JP2898111B2 - Plasma jet torch and plasma jet oscillating method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma jet torch for injecting a high-temperature gas converted into a plasma by an electric arc discharge and a method of swinging the plasma jet torch.

[0002]

2. Description of the Related Art A torch of this kind is used for high-temperature processing or processing of an object, for example, for heating or melting metal.

[0003] For example, Japanese Patent Application Laid-Open No. 54-24249 discloses a defect removal method in which a defect on the surface of a cast metal material or a rolled metal material is removed by melting the metal material surface with a transfer type plasma jet torch. A method is presented. In order to remove a wide range of defects, an electromagnet core is arranged between the plasma jet torch and the metal material, and this is used as a torch.
An orthogonal magnetic field is applied to the arc, ie, the plasma arc current, which transfers from the metal to the metal material to deflect the plasma arc current. By alternately reversing the energizing direction of the electromagnet, the plasma arc current reciprocates and scans the surface of the metal material. Thereby, a wide area of the defect is removed. Japanese Patent Laying-Open No. 54-24249 also discloses a mode in which an electric coil is inserted between a transfer type plasma arc current and a metal material to thereby reciprocate the plasma arc current.

[0004] By the way, non-transfer type plasma arc is
Although high-temperature electrode heating was characteristic, surface treatment of steel sheets on the order of microns requires a uniform and wide range of heat sources. However, there has not been a plasma jet oscillating device in a non-transfer type plasma jet torch.

[0005]

A magnetic flux generator is mounted outside the tip of a non-transferred plasma jet torch to apply an alternating magnetic flux to an ionized high-temperature plasma jet frame to oscillate, but there is a problem. It could not be put to practical use. In other words, since magnetic flux acts on the flow of electric charge in the ionized plasma jet frame, the efficiency is extremely poor compared to the case where magnetic flux acts directly on the arc current, and a high-output magnetic flux generator is required. Becomes The plasma frame emitted on the torch axis has a strong directivity (inertial force), and a high-output magnetic flux generator is required to swing the plasma frame. The magnetic flux generator
Because it is further forward of the tip of the switch, it is in a high-temperature atmosphere and has a problem of heat resistance.

The object of the present invention is to remedy this kind of conventional problems.

[0007]

Means for Solving the Problems According to the first invention of the present application,
The non-transfer type plasma jet torch is composed of an electrode (1), an electrode
(1) an inner nozzle member (6) having a plasma nozzle (6n) at a position facing the tip, a gas flow path for supplying gas to a space between the inner nozzle member (6) and the electrode (1), And a plasma emission opening (11n) at a position facing the plasma nozzle (6n)
An external electrode member (11) having
-H, inserted between the inner nozzle member (6) and the outer electrode member (11), from the plasma nozzle (6n) to the plasma emission opening (1).
A heat insulating cylinder (13) surrounding the plasma flow path going to 1n); and
Electric coil for generating magnetic flux across the heat insulating cylinder (13)
(10);

According to a second aspect of the present invention, there is provided a non-transfer type plasma jet oscillating method, comprising: an inner nozzle member having a plasma nozzle (6n) at a position facing an electrode (1) and a tip of the electrode (1);
(6), a gas flow path for supplying gas to a space between the inner nozzle member (6) and the electrode, an outer electrode member (11) having a plasma emission opening (11n) at a position facing the plasma nozzle, A heat insulating cylinder (13) inserted between the nozzle member (6) and the outer electrode member (11) and enclosing the plasma flow path that advances from the plasma nozzle (6n) to the plasma emission opening (11n), and has a heat insulating cylinder end A magnetic core (9) having two or more pairs of pole tips (9a, 9b, 9c, 9d) facing the outer surface of the body (13) and facing each other with the heat insulating cylinder (13) interposed therebetween, and The magnetic poles (9
a, 9b) and (9c, 9d) of a plasma jet torch comprising a plurality of electric coils (10a, 10b, 10c, 10d) for generating a magnetic flux crossing the heat insulating cylinder (13). The electric coil (10a, 1
0b, 10c, 10d), characterized by applying a sine wave alternating voltage that generates a rotating magnetic field in a space surrounded by the tips of the magnetic pole tips (9a, 9b, 9c, 9d).

Symbols in parentheses indicate corresponding elements in the embodiment shown in the drawings and described later.

[0010]

According to the first aspect of the present invention, the electric coils (10a, 10b, 10c, 10d) are composed of the electrodes (1) to (4).
A magnetic flux crossing the plasma arc current flowing through the inner nozzle (6n), the outer nozzle (8n), the heat insulating cylinder (13), and the outer electrode (11n) is generated.

When a magnetic flux alternating with the arc current flows, a force acts in a direction perpendicular to the flow of the magnetic flux according to Fleming's left-hand rule to bend the plasma arc current. When the direction of the magnetic flux is reversed, the acting force changes in the opposite direction.

When an alternating current is used for the electric coils (10a, 10b, 10c, 10d), the arc can be oscillated at a frequency corresponding to the alternating cycle.

The plasma arc current is a heat source that heats the heating gas to form a plasma jet frame.
The swing of the arc current simultaneously causes the swing of the plasma jet frame.

The position where the magnetic flux is applied is determined by the arc in the torch.
Since the arc current is applied to the constricted portion, a magnetic field sufficient for deflection at the relatively small pole tips (9a, 9b) effectively acts on the plasma arc current. Therefore, the electric coils (10a, 10b, 10c, 10d) can have a relatively small size and a relatively large deflection angle.

Since the plasma arc current is deflected by the action of the magnetic field at the base and directed toward the material to be heat-treated, for example, a metal material, the amount of deflection of the plasma arc current on the surface of the metal material is large. As described above, a relatively large amount of deflection can be obtained with a relatively small electric coil, and a small amount of power is required for applying a deflection magnetic field.

Further, the plasma arc current and the electric coil (1)
0a, 10b, 10c, and 10d), there is a heat insulating cylinder (13), and the electric coils (10a, 10b, 10c, and 10d) are associated with almost no fluctuation of the plasma arc current at the base. ) Is not hit by the plasma frame, and the electric coil is not burned by the plasma frame. Since the heat insulating cylinder (13) is also located at the base of the plasma arc current, it does not touch the plasma arc current even if its diameter is relatively small.

In the method of swinging the plasma jet torch according to the second aspect of the present invention, the operation and effect of the first aspect of the invention are similarly provided, and the number of magnetic poles (9a, 9b, 9c, 9d) is reduced to two. More than one pair and a plurality of electric coils (10a, 10b, 10c, 10d),
Moreover, each of the electric coils (10a, 10b, 10c, 10d) has
Since a sine-wave alternating voltage that generates a rotating magnetic field is applied to the space surrounded by the tips of the magnetic pole tips (9a, 9b, 9c, 9d), the plasma arc current flows between the tip of the electrode (1) and the plasma nozzle (6n). ) Makes a circular motion along a circumference centered on a straight line (the central axis of the electrode 1), and the plasma arc current draws a cone between the metal material from the tip of the electrode (1). Electric coil (10a, 10
Since the alternating current applied to (b, 10c, 10d) is a sine wave, the circular motion is a substantially constant-velocity circular motion, so that the movement of the plasma arc current is very smooth, the shape is stable, and the deflection is large. Substantially no frame fluctuation due to movement.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

[0019]

FIG. 1 shows a longitudinal section of an embodiment of the first invention of the present application, and FIG. 2 shows a plasma jet printer shown in FIG.
-Shows the underside of the switch. FIG. 1 is a sectional view taken along line II of FIG. An electrode base 4 is mounted on the upper end of the torch base 5, and the electrode cap 3 is coupled to the electrode base 4. The electrode cap 3 fastens the chuck 2 through which the electrode 1 has passed, thereby positioning the electrode 1 at the center axis position of the cylindrical main body 5.

