JPH0824376A - Golf club head - Google Patents

Abstract

PURPOSE:To improve initial ball speed and an inner out angle even when a ball is hit below the face center by specifying the centroid depth and centroid height of the head concerning a wood golf club head specified on head weight, head volume and loft angle. CONSTITUTION:Concerning the wood golf club head, a face 1, sole 3 and upper 4 forming a main body part 2 of the head are formed from the same material such as the metal material of small specific gravity, for example. Then, the head weight is set from 175g to 220g, the head volume is set more than 200cc, and the loft angle is set from 5 deg. to 16 deg., respectively. Centroid depth Zg of the head is set deeper than 35mm and similarly, centroid height Hgr is set lower than 20mm. Besides, a member 5 equipped with specified gravity M2 larger than specific gravity M1 of the main body part 2 of the head is fitted along the rear end part of the sole 3, and the relation of respective specific gravity M1 and M2 is set in (M1-M2)>1.5. Thus, the initial ball speed and inner out angle can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wood golf club head.

[0002]

2. Description of the Related Art A wood-based golf club head is made of various materials such as persimmon, synthetic resin, metal and alloy, and is required to have a flight distance. In order for golfers who do not have fast head speeds like professionals and advanced players to fly the ball far, it is important to increase the ball launch speed (ball initial velocity) and launch angle. Further, for a golfer who has difficulty hitting the ball on the sweet spot, a head capable of reducing the reduction in flight distance even if the ball is hit without the sweet spot is desired. For example, a golfer with a slow head speed is shown in FIG.
As shown in (1), when the ball is hit above the center of the face 1 (position A), since the face 1 has a round, the launch angle of the ball is high and the reduction of the flight distance is small. However, when the ball is hit below the center of the face 1 (position C), on the contrary, the launch angle decreases due to the influence of the round. Further, when the ball is hit on a line passing through the center of gravity G and orthogonal to the face 1 (position B), the maximum energy is given to the ball because the center of gravity of the head and the ball are on the same line. The probability of making an impact at this position B is extremely low for general golfers.

Therefore, in order to widen the sweet spot, a golf club head having a large head volume made of a synthetic resin material or various metals (including alloys) has been developed. For example, in the case of a head formed of titanium, aluminum, or an alloy thereof having a small specific gravity, the head volume can be increased without increasing the head weight, and the weight can be distributed around the head, that is, the peripheral weight can be distributed. In addition, it has been attempted to make the position of the center of gravity backward and deepen the depth of the center of gravity to widen the sweet spot.

As shown in FIG. 4, the wood type golf club head has a head body 2 having a face 1 and a sole 3, and the distance from the face center 1A to the center of gravity G is the center of gravity depth Z _G. The height from the horizontal line passing through the sole 3 to the center of gravity G when the sole 3 is soleted is the height of the center of gravity Hg.
r, the angle between the surface orthogonal to the horizontal plane in contact with the sole 3 when the sole 3 is solened and the surface of the face 1 passing through the face center 1A is the loft angle θ. In the conventional head, the center of gravity height Hgr is 21 to 23 mm and the center of gravity depth Zg is about 20 to 30 mm.

[0005]

The center of gravity depth Zg is 20-.
When it is about 30 mm, the moment of inertia about the X axis passing through the center of gravity G of the head shown in FIG. 5 is small, the initial velocity of the ball is reduced due to the variation of the hitting point in the vertical direction of the face 1, and the center of gravity height Hgr is about 21 to 23 mm. If so, the position of the sweet spot on the face of the face 1 is high, and if the ball is hit under the face center 1A, the ball does not rise and the flight distance decreases.

Therefore, according to the present invention, even if a ball is hit under the face center, the ball is raised to suppress the reduction of the flight distance, and even a general golfer having different hitting points can increase the ball initial velocity and launch angle. It is intended to provide a wood-based golf club head.

[0007]

In order to achieve the above object, the present invention is a wood type golf club head having a head weight of 175 to 220 g, a head volume of 200 cc or more, and a loft angle of 5 to 16 °. Center of gravity depth Zg is 35
The height of the center of gravity Hgr of the head is 20 mm or less. The head volume is preferably 320 cc or less.

[0008]

The head of the present invention can be shaken off even by a golfer whose head weight is comparatively weak, and the head volume is 200 cc or more, and a golfer with a low meat ratio is likely to hit somewhere on the face, and the center of gravity is high. Since the depth Zg is 35 mm or more, the range of the sweet spot is widened, the ball is easily raised, and the gear effect is easily activated. If the depth Zg of the center of gravity is made deeper than ever, the moment of inertia of the head around the X axis (see FIG. 5) becomes large. Therefore, even if the sweet spot is moved up and down to hit the ball, the decrease in the initial velocity of the ball is reduced. Further, since the height Hgr of the center of gravity is 20 mm or less, the ball rises even when the ball is hit below the face center.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

In the embodiment shown in FIG. 1, the face 1, the sole 3 and the upper 4 constituting the head body 2 are made of the same material,
For example, it is preferably formed of a metal material having a small specific gravity such as a magnesium alloy, an aluminum alloy, or a titanium alloy. A member 5 having a specific gravity larger than that of the head main body 2 is attached along the rear edge of the sole 3. The member 5 is preferably made of a material such as titanium alloy, stainless steel, copper alloy, or iron. Head body 2
When the specific gravity of the material forming M is M ₁ and the specific gravity of the material forming the member 5 is M ₂ , M ₁ is preferably about 1.75 to 2.8, and M ₂ is preferably about 4 to 16. Specific gravity M
_{The 2} -specific gravity M ₁ is 1.5 to 10, preferably 1.5 to 8. The head body 2 has a side 6 and a hosel 7. It may be the head body 2 without the hosel 7.

FIG. 2 shows the head as seen from the sole 3 side.
The attachment position of the member 5 is shown by cross hatching.

The head thus constructed has a head weight of 175 to 220 g, a head volume of 200 cc or more, and a loft angle θ of 5 to 16 °. The depth Zg of the center of gravity of the head is 35 mm or more, and the height Hgr of the center of gravity of the head is 20 mm.
mm or less.

Next, Table 1 compares Examples 1 and 2 of the present invention with a conventional golf club head.

[0014]

[Table 1]

In Table 1, Hg is the height up to the face center 1A. Ix represents the moment of inertia about the X axis. In Example 1, a head as shown in FIGS. 1 and 2 was formed, the head body 2 was made of a magnesium alloy, and the member 5 was made of stainless steel. In Example 2 as well, a head as shown in FIGS. 1 and 2 is formed, the head main body 2 is made of an aluminum alloy, and the member 5 is made of a copper alloy. The conventional example is formed entirely of a stainless material.

The following Table 2 shows the backspin, the launch angle, the initial velocity of the ball, the carry when the hitting point in the embodiment 1, the embodiment 2, and the conventional example shown in Table 1 is at the face center 1A and above and below the face center 1A. , It indicates the total distance. When there is a hit point on the face center 1A, it is indicated by +, and when there is a hit point under the face center 1A, it is indicated by-, and the unit is mm. D _YG indicates the distance from the face center to the center of gravity Hg.

[0017]

[Table 2]

As is clear from Table 2, in Examples 1 and 2, both the launch angle and the ball initial velocity are higher than in the conventional example even when the hitting point is below the face center 1A. I understand. In Table 2, an experiment was carried out using a trial hitting robot at a head speed of 35 m / sec.

In the embodiment, the head body 2 is made of a metal or an alloy material, but it may be a head using a synthetic resin material, a so-called carbon head, or a combination of carbon and metal, and further the face 1. It may be a composite head in which the material of the head main body 2 is different from that of the other. It is also possible to make the material of the sole 3 a material having a high specific gravity to achieve a low center of gravity.

[0020]

As described above, according to the present invention, the depth of the center of gravity Zg of the head is set to 35 mm or more and the height of the center of gravity Hgr of the head is set to 20 mm or less, whereby the sweet spot range is widened and It becomes easier to raise, and the gear effect becomes easier to work. When the depth Zg of the center of gravity is increased, the moment of inertia of the head around the X-axis is increased, and even if the sweet spot is removed vertically, the decrease in the initial velocity of the ball is suppressed and the flight distance is extended. When the height Hgr of the center of gravity is 20 mm or less, the ball easily rises even when hitting the ball below the face center, and the reduction of the flight distance can be suppressed.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a preferred embodiment of the present invention.

FIG. 2 is a view of the embodiment shown in FIG. 1 viewed from the sole side.

FIG. 3 is an explanatory view when the hitting positions of the balls are different from each other.

FIG. 4 is a diagram illustrating the depth of center of gravity and the height of the center of gravity.

FIG. 5 is a front view showing the X-axis passing through the center of gravity.

[Explanation of symbols]

 1 Face 2 Head Body 3 Sole 4 Upper 5 Member 6 Side 7 Hosel

Claims (4)

[Claims] 1. A wood-type golf club head having a head weight of 175 to 220 g, a head volume of 200 cc or more, and a loft angle of 5 to 16 °, wherein the head has a center of gravity depth Zg of 35 mm or more and a head center of gravity height Hgr. A golf club head characterized by being 20 mm or less. 2. The golf club head according to claim 1, wherein a member having a specific gravity M ₂ larger than the specific gravity M ₁ of the head body is attached along the rear end edge of the sole portion. 3. A golf club head according to claim 2, wherein the relationship between the specific gravities M ₁ and M ₂ is (M ₁ −M ₂ )> 1.5. 4. The golf club head according to claim 1, wherein the head body is made of a metal or an alloy material.