JPH0580291B2 - - Google Patents

Description

[Detailed description of the invention]

[Object of the Invention] (Industrial Field of Application) The present invention relates to a method for manufacturing a mold for punching out a punched product from, for example, a metal plate. (Prior Art) For example, a knock-out type press die is used as a die for press working a steel plate. This mold is constructed as shown in FIG. 11, and a punch back up part 2 having an axis in the vertical direction is provided at the center of the upper surface of a base body 1, and at the upper end of this punch back up part 2. is equipped with punch 3. A stripper 4 forming a flat surface of approximately one height is provided on the outside of the punch 3, and the lower side of the stripper 4 is supported on the upper surface of the base body 1 by spring bodies 5, . Furthermore, an ejector 6 is provided above the punch 3 at a predetermined interval. A die 7 having a lower surface at the same height as the lower surface of the ejector 6 is provided on the outer peripheral side of the ejector 6. The upper surface of the die 7 is connected to a die backup portion 7a, and the ejector 6 is adapted to slide with respect to the die 7. Then, by inserting, for example, a steel plate material 8 between the punch 3 and the die 7 and processing the die 7 and the ejector 6, the steel plate material 8 is sandwiched between the ejector 6 and the punch 3. The die 7 slides down relative to the ejector 6. The steel plate material 8 is then sheared by the punch 3 and die 7 to produce a punched product. In this way, the punch 3 and die 7, etc. that punch out products from steel plate material 8, etc., need to have their cutting blades hardened, and manufacturing involves cutting out the material, finishing, heat treatment of the blade, etc. This required many steps. (Problems to be Solved by the Invention) As described above, the mold blade parts of general press molds require a large number of man-hours to manufacture. For this reason, by cutting a thin steel plate with a laser beam, the blade part can be cut out from the steel plate, and the heat input during cutting can heat it up and rapidly cool it, thereby hardening it and use it as the blade part of a mold. There is a method for manufacturing blade parts, but the blade parts cut and hardened by laser light in this way are thin plates, and the hardened layer formed by hardening is shallow, so it is easy to wear out and is difficult to punch. There were also circumstances in which the system was likely to deteriorate. This invention was made in view of the above-mentioned circumstances, and by heat-treating the steel plate material by irradiating it with laser light and cutting it, a hardened layer is separately formed on the blade part of the mold. The purpose is to provide a method for manufacturing molds with a long life. [Structure of the Invention] (Means for Solving the Problems) The present invention irradiates a hardenable steel plate with a laser beam having a predetermined irradiation area along the outline of a mold to be manufactured. A first hardened layer having a width, and a second hardened layer adjacent to and along the first hardened layer, located on the side of the mold to be manufactured, and having a predetermined width. manufacturing a mold, characterized in that the center part in the width direction of the first hardened layer is cut with a laser beam along the outline of the mold, and the cut edge forms a mold blade part. It's in the method. (Function) Since the hardening layer is doubled, toughness is increased near the blade part, and the life of the mold is improved. (Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 10. First, a mold 9 shown by the chain line A of the steel plate material 8 shown in FIG.
CO ₂ as shown by arrow L for the outline part of
Irradiate with laser light. Here, the steel plate material 8 is, for example, flame hardened steel (SKS-
3). By irradiating the laser beam as shown in FIG. 4 using the defocus method as described above, it is possible to irradiate the laser beam over a predetermined area. Here, what is shown by the chain line L is laser light, and by passing through the condensing range 27,
The focus is removed and the steel plate material 8 is irradiated. The width of the laser beam irradiation is, for example, about 4 mm, and by hardening the outline of the mold blade part to be manufactured with this width, an arc shape is formed from the surface of the steel plate material 8 in the thickness direction. A first hardened layer 10 having a cross section of is formed. Next, as shown in FIG.
A second hardened layer similar to the first hardened layer 10 is formed by irradiating a defocused laser beam as shown by arrow L onto a position adjacent to the inside of the contour of the mold 9 shown by . A hardened layer 11 is formed. As a result, the width of the hardened layers 10, 11 becomes, for example, about 4 mm, and the width of the hardened layers 10, 11 becomes approximately 4 mm.
1 has a depth of about 0.5 mm and is hardened (Vickers
Hardness) can be obtained from maximum Hv700 to minimum Hv400. Next, as shown in FIG. 3, a portion corresponding to the contour is irradiated with a laser beam in a focused state as shown by an arrow L, thereby cutting. Here, the cut portion is, for example, the center portion of the first hardened layer 10 in the width direction. The surface roughness of the cut edge 12 thus cut can be 8.6 μm (Rz (ten point average roughness)). For example, a knock-out type press die was manufactured using the die 9 manufactured by the process described above, and about 7,000 press products 12 having the shape shown in FIG. 10 were punched out. The extracted product was of high quality with a burr height of 30 μm and warpage of 0.1 mm. Here, the dimensions of each part of the press-formed product 12 are as shown in the figure: dimension B is 20 mm, dimension C is 60 mm, dimension D is 10 mm, dimension F is 15 mm, and angle F is 60°. Note that the mold 9 has a decrease in hardness near the overlapping portion 26 of the first hardened layer 10 and the second hardened layer 11, but the width of the overlapping portion 26 is approximately 0.05 mm, which is approximately 40%. hardness has decreased. Here, the vicinity 26 of the overlapping portion is located on the side of the arc-shaped first hardened layer 10 of the second hardened layer 11. However, as mentioned above, about
Judging from the high quality of the press-formed product 12 obtained when 7000 pieces were punched, the decrease in hardness near the overlapped portion 26 can be ignored. Hereinafter, by irradiating the steel plate material 8 with a laser beam having a predetermined irradiation area in a defocused state,
The resulting hardened layers 10 and 11 are continuous with a predetermined width.
In order to confirm that the steel plate material 8 has a hardening effect that improves the toughness, a plurality of test specimens under different conditions as described below were prepared and subjected to a Shalby impact test. First, the test piece was formed into a substantially rectangular plate shape as shown in Fig. 5, with a longitudinal dimension G of 60 mm, a width direction dimension H of 20 mm, a thickness of 3 mm, and a central part in the longitudinal direction. is 0.5mm deep in the width direction, with an included angle of 90°
A notch 13 is formed. The entire edge of the test piece 14 thus formed is irradiated with laser light as described above, and the first
By forming second hardened layers 10 and 11, and cutting the widthwise central portion of the first hardened layer 10 with a laser beam, the entire hardened portion 15 is formed as shown in FIG. A first test piece 16 was fabricated by forming the test piece over the edge. In addition, similarly formed on this first test piece 16,
Furthermore, as shown in FIG. 7, a second test piece 18 was manufactured by forming a hard part 17 in the widthwise central part extending in the longitudinal direction. Here, the hard part 1
7 is formed by irradiating an out-of-focus laser beam. Furthermore, similarly to the first test piece 16, a hard part 15 is formed at the edge, and as shown in FIG.
A third test piece 21 having test pieces 9 and 20 formed thereon was manufactured. Further, after forming the first test piece 16 in the same manner as the first test piece 16, as shown in FIG.
A fourth test piece 25 was manufactured by forming 24. Four test pieces 16,1 manufactured as above
A Charpy impact test was conducted on No. 8, No. 21, and No. 25, respectively. The results are shown in Table 1.

