JPH0325744B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic ultrasonic flaw detection device for non-destructively testing steel products such as round bars or pipes using ultrasonic waves.

[Conventional technology]

FIG. 3 is a conceptual diagram of a conventional device for inspecting a specimen using an ultrasonic automatic flaw detection device, and FIG. 4 is a conceptual diagram of a conveying ski roll shown in FIG. 3.

In Figures 3 and 4, 1 is a material to be inspected such as a round bar for inspection with an automatic ultrasonic flaw detection device, 2 is a motor for rotating the ski roll, and 3 is a device that converts the direction of the rotational force of the motor and transmits it. A miter gear box 4 is a chain coupling gear box which further changes the direction of the rotation of the miter gear box 3 and connects it to the chain. A chain coupling gear box 5 has a preset angle of θ shown in the figure from the center line in the conveying direction of the material to be inspected. A ski roll rotated by a chain connected to the chain coupling spring gear box 4, 5a
and 5b, 5c and 5d, 5e and 5f, and 5g and 5h. 6 applies the rotational force of the motor 2 to each of the ski rolls 5c and 5d, 5e and 5f, and 5.
It consists of shafts 6a, 6b, and 6c for transmitting data to g and 5h. Reference numeral 7 denotes a mechanical part of an automatic ultrasonic flaw detection device, and 8 refers to three sets 8a, 8b, which bring the flaw detection head into contact with the test material and follow the movement of the test material.
8c is a tracking device; 9 is a flaw detection head that is attached to the tracking device and houses a probe that transmits and receives ultrasonic waves to the specimen; 10 is a photoelectric sensor; 10a and 1 are photoelectric sensors;
0c is a light emitter of a photoelectric sensor, and 10b and 10d are light receivers that emit a signal to a computing unit at the moment when the light is blocked by the conveyed test material. 11 is a variable speed controller for rotating the motor 2 in a required stable manner; 12;
13 is a calculator for controlling the contact or separation of the flaw detection head 9 of the tracking device 8 and calculating the speed of the test material by inputting signals from the photoelectric sensor 10; A chain for transmitting data to 13a, 13
b rotates the ski roll in the same direction. 14 is a gear coupling for decelerating and transmitting the rotation of the motor 2, and 15 is a pedestal for supporting the skid roll. The conveyance speed when a test material is transported by a skiwl roll depends on the magnitude of the angle θ of the skiwl roll and the magnitude of the rotation speed of the skiwl roll. Therefore, since it is not possible to immediately determine the conveyance speed from the rotational speed of the ski roll, conventionally two sets of photoelectric sensors 10a and 1 are installed at fixed points on the conveyance line.
A method has been used in which the conveyance speed is determined by the time difference between the moments when the object to be inspected blocks light from two sets of photoelectric sensors using 0b, 10c, and 10d. As shown in FIG. 3, the distance between the photoelectric sensors 10a and 10b is L ₁ (mm). Also, if the time difference between the time when the material to be inspected blocks light from the photoelectric sensors 10a and 10b is T ₁ (seconds), the velocity V ₁ of the material to be inspected is calculated by the calculator 12 as V ₁ =L ₁ /T ₁ ...(1) Desired.

[Problem that the invention seeks to solve]

When detecting flaws in the entire area using an automatic ultrasonic flaw detection device, it is necessary to transport the material at a constant pitch speed.In the method described above, in which the transport speed of the test material is determined from two sets of photoelectric sensors, the test material always moves at a constant speed. However, in an automatic ultrasonic flaw detection device, it is necessary to inspect the edge of the test material, so it is necessary to reduce the transport speed to a low speed near the position where the flaw detection head 9 is brought into contact with the material. There was a problem where it could not be applied. Furthermore, when conveying with a skid roll, the test material may slip due to the conveyance direction vector and the rotation direction vector, making it difficult to convey it at a constant speed.

This invention was made to solve this problem and to accurately determine the speed of the test material even when the speed of the test material changes.

[Means for solving problems]

Since the conveyance speed is related to the set angle θ and the number of rotations of the ski roll, this invention uses a rotation detector that generates rotation pulses on the rotation axis of the ski roll, a counter that counts the pulses generated by the rotation, and the two sets of photoelectric sensors. It is equipped with a sensor and inputs the outer diameter of the material to be inspected, the set angle θ of the squirrel roll, the pulse count value, and the photoelectric sensor signal to a computing unit to determine the conveyance speed.

[Effect]

θ is the setting angle of the ski roll, N is the rotation speed of the ski roll per second, φ ₁ (mm) is the outer diameter of the material to be inspected, φ ₂
The conveying speed V (mm) when (mm) is the outer diameter of the squirrel roll is determined by the following formula.

