JPH06100579B2 - Ultrasonic flaw detector - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to an ultrasonic flaw detector for inspecting a subject such as a rail, and particularly to the vicinity of the end even when the end of the rail has a so-called nose bend. The present invention relates to an ultrasonic flaw detector that can automatically perform ultrasonic flaw detection.

[Technical background of the invention]

In the conventional ultrasonic flaw detection, the rails being conveyed by the conveyance table rollers are irradiated with ultrasonic waves to detect flaws on the rails.As the flaw detection method, multiple ultrasonic probes are used. A water jet vertical flaw detection method that can detect flaws without directly contacting the Specifically, a probe holder is arranged in a conveyance line on which a conveyance table roller is laid, and a plurality of ultrasonic probes are attached to the inner side surface of the probe holder, respectively. The rail 1 shown in FIG. Then, ultrasonic waves are transmitted from the ultrasonic probe while a water jet is performed on the rail running in the probe holder, and the rail is flaw-detected using the water jet as an acoustic medium.

By the way, the rail to be subjected to ultrasonic flaw detection has a cross-sectional shape as shown in FIG. 5, has a length of about 6 to 50 m, and the front and rear ends of the rail 1 are shown in FIG. As shown, it has a bend of about 8 mm / 1.5 m on the outer string called nose bend.

[Problems of background technology]

However, in the ultrasonic flaw detector as described above, even though the rail end has a bend, the rail is simply moved in the probe holder, and the rail bend is not imitated. About 1 m from the front and rear ends of the ultrasonic probe, the ultrasonic beam is detached from the subject due to the bent nose of the rail, and ultrasonic inspection cannot be performed, and eventually manual inspection can be used together. was there.

[Object of the Invention]

The present invention has been made by paying attention to the above points, and even for a subject having a bend at the end, the ultrasonic flaw detection can automatically detect the end of the subject by the probe holder following the bend. To provide a device.

[Outline of Invention]

According to the present invention, the copying mechanism is provided on the support member via the first parallel link mechanism to perform the copying on the subject to be carried in, and the second mechanism is configured to move up and down following the copying mechanism. The probe holder is supported via a parallel link mechanism of, and even in this probe holder, the ultrasonic probe group attached to the probe holder holds a desired distance while being followed by a roller that follows the subject. This is an ultrasonic flaw detection device for performing ultrasonic flaw detection on a subject.

Example of Invention

An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a schematic configuration diagram of the entire apparatus, FIG. 2 is a schematic configuration diagram of a copying mechanism section, and FIG. 3 is a diagram showing a state in which a subject is inserted in a probe holder. In these drawings, reference numeral 10 designates a transport table roller arranged at an appropriate interval.
Thus, the subject, for example, the rail 11 is transported at a required speed. Reference numeral 12 is a pre-humidifying device that sprays a liquid onto the rail 11 to improve the acoustic coupling and wets it.For example, a reverse concave frame 12b is erected on a dolly 12a, and a liquid is provided in the frame 12b. The injection conduit 12c is arranged. Although the liquid ejecting conduit 12c is provided on the upper portion in the drawing, it is assumed to be provided on a part or the entire circumference depending on the shape of the subject or the flaw detection site. Further, a bend correcting portion 14 is arranged on the rail unloading side of the pre-humidifying device 12 via a side guide 13. The side guide 13 has two guide rollers 13a, 13a arranged at a required interval according to the rail width, and has a function of preventing lateral displacement of the rail 11 during conveyance. 13b and 13b are shafts.
The bending correction unit 14 is, for example, a conveyance table roller on the lower side.
10 is arranged, and a bending correction roller 14a is provided so as to face the roller 10. The roller 14a is connected to, for example, a screw driving source 14b via a spring 14c, is normally set to an initial position, and a predetermined pressure is artificially or automatically applied to the bending of the subject according to the bending of the subject. It is like this. Reference numeral 15 is a flaw detection mechanism device for performing ultrasonic flaw detection on the rail 11, which is composed of a support portion 16 in which an L-shaped support member 16b is placed on a carriage 16a, a copying mechanism portion 17, and a probe holder 18. In the copying mechanism unit 17, a support 17b extends in the rail carry-out direction from the lower side of the box-shaped frame 17a, which is opened in the line direction, and the frame 17a can be moved up and down by the first parallel link mechanism 19. Supported by. As shown in FIG. 2, the frame 17a has copying and supplementing rollers 17c on the upper portion and both side portions, and presses the upper surface portion and both side surface portions of the rail 11 at the rail tip detection timing. Reference numeral 17d is a leading edge passage detector, and 17e is a trailing edge passage detector. 20 is a support member 16b and a frame 17a
It is a spring inserted between and. Further, the probe holder 18 has a second parallel link mechanism 21 on the support 17b.
The following rollers 18a and 8b, which are supported in a replaceable manner via the rails, are provided at the upper portion of the rail loading side and the upper and lower portions of the loading side, which follow the vertical movement of the rail 11.
As shown in FIG. 3, the holder 18 is provided with one or a plurality of jet ultrasonic probes 18d, each having a nozzle 18c at the upper and lower portions and both sides thereof according to the shape of the subject. ing. 18e, ... are water jets. 22, 2
Reference numeral 2 denotes a side guide that prevents lateral displacement of the rail carried out from the holder 18, and has the same configuration as the side guide 13.

Next, the operation of the device configured as described above will be described.
When the rail 11 is transported by the transport table rollers 10, ... And enters the pre-humidifying device 12, the liquid 12d is jetted from the liquid jet conduit 12c to the rail 11 constantly or by detecting the rail loading. As a result, the rail 11 gets wet, and dense acoustic coupling becomes possible during ultrasonic flaw detection. Further, the rail 11 output from the pre-humidifying device 12 is regulated by the side guide 13 in the position in the line width direction and is sent to the bend correcting portion 14. In this bend correction unit 14, the interval between the rolls 10 and 14a is set with a margin in advance, and when the rail 11 is carried in, depending on the bend of the rail end measured before or during the rail transfer. Artificial or automatic screw drive source
14b is operated to apply a bending correction roller 14a to the bent portion of the rail 11 to apply pressure, and the bending is corrected to such an extent that it easily enters the flaw detection mechanism device 15.

Further, the rail 11 output from the bending correction unit 14 is sent to the copying mechanism unit 17 of the flaw detection mechanism device 15. Here, when the tip passage detector 17d detects the tip of the rail, the tracing supplement roller 17c is driven by a drive source or the like. , Advance to supplement from the three sides of the upper surface of the rail 11 and both side surfaces of the lower end. At this time, the rail 11 passes through the side guide 13 substantially at the center position of the transport table roller 10 in the body length direction, but may slightly shift from the center position of the transport table roller 10. Further, although the bending of the tip of the rail 11 is corrected by the bending correcting portion 14, the height when the rail 11 enters the copying mechanism portion 17 varies depending on the degree of bending. For this reason, when the tracing supplement rollers 17c, ... Complement the tip bent portion of the rail 11, the copying mechanism portion 17 is supported by the parallel link mechanism 19 and moves in parallel along the lateral and vertical shifts of the rail 11. Further, when it moves forward to the probe holder 18 side, the tracing supplement rollers 17c, ... Follow the rail 11 and feeds to the probe holder 18 side while performing the tracing.

However, the copying mechanism unit 17 follows the behavior of the part of the rail 11 supplemented by the copying supplement rollers 17c, ...
As the tip of the rail moves away from the supplementary rollers 17c, ..., The relative position to the probe holder 18 shifts according to the degree of bending of the tip of the rail. Therefore, the tip of the rail 11 has the following roller 18 on the loading side of the probe holder 18.
When it reaches a, the roller 18a follows and follows the vertical movement of the rail 11, and for example, when passing through the bend of the rail tip, the parallel link mechanism 21 becomes vertical and the probe holder 18 is lifted, so that the rail 11 moves. The probe holder 18 descends as the parallel link mechanism 21 inclines to the right as shown in FIG.

The position of the probe holder 18 changes as the rail tip moves to the rail loading side and the loading side following rollers 18a, 18b, but the relative position variation between the flove 18 and the rail 11 is slight.

As described above, when the rail 11 advances and the rear end of the rail 11 passes the rear end passage detector 17e, the copying supplement rollers 17c, ... Since the mechanism unit 17 and the probe holder 18 are pushed up by the rail 11 via the following rollers 18a and 18b, the parallel link mechanism 1
Lifted in parallel by the action of 9 and 21. This state continues until the rear end of the rail passes the following roller 18b. Therefore, the relative positions of the probe 18 and the rail 11 are maintained with respect to the entire length of the rail 11 by the above operation, and even in the rail 11 having a nose bend, the nozzle 18c is previously formed.
20-30 mm after the water column, which is the acoustic medium of ultrasonic waves ejected from the water column, is disturbed by the passage of the tip of the rail 11
Automatic flaw detection is possible over the entire length except for the rail end 20 to 30 mm corresponding to sec. Normally, the front end and the rear end of the rail 11 have a bend of about 8 mm / 1.5 m of outer chord called nose bend, but the range to be the product is cut off the rail end 50 to 100 mm by neatness. Since the range is the range, the quality of the product can be guaranteed by flaw detection in the range excluding the end portion of 50 mm, and the flaw detection can be sufficiently performed by the copying of the copying mechanism section 17 by the present apparatus. After the flaw detection, the rail 11 is classified into a passing product and a rejecting product, and only the passing product is cut off by the end press straightening in the next step to become a product.

