JPH0465618A - Thickness measuring instrument - Google Patents

Abstract

PURPOSE:To easily the thickness reduction distribution of piping by measuring the internal thickness from an internal surface reflected signal among the ultrasonic wave signals of an ultrasonic sensor, and calculating the thickness reduction state and coloring and displaying it. CONSTITUTION:The position of a contact which is short-circuited with an ultrasonic probe 1 is detected by a position detection sensor 2 and the position in movement is found through an encoder 13. At each ultrasonic probe position, the generation time of the internal surface reflected signal in the ultrasonic wave signal of the ultrasonic sensor 11 in the ultrasonic probe 1 is measured to measure the thickness at each point. Position information and thickness information at each point are led to an arithmetic circuit 7 and the thickness reduction state is calculated from those pieces of information and thickness data at the time of no thickness reduction and displayed on a display unit 8. For the display, a surface scanned by the ultrasonic probe 1 is expanded into a plane. Positions on the plane correspond to inspection positions calculated with the information on the position of the ultrasonic probe 11 and the arrangement of the ultrasonic wave sensor 11 in the ultrasonic probe 1 and on the points colors corresponding to the thickness reduction are displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an ultrasonic wall thickness measuring device that measures the thickness of piping, etc. in various plants and inspects the state of thinning.

[Prior Art] As one of the methods for inspecting the state of thinning of pipes, etc., there has conventionally been the following method. That is, a marking line is made on the inspection surface, and ultrasonic waves are perpendicularly incident on the surface of the pipe using an ultrasonic thickness gauge as shown in FIG. 5, and waves reflected from the inner surface of the pipe are detected. Then, as shown in FIG. 6, the wall thickness is measured by measuring the time from transmission to reception, and the amount of thinning is determined from the difference from the wall thickness when no thinning occurs. Furthermore, the position of the ultrasonic sensor is measured based on the marking line for property damage, etc., and the position of thinning and the condition within the area are recorded. By performing such a process on the entire surface of the pipe, it is possible to know the distribution of thinning of the pipe as a whole.

Further, in order to automatically perform such a process, an automatic inspection device has been developed that can scan the ultrasonic sensor 11 in the circumferential direction and the axial direction, as shown in FIG. To explain its structure, the scanner 130 includes a track 131 installed on the pipe 9, a truck 132 that moves circumferentially on the track, and a scanning shaft 133 that moves axially on the truck. 134 is a controller of this scanner 130. The ultrasonic sensor 11 is attached to the tip of the scanning shaft 133.

The pulser/receiver 4 sends an electric pulse to the ultrasonic sensor 11 to generate ultrasonic waves, and the ultrasonic sensor 11
Amplify the detected signal. Based on the thus detected signal, the distance measuring circuit 5 (thickness measuring circuit)
Measure the time from transmission to reception. Based on the output of the distance measuring circuit 5 and the information on the ultrasonic sensor position from the scanner controller 134, the arithmetic circuit 7 calculates the amount of thinning at each position. The results are then displayed on the display 8.

In this device, the controller 134 automatically scans the ultrasonic sensor 11 in the circumferential direction and the axial direction, measures the thinning at every fixed pitch movement, and displays a color tone corresponding to the amount of thinning on the inspection surface on the display 8. Display on a two-dimensional display surface corresponding to This makes it possible to know the distribution of thinning.

(Problems to be Solved by the Invention) Although automatic inspection is possible using the conventional inspection device shown in FIG. There are many adjacent piping lines and there may not be enough space to install automatic inspection equipment. Furthermore, even if it can be installed, the area that can be automatically inspected is narrow, and the range of application is quite limited. Moreover, you can instruct the device in advance which part to inspect (
There is a need. In addition, installation takes time and inspection efficiency is poor. Furthermore, if the pipe diameter changes, equipment to match it is required, and there is no flexibility.

On the other hand, when the inspection is performed manually, it takes a lot of effort to find the inspection position, and the inspection efficiency is extremely low.

