JPH01262076A - Welding head - Google Patents

Abstract

PURPOSE:To join a pipe with all position welding with less troubles of a cable and hose by composing a rotary body by the annular main electrode holding a welding electrode and constituting a welding head by storing it rotatably into an insulating case. CONSTITUTION:A rotary body 7 is composed by the annular main electrode 3 holding a welding electrode 2 by making a pipe adapted for joining with all position welding and as the plasma welding bed having less troubles on a cable and hose and it is stored rotatably into an annular insulating case 1. A motor 8 as for the driving means driving the rotary body 7 by its rotation is fitted to the insulating case 1, electrifying brushes 14-17 are arranged between the insulating case 1 and main electrode 3 of the rotary body 7, and feeding terminals 31, 32 and the mouthpieces 35, 36 of a gas hose 37 are inserted into the insulating case 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a welding head, and particularly to a plasma welding head suitable for joining pipes by all-position welding.

[Conventional technology]

Conventionally, a plasma welding head that joins pipes by all-position welding consists of a fixed part that clamps to the target pipe, a rotating part that is rotatably supported by this fixed part, and a torch part that is attached to this rotating part. has been done. A welding electrode and a nozzle for plasma welding are arranged inside the torch section, and a positive main cable and a negative pilot cable that supply welding current to these welding electrodes and nozzles, and a plasma gas are supplied to the torch section. A plasma hose and a shield gas hose that supplies shield gas are connected.

During welding, the torch part rotates around the pipe due to the rotation of the rotating part, and at the same time, welding current, plasma gas, and shielding gas are supplied from the cable and hose,
The pipes are joined by all-position welding.

As a principle document regarding plasma welding, there is, for example, the Practical Welding Data Book (published by the Japanese Standards Association).

In addition, related devices of this type include Japanese Patent Application Laid-open No.
There are No. 16743 and Utility Model Publication No. 59-42216. Both publications disclose welding heads for TIG welding rather than plasma welding, but both weld pipes with full position control, and for that purpose, the same fixed parts and rotating parts as mentioned above are used. and a torch section housed in the rotating section.

[Invention or problem to be solved]

However, the conventional welding head described above has a rotating
Since the cables and hoses are directly connected to the -ch part, as the parts 1 to -ch rotate, troubles such as the cables and hoses getting wrapped around the pipe or hitting some corners may cause damage. There was a problem that it was easy to use and very difficult to use.

Therefore, an object of the present invention is to provide a welding head that is easy to use and has fewer troubles related to cables and ports.

[Means to solve the problem]

The above purpose is to configure a rotating body with at least a ring-shaped main electrode that holds a welding electrode, to rotatably house this rotating body in a ring-shaped insulating case, and to drive the rotating body to rotate in the insulating case. This is achieved by a welding head that is equipped with a driving means, a current-carrying brush is disposed between the insulating case and the main electrode of the rotating body, and a power supply terminal and the mouthpiece of the gas hose are inserted into the insulating case.

[Effect]

A cable for supplying welding current and a gas hose for supplying welding dregs are connected to a power supply terminal and a cap that are inserted through an insulating case that is a fixed member.

Therefore, during welding, either the torch section including the welding electrode provided on the rotating body rotates, or these cables and gas hoses do not rotate. Therefore, it is possible to prevent these cables and cusps from getting wrapped around pipes or being damaged by hitting against some corners, thereby reducing troubles and improving usability.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.6 In FIGS. 1 to 4 showing the overall configuration and main cross section of a plasma welding head of the present invention, reference numeral 1 indicates an insulating It is a ring-shaped insulating case made of material, and inside this insulating case 1, as shown in FIG. A rotating body 7 consisting of a pilot electrode 1g115 and an insulating ring 6 inserted between the electrodes 3.5 to separate them is rotatably housed.

A drive motor 8 is attached to the outside of the insulating case 1, as shown in FIG. Insulated pinion 10 that meshes with
are rotatably supported by bearings 11 and 12, respectively. A gear 13 is provided on the outer periphery of the main electrode 3 of the rotating body 7, and an insulating pinion 10 meshes with this gear. As a result, the rotating body 7 including the main electrode 3 is rotationally driven within the insulating case 1. Further, the insulating pinion 10 prevents the potential of the main electrode 3 from being transmitted to the drive motor 8.

