JPH03128132A - Press punching method - Google Patents

Abstract

PURPOSE:To provide the working method of high accuracy for the press punching by forming the pre-punched hole in the plate material, forming largely the half-punched projecting part to the reverse direction against this punching direction, and punching the needless part after pressing this projecting part. CONSTITUTION:The pre-punched hole 20a is formed with the 1st punch 21 of cutting blade along an outline of the inside of the needless part of the plate material 20. The half-punched projecting part 20b is formed to the reverse direction against the needles part punching direction with the 2nd punch 5 which is larger than its hole 20a and whose cutting blade is along the outline of its hole 20a in the inside of the needless part. The half-punched projecting part 20b is subjected to press in working toward the plate material 20 with the nockout 25. After then, the needless part if punched to the punching direction with the 3rd punch 8 whose cutting blade is opposed in correspondence with the needless part. Therefore, the press punching of the products whose width dimension is comparatively smaller against its plate thickness or the products of a small size of piches is possible.

Description

[Detailed Description of the Invention] [Summary] This is a press punching method for removing unnecessary parts of a plate material, with the aim of improving product accuracy. A preliminary punch hole is formed in the plate material with a first punch having cutting blades facing each other along the contour of the unnecessary portion inside the unnecessary portion, and a preliminary punch hole is formed inside the unnecessary portion and is larger than the preliminary punch hole. A second punch having cutting edges facing each other along the outline of the part is used to form a half-punched protrusion in the direction opposite to the direction of punching out the unnecessary part, and the half-punched protrusion is pushed into the plate material by knockout. , a third blade having opposing cutting edges corresponding to the unnecessary portions.
The unnecessary part is punched out in the punching direction using a punch.

[Industrial application field]

The present invention relates to a press punching process for plate materials, and more particularly to a press punching process for forming products with a relatively small width relative to the thickness of the plate material or products with small pinch intervals with high precision.

[Prior Art] The conventional press punching method uses a punch to remove unnecessary parts of a plate material. ,
A widely used processing method is to perform pre-processing (preliminary punching) with a first punch having a cutting edge corresponding to the inside of the unnecessary portion, and then shaving with a second punch having a cutting edge corresponding to the unnecessary portion.

The former has the advantage of being able to mass-produce products efficiently, but i
a) When punching products using the fine pouring method, there is a drawback that the products are easily deformed by the shearing force during punching, which limits the scope of its application.

In addition, in the latter case, since the pre-punched material is further shaved along the unnecessary parts, the punching allowance is reduced, and the shearing force when punching out the unnecessary parts is smaller than in the former case, making it suitable for shaving. The clearance of the mold can be made smaller than that of the former punching die, and the dimensional accuracy of the product can be improved more than that of the former case.

Therefore, these days, when a high degree of dimensional accuracy is required, such processing methods are often used.

FIG. 3 is a diagram illustrating a conventional shaving method, FIG. 4 is a process diagram illustrating an example of a recent shaving press punching method, and FIG. 5 is a diagram illustrating problems.

In the figures, all are shown as cross-sectional views for ease of understanding.

In FIG. 3(A), 1 indicates a plate material with a thickness L that is a material, a indicates an unnecessary part to be removed, C indicates the outline of the unnecessary part a, and furthermore, C indicates the outline of the unnecessary part a. A punch hole 1a (not shown) is punched approximately in the center of the hole 1a along the contour 1 of the unnecessary portion a.

Therefore, a punch 2 having a cutting edge corresponding to the above-mentioned unnecessary part a.
At a predetermined position between a die 3 having a through-hole 3a facing to the stripper 4 and a stripper 4 having a through-hole into which the punch 2 is fitted,
When the plate material 1 is inserted, the state shown in (b) will be obtained.

Next, as shown in (c), when the punch 2 whose clearance δ between the cutting edge and the through hole 3a is generally 1 to 2% of the plate thickness is lowered with a stroke exceeding the plate thickness, the punch 2 is lowered with a stroke exceeding the plate thickness. The outer periphery of is scraped off to remove the required unnecessary portion a.

In this case, the punching allowance (shaving) can be reduced by appropriately setting the holes 1a in the letter L, which allows processing with small shearing force, resulting in a product with high dimensional accuracy. can do.

