JPH08112695A - Internal clamp for piping and welding method - Google Patents

Abstract

PURPOSE: To provide a clamping device of the inner surface of a pipe which can smoothly shift the clamp member and easily executes shield. CONSTITUTION: A main body 1 having channel type cross section is divided with a partition wall 2 to form two divided chambers 31 , 32 and the inner surface of a main body ring is supported with a crossing type supporting rod 4. This supporting rod is fitted to the main body ring with a flange, etc. In both divided chambers of the main body ring, desirably, expansion rings 51 ,2 ,3 , 61 ,3 divided into four pieces are fitted so as to face to these rings. In the expansion ring, seal rings 81 , 82 abutted on the inner surfaces at the abutted part of the pipes are fixed. The expansion ring is expanded/shrunk by bulging built-in rubber tubes 281 , 282 . and according to this action, the seal rings are expanded/shrunk at the overlapping part and closely abutted on the inner surface of the pipe, and the pipe is held by the inner surface of the pipe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal clamp for piping and a welding method.

[0002]

2. Description of the Related Art A conventional backing head, which is divided into a large number of clamps of this type, is moved in and out by a cylinder to hold the inner surfaces of the abutting pipes and weld them from the outer periphery.

[0003]

By the way, in the above clamp, when the clamp is inserted into the pipe, the backing head is operated toward the inlet side to reduce the overall diameter,
After inserting, the diameter is increased by operating it to the exit side, but if you try to easily insert it when the diameter is reduced, the difference from when increasing the diameter during clamping becomes large, and each backing during clamping. A large gap is formed between the heads, making it difficult to supply the shielding argon during welding. On the contrary, if the difference in diameter is made small, there is a problem that it becomes difficult to insert and pass through the pipe, especially the elbow member. Further, since the backing head is operated by the cylinders, it is difficult to operate each cylinder uniformly and simultaneously, and there is a problem that the butting of the pipes is difficult. In addition, when multi-layer (multi-pass) deposition is continuously performed in pipe welding, heat is eventually accumulated in the weld, the temperature of the pipe rises abnormally, and the deterioration of the weld metal and the distortion of the weld become large. is there.

Therefore, in the present invention, the difference in diameter is large and the clamp member can be moved smoothly.
Another object of the present invention is to provide a clamp which is less likely to cause a gap and which can cope with pipes and elbows having different inner diameters and which can secure the quality of weld metal and prevent deformation of a weld joint.

[0005]

In order to solve the above-mentioned problems, the present invention divides a ring-shaped main body ring having a channel-shaped cross section into two dividing chambers by a partition wall in the axial direction. Each expansion chamber is fitted with an expansion ring having a circular arc-shaped cross-section that is divided into a plurality of pieces in the circumferential direction, and a coil spring that abuts the end of each expansion ring with a spring pin protruding from each expansion ring Fix the seal ring that contacts the inner surface of the pipe to each expansion ring on both sides, fix the seal ring joint to the end of each seal ring, and move the seal ring join by sliding to the end of the opposite seal ring. The expansion chambers can be mounted separately so that they can be expanded and contracted independently in both compartments to increase the diameter of each expansion ring. To configure the built-in internal clamp for piping a rubber tube that.

Further, the inner surfaces of the body rings of the two clamps are supported by a hollow cross-shaped support rod, and the two clamp vertical support rods are rotated by a hinge member and a hinge holding member provided at both ends of the connecting rod. An internal clamp for piping, which is held as much as possible and connects two clamps, is constructed.

Further, a shielding gas such as argon gas for welding is flown between both seal rings of the internal clamp to prevent oxidation of the inner surface of the welding bead of the first layer and stop the flowing of the shielding gas in any layer after the second layer. Instead, a cooling gas such as air or nitrogen is caused to flow to prevent the welding bead from overheating due to heat input to the subsequent layer of the welding bead.

[0008]

The present invention is configured as described above. The expansions on both sides are moved by separate rubber tubes to increase the diameter, and the seal rings are attached to both sides of the abutting portion of the pipe. Therefore, even if there is a difference in the wall thickness of the pipes on both sides, the seal rings on both sides are reliably brought into contact with each other.

Further, when the pipe is an elbow in the horizontal direction, the striking rod is axially supported by rotatably holding the supporting rods for supporting the body rings on both sides by the hinge members and the hinge holding members provided at both ends of the connecting rod. Rotate to pass through the clamp.

