JP2011024618A - Racket frame - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a racket frame providing a high hitting angle and high initial velocity when a ball is hit. <P>SOLUTION: The tennis racket frame 1 is made of fiber-reinforced synthetic resin, and includes a face portion 2, a shaft portion 3 and a grip portion 4. A large across-back part 5 of the face portion 2 includes an end of the face portion 2 on the grip portion 4 side to extend, and the top side of the face portion from the large across-back part is a small across-back part whose across back is less than a maximum across back value T<SB>max</SB>-0.2 mm. The ratio L<SB>1</SB>/L<SB>0</SB>of the length L<SB>1</SB>of the large across-back part in the longitudinal direction of the racket to the length L<SB>0</SB>of the face portion in the longitudinal direction of the racket is 20-50%. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a tennis racket frame, and more particularly to a racket frame made of fiber-reinforced synthetic resin.

  2. Description of the Related Art Conventionally, in a tennis racket frame, spin imparting performance and the like have been improved by controlling the size and shape of the back width (thickness in the direction perpendicular to the face surface).

  Japanese Laid-Open Patent Publication No. 9-299516 describes a fiber reinforced synthetic resin racket frame in which the back width T (thickness in the direction perpendicular to the face surface) of the face portion is 22 mm or less. The racket frame of the same issue is for advanced users because it is easy to spin and has good controllability.

  Japanese Patent Application Laid-Open No. 9-75479 describes a racket frame in which a portion having the maximum spine width is disposed between an intermediate position in the racket longitudinal axis direction of the face portion and an end portion on the grip portion side. In the racket frame of the same number, the sweet area is located on the grip side of the face portion, and the sweet area is long distributed in the racket long axis direction.

Japanese Patent Laid-Open No. 9-299516 JP-A-9-75479

  In the above prior art, the launch angle when a ball is hit with a tennis racket is not considered.

  It is an object of the present invention to provide a racket frame that increases the launch angle when a ball is hit.

The racket frame according to claim 1 is a fiber reinforced synthetic resin tennis racket frame having a face portion, a shaft portion, and a grip portion. The back width of the face portion is a maximum back width value T _max −0.2 mm or more and a maximum. The large back width portion having a spine width value T _max or less extends including the end portion on the grip portion side of the face portion, and the back width of the top portion of the face portion is larger than the large back width portion. It is a small back width portion that is less than the maximum back width value T _max −0.2 mm, the length L _{1 of} the large back width portion in the racket long axis direction and the length L _{0 of the} face portion in the racket long axis direction the ratio _L 1 / _{L 0} with is characterized in that 20 to 50%.

The racket frame according to claim 2 is characterized in that, in claim 1, L ₁ is 70 to 170 mm.

The racket frame of claim 3 is characterized in that, in claim 1 or 2, the minimum back width value T _min of the small back width portion is 80 to 90% of the maximum back width value T _max. is there.

  A racket frame according to a fourth aspect of the present invention is the racket frame according to any one of the first to third aspects, wherein the face portion, the shaft portion, and the grip portion are all hollow tubular, and the shaft portion traverses the shaft portion. A reinforcing partition wall portion extending along the extending direction of the shaft portion is provided.

  A racket frame according to a fifth aspect of the present invention is the racket frame according to any one of the first to fourth aspects, wherein the face portion has a thickness S in the face surface direction from an end portion on the grip portion side of the face portion toward an end portion on the top portion side. It is characterized by being smaller.

  A racket frame according to a sixth aspect of the present invention is the racket frame according to any one of the first to fourth aspects, wherein at least one face portion has the same thickness S in the face surface direction from the grip portion side to the top portion side. The other portion of the face portion is characterized in that the thickness S in the face surface direction is reduced from the grip portion side to the top portion side of the face portion.

  As a result of various studies by the present inventor, it has been found that when the rigidity in the direction perpendicular to the face surface on the grip portion side of the face portion is increased, the launch angle of the ball is increased.

