JP2000005353A - Production of thin-walled golf club head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accelerate the reduction in thickness while preventing the nonuniformity of the size, dimensions and thickness of a head body consisting of titanium or titanium alloy by casting and molding the head body, then bringing the shell surface of the head body 6 into contact with a corrosive fluid body, thereby reducing the wall thickness of the shell surface and reducing the wall thickness of the head body. SOLUTION: The head body 10 of the golf club is formed by a lost wax process using, for example, the titanium alloy as a base material and is cast by pouring a refractory coating 12 into a cavity 14. For example, a chemical milling treatment is executed in order to reduce the wall thickness of the head body 10. Namely, an acid is introduced from a sole part opening 16 and is brought into contact with the inside wall surface in order to remove part of the head body 10 by chemically oxidizing and etching the inside of the head body. At this time, a mask 18 is applied on the section not requiring the thickness reduction and a mask plug 20 is packed into a hosel portion. A separately prepd. sole 22 is thereafter mounted at the head body 10, by which the golf club head 10A is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a golf club head, and more particularly to a method for manufacturing a golf club head so as to reduce the weight or maintain the current weight while increasing the head volume.

[0002]

2. Description of the Related Art In general, a club head body made of titanium or a titanium alloy as a base material is manufactured by a lost wax method, a body wax corresponding to the head body is molded by a mold, and a refractory coating is formed around the body wax. (Usually using ceramics). Then
The wax is removed from the interior of the refractory coating to form a cavity corresponding to the head. Then, after pouring from the gate formed in the refractory coating and solidifying, the refractory coating is removed and the head body is taken out, thereby completing the head body forming operation. Since the head main body is usually formed by opening the sole portion, a separately prepared sole is attached to the opening of the sole portion and welded to complete the head main body.

When a cast hollow titanium or titanium alloy golf club head is set to have a thin portion with a thickness of 1 mm or less, if the casting is performed as it is, the cavity gap is thin, and the run-out failure may occur. Yield worsens. Such a material is usually cast with a thickness (1 mm or more) that does not hinder production, and the thickness of the outer surface is reduced by polishing the outer surface after welding the sole.

[0004]

However, in the conventional method, the thickness is not uniform due to the large amount of polishing,
There are problems such as irregular shapes and changes in size and dimensions. There is also a method of polishing the inside with a grinder or the like before welding the sole. However, since the shell surface has a complicated shape, it is difficult to perform uniform polishing.

[0005] For example, the surface roughness of a cast titanium head is about 20 to 30 s, and after the sole welding, the entire surface is polished and finished to 10 s or less for painting. In this case, the polishing thickness is about 0.1 mm including the removal of the undulation, but the polishing amount is about 10 g by weight for a large-sized head having a volume of 300 cc and a surface area exceeding 240 m ² . In the case of a large and light head with a volume exceeding 300 cc and a weight of the order of 180 g, it is necessary to reduce the thickness of each part to near the limit in strength, and the crown and side surfaces are 0.7 to 0.9 m.
m. Also, the thickness tolerance is -0.0
It needs to be suppressed to about 5 + 0.1 mm. However, in the case of a large head having a large surface area, if the amount of polishing is large, the thickness and shape are likely to vary, and a considerable degree of polishing skill is required to maintain the thickness accuracy. Therefore, how to reduce the amount of polishing when manufacturing a large and lightweight head is the key to manufacturing a high quality large and lightweight head.

The present invention focuses on the above-mentioned conventional problems, and makes the thickness of a golf club head made of titanium or a titanium alloy as thin as possible while preventing nonuniformity in size, size and thickness. It is an object of the present invention to provide a method for manufacturing a golf club head made of titanium or a titanium alloy, which can be used.

[0007]

In order to achieve the above object, a method of manufacturing a thin golf club head according to the present invention comprises the steps of: forming a golf club head body by casting; By contacting, the thickness of the head main body shell surface is reduced to reduce the thickness of the head main body.

Second, after the golf club head main body is cast and formed, the weight of the cast head main body is measured to calculate a deviation from the required head main body weight, and the head main body shell surface is changed to a corrosive fluid. The contact is characterized in that the thickness of the head body shell surface is reduced by the weight corresponding to the deviation and the thickness of the head body is reduced.

