JP4868222B2 - Method and apparatus for joining dissimilar metal panels - Google Patents

Description

The present invention relates to a dissimilar metal panel flare joining technique having different melting points, such as dissimilar metal panels, for example, panels made of steel and aluminum alloy materials, and suppresses the generation of brittle intermetallic compounds while joining panels. The present invention relates to a joining method of dissimilar metal panels capable of firmly joining new surfaces, and a joining device applied to such joining.

  Conventionally, in the joining of dissimilar materials using a high energy beam such as an electron beam or a laser beam, the defocused high energy beam is applied to the high melting point material side in order to suppress the formation of brittle intermetallic compounds. A method has been used in which the low melting point material side of the bonding interface is melted and bonded by irradiation and heat transfer from the high melting point material side.

  In such a case, the welding conditions are controlled, only the material on one side (low melting point material) is melted at the joining interface, and the growth of the intermetallic compound layer is suppressed by joining using the diffusion of the material. By reducing the thickness, it is considered that the strength per unit area of the joint can be increased as compared to the case where both materials are melted and joined together. In addition, a method is described in which a steel plate is stacked on an aluminum alloy and a laser beam is irradiated from above the steel plate to join different materials with the interface in a solid phase / liquid phase state.

Non-Patent Document 2 describes a method of joining an aluminum alloy panel to a steel body frame structure by mechanical fastening, that is, driving a rivet or the like from the aluminum alloy side.
“Overview of the National Conference of the Japan Welding Society”, Japan Welding Society, April 2003, Vol. 72, p. 152 Mitsubishi Motors Technical Review 2004, No. 16, p. 82

  However, in the method described in Non-Patent Document 1, in order to suppress the formation of intermetallic compounds at the bonding interface and obtain a good bonding strength, it is necessary to control the bonding conditions very precisely. Since the appropriate bonding condition range is extremely narrow, there is a problem that it is extremely difficult to put it to practical use industrially.

In addition, in this method, the aluminum alloy at the joint interface is melted by heat transfer from the steel plate, so the steel plate must be stacked on the aluminum alloy, and the laser beam must be irradiated from the outer side of the steel plate side. There were restrictions on structural design.
That is, for the purpose of improving fuel efficiency and athletic performance by reducing the weight of the vehicle, a vehicle body structure using a light alloy such as an aluminum alloy for the vehicle body panel is required. For example, in order to enhance the performance improvement effect by lowering the center of gravity When an aluminum alloy is used for the roof panel, the joining structure between the steel member and the aluminum alloy member, which is a vehicle body skeleton structure, is formed by stacking the roof panel made of aluminum alloy on the steel member, and the proximity of the laser head. Since the joining structure must be irradiated with the laser beam from the outside of the vehicle body frame structure, that is, the side of the roof panel made of aluminum alloy, the method of irradiating the laser beam from the steel plate side as described above cannot be applied. It will be.

  Therefore, practically, the method by mechanical fastening described in Non-Patent Document 2 will be studied. However, in this method, when the weight and cost increase or the degree of freedom in external design is restricted. There was a problem that there was.

The present invention has been made in view of the above-described problems in the joining technology of different metal materials. For example, when applied to the joining of an automobile body structure, the intermetallic compound is irradiated by high energy beam irradiation from the outside of the body. It is an object of the present invention to provide a joining method of dissimilar metal panels that can join dissimilar metals without causing generation, weight, and cost increase, and a joining apparatus used for such joining.

  As a result of intensive studies to achieve the above object, the inventors of the present invention have developed a third material that causes a eutectic reaction between at least one of these metal materials between the dissimilar metal panels to be joined. It was found that the above problem can be solved by irradiating the center of the defocused high energy beam to the refractory metal panel in the state of interposing the refractory metal to cause eutectic melting and flaring. The invention has been completed.

That is, the present invention is based on the above knowledge, and in the method for joining dissimilar metal panels of the present invention, when joining a high melting point metal panel and a low melting point metal panel having different melting points, While irradiating the high-melting metal panel or both the refractory metal panel and the low-melting metal panel with a defocused high energy beam with a third material different from these materials interposed therebetween, Relative pressure is applied to the panels, and eutectic melting occurs between at least one of the two panels and the third material, so that the panels are flare-bonded in a continuous or intermittent line shape.

