Patent Description:
Conventionally, in order to ensure the quality of metal plates, such as steel plates, as an inspection target, the steel plates or the like are inspected for surface defects or internal defects by ultrasonic flaw detection or the like. In the ultrasonic flaw detection, a plurality of ultrasonic flaw detection heads as inspection sensors arranged in parallel is brought into contact with a metal plate, such as a steel plate, conveyed on a feed roller of a production line via a water film, and then the metal plate is automatically inspected in on-line, for example. In off-line, the ultrasonic flaw detection heads are moved by a hand carriage or the like to be brought into contact with a stopped metal plate, such as a steel plate, via a water film, and then the metal plate is manually inspected.

In general, the ultrasonic flaw detection heads are connected to an ultrasonic flaw detector body with a flaw detection cable, outputs (results) obtained by the flaw detection by the ultrasonic flaw detection heads are input into the ultrasonic flaw detector body, and the outputs (results) are input into a data processing device to be processed, so that the metal plate is inspected for the presence or absence of internal defects. In the case of the ultrasonic flaw detection, water as a medium for passing ultrasonic waves is sprayed to an inspection surface (surface) of the metal plate, such as the steel plate, so that a water film is formed on the inspection surface (surface) of the metal plate. Therefore, when performing the ultrasonic flaw detection of the metal plate as the inspection target in off-line, the surface of the metal plate is wet with water to be slippery. The metal plate is placed on a skid or the like installed on the floor surface in many cases, and therefore an inspector moves on the wet metal plate with a level difference, which causes a risk that the inspector falls.

In order to perform highly accurate ultrasonic flaw detection, the ultrasonic flaw detection heads as the inspection sensors need to be accurately moved along a predetermined scanning line. However, a preparation to draw the scanning line on the metal plate requires time and labor and, at the same time, there is a limit to the accuracy of the manual movement of the ultrasonic flaw detection heads.

In order to eliminate such inconvenience caused by the manual operations, moving inspection devices for metal plate have been proposed in the past, and, for example, those illustrated in PTLS <NUM> and <NUM> have been proposed.

A moving inspection device for metal plate illustrated in PTL <NUM> is a moving inspection device for metal plate inspecting a metal plate using an indoor position measuring system performing self-position measurement in an indoor space based on the principle of triangulation. The moving inspection device for metal plate includes a carriage having: four wheels capable of rotating forward and backward; and a drive unit rotating and driving the wheels and individually and independently turning and driving the wheels, and traveling over the metal plate surface. The carriage is further mounted with a navigation signal transmitter or a navigation signal receiver constituting the indoor position measuring system and transmitting or receiving an indoor position measuring system signal and is provided with inspection sensors inspecting a metal plate for defects. The moving inspection device for metal plate includes a control means of calculating a deviation from a self position recognized using the indoor position measuring system signal and a target position, instructing the drive unit to rotate the wheels forward, rotate the wheels backward, stop the wheels, and turn each wheel according to the deviation, and causing the carriage to move laterally, obliquely, forward and backward, or turn on the spot to cause the carriage to autonomously travel to a predetermined target position.

A moving inspection device for metal plate illustrated in PTL <NUM> is a moving inspection device for metal plate moving over a metal plate based on information from a position measuring means and inspecting the metal plate for the presence or absence of defects present on the surface of the metal plate or inside the metal plate and including a carriage having at least two wheels capable of rotating forward and backward and a drive unit driving the wheels. The carriage is mounted with flaw detection heads each including an ultrasonic flaw detection probe inspecting the metal plate. The moving inspection device for metal plate includes a control unit calculating a deviation between the position of the inspection device recognized by the position measuring means and a target position, instructing the drive unit to rotate the wheels forward, rotate the wheels backward, and stop the wheels such that the deviation is minimized, and controlling the inspection device to autonomously travel to a predetermined target position. The control means has a function of detecting either or both of a weight change of the inspection device and sliding resistance between the metal plate and the flaw detection heads and feedbacking a correction value obtained from the detected values to the instruction.

However, the conventional moving inspection devices for metal plate illustrated in PTLS <NUM> and <NUM> have had the following problems.

More specifically, in both the moving inspection devices for metal plate illustrated in PTLS <NUM> and <NUM>, the carriage is provided with four wheels capable of rotating forward and backward and is provided with a drive unit rotating and driving each wheel and individually and independently turning and driving each wheel.

Both the moving inspection devices for metal plate illustrated in PTLS <NUM> and <NUM> include a scanning actuator causing the flaw detection heads to scan in the horizontal direction to move the flaw detection heads to an end part position of the metal plate. In the moving inspection devices for metal plate illustrated in PTLS <NUM> and <NUM>, the moving inspection device for metal plate is stopped once at a point in time when an edge detection sensor provided in the moving inspection device for metal plate detects an end part of the metal plate. Then, from that point in time, the flaw detection heads are caused to scan in the horizontal direction by the scanning actuator to move the flaw detection heads to the end part position of the metal plate, thereby performing an appropriate inspection up to the end part of the metal plate.

In such moving inspection devices for metal plate illustrated in PTLS <NUM> and <NUM>, in addition to the fact that the number of wheels themselves is as large as four, the drive unit turning and driving each wheel is required, the scanning actuator itself moving the flaw detection heads is required, and further a control device controlling the scanning actuator is required.

This has posed a problem that the device configuration is complicated and the weight of the entire device significantly increases.

Therefore, the present invention has been made to solve the conventional problems. It is an object of the present invention to provide a moving inspection device capable of appropriately inspecting an inspection target while realizing the simplification of the configuration and significant size reduction/weight reduction of the device, a moving inspection method, and a method for manufacturing a steel material.

The present inventors conducted various studies to solve the above-described problems, and, as a result, have obtained the following findings.

