JP2635477B2 - Ultrasonic flaw detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pouring nozzle (hereinafter, referred to as a pouring nozzle) provided in a pouring tundish of a casting apparatus .
Relates to a device for inspecting a columnar workpiece typified called a workpiece), to an ultrasonic testing apparatus for inspecting non-destructively the presence or absence of internal cracks Te than ultrasonically generated particularly with the work use.

[0002]

2. Description of the Related Art Ultrasonic flaw detection in which an ultrasonic wave having a frequency of about 5 to 10 MHz is made incident on an object to be measured by a probe, and an internal defect is inspected by observing a state of progress or reflection of the ultrasonic wave inside the object. Inspection methods are used for the inspection of various products because nondestructive and internal defects that cannot be seen from the outside can be inspected nondestructively and quickly. It is used.

In the flaw detection inspection, the surface of the workpiece with which the ultrasonic probe comes in contact must be smooth due to the inspection accuracy, and a large amount of oxides and metals adhere around both end faces. In the flaw detection inspection of such a pouring nozzle, an operator has to grind and smooth both end faces of the nozzle with a grinder in advance, and even after polishing, the operator directly manipulates the ultrasonic probe. And inspected while crimping to the end face.

[0004]

However, when the end face of the work is polished by the operator, the end face cannot always be smoothly polished at the same angle with respect to the longitudinal axis of the work. However, since the pressure force of the probe also tends to fluctuate, there is a case where the measurement data greatly varies and an erroneous determination is made, resulting in a problem of lack of reliability.

According to the present invention, in consideration of the above-described current state of ultrasonic inspection for a pouring nozzle, both end faces of the work can be polished smoothly at substantially the same angle with respect to its longitudinal axis, and the end faces can be constantly fixed. It is an object of the present invention to provide an ultrasonic flaw detector capable of bringing an ultrasonic probe into contact with a crimping force.

[0006]

According to the present invention, there is provided an apparatus for inspecting an internal crack of a pouring nozzle , comprising : an apparatus base having a substantially flat upper surface; and an apparatus base provided on the apparatus base. A work supporting means for supporting the pouring nozzle such that a longitudinal axis of the pouring nozzle is substantially parallel to an upper surface of a base; and a work supporting means disposed on an extension of a longitudinal axis of the pouring nozzle to be supported. And the pouring tip
An end surface grinding means is provided to be toward and away from abrading the both end surfaces of the pouring nozzle relative to Le, vertical with respect to the axis
The ultrasonic probe is mounted on a linearly extended ultrasonic probe traveling rail base and
A trolley that can approach and separate from the device base, and a trolley on the trolley
At the same height as the pouring nozzle
A pair of left and right ultrasonic probe holding
Arm and a spring attached to the tip of the holding arm
Connected via a spherical bush by the connected connecting shaft
Mounted on the sensor holding board and the sensor holding board at equal circumferential intervals.
And a plurality of ultrasonic probes provided.

[0007]

Since the end face polishing means is disposed on an extension of the longitudinal axis of the work, the polished surface can always make the same angle with the longitudinal axis. Further, since the ultrasonic probe is urged to both end faces by the probe driving means at a predetermined pressure, the variation of the ultrasonic probe pressing force for each measurement is reduced, and the reliability is increased.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings, taking a flaw detector using a pouring nozzle as an inspection work as an example. FIG. 1 is a plan view of an ultrasonic flaw detector for a pouring nozzle (hereinafter abbreviated as flaw detector) according to the present invention, and FIG. 2 is a front view of the flaw detector. In FIG. 2, the ultrasonic inspection mechanism shown in FIG. 1 is omitted in order to avoid the complexity.

Referring to FIGS. 1 and 2, reference numeral 1 denotes a pouring nozzle as an example of a columnar work, and 2 and 2 'denote clamping devices as an example of a work supporting means for supporting the pouring nozzle 1 on a flaw detector. The clamping devices 2 and 2 ′ are respectively installed on the flat upper surface 3 a of the device base (base) 3.
Reference numeral 4 denotes an apparatus stand on which the apparatus base 3 is placed. or,
As shown in FIG. 2, the heights of the clamping devices 2 and 2 'are adjusted so that the longitudinal axis A is substantially parallel to the upper surface 3a of the device base when the pouring nozzle 1 is clamped. In this embodiment, the nozzle tip side (right side in FIG. 2)
Is positioned slightly higher than the clamp device 2 supporting the pouring nozzle fixing side (the left side in the figure). The clamping devices 2, 2 '
A height adjusting mechanism may be provided so that different types of pouring nozzles can be clamped in the above-described state.

For the pouring nozzle 1 clamped on the apparatus base 3 as described above, two grinder devices 5 and 5 are provided on the apparatus base 3 as end face polishing means for polishing both end faces 1a and 1b. 'Is provided. The grinder devices 5, 5 'are provided with a clamped pouring nozzle axis A
And motor mounts 7, 6 'on which the motors 6, 6' are mounted. The motor mounts 7, 7 'are on the upper surface 3a of the device base.
The guide rails 8 and 8 'are fixed so as to be slidable in the nozzle axis direction.

