TWI697345B - Wood type golf club head - Google Patents

Abstract

The subject of the present invention is to provide a wood-type golf club head with a large flying distance and excellent directional stability. The wood-type golf club head of one aspect of the present invention has a center of gravity distance of 45 mm or more and 50 mm or less, a distance of 110 mm or more in the front and back direction from the shaft center axis to the backmost, and a distance of 80 mm from the shaft center axis The mass of the area behind the above is more than 20% of the total mass.

Description

Wood golf club head

The present invention relates to wood-type golf club heads.

Now, as a wood-type golf club head, a hollow metal one is generally used. Among various clubs, wood-type golf club heads are particularly expected to fly longer.

In order to increase the flying distance of the golf club, increasing the head speed is an effective method. In order to increase the head speed of a golf club, it is known that it is effective to lighten the shaft or lengthen the shaft.

On the other hand, for wood-type golf clubs, in addition to a large flying distance, excellent directional stability is also desired. Especially for amateur golfers, wood-type golf clubs are required to bend less even when they are played crookedly.

However, if the shaft is reduced in weight or lengthened, the operation of the golf club, that is, the swing becomes difficult, and the directional stability deteriorates.

Generally speaking, as a method for increasing the flying distance and improving the directional stability, it is more effective to increase the moment of inertia of the golf club head. For example, in Japanese Patent No. 5519439, Japanese Patent No. 5918196, and Japanese Patent No. 5996573, a wood-type golf club head is proposed that increases the moment of inertia around a vertical axis.

Even if such an improved wood-type golf club head is provided, golfers are still not satisfied, and continue to desire a wood-type golf club with greater flying distance and better directional stability. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 5519439 [Patent Document 2] Japanese Patent No. 5918196 [Patent Document 3] Japanese Patent No. 5996573

[The problem to be solved by the invention]

The subject of the present invention is to provide a wood-type golf club with a large flying distance and excellent directional stability. [Technical means to solve the problem]

The wood-type golf club head of one aspect of the present invention completed in order to solve the above-mentioned problems has a center of gravity distance of 45 mm or more and 50 mm or less, and a distance of 110 mm or more in the front and back direction from the shaft center axis to the backmost, and The mass of the area beyond 80 mm from the shaft center axis is more than 20% of the total mass.

In the wood-type golf club head, it is preferable that the moment of inertia around the axis in the direction of the toe and the toe heel passing through the center of gravity is 3600 gcm ² or more and 5000 gcm ² or less, and the moment of inertia around the axis passing through the center of gravity is preferably The moment of inertia of the shaft is 5500 gcm ² or more and 5900 gcm ² or less.

In the wood-type golf club head, it is preferable that the height of the center of gravity is 38% to 43% of the head height.

In the wood-type golf club head, it is preferable that the volume is 450 cm ³ or more and the protrusion distance of the outer edge from the shaft center axis toward the heel side in front view is 8 mm or less.

In the wood-type golf club head, the distance from the shaft center axis to the heel is preferably 7 mm or less in front view.

In the wood-type golf club head, it is preferable that the distance from the shaft center axis to the center of gravity is 25 mm or more and 45 mm or less.

In the wood-type golf club head, it is preferable that the horizontal length from the heel to the toe is 120 mm or more.

In addition, the dimensions of the wood-type golf club head are measured in a state where the angle (lie) (the angle of the shaft center axis relative to the horizontal plane) of the club head and the shaft is 60°. The "center of gravity distance" refers to the vertical distance from the point where the center of gravity is projected vertically onto the face (the center of gravity point of the face) to the center axis of the shaft. The "front-rear direction" means the direction perpendicular to the vertical plane including the shaft center axis. "Toe" means the horizontal front end of the front view. "Heel" means the point on the side of the shaft where the vertical distance from the outer edge of the front view to the lowest point of the golf club head is 22.23mm. "Toe and heel direction" means the horizontal direction parallel to the vertical plane including the shaft center axis. "Height of the center of gravity" means the vertical distance from the lowest point of the bottom to the center of gravity. [Effects of Invention]

Since the wood-type golf club head of the present invention has a large center of gravity distance, it will increase the flying distance due to the centrifugal force of the wood-type golf club head rotating around the shaft center axis when hitting the ball. The greater the distance, the greater the mass in the rear area, the greater the moment of inertia around the vertical axis, and the excellent directional stability.

