JPH0653181B2 - Iron golf club set - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf club set, and more particularly to improvement of a club head in an iron golf club set.

[Prior art]

In the conventional golf club set, the face surface of each count head is made to have the same surface condition. For example, in a wood club set, a face insert made of ABS resin, paper fiber, aluminum alloy, titanium, fiber reinforced resin, etc. is generally attached to the face surface of the head, but the head of each count in the set is made of the same material. The face insert is also provided, and the surface state of the face insert is also finished.
Therefore, the friction coefficient of the face surface with respect to the ball is the same in the wood club set. Also, in iron club sets, the heads are generally made of materials such as iron and fiber reinforced resin, but the heads of each count in the set are made of the same material, and the face surfaces of the heads are the same. It is finished to the surface condition. Therefore, even in the iron club set, the friction coefficient of the face surface with respect to the ball is the same.

Generally, the trajectory of a ball and the rolling (run) after it falls are
The amount of backspin of the ball, the launch angle, and the launch speed are greatly affected. For example, to obtain a ball with high trajectory, it is necessary to increase those values. Further, in order to increase the rolling (run) of the ball, it is necessary to increase the ejection speed of the ball and reduce the backspin amount and the falling angle of the ball.

The backspin amount of a ball is substantially determined by the coefficient of friction of the face surface against the ball, the loft angle of the head, and the head speed. That is, the larger the value, the larger the backspin amount. On the other hand, the ball launch angle has a relationship that decreases as the backspin amount increases.

[Problems to be Solved by the Invention]

In a conventional iron golf club, a long iron with a small number of counts has a long flight distance, and a middle spin and a short iron with a large count have a backspin to accurately stop the ball to a target. However, when the backspin is applied, the ball rises high, and when the wind blows, the ball is swept away from the target, and the function of the middle and short irons cannot be exhibited.

Therefore, professional golfers and advanced players have made a loft of the head to suppress backspin and prevent the ball from rising when the wind is strong. However, the batting method that requires such special skills was impossible for intermediate and beginners.

In view of the above points, the present invention provides a set of iron clubs in which a ball stays at a desired position in a long iron, and in a middle iron and a short iron, the backspin amount is reduced to prevent the ball from rising too high and being influenced by wind. It is the one we are trying to provide.

[Means for Solving the Problems]

According to the present invention, the above-mentioned problems include an iron golf club set which is composed of a plurality of clubs each having a different number of counts and whose loft angle increases with an increase in the number of counts, by sandblasting the face surface of each club. The iron golf club set is characterized in that a fine uneven surface is formed and the coefficient of friction of the face surface of each club is continuously reduced as the number of counts increases.

[Work]

According to the present invention, the backspin is applied to the ball in the long iron and the hitting ball is slightly higher than the conventional one, but the ball stays at the desired position, and in the middle and short irons, the backspin amount of the ball is reduced. As a result, it does not rise high and is less susceptible to wind.

Further, since the face surface having fine irregularities by sandblasting has many frictional surfaces and the irregularities are shallow, even a weak player can obtain sufficient frictional force. Further, since the face surface has a uniform uneven surface, the frictional force at the time of hitting the ball is stable.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

1 (a) to 1 (d) show an embodiment of the present invention. Iron club sets generally consist of 8 pitches from the 2nd club for long distance to the 9th club for short distance and a pitching wedge equivalent to 10th, but a sand wedge equivalent to 11th. It may be an added set. Alternatively, it may be a half set of iron clubs which is a combination of a club having a count of 3, 5, 7, 9 and a pitching wedge.

Figures 1 (a)-(d) show the four clubs in these sets.
Only 11-14 are shown and the rest of the clubs are not shown. Here, the club of FIG. 1 (a)
From 11 to club 14 in Figure 1 (d), the number of counts is increasing in order. Although not shown, in the set, the club length decreases almost regularly as the number of iron clubs increases from the lowest number iron club so that the flight distance changes regularly. Further, as can be seen from FIGS. 1 (a) to 1 (d), the loft angle of the club heads in the set regularly increases as the iron count increases from the lowest iron count.

