JPS6239762A - Method for ultrasonic flaw detection of tubular body - Google Patents

Abstract

PURPOSE:To prevent the penetration of a liquid medium in a tubular body being a material to be subjected to flaw detection, by supplying compressed gas to the hollow part of a plug rod and expanding the elastic body provided to the leading end of the plug rod in the tubular body. CONSTITUTION:A seal plug 27 is connected to plug body 26 and an elastomer 28 is mounted to the front outer peripheral surface of said seal plug 27 and the front of the elastomer 28 is formed into a conical guide plug 29 so as to be easily inserted in a tubular body and threaded with the plug 27 so as to hold the elastomer 28 on the plug 27. A plug rod 25 is inserted in the tube end of the tubular body and compressed gas such as compressed air is supplied to the plug rod 25 from a gas supply nozzle 30. Compressed gas passes through the small holes 26 provided to the peripheral surfaces of the main body 26 and the seal plug 27 to externally expand the elastomer 28. The expanded elastomer 28 is closely contacted with the tube wall of the tubular body to prevent the penetration of a liquid medium in the tubular body.

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 end 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 using a liquid medium and to minimize the cutoff length of the tube end, the most reliable method is to seal the end with a rubber or other material as described above. Work efficiency was extremely poor as attachment and detachment relied on manual labor. 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. However, 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 to seal the end plug of a tubular body, thereby facilitating automation of sealing work. This is what we provide.

The feature is that in the method of ultrasonic flaw detection in which the liquid medium is supplied into the N through hole and passed through the tubular body which is the material to be tested, it starts immediately before the front end of the tubular body enters the flaw detector. , while following the movement of the tubular body, a hollow plaque rod having a cylindrical elastic body at the tip disposed on the exit and entry sides of the flaw detector is inserted into the tubular body until the rear end advances outside the flaw detector. While entering 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 tightly attached to the inner surface of the tube. By letting.

The present invention provides an ultrasonic flaw detection method for a tubular body, characterized by preventing the liquid medium from entering the tubular body.

[Detailed description of the invention]

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

In Fig. 1, 10 is a flaw detector with a through hole 1 in the axial direction.
1 and is driven at high speed around the axis. Flaw detector 10
Two sets of probes 12.13 are attached in the axial direction of the through hole 11, and guide links 14.13 are installed on the entrance and exit sides.
15 is installed. Through hole 1 of this probe 3 device 10
1 is supplied with a liquid medium through supply pipes 16 and 17. 1
8 is an inlet plug rod support cart installed on the inlet side of the flaw detector 10, and 19 is an outlet plug rod support cart installed on the detector (R) side.These plug rod support carts 18.1
Reference numeral 9 is installed parallel to and above the V-shaped roller table that conveys the tubular body A, and moves in the direction of the arrow a or the direction of the arrow b following the tubular body. 42 is a guide roller, and 43 is a pinch roller box. 44 is an eddy current flaw detection coil provided in front of the ultrasonic flaw detector.

Reference numeral 25 denotes an outlet plug, which, as shown in FIG. 2, includes a hollow plug main body 26, a seal plug 27 having a shoulder portion 45 of an elastic body, an elastic body 28 made of rubber, etc., and a guide provided at the tip. It consists of a plug 29 and a gas supply nozzle 3o coupled 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 screwed into the plug body, and an elastic body 28 can be attached to the front outer peripheral surface.

The front of the elastic body 28 has a cone shape so that it can easily enter the inside of the tubular body A, and is screwed to the seal plug 27. As a result, the elastic body 28
7.

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 2G. When the elastic body 28 is expanded after inserting the plug 25 into the tube end of the tubular body A, 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 support 33, creating a buffer structure that allows the outlet plug support 25 to slide horizontally.

The plug support 33 is freely rotatably connected to the rod 35 by a pin 34, and can be raised and lowered by a cylinder 36.

This cylinder 36 is attached to the outlet plug rod support cart 19.

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.

