JPH01171715A - Shearing method for board material - Google Patents

Abstract

PURPOSE:To prevent the generation of burrs in a sheared portion and improve productivity and a working property by holding the opposite face of a recessed portion which is machiningly hardened due to coiling given to one side by means of one cutting edge and cutting the recessed portion with the other opposing cutting edge together with the cutting edge. CONSTITUTION:In a trim mold 15, after a board material A is carried in a posture with a recessed portion E faced upward, the board material A on a die 22 is pressed and fixed by means of a pad 20 accompanying the lowering of a slide 16 and, as sectional dies 18 are lowered together with the slide 16 while compressing elastic bodies 19, the recessed portion E of the board material A is sheared in between a lower cutting edge 22a and an upper cutting edge 18a. At this time, since the recessed portion E of the board material A is faced upward, the die 22 and the lower cutting edge 22a are opposed to the position from a main body portion to a sheared portion on the opposite face holding the board material without leaving a gap and, further, since the recessed portion E is in a machiningly hardened condition due to the crash at the time of coining, the sheared face is mostly a broken face without having burrs.

Description

[Detailed description of the invention] [Purpose of the invention]

(Field of Industrial Application) The present invention relates to a method for shearing plate materials such as sheet metal materials and car body panels during the forming process, and particularly relates to a method for shearing plate materials suitable for shearing the ends of the product. It is something. (Prior Art) As is well known, sheet metal shearing is performed in various manufacturing fields. For example, in the manufacturing process of automobile bodies, sheet metal material (coil material) is cut into blanks of a certain size. This is normally carried out several times during various molding processes of the blank. Shearing in the above-mentioned car body manufacturing process is performed using a blanking machine, a general molding press die provided with a cutting blade, a trim die, or the like. (Problem to be solved by the invention) However, when shearing plate materials, some curling often occurs at the sheared part, and in order to minimize this curling, it is necessary to constantly adjust the clearance of the cutting blade to maintain accurate clearance. It is essential to perform labor-intensive tasks such as In addition, the above-mentioned banner is safe if the sheared part is covered by another plate material to be hemmed, but in particular, if the sheared part becomes the end of the product as it is, it may be dangerous for people or other There is a high risk of damaging the product, and even if the paint is applied, burrs may protrude from the paint film. Therefore, in the past, after shearing the plate material, the resulting burrs had to be removed, which was an obstacle to improving productivity and workability. (Object of the Invention) The present invention was made in view of the conventional situation, and is capable of preventing the occurrence of burrs due to shearing, and making it unnecessary to remove the burrs in a series of manufacturing processes. The purpose of this invention is to provide a method for shearing plate materials that can contribute to improving productivity and workability.

[Structure of the invention]

