JPH0332999Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a brush type flaw detection device for detecting flaws etc. generated on a surface to be inspected.

(Conventional technical background) Coal-fired power plants generally use belt conveyors to transport coal, but the moving belt of the belt conveyor may be damaged by coal or deteriorate due to long-term use. Cracks may occur. If such a belt conveyor is continued to be used as it is, there is a risk that the moving belt will break and cause unexpected damage, so the moving belt is inspected periodically.

This inspection involves stopping the belt conveyor and
A worker is running on a conveyor belt.

For this reason, the inspection work is inefficient,
In addition, coal dust remains on the surface of the moving belt, which poses health problems.

Therefore, this idea was devised in view of the above problems, and it is a brush-type flaw detector that can easily detect scratches and cracks on a moving belt without the need for workers to crawl on top of the belt conveyor. The purpose is to provide equipment.

(Means for Solving the Problems) In order to achieve the above object, this invention is equipped with a brush that slides into contact with the surface to be inspected, and a detection means that detects the high frequency vibration when the brush vibrates at high frequency. It is something.

(Function) When the brush collides with a scratch or the like on the surface to be inspected, it vibrates at high frequency, and the detection means detects the high frequency vibration.

(Example) Hereinafter, an example of this invention will be described based on the drawings.

FIG. 1 is a schematic perspective view of a brush flaw detection device according to this invention. In the figure, 1 is a brush embedded in a substrate 2, which is made of elastic synthetic resin such as plastic. It is designed to vibrate at high frequencies when subjected to a collision. This brush 1 is, for example, R111
~ Made of nylon with a hardness of about R118, diameter 0.2 mm,
It is 15mm long and is said to be slightly softer than the average toothbrush. The substrate 2 is made of a material that transmits the high-frequency vibrations of the brush 1 to a detector 3 (detection means), which will be described later, without attenuating the high-frequency vibrations of the brush 1, and is made of, for example, metal or plastic similar to the brush 1. Ru.

A detector 3 is attached to the substrate 2, and this detector 3 converts only the high frequency vibration of the brush 1 into an electrical signal and outputs it, and is composed of, for example, a piezoelectric ceramic ultrasonic vibrator. has been done.

FIG. 2 is a block diagram showing the configuration of a signal processing system that processes the electrical signal output from the detector 3. In the figure, 4 is an amplifier that amplifies the electrical signal output from the detector 3; is a display device that displays the waveform of the electrical signal on a display screen.
For example, it consists of an oscilloscope. Next, the operation of the brush type flaw detection device will be explained.

First, as shown in FIG. 3, the flaw detection device is placed on the moving belt B and fixed with a frame (not shown) so that the brush 1 presses the moving belt B with an appropriate pressure. Next, the moving belt B is moved in the direction of the arrow. Then, the brush 1 curves as shown in FIG. 4, and as the moving belt B moves, scratches, cracks P, etc. come to the position of the brush 1.
As shown in FIG. 4, the brush 1 returns to its original shape (straight line) due to elastic force. At this time, brush 1
The tip 1a collides with the opening of a scratch or crack P, etc.
The impact of the collision causes the brush 1 to vibrate at a high frequency. For example, if the brush 1 is as described above, the high frequency vibration caused by collision with the mouth of the brush 1 such as scratches or cracks P is approximately 40KHz to 50KHz.
That's about it. This high frequency vibration of the brush 1 causes the substrate 2
The high-frequency vibrations are transmitted to the detector 3 via the detector 3, which converts the high-frequency vibrations into electrical signals. Then, the waveform of the electrical signal output from the detector 3 is displayed on the oscilloscope as shown in FIG. By the way, since the detector 3 does not output low-frequency vibrations caused by shaking or vibration of the moving belt B as an electric signal, the detector 3 only outputs electric signals due to high-frequency vibrations caused by scratches, cracks P, etc. The presence or absence of scratches, cracks P, etc. can be detected from the displayed waveform. Therefore, unlike the conventional method, there is no need to crawl over the belt conveyor to find scratches or cracks. Further, as shown in FIG. 3, if the flaw detection device is installed so as to be movable up and down at the illustrated position, the presence or absence of flaws, cracks, etc. can be detected without stopping the operation of the belt conveyor.

FIG. 6 shows another embodiment, in which 11 is a rectifier circuit that rectifies the AC voltage, which is the electric signal output from the amplifier 4, into DC voltage, and 12 is the DC voltage output from the rectifier circuit 11. A comparator that compares the reference voltage output from the reference voltage generation circuit 13 and outputs a comparison signal when the DC voltage is higher than the reference voltage; 14 receives the comparison signal output from the comparator 13 and detects scratches, cracks, etc. This is an indicator that lets you know that something is occurring, and can consist of, for example, a lamp or a buzzer. In this embodiment, a comparator 12 is used to remove noise, and a lamp or a buzzer is used to notify the presence or absence of scratches or cracks.

Although the above embodiment describes the case of detecting scratches and cracks on the moving belt B of a belt conveyor, the present invention is not limited to this, and the detection of scratches and cracks on a wall, etc., is also possible. Of course, you can also do it.

(Effects of the invention) As described above, this invention includes a brush that slides against the surface to be inspected, and a detection means that detects high-frequency vibrations when the brush vibrates at high frequencies. It is designed to generate high-frequency vibrations when it collides with scratches, etc., so it is possible to efficiently and easily inspect scratches and cracks on the moving belt without the need for workers to crawl on top of the belt conveyor. In addition, there is no risk of workers' health being harmed by dust such as coal scum, and depending on the installation method, it is possible to detect scratches without stopping the belt conveyor. It has the effect of

[Brief explanation of the drawing]

Figures 1 to 6 show examples of this invention, with Figure 1 being a schematic perspective view of a brush-type flaw detector, and Figure 2 showing a signal processing system for processing electrical signals output from the detector. A block diagram showing the configuration, FIG. 3 is an explanatory diagram showing an example of the use of the brush type flaw detection device, and FIG. 4 is a diagram to explain the movement of the brush.
Figure 5 is a diagram for explaining the waveform of the electrical signal output from the detector, and Figure 6 is a block diagram showing another embodiment of the signal processing system that processes the electrical signal output from the detector. be. 1... Brush, 3... Detector, B... Moving belt, P... Scratch.

Claims (1)

[Scope of utility model registration request] The apparatus includes a brush that slides into contact with a surface to be inspected, and a detection means that detects high-frequency vibration when the brush vibrates at high frequency, and the brush vibrates at high frequency when it collides with a scratch or the like generated on the surface to be inspected. A brush type flaw detection device characterized by: