Note: Descriptions are shown in the official language in which they were submitted.
1079815
The invention relates to apparatus for the welding
of hollow elongated products, and more specifica]ly to mach-
ines for the resistance butt welding of pipes by fusion.
The field of the preferred application of the inven-
tion is the welding of big-bore pipes where the invention may
be employed either in the form of a movable machine welding
individual pipes into a continuous string directly on the site
of laying a pipeline or in the form of stationary equipment
of a field plant located close to the site to supply extended
pipe lengths.
There are known in the art machines for the resis-
tance butt welding of pipelines which are used only for the
welding of individual pipes into a continuous string. Also
known is resista~ce welding equipment finding application only
as a means of joining individual pipes into extended pipe
lengths at field plants.
Further known is a machine for the resistance butt-
; welding of pipes hy fusion comprising a welding transformer
with current leads, said transformer embracing the pipes
~0 welded from the outside, and a manipulator disposed insidethe pipes welded for the purpose of aligning and moving same
in course of welding, said manipulator incorporatlng align-
ing units - one moving relatively to the manipulator body
and the other not - with radially disposed clamps holding
fast the pipes welded and hydraulic cylinders actuating said
pipe clamps,
- 1079815
a rod for moving the manipulator with respect to the welded
joints of pipes and a hydraulic system for feeding and con-
trolling the clamps of the pipes welded as well as a means
of moving the pipes in course of welding. In the known ma-
chine, said hydraulic system of feeding and controlling is
located outside the pipes welded, is bulky and exceeds in
its size the inside diameter of the pipes welded. If the
known machine is used for welding individual pipes into a
continuous pipeline in the field, said hydraulic system of
feeding and control must be disconnected on welding a joint
from the manipulator disposed inside the pipe, hauled to the
next joint and again connected to the manipulator to perform
the next welding cycle. Since all the operations involved
are ardous and labour-consuming, practically it is expedient
to employ the known machine as a stationary equipment for
welding individual pipes into extended pipe lengths.
Another disadvantage of the known machine is the
difficulty experienced in repairing the machine and rendering
it serviceable. The point is that the manipulator body it-
self performs the function of the piston rods of the hydraulic
cylinders actuating the clamps holding fast the pipes welded.
In this case, the breal~down even of a single hydraulic cylin-
der actuating a pipe-holding clamp calls for its repair in
the situ, entailing complete disassembly of the manipulator
or the replacement of at least one of the aligning units.
- . . . . . .. . ~ . . ~ .
107981S
Since the repair of a hydraulic system in situ, particularly
in the field, poses numerous difficulties and is undesirable
the only way out is to replace an entire portion of the
machine wherein most of the components retain their service-
ability.
The main object of the present invention is to
provide a machine for the resistance butt welding of pipes
constructed so that it can be easily employed not only as a
stationary facility but also as a movable one adapted to
cope with the welding of individual pipes into a continuous
pipeline directly in the field.
Another object of the present invention is to
provide a machine for resistance butt welding of a layout
which ensures rapid withdrawal of hydraulic actuating
cylinders and their replacement by spare ones in the field
without taking apart the welding manipulator,
In accordance with an embodiment of the invention,
a machine for the resistance butt welding of pipes by fusion
comprises: a welding transformer embracing the pipes welded
.,
from the outside; current leads of said welding transformer;
a manipulator which serves the purpose of aligning,and moving
the pipes welded in course of welding, is disposed inside the
pipes welded and incorporates: a body of said manipulator;
an aligning unit mounted movably with respect to said body
~of manipulator, an ali~ning unit mounted immovably with
.~ .
~. ,.
.
. . - : . .
~15
respect to said body of manipulator and insulated electric-
ally fro~ said body of manipulator, clamps of the pipes
welded disposed radially in said movable and immova~le
aligning units, hydraulic cylinde~rs of said clamps of the
pipes welded, means of moving the pipes in course of weld- :
ing, hydraulic cylinders of said means of moving the pipes,
the bodies of said cylinders being immovably attached to
said body of said movable aligning unit between said
hydraulic cylinders which are mounted on said aligning unit
and actuate said clamps of one of the pipes welded, piston
rods of said hydraulic cylinders of said means of moving the
pipes in course of welding, said piston rods being immovably
attached to said body of manipulator, a hydraulic system
for feeding and controlling said hydraulic cylinders actuat-
ing the clamps of the pipes welded and said means of moving
the pipes, a rod for moving said manipulator relatively to
the welded joints of pipes, said rod being immovably attached
to said body of manipulator and made hollow a partition sub-
dividing longitudinally the bore of said rod into two spaces,
one intended to be filled with a working fluid and the other
accommodating on said partition said hydraulic system for
feeding and controlling the actuators of said clamps of the
pipes welded and said means of moving the pipes.
