JPH0336630B2 - - Google Patents

Description

Nut 5 of lead screw nut pair 28.
The welding device according to claim 1 or 2, characterized in that the welding device (5) is firmly connected to the housing (22) of the hydraulic cylinder (20).

[Detailed description of the invention]

[Industrial Application Field] The present invention is applicable to pipes, especially small and medium diameter pipes (550mm
The present invention relates to a resistance butt welding device for pipes, and more particularly to a resistance butt welding device for pipes that can be attached from the outside of the pipe to be welded. The invention is applicable to the construction of oil and gas trunk pipelines in the field of oil and gas production and distribution.

[Conventional technology]

The quality of welds produced by resistance butt welding largely depends on the reliability of the clamping of the pipes during welding and the accuracy of the mutual alignment of the pipes. The known apparatus for resistance butt welding of pipes (Su, A, 251719) includes a device for clamping and aligning the pipes during welding, the clamping and aligning devices being provided in each half-housing of the welding apparatus. , mounted on the pipe being welded on both sides of the pipe joint, and operably connected to the flash assembly drive.

Each tightening device includes a tightening die or shoe, which are arranged in two half-rings equally spaced around the circumference of the pipe, the two half-rings enclosing the pipe from two directions and applying hydraulic pressure. Under the action of the cylinder moves in a circular path in the opposite direction.
The half rings are operably connected to the hydraulic cylinder housing via pivoted rods. The operative connection between the half-rings and the shoes is via cam rollers that are press-fitted into the half-rings and pressed against the sloping back surface of each shoe.

When the two half-rings move in opposite circles in a synchronized state maintained by a synchronizer that ensures the accuracy of the center position of the hydraulic cylinder during operation, the cam roller engages the inclined surface of the shoe. drives the shoe uniformly toward the center to tighten and center the pipe.

A disadvantage of this known device is that large energy losses occur due to friction when the cam roller engages the sloped surface of the shoe and when the half rings move within each half housing.

In order to offset this energy loss due to friction, the hydraulic cylinder must be able to provide a sufficiently large tightening force, which inevitably increases the size of the hydraulic cylinder.
The overall size of the device increases.

Moreover, in this known device, the hydraulic cylinder supplying the tightening force is located at a considerable distance from the area of application of the force, so that the tightening device is complicated by additional holding mechanisms and large locking devices. It is.

In another known apparatus for resistance butt welding of pipes (Su, A, 351423), the clamping and alignment of the pipe during welding is carried out by two separate mechanisms of the clamping apparatus. That is, an alignment mechanism and a tightening function are installed on the inside and outside of the pipe being welded, respectively.

The alignment mechanism includes a centering shoe attached to a central carrier bar insertable into the pipe and operably connected to the radial displacement drive, and a centering shoe attached to the axial displacement drive via a lever and holder. and a centering roller.

The clamping device for mounting on the outside of the pipe includes a clamping die or shoe mounted on the end face of the housing of a radially arranged hydraulic cylinder whose respective piston rod is secured to each half housing of the welding device. This tightening shoe applies a tightening force to the outer surface of each pipe.

The hydraulic cylinders of each of the inner centering mechanism and the outer tightening mechanism have common controls.

This known device has less energy loss due to friction than the above-mentioned known device, and the hydraulic cylinder can be made smaller. Since the tightening mechanism and the alignment mechanism are separate, the structure responsible for these functions is simpler, and this, together with the smaller size of the hydraulic cylinder, allows the overall size of the welding device to be smaller. This welding device has high tightening reliability and sufficient accuracy in mutual centering of pipes for thin-walled pipes with relatively large diameters, but for small and medium diameter pipes (up to 550 mm), the insertion of the tightening device is This is inappropriate because the flexible part cannot be fitted into the pipe.

Furthermore, because the overall weight of the welding equipment is relatively large, the handling equipment for setting the pipe installation equipment and other welding equipment in the operating position must have a large load-bearing capacity.

Moreover, this welding device, in which the tightening device has an insertable (inner) part and an outer part, is laborious and time-consuming to set into a pipe joint, thereby reducing the efficiency of pipeline construction.

[Problem to be solved by the invention]

The present invention reduces the overall size and weight as well as shortens the auxiliary work time by optimizing the arrangement of each member of the control valve of the hydraulic cylinder control device and newly connecting these members. did,
The purpose of the present invention is to provide a resistance butt welding device for pipes.