[Means for Solving the Problems] In order to solve the above-mentioned conventional problems, the present invention provides: - A plurality of ultrasonic sensors arranged in a row, rollers arranged at both ends, and an encoder that detects the rotation of these rollers. a flexible band-shaped position detection sensor that can be attached to the surface of the subject; a pulser receiver that excites the ultrasonic sensor to transmit and receive ultrasonic waves; a thickness measurement circuit that calculates the thickness of the specimen; a position detection circuit that can detect the pressed position when a part of the position detection sensor is pressed; and a position of the ultrasound probe calculated based on the signal of the encoder. a wall thickness measuring device characterized by comprising an encoder detection circuit for detecting a wall thickness; and the position detection sensor is inserted between a plurality of sets of positive electrodes and negative electrodes, and the electrical resistance is increased by compression. The present invention proposes a wall thickness measuring device characterized by having a conductive rubber that decreases in thickness.

[Function] In the present invention, since a flexible band-shaped position detection sensor is used, it can easily cope with changes in the pipe diameter.
It is also easy to install. During inspection, by pressing this position detection sensor with an ultrasonic probe, the initial position on the circumference can be automatically detected. Then, by manually moving the ultrasonic probe 7 in the axial direction from there and detecting this moving distance with an encoder inside the ultrasonic probe,
The absolute position of the ultrasound probe can be easily detected.

In the present invention, an inspector with an ultrasonic probe can freely avoid and inspect even if there is a stand supporting the piping, a branch pipe, adjacent piping, etc. In addition, even curved surfaces such as elbows can be scanned by tracing the ultrasonic probe with the human hand, making inspection easy. At this time, the position of the ultrasonic probe is detected by the method described above, and by automatically processing and displaying this information and the wall thickness information from the ultrasonic probe, the wall thickness distribution can be easily known.

[Example] Fig. 1 is an overall view showing an embodiment in which the present invention is applied to a residual pipe inspection device, Fig. 2 is a diagram showing the structure of an ultrasonic probe of this device, and Fig. 3 is a similar diagram. A sectional view showing the structure of the position detection sensor, and FIG. 4 is a wiring diagram of the same position detection sensor.

First, in FIG. 1, reference numeral 1 denotes an ultrasonic probe for measuring the wall thickness of the pipe 9. As shown in FIG. Reference numeral 4 denotes a pulser receiver which sends electric pulses to the ultrasonic probe 1 to generate ultrasonic waves, and also amplifies and outputs the ultrasonic waves reflected on the inner surface of the pipe and detected by the ultrasonic probe 1. Reference numeral 5 denotes a distance measuring circuit (thickness measuring circuit), which measures the time from the transmitted signal to the reflected signal based on the signal from the pulser/receiver 4 to measure the wall thickness. 6 is an encoder detection circuit that detects the moving distance of the ultrasonic probe 1 from the output of an encoder (13 in FIG. 2) built into the ultrasonic probe. 2 is a position detection sensor which is wound around the pipe 9 in the form of a band. Reference numeral 3 denotes a position detection circuit, which detects the position when the part of the position detection sensor 2 is pressed. 7 is an arithmetic circuit which inputs information from the above device and calculates the digit 1 of the ultrasonic probe 1 and the thinning situation, and 8 is a display device which displays the thinning distribution.

Next, as shown in FIG. 2, the ultrasonic probe 1 has a mechanism in which a large number of small ultrasonic sensors 11 are arranged in a straight line inside and are pressed against the inspection surface using springs 15 or the like.

Further, a roller 14 and an encoder 13 are attached to both ends, and when the roller 14 is moved in a direction perpendicular to the plane of the paper, the roller 14 rotates, and the rotation is detected by the encoder I3, and the amount of movement l is detected.
can be known.

Further, each ultrasonic sensor 11 arranged in large numbers is excited by the pulser/receiver 4, and can measure the wall thickness at a large number of points at a time.

As shown in FIG.
．． 25 are arranged in a straight line, and a rubber magnet 21 is attached to the back surface of the flexible sensor. This sensor is attached to the pipe 9 with a rubber magnet 21,
If the top of the rubber sheet 22 is pressed, the electrodes 24 and 25 will come into contact with each other. The pressed position can be determined by detecting with the position detection circuit 3 which point has been touched.

Next, regarding the connection of each electrode of the position detection sensor 2, the fourth
This will be explained using figures. This is an example where there are 9 sets of electrodes (=3×3). Regarding the positive electrode 24, three wires connecting three adjacent contacts are taken out one by one as one signal wire to form a cable 26. For the negative electrode 25, three wires connected to every three contacts are sequentially taken out as one signal wire to form a cable 27. By detecting which wires of the cables 26 and 27 are short-circuited, the positions of the contacts can be known. By connecting in this way, it is possible to obtain m × n contact information with m positive electrode cables and 9 negative electrode cables, and the number of signal line cables from the position detection sensor 2 (m 10 n) can be reduced.

