CA1111913A - Plasma-arc welding and cutting machine - Google Patents
Plasma-arc welding and cutting machineInfo
- Publication number
- CA1111913A CA1111913A CA298,870A CA298870A CA1111913A CA 1111913 A CA1111913 A CA 1111913A CA 298870 A CA298870 A CA 298870A CA 1111913 A CA1111913 A CA 1111913A
- Authority
- CA
- Canada
- Prior art keywords
- nozzle
- electrode
- torch body
- tip
- machine according
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
- H05H1/00—Generating plasma; Handling plasma
- H05H1/24—Generating plasma
- H05H1/26—Plasma torches
- H05H1/28—Cooling arrangements
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K10/00—Welding or cutting by means of a plasma
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
- H05H1/00—Generating plasma; Handling plasma
- H05H1/24—Generating plasma
- H05H1/26—Plasma torches
- H05H1/32—Plasma torches using an arc
- H05H1/34—Details, e.g. electrodes, nozzles
- H05H1/3484—Convergent-divergent nozzles
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
- H05H1/00—Generating plasma; Handling plasma
- H05H1/24—Generating plasma
- H05H1/26—Plasma torches
- H05H1/32—Plasma torches using an arc
- H05H1/34—Details, e.g. electrodes, nozzles
- H05H1/3489—Means for contact starting
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
- H05H1/00—Generating plasma; Handling plasma
- H05H1/24—Generating plasma
- H05H1/26—Plasma torches
- H05H1/32—Plasma torches using an arc
- H05H1/34—Details, e.g. electrodes, nozzles
- H05H1/38—Guiding or centering of electrodes
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Plasma & Fusion (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Mechanical Engineering (AREA)
- Arc Welding In General (AREA)
- Plasma Technology (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A plasma-arc welding and cutting machine is disclosed comprising a body, an electrode, an inert gas chamber, and a cooling water chamber, with a nozzle attached with an opening into which the electrode projects, in which the electrode is movable to and fro within the body so as to move axially within the nozzle opening.
A plasma-arc welding and cutting machine is disclosed comprising a body, an electrode, an inert gas chamber, and a cooling water chamber, with a nozzle attached with an opening into which the electrode projects, in which the electrode is movable to and fro within the body so as to move axially within the nozzle opening.
Description
3~13 This invention xelates to a plasma-axc welding and cutting machine, and particularly to a small-siza pencil type plasma-arc welding and cutting machine which is easily used with one hand and is more effective than a conventional machine.
In the operation o a conventional plasma-arc welding and cutting machine, the end o~ the nozzle is separated by a certain g~p from the surface of the base metal to be welded or cut.
Since the electrode of the conventional machine is arranged a~ a fixed posi~ion with respect to the nozzle, the distance between the electrode and the base metal depends directly on the distance between the end of the nozzle and the base metal. The distance between the electrode and the base metal should be maintained within a certain range so as to Qbtain a stable plasma-arc. Conse~uently it requires a great deal of skill to operata such a c~nventional machine. When an operator uses such a machine, he watches the end of the nozzle in order to maintain the proper distance away ~rom the base metal.
Hence, because the intense light generated by the arc inevitably comes into his eyes, he requires an eye shield.
This kind of plasma-arc welding or cutting machine includes ~low passages for inert gas and for - ~
" .-....
cooling water for cooling the nozzle, resulting in a large machine which must be held in two hands ~hen being used.
Furthermore, it is known that the diameter of the heated spot produced by the plasma-arc on the base-metal is rather large during operation, when the optimum distance between the nozzle and the ~ase metal is maintained. However, if the diameter of the 19 nozzle is made smaller so as to reduce the spot diameter, at a certain point there results a series arc which is generated via the nozzle. Accordingly, it is impossi~le to make the diameter of the plasma-arc as small as one wishes by reducing the diameter or the nozzle.
It is an object of the present invention to provide a small size pencil-type plasma-arc welding and cutting machine free from the abovementioned defects, which is easily held in one hand during use, in which no skill is required to maintain the distance between the electrode and the base metal, in which a small diameter of the heated spot formed by the plasma-arc on the ba~e metal is ~btained (by which smaller work ; 25 piece~ can b~ handled), and in which there is no need : for the operator to observe ths intense light generated by the arc.
This object is accomplished according to the present invention by a plasma-arc welding and cut~ing 9~L3 machine compxising a torch body, an electrode attached within the torch body, an inert gas chamber in the torch body ! a cooling water chamber in the torch body, and a nozzle attached to the torch body, having a tip remote from the torch body and an opening leading from the tip to the inert gas chamber, into which opening the electrode projects partway but not so far as to reach the tip, wherein the electrode is movable to and fro within the torch body so as to move axial~y within the nozzle opening.
The present invention will now be described in detail with respect to some preferred embodiments illustrated in the accompanying drawings, which are given by way of illustration only and thus are not limitative of the present invention, and wh~rein:
Fig. 1 is a longitudinal sectional view of a plasma-arc welding and cutting machine according to the present invention;
Fig. 2 is a longitudinal sectional view of another plasma-arc welding and cutting machine , according to the present invention;
Fig. 3 is a longitudinal sectional view of still another plasma-arc welding and cutting machine according to the present invention; and Fig. 4 is a fr~ent~ry sectional view of the nozzle portion o~ yet another plasma-arc ~eld~ng and cutting machine according to the present invention.