An inner nozzle member 6 is mounted on the lower end of the main body 5, and a centering stone 7 is interposed between the inner nozzle member 6 and the electrode 1.
However, the electrode 1 is positioned such that the central axis of the electrode 1 is aligned with the central axis of the inner nozzle member 6 at the lower end of the main body 5. An inner nozzle (plasma nozzle) 6n is opened at the center position of the lower bottom of the inner nozzle member 6. An electrode gas is supplied to a space between the electrode 1 and the inner nozzle member 6.

An outer nozzle member 8 is attached to the lower end of the main body 5. The outer nozzle member 8 is slightly larger in diameter than the inner nozzle 6n in accordance with the center axis of the outer nozzle member 8 and the center axis of the electrode 1 and the center axis of the inner nozzle 6n. The nozzle 8n is open. Between the lower bottom outer surface of the inner nozzle member 6 and the upper surface of the outer nozzle 8, a ring-shaped insulating collar 14 having a gas passage opened in the radial direction is inserted. A heating gas is supplied to a space between the inner nozzle member 6 and the outer nozzle member 8. Torch cooling water is supplied to the outer nozzle member 8, and the cooling water exits the outer nozzle member 8, passes through the water passage of the main body 5, enters the water passage of the inner nozzle member 6, and exits the inner nozzle member 6. Further, it is discharged outside the torch through the trunk 5.

The upper end of a ring-shaped heat insulating collar 13 is fixed to the lower bottom outer surface of the outer nozzle member 8.
The outer electrode 11 is fixed to the lower end of the substrate. The outer electrode 1
1 is also fixed to the outer nozzle member 8 via an insulating material (not shown). The central axis of the circular space of the heat insulating collar 13 is aligned with the central axis of the outer nozzle 8n. The outer electrode nozzle 11n of the outer electrode 11 has a flattened conical shape connecting a circular opening continuous with the heat insulating collar 13 and an oblong opening shown in FIG. That is, even when the plasma arc current is deflected in the left-right direction, the plasma arc current is substantially reduced to the outer electrode 11.
The shape of the outer electrode nozzle 11 is set so as not to directly hit the nozzle. External electrode cooling water is supplied to a water passage inside the external electrode nozzle 11, and the cooling water is discharged to the outside of the external electrode nozzle 11 through a recovery pipe (not shown).

On the outer side of the heat-insulating collar 13, a magnetic core 9 made of a generally C-shaped laminated body of silicon steel plates is arranged. A pair of magnetic pole tips 9a, 9a, 9b
Sandwich the heat insulating collar 13. That is, the pole tip 9
There is a heat insulating collar 13 between the opposite end faces of a and 9b. An electric coil 10 is wound around the magnetic core 9. The magnetic core 9 is fixed to the outer nozzle member 8 and the outer electrode 11 via an insulating material (not shown).

Electrode 1 (negative electrode) and inner nozzle member 6 (positive electrode)
An arc voltage is applied between the electrode 1 and the inner nozzle 6n to generate an arc between the electrode 1 and the inner nozzle 6n. Then, a positive voltage is applied to the outer nozzle member 8 to apply an arc voltage between the electrode 1 and the inner nozzle 6n. Is shifted between the electrode 1 and the outer nozzle 8n, and then the positive voltage is applied to the outer electrode 11 to shift the arc between the electrode 1 and the outer nozzle 8n between the electrode 1 and the outer electrode nozzle 11n. Then, a plasma arc current is injected from the outer electrode nozzle 11n. This plasma arc current is applied to the electrode 1, the inner nozzle 6
n, the outer nozzle 8n, the heat insulating collar 13 and the outer electrode nozzle 11n are ejected along the extension of the central axis.