[0010]

Embodiments of the present invention will be described in detail with reference to the drawings. A main body ring 1 having a channel-shaped cross section (see FIG. 1) is divided by a partition wall 2 to form two division chambers 3 ₁ and 3 ₂ , and a hollow cross-shaped support for the inner surface of the main body ring 1 is formed. It is supported by a rod 4 (see FIG. 2). This support rod 4 is provided with connecting portions 37 ₁ , 37 ₂ , 37 ₃ , 37 ₄ such as flanges at its tip end portion so that it can be removed between the cross portion of the cross and the body ring 1. And, in both compartments 3 ₁ , 3 _{2 of} the main body ring 1, preferably four channel-shaped expansion rings 5 ₁ , 6 ₁ , 5 are divided.
_{Fit 2} , 6 ₂ , 5 ₃ , 6 ₃ , 5 ₄ , 6 ₄ so as to face each other.

Each expansion ring 5 ₁ , 6 ₁ , 5
Sealing rings 8 ₁ and 8 ₂ that are in contact with the inner surfaces of the pipes 7 ₁ and 7 ₂ to be joined are abutted to the center of the outer periphery of ₂ , 6 ₂ (see FIGS. 4 and 5). For example, at one end of each of the seal rings 8 ₁ , 8 ₁ , 8 ₂ , 8 ₂ fixed to the expansion rings 5 ₂ , 6 ₂ facing the expansion rings 5 ₁ , 6 ₁ , for example, the expansion ring 5 ₂ Pass the bolt 9 through the seal ring 8 ₁ to fix the seal ring joint 10 ₁ to the center side,
A bolt 11 is inserted slightly inward from the other end of the seal ring 8 ₁ of the expansion ring 5 ₁ and a bolt 11 is inserted into a long hole 12 provided in the seal ring joint 10, and one end of the seal ring 8 ₂ of the expansion ring 6 ₁ is located at the center side. The seal ring joint 10 ₂ is fixed to the seal ring joint ₂ by fixing the seal ring joint 10 ₂ to the inner side of the other end of the seal ring 8 ₂ of the expansion ring 6 ₂ facing each other, and the bolt 11 is inserted into the long hole 12 provided in the seal ring joint 10 _2. Through the expansion rings 5 ₁ , 6 ₁ , 5 ₂ , 6 ₂
When the ring expands and contracts, the seal ring shoins 10 ₁ , 10
₂ can be moved.

Further, each expansion ring 5 ₁ , 6
Internal joint members 13 ₁ , each having a channel-shaped cross section, at opposite ends of the inner peripheral surfaces of the end portions (see FIG. 6) of ₁ , 5, ₂ , 6 ₂ ...
One end of 13 ₂ is fixed and the free ends of the inner joint members 13 ₁ and 13 ₂ are opposed to each other, for example, an expansion ring 5 ₁ ,
Fitted on the inner surface of 6 ₁ , each expansion ring 5 ₁ ,
No gap is generated between the expansion rings when 6 ₁ , 5 ₂ , 6 ₂ ... Has reached the maximum diameter.
In addition, each expansion ring 5 ₁ , 6 ₁ , 5 ₂ , 6 ₂
As shown in FIG. 6, the ends of the key-shaped seal plates 36 ₁ and 36 ₂ are fixed to the center of the ends of the ..., and the free ends are opposed to, for example, the inner surfaces of the expansion rings 5 ₁ and 6 ₁ . Gas is prevented from leaking when the expansion rings are fitted and each expansion ring reaches the maximum diameter.

Further, the spring pins 14 ₁ , 1 projecting from the respective inner joint members 13 ₁ , 13 ₂ through the respective ends of the expansion rings 5 ₁ , 6 ₁ , 5 ₂ , 6 ₂ .
4 ₂ projecting a, matching the expansion ring 5 ₁
, 6 ₁ , 5 ₂ , 6 ₂ ... Spring pin 1
4 _1, 14 ₂ coil spring 15 to _1, 15 the coil spring 15 ₁ end respectively fixed to _two, 15 _second haulage each expansion ring 5 _1, 6 _1, 5 _2, 6 ₂
It is designed to hold the reduced diameter of.