Therefore, according to the above configuration, since the rail 11 is pre-moistened by the pre-humidifying device 12 in advance, the acoustic coupling can be made tight at the time of ultrasonic flaw detection, and flaw detection accuracy can be improved. Further, since the side guides 13 and 22 are provided on the rail loading side and the rail unloading side of the flaw detection mechanism device 15, the rail 11
Can pass through the flaw detection mechanism device 15 without being laterally displaced. Further, the copying mechanism section 17 is supported by the supporting member 16b through the first parallel link mechanism 19 and is a copying supplement roller.
Since the rails 11 are complemented by 17c, ..., the rails 11 always move up and down in parallel, and along with this, the probe holder 18 to which the ultrasonic probe group is attached is lifted up in parallel, and the probe holder 18 Following rollers 18a, 18b with rails
Since 11 is followed, it is possible to reliably detect flaws on rail 11 with a bent nose except for the end 50 mm. Therefore, as shown in FIG. 4, the conventional flaw detection device cannot automatically detect flaws only in the flaw detection area B, that is, 1 m from the end, but the flaw detection area port of the flaw detection device of the present invention is 50 from the end.
Except for mm, automatic flaw detection can be performed, and flaw detection work can be simplified and streamlined.

The present invention is not limited to the above embodiment.
For example, the pre-humidifying device 12, the side guides 13 and 22, the bending correction portion 14
Although the flaw detection mechanism device 15 and the like are separately arranged, they may be mounted on the same carriage of all of these elements, and the bending correction portion
14 is not necessarily what you need. Further, although the rail 11 is described as the object to be inspected, any object other than the rail 11 can be applied as long as it has a bent end.

〔The invention's effect〕

As described in detail above, according to the present invention, since it is possible to perform flaw detection on a flaw detection target by irradiating ultrasonic waves while maintaining a desired distance with respect to each ultrasound probe group of the probe holder, the end of the flaw detection target is particularly It is possible to provide an ultrasonic flaw detector which can detect flaws even in the vicinity of the end of a portion having a bend by completely automating, uniformize the quality of products, and improve the efficiency of flaw detection work.

[Brief description of drawings]

1 to 4 are for explaining one embodiment of an ultrasonic flaw detector according to the present invention. FIG. 1 is a schematic diagram showing the entire apparatus, and FIG. FIG. 3 is a schematic configuration diagram of the copying mechanism section shown in FIG. 3, FIG. 3 is a diagram showing a state of rail flaw detection by a probe holder, FIG. 4 is a diagram explaining a comparison of flaw detection areas of a conventional apparatus and this apparatus, and FIG. FIG. 6 is a cross-sectional view of the rail, and FIG. 6 is a view showing a bent state of the rail, which is an object to be inspected by using the conventional device. 10: Transport table roller, 11: Object to be detected (rail), 12: Pre-humidifier, 13, 22: Side guide, 14 ...
… Bending correction part, 15 …… Flaw detection mechanism device, 16 …… Support part, 16
b ... Support member, 17 ... Copying mechanism, 17a ... Frame,
17b ... Support, 17c ... Copy supplement roller, 17d ... Leading edge detector, 17e ... Rear edge detector, 18 ... Probe holder, 18a, 18b ... Following roller, 18d.
Ultrasonic probe, 19 ... first parallel link mechanism, 20 ... spring, 21 ... second parallel link mechanism.

Claims (4)

[Claims] 1. An ultrasonic flaw detector for inspecting a subject whose end portion is formed into a curved portion, wherein a pressure is applied to the subject that is carried in while being subjected to lateral displacement position regulation. A bend correction mechanism section that corrects the bend of the subject, and a predetermined portion of the subject that is supported by the support section so as to be vertically movable via the first parallel link mechanism, and is corrected by the bend correction mechanism section and carried in. A copying mechanism section that makes a copy by bringing a plurality of copying supplement rollers into contact with each other, and is supported on the subject outlet side of the copying mechanism section via a second parallel link mechanism, and is carried in from the copying mechanism section. A probe holder that moves up and down following the up and down movement of the subject to be inspected and irradiates the curved portion of the subject with an ultrasonic beam at a desired interval to detect flaws in the subject. An ultrasonic flaw detector characterized by the above. 2. The copying mechanism section comprises a tip passage detector for detecting a tip portion of a subject, a drive section which operates by receiving a passage detection signal from the tip passage detector, and a forward movement by the operation of the drive section. The ultrasonic flaw detector according to claim 1, further comprising: the plurality of copying supplement rollers that press the upper and side portions of the subject. 3. The probe holder is provided with a following roller that follows the vertical movement of the subject and a surface portion of the subject that is required, and a water jet ultrasonic probe that radiates ultrasonic waves. The ultrasonic flaw detector according to claim 1, wherein the ultrasonic flaw detector has a group. 4. The ultrasonic flaw detector according to claim 3, wherein the following roller can be replaced according to the shape of the subject.