JP2018108341A - Wood type golf club head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce variations in a carry and directivity of a hit ball.SOLUTION: A wood type golf club head 1 includes a face part 2 having a face 2a for hitting a ball. The face 2a includes a first region 10 and a second region 20. The first region 10 is located in a central part in a toe-heel direction of the face 2a, and on the upper side of the face 2a. The second region 20 is formed in a U-shape in a front view of the face 2a so as to be adjacent to the toe side, the heel side, and the lower side of the first region 10. The surface roughness of the second region 20 is larger than the surface roughness of the first region 10.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a wood-type golf club head, and more particularly to a wood-type golf club head that can improve variation in hit distance and directionality of a hit ball.

  When a ball is hit with the face of a golf club head having a loft angle, backspin is generated based on the frictional force with the face. In general, it has been considered that the larger the loft angle and the larger the friction coefficient of the face surface, the larger the backspin amount of the ball.

  However, as a result of various experiments, in golf club heads having a small loft angle such as a wood type golf club head, the backspin amount decreases as the friction coefficient of the face increases, and the back friction decreases as the friction coefficient of the face decreases. It has been confirmed that the amount of spin increases (see Patent Document 1). Such a phenomenon is considered to be affected by recoil generated in the ball.

  Generally, a recoil is a kind of restoring force that causes an elastic twist generated inside a golf ball by contact with a face to return to its original state. When this recoil is strongly developed, the backspin amount decreases. That is, in a golf club head with a small loft angle, the larger the friction coefficient of the face, the higher the action of recoil and the lower the backspin amount of the ball. Conversely, in a golf club head having a small loft angle, the smaller the friction coefficient of the face, the more the action of recoil is suppressed and the backspin amount of the ball increases.

  Patent Document 2 proposes a golf club head that utilizes the phenomenon described above. In this golf club head, the ten-point average roughness of the region on the face that is on the crown side of the sweet spot of the face is smaller than 1.5 (μm), and is on the sole side of the sweet spot of the face The 10-point average roughness of the area under the face is 1.5 to 10 (μm).

  In general, when a ball is hit in the area on the face, the backspin amount of the ball usually decreases due to the gear effect. However, according to the wood type golf club head described in Patent Document 2, since the friction coefficient of the area on the face of the face is small, the action of recoil is weakened and the backspin amount of the ball is greatly reduced. Can be suppressed.

  Also, when the ball is hit in the lower face region, the back spin amount of the ball usually increases due to the gear effect. However, according to the wood type golf club head described in Patent Document 2, since the friction coefficient in the area under the face of the face is large, the recoil action is strengthened to suppress a significant increase in the backspin amount of the ball. can do.

  As described above, according to the golf club head of Patent Document 2, even when the hit points vary up and down the face, the flight distance of the hit ball can be stabilized.

JP 2000-5352 A JP 2004-201787 A

  However, the wood-type golf club head of Patent Document 2 also has a problem that the hit distance of the hit ball tends to vary when the hit point is shifted in the toe-heel direction (left-right direction) of the face.

  The present invention has been devised in view of the above problems, and has as its main object to provide a wood-type golf club head that can improve variation in the flight distance and directionality of a hit ball.

  The present invention is a wood-type golf club head having a face portion having a face for hitting a ball, wherein the face includes a first region and a second region, and the first region is a toe of the face. In the front view of the face, located in the center in the heel direction and on the upper side of the face, the second region is adjacent to the toe side, the heel side, and the lower side of the first region. It is formed in a U-shape, and the surface roughness of the second region is larger than the surface roughness of the first region.

  In another aspect of the invention, it is desirable that the toe side and the heel side of the second region extend to the upper edge of the face.

  In another aspect of the present invention, it is desirable that a boundary between the first region and the second region extends in a convex arc shape toward a lower side of the face in a front view of the face.

  In another aspect of the present invention, it is desirable that a position on the lowermost side of the first region is located at a height position that is ½ of the maximum height of the face or at an upper position.

