JPH03248772A - Torch device for generating arc and its starting method - Google Patents

Abstract

PURPOSE:To remotely generate an arc by releasing electric connection in an energized state after an electrode and a nozzle which are connected electrically are energized and increasing insulation resistance gradually by an arc generator consisting of the electrode, the nozzle and an insulator between both. CONSTITUTION:In starting the arc generator consisting of the electrode 1 for generating the arc, the nozzle 2 capable of having a reverse property thereto and the insulator 3 between both, at the time of starting arc generation, in a state with the electrode 1 and the nozzle 2 connected electrically, energizing is carried out between both and in that state, the electrical connection between both is released and the insulation resistance between both is increased gradually and an arc is generated between those. Consequently, since a high-frequency generator to generate a pilot arc is not used, the arc can be generated without giving an adverse influence by high-frequency noise to peripheral equipment.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for starting an arc generating torch device used in a TIG welding device, a plasma cutting device, etc., a torch device and a starting jig for realizing the starting method, The present invention also relates to a welding device and a cutting device including a torch device or starting jig therefor.

[Conventional technology]

Conventional arc generating torch devices use a high frequency generator to first ignite a pilot arc by applying a pilot arc power supply voltage between an electrode rod and a nozzle.
It is common to then switch to the main arc and extinguish the pilot arc, in which case it is necessary to generate a high frequency for several seconds.

As an improvement plan, as described in Japanese Patent Laid-Open No. 63-5875, a pilot arc is generated only immediately before the main arc is ignited, thereby reducing the high frequency discharge time as much as possible.

Alternatively, as described in Japanese Unexamined Patent Publication No. 63-20169, the electrode is brought into contact with the base material at the time of startup,
After that, they were devised to eliminate the generation of high-frequency noise by separating them and generating an arc.

[Problem to be solved by the invention]

Since the above-mentioned conventional general device uses a high frequency generator, there are problems such as high frequency noise may affect peripheral devices and cause them to malfunction. In addition, as a countermeasure to this problem, Japanese Patent Application Laid-Open No. 63-58 (1983-58) shortened the high frequency generation time.
The device described in Japanese Patent No. 75 still requires a high frequency generator and has some problem of high frequency noise generation.

Furthermore, JP-A-63-201 features a high frequency generator.
In the conventional device described in Publication No. 69, measures were taken to prevent high-frequency noise generation because the electrode and the base material are brought into contact with each other at startup and then separated to generate an arc. The electrode must be kept in contact with the welding or cutting position of the base metal, which poses a problem in terms of operational constraints.

The purpose of the present invention is to eliminate the generation of high frequency noise by generating an arc without using a high frequency generator at the time of startup, and also to make it possible to generate a pilot arc in any state at the time of startup. An object of the present invention is to provide a method for starting an arc generating torch device, an arc generating torch device, a starting jig, a welding device, and a cutting device that reduce operational restrictions and improve workability.

[Means to solve the problem]

In order to achieve the above object, the present invention provides an arc generating device that includes an electrode rod for generating an arc, a nozzle that can have characteristics opposite to the electrode rod, and an insulator for insulating between them. In a method for starting a torch device, when starting to generate an arc, a current is passed between the electrode bar and the nozzle while the electrode bar and the nozzle are electrically connected; By breaking the electrical connection between the two and gradually increasing the insulation resistance between them, an arc is generated between them.

Here, preferably, the electrical connection between the electrode and the nozzle is made by bringing the electrode rod into contact with the nozzle, and by gradually increasing the distance between the electrode and the nozzle, the insulation resistance between the two is gradually increased. .

In addition, a starting jig separate from the torch device is prepared, and the electrode rod and nozzle are electrically connected by bringing the electrode rod and nozzle into contact with the conductive part of this starting jig, and the electrode rod and the nozzle are connected electrically. The insulation resistance between the two may be gradually increased by separating at least one of them from the conductive part of the starting jig.

The present invention also provides an electrode rod for generating an arc;
An electrode rod driving means for changing the relative position of the electrode rod and the nozzle in an arc generating torch device having a nozzle that can have characteristics opposite to those of the electrode rod, and an insulator for insulating between them. It has been established.

Here, the electrode rod driving means may be a manual type including a manual operation section, or a remote control type including a drive section that can be operated remotely.

Further, according to the present invention, the present invention is characterized by comprising the above-mentioned arc generating torch device and a welding power source for arc generating including a constant current circuit that maintains the current flowing between the electrode rod and the nozzle at a set value. A welding device is provided.