Third, after the golf club head main body is cast and formed, several of the cast head main bodies are selected and the shell surface is brought into contact with a corrosive fluid to adjust the weight loss and the wall thickness. The time required for the measurement is measured, the head body shell surface is brought into contact with the corrosive fluid for a time corresponding to the required time by batch processing, and then the weight of each head body is measured and adjusted to the specified weight. By performing the treatment for contact with the corrosive fluid for the above, the thickness of the head main body shell surface is reduced by the weight corresponding to the deviation, and the thickness of the head main body is reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a specific embodiment of a method of manufacturing a thin golf club head according to the present invention will be described in detail with reference to the drawings. FIG. 1 shows the production of the thin golf club head according to the embodiment through the main working steps shown in FIG. First, the club head body 10 is prepared by a lost wax method using titanium or a titanium alloy as a base material. A body wax corresponding to the head body 10 is molded by a mold, and a refractory coating 12 is formed around the body wax. To form This coating 12 may be formed of ceramics. Next, the wax is removed from the inside of the refractory coating 12 to form the cavity 14 corresponding to the head. The head body 10 is manufactured by pouring from a gate (not shown) formed in the refractory coating 12 and solidifying. By removing the refractory coating 12 and taking out the head main body 10, the casting operation of the head main body 10 is completed (FIG. 1 (1)).

Here, it is difficult to set the thickness of the head body 10 to 1 mm or less, considering that the molten metal flows smoothly in the cavity 14 at the time of casting. For this reason, at the time of this casting, the cavity gap is maintained at 1 mm or more, and the flow of the molten metal is adjusted so as to be appropriate. Accordingly, the thickness of the head body 10 cast here is manufactured so that the thickness of the face portion is 3 mm and the thickness of the shell portion excluding the hosel portion is 1 mm.

In order to reduce the thickness of the head body 10 thus cast, a chemical milling process is performed as shown in FIG. 1 (2). This is to chemically remove the inner surface of the head body 10 by oxidative corrosion. Since the casting is usually formed by opening the sole portion, an acid is introduced through the sole portion opening 16 so as to come into contact with the inner wall surface. In this example, since the base material of the head body 10 is titanium, 10% by weight of nitric acid + 2% by weight of hydrofluoric acid is used, and the casting head body 10 is immersed in this liquid. In order to prevent hydrogen absorption into the base material, the processing temperature is set to 60 ° C. or less. Also, the material of the base material,
The amount of hydrofluoric acid is adjusted in consideration of the surface condition, weight loss adjustment, and the like. Then, a mask 18 is applied to a portion that does not need to be reduced in thickness, and a mask stopper 20 is packed in a hosel portion. Thereby, the part other than the part masked can be brought into contact with the acid. The shell thickness is reduced by 0.15mm by such shell milling treatment by chemical milling.
This is taken out of the liquid tank.

Then, the sole 10 prepared separately is mounted and welded and connected as shown in FIG. 1 (3) to complete the head 10A. Sole 22
The head 10A, which forms a closed shell to which is joined, is in a state at the time of casting because the surface is masked. When a ceramic material is cast using titanium as a base material, an alpha layer having a high oxygen concentration is formed on the surface. If the alpha layer remains, it becomes brittle, and a polishing process is performed to remove the alpha layer, and the thickness is further reduced by about 0.05 mm from the surface. Thereby, as shown in FIG. 1 (4), the face part is 2.8 mm, the sole part is 2.0 mm,
Other thin golf club heads having a shell thickness of 0.8 mm are manufactured. Thereafter, the product can be shipped as a product by performing a surface coating process.

FIG. 2 shows a flowchart of a specific processing method of such a process. First, as described above, the club head main body 10 is cast with a ceramic mold in a state where the club head body 10 has a cavity thickness capable of ensuring the flow of the molten metal (step 100). The cast club head body 10 is taken out, and acid-resistant masking is performed on the outer surface to reduce the thickness (step 102). In this embodiment, in order to facilitate the polishing by removing the alpha case (hard), the thinning is performed on the inner surface side of the head shell in order to facilitate the polishing (even fine paper can be shaved and the paper has good holding). Therefore, the mask 18 is applied to the outer surface. In this state, the weight of the head body 10 is measured (step 1).
04). Next, several cast head bodies are selected, and a chemical milling process is performed on them as a trial (step 106). Then, how much the processing time is required is determined while observing the reduced thickness of the head body after the processing (step 108). The chemical milling process is performed on the entire amount at once in the processing time determined in this manner (step 110).