First, <FIG> illustrates a typical movement route of a moving inspection device <NUM> performing four-wheel drive/four-wheel steering. The movement route means that a moving inspection device <NUM> performing four-wheel drive/four-wheel steering moves at a predetermined pitch in a rectangular inspection region of a rectangular steel plate S as an inspection target, and coincides with a center track of the moving inspection device <NUM>. The movement route repeats linear vertical movement and linear horizontal movement, and thus the moving inspection device <NUM> requires four-wheel drive/four-wheel steering. Further, a scanning actuator (not illustrated) singly moving inspection sensors <NUM>, which is described later, is required, which increases the weight of the moving inspection device.

<FIG> illustrates a specific movement route of the moving inspection device <NUM> performing four-wheel drive/four-wheel steering when inspecting the steel plate S as the inspection target by the moving inspection device <NUM>.

The moving inspection device <NUM> first moves along the width direction of the steel plate S from a position where the center as viewed from the plane is located at a point P11 in a first inspection path and, simultaneously therewith, performs the inspection by the inspection sensors <NUM>. Then, the moving inspection device <NUM> stops at a position where the center as viewed from the plane is located at a point P12. Thereafter, the inspection sensors <NUM> are moved to the side edge of the steel plate S by the scanning actuator (not illustrated) (generally a linear slider or the like) as illustrated by the broken line arrows, thereby completing the inspection of the path. Thereafter, in the first movement path, the moving inspection device <NUM> moves by a predetermined distance (the same distance as the inspection pitch) in the longitudinal direction of the steel plate S by turning each of the four wheels (not illustrated) <NUM>° on the spot to reach the next inspection path. Thereafter, the inspection path and the movement path are similarly repeated, so that the inspection of the steel plate S as the inspection target is completed by the moving inspection device <NUM> performing four-wheel drive/four-wheel steering.

In contrast thereto, when movement other than the movement in the movement route is allowed in the inspection of the steel plate S by a moving inspection device, it is not necessary to use the four-wheel drive/four-wheel steering as a wheel drive mechanism. In order to realize the simplification of the device configuration and significant size reduction/weight reduction of the moving inspection device, the present inventors have found that the steel plate S can be inspected by a moving inspection device using the drive of at least two wheels capable of rotating forward and backward, not turning each wheel, and not requiring the scanning actuator causing the inspection sensors to scan.

In order to inspect the steel plate S by such a moving inspection device, first, a rectangular inspection region of a surface Sa of the rectangular steel plate S as the inspection target is divided into two divided regions of a divided region A1 and a divided region A2 across the center line (straight line) in the width direction of the steel plate S as illustrated in <FIG>.

As illustrated in <FIG>, when the steel plate S is inspected, a carriage <NUM> of a moving inspection device body <NUM> is moved in a state where flaw detection heads <NUM> as inspection sensors are directed to side edges A1a, A2a sides of the divided regions A1, A2 facing the above-described center line (straight line) in each of the two divided regions A1, A2, respectively.

A movement route of the moving inspection device body <NUM> when inspecting the steel plate S is briefly described with reference to <FIG>. First, in the divided region A1 of a front half, the moving inspection device body <NUM> moves along the width direction of the steel plate S from a position where the center as viewed from the plane of the moving inspection device body <NUM> with the flaw detection heads <NUM> located on the center line (straight line) is located at a point P1 in a first inspection path and, simultaneously therewith, performs the inspection with the flaw detection heads <NUM>. Then, the moving inspection device body <NUM> stops at a position where the center as viewed from the plane of the moving inspection device body <NUM> with the flaw detection heads <NUM> located at the side edge A1a of the divided region A1 is located at a point P2. Hence, the flaw detection heads <NUM> are located at the side edge A1a of the divided region A1, and therefore a scanning actuator for moving the flaw detection heads <NUM> to the side edge A1a of the divided region A1 is not required.

Then, in the first movement path, two wheels <NUM> provided on both the right and left sides (both sides in the longitudinal direction of the steel plate S) of the carriage <NUM> of the moving inspection device body <NUM> are rotated backward while giving a right/left rotational speed difference to the right and left wheels <NUM>. Thus, the center as viewed from the plane of the moving inspection device body <NUM> moves from the point P2 to a point P3 in a track containing two curves R1, R2, and then the moving inspection device body <NUM> stops. The point P3 is a point where the flaw detection heads <NUM> are located at the other positions on the center line (straight line) (positions where the flaw detection heads <NUM> are shifted by a predetermined distance (corresponding to an inspection pitch D) in the longitudinal direction of the steel plate S with respect to the initial positions of the flaw detection heads <NUM>). The point P3 is a starting point for the next inspection path. The interval between the points <NUM> and <NUM> is the inspection pitch D.

Thereafter, the inspection path and the movement path are similarly repeated, so that the inspection in the divided region A1 of the front half is completed by the moving inspection device body <NUM>.

Then, when the inspection in the divided region A1 of the front half is completed, the moving inspection device body <NUM> is turned <NUM>° (pivotal turn) by rotating the right and left wheels <NUM> forward and backward, so that the flaw detection heads <NUM> are directed to a side edge A2a (opposite side to the side edge A1a) of the divided region A2 facing the above-described center line (straight line). Even when the divided region A2 of the rear half is inspected while the flaw detection heads <NUM> are directed to the side edge A1a side of the divided region A1 without turning the moving inspection device body <NUM><NUM>°, a region between the flaw detection heads <NUM> and the side edge A2a of the divided region A2 becomes a range where the inspection cannot be performed because the flaw detection heads <NUM> cannot be moved by the scanning actuator.

Then, an inspection path and a movement path similar to those in the front half are repeated in the state where the flaw detection heads <NUM> are directed to the side edge A2a side of the divided region A2 facing the center line (straight line), so that the inspection in the divided region A2 of the rear half is completed by the moving inspection device body <NUM>. This makes it possible to inspect the entire rectangular inspection region of the surface Sa of the rectangular steel plate S as the inspection target.

A moving inspection device according to the present invention is defined by claim <NUM>. Dependent claims relate to preferred embodiments.

A method of inspecting an inspection target for a defect in accordance with the present invention is defined by claim <NUM>. Dependent claims relate to preferred embodiments.

