JPH0810362A - Large size hollow metal head of golf club - Google Patents

Abstract

PURPOSE: To improve strength and to reduce dragging force in a hollow metallic head of a golf club, by equipping a protruding bar part in the center of the bottom wall part and forming plural dish type dent part between the protruding bar part and a heal part and a toe part. CONSTITUTION: This head of a golf club 10 is constituted of a shell body which has toe part 32, heal part 30, rear wall part 26, front wall part 28 of the face, upper wall part, and bottom wall part. The bottom wall part is equipped with a protruding bar part 60 at the center and plural dish type dent parts 162, 164 are formed between the protruding bar part 60 and the heel part 30 and the toe part 32 respectively. The both dish type dent parts 162, 164 are separated rearward from the front wall part 28 respectively and equipped with each arc shaped periphery part expanded out toward the heel part 30 and the toe part 32, and are defined in a mutual mirror image relation with respect to a vertical plane extending in the front rear direction to bisect the protruding bar part 60. Further, an outer border line 300 is separated from another dent part 164.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention is broadly applicable to a hollow metal head (metal wood) of a golf club, in which the head size is increased without increasing the weight of the head in order to improve accuracy when hitting a ball. It is about doing. Furthermore, the present invention further prevents the front wall portion (face) from swinging at the time of hitting the ball, and allows the shock wave at the time of hitting the ball to be absorbed by the upper wall portion, the bottom wall portion (sole), and the rear wall portion. It is about forming a.

[0002]

2. Description of the Related Art Among golf club heads, a metal head having a particularly large size and a particularly thin wall has cracks and buckles in its metal wall. There is also a problem that the front wall part (face) swings greatly at the moment of impact of the ball. Therefore, at the moment of impact, the shock wave propagating from the face to the surroundings can be appropriately guided, blocked, diffused, or appropriately changed, while the wall thickness of the wall can be kept thin,
There is a need to provide improved structures or shapes for metal heads.

Further, in this type of golf club head,
It is also required to increase the strength of the thin wall portion and the sole plate and to reduce the drag force acting on the bottom wall portion (sole) at the time of hitting the ball.

[0004]

One of the main objects of the present invention
One is to solve or overcome the above problems and drawbacks. Basically, an improved golf club head according to the present invention includes a front wall portion for hitting a ball, a bottom wall portion, and a toe wall portion and a heel wall portion which are separated from each other, and is characterized by the features. However, two shallow recesses are formed in the bottom wall. One of the two recesses is closer to the heel, and the other recess is closer to the toe. The two recesses are formed so as to be spaced apart rearward from the front wall portion, and the one recess portion has an arc-shaped peripheral edge portion that bulges substantially toward the heel portion. The other recessed portion has a peripheral edge portion that bulges substantially toward the toe portion.

The two recesses are generally provided with a downwardly facing surface that is shallowly recessed upward. The downward surfaces are concave in the front-rear direction and also concave in the heel-toe direction.

It is a further object of the present invention that the outer peripheral contour line when viewed from the direction directly facing the bottom wall portion is such that the toe portion of the golf club head and the back surface of the head are shallowly depressed. It is to provide a golf club head that is separated from the other dish-shaped recess of the groove-shaped recess at a large distance. As shown below, the distance between the outer peripheral contour line in the toe portion and the other recess is
Generally, it is at least 5/8 inch (about 16 mm), and the distance between the outer peripheral contour line on the back surface of the head and the other recess is at least about 1 inch (about 25 mm).
mm). These large intervals are defined by the curved bevels of the head wall, which contributes to the increased strength of the head wall, which allows the head to be upsized. There is.

A further object of the present invention is that the area of the region encompassed by the outer peripheral contour line when viewed from the direction directly facing the bottom wall portion is A, the two dish-shaped recesses, the ridges and the surface When the area of the region defined by the cut surface is B, A> 1.
6B to provide a golf club head. In general, the equation expressing the relationship between A and B is 1.7 <
A / B <2.0.

It is a further object of the present invention to provide a localized structure for the bottom wall which aids in "digging" a poorly lie golf ball from a turf.

A further object of the present invention is that the bottom wall portion comprises a chamfered surface, the chamfered surface of the central ridge between the rear regions of the two localized recesses. It is an object of the present invention to provide a golf club head which extends beyond the rear region and further ahead at an angle that extends rearward and upward. The chamfered surface may be continuous with the peripheral portions of the two dish-shaped recesses, as will be made clear later. The chamfered surface may be spaced from the trailing edge of the golf club head by at least three-quarters of an inch when viewed in a direction directly opposite the bottom wall. .

A further object of the present invention is to provide a bottom wall part of which is defined by a sole plate, the sole plate of which the peripheral edge is located behind the front wall part. It is joined to the border edge of the opening defined by the bottom wall, whereby the sole plate closes the opening and also the central ridge and the two dished recesses. A part of them is a sole plate defined by this soap plate. In this regard, the sole plate is generally adapted to define the majority of the area of the two shallow recesses. Further, the main body portion of the shell-like body of the golf club head may define a bottom wall portion corner plate portion that enhances rigidity integrated with a tubular structure portion that supports the shaft, in which case In, the sole plate is also joined to the corner plate portion, and further, the corner plate portion is
A part of the one recess, which is one of the two recesses that are shallowly recessed, closer to the heel portion of the golf club head may be formed together.

A further object of the invention is a first group of thin,
It is to provide a plurality of dendritic ribs made of metal for shock wave dispersion, and the plurality of dendritic ribs of the first group are
Substantially rearward from the front wall portion, extending integrally with the lower surface along the lower surface of the upper wall portion of the shell-shaped body, and toward the two recessed recesses. It is a raised dendritic rib. The portion of the bottom wall defining the two recesses is recessed upward so as to bulge toward the dendritic ribs.

Further, a plurality of dendritic ribs of the second group may be provided integrally with the upper wall portion and separated from each other, and the plurality of dendritic ribs of the second group are substantially Each of the dendritic ribs extending rearward and connecting to the rear wall portion defined by the shell-like body at a lower rear portion thereof, so that when the golf ball impacts the front wall portion. Is a dendritic rib adapted to receive a rearward load from the upper wall portion and transmit a rearward load to the rear wall portion. In addition, the plurality of dendritic ribs of this second group are also
It is raised toward the two recesses that are shallowly depressed.

