JPH11138268A - Main current switching stud welding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the quantity of heat input required at the time of pushing by preventing or restraining the generation of short circuits during a lifting period in horizontal position welding for a large diameter of stud and in the latter half of the lifting period in penetration welding. SOLUTION: After an auxiliary arc current energizing time tp passes, a first main arc current Ia1 is outputted to shift to a main arc. Thereafter, a second main arc current Ia2 is outputted after the first main arc current energizing time ta1 passes, the expansion of the main arc is enlarged, an arc pressure is also increased, molten metal accumulated in the lower part of ferrule is pushed to the side of a stock to be welded, and whereby short circuits are prevented. Also, in penetration welding, the arc current is increased in the latter half of the lifting period to increase an arc force, the depth and range of penetration for a steel frame are enlarged, and whereby short circuits are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stud welding method for preventing a short circuit during a stud lifting period.

[0002]

2. Description of the Related Art Normally, after a stud tip is brought into contact with a surface of a material to be welded, the stud is pulled up from the material to be welded by a predetermined lifting distance, a main arc is generated, and a molten pool is formed. After the completion of the above, the stud is pushed into the molten pool by a predetermined pushing amount and welded.
Hereinafter, the prior art will be described by dividing into large diameter stud welding, horizontal welding, and thin plate penetration welding.

(1) Conventional technique for welding large diameter studs In welding large diameter studs, a large heat input is required. This heat input mainly depends on the arc voltage, main arc current and main arc current corresponding to the lifting distance. It is determined from the arc current conduction time. On the contrary, since the arc voltage is determined from the pulling distance for obtaining a good welding result, it cannot be freely set to a large value. Further, even if the main arc current energizing time is increased to a certain extent or more, the heat radiation increases with the increase of the main arc current energizing time, so that it is not possible to secure a molten pool for obtaining a predetermined pushing amount. Furthermore, with the increase of the main arc current conduction time, the molten metal of the studs drips and short-circuits occur. In particular, short-circuiting is likely to occur when the studs are partially melted by magnetic blowing. Therefore, the main arc current value is the only set value that can be freely set large to supply a large amount of heat input.

However, if the output capacity of the stud welding power supply has no margin, the main arc current cannot be actually energized. When the stud welding power supply is an engine generator, the output capacity is not large. Also, when the welding cable is extended, the main arc current value is limited by the voltage drop of the welding cable. In such a case, if the short period is sufficiently shorter than the pulling period, the engine generator having the flywheel effect or the stud welding power supply device that controls the main arc current by the semiconductor withstands an overload, and The arc current value can be maintained.

(2) Conventional technique of horizontal stud welding When a stud, particularly a stud having a diameter of 22 mm or more, is welded in a horizontal position, the molten metal and the molten metal at the tip of the stud in the latter half during the main arc are generated. Since the molten metal on the surface of the material to be welded is concentrated on the lower part in the ferrule due to gravity, a short circuit frequently occurs.

FIG. 1 is a view showing a state of a molten metal in a ferrule during horizontal welding. In the drawing, an arc (not shown) is generated between the workpiece 14 and the stud 18 to melt the workpiece 14, and the molten metal of the workpiece accumulates in the lower part of the ferrule 20. Because of the molten metal 31 of the material to be welded accumulated in the lower part of the ferrule due to the gravity, a flash after welding (hereinafter, referred to as an extra bank) cannot be formed on the upper part of the stud.

Therefore, the following method has been proposed to prevent the occurrence of the short circuit and to secure a margin. [Prior art 1] Japanese Patent Application Laid-Open No. 7-14297 discloses a conventional art 1 in which a stud is pulled up continuously or stepwise during a pulling-up period, and the welded material accumulated in a lower portion in a ferrule due to gravity. In this method, the molten metal of the material is kept away from the tip of the stud to prevent a short circuit occurring in the latter half of the pulling period.

[Prior art 2] According to the prior art 2 disclosed in Japanese Patent Application Laid-Open No. Hei 7-284942, the welding current is cut off at a predetermined position during the pressing (position about half of the pressing step), thereby reducing the thickness. This method is intended to suppress the energy consumption so as to secure sufficient strength even with a stud having a diameter to secure the strength and to prevent a short-circuit current after being pushed from flowing.

(3) Prior Art of Thin Plate Penetration Welding As a use of stud welding, a steel plate is disposed on a structure in which a steel frame such as an H-shaped steel or an I-shaped steel is assembled in a construction work or a construction work, and a steel plate ( There is thin plate penetration welding for fixing the deck plate) by stud welding.