A method for manufacturing a steel material according to another aspect of the present invention includes an inspection step of implementing the above-described moving inspection method.

The moving inspection device, the moving inspection method, and the method for manufacturing a steel material according to the present invention can provide a moving inspection device capable of appropriately inspecting an inspection target while realizing the simplification of the configuration and significant size reduction/weight reduction of the device, a moving inspection method, and a method for manufacturing a steel material.

Hereinafter, embodiments of the present invention will now be described with reference to the drawings. The following embodiments illustrate devices and methods for embodying the technical idea of the present invention. The technical idea of the present invention does not specify materials, shapes, structures, arrangement, and the like of constituent parts to the following embodiments. The drawings are schematic. Therefore, it should be noted that the relationship, ratio, and the like between the thickness and the planar dimension are different from the actual relationship, ratio, and the like. The drawings include portions different in mutual dimensional relationships and ratios.

First, the entire inspection system including a moving inspection device according to one embodiment of the present invention is described with reference to <FIG>.

<FIG> illustrates the schematic configuration of the entire inspection system including the moving inspection device according to one embodiment of the present invention. An inspection system <NUM> includes an indoor position measuring system <NUM> and a moving inspection device <NUM>.

The indoor position measuring system <NUM> measures the self-position indoors based on the principle of triangulation and uses an indoor global positioning system (IGPS) in this embodiment. Specifically, the indoor position measuring system <NUM> includes a plurality of navigation transmitters <NUM> arranged indoors, navigation receivers <NUM>, and a current position calculation unit <NUM> (see <FIG>) calculating the position of a moving inspection device body <NUM> by position calculation software.

The moving inspection device <NUM> includes the moving inspection device body <NUM> inspecting a steel plate S as an inspection target for internal defects of the steel plate S and surface defects of the rear surface side of the steel plate S while moving over the surface Sa of the steel plate S and water supply devices <NUM> suppling water W required for the inspection onto the surface Sa of the steel plate S. As the steel plate S as the inspection target, a thick steel plate (plate thickness of <NUM> or more) having a rectangular shape as viewed from the plane is targeted herein.

The moving inspection device body (hereinafter referred to as "inspection device body") <NUM> has a carriage <NUM> having a predetermined plate thickness and having a substantially rectangular shape extending in the right and left direction and in the forward and backward direction as illustrated in <FIG>. The carriage <NUM> is provided with a pair of right and left wheels <NUM> on both sides in the right and left direction on the front side. The pair of right and left wheels <NUM> is individually and independently driven. Each wheel <NUM> has a rotation shaft 32a having first intersecting axis gears 32b at the tip as illustrated in <FIG>. The first intersecting axis gears 32b are meshed with second intersecting axis gears 33b provided at the tip of an output rotation shaft 33a of a speed reduction gear of a wheel driving motor <NUM>. Each wheel <NUM> can be rotated forward and backward by the wheel driving motor <NUM>. The carriage <NUM> is further installed with a driven wheel <NUM> capable of moving in all directions in a substantially center part in the right and left direction on the rear side of the undersurface side.

The carriage <NUM> moves in the forward and backward direction orthogonal to the rotation shaft 32a of each wheel <NUM> over the surface Sa of the steel plate S by the pair of right and left wheels <NUM> capable of rotating forward and backward.

The carriage <NUM> is further provided with flaw detection heads <NUM> each including with an ultrasonic probe as inspection sensors detecting internal defects of the steel plate S and surface defects of the rear surface side of the steel plate S and an ultrasonic flaw detector body <NUM> into which outputs (results) from the flaw detection heads <NUM> are input and which data (calculation)-processes the outputs (results) and outputs the data processing results to an IO board <NUM> described below.

As illustrated in <FIG>, a first raised part <NUM> extending in the right and left direction is erected near the rear end of the upper surface of the carriage <NUM> and a second raised part <NUM> extending in the right and left direction is erected near the front end of the upper surface of the carriage <NUM>. As illustrated in <FIG>, a plurality of first plate members <NUM> extending in the right and left direction to project from the ends in the right and left direction of the carriage <NUM> is installed on the upper surface of the first raised part <NUM> and a plurality of second plate members <NUM> extending in the right and left direction is installed on the upper surface of the second raised part <NUM>. Further, a plurality of third plate members <NUM> extending in the forward and backward direction is installed to bridge the first plate members <NUM> and the second plate members <NUM> on the upper surfaces the first plate members <NUM> and the upper surfaces of the second plate members <NUM>. On the upper surfaces of the third plate members <NUM>, the above-described ultrasonic flaw detector body <NUM> is installed.

A pair of right and left flaw detection heads <NUM> is installed on the rear end sides of the carriage <NUM> below the first plate members <NUM> projecting from the ends in the right and left direction end of the carriage <NUM> as illustrated in <FIG>. Each flaw detection head <NUM> is supported to the first plate members <NUM> by a follow-up mechanism <NUM> causing the flaw detection head <NUM> to follow the unevenness state of the surface Sa of the steel plate S as the inspection target. The follow-up mechanism <NUM> is described in detail later.

The installation distance between the pair of right and left flaw detection heads <NUM> is set to a size of an integral multiple of an inspection pitch D described later.

Further, a pair of navigation receivers <NUM> is erected near both the right and left ends on the second plate member <NUM> and an on-board computer <NUM> and an IO board <NUM> are provided in a control box <NUM> on the upper surface of the carriage <NUM>.

Each navigation transmitter <NUM> of the indoor position measuring system <NUM> emits rotating fan beams. Each navigation receiver <NUM> receives the rotating fan beams emitted from each navigation transmitter <NUM>. At this time, the rotating fan beams are deviated at a predetermined angle, and the three-dimensional coordinate values, i.e., the position or the height, of the navigation receivers <NUM> receiving the rotating fan beams can be measured. Reception information received by the navigation receivers <NUM> is transmitted to the on-board computer <NUM>, and the positions of the navigation receivers <NUM> are calculated by the on-board computer <NUM> according to the principle of triangulation. By the use of signals received from the plurality of navigation transmitters <NUM> and by repeating the calculation, position information of the traveling inspection device body <NUM> mounted with the navigation receivers <NUM> can be acquired in real time.

