JP6973434B2 - Void inspection device and void inspection method - Google Patents

Description

The present invention relates to a void inspection device and a void inspection method, and more particularly to a void inspection device and a void inspection method for inspecting the presence or absence of voids in a mortar filled in a gap between construction materials arranged side by side.

In a structure constructed by arranging construction materials side by side, the gaps between the construction materials (hereinafter, also referred to as joints) are filled with mortar, but the presence of voids in the mortar hinders the use of the structure. There is a risk.

For example, in a brickwork structure such as a coke oven, high-temperature gas flows inside the structure, so if there are voids in the mortar filled in the joints between the bricks, the gas may leak through the voids. There is. In this case, problems such as occurrence of abnormal combustion and deterioration of coke quality may occur. Further, if the mortar dries with the voids contained therein, the strength of the portion thereof may decrease, which may adversely affect the seismic resistance of the structure.

In order to avoid the situation where there are voids in the mortar filled in the joints, the voids can be removed by pushing the mortar into the joints, or after filling the joints with mortar, the construction materials can be removed and peeled off to show the presence of voids. Visually inspect. Since such work requires time and effort, the construction work (construction) of the structure is prolonged.

Examples of the conventional method for inspecting the presence or absence of voids in the filler as described above include the inspection method described in Patent Document 1 and the inspection method described in Patent Document 2.

In the inspection method described in Patent Document 1, in a method of constructing a structure by combining a filler and an inspected plate, a fast neutron beam is irradiated from the outside of the inspected plate and the reflected thermal neutron beam is analyzed. .. This makes it possible to calculate the thickness of the voids that may occur between the inner surface of the plate to be inspected and the filler. In the void inspection method described in Patent Document 1, the water content in the filler is measured in calculating the void thickness, and the void thickness is calculated based on the measurement result.

In the inspection method described in Patent Document 2, in a structure in which concrete is filled inside an outer frame made of a steel plate, an acoustic wave such as an ultrasonic wave is incident from the surface side of the steel plate, and the reflected wave is measured. As a result, the location of the void generated between the steel plate and the concrete is detected, and the depth of the void is estimated.

Japanese Patent No. 5389555 Japanese Patent No. 5541490

However, the inspection methods described in the above two patent documents may be difficult to use as a method for inspecting the presence or absence of voids in the mortar filled in the joint.

When attempting to inspect the presence or absence of voids in the mortar filled in the joints by using the method described in Patent Document 1, workers other than the inspector, including workers who are arranging construction materials such as bricks. The work site is crowded by (other workers), and neutron beams for inspection will be handled in it. Therefore, it is necessary to take measures to prevent other workers from being exposed to radiation, which may increase inspection costs and working hours. In addition, the water content in the mortar filled in the joints is absorbed by construction materials such as bricks and changes every moment. Therefore, it becomes difficult to measure the water content in the mortar, and as a result, the accuracy of the inspection regarding voids may be affected.

When the presence or absence of voids in the mortar filled in the joint is to be inspected by using the method described in Patent Document 2, ultrasonic waves are incident on a construction material such as brick instead of a steel plate. However, unlike a general steel plate, a construction material such as a brick has a non-uniform surface shape and absorbs a medium (liquid) when ultrasonic waves are incident inside. Therefore, the signal strength when the ultrasonic wave is incident on the construction material such as brick is inferior to that when the ultrasonic wave is incident on the steel material, and therefore the ultrasonic wave may not be able to pass through the mortar in the joint. In such a case, it becomes difficult to distinguish between the voids in the joint and the mortar. Further, in the direction perpendicular to the incident surface of the ultrasonic oscillator, there may be a problem that the voids in the mortar filled in the joints are difficult to detect.

The present invention has been made in view of the above circumstances, and an object of the present invention is to solve the following object.
Specifically, the present invention solves the above-mentioned problems of the prior art, and is capable of appropriately inspecting the presence or absence of voids in the mortar filled in the gaps of construction materials, and the void inspection method. The purpose is to provide.

In order to achieve the above object, the void inspection apparatus of the present invention is a void inspection apparatus for inspecting the presence or absence of voids in the mortar filled in the gaps between the construction materials arranged side by side, and is the first electrode and the void inspection apparatus. A voltage application part that applies a voltage between the second electrode and the first electrode and the second electrode, and the first electrode and the second electrode flow between the first electrode and the second electrode with the first electrode and the second electrode inserted in the mortar. It is characterized by having a detection unit for detecting a current.

According to the void inspection apparatus of the present invention configured as described above, two electrodes are inserted into a mortar filled in a gap (that is, a joint) of a construction material, and a change in current flowing between the electrodes is detected. Here, the current changes depending on the presence or absence of the void, and by detecting such a change in the current, it is possible to appropriately confirm the presence or absence of the void.

Further, in the above-mentioned void inspection device, the void inspection device has a determination unit for determining the presence or absence of voids based on the current detected by the detection unit, and the determination unit is the first electrode when the current drops to a specified value or less. It is suitable if it is determined that there is a gap at the position.
With the above configuration, the presence or absence of voids is determined on the device side, so that the inspector (in other words, the user of the void inspection device of the present invention) can more easily inspect the presence or absence of voids.

Further, in the above-mentioned void inspection device, the detection unit detects the current when the first electrode is moved, and visualizes the position of the first electrode when the current detected by the detection unit becomes equal to or less than the specified value. It is even more preferable to have a display unit for displaying the image.
With the above configuration, by visualizing and displaying the position of the first electrode when the current falls below the specified value, it is possible to visualize and confirm the position of the void through the display screen. ..

Further, in the above-mentioned void inspection device, the gap extends along an extension direction that intersects both the depth direction of the gap and the height direction of the gap, and is a position that specifies the position of the first electrode in the extension direction. It is more preferable to have a specific portion.
With the above configuration, it is possible to specify the position of the first electrode in the extension direction, which is necessary for confirming the position of the gap in the extension direction of the gap.

Further, in the above-mentioned void inspection device, it is more preferable that the first electrode has an apex located at the tip of the first electrode and has a shape that becomes thinner toward the apex.
With the above configuration, it becomes difficult for mortar to adhere to the tip of the first electrode. As a result, for example, it is possible to effectively avoid a situation in which the inspection is not performed correctly due to the mortar continuing to adhere to the tip of the first electrode.

Further, in the above-mentioned void inspection apparatus, it is more preferable that the surface of the first electrode is covered with a water-repellent layer made of a water-repellent material.
With the above configuration, it becomes more difficult for the mortar to adhere to the tip of the first electrode. As a result, for example, it is possible to more effectively avoid a situation in which the inspection is not performed correctly due to the continuous adhesion of the mortar to the tip of the first electrode.

