JPH07100679A - Welding process for coated panel member - Google Patents

Abstract

PURPOSE:To prevent a problem caused by the vaporization of coating at the time of welding, which is formed on a surface when joining coated panel members by welding. CONSTITUTION:When welding a coated panel member, first of all, a coating film 22b on the surface of the coated panel member 22, is decomposed and burned by irradiating with a laser beam R or an arc with energy higher than that used at the time of a normal welding. Coated panel members 22 and 24 are welded each other. Welding is continuously performed by a laser beam R or an arc with the normal energy to join the panel members.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding method, and more particularly to a method for welding a painted panel member.

[0002]

2. Description of the Related Art When joining a panel member, particularly a panel member made of metal, joining with an adhesive, joining with a bolt / nut, joining with a rivet, joining by welding, or the like is performed.

[0003]

Joining by welding has the advantages of superior workability during joining and good joining strength as compared with other joining methods. However,
Since the joining by welding is to join the members by melting the panel member by heat, if this is applied to the joining of the panel having the surface coated with the coating film, the coating film is constructed at the time of welding. The paint to be vaporized by the heat during welding,
There is a problem that this mixes in the molten pool, that is, the welded portion to generate blowholes, which deteriorates the quality of welding. Also, when the coating panel members are joined by a welding method such as laser welding or arc welding, the vaporized paint causes
There is also a problem that the laser beam and the like cannot efficiently reach the welded portion. The present invention has been made in view of the above problems, and provides a welding method for a coated panel member capable of preventing a problem caused by vaporization of a coating film when the coated panel members are joined by welding. The purpose is to

[0004]

In order to achieve the above-mentioned object, in the invention of claim 1, a paint panel member for melting and welding the paint film forming portions of a plurality of paint panel members having paint films formed on the surface thereof. In the welding method of No. 2, the welding means removes the coating film at the welded portion of the coating film panel member and welds the coating film panel member. In the invention of claim 2, the welding means removes the coating film before welding the coated panel member. In the invention of claim 3, the welding means removes the coating film while welding the coated panel member. Further, according to the invention of claim 4, there is provided a welding method of a paint panel member, in which a paint film forming portion of a plurality of paint panel members having a paint film formed on a surface thereof is melt-welded, and the paint film is formed by plasma generated during welding. And the coating film panel member is welded. In addition, in the invention of claim 5, the coating panel members are vehicle body panels that form a vehicle body module that is joined to each other to form a vehicle body shell, and the welding is welding of the vehicle body modules. .

[0005]

In the invention of claim 1 having the above-mentioned structure, the welding means removes the coating film at the welded portion of the coating film panel member, welds the coating film panel member, and welds by vaporization of the paint forming the coating film. Suppress the effect on the department. Further, in the invention of claim 2, the welding means removes the coating film before welding the coated panel member to prevent vaporization of the coating material forming the coating film during welding. Further, according to the invention of claim 3, the welding means removes the coating film while welding the coated panel member and suppresses the influence of the vaporization of the paint forming the coating film on the welded portion, while performing an efficient welding operation. Be seen. Further, in the invention of claim 4, the welding means removes the coating film by the plasma generated at the time of welding and welds the coating film panel member, thereby effectively utilizing the plasma. In addition, in the invention of claim 5, the painted panel member is a vehicle body panel constituting a vehicle body module that is joined to each other to form an automobile body shell, and the welding is welding of the vehicle body modules. The problems caused by the vaporization of the coating film are prevented when the vehicle body modules are joined by welding to form the vehicle body shell.

