JP2001120694A - Iron club - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an iron club, the ball striking sound of which can be heard easily. SOLUTION: An iron club, of which the maximum sound pressure of the ball striking sound of a head is in the frequency domain of 2,000 to 8,000 Hz, and 1.15 or more times the maximum value of the sound pressure of the striking sound of a ball.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an iron club which makes it easy to hear a hitting sound.

[0002]

2. Description of the Related Art Conventionally, as a demand for an iron club, a comfortable hitting sound has been demanded in addition to a flight distance and a directionality. Conventional iron clubs having a large thickness called a plain back iron are often used. Since such an iron club does not vibrate very much at the time of hitting, the sound peculiar to the metal material of the head is too small, and the hitting sound of the ball itself is emphasized and heard. Further, recently, a so-called cavity back iron in which a bank-like edge is formed on the periphery of the back portion and the inside thereof is formed in a concave shape has been used.

[0003]

Although the cavity back iron described above has a reduced face thickness, the vibration is suppressed by the bank-like edge of the periphery of the back portion. The fact is that the sound is emphasized and can be heard.

The inventor of the present invention has measured the cause of the conventional cavity back iron, which does not produce a clear metallic sound at the time of hitting the ball, but emphasizes the sound that the ball is distorted, using a hitting sound detection system shown in FIG. Found from the results. This system displays a waveform of a measurement result relating to sound pressure level-frequency at the time of hitting a ball, and can convert and display a maximum sound pressure level generated at a certain frequency into a voltage. A specific measuring method is to detect a hitting sound when the two-piece ball 6 is hit by swinging the iron club 4 set on the golf robot 2 (manufactured by Miyama Corporation). The hitting sound is recorded by the microphone 8 (Yokogawa, Hewlett,
The signal is taken into a dynamic signal analyzer 10 (35670A, manufactured by Yokogawa-Hewlett-Packard) via a Packard Company (35220A), where the sound pressure level-frequency is displayed in a waveform.

FIG. 2 shows a sound pressure level-frequency waveform obtained by the above system when hit with a normal titanium alloy cavity back iron. In this case, the sound generated from the head itself, a so-called metal sound, is estimated to be one peak M1 (converted voltage at 5120 mV at 5120 mV), and another peak M2 region (200
It has been found that the maximum value of the converted voltage is 55.2 mV below 0 Hz. The inventor of the present invention has assumed that the cause of the peak M2 is the sound generated from the ball itself, which is a cause of canceling the metal sound peculiar to the head. A two-piece ball was attached in place of the metal head, and the balls were hit with each other to measure sound pressure level-frequency. FIG. 3 shows the measurement result, and it was found that a similar peak M2 ′ (maximum value is 1792 Hz) occurs in a region of 2000 Hz or less, which is substantially the same as the measurement result shown in FIG. .

Accordingly, the present inventors have conducted various studies on the relationship between the sound pressure level of the hitting sound generated from the ball itself at the time of hitting the ball and the sound pressure level generated from the head itself. We have derived the conditions to be able to hear. That is, an object of the present invention is to provide an iron club in which a hitting sound can be easily heard.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an iron club in which the maximum sound pressure level of the hitting sound of the head is in a frequency range of 2000 to 8000 Hz and the sound pressure level of the hitting sound of the head is reduced. This is achieved by setting the maximum value to 1.15 times or more the maximum value of the sound pressure level of the ball hitting sound. Here, the maximum value of each sound pressure level is obtained from the voltage generated at each maximum sound pressure level detected by the measuring device.

As shown in FIG. 2, the maximum hitting sound pressure level of a head hitting sound is 58.0 mV and the hitting sound pressure of a ball hitting sound from a ball hitting sound produced by a commercially available iron club is shown in FIG. The maximum value is 55.2 mV, and the maximum value of the sound pressure level of the hitting sound of the head is about 1.05 times the maximum value of the sound pressure level of the hitting sound of the ball. In the present invention, heads of various configurations were created and the test hits were repeated.
It was found that when the above ratio was 1.15 times or more, an easy-to-hear metallic sound was obtained.

The maximum value of the sound pressure level of the hitting sound of the head is 2,000 in the same manner as in the conventional iron club.
Although it is preferable that the frequency range be up to 8000 Hz,
Considering the characteristics of human hearing based on the "equal loudness curve" of Mitsuyasu Yamashita's "On-Game Story" (Corona Co., Ltd.), it is desirable to form the frequency range from 2000 to 6000 Hz, which is easier to hear.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an iron club capable of obtaining the above-described ratio relating to the sound pressure level and a measurement result thereof will be described.

FIGS. 4A and 4B are views showing a first embodiment of the present invention. FIG. 4A is a view of the head body of the iron club as viewed from the back side, and FIG. 4B is a view of A in FIG. It is sectional drawing along the -A line (perpendicular line which passes a sweet spot).

The head main body 1 includes a top wall 1a, a sole wall 1b, a toe wall 1c, and a heel wall 1d each having a predetermined thickness, and these are integrally formed in a ring shape (hereinafter, referred to as "ring"). , A portion formed by the top wall 1a, the sole wall 1b, the toe wall 1c, and the heel wall 1d is a ring-shaped portion). A hosel 1e having a hole into which a shaft (not shown) is inserted is formed integrally with the heel wall 1d.

A back wall 1f is formed integrally with the sole wall 1b at the rear end of the ring-shaped portion. This back wall 1f does not block the rear end of the ring-shaped portion,
It is integrated with the sole wall 1b so as to form the opening 3 above. A face member 5 is fixed to the front end surface of the ring-shaped portion by welding or the like.