Further, the dissimilar metal panel joining device of the present invention is a device for flaring the high melting point metal panel and the low melting point metal panel having different melting points, and is arranged to be movable relative to the joined panel. An irradiation head that continuously or intermittently irradiates the bonded panel with a high energy beam while continuously or intermittently moving, and a rotation about an axis substantially parallel to the irradiation direction of the high energy beam by the irradiation head On the other hand, a pressure roller for pressing the bonded panel in a direction substantially perpendicular to the irradiation direction of the high energy beam is provided.

According to the present invention, a high-energy beam defocused with a third material interposed between the low-melting-point metal panel and the high-melting-point metal panel, the high-melting-point metal panel, or the high-melting-point metal panel and the low-melting-point metal panel. While irradiating both of the metal panels, both panels are relatively pressurized, and eutectic melting occurs between at least one of the two panels and the third material, so that both panels are made into continuous or intermittent linear shapes. Since flared bonding is performed, the high-melting point metal panel is irradiated with a high-energy beam mainly from the side of the low-melting point metal panel located outside, so that the new surface of both panels can be obtained without increasing the bonding interface temperature. Joining each other becomes possible, generation of an intermetallic compound is suppressed, and a strong joined state can be obtained without causing an increase in weight or cost.

  Below, the joining method of the dissimilar metal panel of this invention is demonstrated further in detail and concretely.

In the method for joining dissimilar metal panels of the present invention, as described above, the low melting point metal panel and the high melting point metal panel are simply overlapped, and the high energy beam is irradiated from the direction orthogonal to the panel surface to overlap joining. Rather than flaring, that is, both panels are joined at a plane that is substantially perpendicular to the panel surface. As the tolerance of the timing of pressurization with respect to the irradiation of the laser beam is widened, quality improvement such as the strength of the joint joint can be realized. Further, since the laser beam is irradiated in the vicinity where the eutectic melt is discharged , in other words, the position adjacent to the bonding surface of the refractory metal panel, the absorption rate of the laser beam is improved and stable bonding can be realized. Moreover, since the joint part of a component can be positioned in advance, the component accuracy is also improved. Furthermore, by using a flare structure, the joints of the roof panel become smooth and the design properties such as appearance are improved.

  Therefore, even if the high energy beam is applied only to the surface of the refractory metal panel or to both the refractory metal panel and the low melting point panel, the center of the beam where the energy density of the defocused beam is the highest is obtained. It is necessary to be positioned on the high melting point metal panel, and only the peripheral part of the high energy beam hits the low melting point panel and does not hit the center of the beam. It is not preferable that the low melting point panel is melted by direct beam irradiation.

  In the method for joining dissimilar metal panels of the present invention, the high energy beam is applied to the surface where both panels are finally overlapped with the joining surfaces of the high melting point metal panel and the low melting point metal panel facing each other through a gap. While irradiating, both panels can be relatively pressurized in a direction substantially perpendicular to the irradiation direction of the high-energy beam, which makes it possible to directly irradiate the laser beam onto the bonding interface and reduce the heat input. Therefore, it is possible to improve the energy efficiency, and to obtain a low-cost and lightweight joint structure with a high degree of freedom in the joint structure.

Also, the joining surfaces of the high melting point metal panel and the low melting point metal panel are overlapped, and the high melting point is high in the vicinity of the position where the eutectic melt generated in the joining process is discharged, that is, the position adjacent to the joining surface of the high melting point metal panel. While irradiating with an energy beam, both panels can also be relatively pressurized in a direction substantially perpendicular to the direction of irradiation of the high energy beam, and bonded together by relatively pressing in a direction substantially perpendicular to the direction of irradiation of the laser beam. As a result, the tolerance of the pressurization timing with respect to the irradiation of the laser beam is widened, and the quality of the joint joint can be improved. Furthermore, since the laser beam is irradiated in the vicinity of the portion where the eutectic melt is discharged, the absorption rate of the laser beam is improved, stable bonding can be realized, and the joint portion of the component can be positioned in advance. Parts accuracy is also improved.

