JPS5917364A - Iron golf club - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an iron golf club, and particularly to an iron golf club with improved trajectory stability in the vertical direction.

Excluding external factors such as wind, the trajectory of a golf ball is determined by the initial characteristics of the golf ball (initial velocity, launch angle, spin, etc.) based on the impact between the club head and the golf ball, and the characteristics of the golf ball (lift-drag coefficient). , moment of inertia, weight, etc.), and conventionally, the flight distance and lateral direction of the golf ball have been considered important as the functions of the Cibo Luc Club. ]7 However, in golf games where the ball is dropped at a target point, even if the ball deviates from the target point in the left and right directions, or if the ball deviates from the target point in the direction of flight of the ball, the target point From the point of view of the deviation in the fall of the ball, the results are considered to be the same.

Therefore, the inventors of the present invention focused their attention on improving the trajectory stability in the downward direction of 1F, which had not been considered important in the past.

Here, the moment of inertia used in the present invention) IX.

Mechanical factors such as moment Iy1 center height N G % center of gravity depth ZG and critical angle θ are defined as follows/+'. First, as shown in the top view and side view of the golf club head in FIGS. 1a) and 1(b),
The Y and Z axes were defined as follows. In other words, salary 1 figure (
a).

As shown in (b), the sole 4 (!1″
In contact with the plane 8, the predetermined lie angle and loft angle β
jf+, the club head is placed on the 311 plane 8.

17. A straight line passing through the center of gravity G of the club head and parallel to the plane 8 and the face 2 of the club head is assumed, and this straight line is defined as the Z axis. It's a moat, the center of gravity G of the club head.
1, assume a straight line parallel to the face 4 and perpendicular to the Z axis, and define this straight line as the y-axis. Further, assuming that i+'i is perpendicular to the Z-axis and the y-axis and spans the center of gravity G, this straight line is defined as the Z-axis.

Further, a white key C that is in contact with the toe 6 of the golf club head and parallel to the y-axis is assumed on the xy plane, and the distance from the intersection P of this straight line C and the Z-axis to the centroid G is defined as XG. sole 4
Let the distance from the leading edge 10 of the club head to the face 2 of the center of gravity G in the orthogonal projection G'F be the center of gravity distance YG, and the distance from the center of gravity G to the orthogonal projection G' be the one center depth Za. The distance from the plane 8 to the orthogonal projection G' is defined as the height of the center of gravity H4.

Using the x, y, z axes, etc. determined as above, the moment of inertia (IX) is defined as the moment of inertia around the X axis, and the moment of inertia y is defined as the moment of inertia around the y axis.

Finally, the angle formed by a perpendicular line l drawn from the rear upper edge of the club head onto the plane 8 and a straight line passing through the rear upper edge and touching the rear surface of the club head is defined as a critical angle θ.

By the way, as is known from the past, the trajectory of the ball in the left-right direction is determined by the initial characteristics of the ball, including the left-right launch angle and the initial velocity of the ball, which are mainly affected by the magnitude of the moment of inertia (y), and the depth of the center of gravity. It is related to side spin, which is affected by the size of ZG. Similarly, the vertical trajectory of the ball is influenced by the vertical launch angle and initial velocity of the ball, which are influenced by the magnitude of the moment of inertia (IX) of the initial characteristics of the ball, and are mainly influenced by the depth of the center of gravity ZG. It is related to the backspin generated. Therefore, if the initial characteristics of the ball are stabilized, the resulting trajectory and flight distance will be stabilized.

Therefore, the present inventor and others have determined the initial velocity of the ball, flight distance (related to backspin, which is the initial characteristic of the ball), and elevation angle (related to the vertical launch angle, which is the first characteristic of the ball), which determine the stability of the trajectory in the vertical direction. The relationship between the moment of inertia) Ix and the center of gravity depth ZG was investigated by simulation. Here, stability means that the degree of variation is small, and in general, C11 wobble must be evaluated with respect to variation in the hitting point on the face.
In the simulation, I hit the ball at the sweet spot (the point on the face where the widest distance can be obtained) and the ffi+ was based on the 10 points below the sweet spot! 1 'J
The judgment was made based on ``9''. Therefore, the smaller this difference is, the higher the stability is. When performing the simulation, the club head speed was 35 m/s.
s, using an amateur swing mode of horizontal hitting and using an Eagle club head (manufactured by Brideston, trade name). As a result of the 97 rotation, the differences in initial ball speed, flight distance, and elevation angle were determined by inertia. It was confirmed that the larger the moment Ix, the smaller it becomes.

