JP4520761B2 - Racket frame - Google Patents

Description

  The present invention relates to a racket frame made of fiber reinforced resin used for tennis, badminton, squash and the like.

In general, as shown in FIG. 5, a fiber reinforced resin racket frame has a bias layer in which reinforcing fibers are obliquely arranged so that the outer shell 21 maintains the torsional strength and torsional rigidity of the racket frame. 22, the straight layer 23 in which the reinforcing fibers are aligned in the circumferential direction of the racket frame in order to maintain the bending strength and the bending rigidity, and the reinforcing fibers in order to maintain the compressive strength and the compression rigidity. The hoop layer 24 is aligned in a direction perpendicular to the direction.
This type of racket frame is usually formed mainly of a unidirectional prepreg 25 (UD prepreg), but a plurality of prepregs are required to orient the reinforcing fibers in multiple directions. Number) increases, the outer shell 21 increases in thickness, and the mass increases accordingly, making it difficult to reduce the weight.

For this reason, conventionally, textile prepregs such as biaxial woven fabrics and triaxial woven fabrics are often used to supplement such drawbacks.
As shown in FIG. 6, in the biaxial woven fabric 26, the warp yarn 27 and the weft yarn 28 are woven at right angles to each other. Therefore, the warp yarn 27 is arranged so as to be parallel to the circumferential direction of the racket frame. When used, the straight layer 23 and the hoop layer 24, which are referred to when the above-described unidirectional prepreg 25 is used, can be formed simultaneously, and the number of prepregs wound around the core material 29 can be reduced accordingly. Further, as shown in FIG. 7, the triaxial fabric 30 has a warp 31 and two oblique threads 32a and 32b woven together, and thus the straight layer 23 and the bias layer 22 as described above. And the number of plies of the prepreg can be reduced accordingly.

  Conventionally, as these woven fabrics (biaxial woven fabric 26 and triaxial woven fabric 30), the types of reinforcing fibers constituting each yarn and those having isotropic properties having the same fineness are often used. In recent years, for example, as disclosed in Patent Document 1, a proposal to use a triaxial woven fabric having anisotropy using metal fibers as a part of a warp 31 for a racket frame is also generally known. It has become.

JP 2000-342719 A

  However, the conventional racket frame using the biaxial fabric has a problem that the torsional strength and torsional rigidity of the racket frame cannot be maintained, and it is necessary to separately add a bias layer to the biaxial fabric with a unidirectional prepreg or the like. there were. In addition, since the racket frame using the triaxial fabric cannot maintain the compressive strength and compression rigidity of the racket frame, it is necessary to add a separate hoop layer to the triaxial fabric. There is a problem that the mass increases.

  In addition, most of the fabrics used conventionally are isotropic. For example, when a racket frame is formed using a triaxial fabric having isotropic properties, both the bending rigidity and the torsional rigidity are the same. The racket frame tends to be very stiff. Such a rigid racket frame has a drawback that it has a large impact when hitting a ball and it is difficult to obtain a good shot feeling.

A racket frame usually has a region where bending occurs when a ball is hit and a region where twisting occurs. The rigidity characteristics required for each region are different, and the bending rigidity and torsional rigidity are always required to be the same. It is not something.
As shown in FIG. 1, considering the behavior of the racket frame at the time of hitting the ball, the shaft portion 5 including the throat region 4 is greatly bent in the out-of-plane direction, and the connection between the hitting ball portion 3 and the shaft portion 5 is performed. In the racket axis center direction from the point P, the region from 0.05L to 0.25L of the total length L of the hitting ball portion 3 on the top portion 16 side is greatly twisted. As a result of various analyzes by the present inventors, in the region of the shaft portion 5 (particularly, the throat region 4), the bending rigidity affects the resilience performance of the racket frame, and the torsional rigidity affects the shot feeling when hitting the ball. It turned out to have a big impact. Further, in the region from 0.05L to 0.25L of the total length L of the hitting ball 3 from the connecting point P between the hitting ball 3 and the shaft 5 to the top 16 side, the torsional rigidity affects the resilience performance of the racket frame. It was found that the bending rigidity has a great influence on the feel at impact. That is, in the throat region 4, the flexural rigidity is designed to be high, while the torsional rigidity is suppressed to a low level, and the hitting part 3 has a total length L from the connection point P between the hitting part 3 and the shaft part 5 to the top part 16 side. In the range from 0.05L to 0.25L, while designing torsional rigidity high, designing the bending rigidity low makes it possible to provide a racket frame with high rebound and excellent shot feel. However, the conventional woven fabric cannot be adapted to such a rigid design, and both the bending rigidity and the torsional rigidity of the racket frame become stiff, and a racket frame that can obtain a soft feeling cannot be obtained. It was.

