Patent Application
20180296887
The present invention relates to a golf club head.
In recent years, golf club heads have been proposed in which a raised portion extending in the toe-heel direction is provided on the crown portion and a sloped surface is formed as a step between the raised portion and the portion rearward thereof (e.g., JP 2015-29628A). A golfer, by sighting this step, is better able to determine the direction of the shot at address.
JP 2015-29628A is an example of related art.
Incidentally, golfers, in order to better catch the ball or to prevent slicing, sometimes intentionally grip the club at address with the face rotated in a direction that closes the face (e.g., in a direction whereby the face is turned to the left of the target direction in the case of a right-handed club). Note that “better catching the ball” refers, for example, to ensuring that the ball is not launched to the right of the intended launch direction (left-right direction), in the case of a right-handed golfer. However, golfers normally address the ball such that the orientation of the face (e.g., orientation of the upper end edge of the face in the case of a wood-type golf club) is perpendicular to a target line (target direction) as a reference at address. Thus, in the case where the face is closed at address as described above, the orientation of the face is not perpendicular to the target direction, possibly giving rise to a sense of incongruity.
In particular, with a club such as described in JP 2015-29628A, there is a problem in that since a step is formed on the crown portion, the orientation of the face becomes easier to sight, thereby exacerbating the sense of incongruity. The present disclosure was made in order to solve this problem, and an object thereof is to provide a golf club head that is able to reduce the sense of incongruity even when the face is closed at address.
A golf club head according to the invention includes a face portion, a crown portion and a sole portion, the crown portion including a first region extending in a toe-heel direction along at least part of the face portion, a second region arranged further on a back side than the first region, and a step region extending in the toe-heel direction between the first region and the second region and extending downward toward the second region from the first region side, the first region being formed to at least extend from a position Ph that is 20 mm on a heel side to a position Pt that is 25 mm on a toe side based on a face center, and a width Dh of the first region in a face-back direction at the position Ph and a width Dt of the first region in the face-back direction at the position Pt satisfying 1<(Dt/Dh)≤1.35.
In the above golf club head, a difference between the width Dh and the width Dt can be set to 6 mm or less.
In the above golf club heads, a length of the first region in the face-back direction can be set to 5 to 30 mm, between the position Ph and the position Pt.
In the above golf club heads, an angle θ formed by a straight line connecting the position Ph and the position Pt at an end edge on a face side of the first region and a straight line connecting the position Ph and the position Pt at the end edge on a back side of the first region can be configured to satisfy 0 degrees<θ≤8 degrees.
In the above golf club heads, a face angle FA of the face portion can be configured to satisfy −5 degrees≤FA≤0 degrees.
With a golf club head according to the present invention, the sense of incongruity can be reduced even when the face is closed at address.
Hereinafter, an embodiment of a golf club head according to the present invention will be described, with reference to the drawings.
As shown in
The face portion 1 has a face surface which is the surface that hits the ball, and the crown portion 2 adjoins the face portion 1 and constitutes the upper surface of the head 100. The sole portion 3 mainly constitutes the bottom surface of the head 100, and constitutes the outer peripheral surface of the head 100 other than the face portion 1 and the crown portion 2. That is, besides the bottom surface of the head 100, the region extending from the toe side of the face portion 1 around the back side of the head to the heel side of the face portion 1 is also part of the sole portion 3. Furthermore, the hosel portion 4 is a region that is provided adjoining the heel side of the crown portion 2, and has an insertion hole 41 into which the shaft (illustration omitted) of the golf club is inserted. A center axis line Z of this insertion hole 41 coincides with the axis line of the shaft.