Faces 19-22 of heads 15-18 in clubs 11-14
Each is provided with fine unevenness 23 by sandblasting. The surface roughness of the face surfaces 19 to 22 due to the fine irregularities 23 gradually decreases as the number of counts increases.
In this way, the surface condition of the face surface of the clubs in the set is such that the surface roughness gradually decreases as the number of iron clubs increases from the lowest iron count, and therefore the face of the clubs in the set The coefficient of friction of the surface gradually decreases from the lowest iron club count as the iron count increases. In order to change the surface state in this way, for example, the particle size of the blast particles used for each club may be gradually changed according to the count number.

Fig. 2 shows the relationship between the number of counts and the coefficient of friction of the face surface of various iron club sets consisting of combinations of 2nd to 9th clubs and 10th pitching wedges. Shows the relationship between the number of counts in the set shown in FIG. 2 and the loft angle of the head. In FIG. 2, the friction coefficient of the face surface in the conventional iron club set indicated by the score A is approximately 0.3 μ and is constant. On the other hand, the coefficient of friction of the face surface in the iron club set according to the present invention continuously decreases as the number of counts changes, as indicated by direct D and curve E. Note that B and C indicate that the coefficient of friction of the face surface directly increases with an almost constant change rate as the number of counts increases. Again, the relationship between the number of counts and the face surface of the conventional iron club set. Is shown. Also, D
In the set having the characteristic of No. 2, the coefficient of friction of the face surface linearly decreases with an almost constant change rate as the number of counts increases. On the other hand, in the set having the characteristic of E, the friction coefficient gradually decreases as the number of counts increases, and the reduction rate of the friction coefficient gradually increases.

The loft angle of the head in the conventional club set has a change characteristic shown by a dotted line F in FIG.

The loft angle change characteristic of the club set according to the present invention may be the same as that of the conventional one, but as shown by a straight line G in the figure, the degree of increase in the loft angle becomes larger than that of the conventional one as the number of count increases. You can increase it.

Figure 4 three pitching wedge the present invention PW ₁ ~PW ₃
It is an example applied to a club set consisting of.
In this club set, as indicated by a straight line H, the coefficient of friction of the face surface continuously decreases at a substantially constant rate of change within the range of 0.5 to 0.4 as the number of counts increases. Also, the loft angle of the head in this set is 50 (DEG) to 60 (DEG), as shown by the straight line I in FIG.
Within the range up to, the rate of change increases continuously as the number of counts increases.

FIG. 6 shows clubs PW _{1 to} PW having the characteristics shown in FIGS. 4 and 5.
_It shows the flight distance of the ball on the level ground when ₃ is used. In the figure, J ₁ indicates the carry from the hitting position to the falling position of the ball, and J ₂ indicates the rolling distance (run) of the ball after falling. As can be seen from this figure, in this club set, the pitching wedges PW _{1 to} PW ₃ have a constant rate of change in the carry of the ball as the number of counts increases, but the rolling distance of the ball becomes constant. There is.

The coefficient of friction is a measure of the slipperiness of two objects, but in the case of a golf club, as shown in FIG. Since the vertical force works, the head at the same time
The ball 25 slides in the X direction due to the loft angle of 26. At that time, a force R acts on the contact surface, which is opposite to the X direction. This R is a dynamic friction force, and the friction coefficient in the present invention means a ratio μ (μ = R / N) between the dynamic friction force R and the vertical force N.

The friction coefficient μ can be measured by the method shown in FIG. Referring to the figure, an object to be measured 28 whose both sides are the same as the surface state of the face surface of the head is prepared.
Hemispherical ball pieces 29, 30 are applied to both side surfaces of 28, respectively, and are pressed against the object 28 to be measured with a pressure N. Further, the load cell 31 pushes the object 28 to be measured in a direction orthogonal to the pressure N to slide the object 28 to be measured. At that time, the friction coefficient μ is determined by the relationship between the load R and pressure N by the load cell 31.
Ask for.

FIG. 9 shows the trajectory of various clubs having different friction coefficients. In the figure, shows the trajectory of the ball by a long iron with a small friction coefficient. Although the launch angle of the ball is large, the trajectory is low and the flight distance is large because the back spin amount of the ball is small. Shows the trajectory of the ball in the case of another long iron, which differs only in that the friction coefficient is larger than that of. In the case of this long iron, the trajectory is higher and the rolling distance of the ball is shorter than that of this iron. Therefore, the flight distance is stable. Shows the trajectory of a short iron with a small friction coefficient. According to the iron, the ball does not rise as high as the conventional short iron, so it is less susceptible to wind.

