JPH0378577B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for inspecting the corrosion status of large-diameter liquid or gas transfer pipes such as cargo oil pipes installed in oil tankers, and particularly to a traveling device thereof.

A self-propelled vehicle equipped with a traveling device is loaded with a video camera and inspection equipment, and the self-propelled vehicle is driven into the pipe, images the surface condition of the inner surface of the pipe, and transmits the image signal to a monitor room outside the pipe. This allows the surface condition of the tube to be known through the imaging device in the monitoring room.

In addition, the detector was rotated reciprocatingly in the circumferential direction of the tube while the self-propelled vehicle was running, and the inner surface of the tube was inspected with the width of the reciprocating stroke, and the inspection signal was loaded onto the self-propelled vehicle or installed in a monitor room. By automatically recording data through a recording device, it is possible to know the abnormality of the pipe and its extent, and to replace the pipe with a new one to prevent accidents. Prior to inspection of cargo oil pipes, water is poured into the pipes to wash out sludge, etc. that had accumulated at the bottom of the pipes, and the inner surface of the pipes is cleaned.A self-propelled vehicle is then set into the pipes and driven automatically, and detected at the same time. The pipes are inspected by the equipment, and the output test data is automatically recorded on a recording device mounted on a self-propelled vehicle or installed in a monitoring room outside the pipe. For self-propelled vehicles, it is desirable to use an endless belt to avoid giving as much shock to the inspection equipment, video cameras, recording equipment, etc. that are loaded, and to cross the openings of branch pipes that exist in the middle of the piping. .
However, if deposits are still attached to the bottom of the tube even after washing the inner surface of the tube with water, when the self-propelled vehicle rides over the deposits, the bogie will receive some shock, which will appear in the output data of the inspection device. Errors may be added to the output data, and furthermore, there is a risk of damage to various equipment loaded on the self-propelled vehicle.

The present invention has a plurality of support rods that are pivotally fixed to the cart at one end and equipped with a roller at the tip to hold down the downward transition side of the endless belt. By inserting a compression spring with a strong elastic modulus, that is, a strong spring force, between the support rod at the front of the cart and a compression spring with a weak spring force, the weight of the self-propelled vehicle is reduced from the center of the support rod. It is supported by compression springs, and when a self-propelled vehicle runs over sediment in the pipe, the shock is absorbed by the weak compression spring at the front, and the impact of the shock is minimized on the inspection equipment and output data. The purpose is to provide a traveling device that does not require

The block diagram of FIG. 1 shows the signal conversion process of the detector and the remote control.

The detector is installed on a self-propelled vehicle 1 equipped with a traveling mechanism 2, and is kept at a constant height (approximately 20 mm) from the inner inspection surface of the tube, and moves in the axial direction of the tube while reciprocating in the circumferential direction of the tube. , the pipe wall is inspected by the width of the reciprocating rotation of the detector. As the detector, a known magnetic flaw detection sensor having a built-in coil that generates lines of magnetic force and a coil that generates a starting force by changes in the lines of magnetic force can be used. By passing a current through the magnetic field generating coil and forming a closed loop of magnetic field lines passing through the tube wall and the two coils, the detector 3 detects that the tube wall is thinner or cracked due to corrosion. Disturbances occur in magnetic field lines and current.

In order to detect increases and decreases in the current, the output is amplified through a balance section 30 using a bridge circuit or the like, and a detection signal is sent to an automatic recording device 4 mounted on the self-propelled vehicle 1 or installed in a monitor room outside the area. It records automatically.

The detector 3 is not limited to the above-mentioned magnetic detection method, and various types can be employed. For example, a magnetic field may be applied to the tube wall by a detector to generate eddy currents, and disturbances in the eddy currents may be detected at abnormal locations on the tube wall.

Alternatively, it is also possible to detect an abnormality in the tube wall by applying ultrasonic waves or a laser to the tube wall and detecting the phase difference in which the reflected wave is delayed at an abnormal location on the tube wall.

The self-propelled vehicle 1 is equipped with a video camera 10, and the tube wall in the inspection range by the detector 3 is photographed while being illuminated by a built-in illumination device. Video camera 10
The image signal output from the transmitter 1 passes through a signal processing section 11 and a modulating section 12, and is modulated into a signal according to a transmission circuit 13 and transmitted.

In the monitor room on the ship, the received signal from the transmission circuit 13 is passed through a demodulator 14 and reproduced by an image device 15. An image recording device 16 is connected to the image device 15 as necessary to record on a magnetic tape.

Commands to move forward, stop, and reverse to the traveling mechanism of the self-propelled vehicle 1; commands to rotate or stop the motor 54 that reciprocates the detector 3 in the circumferential direction; and start recording to the automatic recording device 4 loaded on the self-propelled vehicle. In order to transmit the command to stop or stop, a communication system using a transmission circuit 13 is configured, and the command signal by turning on/off the switch of the central operating device 6 in the monitor room is converted into a signal by the converter 60 and transmitted. The signal is converted again by the demodulator 61 of the self-propelled vehicle 1 through the transmission circuit 13, and each corresponding command location 62 is operated.