Referring to the drawings, in Fig. 1 there is shown a first embodiment of a small size pencil-type plasma-arc welding and cutting machine according to the present invention.
' 10 A hollow pencil-type torch body 1 made of an insulating material comprises a body la, an upper portion lb, and a lower portion lc of which the lower part is tapered off, the connection between the body la and the lower portion lc being ~ealed by an 0-ring in Qrder to prevent leaking of inert ga~ therethxough, A cooling watex pipe member 2 having a flange 2a in its top end is fitted into the torch body la, the outer sur~ace of the flange 2a contacting the inner surface of the torch body la.
A center $~as pipe member 3 is arranged inside the cooling water pipe member 2, the top of the outer surface of the center gas pipe member 3 contacting the inner surface projecting inwards of the flange 2a.
Accordingly there exists an annular space constituting a cooling water chamber 4 between the two pipe members
In the operation o a conventional plasma-arc welding and cutting machine, the end o~ the nozzle is separated by a certain g~p from the surface of the base metal to be welded or cut.
Since the electrode of the conventional machine is arranged a~ a fixed posi~ion with respect to the nozzle, the distance between the electrode and the base metal depends directly on the distance between the end of the nozzle and the base metal. The distance between the electrode and the base metal should be maintained within a certain range so as to Qbtain a stable plasma-arc. Conse~uently it requires a great deal of skill to operata such a c~nventional machine. When an operator uses such a machine, he watches the end of the nozzle in order to maintain the proper distance away ~rom the base metal.
Hence, because the intense light generated by the arc inevitably comes into his eyes, he requires an eye shield.
This kind of plasma-arc welding or cutting machine includes ~low passages for inert gas and for - ~
" .-....
cooling water for cooling the nozzle, resulting in a large machine which must be held in two hands ~hen being used.
Furthermore, it is known that the diameter of the heated spot produced by the plasma-arc on the base-metal is rather large during operation, when the optimum distance between the nozzle and the ~ase metal is maintained. However, if the diameter of the 19 nozzle is made smaller so as to reduce the spot diameter, at a certain point there results a series arc which is generated via the nozzle. Accordingly, it is impossi~le to make the diameter of the plasma-arc as small as one wishes by reducing the diameter or the nozzle.
It is an object of the present invention to provide a small size pencil-type plasma-arc welding and cutting machine free from the abovementioned defects, which is easily held in one hand during use, in which no skill is required to maintain the distance between the electrode and the base metal, in which a small diameter of the heated spot formed by the plasma-arc on the ba~e metal is ~btained (by which smaller work ; 25 piece~ can b~ handled), and in which there is no need : for the operator to observe ths intense light generated by the arc.
This object is accomplished according to the present invention by a plasma-arc welding and cut~ing 9~L3 machine compxising a torch body, an electrode attached within the torch body, an inert gas chamber in the torch body ! a cooling water chamber in the torch body, and a nozzle attached to the torch body, having a tip remote from the torch body and an opening leading from the tip to the inert gas chamber, into which opening the electrode projects partway but not so far as to reach the tip, wherein the electrode is movable to and fro within the torch body so as to move axial~y within the nozzle opening.
The present invention will now be described in detail with respect to some preferred embodiments illustrated in the accompanying drawings, which are given by way of illustration only and thus are not limitative of the present invention, and wh~rein:
Fig. 1 is a longitudinal sectional view of a plasma-arc welding and cutting machine according to the present invention;
Fig. 2 is a longitudinal sectional view of another plasma-arc welding and cutting machine , according to the present invention;
Fig. 3 is a longitudinal sectional view of still another plasma-arc welding and cutting machine according to the present invention; and Fig. 4 is a fr~ent~ry sectional view of the nozzle portion o~ yet another plasma-arc ~eld~ng and cutting machine according to the present invention.
Referring to the drawings, in Fig. 1 there is shown a first embodiment of a small size pencil-type plasma-arc welding and cutting machine according to the present invention.
' 10 A hollow pencil-type torch body 1 made of an insulating material comprises a body la, an upper portion lb, and a lower portion lc of which the lower part is tapered off, the connection between the body la and the lower portion lc being ~ealed by an 0-ring in Qrder to prevent leaking of inert ga~ therethxough, A cooling watex pipe member 2 having a flange 2a in its top end is fitted into the torch body la, the outer sur~ace of the flange 2a contacting the inner surface of the torch body la.
A center $~as pipe member 3 is arranged inside the cooling water pipe member 2, the top of the outer surface of the center gas pipe member 3 contacting the inner surface projecting inwards of the flange 2a.
Accordingly there exists an annular space constituting a cooling water chamber 4 between the two pipe members
2 and 3, in which cooling water 10ws via inlet and _ 5 _ outlet conduits 5 which are mounted at the top of the cooliny water pipe member 2.
The cooling water pipe member 2 is surrounded by a shield gas pipe member 6 of which the outer surface contacts the inner surface of the torch body la. The shield gas pipe member 6 has an inward projecting flange at its lower end, and contacts the cooling water pipe member 2 at its top end and also at its lower end by the flange.