Hereinafter, the embodiments of the present invention will be described with appropriate reference to the drawings.

[Wooden golf club head] 1 to 3 show a wood-type golf club head according to an embodiment of the present invention. The wood-type golf club head is a golf club head for a driver.

The wood-type golf club head includes a face (playing face) 1, a bottom (bottom) 2, a top (top) 3, and a hosel 5 with a shaft hole 4 for inserting and fixing a shaft not shown.

Examples of the material of the wood-type golf club head include stainless steel, titanium alloy, aluminum alloy, and tungsten. In addition, the wood-type golf club head may be partially formed of different materials.

In addition, Fig. 1 shows that the angle of the club head and the shaft is configured to be 60°, that is, the inclination angle of the shaft center axis C relative to the horizontal direction including the center line of the shaft hole 4, which is the vertical plane of the shaft center axis C. The front side of the wood-type golf club head (face 1 side) when the configuration is 60°. Figure 2 shows the wood-type golf club when the angle between the club head and shaft is 60°. The plane of the club head (the surface on the top 3 sides), Fig. 3 shows a vertical section including the center of gravity of the wood-type golf club head in the front and rear directions, that is, the XX line section in Fig. 1.

<Overall shape>

In the wood-type golf club head, the lower limit of the horizontal length (head length) Lw from the heel Ph to the toe Pt is preferably 120 mm, more preferably 125 mm. On the other hand, the upper limit of the horizontal length Lw from the heel Ph to the toe Pt is preferably 127 mm. When the horizontal length Lw from the heel Ph to the toe Pt does not reach the above lower limit, when hitting the ball, the rotation of the wood-type golf club head around the shaft axis reduces the energy imparted to the ball. It may not be able to sufficiently increase the flight distance. On the contrary, when the horizontal length Lw from the heel Ph to the toe Pt exceeds the above upper limit, it cannot be used in official competitions under the current rules.

The front and rear length (head width) Dw of the wood-type golf club head is preferably less than the horizontal length Lw from the heel Ph to the toe Pt. The lower limit of the length Dw in the front-rear direction is preferably 120 mm, and more preferably 125 mm. On the other hand, the upper limit of the length Dw in the front-rear direction is preferably 127 mm. When the length in the front-rear direction does not reach the above lower limit, since the moment of inertia of the wood-type golf club head around the vertical axis cannot be increased, the directional stability of the ball may be insufficient. On the contrary, when the length Dw in the front-rear direction exceeds the above upper limit, it cannot be used in official competitions under the current rules.

In the wood-type golf club head, the lower limit of the distance Dc in the front and rear direction from the shaft center axis C to the backmost surface (rear end point Pr) is 110 mm, preferably 112 mm, and more preferably 114 mm . On the other hand, as the upper limit of the distance Dc in the front and rear direction from the shaft center axis C to the backmost surface, it is preferably 120 mm, and more preferably 117 mm. When the distance Dc in the front and rear direction from the shaft center axis C to the backmost side does not reach the above-mentioned lower limit, since the inertia moment of the wood-type golf club head around the vertical axis cannot be increased, the directional stability of the ball may be unstable Full of fear. On the contrary, when the distance Dc from the shaft center axis C to the backmost back in the front and rear direction exceeds the above upper limit, the length in the front and rear direction may be too large or it may be difficult to form the necessary angle between the line of play and the surface (lofe ) Is about.

The lower limit of the volume of the wood-type golf club head is preferably 450 cm ³ , and more preferably 460 cm ³ . On the other hand, as the upper limit of the volume of the wood-type golf club head, it is preferably 470 cm ³ . When the volume of the wood-type golf club head does not reach the aforementioned lower limit, since the moment of inertia of the wood-type golf club head cannot be increased sufficiently, the directional stability of the ball may be insufficient. On the contrary, when the volume of the wood-type golf club head exceeds the above upper limit, it cannot be used in official competitions under the current rules.