  And in the joining method of the dissimilar metal panel of this invention, while irradiating a high energy beam relatively moving with respect to both panels (to-be-joined panel), the pressurizing means arrange | positioned in the vicinity of the irradiation point of the high energy beam Both panels can be joined while pressurizing, and at this time, continuous linear joining can be achieved by making the relative movement of the high energy beam to the panel to be joined and the irradiation of the high energy beam continuous. It becomes possible, and continuous linear joining that contributes to improvement of vehicle body rigidity and strength can be realized with high productivity. On the other hand, if the relative movement of the high energy beam and the timing of irradiation are made intermittent, it is possible to perform spot-like or stitch-like joining.

  At this time, while irradiating a high energy beam with a third material different from these materials interposed between the two metal panels, the two panels are relatively pressurized, Since eutectic melting occurs between at least one and joining, the oxide film can be removed from the joining interface at a low temperature, preventing an increase in joining interface temperature and Dissimilar metal bonding including materials that form a dense oxide film on the surface, such as aluminum and magnesium materials, because it is possible to suppress formation and obtain strong bonding between the new surfaces of the bonded panels Can be suitably used.

  At this time, as a specific means for interposing the third material between the two panels, it is desirable to plate the third material on at least one of the panels to be joined. The process of sandwiching the above material as an insert material between the panels can be omitted, and not only the work efficiency is improved by reducing the processing man-hours, but also the plating layer melted by the eutectic reaction together with the surface impurities around the joints. After being discharged, an extremely clean new surface appears from under the plating layer, and a stronger bond is possible.

  For example, when joining a dissimilar metal panel made of a light alloy panel such as an aluminum alloy material or a magnesium alloy material and a steel material, zinc, which is a third metal forming a low melting eutectic with aluminum or magnesium, is used as the steel material. Can be used a so-called galvanized steel sheet whose surface is pre-plated. In this case, it is possible to use a normal commercial steel material that has been galvanized for the purpose of rust prevention as it is without any new plating or special preparation. This makes it possible to perform strong bonding of dissimilar metal panels.

Here, an example of an Al—Zn alloy will be described for eutectic melting.
FIG. 1 shows an Al—Zn-based binary phase diagram. As shown in the figure, the eutectic point (Te) in the Al—Zn system is 655 K, which is much lower than the melting point 933 K of Al. A eutectic reaction occurs at temperature.
Therefore, by using the eutectic points shown in the figure to create eutectic melting of Al and Zn, and using them for bonding effects such as oxide film removal and interdiffusion during bonding of aluminum materials, low temperature bonding can be performed. The growth of intermetallic compounds at the bonding interface can be extremely effectively suppressed.

Here, eutectic melting means melting utilizing a eutectic reaction, and when the composition of an interdiffusion region formed by mutual diffusion of two metals (or alloys) becomes a eutectic composition, a holding temperature. If is equal to or higher than the eutectic temperature, a liquid phase is formed by the eutectic reaction. For example, in the case of aluminum and zinc, the melting point of aluminum is 933 K and the melting point of zinc is 692.5 K, whereas this eutectic metal melts at 655 K, which is lower than the respective melting points.
Therefore, a reaction occurs when the clean surfaces of both metals are brought into contact and heated to 655K or higher. This is called eutectic melting, and Al-95% Zn has a eutectic composition, but the eutectic reaction itself is a constant change unrelated to the alloy components, and the alloy composition only increases or decreases the amount of eutectic reaction. Absent.

On the other hand, an oxide film exists on the surface of the aluminum material, and this is physically destroyed by plastic deformation of the aluminum material due to heating by irradiation with a high energy beam and pressurization at a predetermined temperature immediately after that. Will be.
That is, microscopic projections on the surface of the material rub against each other by pressurization, so eutectic melting occurs from the part where aluminum and zinc contact due to local destruction of some oxide films, and this liquid phase is generated. By accelerating the reaction in which the nearby oxide film is crushed and decomposed and further eutectic melting spreads over the entire surface, the destruction of the oxide film and the joining via the liquid phase are achieved.

  Since the eutectic composition is spontaneously achieved by interdiffusion, composition control is not necessary. The essential condition is that a low melting eutectic reaction exists between the two metals or alloys. In the case of eutectic melting of aluminum and zinc, when using Zn-Al alloy instead of zinc, The composition must be at least 95% zinc.