  On the other hand, as disclosed in Patent Document 1, in a triaxial woven fabric having anisotropy using metal fibers as part of the warp, the warp is arranged so as to be parallel to the circumferential direction of the racket frame. As a result, the bending rigidity can be efficiently increased as compared with the torsional rigidity. However, this is suitable for reinforcing the region where the racket frame is bent, but is not suitable for reinforcing the region where the torsion occurs. That is, in order to reinforce the region where the racquet frame is twisted, it is necessary to stack two triaxial fabrics so that the warp yarns are obliquely crossed with respect to the circumferential direction of the racquet frame. Accordingly, there is a problem that the thickness and mass of the outer shell increase. In addition, in order to reinforce the region where the twist occurs, a triaxial fabric using metal fibers as part of the oblique yarn can be separately created separately from the triaxial fabric having the above-described configuration. The problem arises that the number of molded parts increases and the manufacturing cost increases.

  Therefore, in view of the conventional problems, the present invention provides a racket frame that efficiently increases the bending rigidity and torsional rigidity of the racket frame, is light in weight, has excellent resilience characteristics, and provides a good shot feeling. The purpose is to do.

In order to achieve the above object, the racket frame of the present invention has the following configuration.
That is, the racket frame according to claim 1 of the present invention has warps and wefts woven at right angles to each other, and these warps and two oblique yarns woven obliquely with the wefts, The oblique yarn is a fiber material having a fineness smaller than that of the warp and the weft, or a low elastic yarn made of a fiber material that is different from the warp and the weft and has a lower elasticity than the warp and the weft. A configured four-axis fabric having anisotropy is a racket frame used as a part of a fiber reinforcement of a fiber-reinforced resin outer shell constituting a racket frame, and the four-axis fabric is a hit ball of the racket frame. Is arranged in a region from 0.05L to 0.25L of the total length L of the hitting ball portion on the top portion side in the racket axis direction from the connection point P between the shaft portion and the shaft portion, and the oblique yarn of the 4-axis fabric is The circumference of the racket frame Parallel or relative to, and is characterized in that it is directed in a vertical direction.

The racket frame according to claim 2 of the present invention has warp yarns and wefts woven at right angles to each other, and these warp yarns and two oblique yarns woven obliquely with the weft yarns, The oblique yarn is a fiber material having a fineness smaller than that of the warp and the weft, or a low elastic yarn made of a fiber material that is different from the warp and the weft and has a lower elasticity than the warp and the weft. A configured four-axis woven fabric having anisotropy is a racket frame used as part of a fiber reinforcing material of a fiber reinforced resin outer shell constituting a racket frame, the racket frame including a hitting ball portion, a shaft And a grip portion, the shaft portion has a throat region that branches into a bifurcated shape, the 4-axis fabric is disposed in the throat region, and the warp or weft of the 4-axis fabric is a racket Frey Parallel or to the circumferential length direction of, and is characterized in that it is directed in a vertical direction.

  As described above, in the racket frame of the present invention, since the required strength and rigidity can be expressed by using the four-axis fabric, the number of plies of the unidirectional prepreg forming the racket body layer can be greatly reduced. As a result, the thickness of the outer shell can be designed to be thin, and the mass of the racket frame can be greatly reduced.

  Further, the four-axis woven fabric is placed in a region from 0.05L to 0.25L of the total length L of the hit ball portion from the connection point P between the hit ball portion of the racket frame and the shaft portion to the top portion side in the racket axis direction. By arranging the oblique yarns of the 4-axis fabric so as to face the direction parallel to or perpendicular to the circumferential direction of the racket frame, the oblique yarns composed of the low-elastic yarns of the 4-axis fabric are used. While the bending rigidity of the region is kept low, the torsional rigidity is efficiently increased by the warp or weft. As a result, the torsional rigidity is high in the above-mentioned region, and a good resilience performance is obtained at the time of hitting the ball, and at the same time, the bending rigidity is kept low. And can.