As the lower limit of the height of the center of gravity of the wood-type golf club head (the vertical distance between the center of gravity G and the lowest point Pb of the bottom 2) Hg, the height of the head (the apex Pc of the top 3 and the bottom 2 of the bottom 2) The vertical distance from point Pb) is 38% of Hw, and more preferably 40%. On the other hand, as the upper limit of the center of gravity height Hg, 43% of the head height Hw is preferable, and 42% is more preferable. If the height of the center of gravity Hg does not reach the above lower limit, excess weight must be placed on the bottom 2 and it may be difficult for the golf club to swing correctly. Conversely, if the height of the center of gravity Hg exceeds the above upper limit, the face's center of gravity point Ps, that is, the position at which the kinetic energy can be efficiently transmitted to the best hitting point of the ball, becomes higher, making it difficult to manipulate the golf club.

In the wood-type golf club head, as the lower limit of the average height of the ridge line (top view contour line) of the top 3 and the bottom 2 is preferably 25% of the head height Hw, more preferably 30%. On the other hand, the upper limit of the average height of the ridgeline of the top 3 and the bottom 2 is preferably 50% of the head height Hw, and more preferably 40%. If the average height of the ridgeline between the top 3 and the bottom 2 does not reach the above lower limit, the bottom 2 may easily sweep to the ground or lawn. Conversely, if the average height of the ridgeline between the top 3 and the bottom 2 exceeds the above upper limit, the position of the center of gravity G becomes too high. In order to reduce the position of the center of gravity G, excess weight must be placed on the bottom 2. Therefore, the wood golf ball The club head becomes heavier and the golf club may not be easy to swing correctly.

In the wood-type golf club head, the lower limit of the height of the rear end point (the most rearward point in the front and rear direction on the ridgeline of the top 3 and the bottom 2) Pr is preferably 12% of the head height Hw, More preferably, it is 14%. On the other hand, as the upper limit of the height of the rear end point Pr, 20% of the head height Hw is more preferable, and 18% is more preferable. If the height of the rear end point Pr does not reach the above-mentioned lower limit, the bottom may be easily swept to the ground or lawn. Conversely, if the height of the rear end point Pr exceeds the above upper limit, the position of the center of gravity G becomes too high. In order to reduce the position of the center of gravity G, excess weight must be placed on the top part 2. Therefore, the wood-type golf club head becomes heavier. There is a risk that the golf club is not easy to swing correctly.

In the wood-type golf club head, as the lower limit of the toe height Ht, it is preferably 40% of the head height Hw, more preferably 45%. On the other hand, as the upper limit of the height Ht of the toe portion, it is preferably 50% of the head height Hw, and more preferably 48%. If the toe height Ht does not reach the above lower limit, the bottom may be easily swept to the ground or lawn. Conversely, if the height Ht of the toe exceeds the above upper limit, the position of the center of gravity G becomes too high. In order to reduce the position of the center of gravity G, excess weight must be placed on the sole 2. Therefore, the wood-type golf club head becomes heavier. The golf club is not easy to swing correctly.

As the lower limit of Dg from the shaft center axis C to the center of gravity G of the wood-type golf club head (hereinafter referred to as the depth of the axial center of gravity), it is preferably 25 mm, more preferably 32 mm, and still more Preferably it is 35 mm. On the other hand, as the upper limit of the depth Dg of the shaft center of gravity, it is preferably 45 mm, and more preferably 38 mm. By increasing the depth Dg of the axial center of gravity of the wood-type golf club head, it is easy to rotate the face of the club face in the direction of the ball when hitting the ball. If the axial center of gravity depth Dg does not reach the above lower limit, it is not easy to rotate the wood-type golf club head around the shaft center axis C, and because it is easy to hit the ball with the club face open, it is easy to spin the ball when hitting (slice) the danger. Conversely, if the depth Dg of the axial center of gravity exceeds the above upper limit, the wood-type golf club head tends to spin excessively, and because it is easy to hit the ball with the face closed, there is a risk that a hook may be easily hit.

The lower limit of the center of gravity distance (the distance between the face center of gravity point Ps and the shaft center axis C) Rs of the wood-type golf club head is 45 mm, preferably 46 mm, and more preferably 47 mm. The upper limit of the center of gravity distance Rs of the wood-type golf club head is 50 mm, preferably 49 mm, and more preferably 48 mm. When the center of gravity distance Rs does not reach the above-mentioned lower limit, the effect of increasing the flying distance due to the rotational force around the shaft may be insufficient. On the contrary, when the center of gravity distance Rs exceeds the above upper limit, it may be difficult for the golf club to swing correctly. In addition, since the center of gravity distance Rs is not parallel to the paper surface in the figure, it is shown in parentheses.