Further, the above-mentioned void inspection device has a positioning portion for positioning the first electrode at the initial position by contacting the surface of the construction material, and the initial position is based on the surface position of the mortar in the depth direction of the gap. It is particularly preferable that the position is set.
With the above configuration, the first electrode can be positioned at a regular position (initial position) at the start of inspection. This makes it possible to more appropriately inspect the presence or absence of voids.

Further, in order to solve the above-mentioned problems, the void inspection method of the present invention is a void inspection method for inspecting the presence or absence of voids in a mortar filled in the gaps of construction materials arranged side by side, and the mortar is used. It is characterized by having a step of applying a voltage between the first electrode and the second electrode in a plugged state, and a step of detecting a current flowing between the first electrode and the second electrode.
According to the above method, it is possible to appropriately inspect the presence or absence of voids in the mortar filled in the joint.

According to the present invention, a void inspection device and a void inspection method capable of appropriately inspecting the presence or absence of voids in a mortar filled in a gap (joint) of a construction material are realized.

It is a figure which shows the state of the void inspection using the void inspection apparatus. It is explanatory drawing about the structure of the void inspection apparatus. It is a figure which shows an example of the void existing in a joint mortar. It is a figure which shows the current value when the 1st probe was inserted into the joint mortar at the position A of FIG. It is a figure which shows the current value when the 1st probe was inserted into the joint mortar at the position B of FIG. It is a figure which shows the current value when the 1st probe was inserted into the joint mortar at the position C of FIG. It is a figure which shows the mapping image of the void drawn based on the detection of a current change. It is a side sectional view of each probe. It is a figure which shows the structure of the control system in a void inspection apparatus. It is explanatory drawing of the position specifying mechanism which concerns on the 1st modification. It is explanatory drawing of the position specifying mechanism which concerns on the 2nd modification (the 1). It is explanatory drawing of the position specifying mechanism which concerns on the 2nd modification (the 2). It is a figure which shows the deformation example of the tip part of the 1st probe. It is a figure which shows the positioning part. It is a figure which shows the procedure of a void inspection (the 1). It is a figure which shows the procedure of a void inspection (the 2). It is a figure which shows the procedure of a void inspection (the 3). It is a figure which shows the procedure of a void inspection (the 4).

The void inspection apparatus and the void inspection method according to the embodiment of the present invention will be described in detail below with reference to the preferred embodiments shown in the accompanying drawings.
It should be noted that the embodiments described below are merely examples for facilitating the understanding of the present invention, and do not limit the present invention. That is, the present invention may be modified or improved from the embodiments described below as long as it does not deviate from the gist thereof. Further, as a matter of course, the present invention includes the equivalent thereof.

Further, in the following description, the "mortar" means a mortar in a state before drying, and strictly speaking, a mortar in a state where the ratio of the weight of water to the total weight (moisture content) is 10% or more, and further. Specifically, it means a mortar having a water content of 10 to 30%. The dried mortar will be referred to as "dried mortar" below in order to distinguish it from the mortar before drying.

<< Outline of the void inspection device according to this embodiment >>
The outline of the void inspection apparatus according to this embodiment will be described. The void inspection device according to the present embodiment is used to inspect the presence or absence of voids in the mortar filled in the joints in the structure. Here, the structure has a wall formed by arranging block-shaped construction materials side by side in the vertical direction and the horizontal direction, respectively, and a space (internal space) surrounded by the wall. Joints are gaps in construction materials.
Joints include horizontal joints extending along the horizontal direction and vertical joints extending along the vertical direction, but in the following, unless otherwise specified, the horizontal joints are simply referred to as "joints". The present invention is applicable not only to the presence or absence of voids in the mortar filled in the horizontal joints, but also to the presence or absence of voids in the mortar filled in the vertical joints.

The mortar filled in the joint is used as a binder for binding the construction materials located on both sides of the joint (for easy understanding, the upper side and the lower side of the joint), and is hereinafter referred to as "joint mortar".

In the following, a furnace will be taken as an example of the structure, and a case of inspecting the presence or absence of voids in the joint mortar in the furnace will be described as a specific example. That is, in the following, when the void inspection device according to the present embodiment is used to inspect the presence or absence of voids in the mortar filled in the gaps between bricks in a furnace configured by arranging bricks as construction materials. Will be explained assuming that. Examples of the furnace include a baking furnace such as a coke oven, a heating furnace, a smelting furnace, a fireplace, and an incinerator.

The structure is not limited to the furnace, and may be another structure (for example, an outer wall of a building). The void inspection apparatus of the present invention can also be applied to inspect the presence or absence of voids in joint mortar in structures other than furnaces.

High-temperature combustion gas (gas inside the furnace) flows inside the furnace, but if there are voids in the mortar filled in the gaps (joints) between the bricks, the gas inside the furnace may leak to the outside of the furnace through the voids. There is. Also, the presence of voids can reduce the strength of the furnace. Therefore, from the viewpoint of ensuring the safety and quality of the furnace, it is usually necessary to appropriately inspect the presence or absence of voids in the joint mortar during the construction process of the furnace.

The inspection for the presence or absence of voids in the joint mortar in the furnace (hereinafter referred to as “void inspection” for convenience) is carried out during the construction process of the furnace as described above. Strictly speaking, when a new joint is formed by stacking (arranging) one step of bricks, a void inspection is performed on the mortar filled in the joint each time. However, the present invention is not limited to this, and for example, a void inspection may be performed each time new bricks are stacked one by one.

In the void inspection according to the present embodiment, the presence or absence of voids in the joint mortar is inspected, and the position, shape, size, etc. of the voids are confirmed. Then, if a void is found by the void inspection and the void meets the predetermined conditions, it is judged that the construction is defective, the bricks piled up immediately before are peeled off, the mortar is reconstructed, and the bricks are reloaded. To carry out.

Here, the conditions of the voids judged to be poor construction are not particularly limited, but for example, the size of the voids (specifically, the area or the area ratio with respect to the joint size) exceeds a predetermined value. At times, or when the void penetrates the joint mortar, it can be determined that the construction is defective.

Explaining the rough procedure of the void inspection, the void inspection is carried out by using the void inspection apparatus 10 according to the present embodiment shown in FIG. FIG. 1 is a diagram showing a state of void inspection using the void inspection device 10. In FIG. 1, the X direction is the extension direction of the joint (longitudinal direction of the joint wall), the Y direction is the depth direction of the joint (thickness direction of the furnace wall), and the Z direction is the height direction of the joint. (Vertical direction of the furnace wall).

In the void inspection, the joint formed immediately before the joint (hereinafter referred to as "target joint 2") is targeted, and the entire length of the target joint 2 (the length of the entire target joint in the extending direction of the target joint 2) is covered. The presence or absence of voids in the joint mortar 4 is inspected in real time.