The above-mentioned dendritic ribs transmit, disperse, and attenuate the impact generated by the impact of the ball,
The distribution reduces the concentration of shock waves generated at the connection between the front wall and the upper wall. For example, in the case of a driver with a club head speed of 100 miles / hour (about 160 km / hour), a shock wave is generated at the moment when the club head impacts a golf ball at a high speed, and the impact wave is about ½ milliseconds from the impact. It has already disappeared from the club head by. Further, by making the wall portion of the sole plate into a dish shape, the strength of the structure for transmitting the impact load is increased.

A further object of the present invention is to provide a hosel structure that extends downward toward the inside of the golf club head and has a shaft insertion hole formed therein. With this hosel structure, it is possible to increase the bonding strength between the front wall portion and the sole plate and the heel portion having a dish shape, and reduce the hosel weight, The reduced weight can be used to form the dendritic ribs described above. In this regard, the present invention can provide a golf club head having a larger total volume as compared to a golf club head of the same weight that does not employ a dendritic rib structure. As will be made clear below, by adopting the dendritic rib structure, the wall thickness of the upper wall portion, the toe wall portion, the rear wall portion and the heel wall portion of the hollow head can be reduced.

A further object of the present invention is to control the relative movement of the contacting turfs (during the swing of the golf club), resulting in a reduction of the upward force, ie the drag force during the swing of the head. The bottom wall portion of the golf club head is to generate a force acting on the golf club head.

A further object of the present invention is to provide a golf club headset comprising a plurality of golf club heads, wherein each golf club head comprises a shell, A shell has a toe portion, a heel portion, a front wall portion defining a ball striking face, a top wall portion, and a bottom wall portion, and each face for striking the balls of the golf club heads. Have different angles with respect to the vertical plane,
The bottom wall portion of each golf club head is provided with a ridge portion in the center, and two shallow recessed dish-shaped concave portions similar to each other are formed in the bottom wall portion. One of the two recesses is formed between the protruding portion and the heel portion, the other recess is formed between the protruding portion and the toe portion, and these two recesses are It is formed so as to be separated from the front wall portion rearward, and the one recessed portion has an arc-shaped peripheral portion that bulges substantially toward the heel portion, and the other recessed portion is substantially formed. It has an arcuate peripheral edge portion that bulges toward the toe portion. Each of the recesses of each golf club head may be provided with a downward surface as described below, and the downward surface means, in each golf club head, i) extending in the toe-heel direction. A line of intersection that is formed by a vertical plane that divides the approximately half into
A downwardly concave curve, and ii) a vertical plane extending in the front-rear direction of the golf club head and bisecting the concave portion so as to intersect the surface of the concave portion is a downward concave curve. Is a downward facing surface.

Further, the respective shapes of the two recessed portions of each golf club head are generally in the same relationship with respect to a vertical plane extending in the front-rear direction and substantially dividing the protrusion into two equal parts. It is designed to have a shape. Further, each of the concave portions of each golf club head may be provided with a downward surface as follows, and the downward surface means, in each golf club head, i) the bottom of the golf club head. When the wall is in contact with the turf, the rear region of the downward surface is inclined forward and upward with respect to the trajectory of the forward swing of the golf club head, ii) so that the golf club head is An upward force is generated by the rear region of the downward surface coming into contact with the turf when swung forward along the swing locus, and the upward force causes the bottom wall portion of the golf club head, and thus the upward force. The downward surface is characterized in that the golf club head is pushed up.

It is a further object of the present invention that, in each golf club head, the bottom wall of the golf club head has a surface that widens laterally toward the rear (this surface may be a locally flat surface). So that this surface extends between the rear regions of the two recesses, beyond the rear regions of the ridges, and further forward, at an angle that extends rearwardly upward, whereby The golf club head is designed to reduce the drag force when the golf club head is swung forward in an arc and comes into contact with the turf. In this regard, the edges of the surface and the two recesses that widen laterally toward the rear are guided by forming a shape that bulges upward when the golf club head is viewed from the rear. The contact with the turf and the action of the above-mentioned upward force are strengthened. Further, in each golf club head, a substantially continuous hollow tubular portion made of a metal is used as a hosel portion in the shell-like body, and the shell-like body is formed from the vicinity of the upper wall portion of the shell-like body. The tubular portion has a hole for inserting a club shaft, the hole extending to the vicinity of the bottom wall, and the hole is one of the two shallow dish-shaped recesses. The positions may be aligned with the one concave portion.

It is a further object of the present invention to provide a golf club headset as described above which includes at least two or more of the golf club heads listed below. a) Metal wood whose front wall face is inclined at an angle of about 9 degrees with respect to the vertical direction, and b) Front wall face is about 11 angles with respect to the vertical direction.
Metal wood inclined at an angle of degrees, c) metal wood that is No. 2 wood, d) metal wood that is No. 4 wood, and e) metal wood that is No. 5 wood.

Further objects of the present invention are the following a) and b).
It is to provide a golf club headset including a plurality of golf club heads, which has one of the above characteristics. a) The center of gravity of at least one golf club head among the plurality of golf club heads is calculated from the head height from the bottom head surface to the top head surface when the golf club head is viewed from the front. About 4 from below
The feature is that it is located at a height of 2% to about 50%. b) The center of gravity of each of at least two golf club heads among the plurality of golf club heads is defined as the head height from the bottom head surface to the top head surface when the golf club heads are viewed from the front. Characterized by being located at a height of about 42% to about 50% from below.

A further object of the present invention is to provide an improved golf club set incorporating the structural features, modes of action, and in-use effects described above, and methods of forming the same. To do.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described with reference to the accompanying drawings. The drawing shows a golf club 10 according to a preferred embodiment of the present invention. The golf club 10 includes a shaft 12 (only the lower end portion is shown in the drawing), and the shaft 12 is attached to a head 14. The head 14 is a "wood" club in a club shape, but is made of metal, that is, metal. As shown in FIGS. 6 to 9, the head 14
Consists of a hollow metallic shell 16, which is a shell 1
6 is filled with a filling material 18 of foamed plastic.
A preferred material for this filler is, for example, polyurethane.

A preferred material for making the shell 16 is, for example, titanium or titanium alloy. As a method for manufacturing the shell 16, for example, a "lost wax" casting method known in the art can be adopted. Shell 1
Reference numeral 6 denotes a two-piece structure in which the main body portion 20 and the sole plate 22 are individually formed and then joined. When joining, the peripheral edge portion of the sole plate 22 is welded to the main body portion 20. It will be described in detail later. Note weld points 22a and 22b in FIG.