The ring-shaped portion is made of an iron alloy (7Ni-1).
2Cr-4Si-0.02C-Fe), and the face member is also made of an iron-based alloy (7Ni-12Cr).
-4Si-0.02C-Fe) having a thickness T1 of 2.
It is formed to be 3 mm. Also, back wall 1
f is a thickness T2 of 2.5 mm and a height H to an upper end.
Is set to 25 mm.

As described above, by opening the back side of the head, a clear metallic sound can be obtained without the sound being interrupted when the ball is hit. In particular, by setting the height H of the back wall to 25 mm and making it higher than the sweet spot S, when hitting at the sweet spot S, a reverberation effect is obtained with the back wall, and a clearer hitting sound is obtained. Will be obtained. An acoustic adjustment member 7 made of a material softer than the back wall is fixed to the rear end surface of the back wall 1f to adjust the sound quality and loudness of the hitting sound.

Further, the sole wall 1b of this embodiment is
The rear end side is made thicker, and a groove 1h is formed on the front end side (welding side of the face member) to reduce the contact area between the front end edge of the sole wall 1b and the face member 5. As a result, the effective hitting area is expanded below the face member. In this case, the thickness of the groove portion of the sole wall 1b is 2.5 mm, and the other thickness is 3.0 mm.

FIG. 5 shows the result of measuring the sound pressure level and frequency by fixing the head body having the above structure to the shaft, hitting the ball with the system shown in FIG. 1, and measuring the sound pressure level.
From this waveform, the maximum value M of the sound pressure level of the hitting sound of the head is obtained.
1 is 51.7 mV at 2080 Hz, and the maximum value M2 of the sound pressure level of the ball hitting sound is 41.5 mV at 1792 Hz.
was gotten. That is, the maximum value of the sound pressure level of the hitting sound of the head is 1.times. The maximum value of the sound pressure level of the hitting sound of the ball.
The hitting sound that could be actually heard was 25 times, and was a metallic sound peculiar to the head.

FIGS. 6A and 6B are views showing a second embodiment of the present invention, wherein FIG. 6A is a view of the golf club head body viewed from the back side, and FIG. It is sectional drawing along the B line (perpendicular line which passes a sweet spot). In the embodiments described below, the same parts as those in the above-described embodiments are denoted by the same reference numerals, and description thereof will be omitted.

The sole wall 1b of this embodiment is formed so that the rear end side is thick and the front end side (welding side of the face member) is thin, and the front end edge of the sole wall 1b, the face member 5 and Has a small contact area. Sole wall 1b
With such a configuration, the effective hitting point area can be expanded below the face member as in the above-described embodiment. Further, in this embodiment, the height H to the upper end of the back wall 1f is set to 20 mm, and the sound adjusting member is not fixed.

FIG. 7 shows the result of measuring the sound pressure level and frequency by fixing the head body having the above structure to the shaft, hitting the ball with the system shown in FIG. 1, and measuring the sound pressure level.
From this waveform, the maximum value M of the sound pressure level of the hitting sound of the head is obtained.
1 is 54.8 mV at 5408 Hz, and the maximum value M2 of the sound pressure level of the ball hitting sound is 47.6 mV at 1792 Hz.
was gotten. That is, the maximum value of the sound pressure level of the hitting sound of the head is 1.times. The maximum value of the sound pressure level of the hitting sound of the ball.
By a factor of 15, the hitting sound that can be actually heard is a metallic sound peculiar to the head, as in the above embodiment.

As described above, the iron club is formed such that the maximum value of the sound pressure level of the hitting sound of the head is 1.15 times or more the maximum value of the sound pressure level of the hitting sound of the ball. The hitting sound becomes a metal sound peculiar to the head, and it is possible to realize a golf club which is easy to hear and has a comfortable hitting sound. This also allows the golf player to know the hitting state (whether or not the hitting was successful without removing the sweet spot) from the hitting sound unique to the golf club.

It should be noted that the iron club according to the present invention is not limited to the illustrated one, but can be variously modified in form, material, etc. if the above conditions are satisfied.

[0023]

According to the present invention, it is possible to provide a golf club in which the hitting sound can be easily heard.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a hitting sound detection system for measuring a relationship between a sound pressure level and a frequency according to the present invention.

FIG. 2 is a waveform showing the relationship between sound pressure level and frequency obtained when hitting with a conventional cavity-back type iron club.

FIG. 3 is a waveform showing a relationship between a sound pressure level and a frequency obtained when a two-piece ball is mounted instead of an iron head and the balls are hit with each other in the system shown in FIG. 1;

FIG. 4 is a diagram showing a first embodiment of the present invention;
(A) is a view of the head body of the iron club as viewed from the back side, and (b) is a cross-sectional view taken along line AA (perpendicular line passing through a sweet spot) in (a) of FIG.

5 is a waveform showing the relationship between sound pressure level and frequency obtained when the ball is hit with the iron club shown in FIG. 4;

FIG. 6 is a diagram showing a second embodiment of the present invention;
(A) is a view of the head body of the iron club as viewed from the back side, and (b) is a cross-sectional view taken along line AA (perpendicular line passing through a sweet spot) in (a) of FIG.

7 is a waveform showing the relationship between sound pressure level and frequency obtained when the ball is hit with the iron club shown in FIG. 6;

[Explanation of symbols]

 Reference Signs List 1 head main body 1a top wall 1b sole wall 1c toe wall 1d heel wall 1f back wall 5 face member

Claims (2)

[Claims] The maximum value of the sound pressure level of the hitting sound of the head is in a frequency range of 2000 to 8000 Hz, and the maximum value of the sound pressure level of the hitting sound of the head is the sound pressure level of the hitting sound of the ball. An iron club characterized by being at least 1.15 times the maximum value. 2. The iron club according to claim 1, wherein the maximum value of the sound pressure level of the hitting sound of the head is 2000 to 6000 Hz.