JPH0562031B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for fusion welding resin-laminated metal plates, which allows resin-laminated metal plates to be welded in any joint type.

[Background Art] In recent years, noise reduction measures for many noise-generating machines such as transportation machines and metal processing machines have become a major issue. Such countermeasures should be taken from both the structure and constituent materials of the noise generating body, and resin-laminated steel sheets, generally called vibration-damping laminated steel sheets, are useful materials from the latter point of view.

A vibration-damping laminated steel plate is a composite steel plate that is made by sandwiching a thin resin layer made of a viscoelastic resin between two steel plates, and the strength of the material is provided by the steel plate. The damping action is performed by an intermediate viscoelastic body. The sound reduction effect of vibration-damping laminated steel plates is exclusively related to the absorption of solid sound when the structure itself using this plate is the sound source.
It is most effective as a noise countermeasure. Moreover,
The viscoelastic material that makes up the damping laminated steel plate is a very thin layer compared to the constituent steel plates, and can generally be treated in the same way as a normal steel plate, so this laminated steel plate has a wide range of applications. However, even though the viscoelastic layer of a damping laminated steel plate is very thin, its physical properties are very different from those of the steel plate, so some care must be taken when processing it. That is, since a viscoelastic body is normally an electrical insulator, when performing resistance spot welding in structure assembly, a special method such as the film control method specified in the Japanese Welding Association standard WES7301 must be used.
Furthermore, it is known from Japanese Patent Application Laid-Open No. 133000/1983 that there are problems with the state of the end surface during cutting depending on the application. As in these examples, when using vibration-damping laminated steel plates, there may be cases where conventional techniques cannot be used due to processing technology.

There are many uses for vibration-damping laminated steel sheets, but continuous welding is often essential, such as in oil pans among automobile parts. An oil pan is a part located directly below the cylinder of an automobile engine to store engine oil.Since the oil pan receives vibrations from above, it generates a lot of noise, so vibration-damping laminated steel plates are used to reduce noise. Above all, it is extremely effective. However, when joining members during assembly, airtightness and high strength are required of the joining joint. For this reason,
Arc welding was used when conventional steel plates were used. The type of welded joint in this case is generally a butt joint or a lap joint.

However, when vibration-damping laminated steel plates are used as members, continuous arc welding becomes extremely difficult. This is due to the fact that viscoelastic materials are generally organic substances and are electrical insulators, and that at high temperatures such as in arc welding, gas is generated due to evaporation, thermal decomposition, etc. This is because it is difficult. Therefore, when welding is required, the following methods are generally used.

For example, JP-A-60-003982, JP-A-60-
As shown in Publication No. 87980, heat is applied to the end face of a vibration-damping laminated steel plate to ensure bonding over the entire thickness of the laminated steel plate, and the generated resin decomposition gas is removed from the welding point to the outside using shielding gas. This is a method of discharging it.

Using this method, two sets of joint types can be welded:

One method, as shown in Japanese Patent Application Laid-open No. 60-003982, is to stack a normal steel plate on the bottom and a laminated steel plate on top, and fillet weld the end faces of the laminated steel plates.

Another method, as shown in Japanese Patent Application Laid-Open No. 60-87980, is to butt-weld laminated steel plates at their end faces and butt-weld them within the root gap.

[Problems to be Solved by the Invention] However, in the first joint type described above, it is impossible to weld unless the lower member is a regular steel plate, and if it is a laminated steel plate, heat reflection occurs at the resin interface. At the same time, welding becomes impossible due to the release of decomposed gas from the resin.

In addition, in the second joint type, it is difficult to butt the laminated steel plates together, and it must be done using a backing metal.
In addition, since stable welding must be continued, there is a problem that the work becomes difficult and complicated.

The present invention makes it possible to weld laminated steel plates directly butted against each other in each of the joint types described above without being affected by heat reflection or decomposition gas interference, and without using a backing metal. The object of the present invention is to provide an extremely practical method for melt-joining resin-laminated metal plates, which enables stable welding even within a narrow root gap.

[Means for Solving the Problems] The method of melting and joining resin-laminated metal plates according to the present invention usually involves sandwiching a resin material with a thickness of 0.02 to 0.6 mm between two metal plates with a thickness of 5 mm or less and joining them together. High energy density welding such as plasma welding, pulsed arc welding, laser welding, or electron beam welding when welding one resin-laminated metal plate to another resin-laminated metal plate or a regular metal member. Using the method, under the supply of shielding gas or assist gas, the width of the molten pool is controlled to 5t or less, where t is the total thickness of the joining member, and the width of the molten pool is reduced to the total thickness of the joining member. This method involves melting and joining the parts by penetrating them.

[Function] In the present invention, by using a high energy density welding method, for example, in a plasma welding method,
A so-called keyhole weld is performed because a compressed high-temperature plasma stream is injected at high speed onto the end face or surface of the resin-laminated metal plate. Therefore, almost no heat reflection occurs in the resin layer, and the generated decomposed gas is also discharged to the outside together with the plasma flow and under the action of the shielding gas.

Further, even in the case of pulsed arc welding in TIG welding or MIG welding, a plasma arc column with high rigidity can be obtained, so that the same effect as described above is performed.

