JPH022933A - Mobile flaw detecting apparatus and tank thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention inspects the presence or absence of stress cracks, etc. along the weld line of a gas tank while moving over the surface of a structure such as a spherical gas tank. Regarding ultrasonic flaw detection equipment.

To explain in more detail, the device which is configured as a flaw detection device and has a self-propelled function can be used to detect walls and flat surfaces.

When performing flaw detection in various postures such as facing downward, the couplant liquid (ultrasonic transmission medium interposed between the ultrasonic flaw detection probe and the surface to be tested) is always stably distributed under any conditions. This invention allows it to be supplied between the probe and the surface to be tested.

Furthermore, in order to reduce the consumption of couplant liquid and improve the efficiency of flaw detection work, we propose a control method in which the supply and stop of couplant liquid is controlled in conjunction with probe control. be.

[Conventional technology]

For example, a device that runs on a wall while holding its own weight is disclosed in Japanese Patent Application Laid-open No. 6
This is proposed in Publication No. 2-50281.

In addition to the above-mentioned walking type, a magnetic type, a caterpillar type, and the like have been proposed for this type of traveling device.

Next, structures made by welding, such as spherical gas tanks, generate stress in the welded parts due to welding heat, which may cause stress cracks during long-term use, so they are subject to periodic maintenance. It is required by law to inspect welded parts to check for cracks caused by welding stress. As a means for this type of inspection, it is known to mount an ultrasonic flaw detection device on the above-mentioned traveling device to automatically perform the flaw detection inspection.

Furthermore, when an ultrasonic flaw detection device has a probe close to the surface of the object to be tested, and when performing flaw detection using the ultrasonic waves emitted from the probe, the probe and the flaw to be detected are A couplant solution is interposed between the surfaces to improve the propagation of ultrasonic waves.

Various means have also been proposed for supplying this couplant liquid from the probe side between the surface to be detected and the probe to perform flaw detection operations suitable for the intended purpose.

Finally, as a method for supplying the couplant liquid, a tank for storing the couplant liquid is installed in a part of the machine frame of the self-propelled mechanism, and the couplant liquid is supplied to the probe while moving together with the self-propelled mechanism. For example, the proposal is
It is disclosed in the No. 263 publication.

[Problem to be solved by the invention]

However, this type of conventional technology does not have the ability to function as an ultrasonic flaw detector for inspecting stress cracks along weld lines while moving on a wall surface of a spherical gas tank, for example, due to the following points.

First, in the case of a wall-moving flaw detection device located on a wall, flat surface, or downward facing surface, it is necessary to always supply a stable amount of couplant liquid between the probe of the device and the surface to be tested, regardless of the position. Must be done.

Second, when the entire device is moving on the wall and when the device is fixed for flaw detection inspection, these tasks are usually not done at the same time, but even if they are done at the same time, Even if the probe is placed close to the surface to be inspected, it is better to supply the couplant solution only when the probe is performing flaw detection work, and to stop the supply of the couplant solution at other times. Operation of a pump that effectively supplies and stops couplant fluid so that fluid is not wasted and contamination of the object to be inspected or the wall moving device can be minimized.

It is necessary to have a control method for stopping.

Third, this type of device, which has the ability to move on a wall surface and is likely to be used outdoors, is required to have a configuration that can withstand use in outdoor environments.

It is necessary to take measures that take environmental resistance into consideration, and at the same time, it is necessary to consider the fact that it can be moved while supporting its own weight, so that it is assembled into a compact 1.

The present invention relates to an apparatus that performs flaw detection along a weld line, etc. while moving particularly on a wall surface. Second.
This was done with the aim of solving the third problem.

[Means to solve the problem]

As a means to solve the first problem, the present inventors installed a tank capable of storing the couplant solution on the back of the wall moving device, and moreover, the suction means for drawing out the couplant solution from inside the tank is independent of the orientation of the tank. For example, by attaching a suction port that has both weight and buoyancy to the end of a flexible tube so that the suction port that is always present in the couplant solution can be used to move around in the couplant solution.

