JPS58142844A - Weldable laminated board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laminate plate that takes advantage of the inherent characteristics of the laminate plate and is capable of welding.

Laminated sheets with a three-layer structure consisting of two metal plates (hereinafter referred to as skins) and a synthetic resin layer interposed between them (hereinafter referred to as core) have recently been widely used in the fields of automobiles, building materials, and home appliances. It started to be done. This is because such a three-layer laminated plate is lighter than a single plate, and can ensure higher rigidity with the same weight.

-In terms of fJ, a steel plate with a thickness of 0.2 as a skin material-
A laminated steel plate with a total thickness of 0.8 mm using a 9.4 mm thick synthetic resin as the core material has the same rigidity as a steel plate of the same thickness, but it is about 45-
It's light. In the case of this type of laminate, the degree of weight reduction in consideration of rigidity increases as the core thickness increases under the condition that the skin thickness is constant.

In addition to the advantage of being lightweight, this type of laminate has excellent vibration damping properties compared to single metal, and its surface is less susceptible to scratches and has a better appearance than synthetic resin materials. .

Generally speaking, electrical resistance welding is completely impossible for laminates because the synthetic resin used in them is an electrical insulator, and therefore the only way to join them during assembly is by bolting, adhesives, etc. However, it is disadvantageous in terms of workability and assembly cost.

In order to overcome this disadvantage of the laminate, various methods have been proposed to provide conductivity between the two skins. 1st
As shown in the figure, the most promising method is to mix and contain electrically conductive metal powder (3) in the core (2). In order to ensure that the skin (1) and the metal powder (3) are in contact with each other, the metal powder (3) in the core (2) must be in contact with each other. The metal powder must occupy an extremely large portion of the total core area, 60 to 80 inches, which greatly reduces the inherent lightweight advantage of the laminate, and also reduces the peel strength of the laminate. A significant decline is also inevitable.

The purpose of the present invention is to make it possible to improve the weldability of a laminate to the same level as that of a normal single steel plate, without sacrificing the original characteristics and performance of a laminate, such as light weight and good peel strength. It is in.

That is, the gist of the present invention is that in a laminate having a three-layer structure, as shown in FIG. 2, a spiral ! 4% body (
4) is mixed and contained in a volume ratio of 3 to 301 degrees.

Hereinafter, the conductor (4) will be explained in detail.

If the above-mentioned spiral conductor (4) is adopted as an electrically conductive mixture into the core (2) to ensure electrical conductivity between both skins (IHI), and this is uniformly distributed in the core, By imparting good electrical conductivity to any part between both skins (1) (11) with a much smaller mixing amount than in the conventional case where no metal powder is used, it is possible to form a spiral. This is because the conductor (4) C having a shape is easy to obtain contact with both vanes (1) (11), and also leaves a large amount of room inside for the synthetic resin to fill.
When using this spiral conductor, it is possible to make the proportion of the synthetic resin itself in the core much higher than in the case of conventional metal powder, which may impair the inherent lightweight characteristics of the laminated laminate. Moreover, extremely good weldability can be ensured without deteriorating peel strength.

Examples of the spiral conductor in the laminate of the present invention include helical steel, stainless steel, other nets, aluminum, etc.
It is possible to use any material, such as one made of electrically conductive metal or a low carbon material. This spiral conductor is under one load, that is, before being mixed into the synthetic resin, and its outer diameter, indicated by 0 in Figure 3, is larger than the core thickness t) (see Figure 2). must be used.

In Dot, a spiral conductor (4
) cannot obtain reliable contact with both skins (1) and (1),
Sufficient conductivity cannot be imparted between them. In the case of a conductor with D≧t, the inclination of the helix of the conductor (4) in the core (2) increases due to the pressure bonding during the production of the laminate, resulting in a state in which the two skins are in reliable contact with each other. It fits in. It is preferable that the helical pitch (lp) of the conductor (4) be less than or equal to the diameter of the welding tip in order to ensure conductivity between both skins. Regarding the number of turns of the spiral, there is no problem with the number of turns on the winding tool being one unit.The material forming the conductor (2) may be either linear or plate-like. In this case, the material cross-sectional dimension in the radial direction of the spiral conductor shown in Figure 4 a), ←), that is, the diameter in the case of a linear material, is used, and the width direction is set in the direction of spiral progression. Needless to say, when winding up the core material, the thickness must be less than the thickness of the core material. At this H>%Xt, the helical conductor in the core can maintain a helical form as shown in Figure @2. This means that the helical conductor can be mixed in the core as referred to in the present invention. Therefore, the object of the present invention, which is to obtain good conductivity with a small amount of the electrically conductive mixture, cannot be achieved as described above. Moreover, in this case, it is unavoidable that the conductor (4) makes impressions on the skin material (1) due to pressure bonding during manufacturing.

