JP2812819B2 - Ultrasonic plate thickness measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic thickness measuring apparatus for measuring the thickness of a steel plate such as a tank bottom plate and inspecting the steel plate for defects.

[0002]

2. Description of the Related Art In a tank for storing heavy oil or the like, it is required to periodically measure the thickness of the tank bottom plate in order to inspect the bottom plate for corrosion or the like.

As an apparatus for efficiently performing such an inspection, there is known an ultrasonic plate thickness measuring apparatus as described in, for example, JP-A-62-245958. As schematically shown in FIG. 6, the ultrasonic plate thickness measuring device is configured such that a bogie 2 that automatically travels on a tank bottom plate 1, is mounted on the bogie 2 so as to be able to move up and down, and is pressed against the upper surface of the tank bottom plate 1. And a marking nozzle (not shown) for injecting paint toward the measurement position when the measured value of the thickness is abnormal. . Further, in order to improve the adhesion between the ultrasonic probe 3 and the tank bottom plate 1 and perform good measurement, the couplant injection nozzle 4 for injecting the couplant into the measurement position is provided with an ultrasonic probe. It is provided near the child 3.

The ultrasonic thickness measuring apparatus automatically measures the thickness of the tank bottom plate 1 in accordance with a predetermined procedure according to a command from a control device (not shown). That is,
The control device appropriately issues a command signal, moves the carriage 2, and places the ultrasonic probe 3 on a predetermined measurement position of the tank bottom plate 1. Next, after the couplant is injected from the couplant injection nozzle 4 to the measurement position, the ultrasonic probe 3 is lowered and pressed against the measurement position to measure the plate thickness. The control device collects and records the measurement results from the ultrasonic probe 3 and makes a determination. When an abnormality is found in the measurement results, the control unit causes the marking nozzle to spray paint to mark the position.

[0005]

The conventional ultrasonic plate thickness measuring device as described above has an advantage that the plate thickness measurement and inspection work of the tank bottom plate can be automated. However, in this ultrasonic thickness measuring apparatus, since the ultrasonic probe is simply raised and lowered and pressed against the surface to be measured, a gap may be generated between the ultrasonic probe and the surface to be measured. There is. Such a gap causes a measurement error.

In order to solve this problem, a method of applying a couplant to the surface to be measured has conventionally been adopted. However, in the conventional configuration, the couplant is sprayed obliquely to the surface to be measured by the couplant injection nozzle. Therefore, the coating surface is likely to be uneven, and a gap may remain between the ultrasonic probe and the surface to be measured. In addition, as the couplant has a higher viscosity and a higher acoustic impedance, the gap filling effect and the ultrasonic conductivity are higher. However, in the conventional method of injecting the couplant, the viscosity is low, such as water or oil. There are also problems, such as being able to use only

Accordingly, a first object of the present invention is to provide an ultrasonic plate thickness measuring apparatus capable of improving the adhesion between an ultrasonic probe and a surface to be measured and obtaining a more accurate measurement result. It is in.

A second object of the present invention is to provide an ultrasonic thickness measuring apparatus which can use a couplant having high viscosity and large acoustic impedance.

[0009]

Therefore, according to the first aspect of the present invention, a truck and a truck are attached to the truck via an elevating mechanism so as to be pressed against a surface to be measured. At least one ultrasonic probe for measuring the thickness of the plate, a couplant supply device attached to the carriage near the ultrasonic probe and supplying a couplant on the surface to be measured; A marking nozzle that performs marking by spraying paint on the measurement surface, and an ultrasonic thickness measurement device, comprising: supporting the ultrasonic probe to the lifting mechanism via a gimbal type joint; When the ultrasonic probe is lowered and pressed against the surface to be measured, the ultrasonic probe is rotated.

In the ultrasonic plate thickness measuring apparatus according to a second aspect of the present invention, the couplant supply device drops the couplant at a position vertically below the ultrasonic probe. A tip of the couplant dropping nozzle can be retracted to a position where the tip of the couplant dropping nozzle does not come into contact with the ultrasound probe when the ultrasonic probe descends.

