JPS639440Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a die for punching cardboard sheets such as corrugated paper and paperboard.

[Prior art and its problems] As is well known, cutting dies for punching and cutting thick paper sheets such as corrugated paper into desired shapes for making boxes etc. are made by punching perforated slits through plywood of constant thickness. The cutting blade is supported straight by carving and fitting the cutting blade into the slit. FIG. 5 shows a cutting blade conventionally used in the cutting die, FIG. 6 shows the cutting die with this cutting blade set therein, and FIGS. 7 to 9 show its cross section. As can be seen, a slit is cut into the plywood 1 in the form of a perforation, leaving a communicating part 2, and the cutting blade 3 fitted into the slit has a gate-shaped cut so that it can straddle the communicating part 2. 4 is formed from the side opposite to the cutting edge 5. If the width W of the part of the cutting blade 3 where the notch 4 is formed is small, it will deflect due to the load applied during punching, resulting in defective sheet cutting, so ensure a width that does not cause deflection. A groove 6 in which part of the width W portion is buried in the surface of the portion 2
was formed.

Therefore, when manufacturing the cutting die, there must be a process of machining the groove 6.
When the cutting edge 5 of the cutting blade hits the cardboard sheet, the air in the area surrounded by the cutting blade 3, indicated by reference numeral 7 in the figure, disappears and unnecessary air pressure is released between the cardboard sheet and the plywood 1. In addition to the surface and the cutting blade 3, there was a drawback that the stability of the cutting blade 3 deteriorated.

[Means for Solving the Problems] Therefore, in the present invention, a slit is cut open in the form of a perforation, leaving a communicating part in a plywood of constant thickness, and the cutting blade that is fitted into the slit is provided with the communicating part. A gate-shaped notch is formed on the side opposite to the cutting edge so that the blade can be straddled, a V-shaped protrusion is formed on the upper inner side of the notch, and the tip of the V-shaped protrusion is pierced into the surface of the communicating part. That's what happens.

[Embodiment] The cutting blade according to the present invention has a V-shaped protrusion 8 formed on the upper inner side of the notch 4, as shown in FIG. When this cutting blade 3 is set in the cutting die, the second
3, the tip of the V-shaped protrusion 8 is pierced into the surface of the communicating part 2 of the plywood 1, so that triangular ventilation holes 9, 9 are formed on both sides of the protrusion. Make it. By forming the V-shaped protrusion 8 in the narrow bridge portion of the cutting blade 3 in this manner, this portion is reinforced and is less susceptible to deflection under the large load applied during cutting. Since ventilation holes 9, 9 are formed on both sides of the V-shaped protrusion 8, the air pressure generated by the sealing with the cut sheet during cutting is released through the ventilation holes 9, 9.

Although FIG. 4 shows another embodiment of the cutting blade according to the present invention, two or more V-shaped protrusions 8 may be formed on the upper inner side of the notch 4 in this way.

[Effects of the invention] By simply allowing the V-shaped protrusion to pierce the surface of the communicating part of the plywood, the part of the cutting blade that straddles the communicating part can be reinforced, and cutting defects due to deflection can be avoided. It doesn't happen. This simplifies the manufacturing process of the cutting die. Further, the formation of ventilation holes has the advantage that unnecessary air pressure is not generated.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the cutting blade according to the present invention, Fig. 2 is a perspective view of a cutting die in which the cutting blade is set, Fig. 3 is a sectional view taken along line A-A in Fig. 2, Fig. 4 is a perspective view showing another embodiment of the cutting blade;
Figure 6 is a perspective view of a conventional cutting blade, Figure 6 is a perspective view of a conventional cutting die, Figure 7 is a sectional view taken along line B-B in Figure 6, and Figure 8 is a sectional view taken along line C-C in Figure 7. , FIG. 9 is a sectional view taken along the line D--D in FIG. 7. 1...Plywood, 2...Communication section, 3...Cutting blade, 4
... cut, 5 ... cutting edge, 8 ... V-shaped protrusion.

Claims (1)

[Scope of utility model registration request] A perforation-like slit is cut openwork into a plywood board of a constant thickness, leaving a communicating area, and the cutting blade that is fitted into the slit has a gate-shaped notch on the side opposite to the cutting edge so that it can straddle the communicating area. , and a V is formed on the upper inner side of the notch.
A cardboard sheet cutting die characterized in that a V-shaped protrusion is formed, and the tip of the V-shaped protrusion is pierced into the surface of a communicating part.