FIGS. 2A to 2E are schematic views showing an example of joining a galvanized steel sheet (high melting point metal panel) and an aluminum alloy sheet (low melting point metal panel) as a joining process of dissimilar metal panels according to the present invention. is there.
First, as shown in FIG. 2 (a), a galvanized steel sheet 1 having a galvanized layer 1p functioning as a third metal material that forms a eutectic with Al on at least the surface on the bonding interface side, and aluminum An alloy material 2 is prepared, and as shown in FIG. 2B, the galvanized steel sheet 1 and the aluminum alloy material 2 are overlapped so that the galvanized layer 1p is on the inside. An oxide film 2 c is generated on the surface of the aluminum alloy material 2.

  Next, when the galvanized steel sheet 1 is irradiated with a high energy beam and the joining interface reaches a predetermined temperature range, both panels are pressurized and the joining surfaces are relatively pressed, so that plastic deformation and thermal shock are caused by the pressing. As a result, the oxide film 2c is locally broken at the microscopic contact portion of the material surface as shown in FIG.

  As a result, local contact between zinc and aluminum occurs, and as shown in FIG. 2 (d), eutectic melting of zinc and aluminum occurs and oxidizes together with the eutectic molten metal 3 according to the temperature state at that time. A discharge formed from impurities such as the film 2c and the bonding interface is discharged to the outside (in the direction of the arrow) of the bonded portion, so that a predetermined bonded area is secured. As a result, as shown in FIG. The new surfaces of the alloy material and the steel material are directly joined by the extremely thin reaction layer 4, and a strong metal joint between the steel plate 1 and the aluminum alloy material 2 is obtained. A thin diffusion layer of zinc to the steel may be formed between the reaction layer 4 and the steel material 1 depending on the material and joining conditions, but there is little influence on the joining strength and there is no substantial problem.

As a specific combination of panel materials in the joining method of dissimilar metal panels of the present invention, for example, a combination of a steel material and an aluminum alloy material can be mentioned. At this time, as a third material interposed between both materials, The material is not particularly limited as long as it is a material that forms a low melting point eutectic with an aluminum alloy. For example, in addition to the above-described zinc (Zn), copper (Cu), tin (Sn), silver (Ag) Nickel (Ni) or the like can be used.
That is, the eutectic metal of these metals and Al melts below the melting point of the aluminum alloy material, which is the base material, so that even when joining steel materials and aluminum alloy materials where fragile intermetallic compounds are easily formed, oxidation occurs at a low temperature. The film can be removed, the formation of intermetallic compounds at the bonding interface during the bonding process can be suppressed, and strong bonding becomes possible.

Moreover, when considering the application of the joining method of the present invention to the assembly of an automobile body, the material of the panel to be joined is mostly a combination of steel and aluminum, but in the future, steel and magnesium or aluminum A combination with magnesium is also conceivable.
When joining a steel panel and a magnesium panel, it is possible to cause a eutectic reaction between zinc and magnesium plated on the steel side in the same manner as in the examples described later. Furthermore, when joining an aluminum panel and a magnesium panel, it is possible to use zinc or silver as the third material.

  In the present invention, the third material is not necessarily limited to the pure metal as described above, and eutectic metal includes both binary alloys and ternary alloys. Therefore, at least one of these metals is used. An alloy containing may be used.

In the dissimilar metal panel joining apparatus according to the present invention, as described above, the dissimilar metal panel is disposed so as to be relatively movable, and a high energy beam is continuously applied to the joined panel while continuously or intermittently moving relative thereto. An irradiation head that irradiates the target or intermittently, and a rotation axis that is substantially parallel to the irradiation direction of the high energy beam from the irradiation head, and rotates about this axis while being substantially perpendicular to the irradiation direction of the high energy beam. By providing a pressure roller that presses the panel to be joined in the direction of forming the above, it can be suitably used in the above-described joining method of the present invention.

Furthermore, in the method for joining dissimilar metal panels of the present invention, the low melting point metal panel is a light alloy panel, and the high melting point metal panel can be a vehicle body member made of a galvanized steel sheet. Can be used to obtain a lightweight and highly dynamic body structure at low cost and easily. For example, by using a low melting point metal panel as a roof panel, a lightweight and low center of gravity body can be manufactured inexpensively and easily. can do.

  Hereinafter, the present invention will be specifically described based on examples.

  FIG. 3 is a schematic view showing an example of a bonding apparatus for dissimilar metal panels used in the present invention. The bonding apparatus 10 shown in the figure is an irradiation head 11 that irradiates an Nd-YAG laser, which is a kind of high energy beam. The irradiation head 11 and the pressure roller 12 are movably supported by arms A1 and A2 of the welding robot, respectively. The pressure roller 12 is supported by the irradiation head 11. It follows and moves continuously or intermittently.

The irradiation head 11 is connected to a laser oscillator (not shown) through an optical fiber 14 and irradiates a laser beam B whose focus is adjusted from the tip thereof toward a bonded panel composed of the refractory metal panel 1 and the low melting metal panel 2. Can be done.
On the other hand, the pressure roller 12 can press the low melting point metal panel 2 against the high melting point metal panel 1 by a pressure cylinder 13 and pressurize it.

  In the bonding apparatus 10 having such a structure, continuous linear bonding can be performed by continuously moving and irradiating a laser beam, and dot-like by intermittently moving and moving the irradiation. Alternatively, stitch-like joining can be performed.

FIG. 4 shows a procedure for joining an aluminum alloy roof panel, which is a low melting point metal panel, to a steel body member, which is a high melting point metal panel, using the joining apparatus 10 described above. In addition, the body member in which the steel rail inner 15 (plate thickness: 1.4 mm), the rail outer 16 (plate thickness: 0.8 mm), and the side outer 17 (plate thickness: 0.8 mm) are assembled by welding. A light alloy roof panel 21 (plate thickness: 1.2 mm) is flared from the side outer 17 from the lateral direction.
The side outer 17 is made of a galvanized steel sheet having zinc plated on the surface.

On the other hand, in the roof panel 21 made of aluminum alloy, a joining flange 21a formed at an end thereof is opposed to a joining surface 17a set on the side outer 17 of the vehicle body member via a gap. The defocused laser beam B is emitted toward both the roof panels 21.
At this time, the irradiation site of the high energy beam B is a surface where both panels are finally overlapped, and the central axis of the defocused laser beam B is on the joint surface 17a of the side outer 17 which is a refractory metal panel. The roof panel 21, which is a low melting point metal panel, is positioned so that the outer peripheral portion of the beam B slightly touches it, and while irradiating the laser beam B, both panels are moved substantially perpendicular to the laser beam irradiation direction by the pressure roller 12. Relative pressure is applied in the direction of

  5A and 5B show the vicinity of the laser beam irradiation section in FIG. 4. The irradiation head 11 and the pressure roller 12 of the laser beam B are, as described above, the panel to be joined, that is, The steel body members 15, 16, 17 and the aluminum alloy roof panel 21 are disposed so as to be relatively movable. First, as shown in FIG. And radiating toward the roof panel 21 to heat the vicinity of the joint to a predetermined temperature.

As the laser beam B, an Nd: YAG laser was used, and the laser defocus diameter, laser output, and feed rate were set so as to be equal to or higher than the temperature at which eutectic melting occurred.
Specifically, using a laser oscillator with a maximum output of 3 kW and a lens with a focal length of 150 mm, the beam B is defocused so as to have a spot diameter of 3.5 mm on the irradiated surface, and the laser output is 0.8 kW and the feed speed. Was applied at 0.7 to 1.0 m / min. During the laser irradiation, argon gas was flowed at a flow rate of 25 L / min to shield the joint.

  Immediately behind the beam irradiation position, the joining flange 21a of the roof panel 21 is pressed against the joined surface 17a of the heated side outer 17 by the pressure of the pressure roller 12, as shown in FIG. As a result, the roof panel 21 is brought into close contact with the side outer member 17 of the vehicle body member, and the joining interface is maintained at a temperature at which the eutectic reaction occurs due to heat transfer, and is pressed by the pressure roller 12, whereby FIG. As shown in (e) to (e), eutectic melting occurs at the joining interface, and the roof panel 21 and the vehicle body member are joined at the joining surface 17 a of the side outer 17.