Hence, there exists an annular space constituting a hield gas chamber 7 between the two pipe members 2 and 6, through which an inert shield ga~ supplied from an inlet pipe 8 positioned at the top of the shield gas pipe member 6 flows via openings 9 ~ormed at the lower end thereof, At the lower ~urface of the shield gas pipe member 6, a screw is threaded, with which the female screw tapped on the upper inner surf~ce of the lower torch portion lc engages.
, Atc the enlarged lower portion 3a of the center gas pipe member 3 a conical nozzle 10 is : 25 mounted ~y engaging a male screw formed in the upper cylinder portion lOc of the conical nozzle 10 : with a female screw ~ormed on the lower i:-~ide surface :~ of the enlarged lower portion 3a. An inner top end of an upward oute~ projecting ring lOa of the aonical noz~le 10 i5 contacted with the olter lower .
, : .
l9~3 end of the cooling water pipe member 2, and the top end of the upward outer projecting ring 10 is also in contact with the lower end of the shield gas pipe member 6.
There exists an annular lower cooling water chamber 4a, which leads to the cooling water chamber 4, between the lower part of the center gas pipe member 3 and the upward outer projecting ring lOa.
The inert shield gas which has flowed through the annular space between the two pipe mem~ers 2 and 6 and through ~he openings 9 then ~lows through an annulax space 11 between the lower torch portion lc and the noz21e 10.
The conical noæzle 10 having a tapered nozzle lower end lOb includes a central opening 12 extending along its axis. Radially directed slots 13 are provided in the contact surfAc~ of the nozzle where it touches the workpiece. The lower innex surface of the opening 12 is tapered off corresponding to the nozzle 10. An insulation pipe 14 which is made of a material having high temperature resistance and good heat conductivity, and which in its outer shape conforms to the central opening 12, is inserted in the central opening 12 of the nozzle 10. The lower end of the central hole in the insulation pipe 14 is tapered off.
A center gas ring member 16 is ~itted intv the upper part of the torch body la and is adjacent to the flange 2a of the cooling water pipe member 2 with an insulating ring 15 being interposed therebetween.
An inlet pipe 17 for ~upplying center gas is mounted .. . .
1~ ~1913 to the center gas ring member 16. The upper ~emale screw ring portion 16a of the center gas ring member 16 engages with an exterior threaded surface of a screw ring 18, An electrode holder 19 with an open top hollow for holding an electrode 20 is inserted into the screw ring 18 b~ engaging a lower outer threaded surface of the electrode holder 19 with 1~ the inner threaded surface of the screw ring 18.
The upper torch portion 1~, having a center hole through which the electrode holder 19 passes, is ~:
capped onto the screw ring 18 by engaging its threaded inner surface with the threaded outer surface of the screw ~ing 18. Between the upper torch portion lb and the electrode holder 18 a seal is formed by an O~ring, as shown in Fig. 1. The electrode holder 19 includes an electrode holding portion l9a, projecting downwards into the center gas ring memb~r 16, the insulation ring 15 and the center gas pipe member 3 in such a way that the electrode holding portion l9a does not contact them. The inside lower end surface of the electrode holding portion 19a is tapered off, ~5 A chuck member 21 is fitted into the hollow of the electxode holder 19 and its top end projects over the top end of the electrode holder 19. The lower end . portion of the chuck member 21 is divided longitudinally .
.
into several branches,and t~pered off~
The electrode 20 is gripped firmly by the chuck member 21 which has a long hollow for holding the electrode 20 by pushing downwards the chuck member 21 via a push plate 22 by turning an adjusting knob 23 made of an insulating material, the female scr~w of the adjusting knob 23 engaging with the male screw formed on the upper outer surface of the electrode l~ holder lg.
A guide ring 24 is arranged in the lower end of the center gas chamber 25 of the center gas pipe ~ember 3 and has a central opening along its axis, through which the electrode passes. The outer surface of the guide ring 24 contacts the center gas pipe member 3 and is provided with dual spiral grooves 26.
When the center inert gas passes through the dual spiral ~rooves 26 it acquires a revolving motion, which promotes the thermal pinch effece in the nozzle, and further helps the arc to center in the opening of the insulation pipe 14.
Th~e electrode 20 is easily moved up and down relative to the nozzle by turning the electrode holder l9 by means of a turning ~ing 27 mounted to the electrode holder l9 by a screw 28, , The wçlding operation of the machine of the
The cooling water pipe member 2 is surrounded by a shield gas pipe member 6 of which the outer surface contacts the inner surface of the torch body la. The shield gas pipe member 6 has an inward projecting flange at its lower end, and contacts the cooling water pipe member 2 at its top end and also at its lower end by the flange.
Hence, there exists an annular space constituting a hield gas chamber 7 between the two pipe members 2 and 6, through which an inert shield ga~ supplied from an inlet pipe 8 positioned at the top of the shield gas pipe member 6 flows via openings 9 ~ormed at the lower end thereof, At the lower ~urface of the shield gas pipe member 6, a screw is threaded, with which the female screw tapped on the upper inner surf~ce of the lower torch portion lc engages.
