JP4779722B2 - Panel parts assembly method and panel parts - Google Patents

Description

  The present invention relates to a method of assembling a panel part including a step of fastening and joining one member and an aluminum casting part with a self-piercing rivet, and fastening and joining the one member and the aluminum casting part with a self-piercing rivet. It is related with the panel components.

  In an automobile assembly line, for example, a cast aluminum cast part and a steel plate part are fastened and joined with self-piercing rivets to form a specific panel part. Car body assembly is performed as an opening and closing body, and after the predetermined coating is applied to the entire car body, it is used for vehicle assembly, in addition to assembling various equipment parts and seats to the car body, as well as mounting engines, transmissions, etc. Become.

And when paying attention to the aluminum casting parts that will constitute part of the panel parts by fastening and joining with self-piercing rivets as described above, the aluminum casting parts are taken into account that the coating is applied in the subsequent process In addition to performing degreasing and chemical conversion treatment in a single state in advance, prior to this degreasing and chemical conversion treatment, for example, as described in Patent Document 1, improvement of paintability of aluminum cast parts, that is, to aluminum cast parts In order to improve the adhesion and corrosion resistance of the coating film, blasting such as shot blasting is performed on the surface in advance.
JP 2004-315864 A

  If it is assumed that degrease and chemical conversion treatment is performed in the state of a single cast aluminum part, degreasing and chemical conversion treatment will be performed as a pretreatment for painting after completion of vehicle body assembly, but it will also be performed in advance at the component stage. That is, it is not preferable because the cost is increased due to duplication of processes. Further, when blasting is performed in the state of a single cast aluminum part, the surface of the cast is work-hardened, so that cracks are likely to occur at the joint during fastening and joining by self-piercing rivets in the subsequent process. When a crack occurs in a self-piercing rivet joint, a chemical conversion treatment film is not formed on that part, so the so-called coating film gets worse and white rust is generated. May decrease.

  The present invention has been made paying attention to such a problem, and an aluminum casting part that constitutes a part of a panel part is fastened and joined to another part by a self-piercing rivet in a later process. And an assembly method of panel parts and a panel part that can effectively eliminate secondary problems associated with the blasting process on the premise that the blasting process is performed to improve the paintability. .

  The invention according to claim 1 is based on the assumption that it is a method for assembling a panel part including a step of fastening and joining one member and an aluminum cast part with a self-piercing rivet. A pre-processing step in which blasting is performed in advance on a region other than the self-piercing rivet joint, and one member and an aluminum casting part are overlapped with the self-piercing rivet joint not subjected to the blasting as a non-mating surface. A rivet joining process in which a self-piercing rivet is driven into the self-piercing rivet joint to fasten and join the two parts, and a pierced and joined self-piercing rivet joint with the self-piercing rivet of the base material of the aluminum casting part And a post-processing step for performing the processing.

  More specifically, as described in claim 2, in the rivet joining step, the self-piercing from one member side toward the aluminum casting part is performed so that the self-piercing rivet joining part side of the aluminum casting part has a convex shape. Rivets shall be driven.

  The invention according to claim 8 is the one in which the technique according to claim 1 is grasped as a panel part itself, and one member and an aluminum casting part are overlapped, and then one member is placed in the overlapping portion. Self-piercing rivets are driven from the side, and the aluminum casting parts are plastically deformed so that the convex shape is formed on the aluminum casting part side. The surface of the cast aluminum part including the rivet joint is subjected to shot blasting.

  Therefore, in the inventions according to claims 1 and 8, since the blasting process is preliminarily performed as a pretreatment for the region other than the self-piercing rivet joint portion of the base of the aluminum cast part, the self-piercing rivet joint portion is work-hardened. And no cracks are generated at the time of fastening / joining by self-piercing rivets in the subsequent process.

  In addition, the self-piercing rivet joint portion that has not been subjected to the blasting process as described above is subjected to the same blasting process as a separate post-treatment after the fastening and joining by the self-piercing rivet. The effect of improving paintability can be expected for the rivet joint as well as other parts.

  According to the inventions described in claims 1 and 8, since the blasting process is performed on the base of the cast aluminum part regardless of whether it is a self-piercing rivet joint or not, the paintability is improved. For pierce rivet joints, by performing blasting after self-pierce rivet joining, it is possible to join with self-piercing rivets in a state where it is not work hardened, and it is possible to suppress the occurrence of cracks during self-piercing rivet joining, Even if a crack occurs at the time of self-piercing rivet joining, it can be repaired by crushing the crack by blasting. For example, an operation such as applying a sealing material to the crack is unnecessary, and the number of processing steps can be reduced.