Regarding the difference between the center of gravity depth ZG and flight distance, it was confirmed that the larger the center of gravity depth ZG, the smaller the difference in flight distance, but the relationship between the center of gravity depth ZG and the distance difference The relationship between Ix (moment of inertia) and flight distance was not as significant as the difference between Ix and flying distance. Therefore, the moment of inertia (Ix) is the most important factor for the stability of the trajectory and flight distance in the vertical direction.

As mentioned above, in order to improve the trajectory stability in the vertical direction, the moment of inertia I is inversely proportional to the depth of the center of gravity ZG, and as the depth of the center of gravity Zc increases, the moment of inertia (IX) generally decreases. In addition, the moment of inertia related to left-right direction) I
y and center of gravity depth Z. They are inversely proportional, and the center of gravity depth ZG
As y increases, the moment of inertia y decreases.

Therefore, simply increasing the moment of inertia y and the center of gravity depth ZG will not only not improve the trajectory stability in the vertical direction, but also will not improve the trajectory stability in the vertical direction.
Even if the trajectory stability in the vertical direction can be improved, there is a trade-off between the conventional club head manufacturing method in that the trajectory stability in the left and right directions deteriorates.

- Also, as a function of a golf club, in addition to the above-mentioned horizontal direction and vertical direction, it is important to properly adjust the height of the center of gravity H. This height of the center of gravity HG is related to the sweet spot. It must be placed at a height that allows a 1D and LC golf ball to be hit at the sweet spot on the ground. However, the height of the center of gravity Ha is the moment of inertia Ix
In proportion to the moment of inertia ■ As X increases, the height of the center of gravity HG increases.However, from the perspective of improving the stability of the trajectory in the vertical direction, increasing the moment of inertia) IX increases the height of the center of gravity. f(G becomes high, resulting in a golf club that cannot hit at the sweet spot even if the trajectory is stable.

The present invention has been made based on the above-mentioned viewpoints, and provides an iron golf club that maintains the influence on the height of the center of gravity and the lateral direction at a higher level than the conventional level, and also improves the trajectory stability in the vertical direction. The porpose is to do.

In order to achieve the above object, the configuration of the present invention is as follows: (a) For the No. 3 iron, the moment of inertia) Ix is 4.8 g-relative s e c2 or more, and the moment of inertia ■y is 21.0 g.
@ya・sec or more, center of gravity height H is 200M or less, and center of gravity depth ZG is 3. Q pea or above, (b) For No. 4 iron, moment of inertia) Ix is 5.25 g-
Ho・sec2 or more, limit angle θ is 8 degrees or less, moment of inertia Iy is 22.0 g-wax・sec2 or more, center of gravity height Ha75 is 19.8ya or less, and center of gravity depth ZG is 28 shoulders. Above, <C) For the 5th iron, the moment of inertia) Ix is 5
．． 8g-1 hardness, 8e C' or more, critical angle θ is 6 degrees or less, moment of inertia ■y is 28.0g"a-8ee2 or more, center of gravity height Hc is i9.6Gw or less, and Tunxin Chen Z
a is 2.35- or more; (d) For the No. 6 iron, the moment of inertia Ix is 6.
．． 2g - 8802 or more, critical angle 0 is 5 degrees or less, moment of inertia ■y is 28.5 g ++ mi * s
e c” or more, center of gravity depth i (G is 19.5 M or less, and center of gravity depth zG is 2.15 or more, (e) 7 iron, moment of inertia) Ix is 6
．． 6 g @Zue s e c2 or more, critical angle θ is 3
degree or less, moment of inertia Iy is 24.0g-m5sec
2 or more, the center of gravity height Ha is ISJ, 2 rm or less, and the center of gravity depth Z. is 1.8 m or more, (f) 8: For Zhan iron, 1 shell moment 1
-IX is 7.25 g-flexure sec2 or more, critical angle θ is 1 degree or less, moment of inertia Iy is 24.5g*yi
-seC2 or higher, center of gravity knitted HG is 19. Below OMJ,
And, the depth of the center of gravity Zc is 1.5M or more, (g) For a 9-g iron, the moment of inertia) lx is 8.0 g-see” or more, the limit angle θ is 0 degrees or less, and the moment of inertia Iy is 25. 5 g * m e 8 e
e” or more, center of gravity height E (G is 18.8x or less, and
Center of gravity depth ZG is 1. (h) For the pitching wedge, the moment of inertia X is 9. Qgai amsec” or more, critical angle O is 0 degrees or less, moment of inertia Iy is 27.0 g-period #81
11e'' or more, the center of gravity height FtG is 18.2 [or less], and the center of gravity depth ZC is 1.0m or more.

