JP2007260357A - Blade of table tennis racket - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a table tennis racket light in weight, excellent in rebounding characteristics and control characteristics, obtaining a good ball hitting feeling when a ball is hit, and suitable for offensive or defensive playing by providing a blade with a bending rigidity, a twisting rigidity, bending vibration, and twisting vibration. <P>SOLUTION: The blade of the table tennis racket is formed of a central core member 7 as an essential portion forming the shape of the blade, intermediate members 8 arranged on both sides of the central core member 7, and surface members 9 laminated on external sides of the respective intermediate members. Each intermediate member 8 is a sheet obtained by orienting a number of reinforcing fiber threads in one orientation to form a fiber sheet, laminating the fiber sheets thus formed on each other such that fiber directions are made different from each other, impregnating the fiber sheets with a synthetic resin, and heating and hardening the same. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an improvement of a blade constituting a main body portion of a table tennis racket.

  As shown in FIG. 1, the table tennis racket 1 includes a flat blade 4, a grip member 3 that is superposed on both the front and back surfaces of the grip portion 6 of the blade 4, and one surface of the hitting surface portion 5 of the blade 4 or In general, it is composed of rubber 2 adhered to both the front and back surfaces.

  Conventionally, as the blade 4 constituting the table tennis racket 1 described above, a single plate such as a kite or katsura or a wooden blade formed from plywood has been mainly used. However, in recent years, a combination of the wood and fiber reinforced resin is used. Many blades made of so-called composite materials have become widespread.

  This type of composite material blade is, for example, a fiber reinforced resin layer in which carbon fibers or aromatic polyamide fibers are used as reinforcing fibers between wooden plywood boards, as proposed in Patent Document 1 and Patent Document 2. And has a merit that it can exhibit high resilience and high rigidity as compared with a conventional wooden blade made of only wood.

  The fiber reinforced resin layer is usually formed mainly with a unidirectional prepreg (UD prepreg), but a plurality of prepregs are necessary to orient the reinforcing fibers in multiple directions. Since the number of plies) is increased, the thickness of the fiber reinforced resin layer is increased, the mass is increased, and it is difficult to reduce the weight.

  Further, for the purpose of compensating for such drawbacks, biaxial woven fabrics as shown in FIG. 4a and triaxial woven fabrics as shown in FIG.

  Since the biaxial fabric is woven in two directions at right angles to each other, if the two axes are oriented so as to be in the longitudinal direction of the blade 4 and the direction perpendicular thereto, the two directions can be reinforced at the same time. Accordingly, the number of laminated fiber reinforced resin layers can be reduced. In addition, the triaxial woven fabric has the advantage that the number of layers can be reduced correspondingly because the three directions can be reinforced at the same time because axial yarns in three directions are interwoven.

JP 52-15734 A JP 52-58629 A

  However, there is a problem in that the torsional strength and torsional rigidity of the blade cannot be maintained in a blade made of a composite material using one layer of the biaxial woven fabric so that the axis is oriented in the vertical and horizontal directions. In addition, it was necessary to add a bias reinforcing layer to the biaxial woven fabric with a unidirectional prepreg or the like. In addition, when the triaxial fabric is used, the lateral bending strength and lateral bending rigidity of the blade cannot be maintained. Therefore, it is necessary to add a lateral reinforcement layer to the triaxial fabric. There is a problem that the thickness and mass of the resin layer increase.

  Therefore, in view of such conventional problems, the present invention efficiently sets the bending rigidity and torsional rigidity of the blade, is light in weight, has excellent resilience characteristics and control characteristics, and has a good shot feeling when hitting a ball. The object is to provide a table tennis racket that can be obtained.

In order to achieve the above object, the table tennis racket of the present invention has the following configuration.
That is, in the blade that forms the main body portion of the table tennis racket, the blade is formed by a middle core member, an intermediate member that is laminated on both front and back surfaces of the middle core member, and a surface member that is laminated on the outer side of the intermediate member. A laminated sheet in which at least a part of the intermediate member is a laminated body in which a plurality of fiber sheets in which reinforcing fibers are aligned in one direction are stacked in different directions, and the laminated body is knitted with stitch yarns in the thickness direction. This is a table tennis racket blade formed by a laminated sheet layer impregnated with synthetic resin.

  As described above, in the table tennis racket blade of the present invention, since the required strength and rigidity can be expressed by using the laminated sheet, the number of laminated plies of the reinforcing fiber layer forming the intermediate member is greatly reduced. Can do. As a result, the thickness of the intermediate member can be designed to be thin, and the mass of the blade itself and thus the table tennis racket can be greatly reduced.

In the following, the present invention will be described with reference to preferred embodiments described in detail with reference to the drawings.
FIG. 1 is an external view of a table tennis racket 1 and a longitudinal sectional explanatory view thereof.
FIG. 2 is an explanatory diagram of the configuration of the blade 4 in the region a of FIG. 1, and FIG. 3 is an enlarged explanatory diagram of an intermediate member used in this embodiment.

  The present invention relates to a blade 4 constituting a main body portion of the table tennis racket. Rubber 2 is attached to both sides or one side of a hitting surface portion 5 of the blade 4 via an adhesive or a double-sided tape, and the grip portion 6 is gripped. A table tennis racket 1 is obtained by attaching the member 3.

  The present invention is characterized by the structure of the blade 4, and as shown in FIG. 3, the blade 4 includes a core member 7 that is a basic part of the shape of the blade 4, and the core member 7. It comprises a middle member 8 provided on both sides of the front and a surface member 9 laminated on the outer side. In the present embodiment, the intermediate member 8 is composed of a laminated sheet layer 80 described below in at least a partial region of the blade 4.

  As the material used for the core member 7 and the surface member 9, zelkova, paulownia, cypress, willow, ause material, etc. can be used, and these can be used alone or laminated by laminating these woods. The material and thickness can be determined by design.

  As shown in FIG. 3, the laminated sheet layer 80 is a fiber sheet 82 in which a large number of reinforcing fiber yarns are aligned in one direction, and applies tensile stress along the fiber direction to the reinforcing fibers and also has a fiber cross section. The fiber sheet 82 is formed by unwinding the fibers with pressure, airflow, etc. from the up and down direction of the fiber to form the opened fiber yarns, and the fiber sheet 82 is not crossed up and down, and the fiber The sheets 82 are laminated so that the fiber orientation directions are different, and the laminated fiber sheets are stitched up and down with long fiber stitch yarns 83 in the vertical direction to form a laminated sheet 81, and synthetic resin is applied to the laminated sheet 81. It is formed by impregnation.

The laminated sheet 81 used in the present invention is formed by vertically stacking a plurality of fiber sheets 82. For example, the fiber sheet 82 is carbon fiber having a tensile elastic modulus of 230 to 294 N / mm 2 opened as a reinforcing fiber, and the carbon fiber basis weight is 98 to 200 g / m 2 and the thickness is 0.020 mm or less. It is formed using things.
The fiber sheet a thus formed, the fiber sheet b oriented to be 90 ° with respect to the fiber orientation direction of the fiber sheet a, and + 45 ° with respect to the orientation direction of the fiber sheet a 4 layers of the fiber sheet c oriented to the fiber sheet d and the fiber sheet d oriented to be −45 ° with respect to the orientation direction of the fiber sheet a are stacked, and these are stitched up and down with a stitch fiber 83 of long fibers. Is formed. As the stitch yarn, it is preferable to use one as thin as possible. For example, long fibers such as polyester fiber and nylon fiber are suitable.

  The laminated sheet 81 formed as described above is impregnated with a synthetic resin so as to have a resin impregnation rate of 40 ± 15 wt%, and is heat-cured to a predetermined thickness in advance. Affix it. As a synthetic resin used in the present invention, a thermosetting resin such as an epoxy resin, a vinyl ester resin, an unsaturated polyester resin, or a phenol resin, or a thermoplastic resin such as a nylon resin, a PBT resin, a polyethylene resin, or a polypropylene resin is used. Can do.