FIG. 2 shows a situation in which the inner wall of a pipe is inspected using the apparatus of the present invention.

The cargo oil pipes 7 are fitted into sockets 70 every several tens of meters and connected by so-called mechanical joints in which packings 71 are inserted.

Branch pipes 72 are attached to the main line of the cargo oil pipe at several locations. Before inspecting the cargo oil pipes for corrosion, cracks, etc., seawater is forced into the pipes to clean them and empty them. After that, remove some parts of the piping, such as branches, bends, joints, etc.
After opening the pipe, the self-propelled vehicle 1 is set inside the pipe and the inspection is started.

The detector 3 of the flaw detection device of the self-propelled vehicle 1 is fixed to the lower end of an arm 33 that reciprocates in an inspection range of 60 to 180 degrees with respect to the circumferential direction of the tube. A cable reel 63 is installed outside the pipe, and the self-propelled vehicle 1 runs while pulling out a transmission cable 64 from the cable reel 63. Output signals from the video camera 10 and the detector 3 are transmitted via a cable 64 and connected to a cable 66 from a monitor room on board via a mechanical joint 65 provided on a cable reel 63, allowing centralized control of the monitor room. The reproduced image is displayed on the image device of the disc 6 and is automatically recorded on the recording device 4 at the same time. Further, by operating a switch on the central control panel 6, command signals are transmitted to each part of the self-propelled vehicle 1 via cables 66 and 64.

As shown in FIGS. 3 and 4, the self-propelled vehicle 1 is equipped with a traveling device 2 equipped with endless belts 20, 20 on both sides of a trolley 17, and the loading/unloading device 2 is equipped with endless belts 20, 20 on both sides of a truck 17. The rotation of the motor 21 is regulated to cause the traveling device to move forward, backward, and stop.

The traveling device has an endless belt 20 stretched between a driving pulley 22 and a driven pulley 23 provided at the front and rear of a truck 17, and a roller 24 is installed at the tip of the endless belt 20 on the downward transition side. A plurality of support rods 25, each having a base end pivoted to the side surface of the truck 17, are arranged in parallel and facing each other. Each support rod 25 has a lower end inclined toward the rear of the truck, and a compression spring 28 is provided between a support plate 26 projecting from the side wall of the truck 17 and a receiving plate 27 projecting horizontally from each support rod 25.
is interposed, and the bogie 17 is lifted by the elastic force of the spring 28. The elastic force of the spring 28 is
Alternatively, it can be adjusted by adjusting means (not shown) provided on the receiving plate 27, and the spring 2 at the center of the truck can be adjusted.
8 is adjusted to be the strongest so as to strongly support the cart 17, the springs 28a, 28a at both ends are the weakest, and the springs 28b, 28b in the middle are adjusted slightly stronger. Therefore, even if the endless belt 20 runs over a foreign object attached to the pipe wall while traveling, the weakest compression spring 28a at the front absorbs the shock, and the inspection equipment, other loaded equipment, and output inspection data are protected. It has almost no effect.

Further, on the forward extension of the downward transition side of the endless belt 20 on the bogie side, there is a bracket 18 protruding from the bogie.
A knife blade 19 is disposed at the lower end close to the pipe wall, and is used to remove deposits that remain even after washing with water before inspection, thereby reducing the impact on the self-propelled vehicle. .

As shown in FIG. 5, the endless belt 20 has an outer peripheral surface formed into an arcuate surface to increase the bending area with the inner surface of the tube and to prevent slipping between the tube wall and the endless belt during running.
Further, a locking groove 20a is formed on the inner circumferential surface and engages with protrusions (not shown) formed on the drive and driven pulleys 22 and 23 to prevent slipping with the pulleys and increase rotational driving force. You can also do it.

At the front of the truck, four guide posts 51 are vertically erected on a mounting plate 50 that is removably fixed to the truck, and a table 52 equipped with an inspection device can be moved up and down along the guide posts 51. It is set up.
A screw shaft 53 arranged parallel to the guide post 51 is engaged with the table 52, and the height of the table 52 can be arbitrarily adjusted by rotating the screw shaft 53 in forward and reverse directions.

A motor 54 with a speed reducer is mounted on the table 52, and the output shaft of the motor is connected via a crank mechanism 55 to a rotating shaft 57 bearing on a pillow block 56 on the table.

An arm 33, which is slightly longer than the radius of the tube to be inspected, is attached to the tip of the rotating shaft 57, and a detector 3 is attached to the lower end of the arm 33. The arm 33 is slidably engaged with a block 34 fixed to the tip of the rotating shaft, and the screw shaft 3 hanging from the upper end of the arm 33
5 passes through the block 34 and is rotatably disposed on the arm 33.

