JPH0514868B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to relatively narrow spaces such as fillet welds between a spherical tank and its supporting column, or fillet welds between a large container and its support. This invention relates to an automatic flaw detection device for welds in large structures, which is used to detect flaws in individual welds.

[Prior Art] For example, in order to ensure the safety of the tank, it is necessary to check whether or not cracks have occurred at welded parts between a spherical tank and its supporting pillars.

Conventionally, there has been no automatic inspection of welds in high and narrow places, such as the welds between a spherical tank and its support column, and it has not been possible to automatically inspect welds at high places and in narrow places, such as those between spherical tanks and their supporting columns. Inspecting welds.

[Problems to be solved by the invention] However, in the conventional method of erecting a scaffold to inspect welded parts, it requires a great deal of time and effort to erect the scaffold, and the scaffold must be removed after the inspection is completed. Inspection work cannot be carried out efficiently because it takes time for inspection, and furthermore, the work must be done at high places, which poses a problem in work safety. In addition, there is a limit to the ability of workers to work in narrow spaces, and safe and efficient work cannot be expected.

Therefore, the present invention is designed to automatically inspect welded parts during work at high places without erecting scaffolding, and to allow inspection equipment to easily enter narrow spaces so that work can be carried out efficiently and safely. This is what I am trying to do.

[Means for Solving the Problems] The present invention includes a fixed arm mounted on a trolley capable of moving on the surface of a large structure so as to be freely swingable and undulating, and a telescoping arm attached to the fixed arm. A probe holder supporting a probe is attached to the tip of the telescopic arm, and a proximity ultrasonic sensor is attached to the trolley, and the probe holder is assembled so as to be movable in the axial direction. A pair of tracing sensors are supported on both sides, a telescopic drive mechanism for the telescopic arm, a rotating and undulating drive device for the fixed arm, and a device for processing signals from each of the sensors. This is an automatic flaw detection system for welded parts of large structures.

[Function] A cart is movably placed on the surface of a large structure,
The trolley is driven by itself based on the detection signal from the proximity ultrasonic sensor and is moved close to the welded part to be inspected. The probe is brought into contact with the flaw detection area by the arm's extension/contraction and up/down movements, and in this state, the cart is run while the probe follows the welded area, and at the same time the probe emits ultrasonic waves. , flaw detection is automatically performed at the flaw detection location.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

1 and 2 show an embodiment of the present invention, in which a wheel frame 5 is attached with legs 4 protruding from the front, rear, left and right corners of a truck frame 2 to which a terminal box 3 is attached, and A magnet wheel 6 is rotatably mounted in each wheel frame 5 facing the same direction, and a bogie running motor 7 mounted in each wheel frame 5 is connected to the shaft 8 of the magnet wheel 6. The truck 1 is configured such that the wheels 6 can be independently rotated forward and backward by a motor 7, and furthermore, the wheels 6 are arranged on the outside of each wheel frame 5, that is, the outside of the truck frame 2 in the direction perpendicular to the running direction of the truck 1. Proximity ultrasonic sensors 9 are respectively attached so as to oscillate ultrasonic waves in a direction perpendicular to the running direction of the trolley 1.

A swivel base 10 is mounted on the upper surface of the truck frame 2 so as to be rotatable via a support shaft 11.
1, the bogie frame 2 is attached to the swing gear 12 attached to the
An integrated pinion 14 is meshed with the output shaft of a swing drive motor 13 supported by a swing drive motor 13, and the swing base 10 can be rotated through an angle of 180 degrees or more by driving the motor 13 via the pinion 14 and the swing gear 12. Both sides of the fixed arm 16 are supported by brackets 15 on the swivel base 10 so that they can be raised and lowered, and a cylinder 17 for raising and lowering is interposed between the fixed arm 16 and the swivel base 10, so that the fixed arm 16 can swivel. To be able to freely turn together with a stand 10 and freely rise and fall.