Further, in the ultrasonic plate thickness measuring apparatus according to the third invention according to the third aspect of the present invention, the first invention and the second invention are combined so as to exhibit both features.

[0012]

As described above, if the ultrasonic probe is swingably supported and rotatable, even if the surface to be measured is inclined, the lower surface of the ultrasonic probe follows the inclination. In addition, it is possible to contact both without gaps.

If the couplant is provided with a dropping nozzle so that the couplant can be dropped, a highly viscous couplant can be used, and the ultrasonic probe and the surface to be measured can be used. Will be further improved. In this case, the couplant dripping nozzle is disposed on the descending path of the ultrasonic probe, but does not come into contact with the ultrasonic probe because the retracting mechanism is provided.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the ultrasonic measuring apparatus according to the present invention will be described below in detail with reference to the drawings.

In FIGS. 1 and 2, reference numeral 10 denotes an ultrasonic plate thickness measuring apparatus according to the present invention, and reference numeral 11 denotes a self-propelled bogie. The left and right driving wheels 12, 13 of the cart 11 are respectively
The drive motors 14 and 15 are driven independently and separately. The drive motors 14 and 15 are controlled by a command signal from a control device (not shown) provided outside the carriage 11. The external control device compares position data stored in advance with detection signal data from a distance sensor (for example, an optical sensor) 16 and a movement distance sensor (for example, a rotary encoder) 17 attached to the cart 11, Cart
A travel command signal is issued to move 11 to a predetermined position.

A plurality of ultrasonic probe units 20 are arranged on the carriage 11 at predetermined intervals along a direction perpendicular to the traveling direction. These ultrasonic probe units 20
Is supported by a horizontal support plate 22 in the lifting mechanism 21. The support plate 22 is vertically movably supported by guide posts 23, and is moved up and down via a link mechanism 25 by an elevating drive motor 24 controlled by an external control device.

As shown in FIGS. 3 and 4, each ultrasonic probe unit 20 has a substantially cylindrical shape attached to a support plate 22 (a part of the ultrasonic probe unit 20 is cut away as shown in FIG. 4). Support frame 26, a gimbal joint 27 rotatably mounted inside the support frame 26, an ultrasonic probe 28 supported by the gimbal joint 27, and a support for rotating the gimbal joint 27. It is composed of a rotary drive fixed to the upper part of the frame 26, for example, an air actuator 29.

More specifically, the outer shape of the ultrasonic probe 28 for measuring the thickness of the plate is cylindrical, and a flange portion 30 formed on the cylindrical surface is gimbaled by a pair of support pins 31. It is pivoted inside the inner ring 32 of the joint 27 (FIG. 4). Also, the outer ring 33 of the gimbal type joint 27 is
A coaxial arrangement surrounding the inner ring 32
The inner ring 32 is pivotally supported by a pair of support pins 34. Since the line connecting the support pins 31 is perpendicular to the line connecting the support pins 34, the ultrasonic probe 28 is a gimbal type joint.
It can swing in any direction with respect to the outer ring 33 of 27.

The outer ring 33 of the gimbal joint 27 is supported inside the support frame 26 so as to be rotatable about the axis of the support frame 26. On the outer ring 33,
A cylindrical portion 35 extending upward in the support frame 26 is formed, and the rotation shaft 36 of the air actuator 29 is connected to the center of the upper surface. Therefore, when the air actuator 29 is driven by a command signal from the external control device, the outer ring 33 of the gimbal type joint 27 and, consequently, the ultrasonic probe 28 rotate in the support frame 26.

The ultrasonic probe 28 is of a type capable of measuring only the thickness of a steel sheet from the painted surface of a coated steel sheet, for example, a split type as disclosed in JP-A-63-109310. Is most preferred, but other types may be used. The cable 37 of the ultrasonic probe 28 is connected to an external control device.

