JP2008237355A - Golf club head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maximize inertia moments in the horizontal-vertical directions without changing the position of the center of gravity. <P>SOLUTION: This golf club head is so constituted that, when a sole comes in contact with a horizontal plane with the head body positioned at a prescribed lie angle and the face positioned at a loft angle where the face becomes square in the ball flying direction, the center of gravity in the toe-heel direction of a weight applied to the back side of the head body is positioned on a vertical plane passing through the center of gravity of the head body and passing through a horizontal line in the ball flying direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a metal wood type golf club head capable of adjusting the weight.

  Most of the performance of the golf club is determined by the lie angle, loft angle, club length, swing balance, total weight, and so-called basic specifications. In addition, handy cap (HCP) sweet area design for mistakes, center of gravity design for hitting positions such as high and low, auxiliary detailed design such as address design and shape design for preference, and further countermeasures for sound, vibration, etc. And recent golf club designs are designed to meet golfers' CS (customer satisfaction).

  Among them, various methods for sweet area design have been established and systematized. The pin "answer" model based on the concept that originated in USP 3,042,405 in 1962 brought the basic idea of sweet area design to the golf world as a toe & heel theory in 1966. Weight distribution technology (USP 3,985,363-JP-A-50-64038, Akshnet, 1976), three-dimensional peripheral weight distribution technology using hollow iron technology, and hollow metal heads have been developed.

Furthermore, recently, the field of peripheral weight dispersion technology such as a composite head aiming at a greater effect and a light metal hybrid technology has been greatly expanded by reducing the weight of the head body and combining it with heavy metals. In particular, in a hollow metal head having a three-dimensional expanse, a wood head (see Patent Document 1) in which a weight band of tungsten is arranged on a side portion of a stainless steel head, and a tungsten alloy head on a side portion of a titanium alloy head. Wood head with a plurality of weight bodies (see Patent Document 2), wood head with an annular weight band attached along the inner periphery of the outer shell side wall of the FRP body (see Patent Document 3), the entire surface of the head body or a part thereof A wood head thermally sprayed with tungsten (see Patent Document 4) is known.
JP 2001-19071 A JP 2000-24149 A Japanese Patent Laid-Open No. 2-63482 Japanese Patent Laid-Open No. 10-230028

  The meaning of toe and heel is an increase in the moment of inertia, and the figure of USP 3,042,405 clearly suggests that the maximum moment of inertia is achieved. The moment of inertia is expressed by the square of the mass and the distance from the center of gravity. If the mass is constant, the maximum moment of inertia can be achieved by placing the mass at the farthest place. However, most of the conventional techniques not only express the peripheral weight dispersion, but also the effective weight always starts with the peripheral weight dispersion and does not achieve the maximum moment of inertia. That is, it has been overlooked that the surface around the head is not necessarily the maximum distance.

  Therefore, it is a problem that the added mass collected by reducing the weight of the main body to increase the moment of inertia is not effectively used. In addition, the moment of inertia is related not only to the horizontal direction but also to the vertical stability, there is also an additional mass that is not related to the vertical direction at all, focusing on the horizontal direction. However, the problem is that the mass that has been struggled to increase the moment of inertia is not being used effectively. Yet another problem is that, in many cases, the center of gravity moves depending on the arrangement, even though the added weight is used for head weight adjustment, including cost and manufacturing variations. It is not considered. The position of the center of gravity is the first element of head design that is more important than the moment of inertia. If the position of the center of gravity, particularly the position of the center of gravity in the toe-heel direction of the face changes due to an increase in the moment of inertia, a new problem will occur.

  Even the prior art disclosed in Patent Documents 1 to 4 does not maximize the moment of inertia in the horizontal and vertical directions without changing the position of the center of gravity.

  Accordingly, an object of the present invention is to provide a golf club head that can maximize the moment of inertia in the left-right and up-down directions without changing the center of gravity (in the toe-heel direction) by effectively using the added mass. And

  In order to achieve the above-described object, the present invention provides a back surface of the head body when the head body is in contact with a horizontal plane (sole) at a predetermined lie angle and a loft angle in which the face is squared in the flying line direction. The center of gravity in the toe-heel direction of the weight added to the side passes through the center of gravity G of the head body and is on a vertical plane passing through a horizontal line in the flying ball direction. Further, the additional weight includes the most protruding position of the back side of the head main body and is in contact with the contour of the back side.

  According to the present invention, the weight added to the back side of the head body when the head body is in contact with the horizontal surface (the sole) at a predetermined lie angle and a loft angle in a state where the face is square in the flying line direction. Since the center of gravity in the toe-heel direction passes through the center of gravity of the head body and lies on the vertical plane passing through the horizontal line in the flying ball direction, the additional weight is effectively utilized (in the toe-heel direction) ) The moment of inertia in the horizontal and vertical directions can be maximized without changing the position of the center of gravity.

  In the present invention, it is necessary to grasp the distance between each part of the head and the center of gravity of the head and distribute a limited mass to the position of the furthest head. Now, in discussing the head rotation in terms of directionality, we define the axis of inertia moment in the horizontal and vertical directions around the center of gravity axis. FIG. 1 shows a golf club head body 1 as viewed from above with a predetermined lie angle and a loft angle where the face 2 is in contact with the square in the flying line direction (sole is in contact with the horizontal plane). Is mainly related to the moment of inertia IY around the Y axis (not shown) passing through the paper surface from the bottom to the top, that is, the Y axis (not shown). The inertia moment IX around is related. The flying ball line is a virtual trajectory of the ball flying toward the target, and the square here is perpendicular to the flying ball line.