  Further, the four-axis fabric is arranged so that the warp or weft of the four-axis fabric is oriented in a direction parallel or perpendicular to the circumferential direction of the racket frame on the shaft portion region (particularly the throat region) of the racket frame. By arranging, the torsional rigidity of the shaft portion region is kept low by the oblique yarn composed of the low elastic yarn of the four-axis fabric, and the bending rigidity is efficiently increased by the warp or weft. Thereby, in the said shaft part area | region, since bending resilience is high and favorable resilience performance is obtained at the time of ball | blow hitting, since torsional rigidity is restrained low, a soft feeling was obtained at the time of hit | damage and it was excellent in the hit feeling Can be a racket frame.

  In the four-axis woven fabric used in the present invention, warps and wefts are woven with oblique yarns that are low elastic yarns in a direction of approximately 45 ° with respect to the warps and wefts. Anisotropy can be imparted to the bending rigidity and torsional rigidity of the racket frame. Therefore, by arbitrarily setting the orientation direction of the yarns constituting the four-axis fabric, it is possible to easily perform a rigidity design such as bending rigidity> torsional rigidity or bending rigidity <torsional rigidity. Thus, it is possible to reduce manufacturing effort and cost without increasing the number of molded parts.

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 a diagram illustrating the appearance of the racket frame of the present embodiment, FIG. 2 is a diagram illustrating the configuration in the region a of FIG. 1, and FIG. 3 is an expanded description of a four-axis fabric having anisotropy used in the present embodiment. The figure is shown.

  That is, as shown in FIG. 1, the racket frame 1 of this embodiment includes a hitting ball portion 3 in which a gut 2 is stretched to form a hitting surface, and a throat region that branches into a bifurcated shape and connects to the hitting ball portion 3. 4 includes a shaft portion 5 having 4 and a grip portion 6.

In the racket frame 1 of this embodiment, as shown in FIG. 2, an outer shell 8 made of fiber reinforced resin disposed around the core material 7 is formed by winding and unidirectionally prepreg 9 appropriately. The racket body layer 10 and a four-axis fabric layer 11 disposed around the racket body layer 10 in at least a partial region of the racket frame 1.
As shown in FIG. 3, the four-axis woven fabric layer 11 has two warps 12 and wefts 13, which are orthogonal to each other, woven with each other, and further oblique to the warps 12 and the wefts 13. The yarns 14a and 14b are alternately woven into the warp yarns 12 and the weft yarns 13, and the oblique yarns 14a and 14b are low elasticity yarns having different fineness or types from the warp yarns 12 and the weft yarns 13. It is comprised with the 4-axis fabric 15 which has the anisotropy comprised by these.

  According to the racket frame 1 of this embodiment, by using one of the yarns constituting the four-axis fabric 15 so as to be parallel to the circumferential direction of the racket frame 1, Reinforcing fibers parallel to the circumferential direction, oblique reinforcing fibers, and reinforcing fibers perpendicular to the circumferential direction can be provided at a time. Thereby, since required intensity | strength and rigidity can be expressed, the number of plies of the unidirectional prepreg 9 which forms the said racket main body layer 10 can be reduced significantly. As a result, the thickness of the outer shell 8 can be designed to be thin, and the mass of the racket frame 1 can be greatly reduced.

  In the present embodiment, the four-axis fabric 15 can be used for the entire racket frame 1, but the four-axis fabric 15 can also be used for only a part thereof. At that time, at least the shaft portion 5 region (particularly the throat region 4) of the racket frame 1 and / or the hitting portion toward the top portion 16 in the racket axial direction from the connection point P between the hitting ball portion 3 and the shaft portion 5. It is preferable that the four-axis fabric 15 is used in a region of 0.05 L to 0.25 L of the three full length L.

  When the four-axis fabric 15 is used in the throat region 4, the warp yarn 12 or the weft yarn 13 of the four-axis fabric 15 is disposed so as to be parallel or perpendicular to the circumferential direction of the racket frame 1. It is preferable that the oblique yarns 14 a and 14 b made of the low elastic yarn of the four-axis fabric 15 are arranged so as to be directed in the oblique direction with respect to the circumferential direction of the racket frame 1. In this case, the bending stiffness is efficiently increased by the warp yarn 12 or the weft yarn 13 while the torsional stiffness of the throat region 4 is kept low by the oblique yarns 14a and 14b made of the low elastic yarn. Thereby, in the said throat area | region 4, since bending resilience is high and favorable resilience performance is obtained at the time of ball | blow hitting, since twist rigidity is restrained low, a soft feeling is obtained at the time of hit | damage and it was excellent in the shot feeling A racket frame 1 is obtained.