When the electric coil 10 is energized in the positive direction,
A magnetic flux flows between the magnetic pole tips 9a and 9b as indicated by a dashed line in FIG. 2, and the direction in which the plasma arc current flows (perpendicular to the plane of FIG. 2) and the line connecting the magnetic pole tips 9a and 9b. (Vertical direction in FIG. 2)
The plasma arc current is deflected (for example, leftward) (Fleming's left-hand rule: FIG. 3). Accordingly, the plasma jet frame is similarly deflected. Electric coil 1
When a current is applied in the opposite direction to 0, the plasma arc current is perpendicular to the flowing direction (the direction perpendicular to the plane of FIG. 2) and the line connecting the magnetic pole tips 9a and 9b (the vertical direction in FIG. 2). The plasma arc current is deflected in an appropriate direction (rightward in FIG. 2) (Fleming's left-hand rule). Accordingly, the plasma jet frame is similarly deflected.

FIG. 3 shows how the plasma arc current is deflected when the electric coil 10 is energized. The deflection angle θ of the plasma arc current is determined by the arc current value of the plasma arc current and the magnetic field strength between the magnetic pole tips 9a and 9b, and the magnetic field strength is determined by the current value flowing through the electric coil 10. .

FIG. 4 shows the relationship between the magnetic flux density at the axial center of the electrode 1 between the magnetic pole tips 9a and 9b and the deflection angle of the plasma arc current (arc deflection angle). As the magnetic flux density is increased from 40 gauss to about 120 gauss, the arc deflection angle increases substantially linearly. Such a large deflection at a relatively low magnetic flux density is caused by a plasma arc.
In the case of the arc current, the arc current value is high (for example, 150 A).
Because.

The value of the current flowing through the electric coil 10 and the magnetic pole 9
FIG. 6 shows the relationship with the density of the magnetic flux generated between a and 9b. As shown in FIG. 5, the data of FIG.
The distance between the coils 9b is 40 mm, and the number of turns of the electric coil 10 is 2,000.
Indicates the magnetic flux density at the end position A of the magnetic pole tip 9b.
Data B indicates a magnetic flux density at an intermediate point B on the central axis connecting the magnetic pole tips 9a and 9b, and data C indicates a magnetic flux density at a position off by 5 mm from the central axis.

From the data shown in FIG. 4 and the data A shown in FIG. 6, it is necessary to make the plasma arc current at the axial center position of the electrode 1 (position B in FIG. It is understood that a magnetic flux density of about Gauss is required (FIG. 4), and that a current of about 0.6 A may be passed through the electric coil 10 in order to obtain this magnetic flux density. This current value is considerably smaller than the obtained arc deflection angle.

In the embodiment shown in FIG. 1, the pole tips 9a, 9b
Are a pair, the plasma arc current reciprocates only in one axial direction. As shown in FIG. 7A, the plasma arc current alternately moves to the left (FIG. 3) and to the right by alternately energizing the electric coil 10 in the forward and reverse directions. Reciprocate in the range of °. FIG.
As shown in (A), when the energization in the order of forward energization, energization suspension, and reverse energization is repeated in a pulsed manner, the plasma arc current is deflected by + θ ° deflection position, center position, -θ ° deflection. It takes three positions and stops moving for some time at these positions, but the speed of moving between those positions is extremely fast. That is, since the movement of the plasma arc current becomes a non-uniform movement, the plasma arc current fluctuates due to the reciprocating turn, and the plasma arc current is generated on the surface of the metal material.
It is not possible to obtain a uniform scan (thermal soaking scan) of the current. Therefore,
When uniformly scanning a certain area of the continuous surface of the same metal material, as shown in FIG.
Apply a sine wave AC voltage. As a result, the plasma arc current substantially moves at a constant speed between the turning points (+ θ ° deflection position and −θ ° deflection position), the fluctuation of the plasma arc current decreases, and the scanning of the metal material surface is reduced. Become uniform.

