JPH08150231A - Golf club head and its production method - Google Patents

Abstract

PURPOSE: To provide a golf club head and its production method which stabilizes a ball flight direction as well as enables to reduce vibration and impact caused by hitting a ball. CONSTITUTION: In the golf club head, a core body 25 is filled in an outer shell 19 of a hollow head body 17. The core body 25 is formed from a material with low specific gravity of less than 0.5, and the core body 25 is composed of an outer layer 25a and an inner layer 25b with a lower specific gravity than the outer layer 25a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf club head and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, golf club heads called "wood" have been replaced with natural wood such as persimmons and cherry trees from the viewpoint of stability of quality and ease of material supply, as shown in FIG. The outer shell 3 of which is molded with a metal such as an aluminum alloy or a fiber reinforced resin such as carbon fiber or glass fiber, and a resin core material 5 is filled therein with no gaps, or the actual shell 63- As shown in Japanese Patent No. 154054 or FIG. 17, a resin layer 11 is provided on the inner surface of an outer shell 9 of a hollow head body 7, and a cavity 13 surrounded by the resin layer 11 is formed inside the head body 7. Known golf club heads and the like are known.

Thus, according to the golf club head shown in FIG. 16, the core material 5 absorbs vibrations and impacts at the time of hitting the ball, and the vibrations and impacts on the shaft 15 are damped. In the club head, the resin layer 11 is formed along the outer shell 9.
Since the weight of the head main body 7 is dispersed in the peripheral portion, the moment of inertia during the swing becomes large, and as a result, the directionality of the hit ball is stabilized.

[0004]

However, in the former golf club head shown in FIG. 16, since the core member 5 is uniformly filled in the outer shell 3, the weight of the head main body 1 is surrounded by the peripheral edge. However, there is a drawback in that the ball cannot be sufficiently dispersed in the part, and as a result, a large moment of inertia cannot be obtained during the swing, and the directionality of the hit ball is not stable.

On the other hand, in the conventional example shown in FIG. 17, although the weight of the head body 7 can be dispersed in the peripheral portion, the outer shell 9 is not filled with the resin layer 11 without a gap, so that a hit ball is hit. It has been pointed out that the resin layer 11 cannot sufficiently absorb and damp vibrations and shocks. The present invention has been devised in view of such circumstances, and provides a golf club head capable of stabilizing the directionality of a hit ball and at the same time damping vibrations and impacts generated at the time of hitting the ball, and a manufacturing method thereof. With the goal.

[0006]

In order to achieve such an object, the invention according to claim 1 is a golf club head in which a core material is mounted in the outer shell of a hollow head body.
3. The core material is formed of a low specific gravity material having a specific gravity of 0.5 or less, and the core material is composed of an outer layer portion and an inner layer portion made of a material having a smaller specific gravity than the outer layer portion.
The invention according to claim 1 is the golf club head according to claim 1, wherein the core material is made of a foamed synthetic resin or a synthetic resin mixed with a micro hollow body.

In the method of manufacturing the golf club head according to the third aspect, the cavity in the mold is filled with the material to form the inner layer portion of the core material to be mounted in the outer shell of the head body, and then, The inner layer portion is supported by a support in a separately prepared mold cavity, and the outer layer portion is formed on the outer periphery of the inner layer portion with a material having a larger specific gravity than the inner layer portion to form a core material having a specific gravity of 0.5 or less. After that, the core material is covered with an outer shell, and the invention according to claim 4 is the method for manufacturing a golf club head according to claim 3, wherein the support is placed in the cavity of the mold. It is characterized by being projected. The invention according to claim 5 is the method for manufacturing a golf club head according to claim 3, wherein the support is provided on the inner layer portion of the core material, and the invention according to claim 6 is The method for manufacturing a golf club head according to any one of claims 3 to 5, wherein the material forming the inner layer portion and the outer layer portion is a foamed synthetic resin or a synthetic resin containing a fine hollow body. To do.

Further, in the method of manufacturing a golf club head according to claim 7, the cavity in the mold is filled with a material to form the inner layer portion of the core material to be mounted in the outer shell of the head body, and then the head. The inner layer portion is supported by a support in the outer shell of the main body, and the outer layer portion is formed on the outer periphery of the inner layer portion with a material having a larger specific gravity than the inner layer portion, and the specific gravity is 0.5 or less in the outer shell of the head body. A core material is formed, and the invention according to claim 8 is the method for manufacturing a golf club head according to claim 7, characterized in that the support is provided so as to protrude from the outer shell of the head body. . A method for manufacturing a golf club head according to claim 9 is the method for manufacturing a golf club head according to claim 7 or 8, wherein the material for forming the inner layer portion and the outer layer portion is a synthetic resin foam or a fine resin. It is a synthetic resin containing a hollow body.