The On-board computer <NUM> is a computer system constituted to include a ROM, a RAM, a CPU, and the like and realizing each function described later on software by executing various dedicated programs stored in advance in the ROM and the like.

As illustrated in <FIG>, the on-board computer <NUM> includes the current position calculation unit <NUM> calculating the current position of each navigation receiver <NUM> based on the reception information received by each navigation receiver <NUM>. The on-board computer <NUM> further includes a setting/evaluation unit <NUM> setting a target inspection position and route information and evaluating inspection data and inspection position information from the IO board <NUM>. The on-board computer <NUM> further includes a position deviation calculation unit <NUM> calculating a deviation of the current position with respect to the target inspection position based on the current position of each navigation receiver <NUM> calculated by the current position calculation unit <NUM> and the target inspection position from the setting/evaluation unit <NUM>. The on-board computer <NUM> further includes a drive control unit <NUM> outputting a control signal, such as a speed command, to the wheel driving motor <NUM> such that the deviation calculated by the position deviation calculation unit <NUM> is <NUM> and performing feedback control of the speed (including the rotation direction) of the wheels <NUM>. The drive control unit <NUM> outputs a control signal, such as a speed command, to the wheel driving motor <NUM> such that the deviation is <NUM> and performs the feedback control of the speed (including the rotation direction) of the wheels <NUM>, so that the inspection device body <NUM> autonomously travels along the target travel route.

Although not illustrated, the carriage <NUM> is mounted with a battery as a power source.

Next, the follow-up mechanism <NUM> causing each flaw detection head <NUM> to follow the uneven state of the surface Sa of the steel plate S is described with reference to <FIG>.

Herein, as illustrated in <FIG>, the uneven state of the surface Sa of the steel plate S means not only a case where the surface Sa of the steel plate S has unevenness but all cases where the surface Sa of the steel plate S is uneven, also including a case where the surface Sa of the steel plate S has waviness.

The follow-up mechanism <NUM> includes a sensor holding mechanism <NUM> holding the flaw detection head <NUM> as the inspection sensor and a load adjustment mechanism <NUM> adjusting a load applied to the surface Sa of the steel plate S by the flaw detection head <NUM> held by the sensor holding mechanism <NUM>.

The sensor holding mechanism <NUM> includes a flat plate-like holder 53a holding the flaw detection head <NUM> to surround the periphery of the flaw detection head <NUM> as illustrated in <FIG>. As illustrated in <FIG>, the flaw detection head <NUM> is inserted into a through hole 53f formed in the center of the holder 53a, and the flaw detection head <NUM> is pressed from the outer periphery by a screw member 53e to be held by the holder 53a. The sensor holding mechanism <NUM> further includes a sensor holding frame member 53b fixing the holder 53a holding the flaw detection head <NUM> and surrounding the flaw detection head <NUM> from the periphery. The holder 53a is fixed to the sensor holding frame member 53b by a bolt 53c and a wing bolt 53d.

As illustrated in <FIG> and <FIG>, a first support member <NUM> is fixed to the upper surface of the sensor holding frame member 53b and the first support member <NUM> is rotatably supported around a first hinge <NUM> with respect to a second support member <NUM>. The first hinge <NUM> extends in the X-axis direction as illustrated in <FIG> and <FIG>. More specifically, the sensor holding frame member 53b holding the flaw detection head <NUM> is configured to rotate around the X-axis. The X-axis extends in parallel to and in the forward and backward (width) direction with respect to the surface Sa of the steel plate S.

As illustrated in <FIG>, the second support member <NUM> is rotatably supported around a second hinge <NUM> with respect to a third support member <NUM>. The second hinge <NUM> extends in the Y-axis direction as illustrated in <FIG> and <FIG>. More specifically, the sensor holding frame member 53b holding the flaw detection head <NUM> is configured to rotate around the Y-axis. The Y-axis extends in the right and left (longitudinal) direction parallel to the surface Sa of the steel plate S and orthogonal to the X-axis.

Each of the rotation around the X-axis and the rotation around the Y-axis of the sensor holding frame member 53b is regulated in some cases. Considering the cases, <FIG> illustrate members regulating each of the rotation around the X-axis and the rotation around the Y-axis of the sensor holding frame member 53b.

As illustrated in <FIG>, the third support member <NUM> is attached to the undersurface of a lower flat plate <NUM> having a predetermined plate thickness and extending in the right and left direction and in the forward and backward direction. An end part in the right and left direction of the lower flat plate <NUM> is attached with an attachment plate <NUM> and a rail member <NUM> extending in the Z-axis direction. Above the lower flat plates <NUM>, upper flat plates <NUM> having a predetermined plate thickness and extending in the right and left direction and in the forward and backward direction are provided. As illustrated in <FIG>, the upper flat plates <NUM> are attached to the undersurfaces of the first plate members <NUM> projecting from the ends in the right and left direction of the carriage <NUM>. To the undersurfaces of the upper flat plates <NUM>, attachment plate parts <NUM> each attached with a slider <NUM> at the tip are fixed. The slider <NUM> is configured to move along the rail member <NUM> attached to the lower flat plate <NUM>. More specifically, the slider <NUM> is fixed to the upper flat plate <NUM> fixed to the first plate member <NUM> fixed to the carriage <NUM>, and therefore the lower flat plate <NUM> moves up and down along a direction in which the rail member <NUM> extends. Therefore, the sensor holding frame member 53b holding the flaw detection head <NUM> is configured to move up and down along the Z-axis extending perpendicularly (up and down) to the surface Sa of the steel plate S.