[Means to solve the problem]

The above objects, according to the invention, provide a half-housing that can be attached to the pipe to be welded from the outside on both sides of the pipe joint, a welding transformer, a flash and an upset drive operatively connected to said half-housing. , each piston rod being rigidly connected to each half-housing and provided with a shoe capable of applying a clamping force to the outer surface of each of said pipes;
A pipe resistance butt welding device comprising a plurality of radially arranged hydraulic cylinders, and a control device for the hydraulic cylinders, wherein the control device for the hydraulic cylinders includes a piston rod of each hydraulic cylinder as a component. This is achieved by a resistance butt welding device for pipes, characterized in that it includes: a control valve arrangement with a trailing spool valve; and a common drive device for driving said trailing spool valve.

By providing a common drive for the trailing spool valve of each tightening device, it is possible to synchronize the movement of the hydraulic cylinder and the tightening shoe for each half-housing, so that these shoes can be used only for tightening the pipes to be welded. It can also be used to align pipes within operatively interconnected half-housings. As a result, it is no longer necessary to align the pipes to be welded from the inside, which eliminates the need for a conventional type of alignment mechanism, which reduces the overall weight of the welding equipment and makes it easier to set the welding equipment in the working position. The time required to do so can also be reduced. Furthermore, the apparatus of the present invention is a resistance butt welding apparatus that can be applied to small and medium diameter pipes in which it is not possible to insert the above-mentioned insertion type centering mechanism into the pipe. The weight reduction due to the miniaturization of the entire welding equipment is
A further improvement is achieved by including the piston rod of the hydraulic cylinder as a component in the control device.

In order to reduce the overall size of the welding device, the trailing spool valves are preferably connected to each other and to a common drive via a mechanical coupling device that includes a universal joint shaft.

If this operable connection were to be made by other means, such as a central gear cooperating with a pinion connected to each spool valve, the welding equipment would be mechanically complex, bulky, and heavy. .

A trailing spool valve of each control valve arrangement includes a valve member axially displaceable within the piston rod of each hydraulic cylinder and a valve resiliently pressed axially with respect to the piston rod of each hydraulic cylinder and against the end face of the lead screw. A lead screw with a lead screw displaceably mounted coaxially with the component.
Preferably, the lead screw-nut pair includes a nut pair, and the nut of the lead screw/nut pair is firmly connected to the housing of the hydraulic cylinder.

The control valve device has a structure other than the above,
For example, a rack and pinion mechanism is possible, but what is required is that one member of the mechanism (e.g. the pinion) is connected to the housing of the hydraulic cylinder and the other member (e.g. the rack) is connected to the piston rod of the hydraulic cylinder. is connected to.

Hereinafter, by way of example with reference to the accompanying drawings:
The present invention will be explained in more detail.

〔Example〕

The pipe resistance butt welding apparatus of the present invention shown in the accompanying drawings includes a pair of pipes 3 and 4 to be welded, on both sides of a pipe joint 5.
It comprises two half-housings 1 and 2 (FIG. 1) adapted for mounting from the outside. Originally, housing halves 1 and 2 were connected to line C-C (Figs. 2 and 3).
A member 6 that is removable along the pipes 3 and 4 (Fig. 1) and covers the pipes 3 and 4 (Fig. 1) from opposite sides, respectively.
and 7, the members 6 and 7 being pivotably mounted towards each other about a common pivot 8 (FIGS. 2 and 3). Lock 9 (Figure 2) is half housing 1
and 2 (FIG. 1) are secured together in a closed position.

Half housings 1 and 2 have a mechanism 10 for opening
(Fig. 2), and this mechanism 10 includes:
It includes a hydraulic cylinder 11 mounted within a holder 12 which is operably connected to members 6 and 7 (FIG. 2) of each half-housing via a pivotably supported rod 13. The piston rod 14 (FIG. 3) of the hydraulic cylinder 11 is firmly fixed to the pivot 8.

The half-housing 2 (FIG. 1) has a welding transformer 15 mounted thereon and a flash assembly drive comprising two hydraulic cylinders 16 whose piston rods 17 are rigidly fixed to the half-housing 2. . Hydraulic cylinder 16 extends retained through crosspiece 18 (FIGS. 1-3). A bar 19 attached to the crosspiece 18 is firmly fixed to the housing half 1 and is connected to an opening (not shown) in the housing half 2.
extends through.

Half housings 1 and 2 are connected to hydraulic cylinders 20
(FIGS. 2 and 3). The geometrical axis of this hydraulic cylinder 20, when the housing halves 1 and 2 (FIG. 1) are in the closed position, is aligned with the clamped pipe 3.
and 4 and are preferably equiangularly spaced with respect to these pipes 3 and 4.