, Atc the enlarged lower portion 3a of the center gas pipe member 3 a conical nozzle 10 is : 25 mounted ~y engaging a male screw formed in the upper cylinder portion lOc of the conical nozzle 10 : with a female screw ~ormed on the lower i:-~ide surface :~ of the enlarged lower portion 3a. An inner top end of an upward oute~ projecting ring lOa of the aonical noz~le 10 i5 contacted with the olter lower .
, : .
l9~3 end of the cooling water pipe member 2, and the top end of the upward outer projecting ring 10 is also in contact with the lower end of the shield gas pipe member 6.
There exists an annular lower cooling water chamber 4a, which leads to the cooling water chamber 4, between the lower part of the center gas pipe member 3 and the upward outer projecting ring lOa.
The inert shield gas which has flowed through the annular space between the two pipe mem~ers 2 and 6 and through ~he openings 9 then ~lows through an annulax space 11 between the lower torch portion lc and the noz21e 10.
The conical noæzle 10 having a tapered nozzle lower end lOb includes a central opening 12 extending along its axis. Radially directed slots 13 are provided in the contact surfAc~ of the nozzle where it touches the workpiece. The lower innex surface of the opening 12 is tapered off corresponding to the nozzle 10. An insulation pipe 14 which is made of a material having high temperature resistance and good heat conductivity, and which in its outer shape conforms to the central opening 12, is inserted in the central opening 12 of the nozzle 10. The lower end of the central hole in the insulation pipe 14 is tapered off.
A center gas ring member 16 is ~itted intv the upper part of the torch body la and is adjacent to the flange 2a of the cooling water pipe member 2 with an insulating ring 15 being interposed therebetween.
An inlet pipe 17 for ~upplying center gas is mounted .. . .
1~ ~1913 to the center gas ring member 16. The upper ~emale screw ring portion 16a of the center gas ring member 16 engages with an exterior threaded surface of a screw ring 18, An electrode holder 19 with an open top hollow for holding an electrode 20 is inserted into the screw ring 18 b~ engaging a lower outer threaded surface of the electrode holder 19 with 1~ the inner threaded surface of the screw ring 18.
The upper torch portion 1~, having a center hole through which the electrode holder 19 passes, is ~:
capped onto the screw ring 18 by engaging its threaded inner surface with the threaded outer surface of the screw ~ing 18. Between the upper torch portion lb and the electrode holder 18 a seal is formed by an O~ring, as shown in Fig. 1. The electrode holder 19 includes an electrode holding portion l9a, projecting downwards into the center gas ring memb~r 16, the insulation ring 15 and the center gas pipe member 3 in such a way that the electrode holding portion l9a does not contact them. The inside lower end surface of the electrode holding portion 19a is tapered off, ~5 A chuck member 21 is fitted into the hollow of the electxode holder 19 and its top end projects over the top end of the electrode holder 19. The lower end . portion of the chuck member 21 is divided longitudinally .
.
into several branches,and t~pered off~
The electrode 20 is gripped firmly by the chuck member 21 which has a long hollow for holding the electrode 20 by pushing downwards the chuck member 21 via a push plate 22 by turning an adjusting knob 23 made of an insulating material, the female scr~w of the adjusting knob 23 engaging with the male screw formed on the upper outer surface of the electrode l~ holder lg.
A guide ring 24 is arranged in the lower end of the center gas chamber 25 of the center gas pipe ~ember 3 and has a central opening along its axis, through which the electrode passes. The outer surface of the guide ring 24 contacts the center gas pipe member 3 and is provided with dual spiral grooves 26.
When the center inert gas passes through the dual spiral ~rooves 26 it acquires a revolving motion, which promotes the thermal pinch effece in the nozzle, and further helps the arc to center in the opening of the insulation pipe 14.
Th~e electrode 20 is easily moved up and down relative to the nozzle by turning the electrode holder l9 by means of a turning ~ing 27 mounted to the electrode holder l9 by a screw 28, , The wçlding operation of the machine of the
3~ present invention will now be described.
_ g _ .. . . .
.:
.: .
L9~3 The electrode 20 is connected to the cathode of an electric source 29 via a terminal 30 and the base metal 31 to be welded is connected to the anode of the electric source 29. The electrode 2~ is moved towards the base metal 31 to a point near the lowermo~t end of the nozzle 10 by turning the turning ring 27, Cooling water is supplied to the cooliny water chamber
_ g _ .. . . .
.:
.: .
L9~3 The electrode 20 is connected to the cathode of an electric source 29 via a terminal 30 and the base metal 31 to be welded is connected to the anode of the electric source 29. The electrode 2~ is moved towards the base metal 31 to a point near the lowermo~t end of the nozzle 10 by turning the turning ring 27, Cooling water is supplied to the cooliny water chamber
4. The shield and center inert gases such as argon gas, nitrogen gas, a mixture of these, or the like, are supplied to the shield gas chamber 7 via the inlet pipe 8 and to the center gas chamber 25 via the inlet pipe 17, and they then rush out of the annular space 11 between the lower torch portion lc and the nozzle 10 and out of the central opening 12 of the nozzle 10.
Then the lower end of the nozzle 10 is brought into contact with the base metal 31, xesulting in striking the arc from the lower end of the electrode 20 onto the baje metal 31 just under the electrode 20.
