JPH0482575A - Manufacture of golf club head - Google Patents

Abstract

PURPOSE:To prevent a loft angle from disorder due to thermal contraction by previously welding a relatively thin side wall part to a sole lid and then welding a thick face part to the sole lid to completely fix the sole lid before the thermal expansion of a head body proceeds. CONSTITUTION:A head body 1 is cast in titanium or titanium alloy, and a sole lid 3 is formed of a titanium or titanium alloy plate pressed into a predetermined curved shape and having a balance weight fixed the rear upper surface. Next, an opening 2 of the head body 1 is covered with the sole lid 3 having a balance weight fixed thereto to weld the connection edge of a face part 1A to the sole lid 3 continuously from one end (P1 or P4) rearward. Finally the face part 1A is welded to the connection edge (P1-P4) of the sole lid 3 through the other parts of the side wall face and the connection edge (P1-P2-P3-P4) of the sole lid 3. First the thin side wall part is previously welded to the connection edge (P1-P2-P3-P4) of the sole lid 3 to increase the welding speed so that the connection edge (P1-P2-P3-P4) is fixed before heat spreads over the whole head body 1.

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention relates to a method of manufacturing a hollow metal golf club head made of titanium, titanium alloy, etc. Regarding improvements.

``Conventional technology'' Recently, in place of the traditional wooden golf club head,
Metal golf club heads that have long flight distances and accurate ball hitting directions are becoming popular, and titanium or titanium alloys are particularly excellent as head materials because they provide high repulsive force and corrosion resistance.

As a method for manufacturing this type of metal golf club head, the method disclosed in Japanese Patent Application Laid-Open No. 154186/1986 is well known. This is a method in which three members, a sole member, a face member, and an upper surface member, which are press-molded from titanium or titanium alloy plates, are welded and integrated to form a hollow head.

``Problem to be Solved by the Invention'' However, the above method has a problem in that since three members are welded, the entire length of the welded part is long, and the welding work is time-consuming. In particular, welding titanium or titanium alloys must be performed in an inert atmosphere, requires skill, and polishing and finishing the bead after welding requires a cost proportional to the weld length.

For this reason, it has the drawbacks of low productivity and high manufacturing costs. In addition, since the welding length is large, distortion is large and accuracy is problematic.

Therefore, the present inventors integrally cast a head body 1 with only the bottom open as shown in FIGS. 3 and 4 by a precision casting method using wax molding.
A method was devised in which a press-formed sole plate 3 was placed over the bottom opening 2 of the machine and the entire circumference of the joining edge was welded. According to this method, the total length of the welded portion can be shortened, productivity can be increased, and manufacturing costs can be reduced. In addition, 4 is a shaft insertion part, 5 is a shaft hole, and 6 is a balance weight.

However, when such a golf club head was actually created, after welding the sole plate 3, the head body 1
It was discovered that distortion occurs in the face portion IA (ball hitting portion) formed on the front surface of the ball, causing the loft angle α (the angle formed by the perpendicular line to the sole surface and the face surface) to deviate from the designed value.

The present inventors investigated the cause of this in detail, and as a result, found that there was a problem with the original welding method.

That is, initially, after welding the joint edge between the face part IA and the sole plate 3, other parts were welded continuously (PI-P4→P3-P2→P1 or P4 in Fig. 4). →PI-4P2→P3→P4). This was done in consideration of ensuring high fixing strength at the initial stage of welding since the face portion IA has a larger wall thickness than the other portions.

However, with the above welding method, it takes time to weld the joint edges (P1 to P4) with the thick face part IA, so while welding these parts, the head body is welded through the face part IA. Heat circulates throughout the head body.
After deforming due to thermal expansion, the joining edge with other parts (P4~
P3-P2-PI) will be welded. For this reason,
The head main body 1 is fixed by the sole plate 3 in a thermally deformed state, and distortion occurs in the face portion IA due to thermal contraction etc. that occur after welding is completed.

"Tanu's Means to Solve the Problem" The present invention was made based on the above-mentioned novel findings.
A detailed explanation will be given below using FIG. 1 and FIG. 2.

Note that in these figures, the same parts as in the previous figures are given the same reference numerals.

The symbol l in FIG. 1 is a head main body, and this head main body l
is titanium or titanium alloy (e.g. Ti6wt%Al-
4vt%■). As the casting method, a precision casting method using a lost wax method is suitable.

The head main body 1 is hollow with an opening 2 formed in the bottom surface, and the front side of the side wall portion has a thicker face portion IA than the other portions. Further, a shaft insertion portion 4 having a shaft hole 5 is integrally formed in the upper IC of the head body l.

On the other hand, the reference numeral 3 is a sole lid, and this sole lid 3 is made by pressing the same titanium or titanium alloy plate material as described above.
A pattern is engraved as necessary and a predetermined curved shape is provided. Further, a balance weight 6 is fixed to the rear upper surface of the sole lid 3.

A feature of the method of the present invention is that the welding order of the sole lid 3 is changed.