[0009]

In the golf club head according to the first and second aspects, the core material having a specific gravity of 0.5 or less is filled in the outer shell of the head body, and the outer layer portion having a larger specific gravity than the inner layer portion is the outer portion. Since the outer layer portion is arranged along the shell, the outer layer portion imparts a larger moment of inertia to the golf club head when hitting a ball.

Therefore, when a ball is hit with a golf club equipped with the above-mentioned golf club head, the weight of the head main body is dispersed in the peripheral portion, a large moment of inertia is obtained, and the ball flies with good directionality.
Also, vibration and impact due to impact are generated in the head body,
The core material absorbs such vibrations and shocks and attenuates the vibrations and shocks transmitted to the shaft.

According to the method of manufacturing a golf club head according to the third and subsequent aspects, the golf club head having the above-mentioned action can be easily manufactured.
According to the method of manufacturing the golf club head of claim 9, the specific gravity of the core material can be adjusted by changing the resin material used for the core material, the foaming state of the same resin, the mixing amount of the minute hollow bodies, and the like. Becomes

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 and 2 show a first embodiment of a golf club head according to claims 1 and 2, and in FIG.
Reference numeral 7 denotes a head main body in which a hollow outer shell 19 is molded from a fiber reinforced resin such as carbon fiber [specific gravity 1.2]. A hosel portion 21 is provided on the heel side of the hosel portion so as to project obliquely upward. A shaft 23 formed of a resin material such as metal or FRP is inserted into the shaft 21.

The outer shell 19 of the head main body 17 is filled with a core material 25 made of a low specific gravity material having a specific gravity of 0.5 or less without any gap. The core material 25 is surrounded by the outer layer portion 25a and the outer layer portion 25a. The inner layer portion 2 having a smaller specific gravity than the outer layer portion 25a
5b and. Thus, the material of the core material 25 used in this embodiment is a synthetic foam resin or a synthetic resin mixed with a hollow microbody, and examples of the synthetic foam resin include polyurethane, polystyrene, epoxy, acryl, vinyl chloride, and A.
Resin containing BS, EVA, etc., and mixed with micro hollow bodies is a thermosetting resin such as epoxy resin, unsaturated polyester resin, etc. dispersed with micro hollow bodies made of glass, phenol resin, epoxy resin, etc. A cellular foam material or the like that has been solidified is used.

Since these resin materials have different specific gravities, the outer layer portion 25a and the inner layer portion 25b may be formed by combining the respective resin materials, or the foamed state of the same resin or a minute hollow body. Since various specific gravities can be obtained by changing the mixing amount, the outer layer portion 25a and the inner layer portion 25b may be formed by changing the foaming state or the mixing amount of the minute hollow body, and any of these means. It may be selected as appropriate.

In addition, in the figure, reference numeral 27 denotes a columnar support, which is a support member for supporting the inner layer portion 25b in the mold in an embodiment of a method of manufacturing the head body 17 described later. Function as. Head body 17 according to the present embodiment
Is configured in this way, and the head body 17 is
It is manufactured as follows by the first embodiment of the manufacturing method according to claim 3, claim 5 and claim 6.

First, as shown in FIG. 3, in the space of the mold 33 formed by the cavity 29a of the upper mold 29 and the cavity 31a of the lower mold 31, from the filling port 35 provided in the upper mold 29. The raw material 25b 'of the foamed synthetic resin described above is filled and the inner layer portion 25b is injection-molded. At this time, the above-mentioned support 27 is the cavity 31 of the lower mold 31.
It is pre-inserted into the two insertion holes 37 provided in a, and when the inner layer portion 25b is molded by the mold 35, the support body 27 is integrally projected on the bottom portion of the inner layer portion 25b.

After molding the inner layer portion 25b in this manner, the lower mold 4 of the mold 39 separately prepared as shown in FIG.
The inner layer portion 25b is supported in the single cavity 41a through the support 27. It should be noted that the cavity 41a is provided with two insertion holes 43 into which the respective support bodies 27 can be inserted, and by inserting the respective support bodies 27 into the insertion holes 43, the inner layer portion 25b is provided between the inner layer portion 25b and the cavity 41a. It is designed to be supported with a gap.