The structure of the buoyant force as a suction means can be handled by, for example, making the vicinity of the suction port heavy so that the suction port always faces the ground surface, and attaching a swim bladder on the opposite side. As another example, the suction means itself may be made of buoyant plastic or the like, and weights may be added.

As a means for solving the second problem, the present inventors have developed a system in which the probe is brought close to the surface of the object to be inspected in conjunction with an operation command signal of a probe lifting/lowering cylinder by the action of hydraulic or air pressure.
A control method was adopted in which the operation of a pump that supplies couplant liquid between the probe and the surface to be inspected was started, and the operation of the pump was stopped in conjunction with a signal that recognized the end of the movable mount.

Furthermore, as a means to solve the third problem, the present inventors provided a tank for storing couplant liquid almost at the center of the cover that covers the main mechanical parts of the wall moving device that require environmental resistance. Moreover, the cover and tank are integrated,
I decided to make part of the cover function as a tank.

[Effect]

In the wall surface movable flaw detection device adopting the first configuration described above, the couplant liquid suction port stores the couplant liquid in response to changes in the posture of the device itself as it moves over the surface to be tested. It moves around in the tank as it exists in the couplant solution, ensuring a stable supply at all times. The suction port having this type of structure may be configured to have only a weight without providing buoyancy, so that it can be moved around while submerged in the couplant solution. Furthermore, instead of using a flexible tube, a rigid tube may be used, and the suction port attached to the tip of the tube may be configured to move around using the other end of the tube as a fulcrum. .

According to the second control method described above, it is possible to control the operation and stop of the pump that supplies the couplant liquid only when the couplant liquid is required, in accordance with the procedure of the flaw detection work of the apparatus. How to control pump operation and stop
It can also be controlled by a predetermined program.

The third configuration described above improves the stability of the device when operating under conditions such as wall surfaces, flat surfaces, and downward surfaces. The tank is
It is important to always consider the stability of the entire device when configuring the device, and based on this idea, it can be provided not only in the approximate center of the cover but also in the skirt portion. Even in that case, a design that takes the center of gravity of the device into consideration will probably be adopted.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a side view showing the entire wall surface moving flaw detection device to which the present invention is applied. For ease of explanation, the diagram is a schematic diagram showing only one probe, for example.

This device consists of an outer leg 1 and an inner leg 2, which are provided to support the main body of the device by adsorbing at least the surface F to be inspected, a cover 4 that covers the mechanism that controls the operation of each leg, and Via a movable stand 6 on the side opposite to the surface F to be inspected F of the cover 4,
It has a probe 3 held by a lifting mechanism 7.

In order to supply the couplant liquid to the probe 3, a tank 10 storing the couplant liquid is integrated with the cover 4 and is provided approximately in the center of the cover, and from the tank 10,
Through the pump 11 attached to the tank 10, it is connected to the contactor 3! - Guide the conduit 8a that supplies the liquid. Furthermore, a conduit 8b for returning the used couplant liquid to the tank 10 is led from the probe 3 to the tank 10.

Although the figure shows one probe as an example, in reality, multiple probes are provided, so the supply of couplant liquid from the pump 11 may be sent to each probe through a branching conduit. become.

To move this device with this kind of configuration, the outer leg 1 is attached to the surface F to be inspected, and the outer leg 1 is used as a support to support the device.
The inner leg 2 is separated from the surface F to be inspected, and the inner leg 2 is moved to the left side in the drawing using a moving mechanism, for example, a combination of an electric motor and a screw. When the movement is finished, fix the device by adsorbing the inner leg 2 to the surface to be inspected F, and then attach the inner leg 2
is used as a support, the outer leg 1 is separated from the surface F to be tested, the above-mentioned moving mechanism is operated in reverse to move the outer leg 1, and the leg 1 is similarly attracted and fixed to the surface F to be tested. By repeating this operation, the entire device can be moved a predetermined distance.