  Since the laminated sheet layer 80 used in the present invention is superposed on the fiber sheet 82 using the opened reinforcing fibers, it is light and has good resin impregnation properties. Therefore, by using such a laminated sheet layer 80, The performance can be improved without increasing the mass of the table tennis racket 1.

  In the table tennis racket 1 of the present embodiment, the fiber sheet 82 constituting the laminated sheet 81 uses the reinforced fibers that have been opened, so it is light and has good resin impregnation properties. Further, such a fiber sheet 82 is laminated in two layers such that the fiber orientation direction is parallel to the longitudinal direction of the blade 4 and perpendicular to the longitudinal direction, or ± 2 in the two layers. Since four layers including two 45 ° layers are laminated and stitched together with the stitch yarn 83, the orientation direction of the fibers is not shifted in forming the laminated sheet layer 80. Thereby, required strength and rigidity can be expressed as designed.

  In this embodiment, the laminated sheet layer 80 can be used for the entire blade 4 or only for a part thereof depending on the performance required for the table tennis racket.

    In general, each performance such as resilience performance, control performance or feel at impact required for a table tennis racket is determined by the rigidity of each part of the blade constituting the table tennis racket, i.e., bending for each part such as a ball hitting surface part and a grip part. It has been found that torsional stiffness design is an important factor and does not require the same overall performance.

  In the characteristic design of the blade 4 of the table tennis racket, the present inventor has a region A (particularly 0. 0 L) of the blade total length L from the grip side proximal end portion p1 to the top portion p2 in the longitudinal direction of the blade. 15L to 0.38L) is a region in which the bending rigidity design affects the bending characteristics of the table tennis racket, and the blade total length L extends from the grip side base end portion p1 in the longitudinal direction of the blade 4 to the top portion p2. It was found that the design of the bending rigidity in the region B of 0.42 L to 1.00 L (especially the region of 0.62 L to 0.88 L) has a great influence on the resilience performance of the table tennis racket. By designing various arrangement methods, the optimum bending rigidity for the required play style was designed.

For example, as a racket for reducing the power loss of the swing at the time of hitting the ball to improve the ball separation and hitting the speed ball, by setting the bending rigidity in the region B of the blade 4 shown in FIG. The ball separation is improved and the flexural rigidity of the region A is set high so that the power ball can be hit with less power loss during the swing.
In addition, as a table tennis racket with good ball separation at the time of hitting the ball and emphasizing the operability of the racket, by setting the bending rigidity in the region B of the blade 4 high, In addition, the controllability of the racket during the swing is improved without increasing the bending rigidity of the region A so much.
In addition, the bending rigidity in the longitudinal direction of the region B of the blade 4 is set low to improve the ball feeling, and the ball control property is improved, and the bending rigidity of the region A is set high to reduce power loss during swing. Try to reduce it.

  In the laminated sheet used in the present embodiment, when a plurality of fiber sheets are overlapped, the fibers are laminated with different orientation directions of adjacent sheets, so that the orientation direction when used as an intermediate member is table tennis. Arranged according to the performance design set for the racket.

  As the fibers constituting the fiber sheet, carbon fibers are preferably used, and those having a fineness of 100 to 400 are used.

Example 1
As shown in FIG. 2, as the blade 4, a core member 7 is formed in which a use material 7 b (wall thickness: 0.8 mm) is pasted on both sides of a paulownia material 7 a (wall thickness: 3.5 mm) as a center, An intermediate member and a surface member 7b (thickness: 0.5 mm) made of a brazing material were attached to the outside.

  In this example, a laminated sheet 80 shown in FIG. 3 was used as the intermediate member. This laminated sheet 80 is formed by aligning the opened carbon fibers having a tensile elastic modulus of 230 N / mm 2 so that the fiber basis weight is about 100 g / m 2 to form fiber sheets 82 a, 82 b, 82 c, 82 d, and the orientation direction of the fibers When the fiber sheet 82a is set to 0 °, the fiber sheet 82b is 90 °, the fiber sheet 82c is + 45 °, and the fiber sheet 82d is −45 °. It is formed by impregnation so as to be 30 wt%.

