JPH10288512A - Shape measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shape measuring device that is high in accuracy, excellent in efficiency and also capable of preserving those of data surely. SOLUTION: This measuring device is equipped with a noncontact type laser focus displacement gauge 11 measuring a distance of up to an artificial flaw 2 and an output value of reflected light from this artificial flaw 2, a measuring mechanismic part 15 consisting of a sensor 11a of this displacement gauge 11 and a mobile mechanism 12 scanning this sensor 11a in the three dimensional direction, a control part 16 controlling this measuring mechanismic part 15, and a signal processing part 17 operating a shape of the artificial flaw 2 on the basis of the moving direction and an amount of travel of the sensor 11a via the mobile mechanism 12 by a command out of this control part 16 and an output signal out of the laser focus displacement gauge 11, respectively. With this constitution, a shape of the artificial flaw is measurable quickly, and further, precisely and in an automatic manner. Besides, data are also preservable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the shape of an artificial flaw in a test piece used for ultrasonic testing of a metal material such as a steel pipe or a steel plate.

[0002]

2. Description of the Related Art An artificial flaw provided on a test piece serves as a reference for setting a sensitivity calibration and a judgment level of an ultrasonic flaw detector. Therefore, it is important to quantitatively and precisely measure the depth, width, length, and cross-sectional shape of an artificial flaw in managing the quality of a product.

FIGS. 10 (a) and 11 (a) are diagrams showing paths of an ultrasonic echo 1a and a reflected echo 1b from an artificial flaw 2 when an artificial flaw having a different tip shape is subjected to ultrasonic flaw detection. . When the tip shape of the artificial flaw 2 is square, FIG.
As shown in FIG. 11A, while the reflected echo 1b is reflected at a relatively equal angle and converged, when the tip shape of the artificial flaw 2 is a round U-shaped groove, FIG. As shown in (a), the number of scattered echoes 1c increases. Therefore, when the tip shape of the artificial flaw 2 is a round U-shaped groove, the height of the reflection echo 1b is also apparent as a comparison between FIG. 10 (b) and FIG. 11 (b). It is lower than in the case of flaws. In other words, it can be seen that even if the artificial flaws have the same depth, the determination level differs depending on the shape. In addition,
3 in FIG. 10A and FIG. 11A indicates an ultrasonic probe.

[0004] As described above, if there is a defect in the shape (depth, width, tip shape) of the artificial flaw, the judgment level of the ultrasonic flaw detector changes, and there is a possibility that the product cannot be properly inspected. Therefore, in the calibration of the ultrasonic flaw detector,
It is very important to accurately measure the shape of the artificial flaw provided on the test piece for quality control.

By the way, the depth of the artificial flaw provided on the test piece,
As a method for measuring the width and the length, a direct measurement method using a depth gauge or a skimming gauge and an indirect measurement method using a mold sampling have been conventionally used.

[0006] Of these methods, the direct measurement method using a depth gauge or a skimi gauge measures only the depth or width of an artificial flaw. Is not obtained, there is a possibility that the flaw cannot be determined properly. Therefore, when performing the sensitivity calibration of the ultrasonic flaw detection test apparatus, it is not possible to set an appropriate sensitivity, and there are adverse effects such as overdetection and undetection.

For example, taking depth measurement as an example, if the measurement point of the depth gauge is shifted in the width direction, the measured value may be smaller than the actually measured depth. At this time, when the sensitivity calibration of the ultrasonic flaw detection test device is performed on the test piece based on the measured value, since the sensitivity is higher than a normal state,
An over-detection state occurs during actual ultrasonic flaw detection. As a result, even a portion having no flaw is erroneously detected, which hinders manufacturing.

On the other hand, in an indirect measurement method in which a mold is sampled from an artificial flaw, the cross section of the mold is cut, and the cross-sectional shape is measured with a magnifying microscope, the cross-sectional shape can be confirmed as compared with the direct measurement method. Preservation is also possible, but it is not easy to cut the mold, it takes a long time from sampling to measurement and the efficiency is poor, the mold may not match the actual flaw shape, special skills are required And lack of reliability.

Further, the test piece is subject to severe wear such as aging and contact with a roll at the time of on-site use, and the timing of remanufacturing becomes important. In this case, it is not possible to make an immediate judgment, and as described in the direct measurement method, this is a factor that causes an error in sensitivity calibration. This is when the test piece is made
The same applies to the case where the quality of the manufactured test piece is determined.