Specifically, as shown in FIG. 1, the first probe 11 and the second probe 12 of the void inspection device 10 are inserted into the joint mortar 4 of the target joint 2 in the Y direction. As shown in FIG. 2, electrodes are provided at the tips of the first probe 11 and the second probe 12, and the voltage of the power supply 24 built in the void inspection device 10 is applied between the electrodes. Will be done. FIG. 2 is an explanatory diagram of the configuration of the void inspection device 10, and is a diagram schematically showing an XY cross section of the void inspection device 10 in a used state. In FIG. 2, the inside of the void inspection device 10 (strictly speaking, the inside of the device main body 10H described later) is shown in a simplified manner for convenience of illustration.

The electrode attached to the tip of the first probe 11 is the first electrode 13, and the electrode attached to the tip of the second probe 12 is the second electrode 14.

As shown in FIG. 2, the first probe 11 is attached to the actuator 15 of the void inspection device 10, and is configured to be able to move forward and backward in the Y direction by the actuator 15. The void inspection device 10 advances the first probe 11 further in the Y direction by the actuator 15 after the tip end portion of the first probe 11, that is, the first electrode 13 is inserted into the joint mortar 4. As a result, the first electrode 13 moves linearly along the Y direction, and the insertion amount thereof changes. The insertion amount is the distance that the first electrode 13 has moved from the surface of the joint mortar 4 (the end surface on the front side in the Y direction), and is the “insertion depth”.

After being inserted into the joint mortar 4, the second probe 12 is fixed at that position. The position of the second probe 12 is preferably the tip of the second probe 12, that is, the position where the second electrode 14 is inserted about 5 mm from the surface of the joint mortar 4 in the Y direction. However, the present invention is not limited to this, and for example, the top of the second electrode 14 may be in contact with the surface of the joint mortar 4. Incidentally, in order to further stabilize the posture of the second probe 12 during the inspection, it is desirable that the second electrode 14 is inserted into the joint mortar 4 to some extent (for example, about 5 mm).

When the first electrode 13 and the second electrode 14 inserted in the joint mortar 4 are energized with each other via the mortar, the size between the first electrode 13 and the second electrode 14 corresponds to the applied voltage. Current flows. Since the mortar contains water, it functions as a conductor, and when both the first electrode 13 and the second electrode 14 are in contact with the mortar, the virtual resistance 6 interposed between the electrodes becomes relatively small. A relatively large constant current flows between the first electrode 13 and the second electrode 14.

On the other hand, when the first electrode 13 enters the void, the above-mentioned virtual resistance 6 becomes remarkably high, and the current hardly flows between the first electrode 13 and the second electrode 14, and flows between both electrodes. The current is below the specified value (specifically, near zero).

The difference in the current flowing between the first electrode 13 and the second electrode 14, that is, the change in the current depending on the presence or absence of the void, is detected by the ammeter 22 provided inside the void inspection device 10. .. Then, the void inspection device 10 determines the presence or absence of voids based on the detection result (that is, the magnitude of the current) of the ammeter 22.

More specifically, the actuator 15 moves the first electrode 13 further inward along the Y direction to gradually increase the insertion amount, and the current flowing between the first electrode 13 and the second electrode 14 Is sequentially detected by the ammeter 22. At this time, each time the actuator 15 moves the first electrode 13, the driving amount of the actuator 15 is measured, and the void inspection device 10 specifies (calculates) the insertion amount of the first electrode 13 based on the measurement result.

Then, when the magnitude of the current becomes equal to or less than a specified value (near zero), the void inspection device 10 determines that there is a void at the position of the first electrode 13 at that time. In this way, the void inspection device 10 detects the change in current in association with the insertion amount of the first electrode 13, and thus the presence or absence of a gap at the position where the first electrode 13 exists (strictly speaking, in the Y direction). (Presence or absence of voids) can be determined.

After that, the void inspection device 10 repeats the same operation as described above while changing the insertion position of the first electrode 13 to a plurality of locations in the X direction (extending direction of the target joint 2). At this time, by specifying the position of the first electrode 13 in the X direction by a mechanism described later, the presence or absence of a gap can be inspected in each of the X direction and the Y direction, and the position, shape and size of the gap can be determined. It will be possible to identify.

The method of specifying the position and the like of the void W will be outlined by taking as an example the case where the void W shown in FIG. 3 exists in the joint mortar 4. FIG. 3 is a diagram showing an example of the void W existing in the joint mortar 4, and is an XY cross section of the joint mortar 4.

The first probe 11 is inserted into the joint mortar 4 at each of the positions A, B and C in FIG. 3 in the X direction, and the first electrode 13 is inserted into the joint mortar 4 at each position along the Y direction by the actuator 15 at the back of the target joint 2. As it is moved to the side, the current flowing between the first electrode 13 and the second electrode 14 changes as shown in FIGS. 4A, 4B and 4C, respectively.

4A to 4C are diagrams showing current values when the first probe 11 is inserted into the joint mortar 4 at each of the positions A, B, and C in FIG. In each of FIGS. 4A to 4C, the horizontal axis indicates the insertion amount of the first electrode 13 (distance from the surface position of the joint mortar 4 in the Y direction), and the vertical axis represents the current value detected by the ammeter 22. Is shown.

As can be seen from FIGS. 4A to 4C, the current value sharply decreases when the first electrode 13 enters the void W, and when the first electrode 13 exits the void W and enters the mortar again, the current value decreases. To increase. By visualizing such a tendency, the range of the void W (that is, the edge of the void W) can be specified.

More specifically, the first probe 11 is inserted into the joint mortar 4 at each position of a plurality of inspection positions set at a constant pitch ΔX in the X direction, including the positions A, B and C in FIG. At each inspection position, the current change is detected while increasing the insertion amount of the first electrode 13 by the same procedure as described above. The accuracy of specifying the position of the void W depends on the pitch ΔX of the inspection position in the X direction, and the accuracy improves as the ΔX becomes smaller, but the number of inspection positions increases, so that the inspection takes a long time. Time out. Therefore, in actual operation, it is desirable to determine the required void detection performance (minimum size of the void to be detected) in advance and set ΔX according to the determined value of the space detection performance.

Then, the insertion amount (that is, the position of the first electrode 13 in the Y direction) when the current becomes equal to or less than the specified value in the current change at each inspection position in the X direction is recorded. When the recorded insertion amount is plotted in association with each inspection position on the XY plane and a curve passing through each plot is drawn, the position, shape and size of the gap W are mapped image (as shown in FIG. 5). It can be expressed as an example of an image).
FIG. 5 is a diagram showing a mapping image of the void W drawn based on the detection of the current change. In FIG. 5, the three axes orthogonal to each other are the axes indicating the position in the X direction, the position in the Y direction, and the magnitude I of the current, respectively. In FIG. 5, the graph showing the current change at each of the positions A, B, and C in FIG. 3 is drawn with a solid line, and the graph showing the current change at the other inspection positions is drawn with a broken line.