In the present invention, the proportion of the conductor (4) in the core is limited to a volume ratio of 3 to 30 cm based on the following experimental results. exemplifies the relationship between the volume ratio, peel strength, and spot weldability. The peel strength is as follows: Skin: 0.2111m thick cold rolled steel plate, Core synthetic resin: 20.4m thick polypropylene, Electrically conductive mixture: Spiral metal body (outer diameter without load: approx. 1+W, material diameter The results are the results of a test in accordance with JISK6854 for a laminate of 0.15■. The number of individual nuggets formed was investigated and expressed as a ratio of the number of nugget formations to the total score (20 points).

As is clear from the figure, in order to make spot welding possible completely, the volume ratio of the conductor must be at least 3cm, and the reduction in peeling rate due to the conductor mixed in must be kept within 40cm. In order to achieve this, the volume ratio must also be kept below 30. From the above, in the present invention, the volume ratio of the spiral conductor is 3 to 30.
It is limited to

The skin of the laminate of the present invention may be made of carbon steel, etc.
Any metal plate that is an electrical conductor, such as a stainless steel plate, a copper plate, or an aluminum plate, can be used.

As the synthetic resin for the core, any of the various thermoplastic resins conventionally used in this type of laminate may be used.

Examples include polypropylene, vinyl chloride, acrylic resin, methacrylic resin, cyanomacrylate, polyamide, polyether, adhesive polyolefin, and modified products and composites thereof.

In principle, the laminate of the present invention can be produced using the usual hot press method in which two skin materials and a core material are bonded together under heat using a hot press, or by continuously supplying two strip-shaped skin materials and a core material. However, it can be manufactured by either a roll crimping method in which these are passed through a roll and crimped. In the case of the laminate of the present invention, only the step of pre-mixing the helical conductor (4) into the core material is added.

Next, examples of the present invention will be described.

A: Inventive laminate skin = 0.2 thick cold rolled steel plate Core synthetic resin: Polypropylene (0.4 thick) Helical conductor: Low carbon steel, material diameter 0.15+a, outer diameter 1cm helix The proportion (volume ratio) of the conductor in the core is approximately 7 parts,
Manufacturing method: Hot press method (temperature 230℃, pressure 20kf
fA-tJ) B: Conventional example (weldable type containing metal powder in the core) Skin, core, manufacturing method: Same as above Metal powder: Low carbon steel Proportion of metal powder in the core (volume ratio): Approximately 60% (
(the minimum amount necessary to achieve welding performance).

C: Ordinary laminate skin, core synthetic resin, manufacturing method: Same as above D = cold rolled steel plate (
JISS PCC) Thickness 20, 8■ (same as the total thickness of the laminate with (s Qc, >)) Table 1 compares 1 pupil for the laminates with the above ■ to 0 or the cold-rolled plates with 0. be.

The laminate of the present invention (Table 1) has a weight reduction rate of 39 cm compared to the cold-rolled steel plate 0), and is lighter than the normal laminate C) that does not contain any mixture in the core. It can be said that there is almost no inferiority in this respect. On the other hand, in the conventional example e), which contains the minimum amount of metal powder necessary to make it weldable in the core, the weight reduction rate is extremely low at 18 yen, which means that the weight reduction rate is extremely low compared to the cold-rolled sheet. It can be seen that the advantage has been significantly diminished.

Table 2 shows the results of a T-peel test (based on JIS K6854) conducted on the laminates Q to 0 to investigate the interlayer peel strength.

The laminated base plate of the present invention had approximately the same peel strength as that of the conventional laminated plate C). However, the conventional weldable laminate e) was significantly inferior in peel strength.