  In another aspect of the present invention, it is desirable that the position of the lowermost side of the first region is located at a height position that is 2/3 of the maximum height of the face or below it.

In another aspect of the present invention, in a reference state in which the head is placed on a horizontal plane at a specified lie angle and loft angle, the moment of inertia around the vertical axis passing through the center of gravity of the head is 3500 to 6000 (g · cm ² ), Desirably, the bulge radius of the face is 10 to 16 inches.

  In another aspect of the present invention, the difference in arithmetic average roughness Ra is 0.5 μm or more and the difference in maximum height roughness Rz is 5 μm or more in the first region and the second region. Is desirable.

  In another aspect of the present invention, in the first region and the second region, the difference in arithmetic average roughness Ra is 0.5 to 4 μm, and the difference in maximum height roughness Rz is 5 to 15 μm. It is desirable.

  According to the wood type golf club head of the present invention, the face includes the first region and the second region. The first region is located at the center of the face in the toe-heel direction and on the upper side of the face. The second region is formed in a U shape in front view of the face so as to be adjacent to the toe side, the heel side, and the lower side of the first region. And the surface roughness of the said 2nd area | region is formed larger than the surface roughness of the said 1st area | region.

  According to the wood type golf club head of the present invention, since the first region has a low friction surface, when the ball is hit at the center and the upper side of the face, the action of the recoil is weakened, and the backspin amount Can be suppressed. According to the wood type golf club head of the present invention, since the second region has a high friction surface, when the ball is hit on the lower side of the face, the action of the recoil is strengthened and the back spin amount of the ball is increased. Can be suppressed.

  Further, according to the wood type golf club head of the present invention, since the second region having the high friction surface constitutes the toe side and the heel side of the face, the ball is hit on the toe side or the heel side of the face. When this is done, the action of the recoil can be strengthened, and a significant increase in the side spin amount of the ball can be suppressed. This reduces the bending of the ball in the left-right direction and suppresses variation in flight distance.

  As described above, according to the wood type golf club head of the present invention, it is possible to stabilize the flight distance of the hit ball even when the hit points vary not only on the top and bottom of the face but also on the left and right.

It is a perspective view of the wood type golf club head of this embodiment. It is a front view of the wood type golf club head of this embodiment. It is a top view of the wood type golf club head of this embodiment. It is the sectional view on the AA line of FIG. (A) is a front view of a golf club head, (B) is a partial cross-sectional view of the E1 line. (A)-(C) are top views of a golf club head for explaining toe side hitting and heel side hitting of a face. It is a front view of the wood type golf club head of this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The specific configurations shown in the embodiments and drawings described in detail below are for understanding the contents of the present invention, and the present invention is not limited to these specific configurations. Absent.

  1 to 4 are a perspective view, a front view, a plan view, and a cross-sectional view taken along line AA of FIG. 3 of a golf club head 1 (hereinafter, simply referred to as “head”) of the present embodiment. Each is shown. 1 to 3 show the head 1 in the reference state.

[Head reference state]
The reference state is a state in which the head 1 is placed on the horizontal plane HP while maintaining the loft angle α (FIG. 4) and the lie angle β (FIG. 2). In the reference state, the shaft axis center line CL of the head 1 is arranged in an arbitrary vertical plane VP. The horizontal direction y along the vertical plane VP is the toe-heel direction of the head 1, and the horizontal direction x orthogonal to the vertical plane VP is the front-rear direction of the head 1. A vertical direction z that is orthogonal to both x and y is the vertical direction of the head 1. Unless otherwise stated, the head 1 should be understood as being in a reference state.

[Basic configuration of the head]
As shown in FIGS. 1 to 4, the head 1 of the present embodiment is a wood type having a hollow portion i therein, and more preferably configured as a driver. The wood-type head 1 includes at least a brushy (# 2), a spoon (# 3), a buffy (# 4), and a creek (# 5) in addition to the driver (# 1). The wood-type head 1 includes a head having a similar shape even if the number or name is different from those listed above, for example, a utility type. In a preferred embodiment, the loft angle α of the wood-type head is, for example, 35 degrees or less, more preferably 26 degrees or less.

