JPH0428655Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to an external shape cutting die for punching out a product of a predetermined shape from a material, and in particular, a scrap cutting die for cutting into a plurality of pieces an annular scrap generated around the product by punching. This invention relates to an improvement of a contour cutting die equipped with a cutting edge.

BACKGROUND TECHNOLOGY It has already been done to divide scrap into a plurality of pieces by providing a cutting edge for cutting scrap in an outline cutting die. What is shown in FIGS. 7 to 9 is an example.

In this external shape cutting die, the upper die, which is moved vertically, works together with the lower die to punch out the material.
A part of the upper mold 100 is shown in FIG. The upper mold 100 has an annular block shape, and its lower surface 1
A first main cutting edge 104 having a shape corresponding to the outer circumferential shape of the product is formed on the inner peripheral edge of the cutter 02. The upper die 100 is also formed with a plurality of first scrap dividing cutting edges 106 extending outward from the first main cutting edge 104 on the outside of the first main cutting edge 104 . This cutting edge 106 is formed to intersect with the first main cutting edge 104, and the cutting edge 106 of the first main cutting edge 104
A stepped portion 110 that recedes upward from the intersection with the cutting edge 106 is formed in a portion adjacent to the first main cutting edge 106, forming a recessed portion 111 in which a portion of the first main cutting edge 104 is recessed from the other portion.

On the other hand, the lower mold 112 shown in FIG.
A second main cutting edge 118 formed in a shape corresponding to the first main cutting edge 104 is formed on the outer peripheral edge of the end face of the block 116 on which the block 14 is placed, and a second main cutting edge 118 is provided in close contact with the outer peripheral surface of the block 116. 120 and a second scrap cutting blade 122 having a shape corresponding to the first scrap cutting blade 106. Second scrap cutting blade 122
is arranged a short distance below the second main cutting edge 118, but when viewed from directly above, the end of the second scrap dividing cutting edge 122 on the second main cutting edge 118 side and the second main cutting edge 118 There is no gap between the two.

In this profile cutting die, as the upper die 100 descends, the material 114 is first sheared by the cooperation of the second main cutting edge 118 and the portion of the first main cutting edge 104 other than the retreated portion 111. A recessed portion 111 provided adjacent to the first scrap dividing cutting edge 106 just corresponds to the block 120, and the first main cutting edge 104 connects to the second main cutting edge 118 at this retracted portion 111. On the other hand, interference with the second scrap cutting blade 122, which is provided without a gap, can be avoided. At this stage, the part of the material 114 facing the retreating part 111 is not sheared, and the upper mold 10
0 is further lowered, the retreating portion 11
1 and the second main cutting edge 118, and the material 114 is punched out over its entire circumference. Then, when the upper mold 100 is further lowered from this state, the cutting blades 106, 122 for separating both scrubbers
The scrap generated around the product is divided into multiple pieces.

Problems to be Solved by the Invention In this outline cutting die, when the material 114 is sheared by the portion of the first main cutting edge 104 other than the recessed portion 111, as shown in FIGS. 8 and 9, The crack 124 is generated along a line different from the contour that is expected to be sheared by the retreating part 111, and the part near the crack is further sheared by the retreating part 111, producing fine chips. If the punching process is continued in an environment where there are many cutting chips, the cutting chips will adhere to the surface of the product, causing so-called "bumps" and degrading the surface quality of the product.

Additionally, once a crack has formed, it is difficult to shear cleanly, and burrs are likely to appear on the outer periphery of the product, resulting in poor quality.Furthermore, shearing is not performed continuously over the entire circumference of the product. Therefore, surface distortion occurs in the portion that will be sheared later, and this also causes a problem that the quality of the product deteriorates.

In addition, the second scrap dividing cutting edge 122 and the second main cutting edge 118 are different from the second scrap dividing cutting edge 122 and the second main cutting edge 118.
There was also the problem that it was difficult to form each cutting edge because the two were arranged without any gaps in the longitudinal direction.

Means for Solving the Problems The present invention solves the above problems by (a) forming a first main cutting edge with a shape corresponding to the outer peripheral shape of the product on the inner peripheral edge of the annular end face; and (b) a first mold in which a plurality of first scrap dividing cutting edges extending outward from the first main cutting edge are formed on the outside of the first main cutting edge; A second main cutting edge having a shape corresponding to the first main cutting edge is formed on the periphery, a plurality of second scrap cutting edges corresponding to each of the first scrap cutting edges are formed, and the first In an external shape cutting die with a cutting blade for scrap separation, which includes a second die that works together with the die to punch out the product and divide the scrap, the first main cutting edge is set in the direction of relative movement between the first die and the second die. The first scrap dividing cutting blade is formed in a closed curve having no step part, and the first scrap dividing cutting blade is formed at a position apart from the first main cutting blade in the longitudinal direction, while the second scrap dividing cutting blade is formed at a position apart from the first main cutting blade in the longitudinal direction. A gap in the longitudinal direction of the second scrap dividing cutting blade is formed between the cutting blade and the second main cutting edge, and a portion of the second scrap dividing cutting blade near the second main cutting blade is A movement preventing means is provided which is inclined in a direction away from the first die as it approaches the main cutting edge, and which prevents the scrap from moving to a portion outside the inclined portion of the second scrap dividing cutting edge. It was established.

