JP2001321469A - Golf club head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a soft feeling in striking of a ball. SOLUTION: A golf club head 1, the face 2 to strike a ball with of which is made of a metal material. The face 2 has a rough face 4 formed by making abrasive grains of a metal, average size of which is over 1.0 mm but 2.0 mm or less, collide with the face 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a golf club head capable of improving the feel at impact.

[0002]

2. Description of the Related Art Professional golfers, intermediate golfers, and advanced golfers attach great importance to the feeling of hitting, which is the feeling or feeling transmitted to the hand at the moment of hitting a ball with a golf club. In particular, in the case of an iron type golf club, a soft feel at impact is preferred so as to serve as a guide for properly separating the flight distance. Performance such as the hardness of the ball is strongly related to the feel at impact, but it has been found that different feels can be obtained depending on the club head even when the same ball is hit. Conventionally, in order to obtain a soft feel at impact, for example, using a relatively soft material for the face portion hitting the ball, for example, using a metal material such as fiber reinforced resin or soft iron, or without plating the surface of the face portion Although they are used, they are not yet sufficient, and further improvement in shot feeling is desired.

[0003] The inventors of the present invention have conducted intensive studies in order to obtain a softer feel at impact on the premise that a golf club head in which a ball hitting face is formed of a metal material, and as a result, the face has an average particle size Injecting abrasive grains having a very large particle size of greater than 1.0 mm and 2.0 mm or less, and providing a rough surface portion formed by colliding,
It has been surprisingly found that a very soft feel at impact is obtained, and the present invention has been completed.

Conventionally, abrasive grains have been made to collide with the surface of the face portion in shot blasting, shot peening, or the like (for example, see Japanese Patent Laid-Open No. 10-1).
No. 79824). However, this method mainly improves the appearance of the face portion by colliding abrasive grains with the surface of the face portion, and rounds the groove edge of the face groove formed on the surface of the face portion to cause damage to the ball. This is fundamentally different from the technical problem of the present invention in that the object is to suppress the above. In addition, in connection with such a difference in technical problems, in the publication, the average particle size of abrasive grains is limited to a small one of 1 mm or less at most. Therefore, it does not suggest any of the problems and configurations of the present invention.

[0005] As described above, the present invention is based on the fact that a rough surface formed by colliding abrasive grains having a large average particle diameter with the surface of the face is provided on the face.
It is an object of the present invention to provide a golf club head capable of obtaining a soft feel at impact.

[0006]

According to the present invention, there is provided a golf club head in which a face for hitting a ball is formed of a metal material, wherein the face has an average particle diameter of 1.0 mm.
It is characterized in that it has a roughened surface formed by colliding metal abrasive grains larger than 2.0 mm or less against the face surface.

The rough surface portion can be formed, for example, by colliding the abrasive grains with a face surface in which a face groove extending in the toe and heel directions is formed in advance. It is preferable that the width of the face groove is smaller than the average particle diameter of the abrasive grains.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of an iron-type golf club head, and FIG. 2 is a partially enlarged cross-sectional view perpendicular to the face surface. As shown in the figure, a golf club head (hereinafter, may be simply referred to as a “head”) 1 of the present embodiment has a head body 1a having a face 2 on the front surface of which hits a ball, and a head body 1a. And a shaft mounting portion 1b integrally formed on the heel h side of the shaft 1a and mounted with a shaft (not shown).

In this embodiment, an example in which the entire head 1 is made of a metal material is illustrated. As the metal material, for example, carbon steel, stainless steel, titanium, a titanium alloy, or another material is used. In this example, at least the face surface is substantially formed of a titanium alloy (Ti-6Al-4V). The face surface 2 is filled with, for example, a plate-like dissimilar metal to form the head body 1a.
May be composed of two or more materials.