  Further, the four-axis fabric 15 is placed in a region from 0.05L to 0.25L of the total length L of the hitting ball portion 3 on the side of the top portion 16 in the racket axis direction from the connection point P between the hitting ball portion 3 and the shaft portion 5. When used, the oblique yarns 14 a and 14 b of the four-axis fabric 15 are preferably arranged so as to face in a direction parallel or perpendicular to the circumferential direction of the racket frame 1. In this case, the torsional rigidity is efficiently increased by the warp yarns 12 or the weft yarns 13 while the bending rigidity of the region is kept low by the oblique yarns 14a and 14b formed of the low elastic yarns of the four-axis fabric 15. . As a result, the torsional rigidity is high in the above-mentioned region, and a good resilience performance is obtained at the time of hitting the ball, and at the same time, the bending rigidity is kept low. 1 can be used.

  In the four-axis woven fabric 15 used in the present embodiment, the warp yarn 12 and the weft yarn 13 are woven with oblique yarns 14 a and 14 b that are low elastic yarns in a direction of approximately 45 ° with respect to the warp yarn 12 and the weft yarn 13. Therefore, the bending rigidity and torsional rigidity of the racket frame 1 can be made anisotropic. Therefore, by arbitrarily setting the orientation direction of the yarn constituting the four-axis woven fabric 15, the rigidity design such as bending rigidity> torsional rigidity, or bending rigidity <torsional rigidity can be easily performed, so that there is versatility. It is possible to reduce manufacturing effort and cost without increasing the number of molded parts as in the prior art.

In addition, as the warp yarn 12 and the weft yarn 13 constituting the four-axis fabric 15, carbon fibers are preferably used, and those having a fineness of 100 to 400 are used. The oblique yarns 14a and 14b include carbon fibers having a fineness smaller than that of the warps 12 and the wefts 13, or glass fibers, aramid fibers, metal fibers, and the like having a lower elasticity than the warps 12 and the wefts 13. Preferably used.
Examples of the metal fibers that can be used as the oblique yarns 14a and 14b are beta-type titanium alloys having a body-centered cubic structure, and have a low elastic modulus and high strength represented by “rubber metal” (registered trademark). Examples thereof include metal fibers made of an elastic alloy having compatible superelastic properties. In the case of using such a metal fiber, the metal fiber may be used in a state where 3 to 10 single fibers of the metal fiber are bundled, or one single fiber without focusing the metal fibers. Alternatively, the oblique yarns 14a and 14b may be formed. The fiber diameter of the metal fiber (single fiber) is preferably 50 μm to 200 μm, particularly 80 μm to 150 μm in consideration of ease of weaving when the four-axis fabric 15 is used.

Example 1
As the core material 7, a nylon tube having a width of 27 mm and a length of 1800 mm was prepared.
Moreover, as the prepreg for forming the outer shell 8, a unidirectional prepreg of carbon fiber, a unidirectional prepreg of glass fiber, and a 4-axis woven prepreg were prepared.

  In this embodiment, as the four-axis woven prepreg, as shown in FIG. 3, warps 12 and wefts 13 woven orthogonally to each other are composed of carbon fibers having a fineness of 180, and these warps 12 and wefts A four-axis woven fabric 15 having anisotropy in which oblique yarns 14a and 14b woven in an alternating manner with an oblique angle of ± 45 ° with respect to 13 are made of an aramid fiber having an elastic modulus of 70 Gpa was prepared.

  First, the unidirectional prepreg of the carbon fiber and the unidirectional prepreg of the glass fiber are sequentially laminated and wound around the tube, and then the 4-axis woven prepreg constitutes the throat region 4 of the racket frame. A racket frame molded body was obtained by laminating. At this time, the four-axis fabric prepreg was arranged so that the warp yarns 12 of the four-axis fabric 15 were oriented in a direction parallel to the circumferential direction of the racket frame.

  Thereafter, the racket frame molded body was placed in a mold while being bent along the shape of the racket frame, and after clamping the mold, the compressed air was inserted into the tube and heat-cured to obtain a racket frame of this example. .

(Example 2)
An area from 0.07L to 0.18L of the total length L of the hitting ball portion 3 from the connection point P between the hitting ball portion 3 and the shaft portion 5 of the racket frame 1 to the top portion 16 side in the racket axis center direction. A racket frame molded body was obtained by laminating at a position corresponding to. At this time, the four-axis fabric prepreg was arranged so that one of the oblique threads 14a and 14b of the four-axis fabric 15 was oriented in a direction parallel to the circumferential direction of the racket frame.
Other steps were the same as in Example 1 to obtain a racket frame.