The lower limit of the mass of the wood-type golf club head is preferably 160 g, and more preferably 180 g. On the other hand, as the upper limit of the mass of the wood-type golf club head, it is preferably 230 g, and more preferably 210 g. When the quality of the wood-type golf club head does not reach the above-mentioned lower limit, it may be difficult to distribute the weight to optimize the position of the center of gravity G. On the contrary, when the quality of the wood-type golf club head exceeds the above-mentioned upper limit, the golf club may not be easy to swing correctly.

This wood-type golf club head has a substantially hollow structure, but in order to increase the depth of the center of gravity, it is preferable to form a solid solid area As only at the rear end. In addition, in the wood-type golf club head, in order to reduce the height of the center of gravity G, the front edge of the solid area As is positioned farther down and forward, and the boundary surface between the solid area As and the hollow area is preferably inclined.

As the lower limit of the average inclination angle of the boundary surface between the solid area As and the hollow area of the wood-type golf club head with respect to the horizontal plane, it is preferably 35°, more preferably 40°. On the other hand, as the upper limit of the average inclination angle of the boundary surface between the solid area As and the hollow area with respect to the horizontal plane, it is preferably 55°, more preferably 50°. When the average inclination angle of the boundary surface between the solid area As and the hollow area with respect to the horizontal plane does not reach the above-mentioned lower limit, the depth Dg of the axial center of gravity may not be sufficiently increased. Conversely, when the average inclination angle of the boundary surface between the solid area As and the hollow area with respect to the horizontal plane exceeds the above upper limit, the center of gravity G may become too high.

In this wood-type golf club head, the lower limit of the minimum radius of curvature from the bottom 2 of the front outer edge to the heel Ph is preferably 30 mm, more preferably 32 mm. On the other hand, as the upper limit of the minimum radius of curvature of the area from the bottom 2 to the heel Ph of the outer edge of the front view, it is preferably 50 mm, more preferably 40 mm. When the minimum radius of curvature of the region from the bottom 2 of the front outer edge to the heel Ph does not reach the above lower limit, the center of gravity distance Rs may not be sufficiently increased. Conversely, when the minimum radius of curvature of the area from the bottom 2 of the front outer edge to the heel Ph exceeds the above upper limit, the flight distance may decrease or the curve may change when the face 1 becomes smaller and deviates from the optimal strike point. Big fear.

As a front view, the lower limit of the protrusion distance Rp of the outer edge of the wood-type golf club head from the shaft center axis C to the heel Ph side is preferably 4 mm, and more preferably 5 mm. On the other hand, as a front view, the upper limit of the protrusion distance Rp of the outer edge of the wood-type golf club head from the shaft center axis C to the heel Ph side is preferably 8 mm, and more preferably 7 mm. When the projecting distance Rp of the outer edge of the wood-type golf club head from the shaft center axis C to the root Ph side in front view does not reach the above-mentioned lower limit, it may be difficult to install the hosel 5. On the contrary, when the protrusion distance Rp of the outer edge of the wood-type golf club head from the shaft center axis C to the heel Ph side in front view exceeds the above upper limit, it may be difficult to increase the center of gravity distance Rs.

In the wood-type golf club head, the lower limit of the distance Rh from the shaft center axis C to the heel Ph as a front view is preferably 3 mm, more preferably 4 mm. On the other hand, as the upper limit of the distance from the shaft center axis C to the heel Ph in the front view, it is preferably 7 mm, and more preferably 6 mm. When the distance Rh from the shaft center axis C to the heel Ph in the front view does not reach the above-mentioned lower limit, since the shape of the face 1 is elliptical, the best hitting point may become smaller. On the contrary, when the distance Rh from the shaft center axis C to the heel Ph in the front view exceeds the above upper limit, it may be difficult to increase the center of gravity distance Rs.