Rod 21 of each hydraulic cylinder 20 (Fig. 4)
is rigidly fixed to the half housing 1 or 2 (FIG. 1), and the removable housing 22 (FIG. 4) of each hydraulic cylinder 20 has a shunt at the end opposite to the protruding piston rod 21. 23 is attached. The shoe 23 engages and clamps the pipe 3 or 4 (FIG. 1) and supplies welding current from the respective welding transformer 15 to the pipe 3 or 4. The power supply 23 is connected to the transformer 1 via a flexible power cable (not shown).
5.

According to the present invention, the control system for the hydraulic cylinder 20 includes a control valve arrangement having follower spool valves 24 (FIG. 4), each follower spool valve 24
is a spool valve member 2 mounted within a valve housing 26 for axial reciprocating motion.
Contains 5. The valve housing 26 is connected to the piston 2
7 and lead screw nut pair 2 having lead screw 29
8 is press-fitted into the piston rod 21 of each hydraulic cylinder 20, which is made integrally with the hydraulic cylinder 8.

The valve housing 26 has a large diameter peripheral hole 3 for mounting the valve member 25 therein.
A cylindrical blind hole 30 having numbers 1 and 32 is made inside. The piston rod 21 is provided with a pressure transmission connector 33 and a drain connector 34 that protrude to the outside. Pressure transmission connector 33
communicates with the bore 30 via a pressure passage 35 made in the piston rod 21 and the valve housing 26, the outlet 36 of the passage 35 communicating with the bore 30 located between the two circumferential bores 31 and 32. There is.

The drain connector 34 communicates with the hole 30 via a drain path 37 and the inlets 38 and 39 from the hole 30 to the drain path 37 are on the opposite side of each peripheral hole 31 and 32 with respect to the outlet 36 of the pressure path 35. It is set in. Furthermore, the hole 3 in the area of the peripheral hole 31
0 to the space D above the piston of the hydraulic cylinder 20, and the hole 30 in the area of the peripheral hole 32.
A passage 41 communicating with the space E below the piston of the hydraulic cylinder 20 is made through the walls of the piston rod 21 and the valve housing 26. Piston rod 21 and valve housing 2
Paths 35, 37, 40 made through the walls of 6;
and 41 form a control valve device for each hydraulic cylinder 20 in cooperation with the other members of the follower valve 24 listed above.

The spool valve member 25 includes shoulder portions 42, 43, 44, and 45 that are cylindrical and have a large diameter.
and a narrow tail portion 46 facing the space D above the piston in front of the outermost shoulder portion 45. The two intermediate shoulder portions 43 and 44 have the same or slightly larger width than the peripheral holes 31 and 32, respectively, and
and 32 intervals.

Each pressure transmission connector 33 of all hydraulic cylinders 20 of the two tightening devices is connected to a pump (not shown) and a respective drain connector 34
is connected to a drain tank (not shown).

The follower valve 24 of each hydraulic cylinder 20 of each tightening device is drivably connected to a common drive provided on each housing half 1 or 2 (FIG. 2) with a worm gear reduction device 48.

Each lead screw 29 of all follower valves 24 of each tightening device is interconnected via each bevel gearing 49 (FIG. 4) and universal joint shafts 50 and 51 (FIGS. 2 and 3). and connected to a common drive. Shafts 50 and 51 are connected to universal joint 52 (fourth
(Fig.) is connected to the input shaft of each bevel gear device 49. One of the universal joint shafts 50 (FIGS. 2 and 3) is attached to the worm wheel of the worm gear reducer and acts as its output shaft, while the universal joint shaft in the open part of each half housing 1 or 2 The intoshaft 51 is the coupling 5
3 (which may be any known quick-release coupling) into two parts connectable by. Each lead screw/nut pair 28 (fourth
The lead screw 29 (FIG.) is mounted for axial reciprocating movement within a splined bore of the output shaft of each bevel gearing 49, and this reciprocation is supported by the tail 46 and the valve housing 29.
This movement is coaxial with the valve member 25 pressed against the end face of the lead screw 29 by the compression spring 54 pressed against the bottom of the blind hole 30 of No.6.

The nut 55 of the lead screw/nut pair 28 is secured to the housing 22 of the hydraulic cylinder 20 by a strap 56 and a threaded pin 58, and the housing of each bevel gear 49 is secured to the housing 22 of the hydraulic cylinder 20 by a strap 56 and a threaded pin 58.
and is fixed to each half housing 1 or 2 with a nut 61 via a threaded pin 60.