Here, "the first main cutting edge does not have a step in the direction of relative movement between the first die and the second die" means that there is no discontinuity point in the first main cutting edge and the shearing by the main cutting edge is This means that it is done simultaneously or consecutively all around the product.

Function In the external cutting die configured as above,
Since the first main cutting edge is formed so as not to have a stepped portion, it continuously shears the material over the entire circumference. At this time, interference between the first main cutting edge and the second scrap cutting edge is avoided by the gap formed between the second main cutting edge and the second scrap cutting edge.

Furthermore, since the movement of the outer circumferential side of the annular scrap caused by punching is prevented by the movement prevention means, the inner circumferential portion of the scrap is moved to the second scrap cutting cut as the two dies move relative to each other after punching. The scrap is bent along the inclined portion of the blade and separated from the second main cutting edge, and in this state the scrap is divided into a plurality of pieces by the first and second scrap cutting edges.

Effects of the invention As described above, in the outer shape cutting die according to the present invention,
Since shearing is carried out continuously around the entire circumference of the main cutting edge, there is no cracking in the material as in conventional methods, and quality deterioration due to the generation of chips, burrs, and burrs is avoided. Moreover, a high quality product can be obtained without deterioration in quality due to occurrence of surface distortion.

Furthermore, since a gap is formed in the longitudinal direction of the second scrap dividing cutting blade between the second main cutting edge and the second scrap dividing cutting blade, it is possible to easily form these cutting blades. can.

Embodiments Hereinafter, the present invention will be described in detail based on the drawings, taking as an example a case in which the present invention is applied to a profile cutting die that includes an upper die and a lower die and performs punching by moving the upper die up and down.

FIG. 1 is a diagram showing a part of an upper mold 10 as a first mold viewed from below. The upper mold 10 has an annular block shape, and the inner peripheral edge of the lower surface 12 has a product 14 obtained by punching with the main outer cutting mold.
A first main cutting edge 16 is formed in a shape corresponding to the outer circumferential shape (see FIG. 4). FIG. 4 shows the blank being punched out and the resulting scrap being separated into a product 14 and four scrap pieces 18.

The first main cutting edge 16 is formed in a plane perpendicular to the direction of movement of the upper mold 10 so as to form a continuous closed curve having no step in the direction of movement. Further, on the outer side of the first main cutting edge 16 on the lower surface 12, a first scrap cutting edge 20 extending outward is formed. The first scrap dividing cutting edge 20 has a first main cutting edge 1 in its longitudinal direction.
A partition wall 2 is formed between the first main cutting edge 16 and the recess 22 provided to form the first scrap dividing cutting edge 20.
4 is formed. Although not shown, this first scrap cutting blade 20 is connected to the upper die 10.
They are formed at four locations spaced apart at equal angles.

In addition, a recess 25 shallower than the recess 22 is formed in a portion of the lower surface 12 adjacent to the recess 22, and there is a gap between the recess 25 and the main cutting edge 16 (the length of the first scrap cutting blade 20). distance in direction)
A partition wall portion 26 is formed which is thicker than the partition wall portion 24. A protrusion 28 that is long in the circumferential direction of the upper mold 10 is formed on the bottom surface of the recess 25, and the top end of this protrusion 28 is at the same height as the lower surface 12. In addition, for convenience of manufacture, the upper die 10 is made into four parts separated by the first scrap cutting blade 20 and then assembled integrally.

What is shown in FIG. 2 is the lower mold 3 as the second mold.
It is 0. The lower mold 30 includes a plate-shaped base 32, and a block 34 provided at the center of the base 32 has a block 34 on the top of which has a shape corresponding to the product 14 and has a mounting plate on which the product part of the material is placed. A placement portion 36 is formed. A second main cutting edge 40 having a shape corresponding to the first main cutting edge 16 is formed on the outer peripheral edge of the end surface of the mounting portion 36 on the upper mold 10 side. Further, four legs 42 are formed at equal angular intervals around the block 34 of the base 32, and a longitudinal block 44 is fixed onto each leg 42, respectively. As shown in FIG. 3, each block 44 is fixed to the block 34 with a gap in its longitudinal direction. Each block 44 has the first scrap cutting blade 20.
A second scrap dividing cutting blade 46 corresponding to the second scrap dividing cutting blade 46 is formed.
The part on the side closer to the second main cutting edge 40 curves smoothly so as to move away from the upper die 10 as it approaches the second main cutting edge 40, and forms a convex arc toward the upper die 10 side. A curved portion 48 is formed.

