JPH0110107Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an improvement in the shape of a cutting edge portion that holds a trimming cutting edge of a trimming mold.

[Prior art]

Generally, as shown in Japanese Utility Model Application Publication No. 58-160623, a trimming mold is used to trim the edges of a drawn press work to obtain a predetermined shape. be. By the way, in the drawing process, a part of the material flows inward to form the press work into the desired shape, but if the flow of the material is too large, wrinkles may form in the press work. In order to prevent this, press workpieces have conventionally been provided with a stepped portion for adjusting the inflow amount.
In the trimming process, the workpiece is cut along the trim line on the inner peripheral side of the stepped portion.

Conventionally, there have been trimming molds shown in FIGS. 1 and 2 that cut the press work along the trim line on the inner peripheral side of the stepped portion. In the figure, 1 is a lower mold fixed to the floor etc., and the lower mold 1 has a press work 2 on its upper surface.
When placed, the step portion 2a for adjusting the inflow amount and the flange portion 2c for drawing of the press work 2 are positioned above the side portion of the lower mold 1. Further, a trimming lower mold cutting blade 1a is fixed to the upper outer peripheral corner of the lower mold 1.

Reference numeral 3 designates an upper mold provided opposite to the lower mold 1, which is box-shaped with an open bottom end, and is movable up and down by a drive device (not shown). A connecting flange portion 4a of a planar frame-shaped cutting blade holder 4 is bolted to the lower end surface of the side wall 3a of the upper mold 3, and a cutting edge portion 4b of the cutting blade holder 4 is The cross section has a substantially rectangular shape and has a wall thickness that is substantially the same as the distance t between the trim line 2b and the stepped portion 2a of the work 2.

Further, an upper cutting edge 4c for trimming is fixed to the lower inner peripheral corner of the cutting edge portion 4b, and the upper cutting edge 4c for trimming has a shape corresponding to the lower cutting edge 1a for trimming. , and can come into sliding contact with the outer circumferential surface of the lower cutting edge 1a for trimming.

A plate holder 5, which is also open at the bottom, is disposed inside the upper mold 3, and a biasing spring is provided between the outer bottom surface of the plate holder 5 and the inner bottom surface of the upper mold 3. 6 is provided, and the plate holder 5 is urged downward so that the lower surface of the side wall 5a can press the inner part of the trim line 2b of the workpiece 2.

Next, the operation will be explained.

Trim line 2b of work 2 with this conventional device
In order to cut the workpiece along the upper surface of the lower mold 1, the workpiece 2 is first placed on the upper surface of the lower mold 1 so that the stepped portion 2a and the flange portion 2c are positioned above the side, and then the upper mold 3 is lowered. Then, first, the inside part of the trim line 2b of the workpiece 2 is pressed by the plate holder 5 and the workpiece 2 is fixed on the lower die 1, and then the cutting edge part 4 of the cutting blade holding part 4 is pressed.
b descends while coming into contact with the inner surface of the stepped portion 2a of the workpiece 2, whereby the workpiece 2 is cut along the trim line 2b by the upper cutting edge 4c for trimming and the lower cutting edge 1a for trimming.

By the way, in the above-mentioned trimming operation, a considerably large load is applied to the cutting blade holding part 4, and therefore, the cutting blade part 4b needs to have a thick wall thickness so as to be able to withstand this load. Since the cutting edge portion 4b is inserted between the trim line 2b and the stepped portion 2a of the workpiece 2 during trimming, the distance t must be widened to match the thickness of the cutting edge portion 4b. I don't get it. However, the portion of the workpiece 2 outside the trim line 2b is a portion to be scrapped, and in the conventional apparatus described above, since the distance t between the workpieces 2 is wide, there is a problem in that the amount of scrap due to trimming is large and the yield is poor.
Further, the scrap material generated during the cutting is pushed downward, but at this time, in the conventional device, the scrap material bites into the outer peripheral surface of the lower mold 1, and the scrap material is not processed. The problem was that it was difficult.

In addition, in order to improve the above-mentioned yield, if the workpiece is placed on the lower mold with the step part facing downward, contrary to the above-mentioned conventional example, the thickness of the cutting edge part can be determined regardless of the above-mentioned interval t. Therefore, the yield can be improved. However, if this is done, a device for reversing the workpiece is required, which increases costs, and the flow of the drawing process is no longer smooth, resulting in a decrease in work efficiency.

[Purpose of invention]

The present invention was devised in view of the above-mentioned conventional problems, and aims to provide a trimming mold that can improve the yield of workpieces and facilitate the processing of scrap materials.