Thereafter, the upper mold 45 is closed and the upper mold 45 is closed.
From the filling port 47 provided in the cavity 4 of the lower mold 41.
1a and the cavity 45a of the upper die 45 are filled with a raw material 25a 'of foamed synthetic resin, and the outer layer portion 25a is injection-molded around the inner layer portion 25b to form a core having a specific gravity of 0.5 or less. The material 25 is formed. Next, as shown in FIG. 5, a separate mold 49 is prepared, and the tip of the support 27 protruding from the core 25 is attached to the cavity 51 a of the lower mold 51.
They are respectively inserted into the two insertion holes 53 provided in. As a result, the core material 25 is supported with a gap corresponding to the thickness of the outer shell 19 between the core material 25 and the cavity 51a.

Then, the upper die 55 of the die 49 is closed,
A raw material 19 ′ of a fiber reinforced resin such as carbon fiber or glass fiber is injected from a filling port 57 provided in the upper mold 55 to injection-mold the outer shell 19. Similarly, when the upper mold 55 is closed. , Core material 25 and cavity 5 of upper mold 55
A gap corresponding to the thickness of the outer shell 19 is also formed between the outer shell 5 and the outer shell 5a.

In FIG. 5, reference numeral 58 denotes a pin which is inserted into the pin insertion hole 59 of the upper die 55, and when the outer shell 19 is injection-molded, the pin 58 is inserted into the pin insertion hole 59 and then the outside. After the shell 19 is molded, the pin 58 is removed from the outer shell 19 to form the shaft mounting hole 61 in the hosel portion 21. Then, after the raw material 19 'is cured, the head body 1 is removed from within the mold 49.
7 is taken out, the support 27 protruding from the sole portion of the head body 17 is cut, and the shaft 2 is inserted into the shaft mounting hole 61.
By inserting 3 into the golf club, a golf club having the head body 17 mounted thereon can be obtained.

Since the head body 17 shown in FIG. 1 is constructed in this way, when a ball is hit with a golf club equipped with the head body 17, a specific gravity of 0.
The core material 25 is filled with a light core material 25 of 5 or less.
Since the outer layer portion 25a having a larger specific gravity than the inner layer portion 25b is arranged along the outer shell 19, the weight of the head main body 17 is smaller than that of the conventional example of FIG. 16 in which the core material 5 is uniformly filled. A larger moment of inertia is obtained by being dispersed in the peripheral portion (outer shell 19), and the ball flies with good directionality.

Vibrations and impacts due to impact are generated in the head main body 17. The vibrations and impacts that are transmitted to the shaft 23 by the core material 25 filled in the outer shell 19 with no space therebetween absorb the vibrations and impacts. Attenuate. As described above, according to the golf club head of the present embodiment, a large moment of inertia is obtained at the time of hitting the ball so that the ball flies in a directional manner, and the core material 25 absorbs the vibration and the impact due to the hitting and the shaft 25 Since the vibration and shock transmitted to 23 are attenuated,
6 and FIG. 17, it is possible to solve the drawbacks of the conventional examples while having the advantages of the conventional example.

According to the first embodiment of the method of the present invention described above, it is possible to extremely easily manufacture the head main body 17 made of the fiber reinforced resin having the above-mentioned effect, and the resin used for the core material 25. The specific gravity can be adjusted by changing the material, changing the foaming state of the same resin, the mixing amount of the minute hollow bodies, and the like, which has the advantage that the specific gravity of the core material 21 is extremely easy to adjust.

6 to 8 show a second embodiment of the manufacturing method according to claim 3, claim 5, and claim 6, and in the first embodiment, the outer layer portion 25a of the core member 25 of the head body 17 and Although the inner layer portion 25b is injection-molded, in this embodiment, the outer layer portion of the core material is compression-molded.
The present embodiment will be described below with reference to the drawings. The same components as those in the first embodiment will be designated by the same reference numerals and the description thereof will be omitted.

First, similarly to the method described in FIG. 3 of the first embodiment, the inner layer portion 25b of the head body 17 is molded by the mold 33 as shown in FIG. After molding the inner layer portion 25b in this way, the inner layer portion 25b is wrapped with a raw material 25a 'of synthetic resin mixed with a micro hollow body, and these cavities 63a of a lower mold 63 separately prepared as shown in FIG. It is placed inside and the upper mold 65 is closed. Then, this is heated and compressed to cure the raw material 25a 'of the outer layer portion 25a, so that the core material 25 having a specific gravity of 0.5 or less is molded by the mold 67.