The main body 20 of the shell 16 has an upper surface 24,
The back surface 26 and the face 28, which is a surface on the opposite side of the back surface 26 for hitting a ball, are provided. The face 28 is inclined with a predetermined "pitch angle" with respect to the vertical direction, and the magnitude of this pitch angle depends on the type of club and the desired loft size. The end of the head 14 near the shaft 12 is commonly referred to as the “heel” 30, and the end opposite the heel 30 is the “toe” 32.
is called.

As shown in FIG. 2, face 28 is generally curved from heel 30 to toe 32. The main body portion 20 of the shell 16 has a bottom corner portion 34 (shown in FIG. 10), and the bottom corner portion 34 is integrally formed by casting the front wall portion 28a and the heel wall portion 30a. The sole plate 22 is flush with the sole plate 22, and after the main body 20 and the sole plate 22 are joined by welding, the bottom corner portion 34 and the sole plate 22 form a bottom surface, that is, a sole. To be done.

Next, referring to FIG. 6, the shell 16
The heel wall portion 30a is provided with a substantially continuous hollow tubular portion 36. The tubular portion 36 extends from the above-described bottom corner portion 34 of the main body portion 20 of the shell 16 from the upper opening 38 opening to the upper surface 24 to the elliptical lower opening 40 opening to the bottom surface or sole. It extends to pass. The inner diameter of the tubular portion 36 is substantially uniform in the lengthwise direction, and the shell-shaped body 1 is provided in the middle of the inner wall surface of the tubular portion 36.
An internal small hole 42 that opens to the inside of 6 is formed. The internal small hole 42 is used as an injection port for injecting the foam material 18 into the hollow shell 16 at the time of manufacturing the golf club.

The tubular portion 36 is dimensioned to fit tightly with no gap when the lower end portion of the shaft 12 is inserted. As shown in FIG. 6, the upper opening 38 is formed with a rounded lip portion 43 so that the shaft 12 collides with the corner of the rim of the upper opening 38 and is damaged by the stress. The fear is greatly reduced. A fine groove 44 may be formed in a portion of the inner peripheral wall surface of the tubular portion 36 that extends downward from the upper opening 38, and the groove 44 is a groove of a female screw thread. It is also preferable that the spiral groove is continuous, and it is also preferable that the spiral groove has a plurality of concentric grooves, so that the shaft 12 is better bonded to the tubular portion 36. Can be formed.

In the preferred embodiment of the present invention, the aforementioned lip 43 is formed at the tip of a slightly projecting projection on the heel side end of the club head, the height of this projection being the club. Horizontal plane 20 passing through the highest point of the upper surface 24 of the head
It is set to be equal to or slightly lower than the height of 0.

The shaft 12 is a hollow tube made of an appropriate material. The most common material for shaft 12 is steel, but titanium, carbon and boron composites are also used. When the shaft is made of steel, the outer surface of the shaft is preferably chromium-plated to prevent corrosion. In order to prevent moisture from entering the inside of the shaft 12, a closing plug 46 may be inserted into the lower end portion of the shaft. The closure plug 46 may be made of a suitable elastic material, and for example, a material such as nylon, epoxy, polyurethane, Delrin, or the like can be used. Further, an annular uneven portion may be provided on the wall portion of the shaft so that the plug 46 does not fall off the shaft 12. In such a case, the annular concave and convex portion also functions as an adhesive biting portion. Shaft 1
2, a positioning ring 50 is adhered at a position where the distance from the tip 52 of the lower end portion of the shaft 12 is substantially equal to the length of the tubular portion 36. A suitable material for the positioning ring 50 is glass, for example. For example, fiber reinforced nylon.

To attach the shaft 12 to the head 14, for example, a suitable epoxy adhesive or the like may be used.
At this time, the above-mentioned step groove or screw groove 44 formed on the inner peripheral wall surface of the tubular portion 36 and the above-mentioned uneven portion formed on the shaft 12 serve as an adhesive biting portion, so that a better bonded state is obtained. (If the shaft is plated, the buff is applied to remove the plating on the lower end of the shaft first). During assembly, until the positioning ring 50 abuts the rounded lip portion 43 of the upper opening 38 of the tubular portion 36,
The lower end portion of the shaft 12 is inserted into the tubular portion 36 of the head 14. At this time, the tip 5 of the lower end portion of the shaft 12
2 projects slightly outward from the lower opening 40 of the tubular portion 36. Then, after cutting off the protruding portion of the tip 52, polishing is performed to remove the tip 52 as shown in FIG.
Finish so that it is flush with the sole of the head 14.

According to the structure described above, the shaft can be attached to the head without providing the neck, that is, the hosel protruding to the outside. Therefore, almost all of the head mass can be "effective mass" that contributes to the energy transfer from the player to the ball, with little or no "dead weight" enough to reduce the maximum achievable club head speed. It can be totally eliminated. In this way, the effective mass of the club head can be increased without reducing the maximum achievable club head speed, which results in more efficient energy transfer from the player to the ball and no effort by the player. It is possible to obtain the result that the flight distance of the hit ball is extended even if the player does not perform.

Further, instead of removing the hosel protruding to the outside, the lower end portion of the shaft is penetrated from the upper end to the lower end of the head, and the tip 52 of the lower end portion of the shaft is provided.
Is designed to be flush with the sole. Thus, by eliminating the outwardly projecting hosel, the shaft is positioned within the area between the upper and lower edges of the club head face (this area is often referred to as the "ball control zone"). , So that it can be put in and out of the head. In this way, the lower end of the shaft is set within the control zone, and the shaft extends deep into the shell 16 of the head (for example, until it penetrates into the sole of the head). The physical sensation of the face position (so-called “head sensation”) of the player is much more clearly understood, resulting in more accurate shot control and the ability of a skilled player to “hit” the ball. It's also easy to take advantage of the small work, and moreover, even if the ball hits anywhere on the face, it is possible to more firmly grasp the feel of the impact of the ball. Also,
Increasing the effective mass of the club head and inserting the lower end portion of the shaft 12 into the tubular portion 36 inside the head for firm support further enhances the "head feeling".
Has also contributed to the improvement of.

Furthermore, by eliminating the hosel protruding to the outside, many advantages in the manufacturing process are obtained. For example, if the hosel that protrudes to the outside is provided, the mass that would otherwise be used for the hosel is distributed to the club head portion that can contribute to the effective mass of the club head, so that the total mass of the club head is increased. Its effective mass can be increased without increasing it.
It should be noted that this additional mass should be used to increase the overall size of the club head.

