JP2002166397A - Punching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a punching device capable of reducing burden of work for removing a burr by surely keeping the punched burr on a punching blade side. SOLUTION: In a punching blade 2, a blade edge 21 is formed on a tip part of a cylindrical body 20, and a protrusion 22 protruding inside of the cylindrical body 20 is formed on a predetermined position of an inner peripheral wall of the cylindrical body near the blade edge 21, A disk shaped elastic foam body 4 is pressed onto the punching blade 2 and the disk shaped elastic foam body 4 is punched.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a punching device used for punching holes in a disc-shaped foam by press punching.

[0002]

2. Description of the Related Art For punching a hole 51 by pressing a disk-shaped foam 4 such as urethane, conventionally, for example, FIGS.
A device provided with such a cylindrical punching blade b has been used. The punching blade b is erected on the fixing plate a, and the disk-shaped foam 4 is pressed against the punching blade b to punch out.

[0003]

However, when the disc-shaped foam 4 has been punched and recovered as a foamed product 5, there was a problem that the punched scum 6 remains on the inner wall 51 of the hole of the foamed product 5. Further, when the foamed product 5 is recovered, the scrap 6 is caught on the cut surface, and the elastic recovery direction of the scrap 6 is deviated from the original vertical direction, and the scrap 6 penetrates into the interior 52 of the foamed product 5. (C in FIG. 7). In general, the disc-shaped foam 4 is stacked in multiple stages to reduce man-hours. In such a case, the number of scraps 6 that enter the foamed product 5 increases. These blanks 6 must be removed one by one after the punching process, and the work load is large.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a punching device which ensures that punched-out scraps remain on the punching blade side and eliminates the burden of removing the scraps.

[0005]

In order to achieve the above object,
The gist of the invention according to claim 1 is that the cutting tool includes a cutting blade having a cutting edge formed at a distal end portion of the cylindrical body, and a projection formed at a predetermined position on the inner peripheral wall near the cutting edge toward the inside of the cylinder. A punching apparatus characterized in that a blade-shaped foam having elasticity is applied to a blade and punched by pressing. According to a second aspect of the present invention, in the first aspect, the protrusion is formed on the inner peripheral wall of the cylindrical body so as to be axially symmetric with respect to a center axis of the cylindrical body, and the protrusion has a vertical cross-sectional shape of "C". Alternatively, a punching blade is provided so as to project toward the inside of the cylinder in a “∠” shape, and a plurality of superposed disc-like foams are set between the punching blade and the upper die, and the blade is pressed with the punching blade. The present invention is characterized in that a foam can be punched. Here, the “∠” shape includes an acute angle shape formed by intersecting a downwardly inclined oblique side and a substantially horizontally protruding lower side, as well as a L-shaped shape extending from the tip of a fishing hook to a return portion. This is because the same operation and effect as those of the present invention can be obtained. According to a third aspect of the present invention, there is provided the punching apparatus according to the second aspect, wherein the inside of the cylinder of the punching blade is electrically connected to a hollow chamber formed in the lower die and is erected on the upper surface of the lower die.

According to the first aspect of the present invention, if a projection is formed at a predetermined position on the inner peripheral wall of the cylinder near the cutting edge toward the inside of the cylinder, even if a blank is formed by punching the foam, the scrap is formed by the projection. So that no scrap is entrained when the foam is elastically restored. According to the second aspect of the present invention, when the protrusion is formed axially symmetric with respect to the center axis of the cylindrical body, an external force is uniformly applied to the scrap, and the punched scrap does not move in an unstable manner. In addition, when the projection projects into the cylinder in a vertical cross section in the shape of a letter "K" or "∠", the punched scum punched out by such a shape can be smoothly fed downward. As in the invention of claim 3, when the inside of the cylinder of the punching blade is electrically connected to the hollow chamber formed in the lower mold and is erected on the upper surface of the lower mold,
Since the punched scum can be sequentially fed into the hollow chamber, continuous punching work can be performed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a punching device according to the present invention will be described in detail. 1 to 5 show an embodiment of a punching device according to the present invention. FIG. 1 is a longitudinal sectional view thereof, and FIG. 2 is an enlarged sectional view of a part A of a cutting edge portion of the punching blade of FIG. (B) is an enlarged sectional view of another embodiment different from (a), FIGS. 3 and 4 are explanatory sectional views showing a punched pattern, and FIG. 5 is an explanatory sectional view of a foamed body being punched out into a product.

The punching device comprises a lower die 1, a punching blade 2 and an upper die 3.
And The lower die 1 is a fixed die, and has a hollow base 13 surrounded by an enclosing wall 10 at the center thereof to form a base having a flat upper surface. At the center of the upper surface of the surrounding wall 10, a punching blade 2 is fixed upright. An opening 12 is formed in the surrounding wall 10 on which the cylindrical cutting blade 2 stands, and the inside of the cylinder of the cutting blade 2 is electrically connected to the hollow chamber 13 while maintaining the inside diameter D of the cylinder.

