JPH058079Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a punching die for punching out predetermined shapes of labels, lids, etc. from metal foil, paper, film, or the like.

[Prior Art] In stamping and forming labels, a large number of sheets of metal foil, paper, film, or laminates thereof are stacked one on top of the other, and labels of a predetermined shape are punched out using a punching die. In recent years, with the automation of packaging machines, 300 to 500 sheets, and in some cases as many as 1,000 sheets, are punched out in a single process.

Being able to punch out a large number of labels at once and produce a large number of labels at once increases production efficiency, but it also requires a large pressing force for punching. Each label tends to stick to each other at its cut surfaces, making it difficult to remove each label one by one. To solve this problem, there is a method of sandwiching paper or the like between each label, but this is time-consuming and undesirable from a manufacturing or economic standpoint.

In order to prevent the labels from adhering to each other, a known method is to emboss an object such as a metal foil to be punched out in advance to form irregularities, thereby making it difficult for the labels to stick to each other.

[Problems to be solved by the invention] However, since objects stacked with embossing etc. are easily bent by pressure, cutting cannot be started until the objects stacked on top are bent. Ru. This state is shown in cross section in FIG. In FIG. 6, 1 is a punching die, and 2 is a punched label. As shown in FIG. 6, the labels stacked on top are cut while being bent, and their dimensions are necessarily larger than those on the bottom.

Therefore, in conventional punching, there was a problem in that the dimensions of the upper and lower parts of the stacked labels were different. Further, the prevention of adhesion between the labels on the cut surfaces was not fully satisfactory.

Therefore, the purpose of this invention is to be able to effectively prevent labels from sticking together, to be able to punch out stacked labels without causing any difference in size between the upper and lower sides, and to have a blade that The purpose is to provide a punching die that is hard to break.

[Means for solving the problem] The punching die of this invention has a cylindrical body and an end portion of the body, and the cross section thereof is tapered from the outer surface to the inner surface of the body. In a punching die that is wedge-shaped and has a blade portion at which the tip thereof has protrusions and recesses repeated over the circumference of the body,
The blade is characterized in that the angle formed by the wedge-shaped tip of the protrusion of the blade is larger than the angle formed by the wedge-shaped tip of the recess of the blade.

[Operation] The tip of the blade of the punching die of this invention has a shape in which protrusions and recesses are repeated, and during punching, the protrusion of this blade first comes into contact with the object to be punched. Since the area in contact with the protrusion of the blade portion is very small, the pressure applied to the object to be punched out becomes significantly large when calculated per unit area. Therefore, even if the punching die is pressed with a slight force, the projections will pierce the object to be punched, and cutting will begin before the object bends significantly. Furthermore, since the angle formed by the protrusion of the blade is larger than the angle formed by the recess of the blade, the protrusion is less likely to break. Once cutting starts, the pressing force acts on the cutting, so no large force is applied that would bend the object to be punched, and as a result, the object to be punched can be punched out with almost no bending. .

[Embodiment] FIG. 1 is a perspective view showing an embodiment of this invention. In FIG. 1, a blade portion 3 is formed on one side of a cylindrical punching die 1. As shown in FIG. The blade part 3 is
It is formed by grinding one end of the punching die 1 into a cylindrical shape at regular intervals. Therefore, a protrusion 4 and a recess 5 are formed at the tip of the blade portion 3.

A cross section of the blade portion 3 of the embodiment shown in FIG. 1 is shown in FIG. As shown in FIG. 2, since the protrusion 4 of the blade portion 3 protrudes, when punching is performed using the punching die 1 of this embodiment, the protrusion 4 first comes into contact with an object such as a metal foil. Since the area in which the protrusion 4 contacts the metal foil or the like is very small, the pressure applied per unit area is very large, and the protrusion 4 easily pierces the metal foil or the like. In this way, cutting is started by the protrusion 4 being pierced. Furthermore, due to the wedge effect of the recess 5, punching can be performed without applying a large force. Therefore, when punching is performed using the punching die 1 of this embodiment, punching can be performed without applying a large pressing force to the object to be punched. Therefore, it becomes possible to punch out the object without significantly bending it.

FIG. 3 is a perspective view for explaining another embodiment of this invention. FIG. 3 shows a state in the middle of forming the blade part. That is, in this embodiment, as shown by the solid line in Fig. 3, a slightly obtuse-angled blade is first formed in the same manner as in the conventional method, and then it is ground into a cylindrical shape at regular intervals in the same manner as in the embodiment shown in Fig. 1. protrusion 4
and a recess 5 is formed. This state is shown in imaginary lines in FIG. Incidentally, in this embodiment, the spacing is made slightly wider than in the embodiment shown in FIG. 1, and the parts are ground into a cylindrical shape. FIG. 4 shows a cross section of the blade portion 3 formed in this manner. In this embodiment, since the grinding is performed in a cylindrical shape with a slightly wider interval, as shown in FIG.
It remains unground. Therefore, the angle of the blade of the protrusion 4 is slightly more obtuse than the angle of the blade of the recess 5.

In this way, by making the angle of the blade of the protrusion 4 larger than the angle of the blade of the recess, the protrusion 4 can be made less likely to break.

FIG. 5 is a perspective view showing still another embodiment of this invention. As shown in FIG. 5, the protrusion 4 may be formed on the blade portion 3 by grinding it into a rectangular tube shape.

By punching using the punching die of this invention, it has become possible to punch out over 500 sheets of embossed soft aluminum foil, which was previously the most difficult to punch, in stacks at a time. On the other hand, when punching using a conventional punching die, 50
There was a limited number of pieces. Furthermore, when the punching die of this invention was used, there was no close contact between the labels, and the difference in dimension between the upper and lower sides was so small that it did not cause any problem.

In the above embodiments, a cylindrical punching die is disclosed, but the punching die of this invention is not limited to this shape, and may have other shapes.

Further, in this invention, the shape of the protrusions formed on the blade portion and the spacing between the protrusions can be appropriately selected in consideration of the shape of the label to be punched, the material of the object to be punched, etc.

[Effects of the invention] As explained above, by using the punching die of this invention, compared to conventional punching dies, the angle formed by the protrusion of the blade is larger than the angle formed by the recess of the blade, so the cutting die of this invention is Since there is no fear of breakage and a large number of labels can be punched out at once with high precision, it can be incorporated into an automatic packaging machine and used effectively.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of this invention. FIG. 2 is a sectional view showing the blade portion of the embodiment of FIG. 1. FIG. 3 is a perspective view for explaining another embodiment of this invention. FIG. 4 is a sectional view showing the blade portion of another embodiment of the invention explained in FIG. 3. FIG. 5 is a perspective view showing still another embodiment of this invention. FIG. 6 is a sectional view showing a state of punching using a conventional punching die. In the figure, 1 is a punching die, 3 is a blade, 4 is a protrusion, and 5 is a recess.

Claims (1)

[Claims for Utility Model Registration] A cylindrical body, formed at an end of the body, and having a wedge-shaped cross section tapered from the outer surface to the inner surface of the body; In a punching die having a tip having a protrusion and a recess repeatedly over the circumference of the body, the angle formed by the wedge-shaped tip of the protrusion of the blade is equal to the angle formed by the wedge-shaped tip of the protrusion of the blade. A punching die characterized by an angle larger than the angle formed by the wedge-shaped tip of the die.