[0006]

Embodiments of the present invention will now be described in detail with reference to the drawings. In each embodiment, common members are designated by the same reference numerals, and the description thereof will be omitted. First Embodiment In this embodiment, the welding method for a coated panel member of the present invention is applied to the assembly of a body of a 4-door sedan vehicle. The body of the 4-door sedan vehicle is composed of a plurality of units (body modules) that are joined together to form a body shell B. That is, the body shell B is
It is composed of a body module called a lower body shell BL which is composed of an upper body shell BU forming an upper part of the vehicle body, an underbody part BD forming a lower part of the vehicle body, and a front body part BF forming a front part of the vehicle body. The body shell B is made by joining the vehicle body modules by welding. First, the upper body shell BU, the underbody portion BD, and the front body portion BF will be described with reference to FIG. The underbody portion BD includes a floor panel 1 which is a rectangular plate-shaped member,
It comprises a tunnel 2 formed in the floor panel 1 extending in the vehicle front-rear direction, a cross member 3 mounted in the vehicle width direction attached near the center of the floor panel 1 in the vehicle front-rear direction, and the like. The front body part BF has a pair of left and right front side frames 4 extending toward the front of the vehicle body on both sides in the vehicle width direction, a wheel apron reinforcement 5, a rear end of the front side frame 4, and a front end of a lower portion of the cabin. It includes a dash lower panel 6 to be formed, a front frame rear (torque box) 7 and the like extending outward from the rear end of the front side frame 4 in the vehicle width direction.

Further, the upper body shell BU is composed of a body side panel 8 forming both side portions of the cabin, a rear body 9 forming a rear portion of the vehicle body, a roof panel 10 constituting an upper portion of the cabin, and the like. Further, the side pillars 8 allow the front pillar 11 and the center pillar 1 to be connected.
2, a rear pillar 13, and a pair of left and right side sills 14 extending in the vehicle front-rear direction on both sides of the lower end of the cabin. A floor portion 15 to which the rear seat RS is attached is formed on the upper body shell BU. In the present embodiment, these vehicle body modules (front body portion BF, underbody portion BD, upper body shell BU) are individually made, and then each vehicle body module is painted. Then, on each painted body module,
Install equipment parts such as instrumental panel I, handle, seat S, floor mat, and trim (Fig. 2).
Further, thereafter, the painted vehicle body modules to which the equipment parts are attached are joined by welding to form the vehicle body.
The front body portion BF and the underbody portion BD are joined by welding the lower end portion of the dash lower panel 6 and the front end portion of the floor panel 1. In addition, the underbody portion BD and the upper body shell BU are joined by welding both side edge portions of the floor panel 1 and the side sill 14 (or the bracket attached to the side sill 14).
It is performed by welding the rear end of the floor panel 1 and the floor portion 15 located under the rear seat.

After the body modules are joined by welding to form a body shell, the engine, suspension, and other parts are attached, and the vehicle assembly work is completed. The welded portion in the welding process is not limited to the above-mentioned portion, and may be appropriately changed depending on the structure of the vehicle body or the vehicle body module. For the welding in the welding process, welding with a high-density energy beam such as a laser beam or arc welding is used. Therefore, in the welding process in which the paint panel members forming the vehicle body modules are welded together, the paint forming the coating film of the paint panel members forming the vehicle body modules is vaporized by the heat generated by the welding. In order to prevent the problem caused by the vaporized paint, the following method is adopted in this embodiment. That is, first, a laser beam having an energy higher than the energy used for normal welding or an arc is given for a predetermined time.
The panel (painted panel member) of the vehicle body module on which the coating film is formed is irradiated. By irradiating with higher energy than in the normal welding, the coating film formed on the panel is burned or decomposed, and at the same time, the panels are welded together. Subsequently, welding is continued with a laser beam or an arc having an energy equivalent to the energy during normal welding to join the panels together (see FIG. 3).