A further advantage of eliminating the outwardly projecting hosel is that the cooling of the club head in the mold is more uniform. For comparison purposes, a club head with an outwardly projecting hosel will be described. In such a club head, the hosel and the non-hosel part of the club head shell will have different cooling. It tends to cool at a slow rate, which results in a slight warpage that can cause lofts, lie, and face angles to vary from club head to club head.

In the golf club according to the preferred embodiment of the present invention, the sole shape is as illustrated. As is clear from the figure, the feature of this bottom wall (sole) is that the ridge 60 is formed in the center.
It means that two shallow recesses are formed. One of the two recesses is formed between the ridge 60 and the heel, and the other is the ridge. The two concave portions are formed between the portion 60 and the toe portion, and all of the two concave portions are formed so as to be rearwardly spaced from the front wall portion, and the one concave portion is substantially the heel portion. It has an arcuate peripheral edge that bulges toward
The other recess has an arcuate peripheral edge that bulges toward the toe portion. As a specific example of such two shallow dish-shaped recesses, a recess having a reference numeral 162 between the ridge 60 and the toe portion 32 and a ridge 60 are shown in the drawings. A recess with a reference numeral 164 between it and the heel portion 30 is shown.

The curved perimeter of the recess 162 extends along a looped perimeter path indicated by reference numerals 162a, 162b, 162c and 162d.
Similarly, the peripheral edges of the reference numeral 4 are denoted by reference numerals 164a, 164b, 1
It extends along a looped perimeter path represented by 64c and 164d, both of which are on the surface of the bottom wall as shown. Recess 16
For both Nos. 2 and 164, the maximum depth of the recess measured from the plane including the looped peripheral edge path of the recess is set to be 1/4 inch (about 6 mm) or less, The preferred depth is 1/16 of an inch
m) to 3/16 inch (about 4.5 mm). In this regard, the depth d ₁ shown in FIG.
And the depth d ₂ shown in FIG. 9. If the depth is within this range, the recesses 162 that are recessed in a dish shape,
164, the most recessed surfaces 162 'and 16
It is usually sufficient to prevent the 4'from making direct contact with the ground when stroking the club. Further, even if the bottom wall portion (sole) comes into contact with the ground, the contact area is the lowest portion of the central ridge 60 and the peripheral portions of the recesses 162, 164 or the rear. Areas only, which will be described in more detail later.

Further, the regions 162 'and 164' of the bottom wall portion forming the recesses 162, 164 have a concave shape which is recessed upward in both two directions (front and rear direction and toe-heel direction). Therefore, the strength and the rigidity of the bottom wall portion related to the transmission of the impact load between the bottom wall portion and the front wall portion 28 when the ball is hit are enhanced. Therefore, the wall thickness of the bottom wall portion can be significantly reduced, whereby a larger size head can be provided by "turning away" the saved metal material to another place.

Further, it should be noted that the bottom wall portion has a chamfered surface which is a surface having a chamfered shape which laterally expands toward the rear. The chamfered surface extends between the rear regions of the two recesses 162, 164 beyond the rear region of the ridge 60 and further to the front at an angle that extends rearward and upward.

More specifically, a chamfered surface 56 is formed at the trailing edge of the head, and the chamfered surface 56 is formed.
Is a substantially flat portion that is designed to escape from the curved edge portion 56a with an angle of rising up so that the curved edge portion is located near the center of the sole. 56a, the rear edge portion 5 formed at the portion where the back surface 26 of the club head and the sole plate 22 intersect.
It extends between 8 and. The curved edge portion 56a, which is the lowest portion of the chamfered surface 56, has a protruding portion 60a.
It is connected to the trailing edge of. The ridges 60 extend forwardly therefrom to the positions indicated by 60a and 60b, widening from the positions indicated by 60a and 60b, and below the U-shape of the face 28 of the club head. The shape is such that it is connected laterally to the edge portion 28a. The lower edge 28a is a portion that addresses the turf when the head is swung.

The angle α formed by the chamfered surface 56, which is the surface of the trailing edge of the head, with respect to the horizontal direction is about 18 ° to 25 °.
It is preferable to set it to °. See FIG. 8 for this. The angle α may be changed by ± 5 ° depending on the type of club and the player's preference. This head trailing edge surface 56 minimizes the club head from closing, or "fogging," when the ball is hit "flat", and the aerodynamics of the club head as a whole. It helps reduce drag and significantly increases the achievable club head speed during a swing.

Further, regarding the combination of the shapes of the various portions of the bottom wall portion described above, the protruding portion 60 that bulges downwardly behind the front wall portion and between the dish-shaped recesses 162 and 164. Due to the extension of the bulge of the sole, when the sole (bottom wall) bites into the turf, the sole pushes the turf towards the area of the dished recesses 162 and 164 and thus the turf. I'm going to cut in while trying to separate them. For that reason, the degree of biting into the turf is limited to a degree proportional to or corresponding to the unique shape of this sole as a whole, which is a unique method of limiting the biting into the turf. Has been obtained. As is clear from FIGS. 1 and 2, the front wall portion (face) has a U-shape in which the portions located in front of the recesses 162, 164 and the protruding portion 60 bulge downward. It should be noted that the width of the ridge 60 becomes wider as it goes forward, that is, as it approaches the U-shaped portion of the front wall.

As described above, it is possible to reliably approach a golf ball having a "bad lie". That is, when stroking the club, consider that the turf is a liquid, and strike the ball “out” from the turf by striking the surface of the liquid with the feeling of sliding the sole of the club head. You can With an ordinary golf ball with a lie, it is not necessary to hit it like "digging out". In that case, it is sufficient to hit so that the "footprint" of the shape of the lower surface of this improved sole is attached to the turf, This will be described later.

Next, FIGS. 6, 10 and 11 will be described. The hosel tubular portion 36 extends downwardly and thus into the hollow interior space of the heel portion of the head, into which the shaft 12 can be inserted. So this hosel 36
Is concentrated immediately after the rear surface of the front wall portion 28 near the heel portion, in other words, at a position closer to the rear surface of the front wall portion 28, thereby,
It contributes to the effective mass that gives the ball striking power. Furthermore, the cylindrical wall portion of the hosel 36 is a front wall portion,
The bottom wall portion and the joint portion of the heel wall portion are reinforced. It should also be noted that the above-mentioned corner plate portion (bottom corner portion) 34 of the bottom wall portion 22 is a fillet portion 34 that is a reinforcing portion for increasing the rigidity of the hosel 36. The corner portion 34 further includes a recess 164 in the bottom wall portion.
It also forms part of the dished part. When the sole plate is joined to the shell-shaped body 20, the edge 99 and the edge 99a are welded together, and the edge 10
0 and the edge part 100a are welded. Figure 10
And FIG. 11.