The electrode 20 is then moved away from the base metal 31 by turning the ring 27 to establish the proper electrode distance for welding, keeping however the nozzle 10 in contact with the workpiece. .The machine is moved along the weld line, always maintaining contact between the nozzle 10 ~md the base metal 31.
Cutting of the base metal 31 is performed similarly, except that in this case the flow speed of the center inert gas is faster than in the weld.ing, and the amount of electric current is var.ied according to the thickness of the base metal to be cut.
'' 9~L3 In Fig. 2 thexe is shown anothe~ plasm~-arc welding and cutting machine according to the present invention.
A center gas pipe member 43 having a flange 43a in its top end is fitted into the torch 1, the outer periphery of the flange 43a contacting the inner surface of the torch 1. The center gas pipe member 43 is surrounded by a cooling water pipe member 42, of which the outer surface contacts the inner surface of the torch 1, the top end of the cooling water pipe member 42 contacting the flange 43a. Between the two pipe members 42 and 43 there exists an annular space constituting a cooling water chamber 44, in which cooling water flows.
At the lower outside end ~urface of the cooling water pipe member 42, a screw is threaded, with which the female screw t~pped on the upper inner surface of the lower torch portion engages.
A relatively long guide ring 4~ which has dual spiral grooves in its lower surface is mounted in the lower portion of the center gas pipe member 43.
An electrode holder 46 including an electrode holding portion 46a comprising a chuck form which projects downwards into the center gas chamber 25 is inserted into the screw ring 18, in the same way as ; in the machine illustrated in Fig. 1. The electrode 20 is held ~irmly by the eleatrode holder 46 by engaging a tapered female screw of a screw pipe ~7 with the .
, ' , tapered male screw of ~he electrode holding portion 46a.
A conical no~zle 50 having an upward outer projecting r:ing 50a, a tapered-off lower end portion 50b, and a central inner cylinder portion SOc, and having a central opening 52, is rnounted by engaging a female screw threaded Oll the top inner surface of the upward outer projecting ring 50a with the male screw threaded on the lower ou~er surface of the lower torch body portion, the upper outer surface of the central inner cylinder portion 50c being fitted into the lower inner surface of the center ga~ pipe member 43. A
grooved lower part of the lower torch portion and an upper part of the upward outer projecting ring 50a are covered by a cover 41 made of an insulating material.
There exists an annular lower cooling water chamber 44a which leads to the cooling water chamber 44, between the upward outer projecting ring 50a ~nd the center inner cylinder portion 50c.
A conical insul~tion pipe 54 having a center hole wllich comprises an upper conical cup which is tapered downwards to a small cylindrical opening 55 is inserted in the lower portion of t~le center opening 52 of the nozzle 50.
The natures of the other members are the same as in Fig. l, and therefore the description of them will be omitted for the sake of brevity.
The machine o~ Fig, 2 is operated similarly to that of Fig~ l. That is, the electrode 20 and the base metal 31 are connectad to the cathode and the anode of the electric source 29, respectively. The electrode 20 is moved down close to the small opening 55. The cooling , .
water is supplied to the cooling water chamber 44.
The center inert gas iS supplied to the center gas chamber 25, and it then rushes out of the small opening 55.
Then the lower end of the nozzle 50 is brought into contact with the base metal 31, r~sulting in striking the arc from the lower end of the electrode 20 onto the base metal 31 just under the electrode 20.
The electrode 20 is then moved away from the base metal 31 to establish the proper electrode distance by turning the knob 23. The welding ox cutting of the base metal 31 is then conducted as described above.
In Fig. 3 there is shown still another plasma-arc welding and cutting machine according to the present invention, In this case an electrode holder 66 is inserted into ~he screw ring 18, as in Fig. 1, and includes an electrode holding portion 66a which projects deeply downwards into the center gas chamber 25 and has a chuck portion in its lower end. The electrode 20 is held securely by engaging a tapered female screw of a screw pipe 67 with the tapered male screw of the chuck portion of the electrode holding portion 66a.
A conical nozzle 70 mounted to the lower torch portion in the same manner as the one of Fig~ 2 comprises an outer conical ring member 70a, a central inner cylinder .
. :. - . . : .
-- .
~119~3 member 70c having ~ centx~l opening 72 and ~ tapered lo~er end portion 70b having a small opening 75 in its lo~er end, and a conical insulation ring member 74 arranged between the outer conical ring member 7Oa and the central inner cylinder ~ember 70c at their lower end portion. Accordingly, the two members 7Oa and 70c are insulated from each other by the insulation ring member 74.
The top of the center gas pipe member 43 is connected to the anode of the electric source 29 by a switch 80 and a resistor 81 which are coupled in series with each other via a terminal 82 mounted to the top of the center gas pipe member 4~. Sin~e the central inner cylinder member 70c of the nozzle 70 is in contact with the lower end of the center gas pipe member 43, the central inner cylinder member 70c is electrically connected to the anode of the electric source 29 via the switch BO, the resistor 81, the terminal 82, and the center gas pipe member 43.
The natures of the oth r members are the same as in Fig. 2, and hence the description of them will be omitted for the sake of brevity.
The operation o~ the machine according to the present invention shown in Fig. 3 is as follows:
The electrode 20 and the base metal 31 are ; 30 connected to the cathode and the anode of the electric source 29, respectively. The electrode 20 is adjusted to establish the proper electrode distance for welding or cutting the base metal ~1.
