JP2002205171A - Welding torch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a welding torch with which a deep and thin groove joint can be easily welded. SOLUTION: The welding torch is characterized in that it is provided with: a rectangular cylindrical shield cover 1 with an opening 3 formed near the lower end; a rectangular post-like torch body 4 which is inserted in the center of the shield cover, and which is composed of a highly heat conductive metal with an electrode inserting hole formed near the lower part; a rectangular hollow cooling means which is brought into contact with the side face of the torch body 4, and which is arranged with a desired space apart from the inner side face of the shield cover 1, between the shield cover 1 and the torch body 4; an electrode inserted in the electrode inserting hole of the torch body 4 in a manner the lower end is protruding downward from the torch body 4; a fixing screw 8 which is screwed onto the lower side wall of the torch body 4 through the opening of the shield cover, and which is for fixing the electrode on the torch body 4; and a heat resistant adhesive tape 9 which is placed on the outer side face of the shield cover 1 including the opening for the purpose of covering the opening.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a welding torch for a TIG welding device, and more particularly to a welding torch suitable for welding to a narrow groove.

[0002]

2. Description of the Related Art A TIG welding apparatus is used, for example, for welding a groove. Conventionally, a welding torch of such a TIG welding device has a structure shown in FIGS. 6 and 7.

That is, reference numeral 41 in FIGS. 6 and 7 denotes a cylindrical shield cover. A cylindrical electrode support member 42 having a tapered lower end is inserted concentrically into the shield cover 41 with an outer peripheral surface at a desired interval from an inner peripheral surface of the shield cover 41. I have. The two electrode holding members 43a and 43b are inserted into the cylindrical electrode support member 42. These electrode holding brackets 4
Reference numerals 3a and 43b denote small semi-cylindrical holes 4 each having a semi-cylindrical shape having a tapered lower end at a lower end, and having a columnar electrode to be described later in close contact with a flat surface along the longitudinal direction (longitudinal direction) facing each other.
4a and 44b are formed. A cylindrical holding jig 46 having a through hole 45 into which a cylindrical electrode to be described later is inserted at the center is inserted into the cylindrical electrode support member 42 so as to be positioned on the two electrode holding brackets 43a and 43b. Have been. Columnar electrode 47 whose lower end is tapered
The lower end passes through the semi-cylindrical hole formed by the cylindrical holding jig 46 and the small semi-cylindrical holes 44a and 44b of the two electrode gripping fittings 43a and 43b,
a, 43b.

In a welding torch having such a configuration, a cylindrical holding jig 46 is pressed downward, and the lower holding jig 46 is pressed.
When the two semi-cylindrical electrode holding members 43a, 43b are lowered along the cylindrical electrode support member 42 on the outer periphery thereof, the small semi-cylindrical holes 44 of the semi-cylindrical electrode holding members 43a, 43b are lowered.
Since the inner surfaces of a and 44b are in close contact with the columnar electrode 47,
The cylindrical electrode 47 is connected to the semi-cylindrical electrode holding bracket 43.
a and 43b can be held and fixed. Further, since the shield gas can be injected to the extended end of the electrode 47 through the annular space between the shield cover 41 and the cylindrical electrode support member 42, damage to the electrode and oxidation of the weld metal during welding can be prevented. it can.

[0005]

The welding torch shown in FIGS. 6 and 7 has a structure in which the electrode 47 is gripped and fixed by the two semi-cylindrical electrode grips 43a and 43b, and therefore has a large cross-sectional area. There was a limit to becoming thinner.
As a result, when welding with a narrow groove, it is necessary to protrude and weld only the electrode 47 long in order for the welding torch to be inserted into the groove. However, if the protruding length of the electrode 47 exceeds 50 mm, it becomes difficult to sufficiently inject and supply the shielding gas to the tip of the electrode 47. For this reason, the electrode is damaged and the weld metal is oxidized during welding, so that it is practically impossible to weld a deep narrow groove joint.