The mapping image of the void W obtained by the above procedure is displayed on the monitor 16 included in the void inspection device 10. The inspector who is a user of the void inspection device 10 notices the existence of the void W in the joint mortar 4 by looking at the mapping image of the void W displayed on the monitor 16, and also notices the existence of the void W in the joint mortar 4, and the position, shape and size of the void W. Can be grasped.

The monitor 16 may be integrated with the device main body 10H (a portion other than the monitor 16) of the void inspection device 10, or may be configured by a communication terminal with a monitor separated from the device main body 10H. In the latter case, the monitor 16 composed of a communication terminal is connected to the device main body 10H in a wired or wireless manner, and can be installed at a place away from the device main body 10H.

Further, the void inspection device 10 analyzes the mapping image of the void W to calculate the approximate area of the void W, and the area of the void W with respect to the cross-sectional area of the target joint 2 (strictly speaking, the area of the XY cross section). When the ratio of the above exceeds the threshold value, it is determined that the construction is defective. In this case, it is preferable that the void inspection device 10 notifies the inspector, the worker who performs the brick stacking, and the like through the monitor 16 and the like that the bricks need to be reloaded because the construction is defective.

<< Detailed configuration of void inspection device >>
Next, the detailed configuration of the void inspection device 10 will be described. As shown in FIG. 1, the void inspection device 10 has a device main body 10H and a monitor 16. As shown in FIG. 1, the monitor 16 is provided separately from the apparatus main body 10H. The apparatus main body 10H is provided with a first probe 11 and a second probe 12 in a state in which their respective tip portions extend from the housing of the apparatus main body 10H. As shown in FIG. 2, the apparatus main body 10H includes an actuator 15, an ammeter 22 as a detection unit, and a power supply 24 as a voltage application unit.

Each of the first probe 11 and the second probe 12 is a rod-shaped member, and is generally made of a metal covered with an insulating resin, glass, or the like. The number of each of the first probe 11 and the second probe 12 may be at least one or more, and a plurality of each may be provided. Further, as shown in the side sectional view (YZ cross section) of FIG. 6, each probe is covered with the insulating structural material 17 except for the tip portion (that is, the first electrode 13 and the second electrode 14). There is.

A wiring 18 made of a conductive material is arranged inside the insulating structural material 17, and is electrically connected to the power supply 24.
The outer diameter of each probe is shorter than the joint width (the length of the joint in the Z direction). When the outer diameter of the probe is as small as possible, the insertion hole (opening) formed in the joint mortar 4 when the probe is inserted becomes smaller, and the curing work (for easy understanding, hole closing) after the probe is pulled out is omitted or It is preferable because it can be minimized.

The first electrode 13 and the second electrode 14 are made of a conductive material (for example, metal) and are inserted into the joint mortar 4 at the time of void inspection. When both the first electrode 13 and the second electrode 14 inserted into the joint mortar 4 are in contact with the mortar, a relatively large current flows between the electrodes. On the other hand, when the first electrode 13 inserted into the joint mortar 4 enters the inside of the void in the joint mortar 4, the contact between the first electrode 13 and the mortar is cut off, so that the magnitude of the current is a specified value. It becomes the following. By capturing the change in current as described above, the presence or absence of voids in the joint mortar 4 can be inspected.

Further, in the present embodiment, as shown in FIG. 6, a water-repellent layer 19 formed by applying a water-repellent material is provided on the surfaces of the first electrode 13 and the second electrode 14. .. This is because if the water repellency of the electrode surface is low, the mortar continues to adhere to the electrode, and when the electrode enters the void, the mortar adheres to the electrode, even though the electrode is in the void. This is because a relatively large current flows and causes an erroneous inspection. That is, in the present embodiment, since the surface of each electrode is covered with a water-repellent layer, the water repellency of the electrode surface is improved to suppress the adhesion of mortar, and thus the void inspection is performed more accurately. Is possible.

The water-repellent layer 19 may be provided at least on the surface of the first electrode 13, and the water-repellent layer 19 may not be formed on the surface of the second electrode 14.

Further, both the first electrode 13 and the second electrode 14 have vertices located at their respective tips as shown in FIG. 6, and have a substantially conical shape that becomes thinner toward the vertices. If the tip of the electrode is a flat surface, mortar tends to adhere to the tip surface of the electrode, which causes an erroneous inspection due to the adhesion of mortar as described above. In the present embodiment, the shape of each electrode is substantially conical to suppress the adhesion of mortar, so that the void inspection can be performed with higher accuracy.

The shape of the tip of the electrode may be a conical shape having a slight roundness as shown in FIG. 6, or may be a conical shape sharply pointed at an acute angle. Further, at least the shape of the first electrode 13 may be a shape that becomes thinner toward the apex, and the tip shape of the second electrode 14 is a shape different from the above, for example, a shape in which the tip is a flat surface. You may.

The actuator 15 is composed of a uniaxial actuator, and at the time of void inspection, the first probe 11 including the first electrode 13 is linearly moved along the Y direction to change the insertion amount of the first electrode 13. In the present embodiment, the actuator 15 intermittently pushes the first probe 11 by a fixed amount when pushing the first probe 11 toward the back in the Y direction. In other words, the insertion amount of the first electrode 13 increases intermittently by a predetermined amount.

Further, when the first electrode 13 is inserted to a predetermined insertion amount, the actuator 15 moves the first probe 11 in the direction in which the first electrode 13 is pulled out (that is, the front side in the Y direction) to retract the first electrode 13. The predetermined insertion amount (hereinafter referred to as "maximum insertion amount") is slightly shorter than the thickness of the target joint 2 in the Y direction, and is just before the first electrode 13 penetrates the joint mortar 4. ing. However, the maximum insertion amount may be larger than the thickness of the target joint 2, that is, the joint mortar 4 may be penetrated when the first electrode 13 is inserted to the maximum insertion amount.

The power supply 24 applies a voltage between the first electrode 13 and the second electrode 14 in a state where the first electrode 13 and the second electrode 14 are inserted into the joint mortar 4 in the void inspection. In the present embodiment, the applied voltage can be switched between the DC voltage and the AC voltage, and when the AC voltage is applied, the voltage waveform can be switched between the sine wave and the square wave. ..

The ammeter 22 detects the current flowing between the first electrode 13 and the second electrode 14 through the virtual resistor 6 in the void inspection. The ammeter 22 detects the current when the actuator 15 moves the first electrode 13 along the Y direction, and outputs a signal according to the detection result (specifically, the magnitude of the current value).

As shown in FIG. 7, a processing device 30 is built in the device main body 10H. FIG. 7 is a diagram showing a configuration of a control system in the void inspection device 10. The processing device 30 is composed of a processor such as a microcomputer or an ASIC (Application specific integrated circuit), and controls the actuator 15 to move the first probe 11 forward and backward along the Y direction at the time of void inspection, and the joint mortar 4 The insertion amount of the first electrode 13 with respect to the above is adjusted.