' , . - -Then when the switch 80 is turned on,thc elect~ic cux~ent, weakened by the resistQx 81, leads to the central cylinder member 70c fro~ the anode of the electric source 29, resulting in the striking of a weak pilot arc from the lower end of the electrode 20 onto the tapered lower end portion 70b.
The lower end of the nozzle 70 is brought into contact with the base metal 31 and the inert gas is simultaneously supplied to the center gas chamber 25 so that it may rush out of the small opening 75 of the nozzle, with the result that the pilot arc generated between the electrode 20 and ~ tapered lower end portion 70b is moved instantaneously from the lower end of the electrode to the base metal 31, thereby striking a plasma-arc.
The welding or cutting of the base metal 31 is conducted as described above.
In Fig. 4 there is shown a nozzle portion of another plasma-arc welding and cutting machine according to the present invention.
This has the same structure as that of Fig. 3 except that a conical nozzle ~G includes an upward outer projecting ring 90a and a central inner cylinder portion ~Oc ha~ing a central opening 92 and a tapered lower end portion 90b having a small opening 95 in its lower end.
The upper half part of an insulation ring 94 - . , .
having a central opening leading to the small opening 95 is fitted in the lower end of the nozzle 90. Thus no electrical contact between the central inner cylinder portion 90c and the workpiece can occur when the nozzle is approached squarely to the workpiece.
The ~ame functions and effects are obtained with this machine as with that of Fig~ 3, and the operation is conducted in the same manner.
Although the invention has been described with respect to some embodiments thereof, it should be of course understood by those skilled in the art that other variations are possible, and therefore the scope of the invention is not to be limited by the particular embodiments described, or by the drawings, but only by the claims which follow.
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Then the lower end of the nozzle 10 is brought into contact with the base metal 31, xesulting in striking the arc from the lower end of the electrode 20 onto the baje metal 31 just under the electrode 20.
The electrode 20 is then moved away from the base metal 31 by turning the ring 27 to establish the proper electrode distance for welding, keeping however the nozzle 10 in contact with the workpiece. .The machine is moved along the weld line, always maintaining contact between the nozzle 10 ~md the base metal 31.
Cutting of the base metal 31 is performed similarly, except that in this case the flow speed of the center inert gas is faster than in the weld.ing, and the amount of electric current is var.ied according to the thickness of the base metal to be cut.
'' 9~L3 In Fig. 2 thexe is shown anothe~ plasm~-arc welding and cutting machine according to the present invention.
A center gas pipe member 43 having a flange 43a in its top end is fitted into the torch 1, the outer periphery of the flange 43a contacting the inner surface of the torch 1. The center gas pipe member 43 is surrounded by a cooling water pipe member 42, of which the outer surface contacts the inner surface of the torch 1, the top end of the cooling water pipe member 42 contacting the flange 43a. Between the two pipe members 42 and 43 there exists an annular space constituting a cooling water chamber 44, in which cooling water flows.
At the lower outside end ~urface of the cooling water pipe member 42, a screw is threaded, with which the female screw t~pped on the upper inner surface of the lower torch portion engages.
A relatively long guide ring 4~ which has dual spiral grooves in its lower surface is mounted in the lower portion of the center gas pipe member 43.
An electrode holder 46 including an electrode holding portion 46a comprising a chuck form which projects downwards into the center gas chamber 25 is inserted into the screw ring 18, in the same way as ; in the machine illustrated in Fig. 1. The electrode 20 is held ~irmly by the eleatrode holder 46 by engaging a tapered female screw of a screw pipe ~7 with the .
, ' , tapered male screw of ~he electrode holding portion 46a.
A conical no~zle 50 having an upward outer projecting r:ing 50a, a tapered-off lower end portion 50b, and a central inner cylinder portion SOc, and having a central opening 52, is rnounted by engaging a female screw threaded Oll the top inner surface of the upward outer projecting ring 50a with the male screw threaded on the lower ou~er surface of the lower torch body portion, the upper outer surface of the central inner cylinder portion 50c being fitted into the lower inner surface of the center ga~ pipe member 43. A
grooved lower part of the lower torch portion and an upper part of the upward outer projecting ring 50a are covered by a cover 41 made of an insulating material.
There exists an annular lower cooling water chamber 44a which leads to the cooling water chamber 44, between the upward outer projecting ring 50a ~nd the center inner cylinder portion 50c.
A conical insul~tion pipe 54 having a center hole wllich comprises an upper conical cup which is tapered downwards to a small cylindrical opening 55 is inserted in the lower portion of t~le center opening 52 of the nozzle 50.
The natures of the other members are the same as in Fig. l, and therefore the description of them will be omitted for the sake of brevity.
The machine o~ Fig, 2 is operated similarly to that of Fig~ l. That is, the electrode 20 and the base metal 31 are connectad to the cathode and the anode of the electric source 29, respectively. The electrode 20 is moved down close to the small opening 55. The cooling , .
water is supplied to the cooling water chamber 44.
The center inert gas iS supplied to the center gas chamber 25, and it then rushes out of the small opening 55.
Then the lower end of the nozzle 50 is brought into contact with the base metal 31, r~sulting in striking the arc from the lower end of the electrode 20 onto the base metal 31 just under the electrode 20.