Between the insulating case 1 and the main electrode 3 and pilot electrode 5 of the rotating body 7, there are energized brushes 14, 15, 16, respectively.
．． 17 are arranged, and on the side of each energizing brush facing the insulating case 1, springs 18.
19 are stored. This pressing is done by using springs 18 and 19 to connect each energizing brush to the main power 'lf! 3 and pilot electrode 5
By pressing the electrodes against each other, these electrodes are held in a pinched manner in the axial direction, and welding current is supplied to the corresponding electrodes. As represented by the current-carrying brush 16 in FIG. 6, the current-carrying brushes 16 and 17 are formed with an appropriate number of holes 71420 passing through them in the vertical direction to form a passage for shielding gas.

The main electrode 3, the pilot electrode 5 and the insulating ring 6 of the rotating body 7 are provided with coaxial holes 21, 22, 23 to provide electrode holes for the torch section. Main electrode 3
As shown in FIG. 4, the hole 21 consists of a small diameter part 21a and a large diameter part 211+, and the collets 1 to 24, which have grooves in the upper part of the grip, are screwed into the large diameter part 21b. The welding electrode 2 is firmly held by the welding electrode 24. There is a gap between the small diameter part 21a and the welding electrode 2, and a hole 25 is opened in the cholera l~24 that communicates with the groove in the grasping part of the collet. It forms a passageway. A hole 2 is provided below the collet 24.
An insulating sleeve 26 is inserted over 1, 22, and 23, and there is also a gap between this insulating sleeve 26 and the welding electrode 2, and this gap also serves as a passage for plasma gas. Further below the insulating sleeve 26, the nozzle 4 is screwed into the hole 23 of the pilot electrode 5.

Shielding gas passages 27 are formed in the insulating ring 6 at appropriate intervals in the circumferential direction.

The space between the insulating case 1 and the rotating body 7 is
4.15 into three chambers 28, 29, 30 in the radial direction; forming a plasma gas chamber communicating with the gap between the radially inner second and third chambers 29.3.
0 constitute a shield gas chamber which communicates with each other through a passage 27 of the insulating ring 6 and with the above-mentioned gasket 20 formed in the current-carrying brush 16, 17.

The OI of the insulation case 1 is on the energized brush 15.17! The power supply terminals 31 and 32 are screwed through the I wall, and the power supply terminals 3
A power supply cable 33 connected to a negative power supply of a welding power supply unit (not shown) is connected to the power supply terminal 1, and a power supply cable 34 connected to a positive power supply is connected to the power supply terminal 32.

Furthermore, a base 35.36 communicating with the first and third chambers 28.30 is connected to the (III wall) of the insulating case 1.
A gas hose 37 extending from a plasma gas supply system (not shown) is connected to the cap 35, and a gas hose 38 extending from a shield gas supply system (also not shown) is connected to the cap 36.
is connected.

Holes for passing the filler wire 40, that is, filler guides 41 and 42, are formed in the insulating case 1 and the rotating body 7, respectively. It is open around the circumference. Further, the upper part of the filler cable 42 from the main electrode 2 to the insulating ring 4 is arranged as shown by the broken line in FIG. It is fan-shaped. The filler guides 41 and 42 are provided because, although filler wire is rarely used in plasma keyhole welding for joining pipes, it may be necessary to assist in the formation of a bead.

Elastic bodies 43 and 44 are provided at the lower end of the side wall of the insulating case 1 in order to ensure that the insulating case 1 holds the target pipe P to be joined without interfering with it. The elastic bodies 43 and 44 also have an internal pressure adjustment function of creating a gap with the pipe P and allowing the shielding gas to escape when the internal pressure increases due to filling with the shielding gas, thereby improving the quality of welding.

Next, the operation of the plasma welding head configured as described above will be explained.

First, by passing the end of the target pipe P to be welded through this welding head, the target pipe P is inserted into the welding head and fixed. Next, when the drive motor 8 is driven, its rotation is transmitted to the gear 13 of the main electrode 2 via the drive pinion 9 and the insulating pinion 10, and the rotating body 7 rotates around the pipe P inside the insulating case 1.

At the same time, the power supply terminal 3 is connected to the power supply cable 33.34.
Welding current is supplied to 1.32, and the gas hose 37
．． 38 supplies plasma gas and shield gas to the bases 35 and 36, respectively.