FIG. 2 shows that when a steel plate is placed on a steel frame,
FIG. 4 is a diagram showing a positional relationship between a steel plate and a steel plate in a state in which a steel plate is wavy, and a gap (clearance) is generated between the steel plate and the steel plate. In the same figure, when the steel plate 22 is disposed on the steel frame 21 and the thickness Dp of the steel plate is, for example, a thin plate such as 1.2 [mm], the steel plate 22 is wavy, and the steel frame 21 and the steel plate 22
A clearance (clearance) Dc is generated between the two.

[0030]

(1) Problems to be Solved for Downward or Sideways Welding of Studs of Large Diameter The above-mentioned prior art 1 can prevent a short circuit during a pulling period, but can prevent the studs from being stuck on the upper portions of the studs. It is not possible to form a margin after welding. In addition, the arc length becomes longer, the arc becomes unstable, and magnetic blowing is more likely to occur.

In the prior art 2 described above, welding is normally performed in a situation where a normal arc is stable. But,
First, in the horizontal welding of a large diameter stud, a short circuit is likely to occur before a scheduled short circuit point during pushing. When a short circuit occurs, the heat input is insufficient due to the lack of a proper arc voltage value, and the required amount of pushing cannot be achieved during the pushing, resulting in poor welding. Second, in the normal stud welding method, a short-circuit welding current is applied until the pushing operation is completed, so that even if a short circuit occurs during the pushing operation, it is necessary to apply the short-circuit welding current and push in a predetermined amount of pushing. High heat input.

Considering these two facts, if the welding current is interrupted at a position about one-half of the pushing step as in the above-mentioned prior art 2, if a short circuit occurs, the molten metal is cut off from the time when the welding current is interrupted. Is insufficiently pushed because of rapid solidification. Also, due to the bias of the molten metal,
Extra weld after welding is insufficient at the upper part around the stud, resulting in partial melting. Due to the one-side melting, a welding defect such as an undercut occurs.

(2) Problem to be Solved by Thin Plate Penetration Welding FIG. 3 is a steel plate / stud positional relationship diagram showing the positional relationship between the steel plate and the stud tip when there is a gap between the steel frame and the steel plate. FIG. 4A is a welding start positional relationship diagram showing a state in which the tip of the stud 18 is in contact with the steel plate 22 immediately after the start of the stud welding.
Is set as a reference point P. FIG. 6B is an arc generation positional relationship diagram showing a state in which an arc is generated by pulling up the stud tip, and the stud tip is pulled up from the reference point P in FIG. In position.

FIG. 4C is a short-circuit position relationship diagram showing a state in which a command to push in the stud is issued after a preset time has elapsed from the start of welding and the tip of the stud is pushed in to short-circuit. The tip of the stud is located at a position pushed in by a pushing distance Dd from the reference point P in FIG. FIG. 4D is a diagram showing a time course of the tip position of the stud 18 from the start of welding to the end of welding.
The vertical axis indicates the movement amount M of the stud tip, the symbol indicates the position of the stud tip in FIG. 7A, the symbol indicates the position of the stud tip in FIG. ) Indicates the position of the tip of the stud, and the symbol Dd indicates the pushing distance in FIG.

FIG. 7E is a diagram showing the time course of the output terminal voltage Vd from the start of welding to the end of welding.
In FIG. 9 (E), time ts0 is a short-circuit point in normal welding (hereinafter, referred to as direct welding) which is not such penetration welding, and time ts1 is a short-circuit point in time of such “penetration welding”. As shown in FIG. 3C, this is the time required for the tip of the stud to move by the thickness Dp of the steel plate and the gap Dc, and becomes larger than the time ts0. Further, the time ts2 is a short-circuit point when the tip of the stud is pushed into the steel frame during such a penetration welding, and the steel frame 21 and the steel plate 2
2, the delay time from time ts0 to time ts2 varies because the gap (clearance) Dc is indefinite.

Since the gap Dc is indefinite, the arc length Da becomes Dup + (Dp +
Dc), and (Dp + Dc) as compared with direct welding.
And the variation occurs. Further, at the time of penetration welding, as shown in FIG. 3C, the actual amount of plunge De into which the tip of the stud is pushed into the steel frame is Dd−
(Dp + Dc), which is (Dp + Dc)
+ Dc), and the variation also increases.