The flaw detection work on the surface F to be flawed is carried out with the apparatus fixed as a whole by suctioning the inner and outer legs 1.2 after the apparatus reaches the target surface for flaw detection through the above-described operations. That is, in the above-described state, the probe 3 is brought close to the surface F to be tested by the action of the elevating mechanism 7 which is movably mounted on the movable pedestal 6. Specifically, as shown in FIG. 2, compressed air is guided through a pipe 70 from a separately provided compressed air supply device.

It is fed into the cylinder 71 of the lifting mechanism 7, and the cylinder rod 73 is moved against the spring 72. This operation brings the probe 3 attached to the cylinder rod 73 close to the surface F to be tested.

Note that Figure 2 (a) shows the state of the probe 3 when the entire device is moved by the inner and outer legs, and Figure 2 (b) shows the state of the probe 3 when the probe 3 is close to the surface to be detected F during flaw detection. This shows the state of the probe when performing this.

The probe 3 has a conduit 8 into which the couplant solution is introduced.
a is connected via a check valve 81a. This conduit 8
The couplant liquid introduced by a is guided between the probe surface of the probe 3 and the surface F to be tested, and fills the gap g therebetween. By the way, since the probe 3 moves along the movable mount 6 on the surface F to be tested during the flaw detection operation, the couplant liquid is transferred to the leak-tight seal 3.
Even if you stop it at 1, it will still leak a little. To compensate for the leakage, the conduit 8a continues to supply a constant amount of couplant liquid to the probe 3, but the difference between the supply amount and the leakage amount is returned to the tank 10 through a separate conduit 8b. 81b is
81a is a check valve that operates in the opposite direction.

The operation of this type of configuration will be described below.

Lateral leg 1. The device is moved to a predetermined position by the operation of the inner legs 2, and the entire device is fixed on the surface to be inspected by the inner and outer legs.Then, the lifting mechanism 7 placed on the movable pedestal 6 works. The probe 3 installed in the elevating mechanism 7 is brought close to the surface F to be tested. At this time, the couplant solution has not yet been supplied. Due to the action of the lifting mechanism 7, the couplant liquid supply pump 11 starts operating with the probe 3 close to the surface F to be tested (with a gap g).

Supply of the couplant liquid between the probe 3 and the surface F to be tested is started. When the couplant liquid is supplied to the probe 3, the probe 3 and the surface F to be tested are blocked by the leakage seal 31 and filled.

The supply of couplant liquid is started, and the flaw detection operation begins with the leakage seal 31 of the probe 3 filled with the liquid. 3 moves a predetermined distance.

When flaw detection over a predetermined distance is completed, the supply of couplant liquid is stopped. That is, the operation of the pump 11 is stopped. Next, the supply of compressed air to the lifting mechanism 7 is stopped, and the probe 3 leaves the surface F to be tested. When the pump operation is stopped, the couplant liquid remains in the conduits 8a and 8b, but
It is stopped by check valves 81a, 81b. The couplant liquid left between the probe 3 and the surface to be inspected F remains as it is on the surface to be inspected F, but the amount is less than a few CC even if the remaining amount of all the individual probes is totaled. It is a unit.

After completing the above flaw detection work, this device repeats the operation using the inner and outer legs to move to the first flaw detection starting position.
Perform flaw detection. The couplant solution is consumed little by little each time.