After the batch chemical milling is completed,
Next, the weight and thickness of each head body 10 are measured (step 112). It is checked whether this satisfies the standard (step 114), and if it is not appropriate, reprocessing is performed (step 116), and if so, the sole is welded and the outer surface is polished (step 11).
8). After that, finish coating is performed (step 12).
0), the mounting of the shaft and the like are performed in a separate operation step, and the golf club is obtained.

In the above-described embodiment, an example is shown in which the inner wall of the head main body 10 is subjected to chemical milling to reduce the thickness. However, the outer surface of the head main body 10 may be subjected to chemical milling. This is because the titanium head after casting is subjected to a chemical milling treatment so as to uniformly reduce the thickness and improve the surface roughness so as to reduce the polishing amount.

Specifically, similarly to the above-described embodiment, the club head main body 10 is cast by a ceramic mold in a state having a cavity thickness capable of ensuring a flow of molten metal. The cast club head body 10 has a large surface roughness, and the thickness of the crown portion and the side surface is about 1 mm. Remove from the mold and reduce the thickness from the outer surface side.
Acid-resistant masking is performed on the hosel portion and the inner surface of the shell to reduce the thickness of the head body shell. And this head body 10
Is immersed in a milling solution consisting of 10% by weight of nitric acid + 2% by weight of hydrofluoric acid. In order to prevent hydrogen absorption into the base material, the processing temperature is set to 60 ° C. or less. The same applies to the case where the amount of hydrofluoric acid is adjusted in consideration of the material of the base material, the surface condition, the adjustment of weight loss, and the like. By the treatment of the outer surface by such chemical milling, the surface roughness immediately after casting is extremely reduced, and at the same time, a wall-thinning effect is obtained. The sole is attached to such a head main body, and after the sole is welded, the outer surface is polished to about 10 s, but the polishing load is reduced by improving the surface roughness by chemical milling and adjusting the weight.

[0018]

Embodiment 1 The first embodiment shows an example in which chemical milling is performed on the inner surface of the head 10. Size 3
2.8mm face at 0.8cc, 0.8m crown surface
m, side surface 0.8mm, sole surface 2mm, weight 180
g of a golf club head made of a titanium alloy was manufactured by the following procedure. (1) The golf club head body 10 was cast with a face of 3.0 mm, a crown face of 1.0 mm, and a side face of 1.0 mm by a lost wax method. Weight at this time is 160g
Met. (2) Next, a mask is applied to the outer surface and the hosel hole is plugged, so that the inner surface of the head body 10 is made up of 10% by weight of nitric acid + 2
The head was immersed in a corrosive liquid composed of hydrofluoric acid at a weight% and subjected to chemical milling until the inner wall surface of the head was reduced by 0.15 mm. As a result, the weight of the head main body 10 was reduced to 145 g. (3) Thereafter, the sole 22 was attached to the opening of the head body 10 and covered, and the joint ridge was welded. Thereby, the weight of the sole 22 was added, and the total weight became 190 g. (4) Finally, the alpha layer is removed by polishing the surface, and the final coating is applied to obtain the above-mentioned 300 cc size, face 2.8 mm, crown face 0.8 mm, side face 0.8 mm, A titanium alloy golf club head having a sole surface of 2 mm and a weight of 180 g was obtained.

In this embodiment, when manufacturing a golf club head, the outer surface of the cast head body 10 is masked, and the inner wall surface of the body is brought into contact with an acid to perform chemical polishing to reduce the thickness. By performing the surface polishing and painting, the total weight of the golf club head can be reduced, and the volume capacity can be increased to reduce the thickness.