A telescopic arm 18 is incorporated into the fixed arm 16 at its front end so as to be movable in its axial direction, and a fixed base 19 is extended from the rear end of the fixed arm 16, and a drive motor 20 on the fixed base 19 is connected to the fixed arm 16. The other end of the ball screw 21 connected at one end is connected to the distal end of the telescoping arm 18, and as the ball screw 21 is rotated by the drive of the motor 20, the telescoping arm 18 moves relative to the fixed arm 16. The arm as a whole can be expanded and contracted.

A probe holder 23 with an ultrasonic probe 22 supported at the tip thereof is attached to the tip of the telescopic arm 18 so as to be swingable left and right around a rotating shaft 24, and a sprocket 25 is attached to the rotating shaft 24. or,
Two idler pulleys 26 and 27 are horizontally attached to the front end of the fixed arm 16, and a drive sprocket 30 and an idler pulley 3 are attached to the rear end.
1 is attached horizontally, and two idler pulleys 28 and 29 are attached to the end of the telescoping arm 18 with a horizontal axis, and a wire rope 32 made endless by incorporating a chain in the middle is used for driving as shown in the figure. Sprocket 30, idler pulley 26, 2
8, Sprocket 25, Idler pulley 29,2
7 and 31 in that order, and the above sprockets 25 and 3.
Position the chain part at 0 so that it will not slip and cause malfunction, and then install the drive sprocket 3.
0 is connected to the drive motor 33 on the fixed arm 16, and the motor 33 is driven to rotate the drive sprocket 30 forward or reverse, thereby rotating the sprocket 25 via the wire rope 32.
As a result, the rotating shaft 24 rotates and the probe holder 2
3 allows the telescopic arm 18 to swing to the left and right from the tip. Telescopic arm 18 by motor 20
When the probe expands and contracts, the sprocket 25 does not rotate, so the probe holder 23 is prevented from swinging.

Further, brackets 34 are provided protruding from both left and right sides of the distal end of the probe holder 23, and each bracket 34
A contact copying sensor 35 is supported by each of the contact copying sensors 35, so that the whole can move laterally following the welded part while detecting the welded part by the pair of copying sensors 35.

In addition, on the ground side, there are controls as shown in Figure 3.
A processing device 40 is installed, and the sensors 9, 3
5, and can display the flaw detection results by the ultrasonic probe 22 and the position of the probe 22, and can also issue commands to each motor. . Therefore, the control and processing device 40 on the ground side and each motor and sensor 9, 3
5, the probe 22, etc., by a cable 41.

36 is an attitude control sensor for determining the direction in which the trolley 1 wants to move and moving the trolley 1;
It is installed on the bogie frame 2 side. 37 is an encoder and potentiometer for rotating the fixed arm 16; 38 is an encoder for detecting the travel distance of the trolley 1;
9 is a potentiometer of the probe holder 23.

Next, a case will be described in which a welded part is tested using the flaw detection apparatus having the above-described configuration, for example, a welded part between the spherical tank 42 and its support pillar 43 shown in FIG. 3 is tested.

The truck 1 is attracted to the surface of a spherical tank 42 via a magnetic wheel 6. Now, spherical tank 42
When the weld between the base and the pillar 43 is on the right side of the cart 1, the drive motor 13 is driven to rotate the fixed arm 16 together with the swivel base 10, and the probe 22 is set to face the weld. do.

