JP3469493B2 - Punching knife - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a punching tool for forming cross cuts.

[0002]

2. Description of the Related Art A punching blade shown in FIG. 5 (I) is known as a punching blade for punching a corrugated cardboard sheet or a cardboard sheet into a predetermined shape. This punching blade 40 forms chamfers 42 inclined in opposite directions on both sides of one side portion of a blade plate 41 made of a strip-shaped steel plate, and a cutting blade 43 provided at an intersection of the chamfer 42 is provided on the blade plate 41. It is placed in the center of thickness.

Using the punching blade 40, a T-shaped cut or an H-shaped cut, or, as shown in FIG. 4, a punched hole 30 and a linear cut which is continuous with a part of the outer periphery of the punched hole 30. When punching 31 and 31, as shown in FIG. 5 (II), a plurality of punching blades 40 are combined in a cross shape so that the side surface of one punching blade 40 faces the edge of the other punching blade 40. There is a need.

In this case, the cutting edge 43 of one punching edge 40
If there is a gap at the end of the cutting blade 43 of the other punching blade 40, the cuts formed by the punching blades 43, 43 become discontinuous, so that the other punching blade 40
The edge of the cutting edge 43 of the
It is necessary to make the cutting edge 43 of each punching blade 40, 40 continuous in line with the above.

In order to make the cutting blades 43 continuous, as shown in FIG. 5 (II), the end edge of the other punching blade 40 may be formed along the side surface of the one punching blade 40. It is extremely difficult to bring the whole of the above into contact with the side surface of one punching blade 40, and it is practically impossible.

Therefore, as shown in FIG. 5 (III), if an inclined edge 44 larger than the inclination angle of the chamfer 42 in one punching blade 40 is provided at the end edge of the other punching blade 40, two sheets are provided. It is possible to easily match the cutting blades 43 of the punching blades 40, 40 of the above, but in this case, since the edge of the cutting blade 43 of the other punching blade 40 contacts the chamfer 42 at a point, the cutting blade 43 is punched at the time of punching the sheet. Due to the load acting on, the sharpened portion 45 at the intersection of the cutting edge 43 and the inclined edge 44 is likely to be damaged.

Therefore, conventionally, as shown in FIGS. 6 and 7, a groove 46 into which the edge of the other punching blade 40 is inserted is formed on the side surface of one punching blade 40, and the other punching blade 40 is formed. At the end edge of, a slanted edge 44 that abuts the chamfer 42 of one punching blade 40 is formed.

With the above construction, the punching load acting on both ends of the cutting blade 43 of the other punching blade 40 is supported by the chamfer 42 of the one punching blade 40, so that the end portion of the cutting blade 43 is cut off. It is possible to prevent the loss of
Since the contact width W between the chamfer 42 and the inclined edge 44 is reduced by forming the groove 46, the chamfer 42 is formed.
Compared with the case where the slanted edge 44 is brought into contact with the whole of the above, the slanted edge 44 is easily machined.

[0009]

The punching blades for forming the cross cuts shown in FIGS. 6 and 7 have the following disadvantages.

That is, since the pair of punching blades 40, 40 arranged in a cross shape are mounted by press-fitting into the slit-shaped tool mounting grooves 48a, 48b formed in the punching die 47, one punching blade 40 is formed. Groove 46
Is a blade mounting groove 48 into which the other punching blade 40 is press fitted.
It must be provided at a position facing b. When the forming position is deviated, the other punching blade 40 cannot be assembled. Therefore, when forming the groove 46, positional accuracy is required, processing is very time-consuming, and the mounting of one of the mounting blades 40 on the punching die is
Since it is necessary to mount the groove 46 so as to face the other punching blade 40, there is a problem in that the position is restricted and mounting is troublesome.

Further, it is necessary to form the groove 46 at an appropriate position each time according to the shape of the cross-shaped cut to be formed, and there is a problem that it takes time to manufacture a punching die having the cross-shaped cut.