The welding current supplied to the power supply terminals 31 and 32 is passed from the main electrode 3 and the piezos 1 to 5 to the welding electrode 2 and nozzle 4 via the current-carrying brushes 15 and 17, respectively. Further, the plasma gas supplied to the nozzle 35 flows into the first chamber 28 and from there passes through the above-mentioned = 11- plasma gas passage formed around the welding electrode 2 to become a plasma arc. Appears in the area to be welded. The shielding gas supplied to the base 36 flows into the third chamber 30, from where it also flows into the second chamber 29 through the passage 27, and through the extinguishers 20 of the current-carrying brushes 16 and 17, respectively, to the plasma arc. come out around you. As a result, the part of the pipe P to be welded is plasma keyhole welded.

In this way, when the rotating body 7 rotates once around the pipe P, the pipe P is joined by plasma keyhole welding.

During one revolution of the rotating body 7, the insulating case 1 remains fixed on the pipe P, and the power supply cable 33, 34 and the gas hose 37, 38 are attached to this insulating case. Therefore, when welding the pipe P, these cables and
The hose does not rotate and will not get wrapped around the pipe P or hit any corners and be damaged. Therefore, it is easy to use.

In addition, as a ripple effect, since the shielding gas atmosphere is covered by the insulating case 1, a constant welding quality can be ensured without being affected by the external environment, and light accompanying the arc phenomenon can be shielded. , safety effects can also be obtained.

The above embodiments are particularly suitable when the welding current is small.6 When the welding current becomes large, the electrode must be cooled. FIGS. 7 to 12 show such an embodiment, and in the figures, the same members as those in the embodiment shown in FIGS. 1 to 6 are given the same reference numerals. In addition, in this example, in order to further facilitate attachment and detachment to the target pipe P, a split opening/closing structure is also adopted, as will be understood from the following description.

In FIGS. 7 to 10 showing the overall configuration and main cross sections of the plasma welding head according to this embodiment, the insulating case is divided into two halves, a first and a second half, which are obtained by dividing the insulating case 1 of the first embodiment in the radial direction. The main electrode, pilot electrode and insulating ring of the rotating body also correspond to this, and the main electrode 3, pilot electrode 5 and insulating ring 6 of the rotating body 7 of the first embodiment Similarly divided first and second half holidays 52.53;, 54, 55; 5
6.57 respectively, as a result of which the rotating body has a first and a second half-housing 58.
It consists of 59 pieces. One half 58 of the rotating body holds the welding electrode 2 and nozzle 4 that constitute the torch section in the same manner as in the first embodiment, and the rotating body 58.5
A drive motor 8 and the like constituting the drive means of 9 are mounted.

A hinge 60 is attached to the mating surface portion of the outer peripheral surface of the insulating case half-closed 50.51, and the insulating case half-closed 50.5
1 and the rotating body half-rest 58, 59 can be opened and closed.

In addition, as shown in FIG. 12, a mating spring 61, 62 is attached to a portion of the side surface of the insulating case half-closed 50°51 that is away from the hinge 60, straddling the mating surfaces to maintain the closed state of the half-closed half. It looks like this.

Insulation case half-off 50.51 and main electrode half-off 52.53
Similarly, the energized brushes arranged between the insulating case half-closed 50.51 and the piezo 1 to electrode half-closed 54.55 are connected to the first and second half bodies 63, 64, 65.6, respectively.
It is composed of 6.67.68; 69°70. Each of these energized brush halves is provided with cooling channels 71 and 72 through which cooling water passes. In addition, each energized brush half has a tube 73°74 that connects the adjacent ends of two brush segments that are slightly shorter than a quarter-circle ring shape.
The connecting tubes 73 and 74 communicate the cooling water II in each of the plush segments 1 to 71,72. The periphery of the connecting tube 73 on the energized brush halves 63 to 66 side, together with the brush segment, partitions the space between the insulating case and the rotating body into first to third chambers, as in the first embodiment described above. Therefore, it is covered with a suitable partition member 75. Electric brush half body 67-7
The connection tube 74 on the 0 side is left as it is, and the gap around it constitutes a shielding gas passage corresponding to the tube 20 in the first embodiment.

As shown in FIG. 9, water-cooled power supply terminals 76.77 are screwed into one of the upper current-carrying brush halves 63, 64 through the side wall of the insulating case half 50. , are connected to water-cooled power supply cables 78 and 79, respectively, which are connected to the negative power supply of a cooling water source unit and a welding power supply unit (not shown). Similarly, water-cooled power supply terminals 80.81 are screwed into the other upper current-carrying brush half-holes 67, 68 through the side wall of the insulating case half-hole 50, and these water-cooled power supply terminals 80.81 are, respectively,
It is connected to water-cooled power supply cables 82 and 83 that are connected to the positive power supply of a cooling water source unit and a welding power supply unit (not shown).