Further, the plug rod support cart 19 has a position detector 37,
The amount of horizontal movement of the connecting rod 31 is detected, thereby making it possible to detect the relative positional relationship between the plug support cart 19 and the plug support 25.

On the other hand, as shown in FIG. 4, the entry side plug head 47 has a plug body 48 and a shoulder portion 52. A seal plug having a small hole 53, an elastic body 50, a guide plug 51, and a gas supply nozzle 54
It has almost the same structure as the outlet plug rod 25, but the gas supply nozzle 54 at the rear end is connected to the gas supply hose 5.
5.

As shown in FIG. 5, the hose 55 is wound around a hose reel 57 mounted on the inlet plug support cart 18 so as to be unwound. The entry side plug 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 entry side placket 47 is designed to collide with the first collar 61 and stop when the hose 55 is wound up onto the coil 57.

A clamp device 62 for grasping the inlet plug rod 47 at at least one location is provided at the front 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 6G 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.

The clamping device 62 can raise the entry plug 47 by the hydraulic cylinder 65 so that it does not get in the way when the tubular body A is transported under the support cart 18.

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

In the above scavenging device, 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 outlet plug rod 25 installed on the outlet plug rod support cart 19 is moved by the cylinder 36 to the same level as the axis of the tubular body A. At the same time, the outlet plug support cart 19 is moved in the direction of the arrow b. This exit side seal plug rod 25 is further advanced to enter and pass through the flaw detector, and then it is temporarily stopped to take a position of waiting 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 moving 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 seal plug 27 attached to the tip of the outlet plug n25 is inserted into the opening at the front end of the tubular body A, and the speeds of both are synchronized at the same time.

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 support cart 19 with the outlet plug rod 25 attached thereto.

Immediately after the rear end of the tubular body A passes under the guide plug 51 at the tip of the inlet plug rod 47 mounted on the inlet plug rod support cart 18 that is waiting directly above, the inlet plug rod support cart 18
The cylinder 65 provided at the inlet side plug rod 47 is activated.
is lowered to the same level as the axis of the tubular body A, and the seal plug attached to the tip of the inlet plug rod 47 is moved by moving the inlet plug support cart 56 in the direction of the arrow a at a faster speed than the tubular body Δ. 49 into the rear end opening of the tubular body A, and at the same time synchronize the speeds of both. When this seal plug 49 enters the rear end opening of the tubular body A, high pressure gas is instantly supplied from a gas supply device such as air (not shown) through a hose 55 and a gas supply nozzle, and is attached to the tip of the plug plug 47. The elastic body 50, which is supplied to the seal plug 49 and fitted into the seal plug 49 in the form of a sleeve, is expanded within the tube of the tubular body A and brought into close contact with the tube, thereby preventing the liquid medium from entering the tube.

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 support cart 19 moves in the direction of the arrow a, but the inlet plug support cart 18 stops. The clamping device 62 mounted on the entry side plug support cart 18 is opened after the entry side plug support 47 is inserted into the rear end of the tubular body A and the first elastic body 5o is brought into close contact with the inner surface of the tubular body A. . Therefore, since the inlet plug rod 47 moves together with the tubular body A, the hose on the reel 57 of the inlet plug rod support cart 18 is not unwound even if the inlet plug rod support cart 18 is stopped as described above. , the entrance plug 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. When the front end of the tubular body A passes through the flaw detector and comes out to the outside and reaches an appropriate distance, compressed air (not shown) is supplied to the seal plug 27 that has entered the front end opening of the tubular body A. The valve is opened, the sleeve-shaped elastic body 28 is contracted, and the outlet plug 25 is separated from the front end of the tubular body A.
The outlet plug support cart 19 is moved in the direction of the arrow a at a faster speed than the tubular body A, and the cylinder 36 is operated to lift the outlet plug 25 upward. 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. Output side plug support trolley 1
9 lowers the plug 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 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).
The sleeve-shaped elastic body 50 is contracted to separate the entry side plug rod 47 from the rear end of the tubular body A, and the entry side plug rod support cart 18
The reel 57 mounted on the hose 55 and the inlet plug 47 are returned toward the support cart.