V ₂ =Kφ ₂ /φ ₁・N・cosθ (mm/sec) (2) K is a coefficient that differs depending on the outer diameter of the material to be inspected, including slips during transportation.

First, the number of rotations of the ski roll is converted into pulses by a rotation detector and counted every second by a counter. The count value is input to the arithmetic unit and the count value is inputted to the arithmetic unit (2)
This is an element that determines the conveyance speed by calculating the formula. Next, the time difference T ₁ at the moment when the object to be inspected blocks light from the two sets of photoelectric sensors having a distance difference L ₁ is determined by a calculator, and the conveyance speed V ₁ is determined by the above equation (1).

Letting the ratio of the speeds V ₂ and V ₁ be the correction coefficient α, α can be obtained from the following equation.

α=V ₂ /V ₁ …(3) In equation (3), if α=1, V ₁ and V ₂ are equal, but normally α=1.
The conveyance speed V ₃ =1/αV ₂ (4) obtained by dividing 1/α into equation (2) becomes the corrected speed and becomes the actual conveyance speed of the material to be inspected.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2.

In FIGS. 1 and 2, numerals 1 to 15 are exactly the same as the conventional device. A rotation detector 16 is connected to the rotating shaft of the ski roll 5 through a coupling, and generates a pulse signal corresponding to the rotation speed of the ski roll. 17 is a counter that counts the pulses generated by the rotation detector 16; 18 is a coupling that connects the squirrel roll 5 and the rotation detector 16;

The angle and rotation speed of the ski roll are set in advance, the conveying speed V ₂ is determined by the computing unit 12 using the equation (2), and the material to be inspected is conveyed. The material to be tested consists of two sets of photoelectric sensors (10a and 10b and 10c and 10
Until d) is shielded from light, the conveyance speed obtained by inputting the pulse whose rotational speed is converted by the calculation of equation (2) above is regarded as the actual conveyance speed. Flaw detection head 9
When lowering the speed to a low speed near the position where the material is to be welded, the rotation speed of the ski roll is reduced by the motor 2. Therefore, since the number of pulses from the rotation detector 16 is low, a low speed can be calculated. Immediately at the moment when the photoelectric sensor is shielded from light, the computing unit 12 calculates a correction coefficient using equation (3) above, and executes the calculation using equation (4) above to obtain the actual speed. By using more of the correction coefficient (2) determined by the above equation (3), the actual transport speed of the material to be inspected can be obtained.

〔Effect of the invention〕

Conveying speed using equations (2), (3), and (4) above not only allows you to determine the actual speed even when the speed is variable, but also calculates the speed for each conveyed material to be inspected. Therefore, the conveyance speed is constantly being corrected, and even if the conveyance speed varies from piece to piece,
It has the advantage of being able to obtain accurate conveyance speed.

[Brief explanation of the drawing]

FIGS. 1 and 2 are conceptual diagrams showing one embodiment of the present invention, and FIGS. 3 and 4 are conceptual diagrams showing a conventional device. In the figure, 1 is the material to be inspected, 2 is the motor, 3 is the miter gearbox, 4 is the chain coupling gearbox, 5 is the ski roll, 6 is the shaft,
7 is a mechanism section, 8 is a follow-up device, 9 is a flaw detection head, 1
0 is a photoelectric sensor, 10a and 10c are floodlights, 1
0b and 10d are light receivers, 11 is a variable speed controller, 1
2 is a computing unit, 13 is a chain, 14 is a gear coupling, 15 is a frame, 16 is a rotation detector, 17 is a counter, and 18 is a coupling. Note that the same reference numerals in each figure indicate the same or equivalent parts.

Claims (1)

[Claims] 1. In an ultrasonic automatic flaw detection device that detects flaws over the entire area of a round bar or pipe to be inspected that is conveyed at a constant pitch by rotation of a skew roll with a skew angle set in advance, the rotation for detecting the rotation of the skew roll. a detector, a counter that counts the pulses of the rotation detector, two sets of photoelectric sensors provided at fixed points on the conveyance line, and a calculator that calculates the signal of the photoelectric sensor and the count value of the rotation detector. The speed of the material to be inspected transported by the skew roll is calculated from the outer diameter of the material to be inspected, the skew angle of the skew roll, and its rotation speed, and the two sets of photoelectric sensors spaced apart by a certain distance are tested. An automatic ultrasonic flaw detection device characterized in that the actual speed of the material to be inspected is determined by correcting the calculation speed of the outer diameter of the material to be inspected, the skew angle, and the number of rotations based on the speed determined from the time difference in which the material passes.