In any case, as shown in FIG. 3, since a deflection magnetic field is applied to the plasma arc current at the base near the outer nozzle 8n, the plasma arc current is generated at a relatively low intensity of the deflection magnetic field. The frame portion near the tip of the peak current moves largely left and right, and the deflection amount is large. That is, a relatively large deflection amount can be obtained with the relatively small magnetic core 9 and the electric coil 10. Since the value of the current flowing through the electric coil 10 may be relatively low, power consumption is small. Insulated collar-1
3 is located at the base, the plasma arc current does not directly hit it even if its diameter is relatively small, and the adiabatic collar 13 forms the magnetic pole tips 9a, 9 of the plasma arc current.
b. That is, the heat insulation color 13
However, the arrangement of the magnetic pole tips 9a and 9b can be made compact.

[0032]

Second Embodiment FIG. 8 shows a lower surface of another embodiment,
FIG. 9 shows an enlarged cross section taken along line IX-IX. In this embodiment, the magnetic material core 9 protrudes four branches that form an angle of 90 degrees with each other from the ring-shaped common magnetic path toward the center of the ring. 9a to 9d substantially contact the outer surface of the heat insulating collar 13. Electric coils 10a to 10d are wound around the bases of the four branches, respectively. The outer electrode nozzle 11n is formed in a truncated cone shape in this embodiment because it imparts a conical movement to the plasma arc current. Other structures are the same as those of the first structure described above.
It is the same as the structure of the embodiment.

In the second embodiment, as shown in FIG. 11, electric coils 10a and 10c and electric coils 10b and 10d
The magnetic poles 9a to 9d are formed, for example, in the manner shown in FIG. 10A, then (B), then (C), then (D), and then back to (A). The magnetic field rotates in the space surrounded by the tip surface of the. That is, by energizing the electric coil 10a in the forward direction to magnetize the magnetic pole tip 9a to the N pole and energizing the electric coil 10c in the reverse direction to magnetize the magnetic pole tip 9c to the S pole, As shown,
The magnetic flux Mf flows through the magnetic pole tips 9a to 9c, and the plasma arc
As shown in (A) of FIG.
It is deflected in the same direction F by receiving a force in the direction F toward d. Next, by energizing the electric coil 10d in the positive direction, the magnetic pole 9d is set to N.
10B by magnetizing the magnetic pole 9b and magnetizing the magnetic pole 9b to the south pole by applying a reverse current to the electric coil 10b.
As shown in FIG. 10, a magnetic flux Mf flows from the pole tips 9d to 9b, and the plasma arc current receives a force in the direction F from the pole tips 9a to 9c as shown in FIG. To deflect. Next, by energizing the electric coil 10c in the forward direction to magnetize the magnetic pole tip 9c to the N pole, and energizing the electric coil 10a in the reverse direction to magnetize the magnetic pole tip 9a to the S pole, (C) of FIG. As shown in FIG.
The magnetic flux Mf flows through the magnetic poles 9a, and the plasma arc current flows in the direction F from the magnetic pole tips 9d to 9b as shown in FIG.
And is deflected in the same direction F. Next, the electric coil 1
By energizing the pole tip 9b to the N pole by energizing the pole 0b in the positive direction and energizing the pole tip 9b to the S pole by energizing the electric coil 10d in the reverse direction, as shown in FIG. The magnetic flux Mf flows through the pole tips 9b to 9d, and the plasma arc current is changed from the pole tips 9c to 9a as shown in FIG.
And is deflected in the same direction F by receiving a force in the direction F toward the same direction.