[Curing of invention]

As described above, this invention irradiates a steel plate with a laser beam along the contour of a mold to be manufactured,
Forming a first hardening layer having a predetermined width and a second hardening layer having a predetermined width and extending adjacent to the first hardening layer and located on the side of the mold to be manufactured. Then, the first hardened layer was cut at the center in the width direction along the contour of the mold, and the cut edges formed the blades of the mold. Therefore, even if the plate thickness is relatively thin, mold teeth with high wear resistance can be obtained by the remaining portion of the first hardened layer, and Since the toughness can be improved, it is possible to provide mold blade parts with excellent durability.

[Brief explanation of the drawing]

1 to 11 show an embodiment of the present invention, FIGS. 1 to 3 are side sectional views showing each step of manufacturing the mold blade part of the embodiment, and FIG. 4 shows a laser beam Figure 5 is a side sectional view showing the state in which the beam is irradiated onto a steel plate in an out-of-focus state, Figure 5 is a front view showing the test piece used in the Charpy impact test, Figures 6 to 9
The figure is a perspective view showing a test piece with different numbers of band-shaped hardened layers formed by defocused laser light, and Figure 10 is a product manufactured using a knock-out press mold using a mold. FIG. 11 is a side sectional view of a general knock-out type press die. 8... Steel plate material, 9... Mold component, 10... First hardened layer, 11... Second hardened layer.

Claims (1)

[Claims] 1. A hardenable steel plate is irradiated with a laser beam having a predetermined irradiation area along the outline of a mold to be manufactured, thereby forming a first hardening layer having a predetermined width and this first hardening layer. A second hardened layer is formed which runs adjacent to the treated layer, is located on the side of the mold to be manufactured, and has a predetermined width, and a center portion in the width direction of the first hardened layer is formed along the mold. A method of manufacturing a mold, which comprises cutting along the contour of the mold with a laser beam, and forming a mold blade with the cut edge.