It is also possible to consider a structure in which a conductive rubber whose electrical resistance decreases when compressed is inserted between the positive and negative electrodes 24 and 25, and the electrodes are short-circuited by pressing the rubber. In the connection between the electrodes, the contact surface becomes small and the surface tends to deteriorate due to discharge, but if conductive rubber is used, this problem is eliminated and the durability is improved.

The operation of such a device during use will be described next. An inspector holds the ultrasonic probe 1 in his hand, presses the position detection sensor 2 wound around the pipe 9, and moves the pipe 9 in the axial direction from that position by IQ. At this time, the position of the contact that was first shorted by the ultrasonic probe l is detected by the position detection sensor 2, and the position being moved is detected by the encoder 13.
It is determined by At each ultrasonic probe position, the wall thickness at each point is measured by measuring the generation time of an internal reflection signal among the ultrasonic signals of the ultrasonic sensor within the ultrasonic probe l. The position information and wall thickness information of each of these positions are led to the arithmetic circuit 7, and the thinning situation is calculated from these and the wall thickness data given in advance when no thinning has occurred, and the thinning status is displayed on the display 8. Is displayed. The display is performed by expanding the surface scanned by the ultrasonic probe 1 onto a plane. A point on this plane corresponds to the inspection position calculated from the position information of the ultrasonic probe l and the arrangement of the ultrasonic sensor 11 in the ultrasonic probe 1, and the point is colored with a color corresponding to the thinning described above. Display. This display shows the distribution of pipe wall thinning.

〔Effect of the invention〕

According to the present invention, the following effects can be obtained.

(1) The position of the ultrasound probe can be detected with a simple mechanism,
The mechanism of the device is simple and easy to handle.

(2) Since the ultrasonic probe is scanned manually, even if there are pipe supports, branch pipes, etc., the inspection can be easily avoided, and the range of application is wide.

(3) By using an ultrasonic probe with a plurality of built-in ultrasonic sensors, -A wide range can be inspected by scanning, so the inspection time can be shortened.

[Brief explanation of drawings]

FIG. 1 is an overall view showing an embodiment of the present invention, FIG. 2 is a cross-sectional view showing the structure of an ultrasonic probe in the same embodiment, FIG. 3 is a cross-sectional view showing the structure of a position detection sensor, and FIG. The figure is a wiring diagram of the same position detection sensor. 51 is a diagram for explaining a method of measuring wall thickness using ultrasonic waves, and FIG. 6 is a diagram for explaining a method for determining wall thickness from ultrasonic signals. FIG. 7 is an overall configuration diagram showing an example of a conventional automatic wall thickness measuring device. ■...Ultrasonic probe, 2...Position detection sensor 3...Position detection circuit, 4...Pulsar receiver 5...Distance measurement circuit (thickness measurement circuit) 6...
- Encoder detection circuit 7... Arithmetic circuit 9... Piping 12... Case song 14... Roller 2I... Rubber magnet 24... Electrode (positive) 26... Positive side cable. 101... Ultrasonic propagation path 103... Internal reflection signal 131... Trajectory. 133... Axial scanning axis. 134...Scanner controller. 8...Display unit 11...Ultrasonic sensor 13...Encoder 15...Flip 23...Rubber sheet 25...Electrode (negative) 27...Negative side cable 102...Transmission Signal 130... Scanner 132... Trolley.

Claims (2)

[Claims] (1) Ultrasonic probe that has multiple ultrasonic sensors arranged in a row, rollers arranged at both ends, and an encoder that detects the rotation of these rollers; flexible belt-like position that can be attached to the surface of the subject Detection sensor: a pulser receiver that excites the ultrasonic sensor to transmit and receive ultrasonic waves;
A thickness measurement circuit that calculates the thickness of the object based on the ultrasonic signal; a position detection circuit that can detect the pressed position when a part of the position detection sensor is pressed; and a thickness measurement circuit that can detect the pressed position when a part of the position detection sensor is pressed; A wall thickness measuring device comprising an encoder detection circuit for calculating the position of the ultrasonic probe. (2) Claim (2) characterized in that the position detection sensor has a plurality of sets of positive electrodes and negative electrodes, and a conductive rubber inserted between the positive electrodes and the negative electrodes and whose electrical resistance is reduced by compression. 1) Wall thickness measuring device described.