JP2007083012A - Wood type golf club head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To heighten the effect of further lowering the center of gravity and a damping effect by increasing the ratio of an elastomer and a weight to the overall area of a sole. <P>SOLUTION: In the wood type golf club head, one or two or more concavities 3 are formed so as to make them occupy a half or more of the longitudinal direction and the longitudinal length of a metal sole 2, an elastomer 6 is embedded in the concavities 3, and a weight 7 is fastened to the concavities 3 as if to make it cover the elastomer 6 and to make it flush with the sole 2, and the area of the concavities 3 accounts for 10 to 60% of the overall area of the sole 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wood type golf club head, and more particularly to a wood type golf club head suitable for application to a driver or fairway wood having a sole formed of a metal material.

  An elastic body (thermoplastic elastomer) having a JIS C hardness of 15 to 80 (preferably 20 to 60) is incorporated in the head in order to suppress vibration at the time of ball impact of the golf club head and improve hit feeling and flight distance. Is known (see Patent Document 1). In this example, it is applied to the head of an iron golf club. However, a cylindrical body protruding inside the sole of the wood type golf club head is formed at the substantially center of the sole, and an elastic body is accommodated in the cylindrical body. A structure with a lid is also known. Also in this case, the elastic body suppresses vibration of the head that occurs at the time of impact, and as a result, the hit feeling and the flight distance are improved. In addition, the elastic body suppresses useless vibrations and acts so that an unpleasant feel is not left in the hand even when a miss hit occurs. In addition, the center of gravity has been lowered by using a screw having a large specific gravity such as tungsten.

In addition, in order to lower the center of gravity, there is also known one in which weights are attached to a plurality of recesses formed in the sole. Tungsten copper is used as the weight, and the large weight has a rectangular shape with a length of 1.1815 inches and a width of 0.25 inches. This weight is joined to the recess of the sole by soldering (see Patent Document 2).
JP 2004-89434 A (page 4, FIG. 1) Japanese Patent Laid-Open No. 11-262548 (pages 3 and 4, FIG. 7)

  In the thing which applied the thing of patent documents 1 to a wood type golf club head, although a useless vibration can be suppressed and a low center of gravity can be made, since a weight is a screw, a predetermined height is required, and a surface area is reduced. It could not be widened, and it was difficult to further reduce the center of gravity and suppress vibration. From the aspect of lowering the center of gravity, Patent Document 2 in which long and thin weights are fixed to a plurality of soles is more advantageous. However, the thing of patent document 2 did not have the function to suppress the vibration of the body containing a sole. Further, the elastic body of Patent Document 1 also has a very small proportion of the sole area, and a sufficient vibration suppressing effect has not been obtained yet.

  Accordingly, an object of the present invention is to provide a wood-type golf club head in which the ratio of the elastic body and weight to the entire area of the sole is increased to further reduce the center of gravity and enhance the vibration suppressing effect.

  In order to achieve the above-mentioned object, the present invention forms one or more recesses so as to occupy more than half of the length of the metal sole in the front-rear direction and embeds an elastic body in the recess. The weight is fixed to the concave portion so as to be flush with the sole so as to cover the elastic body so that the concave portion area is 10 to 60% of the total area of the sole.

  As described above, according to the present invention, one or two or more recesses are formed so as to occupy more than half of the length of the metal sole in the front-rear direction, and an elastic body is embedded in the recesses. Since the weight is fixed to the recess so as to be flush with the sole so as to cover the elastic body, the area of the recess is made 10% to 60% of the total area of the sole. Not only can the center of gravity be at the same level as the sole and a relatively large area, but the center of gravity can be lowered sufficiently, and the elastic body accommodated in the recess also exists in a shape along the sole with a relatively large area. , Suppresses unnecessary vibration of the body including the sole, and improves the shot feeling and flight distance.

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

  FIG. 1 is an exploded perspective view of the body 1 of the head as viewed from the sole 2 side. In the center portion of the sole 2, the front and rear direction thereof is more than half of the front and rear length (in this case, 70 to 80%). An oval or water droplet-shaped recess 3 with a narrow rear portion (opposite to the face) is formed. A step portion 5 is formed over the entire circumference between the bottom portion 4 and the sole 2 of the concave portion 3, that is, at a portion corresponding to the thickness of the elastic body 6. An elastic body 6 is embedded in the bottom portion 4 of the concave portion 3, and a weight 7 is press-fitted into the concave portion 3 so as to contact the step portion 5 so as to cover the elastic body 6. The sole 2 is formed of a metal material, and stainless steel 17-4ph is used in the illustrated example. The area of the recess 3 was set to 10 to 60% of the total area of the sole 2.

  The elastic body 6 is preferably an elastomer having elasticity, such as styrene elastomer, olefin elastomer, urethane elastomer, ester elastomer, amide elastomer, 1,2-polybutadiene, ionomer resin, transpolyisoprene, and the like. is there. In particular, urethane elastomers, amide elastomers, and 1,2-polybutadiene are suitable. When the elastomer is a thermoplastic elastomer, the softening temperature is preferably 80 ° C. or higher. This is to prevent plastic deformation of the golf club elastomer housed in the trunk of the automobile during the summer day. When the elastic body 6 has a JIS C hardness of 15 to 80, particularly 18 to 70, particularly 20 to 60, the shot feeling is good. However, rubber vulcanized with sulfur, particularly rubber blended with butyl rubber, and particularly rubber blended with butyl rubber are preferred because they have lower temperature dependency than thermoplastic elastomers. In particular, viscoelastic materials are very effective in suppressing head vibration. Specific examples include butyl rubber, chlorosulfonated polyethylene rubber, acrylonitrile butadiene rubber, natural rubber, silicon rubber, and styrene rubber. Of these, butyl rubber, chlorosulfonated polyethylene rubber, and acrylonitrile butadiene rubber are particularly preferable, but natural rubber and butyl rubber may be mixed and used.

  The viscoelastic material used as the elastic body 6 has a loss coefficient (tan δ) of viscoelastic material of 0.3 or more in the range of −40 ° C. to −10 ° C., or in the range of −40 ° C. to −10 ° C. It is desirable to have a peak value of 0.5 or higher. This loss factor (tan δ) of the viscoelastic material is the ratio of the storage shear modulus (G ′) to the loss shear modulus (G ″), and G ″ / G ′ is called the loss tangent (loss factor) and is expressed as tan δ. Shows how much energy the material absorbs (transforms into heat) as it deforms. The measurement can be obtained with a dynamic viscoelasticity measuring apparatus. The larger the value of tan δ, the more energy is absorbed, the impact resilience becomes smaller in the impact buffer test, and the resonance magnification becomes lower in the vibration test.

  As the weight 7, a tungsten-nickel alloy or a tungsten-copper alloy can be preferably used. These specific gravity should be 9-12. The forming material other than the sole 2 may be the same material as the sole 2 or a composite body in which different materials are combined. The weight 7 has a thickness of 0.5 mm to 2.5 mm, preferably 1.0 mm to 2.0 mm. This is to lower the center of gravity of the head. Further, it is preferable to increase the thickness and weight of the weight 7 as the loft angle increases. In the case of fairway wood, the head volume decreases and the head weight increases as the loft angle increases.

  FIG. 2 is a sectional side view of the head, showing a state in which an elastic body 6 having a thickness of about 2 mm and a weight of about 1 g is embedded in the concave portion 3 and a weight 7 of about 10 g of tungsten-nickel alloy is press-fitted into the concave portion 3. Here, reference numeral 8 indicates a face, and reference numeral 9 indicates a crown. Here, the crown 9 is made as thin as possible by casting with stainless steel, that is, the thickness is set to 0.5 mm to reduce the weight of the crown 9. In addition, the thickness design of the sole 2 has been optimally distributed by computer simulation, and a high moment of inertia with excellent directionality has been achieved while satisfying the operability demanded by professionals and advanced players. While the above-mentioned thin crown reduces the weight by about 5 g, the weight 7 of about 10 g of tungsten alloy is press-fitted into the center of the sole, and the low-center of gravity design by the thick-shaped sole 2 of the optimum shape enables high launch and low spin. Realized a strong trajectory flight.

  FIG. 3 shows an enlarged view of the portion A in which the periphery of the recess 3 of the sole 2 is caulked with the periphery of the weight 7. As the means for fixing the weight 7 to the recess 3, known means such as adhesion can be employed in addition to press-fitting and caulking.