Embodiment 2 The second embodiment shows an example in which chemical milling is performed on the outer surface of the head 10. A titanium alloy golf club head having a size of 300 cc, a crown surface and a side surface of 10.1 mm, a weight of 160 ± 2 g, and a surface roughness of 30 s was produced in the same manner as described above. (1) First, the golf club head body 10 was cast with a crown surface of 1 ± 1.0 mm and side surfaces of 1.0 ± 0.1 mm by a lost wax method. Weight at this time is 160
g. (2) Next, a mask is applied to the inner surface of the head shell and the hosel hole is plugged, so that the outer surface of the head body 10 is 10% by weight.
And then immersed in a corrosive liquid composed of 2% by weight of hydrofluoric acid and subjected to chemical milling to reduce the thickness of the inner wall surface of the head to 0.8 mm. By doing so, the weight of the head body 10 was reduced and the surface roughness was adjusted. (3) After that, the head body formed by chemical milling weighs 150 ± 1 g and has a surface roughness of 15 ± 1 g.
s, crown and side surfaces are 0.8 ± O. The configuration was 1 mm. (4) The head body after chemical milling is finally polished on the surface, the sole layer is polished after welding to about 10 s to remove the alpha layer, and the finish coating is applied to the titanium alloy. The golf club head made was obtained. This finish polishing amount is 5g
Met.

In this embodiment, when manufacturing a golf club head, the outer surface of the cast head body 10 is subjected to chemical polishing by bringing it into contact with an acid to reduce the thickness, and at the same time, the surface roughness is adjusted. By performing the surface polishing and coating in a specific manner, the overall weight of the golf club head is reduced and the surface roughness is improved, so that the polishing amount can be reduced. FIG. 3 shows changes in the surface roughness of the golf head face surface before and after pickling, and specific measurement results are shown in the following table. The measurement results were selected by measuring the surface roughness of two types of golf head face surfaces along the vertical line. Measurement method is J
It conforms to the definition and indication of the surface roughness of ISB0601. The maximum roughness is shown as μmRmax, and the ten-point average roughness is shown as μmRz.

[0022]

[Table 1]

According to the second embodiment, it can be seen that the surface roughness differs before and after the chemical milling treatment, and that the pickling treatment has the effect of greatly reducing the final polishing amount.

[0024]

As described above, according to the present invention, after a golf club head main body is cast and formed, the head main body shell surface is brought into contact with a corrosive fluid, and the head main body shell surface is reduced in thickness. As a result of adopting a configuration that reduces the wall thickness, there is no problem such as uneven wall thickness, irregular shapes, and changes in size and dimensions. The effect is that a golf club head made of titanium or a titanium alloy can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a manufacturing process according to an embodiment.

FIG. 2 is a flowchart of a manufacturing method according to the embodiment.

FIG. 3 is a diagram of measured data of a head face surface roughness of a second embodiment before and after a chemical milling process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Club head main body 10A Club head 12 Refractory coating 14 Cavity 16 Sole part opening 18 Mask 20 Mask plug 22 Sole

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazuto Okamoto 3-1-1, Tamano, Tamano-shi, Okayama Prefecture F-term (reference) in Sanzo Metal Co., Ltd. 2C002 AA02 CH04 LL01 PP02

Claims (3)

[Claims] 1. A method of casting a golf club head body, comprising: bringing a head body shell surface into contact with a corrosive fluid to reduce the wall thickness of the head body shell to reduce the thickness of the head body. A method for manufacturing a thin golf club head, comprising: 2. After casting the golf club head main body, the weight of the cast head main body is measured to calculate a deviation from the required head main body weight, and the head main body shell surface is brought into contact with the corrosive fluid, A method of manufacturing a thin golf club head, wherein the thickness of the head body shell is reduced by reducing the thickness of the head body shell surface by the weight corresponding to the deviation. 3. A time required for adjusting weight loss and wall thickness by casting several golf club head bodies and then selecting several of the casting head bodies and subjecting the shell surface to contact treatment with a corrosive fluid. Is measured, the head body shell surface is brought into contact with the corrosive fluid for a time corresponding to the required time by batch processing, and thereafter, the weight of each head body is measured to adjust the weight to the specified weight. Manufacturing a thin golf club head characterized by reducing the thickness of the head main body shell surface by the weight corresponding to the deviation and reducing the thickness of the head main body by performing a process of contacting with a corrosive fluid. Method.