JPH11276647A - Putter head or iron head of golf club and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smooth the rolling of a ball and to stabilize the directivity of the hit ball as the feel transferred to hands at the time of hitting the ball is soft and the hitting sound is light and has the timbre resembling the timbre of wood and the contact time between the ball and the clubface is long at the time of hitting the ball. SOLUTION: This head consists of <=0.25% C, <=0.30% O and the balance titanium and inevitable impurities. In addition, the putter head or the iron head of the golf club has the clubface comprising a porous titanium sintered compact having a relative density of 78 to 95% and a Young's modulus of 50 to 97 GPa. The head described above is formed by applying a molding pressure of 1.0 to 5.0 t/cm<2> on titanium powder having an average grain size of 50 to 180 μm and subjecting this powder to sintering under a vacuum for 20 to 180 minutes in a temp. region of 1,100 to 1,250 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf club using a titanium powder having high specific strength and excellent corrosion resistance as a raw material and using a porous titanium sintered body produced by vacuum sintering after molding in at least a face portion. With respect to the putter head and the iron head, a putter head or an iron head using a titanium sintered body that has a soft touch transmitted to the hand when hitting a ball, and that can smoothly roll the ball and stabilize the directionality of the hit ball. The present invention relates to the manufacturing method.

[0002]

2. Description of the Related Art Titanium has a high specific strength and is excellent in corrosion resistance.
In recent years, it has also been widely used for familiar articles such as wares and living body members. However, titanium is inferior in machinability such as cutting, so that cutting and forging have been devised to minimize the cutting work. In the case of complex-shaped products, a method of forming into an article by powder metallurgy capable of near net shaping has been adopted. I have been. Titanium, on the other hand, has a problem that it reacts very easily with oxygen at high temperatures, and oxidized titanium has a problem that its toughness is remarkably reduced. In particular, titanium powder cannot be sintered unless it is sintered in vacuum. Was.

In recent years, there have been golf drivers and iron heads as sporting goods that take advantage of the high specific strength of titanium. In particular, a titanium driver has a high specific strength, so that the head volume can be increased, and a high inertia moment can be obtained.
The product is popular because it extends 20 yards, has a wide sweet spot, and improves the direction of the ball.

On the other hand, the weight occupied by the putter in the golf score has reached about 40%, and the key to shortening the score has conventionally been considered to be the putter. Conventionally,
Brass, brass, stainless steel, etc. have been used as the head material. Recently, aluminum alloys or titanium alloys have been used for the putter head material to increase the size of the head,
Alternatively, the inertia moment can be increased, or a weight such as W can be buried in the toe portion and the heel portion of the putter head to improve the weight distribution of the head and to make the rotation of the ball smooth. -A head has been proposed.

[0005] Similar to the putter described above, an approach shot from around the green is emphasized. For this approach shot, a specially designed iron has already been developed, and special processing is applied to the face part to increase the amount of spin given to the ball, and a soft material such as copper or resin is used for the face part Various irons have been proposed. Incidentally, Japanese Patent Application Laid-Open
Japanese Patent Publication No. 329236 discloses a golf club head having a ball striking surface formed of copper, and Japanese Patent Publication No. 2-55059 proposes a product using an ABS resin or an ionomer resin which is an amorphous polymer. ing.

[0006]

However, the greens at the golf course are not smooth and have a difference in height, and the grass of the greens has a regular eye and a reverse eye, so that the ball is not a ball. Or the rolling distances are different. In addition, when hitting a ball, considerable tension is involved, so the shot is often taken or the cup is overturned. Under such circumstances, the conventional putter head is composed of a solid body using brass, brass, or stainless steel, and it is difficult to control a delicate distance by putting under tension.

Also, in recent years, golf balls have been changed to 2-piece balls, which have a longer flight distance from thread-wound balls. Therefore, a pattern comprising a head made of a soft material such as aluminum or titanium has been developed. Although these materials have been used in some parts, these materials are also composed of solid bodies, and it is difficult to control the delicate distance, and it is not enough to absorb vibration and the ball rolls smoothly. Did not.

On the other hand, when constructing a golf course that requires a large site area, it is difficult to secure sufficient land. To compensate for this, particularly in recent golf courses, it is called a pond or a bunker. Some have proposed to diversify the sand area and propose the difficulty of changing to distance. This tendency is remarkable around the green, and the importance of approach shots, such as over bunkers and turret-like greens, is increasing.