An object of the present invention is to provide a welding torch capable of easily welding a deep narrow groove joint.

[0007]

A welding torch according to the present invention comprises a rectangular cylindrical shield cover having an opening formed in the vicinity of the lower end, an electrode insertion hole inserted in the center of the shield cover, and an electrode insertion hole in the vicinity of the lower part. A rectangular column-shaped torch body made of a good heat conductive metal having a hole, and a side surface of the torch body between the shield cover and the torch body, and a desired gap with an inner surface of the shield cover. A cooling means having a rectangular hollow shape arranged with a gap, an electrode inserted into the electrode insertion hole of the torch body such that a lower end thereof protrudes downward from the torch body, and the torch body through an opening of the shield cover. A fixing screw for fixing the electrode to the torch main body, the opening being attached to an outer surface of the shield cover including the opening, and being screwed to a lower side wall of the torch main body. It is characterized in that it has and a heat-resistant adhesive tape for.

[0008] In the welding torch according to the present invention, an auxiliary shield gas injection means for injecting the shield gas toward the lower side of the shield cover may be attached to the outer surface of the shield cover so as to be vertically movable. .

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing a welding torch of the present invention, FIG. 2 is a sectional view of the welding torch of FIG. 1 taken along the line II-II,
FIG. 3 is an enlarged sectional view of a main part of FIG. 1, and a rectangular cylindrical shield cover 1 is supported by a rectangular support plate 2 on the upper side. In the vicinity of the lower portion of the narrow side wall of the shield cover 1, an opening 3 through which a fixing screw described later is inserted is formed.

For example, a rectangular column-shaped torch main body 4 made of a good heat conductive metal such as copper is provided in the rectangular cylindrical shield cover 1 with the wide outer surfaces of the torch main body 4 opposed to each other. 1 is inserted so as to be in contact with the opposed wide inner surface and the opposed narrow outer surface of the torch body 4 is separated from the opposed narrow inner surface of the shield cover 1 by a desired distance. ing. The upper end of the torch main body 4 is fixed to the support plate 2. The torch main body 4 has an electrode insertion hole 5 formed near its lower part. The torch main body 4 has a threaded hole 6 formed in the lower side wall thereof to reach the electrode insertion hole 5.

The cylindrical electrode 7 is inserted into the electrode insertion hole 5 of the torch main body 4 from the lower end surface of the torch main body 4. The electrode 7 is fixed to the electrode insertion hole 5 of the torch main body 4 by a fixing screw 8 screwed into the threaded hole 6 of the torch main body 4 through the opening 3 of the shield cover 1 as shown in FIG. I have. Heat resistant adhesive tape 9
Is attached to the outer surface of the shield cover 1 including the opening 3 after the fixing screw 8 is screwed, and the opening 3
Is blocking.

Two cooling water flow members 10 having a U-shaped cross section
a and 10b are desired for the opposed narrow inner surface of the shield cover 1 between the opposed narrow outer surface of the torch body 4 and the opposed narrow inner surface of the shield cover 1. Are inserted through the support plate 2 so as to leave a gap. As shown in FIG. 2, the cooling water distribution members 10a and 10b have one side wall in contact with a narrow outer side surface of the torch body 4 facing each other, and two side wall end portions facing the shield cover 1. It is fixed to the wide inner surface. The lower ends of the two partition plates 11a and 11b are inserted into the cooling water flow members 10a and 10b at a desired distance from the bottom of the members. As shown in FIG. 2, these partition plates 11 a and 11 b have their side wall ends fixed to the opposed wide inner surfaces of the shield cover 1. Thus, the two partition plates 11a, 11b are connected to the cooling water flow members 10a, 10b.
The cooling water circulation passages 12a and 12b are formed in the cooling water flow members 10a and 10b by inserting and fixing the cooling water into the cooling water circulation members 10a and 10b, respectively. The cooling water flow member 10
a, 10b and partitioning plates 11a, 11b constitute cooling means.