Another important aspect of the present invention is the provision of a first group or set of thin, metallic, dendritic ribs, the dendritic ribs extending from the front wall 28. Substantially rearward, along the lower surface 24b of the upper wall portion 24, the lower surface 24
It may extend integrally with b. See example dendritic ribs 118-123 in this regard. The plurality of dendritic ribs 118 to 123 are formed at intervals in the lateral direction shown by the arrow 120, and their front ends 118a to 123a are formed at the front wall portion 28 and the upper wall portion 24. It is connected to the front wall portion 28 at the connection portion between the and. The lateral width of the portion of the dendritic ribs connected to the front wall portion 28 may be widened. The above configuration serves to disperse and transmit the shock wave or stress wave generated by the impact of the ball from the front wall portion to the upper wall portion. It plays a big role when hit. This in turn helps prevent the upper wall 24, which is a thin metal wall, from cracking or buckling. In addition, the dendritic ribs are formed in a shape that extends like a tree branch with a space between each other, and the space is about ½ inch (about 1 inch).
2.5 mm) to about 3/4 inch (about 19 mm), and the rear ends of the dendritic ribs are further laterally spaced apart.

The above dendritic ribs 118 to 123 have a vertical dimension (rib height) d ₃ of 0.050 to
The dimensions are within the range of 0.070 inch (about 1.3 to about 1.8 mm), and the dendritic ribs are
At any position in the longitudinal direction, on the center line indicated by reference numeral 125, a convex shape bulging toward the inside of the head and on both sides thereof by a reference numeral 126 and 127 is formed a concave shape (FIG. 12). Also,
As a side note to this, as already mentioned, the front wall is generally much thicker than the thickness of the other walls, which makes the front wall stronger and at impact. Even if a large impact load is applied, it will not crack.

To illustrate the typical approximate thickness of each wall, first the front wall is 0.120 inches thick at its thickest portion. The sole plate may be locally thickened near the portion connected to the front wall portion, but if it is limited to other portions,
The thickness of the thickest part is 0.050 inch (about 1.3 mm)
Is. The upper wall is 0.030 inch (about 0.8m
m). Since these thickness dimensions are smaller than those of standard wall heads, the head weight can be larger and the moment of inertia can be larger if the total weight of the head is the same. You can As a result, the "tolerance effect" of hitting the ball at a position off the center of the face is increased. If the head is cast by using titanium or a titanium alloy, which is lighter than steel, a larger head can be formed with the thin thickness illustrated above.

Further, since the dendritic ribs 118 to 123 are arranged along the inner surface shape of the head over their entire length (see FIG. 13), the dendritic ribs extend over a wide range of the upper wall portion 24. It fulfills the function of dispersing shock waves.
The shape of the upper wall portion 24 can be a middle height shape, that is, a shape that bulges shallowly upward. By these, it is possible to reduce the thickness of the upper wall portion 24.

Further provided is a second set or group of thin, metal, dendritic ribs, which are integral with the lower surface of the upper wall 24 along the lower surface thereof. It extends almost backward. The second set of dendritic ribs further includes a laterally extending dendritic rib, the lateral dendritic rib being a second set of dendritic ribs. Of the plurality of dendritic ribs extending substantially rearward. The second set of dendritic ribs is located farther from the front wall of the head than the first set of dendritic ribs. Among the second set of dendritic ribs, a plurality of dendritic ribs extending rearward are formed in a shape that extends like a tree with a space between each other in the lateral direction. The second set of dendritic ribs has a vertical dimension (rib height) of 0.050 to 0.100.
The size is within the range of inch (about 1.3 to about 2.5 mm). As a specific example described above, one lateral dendritic rib 137 formed at a position separated rearward from the first set of dendritic ribs 118 to 123 and different ones on the lateral dendritic rib 137 are different from each other. Five dendritic ribs 13 arranged in a fan shape that are formed by radially radiating from the position to the rear.
8-142.

The dendritic ribs 138 to 142 extend substantially rearward and are connected to the head rear wall portion 26 having a curved shape as a whole. These dendritic ribs function to transfer the rearward load to the rear wall portion 26 when receiving the rearward load from the upper wall portion 24. See FIG. 14 for this.

The dendritic ribs 137 to 142 of the second set have substantially the same shape and size as the dendritic ribs 118 to 123 of the first set. The function of transmitting and dispersing shock waves or stress waves that is substantially the same as that of the pair of dendritic ribs can be exerted, and therefore, the joint portion 146 between the thin upper wall portion 24 and the rear wall portion 26 is provided. The risk of cracking and buckling is greatly reduced. The second set of dendritic ribs 137-142 also follow their length along the shape of the top wall 24, see FIG. Further, the rear end portions of the dendritic ribs 138 to 142 are substantially rearward,
For example, as indicated by reference numeral 139a in FIG. 14, it extends downward and forward along the inner surface of the rear wall portion 26. This configuration enhances the strength of the rear wall portion 26, thereby making it possible to reduce the wall thickness of the rear wall portion 26.

The above-described dendritic ribs project substantially toward the wall portions 162 'and 164' which are recessed upward in a dish shape, and both the upper wall portion and the bottom wall portion are reinforced. Even when the ball hits a relatively high portion of the front wall portion 28 and also hits a relatively low portion, the impact load can be favorably transmitted to the rear.

Yet another important aspect of the present invention is to provide a golf club head as follows, which golf club head comprises a metallic shell, and the shell has It defines an upper wall portion, a bottom wall portion, a front wall portion, a rear wall portion, a toe wall portion, and a heel wall portion, and further, a) a wall portion in which the bottom wall portion is recessed upward in a dish shape. And b) its wall area, which is dished upwards, is provided with downward sloping surface means, said downward sloping surface means being provided when the bottom wall is in contact with the turf. In addition, since the turf which is inclined forward and upward with respect to the trajectory of the swing of the head comes into contact with the downward inclined surface means, an upward force is generated, The upward force acts to push the bottom wall and, by extension, the head upwards. , As a result drag resistance force is reduced, the more kinetic energy is to be transmitted to the ball, a golf club head.