As described above, in the penetration welding, the steel sheet is wavy, and a gap (clearance) is generated between the steel frame and the steel sheet.
At the point of short-circuiting when the tip of the stud is pressed into the steel frame, and since the gap (clearance) Dc between the steel frame and the steel plate is indefinite, the tip of the stud at the time of short-circuiting ts0 at the time of direct welding and the tip of the stud at the time of penetration welding are cut into the steel frame. Short circuit point ts2 when pressed
Since the delay time varies and a larger amount of heat is required than direct welding, a short circuit frequently occurs in the latter half of the pulling-up period in order to set the main arc current conduction time longer.

FIG. 4 is a diagram showing a waveform when a short circuit occurs in the latter half of the main arc current conduction time in the conventional welding operation. FIG. 4A shows a welding current waveform diagram showing a waveform of the output current Io. (B) is an output terminal voltage waveform diagram showing a waveform of the output terminal voltage Vd of the welding power supply device, and (C) is a stud tip movement diagram showing a movement amount M of the stud tip.

As shown in FIG. 1B, in the latter half of the main arc current energizing time ta, the output terminal voltage Vd is changed to the level shown in FIG.
As shown by (1), the arc length becomes short due to the bias of the molten metal in the ferrule 20, and a short circuit occurs.

When the stud 18 is pushed into the workpiece 14 in this state, the actual pushing distance becomes Dd0 due to insufficient pushing, as shown in FIG. Can not. As a result, welding defects such as poor fusion due to the offset of the extra ridges occur. Note that tm is the pushing time.

[0061]

According to a first aspect of the present invention, an arc is generated by pulling up a stud from a material to be welded, and after a period of pulling up, the stud is pushed into the material to be welded by a predetermined pushing amount to perform welding. In the stud welding method, the main current switching stud welding method is to increase the arc current in the latter half of the pulling period.

A stud welding method according to a second aspect of the present invention is to raise a stud having a large diameter from a material to be welded, to generate an arc, and to push the stud into the material to be welded by a predetermined amount after the lifting period is over. In the main current switching stud welding method, the arc current is increased in the latter half of the lifting period to increase the arc force, shorten the overload time of the welding power supply device, and ensure the melting of the material to be welded.

According to a third aspect of the present invention, an arc is generated by pulling up a stud from a material to be welded having a steel plate disposed on a steel frame, and after the lifting period, the stud is pushed into the material to be welded by a predetermined pushing amount. Is a main current switching stud welding method for increasing the arc current and increasing the arc force in the latter half of the lifting period to ensure the melting of the steel frame.

According to a fourth aspect of the present invention, an arc is generated by separating the stud from the material to be welded arranged laterally, and after the lifting period is over, the stud is pushed into the material to be welded by a predetermined pushing amount to perform welding. In the stud welding method, in the second half of the lifting period, the arc current is increased for a short time to increase the arc force, and the molten metal of the material to be welded is pressed against the molten pool to melt the molten metal of the material to be welded and the stud tip. This is a main current switching stud welding method for separating a metal and preventing a short circuit.

[0070]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the main current switching stud welding method of the present invention is as follows. (1) When the start switch 13 is turned on, the welding sequence control circuit 4 starts and outputs the auxiliary arc current Ip preset in the welding condition setting circuit 7 to the welding current command circuit 5. (2) The pull-up command signal Du preset in the welding condition setting circuit 7 is output to the welding gun drive circuit 6 almost simultaneously, and the auxiliary arc current I between the workpiece 14 and the stud 18 is output.
An auxiliary arc is generated by energizing p. (3) After the lapse of the auxiliary arc current conduction time tp, the welding sequence control circuit 4 outputs the first main arc current Ia1 to the welding current command circuit 5, and shifts from the auxiliary arc to the main arc. (4) After the lapse of the first main arc current energizing time ta1, the welding sequence control circuit 4 outputs the second main arc current Ia2 to the welding current command circuit 5, thereby expanding the spread of the main arc and the arc. The pressure also increases and the ferrule 20
A short circuit is prevented by pressing the molten metal accumulated in the lower part of the workpiece toward the material 14 to be welded.