By virtue of the fact that the rod is immovably
attached to the body of manipulator, is made hollow and is
:;
, .
1079815
subdivided longitudinally by the partition into two spaces,
there is a possibility to fill the lower space with a work-
ing fluid and to accommodate in the upper a hydraulic system
for feeding and controlling the actuators o~ the clamps
holding ~ast the pipes welded and the means o~ moving~ the
pipes in course o~ welding.
Since the means of moving the pipes in course o~ weld-
in~ consists o~ a number of hydraulic cy].inders whose bodies
are immovably attached to the body of` the movable aligning
unit between the h~draulic cylinders which are mounted the-
reon and actuate the clamps holding fast one o~ the pipes
welded, there is a possibility to unitize the h~draulic
cylinder~ moving the pipes with those holding these f'ast on
one hand and to create conditions enablin~ a rapid removal
o~ any of' the hydraulic c~linders in the event o~ breakdow~
and the replacement of it by a spare one on the ~ther hand.
It is expedient that the body o* each aligning unit is
given the form o~ a cylinder placed inside another cylinder,
both cylinders being interconnected at the end faces, and
that the hydraulic cylinders actuating the clamps o~ the
pipe~ welded are attached to the outside cylinders whereas
mounted on the inside cylinder with provision for travel
along its axis there is a cone which is rigidly attached
to the piston rods o~ said hydraulic cylinders and interacts
with the pipe clamps receiving support therefrom. Owing to
.
. :
, ~
.
: : .
, .
~079815
said arrangement of aligning unit, the reliability of the
manipulator is enhanced and the movable aligning unit can
be unitized with its immovable counterpart so that the re-
pairability of the manipulator in the field is consequently
promoted.
The present invention will be best understood from
the following detailed description of a preferred embodiment
of the invention when this description is being read in con-
junction with the accompanying drawings in which: .
Fig. 1 is a general view of the machine for the
resistance butt welding of pipes according to the invention ...
used a stat.ionary equipment for welding individual pipes
into extended pipe lengths,
Fig. 2 is a general view of the same machine adaptedfor welding either individual pipes or extended pipe lengths
into a continuous pipeline,
Fig, 3 is a section on line I-I of Fig. 2,
The machine for the resistance butt welding of pipes
disclosed comprises a welding .transformer 1 (Fig. 1) with
current leads 2, said transformer embracing pipes 3--and 4
welded from the outside, and a manipulator 5 disposed inside
`; the p.ipes 3 and 4 welded, The welding manipulator 5 incorpo-
rates a rod 6 immovably attached to a body 7 of the manipu-
. lator 5 disposed whereon are an aligning unit 8 and an
aligning UIlit 9 which are made movable and immovable, res-
1079815
pectively, relatively to the manipulator body 7 and serve
to hold ~ast the pipes 3 and 4 welded.
~ he i~nmovable aligning~ unit 9 is secured to the body 7
of the manipulator 5 by means of two ring hal~es 10 and an
end plate 11. ~he manipulator bod~ 7 is electrically insulat-
ed from the aligning unit 9 by sleeves 12 and a washer 13.
Attached to outside cylinders 14 of the bodies of the align-
ing units 8 and 9 are hydraulic cylinders 15 actuating clamps
16 which hold fast the pipes 3 and 4 welded. Piston rods 17
of the hydraulic c~linders 15 are connected to ccnes 18 moun-
ted o~ inside cylinders 19 of the bodies of the ali~ning
units 8 and 9 with provision for travel along their a~is.
~he side surfaces o~ the cones 18 provide support for the
clamps 16 capable of moving in radial grooves of the outside
cylinders 14 of the bodies of the aligning units 8 and 9.
~he number of the clamps 16 provided in the aligning units 8
and 9 depends on the diameter of the pipes welded. ~he clamps
16 are pressed against the side surfaces of the cones 18 by
the action of return springs 23 diæposed in longitudinal
grooves. Each of the return springs 20 abuts the bottom of
the corresponding clamp 16 with one of its ends and a bar
21 with the other end, said bar being disposed in a transver-
se groove of the clamp 16 and rigidly attached to the outside
cylinder~ 19 vorming the bodies of the aligning units 8 and
9-
-- 7 --
. .