A pair of flanges 38 project from opposite sides of the support frame 26 in opposite directions.
The lower end of a support shaft 39 that extends downward through the support plate 22 of the 21 slidably is screwed. A compression spring 40 is fitted into each support shaft 39 and is disposed between the support plate 22 and the flange portion 38 of the support frame 26. Accordingly, the ultrasonic probe unit 20 is normally suspended from the support plate 22 by the support shaft 39, but when the external force is applied upward, the ultrasonic probe unit 20 elastically rises with respect to the support plate 22. It has become.

Further, in order to bring the ultrasonic probe 28 into close contact with the tank bottom plate 1 and to conduct ultrasonic waves well, a couplant supply device 41 is provided beside each ultrasonic probe unit 20. Then, the couplant is supplied to the measurement position where the ultrasonic probe 28 is pressed. As the couplant, those having high acoustic impedance and high viscosity, such as Sonicoat and glycerin, are preferable. The couplant supply device 41
As clearly shown in FIG. 5, a couplant dripping nozzle 42 for dropping the couplant, and a support block 43 for supporting the nozzle 42
And a couplant supply / distribution device 44 for supplying the couplant to the couplant drop nozzle 42. Couplant feeder
44 is controlled by an external controller, and the couplant tank 45
From FIG. 1, the required amount of couplant is added to the couplant dripping nozzle 42.
And let it drip. In this embodiment, the support block 43
Is swingably attached to the trolley 2, and the position where the tip of the couplant dripping nozzle 42 does not contact the ultrasonic probe unit 20 from the position on the axis A of the ultrasonic probe 28 (in FIG. 5, (The position indicated by the two-dot chain line). The swing of the support block 43 is performed by an appropriate swing drive device (not shown), and the swing drive device is also driven according to a command signal from an external control device.

Referring again to FIG. 1, the ultrasonic plate thickness measuring apparatus 10 according to the present invention includes a marking nozzle 46 similar to the conventional configuration described above, and an abnormal measurement result of the plate thickness of the tank bottom plate 1 is obtained. When there is a mark, a quick-drying paint is sprayed on the tank bottom plate 1 for marking.
Marking nozzle 46 is spray can with paint by piping 47
The paint can be sprayed at appropriate times by pressing a button of the spray can 48 in response to a command signal from an external control device.

The tank bottom plate 1 is inspected after discharging and cleaning the stored oil. However, since oil remains on the upper surface of the tank bottom plate 1, as shown in FIGS. It is preferable to provide an air nozzle 49 in 43 so as to blow off residual oil at the measurement position of the tank bottom plate 1 before dropping the couplant.

Next, the operation of the ultrasonic thickness measuring apparatus 10 having such a configuration will be described.

The external control device determines the distance between the trolley 11 and the side wall of the tank based on the detection signal from the optical sensor 16,
The drive motors 14 and 15 are appropriately controlled to cause the truck 11 to follow the tank side wall and travel. Further, the external control device detects the traveling distance of the bogie 11 based on the detection signal from the rotary encoder 17, and issues a stop command signal when it determines that the ultrasonic probe 28 has reached a desired measurement position. Trolley 11
To stop.

At this time, the ultrasonic probe unit 20, the couplant dripping nozzle 42, and the air nozzle 48 of the ultrasonic plate thickness measuring device 10 are at positions shown by solid lines in FIG. Here, first, in order to blow off residual oil or the like on the tank bottom plate 1, the external controller injects compressed air from the air nozzle 49. Then
By issuing a command signal to the control medium supply / distribution device 44, a required amount of the couplant is dropped from the tip of the control medium drop nozzle 42. In this state, since the tip of the nozzle 42 is on the axis A of the ultrasonic probe 28, the dropped couplant is attached to the vertically lower position of the ultrasonic probe 28, that is, the measurement position.