It should be noted that the support member 2 is provided in the cavity 63a.
Two insertion holes 69 into which 7 can be inserted are provided, and by inserting each support body 27 into the insertion holes 69, the raw material 25a 'enclosing the inner layer portion 25b is surely supported in the cavity 63a. It has become. Thus, after the core material 25 is molded by the mold 67 in this manner, the tip of the support 27 protruding from the core material 25 as shown in FIG. 5 is attached to the cavity 51a of the lower mold 51 as shown in FIG. Two insertion holes 53 provided in
Respectively, and then close the upper mold 55 and close the filling port 57.
A raw material 19 'of a fiber-reinforced resin such as carbon fiber or glass fiber is injected from the above to form the outer shell 19 by injection molding.

After the raw material 19 'is hardened, the head body 17 is taken out from the mold 49, the support 27 protruding from the sole portion of the head body 17 is cut, and the shaft 23 is inserted into the shaft mounting hole 61. By doing so, a golf club head equipped with the head body 17 is obtained. The golf club head manufacturing method according to the present embodiment is configured in this manner, and even if the head body 17 manufactured in this embodiment is mounted and a ball is hit, the outer shell 19
A light core material 25 with a specific gravity of 0.5 or less is filled inside,
In the core material 25, the outer layer portion 25a having a larger specific gravity than the inner layer portion 25b is arranged along the outer shell 19, so that the core material 5
In comparison with the conventional example of FIG. 16 in which the balls are uniformly filled, the weight of the head main body 17 is dispersed more in the peripheral portion, a large moment of inertia is obtained, and the ball flies with good directionality.

Vibrations and impacts due to impact are generated in the head main body 17, and the vibrations and impacts transmitted to the shaft 23 by the core material 25 absorbing the vibrations and impacts are attenuated.
As described above, also with the head body 17 manufactured by the manufacturing method according to the present embodiment, a large moment of inertia is obtained at the time of hitting the ball, and the ball flies with good directionality.
Since the core material 25 sufficiently absorbs the vibration and the shock caused by the impact, the vibration and the shock transmitted to the shaft 23 are attenuated.
Also, it is possible to solve the drawbacks of the conventional examples shown in FIG.

Also according to the second embodiment of the method of the present invention, the head main body 17 made of fiber reinforced resin having the above effects.
Can be manufactured very easily, and the core material 2
The specific gravity of the core material 21 is extremely easy to adjust, such as the specific gravity can be adjusted by changing the resin material used for No. 5 or changing the foaming state of the same resin or the mixing amount of the minute hollow bodies.

9 to 11 show an embodiment of a method of manufacturing a golf club head according to claim 3, claim 4 and claim 6, and in this embodiment, as shown in FIG.
A head plate 75 made of a fiber-reinforced resin according to a second embodiment of claim 1 and claim 2 in which a sole plate 73 is attached to the outer shell 77 of the head plate 75 as described below. Compression molded.

In the outer shell 77, the same resin material as the core material 25 of the head main body 17 shown in FIG. 1 is used, and the core material composed of the outer layer portion 79a and the inner layer portion 79b has a specific gravity of 0.5 or less. 79 is installed without a gap. Thus, the head main body 75 is manufactured by one embodiment of the manufacturing method according to claims 3, 4 and 6 described below.

First, as shown in FIG. 9, from the filling port 87 provided in the upper mold 81 into the space of the mold 85 formed by the cavity 81a of the upper mold 81 and the cavity 83a of the lower mold 83. A raw material 79b 'of foamed synthetic resin is filled and the inner layer portion 79b is injection-molded. The cavity 8
Two protrusions 89 are provided on 3a. When the inner layer portion 79b is molded by the mold 85, two insertion holes 9 are formed in the bottom portion.
0 is formed.

After molding the inner layer portion 79b in this way, the inner layer portion 79b is placed in the cavity 93a of the lower die 93 of the die 91 separately prepared as shown in FIG. Two support bodies 95 that can be inserted into the insertion holes 90 are provided in a protruding manner. When the support bodies 95 are inserted into the insertion holes 90, the inner layer portion 79b is supported with a gap between it and the cavity 93a. It is like this.

Thereafter, the upper mold 97 is closed and the upper mold 97 is closed.
The raw material 79a 'of the foamed synthetic resin is filled into the space formed by the cavities 93a, 97a of the two molds 93, 97 from the filling port 99 provided in the mold, and the outer layer portion 79a is injected around the inner layer portion 79b. By molding, the core material 79 having a specific gravity of 0.5 or less is molded. Then, at this time, the insertion hole 101 that matches the shape of the support 95 is formed in the bottom portion of the core material 79.

