JPH03153480A - Plate drain hole formation - Google Patents

Abstract

PURPOSE:To perform the formation of a drain hole so simply and accurately by forming a recess in a specified area of a plate by means of press working, and forming the drain hole after piercing through a bottom wall of this recess, while forming a side wall of the recess into a drain pipe fitting flange. CONSTITUTION:When a drain hole 12 is formed in a floor panel 11, first a metal sheet plate is formed by a press, and a section crest bead 15 is enhancing rigidity is plurally formed in parallel, while a concave step area 16 for drainage is formed there. Thus, the specified-form floor panel 11 is formed and simultaneously a recess is formed in a specified area within the concave area 16. Next, a bottom part of the recess is punched through, forming the drain hole 12 while a side wall of the recess is left behind as a flange 13. Successively, an upper end of a drain pipe 14 is fitted in an outer circumference of this flange 13 while the upper end flange is welded to an underside part of the floor panel 11. Afterward, a drain tube 17 is fitted in a lower half part of the drain pipe 14, locking it with a grip 19.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for forming a drain hole used when forming a drain hole in a plate material such as a floor panel of a vehicle.

(Prior Art) Forming a drain hole to which a drain pipe can be attached in a floor panel of a vehicle has been conventionally performed in the following manner. That is, first, a metal plate is press-formed to form a floor panel in a predetermined shape with beads, etc., and then, as shown in FIG. form. Next, the 8th
As shown in the figure, by applying burring to the peripheral portion of the drain hole 2, the peripheral edge of the drain hole 2 is curved so as to be pushed downwardly, thereby forming a drain pipe fitting flange 3. As shown in FIG. 9, the upper end of the drain pipe 4 is fitted onto the outer periphery of the thus formed drain pipe fitting flange 3 and welded to the floor panel 1.

(Problems to be Solved by the Invention) However, in the conventional drain hole forming method as described above, a press forming process for press forming the floor panel 1, a punching process for forming the drain hole 2, and a drain hole forming process are required. There is a problem in that three processes including a burring process are required to form the pipe fitting flange 3, and the number of processes is large.

Furthermore, in order to form the drain pipe fitting flange 3, a burring process is used to expand only the peripheral edge of the drain hole 2 of the floor panel 1, so that the upper surface of the peripheral edge of the drain hole 2 of the floor panel 1 is expanded. The sides were stretched and became rough, the paint peeled off, and rust was likely to occur, while the bottom side was pushed in and shrunk, causing wrinkles. Furthermore, the flange 3, which is the peripheral edge of the drain hole 2, is easily stretched and cracked, making it impossible to increase the protruding dimension of the flange 3 beyond a certain level, which prevents reliable installation of the drain pipe 4. was there. Further, since the tip of the flange 3 is formed linearly along the depth direction of the drain hole 2, there is a problem that it is difficult to insert the drain pipe 4 into the flange 3.

(Objective of the Invention) This invention was made to solve the problems of the prior art described above, and it reduces the number of manufacturing steps for drain holes, prevents rust and wrinkles from forming around the periphery of the drain holes, and prevents the drain pipe from forming. To provide a method for forming a drain hole in a plate material by which the protrusion dimension of a fitting flange can be set large and a drain pipe can be smoothly attached.

(Means for Solving the Problems) The present invention is a method for forming drain holes in a plate material finished into a predetermined shape by press forming, and in order to achieve the above object, the drain hole formation area of the plate material is After the recess is formed by molding, the bottom wall of the recess is punched out to form a drainage hole, and the side wall of the recess is formed into a flange for fitting a drain pipe.

(Example) FIG. 1 is a plan view of a main part showing a floor panel 11 of a vehicle manufactured by a method of forming drainage holes in a plate material according to an embodiment of the present invention, and FIG. FIG. As shown in both figures, the floor panel 11 constituting the plate material includes:
In order to increase the rigidity, a plurality of beads 15 having a mountain-shaped cross section are formed in parallel, and a four-stage region 16 for drainage is formed at the rear position of the bead 15, and a drainage hole 12 is provided in the four-stage region 16. . A drain pipe 14 is attached to the peripheral edge of the drain hole 12 on the lower surface side of the floor panel 11, and a drain tube 17 is attached to the drain pipe 14.

