JPH0673559B2 - Racket - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention provides a gut protective material in a gut hole provided in a racket frame having an outer shell layer made of at least a non-wood material such as metal or fiber reinforced plastic. It relates to a racket that is inserted and attached.

[Conventional technology]

In recent years, racket frames for tennis, badminton, squash, etc. using metal materials such as steel and aluminum alloys, and high-strength and high-modulus long fiber reinforced plastic materials such as glass fibers and carbon fibers are increasing. By making a racket frame from these materials, it is possible to obtain a racket that is light in weight, excellent in strength and durability, and excellent in maneuverability and aesthetics. However, such a racket was insufficient in absorbing the vibration generated at the time of impact, as compared with a racket having a wooden frame. As a result, a player who uses a racket having a frame made of metal or fiber reinforced plastic feels discomfort in his hands, elbows, arms, etc., and his elbow pain (so-called tennis elbow) becomes chronic due to long-term use. There was also something to do.

Therefore, a means for absorbing the vibration generated at the time of impact has been developed. For example, the one as shown in FIG. 6 is known. This is made by bending a metal feeder pipe to form a racket frame 100, and the recess of this frame 100.
A large number of gut holes 102 are provided in 101, short tubes 104 integrally formed with synthetic resin strip 103 are inserted into these gut holes 102, and guts are passed through the holes of these short tubes 104. The short tube 104 and the synthetic resin strip 103 are integrally molded with a synthetic resin material, have flexibility and sufficient strength as a material to be used, have a small friction with a gut, and are a nylon resin excellent in gut protection and The glass-reinforced product was used. The synthetic resin strip 103 has a length sufficient to cover the entire circumference of the frame 100 or a length sufficient to cover half the circumference.
It was either one of the two.

[Problems to be solved]

If the conventional synthetic resin strip 103 is molded continuously over the half or the entire circumference of the frame, the die cost becomes high,
It had the drawback that it could not be used for frames of different shapes. In addition, when each one is used independently, in other words, if only the short tube 104 is used without the synthetic resin strip 103, the die cost is low and it can be used for frames of different shapes. However, there is a drawback that the shock absorbing property and the vibration damping property are deteriorated.

Therefore, the present invention controls the increase of the mold cost without lowering the shock absorbing property and the vibration damping property, and has the advantage of being continuous over half or the entire circumference of the frame and the advantage of a discontinuous single product. An object of the present invention is to provide a racket using a gut protective material having both.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention is a racket in which a gut protective material is inserted and attached to a gut hole provided in a racket frame having an outer shell insert made of at least a metal or a fiber-reinforced plastic or the like. At
Connecting the base ends of a plurality of cylinder parts of the gut protective material that are inserted into and installed in the gut holes located in the upper and lower parts, which are central regions in the minor axis direction and the major axis direction of the substantially elliptical face of the racket frame, and on both sides. With gut protective material tan δ 0.0
It is characterized in that it is formed of a synthetic resin material or a rubber material having a thickness of 1 to 1.0, and the tubular portion of the gut protective material that is inserted into and attached to another gut hole is attached without connecting the base ends to each other.

[Action]

When hitting a ball with a racket, the area where the ball frequently hits is the center area of the face.When the ball hits the center area of the face, a large load is applied to both sides and top and bottom of the frame, and both sides of the frame It has been found that the shock absorbing property and the vibration damping property are not deteriorated by connecting the base ends of the gut protective material only to the upper part and the upper and lower parts. By connecting about 11 cylinders on both sides of the frame and about 6 cylinders on the upper and lower parts of the frame, the vibration damping performance when the ball hits the center area of the face is improved. No decrease in the effect was observed even when compared with the continuous ones.

〔Example〕

Preferred embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, a large number of guts 21 ... Are stretched on the face surface 2 of the frame 1, and the guts 21 are attached to the gut holes 3 of the frame 1 (see FIG. 5), respectively. It is inserted through 10 (see FIG. 2) and 11. The gut protective member 11 is composed of only the tubular portion 4 shown in FIGS. 2 and 3 (a) and (b). In Fig. 1, A, A ',
The gut protective material 10 provided in the areas indicated by B and B ', that is, the both side portions and the upper and lower portions of the frame 1 are shown in FIGS.
As shown in the figure, the base ends 5 of the cylindrical portions 4 may be connected. The base end 5 can also be formed into a two-layer structure of an inner layer 5A and an outer layer 5B. That is, as shown in FIG. 4, the outer layer 5B is made of a synthetic resin material or a rubber material capable of effectively absorbing a high frequency up to about 2,000 Hz from a vibration of 100 Hz order that is usually generated by the impact of a ball or the like on a racket. The use of elastic bodies consisting of As such an elastic body, a tan having a frequency range of 0 to 40 ° C and a frequency of 10 to 2,000 Hz is used.
δ is 0.01 to 1.0, or the static flexural modulus is 500 to 15,000
kg / cm ^2, more preferably is suitable material is 1,000~5,000kg / cm ^2. The material forming the outer layer 5B is a urethane-based, ester-based, amide-based, styrene-based, olefin-based, or vinyl-based thermoplastic elastomer, and the rubber material is a high styrene-based SBR-based elastomer, polynorbornene-based elastomer, or urethane-based elastomer. Rubber and butyl rubber are suitable. The inner layer 5A and the tube portion 4 are molded from the same material, and the static bending elastic modulus is 2,000 to protect the gut 21.
The use of ~ 15,000 kg / cm ² of synthetic resin material is preferred. For example, amide resins such as 11 nylon and 6.6 nylon, olefin resins such as polypropylene and polyethylene, AB
The cylindrical portion 4 and the inner layer 5A are molded from a styrene resin such as S or AES, a polycarbonate, an ester resin such as polyethylene terephthalate, an ether resin such as polyacetal, or the like. Since the gut protective material 10 as such a two-layer composite structure needs to have appropriate flexibility, it has a static bending elastic modulus of 1,000 in the temperature range of 0 to 40 ° C. as a whole.
~ 10,000 kg / cm ² is desirable, more preferably 3,
It is 000 to 7,000 kg / cm ² . As a molding means for the gut protective material 10 as a two-layer composite structure, it can be easily molded by a two-color injection molding method, the outer layer 5B is molded separately, and after molding, the outer layer 5B is bonded to the inner layer 5A. May be. When the outer layer 5B is a rubber material rather than a synthetic resin material, the rubber material is set in the injection mold in advance, and the tubular portion 4 and the inner layer are formed.
5A and injection molding synthetic resin material,
Alternatively, a rubber material compression-molded by a mold may be bonded to the previously injection-molded product.