The rear end of the entry side plug rod 47 is the stopper 6 of the support cart 18
1, the winding of the hose 55 by the handle 57 is completed, and at the same time, the cylinder 65 is actuated to lower the clamping device, clamp the inlet plug 47, raise it again, and move the hose 55 to the next tubular body A. is the entry side plug support trolley 18
Wait until it passes below.

If the inlet plug rod 47 is connected to the hose 55 and sent out from the reel 57 in this way, the inlet plug rod support cart 1 is inserted after the seal plug is inserted into the rear end of the tubular body A.
No need to move 8.

Furthermore, the inlet plug 47 can be made very short, and the entire device can also be downsized.

The inlet plug rod 47 and the inlet plug support cart 18 are made to have exactly the same structure as the outlet plug rod 25 and the outlet plug 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 47 and the outlet plug 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 opening of the tubular body. The material is preferably synthetic resin (for example, MC nylon).

Cone-shaped guide plugs 51 and 29 and seal plug 49
．． 27 is connected with a screw so that it can be replaced. The elastic body 28.50 is a sleeve made of rubber or the like having an outer diameter slightly smaller than the inner diameter of the tubular body A, and is secured to the shoulder portion 45.52 of the seal plug 27.49. Plug body 26.4
Air conduits extend radially from the 8-axis center toward the inner circumference of the rubber sleeve 28.50. When compressed air is sent to the nozzle tip through this conduit 3G, the rubber sleeve expands radially and comes into close 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 as they are not necessarily aligned.

For this reason, as mentioned earlier, the guide plug 29.51 is made into a cone shape to make it easier to enter, but it is also possible to make some movement of the outlet and inlet plug rods 25.47 when there is resistance. In the outlet plug rod, pin 3 is attached to rod 35.
A connecting rod 31 held by a spring connected at 4 and capable of sliding left and right is connected to the outlet plug rod, while a rod 66 held by a spring 67 is attached to the inlet plug rod 47. It is coupled to a clamping device 62, which makes it possible to dampen the resistance during said insertion.

In addition, the outlet plug support cart 19 has an outlet plug support 25.
There is a position detector 37 that detects the horizontal movement of the support base *
The speed of the support truck 19 can be adjusted by detecting the position of the outlet plug bar 25 relative to the support truck 19. In addition, tubular body A
If the outlet plug 25 is to be raised after being pulled out from the holder, the cylinder 36 is activated.As shown in the figure, the outlet plug 25 is long, so
The sides may bend downward.

For samurai purposes, a plug lifting platform 40 is provided at a predetermined position on the exit side of the ultrasonic flaw detector, and this platform 40 is raised and lowered by the operation of the cylinder 41.
0 can be operated to raise and lower the outlet plug shaft 25 to prevent deflection.

[Effects] By using the method described above, the present invention reliably prevents the liquid medium required for ultrasonic probe π from penetrating into the inside of the tube to be inspected, and also makes it possible to manually close the stopper, such as rubber, etc. This is an excellent method that can be done automatically without having to do anything.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the overall structure of the device of the present invention, and FIG. 2 is a cross-sectional explanatory diagram showing an example of an outlet plug rod. Fig. 3 is an explanatory 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
The figure is mainly a side view of the inlet plug rod and its support cart. A: Tubular body a, b: Movement direction arrow 10: Ultrasonic flaw detector 18 Two-person plug support trolley 19: Output plug rod support trolley 25: Output plug support 26: Plug support body 27: Seal plug 28: Elastic body 31: Connecting rod 35: Rod 36: Cylinder 38: Wheel 47: Inlet plug rod 49: Seal plug 50: Elastic body 55: Hose 57: Reel 62: Clamp device 65 Niji cylinder

Claims (1)

[Claims] 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 rear end of the tubular body moves out of the flaw detector 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 enter the front and rear ends of the tubular body until the probe advances. 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 flow. An ultrasonic flaw detection method for a tubular body characterized by preventing penetration into the tubular body.