The cooling water passage 71 of the upper insulating brush half-closed 63 and 64 is
The cooling water passages 71 of the lower insulating brush halves 65 and 66 are connected via connection pipes 84, and similarly the cooling water passages 72 of the upper insulating brush halves 67 and 68 are connected to the lower insulating brush halves 69 and 70. The lower insulating brush half 6 is connected to the cooling water passage 72 via a connecting pipe 85, respectively.
The cooling water passages 71 of 5 and 66
9.70 are connected to the cooling water passages 72 via connecting pipes 86, respectively.

In the second embodiment configured in this way, when attaching the welding head around the target pipe P, the set springs 60, 61 are rotated and slid, and the insulating case half-closed 50.51 and the rotating body half-closed 58 are attached. .59 is released from the closed state, these semi-openings are opened around the hinge 60, and the welding head in this open state is moved around the end of the target pipe P.
Positioning of the welding head takes place by closing the welding head again and restoring the dowel springs 60,61.

The rotational drive of the rotating bodies 58 and 59, the supply of welding current, and the supply of plasma gas and shielding gas are substantially performed by the first
This is done in the same way as in the embodiment.

Furthermore, in this embodiment, cooling water is supplied from the water-cooled power supply cable 82.83 via the water-cooled power supply terminal 80.81. The cooling water introduced from the water cooling power supply terminal 80 on one side passes through the path of the E-Low Harney Hohe Torch shown in FIG.
1 and connecting pipe 85, 86, 84, water cooling power supply terminal 7
6 and is returned to the cooling water source unit through the water cooling power supply cable 78. Similarly, the cooling water introduced from the water cooling power supply terminal 81 on the other side passes through the same route to the cooling water passages 72, 21 and connecting pipes 85, 86, respectively.
．． 84, is discharged from the water cooling power supply terminal 77, and is returned to the cooling water source unit through the water cooling power supply cable 79.

Therefore, according to this embodiment, the main electrode and the pilot electrode are effectively cooled by the cooling water passing through the cooling channels 71 and 72, so the welding current can be made larger than in the first embodiment, and the welding current can be increased depending on the application. Applications will expand. Also, since it has a split opening/closing structure, it is easy to attach and detach from the target pipe P.
Usability is further improved.

Figures 13 to 17 show an embodiment of the method of directly cooling the main electrode and pilot electrode, and the same reference numerals are given to the same members as those shown in Figures 1 to 12. .

In this example, the main electrode half-off 52.53 includes:
Cooling channels 90.91 are formed on both sides when viewed in cross section, and these cooling channels 90.91 communicate with each other via passages 92 provided at appropriate intervals in the circumferential direction, as shown in FIG. ing. Similarly, cooling channels 93, 94 and passages 95 are provided in the pilot electrode half-holes 54, 55. Cooling water channels 90.91 and 93.94 each open on the side surface of the brush.

Energized brush half-off 63, 64; 65, 66; 67° 68;
On the side of each of the electrodes 69 and 70 facing the half electrode, there are formed pipes 96 and 97 that communicate with the openings of the cooling water channels 90.91 and 93.94 and supply and receive cooling water. A water-cooled power supply terminal 98.99 penetrates the side wall of the insulating case half-hole 50 and is screwed into the current-carrying brush half-hole 63.67 on one side of the upper side.
The cooling water passages are respectively opened at the ends 96 and 97 through which the cooling water is given and received, and similarly penetrate through the side wall of the insulating case 50 and are screwed into the energized brushes 64 and 68 on the other side above. The cooling water passages of the water-cooled power supply terminals 100' and 101 are opened to holes 96 and 97, respectively. These water-cooled power supply terminals 98 to 101 are connected to the water-cooled power supply cable 10, respectively.
It is connected to a cooling water source unit and a power supply unit via 2,103,104°105. The other half-insulated case 51 is similarly provided with a water-cooled power supply terminal and a water-cooled power supply cable.

In this embodiment, on the insulating case 50 side, cooling water is introduced from water-cooled power supply cables 104 and 105 from water-cooled power supply terminals 100 and 101 through grooves 96 and 97 into cooling water channels 91 and 94, respectively. 17 through passage 92.95 to the opposite cooling water channel 90.9.
3, and from here it passes through sections 96 and 97 to the water cooling power supply terminal 9.
8, 9 and water-cooled power supply cables 102 and 103 are returned to the tank. The same applies to the insulated cable 51 side.

