JP2812575B2 - Golf ball sorting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for sorting golf balls.

[0002]

2. Description of the Related Art In a golf ball production process, since different types of golf balls may be mixed, it is necessary to select golf balls.

[0003] As a conventional golf ball selection method, a method has been known in which a golf ball is sandwiched between an ultrasonic oscillator and a receiver, and the golf ball is discriminated based on the transmission intensity of the ultrasonic wave.

In the above-mentioned conventional method, it takes time to set a golf ball, and it is difficult to apply the method to 100% inspection of a production line. In many cases, several types of balls are placed, and in such a case, different types of golf balls are mixed and must be sorted by type, and the conventional sorting method using the above-described device can completely cope with it. Did not.

Therefore, the present inventor has proposed a method for solving such a problem in Japanese Patent Application No. Hei 1-30845 (Japanese Patent Application Laid-Open No. Hei 2-211283).

That is, in the proposed invention, a golf ball collides with a solid surface, the collision sound generated at this time is frequency-decomposed in a predetermined frequency range, and a predetermined sorting reference value corresponding to the frequency range is determined. In this method, the type of the golf ball is determined by comparing the magnitude of the measured value with the measured value of the collision sound.

[0007]

However, when the inventor subsequently experimented with the above method and confirmed the result of the discrimination, he noticed that erroneous operation sometimes occurred.

Therefore, as a result of repeated trial and error,
The following became clear.

That is, in the method of the present invention, the sound collection sampling of the collision sound has been started at the time of the collision, but at the time of the collision {the moment when the golf ball is in contact with the solid surface}. The sound was extremely loud, and it was found that it was difficult to clearly determine the size depending on the type of golf ball.

Furthermore, it has been found that the sound immediately after the golf ball has left the solid surface shows a clear change depending on the type of the golf ball.

In other words, if the former sound (sound while in contact with a solid surface) is considered to be "noise", a more accurate (small error) golf ball can be selected. I understood.

Accordingly, an object of the present invention is to provide a golf ball selecting method capable of selecting different types of golf balls with higher accuracy.

[0013]

In order to achieve the above-mentioned object, a method for selecting a golf ball according to the present invention is to drop a golf ball having a predetermined height to collide with a solid surface, thereby reducing a collision sound. Sound is collected, sampling starts after 1-3 msec elapses from the time of collision, and the sampled collision sound is
The type of the golf ball is determined by frequency-resolving in the frequency range of 2.5 to 5.0 KHz, detecting the peak value of the frequency-resolved value, and comparing the peak value with a reference value set in advance in the frequency range. It is to determine.

In another method for selecting a golf ball according to the present invention, a golf ball having a predetermined height is dropped and collides with a solid surface, a collision sound is collected, and 1 to 3 msec from the time of collision.
After the lapse of time, sampling is started, the sampled collision sound is frequency-resolved in a frequency range of 2.5 to 5.0 KHz, and a frequency value at a peak value of the frequency-resolved value is detected. The type of the golf ball is determined by comparing the predetermined frequency with a reference frequency set in advance.

[0015]

According to the present invention, the collision sound generated when a golf ball collides with a solid surface can be classified into a sound that is easily attenuated and a sound that is hardly attenuated. That is, as described above, the sound is distinguished into a sound while the golf ball is in contact with the solid surface and a sound from a distance. The former is a loud impact sound in the range of 0 to 3 KHz, and the latter is a loud impact sound of 2.5 to 3 kHz. This is a sound slightly shifted from the resonance frequency of the golf ball in the range of 5.0 KHz. The latter (sound from the distance) is only the resonance frequency of the golf ball, and has a high-level peak in the range of 2.5 to 5.0 KHz when frequency-resolved. Therefore, the former (the sound while in contact with the solid surface) is rapidly attenuated after the collision, and considerably attenuated after 1 msec, whereas the latter is a natural frequency of the golf ball, and the attenuation is slow after 3 msec. But there are quite high peaks.

That is, the peak point in the frequency range of 2.5 to 5.0 KHz differs depending on the type of golf ball, and this peak point is compared with a reference value corresponding to the frequency range of 2.5 to 5.0 KHz. According to the selection method described in the item 1, it is possible to reliably determine the type of the golf ball.