Further, each expansion ring 5 ₁ , 6
_A wire mesh 16 (see FIG. 3) is placed between the seal rings 8 ₁ and 8 _{2 of 1} , 5 ₂ , 6 ₂ ... And a metal plate (copper plate) 17 having a large number of holes formed thereon is projected. The metal plates 17 are placed so that they overlap, and cut and raised portions 18, 18 ... Are provided on both sides of the metal plate 17 at appropriate intervals, and the wire 20, 20 ... Having coil springs 19, 19 is cut and raised portion. It is formed so that it does not depend on the center side through 18, 18, ..., and the polymerized portion of the metal plate 17 can be expanded and contracted according to the expansion and contraction of the expansion rings 5 ₁ , 6 ₁ , 5 ₂ , 6 ₂ . Has become. still,
As shown in FIG. 1, the inner surface of each expansion ring 5 ₁ , 6 ₁ , 5 ₂ , 6 ₂ ... is lined with a channel-shaped cross section 2
1 ₁ and 21 ₂ are fixed.

Each expansion ring 5 ₁ , 6 ₁ , 5
One end of an L-shaped center pin 22 (see FIG. 2) is fixed to a position located in the center of ₂ , 6, ₂ ... And fitted into pipes 23 fixed on both sides of the main body ring 1, and each expansion ring 5 ₁ , 6 ₁ , ... Can be held in place. The stopper pipes 24 ₁ and 24 ₂ are fixed to the body rings 1 located on both sides of the center pin 22, and L-shaped stoppers 25 ₁ and 25 ₂ are fitted therein and fixed with fixing bolts 26 ₁ and 26 ₂ . Stobber 25 ₁ , 2
The free ends of 5 ₂ are expanded rings 5 ₁ , 6 ₁ , 5
It is designed so that it does not protrude to the outer periphery by coming into contact with the upper surfaces of ₂ , 6 ₂ ... In addition, each expansion ring 5 ₁ , 6 ₁ ,
Stoppers 25 ₁ and 25 ₂ are provided at both ends of 5 ₂ , 6 ₂ ...
... is provided.

As shown in FIGS. 1 and 2, a part of the hollow support rod 4 has an inlet 26 'for introducing argon gas and cooling air or nitrogen by switching, and an inlet 26' is provided.
As shown in FIG. 7, a flat portion 27 having the same thickness as the partition wall 2 is formed at both ends of the vertical portion provided with, and the flat wall 27 is positioned by notching the partition wall 2 as shown in FIG. Argon is supplied between the seal rings 8 ₁ and 8 ₂ by opening in the middle between the rings 5 ₁ and 6 ₁ and 5 ₃ and 6 ₃ .

Further, ring-shaped rubber tubes 28 ₁ and 28 ₂ are provided in the compartment chambers 2 and 3 of the body ring 1, respectively.
And the supply pipes 29 ₁ , 29 ₂ provided on the main body ring 1
(See FIG. 1) A pressure fluid is supplied to expand the rubber tubes 28 ₁ and 28 ₂ and the expansion ring 5
₁ , 5 ₂ and 6 ₁ , 6 ₂ are moved separately to enlarge the diameter.

Further, on the inner surface of the body ring 1, as shown in FIGS. 1 and 2, four L-shaped mounting members 30 ₁ and 30 _{2 are} attached.
... to fix the respective mounting members 30 _1, 30 ₂ ... ends bolts casters 31 _1, 31 _2, the mounted height-adjustable by a nut, a total of eight casters 31 _1, 31 ₂ ... a pipe 7 ₁ , 7 ₂ so that they can travel on the inner surface of the clamp A.

The above-mentioned two clamps A are connected to each other to form a connection type clamp. In this connection, the large diameter portions 32 ₁ , 32 ₂ are spaced vertically (in FIG. 1) apart from the center of the vertical member of the support rod 4 on the side where the inlets 26 'of both clamps A, A are provided. , 32 ₃ and 32 ₄ are provided, and the connecting rod 3 is provided between the large diameter portions 32 ₁ and 32 _{2 and} between the large diameter portions 32 ₃ and 32 _{4, respectively.}
Semi-circular hinge members 34 ₁ and 34 fixed to both ends of 3
₂ is fitted, and the arcuate hinge holding members 35 ₁ and 35 ₂ are fixed to the hinge members 34 ₁ and 34 ₂ , respectively, and are held so as to be vertically rotatable around the support rod 4, thereby supporting by rotating the rod 4 in the vertical direction and to be movable in the horizontal direction is curved to the pipe 7 _1, 7 _2.