  The head 1 of the present embodiment is made of, for example, a metal material. Although the said metal material is not specifically limited, For example, 1 type, or 2 or more types, such as stainless steel, maraging steel, pure titanium, a titanium alloy, or an aluminum alloy, is preferable. However, it goes without saying that elements other than metal materials such as fiber reinforced resin may be used in part.

  The head 1 of the present embodiment includes, for example, a face part 2, a crown part 3, a sole part 4, and a side part 5. The hollow part i of the head 1 is defined by the face part 2, the crown part 3, the sole part 4 and the side part 5.

  The front surface of the face portion 2 forms a face 2a that is a striking surface for striking a ball. A score line (groove) extending in the toe-heel direction may be formed on the face 2a in accordance with the custom (not shown).

  As shown in FIG. 2, the face 2a is defined by an upper edge e1, a lower edge e2, a toe side edge e3, and a heel side edge e4. Each of the edges e1 to e4 is defined by a ridge line when a clear ridge line can be identified. On the other hand, when such a clear ridge line cannot be identified, as shown in FIG. 5 (A), a large number of planes E1, E2,... Including a straight line N (FIG. 4) connecting the head gravity center G and the sweet spot SS. 5B, the curvature radius r of the face outer surface contour line Lf is measured from the sweet spot SS side to the face outer side as shown in FIG. 5B. 7.874 inches) are defined as the edges e1 to e4. The face outer surface outline Lf is determined as having no score line (in a state where the score line is smoothly filled).

  As shown in FIGS. 1 and 4, the crown portion 3 is connected to the face portion 2 and constitutes the upper surface of the head. For example, a hosel portion 6 may be provided on the heel side of the crown portion 3. The hosel portion 6 is configured in a cylindrical shape having a shaft insertion hole 6a so that a shaft (not shown) can be fixed. The shaft center line of the shaft insertion hole 6a corresponds to the shaft shaft center line CL.

  As shown in FIG. 4, the sole portion 4 is connected to the face portion 2 to constitute the bottom surface of the head.

  As shown in FIGS. 1 to 3, the side portion 5 connects between the crown portion 3 and the sole portion 4. The toe side and the heel side of the side part 5 are connected to the toe side and the heel side of the face part 2, respectively.

The head 1 of this embodiment has a large volume, preferably 200 cm ³ or more, more preferably 250 cm ³ or more, and still more preferably 300 cm ³ or more. In such a head 1, in the reference state, an inertia moment around the vertical axis passing through the head center of gravity G (hereinafter, such inertia moment is referred to as “right and left inertia moment”) increases. In the present embodiment, the head 1 desirably has a right and left moment of inertia of 3500 to 6000 (g · cm ² ). As described above, the head 1 having a large right and left moment of inertia hardly exhibits the right and left gear effects.

  As shown in FIG. 6A, the left and right gear effect means that when the ball is hit on the toe side or heel side of the face, the head rotates slightly around the vertical axis, This is a phenomenon in which side spin occurs in the direction opposite to the head due to the friction with the head, causing the hit ball to bend such as a hook or a slice. This side spin causes a deterioration in the directionality of the ball with respect to the target flying ball direction. However, in a head having a large moment of inertia on the left and right, even if the hit point is shifted to the toe side or the heel side of the face, the rotational behavior of the head described above becomes small. Can be stabilized.

  In order to further stabilize the directionality of the hit ball and suppress the decrease in the flight distance, it is desirable that the bulge radius R of the face 2a is 10 to 16 inches (254 to 406.4 mm) as shown in FIG. . The bulge radius R is a radius of curvature that defines the bulge of the face 2a outward in the horizontal direction, that is, the size of the “bulge”.

  The original purpose of the bulge is, as shown in FIG. 6 (B), when the hit point of the ball is shifted to the toe side or the heel side of the face 2a, the ball is launched to the right or left side even with the target flying line. There is to make it. As described above, when hitting off-center, the ball is hooked or sliced by the left and right gear effects. However, since the launch direction of the ball is directed in a direction opposite to the direction in which the ball will be bent in advance by the bulge, both are offset and the directionality of the ball with respect to the target flying ball direction is improved.