And the said laminated sheet 81 was affixed on the front and back both surfaces of the said core member 7, and the surface member 9 was arrange | positioned on the outer side, and the braid | blade was formed.
At this time, as shown in FIG. 1, the laminated sheet layer 8 is positioned at a position corresponding to 0.08L of the blade total length L from the grip side base end portion P1 of the blade 4 toward the top portion P2 in the longitudinal direction of the blade 4. Only in a region A corresponding to 0.40 L, the fiber sheet 82a of the laminated sheet layer 80 is the outermost side, and the fiber orientation direction is the longitudinal direction of the blade 4, and the fiber sheet 82b Was placed and stuck so as to face in a direction perpendicular to the longitudinal direction.

(Example 2)
From the grip side base end portion P1 of the blade 4 to the top portion P2 in the longitudinal direction of the blade 4, the laminated sheet layer 80 is moved from a position corresponding to 0.42L of the blade total length L to a position corresponding to 1.00L. It is arranged only in the region B, and is arranged so that the orientation direction of the fiber sheet 82a of the laminated sheet layer 10 is the longitudinal direction of the blade 4 and the fiber sheet 82b is perpendicular to the longitudinal direction. Formed a thing.
Other configurations were the same as those in Example 1.

(Example 3)
From the grip side base end portion P1 of the blade 4 to the top portion P2 in the longitudinal direction of the blade 4, the laminated sheet layer 80 is moved from a position corresponding to 0.08L of the blade total length L to a position corresponding to 0.40L. The laminated sheet layer 80 is arranged in a region A and a region B from a position corresponding to 0.42L to a position corresponding to 1.00L, and the orientation direction of the fibers of the fiber sheet 82a is the longitudinal direction of the blade 4 The fiber sheet 82b is disposed so as to face in the direction perpendicular to the longitudinal direction.
Other configurations were the same as those in Example 1.

  A gripping member 3 and a rubber 2 were attached to each blade obtained in the above example to form a table tennis racket, and a ball was hit with the table tennis racket. It was confirmed that the table tennis rackets of Examples 1 and 2 were able to obtain excellent sensitivity evaluations in performance such as control performance and feel at impact. In addition, the table tennis racket 1 of Example 3 had excellent sensitivity evaluation in performance such as resilience and feel at impact.

The external appearance explanatory drawing showing the front and side of a racket for table tennis. FIG. 2 is an explanatory diagram of a configuration of a blade in a region a in the embodiment of FIG. 1. Expansive explanatory drawing of the lamination sheet used by a present Example. The expansion explanatory drawing of the conventional textile fabric.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Table tennis racket 2 Rubber 3 Grip member 4 Blade 5 Hitting surface part 6 Grip part 7 Core member 7a Paulownia 7b Ause 8 Intermediate member 80 Laminated sheet layer 81 Laminated sheet 82 Fiber sheet 82a Fiber sheet 82b Fiber sheet 82c Fiber sheet 82d Fiber Sheet 83 Stitch yarn 9 Surface member

Claims (2)

  In the table tennis racket blade, the blade is formed of a middle member, an intermediate member laminated on both front and back surfaces of the middle member, and a surface member laminated on the outer side of the intermediate member, At least a part is formed by laminating a plurality of fiber sheets in which reinforcing fibers are aligned in one direction without crossing each other up and down so that the orientation directions of the fibers are different from each other. A table tennis racket blade, characterized in that it is formed of a laminated sheet layer in which a synthetic sheet is impregnated into a laminated sheet formed by stitching a plurality of fiber sheets with stitch yarns in the thickness direction. The fiber sheet is a fiber sheet in which spread fiber yarns are aligned and formed, the fiber basis weight is 100 g / m ² or less, and the thickness of the laminate is 0.1 mm to 0.4 mm. The blade of the table tennis racket according to claim 1.

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