Further, as described above, the bottom wall portion is formed with a dish-shaped recess 60 in the central portion thereof, since the projection portion 60 extending downward in the front-rear direction is formed. The wall area is
The preferred configuration is comprised of two dished recessed regions 162 and 164 located on opposite sides of the ridge 60. Each of the two recessed regions 162, 164 defines a portion of said downwardly sloping surface means (in the latter half of these recessed regions 162, 164), so that the above-mentioned pushing force is applied to the ridge 60. Occurs on both sides of the head, a lifting force balanced in the torsional rotation direction acts on the head.

If necessary, the bottom wall portion of the head for controlling the turf as described above can be integrally formed with the head portion other than the bottom wall portion by casting. That is, it is not always necessary to form the bottom wall portion and the other portion of the head separately, and then weld and join the bottom wall portion to the trailing edge portion of the opening defined in the other portion. It's not something. When integrally forming the bottom wall portion, a casting method can be adopted if a metal material is used, and a molding method can be adopted if a non-metal material is used.

Further, as is clear from the figure, 2 of each head
The two recesses are substantially symmetrical to each other with respect to a vertical plane 400 that extends in the front-rear direction of the head and bisects the ridge 60 vertically. See FIGS. 2 and 6 for this.

Furthermore, as also apparent from the figure, the respective downward faces of the two recesses are i) the respective rear regions 162d 'of the downward faces of the recesses.
And 164d ′ are inclined forward and upward with respect to the trajectory of the front swing of the head when the bottom wall of the head is in contact with the turf, ii) Therefore, the head moves forward along the swing trajectory. When they are swung to, the rear areas of the downward faces come into contact with the turf, thereby generating a balanced upward force, respectively, which upward force the bottom wall of the head, and thus the head. It has a feature that it is pushed up.

The bottom wall and / or other parts of the head may be made of materials other than metal, although titanium, such as titanium, may be used to make a particularly large head. It is preferable to use the metal material.

As used herein, the term "turf" refers to turf, grass, sand, soil, mud, etc. that may be moved by and in contact with the bottom wall of the head. It should be understood as meaning all that is present.

Now, FIG. 5 will be described. Recess 16
2 and 164 have their trailing edges 162e ′ and 16e.
4e ′ has a convex shape that bulges upward when the head is viewed from the rear. Chamfered surface 56 that is a flat surface
Similarly, the rear edge portion 56aa also has a convex shape that bulges upward as shown in FIG.
Are located approximately in the middle of the trailing edges 162e 'and 164e'. These convex shaped trailing edges 162e ', 1
As shown in FIG. 5, 64e ′ and 56aa extend in a row of arcs, and a V-shape is formed between two adjacent trailing edges. The above-mentioned upward force acts as shown by the vector 190 and the vector 191,
These upward forces are generated by the contact of the sloping rear region of the surface of the dish-shaped recess with the turf, as already mentioned. The vector 190 and the vector 191 are almost upward, but are inclined, and the heads of the vectors are inclined so as to approach each other.

Next, FIG. 7 will be described. This head further has the following features. i) The dish-shaped recesses 162 and 164 are formed at positions that are substantially mirror images of each other with respect to a vertical plane 400 that extends in the front-rear direction and vertically divides the ridge 60 into approximately two equal parts. ii) The gradually narrowed end portion of the rear region 162d ′ of the dish-shaped recess 162 intersects the sharp corner 210 defined by the chamfered surface 56, which is an inclined surface.
The gradually narrowed end portion of the rear region 164d 'of 4 intersects a sharp corner 211 defined by a chamfered surface 56, which is also an inclined surface. In addition, the boundary between the sharp corners 210 and 211 is a portion where the chamfered surface 56 intersects with the outer peripheral portion 213 of the bottom wall portion which is rounded and bulges out of the head.
The chamfered surface 56 is defined by the region where the lateral width of the rear end of the protrusion 60 intersects with the widened region, and the above is as shown in the drawing. The sharp corner 210 and the sharp corner 211 are
The distance from the face 28, which is the front wall of the head, is approximately equal to each other, and the chamfered surface 56 has two chamfers 162 and 164 in the rear regions 162 'and 16 of the respective recesses 162 and 164.
It is located in the center between 4 '. iii) The above-mentioned vertical plane 400 also divides the chamfered surface 56 into approximately two halves, so that the sharp corners 210 and 211 are located at substantially the same distance from the vertical plane 400. The vertical plane 400 further includes a rear area 213 of the head.
It also intersects with a.

The above characteristics also contribute to the generation of upward forces that are balanced with each other as described above.

Referring again to FIG. 2, as is apparent from the drawing, the illustrated particularly large large metal head has an outer peripheral contour line 3 when viewed from the direction directly facing the bottom wall portion.
00 is separated from the toe portion and the back surface of the head with a large gap from the dish-shaped recess 162 that is shallowly recessed. That is, as shown in the figure, the outer peripheral contour line 300 is separated from the recess 162 by a space S _{1 in} the toe portion of the head, and is separated from the recess 162 by a space S ₂ on the back surface of the head. The typical dimension of the spacing S ₁ is at least about 5/8 inch (about 16 mm), and its preferred dimension is, for example, about 3/4 inch to about 7/8 inch (about 19 mm to about 22 mm). Is. Also, the typical size of the spacing S ₂ is at least 1 inch (about 25 mm), and its preferred size is, for example, about 1 inch to about 1 and 3/8 inch (about 25 mm to about 35 mm). Each of these dimensions is a plane distance in a bottom view as seen from the direction directly facing the bottom wall portion as shown in FIG.

In the large size metal wood head, the relatively large spacings S ₁ and S ₂ serve to increase the strength required in a structure having a particularly thin wall thickness. The reason for this is that by increasing the distance between them, the wall portion of the head in the portion related to the distance comes to have a “tumble home”, which is an arcuate region that is largely swollen and inclined. Interval S ₁
And the wall portion 30 related to the space S _2.
See 2 and.

Further, when viewed from the direction of FIG. 2, the outer peripheral contour line 300 of the entire head and the chamfered shape surface 56 at the rear portion of the head.
The spacing S ₃ between and is at least three-quarter inches (about 19 m) for a particularly large large head as shown.
m), and the head surface 213c of the portion related to the distance S ₃ is inclined upward and outward from the chamfered surface 56 toward the contour line 300.