This embodiment is constructed as described above,
In the unused state, the coil springs 15 ₁ , 15
Each expansion ring 5 ₁ , 6 by the indexing force of _2
1 , 5, ₂ , 6 _2, ... Are in a state in which the respective end portions are abutted with each other and the diameter is the minimum.

In this state, the connected internal clamps of this embodiment are inserted from either direction of the pipes 7 ₁ , 7 ₂ and moved by the casters 31 ₁ , 31 _2, ...
Connect the seal rings 8 ₁ and 8 ₂ of _one clamp A to the pipe 7
_The movement is stopped when it is located on both sides of the abutting part of ₁ , 7 ₂ .

Thereafter, when a pressure fluid such as compressed air such as rubber tubes 28 ₁ and 28 ₂ is supplied from the supply pipes 29 ₁ and 29 ₂ , the rubber tubes 28 ₁ and 28 ₂ expand, and the expansion rings 5 ₁ , 6 ₁ , 5 respectively. Press ₂ , 6, ₂ ... By this action, each expansion ring 5 ₁ , 6 ₁ ,
5 ₂ , 6 ₂ ... move to the outer peripheral side in the main body ring 1 to open the gaps between the ends of the expansion rings 5 ₁ , 6 ₁ , 5 ₂ , 6, ₂ ... and seal rings 8 ₁ , 8 ₂ to connect the pipe 7. ₁ , 7 ₂
Abut the inner surface of. When welding the elbow portion, for example, the rubber tube 28 ₂ on the straight pipe side is expanded, the seal rings 8 ₁ , 8 ₂ are fixed, and then the rubber tube 28 on the elbow side is expanded.

At this time, the seal ring joint 10 ₁ ,
The seal rings 8 ₁ and 8 ₂ are moved by the movement of the bolt 11 in the elongated hole 12 of 10 ₂ . For example, pipe 7
When there is a difference in wall thickness between ₁ and 7 _2, the expansion rings 5 ₁ and 6 ₁ ... and the expansion rings 5 ₂ and 6 ₂
... move separately and surely bring the seal rings 8 ₁ and 8 ₂ into contact with the inner surfaces of the pipes 7 ₁ and 7 ₂ .

On the other hand, when the inert gas is supplied from the inlet 26, the space between the seal rings 8 ₁ and 8 ₂ is filled with the inert gas. In this state, welding is performed at the groove of the abutting portion of the pipes 7 ₁ and 7 ₂ to prevent oxidation. In any layer after the second layer, the flow of the shield gas is stopped and a cooling gas such as air or nitrogen is caused to flow instead to prevent the welding bead from overheating due to heat input in the subsequent pass of the welding bead.

When the clamp is passed through the elbow or when the clamp is expanded, it is necessary to adjust the height of the caster located on the side opposite to the operator to bring the pipe and the caster into the joint. Is the connecting part 37 ₁ ...
At 37 ₄ , the support rod 4 is removed, and the operator moves in or out, or the hands are put in or out to adjust the height of the casters.

After the welding is completed, if the supply of the inert gas or the cooling gas is stopped and the supply of the pressure fluid to the rubber tubes 28 ₁ , 28 ₂ is stopped, the coil springs 15 ₁ , 1
5 Each expansion ring ₂ of contractile force 5 _1, 6 _1,
5 ₂ , 6 ₂ ... are reduced while discharging the fluid of the rubber tubes 28 ₁ , 28 ₂ , and each expansion ring 5
_1, 6 _1, 5 _2, 6 ₂ ... reduced in a state where each end is in contact with the ends. After that, it is moved to the next pipe butt portion.

At the time of this movement, when passing through the elbow that is bent in the horizontal direction, the support rod 4 is rotated in the axial direction with respect to the connecting rod 33 and is passed therethrough.

[0028]

EFFECTS OF THE INVENTION Since the present invention has the above-described structure and operation, the seal ring can be securely provided even if the expansion and contraction of the expansion rings on both sides causes the pipes on both sides to have different wall thicknesses. The groove can be welded by contacting the inside of the pipe and sealing the inert gas.