Then, as shown in FIG.
5, the sole plate 73 on which the protrusion 103 having the same shape as that of the mold 5 is formed is disposed in the cavity 107a of the lower mold 107 of the mold 105 separately prepared, and the insertion hole 101 is formed.
The core material 79 except the opening is covered with an unmolded fiber reinforced resin sheet such as carbon fiber or glass fiber. And
Inserting the protrusion 103 of the sole plate 73 into the insertion hole 101, disposing the core material 79 covered with the fiber reinforced resin sheet on the sole plate 73, closing the upper mold 109, and heating and compressing it. The head body 75 is molded by compression molding the outer shell 77.

After the fiber reinforced resin sheet is cured, the head main body 75 is taken out from the mold 105, and the shaft is inserted into the molded hosel portion 110 to obtain a golf club with the head main body 75 mounted. Becomes The head main body 75 according to this embodiment is manufactured in this way, and when a ball is hit with a golf club equipped with the head main body 75, the head main body 1 according to each of the above embodiments is produced.
Similar to 7, a light core material 79 with a specific gravity of 0.5 or less inside the outer shell 77
Since the outer layer portion 79a having a larger specific gravity than the inner layer portion 79b is arranged along the outer shell 77, the weight of the head main body 75 is smaller than that of the conventional example of FIG. The ball is further dispersed in the peripheral portion, a large moment of inertia is obtained, and the ball flies with good directionality.

Vibrations and impacts due to impact are generated in the head main body 75, and the vibrations and impacts transmitted to the shaft by the core material 79 absorbing such vibrations and impacts are attenuated. In this way, the head body 7 manufactured by the manufacturing method of the present embodiment.
5, also a large moment of inertia is obtained at the time of hitting the ball so that the ball flies in a directional manner, and the vibration and impact due to the impact are sufficiently absorbed by the core material 79 and the vibration and impact transmitted to the shaft are attenuated. , As in the above embodiments,
It is possible to achieve the intended purpose.

Also by the above-described embodiment of the method of the present invention, it is possible to extremely easily manufacture the head main body 75 made of fiber reinforced resin having the above effects, and
Specific gravity can be adjusted by changing the resin material used for the core material 79, changing the foaming state of the same resin, the mixing amount of the minute hollow bodies, and the like, and it is also very easy to adjust the specific gravity of the core material 79.

FIG. 12 shows a third embodiment of the golf club head according to claims 1 and 2, and in the figure, 111
Is a head body in which a hollow outer shell 113 is formed of a metal such as a magnesium alloy [specific gravity 1.8] or an aluminum alloy [specific gravity 2.7]. The outer shell 113 is a face portion or a back portion except for a sole portion. Outer shell body 1 integrally molded with
13a and a sole portion 113b welded to the sole side thereof
And are made of the same material.

A hosel portion 115 is provided obliquely upward on the heel side of the outer shell body 113a, and a shaft formed of metal or FRP is inserted into the shaft mounting hole 117 of the hosel portion 115. It has become so.
The shaft mounting hole 117 communicates with the inside of the hollow outer shell 113, and the shaft mounting hole 117 also functions as a filling port for the resin material, as described later.

Then, in the outer shell 113 of the head body 111, a core material 119 made of a low specific gravity material and having a specific gravity of 0.5 or less.
The core material 119 is also configured with an outer layer portion 119a and an inner layer portion 119b surrounded by the outer layer portion 119a having a smaller specific gravity than the outer layer portion 119a. Thus, as the material of the core material 119 used in this embodiment, the same foam synthetic resin as that in each of the above-mentioned embodiments or a synthetic resin containing a minute hollow body is used. Since these materials have different specific gravities, as described above, different materials are combined to form the outer layer portion 119.
a and the inner layer portion 119b may be formed, or various specific gravities can be obtained by changing the foaming state of the same resin or the mixing amount of the micro hollow body. The outer layer portion 119a and the inner layer portion 119b may be formed by changing the amount of body mixture and the like, and the selection is arbitrary.

In addition, in the figure, 121 is an outer shell body 113a.
Is a columnar support member integrally formed on the inner surface of the top side of the support member 121. The support member 121 is a support member that supports the inner layer portion 119b in the outer shell 113 in the embodiment of the method for manufacturing the head body 111 described later. Function as. The head main body 111 according to this embodiment is configured in this way, and the head main body 111 is manufactured by the first embodiment of the invented method according to claims 7 to 9 described below.

As shown in FIG. 13, the hollow outer shell 113 is manufactured by casting the outer shell main body 113a and the sole portion 113b in separate molds and then welding them together. Prior to welding, the inner layer portion 119b is held in the outer shell body 113a with a certain gap therebetween via the above-mentioned support 121. Although not shown, the inner layer portion 119
b is also the same as the inner layer portions 25b and 79b of the respective embodiments described above,
It is separately injection-molded by using a mold, and the insertion hole 123 of the support 121 is formed in the upper part thereof.