Further, according to the selection method of claim 2, the frequency value of the peak point in the frequency range of 2.5 to 5.0 KHz is compared with the reference frequency value corresponding to the frequency range of 2.5 to 5.0 KHz. The type of the golf ball can be reliably determined.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing embodiments.

FIG. 1 shows a sorting device used in the golf ball sorting method according to the present invention. The sorting device includes a solid 1 made of an iron lump or the like and a microphone or the like disposed near the solid 1. A sound device 2 and a frequency analyzer 3 connected to the sound pickup device 2
And a computer 4 connected to the frequency analyzer 3.

The solid 1 has a resonance frequency of 2.5 to 2.5.
Instead of 5.0 KHz, the frequency analyzer 3 receives the signal from the sound pickup 2 and performs frequency decomposition.
The data from the frequency analyzer 3 is input and data processing is performed to determine the type of the golf ball 5.

Next, a sorting method according to the present invention using the above-described sorting apparatus will be described with reference to a flowchart shown in FIG.

First, a golf ball 5 having a predetermined height H from the solid surface 1a is allowed to fall freely and hit the surface 1a. The collision sound generated at this time is collected by the sound pickup device 2, and sampling is started 1 to 3 msec after the collision.

The sampled collision sound is frequency-decomposed by the frequency analyzer 3 in the frequency range of 2.5 to 5.0 KHz, and the result is input to the computer 4.

The computer 4 detects a peak value of the frequency-resolved value, compares the peak value with a reference value set in advance in a frequency range of 2.5 to 5.0 KHz, and determines that the peak value is smaller than the set reference value. If so, the measured golf ball 5 is, for example, a type A golf ball, and if the peak value is larger than the set reference value, the measured golf ball 5 is a type B golf ball.

Thus, the reference value is set to a substantially intermediate value between the peak point of the golf ball 5 of type A and the peak point of the golf ball 5 of type B.

By the way, the sound generated at the time of collision includes the sound during the contact between the golf ball 5 and the solid 1 (hereinafter referred to as the sound).
The sound of. ) And a sound after leaving the golf ball 5 (hereinafter referred to as a sound). The sound is a loud impact sound in the range of 0 to 3 KHz due to frequency decomposition, and the sound is The sound is slightly shifted from the resonance frequency of the golf ball in the range of 2.5 to 5.0 KHz.

The sound is the resonance frequency of the golf ball 5, and has a high-level peak in the range of 2.5 to 5.0 KHz when frequency-resolved. In addition, the sound of the sound rapidly attenuates after the collision, and attenuates considerably after 1 msec. On the other hand, since the sound of the sound is a natural frequency of the golf ball 5, the attenuation is slow and a very high peak exists even after 3 msec. Become. Therefore, in the present invention, the sampling of the collision sound is performed after a lapse of 1 to 3 msec from the collision.

FIG. 5 is a flowchart of another sorting method according to the present invention. In this case, similarly to the above-described embodiment, first, a golf ball 5 having a predetermined height H is allowed to fall freely and a solid surface is formed. Collision with 1a. The collision sound generated at this time is collected by the sound pickup device 2, and after 1 to 3 msec from the collision,
Start sampling.

Then, the sampled collision sound is frequency-decomposed by the frequency analyzer 3 in the frequency range of 2.5 to 5.0 KHz, and the result is input to the computer 4.

The computer 4 detects the frequency value at the peak value of the frequency-resolved value,
A reference frequency value set in advance in a frequency range of 5.0 KHz is compared with a reference frequency value. If the frequency value is smaller than the reference frequency value, the measured golf ball 5 is, for example, a golf ball of type C, and the frequency value is If it is larger than the reference frequency value, the measured golf ball 5 is, for example, a golf ball of type D.

Thus, the reference frequency value is substantially an intermediate value between the frequency value corresponding to the peak value of the type C golf ball 5 and the frequency value corresponding to the peak value of the type D golf ball 5. Set.

Next, an experimental example will be described.

Experimental Example 1: Two types of golf balls having different structures (that is, a one-piece golf ball A having a single rubber layer and a two-piece golf ball B having a rubber layer covered with plastic) are solid. The sample was dropped freely from a height of 50 cm from the surface 1a and selected according to the flowchart shown in FIG. 2, and the results are shown in FIGS.