In the wall movable flaw detection device that performs the above operations, the attitude of the entire device changes as it moves by the inner and outer legs 1 and 2, and flaw detection may be performed on a vertical wall surface. FIG. 3 shows an embodiment of a tank 10 for storing couplant liquid. The tank 10, which also serves as a part of the cover 4, has an injection port 12, and the couplant liquid can be injected into the tank on the ground before flaw detection work. Also tank lO
A pump 11 is attached to the pump 11, and a conduit 8a is led out from the pump 11 to lead the couplant liquid to a probe 3 (not shown). An inlet 13 for introducing couplant liquid into the pump is provided inside the tank 10 of the pump 11 . A flexible tube 14 is connected to this inlet 13, and the tip of the tube 14 has a suction tube that is submerged in the couplant liquid and has its weight and buoyancy adjusted so that it always faces the ground surface. An outlet 15 is provided. The figure shows the cover 4 with the device fixed to the wall surface, but with a tank of this kind of configuration, the probe 3 is always visible regardless of its posture or the amount of couplant liquid. A stable supply of couplant solution can be provided. Furthermore, even if the tank 10 is inverted, the flexible tube 14
Because of the configuration of the suction port 15, the suction port 15 always exists in the couplant solution with it facing the ground surface, and its effect remains unchanged. In addition, if the flaw detection work takes a long time,
The liquid level in the tank 10 decreases as the couplant liquid is gradually consumed, but the rate can be determined by design calculations, taking into account the tank capacity and tank shape. This diagram is
This is one embodiment, and a structure has been described in which the tank 10 is integrally provided as a part of the cover 4 almost in the center of the cover. It is possible.

FIG. 4 diagrammatically shows an embodiment of the structure of such a tank 10.

The figure (A) shows a tank 10 that stores Kaburan liquid over the entire upper surface of the cover 4, which covers the main mechanical parts of the wall moving flaw detection device from the viewpoint of environmental resistance and aesthetics. This is what I did. With this configuration, there is no need to consider the storage space of the tank 10 when designing the mechanism section, and compactness is achieved, but on the other hand, the height increases.

FIG. 2B shows an embodiment in which a tank 10 is provided in the skirt portion of the cover 4. In the case of this embodiment, it is necessary to design it while taking into consideration the space factor of the mechanism part.
Since the location where the couplant solution is stored is closer to the center of the entire device, it has the effect of lowering the center of gravity.

Figure (C) shows an embodiment in which a tank 10 is provided in a manner that projects outward from the upper surface of the cover 4, and is a modification of Figure (A).

Figure (D) shows an embodiment in which a tank 10 is provided by dividing a part of the skirt portion of the cover 4, and is a modification of Figure (B).

In the same figure (E) and (F), from a design consideration to improve the weight of the couplant liquid applied to the cover 4, the tank 10 is not fixed to the cover, but is installed near the cover using a separate fixing means. This is an example.

In this case, there will be no problem in placing the tank 10 outside the cover 4 as long as the purpose can be achieved. However, it goes without saying that in this case as well, the tank 10 can be turned over as the wall surface moves, the aesthetic appearance is not spoiled, and the tank 10 can be placed on the back of the main body of the device.

FIG. 5 shows another embodiment of the configuration of the couplant liquid suction port 15.

In FIG. 5(A), the tube 14 that communicates between the suction port 15 and the pump 11 is replaced with a rigid tube, and instead, the suction port 15 is made to be able to rotate using the inlet port 13 as a fulcrum. It is. This type of suction port is suitable for devices whose movement range is limited.

In the same figure (B), a tube 14 having a suction port 15 and a pipe 13a configured as a reinforcing beam of the tank 10 are used to connect the inlet port through which the pump 11 introduces the couplant solution. It is. This type of configuration is suitable for such devices that need to store a large amount of couplant fluid.

In the same figure (c), the suction port 15 also serves as an inlet, and an elastic bag material 19 is airtightly attached between the suction port 15 and the inlet 12 for injecting the couplant solution into the tank 10. It is something that With this type of configuration, the couplant solution is injected into the bag material 19, and the injection port 1 is filled with no air.
2, the bag material 19 shrinks as the couplant solution is consumed, so the supply of the couplant solution does not stop.

Although this configuration has the effect of reducing the pump capacity, it requires pressure when injecting the couplant liquid from the injection port 12, so its application will be limited to cases where special couplant liquid is used. .