Here, the reference state when setting the golf club head 100 on the ground will be described. First, as shown in
In the present embodiment, the boundary between the face portion 1 and the crown portion 2 and between the face portion 1 and the sole portion 3 can be defined as follows. That is, in the case where a ridgeline is formed therebetween, this ridgeline will be the boundary. On the other hand, in the case where a clear ridgeline is not formed, in each of cross-sections E1, E2, E3 and so forth that contain a straight line N connecting a head center of gravity G and a sweet spot SS, as shown in
Also, in the present embodiment, the boundary between the crown portion 2 and the sole portion 3 can be defined as follows. That is, in the case where a ridgeline is formed between the crown portion 2 and the sole portion 3, this ridgeline will be the boundary. On the other hand, in the case where a clear ridgeline is not formed therebetween, the contour when the head is set in the reference state and viewed from directly above the center of gravity of the head 100 will be the boundary.
Also, the head 100 can, for example, be formed with a titanium alloy (Ti-6Al-4V) having a specific gravity of substantially about 4.4 to 4.5. Also, apart from a titanium alloy, the head can also be formed using one or two or more materials selected from stainless steel, maraging steel, an aluminum alloy, a magnesium alloy and an amorphous alloy, for example.
Also, the volume of this golf club head 100 is from 80 cm3 to 460 cm3 inclusive, for example.
The golf club head 100 according to the present embodiment is constituted, as shown in
Accordingly, the surface that is integrally formed as a result of the peripheral portion 15 of the face member 102 being attached to the head main body 101 constitutes the crown portion 2 and the sole portion 3 of the head 100. Thus, strictly speaking, the crown portion 2 and the sole portion 3 of the head main body 101 are part of the crown portion 2 and the sole portion 3 of the head 100, although, in this specification, these portions of the head main body 101 may also be referred to simply as the crown portion 2 and the sole portion 3, without making this distinction.
Next, the crown portion 2 will be described. As shown in
This sloped surface 23 is configured so as to extend upward, moving toward the face portion 1 side. The sloped surface 23 can thereby be sighted from above, when the golf club head 100 is set in the reference state. That is, the sloped surface can be sighted by the golfer at address. The sloped surface 23 is formed along the raised portion 21, and is thus formed to be U-shaped in plan view, similarly to the raised portion 21.
As shown in
1<(Dt/Dh)≤1.35 (1)
Note that (Dt/Dh) is preferably 1.3 or less, and more preferably 1.25 or less. Also, (Dt/Dh) is preferably 1.05 or more, and more preferably 1.1 or more.
That is, the raised portion 21 is formed such that Dt is greater than Dh. Specifically, the lengths of Dt and Dh are, for example, preferably set such as shown in the following in equations (2) and (3).
10 mm≤Dt≤30 mm (2)
6.5 mm≤Dh≤30 mm (3)
Within the range from the position Pt to the position Ph, the width D of the raised portion 21 preferably satisfies the following in equation (4).
5 mm≤D≤30 mm (4)
Also, a difference Dn between Dt and Dh is preferably set as follows.
Dn≤6 mm (5)
Note that Dn is more preferably set to 5 mm or less, and is particularly preferably set to 4 mm or less.
Also, a straight line L1 connecting an end edge Pt1 on the face side of the raised portion 21 at the position Pt and an end edge Ph1 on the face side of the raised portion 21 at the position Ph is prescribed. Furthermore, a straight line L2 connecting an end edge Pt2 on the back side of the raised portion 21 at the position Pt and an end edge Ph2 on the back side of the raised portion 21 at the position Ph is prescribed. In this case, an angle θ formed by the straight line L1 and the straight line L2 preferably satisfies the following in equation (6).
0<θ≤8 degrees (6)
Note that the face center can be defined as follows.
