KR101019053B1 - Purging Apparatus For Pipe Welding - Google Patents

Abstract

The present invention relates to an internal pipe purging device, and more particularly, to an internal pipe purging device that controls a flow rate of argon gas while observing a back bead shape inside a weld pipe without entering an inside pipe of a worker. According to the pipe purging device according to the present invention, it is unnecessary to work inside the pipe of the worker for installing the barrier film, thereby reducing the time and labor in performing the purging operation, minimizing the interval between the barrier film for purging work and purging gas flow rate The operator can control the outside of the pipe to reduce the waste of purging gas and purging waiting time, and remove the remaining argon gas after welding through the gas exhaust to eliminate the risk of the worker's working environment. The monitoring unit has the advantage of checking the status of the back bead without entering the operator inside the pipe. In addition, according to the present invention, by supplying air to the airbag, the kinematically constrained roller link expands with the airbag so that the airbag expands in a state where the guide roller supports the pipe wall and is caused by friction by the inner wall of the pipe. By preventing the inclination, the present pipe internal purging device can maintain a positive posture.

Purging, back bead inspection, pipe welding

Description

Purging Apparatus For Pipe Welding

The present invention relates to an internal pipe purging apparatus, and more particularly, after welding while measuring the concentration of oxygen and argon gas and controlling the flow rate of argon gas while observing the back bead shape inside the weld pipe without entering the pipe of the operator. The present invention relates to a pipe purging device for removing argon gas residual amount in a pipe.

In general, to prevent oxidation of beads and to secure welding quality, a pipe is installed at both ends of the welded pipe when welding the pipe. Insert the barrier film into the pipe to be welded, perform fit-up between the welded pipes, and tape the pipe welded area to seal it, and then inert gas such as argon (Ar) to prevent oxidation of the weld bead. Inject

This operation is called purging, which is an important task to prevent oxidation of the internal welds of welded pipes.

After purging, the welding is performed, the barrier is removed, and the operator directly enters the inside of the pipe to visually check the back bead condition of the weld pipe. The above barrier is generally used with a sponge and the amount of gas for purging is determined based on the operator's experience.

As described above, in purging operation, a sponge is usually used as a barrier, and in the case of pipe welding of a long pipe, sponge requires a lot of time and labor for installation and removal.

In addition, when the worker installs the barrier material of the sponge material, the time required to inject the required amount of argon gas, etc. for purging because the space inside the pipe that is sealed by the barrier film becomes wider than necessary due to the limited space inside the pipe (hereinafter, Material consumption, such as a long purging waiting time) and a sponge consumption when dismantling the barrier, are also a serious problem.

And when the worker enters the pipe for visual inspection of the back bead after the welding after the purging operation, there is a problem that there is always a risk of a fatal threat to the worker's life due to low oxygen concentration. In particular, in the case of visual inspection, if argon gas, which is heavier than air, accumulates under the pipe and the worker drinks argon gas, an argon poisoning accident may occur.

The present invention has been made to solve the above problems, it is unnecessary to work inside the pipe of the operator to install the barrier membrane, minimize the gap between the barrier membrane and reduce the waste of purging gas and purging waiting time, the operator to purge gas flow rate The present invention provides a pipe purging device that can be controlled outside the pipe and removes the remaining argon gas after welding, thereby eliminating the danger of the worker's working environment.

In another aspect, the present invention provides a pipe purging device that can maintain the posture by preventing the inclination due to friction between the air bag and the pipe inner wall when injecting air into the air bag.

The above object is in the pipe purging device for hermetically purging both ends of the welded pipe, the hollow portion is formed with a hollow body, the left and right body provided with an air inlet, gas supply port and gas exhaust; Left and right airbags fixed to the outside of the left and right bodies, respectively, which expand and contract to open and close both ends of the weld pipe; An air supply installed inside the left and right bodies to supply and exhaust air to the left and right airbags; A gas supply unit installed inside the left and right bodies and connected to the gas supply port to supply a purging gas to the welded pipe, and installed inside the left and right bodies, and connected to the gas exhaust mechanism. And a gas exhaust unit configured to exhaust the purge gas inside the welded pipe; and a controller for controlling the air amount of the air supply and exhaust pipe, the gas supply amount of the gas supply pipe, and the gas exhaust amount of the gas exhaust pipe. It is realized by an internal purging device.

In addition, the present invention includes one or more left and right guide rollers installed at one end of the left and right body to easily move the inside of the pipe, wherein the left and right guide rollers of the left and right body, respectively One end is connected to the roller link, and the roller link is kinematically constrained to the left and right airbags, respectively, to expand or contract in the radial direction of the airbag when the airbag is inflated or contracted.

The roller link has a structure such that the distance from the end of the guide roller to the central axis of the body is greater than the radius of the airbag, and the roller link may comprise a cylinder and a piston.