Thereafter, the external control device issues a command signal to the swing drive device of the couplant supply device 41 to issue a command signal to the support block 43.
To retract the couplant dripping nozzle 42 from the elevation path of the ultrasonic probe unit 20 (the position indicated by the two-dot chain line in FIG. 5). Subsequently, the lifting drive motor 24 of the lifting mechanism 21 is controlled to lower the support plate 22 and the plurality of ultrasonic probe units 20 attached thereto, and each ultrasonic probe 28 comes into contact with the surface to be measured. Then, the air actuator 29 of each ultrasonic probe unit 20 is driven, and the ultrasonic probe 28 is rotated as described above. As a result, the ultrasonic probe 28
The lower surface of the ultrasonic probe 28 is rubbed against the measurement position of the tank bottom surface 1 and the ultrasonic probe 28 is swingable in all directions by a gimbal type joint 27. 1 is completely adhered via a couplant. Further, since the compression spring 40 is disposed between the ultrasonic probe unit 20 and the support plate 22, the ultrasonic probe
After pressing the tank 28 on the tank bottom plate 1, a constant pressing force is applied to further improve the adhesion between the two.

After the ultrasonic probe 28 is brought into close contact with the tank bottom plate 1, the external control device transmits an ultrasonic wave from each ultrasonic probe 28 and receives a reflected signal of a reflected wave reflected by the tank bottom plate 1. From the ultrasonic probe 28, and measures and records the plate thickness. At the same time, the external control device compares the previously stored thickness data at that position with the detected thickness to determine whether there is an abnormal thickness.

If there is no abnormality in the plate thickness, the operation is performed in the reverse manner to rotate the ultrasonic probe 28 from the tank bottom plate 1 in the opposite direction and raise the ultrasonic probe 28. Return it to just below the ultrasonic probe 28.

If it is determined that the thickness is abnormal,
The external control device issues a command signal to press the button of the spray can 45, and paints the paint from the marking nozzle 46 to the tank bottom plate 1.
Spray on the top to mark the abnormal part. With this marking, after the automatic measurement by the ultrasonic plate thickness measuring device 10 is completed, it is possible to perform more detailed measurement at the site. After the marking, the ultrasonic probe unit 20 and the couplant supply device 41 are returned to the initial positions in the same manner as described above.

Thereafter, the carriage 11 is again driven by a predetermined distance, and the above operation is repeated to continue the thickness measurement over the entire tank bottom plate 1.

In the ultrasonic plate thickness measuring apparatus 10 according to the above-described embodiment, the means for rotating the ultrasonic probe 28 so as to swing and the couplant dripping nozzle 42 from the elevation path of the ultrasonic probe unit 20 Although both of them are provided, the measurement performance is greatly improved as compared with the conventional case.

That is, if the ultrasonic probe 28 is supported so as to be able to swing and can be rotated, the lower surface of the ultrasonic probe 28 is kept in the tank even if the measurement position of the tank bottom plate 1 is inclined. Following the inclination of the bottom plate 1, the two can contact each other without any gap. Therefore, even if the couplant having low viscosity is only injected from the injection nozzle as in the conventional configuration, the adhesion required for the thickness measurement can be sufficiently obtained.

If a means for retracting the couplant dripping nozzle 42 from the elevation path of the ultrasonic probe unit 20 is used, a highly viscous couplant can be used,
Only with that, the gap between the ultrasonic probe 28 and the tank bottom plate 1 is filled, and accurate measurement can be performed. Therefore, it will be understood that the ultrasonic probe 28 may be simply lowered vertically and brought into contact with the tank bottom plate 1.

The mechanism for retracting the couplant dripping nozzle 42 from the ultrasonic probe unit 20 employs not only the swing means as in the above-described embodiment but also a mechanism for extending and contracting the support block 43. May be.

The control device may be mounted on the cart 11, or the cart 11, the air actuator 29 and other driving devices may be manually operated without the control device.

Further, in the above embodiment, a plurality of ultrasonic probes are used.
Although 28 are arranged in a straight line, other arrangements are possible.

[0039]

As described above, according to the present invention, the ultrasonic probe is swingably supported and is pressed against the surface to be measured while rotating. This improves the adhesiveness of the sheet, makes it possible to accurately measure the thickness of the sheet, and obtains a highly reliable inspection result.

Also, by adopting a configuration in which the couplant is dropped, a viscous material having a high acoustic impedance can be used as the couplant, and a gap is generated between the ultrasonic probe and the surface to be measured. Can even fill it,
Plate thickness measurement can be performed more accurately. Further, when the ultrasonic probe is separated from the surface to be measured after the measurement, the couplant remains at the measurement position in a dot-like manner, so that it also functions as a marking of the measurement position.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing an embodiment of an ultrasonic plate thickness measuring apparatus according to the present invention, from which an upper plate of a carriage is removed.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view showing an ultrasonic probe unit in the ultrasonic plate thickness measuring apparatus according to the present invention.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a side view showing an ultrasonic probe unit and a couplant supply device in the ultrasonic plate thickness measuring apparatus according to the present invention.

FIG. 6 is a sectional view similar to FIG. 2, showing a conventional ultrasonic plate thickness measuring apparatus.

[Explanation of symbols]

 1 Tank bottom plate 10 Ultrasonic thickness measuring device 11 Cart 20 Ultrasonic probe unit 21 Elevating mechanism 27 Gimbal type joint 28 Ultrasonic probe 29 Air actuator (rotary drive) 41 Coupling material supply device 42 Coupling material dropping nozzle 46 Marking nozzle 49 Air nozzle

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Osamu Takahashi 8-19-20 Higashisuna, Koto-ku, Tokyo To-Yokanets Co., Ltd. (56) References JP-A-63-98560 (JP, A) -170563 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01B 17/02 G01N 29/00-29/06

Claims (3)

(57) [Claims] 1. A trolley, at least one ultrasonic probe for measuring a thickness, which is attached to the trolley via a lifting mechanism and is pressed against a surface to be measured, and the ultrasonic probe An ultrasonic plate thickness, comprising: a couplant supply device that is attached to the carriage in the vicinity of the probe and supplies a couplant on the surface to be measured; and a marking nozzle that sprays paint on the surface to be measured to perform marking. In the measurement device, while supporting the ultrasonic probe to the lifting mechanism via a gimbal joint, when the ultrasonic probe is lowered and pressed against the surface to be measured, the ultrasonic probe is An ultrasonic plate thickness measuring device characterized by being rotated. 2. A trolley, at least one ultrasonic probe for measuring a thickness, which is attached to the trolley via a lifting mechanism and is pressed against a surface to be measured, and the ultrasonic probe An ultrasonic plate thickness, comprising: a couplant supply device that is attached to the carriage in the vicinity of the probe and supplies a couplant on the surface to be measured; In the measurement device, the couplant supply device includes a couplant dripping nozzle that drops the couplant at a position vertically below the ultrasonic probe, and when the ultrasonic probe descends, the couplant is An ultrasonic plate thickness measuring device, wherein a tip of a dropping nozzle can be retracted to a position where it does not contact the ultrasonic probe. 3. A trolley, at least one ultrasonic probe for measuring the thickness of the trolley, which is attached to the trolley via a lifting mechanism and is pressed against a surface to be measured, and the ultrasonic probe An ultrasonic plate thickness, comprising: a couplant supply device that is attached to the carriage in the vicinity of the probe and supplies a couplant on the surface to be measured; and a marking nozzle that sprays paint on the surface to be measured to perform marking. In the measurement device, while supporting the ultrasonic probe to the lifting mechanism via a gimbal joint, when the ultrasonic probe is lowered and pressed against the surface to be measured, the ultrasonic probe is To rotate, and the couplant supply device, provided with a couplant dripping nozzle that drops the couplant at a vertically lower position of the ultrasonic probe, when the ultrasonic probe descends, The couplant dripping Le the tip of the ultrasonic thickness measuring device, characterized in that to be able to retreat to a position that is not in contact with the ultrasonic probe.