The processing apparatus 30 determines the presence or absence of voids in the joint mortar 4 based on the current detected by the ammeter 22 in the void inspection. That is, in the present embodiment, the processing device 30 functions as a determination unit and determines the presence or absence of a gap based on the signal output from the ammeter 22. The processing apparatus 30 has a gap at the position of the first electrode 13 when the current drops to a specified value or less (near zero) during the period when the first electrode 13 is inserted into the inner side of the joint mortar 4 in the Y direction. Is determined to exist.

The processing apparatus 30 switches the voltage applied between the first electrode 13 and the second electrode 14 between the DC voltage and the AC voltage in the void inspection. The housing of the apparatus main body 10H is provided with the operation panel 32 shown in FIG. 7, and the inspector selects the type of voltage through the operation panel 32. The processing device 30 sets the applied voltage to the type of voltage selected by the inspector among the DC voltage and the AC voltage. Applying an AC voltage is advantageous in that noise of a DC component of the applied voltage can be removed, but is disadvantageous over DC voltage in that signal processing becomes complicated.

The processing device 30 has a function of changing the waveform of the AC voltage when the applied voltage is an AC voltage. That is, in the present embodiment, the processing device 30 functions as a waveform changing unit, and changes the waveform of the AC voltage applied by the power supply 24 to the waveform selected by the inspector from the sine wave and the square wave through the operation panel 32. .. If the voltage waveform is a rectangular wave, it is possible to suppress the influence of eddy current in the void inspection.

The processing device 30 identifies the position of the first electrode 13 in the X direction and the Y direction in cooperation with the position specifying mechanism described later at the time of the void inspection. That is, in the present embodiment 30, the processing device 30 functions as a position specifying unit. The processing device 30 cooperates with a position specifying mechanism (for example, a wheel 41 with a rotary encoder described later), and X of the first electrode 13 in a state where the first probe 11 is inserted into the joint mortar 4. Identify the position in the direction. Further, in the processing device 30, each time the actuator 15 intermittently pushes the first probe 11 into the joint mortar 4 in a fixed amount along the Y direction, the position of the first electrode 13 in the Y direction (strictly speaking). , The moving distance from the surface of the joint mortar 4) is specified.

The processing device 30 creates a void mapping image according to the above procedure based on the detection result of the ammeter 22 and the position of the specified first electrode 13, and displays the created mapping image on the monitor 16. That is, in the present embodiment, the processing device 30 functions as a display unit, and the position of the first electrode 13 at the time when the current flowing between the first electrode 13 and the second electrode 14 becomes equal to or less than a specified value is determined. Visualize and display. The processing apparatus 30 displays the above mapping image as an image showing the position of the first electrode 13 in each of the X direction and the Y direction when the current becomes equal to or less than the specified value.

The processing device 30 analyzes the above mapping image, calculates the area ratio of the voids with respect to the cross-sectional area of the target joint 2, determines whether or not the target joint 2 is a construction defect from the calculated value, and the determination result. May be displayed on the monitor 16 together with the above mapping image.

Next, a mechanism for specifying the position of the first electrode 13 in the X direction in cooperation with the processing device 30 will be described. In the present embodiment, a wheel 41 equipped with a rotary encoder is attached to the apparatus main body 10H. The wheel 41 is a rotating body with a rotary encoder, and as shown in FIG. 1, is a surface of the housing of the apparatus main body 10H facing the furnace wall (hereinafter referred to as “opposing surface”) at the time of void inspection. It is rotatably provided at adjacent positions.

Further, the wheel 41 is separated from the facing surface during the period in which the first electrode 13 and the second electrode 14 are inserted into the joint mortar 4. On the other hand, when the first electrode 13 and the second electrode 14 are pulled out from the joint mortar 4 and the apparatus main body 10H is conveyed in the X direction, the wheel 41 rotates so as to roll on the furnace wall while the outer peripheral surface thereof is in contact with the furnace wall. do. At this time, the rotary encoder mounted on the wheel 41 outputs a signal according to the rotation amount of the wheel 41, and specifically, outputs a pulse signal every time the wheel 41 rotates by a predetermined amount.

Then, when the apparatus main body 10H is transported from the previous inspection position to the next inspection position in the X direction, the first electrode 13 and the second electrode 14 are inserted into the joint mortar 4 again at the position after the transfer. Then, the processing device 30 identifies the position of the first electrode 13 in the X direction (that is, the position after the transfer) based on the signal output by the rotary encoder during the transfer of the device body 10H.

As described above, in the case shown in FIG. 1, the processing device 30 and the wheel 41 with the rotary encoder cooperate to form the position specifying portion. In other words, in the case of FIG. 1, the position specifying portion is formed. It has wheels 41 with rotary encoders. Then, each time the apparatus main body 10H is conveyed in the X direction, the position of the first electrode 13 after the transfer in the X direction is specified.

When performing a void inspection with each joint as the target joint 2, first, the apparatus main body 10H is set at a predetermined position with respect to the target joint 2 in the X direction, and at that position, the first electrode 13 and the second electrode 13 and the second The electrode 14 is inserted into the joint mortar 4. The position of the first electrode 13 at this time corresponds to the first inspection position.

At the first inspection position, when the first electrode 13 is inserted into the joint mortar 4 by the actuator 15 up to the maximum insertion amount, the first electrode 13 is pulled out from the joint mortar 4, and then the main body of the apparatus including the first electrode 13. The entire 10H is conveyed along the X direction. During this time, the wheel 41 rotates while rolling on the furnace wall along with the transfer of the first electrode 13 in the X direction, and the rotary encoder mounted on the wheel 41 outputs a signal according to the rotation amount of the wheel 41.

When the first electrode 13 reaches the next inspection position, it is inserted into the joint mortar 4 again at the inspection position. Further, the processing apparatus 30 calculates the transport amount of the first electrode 13 in the X direction based on the signal output by the rotary encoder during the transport of the first electrode 13, and is separated from the first inspection position by the calculated transport amount. The position is specified as the position (inspection position) of the first electrode 13 after transportation.

After that, every time the first electrode 13 is conveyed from the previous inspection position to the next inspection position in the X direction, the position of the first electrode 13 in the X direction after the transfer is specified by the above procedure. ..

The mechanism for specifying the position of the first electrode 13 in the X direction is not limited to the above-mentioned mechanism, and other mechanisms can be considered. As another mechanism for specifying the position of the first electrode 13, for example, the mechanism shown in FIG. 8 (hereinafter, the position specifying mechanism according to the first modification) can be considered. FIG. 8 is an explanatory diagram of the position specifying mechanism according to the first modification.