At this time, when pressing the roof panel 21 made of aluminum alloy, the vehicle body member, which is a structural member made of the steel panels 15, 16, and 17, has a sufficiently high rigidity. On the other hand, since the presser T from the vehicle interior side is not required as compared with the case of joining by the rivet R as shown in FIG. 8, the joining position and structure of the roof panel 21 and the vehicle body member are set relatively freely. Therefore, the degree of freedom in design is high, and the width of the joining flange can be eliminated, so that the degree of freedom in design can be improved and design can be improved.
In addition, the laser beam B can be directly irradiated onto the bonding interface, energy efficiency for heat input can be improved, the degree of freedom of the bonding structure is high, and the strength is high and unique only by continuous bonding. A lightweight joint structure can be obtained.

Note that the shape of the joint flange 21a of the roof panel 21 is a curved shape having a curvature or a convex curved portion, so that the surface oxide film is deformed by pressurization. Breaking easily occurs, the eutectic melt generated in the joining process is smoothly discharged to the periphery of the joined portion, and the effect of the present invention can be further ensured.
Further, by providing the concave portion (step) 21b in the roof corner portion of the roof panel 21, the degree of freedom of the incident angle of the laser beam B can be increased, and the deformation and dimensional error due to the thermal strain of the roof are absorbed. be able to.

(Example 2)
FIG. 6 shows another example of joining a steel vehicle body member, which is a high melting point metal panel, and an aluminum alloy roof panel, which is a low melting point metal panel. A procedure for joining the vehicle body member in which the rail inner 15, the rail outer 16, and the side outer 17 are assembled by welding and the roof panel 21 made of aluminum alloy will be described.
That is, as shown in the drawing, a light alloy roof panel 21 is flared from the side outer 17 of the vehicle body member from the lateral direction. The side outer 17 is made of a galvanized steel plate.

In the aluminum alloy roof panel 21, a joining flange 21a formed at an end thereof is arranged in close contact with a joining surface 17a set on the side outer 17 of the vehicle body member, and the defocused laser beam B is applied to the side outer member of the vehicle body member. Irradiation is centered on 17.
The irradiation position of the high-energy beam B at this time corresponds to a portion adjacent to the bonding surface 17a of the side outer 17 from which the eutectic melt generated in the bonding process is discharged at the center of the defocused beam B. In this way, the outer peripheral portion of the beam B is slightly touched to the roof panel 21 which is a low melting point metal panel. Then, while irradiating the laser beam B, the pressure roller 12 relatively pressurizes both panels in a direction substantially perpendicular to the laser beam irradiation direction.

FIGS. 7A and 7B show the vicinity of the laser beam irradiation portion in FIG. 6. First, as shown in FIG. 5A, the laser beam B is directed toward the side outer 17 and the roof panel 21. And the vicinity of the adjacent portion of the bonding surface 17a from which the eutectic melt is discharged is heated to a predetermined temperature.
At this time, using the same laser oscillator and lens as described above, the beam B is defocused so as to have a spot diameter of 3.5 mm on the irradiation surface, the laser output is 0.8 kW, and the feed rate is 0.7-1. Irradiation was performed at 0 m / min. During the laser irradiation, similarly, argon gas was allowed to flow at a flow rate of 25 L / min to shield the joint.

  A pressure roller 12 is disposed near the laser beam irradiation position, and the pressure is pressed against the bonding flange 21a of the roof panel 21 against the heated bonding surface 17a of the side outer 17. As a result, the roof panel 21 is brought into close contact with the side outer member 17 of the vehicle body member, the joining interface is maintained at a temperature at which the eutectic reaction occurs, and the pressure applied by the pressure roller 12 is shown in FIGS. Thus, eutectic melting occurs at the joint interface, and the roof panel 21 and the vehicle body member are joined at the joint surface 17a.

At this time, as in the above-described embodiment, there is no need to press from the vehicle interior side, so design and design freedom are higher than in rivet joining, and design can be improved.
In addition, since the laser beam B is irradiated in the vicinity of the position where the eutectic melt is discharged, the laser beam absorptance is improved and stable bonding can be realized. Furthermore, since the joint part of a component can be positioned in advance, the component accuracy is also improved.