When the pulse current is applied as shown in FIG. 11A, the plasma arc current is changed as shown in FIGS.
(B), (C), and (D) take four positions and stay at each position for a relatively long time, but the movement between the positions is rapid, resulting in a non-uniform movement in a quadrangular shape. . The energization suspension time of each electric coil is set to zero or a very short time, and another set of electric power is supplied to one set of electric coils (for example, 10a and 10c) during the forward and reverse energization periods (for example, the midpoint of the energization period). When the energizing cycle and energizing phase difference are reduced in a manner in which the forward and reverse energization of the coils (10b, 10c) are started, the plasma arc current becomes (A), (AB), (B),
(BC), (C), (CD), (D), and (DA) take eight positions, and the movement between the positions is abrupt and stays relatively long at each position. It becomes fast movement. This unequal-velocity motion drawing an octagon is closer to a circular motion, and is a smoother motion than the unequal-velocity motion drawing a quadrangle described above.
The fluctuation of the tip frame due to the deflection movement of the plasma arc current is small.

In a preferred embodiment of the present invention, in order to make the plasma arc current deflection movement smoother,
As shown in FIG. 11B, a sinusoidal alternating current is applied to the electric coils 10a to 10d. That is,
An AC voltage of a required level is applied to the electric coil 10a, and the AC voltage applied to the electric coil 10 is delayed by 270 degrees in phase to the electric coil 10b, and 180 degrees delayed in phase to the electric coil 10c. The applied AC voltage is applied to the electric coil 10d, and an AC voltage delayed by 90 degrees is applied to the electric coil 10d. As a result, a substantially complete constant-velocity circular motion magnetic field is generated in the space surrounded by the tip surfaces of the magnetic pole tips 9a to 9d, and the plasma arc current makes a constant circular motion. Therefore, the movement of the plasma arc current is smooth, and the fluctuation of the plasma arc current frame due to the movement does not occur. Further, the heating of the surface of the metal material within the scanning width of the plasma arc current becomes more uniform.

[0036]

The plasma jet torch of the first invention of the present application is a non-transitional torch, in which an electric coil for generating a magnetic flux is installed inside the torch, and an arc current for generating a plasma jet is generated. Since the magnetic flux is applied directly, the efficiency is very high, and a reliable swing can be obtained with a small amount of magnetic flux. The heat resistance of the electric coil has been sufficiently improved.

In the swinging method of the non-movable type plasma jet according to the second invention of the present application, the same effects as those of the first invention described above are similarly obtained, and the magnetic poles (9a, 9b, 9c, 9d) are obtained. )
And two or more pairs of electric coils (10a, 10b, 10c, 10d), and each of the electric coils (10a, 10b, 10c, 10d) has a magnetic pole tip (9a, 9b, 9c, 9d). ), A sine wave alternating voltage that generates a rotating magnetic field is applied to the space surrounded by the tip of
The plasma arc current makes a circular motion along a circumference centered on a straight line (center axis of the electrode 1) connecting the tip of the electrode (1) and the center of the plasma nozzle (6n). But,
Draw a cone between the metal material and the tip of the electrode (1). Since the alternating current applied to the electric coils (10a, 10b, 10c, 10d) is a sine wave, the circular motion is a substantially constant-velocity circular motion, so that the movement of the plasma arc current is very smooth and shaped. Is stable, and the frame does not substantially fluctuate due to the deflection motion.

[Brief description of the drawings]

1 is a longitudinal sectional view of a first embodiment of the first invention of the present application, and is a sectional view taken along the line II of FIG. 2;

FIG. 2 is a plan view showing a lower surface of the plasma jet torch shown in FIG.

FIG. 3 is a longitudinal sectional view showing a part of the plasma jet torch shown in FIG. 1, and shows a deflected plasma arc current.

4 is a graph showing a relationship between a magnetic flux density between magnetic pole tips and an arc deflection angle of a plasma arc current of the plasma jet torch shown in FIG. 3;

FIG. 5 is a reduced plan view showing magnetic flux density measurement points of the plasma jet torch shown in FIG. 2;

FIG. 6 is a graph showing a relationship between an electric current flowing through an electric coil and a magnetic flux density at a magnetic flux density measurement point shown in FIG. 5;

7 is a time chart showing a waveform of a current flowing through an electric coil 10 of the plasma jet torch shown in FIG.