In this wood-type golf club head, the lower limit of the mass of the area behind the shaft center axis C more than 80 mm is 20% of the total mass of the head, preferably 21%, more preferably 22% . On the other hand, as the upper limit of the mass of the area at a distance of 80 mm or more from the shaft center axis C, it is preferably 30% of the total mass of the head, and more preferably 28%. When the mass of the area behind the shaft center axis C at a distance of 80 mm or more does not reach the above lower limit, the directional stability of the ball may be insufficient due to the decrease of the moment of inertia around the vertical axis. Conversely, when the mass of the area behind the shaft center axis C at a distance of 80 mm or more exceeds the above upper limit, the wood-type golf club head becomes heavier, so that the golf club may not be easy to swing correctly.

As the lower limit of the moment of inertia of the wood-type golf club head around the axis passing through the toe of the center of gravity G and the toe heel direction, it is preferably 3600 gcm ² , more preferably 4000 gcm ² . On the other hand, as the upper limit of the moment of inertia of the wood-type golf club head around the axis passing through the toe of the center of gravity G and the heel direction, it is preferably 5000 gcm ² , and more preferably 4500 gcm ² . When the moment of inertia of the wood-type golf club head around the axis passing through the toe of the center of gravity G and the heel direction does not reach the above lower limit, the rotation given to the ball becomes unstable and the golf club flies The distance may become insufficient. On the contrary, when the moment of inertia of the wood-type golf club head around the axis passing through the toe of the center of gravity G and the heel direction exceeds the above upper limit, the wood-type golf club head becomes heavier. It is not easy to swing correctly.

Examples of the wood-type golf club head by the lower limit of the moment of inertia about the vertical axis of the center of gravity G of, preferably 5500gcm ^2, more preferably 5700 gcm ^2. On the other hand, the upper limit of the moment of inertia of the wood-type golf club head around the vertical axis passing through the center of gravity G is preferably 5900 gcm ² . When the moment of inertia of the wood-type golf club head around the vertical axis passing through the center of gravity G does not reach the above lower limit, the directional stability of the ball may be insufficient. On the contrary, when the inertia moment of the wood-type golf club head around the vertical axis passing through the center of gravity G exceeds the above upper limit, it cannot be used in official competitions under the current rules.

＜face＞ The face 1 is formed as a flat surface (strictly speaking, it has a small curvature called protrusions and undulations, and is convex at the front), and a plurality of scratch lines (small grooves) may be formed on the surface. On the contrary, the face 1 is a flat area where the curvature of the surface in the front side portion of the wood-type golf club head is particularly small. The scoring line formed on the face 1 prevents the ball from sliding with respect to the face 1 during play, so that it is easy to give back spin to the ball according to the angle of the line of play of the face 1 to the face of the play.

The lower edge of the front face 1 of the wood-type golf club head can be curved downward convexly, but it is preferably designed such that the lowest point is located directly below the center of gravity point Ps of the face of the ball.

The lower limit of the average thickness of the face 1 is preferably 2.0 mm, and more preferably 2.5 mm. On the other hand, as the upper limit of the average thickness of the face 1, it is preferably 4.0 mm, and more preferably 3.0 mm. When the average thickness of the face 1 does not reach the above lower limit, the strength of the face 1 may be insufficient. On the contrary, when the average thickness of the face 1 exceeds the above upper limit, the deflection of the face 1 during play may decrease and the transmission efficiency of the kinetic energy to the ball may decrease or it may be difficult to increase the depth Dg of the axial center of gravity. .

As the lower limit of the height of the projected center of gravity of the wood-type golf club head (the distance from the lower end of the face 1 to the height of the center of gravity G) Hp, it is preferably 53% of the maximum height of the face 1 and more preferably 50% . On the other hand, as the upper limit of the height of the projected center of gravity Hp, it is preferably 60% of the maximum height of the face 1, and more preferably 58%. If the height of the projected center of gravity Hp does not reach the above-mentioned lower limit, excess weight must be placed on the bottom portion 2 and the golf club may not be easy to swing correctly. Conversely, if the height of the projected center of gravity Hp exceeds the above upper limit, the position at which the kinetic energy can be efficiently transmitted to the best hitting point of the ball becomes higher, which may make it difficult to manipulate the golf club.

<Bottom> The sole 2 extends continuously from the lower edge of the face 1 and forms the sole of the wood-type golf club head. In addition, the bottom 2 in this case not only means the part of the wood-type golf club head that can abut on the ground, but also means the wood-type including the so-called skirt part connected with the top 3 The entire face of the golf club head viewed from below. The bottom 2 is preferably formed into a convex shape downward as a whole, so that it is not easy to sweep to the ground during a swing.