SUMMARY OF THE INVENTION An object of the present invention is to provide a punching blade which is not restricted in the mounting position and a punching tool which can easily manufacture a punching die for forming cross cuts.

[0013]

In order to solve the above problems, in the punching blade according to the present invention, one side of the blade plate is used.
Form chamfers that incline in opposite directions on both sides of the part, and
Two punching blades with chamfer intersections as cutting edges,
The edge of the other punching blade faces the side of one punching blade.
To make cross cuts in the sheet.
In a punching blade that has been cut, the side of the one punching blade
Surface of the punching blade with a thin wall thickness over the entire length.
Step is formed, and the step edge is formed on the edge of the other punching blade.
The protrusion is provided on the above-mentioned part, and the above-mentioned
One of the punching blades has a chamfer that is supported by a chamfer .

[0014]

As described above, when the step portion is formed on the side surface of one punching blade, the other punching blade can be formed into a cross-shaped combination over the entire length of one punching blade.
There is no restriction on the position when mounting one punching blade to the punching die, the combination of arranging two punching blades in a cross shape is easy, and a punching die that forms a crossing cut is easily manufactured. You can

Further, since the inclined edge is supported by the chamfer of the one punching blade by the cross-shaped combination of the two punching blades, the load at the time of punching the sheet imparted to the end of the cutting blade of the other punching blade. Will be supported by the chamfer, and it is possible to effectively prevent the cutting edge from being damaged.

[0017] Here, when the edge bottom of the other punching blade provided projections for abutting the side surface of the thick portion of one of the punching blade, the abutment of the side surface of the projection and the thick portion, the other Since the punching blade of is prevented from moving in the length direction, the other punching blade can be stably attached to the punching die.

Further, by forming an inclined edge in the lower outer periphery of the protrusion in a direction away from the side surface of the thick portion, the other punching blade can be easily formed in the blade mounting groove formed in the punching die. Can be pressed into. [Detailed Description of the Invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 shows a punching hole 30 shown in FIG. 4 and a punching die for forming a notch 31 in a part of the outer periphery of the punching hole 30. The punching blade 10 attached to the template 1 of the punching die A comprises a combination of a first punching blade 11 for forming a punching hole and a second punching blade 21 for forming a cut.

As shown in FIGS. 2 and 3, the first punching blade 11 has a blade plate 12 made of a strip-shaped steel plate, and chamfers 13, 14 on both sides of one side of the blade plate 12.
Is formed, and a cutting edge 15 is provided at the intersection of the chamfers 13 and 14.

In the embodiment, the chamfer 13 formed on one side surface of the blade plate 12 is a two-stage chamfer, and the inclination angle of the first chamfer 13a formed on the cutting edge side is followed by the inclination angle of the second chamfer 13b. Although the number is larger, the number of stages of the chamfer 13 is not limited to this.
For example, it may be a one-stage chamfer, or may be a three-stage chamfer whose inclination angle increases toward the chamfer on the cutting edge side.

A step portion 16 is formed on the other side surface of the blade plate 12. Due to the formation of the step portion 16, the blade tip side of the blade plate 11 is formed as a thin wall portion 17 as a whole.

The first punching blade 11 having the above-mentioned structure is formed into the same shape as the punching hole 30 shown in FIG. 4 by bending with the other side having the step portion 16 formed on the outside, and as shown in FIG. , Is press-fitted into a slit-shaped blade mounting groove 2 formed in the template 1.

As shown in FIGS. 2 and 3, the second punching blade 21 has chamfers 23 and 24 formed on both surfaces at one side of a blade plate 22 made of a strip-shaped steel plate, and the chamfers 23 and 24 intersect each other. The cutting blade 25 formed on the
It consists of a center blade located in the center of the thickness. here,
The chamfers 23 and 24 may have any of 1 to 3 stages.