Whether the single-layer structure or the double-layer structure described above is used, the upper and lower parts A and A'of the frame 1 and both side parts
The gut protective material 10 used for B and B ′ is tan δ 0.01 to 1.0
Is molded from a synthetic resin or rubber material. Frame 1
The number of the tubular portions 4 of the gut protective material 10 used for the upper and lower portions A and A'is six, but needless to say, the number is not limited to six, and both side portions B and B'of the frame 1 Needless to say, the number of the tubular portions 4 of the gut protective member 10 shown in FIG. 3 used in FIG. 3 is not limited to that shown in the figure. Upper and lower part of frame 1
The gut protective material 11 used for the gut holes 3 other than A, A'and both side parts B, B'is not a continuous base end but an independent cylinder body 4. Here, tan δ means the ratio of the loss elastic modulus (E ″) and the storage elastic modulus (E ′).
That is, tan δ = E ″ / E ′. Here, the storage elastic modulus (E ′) is the elastic modulus in the same phase as the vibration stress and is called the dynamic elastic modulus or simply elastic modulus. The loss elastic modulus (E ″) is an elastic modulus advanced by 90 degrees from the vibration stress. This is called the loss tangent of tanδ, or this tanδ
Is a measure of energy loss per cycle of oscillatory stress. The measurement of tan δ is based on the sinusoidal strain y = y ₀ · s
When inωt is given, the phase difference of response stress to this strain (deviation of response to given vibration) δ is measured,
Find its tangent tan δ.

As shown in FIG. 5, A, A ', B, B'shown in FIG.
In each of the areas, the cylindrical body 4 can be made to project to the inner field side of the frame 1, that is, the face surface 2 side by 1 to further improve the vibration absorbing property. The protrusion amount l at this time is 5 mm
The above is preferable.

〔effect〕

As described above, according to the present invention, the gut protective material is inserted into the gut hole provided in the racket frame having the outer shell layer made of a non-wood material such as metal or fiber reinforced plastic hand and attached. In the racket, the base ends of a plurality of tubular parts of the gut protective material that are attached by being inserted into the gut holes located at the upper and lower parts and the both side parts which are central regions in the minor axis direction and the major axis direction of the substantially elliptical face of the racket frame. The gut protection material
Molded with a synthetic resin material or rubber material with δ 0.01 to 1.0, and inserted it into the other gut hole, the gut protective material was attached without connecting the base parts to each other, so the ball is in the center of the face. As a result of experiments, it was found that the shock absorption and the vibration damping are the same as in the case where the conventional gut protective material whose base end is continuous over the entire circumference of the frame is used as long as the area is covered. The vibration absorbing property and the vibration damping property were the same as before, and the mold cost could be reduced to about two-thirds of the conventional cost. In parts other than the upper and lower parts of the frame and both sides,
Since it is possible to use a cylindrical body whose base end is not continuous, it can be used for frames of various shapes, and the versatility becomes high in this part.

[Brief description of drawings]

FIG. 1 is a front view showing a preferred embodiment of the present invention, FIG. 2 is a front view showing a gut protective material used in the regions of A and A'of FIG. 1, and FIGS. 3 (a) and 3 (b). ) Is a front view and a plan view showing the gut protective material used in the regions of B and B ′ of FIG. 1, FIG. 4 is a sectional view taken along line IV-IV of FIG. 2, and FIG. 5 is a tubular portion of the gut protective material. FIG. 6 is a perspective view showing an example in which the frame is projected to the inner side of the frame, and FIG. 6 is a perspective view showing a conventional example. 1 …… Frame, 3 …… Gut hole, 4 …… Cylinder part, 5 …… Base end, 10,11 …… Gut protective material, 21 …… Gut.

Claims (1)

[Claims] 1. A gut protective material (10) is inserted into a gut hole (3) provided in a racket frame (1) having an outer shell layer made of a non-wood material such as metal or fiber reinforced plastic and attached. In the racket, the substantially elliptical face (2) of the racket frame (1)
The upper and lower parts (A,
A ') and a plurality of tubular base ends (5) of the gut protective material (10) which are inserted and mounted in the gut holes (3) located on both sides (B, B'), and the gut protective material ( 10) to tan
The tubular portion (4) of the gut protective material (11), which is molded from a synthetic resin material or a rubber material having δ 0.01 to 1.0 and is inserted into another gut hole (3) to be attached, has its base ends (5) attached to each other. A racket characterized by being installed without being connected.