That is, in this method, first, as shown in FIG. 2, the sole lid 3 to which the balance weight 6 is fixed is placed over the opening 2 of the head body 1, and then one end ( Start welding continuously from PI or P4) toward the rear. Then, the joint edge between the other part of the side wall surface and the sole lid 3 (P1-P2-P3-P4)
Finally, the joint edge (Pl-P4) between the face [IA and the sole lid 3] is welded. Actually, the following two orders are possible, and there is no difference in the welding results between the two.

■ pt→P2→P3→P4→P1 ■ P4→P3→P2→P1→P4 Note that welding must be performed continuously except at the start and end points so that no seams occur. If the number of discontinuities increases, seam marks with different gloss will remain on the bead even after the weld is polished, which not only impairs the aesthetic appearance, but also causes bead overlap at the seam, causing cavitation of the weld. It may happen.

The welding method may be any conventionally used method, such as TIG welding, MIG welding, electron beam welding, etc., and welding can be performed in an inert atmosphere such as argon or in a vacuum.

According to the method for manufacturing a golf club head having the above configuration, the joint edge (PI to P2) between the thin side wall portion and the sole lid 3
~P3~P4) are welded first, so a high welding speed can be achieved, and the joining edges (Pi~P2~P3~P4) can be fixed before heat is distributed throughout the head body l. can.

Then, after fixing the sole lid 3 almost in this way,
Joint edge between thick face part IA and sole lid 3 (P4~
Since the sole cover 3 is welded to the head body 1, the sole cover 3 can be completely fixed to the head body 1 before thermal expansion of the head body 1 due to heat conduction progresses. Therefore, distortion of the face portion IA due to heat shrinkage after completion of welding does not occur, and deviations in the loft angle α can be prevented.

Note that the golf club head to which the present invention is directed is not limited to the shape shown in the drawings, and can also be applied to heads using metal materials other than titanium and titanium alloys.

"Example" Next, examples will be given to demonstrate the effects of the present invention.

By the lost wax method, titanium alloy (Ti-6wt%)
A head body l having the shape shown in FIGS. 1 and 2 was precision cast using Al-4wt%V). The dimensions of each part are as follows.

Horizontal major axis: 70 friends! Horizontal minor axis + 55xz Height (excluding shaft insertion part 4): 40ju + wall thickness of base part IA: 3.2 Ilu + wall thickness of other side wall parts: 1
．． 5. Shoulder design loft angle α: 11°Meanwhile, the sole lid 3 was formed by pressing a pure titanium metal plate. The dimensions are as follows.

Long axis: 69++++w Short axis: 541 summer thickness, 2.5 feet! Next, the sole lid 3 was welded to the opening of the head body using the following three methods (1) to (3), respectively, and cooled to room temperature.

■ PI → P2 → P3 → P4 → Pi (Experiment example 1) ■ P
4-P3→P2→PI-P4 (Experiment Example 2) ■ PI-4
P4→P3→P2→Pi (comparative example) Welding conditions are as follows.

Welding method + TiC method Welding atmosphere: Ar Welding configuration crab 60-80A Welding rod type: Ti-3vt%Al-2,5wt%V Face part welding speed 5c/sin.

Welding speed for other side walls +7cx/win.

Next, the loft angle α of the three types of golf club heads obtained was measured, and the deviation of the angle from the set loft angle was calculated. The results are shown in the table below.

"Effects of the Invention" As explained above, in the method for manufacturing a golf club head according to the present invention, since the joining edge between the relatively thin side wall part of the head body excluding the face part and the sole cover is first welded, A high welding speed can be achieved, and the sole cover is almost fixed before heat spreads throughout the head body l. Next, the joint edge between the thick face part and the sole lid is welded, so the sole lid can be completely fixed before the thermal expansion of the head body progresses due to heat conduction, and the sole lid can be completely fixed by heat contraction after welding is completed. It is possible to prevent the occurrence of distortion in the face portion and to prevent deviations in the loft angle.

[Brief explanation of drawings]

1 and 2 are a longitudinal sectional view and a bottom view of a head showing a method of manufacturing a golf club head according to the present invention,
3 and 4 are a longitudinal sectional view and a bottom view of a head showing a conventional manufacturing method. l...Head body, IB...Other side wall parts, 3...Sole lid, 5...Shaft hole, IA...Face part, 2...Opening part, 4...Shaft insertion part, 6...Balance weight.

Claims (2)

[Claims] (1) The front end of the side wall has a relatively thick face compared to the other parts of the side wall, and the hollow head body with an opening at the bottom is integrally made of metal. While casting, a flat sole lid having a shape corresponding to the opening is formed of metal, this sole lid is placed over the opening, and the sole lid is inserted backward from one end of the joining edge of the face portion and the sole lid. The golf club head is characterized in that welding is started continuously toward the end of the golf club head, and then welding is continued to the joining edge between the other part of the side wall surface and the sole lid, and finally the joining edge between the face part and the sole lid. Production method. (2) The method for manufacturing a golf club head according to claim 1, wherein the metal is titanium or a titanium alloy.