Explaining the position specifying mechanism according to the first modification, in the configuration shown in FIG. 8 (first modification), an indoor GPS (iGPS: indoor Global Positioning System) is used as the position specifying mechanism. More specifically, in the first modification, the position sensor 42 for iGPS is mounted on the apparatus main body 10H. The position sensor 42 outputs a signal according to the three-dimensional position of the position sensor 42 itself in the space where the void inspection device 10 is used (in other words, in the space where the void inspection is performed).

The position sensor 42 includes an antenna (not shown), and periodically receives a signal (radio wave signal) transmitted from the base station 43. When the position sensor 42 receives a radio wave signal from the base station 43, the position sensor 42 identifies its own three-dimensional position based on the received signal, and outputs a signal corresponding to the specified three-dimensional position. The processing device 30 identifies a three-dimensional position (that is, a position in each direction of XYZ) of the device main body 10H based on the output signal of the position sensor 42, and uses the identification result of the first electrode 13 in the X direction. Identify the position.

As described above, in the first modification, the processing device 30 and the position sensor 42 form the position specifying portion. In the modified example, the position specifying portion has the position sensor 42, and the position of the first electrode 13 in the X direction can be appropriately specified by iGPS.

As a second modification of the mechanism for specifying the position of the first electrode 13, for example, the mechanism shown in FIGS. 9 and 10 (hereinafter, the position specifying mechanism according to the second modification) can be considered. 9 and 10 are explanatory views of the position specifying mechanism according to the second modification, FIG. 9 is a diagram corresponding to FIG. 1, and FIG. 10 is a diagram corresponding to FIG. 2.

In the second modification, as shown in FIGS. 9 and 10, a plurality of first probes 11 are arranged at equal intervals in the X direction. Further, in the second modification, as shown in FIG. 10, the first electrode 13 is configured by the movable electrode 13a provided at the tip of each of the plurality of first probes 11. That is, the first electrode 13 according to the second modification has a plurality of movable electrodes 13a arranged along the X direction, and the movable electrodes 13a are arranged so as to be evenly spaced in the X direction. ..

In the second modification, as shown in FIGS. 9 and 10, eight movable electrodes 13a are arranged, but the number of movable electrodes 13a (in other words, the number of the first probe 11) is particularly limited. However, it may be at least two or more.

Further, in the second modification, each of the plurality of movable electrodes 13a is inserted into the joint mortar 4 at the same time as shown in FIG. 10, and the insertion amount of each movable electrode 13a is adjusted by the actuator 15. Incidentally, in the configuration shown in FIG. 10, an actuator 15 is provided for each first probe 11 (in other words, for each movable electrode 13a), and the insertion amount of each movable electrode 13a can be adjusted individually. .. However, the present invention is not limited to this, and a single actuator 15 is provided, and the plurality of movable electrodes 13a may be moved at the same time by the actuator 15.

In the second modification, each of the plurality of movable electrodes 13a forms a separate circuit with the second electrode 14, and the individual circuits are connected in parallel as shown in FIG. .. That is, in the second modification, the power supply 24 applies an equal voltage between each movable electrode 13a and the second electrode 14, and a current flows between each movable electrode 13a and the second electrode 14, respectively. The change in the current is detected by the ammeter 22 provided for each movable electrode 13a. Thereby, in the second modification, the presence or absence of a plurality of cavities can be inspected at the same time at the respective arrangement positions of the plurality of movable electrodes 13a in the X direction.

In the second modification, since the movable electrodes 13a are arranged at equal intervals in the X direction, the position of each movable electrode 13a in the X direction can be specified based on the interval between the movable electrodes 13a.

In the second modification, the processing device 30 stores the distance between the movable electrodes 13a. Further, in the second modification, when performing the void inspection, the device main body is arranged so that the movable electrode 13a farthest from the second electrode 14 in the X direction is arranged at the first inspection position among the plurality of movable electrodes 13a. Set 10H. As a result, the distance of each movable electrode 13a from the first inspection position is specified, so that the position of each movable electrode 13a in the X direction can be specified.

The mechanism for specifying the position of the first electrode 13 has been described above with three examples, but each example is merely an example of the position specifying mechanism. That is, any mechanism that can specify the position of the first electrode 13 in the X direction can be freely used. For example, the position of the first electrode 13 may be specified by using an optical method. Specifically, a light emitting device is mounted on the main body 10H, and a sensor array extending in the X direction is attached to the furnace wall side. The position of the first electrode 13 in the X direction may be specified by specifying the position where the irradiation light from the light emitting device is received in the sensor array.

As shown in FIG. 6, the first probe 11 is provided with only one first electrode 13 at the tip of the first probe 11, but as shown in FIG. 11, a plurality of first probes 11 are provided at the tip of the first probe 11. The first electrodes 13 may be provided separately from each other. FIG. 11 is a diagram showing a modified example of the tip portion of the first probe 11.

In the configuration shown in FIG. 11, each of the plurality of first electrodes 13 is inserted into the joint mortar 4 at different positions in the Z direction. In the configuration shown in FIG. 11, the core material 21 is arranged at the center of the first probe 11, and four first electrodes 13 are arranged around the core material 21. Then, when the first probe 11 is inserted into the joint mortar 4, the four first electrodes 13 are inserted into the joint mortar 4 at different positions in the Z direction.

Further, inside the first probe 11 (strictly speaking, a portion excluding the first electrode 13), wiring is provided separately for each first electrode 13. With such a configuration, the presence or absence of voids can be inspected at a plurality of points within the range where the first probe 11 exists in the Z direction, the resolution (inspection resolution) in the Z direction is improved, and the presence or absence of voids is tertiary. It is possible to inspect in the original (X, Y, and Z directions respectively).

By the way, the first probe 11 and the second probe 12 are inserted into the joint mortar 4 by a predetermined amount when performing the void inspection. That is, the first electrode 13 and the second electrode 14 are arranged at positions slightly inserted into the joint mortar 4 in the Y direction at the start of the inspection. The position of the first electrode 13 in the Y direction at this time corresponds to the initial position of the first electrode 13. The initial position is a position set with reference to the surface position of the joint mortar 4 in the Y direction, and specifically, is a position located on the back side by a predetermined distance from the surface position.

If the positioning portion 26 shown in FIG. 12 is provided on the facing surface of the apparatus main body 10H, the first electrode 13 can be positioned at the initial position at the start of inspection. FIG. 12 is a view showing the positioning unit 26, and is a sectional view taken along line XY of the apparatus main body 10H provided with the positioning unit 26. In FIG. 12, the inside of the apparatus main body 10H is shown in a somewhat simplified manner for convenience of illustration.

The positioning portion 26 is a portion protruding outward from the facing surface of the apparatus main body 10H, and its length depends on the initial position (that is, the amount of insertion of the first electrode 13 into the joint mortar 4 at the start of inspection). It is designed to be long.