The electrode 20 is then moved away from the base metal 31 to establish the proper electrode distance by turning the knob 23. The welding ox cutting of the base metal 31 is then conducted as described above.
In Fig. 3 there is shown still another plasma-arc welding and cutting machine according to the present invention, In this case an electrode holder 66 is inserted into ~he screw ring 18, as in Fig. 1, and includes an electrode holding portion 66a which projects deeply downwards into the center gas chamber 25 and has a chuck portion in its lower end. The electrode 20 is held securely by engaging a tapered female screw of a screw pipe 67 with the tapered male screw of the chuck portion of the electrode holding portion 66a.
A conical nozzle 70 mounted to the lower torch portion in the same manner as the one of Fig~ 2 comprises an outer conical ring member 70a, a central inner cylinder .
. :. - . . : .
-- .
~119~3 member 70c having ~ centx~l opening 72 and ~ tapered lo~er end portion 70b having a small opening 75 in its lo~er end, and a conical insulation ring member 74 arranged between the outer conical ring member 7Oa and the central inner cylinder ~ember 70c at their lower end portion. Accordingly, the two members 7Oa and 70c are insulated from each other by the insulation ring member 74.
The top of the center gas pipe member 43 is connected to the anode of the electric source 29 by a switch 80 and a resistor 81 which are coupled in series with each other via a terminal 82 mounted to the top of the center gas pipe member 4~. Sin~e the central inner cylinder member 70c of the nozzle 70 is in contact with the lower end of the center gas pipe member 43, the central inner cylinder member 70c is electrically connected to the anode of the electric source 29 via the switch BO, the resistor 81, the terminal 82, and the center gas pipe member 43.
The natures of the oth r members are the same as in Fig. 2, and hence the description of them will be omitted for the sake of brevity.
The operation o~ the machine according to the present invention shown in Fig. 3 is as follows:
The electrode 20 and the base metal 31 are ; 30 connected to the cathode and the anode of the electric source 29, respectively. The electrode 20 is adjusted to establish the proper electrode distance for welding or cutting the base metal ~1.
' , . - -Then when the switch 80 is turned on,thc elect~ic cux~ent, weakened by the resistQx 81, leads to the central cylinder member 70c fro~ the anode of the electric source 29, resulting in the striking of a weak pilot arc from the lower end of the electrode 20 onto the tapered lower end portion 70b.
The lower end of the nozzle 70 is brought into contact with the base metal 31 and the inert gas is simultaneously supplied to the center gas chamber 25 so that it may rush out of the small opening 75 of the nozzle, with the result that the pilot arc generated between the electrode 20 and ~ tapered lower end portion 70b is moved instantaneously from the lower end of the electrode to the base metal 31, thereby striking a plasma-arc.
The welding or cutting of the base metal 31 is conducted as described above.
In Fig. 4 there is shown a nozzle portion of another plasma-arc welding and cutting machine according to the present invention.
This has the same structure as that of Fig. 3 except that a conical nozzle ~G includes an upward outer projecting ring 90a and a central inner cylinder portion ~Oc ha~ing a central opening 92 and a tapered lower end portion 90b having a small opening 95 in its lower end.
The upper half part of an insulation ring 94 - . , .
having a central opening leading to the small opening 95 is fitted in the lower end of the nozzle 90. Thus no electrical contact between the central inner cylinder portion 90c and the workpiece can occur when the nozzle is approached squarely to the workpiece.
The ~ame functions and effects are obtained with this machine as with that of Fig~ 3, and the operation is conducted in the same manner.
Although the invention has been described with respect to some embodiments thereof, it should be of course understood by those skilled in the art that other variations are possible, and therefore the scope of the invention is not to be limited by the particular embodiments described, or by the drawings, but only by the claims which follow.
.
Claims (7)
1. A plasma-arc cutting machine comprising:
a torch body;
an electrode attached within the torch body;
an inert gas chamber in the torch body;
a cooling water chamber in the torch body; and a nozzle attached to the torch body and having a tip remote from the inert gas chamber, said electrode being movable to and fro within the torch body so as to move axially within said nozzle;
said nozzle having adjacent the tip thereof an insulation pipe having a center hole which comprises an upper conical cup tapered downwards forming a small cylindrical opening which is gradually spread in the downward direction.
a torch body;
an electrode attached within the torch body;
an inert gas chamber in the torch body;
a cooling water chamber in the torch body; and a nozzle attached to the torch body and having a tip remote from the inert gas chamber, said electrode being movable to and fro within the torch body so as to move axially within said nozzle;
said nozzle having adjacent the tip thereof an insulation pipe having a center hole which comprises an upper conical cup tapered downwards forming a small cylindrical opening which is gradually spread in the downward direction.
2. A machine according to claim 1, wherein a shield inert gas chamber is provided in the torch body, and wherein there exists an annular space communicating with the shield inert gas chamber between the outer surface of the nozzle and the lower portion of the torch body.
3. A machine according to claim 1, wherein the part of the nozzle from its tip to a portion directly surrounding the tip of the electrode is an insulator.
4. A machine according to claim 3, wherein radially directed slots are provided in the contact surface of the nozzle where it touches the workpiece during use.