The upper surface of the block 44 has a recess 50 that crosses the block 44 in the circumferential direction of the second main cutting edge 40.
is formed. This recess 50 intersects with the second scrap cutting blade 46, and the intersecting part is also a cutting blade and forms a part of the second scrap cutting blade 46. . The concave portion 50 and the protrusion 26 constitute a movement preventing means for holding down the scrap produced by punching the material and preventing its movement as described later.

Next, a description will be given of the operation of punching out a material using the outer shape cutting die configured as described above.

During punching, the upper die 10 is lowered, and the first main cutting edge 16 and the second main cutting edge 40 work together to simultaneously shear the entire length of the cutting edges 16 and 40, and the material is separated into the product 14 and the annular scrap. 56
(See Figure 5). At this time, by fitting the partition wall portion 24 into the gap between the second main cutting edge 40 and the second scrap cutting edge 46,
The first main cutting edge 16 and the second scrap dividing cutting edge 46
Therefore, interference with the first main cutting edge 16 can be avoided.
In this external cutting die, which has no step in the direction of movement of the upper die 10 and is formed to form a closed curve in one plane, punching is performed simultaneously over the entire length of the main cutting edge in one plane. It will be destroyed.

After the material is punched out, the upper mold 10 is further lowered so that the protrusion 26 intersects the recess 50, and the part of the annular scrap 56 cut off from the product 14 outside the curved part 48 is Fifth
A bead 58 is formed by recessing within the recess 50 as shown in FIG. This bead 58
The outer periphery of the scrap 56 is fixed to the block 44 by engagement with the recess 50, and in this state the inner periphery of the scrap 56 is bent along the curved portion 48, so that the inner periphery of the scrap 56 is bent into the recess. He is drawn to the 50 side. Furthermore, the formation of the bead 58 itself causes the inner peripheral portion of the scrap 56 to be drawn toward the recess 50 side. Therefore, the first and second scrap cutting blades 20, 46
Despite the fact that the ends of the first and second main cutting edges 16, 40 are spaced outward from both the main cutting edges 16, 40, the scrap 56 is connected to both the scrap dividing cutting edges 20, 46. It is then sheared without any trouble.
It is divided into four scrap pieces 18.

In this external shape cutting die, the size of the gap between the second main cutting edge 40 and the second scrap dividing cutting edge 46 is a,
When the upper mold 10 is lowered to the lowering end position shown by the dashed line in FIG. It is determined in this way. The partition wall portion 24 needs to have a certain thickness in order to ensure strength, and therefore, the size a of the gap into which the partition wall portion 24 fits should be larger than that thickness. is necessary. Furthermore, if the insertion depth b is too long, problems such as so-called "bulging" will occur, so it is necessary to keep it below a certain value. Under such constraints, when the gap size a and the insertion depth b are appropriately selected, and the shape of the curved portion 48 is appropriately set,
The scrap 56 is placed along the curved portion 48, and the position of its inner peripheral edge is determined. And that position is at depth b
If the scrap 56 is located above the lower end of the partition wall 24 that has been inserted, the scrap 56 can be sheared;
This means that the gap size a, the insertion depth b, and the shape of the curved portion 48 are appropriate. However, scrap 5
6 is located below the lower end of the partition 24, the portion near the inner periphery will not be sheared. Therefore, the shape of the curved portion 48 is changed so that the inner periphery is located below the lower end of the partition 24. Position it higher up. Note that, as mentioned above, the formation of the bead 58 also causes the inner peripheral edge of the scrap 56 to rise, so this rise can be used as a margin to ensure reliable shearing, and this rise can also be used as a margin. The dimensions of each part can also be determined taking this into account.

As described in detail above, the profile cutting die of this example can simultaneously punch out the material around the entire circumference of the main cutting edge, thereby eliminating the generation of chips, bumps, burrs, and surface distortion, resulting in high quality. Product 14 can be obtained.

Further, the annular scrap 56 after the product 14 is punched out is restrained by the protrusion 28 and the recess 50, and the inner circumference of the scrap 56 is pulled toward the recess 50 by the formation of the bead 58. Therefore, the component of the shear line for dividing the scrap 56 in the mold movement direction can be short,
The amount of biting of the first main cutting edge 16 into the second main cutting edge 40 (the insertion depth b of the partition wall portion 24) can be reduced.