In a wall surface moving flaw detection device provided with a tank 10 having this type of configuration, it is more effective to suppress the consumption of couplant liquid as much as possible and to make the tank 10 smaller. Therefore, in the present invention, when the probe 3 performs flaw detection work, the pump is operated to supply couplant liquid to the probe 3, and when not, the pump is stopped to stop the flow of the couplant liquid. ing.

FIG. 6 is a block diagram showing one embodiment of a method for controlling supply and stop of couplant liquid.

A tank 10 containing the couplant solution communicates with the probe 3 via a pump 11 to supply the couplant solution. The pump 11 at this time is controlled by the pump control unit 110,
Running and stopping are performed.

As already mentioned above, the reason why the couplant liquid is required between the probe 3 and the surface F to be tested is that the probe 3 is
This is when the object is brought close to the surface to be tested by the elevating mechanism 7 holding the object. Reference numeral 700 denotes a circuit that instructs the pump control section 110 to operate the pump, and this pump operation instruction is transmitted via a timer 710 from the control section 700 for feeding air into the lifting mechanism 7 and moving the cylinder 7b. The purpose of the timer 710 is to supply the couplant liquid in consideration of the operation of the lifting mechanism 7 and the time delay until the probe 3 placed on the lifting mechanism approaches the surface F to be tested. It is intended to do so. It goes without saying that this timer 710 is designed to allow the setting of its delay time to be changed.

The probe 3 has its leakage seal 3 through the above control operation.
1 is filled with couplant liquid and ready to start flaw detection work.

Next, the probe 3 performs flaw detection by moving on the movable mount 6, and when the flaw detection for a certain distance is completed, the probe 3 is moved away from the surface to be detected F at - degree and the entire main device is moved. must be moved by manipulating the medial and lateral legs. When the probe 3 is moved away from the surface F to be tested, the leakage seal 31 is separated from the surface F to be tested. Therefore, if the pump 11 continues to supply the couplant liquid, the couplant liquid will flow onto the surface to be tested. It may leak out and cause contamination, as well as waste of the couplant solution.

Therefore, the pump 11 that supplies the couplant liquid is configured to stop operation when the pump control section 110 receives a signal from the control section 600 of the movable gantry 6. This command signal for stopping the operation can be achieved by providing the movable gantry control unit 600 with a counter function that adds up the distance.

Note that this operation stop command may be a reverse rotation command for the pump 11.

Although one embodiment of the control method has been described above, commands to operate and stop the pump 11 can also be issued only from the lifting mechanism control section 700. In addition, if this type of wall-moving flaw detection device itself is controlled and operated entirely by programmed commands, the above-mentioned pump operation and stop control can be controlled using the time axis of the program. Needless to say.

〔Effect of the invention〕

As described above, according to the wall movable flaw detection apparatus according to the present invention, the tank for storing the couplant liquid is placed on the back, and the couplant liquid suction port of the tank is configured to always exist in the couplant liquid, so that the entire apparatus can be improved. Even when the probe is moved and positioned on any surface such as a wall surface, a flat surface, a downward facing surface, etc., stable couplant liquid can be supplied between the probe and the surface to be inspected during flaw detection work. In addition, by starting and stopping the pump that supplies the couplant liquid at the same time as the probe flaw detection work, consumption of the couplant liquid can be minimized and flaw detection work can be repeated over a long period of time. At the same time, the tank can be made smaller due to the lower consumption amount, and there is an effect of suppressing an increase in the weight of the entire device.

Further, even during flaw detection work, the couplant liquid will not flow out onto the surface to be tested, and the structure to be tested will not be contaminated.

Furthermore, by providing the couplant liquid storage tank in the cover that covers the mechanism, it was possible to improve the stability of the entire device without impairing its aesthetic appearance.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the entire wall surface moving flaw detection device to which the present invention is applied, and FIGS. 2(a) and 2(b) are. FIG. 3 is a partial cross-sectional view showing the state of the probe. FIG. 3 is a partial sectional view showing the structure of a tank for storing the couplant solution of the present invention, FIGS. A) to (C) are schematic diagrams showing other embodiments of a suction port provided in the tank. FIG. 6 is a block diagram for explaining the control of the couplant liquid supply pump of the wall moving flaw detection device to which the present invention is applied. 1... Outer leg, 2... Inner leg, 3... Probe, 4
...Cover, 6.Movable frame, 7.Elevating mechanism,
8a, 8b... Conduit, 10... Tank, 11...
Pump, 12... Inlet, 13... Inlet, 14.
...tube, 15... suction port, F... surface to be inspected,
19... Bag material. Tail 1 map Fu 2-ku (a) (b) Taku 4 map (a) ni) (e) (viii) High S map

Claims (1)

[Scope of Claims] 1. A flaw detection means including a probe that performs flaw detection on an object to be flawed, a storage means for a couplant liquid supplied between the probe and the surface of the object to be flawed, and a means for storing a couplant liquid, In a flaw detection apparatus having a pump means for drawing out the liquid, and a moving means on which each of the above means can be placed and moved over a surface of an object to be detected which can constitute at least a wall surface or a downward surface, the couplant liquid in the storage means is A mobile flaw detection device characterized by having a means for sucking out irrespective of the orientation of the storage means. 2. A flaw detection means including a probe that performs flaw detection on an object to be flawed, a storage means for a couplant liquid supplied between the probe and the surface of the object to be flawed, and a pump means for drawing out the couplant liquid. and a flaw detection apparatus having a moving means on which each of the above means can be placed and movable over the surface of the object to be tested which can constitute at least a wall surface or a downward facing surface, an outlet of the pump means for drawing out the couplant liquid from the storage means. A mobile flaw detection apparatus characterized in that a suction port is provided so as to be always present in the couplant liquid when the storage means is tilted at an angle of 90° or more with respect to a horizontal plane. 3. A flaw detection means including a probe that performs flaw detection on the object to be flawed, a storage means for a couplant liquid supplied between the probe and the surface of the object to be flawed, and a pump means for drawing out the couplant liquid. and a flaw detection apparatus having a moving means on which each of the means is mounted and capable of moving over the surface of the object to be tested which can constitute at least a wall surface or a downward facing surface, wherein the storage means is always at approximately 90 degrees with respect to a horizontal plane. 1. A mobile flaw detection device, characterized in that the couplant liquid outlet is provided near the bottom of the storage means. 4. A flaw detection means including a probe that performs flaw detection on an object to be flawed, a supply means for supplying couplant liquid between the probe and the object to be flawed, a storage means for storing the couplant liquid, and the flaw detection means , a flaw detection apparatus having a supply means and a means for moving the storage means along the surface of the object to be inspected, a movable member having a hollow space between a couplant liquid suction port and an outlet provided in the storage means. 1. A mobile flaw detection device, characterized in that the suction port is connected to the couplant liquid and is configured such that the suction port is located within the couplant liquid. 5. The mobile flaw detection device according to claim 4, wherein the movable member is constituted by a flexible tube. 6. The mobile flaw detection apparatus according to any one of claims 1 to 5, wherein the suction means has buoyancy and weight and is present in the couplant liquid, so that the suction port always faces the ground surface. 7. A probe having a conduit for supplying couplant liquid and a conduit for returning the couplant liquid to a tank, characterized in that a check valve is provided at the connection between the conduit and the probe. The mobile flaw detection device according to any one of claims 1 to 4, which uses a probe. 8. A flaw detection means including a probe that performs flaw detection on the object to be flawed, a storage means for a couplant liquid supplied between the probe and the surface of the object to be flawed, and a pump means for drawing out the couplant liquid. a flaw detection apparatus having: a moving means on which each of the means is placed and movable over the surface of the object to be tested, which can constitute at least a wall surface or a downward surface; and a cover that covers a mechanical part of the moving means; A tank of a mobile flaw detection device, in which the storage means is a tank, and the tank is integrally formed with the cover.