On the other hand, the left and right body may be connected by a universal joint that can rotate about three axes, such as a spring or ball joint.

The left body and the right body are formed in a cylindrical shape, a back bead monitoring unit for monitoring the back bead inside the welded pipe is installed between the left body and the right body. The back bead monitoring unit includes a camera photographing the shape of the back bead inside the welded pipe, a seat on which the camera is seated, and driving means for rotating the seat along the back bead. On the other hand, the back bead monitoring unit may be configured to further include a camera position control unit for adjusting the position of the camera by controlling the driving means.

An oxygen concentration measuring sensor and a gas pressure measuring sensor are installed between the cylindrical left body and the right body. In addition, a back bead image unit for displaying the shape of the back bead taken by the back bead monitoring unit in real time and an oxygen concentration display unit for displaying the oxygen concentration measured by the oxygen concentration measurement sensor in real time and the gas pressure measurement sensor The display unit may further include a display unit configured to display a gas pressure in real time.

According to the present invention, the pipe purging device of the present invention can reduce the time and labor in performing the purging work because the worker's pipe work is not necessary to install the blocking film, and minimize the gap between the blocking film for the purging work and reduce the purging gas flow rate. Allows the operator to control outside the pipe, reducing waste of purging gas and purging waiting time, eliminating residual argon gas after welding through the gas exhaust, and eliminating the risk of the operator's working environment. It is advantageous to check the status of the back bead without entering the inside of the pipe through the wealth.

In addition, according to the present invention, by supplying air to the airbag, the kinematically constrained roller link expands with the airbag so that the airbag expands in a state where the guide roller supports the pipe wall and is caused by friction by the inner wall of the pipe. By preventing the inclination, the pipe purging device of the present invention maintains a positive posture to reliably block both ends of the welded portion.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

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

1 is a view showing the configuration of an embodiment for the internal pipe purging device according to the present invention.

As shown in FIG. 1, in the exemplary embodiment, the left and right airbags 20A and 20B, which serve as barriers and the left and right bodies 10A and 10B, and the air supply / exhaust unit 30 and the gas supply unit ( 40, the gas exhaust unit 50, and further comprises a control unit 90 for controlling the above components.

The air supply / exhaust unit 30, the gas supply unit 40, the gas exhaust unit 50, and a control cable (not shown) are included in one flexible hose.

The left and right bodies 10A and 10B have a cylindrical shape with hollow portions, and air inlets 11A and 11B, a gas supply port 12 and a gas exhaust port 13 are formed on the surfaces of the left and right bodies 10A and 10B. In one embodiment, one air inlet 11A and a plurality of gas supply holes 12 are formed in the left body 10A, and one air inlet 11B and a plurality of gas exhaust ports are formed in the right body 10B. (13) is formed. If necessary, the gas supply port 12 and the gas exhaust port 13 may be formed only on one of the left and right bodies 10A and 10B, and the number thereof may vary depending on the diameter of the pipe.

The diameters of the left and right bodies 10A and 10B may include a diameter of the flexible hose including the air supply / exhaust unit 30, the gas supply unit 40, the gas exhaust unit 50, and control cables (not shown). The design takes into account the space required for the movement of the camera and the back-bead monitoring unit to be described below.

The left and right airbags 20A and 20B are respectively fixed to the outside of the left and right bodies 10A and 10B and supplied through the air inlets 11A and 11B formed on the surfaces of the left and right bodies 10A and 10B. Air is supplied from the exhaust (30).

As shown in FIG. 1, the air supply / exhaust portion 30 is formed in an elongated tubular shape and is connected to the air manifold 31 through the inside of the left and right bodies 10A and 10B and connected to the air manifold 31. Branch) is connected to the air inlet 11A of the left body 10A and the air inlet 11B of the right body 10B, respectively.

When air is supplied from the air supply / exhaust unit 30, the left and right airbags 20A and 20B expand and block both ends of the inside of the welded pipe to form a sealed space inside the pipe between the left and right airbags 20A and 20B. When the air is released to the air supply / exhaust part 30, the left and right airbags 20A and 20B contract and open both ends of the inside of the weld pipe.

On the other hand, the gas supply unit 40 supplies the argon gas for purging in the pipe sealed by the left and right airbag (20A, 20B). The gas supply part 40 is also formed in an elongate tube shape and is connected to the gas supply manifold 41 through the inside of the left body 10A and branched from the gas supply manifold 41 to thereby provide a plurality of the left body 10A. It is connected to the gas supply port 12, respectively.

The gas exhaust unit 50 serves to exhaust the argon gas supplied for purging into the pipe sealed by the left and right airbags 20A and 20B. The gas exhaust part 50 is also formed in an elongated tube form and is connected to the gas exhaust manifold 51 through the inside of the left and right bodies 10A and 10B and branched from the gas exhaust manifold 51 to the right body 10B. Are connected to a plurality of gas exhaust ports 13).

