JPH0664154U - Trackless flaw detector - Google Patents

Abstract

(57) [Summary] [Purpose] Even if there is a step or other obstacle along the travel route, the vehicle will run smoothly without being affected by such an obstacle. [Structure] In a trackless flaw detector 1 in which front, rear, left and right magnet wheels 5, 5, ...
Is divided into a front body 8a on the front side in the traveling direction and a rear body 9a on the rear side.
The rear body 9a and the rear body 9a are flexibly connected to each other by the pin 12.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a trackless flaw detector for flaw detection of welded parts such as reactor pressure vessels.

[0002]

[Prior art]

 Generally, in-service inspections of pressure vessels in nuclear power plants are carried out by remotely moving a flaw detector equipped with an ultrasonic probe, due to the constraints of a narrow working space and radiation. In addition, since the inspection volume of such pressure vessels is very large, sampling inspections are conducted every year by performing flaw detection in several areas.

By the way, in recent years, as a flaw detection device used for the inspection during the in-service period, a non-track type device which travels on a pressure vessel without using a track to perform a flaw detection has been studied. This non-railway type flaw detector is designed so that the front, rear, left, and right magnet wheels mounted on the body of the vehicle are independently driven to rotate by drive motors. It runs on the outer wall of the machine to the specified inspection point and inspects for defects such as flaws and cracks in the welded part in the inspection point.

[0004]

[Problems to be solved by the device]

 However, since the trackless flaw detector described above uses an integrated body structure, if there is a step such as a step in the travel route, the wheel will become stuck on the step and the vehicle cannot travel. I will end up. If the attraction force of the magnet wheels is increased for the purpose of solving this, the wheels will peel off due to the impact, but the flaw detector will be dropped, though the wheels try to forcefully get over the steps.

Therefore, an object of the present invention is to provide a trackless flaw detection apparatus that can smoothly travel without being affected even if there is an obstacle such as a step in the travel route.

[0006]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention is a trackless flaw detection device in which front, rear, left and right magnet wheels mounted on a vehicle body are independently driven by wheel drive motors. It is divided into a front body and a rear body at the rear, and the front body and the rear body are flexibly connected to each other.

[0007]

[Action]

 According to the above configuration, the traveling vehicle body is divided into the front body and the rear body, and the bodies are flexibly connected to each other, so that even if there is a step such as a step in the travel route, the two bodies bend each other. By doing so, we can overcome this and move forward.

[0008]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a schematic configuration of a trackless flaw detector according to this embodiment. The trackless flaw detection apparatus 1 mainly includes a traveling carriage 2 that travels on a structure such as a steel container without a track, and a flaw detection mechanism 3 that is installed in front of the traveling carriage 2 in the traveling direction. The traveling trolley 2 has four magnet wheels 5 which are independently driven to rotate forward, backward, left and right, and the attraction force of these magnet wheels 5 allows the wheels to travel on the outer wall of a container or the like without a track. The flaw detection mechanism 3 has a flaw detection head 7 suspended from a scanning arm 6 mounted in front of the traveling carriage 2. While the carriage 2 is traveling along the welding line Y, the flaw detection head 7 reciprocates in a direction orthogonal to the direction. By doing so, the inside of the welding line Y can be detected.

In the flaw detector 1 of this embodiment, in order to allow the traveling vehicle 2 to smoothly travel even if there is a step or the like in the middle of the traveling route, the traveling vehicle 2 is installed in front of the front vehicle 8 in the traveling direction and in the rear direction. It is divided into a rear carriage 9 and these carriages 8 and 9 are flexibly connected to each other by a connection joint 14. That is, a pair of left and right magnet wheels 5 and 5 are rotatably supported on the bodies 8a and 9a of the trucks 8 and 9 as front wheels and rear wheels, respectively, and a wheel drive motor (not shown) is attached to these magnet wheels 5. It is connected. The connecting joint 14 between the bogies 8 and 9 is formed by fitting a projection 11 extending from the rear end of the front bogie 8 into a groove 10 formed at the front end of the rear bogie 9 so that the groove 10 and the projection 11 are By inserting the pin 12 into the fitting portion from the lateral direction, both carriages 8 and 9 can be bent around an axis orthogonal to the traveling direction. Leaf springs 13 for maintaining the postures of the carriages 8 and 9 in a straight line are installed on the upper and lower portions of the carriages 8 and 9, respectively. The leaf spring 13 has its base end side attached to the upper and lower surfaces of the rear carriage 9 and holds the front carriage 8 from above and below at its extended end.