Here, the values of the center of gravity height H6, the moment of inertia lTy, and the center of gravity depth zG are limited in order to maintain the influence on the center of gravity height H and the left-right directionality at a level higher than the conventional level.

By the way, among the iron golf clubs conventionally available on the market, the maximum value of the moment of inertia Ix of the golf club that satisfies the above-mentioned restrictions regarding the center of gravity height H, c, the moment of inertia Iy, and the center of gravity depth ZG is the first As shown in the table.

Table 1 (The unit of numbers in the table is g-parrot・8ee", ■3~
■9 indicates the iron and PWd pitching wedge for the subscript 5. ) As a result of measuring the number 3 iron as an example, the average value of the moment of inertia) IX is 4.25g-M・5ee2
The difference in flight distance between the sweet spot and the point 101 m below the sweet spot for this moment of inertia (Ix) is 21.7 m, and the moment of inertia (Ix) in Table 1 is 4. , (3,ga +a・S e
The distance difference for c2 3 iron is 20.6
m f ii Uta 1, therefore, the moment of inertia IX is 4.25 g・vrx・s e c” to 4., 5
When J”61 is added to g*IAm・5ec2, the trajectory stability in the vertical direction is improved with respect to the difference in flight distance.

In the present invention, the moment of inertia (Ix) is determined as shown in Table 2 in order to further improve the trajectory stability in the vertical direction.

Table 2 (The units of numbers in the table are geXII・BeC.)
In addition, it has been confirmed that the trajectory stability is saturated when the moment of inertia (IX) exceeds a predetermined value, so the lower limit value of the moment of inertia x, moment of inertia y, center of gravity depth 2G, and upper limit value of center of gravity height HG are , is preferably set to the values shown in Table 3 below.

As a result, the difference in flight distance was 19.5m, which was 10.1% of the difference in flight distance with the conventional moment of inertia Ix4, 25gmm5aec" (average value), and the trajectory stability in the vertical direction was improved. Furthermore, when looking at the deflection angle, which is used to predict the point of fall of a golf ball, the difference in elevation angle of the club of the present invention compared to that of the average conventional iron golf club was found to be 5% higher. The ratio of corner differences improved as shown in Table 4.

Table 4 Next, in order to increase the moment of inertia (Ix) and the depth of the center of gravity Za, it is sufficient to distribute the mass of the club head in two axial directions, but the mass 1 can be distributed in two axial directions without limit. In this case, the rear surface of the club head enters the field of vision at address, resulting in poor address feeling, and as a result, flight distance, vertical trajectory stability, etc. are not affected. In this case, a sensory test of address feeling was conducted on five amateur golfers, and the critical angle θ was determined as shown in Table 5.

Table 5 Note that the reason there is no limit angle θ limit for No. 3 iron ■3 is that with conventional long irons, the back of the club head is generally in the field of vision at address, so the address feeling is This is because it does not affect.

In order to distribute the mass in two axial directions while limiting the protrusion of the rear part of the tap head using the above limit angle θ, the second
As shown in Figure (1), place the club head on the face part 2.
After dividing into three parts: 0, middle rib part 22, and rear part 24, and adjusting the amount by scraping the inner surface of the rear part 24,
Welding is performed in the state shown in FIG. 2 (2) to form a hollow portion inside the club head. That is, after determining the outer shape of the rear portion 24 according to the limit angle θ, by processing the inner surface of the rear portion 24 as described above, the limit angle θ and the depth of the center of gravity Z
We manufacture club heads that satisfy conditions such as c. Examples of two batches produced by the above method are shown in Table 6.

Table 6 Note that the upper part of the hollow rib may be cut out as shown in FIG. 3 for the club head.

Figure 4 (a), (b) and Figure 5 (a), (b)
2 shows another embodiment of the present invention. Figure 4 (a), (b)
In this example, the height in the Z-axis direction is 411 m and the width in the XX-axis direction is 4.
The hollow part in the club head is partitioned using a flexible rib 26, and the face thickness is set to 2.5 gIR.

The moment of inertia Ix of this club head is 6.4g11
R118ee”, moment of inertia Iy is 26.5g5a
@sec” Center of gravity height HG is 19.1XI, center of gravity depth ZG
is 8. The Or limit angle θ was −7. In addition, rib 26
The cross-sectional shape is not limited to a rectangle, but may be a trapezoid with a maximum width of 2 to 102 g, or a plurality of ribs 26 may be provided.