Thereafter, as shown in FIG. 12, the outer shell body 1
13a is welded to the sole portion 113b, and the raw material 119 made of foamed synthetic resin is put into the outer shell 113 through the shaft mounting hole 117.
The outer layer portion 119 is filled around the inner layer portion 119b with a '.
a core material 11 having a specific gravity of 0.5 or less by injection molding a
Mold 9. Then, after the raw material 119a 'is cured, a shaft (not shown) is attached to the shaft attaching hole 117 to obtain a golf club having the head main body 111 attached thereto.

A metal head body 111 according to this embodiment.
Is configured in this way, the head body 11
When a ball is hit with a golf club equipped with No. 1, a light core material 119 having a specific gravity of 0.5 or less is installed in the outer shell 113, and the core material 119 has an outer layer portion 119a having a larger specific gravity than the inner layer portion 119b. 16 are arranged along the outer shell 113, the weight of the head main body 111 is more dispersed in the peripheral portion than in the conventional example of FIG. 16, and a large moment of inertia is obtained, so that the ball flies with good directionality. Becomes

Also in this embodiment, vibrations and impacts due to striking are generated in the head body 111. The core material 11 filled with such vibrations and impacts in the outer shell 113 without any gaps.
9 absorbs the vibration and shock transmitted to the shaft. As described above, also with the golf club head according to the present embodiment, a large moment of inertia is obtained at the time of hitting the ball so that the ball flies in a directional manner, and the core material 119 absorbs vibration and impact due to hitting and the shaft is absorbed by the shaft. Since the transmitted vibrations and shocks are attenuated, the advantages of the conventional example shown in FIG. 16 and FIG.

According to the embodiment of the method of the present invention described above, it is possible to extremely easily manufacture the metal head body 111 having the above-mentioned effects, and the core material 119 is manufactured.
The specific gravity of the core material 119 can be adjusted very easily, for example, the specific gravity can be adjusted by changing the resin material used for the above, changing the foaming state of the same resin, the mixing amount of the minute hollow bodies, and the like.

FIG. 14 shows a fourth embodiment of the golf club head according to claims 1 and 2, and in the drawing, 125
Is a head body in which a hollow outer shell 127 is formed, and the outer shell 127 is an outer shell body 127a formed of a metal such as a magnesium alloy [specific gravity 1.8] and a sole plate attached to the sole side thereof. As shown in FIG. 15, the sole portion of the outer shell body 127a includes a metal having a larger specific gravity than the outer shell body 127a (for example, stainless steel [specific gravity 7.8], copper alloy [specific gravity 7]. .8-
8.9], nickel alloy [specific gravity 8.7], and titanium [specific gravity 4.5 to 4.6]) formed sole plate 127.
The fitting hole 129 of b is provided.

The fitting hole 129 is formed in a slightly undercut shape, and a flange 131 for bolting the sole plate 127b is formed at the peripheral edge of the opening, and the sole plate 127b is formed in the fitting hole 129. After press-fitting, this is attached to the outer shell body 127a with an adhesive and then fixed with screws 133. A hosel portion 135 is provided on the heel side of the outer shell body 127a so as to project obliquely upward, and a shaft is attached to a shaft mounting hole 137 provided in the hosel portion 135.

In the outer shell 127 of the head body 125, a core material 139 made of a low specific gravity material and having a specific gravity of 0.5 or less is similarly mounted without a gap, and the core material 139 also has an outer layer portion 139a. Surrounded by this, the inner layer portion 139b has a smaller specific gravity than the outer layer portion 139a. Thus, as the material of the core material 139 used in this embodiment, the same foam synthetic resin as that in each of the above-mentioned embodiments or a synthetic resin containing a minute hollow body is used. Since these materials have different specific gravities as described above, different materials may be combined to form the outer layer portion 139a and the inner layer portion 139b.
Further, since various specific gravities can be obtained by changing the foaming state of the same resin or the mixing amount of the minute hollow bodies, the outer layer portion 139 is changed by changing the foaming state of the same resin or the mixing amount of the minute hollow bodies.
You may form a and the inner layer part 139b.

In addition, in the figure, 141 is an outer shell body 127a.
Is a columnar support body formed on the inner surface of the top side, and the support body 141 also functions as a support member for supporting the inner layer portion 139b in the outer shell 127 in the embodiment of the method of manufacturing the head body 125 described later. To do. Head body 1 according to the present embodiment
25 is configured in this way, and the head main body 12
5 is manufactured by the second embodiment of the invention method according to claims 7 to 9 described below.