The second punching blade 21 is the first punching blade 1
1 is arranged so as to intersect with a part of the outer periphery of the mold 1, and as shown in FIG. 1, it is mounted by press fitting into a blade mounting groove 3 formed in the template 1.

First of the blade plate 22 in the second punching blade 21
A projecting portion 26 that overhangs the stepped portion 16 is formed at the upper part of the edge facing the punching blade 11. An inclined edge 27 that is supported by the chamfer 14 of the first punching blade 11 is formed at the end edge of the protruding portion 26, and the end of the cutting edge 15 of the second punching blade 21 is the cutting edge 15 of the first punching blade 11. Are in point contact with.

As shown in FIG. 2, a protrusion 28 that abuts against the side surface of the thick portion 18 of the first punching blade 11 is provided below the end edge of the second punching blade 21. An inclined edge 28a that is inclined in a direction away from the side surface of the thick portion 18 is formed in the lower outer periphery.

Here, as the blade plates 12 and 22 of the first punching blade 11 and the second punching blade 21, strip-shaped steel plates having a plate thickness of 0.7 mm are used, and the step portion 1 formed on the first punching blade 21 is used.
6 has a width of about 0.2 mm, but the blade plates 12, 22
And the width of the step portion 16 are not limited to this. For example, the thickness of the blade plates 12, 22 is 0.9 mm, 1.4 mm
The step portion 16 formed on the first punching blade 11 may be
The width dimension of is properly determined according to the thickness of the blade plate 12.

In the punching die having the above-mentioned structure, the punching tool A is pushed into the sheet to form a notch for forming a punch hole in the sheet and a notch extending in a cross direction from a part of the notch. After the punching, the punching scraps on the inner side surrounded by the notches for forming the punching holes are removed, whereby the punched product shown in FIG. 4 can be obtained.

At the time of punching the sheet, since the inclined edge 27 formed on the protruding portion 26 of the second punching blade 21 is supported by the chamfer 14 of the first punching blade 11, the cutting edge of the second punching blade 21 is cut. The punching load acting on the ends of 25 is supported by the chamfer 14 of the first punching blade 11. For this reason, it is possible to prevent the end of the cutting blade 25 of the second punching blade 21 from being damaged.

As shown in the embodiment, the first punching blade 1
The stepped portion 16 formed on the first protruding portion 21 of the second punching blade 21
When 6 is received, the cutting edge 25 of the second punching edge 21
Since the punching load acting on the end portion of the second punching blade 21 can be shared by the chamfer 14 of the first punching blade 11 and the step 16, the chipping of the end of the cutting blade 25 in the second punching blade 21 can be prevented more effectively. can do.

As shown in FIG. 4, when punching a product in which the notches 31 are continuous in the punching holes 30, the ends of the cutting blades 25 of the second punching blade 21 are aligned with the cutting blades 15 of the first punching blade 11. It is necessary to attach the first punching blade 11 and the second punching blade 21 to the die plate 1 of the punching die with a combination in which they are arranged in a cross shape.

At this time, as shown in FIG. 6, a groove 46 for positioning the end edge portion of the second punching blade 21 is formed on the first punching blade 11.
Is formed, as described above, the groove 46 has the second groove 46.
First to match the cutting edge of the blade where the punching blade 21 is attached.
It is necessary to mount the punching blade 11 with high precision, and it takes time to manufacture the punching die A.

However, since the step portion 16 is formed on the side surface of the first punching blade 11 and the second punching blade 21 can be formed in an intersecting combination over the entire step portion 16, the first punching blade 11 can be formed. Since the position accuracy is not required for the attachment of the punching die, the first punching blade 11 and the second punching blade 21 need only be press-fitted into each of the tool attachment grooves 2 and 3 formed in the die plate 1, so that the punching die is It can be easily manufactured.