Therefore, the main $152.53 and the pilot electrode 54
．． 55 are directly cooled by the cooling water flowing through the respective cooling channels, making it possible to cool these electrodes more effectively.

The above embodiments apply the present invention to plasma welding-20
- Although this is an example in which the present invention is applied to a RAD, the present invention is not limited to this, and can be applied to other similar welding heads that perform all-position welding, such as a TIG welding head.

〔Effect of the invention〕

As is clear from the above, according to the welding head of the present invention, the power supply cable and the gas hose are connected to the power supply terminal and the base inserted through the insulating case, which is a fixed member, so even if the rotating body rotates during welding, The cables and gas hoses do not rotate, and the cables and gas hoses do not get wrapped around pipes or hit against any corners and are damaged, which greatly improves usability. In addition, as a ripple effect, the gas atmosphere covering the welded part is maintained in a good condition, making it less susceptible to external environment, and ensuring welding quality. Furthermore, it becomes possible to block welding light, and a safety effect can also be obtained.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing a plasma welding head according to an embodiment of the present invention, with a part of the side wall of the insulating case and a part of the current-carrying brush at a different position removed;
Figure 2 is a cross-sectional view taken along the line ■-■ in Figure 1;
1, FIG. 4 is a sectional view taken along line IV-IV in FIG. 1, and FIG. 5 is a sectional view of the rotating body of the plasma welding head and 6 is a developed view of the members constituting the torch portion, FIG. 6 is a cross-sectional view taken along line vI to ■ in FIG. 4, and FIG. 7 is a cross-sectional view showing a plasma welding head according to another embodiment of the present invention. This is a similar figure to Figure 1.
Figure 8 is a sectional view taken along the line ■-■ in Figure 7;
The figure is a cross-sectional view taken along the line IX-IX in FIG. 7, and FIG. 10 is a cross-sectional view taken along the line X-X in FIG.
1 is a view seen from the XI force direction in FIG. 7, FIG. 12 is a sectional view taken along the line X--X in FIG. 8, and FIG. 13 is a diagram showing still another embodiment of the present invention. FIG. 14 is a cross-sectional view taken along the line XIV-XIV of FIG. 13, and FIG.
The figure is a sectional view taken along the line xv-xv in FIG. 13, and FIG. 16 is a cross-sectional view taken along the line
22 = sectional view, and Fig. 17 is X VU -X of Fig. 14
FIG. 3 is a cross-sectional view taken along the Vll line. Explanation of symbols 1... Insulating case 2... Welding electrode 3...
Main electrode 4... Nozzle 5... Pilot 1
Electrode 6...Insulating ring 7...Rotating body 8...Drive motor (drive means) 14-17...Electrifying brushes 28-30...Chamber Applicant Hitachi, Ltd. Agent Patent attorney Haru Japan Figure 11 Figure 12 Tod N Figure 15

Claims (4)

[Claims] (1) A rotating body is configured with at least a ring-shaped main electrode that holds a welding electrode, and this rotating body is rotatably housed in a ring-shaped insulating case, and a drive that rotationally drives the rotating body in the insulating case. A welding head characterized in that a current-carrying brush is arranged between an insulating case and a main electrode of a rotating body, and a power supply terminal and a gas hose mouthpiece are inserted into the insulating case. (2) The rotating body is composed of a ring-shaped main electrode that holds the welding electrode, a ring-shaped pilot electrode that holds the nozzle, and an insulating ring that separates these electrodes, and the insulating case and the main electrode of the rotating body Each energizing brush is arranged between the energizing brush and the pilot electrode, and the space between the insulating case and the rotating body is partitioned to form a plurality of chambers for guiding plasma gas and shielding gas. The welding head according to claim 1, characterized in that plasma gas and shielding gas are guided into and out of the nozzle. (3) dividing the rotating body and the insulating case into halves in the radial direction to form first and second halves;
3. The welding head according to claim 1, wherein the halves of the welding head are connected by a hinge means so that the welding head can be opened and closed. (3) The welding head according to claim 1 or 2, wherein the current-carrying brush is provided with a cooling channel through which cooling water flows. (4) On the main electrode and pilot electrode of the rotating body,
Claim 2, characterized in that a cooling channel through which cooling water flows is provided, and a groove for delivering and receiving the cooling water is formed on the side of each energizing brush facing the main electrode and the pilot electrode. welding head.