JPS6296806A - Detecting method of change in surface of body - Google Patents

Abstract

PURPOSE:To make it possible to perform simple, accurate detection of the state of a surface readily regardless of the fine or coarse state of the surface to be detected, by comparing sound, which is generated by blowing compressed air, with a preset value, and generating a detected output when the compared value reaches a specified ratio. CONSTITUTION:When compressed air at 1-2 atmospheric pressure is blown from a nozzle 3, sound corresponding to the surface of a body to be detected 4 is generated and received by a microphone 9. The received sound passes a bandpass filter 12 and the like, and the sound volume is detected by a volume indicator 13. The detected sound volume is compared with a preset sound volume in a preset value indicator 14 in a comparator 15. When the ratio of both values reaches a specified range, the detected value, at which the surface of the body 4 is changed by a specified value, is generated. Thus, the state of the surface such as cut parts of continued paper and the like can be detected, readily, simply and accurately regardless of the fine and coarse state of the surface to be detected. When the frequency of the generated sound is used, the same result can be obtained.

Description

Detailed Description of the Invention (Industrial Field of Application) This invention is useful for detecting objects that are difficult to detect by optical, electric, or mechanical devices, such as cuts or grooves in continuously fed flat objects. It relates to a method for detecting changes in the surface of an object whose purpose is to detect changes in the surface, and belongs to the industrial field of manufacturing, selling, and using detection equipment.

(Prior art) Conventionally, to detect surface changes of objects, electrical, optical,
Various detection methods and devices, such as mechanical or ultrasonic detection methods, have been proposed and used.

(Problem to be solved by the invention) However, in the case of objects whose surfaces are relatively non-uniform (e.g. urethane board) or objects that hardly change (e.g. detecting cuts in paper etc.), the former is difficult to use with precision equipment. In the latter case, it is often difficult to detect with conventional technology such as electrical or optical, and if these are installed so that they can be detected with conventional technology, there are problems such as huge equipment costs. was there.

(Means for solving the problem) However, this invention attempts to detect the surface condition of an object by capturing the sound generated by blowing pressurized air and searching for changes in the sound. Even if the surface was finished with high precision or was finished in a rough state, we succeeded in accurately capturing and detecting the desired change.

That is, this invention blows pressurized air onto the detection surface, captures the sound generated by this, measures the volume and/or frequency, and compares the measured value with a preset value. They succeeded in accurately detecting the desired change in surface condition and solved the problems of the conventional methods.

The pressurized air in the above is blown onto the detection surface from the nozzle or slit, and the pressure is 1 to 2 Kg/
It was recognized that the purpose could be achieved sufficiently with CD.

Detection can be done either by using a volume indicator and a frequency display, or by using only a volume indicator, but in the latter case, the change value to be detected is determined through preliminary experiments, this is set on the setting indicator, and the comparison is made. When a predetermined detection value is reached, the signal is output through a device, and various devices are operated to perform the required detection and its automatic control.

For example, when a predetermined length of paper is continuously fed, the cutting edge of the paper is accurately captured and the necessary processing (for example, printing or surface treatment) is automatically performed on each paper can.

(Operation of the invention) That is, this invention captures the sound generated by blowing pressurized air, compares it with a preset value, and outputs a detection output when the comparison value reaches a predetermined ratio. So,
The desired surface state can be easily detected regardless of the refinement of the surface to be detected.

(Example) Next, embodiments of the invention will be described.

As shown in Fig. 2, pressurized air (e.g. 2 K9/ci) is fed from the air source as indicated by arrow 1, and the pressure is adjusted to a constant level by operating the pressure reducing valve 2 (e.g. 9/c to '1.5').
d) After spraying, spray from the nozzle 3 onto the upper surface of the object to be detected 4. In this case, the nozzle hole of the nozzle 3 has an inner diameter of 1.2 am+
1. The distance from the top surface of the detected object 4 is 10 to 20tI! It's in R. In this case, the pressurized air travels straight as shown by arrow 5,
The light then diffuses as shown by arrow 6, but the vibration state of the diffused air changes depending on the surface state of the object to be detected, and the surface change can be interpreted as a change in sound. For example, as shown in FIG. 3, if there is a groove 7 on the surface of the object to be detected 4, a part or almost all of the pressurized air flows along the groove 7 in the direction of arrow 8. Inevitably, different sounds are generated depending on whether there is a groove or not, and the groove can be detected. In the above, the sound generated by blowing pressurized air is collected by the microphone 9, and is collected by the amplifier 10, the attenuator 11,
The signal is sent to the volume indicator 13 via the bandpass filter 12. Next, the numerical value on the indicator and the preset value indication ff'1
After comparing the numerical value set in 14 with the comparator 15, when the ratio of both numerical values reaches a predetermined value, an output is made as shown by the arrow 16, thereby activating the automatic device. In the above, the attenuator 11 is adjusted to the optimum level by looking at the numerical value indicated by the volume indicator 13. Then, unnecessary frequencies are blocked by a bandpass filter 12. The comparator 15 compares two quantities of electricity, but since the collected amount is always less than the set value and exceeds the set value when it changes, it generates a pulse signal at that time and maintains this pulse signal for a certain period of time. It is set to output when it is executed.

(Effect of the invention) That is, according to the present invention, pressurized air is blown onto the detection surface, the sound generated by this is captured, and when the change in the sound becomes abnormal in relation to the set value, the output is output. This has the effect that the desired detection can be performed accurately regardless of the refinement of the surface to be detected. Easy to use, without the need for precision equipment or advanced technology.
And it has an effect that can be detected accurately.

[Brief Description of the Drawings] Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is a sectional view showing the state in which pressurized air is blown from the nozzle, and Fig. 3 is a sectional view showing the movement of the detection surface. FIG.

Claims (1)

[Claims] 1. Pressurized air is blown onto the surface to be detected, the sound generated by this is captured, the volume and/or frequency are measured, and the measured value is compared with a preset value. Method 2 for detecting changes in the surface of an object, characterized by outputting and detecting when the numerical ratio falls within a predetermined range Pressurized air is blown from a small-diameter nozzle, and the pressure is set to 1 to 2 kg/cm^2. Detection method 3 for detecting surface change of an object according to claim 1 Detection is performed by comparing a volume indicator and a set value indicator, and outputs when the indicated values of both have a predetermined relationship. A method for detecting a change in the surface of an object according to claim 1