.
.
'' ' .
.
,
1079815
'L'he movable aligning unit 8 is displaced relatively tothe manipulator body 7 with the aid of a means of moving
the pipes in course of welding which is a mechanism made
up of a number o~ hydraulic cylinders 22 whose bodies are
immovably attached to the outside cylinder 14 of the body
o~ the movable aligning unit 8 between the hydraulic cylin-
ders 15 actuating the clamps 16 holding fast the pipe 3 whe-
reas the pi~ton rod~ 23 of the hydraulic cylinder~ 22 are
immovabl~ attached to the ~ody 7 of the manipulator 5. ~he
rod 6 serving to move the manipulator 5 with respect to the
pipes 3 and 4 welded is immovably attached to the body 7.
~he rod 6 is made hollow and ~itted with a partition 24
subdividing longitudinall~ the rod bore into two spaces.
While the lower space 25 o~ the rod 6 serves as a reservoir
for the ~luid used in the hydraulic system o~ the manipula-
tor 5, the upper space 26 of the rod 6 accommodates on the
partition 24 a hydraulic system 27 which serves the purpose
of feeding and controlli~g the hydraulic c~linders 15 ac-
tuating the clamps 6 o~ the pipes 3 and 4 welded and also
the hydraulic cylinders 22 mo~ing the pipes 3 and 4 in
course o~ welding. Hinged co~er plates 28 are fitted to the
rod 6 to prevent ~oreign articles and sludge ~rom entering
the hydraulic system 27.
~ he external items of the welding machine, i.e., the
trans~ormer 1 and the current leads 2, are secured to a roll
-- 8 --
, ~
~079~15
table 29 which, dependin~ on the conditions, is either
placed on the ground if the machine is used as a stationary
plant or is suspended ~rom a pipe-laying boom or a~y other
handling means i~ the machine is employed in its movable
application. ~he manipul~tor 5 is provided with several
~airs o~ wheels 30 which rest on the pipes 3 and 4 welded
and serve to move the manipulator 5 relatively to the pi-
pes. ~he wheels 30 in each pair are arranged one with res-
pect to the other so as to form an angle o~ 60-90 deg.
When operating under stationary conditions for joining
individual pipes i~to extended pipe lengths as shown in
Fig. 1, the manipulator 5 is secured with one o~ its ends in
a bearing 31 resting on a bracket 32 which is held ~ast to
the roll 3~able 29. r~he other poin-t of support for the mani-
pulator 5 is provided in the ~orm of a plate 33 which is
fitted to the rod 6 o~ the manipulator 5 and comes abutting
against a aack 34 i~ the pipe 3 is absent. In a stationary
application o~ the weldin~ machine, the pipes are moved re-
latively to the manipulator 5 by means o~ rollers 35 of the
roll table 29, said rollers obtaining motion ~rom a drive
(not shown in ~ig~ 1).
In case the welding machine is employed ~or joining pi-
pes into a continuous pipeline as shown in ~'ig~ 2, the ma-
nipulator 5 can be moved ~rom joint to joint by various
means as, ~or example, a tractor hitched to the rod 6 or
the power-driven wheels 30.
g _
107981~
.
The machine operates on the ~ollowing lines. Bef`ore
welding is started, the aligning units 8 and 9 are set
apart a~ far as possible. ~or welding under stationary condi-
tions (see Fig. 1), the pipe 3 is fed by the rollers 35 of
the roll table 29 towards the manipulator 5 until it reaches
the jack 34. At this instant the jack 34 is lowered and the
manipulator 5 enters the pipe 3 with its ~ront wheels 30
and then the travel of the pipe 3 down the roll tahle 29
towards the bracket 32 is resumed, continuing until the
right-hand end ~ace of the pipe, as shown in the drawing,
is midway between the aligning units 8 and 9. At this stage,
the clamps 16 of the aligning unit 8 are applied to the pipe
3 by ~dmitting working ~luid into the spaces A o~ the hyd-
raulic cylinders 15 o~ the aligning unit 8 whereas the ~luid
contained in the spaces B o~ said cylinders is drained into
the lower space 25 of the rod 6. As a result, the cone 18
con~ected to the piston rods 17 of the hydraulic cylinders
15 moves in the aligning unit 8 to the ri~ht according to
the drawing so that its side surface ~orces the clamps 16
o~ the aligning unit 8 apart~ this action applyi~g the
clamps to the pipe 3 which is consequently held ~ast. Next,
tho pipe 4 is placed on the roll table 29 and b~ the rollers
35 into a position where it co~tacts the pipe 3 and must be
clamped by the clamps ~6 of the aligning unit g. To that end,
working ~luid is admitted into the spaces A o~ the hydraulic
- 10
..