  Similarly, as the surface shape of the joining flange 21a of the aluminum alloy roof panel 21, by forming a curved surface or a curved surface having a convex shape, the surface oxide film is easily broken due to deformation during pressurization. The resulting eutectic melt can be smoothly discharged to the periphery of the joint and can be made more effective.

From the viewpoint of increasing the degree of freedom of the incident angle of the laser beam, it is also desirable to provide a similar recess 21b at the roof corner of the roof panel 21. Can be absorbed.
Further, by forming a curved surface 17b having a gentle curvature at the corner portion in the vicinity of the joint portion of the side outer 17 constituting the vehicle body member, the irradiation region of the defocused laser beam B can be ensured.

It is a graph which shows the eutectic point in an Al-Zn type binary phase diagram. (A)-(e) is process drawing which shows roughly the joining process of the dissimilar-metal panel which interposed the 3rd material. It is a schematic explanatory drawing which shows one Example of the joining apparatus of this invention. It is sectional drawing which shows the joining procedure of the dissimilar-metal panel by the 1st Example of this invention. (A) And (b) is explanatory drawing which shows the vicinity of the beam irradiation part in FIG. It is sectional drawing which shows the joint point of the dissimilar-metal panel by the 2nd Example of this invention. (A) And (b) is explanatory drawing which shows the vicinity of the beam irradiation part in FIG. It is a schematic sectional drawing which shows the example of a joining structure by the rivet of a steel vehicle body member and an aluminum roof panel.

Explanation of symbols

1, 17 Galvanized steel sheet (high melting point metal panel)
1p Zinc plating layer (third material)
2, 21 Aluminum alloy material (low melting point metal panel)
3 Eutectic Molten Metal 4 Reaction Layer 10 Dissimilar Metal Panel Joining Device 11 Irradiation Head 12 Pressure Roller

Claims (8)

  When joining a high melting point metal panel and a low melting point metal panel having different melting points, a defocused high energy beam is applied to the high melting point with a third material different from the metal panel interposed between the two panels. While irradiating the metal panel, or both the high melting point metal panel and the low melting point metal panel, both the panels are relatively pressed to cause eutectic melting between at least one of the two panels and the third material. A method for joining dissimilar metal panels, characterized in that the panels are flared in a continuous or intermittent line shape.   The bonding surface of the high melting point metal panel and the low melting point metal panel is opposed to each other through a gap, and a high energy beam is irradiated to the surface where both panels are finally overlapped, and both panels are substantially the same as the irradiation direction of the high energy beam. 2. The method for joining dissimilar metal panels according to claim 1, wherein relative pressurization is performed in a direction forming a right angle. The bonding surfaces of the refractory metal panel and the low melting metal panel are overlapped, and a high energy beam is irradiated to a position adjacent to the bonding surface of the refractory metal panel , and both panels are substantially perpendicular to the irradiation direction of the high energy beam. 2. The method for joining dissimilar metal panels according to claim 1, wherein relative pressure is applied in the direction.   The method for joining dissimilar metal panels according to any one of claims 1 to 3, wherein at least one of the two panels is plated with a third material.   5. The method for joining dissimilar metal panels according to claim 4, wherein one of the two materials is a galvanized steel sheet, and zinc plated on the galvanized steel sheet is used as the third material. 6. The dissimilar metal according to claim 1, wherein the low melting point metal panel is a light alloy panel, and the high melting point metal panel is a vehicle body member made of a galvanized steel sheet. Panel joining method . The method for joining dissimilar metal panels according to claim 6 , wherein the low melting point metal panel is a roof panel of an automobile body. A joining device for flaring a high melting point metal panel and a low melting point metal panel having different melting points,
An irradiation head that is disposed so as to be relatively movable with respect to the bonded panel, and that continuously or intermittently irradiates the bonded panel with a high energy beam continuously or intermittently;
A pressure roller is provided that presses the panel to be bonded in a direction substantially perpendicular to the irradiation direction of the high energy beam while rotating about an axis substantially parallel to the irradiation direction of the high energy beam by the irradiation head. Dissimilar metal panel joining device.

Images