Next, ultrasonic waves are emitted from the proximity sensors 9 attached to the two wheel frames 5 in the direction in which the telescoping arm 18 protrudes from the fixed arm 16, and the portion rising from the surface of the spherical tank 42, That is, the spherical tank 42 at the upper end of the pillar 43
By detecting the position of the welded part and driving each magnet wheel 6 independently, the trolley 1 is moved in the right direction in the figure while running in a zigzag pattern.
The trolley 1 is gradually brought closer to the detected position. When the dolly 1 approaches the welded part of the upper end of the pedestal 43 with the spherical tank 42 by a predetermined distance and the flaw detection starting point is determined as described above, a signal from the proximity sensor 9 is transmitted to the control and processing equipment on the ground. 40 processed and cart 1
A command is given to the side, and the traveling of the trolley 1 is stopped. Next, the telescopic arm 18 is telescopically operated or the probe holder 23 is further swung, so that the pair of contact tracing sensors 35 are brought into contact with the upper ends of the pillars 43, and the orientation of the probe 22 is aligned with the welding line. Fine grain adjustments are made so that they are orthogonal to each other. next,
The undulating cylinder 17 is actuated vertically to push up the rear end side of the fixed arm 16, thereby pressing the tip side of the extensible arm 18 against the flaw detection area and bringing the probe 22 into contact with the flaw detection area. In this state, ultrasonic waves are applied to the welded part from the probe 22 to perform flaw detection, and at the same time, the probe 22 is moved along the welded part while rotating the magnetic wheel 6 of the cart 1. These controls are performed by control on the ground side and commands from the processing device 40 based on signals from the contact tracing sensor 35 that is in contact with the upper end of the pedestal 43. In addition, when the weld line which is a flaw detection location is not a straight line, the probe 22 is swung as appropriate, or the entire arm is slightly rotated. The probe 22 is oscillated by rotating the driving sprocket 30 and rotating the sprocket 25 via the wire rope 32.

In addition, when performing flaw detection on the welded part on the left side of the trolley 1 in the figure, the drive motor 13 moves the fixed arm 1
6 together with the swivel base 10 from the state shown in FIG. 1, and the proximity sensor 9 attached to the outside of the two wheel frames 5 located on the left side of FIG. In the same manner as described above, the cart is moved in a zigzag pattern to bring the entire object close to the flaw detection position and roughly controlled, and then the contact tracing sensor 23 is used to perform accurate positioning.

In addition, in the above embodiment, a case where a fillet weld between a spherical tank and its supporting column is inspected for flaws is exemplified, but the flaw detection is not limited to a spherical tank, but the same applies to a weld of a large container having an arcuate surface. Of course it can be done.

[Effects of the Invention] As described above, according to the present invention, the following excellent effects can be achieved.

Flaw detection of welded parts of large structures can be automatically performed without erecting scaffolding, and flaw detection work can be carried out efficiently and safely.

Since flaw detection can be carried out without scaffolding, flaw detection can be carried out even when tanks, etc. are in operation.

A fixed arm is mounted on a trolley so that it can be rotated and raised, a telescopic arm is telescopically assembled to the fixed arm, and a probe holder supporting a probe is attached to the tip of the telescopic arm. Therefore, the probe can be easily entered into narrow places, and flaw detection in narrow places can be carried out automatically.Flaw detection can also be carried out over a wide range, and even curved surfaces can be detected. be able to.

Since a pair of tracing sensors are provided on both sides of the probe holder, the probe can always be held at a constant angle with respect to the weld line.

Since the cart is equipped with a proximity sensor, the cart can be automatically moved to the flaw detection location.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing one embodiment of the present invention, and FIG.
1 is a side view of FIG. 1, and FIG. 3 is a perspective view showing the operating state of the device of FIG. 1. 1 is a truck, 2 is a truck frame, 5 is a wheel frame, 6 is a magnetic wheel, 7 is a motor for driving the truck, 9 is an ultrasonic sensor for detecting the flaw detection starting point, 10
is a swivel base, 12 is a swivel gear, 13 is a drive motor,
16 is a fixed arm, 17 is a cylinder for elevating, 18
20 is a telescopic arm, 20 is a drive motor, 21 is a ball screw, 22 is an ultrasonic probe, 23 is a probe holder, 24 is a rotating shaft, 32 is a wire rope, and 33 is a drive motor.

Claims (1)

[Claims] 1. A fixed arm is mounted on a trolley that can move on the surface of a large structure so as to be able to freely rotate and raise and lower, and a telescoping arm is attached to the fixed arm so as to be movable in the axial direction of the telescoping arm. A probe holder supporting a probe is attached to the tip of the probe, a proximity ultrasonic sensor is attached to the cart, a pair of tracing sensors are supported on both sides of the probe holder, and the telescopic 1. An automatic flaw detection device for a welded part of a large structure, comprising an arm extension/retraction drive mechanism, a fixed arm rotation/levitation drive device, and a device for processing signals from each of the sensors.