5. A machine according to claim 1, wherein the inner part of the nozzle directly surrounding the tip of the electrode is a conductor.
6. A machine according to claim 5, wherein an electrical connection from the outside of the machine is provided to said inner part of the nozzle and wherein said inner part of the nozzle is insulated from any electrical contact with the workpiece when the nozzle is approached squarely thereto.
7. A machine as in claim 6, wherein an insulating ring is provided as forming the tip of the nozzle.
Applications Claiming Priority (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP52-34731 | 1977-03-30 | ||
| JP3473177A JPS53119755A (en) | 1977-03-30 | 1977-03-30 | Plasma welding machine |
| JP1510478A JPS5851790B2 (en) | 1978-02-13 | 1978-02-13 | plasma welding machine |
| JP1510578A JPS5851791B2 (en) | 1978-02-13 | 1978-02-13 | plasma welding machine |
| JP53-15104 | 1978-02-13 | ||
| JP53-15105 | 1978-02-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1111913A true CA1111913A (en) | 1981-11-03 |
Family
ID=27280876
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA298,870A Expired CA1111913A (en) | 1977-03-30 | 1978-03-14 | Plasma-arc welding and cutting machine |
Country Status (7)
| Country | Link |
|---|---|
| CA (1) | CA1111913A (en) |
| DE (1) | DE2813804C2 (en) |
| FR (1) | FR2385483A1 (en) |
| GB (1) | GB1598574A (en) |
| HK (1) | HK39484A (en) |
| MY (1) | MY8500511A (en) |
| SG (1) | SG17384G (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4300033A (en) * | 1979-06-14 | 1981-11-10 | Rensselaer Polytechnic Institute | Reduced operating noise nozzle for electric arc cutting device |
| DE3216556A1 (en) * | 1982-05-04 | 1983-11-17 | Messer Griesheim Gmbh, 6000 Frankfurt | Plasma torch, in particular a plasma-powder surfacing torch |
| SE444902B (en) * | 1983-09-29 | 1986-05-20 | Adolf Gunnar Gustafson | SKERBRENNARE |
| FR2556549B1 (en) * | 1983-12-07 | 1986-10-17 | Soudure Autogene Francaise | METHOD OF LIGHTING AN ARC FOR A WELDING OR CUTTING TORCH AND TORCH SUITABLE FOR CARRYING OUT THIS METHOD |
| DE3435680A1 (en) * | 1984-09-28 | 1986-04-03 | Fried. Krupp Gmbh, 4300 Essen | PLASMA TORCH |
| FR2596942B1 (en) * | 1986-04-07 | 1988-11-25 | Rodrigues Francis | UNIVERSAL PLASMAGEN TORCH |
| AT385166B (en) * | 1987-03-30 | 1988-02-25 | Inst Elektroswarki Patona | BURNER FOR PLASMA JET PROCESSING OF MATERIALS |
| DE8904460U1 (en) * | 1989-04-10 | 1989-06-29 | Krupp Medizintechnik GmbH, 4300 Essen | Microplasma welding device |
| US5514848A (en) * | 1994-10-14 | 1996-05-07 | The University Of British Columbia | Plasma torch electrode structure |
| GB0002704D0 (en) * | 2000-02-08 | 2000-03-29 | Circle Technical Services Limi | Gas cutting shroud |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL295002A (en) * | 1962-07-13 | |||
| CH408230A (en) * | 1964-05-11 | 1966-02-28 | Secheron Atel | Welding process of thin sheets, using an electric arc |
| DE1615352B2 (en) * | 1967-11-02 | 1971-09-02 | VEB Mansfeld Kombinat Wilhelm Pieck, χ 4250 Lutherstadt Eisleben | CIRCUIT ARRANGEMENT AND DEVICE FOR PLASMA HAND TURNERS |
| DE1790209B1 (en) * | 1968-09-28 | 1971-10-14 | Siemens Ag | GAS TABILIZED ARC BURNER |
| BE795236A (en) * | 1972-02-09 | 1973-05-29 | Vysoka Skola Banska Ostrava | PLASMA BURNER WITH AXIAL STABILIZING GAS SUPPLY |
-
1978
- 1978-03-14 GB GB10141/78A patent/GB1598574A/en not_active Expired
- 1978-03-14 CA CA298,870A patent/CA1111913A/en not_active Expired
- 1978-03-29 FR FR7809032A patent/FR2385483A1/en active Granted
- 1978-03-30 DE DE2813804A patent/DE2813804C2/en not_active Expired
-
1984
- 1984-02-25 SG SG173/84A patent/SG17384G/en unknown
- 1984-05-03 HK HK394/84A patent/HK39484A/en unknown
-
1985
- 1985-12-30 MY MY511/85A patent/MY8500511A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| DE2813804C2 (en) | 1982-12-09 |
| GB1598574A (en) | 1981-09-23 |
| FR2385483B1 (en) | 1983-01-21 |
| DE2813804A1 (en) | 1978-10-05 |
| HK39484A (en) | 1984-05-11 |
| SG17384G (en) | 1985-03-08 |
| MY8500511A (en) | 1985-12-31 |
| FR2385483A1 (en) | 1978-10-27 |
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Legal Events
| Date | Code | Title | Description |
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| MKEX | Expiry |