JPS6360728A - Draw molding method and equipment therefor - Google Patents

Abstract

PURPOSE:To enable the title method to mold even a stepped molded product and deep-draw molded product by one process, by a method wherein at the time of draw molding though pressing, along with formation of a bead on a circumferential part of a material in the course of molding a rising wall surface to be formed on the material is pressed. CONSTITUTION:A cam surface on the other end side of a passive cam 12 and a cam surface 15a of a draw bead member 15 are slided each other through a movement of the passive cam 12 and a bead S2 is formed on an outer circumferential part S1 of a material S by ejecting a draw bead member 15 upward through a bottom force 8. Tension from an external circumferential part side of the material S is controlled by molding of the bead S2. On the one hand, a pressing tool 16 is ejected into a cavity 13 by a spring member 17 and presses against a rising wall S3 of the material S to which draw molding has been kept performing with a punch 10. As the tension of the rising wall S3 of the material S is controlled in the course of the molding like this, generation of creases on the rising wall S3 is prevented. Therefore, even a stepped molded product and deep-draw molded product can be molded by one process.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an improvement in a drawing method using a press and an apparatus therefor.

(Prior Art) Conventionally, various drawing methods and devices have been devised in order to prevent forming defects such as cracks and wrinkles from occurring in the molded product during drawing using a press.

For example, there are techniques disclosed in JP-A-59-208120 and JP-A-80-190327.

To give a brief explanation of these, when the material is drawn with a punch, a bead is formed on the outer periphery of the material (wrinkle pressing surface) in order to apply tension to the material when the material is drawn with a punch. Draw forming is performed while controlling the tension generated in the material by changing the height of the bead member. As for the device, a drawing bead member is installed in a slot formed in the surface facing the material of the upper die so as to be movable up and down, and a bead height control device for moving the drawing bead member up and down is attached to the punch. It is designed to operate in conjunction with the vertical movement of the

Next, what is published in Japanese Patent Application Laid-Open No. 130-190327 is
When the material is drawn with a punch, the extrusion force applied to the end of the material is controlled in relation to the vertical movement of the punch, and the device consists of an upper die and a lower die. The extrusion member is arranged so as to be movable in the direction along the mating surface with the mold, and is operated in conjunction with the vertical movement of the punch.

As described above, in conventional molding methods and molding apparatuses, tension is controlled by extruding the outer periphery (wrinkle pressing surface) of the material or forming beads.

(Problems to be Solved by the Invention) However, the conventional technology has the following problems.

For example, when molding a molded product 1 having a stepped portion as shown in FIG. The sizes of are different, and as a result, the boundary part (near 0 part)
Cracked.

Problems such as wrinkles, etc., and warping of the vertical wall 6 side occur, but in the conventional technology, the outer periphery (wrinkle holding surface) 2 is pushed out from the end, or the outer periphery (wrinkle holding surface) 2 is formed with beads 7, etc. Since the tension is controlled by forming the structure, there is a problem that the tension cannot be locally controlled and the above-mentioned problems cannot be solved.

In addition, when forming a molded product with a vertical wall surface by deep drawing, the distance from the outer periphery (wrinkle holding surface) that controls tension to the drawing tip is long, so the tension cannot be controlled all the way to the tip, causing problems such as wrinkles and warping. There was a problem that this occurred.

Therefore, when molding stepped molded products or deep-drawn molded products, the drawing process is divided into two stages, which causes problems such as poor productivity and high manufacturing costs. .

The present invention has been made in view of the above problems, and
The purpose of this is to simultaneously control the tension by the beats and the tension on the vertical wall surface of the material being formed, so that even stepped molded products and deep-drawn molded products can be molded in one step. It is in.

(Means for solving the problem) As a means to solve the above problem and achieve the purpose, a bead is formed on the outer periphery of the material during the drawing process using a press, and a bead is formed on the material. This is a forming method in which a vertical wall surface is pressed, and the device for this purpose is to attach a drawing bead member for forming a bead on the outer periphery of the material in a retractable manner to a lower die, and to attach the drawing bead member to the lower die so that the drawing bead member can be retracted. The pressing tool is operated in conjunction with the vertical movement of the punch that draws and forms the material, and a pressing tool is provided on the lower die side that forms the vertical wall surface of the material so that it can protrude toward the cavity side, and the pressing tool is attached to the cavity side. It is equipped with an elastic member that gives force.

(Function) First, in the molding method of the present invention, at the initial stage of molding, the tension of the material is not controlled so that the tension freely acts on the material, thereby preventing cracks that tend to occur at the early stage of molding. During molding, a bead is formed on the outer periphery (wrinkle suppressing surface) of the material to control the tension, and a vertical wall surface formed on the material is pressed to control the tension of the vertical wall. In this way,
The tension is controlled by pressing against the vertical wall, which cannot be controlled from the outer periphery of the material, to prevent wrinkles from forming.