[0080]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 5 and 6, a schematic operation example of a main current switching stud welding method according to the present invention from the start to the end of welding will be described. (1) For stud welding, a welding gun 2 shown in FIG.
Of the auxiliary arc current Ip shown in FIG.
Is lifted from the workpiece 14 to generate an auxiliary arc. (2) Next, when the auxiliary arc current supply time tp elapses, the first main arc current Ia1 is reduced from the auxiliary arc current Ip.
Switch to. (3) After a preset first main arc current energizing time ta1 has elapsed, a second main arc current Ia2 having a current value larger than the first main arc current Ia1 is applied to the first main arc current energization time ta1. The current is supplied for the second main arc current supply time ta2 which is longer than the time ta1. (4) After the passage of the second main arc current conduction time ta2, the stud during arc generation is pushed into the workpiece and short-circuits with the workpiece, and the short-circuit current Is is set for a preset short-circuit time ts.
, The welding current is interrupted, and the welding is terminated.

FIG. 5 is a block diagram of a stud welding apparatus for carrying out the main current switching stud welding method of the present invention.

FIG. 6 is an output waveform diagram of a stud welding apparatus for carrying out the main current switching stud welding method of the present invention.
FIG. 3A is a welding current waveform diagram showing a waveform of the output current Io, and FIG. 3B is an output terminal voltage Vd of the welding power supply device.
FIG. 7C is a stud tip movement diagram showing the movement amount M of the stud tip.

Hereinafter, a block diagram of the stud welding apparatus of FIG. 5 and an output waveform diagram of FIG. 6 will be described. The stud welding device shown in FIG. 5 includes a welding power supply device 1, a welding gun 2, and a welding control device 3. This welding power supply device 1
Outputs a welding current consisting of an auxiliary arc current Ip, a first main arc current Ia1, and a second main arc current Ia2 to the welding gun 2, and outputs the welding current from a welding current command circuit 5 of a welding control device 3 to be described later. The output current Io according to the output current command signal
And a welding current output circuit 15 composed of a semiconductor switching element such as a thyristor for controlling the welding current according to the current command signal.

The welding control device 3 determines the auxiliary arc current Ip,
The auxiliary arc current conduction time tp and the first main arc current Ia
1. A welding condition setting circuit for setting a first main arc current energizing time ta1, a second main arc current Ia2, a second main arc current energizing time ta2, a pull-up command signal Du for operating the welding gun 2, and the like. 7, a welding sequence control circuit 4 for controlling a series of stud welding sequences according to welding condition setting values preset in the welding condition setting circuit 7, and a welding condition setting signal output from the welding sequence control circuit 4. Then, a welding current command circuit 5 for outputting a current command signal to the welding current output circuit 15 and a welding gun drive circuit 6 for outputting a drive signal for driving the welding gun 2 corresponding to the set value of the welding condition setting circuit 7 Consists of

Next, the operation of the block diagram of the stud welding apparatus shown in FIG. 5 for carrying out the main current switching stud welding method of the present invention shown in FIG. 6 will be described. When the start switch 13 is turned on, the welding sequence control circuit 4 starts, and outputs the auxiliary arc current Ip preset in the welding condition setting circuit 7 to the welding current command circuit 5. Also, the welding condition setting circuit 7
Is output to the welding gun drive circuit 6 and the auxiliary arc current I
By outputting p, an auxiliary arc current Ip is supplied between the workpiece 14 and the stud 18 to generate an auxiliary arc. After the lapse of the auxiliary arc current supply time tp, the welding sequence control circuit 4 sends the first main arc current Ia1 to the welding current command circuit 5
To make the transition from the auxiliary arc to the main arc.

Thereafter, the first main arc current conduction time ta1
, The welding sequence control circuit 4 outputs the second main arc current Ia2 to the welding current command circuit 5 to increase the spread of the main arc and the arc pressure,
The molten metal stored in the lower part of the ferrule 20 is pressed against the material to be welded 14 to prevent a short circuit.

Here, the second main arc current Ia2 is equal to the first main arc current Ia2.
Is approximately 10% larger than the main arc current Ia1, and the second main arc current energization time ta2 is appropriate when the time is approximately 10% of the first main arc current energization time ta1. It has been confirmed from experiments that welding results can be obtained.

After the lapse of the second main arc current energizing time ta2, the stud 18 is pushed into the molten pool of the workpiece 14 by a preset pushing pattern. Here, the preset pushing pattern refers to a pull-up distance, a pushing distance, a pushing speed, a pushing speed switching, etc. of the stat 18 which is adjusted by the welding gun 2 or set by the welding condition setting circuit 7.