Next, the load adjustment mechanism <NUM> adjusts a load applied to the surface Sa of the steel plate S by the flaw detection head <NUM> held by the sensor holding mechanism <NUM>. As described above, the sensor holding frame member 53b holding the flaw detection head <NUM> moves up and down along the Z-axis extending perpendicularly (up and down) to the surface Sa of the steel plate S. Therefore, when no load acts on the sensor holding frame member 53b, the self-weight of the entire configuration up to the lower flat plate <NUM> including the flaw detection head <NUM> and the sensor holding frame member 53b acts on the surface Sa of the steel plate S. When the self-weight of the entire configuration up to the lower flat plate <NUM> including the flaw detection head <NUM> and the sensor holding frame member 53b acts on the surface Sa of the steel plate S, the load is excessively large in the flaw detection by the flaw detection head <NUM>, which hinders the flaw detection. Therefore, in this embodiment, the load adjustment mechanism <NUM> adjusts the load applied to the surface Sa of the steel plate S by the flaw detection head <NUM>.

In the load adjustment mechanism <NUM>, bushes <NUM> each including a flange 62a at one end of a hollow pipe part are press-fitted and fixed to the vicinity of both ends in the forward and backward direction of the lower flat plate <NUM> such that the flange 62a is in contact with the upper surface of the lower flat plate <NUM> and the hollow pipe part is inserted through the lower flat plate <NUM> and projects downward from the lower flat plate <NUM> as illustrated in <FIG>. A shaft <NUM> inserted through each bush <NUM> is fixed to the upper flat plate <NUM>. Near the lower end of each shaft <NUM>, a male screw part is formed and a plurality of nuts <NUM> for load adjustment is screwed into the male screw part. A metal washer <NUM> is arranged above each nut <NUM>, a metal washer <NUM> is arranged below each bush <NUM>, and a compression coil spring <NUM> is arranged to surround each shaft <NUM> between both the metal washers <NUM>, <NUM>. The compression coil spring <NUM> acts to push the lower flat plate <NUM>, i.e., the entire configuration up to the lower flat plate <NUM> including the flaw detection head <NUM> and the sensor holding frame member 53b, upward via the bush <NUM>. On the other hand, a metal washer <NUM> is arranged above the flange 62a of the bush <NUM> and a compression coil spring <NUM> is arranged to surround the shaft <NUM> between the metal washer <NUM> and the undersurface of upper flat plate <NUM>. The compression coil spring <NUM> acts to push the lower flat plate <NUM>, i.e., the entire configuration up to the lower flat plate <NUM> including the flaw detection head <NUM> and the sensor holding frame member 53b, downward via the bush <NUM>. By adjusting the push-up force by the compression coil spring <NUM> and the push-down force by the compression coil spring <NUM>, the load applied to the surface Sa of the steel plate S by the entire configuration up to the lower flat plate <NUM> including the flaw detection head <NUM> and the sensor holding frame member 53b is adjusted.

In usual, the load is adjusted such that a value obtained by subtracting the push-down force by the compression coil spring <NUM> from the push-up force by the compression coil spring <NUM> is positive. Thus, it is configured so that the entire configuration up to the lower flat plate <NUM> including the flaw detection head <NUM> and the sensor holding frame member 53b is pushed upward, so that the self-weight of the entire configuration up to the lower flat plate <NUM> including the flaw detection head <NUM> and the sensor holding frame member 53b acting on the surface Sa of the steel plate S is subtracted.

Thus, the load applied to the surface Sa of the steel plate S by the flaw detection head <NUM> is adjusted.

As described above, the follow-up mechanism <NUM> includes the sensor holding mechanism <NUM> holding the flaw detection head <NUM> as the inspection sensor and the load adjustment mechanism <NUM> adjusting the load applied to the surface Sa of the steel plate S by the flaw detection head <NUM> held by the sensor holding mechanism <NUM>. The sensor holding mechanism <NUM> rotates around the X-axis extending in parallel to the surface Sa of the steel plate S and the Y-axis extending in a direction parallel to the surface Sa of the steel plate S and orthogonal to the X-axis, and moves up and down along the Z-axis extending perpendicularly to the surface Sa of the steel plate S.

Thus, as illustrated in <FIG>, when the flaw detection head <NUM> scans (moves over) the surface Sa of the steel plate S, the flaw detection head <NUM> held by the sensor holding mechanism <NUM> rotates around the X-axis and the Y-axis in a state where a predetermined load is applied to the surface Sa of the steel plate S according to the uneven state of the surface Sa of the steel plate S. Further, the flaw detection head <NUM> can move up and down along the Z-axis, and thus the flaw detection head <NUM> can follow the uneven state of the surface Sa of the steel plate S with an appropriate pressing force.

As illustrated in <FIG>, the inspection device body <NUM> is installed with a flow adjustment plate <NUM>. The flow adjustment plate <NUM> is installed with a flow adjustment plate attachment member <NUM> on the undersurface of the carriage <NUM> to project from the carriage <NUM> in the advancing direction (backward direction) in an inspection path of the inspection device body <NUM> as illustrated in <FIG>.

The inspection device body <NUM> advances toward the backward side of the carriage <NUM> in the inspection path and advances to the front side of the carriage <NUM> in a movement path, which is described later.

The flow adjustment plate attachment member <NUM> includes a pair of right and left support leg parts 74a extending downward from the undersurface of the carriage <NUM> and an arc-shaped attachment plate part 74b attached to the rear ends of both the support leg parts 74a to be bridged therebetween and having a projecting and arc-shaped rear side.

As illustrated in <FIG>, the flow adjustment plate <NUM> has a first arc surface 73a and a second arc surface 73b having a slightly smaller diameter than the diameter of the first arc surface 73a, has an arc shape formed into a predetermined plate thickness, and is attached to the rear surface of the arc-shaped attachment plate part 74b such that the first arc surface 73a projects toward the advancing direction in the inspection path of the inspection device body <NUM>. The flow adjustment plate <NUM> is attached to the arc-shaped attachment plate part 74b to form a gap such that a water film is formed between the flow adjustment plate <NUM> and the surface Sa of the steel plate S.

The flow adjustment plate <NUM> pushes out the water W supplied onto the surface Sa of the steel plate S from the water supply devices <NUM> in the advancing direction and forms streamlines for supplying the water between the flaw detection heads <NUM> and the surface Sa of the steel plate S simultaneously with the movement of the inspection device body <NUM>.