  2 shows the leading edge from the center of gravity G by measuring and processing the center of gravity and the maximum width of the head by setting a commercially available metal driver to the state shown in FIG. The relationship between 3 (horizontal axis) and the center of gravity G to backside 4 (head maximum width-center of gravity depth: vertical axis) is illustrated. From FIG. 2, the depth of the center of gravity is in the range of 22.5 to 37.5 mm, but it is 45 to 60 mm from the center of gravity G to the back side 4, and it can be seen that the rear side from the center of gravity G is overwhelmingly longer than the front side.

  FIG. 3 shows the ratio obtained by dividing the horizontal axis from the center of gravity G to the toe 5 and the vertical axis from the center of gravity G to the backside 4 by the length from the center of gravity G to the toe 5. Since the ratio value is often less than 1.0, there are many club heads in which the length from the center of gravity G to the toe 5 is slightly longer than the center of gravity G to the back side 4, but this is because of the shape In problem, it can be considered that the distance from the center of gravity G to the toe 5 and the distance to the back side 4 are substantially equal. Incidentally, in the case of a normal driver, since the toe 5 to the backside 4 can be approximated to a substantially constant arc, the distance from the center of gravity G is constant everywhere on the toe 5 to the back side 4, and the additional weight is increased to 5 IY is almost equal wherever the backside 4 is placed (along the contour). On the other hand, IX is maximized on the backside 4 side, and weight is added to the backside 4 side from the viewpoint of weight distribution that works effectively on both the moments of inertia IX and IY related to the vertical and horizontal directions. Is the most effective weight addition.

  Next, the relationship between the position of the center of gravity G in the direction of the heel 6 from the toe 5 and the position where the back side 4 of the head body 1 protrudes most will be discussed. The position of the center of gravity in the toe-heel direction is usually designed with the face center as a target, and the Z-axis passing through the center of gravity G of the head is usually the most on the back side 4 of the head body 1 as shown in FIG. The shape design is made so as to pass through the vicinity of the protruding position. This is because the golfer feels the feeling of hooks and slices as the position moves from the toe 5 to the heel 6, which is an important shape design element. Also, the additional weight used for head weight adjustment varies depending on the degree of adjustment. To avoid the center of gravity movement in the toe-heel direction due to the additional weight, the center of gravity of the additional weight is set on the Z axis. Must be coincident on the containing vertical plane.

To summarize the above,
(1) From the viewpoint of weight distribution that works effectively on the moments of inertia IX and IY related to the vertical and horizontal directions, weight addition is arranged on the backside 4 side.
(2) In order to avoid the movement of the center of gravity in the toe-heel direction due to the additional weight of different weights, the center of gravity in the toe-heel direction of the additional weight passes through the center of gravity G of the head body and is a horizontal line in the flying ball direction. On a vertical plane that passes through
It becomes. From these conditions, the head configuration of FIG. 4 can be obtained.

  FIG. 4 shows the head body 1 as seen from above when the head body 1 is in contact with the horizontal plane (sole) at a predetermined lie angle and the loft angle where the face 2 is in contact with the square in the flying line direction. 1 and an additional weight 10, passing through the center of gravity G of the head body 1, the horizontal axis perpendicular to the flying ball direction and the horizontal line perpendicular to the Z axis as the X axis, the direction perpendicular to the X axis and the Z axis, The line passing through the paper from the bottom to the top is the Y axis (not shown), and the center of gravity G ′ of the additional weight 10 is on the vertical plane passing through Z. The additional weight 10 is the most on the back side 4 of the head body 1. In addition to including the protruding position, the other end face of the additional weight 10 is in contact with the contour of the backside 4 and is balanced in accordance with the angle on the Z-X plane of the face 2. It is inclined by an angle A in the range of degrees.

The top view of a head main body. A graph showing the relationship from the center of gravity of the head body to the leading edge and from the center of gravity to the backside. The graph which shows the ratio which divided the length (mm) from a gravity center to a toe, and the length from a gravity center to a back side by the length (mm) from a gravity center to a toe. The top view of the head main body which added additional weight.

Explanation of symbols

1 Head body 2 Face 3 Leading edge 4 Backside 5 Toe 6 Heel 10 Additional weight

Claims (3)

  When the head body is in contact with the horizontal plane at a predetermined lie angle and a loft angle where the face is square in the direction of the flying ball (to the sole), the weight added to the back side of the head body in the toe-heel direction A golf club head characterized in that the center of gravity is on a vertical plane passing through the center of gravity of the head body and passing through a horizontal line in the flying ball direction.   2. The golf club head according to claim 1, wherein the additional weight includes a position at which the back side of the head body protrudes most, and contacts the contour of the back side.   When the other end surface not in contact with the additional weight club head passes through the center of gravity of the head body and the horizontal line in the flying ball direction is the Z axis, and the horizontal line perpendicular to the Z axis is the X axis, 3. The golf club head according to claim 1, wherein the golf club head is tilted by an angle A in a range of 86 to 90 degrees with respect to the Z axis in order to balance in accordance with a direction on the Z-X plane.

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