(Example 3)
The position where the throat region 4 of the racket frame 1 is configured with the four-axis woven prepreg, and the connecting portion P between the hitting ball portion 3 and the shaft portion 5 from the connecting portion P of the hitting ball portion 3 toward the top portion 16 in the racket axial direction. A racket frame molded body was obtained by laminating at a position corresponding to a region up to ˜0.18L. At this time, the four-axis fabric prepreg laminated on the throat region 4 is arranged so that the warp yarns 12 of the four-axis fabric 15 are oriented in a direction parallel to the circumferential direction of the racket frame, and the hitting portion The four-axis fabric prepreg laminated in the region from the connection point P between the shaft 3 and the shaft portion 5 to 0.07L to 0.18L of the total length L of the hitting ball portion 3 has one of the oblique threads 14a and 14b of the four-axis fabric 15 The racket frame was arranged so as to face in a direction parallel to the circumferential direction of the racket frame.
Other steps were the same as in Example 1 to obtain a racket frame.

Example 4
As shown in FIG. 4, the warp yarn 12 and the weft yarn 13 are made of carbon fibers having a fineness of 180 as a four-axis woven prepreg, and the warp yarn 12 and the weft yarn 13 are ± 45 °. The anisotropy composed of the oblique fibers 14a and 14b that are obliquely woven in an alternating manner with metal fibers 18 (one single fiber) made of rubber metal (manufactured by Toyota Central R & D Co., Ltd.) having a fiber diameter of 100 μm. A four-axis fabric 17 was prepared.
Like the third embodiment, the four-axis woven prepreg is hit to the top portion 16 side in the racket axial direction from the position constituting the throat region 4 of the racket frame 1 and the connection point P between the hitting ball portion 3 and the shaft portion 5. The four-axis fabric prepreg that is disposed in a position corresponding to the region from 0.07L to 0.18L of the total length L and is laminated on the throat region 4 is such that the warp yarn 12 of the four-axis fabric 17 is in the circumferential direction of the racket frame. The four axes are arranged so as to face in a direction parallel to the ball, and are laminated in the region from 0.07L to 0.18L of the total length L of the hit ball portion 3 from the connection point P between the hit ball portion 3 and the shaft portion 5. The fabric prepreg was disposed so that one of the oblique threads 14a and 14b of the 4-axis fabric 17 was oriented in a direction parallel to the circumferential direction of the racket frame.
Other steps were the same as in Example 1 to obtain a racket frame.

(Comparative Example 1)
The four-axis woven prepreg corresponds to a region constituting the throat region 4 of the racket frame and a connecting point P between the hitting ball portion 3 and the shaft portion 5 to a region from 0.07 L to 0.18 L of the hitting ball portion 3 overall length L. A racket frame molded body was obtained by laminating at the position. At this time, the four-axis fabric prepreg laminated in the throat region is arranged so that one of the oblique threads 14a and 14b of the four-axis fabric 15 is oriented in a direction parallel to the circumferential direction of the racket frame. In addition, the four-axis fabric prepreg laminated in the region from the connection point P between the hitting ball portion 3 and the shaft portion 5 to 0.07L to 0.18L of the hitting ball portion 3 overall length L is a warp 12 of the four-axis fabric 15 is a racket. It arrange | positioned so that it might face in the direction parallel to the circumferential direction of a flame | frame.
Other steps were the same as in Example 3 to obtain a racket frame.

(Comparative Example 2)
Both the 4-axis woven prepreg laminated in the throat area 4 and the 4-axis woven prepreg laminated in the area from 0.07L to 0.18L of the hit ball part total length L from the connection point P of the hit ball part 3 and the shaft part 5 are both The warp yarns 12 of the four-axis fabric 15 were arranged so as to face in a direction parallel to the circumferential direction of the racket frame.
Other steps were the same as in Comparative Example 1 to obtain a racket frame.

(Comparative Example 3)
The 4-axis woven prepreg laminated in the throat area 4 and the 4-axis woven prepreg laminated in the area from 0.07L to 0.18L of the overall length L of the hit ball 3 from the connection point P between the hit ball 3 and the shaft 5 are: Both were arranged so that one of the oblique threads 14a, 14b of the four-axis fabric 15 was oriented in a direction parallel to the circumferential direction of the racket frame.
Other steps were the same as those in Comparative Examples 1 and 2, and a racket frame was obtained.