As the lower limit of the average thickness of the bottom 2 (except for the solid part), it is preferably 0.4 mm, more preferably 0.6 mm. On the other hand, as the upper limit of the average thickness of the bottom 2 is preferably 1.0 mm, more preferably 0.7 mm. If the average thickness of the bottom 2 does not reach the above lower limit, the strength of the bottom 2 may be insufficient. Conversely, if the average thickness of the sole 2 exceeds the above upper limit, it may be difficult to increase the depth Dg of the axial center of gravity of the wood-type golf club head.

＜Top (crown)＞ The top 3 is continuously extended from the upper edge of the face 1 and constitutes the upper surface of the wood-type golf club head. In more detail, the top 3 is a convex curved surface extending rearward and upward from the upper edge of the face 1, curved, and extending downward from the rear end to connect with the bottom 2.

As the lower limit of the average thickness of the top 3 (except for the solid part), it is preferably 0.3 mm, and more preferably 0.4 mm. On the other hand, as the upper limit of the average thickness of the top 3, it is preferably 0.8 mm, more preferably 0.6 mm. If the average thickness of the top 3 does not reach the above lower limit, the strength of the top 3 may be insufficient. Conversely, if the average thickness of the top 3 exceeds the above upper limit, it may be difficult to increase the center of gravity height Hg and the depth of the axial center of gravity Dg of the wood-type golf club head.

The lower limit of the distance from the shaft center axis C to the apex Pc of the top 3 in the front and rear direction is preferably 15 mm, and more preferably 17 mm. On the other hand, as the upper limit of the distance from the shaft center axis C to the apex Pc of the top 3 in the front and back direction, it is preferably 21 mm, and more preferably 19 mm. If the front and rear distance from the shaft center axis C to the apex of the top 3 does not reach the above lower limit, it is difficult to set the shape of the top 3 to efficiently transmit the kinetic energy of the wood-type golf club head when hitting the ball. The shape of it. Conversely, if the distance in the front and back direction from the shaft center axis C to the apex of the top 3 exceeds the above upper limit, the position of the center of gravity G may become too high when the shape of the top 3 is optimized.

＜Hose hose＞ The hosel 5 is a cylindrical body in which the front end of the shaft (not shown) is inserted into the fixed shaft hole 4. The hosel 5 is protrudingly arranged at the front part of the heel part Ph side of the top part 3 at a specific angle. The hosel 5 is preferably formed integrally with at least the top 3.

<Function> Generally speaking, when a golfer hits the ball, the golf club head rotates around the shaft while hitting the ball. The rotation speed of the golf club head around the shaft varies from golfer to golfer, and is roughly around 600 rpm. In an average driver golf club head, the center of gravity distance Rs from the shaft center axis to the face center of gravity is about 38 mm. In this case, the speed of the center of gravity of the club face when the golf club head rotates around the shaft center axis is approximately 2.4 m/s.

On the other hand, in this wood-type golf club head, even if the center of gravity distance Rs is 45 mm, the speed at the center of gravity point of the club face caused by the rotation of the golf club head at the same angular velocity will increase to about 3.0m/ s. If the speed difference of the center of gravity of the club face is 0.6 m/s, it can be said that there is a difference of about 3 yards if it is replaced by the flight distance of the ball. Currently, various rules have been established for golf. For golfers, it is a great advantage to increase the flight distance of 3 yards by designing the golf club head.

Generally speaking, if the center of gravity distance Rs of the golf club head becomes longer, it is difficult for the club head to rotate, and therefore it is easy to induce hitting errors. In response to this, by increasing the axial center of gravity depth Dg, since the center of gravity advances in the direction of the club head when hitting the ball, the rotation of the golf club head is promoted, so that the golf club can be easily manipulated and hitting errors can be suppressed.

In an average driver golf club head, the depth Dg of the axial center of gravity is about 15 mm to 20 mm. Even with this degree of axial center of gravity depth Dg, if the center of gravity distance Rs is about 38 mm, even amateur golfers can spin the golf club without any problems. However, when the center of gravity distance Rs is 45 mm or more, if the depth Dg of the axial center of gravity is 22 mm or more, it will be extremely difficult for amateur golfers to manipulate the golf club.

This wood-type golf club head increases the mass of the rear area at a distance of more than 80 mm from the shaft center axis C, so that the axial center of gravity depth Dg becomes relatively large. Therefore, despite the relatively large flight distance of the wood-type golf club head, the directional stability of the ball is still excellent.

[Other embodiments] The above-mentioned embodiment does not limit the structure of the present invention. Therefore, the above-mentioned embodiment may omit, replace or add the constituent elements of each part of the above-mentioned embodiment based on the description of this specification and technical common sense, and all of these should be interpreted as belonging to the scope of the present invention.

The present invention can also be applied to wood-type golf clubs other than drivers. [Example]

Hereinafter, the present invention will be described in detail based on examples, but it should not be interpreted as limiting the present invention based on the description of the examples.

(Trial work 1) The trial work is as follows: the center of gravity distance is 45 mm, the depth of the axial center of gravity is 20 mm, the length from the heel to the toe is 126 mm, and the distance from the shaft center axis to the back of the shaft is 92 mm, the moment of inertia around the vertical axis passing through the center of gravity is 4000g/cm ² , the moment of inertia around the axis passing through the toe and heel direction of the center of gravity is 2800gcm ² , the mass of the area behind the shaft center axis distance of more than 80 mm Proportion of 5% right-handed golf club head trial work 1.

(Trial work 2) For a center of gravity distance of 45 mm, a shaft center of gravity depth of 35 mm, a length from heel to toe of 126 mm, and a distance of 115 mm from the shaft center axis to the back of the shaft, passing through the center of gravity The moment of inertia of the vertical axis is 5600g/cm ² , the moment of inertia about the axis passing through the center of gravity and the direction of the toe is 4500gcm ² , and the mass ratio of the area behind the shaft center axis distance of 80 mm or more is 22% Trial work 2 of the golf club head, using a robot, set the head speed to 40m/s, and set the ball to collide with the center of gravity of the face for trial play.

During the trial hitting, measure the ball hitting angle (the angle of inclination relative to the front and rear direction) and the distance between the landing point and the center line in the front and rear direction. The measurement results are shown in Table 1 below.

[Table 1]

Only the trial work of a golf club head with a large center of gravity distance and a small depth of the axial center of gravity 1 Since the club face did not rotate at the moment of impact and the ball was played in an open state to the right, the ball was hit in the right direction. As a result, the landing point It is also 12 yards away from the center to the right.

On the other hand, the trial work 2 of a golf club head that not only has a large center of gravity distance but also a large axial center of gravity distance, is considered to be almost straight because the face of the club is properly rotated to face the front when hitting the ball. , The landing point is almost at the center.

It is generally believed that if the horizontal distance from the front and back of the club face to the center of gravity position inside the club head, that is, the greater the depth of the center of gravity, the easier the golf club head will retract (it is less likely to hit the ball in a right-open state) . However, the value of the depth of the center of gravity varies not only according to the position of the inner center of gravity of the head but also according to the position of the face. After all, it is the relationship between the position of the center of gravity and the center axis of the shaft that determines the ease of retracting the face of the golf club head. Therefore, by increasing the depth of the axis of gravity, the center of gravity distance can be increased more reliably and the face becomes difficult to retract. The face of the golf club head retracts.

Secondly, using the trial works 1 and 2 of these golf club heads, adjust the orientation of the club face during positioning so that the club face faces the front when hitting the ball and set up a robot to make the ball collide from the center of gravity of the club face to the toe Deviate 20 mm to hit the ball. The measurement results are shown in Table 2 below.

[Table 2]

Trial work 2 of a golf club head with a larger mass ratio in the area behind the shaft center wheelbase of 80 mm or more, and a golf club head with a smaller mass ratio in the area behind the shaft center wheelbase of 80 mm or more Compared with trial work 1, it was confirmed that the directional stability of the ball was better.

This can be considered to be due to the larger moment of inertia between the golf club head trial work 2 and the golf club head trial work 1, and the smaller deviation in the direction of the ball when hitting at the toe side 20 mm. As a result, the deviation of the landing position from the center becomes smaller compared to the trial work 1 of the golf club head. That is, it can be considered that due to the difference in the magnitude of the moment of inertia around the vertical axis passing through the center of gravity, the rotation angle of the golf club head when hitting at a position far from the center of gravity point of the face becomes smaller, and the directionality of the golf club can be improved.