Furthermore, according to the present invention, the present invention is characterized by comprising the above-mentioned arc generating torch device and a cutting power source for arc generating including a constant current circuit that maintains the current flowing between the electrode rod and the nozzle at a set value. A cutting device is provided.

The present invention also provides an electrode rod for generating an arc;
In a starting jig for an arc generating torch device, which has a nozzle that can have characteristics opposite to those of the electrode rod, and an insulator for insulating between them, the electrode rod and the nozzle are connected to each other when the torch device is set. A conductive portion is provided in which at least one of the electrode rod and the nozzle separates as the contact occurs and the state is released.

According to the present invention, the above-mentioned arc generating torch device and starting jig, and an arc generating welding power source including a constant current circuit that maintains the current flowing between the electrode rod and the nozzle at a set value are provided. Provided is a welding device comprising:

Further, according to the present invention, the above-mentioned arc generating torch device and starting jig, and an arc generating cutting power source including a constant current circuit that maintains the current flowing between the electrode rod and the nozzle at a set value; Provided is a cutting device comprising:

[Effect]

The electrode rod serves as one electrode when generating an arc between the nozzle or the base material. The nozzle becomes an electrode of opposite polarity to the electrode rod when a pilot arc is generated. The electrode rod and nozzle are usually insulated by an insulator. At startup, a current is passed between the electrode rod and the nozzle in a state where they are electrically connected, and the electrical connection is then released to gradually increase the insulation resistance between the two. At this time, even if the insulation resistance between the electrode rod and the nozzle increases, if the current is adjusted to the set value within a certain voltage range, the current flowing through the electrode rod and nozzle with the electrode rod and nozzle electrically connected can be is maintained at the set value and no overcurrent flows.

Further, even if the insulation resistance between the electrode rod and the nozzle increases, the current is maintained, so an arc is generated between them and a pilot arc is formed.

After the pilot arc is generated, welding or cutting can be performed by bringing the torch device close to the base material to be welded or cut and shifting from the pilot arc to the main arc. The main arc is between the electrode rod and the base metal (
The arc can be generated between the electrode rod and the nozzle (transfer type) or between the electrode rod and the nozzle (non-transfer type).

The electrode rod driving means has the function of establishing and releasing the electrical connection described above by changing the relative positional relationship between the nozzle and the electrode rod.

The welding power source or cutting power source that constitutes the welding device or cutting device has the above-mentioned current adjustment function using a constant current circuit, that is, it can set the current within a certain voltage range even if the insulation resistance between the electrode rod and the nozzle increases. It serves the function of adjusting the value.

The starting jig performs the function of establishing and releasing the above-mentioned electrical connection in place of the electrode rod driving means, and by setting the torch device on this starting jig, the relative relationship between the electrode rod and the nozzle is established. By changing the insulation resistance between the two without changing the positional relationship, the same effect as above can be achieved.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. In this embodiment, the present invention is applied to an arc generating torch device for a plasma welding device or a cutting device.

In FIGS. 1 and 2, the arc generating torch device of this embodiment includes an electrode rod 1 that becomes one electrode when an arc is generated, a nozzle 2 that can have the opposite polarity to the electrode rod 1, and It is composed of an insulator 3 for insulating the nozzle 2. The electrode rod 1 is connected to an electrode rod drive mechanism 4 that is partially or entirely made of an insulating material. When the handle 4a of the electrode rod drive mechanism 4 is rotated, the shaft 4
The male threaded portion 4c that engages with the female threaded portion 3a of the insulator 3 via b rotates, and the relative position of the electrode rod 1 with respect to the insulator 3 changes, and as a result, the relative position of the nozzle 2 and the electrode rod l changes.

Further, the electrode rod 1 is connected to one electrode of a welding or cutting power source through a cable 6 housed in a torch hose 8 and a ring 5 connected to the cable 6 and rotatably connected to the electrode rod 1. electrically connected. On the other hand, the nozzle 2 is electrically connected to the other electrode of the power source via a cable 7 housed in a torch hose 8.

FIG. 3 shows the configuration of a transition type welding or cutting device using the above-mentioned arc generating torch device. In this embodiment, the electrode rod 1 of the torch device is connected via a cable 6 to a negative terminal 1o, and the nozzle 2 is connected via a cable 7 to a positive terminal 11 for a pilot arc. Further, the object to be welded or cut 14 is connected to a main arc positive terminal 12 of the power source 9 via a cable 13. In addition, when performing plasma cutting, a working gas such as argon is flowed into the torch device as shown by an arrow 17, and a plasma flow is generated from the tip of the nozzle 2.