The present invention is based on such knowledge. In the racket frame of the present invention, the large back width portion of the face portion whose back width is not less than the maximum back width value T _max −0.2 mm and not more than the maximum back width value T _max is the grip portion side of the face portion. Therefore, the rigidity in the direction perpendicular to the face surface near the grip portion is high, and the launch angle of the ball is high.

  If a reinforcing partition wall portion is provided in the shaft portion, the rigidity of the shaft in the direction perpendicular to the face surface is increased, thereby further increasing the launch angle.

(A) The figure is a front view of the racket frame which concerns on embodiment, (b) The figure is a side view. It is the II-II sectional view taken on the line of FIG. It is the III-III sectional view taken on the line of FIG. It is explanatory drawing of the measuring method of bending deflection amount. It is explanatory drawing of the measuring method of a hoop deflection amount.

  Hereinafter, embodiments will be described with reference to FIGS. 1 to 5.

  FIG. 1 (a) is a front view of the racket frame 1 according to the embodiment, and FIG. 1 (b) is a right side view thereof. The racket frame 1 includes a face portion 2, a shaft portion 3, and a grip portion 4. The face part 2, the shaft part 3, and the grip part 4 are all made of fiber reinforced synthetic resin. The face portion 2 is provided with a gut insertion hole, and the gut is stretched through a grommet (not shown). The face portion 2 is substantially elliptical. The face portion 2 includes a large back width portion 5 constituting the grip portion 4 side and a small back width portion 6 constituting the top portion side. The large back width portion 5 extends including the end portion of the face portion 2 on the grip portion 4 side.

The “large back width portion” means that when the back width of the face portion where the back width (thickness in the direction perpendicular to the face surface) is the maximum is the maximum back width value _Tmax , It means a portion where the back width including the largest portion is a maximum back width value T _max −0.2 mm or more and a maximum back width value T _max or less. In addition, the “small width portion” means a portion of the face portion whose back width is less than the maximum back width value T _max −0.2 mm.

Racket long axial length _{L 1} of the Daicel width portion 5 is 25 to 60% of the length _{L 0} of the racquet longitudinal direction of the face portion 2, and more preferably 30-50%.

The length of the racquet longitudinal direction of the face portion 2 _{L 0} is 300~380mm especially about 330~350mm are preferred. In this case, Daicel the length _{L 1} of the wide portion 5 is a 70~170mm particularly 100~140mm about. The length L ₀ of the face portion 2 in the racket major axis direction is a distance from the outer peripheral surface on the top side of the face portion 2 to the outer peripheral surface on the shaft portion 3 side.

The maximum back width value T _max is preferably about 22 to 30 mm, particularly about 24 to 28 mm.

In the present embodiment, the back width of the small back width portion 6 gradually decreases from the end portion on the large back width portion 5 side toward the top side, and the end portion on the top portion side of the face portion 2 is the smallest. It is the back width (minimum back width value T _min ). However, the shape of the small back width portion 6 is not limited to this as long as the back width is less than T _max −0.2 mm. For example, the back width partially extends from the grip portion 4 side to the top side. The back width may be partially the same from the grip portion 4 side to the top side. In the present embodiment, the back width of the shaft portion 3 gradually decreases from the face portion 2 side toward the grip portion 4 side, and the shaft portion 3 has the largest back width at the end on the grip portion 4 side. and it has a small back width value T _S. In this embodiment, the minimum back span value T _S of the shaft portion 3 is smaller than the minimum spine width value T _min of the face portion 2 may be identical to the minimum spine width value T _min It may be larger than the minimum back width value _Tmin .

The difference T _max −T _min between the maximum back width value T _max and the minimum back width value T _min is preferably about 2 to 8 mm, particularly about 4 to 6 mm. Minimum back span value _{T min} is preferably 80 to 90% of the maximum back span value _{T max.}

Racket long axial length _{L 2} of small spine width portion 6 180~260mm especially about 200~250mm are preferred. Note that L ₁ + L ₂ = L ₀ .