A projection 28 that abuts the side surface of the thick portion 18 of the first punching blade 11 at the lower end of the edge of the second punching blade 21 which is arranged to intersect with a part of the first punching blade 11. With the provision of, the second punching blade 21 is prevented from moving in the lengthwise direction due to the abutting of the side surface of the thick portion 18 and the side surface of the protrusion 28,
The second punching blade 21 can be stably attached to the template 1.

In addition, an inclined edge 28a is formed on the lower portion of the outer periphery of the protrusion 28.
Is formed, the blade mounting groove 3 formed in the template 1
On the other hand, the second punching blade 21 can be easily press-fitted, and the mounting of the second punching blade 21 can be facilitated.

In the embodiment, as shown in FIG. 4, the punching of the product consisting of the punched hole 30 and the notch 31 has been described as an example, but the punched product is not limited to this, and the notch is T-shaped, H-shaped or not. It may be a cross-shaped product. When forming such a notch, the first
The chamfer 14 of the punching blade 11 supports the inclined edge 27 of the second punching blade 21 so that the first punching blade 11 and the second punching blade 21 are arranged in a combination of T-shape, H-shape or cross shape. .

Further, in the embodiment, an example in which the punching tool A is attached to the flat plate type die 1 is shown, but the shape is not limited to this, for example, a rotary punching type cylindrical die plate. It may be.

[0040]

As described above, according to the present invention, by forming the step portion having a thin blade edge portion of one punching blade on the side surface of one punching blade, the other of the punching blades is provided over the entire length of the other punching blade. The punching blades may be in a crossed combination such that the ends of the cutting blades coincide with the cutting edges of one of the punching blades.

Therefore, when the one punching blade is attached to the template, there is no restriction on the position, and since the width of the chamfer can be reduced by forming the step portion, the chamfer collides with the chamfer. The inclined edge is easily formed, and the punching die that forms the cross cuts can be easily manufactured.

Further, since the inclined edge formed at the end edge of the other punching blade is supported by the chamfer of one punching blade, the the end of the cutting edge of the other punching blade lacking the load during the sheet punching Can be effectively prevented.

[Brief description of drawings]

FIG. 1 is a perspective view showing a part of a punching die to which a punching tool according to the present invention is attached.

FIG. 2 is an enlarged sectional view showing a part of the punching blade of FIG.

FIG. 3 is a perspective view showing a part of the punching blade of FIG.

FIG. 4 is a perspective view showing a part of a punched product.

FIG. 5 (I) is a perspective view showing a conventional punching blade, (I)
(I) and (III) are cross-sectional views showing the punching blades arranged in a cross shape.

FIG. 6 is a sectional view showing a conventional punching blade.

FIG. 7 is a plan view of the punching tool shown in FIG.

[Explanation of symbols]

11 First punching blade 12 blades 13, 14 Chamfa 15 cutting edge 16 steps 17 Thin wall 18 Thick part 21 Second punching blade 22 blades 23, 24 Chamfa 25 cutting edge 26 Projection 27 Inclined edge 28 Projection 28a inclined edge

Claims (3)

(57) [Claims] 1. A chamfer inclined in opposite directions is formed on both sides of one side of a blade plate, and two punching blades each having a crossing portion of the chamfer as a cutting blade are provided on one side surface of one punching blade and the other cutting blade. In a punching blade in which the edges of the punching blades are combined so as to face each other so as to form a cross-shaped cut in the sheet, on the side surface of the one punching blade, the blade tip portion of the punching blade is made thin throughout the length. A step portion is formed, and a protruding portion projecting above the step portion is provided at the end edge of the other punching blade, and an inclined edge supported by the chamfer of the one punching blade is formed at the end edge of the protruding portion. A punching blade characterized by doing. 2. A punching tool according to claim 1, characterized in that a projection for abutting the side surface of the blade plate in one punching blade edge lower portion of the other punching blade. 3. The punching blade according to claim 2 , wherein an inclined edge that is inclined in a direction away from a side surface of the blade plate of the one punching blade is formed in a lower outer peripheral portion of the protrusion.