For each of the motor mounts 7, 7 ', grinder devices 5, 5' are provided with nozzle end surfaces 1a, 1b.
Screws 10, 1 rotated by grinder traveling motors 9, 9 'so that they can approach and separate from
0 'is screwed. In addition, regarding this end face polishing means,
Although not shown, as another embodiment, a structure in which a conventional hand grinder can be attached to the motor mount may be used, and the movement of the polishing unit is manually performed by a handle provided on a general lathe. But it is good.

As apparent from FIG. 1, according to the present embodiment, an ultrasonic inspection mechanism is provided on the side of the apparatus base 3. The mechanism includes an ultrasonic probe traveling rail base 11 extending perpendicularly to the illustrated axis A as viewed from above.
And an ultrasonic probe holding device 12 mounted on the rail base 11 and movable with respect to the pouring nozzle 1 fixed to the device base 3. The holding device 12 includes a rail. A screw screw 14 rotated by an ultrasonic probe traveling motor 13 fixed to the base 11 is screwed into the ultrasonic probe holding device 1 by rotation of the screw screw 14.
2 can move toward and away from the pouring nozzle 1 on the rail base 11.

The ultrasonic probe holding device has a carriage 15 directly mounted on the rail base 11.
In addition, the movement along the direction of the axis A of the two substantially L-shaped ultrasonic probe holding arms 16 and 16 ′ that can move in parallel to the axis A at the same height position as the pouring nozzle 1 is performed. The nozzle clamping force of the ultrasonic probe holding arms 16, 16 ', that is, the probe crimping force is made constant by the spring 26 . In addition, regarding the other components of the holding device 12, 18a, 18b and 18c in FIG.
Reference numeral 19a and 19b denote holders for holding the movable members 16 'and 16' so that they can move.

The ultrasonic probe 20 in this embodiment is provided at the L-shaped tip of each of the holding arms 16, 16 'described above. FIG. 3 is a cross-sectional view in which an installation portion of the ultrasonic probe 20 in contact with the end surface 1a of the pouring nozzle 1 is enlarged.
According to the present embodiment, four ultrasonic probes 20 are used for ultrasonic inspection of one end surfaces 1a and 1b of the nozzle, and these are provided with a sensor fixing bush 22 for one sensor holding plate 21. It is attached at equal intervals around the circumference.

As described above, the connection between the sensor holding board 21 provided with each ultrasonic probe 20 and the holding arm 16 is made by the connecting shaft 24 inserted into the bush 23 fixed to the tip of the arm. A bolt 25 is screwed into an end of the arm 24 on the arm side to prevent it from falling off, while an end 24 a on the sensor holding board side is formed in a substantially spherical shape, and a hole 21 a formed in the center of the sensor holding board 21 is formed. Inserted spherical
Ash is formed. In this embodiment, the arm 16
Between the pouring nozzle 1 and the ultrasonic probe 20
There Ru Tei also provided a spring for absorbing the shock at the time of contact.

Thus, the connecting shaft 24 and the sensor holding plate 21
Are connected via the spherical end portion 24a, so that the connecting shaft 24
Since the sensor holding plate 21 itself can pivot with respect to
Even if the polishing surface of the pouring nozzle 1 is not perpendicular to the nozzle axis A, the sensor holding plate 21 can also be inclined following this inclined polishing surface. Complete end contact is achieved. It should be noted that these elements described above are naturally provided in the other holding arm 16 'in the same manner, and the ultrasonic probes 20 are positioned and arranged so as to face each other.

An internal crack inspection procedure of the pouring nozzle 1 by the ultrasonic flaw detector configured as described above will be briefly described below. First, the worker checks the pouring nozzle 1 to be inspected.
(New or used) is fixed on the device base 3 by the clamping devices 2 and 2 ', and then the grinder traveling motors 9 and 9' are operated to drive the motors 6 and 6 'with a polishing machine to the nozzle end surfaces 1a and 1a. 1b, the motors 6, 6 'are further driven to polish the end surface, and the contact surface of the ultrasonic probe 20 is formed.

When the end surface polishing is completed in this way, the operator next causes the motors 6, 6 'to wait from the end surfaces 1a, 1b, and then drives the ultrasonic probe traveling motor 13 to The ultrasonic probe holding device 12 is moved toward the pouring nozzle 1. At this time, the arms 16 and 16 'have been moved to the open side in advance by the electric cylinder 17 so that the distance between the opposed ultrasonic probes exceeds the length of the pouring nozzle 1.