In the present embodiment, the face surface 2 is provided with vertical lines L1 and L2 extending substantially vertically on the toe t side and the heel h side, respectively, and an approximate hitting area is defined therebetween. And this vertical line L1,
Between L2, when the head 1 is placed on a horizontal surface in accordance with the prescribed lie angle and loft angle, the toe t and the heel h
An example is shown in which a face groove 3 extending in the direction, that is, substantially horizontally, is recessed. The face groove 3 plays an important role in, for example, increasing the frictional force with the ball when hitting the ball on the face surface 2 and giving the ball spin.
In this example, as shown in an enlarged manner in FIG. 2, a cross section perpendicular to the face surface 2 and having a substantially triangular groove cross section is illustrated.

The face groove 3 has a groove width GW of 0.9 mm or less according to the golf rules of the Japan Golf Association.
The groove depth GD is specified as 0.5 mm or less. The head 1 of the present embodiment has a face groove 3 conforming to this rule, for example, a groove width GW of 0.5 to 0.9 mm and a groove depth GD
Is set at 0.3 to 0.5 mm. The groove length of the face groove 3 can be variously determined according to the shape of the face surface 2.
Such a face groove 3 can be recessed by various methods using, for example, a convex portion of a mold, or a press, a cutting tool, or the like.

In this embodiment, metal abrasive grains having an average particle diameter of more than 1.0 mm and not more than 2.0 mm are applied to the face surface 2 in which the face grooves 3 are formed in advance.
The head 1 is manufactured by providing a rough surface portion 4 formed by colliding the head 1. The rough surface portion 4 of this example is formed in a region surrounded by the vertical lines L1 and L2, the upper edge 2a of the face surface 2, and the lower edge 2b of the face surface 2, and the ball is hit normally. In such a case, the ball is formed so as to be able to reliably contact the rough surface portion 4. As a result of various experiments by the inventors, it has been found that the head 1 having such a rough surface portion 4 can obtain a very soft feel when hitting a ball.

Further, by reducing the above-mentioned abrasive grains on the face surface 2 in which the face grooves 3 are formed in advance as in the present embodiment, the groove walls 3a of the face grooves 3 are formed as shown in FIG. Since the edge 3b intersecting with the face surface 2 can be rounded by abrasive grains, the ball is prevented from being damaged. When the face groove 3 is formed, for example, at the time of casting, the face surface 2 is first polished,
Of the edge portion 3 by causing abrasive grains to collide with the face surface 2.
It is desirable to round b. Further, when the face groove 3 is formed by pressing, cutting, or the like, it is preferable because the burr formed on the edge of the face groove 3 can be removed at the same time as forming the rough surface portion 4.

In the present invention, the shape of the abrasive grains used to form the rough surface portion 4 is not particularly limited. For example, a so-called steel shot made of a substantially spherical small iron ball or a non-spherical cast steel having an acute angle portion is used. Abrasive materials such as crushed granules of steel grids, and further, wire cuts obtained by cutting wires into small pieces are suitably used, and it is also possible to use one kind or a mixture of two or more kinds. The shape and material of the abrasive grains are not particularly limited as long as they are made of metal, but preferably have a specific gravity of 6 or more, more preferably steel. Since such an abrasive has a high surface hardness and a large specific gravity, the rough surface portion 4 can be formed on the face surface 2 by spraying and colliding for a relatively short time, and the forming efficiency of the rough surface portion 4 can be increased. As examples of such abrasive grains, those specified in, for example, JIS F-G140 and FG-170 are desirable. When the abrasive grains are a non-metallic material, the surface hardness and specific gravity of the abrasive grains become small, and it is possible to form the rough surface portion 4 having high efficiency and sufficient roughness with an average particle diameter in the limited range. It will be difficult.

In the present specification, the “average particle size” of the abrasive grains is defined as a plurality of meshes each having a mesh of 0.1 mm, and the abrasive grains are allowed to pass through the respective meshes. Is determined by weighted average based on For example, the passage rate of the abrasive grains is 97% or more with a mesh of X mm mesh, 5% with the same (X-0.1) mm, 80% with the same (X-0.2) mm, and (X-0.3 ) Mm and 10%, (X-0.
4) When 5% in mm and less than 3% in (X-0.5) mm,
The average grain size of the abrasive grains is {(X-0.1) + X} × 0.05 / 2 + {(X-0.
2) + (X-0.1)｝ × 0.8 / 2 + ｛(X-0.
3) + (X-0.2)｝ × 0.1 / 2 + ｛(X-0.
4) + (X−0.3)｝ × 0.05 / 2. Note that, as described above, the maximum and the minimum of the mesh have a 3% tolerance.