In this embodiment, as shown in FIG. 12, a pair of left and right positioning portions 26 are provided. One positioning unit 26 is provided at a position adjacent to the second probe 12 on the opposite side of the first probe 11, and the other positioning unit 26 is adjacent to the first probe 11 on the opposite side of the second probe 12. It is provided at a suitable position. The number of positioning portions 26 is not particularly limited, and at least one may be provided.

Then, when the apparatus main body 10H provided with the pair of positioning portions 26 was set at the position at the start of inspection, the extension direction tip surfaces of the respective positioning portions 26 were stacked on the furnace wall (strictly speaking, at that time). It is brought into contact with the surface of the brick 8). As a result, as shown in FIG. 12, the first probe 11 is inserted into the joint mortar 4 and the first electrode 13 is arranged at the initial position. At this time, the second probe 12 is also inserted into the joint mortar 4, and the second electrode 14 is arranged at a position where the second electrode 14 is inserted by a specified amount (for example, about 5 mm) with respect to the joint mortar 4.

By positioning by the positioning unit 26 as described above, the first electrode 13 can be appropriately positioned at the initial position in the Y direction. Since the first electrode 13 can be positioned at a regular position (initial position) at the start of the inspection in this way, the first electrode 13 can be appropriately displaced in the Y direction thereafter. As a result, the presence or absence of a void at the position of the first electrode 13 can be inspected while accurately grasping the position of the first electrode 13, so that the accuracy of the void inspection is improved.

<< Operation example of void inspection device >>
Next, as an operation example of the void inspection device 10 described above, the procedure of the void inspection performed using the void inspection device 10 will be described with reference to FIGS. 13A to 13D. 13A to 13D are views showing the procedure of the void inspection, and is a view of the void inspection device 10 as viewed from above. Incidentally, the state during the inspection changes in the order of FIGS. 13A, 13B, 13C and 13D.

The void inspection method described below employs the void inspection method of the present invention. In other words, the content of the void inspection described below corresponds to an example of the void inspection method of the present invention. do. Incidentally, in the following description, the case where the void inspection device 10 is provided with the wheel 41 with the rotary encoder described above as a mechanism for specifying the position of the first electrode 13 in the X direction will be described as an example. do. Further, in the following description, it is assumed that one first electrode 13 is provided at the tip of the first probe 11.

In the process of constructing the furnace wall, one stage of bricks 8 can be stacked (arranged) on the bricks 8 (strictly speaking, a row of bricks 8 in the next lower stage) located directly below it along the X direction. ), A new joint is formed, and the void inspection is performed with the joint as the target joint 2. In carrying out the void inspection, the inspector holds the apparatus main body 10H of the void inspection apparatus 10 and sets the apparatus main body 10H at a predetermined position in the X direction and the Z direction. By setting the apparatus main body 10H at a predetermined position, the first probe 11 and the second probe 12 are located at the same height as the target joint 2 in the Z direction, and the tip portion of the first probe 11 is in the X direction. It will be placed at the first inspection position.

After that, the inspector brings the apparatus main body 10H close to the target joint 2 in the Y direction, and inserts the tips of each of the first probe 11 and the second probe 12 into the joint mortar 4 of the target joint 2. As a result, as shown in FIG. 13A, the first electrode 13 at the tip of the first probe 11 is arranged at the initial position. At this time, if the above-mentioned positioning portion 26 is provided on the apparatus main body 10H, the first electrode 13 can be easily and appropriately placed at the initial position by bringing the tip of the positioning portion 26 into contact with the surface of the brick 8. Can be positioned.

When the inspector instructs the operation panel 32 to start the inspection (not shown) when the above preparations are completed, the void inspection is started. The positions of the first electrode 13 at the start of the inspection in each of the X direction and the Y direction are stored by the processing device 30.

When the void inspection is started, the processing device 30 controls the actuator 15, and the actuator 15 intermittently moves the first probe 11 to the back side in the Y direction by a predetermined amount. As a result, as shown in FIG. 13B, the insertion amount of the first electrode 13 in the joint mortar 4 is increased by a constant amount. At this time, the processing device 30 calculates the amount of movement of the first electrode 13 in the Y direction from the amount of movement of the actuator 15, and based on the calculated amount of movement, the position of the first electrode 13 after movement (position in the Y direction). To identify.

Further, while the operation of the actuator 15 is interrupted (in other words, while the first electrode 13 is stationary), the first electrode 13 and the second electrode 13 inserted into the joint mortar 4 by the power supply 24. A voltage is applied between the electrodes 14. At this time, of the DC voltage and the AC voltage, the voltage selected by the inspector through the operation panel 32 is applied. When the AC voltage is selected, the AC voltage is applied in the waveform selected by the inspector through the operation panel 32 among the sine wave and the square wave.

Further, the current flowing between the first electrode 13 and the second electrode 14 is detected by the ammeter 22. While the first electrode 13 is inserted to the back side in the Y direction, the current becomes relatively large in the place where the first electrode 13 is in contact with the mortar, while the current is relatively large in the place where the first electrode 13 is in the void. , The current is below the specified value. The ammeter 22 detects a change in the current depending on the presence or absence of such a gap.

When the ammeter 22 detects a current, the ammeter 22 outputs a signal according to the detection result, and the processing device 30 receives an output signal from the ammeter 22. Then, the processing device 30 determines the presence or absence of a gap based on the received signal (in other words, the current detected by the ammeter 22). Specifically, when the current drops to a specified value or less (near zero) when the first electrode 13 is displaced to the back side in the Y direction, the processing apparatus 30 causes the first electrode 13 in the Y direction at that time. It is determined that there is a gap at the position of.

In the above procedure, while increasing the insertion amount of the first electrode 13 by the actuator 15, the presence or absence of a gap at the position of the first electrode 13 is sequentially determined at each time point (in other words, the insertion amount). Then, when the first electrode 13 is inserted to the maximum insertion amount, the processing device 30 controls the actuator 15 so as to move the first probe 11 in the direction in which the first electrode 13 is pulled out.

When the first electrode 13 returns to the initial position in the Y direction due to the retreat of the first probe 11, the inspector holds the device main body 10H and moves the device main body 10H in the direction of the arrow in FIG. 13C. As a result, the first probe 11 and the second probe 12, which had been previously inserted into the joint mortar 4, are pulled out from the joint mortar 4. After that, the outer peripheral surface of the wheel 41 with the rotary encoder attached to the apparatus main body 10H is brought into contact with the furnace wall (strictly speaking, the surface of the bricks 8 stacked at that time).

The inspector carries the apparatus main body 10H along the X direction while rolling the wheels 41 on the furnace wall. During this time, the wheels 41 rotate along with the transportation of the apparatus main body 10H, and each time the wheels 41 rotate by a predetermined amount, the rotary encoder mounted on the wheels 41 outputs a signal.