As described above, the sensor holding plates 21 and 21 'at the end of each arm are placed on the extension of the nozzle axis A.
Is positioned, the operator then drives the electric cylinder 17 again to reduce the distance between the tips of the arms 16 and 16 ', and moves each ultrasonic probe 20 to both end surfaces of the pouring nozzle 1. 1a and 1b. According to the present invention, the sp
Nozzle surface 1a of the ultrasonic probe 20 by the ring 26,
The pressing force to 1b is always constant for each inspection, and the inspection error due to the uneven pressing force is reduced.

In order to keep the pressing force constant, the reaction force from the nozzle received by the electric cylinder 17 is always detected, and when the reaction force reaches a predetermined value, the driving of the electric cylinder 17 is automatically performed. The drive may be controlled by a computer or the like so as to be temporarily stopped. When the pouring nozzle 1 is clamped by the arms 16 and 16 'as described above, the operator turns on the power of each ultrasonic probe 20 and the ultrasonic probe on the arm 16 side. Transmit the ultrasonic waves from the probe 20 toward the inside of the nozzle, receive the ultrasonic waves from the inside of the nozzle by the ultrasonic probe 20 on the arm 16 'side, and observe the ultrasonic wave propagation state at this time. By
Inspect the inside of the nozzle.

The ultrasonic inspection by the ultrasonic probe 20 can be performed sequentially and continuously among four sets of ultrasonic probes by, for example, a channel switching device (not shown). The inspection area can be expanded by rotating the pouring nozzle 1 or improving the apparatus so that the sensor holding boards 21 and 21 'can be rotated. After the ultrasonic inspection of the pouring nozzle is completed in this way, each arm 1
6 and 16 'are separated from the nozzle end surfaces 1a and 1b, and then the ultrasonic probe holding device 12 is separated from the device base 3 to release the clamp devices 5 and 5', thereby completing a series of inspection operations.

The embodiments of the present invention have been described above.
When the above-described apparatus is used for the flaw detection inspection, the inspection can be performed with a small number of people as compared with the conventional manual operation (this apparatus: 1
Name, conventional: 2 or more) and the inspection time is 20 times
Minutes to 5 minutes. In addition, in the flaw detector according to the present embodiment, since the fixing portion of the ultrasonic probe is attached to the arm with a so-called spherical bush, the ultrasonic probe can always contact the ultrasonic probe perpendicular to the nozzle end face, It is possible to reduce the influence of the end surface polishing variation on the inspection data.

[0023]

As described above, according to the present invention, since the conventional flaw detection inspection work is performed by the present flaw detection apparatus, the labor and the inspection time of the inspection worker can be reduced. Further, since the end surface polishing means of the work provided in the present flaw detection device is disposed on an extension of the longitudinal axis of the work, the polished surface always forms substantially the same angle with the longitudinal axis of the work. Can always be measured and inspected under the same conditions.

In addition, since the ultrasonic probe used in the present flaw detector is urged to both end surfaces by a predetermined pressure by the probe driving means, there is a variation in the ultrasonic probe crimping force for each measurement. And the reliability of the measurement also increases in this respect.

[Brief description of the drawings]

FIG. 1 is a plan view of an ultrasonic flaw detector according to the present invention.

FIG. 2 is a front view of the ultrasonic flaw detector of FIG. 1, in which an ultrasonic probe holding mechanism is omitted.

FIG. 3 is an enlarged cross-sectional view of an ultrasonic probe mounting portion of the ultrasonic flaw detector of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Pouring nozzle 2, 2 '... Clamping device 3 ... Device base 5, 5' ... Grinder device 17 ... Electric cylinder 20 ... Ultrasonic probe A ... Nozzle longitudinal axis

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-83161 (JP, A) Japan Society for the Promotion of Science, 19th Committee of Steelmaking, “Ultrasonic flaw detection method (revised new edition)”, p. 228-229 and P.I. 366-369, Nikkan Kogyo Shimbun (July 30, 1974)

Claims (1)

(57) [Claims] An apparatus for inspecting internal cracks of a pouring nozzle , comprising : a device base having a substantially flat upper surface; and a pouring nozzle provided on the device base and having a longitudinal axis aligned with the upper surface of the base. a workpiece support means for supporting the pouring nozzle <br/> so as to be substantially parallel Te, supported by the pouring nozzle
The pouring device is arranged on the extension of the longitudinal axis of the
The pouring nozzle is provided so that it can approach and separate from the nozzle.
An end surface grinding means for grinding the end faces of the Le, relative to the axis
Is placed on the vertically extending ultrasonic probe travel rail base.
A carriage that can approach and separate from the device base;
At the same height position as the pouring nozzle provided on the car, the shaft
A pair of left and right ultrasonic probes that can move parallel to the line
Holding arm and a spring inserted into the tip of the holding arm
Connected via a spherical bush by the attached connecting shaft
Sensor holding board and attached to the sensor holding board at equal circumferential intervals
An ultrasonic flaw detector comprising: a plurality of ultrasonic probes formed .