FIG. 4 shows the configuration of the welding or cutting power source 9. The power source 9 mainly includes a transformer 91 for setting an external AC power source 9o to an appropriate voltage, a converter 92 for converting AC current into DC current, an electrode rod 1 and a nozzle 2, or a base material (
a constant current circuit 93 for keeping the current flowing between the electrode rod l and the nozzle 2 constant;
It is comprised of a switch 94 for transferring the pilot arc generated between the electrode rod 1 and the base material 14 and switching it to the main arc.

At startup, as shown in FIG. 2, the handle 4a of the electrode rod drive mechanism 4 is rotated to move the electrode rod 1 forward, keeping the tip of the electrode rod 1 and the inner surface of the nozzle 2 in contact with each other. The welding or cutting power source 9 is activated, and a current is passed between the electrode rod 1 and the nozzle 2. At this time, the electrode rod 1 and the nozzle 2 are short-circuited, but the constant current circuit 93 in the power supply 9
The current value is protected from exceeding a certain set value. Thereafter, when the handle 4a of the electrode rod drive mechanism 4 is rotated in the opposite direction to the above and the electrode rod 1 is moved backward, the electrode rod 1 is separated from the nozzle 2. At this time, the potential difference between the electrode rod 1 and the nozzle 2, that is, the insulation resistance increases, but
A constant current flows between the electrode rod 1 and the nozzle 2 by the constant current circuit 93 of the power source 9, causing dielectric breakdown between the electrode rod 1 and the nozzle 2, and a pilot arc 15 is generated.

After the pilot arc 15 is generated, when the torch device is brought close to the workpiece 14 to be welded or cut, the pilot arc 15 serves as a pilot flame for the potential difference that occurs between the workpiece 14 to be welded or cut and the electrode rod 1, causing insulation. Destruction occurs and main arc 16 flows.

When the main arc 16 flows, the constant current circuit 93 of the power supply 9
The main arc current is detected in the main arc current, and after a certain period of time, the switch 94 is activated to cut off the pilot arc current.

According to this embodiment, since a high frequency generator is not used to generate the pilot arc, it is possible to eliminate the influence of high frequency noise on peripheral equipment. Further, when generating a pilot arc, it is not necessary to set the arc generating torch device in advance to the welding or cutting position of the base material (workpiece or workpiece) 14, which has the effect of improving work efficiency.

Another embodiment of the present invention will be described with reference to FIGS. 5 and 6. In the embodiments described above, the electrode rod drive mechanism was operated manually, but in this embodiment, it is operated remotely manually or automatically.

In FIG. 5, the torch device for arc generation of this embodiment includes an electrode rod 21 which becomes one electrode when an arc is generated, a nozzle 22 which can have a polarity opposite to that of the electrode rod 21, and the electrode rod 21 and the nozzle 22. and an insulator 23 for insulating the. An electrode rod drive mechanism 24 is connected to the electrode rod 21 .

The electrode rod drive mechanism 24 drives the electrode rod 21 via the rod 24b.
The piston 24a can move in the axial direction within a cylinder 23a formed in the insulator 23, and as the piston 24a moves, the nozzle 22 and the electrode rod are moved. As shown in FIG. 6, the piston 24a, whose relative position with respect to the torch hose 21 changes, is driven by an air unit 48 via air lines 29 and 30 housed in the torch hose 28.

Compressed air is supplied from the air unit 48 to the airline 29, and when the airline 30 is opened to the atmosphere, the electrode rod 21
moves backward and away from the nozzle 22, and conversely the air line 30
When compressed air is supplied to the air line 29 and the air line 29 is opened to the atmosphere, the electrode rod 21 moves forward and comes into contact with the nozzle 22.

Further, the electrode rod 21 is connected to one electrode 40 of the welding or cutting power source 39 with a cable 26 housed in the torch hose 28 and a ring 25 that is slidably connected to the electrode rod 21. electrically connected via. On the other hand, the nozzle 22 is electrically connected to the other electrode 41 of the power source 39 via a cable 27 housed in the torch hose 28. The configuration of the power supply 39 is the fourth
The configuration is substantially the same as that of the power supply 9 shown in the figure.

At startup, compressed air is supplied to the airline 30 by the air unit 48, the airline 29 is opened to the atmosphere, and the tip of the electrode rod 21 is kept in contact with the inner surface of the nozzle 22, and the power source 39 is turned on. It is activated and a current is passed between the electrode rod 21 and the nozzle 22. After this, air unit 48
By reversing the air supply line, that is, supplying compressed air to the airline 29, opening the airline 30 to the atmosphere, and gradually retracting the electrode rod 21, a pilot arc is created in the same manner as in the first embodiment. can be generated and the main arc can be generated.