The gas supply unit 40 and the gas exhaust unit 50 supplies and exhausts argon gas for purging the inside of the pipe.

Meanwhile, as shown in FIG. 1, a back bead monitoring unit 60 is installed between the left and right bodies 10A and 10B to monitor the shape of the back bead inside the welded pipe.

The back bead monitoring unit 60 rotates the camera 61 for photographing the shape of the back bead inside the welded pipe and the seating part 62 and the seating part 62 on which the camera 61 is seated along the back bead. It comprises a drive means (63).

The camera 61 captures the bead shape inside the weld pipe while rotating in the x-axis direction by the drive means 63. The seating part 62 is coupled to the driving means 63 while the camera 61 is seated, and rotates about the x-axis direction. Therefore, when installing the embodiment inside the welded pipe so that the camera 61 of the back bead monitoring unit 60 is located in the welded pipe.

On the other hand, the camera position control unit 64 controls the position of the camera 61 of the back bead monitoring unit 60. The camera position control unit 64 controls the driving means 63 to adjust the position of the camera 61 so that the operator can observe the state of the back bead at the desired position without entering the pipe.

As shown in FIG. 1, an oxygen concentration measuring sensor 70 is installed between the left and right bodies 10A and 10B to check the amount of oxygen inside the pipe. In addition, a gas pressure measuring sensor 75 is installed between the left and right bodies 10A and 10B to measure the argon gas pressure inside the pipe. This is to reduce waste of argon gas by adjusting the amount of argon gas for optimum welding according to the measured oxygen amount.

FIG. 2 is a simplified diagram illustrating the control unit 90 and the display unit 100 of the components of the exemplary embodiment shown in FIG. 1.

The air amount of the air supply / exhaust unit 30, the gas supply amount of the gas supply unit 40, and the gas exhaust amount of the gas exhaust unit 50 are controlled according to the operator's operation through the control unit 90. The control unit 90 turns on / off the air supply / exhaust unit 30 to expand or contract the left and right airbags 20A and 20B, the gas supply unit 40, and the gas exhaust unit 50. Gas supply and exhaust control unit 92 for adjusting the amount of argon gas for purging by turning on / off.

Meanwhile, the oxygen concentration measured by the oxygen concentration sensor 70, the gas pressure measured by the gas pressure sensor 75, and the back bead image photographed by the back bead monitoring unit 60 are respectively the back bead of the display unit 100. It is displayed to the operator through the image unit 110, the oxygen concentration display unit 120 and the gas pressure display unit 130.

The operator checks the oxygen concentration and the argon gas pressure with the naked eye through the oxygen concentration display unit 120 and the gas pressure display unit 130, adjusts the amount of argon gas for purging, and enters the bag without entering the pipe through the back bead image unit 110. By monitoring the condition of the beads, the worker can be prevented from being exposed to dangerous working conditions.

3 is a view showing the guide roller 80 and its link portion.

When the airbags 20A and 20B are inflated due to friction with the pipe wall, the airbags 20A and 20B do not maintain a normal posture and are inclined, so that the pipe purging device itself according to the present invention may also tilt. To prevent this problem, if the airbag 20A, 20B is inflated and the guide roller 80 is inflated at the same time, the airbag 20A, 20B is still in contact with the pipe inner wall while the guide roller 80 is still in contact with the pipe inner wall. When (20A, 20B) is expanded, friction between the airbags 20A, 20B and the pipe wall can be minimized.

The present invention includes one or more left and right guide rollers 80 which are installed at one end of the left and right bodies 10A and 10B to allow easy movement inside the pipe, and the left and right guide rollers 80 are One end of the left and right bodies 10A, 10B and roller links 82 and 83 are installed, respectively, and the roller links 82 and 83 are air bag links 84 to the left and right air bags 20A and 20B, respectively. Kinematically constrained to expand or contract in the radial direction of the airbags 20A and 20B when the airbags 20A and 20B expand or contract.

The roller links 82 and 83 have a structure such that the distance 85 from the end of the guide roller 80 to the central axis of the bodies 10A and 10B is equal to or greater than the radius 25 of the airbags 20A and 20B. In addition, the roller link may include a cylinder 82 and a piston 83.

When the guide roller 80 has the structure as described above, the roller link mechanically constrained to the airbags 20A and 20B, which are expanded when the air is supplied to the airbags 20A and 20B, is expanded together with the airbags 20A and 20B. This prevents the airbags 20A and 20B from inflating in the state where the guide roller 80 is supported on the pipe wall and prevents the inclination due to friction caused by the pipe inner wall so that the pipe purging device of the present invention can maintain a posture.