Further, in the particularly large large head shown, the area of the region encompassed by the outer peripheral contour line 300 is A when viewed from the direction of FIG. 2, and the dish-shaped recesses 162 and 164 are provided.
When the area of the region defined by the contour line defined by the ridge 60 and the chamfered surface 56 is B, A> 1.6
B is set. This defines one important characteristic, especially for large large heads, which is the element 16 associated with it.
That is, 2, 164, 60, and 56 are relatively localized with respect to the size of the outer circumference of the entire head. It is preferable that the relationship between A and B is 1.7> A / B> 2.0. Strength enhancement for thin-walled heads has been achieved by taking relatively large areas of the tumble home, which are indicated by reference numerals 301, 302, 213a, and further by reference numerals 305 and 306. It is as follows. As an example of typical head dimensions, the TH and FR dimensions shown in FIG. 10 are as follows, for example. TH (toe-heel direction length) = about 4 and 3/8 inch (about 111 mm) FR (front and rear direction length) = about 3 and 3/4 inch (about 95 mm)

The wall thickness of the upper wall and the rear wall of this head is about 0.055 inch (about 1.4 mm). Further, the wall thickness of the front wall portion is about 0.130 inch (about 3.3 mm) at its center portion, and becomes gradually thinner toward the heel side and toe side ends, and at the ends thereof, it is about 0. 110
It is inch (about 2.8 mm). The wall thickness of the sole is approximately 0.070 inch (1.8 mm).

By incorporating the present invention described above, it is possible to provide No. 1 to No. 7 metal woods having different front wall angles. Also, a set of those woods can be provided. The scope of the present invention includes such a set. Each head is
The center of gravity is positioned about 42% to about 50% from the bottom of the head height from the bottom head surface to the top head surface when the head is viewed from the front.

[Brief description of drawings]

FIG. 1 is a side view of a golf club head according to a preferred embodiment of the present invention viewed from the head front side.

2 is a bottom view of the golf club head of FIG. 1. FIG.

3 is a side view of the golf club head of FIG. 1 viewed from the toe side.

4 is a side view of the golf club head of FIG. 1 viewed from the heel side.

5 is a side view of the golf club head of FIG. 1 viewed from the back side of the head.

6 is a cross-sectional side view taken along line 6-6 of FIG.

7 is a cross-sectional side view taken along line 7-7 of FIG.

8 is a cross-sectional side view taken along line 8-8 of FIG.

9 is a cross-sectional side view taken along line 9-9 of FIG.

10 is a bottom view of the golf club head of FIG. 1, but before the sole plate is attached.

11 is a bottom view of a sole plate that fits into the bottom opening shown in FIG.

FIG. 12 is a partial cross-sectional view showing a dendritic rib structure.

FIG. 13 is a partial cross-sectional view showing a dendritic rib extending rearward from the front wall portion of the head.

FIG. 14 is a partial cross-sectional view showing a dendritic rib extending rearward and downward along the upper wall portion and the rear wall portion of the head.

15 is a perspective view of the golf club head of FIG. 1. FIG.

16 is a top view of the golf club head of FIG.

[Explanation of symbols]

 10 Golf Club 12 Shaft 14 Head 16 Shell-like Body 22 Bottom Wall (Sole Plate) 24 Upper Wall (Upper Surface) 26 Rear Wall (Back) 28 Front Wall (Face) 30 Heel 32 Toe 60 Protrusion 162 Dish-shaped recess 164 Dish-shaped recess 300 Perimeter contour line

Claims (35)

