Golf club head

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Industrial application field]

The present invention relates to a golf club head such as an iron club.

【0002】

[Conventional technology]

Conventionally, as this type, a face is formed on the front surface of an iron head body provided with a hosel on the negative side in FIGS. 1 and 3 of JP-A-6-134047, and a score is formed on the ball striking surface of the face. An iron club set in which a line is formed and a cavity is formed on the back surface of the iron head body is disclosed.

【0003】

[Problems to be Solved by the Invention]

In the prior art, the face is required to have strength and fatigue resistance to withstand a ball shot, and therefore the face is required to have a predetermined thickness.

【0004】

However, since the face needs to have a predetermined thickness, the weight balance of the head body cannot be freely set accordingly. For this reason, there is a problem that the position of the center of gravity of the head body cannot be adjusted, and the expansion setting of the sweet area and the bed balance cannot be freely set.

【0005】

Therefore, an object of the present invention is to solve the above-mentioned problems and to provide a golf club head in which the center of gravity or the like can be set relatively freely without being limited by the thickness of the face.

【0006】

[Means for solving problems]

The present invention according to claim 1 is a golf club head characterized in that a high hardness layer is formed on the ball striking surface of the face of the head body.

【0007】

The golf club head according to claim 1, wherein the head body is made of steel and the high hardness layer is formed by carburizing and quenching.

【0008】

[Action]

According to the configuration according to claim 1, the strength can be improved and the thickness of the face can be reduced, and the weight distribution of the head body can be freely set accordingly.

【0009】

According to the configuration according to claim 2, the face strength of the steel head body can be improved and the thickness thereof can be reduced, and a high hardness layer can be reliably formed at a predetermined position.

【0010】

[Example]

Hereinafter, examples of the present invention will be described with reference to the drawings. For example, the head body 1 made of steel such as carbon steel for mechanical structure such as S10C to S50C, preferably S10C and S20C, and rolled steel for general structure such as SS41 is provided with a hosel 3 for connecting the shaft 2 on the negative side. A face 4 is formed on the front side, and a ball striking surface 5 is formed on the face 4. The ball striking face 5 is a region sandwiched between the left and right alternate long and short dash lines in FIG. 2, and is substantially the same as the range in which the score line 6 is formed. On the other hand, a weight portion 8 is formed on the back surface of the head body 1 via a recess 7 at the bottom surface of the back surface, forming a so-called cavity back structure. In the figure, 9 indicates the heel and 10 indicates the top. Further, a high hardness layer 11 having a thickness A of, for example, 0.1 to 0.5 mm, preferably about 0.25 mm is formed only on the ball striking surface 5 of the head body 1. The hardness of the high hardness layer 11 is, for example, a Vickers hardness (Hv) of 500 or more, preferably 600 to 700, and the other parts have a Vickers hardness (Hv) of about 200 including the heel 8 side. It is said.

【0011】

Next, the manufacturing method will be described. The steel material is hot forged by a press device in which an upper die and a lower die are set to produce a forged product. Next, the score line 6 is formed by cutting or the like, and is finished to a predetermined size by polishing or the like. After that, only the surface hardening portion 5A corresponding to the ball striking surface of the forged product is surface-hardened. Carburizing and quenching is used as this surface hardening treatment.

【0012】

In the carburizing and quenching, carbon is infiltrated into steel to increase the amount of carbon only on the surface portion, and then quenching is performed to form a highly hardened layer 11 having a high carbon concentration on the surface portion, and this carburizing and quenching is performed. There are a gas carburizing method, a solid carburizing method, and a liquid carburizing method. In the gas carburizing method, the part other than the ball striking surface corresponding portion 5A is copper-plated in advance, and methane, propane, butane, etc. are treated with air. For example, H which was mixed and decomposed by heat absorption.₂40%, CO20%, N₂40% gas, or methanol or the like is dropped into a heated electric furnace, for example, CO30%, H₂A carburizing gas composed of 70% gas is passed through a heating furnace, and the forged product is put therein to carburize only the ball striking surface equivalent portion 5A at 850 to 1000 degrees Celsius.