In addition, it can be considered that the golf club head trial work 2 is compared with the golf club head trial work 1, due to the greater depth of the axis of gravity, it will not hit with the face open, and the distance from the center of gravity is greater. The speed increases, the flight distance is elongated, and because the moment of inertia around the vertical axis passing through the center of gravity is larger, the directional stability is also higher even when hitting at a position far from the center of gravity of the club face. Therefore, the trial work 1 of the golf club head is very easy to handle for amateur golfers, and an improvement in the score can be expected. [Industrial availability]

The wood-type golf club head of the present invention can be preferably used as a golf club head for a driver.

1‧‧‧Face 2‧‧‧Bottom 3‧‧‧Top 4‧‧‧Shaft hole 5‧‧‧Hose As‧‧‧Solid area C‧‧‧Shaft shaft Dc‧‧‧The distance from the shaft center axis to the back and front direction Dg‧‧‧Axis of gravity depth Dw‧‧‧The length of the front and rear direction G‧‧‧center of gravity Hg‧‧‧Center of gravity height Hp‧‧‧Projection center of gravity height Ht‧‧‧Toe height Hw‧‧‧Head height Lw‧‧‧Horizontal length from heel to toe Pb‧‧‧The lowest point Pc‧‧‧Vertex Ph‧‧‧ heel Pr‧‧‧back endpoint Ps‧‧‧Face point of gravity Pt‧‧‧toe Rh‧‧‧The distance from the shaft center axis to the heel Rp‧‧‧Outer edge protrusion distance from the shaft center axis Rs‧‧‧Center of gravity distance X-X‧‧‧line

Fig. 1 is a schematic front view of a wood-type golf club head according to an embodiment of the present invention. Figure 2 is a schematic top view of the wood-type golf club head of Figure 1; Fig. 3 is a schematic X-X sectional view of the wood-type golf club head of Fig. 1.

1‧‧‧Face

2‧‧‧Bottom

3‧‧‧Top

4‧‧‧Shaft hole

5‧‧‧Hose

C‧‧‧Shaft shaft

G‧‧‧center of gravity

Hg‧‧‧Center of gravity height

Hp‧‧‧Projection center of gravity height

Ht‧‧‧Toe height

Hw‧‧‧Head height

Lw‧‧‧Horizontal length from heel to toe

Pb‧‧‧The lowest point

Pc‧‧‧Vertex

Ph‧‧‧ heel

Ps‧‧‧Face point of gravity

Pt‧‧‧toe

Rh‧‧‧The distance from the shaft center axis to the heel

Rp‧‧‧Outer edge protrusion distance from the shaft center axis

Rs‧‧‧Center of gravity distance

X-X‧‧‧line

Claims (7)

A wood-type golf club head with a center of gravity distance of 45mm or more and 50mm or less, a distance of 110mm or more from the shaft center axis to the back of the shaft, and the mass of the area behind the shaft center axis 80mm or more. The mass is more than 20%, where the center of gravity distance is the vertical distance from the point where the center of gravity is projected vertically on the face to the center axis of the shaft. A wood type golf club head according to item 1 of the request, wherein the moment of inertia of the shaft (toe heel) about the direction of the toe portion and the heel portion through the center of gravity of ² or more or less 5,000 gcm 3600gcm ^2, the moment of inertia about a vertical axis through the center of gravity It is 5500gcm ² or more and 5900gcm ² or less. Such as the wood-type golf club head of claim 1 or 2, in which the height of the center of gravity is 38% to 43% of the height of the head. For example, the wood-type golf club head of claim 1 or 2, in which the volume is 450 cm ³ or more, and the protruding distance of the outer edge from the shaft center axis toward the heel side in front view is 8 mm or less. For example, the wood-type golf club head of claim 1 or 2, wherein the distance from the shaft center axis to the heel in front view is less than 7mm. For example, the wood-type golf club head of claim 1 or 2, wherein the distance from the shaft center axis to the center of gravity is 25mm or more and 45mm or less. Such as the wood-type golf club head of claim 1 or 2, wherein the horizontal length from heel to toe is 120mm or more.

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