The traveling carriage 2 is also equipped with a travel meter, a vertical sensor, etc., which are not shown, and detects the position and orientation of the flaw detector 1 at any time and transmits it to an external computer (not shown) through a cable. You can do it.

Next, a flaw detection inspection of the reactor pressure vessel by the apparatus having the above configuration will be described.

When flaw detection is performed on the welded portion of the reactor pressure vessel, first, as shown in FIG. 3, the trackless flaw detection apparatus 1 is adsorbed to a predetermined mounting position A on the outer wall of the pressure vessel 20, and a wheel drive motor is used. Drive a wheel (not shown) to drive the wheels from the mounting position A to the required inspection point B. The traveling at this time is, for example, traveling the flaw detection device 1 right above the mounting position A, reversing the left and right wheels 5 at a predetermined height position C to change the direction by 90 °, and then, in the horizontal direction ( Drive in the circumferential direction to reach the required inspection point B. When the flaw detection device 1 reaches the inspection point B, the flaw detection head 7 reciprocates in the direction orthogonal to the welding line Y while the wheels travel along the welding line Y, and the welding line Y at the inspection point B is inspected.

By the way, since the pressure vessel 20 is assembled by welding steel plates in the circumferential direction and the vertical direction, if there is a misalignment between the steel plates, a step is formed at the welded part of the pressure vessel 20. If there is a step D in the middle of the traveling path of the flaw detection device 1, when the flaw detection device 1 crosses the step D, the flaw detection device 1 receives resistance and may be unable to travel. However, in this embodiment, since the traveling carriage 2 is divided into the front carriage 8 and the rear carriage 9 and the two carriages 8 and 9 are flexibly connected, it is possible to travel over the step D without any trouble. it can. That is, when the flaw detector 1 crosses a step, as shown in FIG. 2, first, when the front wheels 5, 5 reach the step D, the front carriage 8 causes the upper leaf spring to move due to the running resistance from the step D. It bends upward against the urging force of 13 and smoothly climbs up the slope of step D (Fig. 2 (b)). After that, when the rear wheels 5, 5 reach the step D, the front carriage 8 and the rear carriage 9 are bent against the biasing force of the lower leaf spring 13 contrary to the above, and the rear carriage 9 climbs the inclined surface. (Fig. 2 (d)). In this way, when both carriages 8 and 9 climb over the step D, the repulsive force of the lower leaf spring 13 restores the original state and further travels (FIG. 2 (e)).

As described above, in the trackless flaw detector 1 of this embodiment, the traveling carriage 2 is divided into the front carriage 8 and the rear carriage 9, and the carriages 8 and 9 are flexibly connected to each other, whereby Even if there is an obstacle such as a step D on the way, it becomes possible to travel along the step D without being impeded. Moreover, since the impact that the flaw detection device 1 receives from the step D can be alleviated by the bending of the two carriages 8 and 9, the magnet wheel 5 does not peel off from the pressure vessel 20, and the flaw detection device 1 can be reliably passed over the step D. You can move forward.

In the above embodiment, an example of performing flaw detection inspection of the reactor pressure vessel 20 has been described, but flaw detection of the same type of pressure vessel or tank may be performed. Further, in the flaw detector 1 of the above-described embodiment, the leaf spring 13 is installed between the front carriage 8 and the rear carriage 9, but these carriages 8 and 9 may be simply connected by pins or the like so as to be bendable.

[0017]

[Effect of device]

 In short, according to the present invention, the traveling vehicle body is divided into the front body in the traveling direction and the rear body in the rear direction, and the front body and the rear body are bendable with respect to each other. Even if there is, you can drive smoothly without being affected by the obstacle.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an embodiment of the trackless flaw detector of the present invention.

FIG. 2 is a view for explaining the operation of the trackless flaw detector of the present invention.

FIG. 3 is a diagram for explaining flaw detection inspection of a reactor pressure vessel by the trackless flaw detector of the present invention.

[Explanation of symbols]

 1 Trackless flaw detector 2 Traveling trolley 4 Traveling vehicle body 5 Magnet wheels 8 Front trolley 8a Front body 9 Rear trolley 9a Rear body 12 pins

Claims (1)

[Scope of utility model registration request] 1. A trackless flaw detection apparatus in which front, rear, left and right magnet wheels mounted on a vehicle body are independently driven by wheel drive motors, respectively. A trackless flaw detector, characterized in that it is divided and the front body and the rear body are flexibly connected to each other.