JP4365676B2 - Wood type golf club head - Google Patents

Description

  The present invention relates to a wood type golf club head capable of enlarging a sweet area according to a hitting point distribution of a golfer.

  Conventionally, for the purpose of improving the flight distance, the primary natural frequency of the face portion has been reduced by making the thickness of the peripheral portion of the face surface smaller than the thickness of the central portion. As a result, the primary natural frequency of the face portion approaches that of a golf ball, energy loss at the time of hitting is reduced, and the resilience performance of the face portion is increased (see, for example, Patent Documents 1 and 2 below).

JP-A-9-192273 JP-A-9-299519

  However, it is extremely difficult for a general golfer to hit the ball at the same position on the face surface, specifically at the sweet spot that is said to have the longest flight distance. For this reason, an effective flight distance cannot be improved even if the coefficient of restitution near the sweet spot of the face portion is simply increased for a golfer whose hitting point is not stable.

  As a result of the inventors' experiment, as shown in FIG. 7, the variation in hit points of general golfers spreads in an ellipse c whose major axis is in the direction b from the upper toe of the face surface a to the lower heel. Is known. For example, the following patent document has been proposed as an attempt to approximate a sweet area (a certain region on the face surface where the decrease in flight distance is small) to this hit point distribution.

JP-A-5-57034 Japanese Patent Laid-Open No. 9-149954 JP 2000-308700 A

  In Patent Documents 3 to 4, a weight body is provided at a specific position of the head to increase the moment of inertia of the golfer in the hit point distribution direction. However, in order to obtain such an effect, it is necessary to provide a weight body having a certain weight. Since the upper limit of the head weight is almost determined by the relationship with the swing balance etc., if a heavy weight body is provided, a large amount of weight is used, and in reality, the head must be downsized. . Such a head has not only a sense of security when set up, but also has a smaller sweet area compared to a large head, so it has an effect of improving the flight distance for golfers with uneven hit points. It ’s hard to say.

  Further, in Patent Document 5, as a specific example, it is described that the principal moments of the head such as the face length, the maximum head height, the head width, etc. are changed to increase the moment of inertia of the golfer's hitting point distribution direction. ing. However, such a method has a drawback that the degree of freedom of the head shape is reduced, and a sense of incongruity tends to occur when the head is held.

  The present invention has been devised in view of the above problems, and based on adjusting the thickness distribution of the face surface, by expanding the sweet area by approximating the hit point distribution of a general golfer, An object of the present invention is to provide a wood type golf club head capable of absorbing a variation in hitting point distribution of a golfer and stably obtaining a large flight distance.

The invention described in claim 1 is a wood-type golf club head having a hollow structure having a face surface for hitting a ball, wherein the face surface is an arbitrary portion on the periphery of the sweet spot and the face surface from the sweet spot. From the sweet spot, a central region having a substantially constant thickness with a position separated by 0.4 times the distance of the length of the straight line K connecting the point of A peripheral region composed of an annular region having a position separated by a distance of 7 times as an inner edge and a position separated by a distance of 0.9 times the length of the straight line K as an outer edge; and from the outer edge of the central region to the periphery None the region up to the inner edge of the region and includes a thick transition section thickness is gradually reduced toward from the central region to the peripheral region, yet the peripheral region is arranged a shaft axis in a vertical plane defined No la In a reference state in which the face surface is a loft angle of the head and the sole portion is grounded to a horizontal plane, the angle is 25 degrees with respect to the horizontal plane, perpendicular to the vertical plane and passing through the sweet spot and with the toe side up. A toe upper region in the peripheral region having a substantially constant thickness and a range of 15 degrees left and right on the heel side centering on the inclined plane. And a heel lower region in the peripheral region having a substantially constant thickness and a remaining region other than that, and a thickness Tc of the central region is 2.5 to 3.5 (mm), and The toe upper region thickness Tt and the heel lower region thickness Th are 1.5 to 2.5 (mm), and the remaining region average thickness Te is 2.0 to 3.3 (mm). And Serial the thickness Tc (mm) of the central region, the thickness Tt (mm) of the toe top region, the heel lower region the thickness Th (mm), the average thickness of Te and is the following relationship of the residual area It is a wood type golf club head characterized by satisfying the above.
1.2 mm ≧ Tc−Te ≧ 0.4 mm and Te> Tt and Te> Th

Furthermore the invention of claim 2, to each average thickness Te1 of the remaining area of the crown side of the remaining regions B3, was smaller than the average thickness Te2 of the sole side of the remaining area of the remaining region B4, claim The invention of No. 3 is characterized in that the average thickness Te2 of the residual region B4 on the sole side of the residual region is smaller than the average thickness Te1 of the residual region B3 on the crown side of the residual region .