[0010]

As described above, when the shape of an artificial flaw provided on a test piece is measured by a conventional direct measuring method or indirect measuring method, there is a problem in accuracy and efficiency. Further, there is a problem in performing the sensitivity calibration of the ultrasonic flaw detection test apparatus from the aspect of accuracy. In addition, the direct measurement method has a problem in data storage.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and a non-contact type laser focus displacement meter is three-dimensionally scanned with respect to an object to be measured. It is an object of the present invention to provide a device capable of measuring a shape quickly, precisely, and automatically.

[0012]

In order to achieve the above-mentioned object, a shape measuring apparatus according to the present invention comprises a non-contact laser for measuring a distance to an object to be measured and an output value of reflected light from the object to be measured. The sensor of the focus displacement meter is scanned in a three-dimensional direction, and the shape of the object to be measured is calculated by the signal processing unit based on the moving direction and the movement amount of the sensor and the output signal from the laser focus displacement meter. . By doing so, the cross-sectional shape including the depth, width, and tip shape of the measured object can be measured quickly, precisely, and automatically.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A shape measuring apparatus according to the present invention comprises a non-contact type laser focus displacement meter for measuring a distance to an object to be measured and an output value of reflected light from the object to be measured, and a laser focus displacement meter. A measuring mechanism unit comprising a sensor and a moving mechanism for scanning the sensor in a three-dimensional direction;
A control unit that controls the measuring mechanism unit, a moving direction and a moving amount of the sensor via a moving mechanism according to a command from the control unit, and a shape of the object to be measured based on an output signal from a laser focus displacement meter. It is provided with a signal processing unit for calculating.

In the shape measuring apparatus of the present invention, after the sensor of the measuring mechanism is disposed so as to face, for example, a U-shaped artificial flaw, the sensor is focused. Next, the vicinity of the artificial flaw is scanned by the moving mechanism, and the output level of the reflected light is recorded. Then, the sensor is scanned again to input the output value of the reflected light, and the width of the artificial flaw is measured. After measuring the width of the artificial flaw, the sensor is moved to the center of the width of the measured artificial flaw, and the sensor is scanned in the height direction to measure the depth at the center of the width of the artificial flaw. After measuring the depth at the center of the width,
The sensor is again scanned in the width direction to measure the depth in the width direction. Thereby, the cross-sectional shape of the artificial flaw can be measured.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A shape measuring apparatus according to the present invention will be described below with reference to an embodiment shown in FIGS. FIG. 1 is a drawing showing the overall configuration of the shape measuring device of the present invention, FIG. 2 is an explanatory view showing a state where the measuring mechanism of the shape measuring device of the present invention is installed on a steel pipe, and FIG. FIG. 4 is a schematic configuration diagram of a measurement mechanism unit of the measurement device, and FIG. 4 is a schematic configuration diagram of a sensor of the shape measurement device of the present invention.

In FIG. 1 to FIG. 4, reference numeral 11 denotes a non-contact laser focus displacement meter for measuring the depth of an artificial flaw 2 provided on a test piece 4 in units of 1 μm.
1a can be scanned in a three-dimensional direction by a moving mechanism 12 including an X-axis (for example, tube circumferential direction) moving unit 12a, a Y-axis (for example, tube axis direction) moving unit 12b, and a Z-axis (for example, vertical direction) moving unit 12c. Is configured.

For example, as shown in FIG. 4, the sensor 11a employs an automatic focus position detection method using a tuning fork 11aa that can be vibrated in a range of ± 0.3 mm at a pitch of 0.1 μm by an electromagnet (not shown). . That is, the laser beam emitted from the semiconductor laser 11ab includes two half mirrors 11ac and a collimating lens 1ac.
1ad, the test piece 4 is irradiated through the objective lens 11ae, and the objective lens 11ae by the vibration of the tuning fork 11aa.
, Movement of the objective lens 11ae at the time of focusing on the test piece 4 is detected by the position detector 11ai.
This is taken into the laser focus displacement meter 11 as a position signal. And this movement distance is artificial flaw 2
Of depth.