By rotating the knob 36 at the upper end of the screw shaft 35 in the forward and reverse directions, the screw shaft 35 rotates while engaging with the block 34, and the arm 33 can be raised and lowered.

The self-propelled vehicle 1 can further be equipped with a recording device 4 and a power source 40 such as a battery, and the power source 40 powers the motor 21 of the traveling device 2 and the motor 5 of the inspection device.
4. Although the recording device 4 and the video camera 10 are driven, the power source 40 may not be installed in the self-propelled vehicle, but may be provided by integrating a power line into the transmission circuit 13 and supplying power from outside the area.

The video camera 10 has a mounting plate 51 and a table 52.
A built-in lamp installed in the space between the tube and the tube illuminates the transition range of the detector 3 at the tip of the arm 33, images the condition of the tube wall surface, and sends an output signal to the onboard monitor room. be.

However, when inspecting the inner surface of the pipe, the screw shaft 5
3 to raise and lower the table 52, and
7 to match the height of the center line of the tube to be inspected.
Next, turn the knob 36 on the upper end of the arm 33 to
Adjust the height to a certain height (approximately 20 mm) from the surface to be inspected.

Once the self-propelled vehicle 1 has been installed on the inner wall of the pipe 7, the motor 54 is driven to rotate the arm 33 back and forth at an appropriate speed (for example, about twice per second), and at the same time the traveling device motor 21 is driven. endless belt 20
to move the self-propelled vehicle 1 forward in the direction of the tube axis.

In the monitor room, the piping diagram is compared with the image sent from the video camera to constantly check the inspection position of the self-propelled vehicle 1 and monitor the reproduced image.

Since the rotation axis 57 of the arm 33 rotates in alignment with the central axis of the tube, the detector 3 is swung horizontally in the circumferential direction of the tube with almost no change in height from the inspection surface and in the axial direction of the tube. and inspect the inner surface of the tube in a range of approximately 60 to 180°.

If the detector 3 forms a closed-loop magnetic field line magnetic circuit including the tube wall, and detects the disturbance of the magnetic field lines and issues an output signal, during the transition of the detector 3, if the tube wall is normal, the magnetic field lines will be disturbed. does not occur, and a closed loop is formed with a constant strength, so a constant voltage is recorded on the recording surface of the recording device 4.

If cracks or corrosion occur on the tube wall, the resistance of the magnetic circuit increases each time the detector 3 passes an abnormal point, and the disturbance in the magnetic field lines appears on the recording surface as a voltage strength or weakness, which immediately indicates the abnormality of the tube. It can be determined.

As described above, in the present invention, by using the endless belt 20 as the endless track of the traveling device, smooth running is realized, and since the bogie is not vibrated during running, the inspection data has fewer errors.

In addition, by adjusting the spring force of the compression spring 28 interposed between the support rod 25 that presses down the endless belt and the truck, the self-propelled vehicle's own weight is supported by the strong spring 28 in the center, and foreign objects on the road surface are supported by the self-propelled vehicle. The shock caused by this can be absorbed by the weak spring 28a at the front, and the influence on the loaded equipment and output data can be reduced as much as possible. Moreover, since the detector 3 is directed downward and performs inspection by swinging back and forth over a predetermined width, it is possible to concentrate the inspection on the bottom of the tube, where corrosion is most likely to occur. However, it exhibits many excellent effects, such as not interfering with the reciprocating swing of the detector within a predetermined width.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram showing the principle of the pipe inner surface inspection device;
Figure 2 is an explanatory diagram showing how the pipe inner surface inspection device is used, Figure 3 is a front view of the self-propelled vehicle, Figure 4 is a left side view of the self-propelled vehicle, and Figure 5 is a partially broken endless belt. It is a slope view. DESCRIPTION OF SYMBOLS 1... Self-propelled vehicle, 2... Traveling device, 20... Endless belt, 22... Drive pulley, 23... Driven pulley, 25... Support rod, 28, 28a... Compression spring, 3... Detector .

Claims (1)

[Claims] 1. An inspection device that detects abnormalities such as pipe corrosion and cracks is placed at the front of a self-propelled vehicle, and the detector is directed downward and swings back and forth at a predetermined width in a direction perpendicular to the direction of travel. An endless belt is stretched between a driving pulley and a driven pulley arranged on both sides, and a support rod is attached to the downward transition side of the endless belt, the base end of which is pivoted to the side of the truck of the self-propelled vehicle, and the tip of which is equipped with a roller. A plurality of these are arranged in parallel, and a compression spring is interposed between the support rod and the side of the bogie, and the compression spring has a strong spring force when applied to the support rod in the center of the self-propelled vehicle, and The running device of the pipe inner surface inspection device is set to a weak spring force for the support rod in the section.