JPH04327370A - Arc spot welding method - Google Patents

Abstract

PURPOSE:To prevent perforation of a rear side plate and generation of deposition on packing material by reducing the depth of melting by weld metal in the method to join two superposed plates by arc spot welding of a wire supply system. CONSTITUTION:When a surface side plate 1 and the rear side plate 2 are superposed on each other and joined together by arc spot welding of the wire supply system, a twist wire 3A is used as a wire.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining two stacked plates by wire-fed arc spot welding.

0002

[Prior Art] Conventionally, as shown in FIG. 2, a front plate material 1 (plate thickness t1) is
When joining the back side plate material 2 (plate thickness t2) in an overlapping state, a small hole is made in the front side plate material 1 using an arc at the welding position of the front side plate material 1, and welding from the wire 3 is performed in this hole. By pouring the metal 5, the plate materials 1 and 2 are joined together (see, for example, Japanese Patent Laid-Open No. 139187/1987). In addition, in the figure, 4 is a nozzle that covers the arc welding part.

0003

[Problems to be Solved by the Invention] However, in the conventional arc spot welding method, the weld metal 5 from the wire 3 hits directly below the wire 3, and the depth of fusion by the weld metal 5 becomes large, causing damage to the back side plate material. When the plate thickness t2 of 2 is small, there is a risk that the weld metal 5 will make a hole in the back side plate 2 and welding to the backing material (backing material) arranged on the back side of the back side plate 2 will occur.

The present invention aims to solve these problems, and provides an arc spot welding method that reduces the fusion depth of the weld metal and prevents the formation of holes in the back plate material and welding to the backing material. The purpose is to provide

[0005]

[Means for Solving the Problems] In order to achieve the above object, the arc spot welding method of the present invention provides a method for welding a front side plate and a back side plate when superimposing them and joining them by wire-fed arc spot welding. It is characterized by using twisted wire as the wire.

[0006] Furthermore, a hole may be formed in advance in the front plate at the welding position between the front plate and the back plate.

[0007]

[Function] In the above-described arc spot welding method of the present invention, by using a twisted wire, rotational movement of the welding arc occurs during welding, and it is possible to prevent the arc from spreading laterally and concentrating the weld metal directly under the wire. .

[0008] Furthermore, by drilling a hole in advance in the front plate at the welding position to form a hole, it is possible to prevent the weld metal from arc spot welding from pouring into the hole and bulging out from the front plate. With,
Even if the front plate material is thick, sufficient penetration can be obtained to join the front plate material and the back plate material with the weld metal.

[0009]

[Embodiment] An arc spot welding method as an embodiment of the present invention will be explained below with reference to the drawings.
) is a schematic cross-sectional view showing the state during welding, and FIG.
) is a schematic cross-sectional view showing the state after welding.

As shown in FIG. 1(a), in this embodiment,
Before overlapping the front plate material 1 (plate thickness t1) and the back plate material 2 (plate thickness t2) and joining them by wire-supplied arc spot welding, the front plate material 1 is at the welding position of the front plate material 1 and the back plate material 2. A hole 1a having a diameter φ is formed in advance by drilling.

In this embodiment, the holes 1a are formed in the front plate material 1 at the welding position, and as shown in FIG. 1(a),
As shown in (b), arc spot welding is performed using the twisted wire 3A.

The twisted wire 3A used here is
It is constructed by twisting two wires together, and conventionally,
What was used for butt welding of extra-thick steel plates,
In the present invention, it is used for arc spot welding.

The twisted wire 3A in this embodiment is, for example, a 0.8 mm x 0.8 mm stranded wire (outer diameter 1.6 mm) with a twisting pitch of 3 to 5 mm. In addition, the welding conditions in this example include, for example, welding current 470 to 500 A, welding voltage 36 to 38 V, arc spot time 2.0 to 2.5 seconds, spot hole diameter (φ) 15
~20 mm, and CO2 is used as the shielding gas.

Now, when arc spot welding is performed using the twisted wire 3A under such welding conditions, the characteristic is that rotational movement of the welding arc occurs, the arc spreads and disperses laterally, and the weld metal 5 is poured into the hole 1a of the front plate 1 while spreading out without being concentrated directly under the wire.

[0015] As a result, as in this embodiment, the front plate material 1
Since the hole 1a is formed in the twisted wire 3A,
Even if the arc from directly hits the back plate material 2, the weld metal 5
The melting depth of the back side plate 2 in the thickness direction is reduced, and the occurrence of holes in the back side plate 2 and welding to the backing material is reliably prevented.

Furthermore, by forming the hole 1a, the structure shown in FIG.
As shown in b), it is possible to prevent the weld metal 5 from rising significantly from the front plate 1, and also to reduce the thickness t1 of the front plate 1.
Even if the front plate material 1 is thick, sufficient penetration for joining the front plate material 1 and the back plate material 2 can be obtained, and restrictions on increasing the thickness of the front plate material 1 can be relaxed.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and even if there are design changes without departing from the gist of the present invention, they are included within the scope of the present invention.

[0018]

As described in detail above, according to the arc spot welding method of the present invention, by performing arc spot welding between the front side plate material and the back side plate material using a twisted wire as the wire, the molten metal by the weld metal can be reduced. By reducing the depth, it is possible to prevent holes in the back plate material and welding to the backing material.

[0019] Furthermore, by forming a hole in advance in the front plate material at the welding position, it is possible to prevent the weld metal from protruding significantly and to improve the fit of the product.
This also has the effect of easing restrictions on increasing the thickness of the front plate material.

[Brief explanation of drawings]

FIG. 1 shows an arc spot welding method as an embodiment of the present invention, in which (a) is a sectional view showing the state during welding, and (b) is a sectional view showing the state after welding. .

FIG. 2 is a sectional view showing a welding state by a conventional arc spot welding method.

[Explanation of symbols]

1 Front plate material 1a
Hole

Claims (2)

[Claims] 1. An arc spot welding method characterized in that a twisted wire is used as the wire when overlapping a front side plate material and a back side plate material and joining them by wire-supplied arc spot welding. 2. The arc spot welding method according to claim 1, wherein a hole is previously formed in the front plate material at a welding position between the front plate material and the back plate material.