As shown in FIG. 3A, when the abrasive grains 7 are spherical as shown in FIG.
When the abrasive grains 7 are non-spherical as in (B), the maximum length S is used as the particle size for convenience.

If the average grain size of the abrasive grains is 1.0 mm or less, sufficient roughness cannot be given to the rough surface portion 4 and the shot feeling cannot be made soft and mild. On the other hand, if the average grain size of the abrasive grains exceeds 2.0 mm, the rough surface portion 4 becomes too rough, so that it becomes difficult to obtain a mild shot feeling, and the ball is easily damaged, and the face surface 2 Marks of the ball are likely to stick. From such a viewpoint, the average particle diameter of the abrasive grains is more preferably 1.2 to 1.8 mm, and still more preferably 1.3 to 1.7 mm.

As a method of causing the abrasive grains to collide with the face surface 2, various methods such as sand blasting, shot peening, grit blasting, and liquid honing are known. In the present invention, any of these methods is used. It can be performed using: The abrasive grains are accelerated by any means such as gas, liquid, or centrifugal force and are ejected toward the face surface 2 and collide with the face surface 2.
The rough surface portion 4 can be formed on the substrate. As an example, in a direct pressure blast machine that accelerates and jets abrasive grains using high-pressure air,
For example, 0.1 to 1.0 MPa, more preferably 0.4
The air pressure is set to about 0.6 MPa.
The collision is desirably performed for 00 seconds, more preferably 60 to 120 seconds. If the air pressure is too low or the injection time is too short, the rough surface portion 4 cannot be formed with sufficient roughness, and the shot feeling tends not to be improved, and conversely, the air pressure is too high, or If the injection time is too long, the roughness tends to be too large and the shot feeling tends not to be improved.

If the groove width GW of the face groove 3 is larger than the average particle diameter of the abrasive grains, the abrasive grains
a, and an uneven surface is formed on the groove wall 3a.
When such an uneven surface is formed on the groove wall 3a, the brightness of the face wall 3 on the groove wall 3a is lost, and the appearance tends to deteriorate. In order to solve such a problem, the face surface 2
The face groove 3 can be recessed after the rough surface portion 4 is formed. However, in this case, the edge 3b of the face groove 3 becomes sharp, and the ball tends to be easily damaged.

In the head 1 of the present embodiment, the groove width GW and the groove depth GD of the face groove 3 are both smaller than the average particle diameter of the abrasive grains, and the abrasive grains collide with the face surface 2. When the rough surface portion 4 is formed, an improvement is made so that the abrasive grains do not substantially collide with the groove walls 3 a of the face grooves 3 formed in advance on the face surface 2. Accordingly, it is possible to prevent uneven portions from being formed on the groove walls and the like of the face groove 3 and prevent the appearance of the face groove 3 from deteriorating. Scratches are prevented.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An iron-type golf club head (# 3, # 5, # 7, # 9, P) having the same shape as shown in FIG.
W, AW, SW) were prototyped, and a rough steel portion was formed by colliding a spherical steel shot against the face surface at an air pressure of 0.6 MPa for 20 seconds. Each face groove has a groove width of 0.
8 mm and a groove depth of 0.4 mm. The average particle size is 1.24.
A head having a rough surface portion formed by a steel shot having a diameter of 1.4 mm is referred to as Example 1, a head having a rough surface portion formed by a steel shot having an average particle size of 1.44 mm is referred to as a second embodiment, and the average particle size is 1.7.
Example 3 was a head having a rough surface portion formed by a 1 mm steel shot. As Comparative Example 1, the average particle size was 0.1%.
A prototype was also made of a head in which 4 mm of silica sand was crushed at an air pressure of 0.6 MPa for 20 seconds, and a head in which a steel shot having an average particle diameter of 0.95 mm was crushed at an air pressure of 0.6 MPa for 20 seconds as Comparative Example 2.