  In addition, when painting is performed on panel parts after assembly, including degreasing and chemical conversion treatment as pre-painting treatment, it is not necessary to perform degreasing and chemical conversion treatment in the state of a single cast aluminum part, resulting in increased costs due to process duplication. There is no.

  FIG. 1 and the following drawings show a more specific embodiment of the present invention, and show an example when applied to the assembly of panel parts that constitute a part of a car body of an automobile. FIG. 1 shows a rough flow of a series of processes from casting of an aluminum casting part to vehicle assembly for a panel part made of an aluminum casting part and a steel plate part, and FIG. 2 shows an enlarged cross-sectional view of the main part of the panel part. .

  As shown in FIGS. 1 and 2, the aluminum casting part (hereinafter simply referred to as “casting part”) 1 cast in the casting step S <b> 1 is left as it is or after a predetermined finishing process such as machining is performed. As will be described later as a rivet joining process, this body assembly process S3 is used as a rivet joining process, and, for example, a steel plate part 2 as a counterpart and a self-piercing rivet 3 are fastened and joined to form a panel part 4; The vehicle body is assembled using the panel component 4 as a part of the vehicle body component, for example, a vehicle frame member or an opening / closing member. Then, the assembled vehicle body is put into the painting process S5, and a predetermined coating is applied. In addition, in the vehicle assembly process S6, which is a subsequent process, in addition to various outfitting parts, an engine or a transmission is assembled to the vehicle body to complete the vehicle. The degree will be increased. Note that the coating process S5 includes a plurality of processes such as undercoating, intermediate coating, and topcoating as well as degreasing and chemical conversion as pretreatment as is well known.

  As described above, the cast part 1 after casting is fastened and joined to the mating steel plate part 2 with the self-piercing rivet 3 in the body assembly process S3 as a rivet joining process. However, prior to fastening and joining with the self-piercing rivet 3, as shown in FIG. 3 in addition to FIG. It is assumed that a shot blast process is performed in advance on a portion excluding the self-piercing rivet joint portion 5 which is a portion involved in the joining. The self-piercing rivet joint 5 referred to here is exposed to the outside when it is fastened and joined with the mating steel plate part 2 and the self-piercing rivet 3 in the base of the cast part 1 to form a panel part 4. By the driving of the self-piercing rivet 3 (not including the surface of the base of the casting part 1 that will be concealed as the panel mating surface when it is joined to the mating steel plate part 2) A region that includes a portion that directly receives the pressing force and its vicinity. In FIG. 3, the shot blast processing target area is hatched, and the portion is indicated by Bs1.

  If shot blasting is not performed, the amount of chemical conversion film will be insufficient at the pre-treatment stage of the coating step S5, which is a subsequent step, and it will easily lead to a decrease in rust prevention and poor appearance. The shot blasting process is performed on the portion excluding the self-piercing rivet joint 5 when the shot blasting process is performed up to the self-piercing rivet joint 5 as shown in FIG. This is because the crack C is likely to occur during the fastening and joining by the self-piercing rivet 3, and this is to prevent the crack C from occurring. FIG. 4 shows the occurrence of a crack C at the embossed portion 12 formed on the casting part 1 side by plastic deformation as the self-piercing rivet 3 is driven, as will be described later.

  The pre-blasting process is performed with the self-piercing rivet joint 5 masked. For example, the self-piercing is performed with a shock-absorbing sheet such as a vibration damping material or an outer plate reinforcing material. After covering the rivet joint 5, the entire base of the cast part 1 is subjected to shot blasting. More specifically, for example, as shown in FIG. 5, a metal sheet 7 such as aluminum lined with an adhesive sheet 6 is used as a masking sheet so as to cover the self-piercing rivet joint 5. Then, the entire base of the cast part 1 is subjected to shot blasting.