Next, in the forming apparatus of the present invention, 1. In conjunction with the lowering of the punch, a drawing bead member is projected from the middle of forming the material to form a bead on the outer periphery of the material to control tension, and at the same time form a vertical wall of the material. The tension of the standing wall is controlled by pressing the vertical wall surface of the substrate with a pressing tool protruding from the lower mold part toward the cavity side. Further, since the pressing tool is urged by the resilient member, it retreats against the pressing force of the punch at the end of forming to ensure clearance between it and the punch, so that the material is not deformed.

In this way, in the initial stage of molding, tension is applied freely to the material to prevent cracking, and from the middle of molding, the tension of the material is controlled by forming beads and pressing with a pressing tool to prevent wrinkles, warping, etc. do.

(Example) Next, embodiments of the present invention will be described based on the drawings.

First, the configuration of the molding apparatus of this embodiment will be explained with reference to FIG. 1. 8 is a lower mold, 9 is an upper mold which presses and holds a plate-shaped material S with the lower mold 8, and 10 is a descending mold to hold the material S. It is a punch for drawing and forming.

A fixed cam 11 is attached to the punch 10 and extends through the upper die 9 and projects toward the lower die 8 side.

The lower mold 8 is provided with a horizontally movable passive cam 12, and the cam surface 11a of the fixed cam 11 comes into contact with the cam surface 12a at one end of the passive cam 12, thereby opening the cavity 13.
be moved to the side. Further, the passive cam 12 is always urged in the direction opposite to the cavity 13 by a resilient member 14 14 such as a spring or rubber. A cam surface 12b is also formed on the other end side of the passive cam 12, and the cam surface 12b is engaged with the cam surface 15a of the aperture bead member 15 that can be retracted upward from the lower die 8. And the drawing bead member 15
The upper die 9 in the projecting direction is provided with a recess 8a that cooperates with the tip of the drawing bead member 15 to form a bead.

On the other hand, a pressing portion 16 is slidably provided at a portion of the lower mold 8 that forms the vertical wall of the material S, and is constantly urged to protrude into the cavity 13 by an elastic member 17 such as a spring or rubber. The suppressing portion 16 and the passive cam 1
A gap of a predetermined length is formed between 2 and 2.Next, the operation of one or more configurations will be explained with reference to FIGS. 3 and 4.

After the upper die 9 descends and presses and holds the material S with the lower die 8,
When the punch lO descends and starts drawing the material S, the cam surface 11a of the fixed cam 11 attached to the punch lO
The passive cam 12 of the lower die 8 is moved toward the cavity 13 side. At this time, until the fixed cam 11 comes into contact with the passive cam 12, the material S is drawn by the punch 1O without controlling the tension, so that cracks that tend to occur in the initial stage of forming are prevented.

Next, passive cam! 2, the cam surface 12b on the other end side of the passive cam 12 and the cam surface of the aperture bead member 15! 5a
slides, and the drawing bead member 15 protrudes upward from the lower mold 8 to form a bead S2 on the outer peripheral part (wrinkle pressing surface) St of the material S. By forming this bead S2, the material S
Controls the tension from the outer periphery side.

On the other hand, the pressing tool 16 is projected into the hollow hole 13 by a resilient member 17, and presses the vertical wall S3 of the material S that has been drawn and formed by the punch 10 (see FIG. 3). Since the tension of the standing wall S3 of the material S is controlled midway, it is possible to prevent wrinkles on the standing wall surface that cannot be prevented by the beads S2.

Subsequently, as shown in FIG. 4, at the bottom dead center of processing (at the end of drawing forming), the pressing tool 18 retreats against the resilient member 17, comes into contact with the passive cam 12, and is stopped at a predetermined position. For,
Clearance between the punch 10 and the lower die 8 is ensured.

Note that the amount of vertical movement of the aperture bead member 15 and the pressing tool 16
The amount of movement can be easily adjusted by changing the thickness of the cam surface 11a of the fixed cam 11.

(Effects of the Invention) As explained in detail above, when performing drawing forming, a bead is formed on the outer periphery of the material during forming to adjust the tension, and the vertical wall surface formed on the material is pressed to Since the tension is controlled in areas that cannot be controlled from the outer periphery, even stepped molded products and deep-drawn molded products can be molded in one step.

Furthermore, by shortening manufacturing time and reducing the number of defective products, productivity can be improved and manufacturing costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of the main part of an embodiment of the present invention, and FIG. 2 is a
FIGS. 3 and 4 are perspective views showing an example of molded products to be molded by the present invention; and FIGS. 3 and 4 are longitudinal cross-sectional views of essential parts showing the operating state of the apparatus shown in FIG. 8. Lower fist type 10φ. Punch 15φ. Squeezing bead member 16.φ. Pressing tool Fig. 1

Claims (2)

[Claims] (1) A draw-forming method characterized in that, during draw-forming using a press, a bead is formed on the outer periphery of the material during the forming process, and a vertical wall surface formed on the material is pressed. (2) A drawing bead member for forming a bead on the outer periphery of the material is removably attached to the lower die, and the drawing bead member is operated in conjunction with the vertical movement of the punch that draws and forms the material. A drawing forming apparatus, characterized in that a pressing tool is provided in a region on the lower die side that forms a vertical wall surface on a material so as to be able to protrude toward the cavity side, and a resilient member is provided for biasing the pressing tool toward the cavity side.