1079B15
cylinders 15 of the alig~ing~ unit 9 whereas -the fluid con-
tained in the spaces B o~ said cylinders is drained into the
space 25. AS a result~ the cone 18 of the aligning unit 9 : -
connected to the piston rods 17 of the hydraulic cylinders
15 moves in the ali~nin~ unit 9 to the left according to
th~ drawin~ so that its side surface forces the clamps 16
of the aligning unit 9 apart, this action applyin~ the
clamps to the pipe 4 which is consequently held fast.
Since the aligning~ units 8 and 9 are of the same size
and are accommodated on the same body 7~ the clamping of
the pipes 3 and 4 brings said pipes into alignment one with
the other. Once the pipes are clamped, the current leads 2
~rom the welding transformed 1 are applied to the pipes and
the current is cut in~ After that, working Yluid is admit-
ted into the spaces C of the hydraulic cylinders 22 accord-
ing to a special programme, using the system 27 o~ ~eeding
and control, whereas the fluid contained in the space D is
drained into the lower space 25 of the rod 6. This causes
the bodie~ of the hydraulic cylinders 22 to start moving
integrally with the aligning unit 8 and the pipe 3 so as to
enable the process o~ resistance butt welding by fusion to
take place.
0~ completing the process of welding finished by upset-
ting, workin~ fluid is admitted into the spaces B of the
hydraulic cylinders 15 of the aligning units 8 and 9 whereas
-
10'79815
the ~luid contained in the spaces A of said cylinders i~
drained into the space 25 of the rod 6. The distance between
the coneæ 18 of the aligning units 8 and 9 consequently in-
creases and the clamps 16 o~ the aligning units 8 and 9 move
inwardly towards the axis of the body 7 of the manipulator
5 under the action of the springs 20, releasing thus the
hold on the pipes 3 and 4 welded. On removing the current
leads 2 o~ the welding transformer 1 ~rom the pipee 3 and 4
welded, ~luid is admitted into the spaces D of the hydraulic
cylinders 22 wheres the Yluid contained in the space~ C o~
said cylinders is drained into the space 25. This causes the
aligning units 8 and 9 to move apart and the pipes 3 and 4
welded, which are in fact a double-length section, are car-
ried by the roller~ 35 o~ the roll table 29 to the right,
leaving the welding machine. As soon as the left-hand end
face o~ the double-length pipe ~ection passes the jack 34 on
its way to the right, said jack is li~ted, giving support
to the manipulator 5 which rests thereupon with the plate
33. ~he double-length pipe section continues its right-
ward travel, giving way to the next pair of pipes, and the
welding cycle is then repeated.
If the welding machine is used for joi~ing individual
pipes into a continuous pipeline (see Fig. 2), the welding
manipulator 5 is moved by some means o~ handling, a tractor
~or example, in ~he pipe 4 through the intermediary of the
12 _
~ . ..
,
' ~ '
1079815
rod 6 as far as this is necessary to place -the left-harld end
~ace of said pipe midway between the ali~ninOr units 8 and 9.
~he clamps 16 of the ali~ning unit 9 take hold o~ the pipe
4 in the same sequence of events as described above and then
a next pipe 3 is fed onto the manipulator 5, using the pipe-
-laying boom, by an amount ~-Jhich places the pipe 3 in con-
tact with the pipe 4. On clampingr the pipe 3 with the clamps
16 of the alig~in~ unit 8, the roll table 29 is moved with
the aid o~ the pipe-laying boom -to the le~t so that the
joint between the pipes 3 and 4 is midway between the cur-
rent leads 2 of the trans~ormer 1. Next, the current leads
2 of the welding transformer 1 are applied to the pipes 3
and 4 to be welded and the current is ~witched on to start
the process of resistance but welding by continuous ~usion
which goes on as des¢ribed above. On completin~ the welding,
the pipes 3 and 4 are released of both the clamps 16 of -the
aligning units 8 and 9 and of the current leads 2 and 1. ~he
aligning units 8 and 9 are moved apart to set the welding
machine into starting poisition, the welding manipulator 5
is transfered to the le~t-hand end face of the pipe 3, using
the handling means a~ailable t and then the welding cycle is
repeated.
- 13
'
.