A conventional approach club head is made of soft iron, stainless steel, or the like, and is generally made of the same material as the medium- and long-distance iron heads, except that only the head angle called a loft angle is increased. there were. In this situation, it is difficult to control delicate distances and achieve a stable direction in tension. Therefore, recently, in order to realize a delicate distance and control, an iron head for approach using a soft material such as copper or resin on the face surface of the club head has been proposed. However, unlike the putter, the iron head for approach, which often makes full shots, is severely abraded with copper or resin and has a problem in terms of life. Further, copper or resin did not absorb vibration sufficiently, and delicate distance control and directional stability were not sufficient.

In the present invention, a titanium powder is used as a raw material, and a porous titanium sintered body having excellent flexibility and excellent vibration damping properties is formed on at least the face surface.
The feel transmitted to the hand when hitting is soft and the delicate distance is easy to control, and the contact time between the face surface and the ball becomes longer when hitting, the rotation of the ball is smooth and the directionality of the hitting ball can be stabilized A golf club putter head or iron head is provided, and a method of manufacturing the same is provided. .

[0011]

The gist of the present invention is that the relative density produced from titanium powder as a raw material is 7%.
A putter head or iron head for a golf club, wherein a porous titanium sintered body having a modulus of 8 to 95% and a Young's modulus of 50 to 97 GPa is formed on at least the face surface.

Also, a titanium powder having an average particle size of 50 to 180 μm is filled into a mold having a recess having a predetermined shape.
A molding pressure of 0 to 5.0 t / cm 2 is applied to form a titanium powder compact, and then at a temperature of 1100 to 1250 ° C. for 20 minutes to
By sintering for 180 minutes under a vacuum of 10 -3 to 10 -6 Torr, at least the face surface has a chemical composition of C:
0.25% or less, O: 0.30% or less, the balance being titanium and unavoidable impurities, and a relative density of 78 to 9
A golf club pattern comprising a porous titanium sintered body having a modulus of 5% and a Young's modulus of 50 to 97 GPa.
This is a method for manufacturing a head or an iron head.

In the above, the average particle size of the titanium powder is 5
The reason for setting the particle size to 0 to 180 μm is that the finer the titanium powder, the higher the density of the sintered body becomes. If the titanium powder is less than 50 μm, the relative density easily exceeds 95%. This is because the pores existing in the ball become large, and a uniform porous sintered body cannot be obtained, the vibration damping is slow, the feel at impact becomes dull, and the directionality of a stable ball at the time of hitting cannot be obtained.

The reason why the chemical composition of the porous titanium sintered body is C: 0.25% or less and O: 0.30% or less is as follows.
When the contents of C and O are increased, the tensile strength and proof stress of the porous titanium sintered body become too high, so that a flexible sintered body cannot be obtained, and a stable ball direction at the time of hitting the ball cannot be obtained. This is because the hitting sound also becomes hard.

The reason why the relative density of the porous titanium sintered body is set to 78 to 95% is that when the relative density of the porous titanium sintered body decreases, the strength such as tensile strength decreases, and
%, The strength and wear resistance required for a putter head or iron head cannot be obtained. Conversely, if the relative density is too high, a flexible porous sintered body cannot be obtained,
Since the vibration damping characteristics are poor, the feel when hitting the ball is hard, the contact time between the ball and the face surface is short when hitting, and the directional stability of the ball is poor, the upper limit is set to 95%. The upper limit is more preferably 93%.

The reason for setting the Young's modulus to 50 to 97 GPa is that when the Young's modulus of the porous titanium sintered body is low, it is difficult to transmit necessary rotational force to the ball at the time of hitting the ball, and a sufficient distance cannot be obtained. The lower limit was set to 50 GPa. Also,
If it exceeds 97 GPa, a flexible porous titanium sintered body cannot be obtained, the hitting sound is heavy, and the distance control becomes difficult.

In manufacturing a putter head or an iron head comprising a porous titanium sintered body on at least the face surface, the titanium powder having the above average particle size is filled into a mold having a recess having a predetermined shape. .0
A molding pressure of 5.0 t / cm2 is applied to form a titanium powder compact, and then in a temperature range of 1100 to 1250 ° C for 20 minutes to
Sintering is performed for 180 minutes under a vacuum of 10 -3 to 10 -6 Torr so that the relative density is 78 to 95% and the Young's modulus is 50 to 97G.
A porous titanium sintered body made of Pa can be obtained.