The cooling water flow members 10a, 10b
Is inserted into the shield cover 1 and fixed,
Between the cooling water flow members 10a, 10b and the inner surface of the shield cover 1, two shield gas flow spaces 13a,
13b are respectively formed.

The auxiliary shield gas injection member 14 is mounted on the outer periphery of the shield cover 1 so as to be vertically movable. The auxiliary shield gas injection member 14 is fitted on the outer periphery of the shield cover 1 and has a hollow rectangular annular body 16 having a gas injection porous metal plate 15 at the bottom, and is connected to the outer peripheral side wall of the hollow rectangular annular body 16. And a supply pipe 17 for the shielding gas.

According to the welding torch having such a configuration, when the columnar electrode 7 is fixed to the electrode insertion hole 5 of the torch main body 4, as shown in FIG. By screwing into the threaded hole 6 of the torch main body 4 through the part 3 and fixing it to the electrode insertion hole 5 of the torch main body 4, the shield cover 1 including the torch main body 4 is thinned to have a flat rectangular cross section. be able to.

Further, by forming the opening 3 near the lower portion of the shield cover 1, the operation of screwing the fixing screw 8 into the threaded hole 6 of the torch body 4 can be performed simply and smoothly.

Further, a heat-resistant adhesive tape 9 is adhered to the outer surface of the shield cover 1 including the opening 3 after the fixing screw 8 is screwed, and the opening 3 is closed, so that welding to be described later is performed. In the process, the shielding gas is
Therefore, a sufficiently good shield gas can be jetted toward the electrode 7 without escaping from the outside of the shield cover 1.

(Embodiment 1) Hereinafter, a method of welding a deep narrow groove joint using the thin welding torch will be described with reference to FIG.

The shield cover 1 including the electrode 7 is inserted into the deep and narrow groove 22 of the joints 21a and 21b. Cooling water circulation channels 12a, 1 in cooling water circulation members 10a, 10b
Cooling water is supplied to 2b to cool the copper torch body 4 for fixing the electrode 7. By supplying a desired welding power to the electrode 7 through the torch body 4, the bottom of the groove 22 is TIG-welded. At this time, the shield gas is supplied to the two shield gas circulation spaces 13a and 13b to inject the shield gas toward the electrode 7 protruding from the torch main body 4, and the shield gas is supplied to the auxiliary shield gas injection member 14 Is supplied to the inside of the hollow rectangular annular body 16 through the supply pipe 17, and is sprayed from the porous metal plate 15 thereunder toward the lower end side of the shield cover 1. Such injection of the shielding gas can prevent damage to the electrode 7 and oxidation of the weld metal 23 in the groove 22. While continuing to cool the torch body 4 made of copper for fixing the electrode 7, supply welding power to the torch body 4, and supply the shielding gas, the electrode 7
The groove 22 is filled with weld metal by moving the shield cover 1 including the groove 22 in the width direction of the groove 22 and moving the groove upward (the auxiliary shield gas injection member 14 is also raised). The welding of the joints 21a and 21b is completed.

Therefore, according to the welding torch of the present invention, a deep narrow groove joint can be welded soundly.

Further, by providing the auxiliary shield gas injection member 14 together, it is possible to perform welding with a large current while effectively preventing oxidation of the weld metal. Moreover, by making the auxiliary shield gas injection member 14 vertically movable, the auxiliary shield gas injection member 14
Therefore, the oxidation of the weld metal can be more effectively prevented.

In fact, using the welding torch shown in FIGS. 1 to 3 above, a joint having a groove having a depth of 200 mm and a width of 12 mm, a welding current of 280 A, a welding voltage of 10 V, a welding speed of 100 mm / min, and a shield from the torch. Gas flow 40L
/ Min, TIG welding was performed under the conditions of a shield gas flow rate of 150 L / min from the auxiliary shield gas injection member 14, and a sound welding was performed.

(Embodiment 2) A method of welding a deep narrow groove joint in a horizontal position using the thin welding torch will be described below with reference to FIG.