FIG. 3 shows the impact sound of the golf ball shown in FIG.
FIG. 4 is a waveform diagram in which the collision sound of the golf ball B is 2.5 to 5.0 KHz.
FIG. 4 is a waveform diagram obtained by frequency decomposition in a frequency range of Hz. In addition, 100 golf balls were prepared, and the average value was shown. In this case, the reference value was set to 40 dB and indicated by a broken line. P indicates a peak point (value).

[0035]

[Table 1]

Therefore, according to this method, it is possible to reliably discriminate between two types of golf balls having different structures.

Experimental Example 2: A golf ball having the same structure but different compression (ie, a two-piece golf ball having a rubber layer covered with plastic and having a compression of 100, and a two-piece golf ball having a rubber layer covered with plastic) Golf ball and compression
110) was dropped freely from a height of 50 cm from the solid surface 1a and selected according to the flowchart shown in FIG. 5, and the results are shown in FIGS.

FIG. 6 shows the impact sound of the golf ball of C,
FIG. 7 is a waveform diagram in which the frequency of the golf ball in D is 2.5 to 5.0 KHz.
FIG. 4 is a waveform diagram obtained by frequency decomposition in a frequency range of Hz. Also in this case, 100 golf balls were prepared, and the average value was shown. The reference frequency value in this case is
4125 Hz and indicated by a broken line. In addition, P has shown the peak point.

[0039]

[Table 2]

Therefore, according to this method, two types of golf balls having different compressions can be reliably selected.

It should be noted that the present invention is not limited to the above-described embodiment, and the design can be freely changed without departing from the scope of the present invention. For example, the predetermined height H of the golf ball 5 is 50 cm.
The present invention is not limited to this. The golf ball 5 may be freely changed, and the golf ball 5 may be dropped artificially or by using a device such as a launching machine. Further, it is preferable to use a combination of the method according to the flowchart shown in FIG. 3 and the method according to the flowchart shown in FIG.

[0042]

Since the present invention is configured as described above,
The following effects are obtained.

The frequency of the impact sound differs depending on the type of golf ball, and particularly, significantly differs at the peak point in the frequency range of 2.5 to 5.0 KHz. If the frequency is set and sorting is performed by the method according to the present invention, golf balls 5 of different types can be accurately sorted.
That is, the golf ball 5 is moved from the predetermined height H to the solid surface 1a.
If it is dropped, the type of golf ball can be selected, and the operation is extremely simple.

Accordingly, in the production process, the selection of the golf balls 5 can be performed efficiently and continuously, and the inspection of all the golf balls 5 can be easily performed.

Further, if the method according to the present invention is performed at a golf driving range, it is possible to easily and surely select balls after the driving, and the golf driving range has various types of golf balls 5 according to the needs of the player. Even if you use…, you can fully respond.

[Brief description of the drawings]

FIG. 1 is a simplified diagram of a sorting device used in a sorting method according to the present invention.

FIG. 2 is a flowchart illustrating an embodiment of the present invention.

FIG. 3 is a frequency exploded view.

FIG. 4 is a frequency decomposition diagram.

FIG. 5 is a flowchart showing another embodiment.

FIG. 6 is a frequency exploded view.

FIG. 7 is a frequency exploded view.

[Explanation of symbols]

 1a solid surface 5 golf ball H predetermined height

Claims (2)

(57) [Claims] 1. A golf ball 5 having a predetermined height H is dropped and collides with a solid surface 1a to collect a collision sound. After a lapse of 1 to 3 msec from the collision, sampling is started, and the sampled collision sound is obtained. Is decomposed in the frequency range of 2.5 to 5.0 KHz, a peak value of the frequency-resolved value is detected, and the peak value is compared with a reference value set in advance in the frequency range to obtain a golf ball 5. A method of selecting a golf ball, wherein the type of the golf ball is determined. 2. A golf ball 5 having a predetermined height H is dropped and collides with a solid surface 1a to collect a collision sound. After a lapse of 1 to 3 msec from the time of the collision, sampling is started. By resolving the frequency in the frequency range of 2.5 to 5.0 KHz, detecting the frequency value at the peak value of the frequency-resolved value, and comparing the frequency value with a reference frequency preset in the frequency range. And a method of selecting a golf ball.