Then, a shaft was mounted on each head to manufacture an iron type golf club, and a test hit test was conducted with six golfers having a handicap of 20 or less, and the feel at impact, the launch angle of the ball, and the amount of back spin were examined. . With respect to the feel at impact, a tester of an advanced golfer out of six randomly selected handicap players with a handicap of 20 or less was given a test hit, and evaluated on a 5-point scale, and the average value is shown. The larger the value, the softer the shot feeling and the better the feeling. Tables 1 to 3 show test results and the like.

[0023]

[Table 1]

[0024]

[Table 2]

[0025]

[Table 3]

As a result of the test, the example of the embodiment is a conventional example,
It can be confirmed that the shot feeling is softer than in the comparative example and the backspin amount is sufficiently obtained. Further, as shown in Japanese Patent Application Laid-Open No. H11-253584 previously proposed by the present applicant, the head of the example has a lower backspin in the so-called long iron and middle iron having a lower loft angle than the head of the comparative example. It was confirmed that the state was obtained and the launch angle was large, which was useful for improving the flight distance.

Next, in the head, the groove width of the face groove is constant at 1.2 mm, the groove depth is constant at 0.4 mm, and the average particle diameter of the abrasive grains is varied to form a rough surface portion.
A test was performed to measure the radius of curvature of the edge of the face groove and the appearance of the groove wall of the face groove. The results are shown in Table 4. In the case of the example, the edge of the face groove was sufficiently rounded, and the groove wall was not substantially formed with irregularities. It was also confirmed that the appearance of the face groove could be improved while preventing the appearance of the face groove. The radius of curvature of the edge portion is, as shown in FIG. 4, a crossing point A between the virtual extension line V1 of the face surface and the face groove, and the virtual extension line V2 of the groove wall, as shown in FIG.
The radius R of an arc passing through three points, an intersection B of the edge part and an intersection C of the edge part and a straight line V3 inclined at 45 ° to the face surface was measured.

[0028]

[Table 4]

[0029]

As described above, according to the first aspect of the present invention, metal abrasive grains having an average particle size of more than 1.0 mm and 2.0 mm or less collide with the face surface. By providing the rough surface portion thus formed, a very soft feel at impact can be obtained, and a golf club head that is easy to use for professionals and advanced users can be provided.

When the rough surface is formed by colliding the abrasive grains with the face surface in which the face grooves are formed in advance as in the second aspect of the present invention, smooth processing is performed by rounding the groove edges of the face grooves. This can prevent the ball from being damaged.

Further, when the width of the face groove is smaller than the average particle diameter of the abrasive grains, the abrasive grains may enter the face groove when forming the rough surface portion. Intrusion can be substantially prevented. Thereby, it becomes possible to round the edge portion of the face groove while preventing the roughening of, for example, a groove wall in the face groove without reducing the productivity of the head, and it is possible to obtain a softer shot feeling,
In addition, damage to the ball can be prevented.

[Brief description of the drawings]

FIG. 1 is a front view illustrating an example of a head according to an embodiment.

FIG. 2 is an enlarged sectional view showing the face groove.

FIGS. 3A and 3B are schematic diagrams illustrating abrasive grains.

FIG. 4 is a schematic view showing a method for measuring a radius of curvature of an edge portion of a face groove.

[Explanation of symbols]

 Reference Signs List 1 golf club head 2 face surface 3 face groove 4 rough surface portion

Claims (3)

[Claims] 1. A golf club head in which a face for hitting a ball is formed of a metal material, wherein said face has an average particle diameter of more than 1.0 mm and not more than 2.0 mm. A golf club head comprising a rough surface formed by causing particles to collide with the face surface. 2. The method according to claim 1, wherein the rough surface portion is formed by colliding the abrasive grains with a face surface in which a face groove extending in the toe and heel directions is formed in advance.
The golf club head as described. 3. The golf club head according to claim 2, wherein a width of said face groove is smaller than an average particle diameter of said abrasive grains.