Further, as the second scrap dividing cutting edge 46 approaches the second main cutting edge 40, it smoothly curves away from the upper mold 10, and curves convexly toward the upper mold 10 (in this embodiment, Since it is tilted so as to form an arc (circular arc), the distance from the inclination start part (curved start part) to the terminal end part can be longer than when it is tilted linearly. That is, it is possible to increase the width of the inner circumference of the scrap 56 that is bent along the inclined portion of the second scrap cutting cutting edge 46, and thereby it is possible to increase the size a of the gap. As a result, the strength of the partition wall portion 24 can be easily ensured.

However, the portion of the second scrap dividing cutting edge 46 closer to the second main cutting edge 40 may be inclined along a straight line that moves away from the upper die 10 as it approaches the second main cutting edge 40. It may also be a shape.

Further, in the above embodiment, in the upper die 10, the first main cutting edge 16 and the first scrap dividing cutting edge 2 are
0 are formed in the same block, but they may be provided in separate blocks.Also, in the lower die 30, the second main cutting edge 40 and the second scrap dividing cutting edge 46 may be formed into an integrated block. It may be provided.

Further, it is also possible to use a presser pad attached to the first mold via an elastic member as a movement prevention means for preventing movement of the outer peripheral portion of the annular scrap.

Furthermore, the present invention is not limited to an outline cutting die in which punching is performed in one plane, but can also be applied to an outline cutting die in which punching is performed along a closed curve drawn in a three-dimensional space.

Although not illustrated in detail, the present invention can be implemented in various modifications and improvements based on the knowledge of those skilled in the art.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a main part of an upper die of an external shape cutting die according to an embodiment of the present invention, and FIG. 2 is a perspective view showing a lower die. FIG. 3 is a front sectional view showing the main parts of the lower mold. FIG. 4 is a perspective view showing a state in which a product is punched out from the material by the cutting die and the scrap is divided. 5 and 6 are a perspective view and a front sectional view, respectively, showing the scrap cutting process using the cutting die.
FIG. 7 is a perspective view showing the upper die of a conventional outer shape cutting die, and FIGS. 8 and 9 are a perspective view and a front sectional view, respectively, showing the process of punching out a material using the outer shape cutting die. 10...Top mold, 12...Bottom surface, 14...Product,
16...First main cutting edge, 20...First scrap dividing cutting edge, 28...Protrusion, 30...Lower mold, 40...
...Second main cutting edge, 46...Second scrap dividing cutting edge, 48...Curved portion, 50...Concave portion, 56...Scrap.

Claims (1)

[Claims for Utility Model Registration] (1) A product of a predetermined shape is punched out of a material, and the annular scrap produced around the product by the punching is cut into multiple pieces by cutting out the above-mentioned parts on the inner periphery of the annular end face. A first main cutting edge having a shape corresponding to the outer peripheral shape of the product is formed, and a plurality of first scrap dividing cutting edges extending outward from the first main cutting edge are formed on the outside of the first main cutting edge. A second main cutting edge having a shape corresponding to the first main cutting edge is formed on the outer peripheral edge of the end face on the first die side, and each of the first scrap cutting cutting edges A plurality of second scrap cutting blades corresponding to the above-mentioned second mold are formed, and the second mold cooperates with the first mold to punch out the product and divide the scrap. The first main cutting edge is formed into a closed curve having no step in the direction of relative movement between the first die and the second die, and the first scrap dividing cutting edge is formed from the first main cutting edge to the first cutting edge. The scrap cutting blade is formed at a distance in the longitudinal direction, and a gap is formed in the longitudinal direction of the second scrap cutting cutting blade between the second scrap cutting blade and the second main cutting blade. At the same time, the portion of the second scrap dividing cutting edge that is closer to the second main cutting edge is tilted in a direction that moves away from the first mold as it approaches the second main cutting edge, and ,
An external cutting die with a scrap cutting blade for scrap cutting, characterized in that a movement preventing means is provided for preventing movement of the second scrap cutting blade to a portion outside the inclined portion. (2) The scrap cutting blade according to claim 1, wherein the inclined portion of the second scrap cutting blade forms a curve that is smoothly curved convexly toward the first mold side. Outline cutting die. (3) The movement prevention means includes a protrusion formed on the first mold adjacent to the first scrap cutting blade, and a protrusion formed on the second mold adjacent to the second scrap cutting blade. A cutting blade for cutting scrap according to claim 1 or 2, which comprises a recessed part formed therein, and which restrains a part of the scrap while being curved by the protruding part and the recessed part. Outline cutting die.