Further, since the two clamps respectively connect the support rods so as to be rotatable in the axial direction, the pipes can be passed even if they are elbows, and the pipe axis is inclined with respect to the ground. However, the clamps on the target side can be easily set after being held by the clamps on the anchor side. During welding, it is possible to prevent oxidation by supplying an inert gas, ensure the quality of the weld metal by the cooling gas, and prevent deformation of the welded portion.

[0030]

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of an internal clamp for piping and a welding method according to the present invention.

FIG. 2 is a side view with a part cut away.

FIG. 3 is a cross-sectional view showing portions of a main body ring and an expansion ring.

FIG. 4 is a plan view of an expansion ring.

FIG. 5 is a side view with a part cut away.

6 is a sectional view taken along the line BB of FIG.

FIG. 7 is a plan view showing the relationship between the flat portion of the support rod and the partition wall.

[Explanation of symbols]

1 Main body ring 2 Partition wall 3 ₁ division room 3 ₂ division room 4 Support rod 5 ₁ Expansion ring 5 ₂ Expansion ring 5 ₃ Expansion ring 5 ₄ Expansion ring 6 ₁ Expansion ring 6 ₂ Expansion ring 6 ₃ Expansion ring 6 ₄ Expansion Ring 7 ₁ Piping 7 ₂ Piping 8 ₁ Seal ring 8 ₂ Seal ring 9 Bolt 10 ₁ Seal ring joint 10 ₂ Seal ring joint 11 Bolt 12 Long hole 13 ₁ Inner joint member 13 ₂ Inner joint member 14 ₁ Spring pin 14 ₂ Spring pin 15 ₁ Coil spring 15 ₂ Coil spring 16 Wire mesh 17 Metal plate 18 Cut and raised part 19 Coil spring 20 Wire 21 ₁ Inner line 21 ₂ Inner line 22 Center pin 23 Pipe 24 ₁ Stopper pipe 24 ₂ Stopper -Pipe 25 ₁ Stopper 25 ₂ Stopper 26 ₁ Bolt 26 ₂ Bolt 26 'Inlet 27 Flat part 28 ₁ Rubber tube 28 ₂ Rubber tube 29 ₁ Supply pipe 29 ₂ Supply pipe 30 ₁ Mounting member 30 ₂ Mounting member 30 ₃ Mounting member 30 ₄ Mounting member 31 ₁ Caster 31 ₂ Caster 32 ₁ Large diameter part 32 ₂ Large diameter part 32 ₃ Large diameter part 32 ₄ Large diameter part 33 Connecting rod 34 ₁ Hinge member 34 ₂ Hinge member 35 ₁ Hinge holding material 35 ₂ Hinge holding material 36 ₁ seal plate 36 ₂ seal plate 37 ₁ connection part 37 ₂ connection part 37 ₃ connection part 37 ₄ connection part A clamp

Claims (3)

[Claims] 1. An arc-shaped main ring, which has a channel-shaped cross section and is divided into two division chambers by a partition wall in the axial direction, and each division chamber is divided into a plurality of portions in the circumferential direction. Insert the expansion ring with the cross-section channel type of
Attach a coil spring that abuts the end of each expansion ring to the protruding spring pin on each expansion ring, fix the seal ring that contacts the inner surface of the pipe to each expansion ring on both sides, and seal the end of each seal ring. Fix the ring joint,
The seal ring join is slidably attached to the ends of the opposing seal rings, and a ring-shaped expandable rubber tube is built in each of the compartments to increase the diameter of each expansion ring independently. An internal clamp for piping that has been characterized. 2. The inner surface of the body rings of the two clamps is supported by a hollow cross-shaped support rod, and the two clamp vertical support rods are rotated by a hinge member and a hinge holding member provided at both ends of the connecting rod. The internal clamp for piping according to claim 1, wherein the two clamps are connected so as to be held so that they can be held. 3. A welding shield gas is flowed between both seal rings of the internal clamp of claim 1 to prevent oxidation of the inner surface of the weld bead of the first layer and to pass a shield gas in any layer after the second layer. A welding method characterized in that a cooling gas such as air or nitrogen is caused to flow instead of stopping to prevent the welding bead from overheating due to heat input in the subsequent pass of the welding bead.