Shows the trajectory of the ball in the case of another short iron, which is different only in that the coefficient of friction is larger than that of the iron. It can be seen that the short iron has a high ball and is easily affected by the wind.

〔The invention's effect〕

According to the present invention, the coefficient of friction of the face surface between the clubs in the set continuously decreases as the number of counts increases, so in the long iron, the hit ball is slightly higher than the conventional long iron, but the backspin is high. As a result, the sphere easily stops at the desired position. On the other hand, the middle and short irons require directionality and accuracy of the ball to be hit, and the ball tends to be slower as the number of used balls is larger than that of the long iron. Therefore, the conventional golf club has a number when the wind is strong. Hitting a ball with a large number of clubs was not speedy, and the ball went up high, so it was affected by the wind.

On the other hand, according to the present invention, while following the structure of a normal golf club in which the loft angle is increased by increasing the number of counts, a set of normal golf clubs in which the friction coefficient of the club face surface is decreased by increasing the number of counts. With a face structure that is the opposite of the one adopted, the tendency to increase the trajectory of the ball is suppressed and the technical idea of reducing the influence of the wind on the ball during flight is recalled. In the iron golf club set, which has a larger loft angle as the number of counts increases, a fine uneven surface is formed on the face surface of each club by sandblasting, and the friction coefficient of the face surface of each club is Adopting a configuration that decreases continuously as it increases. As a result, the middle and short irons tend to have a higher trajectory in response to an increase in the loft angle as the number of counts increases, while the friction coefficient of the face surface is reduced in response to an increase in the number of counts. The backspin amount of the hitting ball can be surely reduced compared to the conventional club, and the trajectory of the hitting ball will not be so high as in the conventional one, but the trajectory will be low, which is less affected by the wind and the directionality of the hitting ball even on a windy day. Is a better one. Therefore, even an intermediate player and an beginner can exert an effect of accurately controlling a hit ball in the wind without using a special technique.

Further, in the present invention, since the friction coefficient of the face surface is given by sandblasting, the obtained friction surface is a fine shallow surface with a large area, and the friction surface is formed by a conventional groove. To
When a weak player hits the ball, the ball does not bite into the groove, and there is no fear that the required frictional force will not be obtained, and sufficient frictional force is obtained. Further, in the case where the frictional force on the face surface is changed by changing the groove interval, when the groove interval is wide, the frictional force changes depending on whether or not the ball hits the groove at the time of hitting, and the frictional force is not stable. On the other hand, in the present invention, since the uneven surface is uniformly formed by sandblasting, the frictional force does not change and the frictional force at the time of hitting the ball is always stable.

[Brief description of drawings]

1 (a) to 1 (d) are perspective views of main parts of four clubs in an iron club set according to an embodiment of the present invention, and FIG. 2 is a conventional golf club set and the present invention. FIG. 3 is a graph showing the friction coefficient change characteristics of each club in various iron club sets, FIG. 3 is a graph showing two modes of the loft angle change characteristics of the club head in the golf club set shown in FIG. 2, and FIG. FIG. 5 is a graph showing the friction coefficient change characteristics of each club when the invention is applied to a set consisting of three pitching wedges. FIG. 5 is a graph showing the loft angle change characteristics of the club head in the golf club set shown in FIG. FIG. 6 is a graph showing the flight distance of the ball by the club shown in FIG. 4, and FIG. 7 is a graph for explaining the relationship between the force generated at the time of ball impact and the friction coefficient. FIG 8 Figure showing the measurement principle of the friction coefficient, FIG. 9 is a diagram showing various ball trajectory. 11-14 ... Iron club, 15-18 ... Head, 19-22 ... Face surface, 23 ... Asperity, 25 ... Ball, 26 ... Club head, 27 ... Face surface, 28 ... Measured Things, 29, 30 …… Ball pieces, 31 …… Load cell.

Claims (1)

[Claims] 1. An iron golf club set comprising a plurality of clubs each having a different number of counts and having a loft angle that increases as the number of counts increases. A fine rugged surface is formed on the face surface of each club by sandblasting. An iron golf club set, which is formed by continuously reducing the friction coefficient of the face surface of each club as the number of counts increases.