[Structure of the idea]

In the present invention, in a trimming mold, the cutting edge portion that holds the upper cutting edge for trimming is formed so that its lower end is thinner than the distance between the trim line and the stepped portion of the workpiece, and thicker as it approaches the base. death,
Furthermore, a rib-shaped cutter is formed on the side circumferential surface of the step part of the cutting edge, so that when trimming the workpiece, the flange of the workpiece is first slightly cut open by the cutting edge, and then the upper die is cut open. As it descends, these parts are pushed apart and cut wide open. In other words, the flange is deformed and cut open. Therefore, the lower end of the cutting edge can be thinned to match the trim line of the workpiece without reducing the strength of the cutting edge. The distance between the workpiece and the stepped part can be narrowed, and the stepped part of the workpiece is cut open with a cutter so that there is no problem in trimming.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

3 and 4 show an embodiment of the present invention.
In the figure, the same reference numerals as in FIGS. 1 and 2 indicate the same or equivalent parts, and 14 is a cutting blade holding part whose connecting flange part 14a is fixed to the upper die 3;
The cutting blade holding part 14 is shaped like a flat frame, and the lower end of the cutting blade part 14b is formed to be slightly thinner than the distance t between the trim line 2b and the stepped part 2a of the workpiece 2, and is within the distance t. The cutting edge portion 14b has an inclined surface 1 that slopes outward as it approaches its base, that is, the flange portion 14a.
4e and is thicker than the lower end.

A large number of cutters 14d are protruded at predetermined intervals on the circumferential surface of the cutting edge portion 14b on the side of the stepped portion 2a, and the cutters 14d have a triangular cross section as shown in FIG. It extends from the lower end of the cutting edge 14 to the flange 14a.

Next, the operation will be explained.

To explain the case in which the floor panel 2, which is a workpiece, is trimmed using the apparatus of this embodiment, the floor panel 2 is first placed on the lower die 1, and then the upper die 3 is placed on it, as in the case of the conventional apparatus described above. Make it descend. Then, the floor panel 2 is pressed down by the plate presser 5.
is fixed to the upper surface of the lower mold 1, and the lower end of the cutting blade portion 14b of the cutting blade holding portion 14 descends while coming into contact with the inner surface of the stepped portion 2a. At this time, the cut position A of the floor panel 2 shown in FIG. While being cut open, the floor panel 2 is pushed outward by the inclined surface 14e as shown by the solid line in FIG. Ru.

In this way, in this embodiment, the lower end of the cutting edge 14b is made thinner and the upper end is thicker, and the cutting edge 14b is made thinner in order to further strengthen the cutting edge 14b.
Since the rib-shaped cutter 14d is provided protrudingly on the side circumferential surface of the stepped portion 2a, the interval t between the floor panels 2 can be narrowed without reducing the strength of the cutting edge portion 14b.
As a result, the portion that becomes scrap can be reduced, and the yield of workpieces can be improved. In addition, when trimming the workpiece, at the cutting position A of the floor panel 2, the rib-like cutter 14d is first used to trim the step part 2.
A and the flange part 2c are slightly incised, and then as the upper die is lowered, these parts expand outward and are cut wide. In other words, the flange part is deformed and cut open. Making the upper part of the blade part 14b thicker than the interval t does not impede the trimming process, and furthermore, the biting force of the scrap material to the lower mold 1 is weakened by the cut, and the scrap material can be easily removed from the lower mold 1. It can be removed easily, making it easier to process scrap materials.

[Effect of idea]

As described above, according to the trimming mold according to the present invention, the cutting edge portion that holds the upper die cutting edge for trimming is formed such that the lower end thereof is thinner than the distance between the trim line and the stepped portion of the workpiece, and The cutting edge is thicker than this, and a rib-shaped cutter is formed on the outer circumferential surface of the cutting edge, which has the effect of reducing the scrap portion of the workpiece and improving the yield of the workpiece without reducing the strength of the cutting edge. Also, when trimming a workpiece, the step part and flange part of the workpiece are first slightly cut open by the cutting blade, and then these parts are pushed open and cut wide open by the lowering of the upper die, which means that the flange part is deformed. As a result, the biting force of the scrap material against the lower mold is weakened, which has the effect of making the processing of the scrap material easier.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional trimming die, Fig. 2 is an enlarged sectional view of its cutting edge portion, and Fig. 3 is an enlarged view of the cutting edge portion of a trimming die according to an embodiment of the present invention. 4 is a sectional view taken along the line -- in FIG. 3, and FIG. 5 is a perspective view of the workpiece. 1...lower die, 1a...lower die cutting blade for trimming,
2...Workpiece, 2a...Step part, 2b...Trim line, 3...Upper die, 4c...Upper die cutting blade for trimming, 14b...Cutting blade part, 14d...Cut, 1
4e... Slanted portion, t... Distance between trim line and stepped portion.

Claims (1)

[Scope of utility model registration request] A trimming mold for cutting a draw-formed workpiece having a step portion for adjusting an inflow amount at a trim line on the inner peripheral side of the step portion, the workpiece being mounted so that the step portion is located above the side portion. a lower mold that can be placed, a lower cutting edge for trimming formed on the upper outer circumferential corner of the lower mold, an upper mold that is movable up and down facing the lower mold, and a lower end of the upper mold. a cutting blade part provided in the part, the thickness of which is thinner at the tip than the distance between the trim line of the workpiece and the step part, and thicker toward the step part as it approaches the base; and a lower part of the cutting blade part. an upper cutting edge for trimming provided at an inner circumferential corner portion and corresponding to the lower cutting edge for trimming; and an upper cutting edge for trimming provided on the side circumferential surface of the stepped portion of the cutting edge portion and extending from the tip of the cutting edge to the base. A trimming mold characterized by having a rib-shaped cutter.