【0013】

The solid carburizing method uses Na for granular charcoal, coke, etc.₂CO₃, BaCO₃The carburizing agent containing the above is used by arranging it in the part corresponding to the ball striking face 5A, and when it is heated to 900 to 950 degrees Celsius, the carbon in the carburizing agent reacts with the oxygen in the air existing in the gap of the carburizing agent. CO is generated, and CO reacts with steel to diffuse carbon into the steel. The carburized layer is formed by keeping it warm for an appropriate period of time, and then quenching and tempering are performed to obtain the high hardness layer 11. Is what forms. In the liquid carburizing method, a carburizing agent containing NaCN and KCN as main components is heated to 800 to 900 degrees Celsius to melt it, and the forged product is immersed. At this time, N generated by the decomposition of CN diffuses into the steel, resulting in carburizing and carburizing (carburizing and carburizing) treatment. After the predetermined heating and holding is completed, quenching is performed as it is, and the baking is performed.

【0014】

Of the carburizing and quenching, the gas carburizing method is the most preferable for surface hardening treatment of only the ball striking surface corresponding portion 5A. This is because the carburizing becomes uniform, the surface carbon concentration can be adjusted relatively easily, and the thermal efficiency is good.

【0015】

As described above, in the above embodiment, by making only the ball striking surface 5 of the steel head body 1 the high hardness surface 11, it is possible to improve the wear resistance and the fatigue limit as mechanical properties. As a result, the wall thickness B of the face 4 can be reduced to 2.5 mm or less, for example, 2 mm, and the weight of the face 4 can be increased by increasing the weight of the weight portion 8, for example, to increase the distance between the face 4 and the head center of gravity G. Then, the sweet area can be expanded in proportion to the distance, and the weight balance can be adjusted by setting the edge side 4A around the face 4 as the wall thickness.

【0016】

Further, the head body 1 is made of steel, and the high hardness surface 11 formed only on the ball striking portion 5 is formed by carburizing and quenching, so that the heel 9 side is not hardened, and therefore the heel 9 side is made of steel. The toughness of the steel is secured, and the strength at the time of shot can be demonstrated. The present invention is not limited to the above embodiment. For example, the material of the head body may be stainless steel, titanium, a titanium alloy or another metal, and even in such a case, the ball striking surface of the face is high. Since the hardness layer can be formed to improve the fatigue resistance of the face and the face can be made thinner, the head weight can be freely distributed accordingly. Further, the head can be variously deformed such that it can be used as a pitching wedge or the like. Further, in the above embodiment, the case of carburizing and quenching of steel is shown as the surface hardening treatment, but induction hardening or nitriding may be used. In induction hardening, the forged product placed in a coil (inductor) is heated by an induced current from an alternating current of 1 kHz to 500 kHz flowing through the coil and then cooled. The nitriding makes the forged product liquid nitrogen or NH.₃When heated to 500 to 600 degrees Celsius in a suitable source of nitrogen such as gas, nitrogen atoms diffuse into alpha iron, hardening by precipitation of fine N compounds, and cooling after heating.

【0017】

[Effect of the invention]

The present invention according to claim 1 is a golf club head characterized in that a high hardness layer is formed on the ball striking surface of the face of the head body, and the face can be made thinner by improving the fatigue resistance of the face. Minute head weight can be freely distributed.

【0018】

The present invention according to claim 2 is the golf club head according to claim 1, wherein the head body is made of steel, and the high hardness layer is formed by carburizing and quenching. Can be reliably provided, and a sweet area or a golf club head having an excellent weight balance can be provided.

[Simple explanation of drawings]

[Figure 1]

It is sectional drawing which shows the Example of this invention.

[Figure 2]

It is a perspective view which shows the Example of this invention.

[Explanation of symbols]

1 Head body 4 faces 5 ball striking face 11 High hardness layer