The sensor 11a has a built-in ultra-compact CCD camera 11af, which receives the reflected light from the test piece 4 through the one half mirror 11ac and looks at the monitor for artificial flaws. Movement and adjustment to the position 2 can be performed. Note that 1 in FIG.
1ag is a light receiving element for receiving the reflected light from the test piece 4;
An amplifier 1ah amplifies the reflected light received by the light receiving element 11ag. The reflected light amplified by the amplifier 11ah is taken into the laser focus displacement meter 11.

X-axis moving section 1 constituting the moving mechanism 12
2a, the Y-axis moving unit 12b, and the Z-axis moving unit 12c, as shown in FIG. 3, for example, appropriately rotate the rotations of the output shafts of the X-axis pulse motor 12aa, the Y-axis pulse motor 12ba, and the Z-axis pulse motor 12ca. This is converted into horizontal movement via power transmission means, and the sensor 11a is moved in the X-axis, Y-axis, and Z-axis directions, for example, in units of 1 μm.

Reference numeral 13 denotes, for example, two pairs of electromagnets for fixing the sensor 11a and the moving mechanism 12 at predetermined positions on the test piece 4.
It is installed on the axis moving unit 12b. Then, by appropriately changing the positions of the electromagnets 13, as shown in FIG. 2, for example, when the test piece 4 is a steel pipe, the test piece 4 is fixed to the inner surface of the steel pipe to measure the inner surface shape of the steel pipe. It is fixed to the outer surface of a steel pipe to measure the outer shape of the steel pipe.

Reference numeral 15 denotes a measuring mechanism comprising the sensor 11a, the moving mechanism 12, the linear guide 14, and the electromagnet 13. The X-axis moving section 12 of the measuring mechanism 15 is provided.
The movement of the a-axis moving unit 12b and the Z-axis moving unit 12c and the fixing by the electromagnet 13 are controlled by the control unit 16.

Reference numeral 17 denotes a signal processing unit.
The sensor 1 via the moving mechanism 12 according to a command from the
The shape of the artificial flaw 2 is calculated based on the moving direction and the moving amount of 1 a and the output signal from the laser focus displacement meter 11. Note that reference numeral 18 in FIG. 1 denotes a display unit for displaying the result of the calculation performed by the signal processing unit 17 and 19 in FIG.
4 shows a fixing screw.

The shape measuring apparatus of the present invention is configured as described above. Next, the procedure for measuring the U-groove-shaped artificial flaw 2 provided on the test piece 4 using this shape measuring apparatus will be described with reference to FIGS. This will be described with reference to FIG. First, the measuring mechanism 15 is fixed by the electromagnet 13 at a position where the artificial flaw 2 of the test piece 4 and the sensor 11a of the measuring mechanism 15 face each other. And X,
The coordinates of the Y and Z axes are taken into the signal processing unit 17 as “positioning data”. After the positioning of the sensor 11a, the sensor 11a is focused.

Next, based on a signal from the control unit 16 based on the "positioning data", for example, the X-axis moving unit 12a is operated, and as shown in FIG.
The scanning of the vicinity is performed. Then, the output level of the reflected light when the sensor 11a scans the vicinity of the artificial flaw 2 is recorded.

Thereafter, the sensor 11a is again scanned in the X-axis direction at a pitch of, for example, 1 μm from the measurement start point to the measurement end point when the output level measurement of the reflected light is performed. The value is input to the signal processing unit 17. Then, a section in which the output value of the input reflected light is smaller than the output value obtained when the width measurement is performed is determined as the width of the flaw. Thereby, the width measurement of the artificial flaw 2 is completed.

After measuring the width of the artificial flaw 2, as shown in FIG. 6, the X-axis moving part 12a is operated, and the sensor 11a is moved to the center of the measured width of the artificial flaw 2. Then Z
The axis moving unit 12c is operated, and the sensor 11a is moved up and down to scan and focus the sensor 11a, and the depth at the center of the width of the artificial flaw 2 is measured.

After measuring the depth at the center of the width of the artificial flaw 2,
As shown in FIG. 7, similarly to the previous width measurement, the sensor 11a is again scanned in the X-axis direction at a pitch of 1 μm from the measurement start point to the measurement end point, and the artificial flaw 2 is scanned at every 1 μm pitch. Measure the depth in the width direction.