FIG. 8 is a plan view showing the lower surface of the second embodiment of the first invention of the present application.

FIG. 9 is an enlarged sectional view taken along line IX-IX of FIG. 8;

FIG. 10 shows an electric coil 10a according to a second embodiment shown in FIG.
When a current shown in FIG.
FIG. 4 is a plan view showing a direction Mf of a magnetic flux generated between magnetic pole ends.

11 is an electric coil 10a according to the second embodiment shown in FIG.
10A to 10D are time charts showing waveforms of a current flowing through the coil, and FIG. 6B shows a waveform of a current flowing through the electric coil in the embodiment of the second invention of the present application.

FIG. 12 shows an electric coil 10a according to the second embodiment shown in FIG.
When a current shown in FIG.
FIG. 12A is a plan view showing the direction Mf of the magnetic flux generated between the magnetic pole ends. FIG. 12A shows the timing a shown in FIG. 11B, and FIG. ), And FIG. 12 (B) shows the timing b shown in FIG. 11 (B), and FIG.
FIG. 1B shows the timing bc shown in FIG.
2 (C) shows the timing c shown in FIG. 11 (B), FIG. 12 (CD) shows the timing cd shown in FIG. 11 (B), and FIG. 12 (D) shows the timing c shown in FIG. FIG. 12B shows the timing d shown in FIG. 11B, and FIG. 12D shows the timing da shown in FIG. 11B.

[Explanation of Signs] 1: Electrode 2: Chuck
3: Cap 4: Electrode stand 5: Backbone
6: Inner nozzle member 6n: Inner nozzle 7: Centering stone 8: Outer nozzle member 8n: Outer nozzle 9: Magnetic core
9a-9d: Magnetic pole 10, 10a-10d: Electric coil
11: Outer electrode 11n: Outer electrode nozzle 12: Coil lead
12a, 12b: Terminal 13: Insulated color 14: Insulated color

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Iwao Sakai 7-6-1, Higashi Narashino, Narashino City, Chiba Prefecture Nippon Steel Welding Industry Co., Ltd. Equipment Division (56) References JP-A-51-135852 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) B23K 10/00 504 H05H 1/40 B23K 9/08

Claims (2)

(57) [Claims] An electrode, an inner nozzle member having a plasma nozzle at a position facing a tip of the electrode, a gas flow path for supplying gas to a space between the inner nozzle member and the electrode,
And a non-transitional plasma jet torch having an outer electrode member having a plasma emission opening at a position facing the plasma nozzle, interposed between the inner nozzle member and the outer electrode member, and A heat-insulating cylinder surrounding the plasma flow path leading to the plasma emission opening; and
A non-transferring plasma jet torch comprising: an electrical coil for generating a magnetic flux across the insulated cylinder. 2. An electrode, an inner nozzle member having a plasma nozzle at a position facing a tip of the electrode, a gas flow path for supplying gas to a space between the inner nozzle member and the electrode,
An outer electrode member having a plasma emission opening at a position facing the plasma nozzle, a heat insulating cylinder interposed between the inner nozzle member and the outer electrode member and surrounding a plasma flow path from the plasma nozzle to the plasma emission opening; A magnetic core having two or more pairs of magnetic poles having a tip end surface facing the outer surface of the heat-insulating cylinder and facing each other with the heat-insulating cylinder interposed therebetween; and a magnetic core wound around the magnetic core and facing each other. A plurality of electric coils for generating a magnetic flux traversing the heat insulating cylinder between the magnetic poles, in each of the electric coils in a space surrounded by the tip of the magnetic pole. A non-transitional plasma jet oscillating method, characterized by applying a sinusoidal alternating voltage that generates a rotating magnetic field.