When the device body 10H is transported from the first inspection position to the next inspection position in the X direction, the posture of the device body 10H is restored at that position, and the facing surface of the device body 10H faces the furnace wall (strictly speaking). To be parallel to the furnace wall). Then, as shown in FIG. 13D, the first probe 11 and the second probe 12 are inserted into the joint mortar 4 at the position after transportation. As a result, the first electrode 13 and the second electrode 14 are respectively positioned in the Y direction, and the first electrode 13 is arranged at the initial position. Further, the processing device 30 specifies the position of the first electrode 13 in the X direction (that is, the position after the transfer) based on the signal output by the rotary encoder during the transfer of the device main body 10H. The processing device 30 calculates the transport amount of the device main body 10H in the X direction based on the output signal from the rotary encoder, and sets the position away from the first inspection position by the calculated transport amount by the first electrode 13 after transport. Specify as the position (inspection position) of.

Then, the first probe 11 is inserted into the joint mortar 4 at the position after transportation, and the presence or absence of voids in the joint mortar 4 is inspected by the same procedure as the above-mentioned procedure. That is, at the next inspection position, a voltage is applied between the first electrode 13 and the second electrode 14 while specifying the position of the first electrode 13 (the position in the Y direction), and the current flowing between the two electrodes is applied. By detecting the change in, it is determined whether or not there is a gap in the joint mortar 4 at each position in the Y direction. This operation is repeated until the insertion amount of the first electrode 13 reaches the maximum insertion amount.

After that, the series of steps described above (that is, transporting the apparatus main body 10H, inserting a probe, specifying the position of the first electrode 13, applying a voltage, detecting a current change, and determining the presence or absence of a gap) are constant in the X direction. Is repeated every pitch ΔX. As a result, the presence or absence of voids in the joint mortar 4 is inspected over the entire target joint 2.

After that, the processing apparatus 30 plots the position of the first electrode 13 in the Y direction at the time when the current becomes equal to or less than the specified value at each inspection position in the X direction on the XY plane, and draws a curve passing through each plot. Draw to create a mapping image of the voids. The processing device 30 displays the above mapping image on the monitor 16. At this time, the area ratio of the voids obtained by analyzing the mapping image to the cross-sectional area of the target joint 2 and the quality of the construction of the target joint 2 determined from the area ratio are displayed on the monitor 16 together with the above mapping image. Suitable.

The inspector confirms whether or not a gap that may affect the use of the furnace exists in the joint mortar 4 of the target joint 2 by looking at the mapping image or the like displayed on the monitor 16.
When the above steps are completed, the void inspection for one joint (target joint 2) is completed.

According to the void inspection apparatus described above and the void inspection method using the apparatus, the presence or absence of voids in the joint mortar 4 can be inspected relatively easily and appropriately. In the above embodiment, the current flowing between the electrodes is detected with the first electrode 13 and the second electrode 14 inserted in the joint mortar 4. Here, since the current changes depending on the presence or absence of voids, it is possible to appropriately inspect the presence or absence of voids in the joint mortar 4 by detecting the current.

The void inspection according to the above embodiment is easier than the method of inspecting the presence or absence of voids using a neutron beam as in the method described in Patent Document 1, and the time of moisture in the joint mortar 4 Since the effect of the change on the inspection result is small, the presence or absence of voids can be inspected with high accuracy.

Further, since the void inspection according to the above embodiment does not inspect the presence or absence of voids using ultrasonic waves as in the method described in Patent Document 2, when ultrasonic waves are incident on a construction material such as bricks. Due to the inferior signal strength of the joint mortar 4, it is difficult to detect voids in the joint mortar 4. With the above inspection method, the presence or absence of voids can be inspected more appropriately than the inspection method described in Patent Document 2.

As described above, according to the void inspection according to the above embodiment, the presence or absence of voids in the joint mortar 4 can be appropriately inspected in the process of constructing the furnace. Therefore, even if a void is generated, it is possible to grasp the existence of the void and take appropriate measures such as reloading the bricks, so that the void can be eliminated and the generation of a large-scale gas leak can be suppressed. It will be possible. In addition, since it is possible to suppress the risk that problems such as a decrease in structural strength due to voids may occur, it is possible to improve the construction quality of the brickwork structure.

In the above embodiment, when the device main body 10H is transported, it is determined to be transported by an inspector (that is, by hand), but the present invention is not limited to this, and for example, it is transported by a robot or a self-propelled mechanism. You may. Further, the device main body 10H may be mounted on an unmanned aerial vehicle such as a drone, and the device main body 10H may be transported by remotely controlling the unmanned aerial vehicle.

2 Target joint 4 Joint mortar 6 Virtual resistance 8 Brick 10 Void inspection device 10H Device body 11 1st probe 12 2nd probe 13 1st electrode 13a Movable electrode 14 2nd electrode 15 Actuator 16 Monitor 17 Insulation structural material 18 Wiring 19 Water repellent Layer 21 Core material 22 Ammeter 24 Power supply 26 Positioning unit 30 Processing device 32 Operation panel 41 Wheel 42 Position sensor 43 Base station W void

Claims (8)

It is a void inspection device that inspects the presence or absence of voids in the mortar filled in the gaps of construction materials arranged side by side.
With the first and second electrodes,
A voltage application unit that applies a voltage between the first electrode and the second electrode,
A void inspection apparatus comprising: a detection unit for detecting a current flowing between the first electrode and the second electrode with the first electrode and the second electrode inserted in the mortar. It has a determination unit for determining the presence or absence of the void based on the current detected by the detection unit.
The void inspection device according to claim 1, wherein the determination unit determines that the void is present at the position of the first electrode when the current drops below a specified value. The detection unit detects the current when the first electrode is moved, and receives the current.
The void inspection device according to claim 1 or 2, further comprising a display unit that visualizes and displays the position of the first electrode when the current detected by the detection unit becomes a specified value or less. The gap extends along an extension direction that intersects both the depth direction of the gap and the height direction of the gap.
The void inspection apparatus according to any one of claims 1 to 3, further comprising a position specifying portion for specifying the position of the first electrode in the extending direction. The void inspection apparatus according to any one of claims 1 to 4, wherein the first electrode has an apex located at the tip of the first electrode and has a shape that becomes thinner toward the apex. The void inspection apparatus according to any one of claims 1 to 5, wherein the surface of the first electrode is covered with a water-repellent layer made of a water-repellent material. It has a positioning unit that positions the first electrode at the initial position by coming into contact with the surface of the construction material.
The void inspection apparatus according to any one of claims 1 to 6, wherein the initial position is a position set with reference to the surface position of the mortar in the depth direction of the gap. It is a void inspection method that inspects the presence or absence of voids in the mortar filled in the gaps of construction materials arranged side by side.
The step of applying a voltage between the first electrode and the second electrode in the state of being inserted into the mortar, and
A void inspection method comprising: a step of detecting a current flowing between the first electrode and the second electrode.

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