Thereafter, during the short-circuit time ts, the short-circuit current Is
At this time, the short-circuit current Is is applied continuously to the second main arc current Ia2.
The short-circuit time t due to the difference in the welding conditions of the workpiece 14
Even if s0 varies, the arc continues at the time of pushing, and the surplus can be finished uniformly. The output terminal voltage Vd when the first main arc current Ia1 is applied is the welding voltage Va1 during the first main arc current, and the output terminal voltage Vd when the second main arc current Ia1 is applied. Terminal voltage is Vd
Is the welding voltage Va2 during the second main arc current.

FIG. 7 is a view showing the shape of the extra bank after the horizontal welding is completed. FIG. 7A shows an example in which the welding strength is insufficient because the extra bank welded by the conventional welding method is not properly formed. FIG. 4B is a diagram showing an example in which the weld metal is appropriately formed by the welding method according to the present invention, so that the welding strength is ensured.

When the diameter of the stud is large, the amount of heat input is large. Therefore, when the material to be welded is a thin plate and the welding posture is horizontal, it is difficult for the surplus to remain in the upper part around the stud after welding. Easy welding failure.

However, according to the present invention, before the stud is pushed in, the main arc current value is increased continuously or intermittently to increase the arc pressure, and the molten metal causing the short-circuit is pressed against the welded portion to cause the short-circuit. In addition to preventing, especially in sideways welding, after the molten metal is additionally formed by the increased main arc current, the stud is pushed into the work piece, leaving the molten metal on the top of the stud and the upper part around the stud after welding. To form a margin.

FIGS. 11A and 11B show that when the stud 18 is welded to the material to be welded 14, the extra bank 30 shown in FIG. Although the strength is insufficient, the extra bank 30 shown in FIG. 3B is also formed on the upper part of the stud 18 to secure the welding strength.

[1000]

The welding method of the present invention has the following common effects, but the magnitude of the effect differs depending on the welding state to which the present invention is applied. (1) The arc force is increased by increasing the arc current, and the penetration depth of the material to be welded is increased. (2) Increasing the arc current to increase the spread of the arc to increase the penetration range of the material to be welded. (3) The arc force is increased by increasing the arc current, and the molten metal of the material to be welded is pressed against the material to be welded to prevent a short circuit from occurring. (4) Since the heat input that greatly affects the penetration is required in the latter half of the pulling period, this necessary large heat input is supplied only in the latter half of the pulling period to reduce the total heat input and reduce the power. Save on quantity. (5) The required large heat input is supplied only in the latter half of the pulling period to shorten the overload time of the welding power supply, thereby raising the welding power supply even when the output capacity of the welding power supply is insufficient. If it is a short time that is sufficiently shorter than the period, the engine generator or the stud welding power supply device can withstand the overload and conduct the increased arc current. (6) The required large heat input is supplied only in the second half of the raising period to shorten the overload time of the welding power supply, so that the output capacity of the welding power supply has no margin and the welding cable can be extended. When the main arc current value is limited by the voltage drop of the welding cable, if the engine generator or stud welding power supply unit withstands overload for a short time sufficiently shorter than the raising period, the increased arc A current can be passed. (7) Since the arc length is not excessively large as compared with the method of increasing the pulling distance in the latter half of the pulling period, the arc is stable, and welding defects such as undercuts are less likely to occur.

[1002] According to a third aspect of the present invention, an arc is generated by pulling up a stud having a steel plate disposed on a steel frame from a material to be welded, and pushing the stud into the material to be welded by a predetermined amount after the lifting period. In the penetrating stud welding, the arc current is increased in the latter half of the lifting period to increase the arc force, thereby increasing the penetration depth and range of the steel frame. In this penetration welding, a larger amount of heat input is required than in direct welding, so that the main arc current conduction time needs to be set longer. Therefore, in this penetration welding, a short circuit frequently occurs in the latter half of the pulling-up period. Therefore, the short circuit can be prevented by increasing the main arc current before pushing.

[1004] The method according to claim 4, wherein the stud is separated from the material to be welded arranged laterally to generate an arc, and after the lifting period is over, the stud is pushed into the material to be welded by a predetermined pushing amount to perform welding. In stud welding, in the latter half of the pulling period, the arc current is increased for a short time to increase the arc force, and the molten metal is pressed against the material to be welded and separated from the molten metal at the tip of the stud to prevent short circuit. .

[Brief description of the drawings]

FIG. 1 is a diagram showing a state of a molten metal in a ferrule during a horizontal welding.