Since the coating in the vicinity of the welded portion is removed by the irradiation of energy higher than usual, welding with normal energy is performed in a state where the surface of the panel member is not coated. Therefore, it is possible to prevent the generation of blow holes due to the inclusion of the evaporated paint. Also, as shown in FIG. 4, the energy of the laser beam or arc used for welding is
It may be changed continuously. Second Embodiment Next, a second embodiment of the present invention will be described. Like the first embodiment, this embodiment uses the welding method of the present invention for assembling the body shell of an automobile, and therefore the description of common parts will be omitted. The difference between this embodiment and the first embodiment is the welding process. That is, in the first embodiment,
While welding is performed by changing the energy intensity,
In the present embodiment, the laser beam is further divided into two on the premise that welding is performed continuously while moving the laser beam. The details will be described below. In the present embodiment, the laser beam R used for welding is divided into two by the beam splitter 20, one beam R1 is used as a laser beam for removing the coating film, and the other beam R2 is used as a welding laser beam. The painted panel members 22 and 24 that form the vehicle body module are joined by welding using R1 and R2. Laser beam R emitted from a torch (not shown)
Is a beam splitter such as a half mirror 20.
R2 is divided into two. The welding laser beam R2 that has passed through the half mirror 20 is converged by a converging optical system such as a lens 21 and is applied to the welded portion on the coating panel member 22 to be welded. On the other hand, the laser beam R1 for removing the coating film, which is reflected by the half mirror 21 and separated from the laser beam R2 for welding, is reflected and converged by an optical system such as a parabolic mirror 23 and R2 of the coating panel member 22. The coating panel member 22 is irradiated at a position on the front side of the irradiation position (see FIG. 5). Here, the present embodiment is premised on welding that is performed continuously while moving the laser beam R in the direction shown by the arrow in FIG. 5, for example, and the front side means the front side in the moving direction of the beam R.

Therefore, in the welding of this embodiment, first, the laser beam R1 for removing the coating film is applied to the coating film 22b formed on the panel body 22a of the coating panel member 22, and the coating film is formed by the laser beam R1. 22b is removed. Next, the panel body 22a from which the coating film 22b has been removed along with the movement of the beam R is irradiated with the welding laser beam R2, and the coating panel member 22 and the other panel member 24 are joined by welding. . The energy intensity of the coating film removing laser beam R1 may be such that the coating film can be removed. Further, the ratio of the energy intensity between the coating removing laser beam R1 and the welding laser beam R2 can be appropriately changed depending on the characteristics of the beam splitter 20. Third Embodiment In this embodiment, as in the first embodiment, the welding method of the present invention is used for assembling the body shell of an automobile, and the description of common parts will be omitted. The difference between this embodiment and the first embodiment is in the welding process. That is, in the first embodiment, welding is performed by changing the energy intensity, whereas in the present embodiment, a laser beam or
Welding is performed while removing the coating film by the plasma generated by the laser beam or the arc, assuming continuous welding while moving the welding beam such as an arc.

When welding is performed using the laser beam R or an arc or the like, the air in the vicinity of the welded portion W becomes plasma due to the laser beam R or the like, and as shown by P in FIG. Stay at. In the present embodiment, this plasma P is sent to the front side in the direction of travel of the beam by the side gas used to prevent oxidation of the welded portion W, and the coating film is removed by this plasma P. Hereinafter, the case where welding is performed by a laser beam will be described as an example, but the configuration of the present embodiment may be applied when performing welding by an arc. The laser beam generating torch T used in the welding method of the present embodiment has a side for supplying the side gas to the weld W from a cylinder B containing an inert side gas such as argon, helium and nitrogen. A gas supply device 30 is attached (FIG. 7). The gas blowing portion 30a of the supply device 30 is provided with the laser beam R of the torch T.
It is attached to the rear side in the traveling direction (arrow direction in FIG. 7) and blows out the side gas toward the front side in the traveling direction of the laser beam R. Therefore, in the welding process, the plasma P generated by the laser beam R is pushed to the front side in the traveling direction of the laser beam R by the side gas blown from the gas blowing portion 30a.