In the embodiments shown in FIGS. 5(a) and 5(b), a cylindrical or truncated conical pin 30 extending in the Z-axis direction is provided so that the hollow portion within the club head is not partitioned. The maximum diameter of this pin is preferably 3 to IOM, and in the figure, a cylindrical pin with a diameter of 8M is used. Note that the pin may be hollow, or a plurality of pins may be provided.

Providing ribs and pins as in the above embodiments has the effect of improving the feel on impact.

As explained above, according to the present invention, it is possible to obtain the effect that the trajectory stability in the vertical direction is improved compared to the conventional one.

[Brief explanation of the drawing]

Figures 1 (a) and (b) are diagrams for explaining the mechanical factors according to the present invention, and Figures 2 (1) and (2) are diagrams for explaining the mechanical factors according to the present invention. Explanatory diagrams, Figures 3 (a), (b), Figures 4 (a), (b), and Figure 5
Figures (a) and (b) are a front view and a side view showing an embodiment of a club head according to the present invention. 2. Face, 40 sole. 6... Tou. Agent Tatsuyuki Unuma (and 2 others) (b) Figure 4 Figure 5 (0) 0

Claims (1)

[Claims] (1) In an iron golf club in which a club head is fixed to one end of the shaft and is classified into a plurality of types according to the loft angle, a golf club that is assumed to be in the club head, passes through the center of gravity of the club head, and is connected to the club head. When the club head is installed on a plane with a lie angle and a loft angle of constant Hf, the moment of inertia around the X axis parallel to the plane and the face of the club head is IX, and The angle formed by a perpendicular line drawn on the plane and a straight line that captures the upper edge of the rear side and touches the rear surface of the club head is defined as the critical angle θ, which is assumed to be perpendicular to the X-axis and is the center of gravity of the club head. The moment of inertia around the Y axis passing through and parallel to the face is i
y, and the IE from the plane to the face of the center of gravity
Let the distance to the projection be the center of gravity, HG, and +S from the center of gravity.
il When the distance to the restraining projection is the center of gravity depth Zc, (a) For the No. 3 iron, the moment of inertia IX is 4
．． 8g@request・8e02 or more, moment of inertia Iy is 21.0 g exmm sec2 or more, center of gravity height HG is 20.0m or less, and center of gravity depth 2. ga'd,
Q ym or more, (b) For the 4th iron, the moment of inertia) I work is 5.25 g 6 wi a s'e c
2 or more, critical angle θ is 8 degrees or less, moment of inertia IV is 2
2.0 g-u・sec2 or more, center of gravity height Hc is 198 mm or less, center of gravity depth 'la is 2.8 m or more, (C) Moment of inertia for No. 5 iron) IX is 5 .8g*m・s e c" or more, limit angle θ is 6 degrees or less, moment of inertia ■y is 28.0 g・tak・s e c2
Above, the height of the center of gravity HG is 19.6 m or less, and the depth of the center of gravity zq is 2.35 m or more, (d) Moment of inertia) Ix for No. 6 iron is 6
．． 2 g am8 s e c2 or more, limit angle θ is 5 degrees or less, moment of inertia Iy is 28.5 g・shoe・s e
c2 or more, center of gravity height HG is 19.5m or less, and center of gravity depth ZG is 2.15x or more. (e) For No. 7 iron, moment of inertia: [x is 6. ．． 6 g -M・8 e e2 or more, critical angle θ is 3
degree or less, moment of inertia l-I y is 24.0 g-2m
s e c” or more, heavy equipment IIG is 19.21D or less, and center of gravity depth ZG is 1.8 or more, (f) For No. 8 iron, moment of inertia) Ix is 7
．． 25 g-brow/sec2 or more, critical angle O is 1 degree or less, inertia mono 71-I y is 24.5 g-uam
s e c2 or more, east center surface Hc is 190 terms or less, and center of gravity depth Z G 75K1.5 ysii or more, (
g) 9@For irons, moment of inertia) Ix is 80
g*tm・5eC2 or more, limit angle θ is 0 degrees or less, moment of inertia ■y is 25,5g11w&・5eC2 or more, 1
F center height 11 G is 188 or less and center of gravity depth ZG
is 10 or more, 01) For the flat angle, the moment of inertia Ix is i), Q g *IAM” S e 02 or more, the limit angle O is 0 degrees or less, and the moment of inertia ■y is 27.0
g-ff・s e c' or more, - center of gravity height i (6 is l
82rmA or less and +4i heart rate Z. is 1. O
wn That's all, club.