  Here, in the case of a so-called large part having a large shape and weight of the cast part 1, a gripping jig that grips and clamps the cast part 1 itself may be used to assist in handling such as changing the posture. . In such a case, as shown in FIG. 6, a gripping jig 11 formed by coupling a clamp plate 9 to a base block 8 with a hinge pin 10 is also used as a masking jig. When the tool 11 is gripped and clamped so as to shield the self-piercing rivet joint 5 in the base of the cast part 1, the same as the masking by the metal sheet 7 is performed. A masking effect is obtained, which is advantageous in terms of cost. The entire surface of the clamp plate 9 does not necessarily need to be in close contact with the self-piercing rivet joint 5. In short, it is functionally sufficient if the collision of the shot S with the self-pierce rivet joint 5 can be blocked.

  In addition, the shot blasting process in the blasting process S2 described above is performed as a pretreatment of the coating process S6 including a degreasing / chemical conversion process in a post process, such as an oxide film or a release material adhering to the base surface of the casting part 1. For the purpose of removal, shot blasting using, for example, stainless steel balls as the shot material is more suitable than sandblasting.

  The casting part 1 in which the shot blasting process has been performed on the region Bs1 other than the self-piercing rivet joint portion 5 is provided to the next vehicle body assembly step S3, and this vehicle body assembly step S3 is used as a rivet joint step. As shown in FIG. 7, after the self-piercing rivet joint 5 is overlapped with the mating steel plate part 2 with the non-mating surface side, the self-piercing rivet 3 is driven into the overlapping portion from the steel plate part 2 side. Both are fastened and combined, and assembled as a panel component 4. The enlarged cross section of the self-piercing rivet joint 5 is as shown in FIG. 2, and the self-piercing rivet 3 reaches the back surface of the casting part 1 by driving the self-piercing rivet 3 from the steel plate part 2 side which is the counterpart. However, the part into which the self-piercing rivet 3 is driven out of the cast part 1 is plastically deformed so as to be a convex and circular embossed part 12. In addition, when the casting part 1 and the steel plate part 2 are joined, an adhesive 13 is previously placed on the mating surfaces of at least the part corresponding to the self-piercing rivet joining part 5 as a measure against electrolytic corrosion. .

  Further, when the cast part 1 and the steel sheet part 2 are fastened and joined with the self-piercing rivet 3 to form the panel part 4, as shown in FIG. 9 in addition to FIGS. In the processing step S4, a shot blasting process is performed as a post-processing on the self-piercing rivet joint 5 that has not been subjected to the shot blasting process first in the casting part 1 (the shot blasting processing area in the blasting process step S4 is indicated by a symbol Bs2). ). The self-piercing rivet joint 5 includes the embossed portion 12 of FIG. 2 generated by driving the self-piercing rivet 3.

  When the self-piercing rivet 3 is driven, the embossed portion 12 is not hardened because shot blasting is not performed. Therefore, when the self-piercing rivet 3 is driven, the embossed portion 12 is plastically deformed from the flat state to the embossed portion 12 as much as possible. Although the generation of cracks C is suppressed, the possibility of cracks still remains. However, even if a fine crack C occurs in the embossed portion 12, it can be repaired by crushing the crack C by performing shot blast processing on the portion later as described above.

  Further, when the cast part 1 and the steel sheet part 2 are assembled and joined as the panel part 4 by fastening and joining with the self-piercing rivet 3, at least the portion corresponding to the self-piercing rivet joint 5 is electrolytically eroded. As described above, the adhesive 13 is interposed in advance as a countermeasure. In this case, as shown in FIG. 10, the adhesive 13 may protrude at the edge of the panel component 4 and close to the self-piercing rivet joint 5 due to the pressing force of the self-piercing rivet 3. Therefore, the protruding adhesive 13 can be removed by positively performing the shot blasting process on the edge where the adhesive 13 protrudes during the shot blasting process in the blasting process S4. In particular, when the shot blasting process is performed after the stainless steel balls used as the shot material are cooled in advance, the adhesive 13 can be removed more effectively.

  Thus, the panel component 4 assembled through the steps S1 to S4 in FIG. 1 constitutes a part of the vehicle body as, for example, a vehicle body skeleton member or an opening / closing body, and the painting step S5 and the vehicle assembly step S6 Through each step, the degree of completion as an automobile is increased.

  Here, the coating step S5 includes a plurality of steps such as undercoating, intermediate coating, and top coating in addition to degreasing and chemical conversion treatment. As described above, the casting part 1 and the steel plate part 2 are self-pierced. In addition to the degreasing and chemical conversion treatment, the panel component 4 that is fastened and joined with the rivet 3 is also subjected to various treatments such as undercoating, intermediate coating, and topcoating. In this case, the portion other than the mating surface with the steel plate part 3 in the base of the cast part 1 is subjected to the shot blasting process in advance on the entire surface regardless of whether it is the self-piercing rivet joint part 5 or not. In addition, the coating film can be satisfactorily mounted and the original paintability can be secured.