Meanwhile, the left and right bodies 10A and 10B may be connected by the spring 15 to have a constant angle with each other. The spring 15 may be replaced with a universal joint that can rotate about three axes, such as a ball joint. When the left and right bodies 10A and 10B are connected by the springs 15, the pipe purging device of the present invention maintains posture not only in a straight pipe but also in a curved pipe, and seals both ends of the inside of the pipe. Purging can be done.

One end of the cylindrical left body 10A and the right body 10B is provided with a plurality of guide rollers 80 so that the purging device can easily enter the pipe. The guide roller 80 allows for easy entry into the pipe, particularly as the purging device passes through the curved pipe.

Hereinafter, a method of operating the pipe purging device 1 according to the present invention will be described.

Align the pipe to be welded and move the pipe internal purging device 1 to the welding site inside the pipe. Thereafter, air is supplied to the airbags 20A and 20B through the air supply / exhaust unit 30 to block both ends of the inner portion of the welding portion, and at this time, a roller link mechanically constrained to the airbag by the airbag link 84. By expanding the 82 and 83 together with the airbags 20A and 20B, the airbags 20A and 20B expand while the guide roller 80 supports the pipe wall, thereby preventing the inclination due to friction by the pipe inner wall. The pipe internal purging device 1 of the present invention maintains a standing posture.

When the welding part is blocked by the airbags 20A and 20B, an inert gas such as argon (Ar) is injected through the gas supply part 40 to purge, and welding is performed outside the pipe. During the welding or after the welding is completed, the back bead state of the pipe is checked through the back bead monitoring unit 60, and the inert gas is removed through the gas exhaust unit 50. Next, the air is discharged from the airbags 20A and 20B through the air supply / exhaust unit 30, and the pipe internal purging device 1 is taken out.

It has been described so far limited to one embodiment of the present invention, the technology of the present invention can be easily modified by those skilled in the art. Such modified embodiments should be included in the technical spirit described in the claims of the present invention.

1 is a view showing the configuration of an embodiment for the internal pipe purging device according to the present invention.

FIG. 2 is a simplified diagram illustrating a control unit and a display unit of the components of the exemplary embodiment shown in FIG. 1.

3 is a view showing a guide roller and a link portion thereof.

<Description of the symbols for the main parts of the drawings>

10A, 10B: left and right body 15: spring connection

20A, 20B: Left and right airbags 30: Air supply and exhaust

40: gas supply part 50: gas exhaust part

60: back bead monitoring unit 70: oxygen concentration sensor

80: guide roller 90: control unit

100: display unit

Claims (8)

In the pipe purging device for hermetically sealing and purging both ends of the welded pipe, A hollow part is formed and includes left and right bodies provided with an air inlet, a gas supply port, and a gas exhaust port; Left and right airbags fixed to the outside of the left and right bodies, respectively, which expand or contract to open and close both ends of the inside of the weld pipe; An air supply to supply and exhaust air to the left and right airbags; A gas supply unit supplying a purging gas into the pipe through the gas supply port; A gas exhaust unit configured to exhaust the purging gas inside the pipe through the gas exhaust port; A control unit for controlling an air amount of the air supply / exhaust unit, a gas supply amount of the gas supply unit, and a gas exhaust amount of the gas exhaust unit; And And one or more left and right guide rollers installed at one end of the left and right bodies so as to easily move inside the pipe. The left and right guide rollers are connected to one end of the left and right bodies by a roller link, respectively. And the roller links are kinematically constrained to the left and right airbags, respectively, to expand or contract in the radial direction of the airbag when the airbag inflates or contracts. The method of claim 1, And the roller link has a structure such that a distance from an end of the guide roller to a central axis of the left and right bodies is greater than a radius of the left and right airbags. The method according to claim 1 or 2, And the left and right bodies are connected by springs or universal joints. The method according to claim 1 or 2, The left and right bodies are formed in a cylindrical shape, And a back bead monitoring unit installed between the left and right bodies to monitor the back bead inside the welded pipe. The method of claim 4 The back bead monitoring unit, A camera for photographing the shape of the back bead inside the welded pipe; A seating part on which the camera is mounted; Drive means for rotating the seating portion along the back bead; Pipe internal purging device comprising a. The method of claim 5, The back bead monitoring unit further comprises a camera position control unit for controlling the position of the camera by controlling the drive means. The method of claim 6, A purging device inside the pipe, wherein an oxygen concentration measuring sensor and a gas pressure measuring sensor are installed between the cylindrical left body and the right body. The method of claim 7, wherein A back bead image unit which displays the shape of the back bead photographed by the back bead monitoring unit in real time; An oxygen concentration display unit displaying the oxygen concentration measured by the oxygen concentration sensor in real time; A gas pressure display unit displaying the gas pressure measured by the gas pressure measuring sensor in real time; Pipe internal purging device further comprising.

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