Tennis racket with lengthened racket frame length L ₁ of to a large spine width portion 5 as described above, a large launch angle. Moreover, the tendency for the amount of spins to increase is recognized. The reason why the launch angle becomes large by increasing the length L ₁ of the larger spine width portion 5 of the racquet frame 1, is presumed as follows. That is, in general, a tennis racket is often shaken so as to rub the ball diagonally upward from below so as to apply a top spin to the hit ball. In this case, the face surface hits the ball slightly downward from the vertical surface. Therefore, a force is applied from the ball to the face surface so as to push it back toward the rear side and slightly in the lower half side (ground side). When the L ₁ is small, the delay in coming than the top side is faint while the face center of the face portion 2, the downward extent of the amount corresponding to the face of this delay becomes stronger, the launch angle is low. Further, the amount of the top side pushed back by the reaction force received from the ball increases, and this also reduces the launch angle. In contrast, when the length L ₁ of Daicel width portion 5 as in the present invention, the bending deflection amount (described later) is reduced, top side of the delay is reduced during the swing, also the top side of the ball The amount pushed back is also reduced, which increases the launch angle.

  In the present embodiment, the thickness S in the face surface direction of the face portion 2 decreases from the grip portion 4 side toward the top side.

The thickness S of the face portion 2 in the face surface direction is preferably 9.5 to 10.8 mm, particularly about 10 mm. The minimum value _{S min} of the thickness S is in particular about 95% about 90% to 100% of the maximum value _{S max} is preferred.

Reducing the thickness S ₁ of the face direction of the Daicel width portion 5, hoop deflection of the face part 2 (described later) is increased. Thus, when the amount of deflection of the hoop was large, a tendency for the initial speed to increase was recognized. The reason is considered to be that the amount of deformation of the ball at the time of hitting the tennis ball becomes small, and therefore energy loss accompanying the deformation of the ball is reduced. The _{S 1} is, 10～11Mm especially about 10.2~10.8mm are preferred.

The ratio T _max / S ₁ × 100% of the thickness S ₁ (FIG. 2) of the face portion 2 in the large back width portion 5 in the face surface direction and the maximum back width value T _mzx is 230 to 290%, particularly 245 to 270. % Is preferred. This is for suppressing or eliminating an increase in weight of the racket frame even if the back width of the large back width portion 5 is increased.

  The bending deflection amount and the hoop deflection amount will be described below.

I Bending deflection
The bending amount is the bending of the racket frame 1 when the base end of the racket frame 1 is fixed over a range of 150 mm and a load P of 6 kg is applied to the tip of the racket frame 1 in the direction perpendicular to the gut surface. The displacement W (mm) is measured.

II Hoop deflection
As shown in FIG. 5, the hoop deflection amount means that the axial direction of the racket frame 1 is parallel to the surface plate 7, and a load of 100 kg perpendicular to the axial direction is added to the maximum width portion of the head portion (face portion). The displacement (mm) in the load application direction is measured.

  In this embodiment, as shown in FIG. 3, a reinforcing partition wall portion 3 a is provided on the shaft portion 3. The reinforcing partition wall 3a is located on the extended surface of the face surface. The reinforcing partition wall portion 3a may be provided on the entire shaft portion 3, may be provided only on a part thereof, or may be omitted. By providing the reinforcing partition wall portion 3a, the bending amount of the racket frame 1 is reduced. The reinforcing partition wall 3a may be provided in a direction perpendicular to the face surface or in an oblique direction. Further, both the reinforcing partition wall portion 3a in the face surface direction and the reinforcing partition wall portion in the direction perpendicular to the face surface may be provided.

The racket frame of the present invention is made of fiber reinforced synthetic resin. As this reinforcing fiber, those having a tensile elastic modulus of 10 to 40 ton / mm ^2, particularly 16 to 30 ton / mm ² are suitable, and carbon fiber, boron fiber, alumina fiber, ultrafine iron wire, Ti—Si—C—O. System fiber (trade name Tyranno fiber), aromatic polyamide fiber, aromatic polyester fiber, ultra-high molecular weight polyethylene fiber, etc. can be used, but carbon fiber is also preferred from the viewpoint of cost.