(Means for Solving the Problems) In the method for shearing a plate material according to the present invention, first, coining is performed on one side of the portion of the plate material to be sheared to form an intermediate portion in a work-hardened state. In the above process, as an example is shown in FIG. 1, the plate material A is tX! While holding, the plate material A is crushed by a punch D facing the die B, thereby forming an intermediate portion E in the plate material A, as shown in FIG. The intermediate portion E becomes in a work-hardened state by being crushed by the punch D, that is, by coining. Next, while holding the opposite surface of the intervening portion with one cutting blade, the intervening portion is sheared between the one cutting blade and the corresponding other cutting blade. In the above process, as shown in an example in FIG. 3, if the intermediate portion E is directed upward, the lower surface of the plate material A is held by the lower cutting edge F, and the cutting edge F and the pad G opposite thereto are held. The plate material A is sandwiched between the two, and the lower cutting blade F and the upper cutting blade H shear the intermediate portion E. Note that the die B, pads C, G, punch D, and cutting edges F, H described above can be made to correspond to, for example, each component in the press mold, and are not limited to the illustrated example. (Operation of the Invention) The above-described method for shearing a plate material changes the ductility of the sheared portion to a small state by bringing the sheared portion of the plate material into a work hardening state. Furthermore, by holding the surface opposite to the intervening portion with one of the cutting blades, the plate material can be sufficiently held to the position of the sheared portion without creating a gap between the cutting blade and the plate material. The sheared surface of the plate material sheared in this state has low ductility in the sheared part, as mentioned above.
Most of it becomes a fractured surface, the burrs are extremely small, and there is virtually no burr. (Example) Hereinafter, an example according to the present invention will be described based on the drawings. 4 to 7 are diagrams illustrating an example of an apparatus applicable to the plate shearing method of the present invention, and FIGS.
The drawing die 1 is shown in the figure, and the trim die 15 is shown in FIGS. 6 and 757. That is, the drawing die 1 includes a punch 3 on an upper inner slide 2, and a blank holder 5 on an outer slide 4 provided on the outer peripheral side of the inner slide 2.
The lower bolster plate 6 is provided with a diamond facing the punch 3 and the blank holder 5. On one side of the punch 3, there is formed a storage section 3a that opens downward, and an insert punch 8 for coining is stored in this storage section 3a. The insert punch 8 has a T-shaped cross section as a whole, and the base portion 8a at the upper end is fixed to the inner upper surface of the storage portion 3a with a port 9. 8b protrudes from the lower surface of the punch 3. Further, a sub pad 11 is suspended from the lower surface of the base 8a via a rigid body 10. When the sub-pad 11 is not processed, its lower surface protrudes to approximately the same height as the processed portion 8b, as shown by the imaginary line in FIG. Note that the insert punch 8 has a trim type 1 to be described later.
This is provided in accordance with the position of the plate material to be sheared according to No. 5. On the other hand, the trim mold 15 has a holder 1 on the upper slide 16.
7, and an upper cutting edge 1 is provided on the lower surface of the outer peripheral side of this holder 17.
Attaching the sectional die 18 having 8a,
A pad 20 is suspended from the central lower surface of the holder 17 via an elastic body 19 and a retainer (not shown). The pad 20 is in a position ahead of the sectional die 18 when the slide 16 is lowered. Further, the trim mold 15 includes a die 22 on the lower bolster plate 21, which faces the pad 20 and has a lower cutting edge 22a corresponding to the upper cutting edge 18a. Attached to the outer periphery of the die 22 are scrap chutes 23 and 24 having a downward slope toward the outside of the die. Next, the method of shearing a plate according to the present invention will be explained together with the operations of the drawing die 1 and trim die 15. In the drawing die 1, when a plate material A in a flat plate shape or a preformed state is carried in, the outer slide 4 descends first and holds the end of the plate material A between the blank hole 5 and the shoulder of the diamond. Thereafter, the inner slide 2 is lowered to draw the plate material A between the punch 3 and the diamond. In addition, during the above-described drawing process, the drawing die 1 presses and fixes both sides of the sheared part with the sub-butts 11 while compressing the elastic body 10 after the sub-butts 11 come into contact with the plate material A. In addition, a section E having a V-shaped cross section is formed (coined) in the plate material A by the processing section 8b of the insert punch 8. The section E formed in this way becomes a work hardened state due to the above-mentioned crushing. Next, the trim mold 15 is loaded with the plate material A with the part E thereof facing upward, and then presses and fixes the plate material A on the die 22 with the pad 20 as the slide 16 descends, and then presses and fixes the plate material A on the die 22 with an elastic body. By lowering the sectional die 18 together with the slide 16 while compressing the sectional die 19, the portion E between the plate material A is sheared between the lower cutting blade 22a and the upper cutting blade 18a. At this time, since the plate material A has the intermediate portion E facing upward, the die 22 and the lower cutting blade 22a correspond from the main body portion to the position of the sheared portion on the opposite surface (lower surface) and are held without any gaps. , and the intermediate part E
Since it is in a state of work hardening, most of its sheared surface becomes a fractured surface, with no burrs. Also,
Stirrup S after shearing is scrap shoe) 23.2
4, it is discharged from the mold. A process using such a drawing die 1 and a trim die 15 corresponds to, for example, a process of forming an automobile body panel,
Since it does not produce burrs, it is extremely useful for applications where the sheared part is used as the end of the product. Although the diagram shows the case where the gap E is formed only on one side of the plate material A, it is of course possible to form the gap part over the entire circumference of the drawn portion. Furthermore, in the case of the above process, it is not always possible to shear the center of the approximately V-shaped space E due to the positioning error of the plate material A carried in, so for example, as shown in FIG. It is also good to form a portion e and keep the sheared portion flat.

【Effect of the invention】

As explained above, according to the method for shearing a plate material of the present invention, coining is performed on one side of the sheared portion of the plate material to form a work-hardened intermediate portion, and then the opposite surface of the intermediate portion is turned to one side. This method has the advantage of being able to prevent burrs from forming in the sheared part by shearing the space between the one cutting blade and the corresponding other cutting blade while holding it with the cutting blade. This makes it possible to eliminate the need for the burr removal work in a series of manufacturing processes, thereby improving productivity and workability.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view explaining the process of forming a gap in a plate, Fig. 2 is a cross-sectional view of the plate after forming the gap, Fig. 3 is a cross-sectional view explaining the shearing process, and Figs. The figure shows an example of an apparatus applicable to the plate shearing method of the present invention.
The figure is a sectional view of the drawing die, Figure 5 is an enlarged sectional view of the drawing die near the insert punch shown in Figure 4, Figure 6 is a sectional view of the trim die, and Figure 7 is the trim die shown in Figure 6. FIG. 8 is an enlarged cross-sectional view of the vicinity of the cutting blade, and is a cross-sectional view of a plate material explaining another example of the shape of the intermediate portion. A... Plate material, E, e... Intermediate portion, F, 22a... Lower cutting blade (one cutting blade), H, 18a
... Upper cutting edge (other cutting edge).

Claims (1)

[Claims] (1) After coining one side of the part to be sheared of the plate material to form a work-hardened concave part, while holding the opposite side of the concave part with one cutting blade, A method for shearing a plate material, comprising shearing the concave portion with the other corresponding cutting blade.