The cutting blade 2 has a cylindrical shape and is provided with a cutting edge 21 having an acute angle cut at the tip as shown in the figure. The cutting edge 21 is a portion for cutting the foam 4. The height Z from the lower mold upper surface 11 to the cutting edge 21 of the punching blade 2 substantially matches the height of the foam 4 when a predetermined number of the foams 4 are compressed by punching (when the mold is closed) ( (Fig. 3). At a predetermined position on the inner peripheral wall of the cylinder near the cutting edge 21, a projection 22 is formed toward the inside of the cylinder. The position near the cutting edge 21 where the projection 22 is provided refers to a predetermined position where the distance L from the cutting edge 21 to the projection 22 (projection tip 220) is set to be smaller than the thickness t of the disk-shaped foam 4 used for punching. . In the punching process, the scrap 6 falls over the projection 22 and falls down, or the scrap 6
And captures to the product 5 side when the elasticity of the product 5 is restored.
This is because there is an aim to prevent the pulling of the sword (see later). Even if the scrap 6 is captured at the projection 22,
If the projection shape can be ensured, the projection position is as close as possible to the cutting edge 21.
It is desirable to get closer. This is to prevent as much as possible of the scrap 6 from passing through the projection 22 and pulling the scrap 6 upward to come off when the foam 4 is elastically restored.

The scum 6 formed by punching the foam 4 is temporarily stored in the cylinder of the cylindrical cutting blade 2.
6, the foam 4 finishes punching and becomes a product 5, and when the product 5 releases the compression and is restored, the scraps 6 are put together in the product 5. There was a disadvantage that they stuck. In the present invention, by providing the projection 22, it is possible to completely prevent the scraps 6 from sticking together when the product 5 releases the compression and restores.

The projections 22 may be provided partially without rotating around the inner peripheral wall of the cylindrical body 20. Here, the projections 22 are provided on the inner peripheral wall of the cylindrical body 20 around the central axis of the cylindrical body. Formed symmetrically. This is to prevent the punched scum 6 from moving unstably while maintaining a uniform balance. Further, in the present embodiment, the protrusion 22 is formed so as to protrude into the cylinder in the shape of a vertical cross-section. This is because the scrap 6 formed by the punching process can be smoothly fed into the hollow chamber 13 of the lower die 1.

In detail, a slope shape (projection height α) is set on the upper side 221 of the projection 22 so that the scrap 6 formed by punching the foam 4 can smoothly pass over the projection 22 (FIG. 2 a). Further, when the product 5 releases the compression and recovers, the slope (the height β) is formed on the lower side 222 of the projection 22 so that the scrap 6 that has climbed over the projection 22 can be prevented from being drawn and entrained. Set. It is more preferable that the lower side of the protrusion 22 has a vertical cross-section “∠” in which the lower side 222 can reliably perform the function of the stopper. The protrusion 22 of the present embodiment projects in the shape of a vertical cross section “C” toward the inside of the cylinder as shown in FIG. 2A. For example, the protrusion upper side 221 can be curved as shown in FIG. . The numerical values of the protrusion heights α and β of the protrusions 22 are appropriately selected. To make it easier for the scrap 6 to fall down,
More preferably, the inner diameter of the cylinder below the protrusion 22 is set to be larger than the inner diameter of the cylinder above the protrusion 22, and the height of the protrusion is set to α <β.

The upper die 3 is a plate-shaped movable die, which is disposed to face the lower die 1 and has a flat lower surface. A plurality of superimposed foams 4 are set between the upper mold 3 and the lower mold 1 (the cutting blade 2), and the upper mold 3 is pushed down to form the foam 4
Is pressed, the foaming body 4 can be punched by the punching blade 2.

The foam 4 is a disc-like foam 4 of a predetermined thickness t made of elastic urethane foam or the like. Such a disc-shaped foam 4 is usually stacked in multiple stages and subjected to press punching. Also in the present invention, a plurality of foams 4 are laminated to form a laminated body, which is pressed against the punching blade 2 and punched.

Next, a press punching method using the punching device will be described together with its operation. First, the mold is opened, and a plurality of foamed bodies 4 superposed between the upper mold 3 and the lower mold 1 are set so that the punched portion faces the punching blade 2 (FIG. 1). The foam 4 here is three-tiered.