Furthermore, even in the case of laser welding or electron beam welding, both have extremely high energy density and suppress heat conduction from the component surface, making it possible to achieve deep penetration welding. It is possible to obtain the same effect as the method.

[Example] Examples of the present invention will be described below.

FIG. 1 is an explanatory diagram of lap welding of resin-laminated metal plates by a typical plasma welding method, and FIG. 2 is a longitudinal sectional view thereof. In the figure, 1 and 2 are resin-laminated metal plates, 3 is a plasma torch, 4 is a plasma arc, 5 is a filler wire, 6 is a molten pool, and 7 is a weld bead.

The resin laminated metal plates 1 and 2 are integrated by sandwiching thin resin layers 13 and 23 between two metal plates 11 and 12 and 21 and 22, respectively, and the thickness of each metal plate is usually 5 mm or less, and the thickness of the resin layer is in the range of 0.02 to 0.6 mm.

When such resin laminated metal plates 1 and 2 are overlapped and lap welded by plasma welding, the concentrated plasma arc 4 penetrates the lower resin laminated metal plate 2, and the molten pool 6 reaches the back surface, resulting in a sound weld. Bead 7 is obtained. In this case,
Since it is practically difficult to detect the degree of concentration or convergence of the plasma arc 4, the width W of the molten pool 6
It is appropriate to measure Then, the concentration degree of the plasma arc 4 is controlled so that the width W of the molten pool 6 satisfies W≦5t, where t is the total thickness of the joining members, that is, the upper and lower resin laminated metal plates 1 and 2.

Further, in this case, since the end face of the resin laminated metal plate 1 is open to the outside, the decomposed gas of the resin layer 13 is discharged by the shielding gas injected from the plasma torch 3, and the decomposed gas of the resin layer 13 is exhausted.
The decomposed gas is discharged to the outside from the back surface by this shielding gas and the high-speed plasma arc 4 that performs keyhole welding. Therefore, welding defects due to these decomposed gases do not occur.

FIG. 3 shows the welding results of various joints obtained by the above plasma welding method, and the middle row shows the cross-sectional shape of the weld bead relative to the groove shape in the upper row. For comparison, welding results obtained by a general covered arc welding method are shown in the lower row. In addition, the welding conditions are a
For welding current 15A, welding speed 10cm/min,
Wire feed rate 1.5φ x 15cm/min, shield gas (Ar + 5% H ₂ ) 5/min, pilot gas (Ar) 1/min, welding current 19A, welding speed 10cm/min, wire feed for b to d. Feeding amount 1.5φ
×15 cm/min, and the gas conditions were the same as above. In addition, the welding conditions for covered arc welding are: a welding current 70A, welding speed 40cm/min, b~
For d, welding current is 75A and welding speed is 40cm/
It was set as min. In the figure, 8 is a normal steel plate.

As is clear from FIG. 3, according to this method, satisfactory results were obtained for all joint types.
That is, according to this method, all weld beads become through beads, and a good bead shape can be continuously obtained. Of course, it is also possible to form arbitrary beads intermittently. On the contrary,
In covered arc welding, the bead does not penetrate due to the insulating effect of the arc heat due to the resin layer, and since a large amount of decomposed gas is generated from the resin layer, the arc becomes unstable and does not form a normal bead shape.

In addition, when using the conventional method (TIG welding) for laminated metal plates plated with Zn or Zn alloy, defects such as blowholes may occur due to Zn vapor, and a healthy bead may not be formed due to instability of the arc. In the method of the present invention, since the resin layer has a high ability to discharge decomposed gas, a healthy bead is formed without the above defects.

The method of the present invention is not limited to the plasma arc welding method described above, but can be applied to all high-energy density welding methods such as TIG and MIG pulsed arc welding, laser welding, and electron beam welding. It is.

[Effects of the Invention] As described above, according to the present invention, a penetrating bead can be formed in a resin-laminated metal plate by adopting a high-energy density welding method and by controlling the width of the molten pool at that time to a predetermined value or less. Since it is formed and then fused and joined, all types of joints are possible, and since the resin layer has a high ability to discharge decomposed gas, it has the effect of obtaining an extremely good weld bead. As a result, the use of resin-laminated metal plates can be expanded, and its practical value is extremely large.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing the welding of resin-laminated metal plates by the plasma arc welding method of the present invention, Figure 2 is a longitudinal cross-sectional view of Figure 1, and Figure 3 shows the welding results of the present method and the conventional method. FIG. 1, 2... Resin laminated metal plate, 11, 1
2, 21, 22... Metal plate, 13, 23... Resin layer, 6... Molten pool.

Claims (1)

[Claims] 1. A plasma welding method in the case of welding a resin-laminated metal plate, which is integrated by sandwiching a thin resin layer between two metal plates, to the other resin-laminated metal plate or a normal metal member. Using high-energy density welding methods such as pulsed arc welding, laser welding, or electron beam welding, the width of the weld pool is reduced to the total thickness of the parts to be joined using a shielding or assist gas supply. 1. A fusion welding method for resin-laminated metal plates, characterized in that the molten pool penetrates the entire thickness of the joining member to perform fusion welding while controlling the pressure to be 5t or less.