Next, the water supply devices <NUM> are described. The inspection device body <NUM> inspects the steel plate S for internal defects of the steel plate S and surface defects of the rear surface side of the steel plate S by ultrasonic the flaw detection, and therefore the surface (inspection surface) Sa of the steel plate S requires water as a medium for passing ultrasonic waves. To spray this water onto the surface Sa of the steel plate S, the moving inspection device <NUM> includes the water supply devices <NUM> supplying the water W required for the inspection onto the surface Sa of the steel plate S as illustrated in <FIG>.

The water supply devices <NUM> are provided separately from the inspection device body <NUM>. In this embodiment, as illustrated in <FIG>, a pair of water supply devices <NUM> is installed on the end surfaces on the long-side sides facing each other of the steel plate S formed in a rectangular shape.

Each water supply device <NUM> includes a nozzle <NUM> supplying the water W onto the surface Sa of the steel plate S as illustrated in <FIG>. The nozzle <NUM> includes a flat spray nozzle, and the water W is jetted from the nozzle <NUM> to spread in a fan shape.

Herein, the nozzle <NUM> is attached by a fixing member 82a onto an attachment plate <NUM> of a rectangular flat plate shape fixed to a magnet-type attachment base <NUM> such that the upper surface is flush with the attachment base <NUM>, the attachment base <NUM> being detachably attached to the end surface of the steel plate S such that the upper surface is flush with the surface Sa of the steel plate S.

A hose <NUM> is connected to each nozzle <NUM>, and the two hoses <NUM> are connected to a hose <NUM> connected to a water supply source (not illustrated) by a joint <NUM>.

When the water W is supplied from the water supply source to the nozzles <NUM> via the hose <NUM> and the hoses <NUM>, the water W is jetted from the nozzles <NUM> in a fan shape and supplied onto the surface Sa of the steel plate S through the upper surface of the attachment plate <NUM> and the upper surface of the attachment base <NUM>. Thus, the water W is sprayed onto the surface Sa of the steel plate S.

As described above, in the moving inspection device <NUM> according to this embodiment, the water supply devices <NUM> supplying the water W required for the inspection onto the surface Sa of the steel plate S as the inspection target are installed separately from the inspection device body <NUM>, and therefore the inspection device body <NUM> itself is reduced in size and weight, so that the moving inspection device <NUM> capable of realizing significant size reduction/weight reduction can be achieved. One in which a water tank is installed in the inspection device body <NUM> itself requires, when the water W is used up, labor of supplying the water W to the water tank again. However, the moving inspection device <NUM> according to this embodiment has eliminated a fear of using up water.

Next, a moving inspection method using the moving inspection device <NUM> illustrated in <FIG> is described with reference to <FIG>, <FIG>, and <FIG>. <FIG> is a view for explaining a movement route of a moving inspection device body when detecting flaws inside a steel plate as the inspection target. <FIG> is a view illustrating an example of an inspection pattern according to JIS G0801: Ultrasonic testing of steel plates for pressure vessels, in which the moving inspection device body moves in the movement pattern illustrated in <FIG> to detect flaws inside the steel plate. <FIG> is a view illustrating the state where the inspection region of the steel plate as the inspection target is divided into two divided regions across the center line (straight line), which is described above.

First, in the moving inspection of the steel plate S using the moving inspection device <NUM>, the water W is supplied onto the surface Sa of the steel plate S as the inspection target from the water supply devices <NUM>, so that the water W is uniformly sprayed onto the surface Sa of the steel plate S. The supply of the water W by the water supply devices <NUM> is constantly performed during the inspection of the steel plate S.

Then, the inspection device body <NUM> of the moving inspection device <NUM> is moved over the surface Sa of the steel plate S in the movement pattern illustrated in <FIG> to detect flaws inside the steel plate S.

Herein, the current position calculation unit <NUM> of the on-board computer <NUM> mounted in the inspection device body <NUM> calculates the current positions of the navigation receivers <NUM> based on the reception information received by the navigation receivers <NUM>. The position deviation calculation unit <NUM> calculates a deviation of the current position with respect to the target inspection position based on the current positions of the navigation receivers <NUM> calculated by the current position calculation unit <NUM> and the target inspection position from the setting/evaluation unit <NUM>. The drive control unit <NUM> outputs a control signal, such as a speed command, to the wheel driving motor <NUM> such that the deviation calculated by the position deviation calculation unit <NUM> is <NUM> and performs feedback control of the speed (including the rotation direction) of the wheels <NUM>, so that the inspection device body <NUM> autonomously travels along the target travel route.

Herein, in order to define the movement route, i.e., the target travel route, of the inspection device body <NUM>, an inspection region formed in a rectangular shape of the surface Sa of the rectangular steel plate S is divided into the two divided regions of the divided region A1 and the divided region A2 having the rectangular shapes across the center line (straight line) in the width direction of the steel plate S as illustrated in <FIG>. The center line extends in the longitudinal direction of the steel plate S at the center position (L/<NUM>) in the width direction with respect to the steel plate S having a width L.

Then, in the divided region A1 of the front half, the inspection device body <NUM> repeats the inspection path and the movement path constituting the movement route described later from one end side in the longitudinal direction of the steel plate S (left end side of the steel plate S in <FIG>) to the other end side in the longitudinal direction of the steel plate S (right end side of the steel plate S in <FIG>), thereby detecting flaws inside the steel plate S.

Herein, as illustrated in <FIG>, the carriage <NUM> of the inspection device body <NUM> is arranged such that the flaw detection heads <NUM> are directed to the side edge A1a of the divided region A1 facing the above-described center line (straight line) in the divided region A1 of the front half of the two divided regions A1, A2. More specifically, the carriage <NUM> is arranged such that the rear end side of the carriage <NUM> is directed to the side edge A1a of the divided region A1. Then, the carriage <NUM> is moved to the position where the center as viewed from the plane of the inspection device body <NUM> with the flaw detection heads <NUM> located on the above-described center line (straight line) is located at the point P1.