That is, after the outer shell body 127a and the sole plate 127b are cast by a mold, the sole plate 127b
Is attached to the outer shell body 127a to form the outer shell 127. Prior to attaching the sole plate 127b, first, the inner layer portion 139b is opened in the outer shell body 127a via the support body 141 described above. Hold. still,
Although not shown, the inner layer portion 139b is also separately injection-molded using a mold, and the support body 141 is formed on the upper portion thereof.
Insertion hole 143 is formed.

Thereafter, the inner layer portion 139b is covered with a raw material 139a 'made of synthetic resin containing a minute hollow body, and the sole plate 127b is attached to the outer shell body 127a.
Then, these are heated at, for example, about 100 ° C.
The core material 139 having a specific gravity of 0.5 or less is molded in the outer shell 127 by hardening 39a '. And raw material 13
After hardening 9a ', a shaft (not shown) is attached to the shaft attachment hole 137 to remove the head body 12
A golf club equipped with No. 5 will be obtained.

A metal head body 125 according to this embodiment.
Is configured in this way, the head body 12
When a ball is hit with a golf club equipped with 5, the sole plate 127b lowers the center of gravity of the head body 125,
Of course, the outer layer portion 139a having a larger specific gravity than the inner layer portion 139b.
Are arranged along the outer shell 127 of the head main body 125, a larger moment of inertia is obtained as compared with the above embodiments, the head speed is increased, and the ball flies with good directionality.

Also in this embodiment, vibrations and impacts due to impact are generated in the head body 125. The core material 13 filled with such vibrations and impacts in the outer shell 127 without any gaps.
The vibration and shock transmitted to the shaft by 9 are attenuated. As described above, also with the golf club head according to the present embodiment, a large moment of inertia is obtained at the time of hitting the ball so that the ball flies in a directional manner, and the core material 139 absorbs the vibration and the shock due to the hitting and the shaft is absorbed by the shaft. Since the transmitted vibrations and shocks are attenuated, the advantages of the conventional example shown in FIG. 16 and FIG.

The metal head body 125 having the above-mentioned effect is obtained by the embodiment of the method of the present invention.
Can be manufactured very easily, and the core material 13
The specific gravity can be adjusted by changing the resin material used for No. 9, the foaming state of the same resin, the mixing amount of the minute hollow bodies, and the like.

In each of the above-mentioned embodiments, the entire circumference of the inner layer portion is covered with the outer layer portion. However, for example, the bottom portion of the inner layer portion is brought into contact with the sole portion of the outer shell or the inner surface of the sole plate to cover the bottom portion. It is also possible to use a golf club head in which the periphery of the removed inner layer portion is covered with the outer layer portion. Thus, even with the golf club head having such a structure, the intended purpose can be achieved as in the above-described embodiments.

Furthermore, although the present invention and the method of the present invention are applied to the wood golf club head in each of the above embodiments, it is needless to say that the present invention can be applied to an iron club head. In the core material of the present invention, it is preferable that the outer layer portion has a specific gravity of 0.5 or less and the inner layer portion has a specific gravity of 0.2 or less to increase a difference in specific gravity between the two and obtain a larger moment of inertia.

[0059]

As described above, according to the golf club heads of the first and second aspects, a large moment of inertia is obtained at the time of hitting the ball, and the ball flies with good directionality.
At the same time, there is an advantage that vibration and impact due to impact are reduced by the core material and vibration and impact transmitted to the shaft are damped.

According to the method for manufacturing a golf club head described in claims 3 and below, it is possible to easily manufacture a golf club head having the above effects. or,
According to the golf club head and the manufacturing method thereof according to claims 2, 6 and 9, it is possible to change the resin material used for the core material, the foaming state of the same resin, the mixing amount of the minute hollow bodies, and the like. There is an advantage that the specific gravity of the core material can be adjusted very easily, for example, the specific gravity can be adjusted with.