The measured values of the output levels of the width and the depth, the respective moving directions and the moving distances are taken into the signal processing unit 17 and subjected to arithmetic processing to convert the depth and the width of the artificial flaw 2 into coordinate values.
From these coordinate values, the cross-sectional shape of the artificial flaw 2 can be measured. The result of measuring the artificial flaw 2 of the U-groove shape using the shape measuring device of the present invention (width: 1.000 mm, depth: 1.682 mm)
Is shown in FIG. FIG. 9 shows a result (width: 1.000 mm, depth: 1.681 mm) obtained by cutting the measurement site of the artificial flaw 2 having obtained the measurement result shown in FIG.
Shown in 8 and 9, it can be seen that the depth and width can be measured with an accuracy of ± 1 μm.

The measurement time required for obtaining the results shown in FIG. 8 is about 5 minutes after the measurement mechanism 15 is fixed to the test piece 4, and the conventional indirect time shown in FIG. The time was greatly reduced as compared with about two days of the molding method using the measuring method.

In the above-described embodiment, the case of measuring the shape of the artificial flaw 2 whose length (Y-axis direction in this embodiment) is guaranteed has been described. When measuring a minute dimensional shape, it goes without saying that the above-described operation is performed at a constant pitch in the length direction.

The measuring range of the laser focus displacement meter 11 constituting the shape measuring apparatus of the present invention is ± 0.3 m.
m (= 0.6 mm), the measurement depth is 0.6 mm
If it is within the range, it is not necessary to operate the Z-axis moving unit 12c.

[0032]

As described above, according to the shape measuring apparatus of the present invention, the cross-sectional shape including the depth, width, and tip shape of the object to be measured is measured quickly, precisely, and automatically. can do. In addition, according to the shape measuring device of the present invention, data can be stored.

[Brief description of the drawings]

FIG. 1 is a drawing showing the overall apparatus configuration of a shape measuring apparatus according to the present invention.

FIG. 2 is an explanatory view showing a state where a measuring mechanism of the shape measuring apparatus of the present invention is installed on a steel pipe.

FIG. 3 is a schematic configuration diagram of a measuring mechanism of the shape measuring apparatus of the present invention.

FIG. 4 is a schematic configuration diagram of a sensor of the shape measuring device of the present invention.

5A and 5B are explanatory diagrams for measuring the width of an artificial flaw using the shape measuring apparatus of the present invention, wherein FIG. 5A is an explanatory diagram of a positional relationship between a sensor and an artificial flaw, and FIG. It is a level diagram.

FIGS. 6A and 6B are explanatory diagrams when adjusting the depth position of an artificial flaw using the shape measuring apparatus of the present invention, wherein FIG. 6A is an explanatory diagram of a positional relationship between a sensor and an artificial flaw, and FIG. FIG.

FIGS. 7A and 7B are explanatory diagrams for measuring the depth of an artificial flaw using the shape measuring apparatus of the present invention, wherein FIG. 7A is an explanatory diagram of a positional relationship between a sensor and an artificial flaw, and FIG. It is an output level diagram.

FIG. 8 is a view showing a measurement result when the shape of an artificial flaw is measured using the shape measuring apparatus of the present invention.

FIG. 9 is a diagram showing a cutting result when an artificial flaw is actually cut.

10A is a diagram showing a path of an ultrasonic echo and a reflected echo from an artificial flaw when the tip shape of the artificial flaw is square, and FIG. 10B is a diagram showing a height of the reflected echo. .

11A is a diagram showing a path of an ultrasonic echo and a reflected echo from an artificial flaw when the tip shape of the artificial flaw is a round U-shaped groove, and FIG. 11B is a view showing the height of the reflected echo. FIG.

[Explanation of symbols]

 2 Artificial flaw 4 Test piece 11 Laser focus displacement meter 11a Sensor 12 Moving mechanism 15 Measurement mechanism section 16 Control section 17 Signal processing section

Claims (1)

[Claims] 1. A non-contact laser focus displacement meter for measuring a distance to an object to be measured and an output value of reflected light from the object to be measured, a sensor of the laser focus displacement meter, and scanning the sensor in a three-dimensional direction. A measuring mechanism comprising a moving mechanism to be moved, a control unit for controlling the measuring mechanism, a moving direction and a moving amount of the sensor via a moving mechanism instructed by the control unit, and a signal from the laser focus displacement meter. A shape measuring apparatus comprising: a signal processing unit that calculates a shape of an object to be measured based on an output signal.