain valve 18, the bat base material 2 is removed from the pressure-resistant container 11, and the covering member 3 is removed. Get 1. In addition, when a soft tree species is used among the above-mentioned tree species, the amount of compressive deformation in the bat base material 2 becomes large, so that the unevenness of the outer surface of the wooden bat 1 obtained in the removing step becomes severe. Therefore, a finishing step may be added after the removing step. The finishing step is a step of cutting the outer surface, and the outer surface is processed smoothly like a normal bat to obtain the wooden bat 1.

According to the manufacturing method described above, after the bat base material is softened, the bat base material is pressurized by hydrostatic pressure, so that the entire bat base material is not destroyed without destroying the tissue such as the cell wall inside the wood of the bat base material. Can be compressed uniformly, and
Because the compressed state is fixed by cooling in the compressed state, the outer surface is hardened without using a resin, and breakage caused by continuous hitting can be prevented,
A wooden bat with improved durability is obtained.

In the manufacturing method of the present invention, a mold for compressing the bat base and a resin for fixing the compressed state in the conventional manufacturing method of the compressed bat are not required. It is possible to omit the work of setting and taking out the mold, the work of injecting resin, and the finishing work such as deburring and polishing after these working steps. Therefore, the wooden bat of the present invention can be manufactured efficiently. In addition, it is possible to suppress an increase in manufacturing cost caused by manufacturing a mold, a jig, and the like and using a resin. Further, not using the resin prevents the wooden bat itself from increasing its mass, and there is no possibility that the wooden bat will have a bad influence on the natural environment when it is disposed.

[0022]

EXAMPLES Specific examples in the manufacturing method of the present invention will be described. The log used was Aodamo wood, which has been conventionally used as a bat material. First, a bat base material is formed by shaving the raw wood of the Aodamo wood into the same size as the bat shape to be used using a lathe or the like. The bat base material is covered with a film made of a thermoplastic resin formed in a bag shape, air in the film is drawn out from the opening of the film by a vacuum pump, and a vacuum is formed. Seal with a sealing device such as. Thereafter, the sealed bat base is placed in a pressure vessel of a compression molding apparatus, and a lid of the pressure vessel is closed. Next, the atmosphere in the pressure vessel was heated to 120 ° C. by the heater in the pressure vessel,
The wood structure is softened by heating the bat base for a period of time. Then, 95 ° C. water flows into the pressure-resistant container by a pump to fill the entire pressure-resistant container. further,
3. By continuing the inflow of water, the water pressure in the pressure-resistant container is increased to 4.
Increase to 5MPa. Thereafter, while the cold water is injected from the pump and drained from the relief valve, the water temperature is lowered while the water pressure is kept constant. This cooling step is performed for approximately one hour, and when the water temperature reaches about 30 ° C., the water in the pressure-resistant container is discharged from the drain valve, the bat base material is taken out of the pressure-resistant container, and the covering member is removed. By doing so, a wooden bat of this example was obtained.

In the wooden bat of this embodiment obtained by the above-described manufacturing process, the outer surface of the wooden bat has a uniform hardness, and particularly in the surface layer, the wood structure is homogenized. . Further, on the outer surface of the wooden bat of the present embodiment, irregularities are formed, and the early material portion that is easily deformed at a relatively low density is formed as a concave portion. A durability test was conducted in which the wooden bat of this example was repeatedly hit, and it was confirmed that the bat had excellent durability without dents or damage due to hit balls.

[0024]

As described above, the wooden bat compressed by the hydrostatic pressure is uniformly pressed on the entire outer surface regardless of the shape of the outer surface. Since the hardness of the outer surface is uniform and the wood structure is homogenized into a dense structure, breakage can be prevented and durability can be improved.

In the manufacturing method of the present invention, a pressed wooden bat is obtained by pressing with a hydrostatic pressure using a compression molding apparatus, so that a mold and a jig are not required, and the manufacturing cost can be reduced. . Furthermore, since the compressed shape can be fixed by cooling the bat base material that is compressed by the hydrostatic pressure, it is possible to suppress an increase in mass and a manufacturing cost due to the use of the resin, It is possible to manufacture efficiently without adversely affecting the natural environment.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a method for manufacturing a wooden bat according to the present embodiment.

FIG. 2 is an explanatory view showing an apparatus for manufacturing the wooden bat of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wooden bat 2 Bat base material 3 Covering member 4 Opening 10 Compression molding device 11 Pressure-resistant container 12 Water tank 13 Pump 14 Heater 15 Lid 16 Air release valve 17 Relief valve 18 Drain valve

Claims (4)

[Claims] 1. A wooden bat which is compressed by hydrostatic pressure. 2. The wooden bat according to claim 1, wherein irregularities are formed on an outer peripheral surface of the wooden bat. 3. The wooden bat according to claim 1, wherein the outer peripheral surface of the wooden bat is smooth. 4. A step of shaving a bat base material from a log,
A step of covering the bat base material with a coating member, a step of heating the bat base material covered with the coating member in a pressure vessel to soften the bat base material, and applying a hydrostatic pressure to the softened bat base material. And a step of cooling the bat base while keeping the bat base pressed, and a step of removing the bat base from the pressure-resistant container and removing the covering member. How to make wooden bats.