  On the other hand, as shown in FIG. 6C, the head having a large right and left moment of inertia is less affected by the left and right gear effects and has less ball side spin. For this reason, if the bulge radius R is small, a ball that has been greatly launched to the left and right cannot return to the target flying line direction. From such a viewpoint, in this embodiment, the bulge radius R is set to 10 to 16 inches.

  As shown in FIG. 2, in the head 1 of the present embodiment, the face 2 a includes a first region 10 and a second region 20.

  The first region 10 is located at the center of the face 2a in the toe-heel direction and on the upper side of the face 2a. More specifically, the first region 10 extends from the upper edge e1 of the face 2a to the lower side of the face 2a. The first region 10 ends without reaching the lower edge e2, the toe side edge e3, and the heel side edge e4 of the face 2a.

  The second region 20 is formed as a U-shaped region in front view of the face 2a so as to be adjacent to the toe side, the heel side, and the lower side of the first region 10. In the present embodiment, the second region 20 extends from the toe side of the upper edge e1 of the face 2a to the heel side of the upper edge e1 of the face 2a along the first region 10, and the first region 10 extends to the toe side. Surrounding from the side, bottom and heel side. In the second region 20, the toe side and the heel side, for example, extend to the upper edge e1 of the face 2a. Further, the second region 20 reaches, for example, the toe side edge e3, the heel side edge e4, and the lower edge e2, and essentially forms a remaining region excluding the first region 10 of the face 2a.

  In the head 1 of the present embodiment, the surface roughness of the second region 20 is larger than the surface roughness of the first region 10. For this reason, the second region 20 has a higher coefficient of friction than the first region 10.

  According to the head 1 of the present embodiment, when the ball is hit at the center and the upper side of the face 2a of the head 1, the ball contacts the first region 10 having a relatively low coefficient of friction. For this reason, the effect | action of a recoil is weakened and the ball | bowl can suppress the significant reduction | decrease of the backspin amount by extension.

  Further, according to the head 1 of the present embodiment, when the ball is hit on the lower side of the face 2a of the head 1, the ball contacts the second region 20 having a relatively high coefficient of friction. For this reason, the effect | action of a recoil is strengthened and the ball | bowl can suppress the significant increase in a backspin amount by extension.

  As described above, according to the head 1 of this embodiment, since the change in the backspin amount due to the so-called vertical gear effect is suppressed, the hit ball even when the hit point varies in the vertical direction of the face 2a. The flight distance is stable.

  Here, if the position 10P on the lowermost side of the first region 10 is too low, when the ball is hit on the lower side of the face 2a, the ball comes into contact with the first region 10 and the backspin amount increases excessively. The flight distance may be impaired. From this point of view, as shown in FIG. 7, the position 10P on the lowermost side of the first region 10 is located at a height position that is ½ of the maximum height H of the face 2a or above it. Is desirable. The maximum height of the face 2a is defined as the vertical height from the horizontal plane HP to the highest position of the upper edge e1 of the face 2a.

  Conversely, if the position 10P on the lowermost side of the first region 10 is too high, the ball will come into contact with the second region 20 when hit on the upper side of the face 2a, the backspin amount will decrease excessively, and the ball will also hit The flight distance may be impaired. From this point of view, it is desirable that the position 10P on the lowermost side of the first region 10 is located at a position that is 2/3 of the maximum height H of the face 2a or below it. The sweet spot SS of the head is also preferably located between a height position that is 1/2 of the maximum height H of the face 2a and a height position that is 2/3 of the maximum height H of the face 2a. . In a particularly preferable aspect, the sweet spot SS of the head and the position 10P on the lowermost side of the first region 10 are preferably provided at the same height.

  Further, as shown in FIG. 7, the width CW of the first region 10 in the toe-heel direction is preferably in the range of 40% to 60% of the maximum width FW of the face 2a in the toe-heel direction.