The shield cover 1 including the electrode 7 is inserted into the deep and narrow groove 32 of the joints 31a and 31b in a lateral posture. Cooling water is supplied to the cooling water circulation channels 12a and 12b in the cooling water circulation members 10a and 10b, respectively, to cool the copper torch body 4 that fixes the electrode 7. By supplying a desired welding power to the electrode 7 through the torch main body 4, the groove 3 is formed as shown in FIG.
2 Perform bottom beat welding on the bottom. At this time, the shield gas is supplied to the two shield gas circulation spaces 13a and 13b to inject the shield gas toward the electrode 7 protruding from the torch main body 4, and the shield gas is supplied to the auxiliary shield gas injection member 14 Is supplied to the inside of the hollow rectangular annular body 16 through the supply pipe 17 and is sprayed from the porous metal plate 15 thereunder toward the lower end side of the shield cover 1. Such injection of the shielding gas damages the electrode 7 and weld metal of the groove 32 (beat weld).
23 can be prevented from being oxidized. While continuing to cool the torch body 4 made of copper fixing the electrode 7, supply the welding power to the torch body 4, and supply the shielding gas, the position of the electrode 7 on the shield cover 1 was changed while FIG.
As shown in (b), lower beat welding is performed on the lower part of the upper beat weld. Thereafter, the upper beat welding and the lower beat welding are repeated to fill the groove 32 with the welding metal 33 as shown in FIG. 5C, thereby completing the welding of the joints 31a and 31b.

Therefore, according to the welding torch according to the present invention, a deep narrow groove joint can be soundly welded in a horizontal position.

[0027]

As described above in detail, according to the present invention, it is possible to provide a welding torch which can easily weld a deep narrow groove joint and can perform sound welding.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a welding torch of the present invention.

FIG. 2 is a cross-sectional view of the welding torch of FIG. 1 taken along the line II-II.

FIG. 3 is an enlarged sectional view of a main part of FIG. 1;

FIG. 4 is a perspective view for explaining welding of a deep narrow groove joint according to the first embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a step of welding a deep narrow groove joint in a lateral posture according to the second embodiment of the present invention.

FIG. 6 is a longitudinal sectional view showing a conventional welding torch.

FIG. 7 is a sectional view of the welding torch of FIG. 6 taken along the line VII-VII.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Shield cover, 3 ... Opening, 4 ... Torch main body, 5 ... Electrode, 8 ... Fixing screw, 9 ... Heat resistant adhesive tape, 10a, 10b ... Cooling water distribution member, 14 ... Auxiliary shield gas injection member, 21a, 21b, 31a, 31b ... joint, 22, 32 ... groove.

Continuation of the front page (72) Inventor Satoshi Konishi 2-1-1, Shinhama, Arai-machi, Takasago-shi, Hyogo F-term in Takasago Works, Mitsubishi Heavy Industries, Ltd. (reference) 4E001 AA03 BB07 LH04 NA01

Claims (2)

[Claims] 1. A rectangular cylindrical shield cover having an opening formed in the vicinity of a lower end thereof, and a good heat conductive metal inserted in the center of the shield cover and having an electrode insertion hole formed in the vicinity of a lower portion. A rectangular column-shaped torch main body, and a rectangular hollow cooling means arranged between the shield cover and the torch main body, in contact with a side surface of the torch main body, and arranged with a desired gap from an inner side surface of the shield cover. An electrode inserted into the electrode insertion hole of the torch main body such that a lower end protrudes downward from the torch main body, and is screwed to a lower side wall of the torch main body through an opening of the shield cover. A fixing screw for fixing to the torch main body; and a heat-resistant adhesive tape for closing the opening attached to the outer surface of the shield cover including the opening. Welding torch according to claim. 2. The apparatus according to claim 1, wherein an auxiliary shield gas injection means for injecting the shield gas toward a lower side of the shield cover is vertically movably attached to an outer surface of the shield cover. Item 2. A welding torch according to Item 1.