The drain holes 12 are formed in the floor panel 11 in the following manner. First, a metal plate material is press-molded to form a floor panel 18 having a predetermined shape and including beads 15 and recessed step areas 16.

At this time, by using the press forming described above, the recesses 18 are simultaneously formed in the area in which the drain holes are to be formed in the four-stage area 16.

Subsequently, as shown in FIG. 4, the bottom wall of the recess 18 is punched out to form a drain hole 12, and the side wall of the recess 18 is left as a flange 13 for fitting a drain pipe.

Drain pipe fitting flange 13 thus formed
As shown in FIG. 5, the upper end portion of the drain pipe 14 is fitted onto the outer periphery of the drain pipe 14, and the upper end flange portion 14a of the drain pipe 14 is welded to the lower surface of the floor panel 11. Then, as shown in FIG. 6, the drain tube 17 is fitted into the lower half of the drain pipe 14 and fixed with a grip 19.

According to this drain hole forming method, after forming the recess 18 using press molding of the floor panel 11, it is only necessary to punch out the drain hole 12 in the bottom wall of the recess 18. Only two steps are required, and the conventional burring step is omitted, reducing the number of steps accordingly.

In addition, since the drain pipe fitting flange 13 is formed by the side wall of the recess 18 by press molding, the drain hole is formed without only the peripheral edge of the drain hole 2 being locally stretched significantly as in the conventional example. The entire area of the predetermined area is stretched by a small amount. As a result, the flange 13 at the periphery of the drain hole 12 is not cracked.
The projecting dimension of the drain pipe 14 can be set to be large, and the drain pipe 14 can be reliably attached to the flange 13. Furthermore, since the burden on the peripheral edge of the recess 18 due to stretching during press forming is reduced compared to the conventional case, the upper surface side of the peripheral edge of the recess 18 does not become rough and rust is prevented from forming.
No wrinkles are formed on the bottom side.

Further, after forming the recess 18, the bottom wall of the recess 18 is punched out to form the drain hole 12, so the lower end of the flange 13 has a shape that is curved inward, and the curved portion 2
0 serves as a guide and connects the drain pipe 14 to 7 lunges 13
can be inserted smoothly.

In the above embodiment, the case where the drain hole 12 is formed in the floor panel 11 has been described, but the method of forming the drain hole in the plate material of the present invention is not limited thereto. It can also be applied when

(Effects of the Invention) As described above, according to the method for forming drain holes in a plate material of the present invention, after forming a concave portion by press molding in a region where a drain hole is to be formed in a plate material, the bottom wall of the concave portion is punched out to drain water. Since the hole is formed and the side wall of the recess is formed into a flange for fitting the drain pipe, the conventional burring process is omitted, reducing the number of processes, and rust and wrinkles do not occur on the periphery of the drain hole. The projecting dimension of the drain pipe fitting flange can be set large, and the drain pipe can be installed smoothly.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a main part showing a floor panel of a vehicle to which a method of forming drain holes in a plate material according to an embodiment of the present invention is applied;
FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, FIGS. 3 to 6 are sectional views for explaining the method of forming drain holes in the plate material of the above-mentioned embodiment, and FIGS. 7 to 9 2A and 2B are cross-sectional views for explaining a conventional method for forming drain holes in a plate material. 11...Floor panel, 12...Drain hole, 13.
... Drain pipe fitting flange, 18... recess

Claims (1)

[Claims] (1) A method for forming a drain hole in a plate material finished into a predetermined shape by press forming, the method comprising: forming a recessed portion by the press forming in the area where the drain hole is planned to be formed in the plate material, and then punching out the bottom wall of the recessed portion. A method for forming a drain hole in a plate material, comprising forming a drain hole and forming a side wall of the recess into a flange for fitting a drain pipe.