Subsequently, the carriage <NUM> of the inspection device body <NUM> is moved along the width direction of the steel plate S from the position where the center as viewed from the plane of the inspection device body <NUM> is located at the point P1 in the first inspection path in the movement route, and, simultaneously therewith, flaws inside the steel plate S are detected by the flaw detection heads <NUM>. Then, the inspection device body <NUM> is stopped at a position where the center as viewed from the plane of the inspection device body <NUM> with the flaw detection heads <NUM> located at the side edge A1a of the divided region A1 is located at the point P2. More specifically, in the first inspection path, the flaw detection heads <NUM> detect flaws inside of the steel plate S while linearly moving from the position on the center line (straight line) to the position on the side edge A1a of the divided region A1. This eliminates the necessity of a scanning actuator moving the flaw detection heads <NUM> to the side edge A1a of the divided region A1.

Thereafter, the carriage <NUM> of the inspection device body <NUM> is rotated backward while giving a right/left rotational speed difference to the pair of right and left wheels <NUM>. Thus, the center as viewed from the plane of the inspection device body <NUM> moves from the point P2 to the point P3 in the track containing the two curves R1, R2, and then the carriage <NUM> of the inspection device body <NUM> stops. The point P3 is a point where the flaw detection heads <NUM> are located at positions on the center line (straight line) different from the above-described positions on the center line (straight line) (positions where the flaw detection heads <NUM> are shifted by a predetermined distance (corresponding to the inspection pitch D) in the longitudinal direction of the steel plate S with respect to the initial positions of the flaw detection heads <NUM>). The point P3 is a starting point for the next inspection path. More specifically, the flaw detection heads <NUM> move in the track containing the two curves R1, R2 from the positions on the side edge A1a of the divided region A1 to the other positions on the center line (straight line). In this movement path, the flaw detection is simultaneously performed by the flaw detection heads <NUM>, but inspection data is erased by the setting/evaluation unit <NUM> described later.

Thereafter, the inspection path and the movement path are similarly repeated, and the inspection device body <NUM> completes the flaw detection inside the steel plate S in the divided region A1 of the front half. At this time, as illustrated in <FIG>, a plurality of duplicate inspection avoidance regions B is provided. In each duplicate inspection avoidance region B, no inspection path is provided and only the movement path is provided to avoid the duplicate inspection by the flaw detection head <NUM> provided on the left side of the carriage <NUM> and the flaw detection head <NUM> provided on the right side of the carriage <NUM>.

Then, when the flaw detection inside the steel plate S of the divided region A1 of the front half is completed, the two right and left wheels <NUM> are rotated forward and backward to rotate the inspection device body <NUM><NUM>° (pivot turn), so that the detection heads <NUM> are directed to the side edge A2a side of the divided region A2 facing the above-described center line (straight line). Even when the flaw detection heads <NUM> detect flaws inside the steel plate S in the divided region A2 of the rear half while the flaw detection heads <NUM> are directed to the side edge A1a side of the divided region A1 without turning the inspection device body <NUM><NUM>°, a region between the flaw detection heads <NUM> and the side edge A2a of the divided region A2 becomes a range where the inspection cannot be performed because the scanning actuator moving the flaw detection heads <NUM> is not provided.

Subsequently, in the divided region A2 of the rear half, the inspection device body <NUM> repeats an inspection path and a movement path constituting the movement route similar to those in the front half from the other end side in the longitudinal direction of the steel plate S (right end side of the steel plate S in <FIG>) to one end side in the longitudinal direction of the steel plate S (left end side of the steel plate S in <FIG>) in a state where the flaw detection heads <NUM> are directed to the side edge A2a side of the divided region A2 facing the center line (straight line). Thus, the inspection device body <NUM> detects flaws inside the steel plate S in the divided region A2 of the rear half. This makes it possible to inspect the entire inspection region having the rectangular shape of the surface Sa of the rectangular steel plate S as the inspection target. At this time, as with the divided region A1 of the front half, the plurality of duplicate inspection avoidance regions B is provided to avoid the duplication inspection by the flaw detection head <NUM> on the left side and the flaw detection head <NUM> on the right side.

Thus, as in the example of the inspection pattern according to JIS G0801: Ultrasonic testing of steel plates for pressure vessels illustrated in <FIG>, the flaw detection inside the steel plate S is carried out at the inspection pitch D along the longitudinal direction of the steel plate S.

The inspection pitch D is about <NUM>, <NUM>, <NUM>, or <NUM>.

Then, as illustrated in <FIG>, the inspection data obtained by the flaw detection heads <NUM> is transmitted to the setting/evaluation unit <NUM> of the on-board computer <NUM> via the ultrasonic flaw detector body <NUM> and the IO board <NUM> for evaluation.

As described above, according to the moving inspection device <NUM> of this embodiment, the inspection device body <NUM> includes: the carriage <NUM> moving by the two wheels <NUM> capable of rotating forward and backward in the forward and backward direction orthogonal to the rotation shafts 32a of the wheels <NUM> over the surface Sa of the steel plate S as the inspection target; and the flaw detection heads <NUM> as two inspection sensors arranged on the rear end side of the carriage <NUM> and inspecting the steel plate S for defects. The inspection region having the rectangular shape of the steel plate S is divided into the two divided regions A1, A2 formed in the rectangular shapes across the center line (straight line) and the carriage <NUM> of the inspection device body <NUM> move in the state where the flaw detection heads <NUM> are directed to the side edges A1a, A2a sides of the divided regions A1, A2 facing the center line (straight line) in each of the two divided regions A1, A2, respectively.

Thus, the steel plate S can be inspected by the moving inspection device body <NUM> using the drive of at least the two wheels <NUM> capable of rotating forward and backward, not turning each wheel <NUM>, and not requiring the scanning actuator causing the flaw detection heads <NUM> to scan. Therefore, the moving inspection device <NUM> capable of appropriately inspecting the steel plate S as the inspection target while realizing the simplification of the configuration and significant size reduction/weight reduction of the device.