  As the synthetic resin, epoxy resin, nylon and the like are preferable, but epoxy resin is preferable in terms of strength, durability and price.

  In order to manufacture the racket frame of the present invention, a fiber-reinforced synthetic resin racket frame in which a plurality of prepreg sheets are laminated around a core material and placed in a cavity having a frame shape of a mold and heated. According to this manufacturing method. In addition, the elasticity modulus of a fiber reinforced synthetic resin can be changed by changing the quantity and orientation direction of the fiber in a prepreg sheet. Moreover, the density of a fiber reinforced synthetic resin can be changed by changing the quantity of the fiber in a prepreg sheet.

  The racket frame of the present invention is made of fiber-reinforced synthetic resin, but a metal such as titanium or a different material such as rubber may be partially used.

The above embodiment is an example of the present invention, and the present invention is not limited to the above embodiment. For example, in the above-described embodiment, the thickness S in the face surface direction of the face portion 2 is reduced from the grip portion 4 side toward the top side. However, the present invention is not limited to this, and the grip portion is partially limited. The thickness S may be the same from the 4 side toward the top side. For example, the thickness S ₁ of the face direction of Daicel width portion 5 may be the same toward the top side from the grip portion side.

Examples 1-3, Comparative Examples 1-3
A racket frame having the shape shown in FIG. 1 and specifications as shown in Table 1 was manufactured using a carbon fiber reinforced epoxy resin. The total length of this racket frame is 685 mm, and the area of the gut surface is 100 cm ² .

A nylon gut having a cross-sectional area of 1.77 mm ² was stretched on this racket frame with a tension of 54 pounds (24.5 kg) to obtain a tennis racket.

  This tennis racket was mounted on a trial hitting robot machine, a tennis ball flying horizontally at a speed of 45 km / h was hit back, photographed with a high-speed camera, and the launch angle, initial speed and spin amount were measured. The face surface was slightly downward (by 15 °) from the vertical surface. The swing trajectory of the face part was upward by 30 ° with respect to the horizontal, and a top spin was applied. The results are shown in Table 1.

  From Table 1, it is recognized that the tennis rackets of Examples 1 to 3 have a high launch angle and a large initial speed.

1 Racket frame 2 Face 3 Shaft 4 Grip 5 Large back width

Claims (6)

In a tennis racket frame made of fiber reinforced synthetic resin having a face part, a shaft part and a grip part,
Of the face portion, a large back width portion whose back width is not less than the maximum back width value T _max −0.2 mm and not more than the maximum back width value T _max extends including the end portion of the face portion on the grip portion side. And
The top side of the large back portion of the face portion is a small back width portion whose back width is less than the maximum back width value T _max −0.2 mm,
Racket frame ratio L _{1 /} L ₀ of the racket long axial length L ₁ and the racket long axial length L ₀ of the face portion of the large back span portion is characterized by a 20-50% . According to claim 1, racquet frame, wherein _{L 1} is 70～170Mm. 3. The racket frame according to claim 1, wherein a minimum back width value _Tmin of the small back width portion is 80 to 90% of the maximum back width value _Tmax . In any one of Claims 1 thru | or 3, the said face part, a shaft part, and a grip part are all hollow tubular,
A racket frame characterized in that a reinforcing partition wall portion is provided in the shaft portion so as to cross the shaft portion and extend along the extending direction of the shaft portion.   5. The thickness S of the face portion in the face surface direction according to claim 1, wherein the thickness S of the face portion decreases from the end portion on the grip portion side toward the end portion on the top portion side. And racket frame. In any one of claims 1 to 4, at least one portion of the face portion has the same thickness S in the face surface direction from the grip portion side to the top portion side of the face portion,
The other part of the face part is a racket characterized in that the thickness S in the face surface direction decreases from the grip part side to the top part side of the face part.

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