[Claims] 1. A shell-shaped body comprising a tow part,
A golf club head having a heel portion, a rear wall portion, a front wall portion defining a ball striking face, a top wall portion, and a bottom wall portion, wherein the bottom wall portion has a ridge portion at the center. In the bottom wall portion, two shallow dish-shaped concave portions are formed, and one concave portion of the two concave portions is formed between the protruding portion and the heel portion, The other concave portion is formed between the protruding portion and the toe portion, and the two concave portions are formed so as to be separated rearward from the front wall portion, and the one concave portion is substantially the heel. Has a circular arc-shaped peripheral portion that bulges toward the toe portion, and the other recessed portion has a circular arc-shaped peripheral portion that bulges toward the toe portion.
The two recesses are formed at positions that are substantially mirror images of each other with respect to a vertical plane that extends in the front-rear direction and divides the protrusion into substantially two halves. The outer peripheral contour line when viewed from the direction directly facing the part,
The golf club head is characterized in that the toe portion and the back surface of the head of the golf club head are spaced apart from the other of the two shallow dish-shaped recesses with a large distance. 2. The distance between the outer peripheral contour line of the toe portion and the other concave portion is at least about 5/8 inch (about 16 mm).
The described golf club head. 3. The distance between the outer peripheral contour line on the back surface of the head and the other recess is at least about 1.
The golf club head according to claim 1, wherein the golf club head has an inch (about 25 mm). 4. The lateral width of the protruding portion at the center of the bottom wall portion increases as it approaches the front wall portion between the front regions of the two dish-shaped recesses. Item 1. A golf club head according to item 1. 5. The bottom wall portion has a chamfered surface,
The chamfered surface extends beyond the rear region of the ridge between the rear regions of the two dish-shaped recesses and further ahead,
The golf club head according to claim 1, wherein the golf club head extends at an angle that extends rearward and upward. 6. The gap between the outer peripheral contour line and the chamfered surface on the back surface of the head when viewed from the direction directly facing the bottom wall portion is at least about 3/4 inch (about 19 inches).
mm), the golf club head according to claim 5. 7. A downward surface that is inclined upward and outward from the other dish-shaped recess toward the outer peripheral contour line when viewed from the direction directly facing the bottom wall portion. The golf club head according to claim 1, wherein 8. The area of the region encompassed by the outer peripheral contour line when viewed from the direction directly facing the bottom wall portion is A, and the area is 2
The golf club according to claim 5, wherein A> 1.6B, where B is an area of a region defined by one dish-shaped recess, the ridge and the chamfered surface. head. 9. The golf club head according to claim 8, wherein 1.7 <A / B <2.0. 10. The golf club head according to claim 1, wherein the two recesses each have a downward surface having a dish shape that is shallowly recessed upward. 11. The bottom wall portion is partially defined by a sole plate, and the sole plate is
The peripheral edge portion is joined to the boundary edge portion of the opening defined by the bottom wall portion, and the ridge portion and the two concave portions are partially defined by the sole plate. The golf club head according to claim 1, wherein: 12. The golf club head according to claim 1, wherein the surfaces of the two recesses are connected to both sides of the protrusion in an arc shape. 13. The golf club head according to claim 1, wherein a lower portion of the front wall portion is in front of the protrusion and the two recesses and has a U-shape. . 14. A substantially continuous hollow metallic tubular portion is disposed in the heel portion of the shell from near the upper wall of the shell to the bottom wall of the shell. The tubular portion has a hole for inserting a club shaft, the hole extending to the vicinity of the portion, and the hole is provided with the one of the two shallow dish-shaped concave portions. The golf club head according to claim 1, wherein the positions are aligned with each other. 15. The golf club head according to claim 10, wherein the downward surface is a concave surface in the front-rear direction. 16. The club head according to claim 15, wherein the downward surface is also concave in the heel-toe direction. 17. The bottom wall portion includes a sole plate, and the sole plate has a peripheral edge portion joined to an edge portion of a shell-like body that defines a bottom opening. 6. The golf club head according to claim 5, wherein most of the two recesses that are shallowly recessed define a region. 18. The bottom wall includes a sole plate, the sole plate having a peripheral edge joined to a shell edge defining a bottom opening, the sole plate comprising: Forming a majority region of the two recesses that are shallowly recessed, the sole plate further defining the ridge and the chamfered surface. Item 5. A golf club head according to item 5. 19. The bottom wall portion includes a sole plate, and the sole plate has a peripheral edge portion joined to an edge portion of a shell-like body that defines a bottom opening. Defining the majority of the region of the two shallow recesses, the shell being integral with the tubular portion,
Defining a bottom wall corner plate portion, the sole plate is also joined to the corner plate portion,
The said corner plate part forms a part of said one recessed part between the said protrusion part and the said heel part among the said two recessed parts which were made into the shallow depression. Golf club head. 20. A first group of thin, metal, shock-wave-dispersing dendritic ribs, the first group of dendritic ribs extending from the front wall portion. Extending substantially rearward along the lower surface of the upper wall portion of the shell-like body with the lower surface, and the plurality of dendritic ribs of the first group are shallowly recessed. The golf club head according to claim 1, wherein the golf club head is raised toward the two recesses. 21. A second group of a plurality of dendritic ribs, which are integral with and spaced apart from the upper wall portion, are included.
The plurality of dendritic ribs of the group extend substantially rearward and are connected to the rear wall portion defined by the shell-like body at the lower rear side, whereby the golf ball is provided with the front wall. The rearward load at the time of collision with the section is transmitted from the upper wall section, and the plurality of dendritic ribs of the second group are also projected toward the two shallow recesses. 21. The golf club head according to claim 20, wherein 22. The plurality of dendritic ribs of the first group,
22. The golf club head according to claim 21, wherein the golf club heads are separated from each other in the toe-heel direction, and the plurality of dendritic ribs of the second group are also separated from each other in the toe-heel direction. 23. A metal shell, which defines an upper wall portion, a bottom wall portion, a front wall portion, a rear wall portion, a toe wall portion, and a heel wall portion. In the golf club head, a) a plurality of dendritic ribs integrated with the inner surfaces of the upper wall portion and the rear wall portion; and b) a plurality of tree branches where the bottom wall portion is integrated with the upper wall portion. Has two dish-shaped walls curved upwards so as to bulge toward the ribs, the two dish-shaped walls being between the heel portion and the toe portion and spaced apart from each other, One of the two dish-shaped wall portions defines one recess that is relatively close to the toe portion, and the other dish-shaped wall portion is another recess that is relatively close to the heel portion. C), the golf club head has an outer peripheral contour line when viewed from a direction directly facing the bottom wall portion. A golf club head, wherein the toe portion and the back surface of the head of the buhead are spaced apart from the shallow recessed recess defined by the other dish-shaped wall portion with a large distance. 24. The ridge portion projects downwardly behind the front wall portion, and the ridge portion cooperates with the two recesses during a stroke of a golf club so that a turf is directed toward the two recesses. To guide them into the recesses, the recesses sloping their surfaces forward and upward so that a relatively rearwardly moving turf contacts the surfaces of the recesses. The contact between the surface of the concave portion and the turf generates an upward force on both sides of the ridge portion, thereby pushing up the bottom wall portion and thus the golf club head upward. The golf club head according to claim 1. 25. The center of gravity of the golf club head is about 42% to about from the bottom of the head height from the lowermost head surface to the uppermost head surface when the golf club head is viewed from the front. The golf club head of claim 5, wherein the golf club head is positioned at a height of 50%. 26. The golf club head according to claim 1, wherein the golf club head is made of a metal material containing titanium. 27. The golf club head according to claim 8, wherein most of the components are made of a metal material composed of titanium. 28. The minimum wall thickness of at least one of the walls forming the golf club head is less than or equal to about 0.060 inches (about 1.5 mm). The golf club head according to claim 26. 29. The wall thickness of the upper wall portion is about 0.055 inch (about 1.4 mm), and the minimum wall thickness of the front wall portion is about 0.130 inch (about 3.3 mm). About 0.110
The golf club head according to claim 1, wherein the golf club head has an inch (about 2.8 mm) or less. 30. A metal shell, the shell defining a toe portion, a heel portion, a rear wall portion, a front wall portion defining a ball striking face, a top wall portion, and a bottom wall. In the golf club head having a portion, the bottom wall portion has a wavy inclined surface localized within the first outer peripheral contour, and the wavy inclined surface is formed so as to come into contact with the turf. And the golf club head is formed so as to exert an upward force on the golf club head by contacting the turf, the golf club head being viewed from a direction directly facing the bottom wall portion. The second outer peripheral contour line, which is the entire outer peripheral contour line, is largely separated from the first outer peripheral contour line at least as it approaches the toe portion and the back surface of the head, and the shell of the golf club head is , The above The golf club head, characterized in that inclined upwardly outwardly while curving between the outer peripheral contour and said second outer circumferential contour. 31. When the area of the region included by the first outer peripheral contour line is B and the area of the region included by the second outer peripheral contour line is A, A> 1.6B. 31. The golf club head according to claim 30. 32. The golf club head of claim 31, wherein 1.7 <A / B <2.0. 33. The center of gravity of the golf club head is about 42% to about from the bottom of the head height from the lowermost head surface to the uppermost head surface when the golf club head is viewed from the front. The golf club head of claim 1, wherein the golf club head is positioned at a height of 50%. 34. A golf club headset comprising a plurality of golf club heads, each golf club head being the golf club head of claim 1. 35. The center of gravity of each golf club head is about 42% to about the bottom of the head height from the lowermost head surface to the uppermost head surface when the golf club head is viewed from the front. The golf club headset of claim 34, wherein the golf club headset is positioned at a height of 50%.