Still another embodiment of the present invention will be described with reference to FIG.

This embodiment differs from the above embodiments in that it does not have an electrode rod drive mechanism, but instead is provided with a starting jig.

The arc generating torch device of this embodiment has a general structure. That is, the torch device is composed of an electrode rod 51 that serves as one electrode when an arc is generated, a nozzle 52 that can have the opposite polarity to the electrode rod 51, and an insulator 53 for insulating these electrode rods 51 and nozzle 52. ing.

Further, the electrode rod 51 is electrically connected to one electrode of a welding or cutting power source via a cable 56 housed in a torch hose 58, and the nozzle 52 is connected to the other electrode of the power source and to the torch hose 58. They are electrically connected via a cable 57 housed therein. The configuration of the power supply is substantially the same as that of the power supply 9 shown in FIG.

The starting jig 60 includes a shorting pin 60a that is a conductor for bringing the electrode rod 51 and the nozzle 52 into contact, a guide 60c for positioning the torch device, and a pedestal 60b that is an insulator for fixing them. It consists of

At the time of startup, as shown in FIG.
2, and is inserted and set along the guide 60c so as to contact both the nozzle 52 and the electrode rod 51. In this state, start the welding or cutting power source, and connect the electrode rod 51 and nozzle 52 via the shorting pin 60a.
A current is passed between 0 and 0. After that, when the arc generating torch device is removed from the starting jig 60, the electrode rod 51 and nozzle 5
A pilot arc is generated due to the potential difference created between the two. Thereafter, the main arc is generated in the same manner as in the previous embodiment, and welding or cutting operations can be performed.

Still another embodiment of the present invention will be described with reference to FIGS. 8 and 9. In this embodiment, the present invention is applied to an arc generating torch device for a TIG welding device.

In FIG. 8, the torch device of the present embodiment includes an electrode rod 71 that becomes one electrode when an arc occurs, a nozzle 72 that can have opposite characteristics to the electrode rod 71, and a structure for insulating the electrode rod 71 and the nozzle 72. It is composed of an insulator 73.

The electrode rod 71 is connected to an electrode rod drive mechanism 74 that is partially or entirely made of an insulating material. Further, a conductor 71a is fixed near the tip of the electrode rod 71, and the nozzle 7
An insulator 72a and a conductor 72b, which can be contacted by the conductor 71a, are fixed to the inner periphery of the conductor 2.

When the handle 74a of the electrode rod drive mechanism 74 is rotated,
The electrode rod 71 rotates via the shaft 74b, and the electrode rod 7
The relative positions of the conductor 71a of the nozzle 72 and the insulator 72a and the conductor 72b of the nozzle 72 are shown in FIGS.
It changes as shown in b).

Further, the electrode rod 71 is connected to one electrode of the welding power source, and a cable 76 and a cable 76 housed in the torch hose 78 are connected to each other.
6 and is electrically connected via a ring 75 slidably connected to the electrode rod 71. On the other hand, the nozzle 72 is electrically connected to the other electrode of the power source via a cable 77 housed in a torch hose 78. The configuration of the power supply is substantially the same as that of the power supply 9 shown in FIG.

At startup, as shown in FIG. 9(a), the handle 74a of the electrode rod drive mechanism 74 is rotated to keep the electrode rod 71 and nozzle 72 in contact via the conductor 71a and the conductor 72b. The welding power source is started and a current is passed between the electrode rod 71 and the nozzle 72. Thereafter, as shown in FIG. 9(b), the handle 74a of the electrode rod drive mechanism 74 is rotated to separate the conductor 71a and the conductor 72b. At this time,
Although the potential difference between the electrode rod 71 and the nozzle 72 increases,
Due to the constant current circuit of the power supply, a constant current flows between the electrode rod 71 and the nozzle 72, causing dielectric breakdown between the electrode rod 71 and the nozzle 72 and generating a pilot arc. The subsequent operations are the same as in the first embodiment.

In addition, although the above embodiment has been described as an example of a transition type in which the main arc is generated between the electrode rod and the base metal, a non-transition type in which the pilot arc itself is used as the main arc for welding or cutting may also be used. Of course.

In addition, in the above embodiments, the power supply does not include a high-frequency generator, but if a high-frequency generator can also be used in conjunction with the power supply, and it is used in a place where the influence of high-frequency noise on peripheral devices is not a problem, The configuration may be such that the activation means can be selectively used, such as activation using a high-frequency generator as in the past.

〔Effect of the invention〕

According to the present invention, since a high frequency generator is not used to generate a pilot arc, it is possible to eliminate the influence of high frequency noise on peripheral equipment. Furthermore, since it is not necessary to set the arc generating torch device in advance at the welding or cutting position of the base material (workpiece to be welded or workpiece to be cut) when generating the pilot arc, work efficiency can be improved.