First, an arbitrary point Po is determined generally in a vicinity of the middle of the face portion 1 (face surface) in the toe-heel direction and the up-down direction. A line x extending in the toe-heel direction is drawn through this point Po, and a midpoint Px of this line x is determined. Next, on the face portion 1, a line y extending in the up-down direction is drawn through the point Px, and a midpoint Py of this line is determined. A process of redrawing the line extending in the toe-heel direction through the point Py determined in this way as the line x and thereafter redetermining the point Py in a similar manner to that described above is then repeatedly performed. A new point Py at which the distance between the previous point Py and the new point Py becomes 0.5 mm or less during the repetitions of this process is defined as the face center. Note that, more specifically, the above line x passing through the point Po is the line of intersection between the face surface (surface of the face portion 1) and a plane that contains the normal of the face surface passing through this point Po and is parallel to the toe-heel direction. Also, more specifically, the above line y passing through the point Px is the line of intersection between the face surface and a plane that contains the normal of the face surface passing through this point Px and is parallel to the up-down direction. Also, more specifically, the above line x passing through the point Py is the line of intersection between the face surface and a plane that contains the normal of the face surface passing through this point Py and is parallel to the toe-heel direction. Note that the lengths of the above lines x and y are measured along the face surface.
Also, as shown in
The structure of the face portion 1 and the sole portion 3 is not particularly limited. With regard to the face portion 1, the thickness thereof can be appropriately changed, for example. Also, a face angle FA preferably satisfies the following in equation (7).
−5 degrees≤FA≤0 degrees (7)
Note that the face angle FA is defined as follows. First, a straight line FL connecting two points F1 and F2 on the face surface at positions respectively spaced by 40 mm on the toe side and the heel side of the face center is drawn with the head in the reference state. The angle formed by this straight line FL and a straight line extending parallel to the toe-heel direction is defined as the face angle FA. Note that in the case where the points F1 and F2 cannot be taken on the face surface of the head due to the size of the face surface, a straight line connecting two points on the face surface at positions respectively spaced by 30 mm on the toe side and the heel side of the face center is determined as the straight line FL. Also, the sign of the face angle FA is positive in the case where the face is turned in a direction that closes the face (discussed above), and is negative in the case where the face is turned in a direction that opens the face (e.g., in a direction whereby the face is turned to the right of the target direction, in the case of a right-handed club).
Also, with regard to the structure of the sole portion 3, recesses and protrusions can be appropriately formed and the thickness can be changed from a design or performance viewpoint.
Next, an example of the manufacturing method of the above golf club head will be described. First, the abovementioned head main body 101 and face member 102 are prepared. A head main body 101 and a face member 102 such as described above can be produced with various methods. For example, the head main body 101 can be manufactured by casting such as a well-known lost wax precision casting process. Also, the face member 102 can be manufactured by a method such as forging, plate pressing or casting, for example.
The golf club head is then completed when predetermined coating is performed after joining these portions by welding (TIG (tungsten inert gas) welding, plasma welding, laser welding, brazing, etc.), for example.
According to the above embodiment, the following effects can be obtained.
(1) In the crown portion 2, the raised portion 21 is formed higher than the base portion 22 via the sloped surface 23, thus enabling the height of the face portion 1 to be increased by the height of the raised portion 21. Thus, the rebound performance of the face portion 1 can be improved. Also, in the crown portion 2, only the raised portion 21 is formed higher, and the base portion 22 occupying most of the crown portion 2 is formed at a lower position than the raised portion 21, thus enabling the center of gravity of the head to be lowered.
(2) At address, the orientation of the head can be determined utilizing the end edge on the back side of the raised portion 21. At this time, since the widths Dt and Dh of the raised portion 21 satisfy in equation (1), the end edge on the back side of the raised portion 21 extends such that the distance between the end edges of the raised portion 21 on the back and face sides is greater at the position Pt on the toe side than at the position Ph on the heel side. Thus, the following effects can be obtained.
Golfers, in order to better catch the ball or to prevent slicing, sometimes intentionally grip the club at address with the face rotated in a direction that closes the face (e.g., in a direction whereby the face is turned to the left of the target direction, in the case of a right-handed club). At this time, the upper end edge of the face surface (end edge on the face side of the raised portion 21) slopes relative to the target line rather than being orthogonal thereto, whereas the end edge on the back side of the raised portion 21, due to satisfying the above in equation (1), extends in a direction orthogonal to the target line. That is, as shown in
(3) Also, when the above in equations (2) to (6) are satisfied in addition to the above in equation (1), the golfer is better able to address the ball without feeling any sense of incongruity, even with the face surface in a closed state.