Subsequently, the upper mold 3 is lowered and the foam 4 is pressed against the lower mold 1 (open arrow in FIG. 3). As a result, the foam 4 is clamped between the lower mold 1 and the upper mold 3. The foam 4 is crushed into a compressed state. Since the punching blade 2 is erected on the lower die 1, the foam 4 is sandwiched between the punching blade 2 and the upper die 3 and the foam 4 is pressed against the punching blade 2 to perform punching. In this way, the foam 4 is punched at a predetermined location by the punching blade 2 to form a product 5, while the punched scrap 6 enters the cylinder of the punching blade 2, and the scrap 6 sequentially passes over the projection 22 in a balling state. Falling down. The punching blade 2 is electrically connected to the hollow chamber 13 provided in the lower mold 1 with the size of the inner diameter of the cylinder, and the punching waste 6 is collected in the hollow chamber 13, so that the punching process can be repeatedly performed. It should be noted that the cut waste 6 punched out of the foam 4 at the top stops as it is hooked on the projection 22 as shown in FIG.

Thereafter, the upper mold 3 is moved upward to return to the mold open state.
Along with this, the foam 4 in the compressed state, that is, the product 5 after the punching process is elastically restored (FIG. 4). At this stage of elastic recovery, the scrap 6 located at the projection 22 also attempts to return together, but cannot return because it is hooked on the projection 22. A compression portion 61 is formed on the scrap 6 by the projection 22, and the reaction force acts on the compressed portion 61, and the compressed portion 61 is captured by the projection 22. Absent. In the case of the scrap 6 having passed over the projection 22, the hollow chamber 1 serving as an open space is provided.
3, the product 5 is not affected at all even if the product 5 is elastically restored. If the product 5 is elastically restored and then removed from the mold, a desired product 5 having a punched hole 51 at a predetermined position is obtained. The scum 6 is inserted into the hole 51 of the product 5 or the product 5
The conventional defect that had penetrated the inside of the is gone. After that, it can be repeatedly produced through the same steps.

In the punching apparatus thus configured, the cutting waste 6 enters the cylinder of the punching blade 2 by punching.
Since the projection 22 is formed near the cutting edge 21, the scrap 6 is first caught on the projection 22. In the case of punching the foams 4 stacked in multiple stages, as shown in FIG. 3, the scrap 6 punched later presses the former scrap 6 downward, and the pushed scrap 6 is pushed downward beyond the projection 22. Go sequentially. When moving to the subsequent mold opening operation, the last scrap 6 remains stuck on the projection 22, but the scrap 6 is locked in a compressed state by the projection 22, and the foam is elastically restored. It does not move up with the product 5. Therefore, the foamed product 5 can be taken out while being separated from all the scraps 6. Heretofore, the burden of removing the scraps 6 that have entered the product 5 after the punching process has been removed by the operator one by one.

In addition, in the present invention, since the punching blade 2 is connected to the hollow chamber 13 formed in the lower mold 1 while keeping the size of the inner diameter of the cylinder, and stands upright on the upper surface 11 of the lower mold, it exceeds the protrusion 22. The scum 6 that is directed downward is accumulated in the hollow chamber 13 one after another. Continuous punching of the foam 4 becomes possible.

The present invention is not limited to the embodiment described above, but can be variously modified within the scope of the present invention depending on the purpose and application. Lower mold 1, upper mold 3, punching blade 2, cylinder body 20,
The shape, size, number, material, and the like of the blade edge 21, the protrusion 22, the foam 4, and the like can be appropriately selected according to the application.

[0021]

As described above, in the punching apparatus of the present invention, the punched scum is stored in the punching blade side and further in the hollow chamber, so that the burden of removing the scum in the product is strong. It is possible to eliminate the conventional labor that has been done, and to exert an excellent effect.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of a punching device according to the present invention.

2A is an enlarged sectional view of a portion A of a cutting edge portion of the punching blade of FIG. 1, and FIG. 2B is an enlarged sectional view of another embodiment of FIG.

FIG. 3 is an explanatory sectional view showing a punching pattern.

FIG. 4 is an explanatory sectional view showing a punching pattern.

FIG. 5 is an explanatory sectional view in which a foam is punched out to be a product.

FIG. 6 is an explanatory sectional view of a conventional technique.

FIG. 7 is an explanatory sectional view of a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lower mold 13 Hollow chamber 2 Pull-out blade 20 Cylindrical body 21 Cutting edge 22 Projection 3 Upper mold 4 Foam

Claims (3)

[Claims] A cutting board having a cutting edge formed at a tip portion of a cylindrical body and having a projection formed at a predetermined position on an inner peripheral wall near the cutting edge toward the inside of the cylinder, wherein the cutting blade has elasticity. A punching device characterized in that a foamed body is pressed and punched out. 2. The projection is formed on the inner peripheral wall of the cylinder in an axially symmetric manner with respect to the center axis of the cylinder, and the projection is formed into a vertical cross-section “く” or “∠” in the cylinder. A punching blade is provided so as to protrude in the direction, and a plurality of superposed disc-shaped foams are set between the punching blade and the upper die so that the foaming can be punched by the punching blade by setting and pressing. The punching device according to claim 1. 3. The punching device according to claim 2, wherein the inside of the cylinder of the punching blade is electrically connected to a hollow chamber formed in the lower die and stands upright on the upper surface of the lower die.