In the above, the molding pressure for the titanium powder was set to 1.0 to 5.0 t / cm 2 because the molding pressure was 1.
If it is less than 0 t / cm 2, the titanium powder compact is easily broken when it is removed from the mold after the molding, and the titanium powder compact is chipped or broken during transportation to the vacuum sintering furnace, and the relative density is 78%. This is because the above porous titanium sintered body cannot be obtained. The molding pressure is 5.0t
/ Cm2, the relative density of the porous titanium sintered body becomes 9
If it exceeds 5%, a flexible porous titanium sintered body cannot be obtained.

Further, the sintering temperature in the temperature range of 1100 ° C. to 1250 ° C. in vacuum sintering of the titanium powder compact is that when the sintering temperature is lower than 1100 ° C., the strength and strength required for a putter head or an iron head are obtained. A porous titanium sintered body having wear resistance cannot be obtained. Also, 12
If it exceeds 50 ° C., the upper limit of the relative density of the sintered body is 95%.
Beyond.

When the degree of vacuum is set to 10 -3 to 10 -6 Torr, if the pressure is less than 10 -3 Torr, oxygen penetrates into the porous titanium sintered body, and the strength increases more than necessary due to an increase in the amount of oxygen. However, a flexible porous titanium sintered body cannot be obtained.
Further, it is uneconomical to use a high vacuum exceeding 10 -6 Torr.

As described above, at least the face surface of the putter head or iron head of the golf club of the present invention is formed using soft titanium powder having a predetermined particle size at a low molding pressure, and then at a low sintering temperature range. By performing vacuum sintering, the content of C and O is suppressed, and the relative density is 78-9.
Since it is made of a porous titanium sintered body having a flexibility of 5% and a Young's modulus of 50 to 97 GPa, even a hard ball such as a two-piece ball has excellent vibration damping characteristics. The touch transmitted to the hand by absorbing the vibration of the hand is soft, and the control of a delicate distance can be realized. Also, the hitting sound is light and has a wood-like sound, and the contact time between the ball and the face surface at the time of hitting the ball is extended, so that the ball can be rolled smoothly and the directionality can be stabilized.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be specifically described with reference to Tables 1, 2 and 3. (Example)

[0023]

[Table 1]

Table 1 shows the average particle size of titanium powder produced by hydrodehydrogenation treatment when producing a putter head or iron head having the porous titanium sintered body of the present invention at least on the face surface. It shows the chemical composition of a porous titanium sintered body produced by subjecting a titanium powder to a later-described molding and vacuum sintering. No. 1 and 2
No. corresponds to the present invention. 3 and 4 are
This was used for comparison to prove the effect of the present invention.

[0025]

[Table 2]

Table 2 shows that the above-mentioned titanium powder was filled in a mold having a predetermined concave portion, and the molding pressure, vacuum sintering temperature, sintering time and vacuum degree applied at the time of molding were 10-3 Torr. FIG. 3 shows the results of preparing a test piece from a porous titanium sintered body manufactured under the same conditions and measuring the relative density and Young's modulus thereof. In Table 2, no. 1
No. 4 to No. 4 are porous titanium sintered bodies manufactured under the molding pressure and vacuum sintering conditions of the present invention. The porous titanium sintered body has a relative density of 80 to 93% and a Young's modulus of 55 to 96.
GPa.

A putter head was formed from a porous titanium sintered body having a low relative density and a low Young's modulus according to the production method of the present invention, and as a result of examining the feel at the time of hitting the ball, the sound of hitting the ball and the directionality of the ball, N, which is a conventional pure titanium ingot shown in Table 2,
o. Compared to 9, all have flexibility and excellent vibration damping characteristics, so the feel at the time of hitting is soft, the contact time with the face surface at the time of hitting is long, and the directionality of the ball is stable. Was confirmed.