The movement route of the inspection device body <NUM> includes the inspection path and the movement path in each of the two divided regions A1, A2. In the inspection path, the steel plate S is inspected while the flaw detection heads <NUM> linearly move from the position on the center line (straight line) to the positions on the side edges A1a, A2a of the divided regions A1, A2, respectively. In the movement path, the flaw detection heads <NUM> move in the track containing the two curves R1, R2 from the positions on the side edges A1a, A2a of the divided regions A1, A2, respectively, to the other positions on the center line (straight line).

Thus, the steel plate S can be surely inspected for defects by the moving inspection device body <NUM> using the drive of at least the two wheels <NUM> capable of rotating forward and backward, not turning each wheel <NUM>, and not requiring the scanning actuator causing the flaw detection heads <NUM> to scan.

Further, according to a moving inspection method of this embodiment, the steel plate S as the inspection target is inspected for defects using the above-described moving inspection device <NUM>. Therefore, the steel plate S as the inspection target can be inspected for defects using the moving inspection device <NUM> capable of appropriately inspecting the steel plate S while realizing the simplification of the configuration and the significant size reduction/weight reduction of the device.

The steel plate S as a steel material is manufactured through an inspection step of implementing the moving inspection method.

The embodiments of the present invention are described above but the present invention is not limited thereto and can be variously altered or modified.

For example, the inspection target to be inspected by the moving inspection device <NUM> is not limited to the steel plate S.

The inspection target is not limited to the rectangular shape, the inspection region of the inspection target is not limited to the case of being formed in the rectangular shape, and each of the two divided regions A1, A2 is not limited to the case of being formed in the rectangular shape.

The inspection of the steel plate S for defects by the moving inspection device <NUM> may also include inspecting the steel plate S for all defects including internal defects of the steel plate S and surface defects of the front surface side and the rear surface side of the steel plate S without being limited to the inspection of the steel plate S for internal defects and surface defects of the rear surface side of the steel plate S by the ultrasonic flaw detection.

The inspection device body <NUM> is not limited to one having the structure illustrated in <FIG> and <FIG> to <FIG> and may be any one inspecting the steel plate S for defects while moving over the surface Sa of the steel plate S as the inspection target.

The pair of right and left wheels <NUM> capable of rotating forward and backward is provided but at least two wheels may be provided and three or four wheels may be acceptable.

The pair of right and left flaw detection heads <NUM> as the inspection sensors is installed but the number of the flaw detection heads <NUM> may be one or three or more.

The flaw detection heads as the inspection sensors are installed on the rear end side of the carriage <NUM> but may be installed on the front end side of the carriage <NUM>. However, in this case, when the carriage <NUM> is moved over the surface Sa of the steel plate S, the flaw detection heads <NUM> are moved in a state of being directed to the side edges A1a, A2a sides of the two divided regions A1, A2 facing the center line (straight line) in each of the two divided regions A1, A2, respectively. More specifically, the carriage <NUM> is moved in a state where the front end side of the carriage <NUM> is directed to the side edges A1a, A2a of the divided regions A1, A2, respectively.

When the inspection region formed in the rectangular shape of the steel plate S is divided into the two divided regions A1, A2 formed in the rectangular shapes, the inspection region may be divided across a straight line at a position other than the center in the width direction of the steel plate S without being limited to the case where the inspection region is divided at the center line in the width direction of the steel plate S.

The movement path of the inspection device body <NUM> is designed such that the flaw detection heads <NUM> move in the track containing the two curves R1, R2 from the positions on the side edges A1a, A2a of the divided regions A1, A2, respectively, to the other positions on the center line (straight line). However, the track in this movement path may include a curve, and may be a track containing only one curve, may be a track containing two or more curves, or may be a track containing a curve and a straight line.

A steel plate provided with artificial defects (o, Δ, □) was inspected using the moving inspection device <NUM> illustrated in <FIG> as a moving inspection device according to Examples. An inspection map therefor is illustrated in <FIG>. The inspection map was created by associating the position of the inspection device body <NUM> with inspection data at that position.

The positions and the shapes of the artificial defects (∘, Δ, □) provided on the steel plate were accurately known in advance, and thus it was able to be confirmed that the inspection by the moving inspection device according to Examples had sufficient accuracy.

The mass of conventional moving inspection devices (moving inspection devices having a configuration similar to that illustrated in PTL <NUM> or PTL <NUM>) is about <NUM> (exceeds <NUM> when filled with water) because a water tank was provided, and thus the conventional moving inspection devices were very heavy. Therefore, a lifter or the like was used in the movement between steel plates of the moving inspection devices, and thus there was room for improvement.

Claim 1:
A moving inspection device comprising:
a moving inspection device body (<NUM>) configured to inspect an inspection target for a defect while moving over a surface of the inspection target, wherein
the moving inspection device body (<NUM>) includes:
a carriage (<NUM>), at least two wheels (<NUM>) capable of rotating forward and backward over the surface of the inspection target in a forward and backward direction orthogonal to rotation shafts (32a) of the wheels (<NUM>), and a wheel driving motor (<NUM>), the carriage (<NUM>) configured to move by the two wheels (<NUM>); and
at least one inspection sensor (<NUM>) arranged on a front end side or a rear end side of the carriage (<NUM>) and configured to inspect the inspection target for a defect,
a control unit for controlling the moving inspection device to travel to a predetermined target position, the control unit being able to output a control signal to the wheel driving motor (<NUM>) and performing feedback control of the speed of the wheels (<NUM>),
wherein the control unit is adapted to divide an inspection region of an inspection target into two divided regions across a straight line, and
wherein the control unit is configured to control the moving inspection device such that the carriage (<NUM>) of the moving inspection device body (<NUM>) moves in a state where the inspection sensor (<NUM>) is directed to a side edge (A1a or A2a) of the divided region (A1 or A2) facing the straight line in each of the two divided regions (A1, A2).