[Operation]

The operation of the pipe resistance butt welding apparatus of the present invention will be described below.

The device of the invention is suspended from a pipe laying device (not shown) in the open state (FIG. 3) and attached to the end of the pipe (3 or 4) to be welded at the leading edge of the pipeline under construction. , a half-housing 2 is arranged projecting from this pipe (for example pipe 3). Next, set the other pipe to be welded (for example, pipe 4) against the former pipe (pipe 3).
The end of the latter pipe (pipe 4) is now in the half housing 2.

By supplying working fluid under pressure to the area below the piston of the hydraulic cylinder 11 of the half-housing 1, the hydraulic cylinder 11 is driven together with the holder 12 in the direction of the pivot 8 (FIG. 3), thereby causing the rod to move. 13 to tilt the members 6 and 7 of the half housing 1 so that the members 6 and 7 are placed over the pipe 3 and closed. Half housing 1 (Figure 2)
is maintained in the closed position by a lock 9, the two parts of the separate universal joint shaft 51 being connected by a coupling ring 53, thereby coupling the trailing spool valves 24 to each other and to a common drive. The kinetic chain connected to is closed.

Next, the pressurized working fluid is transferred to the pressure transmission connector 33 (the fourth
) and a pressure line 35 into the bore 30 of the valve housing under the annular space delimited by the shoulders 43 and 44 of the valve member 25. At this stage, the valve member 25 is in a neutral position, and the peripheral holes 31 and 32 are closed by shoulder portions 43 and 44, respectively, which are the same or slightly wider in width. By starting the electric motor 47 (Fig. 2), the lead screw 29 (Fig. 4) of the lead screw/nut pair 28 via the worm gear reducer 48 (Fig. 2);
Universal joint shaft 50 and 51
and a bevel gear device 49 of each hydraulic cylinder 20
(Figure 4). While being thus rotated within a nut 55 fixed to the housing 22, each lead screw 29 is moved axially through the spry hole of the output shaft of each bevel gearing 49 from the center of the tightening device toward the periphery. Move to. The valve member 25 is pressed against the end face of the lead screw 29 by the compression spring 24 to follow the movement of the lead screw 29, and has a shoulder portion 42 that engages with the inner wall of the hole 30.
and 45 within the bore 30 of the valve housing towards the position shown in detail in FIG. In this position, an open slit appears between the edges of the peripheral holes 31 and 32 of the bore 30 of the valve housing 26 and the adjacent edges of each shoulder part 43 and 44. As a result, the working fluid is supplied from below the ring-shaped space of the spool valve member 25 into the peripheral hole 31 and from there flows into the space D above the piston of the hydraulic cylinder 20 via the path 40. At the same time, the working fluid filling the space E below the piston of the cylinder 20 passes through the path 41 and the slit between the shoulder 44 and the peripheral hole 32 into the ring-shaped space G between the shoulders 44 and 45 of the spool valve member 25. After flowing into the drain, it enters the drain path 37 via the inlet 39 and further flows from the drain transfer connector 34 to a drain tank (not shown). Piston upper space D (Fig. 4)
The pressure of the working fluid therein moves the housing 22 of the hydraulic cylinder 20 together with the shoe 23 relative to the piston rod 21 fixed to the half-housing 1 towards the pipe 3 which is about to be clamped. Strap 56 together with nut 55,
While moving together with the housing 22 of the hydraulic cylinder 20, the lead screw 29 is pushed in the axial direction. Lead screw 29
The nut 55 is moved in a direction opposite to the displacement of the nut 55 while continuing to rotate under the action of the motor 47.
Move in the direction away from. With the valve member 25 pressed against the end face of the lead screw 29 and acting as a trailing spool valve, it maintains the position shown in FIG. The pressure in the space D above the piston reaches a predetermined value for all the shoes 23 to press the pipe 3 with the required tightening force. As a result, a pressure-operated electrical relay (not shown) within the control system of the tightening device responds and sends a signal to disconnect the power supply circuit to motor 47 (FIG. 2), which in turn causes the lead screw 29 (FIG. 4) to stops rotating.

While the pipe 3 is thus tightened by the action of the hydraulic cylinder 20, the following spool valve 24 is driven synchronously by a common drive, so that the pipe 3 is automatically aligned with the half housing 1. .