According to a fourth aspect of the present invention, in the reference state, the face surface has an aspect ratio (W / H) that is a ratio of a face length W to a face height H of 1.5 to 2.5. It is characterized by that.

  In the wood type golf club head of the present invention, the central region has the largest thickness, and a peripheral region having a small thickness is formed outside thereof. In this peripheral region, the toe upper region and the heel lower region are further reduced in thickness. Thereby, a sweet area expands in a toe upper part direction and a heel lower part direction, and approximates the hitting point distribution of a general golfer. Such an operation can be realized without increasing the weight of the head and without limiting the head shape.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view of a wood-type golf club head (hereinafter, simply referred to as “head”) 1 of the present embodiment, FIGS. 2 and 3 are front views of the head viewed from the face side, and FIG. 2 is a partial end view of YY in FIG. 2, and FIG. 5 is a perspective view of the face portion cut out and viewed from the back (partly exaggerated with respect to thickness).

  In the figure, a head 1 according to this embodiment includes a face portion 3 having a face surface 2 that is a surface for hitting a ball, a crown portion 4 that is connected to the upper edge 2a of the face surface 2 and forms the upper surface of the head, and a face surface 2. The bottom 5b is connected to the bottom edge 2b of the head portion, the crown portion 4 and the sole portion 5 are joined, and the toe side edge 2c of the face surface 2 passes through the back face and extends to the heel side edge 2d of the face surface 2. A hollow structure having a side portion 6 and a hosel 7 provided on the heel side of the crown portion 4 and fitted with one end of a shaft (not shown) and having a hollow portion i provided therein is exemplified. The Further, a peripheral edge Pe surrounding the face surface 2 is formed by the upper edge 2a, the lower edge 2b, the toe side edge 2c and the heel side edge 2d.

In the above embodiment, the driver (# 1) is exemplified, but at least the plastic (# 2), spoon (# 3), buffy (# 4), and creek (# 5) are included in the wood type golf club head. Is included. The head volume is not particularly limited, but a large head of 300 cm ³ or more is preferable in order to increase resilience.

The hosel 7 has a cylindrical shape having an insertion hole 7a of the shaft is inserted, the axial center line CL of the insertion hole 7a coincides substantially with the axis of the shaft to be inserted later. Therefore, the shaft axis line can be substituted by the axial center line CL of the insertion hole 7a.

  1 to 3 all show the reference state of the head 1. The reference state of the head 1 means that the axial center line CL of the insertion hole 7a is arranged in a vertical plane VP1 (parallel to the paper surface in FIGS. 2 and 3) and is tilted at a specified lie angle α and the face surface. 2 is a loft angle β (real loft angle) determined for the head, and the sole portion 5 is in contact with the horizontal plane HP.

  The head 1 is made of, for example, an aluminum alloy, titanium, a titanium alloy, stainless steel, maraging steel, or other various metal materials. For example, when the head is composed of two or more parts, different materials can be used for each. Further, a fiber reinforced resin can be used for a part or the whole of the head 1. The manufacturing method is not particularly limited, and for example, two or more members prepared by forging, casting, pressing, or the like can be appropriately integrated and manufactured. Further, the hollow portion i inside the head may be left as it is, or a foamed resin or a weight member may be provided. In this case, the filler or the like is preferably arranged so as not to contact the back surface of the face portion 3 so as not to impair the resilience of the face portion 3.

  The inventors appropriately control the thickness of each area of the face surface 2 as follows to expand the sweet area in the upper toe direction and the lower heel direction of the face part to approximate the hitting point distribution area of a general golfer. I found out. For this purpose, the face surface 2 is virtually divided as follows to control its thickness. First, the face surface 2 is virtually divided into a central area A and a peripheral area B as shown in FIG.

  As shown in FIG. 3, the central region A has a length L of a straight line K connecting the sweet spot SS on the face surface 2 and an arbitrary point Pei on the peripheral edge Pe of the face surface 2. A position where the distance 0.4L, which is 0.4 times the distance, is a closed region having the outer edge e1. Such a central area A has a shape approximately approximate to the contour of the peripheral edge Pe of the face surface 2. Although there are variations in hit points, the central area A is an area where the ball is hit most frequently.

  Here, the sweet spot SS is a point where the normal line drawn from the center of gravity G of the head to the face surface 2 intersects the face surface 2 as shown in FIG. Further, the peripheral edge Pe of the face surface 2 is determined as a ridge line when it is formed by a clear ridge line. However, when the ridgeline is not clear, as shown in FIG. 6 (A), the face cross section of one of the planes E1, E2,... Including a straight line connecting the center of gravity of the head (not shown) and the sweet spot SS. In FIG. (B)), a position where the curvature radius r of the face outer surface contour line Lf is 200 mm for the first time from the center side of the face surface 2 is defined as the peripheral edge Pe. When the face surface 2 forms a curved surface by bulges and / or rolls, the sweet spot SS and the straight line K are defined by a shape obtained by projecting the face surface 2 onto the vertical surface VP1.

  Further, the peripheral region B has an inner edge e2 at a position that is separated from the sweet spot SS by a distance 0.7L that is 0.7 times the length L of the straight line K, and the length L of the straight line K from the sweet spot SS. This is a ring-shaped region having the outer edge e3 as a position separating a distance 0.9L which is 0.9 times the distance. The peripheral area B has less chance of contact with the ball than the central area A.

  Further, as shown in FIG. 2, the peripheral area B is further virtually divided into a toe upper area B1, a heel lower area B2, and remaining areas B3 to B4 in the reference state.

  In order to set each area, an inclined plane IP is first set. The inclined plane IP is a plane that intersects the vertical plane VP1 at a right angle, passes through the sweet spot SS, and is inclined at 25 degrees with respect to the horizontal plane HP with the toe side up. Then, a toe upper region B1 is a peripheral region that is a range of 15 degrees left and right on the toe side around the inclined plane IP, and a heel lower region is a peripheral region that is a range of 15 degrees left and right on the heel side about the inclined plane IP Let B2. The line of intersection between the inclined plane IP and the face surface 2 substantially coincides with the straight axis b of the ellipse c of the spot distribution shown in FIG.

  Further, in the peripheral area B, the area other than the above is the remaining area, and specifically includes a crown-side residual area B3 located on the crown side and a sole-side residual area B4 located on the sole side.

Then, the thickness Tc (mm) of the central region A, the thickness Tt (mm) of the toe upper region B1, the thickness Th (mm) of the heel lower region B2, and the average thickness Te of the remaining regions B3 and B4 Is defined to satisfy the following relationship.
Tc> Te and Te> Tt and Te> Th
The average thickness Te of the remaining regions B3 and B4 is an average value of the average thickness Te1 of the crown-side residual region B3 and the average thickness Te2 of the sole-side residual region B4.

  Thus, in the head 1 of the present invention, the thickness of the toe upper region B1 and the heel lower region B2 in the peripheral region B is not simply made thinner than the thickness of the central region A. By setting Tt and Th to be thinner, the sweet area having a large coefficient of restitution can be expanded in the direction of the thin portion. Thereby, since the sweet area and the variation area of the hit points of a general golfer are approximated, a large flight distance can be stably obtained even in a general golfer whose hit points are not stable. Also, such an effect can be achieved without increasing the head weight or limiting the head shape.

Here, it is assumed that the thickness Te is calculated by weighting the thickness of each part in consideration of the area. That is, the average thickness Te can be calculated by the following formula.
TeΣ (Te · Si) / ΣSi (i = 1, 2,...)
Here, Tei is an actual thickness of an arbitrary region i of the remaining region , and Si is an area of the region i occupied by the actual thickness Tei . In any thickness, the dent such as the score line provided on the face surface is calculated in a state where it is filled.

Here, the thickness Tc of the central region A is preferably 2.5 mm or more, more preferably 2.7 mm or more. Since the central area A has many chances of collision with the ball as described above, if the thickness Tc is less than 2.5 mm, there is a tendency that cracking or deformation is likely to occur due to impact at the time of hitting. On the other hand, even if the thickness Tc is too large, the resilience performance of the face portion 3 tends to deteriorate. From such a viewpoint, the thickness Tc is preferably 3.5 mm or less, more preferably 3.2 mm or less. As shown in FIG. 5 , the central region A is formed with a substantially constant thickness Tc . This is useful for making the amount of deformation uniform when hitting in the central region A and enlarging the sweet area.

  The average thickness Te of the residual region B3 on the crown side and the residual region B4 on the sole side is preferably 3.3 mm or less, more preferably 3.0 mm or less. When the average thickness Te exceeds 3.3 mm, the peripheral area B of the face surface 2 is difficult to bend when the ball is hit, and the resilience performance tends to deteriorate. On the other hand, if the average thickness Te is too small, the strength of the remaining regions B3 to B4 is insufficient, and the durability of the face portion 3 tends to deteriorate. From such a viewpoint, the average thickness Te is preferably 2.0 mm or more, and more preferably 2.2 mm or more.

As a particularly preferred embodiment, the difference (Tc−Te) from the thickness Tc of the central region A is preferably 0.2 mm or more, more preferably 0.4 mm or more. On the other hand, even if the difference in thickness is too large, a rigid step is likely to occur in the face portion 3 and the durability may be impaired. From such a viewpoint, the difference in thickness (Tc−Te) is desirably 1.2 mm or less, more preferably 1.0 mm or less. In the present invention, the thickness difference (Tc−Te) is set to 0.4 mm or more and 1.2 mm or less.

  In the present embodiment, the average thicknesses Te1 and Te2 of the remaining region B3 on the crown side and the remaining region B4 on the sole side are both formed with substantially the same thickness. You can make a mistake. For example, when the average thickness Te1 of the residual region B3 on the crown side is smaller than the average thickness Te2 of the residual region B4 on the sole side, the crown portion side of the face surface is bent relatively larger at the time of hitting, The apparent loft angle can be increased to increase the ball launch angle. This is very useful for improving the flight distance of a less powerful golfer who is difficult to raise the ball.

  On the other hand, if the average thickness Te2 of the residual region B4 on the sole side is set to be smaller than the average thickness Te1 of the residual region B3 on the crown side, the sole portion side of the face surface 2 is relatively larger when the ball is hit. However, the ball launch angle can be reduced by reducing the apparent loft angle. This suppresses the height of the hit ball in a powerful golfer who tends to raise the ball easily and is greatly useful for improving the flight distance.

In addition, the thickness Tt of the toe upper region B1 and the thickness Th of the heel lower region are both preferably 2.5 mm or less, more preferably 2.3 mm or less. If the thicknesses Tt and Th exceed 2.5 mm, it becomes difficult to secure a large amount of deflection at the top of the toe and the bottom of the heel when hitting, and as a result, the effect of expanding the sweet area at the top of the toe and the bottom of the heel is obtained. It's hard to be done. On the contrary, if the thicknesses Tt and Th are too small, the strength of the toe upper region B1 or the heel lower region B2 tends to be insufficient, and the durability of the face portion 3 tends to deteriorate. From such a viewpoint, the thicknesses Tt and Th are both 1.5 mm or more, more preferably 1.8 mm or more.

  As a particularly preferable aspect, the difference (Te−Tt) and (Te−Th) from the average thickness Te of the remaining regions B3 and B4 is preferably 0.2 mm or more, more preferably 0.3 mm or more. On the other hand, even if the difference in thickness is too large, a rigid step is likely to occur in the peripheral region of the face portion 3 and the durability may be impaired. From such a viewpoint, the difference in thickness is desirably 1.0 mm or less, more preferably 0.8 mm or less.

In the present embodiment, the toe upper region B1 and the heel lower region B2 are formed with a substantially constant thickness. Further, the thicknesses Tt and Th are exemplified as being substantially the same .

  Further, the head 1 is exemplified in that a thick transition portion C in which the thickness gradually decreases from the central region A toward the peripheral region B between the central region A and the peripheral region B is exemplified. By providing such a thick transition portion C, the thickness change from the central region A to the peripheral region B becomes smooth, and a large rigid step can be prevented from being formed. Accordingly, stress concentration is eased at the time of hitting, and the durability of the face portion 3 is improved.

  Further, in such a head that does not have the thick transition portion C and the thickness changes in a stepped manner, for example, when the ball is hit on the toe or heel side with respect to the sweet spot SS, the deflection of the face portion 3 is the peripheral region B. Concentrate on and get extremely small. This not only greatly reduces the flight distance, but also the face portion 3 cannot bend uniformly, so that various frequency sounds (vibrations) are generated at the time of hitting, and the reverberation is short and feels like a hitting sound. Further, it is not preferable. On the other hand, the head 1 of this embodiment can make the deflection of the face portion 3 uniform and large even when a ball is hit in the toe or heel direction of the face surface 2, and can prevent a large loss in flight distance. . Further, since the reverberant sound is prolonged, the hitting feeling can be improved.

  Since the thick transition portion C is formed between the central region A and the peripheral region B, the width dimension and the like are limited by the shape between them. The thick transition portion C may be provided in the width dimension of the entire region between the central region A and the peripheral region B, or a part of the width may be used. Preferably, the width GW1 of the thick transition portion C is 2 mm or more and 10 mm or less. If the thickness is less than 2 mm, the change in thickness becomes abrupt so that the effect of reducing the rigidity step is poor. Conversely, if the thickness exceeds 10 mm, it tends to be difficult to bend the peripheral region B sufficiently large. It is particularly preferable that the thick transition portion C is smoothly connected to the central region A and / or the peripheral region B through an arc having a curvature radius of 3 mm or more. In FIG. 5, only the ridgeline of the thick transition portion C is described so that the shape can be easily understood.

  Further, as shown in FIG. 2, for example, the thick-walled transition portion C does not have a constant width but a width in the direction of the inclined plane IP (in other words, the major axis direction of the ellipse that divides the hit point distribution area of a general golfer). The thing which becomes large is illustrated. This flexes the thinned toe upper region B1 and heel lower region B2 uniformly and greatly, not locally. Therefore, it helps to expand the sweet area without impairing durability.

  As shown in FIGS. 2 and 5, the head 1 is provided with a thin transition portion D whose thickness gradually decreases toward the toe upper region B1 or the heel lower region B2 in the remaining regions B3 and B4. Such a thin transition portion D, like the above-described thick transition portion C, smoothes the change in thickness in the peripheral region B, prevents a large rigidity step, and relaxes stress concentration at the time of hitting. In particular, since the peripheral region B is small in thickness, the durability of the face portion 3 can be effectively improved by providing the thin transition portion D. The minimum width GW2 projected onto the face surface 2 of the thin transition portion D is not particularly limited, but if it is too small, the thickness tends to change rapidly, so about 2 to 5 mm is desirable.

  As shown in FIG. 3, the face surface 2 has, in the reference state, the face length W that is the maximum length in the toe and heel directions along the vertical surface VP1, and the maximum length in the crown and sole directions. The aspect ratio (W / H), which is the ratio to the face height H, is preferably 1.5 to 2.5. When the aspect ratio is less than 1.5, the head becomes excessively thick (deepening), and as a result, the hitting point is close to the sole portion side, so that the ball is difficult to rise and the flight distance is easily lost. On the other hand, when the aspect ratio exceeds 2.5, the head becomes excessively thin (shallow), it is difficult to improve the resilience, and the stability at the time of address tends to be impaired.

A head of a driver with a head volume of 380 cm ³ and a real loft angle of 10 ° was manufactured according to the specifications in Table 1. Each head was manufactured by welding a face member of Ti-15V-6Cr-4Al (DAT55G: made by Daido Special Steel) to a cast head body of Ti-6Al-4V. The thickness of the face member was adjusted by NC processing. Then, a shaft was fixed to each test head to produce a 45-inch wood type golf club, and the following tests were performed.

<Restitution coefficient>
The coefficient of restitution of the head is S. G. A. Measured based on the Procedure for Measureing the Velocity Ratio of a Club Head for Conformance to Rule 4-1e, Revision 2 (February 8, 1999). The larger the value, the better.

<Actual test>
An actual hit test of 10 balls by 5 golf players (HDCP 10-25, head speed 40-45 m / s) was carried out, and the average value and standard deviation of the total flight distance (carry + run) of the hit balls were measured.

<Durability test>
Attach the test club to a swing robot (Shot Robo III, manufactured by Miyamae Co., Ltd.), adjust the head speed to 50 m / s and hit 3000 consecutive 3-piece golf balls at the sweet spot. It was confirmed whether cracking or damage occurred. Table 1 shows the test results.

  As a result of the test, it can be confirmed that the flying distance of the head of the example is remarkably increased and the standard deviation thereof is small as compared with the comparative example. This is considered to be due to the fact that the sweet area approximates the hitting point distribution of a general golfer.

It is a perspective view of the wood type golf club head of this embodiment. It is a front view in the reference | standard state of FIG. It is a front view in the standard state of Drawing 1 explaining each field. FIG. 3 is a YY partial end view of FIG. 2. (A), (B) is a diagram for demonstrating the periphery of a face surface. It is the perspective view which cut out the face part and was seen from the back. It is a front view explaining hitting point distribution of a general golfer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wood type golf club head 2 Face surface 3 Face part 4 Crown part 5 Sole part 6 Side part 7 Hosel part 7a Shaft insertion hole CL Axis centerline VP1 of shaft insertion hole Vertical plane HP Horizontal plane IP Inclination plane A Central area B Peripheral area B1 Toe upper area B2 Heel lower area B3, B4 Residual area SS Sweet spot

Claims (4)

A wood-type golf club head having a hollow structure having a face surface for hitting a ball,
The face surface substantially has a position that is separated from the sweet spot by 0.4 times the distance of the length of a straight line K connecting the sweet spot and an arbitrary point on the periphery of the face surface. A central region of constant thickness ;
It consists of an annular region whose inner edge is a position separated by 0.7 times the length of the straight line K from the sweet spot and whose outer edge is a position separated by 0.9 times the length of the straight line K. The surrounding area ,
And a said outer edge from said without the region to the inner edge of the peripheral area and the thick transition portion gradually reduced in thickness toward the center region to the peripheral region of the central region,
In addition, the peripheral region is arranged in a standard state in which the shaft axis is arranged in a vertical plane and tilted at a specified lie angle, and the face portion is a loft angle of the head and the sole portion is grounded to a horizontal plane.
It is perpendicular to the vertical plane, passes through the sweet spot, and forms a range of 15 degrees to the left and right of the toe side with a tilt plane inclined at 25 degrees with respect to the horizontal plane with the toe side up, and with a substantially constant thickness . A toe upper region in a certain peripheral region, a heel lower region in the peripheral region that forms a range of 15 degrees left and right on the heel side with the inclined plane as a center and has a substantially constant thickness , and other remaining regions Consists of
The thickness Tc of the central region is 2.5 to 3.5 (mm), the thickness Tt of the toe upper region and the thickness Th of the heel lower region is 1.5 to 2.5 (mm), Moreover, the average thickness Te of the remaining region is 2.0 to 3.3 (mm) ,
Moreover the thickness Tc (mm) of the central region, the thickness Tt (mm) of the toe top region, the heel lower region the thickness Th (mm), the average thickness Te of the remaining area is below A wood-type golf club head characterized by satisfying the relationship.
1.2 mm ≧ Tc−Te ≧ 0.4 mm and Te> Tt and Te> Th The wood-type wood according to claim 1 , wherein an average thickness Te1 of the residual region B3 on the crown side of the residual region is smaller than an average thickness Te2 of the residual region B4 on the sole side of the residual region . Golf club head. The wood-type wood according to claim 1 , wherein an average thickness Te2 of the residual area B4 on the sole side of the residual area is smaller than an average thickness Te1 of the residual area B3 on the crown side of the residual area . Golf club head.   The aspect ratio (W / H), which is a ratio of a face length W to a face height H, is 1.5 to 2.5 in the reference state. 4. The wood type golf club head according to any one of 3 above.

Images