[Brief description of drawings]

FIG. 1 is a sectional view of a head body in a first embodiment of a golf club head according to claims 1 and 2.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a cross-sectional view of a mold showing a manufacturing process of an inner layer portion in the first embodiment of the method for manufacturing a golf club head according to claims 3, 5 and 6;

FIG. 4 is a cross-sectional view of a mold showing the manufacturing process of the outer layer portion in the first embodiment of the method for manufacturing a golf club head according to claims 3, 5 and 6;

FIG. 5 is a cross-sectional view of a mold showing a manufacturing process of an outer shell in the first embodiment of the method for manufacturing a golf club head according to claims 3, 5 and 6;

FIG. 6 is a cross-sectional view of a mold showing a manufacturing process of an inner layer portion in a second embodiment of the method for manufacturing a golf club head according to claims 3, 5 and 6;

FIG. 7 is a cross-sectional view of a mold showing a manufacturing process of an outer layer portion in a second embodiment of the method for manufacturing a golf club head according to claims 3, 5 and 6;

FIG. 8 is a cross-sectional view of a mold showing a manufacturing process of an outer shell in a second embodiment of the method for manufacturing a golf club head according to claim 3, claim 5, and claim 6;

FIG. 9 is a cross-sectional view of a mold showing a manufacturing process of an inner layer portion in an embodiment of the method for manufacturing a golf club head according to claims 3, 4 and 6;

FIG. 10 is a cross-sectional view of a mold showing a manufacturing process of an outer layer portion in an embodiment of a method for manufacturing a golf club head according to claims 3, 4 and 6;

FIG. 11 is a cross-sectional view of a mold showing a manufacturing process of an outer shell in an embodiment of the method for manufacturing a golf club head according to claims 3, 4 and 6;

FIG. 12 is a sectional view of a head main body in a third embodiment of the golf club head according to claims 1 and 2;

FIG. 13 is an exploded cross-sectional view of the outer shell showing a state in which the inner layer portion is held by the outer shell main body in the first embodiment of the method for manufacturing a golf club head according to claims 7 to 9.

FIG. 14 is a sectional view of a head main body in a fourth embodiment of the golf club head according to claims 1 and 2;

FIG. 15 is an exploded cross-sectional view of the outer shell showing the manufacturing process of the outer layer portion in the second embodiment of the method for manufacturing a golf club head according to claims 7 to 9.

FIG. 16 is a cross-sectional view of a conventional golf club head.

FIG. 17 is a cross-sectional view of another conventional golf club head.

[Explanation of symbols]

 17, 75, 111, 125 Head body 19, 77, 113, 127 Outer shell 23 Shaft 25, 79, 119, 139 Core material 25a, 79a, 119a, 139a Outer layer portion 25b, 79b, 119b, 139b Inner layer portion 27, 95 , 121, 141 support 29, 45, 55, 65, 81, 97, 109 upper mold 31, 41, 51, 63, 83, 93, 107 lower mold 33, 39, 49, 67, 85, 91, 105 mold 71 sole part 73, 127b sole plate 89 protrusion 129 fitting hole 131 tsuba

Claims (9)

[Claims] 1. A golf club head in which a core material is mounted inside the outer shell of a hollow head body, wherein the core material is
A golf club head, characterized in that it is formed of a low specific gravity material having a specific gravity of 0.5 or less, and the core material is composed of an outer layer portion and an inner layer portion made of a material having a smaller specific gravity. 2. The golf club head according to claim 1, wherein the core material is made of a foamed synthetic resin or a synthetic resin mixed with a fine hollow body. 3. Filling a cavity in a mold with a material,
Form the inner layer of the core material to be installed in the outer shell of the head body,
Next, the inner layer portion is supported by a support in a cavity of a separately prepared mold, and the outer layer portion is formed on the outer periphery of the inner layer portion with a material having a larger specific gravity than the inner layer portion to form a core material having a specific gravity of 0.5 or less. A method for manufacturing a golf club head, characterized in that after molding, the core material is covered with an outer shell. 4. The method of manufacturing a golf club head according to claim 3, wherein the support is provided so as to project into the cavity of the mold. 5. The method of manufacturing a golf club head according to claim 3, wherein the support is provided so as to protrude from the inner layer portion of the core material. 6. The golf club head according to claim 3, wherein the material forming the inner layer portion and the outer layer portion is a foamed synthetic resin or a synthetic resin containing a minute hollow body. Manufacturing method. 7. A cavity is filled with a material in a mold,
Form the inner layer of the core material to be installed in the outer shell of the head body,
Then, the inner layer portion is supported by a support in the outer shell of the head body, and the outer layer portion is formed on the outer circumference of the inner layer portion with a material having a larger specific gravity than the inner layer portion to form a specific gravity of 0. 5
The following core material was shape | molded, The manufacturing method of the golf club head characterized by the above-mentioned. 8. The method of manufacturing a golf club head according to claim 7, wherein the support is provided so as to protrude from the outer shell of the head main body. 9. The method for manufacturing a golf club head according to claim 7, wherein the material for forming the inner layer portion and the outer layer portion is a foamed synthetic resin or a synthetic resin containing a minute hollow body. .