The other pipe 4 is tightened in the same manner as the pipe 3 described above by means of a tightening device provided in the housing half 2. Since the housing halves 1 and 2 are interconnected by a bar 19, the pipe 4 to be welded is aligned with the pipe 3 fixed to the housing half 1.

After the two pipes 3 and 4 are thus tightened and aligned, the half-housings 1 and 2
(FIG. 1) are pressed together by the power cylinder 16 of the flash assembly drive, and the pipes 3 and 4 are resistance butt welded in a known manner.

Releasing the tightening device and closing half-housings 1 and 2 after welding is completed is accomplished by rotating the electric motor 47 (FIG. 2) of each tightening device in the opposite direction.
The procedure is reversed by displacing the spool valve member 25 in the opposite direction as shown in the figure. Once the housing halves 1 and 2 (FIG. 1) have been opened, the pipe resistance butt welding device is moved to the next weld location and the tightening, alignment and welding described above is repeated.

The pipe resistance butt welding equipment of the present invention is relatively lightweight and can be used in a wide range of pipe diameters (550mm
It is suitable for welding (including up to), and the pipes to be welded can be reliably tightened and accurately aligned, resulting in high-quality welds.

[Brief explanation of drawings]

FIG. 1 is a side view showing an embodiment of the pipe resistance butt welding apparatus of the present invention, FIG. 2 is a sectional view taken along the line - in FIG. 1, and FIG. 3 is a position shown in FIG. 4 is an enlarged sectional view taken along the line - of FIG. 2 showing the follower spool valve in the neutral position;
FIG. 5 is a further enlarged sectional view of area B in FIG. 4 showing the spool valve displaced from the neutral position, and FIG. 6 is a cross-sectional view of region B in FIG. FIG. 6 is an enlarged sectional view corresponding to FIG. 5 showing a state displaced in the direction; 1, 2... Half housing, 3, 4... Pipe,
5... Pipe joint (joint), 6, 7...
Members of the half housing, 8... Pivot, 9... Lock, 10... Mechanism for opening the half housing, 11...
... Hydraulic cylinder, 12 ... Holder, 14 ... Piston rod, 13 ... Pivot rod, 15 ...
Welding transformer, 16...Hydraulic cylinder, 17...
Piston rod, 18...Cross piece, 19...
... Bar, 20 ... Hydraulic cylinder, 21 ... Piston rod, 22 ... Hydraulic cylinder housing,
23...Show, 24...Following spool valve,
25...Valve member, 26...Following valve housing, 27...Piston, 28...Lead screw/nut pair, 29...Lead screw, 30...Blind hole, 3
1, 32...Peripheral hole, 33...Pressure transmission connector, 34...Drain connector, 35...Pressure path, 36...Outflow port of the path, 37...Drain path, 38, 39...Flow in the drain path entrance, 40,
41...Route, 42, 43, 44, 45...Shoulder part of spool valve member, 46...Tail part, 4
7... Electric motor, 48... Worm gear reducer, 49... Bevel gear device, 50, 51... Universal joint shaft, 52... Universal joint, 53... Quick release coupling, 54... Spring , 55... Nut, 56... Strap, 57... Threaded pin,
58...nut, 59...strap, 60...
Threaded pin, 61...nut.

Claims (1)

Claims: 1 housing halves 1 and 2 attachable from the outside on both sides of the pipe joint 5 to the pipes 3 and 4 to be welded; a welding transformer operably connected to said housing halves 1 and 2; a radial flashing and upset drive, with a respective piston rod 21 rigidly connected to each housing half 1 and 2, and equipped with a shoe 23 capable of applying a clamping force to the outer surface of each of said pipes 3 or 4; A pipe resistance butt welding device comprising a plurality of arranged hydraulic cylinders 20 and a control device for the hydraulic cylinders 20, wherein the control device for the hydraulic cylinders 20 constitutes a piston rod 21 of each hydraulic cylinder 20. An apparatus for resistance butt welding of pipes, characterized in that it comprises: a control valve arrangement having a trailing spool valve 24 as a member; and a common drive device for driving said trailing spool valve 24. 2. The follower spool valves (24) are connected to each other and to the common drive device via a mechanical coupling device comprising universal joint shafts (50 and 51).
Welding equipment as described. 3 a valve member 2 in which the trailing spool valve 24 of each said control valve arrangement is axially displaceable within the piston rod 21 of each said hydraulic cylinder 20;
5, and the piston rod 20 of each hydraulic cylinder 20.
a lead screw having a lead screw 29 displaceably mounted axially with respect to and coaxially with a valve member 25 resiliently pressed against the end face of the lead screw;