(4) Also, when the above in equation (7) is satisfied, the face is square (orthogonal to the target line) or the face is open (e.g., face is turned to the right of the target direction, in the case of a right-handed club), in the reference state. Thus, when the club is gripped at address with the head in the reference state, the end edge on the back side of the raised portion 21 extends in a direction that is open to the target direction (e.g., in a direction whereby the direction orthogonal to the end edge on the back side of the raised portion 21 is turned to the right of the target direction, in the case of a right-handed club). Golfers tend to feel a sense of incongruity in the case where the point of reference at address is turned in a direction that is closed relative to the target direction. Therefore, this sense of incongruity can be eliminated by satisfying the above in equation (7).
Although an embodiment of the present invention is described above, the present invention is not particularly limited to the above embodiment, and various modifications can be made without departing from the spirit of the invention. Also, the following variations can be appropriately combined. Modifications such as the following can be made, for example.
<7-1>
In order to obtain the abovementioned effects, the raised portion 21 need only be formed such that at least in equation (1) is satisfied. Accordingly, in equations (2) to (7) need only be appropriately set if needed.
In the above embodiment, the raised portion 21 is formed to be U-shaped in plan view, but is not particularly limited thereto. That is, as long as in equation (1) is satisfied, an end edge 211 on the back side of the raised portion 21 can, for example, be formed linearly, as shown in
<7-2>
In the above embodiment, the sloped surface 23 is formed to be U-shaped in plan view, but is not limited thereto, and need only extend generally in the toe-heel direction. Accordingly, the sloped surface 23 can also be formed in a band shape extending generally straight in the toe-heel direction, for example. Also, the sloped surface 23 may not necessarily be flat. For example, the sloped surface can also be formed to be curved. Furthermore, the region between the raised portion 21 and the base portion 22 need not necessarily be formed as a slope, and may be a step that extends in the up-down direction.
<7-3>
The head according to the above embodiment is constituted by combining a head main body having at least the crown portion 2 with other portions, but the present invention can also be applied to a head in which only the crown portion 2 is formed separately. For example, the head can be constituted by fitting the crown portion 2 into an opening for the crown portion formed in a head main body that includes a face portion, a side portion and a sole portion. Also, a cup face structure need not be adopted, and the head can be constituted by fitting a plate-like face member into an opening formed in the face portion 1 and welding the face member to the head main body.
Hereinafter, working examples of the present invention will be described. The present invention is, however, not limited to the following working examples.
Here, golf club heads having generally the same shape as
Twenty golfers tested the golf clubs produced as described above. That is, sensory analysis was conducted in fine weather conditions as to whether any sense of incongruity was felt when the face surface was closed at address. As a result, with working examples 1 and 2, all of the golfers responded that they did not feel any sense of incongruity at address.
On the other hand, with the comparative example 1, 60 percent of the golfers responded that they felt a sense of incongruity at address. With the comparative example 1, the end edge on the face side and the end edge on the back side of the raised portion were parallel to each other, and thus the sense of incongruity was apparently due to the fact that not only the end edge on the face side of the raised portion but also the end edge on the back side was not orthogonal to the target line (the toe side was angled to the face side), when the face surface was closed at address.
Also, with the comparative example 2, 25 percent of the golfers responded that they felt a sense of incongruity at address. With the comparative example 2, the width of the raised portion on the toe side was much greater than on the heel side, and thus the angle formed by the end edge on the face side of the raised portion and the end edge on the back side was apparently felt to be excessively large. Thus, a sense of incongruity was apparently felt due to the fact that the end edge on the back side of the raised portion was not orthogonal to the target line (the toe side was angled steeply to the back side), when the face surface was closed at address.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017-080989 | Apr 2017 | JP | national |