Furthermore, by configuring the electrode rod driving means to be remotely controlled, it is possible to generate an arc remotely without using a high-frequency generator, so it can be applied to remote cutting devices that do not require a high-frequency generator. can do.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the structure of an arc generating torch device according to an embodiment of the present invention, and FIG. 2 is a sectional view showing the state of the arc generating torch device shown in FIG. 1 at startup. 3 is a configuration diagram of a welding device or cutting device using the arc generating torch device shown in FIG. 1, and FIG. 4 shows the configuration of a power source for the welding device or cutting device shown in FIG. 3. 5 is a sectional view showing the structure of an arc generating torch device according to another embodiment of the present invention, and FIG. 6 is a welding device or a welding device using the arc generating torch device shown in FIG. FIG. 7 is a sectional view showing the structure of an arc generating torch device and a starting jig according to still another embodiment of the present invention, and FIG. 8 is a configuration diagram of a cutting device according to still another embodiment of the present invention. 9 is a cross-sectional view showing the structure of the arc generating torch device according to the embodiment, and FIGS. 9(a) and 9(b) are FIG. 8 IX showing the state of the arc generating torch device shown in FIG. 8 at startup; -IX sectional view. Explanation of symbols 1, 21; 51; 71... Electrode rod 2; 22; 52; 72... Nozzle 3; 23; 53; 73... Insulator 4, 24; 74... Electrode rod drive mechanism 9...Power source 15...Pilot arc 16...Main arc 60...Starting jig 60a...Short circuit pin (conductive part) 93...Constant current circuit

Claims (11)

[Claims] (1) In a method for starting an arc generating torch device that includes an electrode rod for generating an arc, a nozzle that can have characteristics opposite to the electrode rod, and an insulator for insulating between them, At the time of activation to generate the current, a current is passed between the electrode bar and the nozzle while the electrode bar and the nozzle are electrically connected, and the electrical connection between the electrode bar and the nozzle is released while the current is flowing; A method for starting an arc generating torch device, characterized in that an arc is generated between the two by gradually increasing the insulation resistance between the two. (2) In the method for starting an arc generating torch device according to claim 1, the electrode rod and the nozzle are electrically connected by bringing the electrode rod and the nozzle into contact, and a gap between the electrode and the nozzle is gradually opened. A method for starting an arc generating torch device characterized by gradually increasing insulation resistance between the two. (3) In the method for starting an arc generating torch device according to claim 1, a starting jig separate from the torch device is prepared;
electrically connecting the electrode rod and nozzle by bringing the electrode rod and nozzle into contact with a conductive part of the starting jig, and separating at least one of the electrode rod and the nozzle from the conductive part of the starting jig; A method for starting an arc generating torch device characterized by gradually increasing insulation resistance between the two. (4) In an arc generating torch device comprising an electrode rod for generating an arc, a nozzle that can have opposite characteristics to the electrode rod, and an insulator for insulating between them, the electrode rod and the nozzle A torch device for generating an arc, characterized in that it is provided with an electrode rod driving means for changing the relative position with respect to the electrode rod. (5) The arc generating torch device according to claim 4, wherein the electrode rod driving means is a manual type including a manual operation section. (6) The arc generating torch device according to claim 4, wherein the electrode rod driving means is of a remote control type including a remotely controllable drive section. (7) It is characterized by comprising the arc generating torch device according to claim 4 and a welding power source for arc generating including a constant current circuit that maintains the current flowing between the electrode rod and the nozzle at a set value. Welding equipment. (8) A torch device for arc generation according to claim 4, and a cutting power source for arc generation including a constant current circuit that maintains the current flowing between the electrode rod and the nozzle at a set value. Cutting device. (9) A starting jig for a torch device for arc generation, which includes an electrode rod for generating an arc, a nozzle that can have characteristics opposite to those of the electrode rod, and an insulator for insulating between them, A starting jig comprising a conductive part that contacts the electrode rod and the nozzle in a state in which a torch device is set, and causes at least one of the electrode rod and the nozzle to separate as the state is released. (10) The arc generating torch device and the starting jig according to claim 9, and a welding power source for arc generation including a constant current circuit that maintains the current flowing between the electrode rod and the nozzle at a set value. A welding device characterized by: (11) The torch device for arc generation and the starting jig according to claim 9, and a cutting power source for arc generation including a constant current circuit that maintains the current flowing between the electrode rod and the nozzle at a set value. A cutting device characterized by: