JPH028265B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object] The present invention relates to an ultrasonic flaw detection method for a tubular body, and particularly to an ultrasonic flaw detection method for preventing a liquid medium from penetrating into a tubular body that is a material to be flaw-detected.

[Problems with conventional technology]

Conventionally, an ultrasonic flaw detector with a probe attached to the inner surface of the through hole is used, the instrument is rotated at high speed around the axis of the through hole, and a liquid medium (generally water) is supplied into the through hole. However, in the method of ultrasonic flaw detection by passing through a tubular body, which is the material to be tested, the ends of the tubular body are sealed in advance with rubber or plastic plugs, or high-pressure air is injected from the ends of the tube. A method of preventing liquid medium from entering the pipe from the other end using the air pressure has been considered.

This is because when the tubular body passes through the through-hole of the flaw detector and a liquid medium enters the inside from the open end, the tubular body rotates integrally with the liquid medium attached to the inner peripheral surface. This is because the ultrasonic waves emitted from the probe are reflected by the liquid medium and become noise echoes that impede flaw detection.

In order to prevent such flaw detection troubles caused by liquid media and to shorten the dead zone at the end of the tube as much as possible, the most reliable method is to use rubber or other end plug seals as described above. Because I was relying on them, my work efficiency was extremely poor. In addition, in the method of injecting air from the tube end as described above, when the open end of the tube passes through the through hole of the flaw detector, the liquid medium in the flaw detector is sprayed by the injection of high-pressure air from the tube end. Furthermore, as the inner diameter of the tube increases, the amount of high-pressure air supplied also increases, making the working environment even worse.

[Structure of the invention]

In view of the problems of the prior art, the present invention provides a method that uses gas pressure such as air to inflate an elastic body and seal the ends of a tubular body, thereby facilitating the automation of sealing work. This is what we provide.

The feature is that in the method of ultrasonic flaw detection in which a liquid medium is supplied into the through-hole and passed through the tubular body which is the material to be tested, from just before the front end of the tubular body enters the flaw detector, While following the movement of the tubular body, hollow plug rods having cylindrical elastic bodies at the tips disposed on the exit and entry sides of the flaw detector are inserted into the tubular body until the rear end advances outside the flaw detector. at the front and rear ends of the plug rod, compressed gas is supplied to the hollow part of the plug rod, and the cylindrical elastic body attached to the tip of the plug rod is expanded within the tubular body and brought into close contact with the inner surface of the tube. By this,
The present invention provides an ultrasonic flaw detection method for a tubular body, characterized by preventing the liquid medium from entering the tubular body.

[Specific description of the invention]

The invention will now be described in detail with reference to illustrated embodiments.

In FIG. 1, 10 is a flaw detector, which is provided with a through hole 11 in the axial direction and is driven around the axial center at high speed. At least two sets of probes 12 and 13 are attached to the flaw detector 10 in the axial direction of the through hole 11, and guide rings 14 and 15 are attached to the entrance and exit sides. A liquid medium is supplied into the through hole 11 of the flaw detector 10 from supply pipes 16 and 17. 1
Reference numeral 8 denotes an inlet plug rod support cart installed on the inlet side of the flaw detector 10, and 19 denotes an outlet plug rod support cart installed on the outlet side of the flaw detector. These plug rod support carts 18 and 19 are installed parallel to and over the V-shaped roller table that conveys the tubular body A, and follow the tubular body in the direction of the arrow a or the direction of the arrow b. Moving. 42 is a guide roller, and 43 is a pinch roller box. 4
4 is an eddy current flaw detection coil provided in front of the ultrasonic flaw detector.

Reference numeral 25 denotes an outlet plug rod, which, as shown in FIG. 2, includes a hollow plug body 26 and an elastic stopper shoulder 4.
5, an elastic body 2 such as rubber, etc.
8. Consists of a guide plug 29 provided at the tip and a gas supply nozzle 30 connected to a gas supply device such as air.

The hollow part of the plug body 26 reaches the back surface of the elastic body 28, which is the hollow part of the seal plug, and communicates with the inner circumferential surface of the elastic body through a number of small holes 46 provided on the circumferential surface of the seal plug 27. .

In the drawings, the hollow portion of the plug body 26 has a pore shape, but it may have a wide diameter hollow portion.

The seal plug 27 is fitted or threadedly connected to the plug body, and an elastic body 28 can be attached to the front outer peripheral surface.

In front of the elastic body 28 is a guide plug 29 having a cone shape so that it can easily enter the inside of the tubular body A.
is screwed to the seal plug 27. This holds the elastic body 28 on the seal plug 27.

When compressed gas such as air is supplied from the gas supply nozzle 30, the elastic body 28 is expanded outward via the plug body 26. Plug rod 2 is attached to the tube end of tubular body A.
When the elastic body 28 is expanded after the tube 5 is inserted, the tube end is isolated from the outside and sealed.

The rear end of the outlet plug rod 25 is connected to a connecting rod 31 and fitted into a plug rod support 33 .

Springs 32 are attached to the left and right sides of the plug rod support 33, creating a buffer structure that allows the outlet plug rod 25 to slide horizontally.

The plug rod support 33 is freely rotatably connected to the rod 35 by a pin 34, and is connected to the cylinder 36.
It is now possible to go up and down.

This cylinder 36 is connected to the outlet plug rod support cart 1
It is installed on 9.

The outlet side plug rod support cart 19 has a motor 39 that drives wheels 38, and moves forward and backward in the direction in which the tubular body A is transferred.

In addition, a position detector 37 is mounted on the plug rod support cart 19.
, the amount of movement of the connecting rod 31 in the horizontal direction can be detected, and thereby the relative positional relationship between the plug rod support cart 19 and the plug rod 25 can be detected.

On the other hand, the inlet plug rod 47 includes a plug rod main body 48, a shoulder portion 52, a seal plug having a small hole 53, an elastic body 50, and a guide plug 51, as shown in FIG.
and a gas supply nozzle 54, the outlet plug rod 2
5, but a gas supply nozzle 54 at the rear end is directly connected to a gas supply hose 55.

As shown in FIG. 5, the hose 55 is wound around a hose reel 57 mounted on the inlet plug rod support cart 18 so that it can be unwound. The entry plug rod support cart 18 has wheels 59 and is driven by a motor 58 on rails 60 so that it can run.

The rear end of the inlet plug rod 47 collides with a stopper 61 and stops when the hose 55 is wound up on the reel 57.

A clamp device 62 for grasping the inlet plug rod 47 at at least one location is provided at the front portion of the support cart 18, and this clamp device grasps and releases the inlet plug rod 47 by the operation of a hydraulic cylinder 63. The clamp device 62 is mounted on a frame 64 and is configured to be raised and lowered by the operation of a hydraulic cylinder 65. Furthermore, this cylinder 65 is connected to a rod 66 fixed to the support cart 18.
It is attached to a support member 68 that can slide left and right while its top is biased by left and right springs 67. A position detector 69 is further provided in front of the support cart 18.

In the figure, 70 indicates a roller table 70.

The clamping device 62 lifts the inlet plug rod 47 using a hydraulic cylinder 65 and attaches it to the support cart 18.
When the tubular body A is conveyed on the lower side of the tube, it can be prevented from getting in the way.

Generally, an eddy current flaw detector is installed in parallel with an ultrasonic flaw detector, so it is desirable not to use metal materials such as plug rods and hoses that would interfere with eddy current flaw detection. . especially,
It is preferable to use a material with excellent strength, such as fiber-reinforced plastic, for the plug rod.

In the above configuration apparatus, when the tubular body A is subjected to ultrasonic flaw detection, it is carried out as follows.

That is, when the tubular body A is carried onto the V-shaped roller table 70 on the entry side, the plug rod support cart 19 on the exit side
The outlet plug rod 25 installed in the cylinder 36 is lowered to the same level as the axis of the tubular body A, and the outlet plug rod support cart 19 is moved in the direction of the arrow b. This outlet side seal plug rod 25 is further advanced to enter and pass through the ultrasonic flaw detector. Next, this is temporarily stopped and the position is set to wait for the tube to come from the left side in the drawing. When the tip of the tubular body approaches the outlet plug, the outlet plug rod support cart starts to move to the right, and before the front end of the tubular body A moves in the direction of arrow a and enters the flaw detector, the outlet plug rod 25 The seal plug 27 attached to the tip of the tubular body A is inserted into the opening at the front end of the tubular body A, and at the same time, the speeds of both are synchronized.

When the seal plug 25 enters the opening at the front end of the tubular body A in this manner, high-pressure gas such as air (not shown) is instantly supplied to the elastic body attached to the tip of the seal plug 25 through the gas supply nozzle 30. The end of the tubular body A is sealed by supplying the elastic body 28 to the small hole 46 on the back side of the tubular body A and inflating the elastic body 28 fitted into the seal plug 27 in the shape of a sleeve into the tube of the tubular body A so as to make a tight contact therewith. .

The tubular body A moves in the direction of the arrow a together with the outlet plug rod support cart 19 with the outlet plug rod 25 attached thereto.

The entry plug rod 47 is mounted on the entry plug rod support cart 18 with the rear end of the tubular body A waiting directly above it.
Immediately after passing under the guide plug 51 at the tip, the cylinder 65 provided on the inlet plug rod support cart 18 is operated to lower the inlet plug rod 47 to the same level as the axis of the tubular body A, and the inlet plug rod 47 is lowered to the same level as the axis of the tubular body A. By moving the plug rod support cart 18 in the direction of arrow a at a faster speed than the tubular body A, the seal plug 49 attached to the tip of the entry side plug rod 47 enters the rear end opening of the tubular body A, and both of them are simultaneously moved. Synchronize with speed. When the seal plug 49 enters the rear end opening of the tubular body A, high pressure gas is instantly supplied to the hose 55 from a gas supply device such as air (not shown).
The gas is supplied through a gas supply nozzle to the seal plug 49 attached to the tip of the plug rod 47, and the elastic body 50 fitted in the shape of a sleeve to the seal plug 49 is expanded in the pipe of the tubular body A to bring it into close contact with the seal plug 49. , prevent liquid medium from entering the pipe.

The tubular body A thus advances in the direction of the arrow a with the seal plugs 27 and 49 attached to the openings at the front and rear ends. The outlet plug rod support cart 19 moves in the direction of the arrow a, but the inlet plug rod support cart 18 stops. The clamp device 62 attached to the inlet plug rod support cart 18 is opened after the inlet plug rod 47 is inserted into the rear end of the tubular body A and the elastic body 50 is brought into close contact with the inner surface of the tubular body A. . Therefore, since the inlet plug rod 47 is coupled with the tubular body A and moves, the inlet plug rod support cart 18 is moved as described above.
Even when the trolley 18 is stopped, the hose on the reel 57 of the trolley 18 is unwound, and the inlet plug rod moves as the tubular body A is transferred. When the tubular body moves further, it passes through the through hole of the ultrasonic flaw detector 10, but the liquid medium does not enter into the tube of the tubular body A. The front end of tubular body A passes through the ultrasonic flaw detector and exits outside.
When a suitable distance is reached, the compressed air supplied to the seal plug 27 entered into the front end opening of the tubular body A is opened by a valve (not shown), the sleeve-shaped elastic body 28 is contracted, and the tubular body A is closed. Release the outlet plug rod 25 from the front end of the body A, move the outlet plug rod support cart 19 in the direction of arrow a at a faster speed than the tubular body A, and actuate the cylinder 36 to move the outlet plug rod 25 upward. lift. After this, the tubular body A, which has arrived late, passes under this and moves on the V-shaped roller table to the next process. The outlet plug rod support cart 19 lowers the plug rod 25 by operating the cylinder and moves it again in the direction of the arrow b for sealing the next tubular body A. On the other hand, when the rear end of the tubular body A passes through the ultrasonic flaw detector, the compressed air supplied to the seal plug 49 entered into the rear end opening of the tubular body A is opened by a valve (not shown), and the sleeve The shaped elastic body 50 is contracted to release the inlet plug rod 47 from the rear end of the tubular body A, and the reel 57 mounted on the inlet plug rod support cart 18 is wound up to remove the hose 55 and the inlet plug rod 47. Return to the direction of the support trolley. When the rear end of the inlet plug rod 47 comes into contact with the stopper 61 of the support cart 18, winding of the hose 55 by the reel 57 is completed, and at the same time, the cylinder 65 is actuated to lower the clamp device and the inlet plug rod 47 is moved. It is clamped, raised again, retreated in direction b, and waits until the next tubular body A passes below the entry side plug rod support cart 18.

When the inlet plug rod 47 is connected to the hose 55 and fed out from the reel 57 in this way,
After inserting the seal plug into the rear end of the tubular body A, there is no need to move the inlet plug rod support cart 18 significantly, and the inlet plug rod 47 can be made very short, allowing the overall device to be downsized.

The inlet plug rod 47 and the inlet plug rod support cart 18 are made to have exactly the same structure as the outlet plug rod 25 and the outlet plug rod support cart 19, and are moved to follow the movement in and out of the tubular body A. You can also do that.

The inlet plug rod 47 and the outlet plug rod 25 may have basically the same structure.

The tips of the inlet and outlet plug rods are spindle-shaped (cone-shaped) so that they can easily enter the end openings of the tubular body. The material is preferably synthetic resin (for example, MC nylon).

The cone-shaped guide plugs 51 and 29 and the seal plugs 49 and 27 are connected with screws so that they can be replaced. The elastic bodies 28 and 50 are sleeves made of rubber or the like having an outer diameter slightly smaller than the inner diameter of the tubular body A.
The seal plugs 27 and 49 are engaged with shoulders 45 and 52 of the seal plugs 27 and 49, respectively. Air conduits extend radially from the axes of the plug rod bodies 26, 48 toward the inner circumferences of the rubber sleeves 28, 50. When compressed air is introduced into the nozzle tip through this conduit 36, the rubber sleeve radially expands into tight contact with the inner surface of the tube. In this way, even if the end of the tube enters the flaw detector, no liquid medium will enter.

When inserting the guide plugs at the tips of the outlet and inlet plug rods 25, 47 into the openings at the ends of the tubular body A, there is some resistance because they are not necessarily aligned.

For this reason, as mentioned above, the guide plugs 29 and 51 are made into a cone shape to facilitate insertion, but when resistance is met, the outlet and inlet plug rods
At the outlet plug rod, a connecting rod 31 held by a spring that can slide left and right and connected to a rod 35 by a pin 34 is connected to the outlet plug rod so that the rods 5 and 47 can be moved to some extent; In the inlet plug rod, a rod 66 held by a spring 67 is connected to a clamping device 62 of the inlet plug rod 47, thereby making it possible to dampen the resistance during insertion.

Further, the outlet plug rod support cart 19 has a position detector 37 that detects the horizontal movement of the outlet plug rod 25, and detects the position of the outlet plug rod 25 with respect to the support cart 19 to determine the speed of the support cart 19. Can be adjusted. In addition, the outlet plug rod 2 from the tubular body A
5 and then raise it by operating the cylinder 36. As shown in the figure, since the outlet plug rod 25 is long, the tip guide plug 29
The sides may bend downward.

For this purpose, a plug rod elevating table 40 is provided at a predetermined position on the exit side of the ultrasonic flaw detector, and is moved up and down by the operation of the cylinder 41. This elevating table 40 is operated simultaneously with the operation of the cylinder 36. Deflection can be prevented by raising and lowering the plug rod 25.

[Effects] The present invention uses the method described above to reliably prevent the liquid medium required for ultrasonic flaw detection from entering the inside of the pipe to be flaw-detected, and also to manually seal the pipe with rubber or the like. This is an excellent method that can be done automatically.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the overall structure of the present device;
FIG. 2 is a cross-sectional explanatory diagram showing an example of the outlet plug rod;
Fig. 3 is mainly a side view of the outlet plug rod and its support cart, Fig. 4 is a cross-sectional view showing an example of the inlet plug rod, and Fig. 5 is mainly the inlet plug rod and its support cart. FIG. A: Tubular body, a, b: Movement direction arrow, 10: Ultrasonic flaw detector, 18: Entrance plug rod support cart, 1
9: Outlet side plug rod support trolley, 25: Outlet side plug rod, 26: Plug rod body, 27: Seal plug,
28: Elastic body, 31: Connecting rod, 35: Rod, 3
6: Cylinder, 38: Wheel, 47: Inlet side plug rod, 49: Seal plug, 50: Elastic body, 55:
Hose, 57: Reel, 62: Clamp device, 6
5: Cylinder.

Claims (1)

[Claims] 1 In a method of ultrasonic flaw detection in which a liquid medium is supplied into a through-hole while passing through a tubular body, which is the material to be tested, the front end of the tubular body moves from just before it enters the flaw detector until the rear end is outside the flaw detector. While following the movement of the tubular body, a hollow plug rod having a cylindrical elastic body at the tip disposed on the exit and entry sides of the flaw detector is inserted into the front and rear ends of the tubular body until it advances to the front and rear ends of the tubular body. At the same time, compressed gas is supplied to the hollow part of the plug rod, and the cylindrical elastic body attached to the tip of the plug rod is expanded within the tubular body and brought into close contact with the inner surface of the tube, thereby causing the liquid medium to An ultrasonic flaw detection method for a tubular body, characterized by preventing intrusion into the tubular body.