(Comparative Example 4)
As the 4-axis fabric prepreg, an isotropic 4-axis fabric in which all of the warp 12, the weft 13, and the oblique yarns 14a and 14b are composed of carbon fibers having a fineness of 180 was used.
Similar to the third embodiment, this is at a position corresponding to the throat area 4 of the racket frame and the connection point P between the hitting ball part 3 and the shaft part 5 to the area from 0.07L to 0.18L of the total hitting part L. A racket frame molded body was obtained by laminating.
Other steps were the same as in Example 3 to obtain a racket frame.

(Comparative Example 5)
In Example 3, a racquet frame molded body in which a total of four layers of a straight layer, a bias layer, and a hoop layer were laminated using a unidirectional prepreg of carbon fiber instead of the four-axis woven prepreg was prepared to obtain a racquet frame.

  Actual hitting tests were conducted on these racket frames. In this actual hit test, the ball is hit with the racket frames of Examples 1 to 3 and Comparative Examples 1 to 5 for a general amateur player, and the rebound performance at the time of hitting experienced by the player at that time, Evaluations such as feel at impact (feeling) and operability (ease of swinging) were performed. The test results at this time are shown in Table 1 below.

  From such test results, the racket frames of Examples 1 to 4 have superior operability as compared to the racket frames of Comparative Examples 1 to 5, and the resilience performance at the time of hitting the ball, the feel at impact, etc. It was confirmed that an excellent effect was obtained in the characteristics.

The external appearance explanatory drawing of the racket frame of a present Example. FIG. 2 is an explanatory diagram of a configuration in a region a of FIG. 1. Expansion explanatory drawing of the 4-axis fabric which has anisotropy used by a present Example. FIG. 4 is an enlarged explanatory view of a four-axis fabric having anisotropy used in Example 4. Structure explanatory drawing of the conventional racket frame. The expansion explanatory drawing of the conventional textile fabric. The expansion explanatory drawing of the conventional textile fabric.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Racket frame 2 Gut 3 Hitting ball part 4 Throat area | region 5 Shaft part 6 Grip part 7 Core material 8 Outer shell 9 Unidirectional prepreg 10 Racket main body layer 11 Four-axis fabric layer 12 Warp 13 Weft 14a Oblique thread 14b Oblique thread 154 Axis fabric 16 Top portion 17 4 Axis fabric 18 Metal fiber 21 Outer shell 22 Bias layer 23 Straight layer 24 Hoop layer 25 Unidirectional prepreg 26 Biaxial fabric 27 Warp yarn 28 Weft yarn 29 Core material 30 Triaxial fabric 31 Warp yarn 32a Oblique yarn 32b Diagonal thread

Claims (2)

It has warps and wefts woven at right angles to each other, and these warps and two oblique yarns woven obliquely to the wefts, and the oblique yarns are finer than the warps and wefts. A four-axis woven fabric having anisotropy made of a low elastic yarn made of a low elastic yarn made of a fiber material having a small elasticity or different from the warp and the weft and having a lower elasticity than the warp and the weft. A racket frame used as a part of a fiber reinforcement of a fiber reinforced resin outer shell constituting the frame,
  The four-axis woven fabric is disposed in a region from 0.05L to 0.25L of the total length L of the hitting ball portion L from the connection point P between the hitting ball portion and the shaft portion of the racket frame to the top portion side in the racket axis direction. The racquet frame is characterized in that the oblique yarns of a four-axis fabric are oriented in a direction parallel or perpendicular to the circumferential direction of the racquet frame. It has warps and wefts woven at right angles to each other, and these warps and two oblique yarns woven obliquely to the wefts, and the oblique yarns are finer than the warps and wefts. A four-axis woven fabric having anisotropy made of a low elastic yarn made of a low elastic yarn made of a fiber material having a small elasticity or different from the warp and the weft and having a lower elasticity than the warp and the weft. A racket frame used as a part of a fiber reinforcement of a fiber reinforced resin outer shell constituting the frame,
The racket frame includes a hitting ball portion, a shaft portion, and a grip portion. The racket frame has a throat region where the shaft portion branches in a bifurcated shape, and the 4-axis fabric is disposed in the throat region. A racket frame characterized in that the warp or weft of the shaft fabric is oriented in a direction parallel or perpendicular to the circumferential direction of the racket frame.

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