FIGS. 4 to 6 show # 3 fairway wood (product of the present invention) applied to the fairway wood # 3 (product of the present invention), head volume 158 cm ³ , loft angle 15 °, stainless steel body for advanced users. Name: Tour stage F-ST) is comparative example 1, head volume 170cm ³ , loft angle 14 °, # 3 fairway wood (product name; tour stage) with stainless steel body and tungsten weight inside to shorten the center of gravity distance F−ST ⁺ ) is Comparative Example 2 and is a graph comparing “center of gravity height”, “center of gravity distance”, and “moment of inertia”. The product of the present invention has a higher face height than Comparative Example 1, but the center of gravity height could be lowered. This provided a strong trajectory that did not blow up even at high head speeds of professionals and advanced players. Further, the center-of-gravity distance was longer than that of Comparative Examples 1 and 2, by making it a horizontally long shape. Furthermore, the moment of inertia in the lateral direction is increased and the directionality is excellent.

  In the embodiment described above, one recess 3 is formed at the center of the sole. However, a pair of left and right, two in the center and three on the left and right, or four or more may be used. Further, the weight 7 and the concave portion 3 can be formed in various shapes. When the depth of the center of gravity is desired to be increased, the weight distribution can be increased in the rear portion of the sole 2.

  The sole 2 includes a golf club head of the present invention containing viscoelastic butyl bromide rubber and a golf club head of the present invention containing an elastic urethane elastomer and the golf club of the comparative example described above. A feeling test was conducted. As a result, compared with the golf clubs of Comparative Examples 1 and 2, the golf club head with the viscoelastic body had the best hit feeling, and then the golf club head with the elastic body had good hit feeling and had an effect. It was. This is due to the effect of the elastic body and viscoelastic body.

  In addition to the means for fixing the weight 7 to the sole 2 shown in FIG. 3, as shown in FIGS. 7 and 8, a protruding piece 3 </ b> A continuous along the outer periphery of the recess 3 at the boundary with the recess 3 of the sole 2. A notch recess 7A is formed on the outer periphery of the weight 7, and after the weight 7 is fitted into the recess 3, the protruding piece 3A is crushed, and the notched recess 7A is filled with the protruding piece 3A. In this way, the weight 7 can be fixed to the sole 2 by plastic deformation. The concave portion 3 has a two-stage structure of a small concave portion 30 and a large concave portion 31, and an elastic body 6 is disposed in the small concave portion 30 and a weight 7 is disposed in the large concave portion 31 (FIG. 3). The same applies to the embodiment of FIG. The large concave portion 31 is formed to be about 1 to 5 mm larger than the outer periphery of the small concave portion 30 and presses the outer peripheral edge of the weight 7 to the step portion 5 (see FIG. 1).

  FIGS. 9 and 10 also show other fixing means of the weight 7, the groove 3 </ b> B is formed on the outer periphery of the recess 3, the protrusion 7 </ b> B is formed on the outer periphery of the weight 7, and the protrusion 7 </ b> B is press-fitted into the groove 3 </ b> B. Thus, the weight 7 is fixed to the sole 2 by plastic deformation.

The perspective view seen from the sole side. FIG. The expanded sectional view of a weight adhering part. Comparison graph of center of gravity height. Comparison graph of center of gravity distance. Comparison graph of moment of inertia. The expanded sectional view before fixation which shows the other means of weight fixation. The expanded sectional view after the adhering of FIG. The expanded sectional view before fixation which shows another means of weight fixation. The expanded sectional view after the adhering of FIG.

Explanation of symbols

1 Body 2 Sole 3 Recess 6 Elastic Body 7 Weight

Claims (4)

  One or more recesses are formed so as to occupy more than half of the length of the metal sole in the front-rear direction, and an elastic body is embedded in the recess, and the sole and the recess are covered with the elastic body. A wood-type golf club head, wherein a weight is fixed so as to be flush with each other, and a recessed area is 10 to 60% of a total area of the sole.   2. The wood type golf club head according to claim 1, wherein a tungsten alloy is used as the weight and is press-fitted into the recess.   The wood-type golf club head according to claim 1 or 2, wherein a weight is brought into contact with a step portion formed above the bottom portion of the concave portion, and an elastic body is embedded behind the step portion.   4. The wood type golf club head according to claim 1, wherein the crown of the body is formed to have a thickness of 0.5 mm ± 0.1 mm. 5.

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