The figure which shows more concrete embodiment of this invention, and is process explanatory drawing which shows the flow of a series of rough processes from casting of aluminum casting components to vehicle assembly about the panel components which consist of aluminum casting components and steel plate components. The expanded sectional view of the self-piercing rivet junction part in panel components. It is a figure which shows the detail of the process in the blasting process S2 of FIG. 1, The same figure (A) is a perspective view which shows the outline of aluminum casting components, (B) is an expanded cross section along the b1-b1 line | wire of the same figure (A). Illustration. Explanatory drawing which shows the crack generation condition in the embossed part of FIG. Cross-sectional explanatory drawing which shows an example of the masking process in the case of the blasting process of FIG. It is a figure which shows another example of the masking process in the case of the blasting process of FIG. 3, (A) is the perspective view, (B) is expanded sectional explanatory drawing along the aa line | wire of the same figure (A). It is a figure which shows the self-piercing rivet coupling | bonding state in the vehicle body assembly process of FIG. 1, (A) is a perspective view which shows the outline of a panel component, (B) is expanded sectional explanatory drawing which follows the b2-b2 line | wire of the same figure (A). . It is a figure which shows the detail of the process in the blasting process S4 of FIG. 1, the same figure (A) is a perspective view which shows the outline of a panel component, (B) is expanded sectional explanation along the b3-b3 line | wire of the same figure (A). Figure. FIG. 9 is an enlarged explanatory view showing details of the blasting process of FIG. 8. FIG. 8 is an enlarged explanatory view showing details of a blasting process when an adhesive is used in combination with the self-piercing rivet bonding of FIG. 7.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Aluminum casting part 2 ... Steel plate part as one member 3 ... Self-piercing rivet 4 ... Panel part 5 ... Self-piercing rivet joint 7 ... Metal sheet (masking sheet)
11 ... Gripping jig (masking jig)
DESCRIPTION OF SYMBOLS 12 ... Embossed part 13 ... Adhesive Bs1 ... Shot blast processing area | region Bs2 ... Shot blast processing area | region S2 ... Blast processing process as a pre-processing process S3 ... Car body assembly process as a rivet joining process S4 ... Blast processing process as a post-processing process

Claims (8)

A method of assembling a panel part including a step of fastening and joining one member and an aluminum cast part with a self-piercing rivet,
A pre-processing step of performing a blasting process in advance on a region other than the self-piercing rivet joint in the base of the aluminum casting part;
The self-piercing rivet joint that has not been subjected to the blasting process is used as a non-mating surface and one member and an aluminum casting part are overlapped, and then the self-piercing rivet joint is driven into the self-piercing rivet joint to fasten both. Rivet joining process to join,
A post-processing step of performing a blasting process on a self-piercing rivet joint portion which is fastened and joined with a self-piercing rivet among the base material of the aluminum casting part;
A method for assembling a panel part, comprising: 2. The panel part assembling method according to claim 1, wherein in the rivet joining step, a self-piercing rivet is driven from one member side toward the aluminum cast part so that the aluminum cast part side has a convex shape.
In the rivet joining process,
While driving the self-piercing rivet with an adhesive interposed between one member and the aluminum casting part,
The panel component assembling method according to claim 1 or 2, wherein in the post-processing step, a blasting process is also performed on the protruding portion of the adhesive.   4. The method of assembling a panel part according to claim 3, wherein the one member is a steel plate part.   5. A method of assembling a panel part according to claim 1, wherein at least the blasting process in the pre-processing step is performed after masking the non-processing target area.   6. The panel component assembling method according to claim 1, wherein the blasting process is a shot blasting process.   The panel component assembling method according to any one of claims 1 to 6, further comprising a coating step of coating the surface of the cast aluminum component including at least the self-piercing rivet joint portion after the post-processing step. After superposing one member and an aluminum casting part, the self-piercing rivet is driven into the overlapped part from one member side, and the two parts are fastened and joined while plastic deformation so that the aluminum casting part side has a convex shape. Panel parts
A panel part characterized in that after self-piercing rivet joining, a surface of an aluminum casting part including a convex self-piercing rivet joining part is subjected to shot blasting.