No. 2 shown in Table 2 5-No. No. 8 is a porous titanium sintered body manufactured for comparison with the present invention. Nos. 5 and 6 have high sintering temperatures and 6
Since the sintering time is longer than that of the present invention, the relative density is no. No. 5 is 97; 6 is 98% and the Young's modulus is
5 is 103 GPa, No. 5 6 is as high as 105 GPa, a porous titanium sintered body having flexibility cannot be obtained, and since the vibration damping property is inferior, the feel at impact is hard, and the contact time between the ball and the face at the time of hitting does not increase, The direction of the sphere was bad.

Further, No. No. 7 has a relative density of 97% and a Young's modulus of 97% because the molding pressure of the titanium powder is as high as 5.5 t / cm 2 and the C and O contents of the porous titanium sintered body are higher than those of the present invention. 105 GPa. A porous titanium sintered body having the same flexibility as in Nos. 5 and 6 could not be obtained, the shot feeling was hard, and the directionality of the sphere was poor.

Further, in the case of In the case of Comparative Material No. 8, the sintering progressed due to the fine average particle size of the titanium powder of 45 μm, the relative density increased to 97%, and the Young's modulus increased to 103 GPa. 5-No. As in the case of 7, a porous titanium sintered body having flexibility could not be obtained, and the shot feeling was hard due to poor vibration damping characteristics, and the directionality of the ball when hit was poor.

Table 3 shows the vibration damping characteristics of a porous titanium sintered body having a relative density of 85% produced by the production method of the present invention and pure titanium ingot, soft iron and copper used as conventional materials. The results are shown. In addition, the measuring method was a vertical hanging type using a string, hammering was performed on a 100 mm × 40 mm × 30 mm test piece, and the time required for the amplitude of the acoustic vibration to attenuate to １ ／ at that time was defined as a measured value.

[0032]

[Table 3]

From Table 3, it can be seen that the porous titanium sintered body produced by the method of the present invention has a very excellent vibration damping property, and in addition to soft iron which has been conventionally used as a material for golf heads, recently The value was less than half the measured value of the titanium ingot used as the material for the head, iron head, and putter head. Furthermore, the value of this porous titanium sintered body was much higher than the measured value of copper used on the face surface of a putter head or an approach head for the purpose of improving the feel at impact and increasing the spin rate. .

[0034]

As described above, the putter head or iron head of the golf club of the present invention suppresses the C and O contents of the titanium sintered body and has a relative density of 78 to 95%.
By setting the Young's modulus to 50 to 97 GPa, a porous and flexible titanium sintered body is formed, and at least the face surface of the putter head is constituted by the porous titanium sintered body. Therefore, due to the flexibility of soft titanium and porous titanium sintered body, the feel transmitted to the hand at the time of hitting is soft, the hitting sound is light, and the sound is similar to wood, and the rolling of the ball at the time of hitting is smooth In addition, the directionality of the hit ball can be stabilized. Further, since it is a porous titanium sintered body, it has excellent wear resistance, and has a sufficient life even in an approach iron head having many full shots.

Continuing from the front page (72) Inventor Kiyoshi Takamura 1 Wanowari Arao-cho, Tokai City, Aichi Prefecture Inside Aichi Steel Corporation (72) Inventor Katsumi Bando 1-Wanowari Arao-cho, Tokai City, Aichi Prefecture Inside Aichi Steel Corporation (72) Inventor Yoshiyoshi Owan 1 Wanowari, Arao-cho, Tokai City, Aichi Prefecture Inside Aichi Steel Corporation

Claims (2)

[Claims] 1. A porous titanium sintered body having a relative density of 78 to 95% and a Young's modulus of 50 to 97 GPa manufactured by vacuum sintering after forming a mold using titanium powder as a raw material is formed on at least the face surface. A golf club putter head or iron head. 2. A titanium powder having an average particle size of 50 to 180 μm is filled into a mold having a concave portion having a predetermined shape, and the powder having a mean particle size of 1.0 to
A molding pressure of 5.0 t / cm2 is applied to form a titanium powder compact, and then in a temperature range of 1100 to 1250 DEG C. for 20 minutes to 1 hour.
By sintering under vacuum of 10 -3 to 10 -6 Torr for 80 minutes, at least the face surface has a chemical composition of C:
0.25% or less, O: 0.30% or less, the balance being titanium and unavoidable impurities, and a relative density of 78 to 9
A golf club pattern comprising a porous titanium sintered body having a modulus of 5% and a Young's modulus of 50 to 97 GPa.
A method for manufacturing a head or an iron head.