Next, the welding process of this embodiment will be described with reference to FIG. In FIG. 8, a torch T (not shown in FIG. 8) as described above is used, and the coating panel member 31 and the other panel member 32 are continuously moved while moving the welding beam R in the direction of the arrow. Shows welding. As described above, the plasma P generated by the beam R is pushed forward by the side gas blown from the gas blowing portion 30a in the traveling direction of the beam R (the direction of the arrow in FIG. 8). Therefore, the coating film 31b formed on the panel body 31a of the coating panel member 31 on the front side in the traveling direction of the beam R (the direction of the arrow in FIG. 8) is decomposed or burned by the high temperature plasma P and removed. It Further, as shown in the modified example of FIG. 9, a suction device 33 for sucking the plasma P and the side gas may be provided on the front side in the traveling direction of the beam R with the irradiation position of the beam R sandwiched therebetween. In this modified example, the plasma P ′ and the side gas that have been pushed forward by the side gas blown out from the blowout part 30a are sucked by the suction device 33, so that the plasma P ′ is laterally (as shown in FIG. 10). It does not spread in the direction orthogonal to the traveling direction of the beam R). Therefore, the beam R
It is possible to remove the coating film only in a necessary minimum region (that is, the irradiation region of the beam R) corresponding to the irradiation position of 1.

Further, as shown in FIG. 11, the side gas auxiliary blow-out portions 34 are provided on both sides of the side gas blow-out portion 34a.
Even if b and 34c are provided and side gas is injected from the auxiliary blowout portions 34b and 34c toward the gas blowout direction from the central main blowout portion 34a to prevent the diffusion of the plasma P ″, the modification of FIG. Although the present invention has been described above with reference to the examples relating to the welding of the body panels constituting the vehicle body module of the automobile, the present invention is not limited to these examples, and the coated panel is not limited thereto. It is applicable to welding of all members.

[0014]

According to the present invention described in detail above, it is possible to effectively prevent the problem that occurs when joining painted panel members by welding.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing a vehicle body module joined by a welding method according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a state in which equipment parts are attached to the vehicle body module of FIG.

FIG. 3 is a graph showing a change in energy of a beam or the like irradiated in the welding method of the first embodiment of the present invention.

FIG. 4 is a graph showing a change in energy of a beam or the like irradiated in the welding method of the modified example of the first embodiment of the present invention.

FIG. 5 is an explanatory diagram of a laser beam used in the welding method according to the second embodiment of the present invention.

FIG. 6 is an explanatory diagram of a third embodiment of the present invention.

FIG. 7 is a schematic view of a torch used in a third embodiment of the present invention.

FIG. 8 is an explanatory view of a welding method of a third embodiment of the present invention using the torch of FIG.

FIG. 9 is an explanatory view of a modification of the third embodiment of the present invention.

FIG. 10 is an explanatory diagram of a modification of the third embodiment of the present invention.

FIG. 11 is an explanatory diagram of another modification of the third embodiment of the present invention.

[Explanation of symbols]

 R beam W Welded part 20 Half mirror 21 Lens 22 Paint panel member 22a Panel body 22b Coating film 23 Parabolic mirror 24 Coating film panel member

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location B23K 26/06 C B62D 24/00 (72) Inventor Risuke Nakanishi Shinchi Fuchu-cho, Aki-gun, Hiroshima Prefecture 3 No. 1 Mazda Co., Ltd. (72) Inventor Masatoshi Shinomori No. 3 Shinchi, Fuchu-cho, Aki District, Hiroshima Prefecture Mazda Co., Ltd.

Claims (5)

[Claims] 1. A welding method of a paint panel member, wherein a paint film forming portion of a plurality of paint panel members having a paint film formed on a surface thereof is melt-welded, wherein the welding means is a welding part of the paint film panel member. A method for welding a coated panel member, which comprises removing a coating film and welding a coated panel member. 2. The welding method for a coated panel member according to claim 1, wherein the welding means removes the coating film prior to welding the coated panel member. 3. The method for welding a painted panel member according to claim 1, wherein the welding means removes the coating film while welding the painted panel member. 4. A welding method of a paint panel member, wherein a paint film forming portion of a plurality of paint panel members having a paint film formed on its surface is melt-welded, the paint film being removed by plasma generated during welding. A method for welding a coated panel member, which comprises welding a coated panel member. 5. The vehicle body panel, wherein the painted panel members are joined together to form a vehicle body module forming a vehicle body shell, and the welding is welding of the vehicle body modules. Welding method of painted panel member