FIG. 2 is a diagram showing a positional relationship between a steel plate and a steel plate when a steel plate is undulated and a gap (clearance) is formed between the steel plate and the steel plate when the steel plate is provided on the steel plate.

FIG. 3 is a steel plate-stud positional relationship diagram showing a positional relationship between a steel plate and a stud tip when there is a gap between a steel frame and a steel plate.

FIG. 4 is a diagram showing a waveform when a short circuit occurs in the latter half of the main arc current conduction time in a conventional welding operation, and FIG. 4 (A) shows a welding current showing a waveform of an output current Io. FIG. 7B is a waveform diagram, FIG. 8B is an output terminal voltage waveform diagram showing a waveform of the output terminal voltage Vd of the welding power supply device, and FIG. 8C is a stud tip movement diagram showing a movement amount M of the stud tip. is there.

FIG. 5 is a block diagram of a stud welding apparatus for performing the main current switching stud welding method of the present invention.

FIG. 6 is an output waveform diagram of a stud welding apparatus for performing the main current switching stud welding method of the present invention, and FIG. 6 (A) is a welding current waveform diagram showing a waveform of an output current Io; FIG. 3B is an output terminal voltage waveform diagram showing a waveform of the output terminal voltage Vd of the welding power supply device, and FIG. 3C is a stud tip movement diagram showing a movement amount M of the stud tip.

FIG. 7 is a view showing a surplus shape after completion of lateral welding, and FIG. 7 (A) shows insufficient welding strength due to an improperly formed surplus welded by a conventional welding method. It is a figure which shows an example, and the same figure (B) is a figure which shows the example in which the welding strength is ensured because the excess welded by the welding method of this invention is formed appropriately.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 welding power source 2 welding gun 3 control device 4 welding sequence control circuit 5 welding current command circuit 6 welding gun drive circuit 7 welding condition setting circuit 9 welding current output circuit 13 start switch 14 material to be welded 15 welding current output circuit 18 stud 20 fell -Lead 21 Steel frame 22 Steel plate 30 Extra bank 31 Molten metal of the material to be welded accumulated in the lower part of the ferrule due to gravity Dc Gap (clearance) between steel frame 21 and steel plate 22 Dd Push distance (setting value = actual value) Dd0 (Actual) indentation distance when insufficient indentation occurs Dp Thickness of steel sheet Du Pulling distance (setting value = actual value) / pulling command signal Dup Pulling distance from reference point P Ia Welding current Ia1 First main arc current Ia2 Second main arc current Io Output current Ip Auxiliary arc current Is Short circuit current M Stud tip End moving amount ta Main arc current conduction time ta1 First main arc current conduction time ta2 Second main arc current conduction time tp Auxiliary arc current conduction time ts0 Short-circuit point in direct welding ts1 Stud tip in through welding Ts2 Short-circuit point at which the tip of the stud is pressed into the steel frame during penetration welding ts Short-circuit time tm Push-in time Va1 Welding voltage during the first main arc current Va2 During the second main arc current Welding voltage Vd output terminal voltage

 ──────────────────────────────────────────────────の Continuation of the front page (72) Inventor Shoji Harada 2-29, Minamimori-cho, Kita-ku, Osaka City Inside Daihen Stud Co., Ltd.

Claims (4)

[Claims] 1. A stud welding method in which a stud is pulled up from a material to be welded to generate an arc, and after a pulling-up period is completed, a stud is pushed into the material to be welded by pushing a predetermined amount into the welded material. Main current switching stud welding method to increase arc current. 2. A downward stud welding method in which a stud having a large diameter is pulled up from a material to be welded to generate an arc, and after the raising period is over, a stud is pushed into the material to be welded by a predetermined pushing amount to perform welding. In the latter half of the main current switching stud welding method to increase the arc current. 3. A penetrating stud which raises a stud from a material to be welded having a steel plate disposed on a steel frame to generate an arc, and pushes the stud into the material to be welded by a predetermined pushing amount after the lifting period to weld. In the welding method,
A main current switching stud welding method that increases the arc current in the second half of the pulling period. 4. A horizontal stud welding method in which an arc is generated by separating a stud from a material to be welded disposed laterally and an arc is generated, and after a lifting period, the stud is pushed into the material to be welded by a predetermined pushing amount to perform welding. A main current switching stud welding method that increases the arc current in the second half of the pulling period.