  Furthermore, according to the head 1 of the present embodiment, the entire region on the toe side and the heel side of the face 2 a is formed as the second region 20. Therefore, when the ball is hit on the toe side or the heel side of the face 2a of the head 1, the ball comes into contact with the second region 20 having a relatively high coefficient of friction. For this reason, the action of the recoil is enhanced in the ball, and as a result, the side spin can be adjusted to an appropriate amount by the left and right gear effects. This reduces the bending of the ball in the left-right direction and suppresses variation in flight distance. Such an action is particularly effective in the head 1 having a large left and right moment of inertia and a large bulge radius as in this embodiment.

  In a preferred embodiment, it is desirable that the boundary 30 between the first region 10 and the second region 20 extends in a convex arc shape toward the lower side of the face 2a in the front view of the face 2a. In the present embodiment, a mode is shown in which the boundary 30 smoothly extends along the toe side edge e3, the lower edge e2 and the heel side edge e4 of the face 2a. However, the present invention is not limited to such an aspect, and the boundary 30 can be changed to various aspects. For example, the boundary 30 may be V-shaped.

  As described above, according to the head 1 of the present embodiment, the flying distance of the hit ball can be stabilized even when the hit points vary not only in the vertical direction of the face 2a but also in the horizontal direction. There is an effect.

  As described above, in the head 1 of this embodiment having a large left and right moment of inertia, the action of the left and right gear effects is weakened, but when the striking point deviates greatly on the toe side or the heel side of the face 2a. The side spin amount tends to increase. From such a viewpoint, it is desirable that the surface roughness of the second region 20 gradually increases from the center in the toe / heel direction of the face 2a toward the toe side and the heel side. According to such an aspect, even when the hit point is largely deviated by the toe side or the heel side of the face 2a, the action of the recoil can be further enhanced, the side spin can be appropriately controlled, and the left and right bends can be reduced.

  The surface roughness of the first region 10 and the second region 20 can be evaluated with various parameters. For example, various surface roughness parameters defined in JIS-B-0601 can be used.

  As the surface roughness, for example, an arithmetic average roughness Ra may be used. For example, in the first region 10 and the second region 20, the difference in arithmetic average roughness Ra is preferably 0.5 μm or more. When the difference of the arithmetic average roughness Ra is less than 0.5 μm, the surface roughness of the first region 10 and the second region 20 approaches the same, and therefore, the effect of suppressing the variation in the flight distance when the hit points vary. There is a possibility that it cannot be obtained sufficiently. On the other hand, if the difference in the arithmetic average roughness Ra is too large, the golf rule may be deviated. From such a viewpoint, the difference in the arithmetic average roughness Ra in the first region 10 and the second region 20 is more preferably in the range of 0.5 to 4 μm, and further preferably in the range of 1 to 4 μm. Is desirable.

  The arithmetic average roughness Ra of the first region 10 is not particularly limited, but is preferably about 1 to 3 μm.

  Further, as the surface roughness, the maximum height roughness Rz may be used together with the arithmetic average roughness Ra or instead of the arithmetic average roughness Ra. For example, the difference in the maximum height roughness Rz between the first region 10 and the second region 20 is desirably 5 μm or more. When the difference in the maximum height roughness Rz is less than 5 μm, the surface roughness of the first region 10 and the second region 20 approaches the same, so that the effect of suppressing variation in flight distance when the hit points vary is sufficient. May not be obtained. On the other hand, if the difference in the maximum height roughness Rz is too large, the golf rule may be deviated. From such a viewpoint, the difference in the average height roughness Rz between the first region 10 and the second region 20 is more preferably 5 to 15 μm, and further preferably 7 to 13 μm.

  The maximum height roughness Rz of the first region 10 is not particularly limited, but is preferably about 10 to 18 μm.

  The first region 10 and the second region 20 can be easily formed, for example, by performing shot blasting or polishing under different processing conditions.

  As mentioned above, although embodiment of this invention was described in detail, it cannot be overemphasized that this invention is not limited to said embodiment, and can be changed into a various aspect. In particular, the embodiments should not be strictly interpreted as being independent of each other. For example, an aspect obtained by replacing some elements in one embodiment with elements described in another embodiment should be understood as the scope of the disclosure of the present invention.

In order to confirm the effect of the present invention, based on the specifications shown in FIGS. 1 to 4 and Table 1, hollow type wood-type golf club heads made of titanium alloy having different surface roughnesses of the face were produced. A blow test was conducted. The common specifications of the wood-type golf club used for the test are as follows.
Club total length: 45 inches Head volume: 460cm ³
Loft angle: 10 degrees Head moment of inertia: 4000 g · cm ²
Bulge radius: 12 inches Maximum face height H: 54 mm
First area width CW / face maximum width FW: 64%

  For the surface roughness (Ra, Rz) of the face, the product name “INFINITE FOCUS optical 3D Measurement Device G4f” manufactured by Alicona is used. In each area, three points (arbitrary) are measured and the average value is shown. It was.

In the hit test, each golf club is mounted on a swing robot and adjusted to a head speed of 45 m / s. Each ball is hit at a predetermined position on the face with six shots, and the average flight distance and back spin amount are Measured. The ball hitting position of the face is as follows.
Reference hit: Face center (up / down of face and middle position in toe / heel direction)
5 mm upper impact: position 5 mm above the face center 10 mm upper impact: position 10 mm above the face center 5 mm lower impact: 5 mm position below the face center The results of the test are shown in Table 1.

  As a result of the test, it was confirmed that the variation in the flight distance was suppressed in the head of the example as compared with the comparative example.

Next, by changing the surface roughness, the moment of inertia of the right and left, and the bulge radius of the second region described in Table 2, the hit ball when hit at a position 20 mm toe side and 20 mm heel side from the face center, respectively. The lateral spin amount and the lateral displacement amount of the hit ball with respect to the target flying line direction were measured.
The test results are shown in Table 2.

  As a result of the test, it was confirmed that the direction of the hit ball of the head of the example was significantly improved as compared with the comparative example.

DESCRIPTION OF SYMBOLS 1 Wood type golf club head 2 Face part 2a Face 10 1st area | region 10P The position 20 lowermost side of 1st area | region 2nd area | region 30 Boundary e1 Upper edge H of face Maximum height R of bulge radius

Claims (8)

A wood-type golf club head having a face portion having a face for hitting a ball,
The face includes a first region and a second region;
The first region is located in the center of the face in the toe-heel direction and on the upper side of the face,
The second region is formed in a U shape in a front view of the face so as to be adjacent to a toe side, a heel side, and a lower side of the first region,
A wood-type golf club head, wherein the surface roughness of the second region is larger than the surface roughness of the first region.   The wood-type golf club head according to claim 1, wherein a toe side and a heel side of the second region extend to an upper edge of the face.   3. The wood-type golf club head according to claim 1, wherein a boundary between the first region and the second region extends in a convex arc shape toward a lower side of the face in a front view of the face.   The wood-type golf club head according to any one of claims 1 to 3, wherein a position on a lowermost side of the first region is located at a height position that is ½ of a maximum height of the face or at an upper position. .   The wood-type golf club head according to any one of claims 1 to 4, wherein a position on a lowermost side of the first region is located at a height position that is 2/3 of the maximum height of the face or below the height position. . In a reference state where the head is placed on a horizontal plane at a specified lie angle and loft angle, the moment of inertia around the vertical axis passing through the center of gravity of the head is 3500 to 6000 (g · cm ² ),
6. The wood type golf club head according to claim 1, wherein the bulge radius of the face is 10 to 16 inches.   7. The difference between the arithmetic average roughness Ra is 0.5 μm or more and the difference in maximum height roughness Rz is 5 μm or more between the first region and the second region. The wood-type golf club head described.   7. The difference between the arithmetic average roughness Ra is 0.5 to 4 μm and the difference in maximum height roughness Rz is 5 to 15 μm between the first region and the second region. A wood type golf club head according to crab.

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