Table 3 shows the weldability of the N and e) weldable laminates. The investigation was conducted by preparing two laminates of the same type and spot welding (tip tip diameter 6--, 40
■8 bulb heads, current 8000A, pressure 150 - energization time 0
．． 1 second) and then measured the static strength of the welded part. In addition, the same table also shows the case where two 0.4-inch thick cold-rolled steel plates were welded under the same conditions as above.

Regarding weldability, not only the laminated plate thickness of the present invention but also the conventional example 113) in which no metal powder was used was extremely good. Furthermore, the static strength after spot welding is higher than that of cold-rolled steel sheets.

It shows.

As is clear from the following explanation, the laminate of the present invention is completely weldable, and even compared to ordinary laminates that cannot be welded, it is inferior in terms of peel strength and weight. There is no
That is, the present invention can improve the ease of assembly and workability of a laminate to the same level as that of a cold-rolled sheet without impairing the excellent characteristics inherent to the laminate, and its practicality is extremely high.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing the internal structure of a conventional weldable laminate in which metal powder is mixed in the core, and FIG. 2 is a vertical cross-sectional view 6 showing the most preferable example of the laminate of the present invention. Figure 3 is a side view illustrating the spiral conductor used in the laminate of the present invention, Figure 4 &), (0) is a side view illustrating the same conductor using linear and plate-shaped materials, respectively. Figure 5 a), ←
) is a diagram showing the relationship between the volume ratio of the helical metal body 6 to the synthetic resin, the peel strength of the laminate, and the weldability θ. In the figure, 1: Niskin, 2: core, 3: metal powder, 4: spiral conductor. Applicant: Sumitomo Metal Industries, Ltd. Figure 5 (a) Core mid-career recruitment 2-shell plan 6-sen crest return to arc balance (rice ＼ 并RA) Core with old A3-sen Buddha body. O ratio (441 ratio)
No. 1 Intellectual Figure 3 Figure 2 Voluntary procedure amendment January 18, 1982 Director of the Japan Patent Office Kazuo Wakasugi 1, Indication of the case 1986 Patent Application No. 25756 2, Name of the invention Weldable Laminated Plate 3, Relationship with the Amendment Case Patent Applicant Address 5-16 Kitahama, Higashi-ku, Osaka Name (21
1) Sumitomo Metal Industries, Ltd. 6, "Detailed Description of the Invention" column and "Brief Description of Drawings" column of the specification subject to amendment, Drawing 7, Contents of the amendment (1) No. 1 of the specification In the 4th line of page 5, [D<t,...
・" is changed to "If D≦t,..." and the 6th line of the same line is "
``...D≧t'' is corrected to ``...D>t''. (2) From page 5, line 18 to line 14 of the specification, the phrase ``...--Due to the winding, any number of volumes may be considered as one unit'' has been amended as follows. ``...It doesn't matter if more than half a turn or any number of turns can be used as a unit. If half a turn to one turn is taken as a unit, it will not be a nine-fold distribution as shown in Figure 2, but the shape of a spiral Due to its nature, the upper and lower skins are in perfect contact with the helical body no matter how they are distributed.'' (3) In the 8th line of page 6 of the specification, ``
It is also unavoidable that the impressions of the conductor (4) overlap. ”
Then add the following. ``If the number of spiral winders is relatively small, ranging from half a turn to one turn, the length L) in the winding direction of the spiral shown in Figure 4 (c) is the core thickness δ before being mixed with the synthetic resin. The cross section of the helical material must be determined so that it is long and compressed in the winding direction so that the shortest length is shorter than the core thickness in the minimum state.If the minimum shortened length is thicker than the core thickness. skin material (1
) is indented by the spiral body. ”(4
) Add the following to page 12, line 10 of the statement, before it says [Figure 5 (a), chivalry) is...''. "(C) is a side view of a conductor with about one turn." (5)
I am correcting Figure 4 of the drawing as shown in the attached sheet. Above Figure 4 (c)

Claims (1)

[Claims] (1) A weldable laminate made of two metal plates with a synthetic resin interposed between them, characterized in that the synthetic resin layer is mixed with a spiral conductor of 3 to 30 pieces by volume. Laminated board.