However, the fine and lightweight punching shavings S generated during shaving tend to adhere to punches, etc., and the punching scum S is difficult to remove, causing scraps to rise, resulting in product defects and mold breakage. There is a thing.

Therefore, improvement measures are being considered to avoid this drawback.

In FIG. 4, (1) is a cross-sectional view of the plate material 1 (thickness L) before processing, and the broken line l in the figure indicates the outline of the unnecessary portion a.

In addition, in (2), a lower mold plate 6 into which a punch 5 having a cutting edge formed at least inside the unnecessary part a of the plate material 1 is fitted from below so as to be vertically movable, and a position facing above the punch 5. When the plate 1 is sandwiched between the plate 1 and a diamond having a through hole 7a and the punch 5 is pushed up with a stroke that does not exceed the thickness L of the plate 1, a half-punched protrusion ( lb (hereinafter simply referred to as a protrusion) is formed.

Therefore, after removing the plate material 1 from between the lower template plate 6 and the diamond,
A stripper 9 has a through hole into which a punch 8 having a cutting edge formed along the outline l of an unnecessary part a of the plate material 1 is fitted from above so as to be able to move vertically, and a through hole 10a is provided at a position opposite to the punch 8. When the punch 8 is sandwiched between the die 10 so that the protruding part 1a of the plate l is opposed to the punch 8, the protruding part 1b of the unnecessary part a is pushed back into the plate l by the punch 8 ( 3) is reached.

Next, when the punch 8 is further moved downward to the state shown in (4), the area along the outline of the protruding part 1b and the unnecessary part a outside thereof is sheared together, and as a result, shown in (5). The unnecessary portion a is removed from the plate material 1 as shown in FIG.

In such a case, the inside of the unnecessary part a is once half punched in the opposite direction to the punching direction, and then the unnecessary part a is punched out in a predetermined direction. It means.

Therefore, even if the mold clearance is set to the same value as a conventional shaving mold (l~2% of the plate thickness), the minute scraps that occur during conventional shaving will not be generated, and as a result, the product will be finished. This eliminates defects and mold damage, making it possible to achieve highly productive and highly accurate punching.

In Fig. 5 for explaining the problem, ■ is a cross-section of the unprocessed plate material 1 (thickness) similar to Fig. 4 (1); 33 contours are shown.

(2) is a pre-process for punching out and removing the first unnecessary portion a of the plate material 1, using the punch 5 described in FIG. 4 (2). A protrusion 1b similar to that shown in FIG. 4 is formed at least inside the unnecessary portion a1 of the plate l using a lower mold plate 6 and a diamond.

In this case, due to the shearing force during processing, the plate material (CI+C
Stretching C1, C1 occurs in the I direction, and a relative positional shift occurs between the protruding portion 1b and the unnecessary portion at (as a result, the contour N).

As a result, the punch 8. for shaving off the unnecessary part a explained in FIG. 4(3). As shown in process (■) using the stripper 9 and the die lO, the unnecessary part at (
With respect to the contour 11), the protruding portion ib (contour i,'') is biased to the left side, for example, as shown in the figure, and the area shaved by the punch 8 becomes non-uniform.

In particular, this misalignment results in breaking the shearing conditions at the cutting edges on both sides of the punch 8, and together with the fact that the plate material 1 is being pressed by the stripper 9, the remaining portion (product) on the end surface side is pulled in the direction d in the figure. It will be crowded.

The diagram in the circle ■-1 shows the deformation caused by the misalignment using a comb-blade-shaped terminal as an example, and when removing the unnecessary part a, the comb-blade-shaped terminal 1e falls toward the unnecessary part a1. It shows.

On the other hand, at the time of (①), the second unnecessary part a has already been formed in the previous process.
A protrusion 1b corresponding to 2 is formed, but especially when the second unnecessary part a2 is close to the first unnecessary part a1, the repulsive force e of shearing by the punch 8 is applied to the protrusion. By acting on the portion tb, the protruding portion 1b, which should remain at rest in a half-opened state, is separated from the plate material l as indicated by lb' shown in (■).

(2) shows a state in which the second unnecessary portion a2 of the plate material 1 is punched out and removed by the same method as (2).

In this case, the processing method is similar to the conventional general processing method explained in FIG. 3, and the fine and lightweight punched debris generated during shaving causes product defects and damage to the mold.

[Problem to be solved by the invention]

Recent improved shaving punching methods have problems such as deformation of the product, product defects, and mold breakage, especially when the unnecessary parts to be removed are close together or the processing pitch is small.

[Means for Solving the Problems] The above-mentioned problem lies in the press punching method for removing unnecessary parts of a plate material, which has cutting edges that are opposed to each other along the contour of the unnecessary part inside the unnecessary part of the plate material. A first punch forms a preliminary punching hole in the plate material, and a second punch having a cutting edge that is larger than the preliminary punching hole and faces inside the unnecessary portion along the contour of the unnecessary portion is used to punch the unnecessary portion. After forming a half-punched protrusion in the opposite direction to the punching direction and pushing the half-punched protrusion into the plate material by knockout, a third punch having an opposing cutting edge corresponding to the unnecessary part is used to punch out the half-punched protrusion. This problem is solved by a press punching method in which unnecessary parts are punched out in the punching direction.

[For production]

If the shearing force applied to the plate material during punching is absorbed inside the punched part, the shearing force transmitted from the punched part to the outside can be weakened.

In the present invention, by forming in advance a preliminary hole smaller than the half-blanked protrusion inside the protruding part, the elongation of the plate material that occurs when forming the protruding part is absorbed by the preliminary hole, and the protruding part is pushed into the plate material. I try to remove unnecessary parts by shaving.

Therefore, even if the unnecessary parts to be removed are close to each other or the machining pitch is small, the product will not be deformed, and the protruding parts will not separate from the plate material, so there will be no generation of scraps, resulting in product defects or mold damage. It does not induce

(Example) FIG. 1 is a process diagram illustrating the press punching method according to the present invention, in which (A) shows the raw material, (B) the first step, (C) the second step, (D) represents the third step.

Further, FIG. 2 is a sectional view of the structure of a processing apparatus that implements the second step (C) of the present invention.

In FIG. 1, (A) shows a cross section of the plate material 20 (thickness t) before processing, and the broken line l in the figure represents the outline of the unnecessary part a.

Therefore, as shown in Figure (B), a preliminary punching hole 20a is formed in the center area inside the unnecessary part a of the plate material 20 using a punch 21 having a cutting edge shaped approximately along the outline l of the unnecessary part a. .

In addition, 22 in the figure indicates a stripper into which the punch 21 fits, and 23 indicates a through hole 2 at a position corresponding to the punch 21.
3a is shown.

Therefore, similarly to FIG. 4(2), the punch 5, which is larger than the preliminary punch hole 20a and has a cutting edge along the contour i, is fitted from below inside the contour C of the unnecessary part a of the plate material 20. When the plate material 20 is sandwiched between the template 6 and the diamond corresponding to the punch 5 so that the preliminary punch 7L20a is located at the center, and the punch 5 is pushed up with a stroke that does not exceed the thickness L of the plate material 20, As shown in Figure (C-1), a half-punched protrusion (hereinafter referred to as a protrusion) 20b can be formed.

In this case, since the preliminary punching hole 20a is previously formed approximately at the center of the protrusion 20b, the elongations cl and cz of the plate material shown in FIG.

Therefore, the unnecessary part a and the protruding part 20b explained in FIG.
Since no misalignment occurs between the two, the product will not be deformed.

Then, when the punch 5 is lowered and the protrusion 20b is pressed down from above with a knockout 25 having approximately the same diameter as the punch 5, the protrusion 20b is pushed into the plate material 20, resulting in the state shown in Figure (C-2). It can be done.

Next, as explained in FIG. 4(3), a stripper 9 having a through hole into which the punch 8 having a cutting edge formed along the contour l of the unnecessary part a of the plate material 20 is fitted corresponds to the punch 8. When the punch 8 is moved downward so that the protrusion 20b of the plate material 20 is sandwiched between the die 10 and the punch 8 and passes through the plate material 20, the unnecessary portion a is sheared and pushed out. Then, through figure (D-1), figure (D-
It is removed from the plate material 20 as shown in 2).

In particular, the shearing force caused by the punch 8 in this case also applies to the preliminary punch hole 2.
Since it is absorbed by 0a, the shearing repulsive force e explained in FIG. 5 (■) does not occur.

Therefore, even if the protrusions 20b are formed in close positions, the detachment of the protrusions as explained in FIG.
As a result, the phenomenon shown in FIG. 5 (■) is eliminated, and product defects and mold breakage due to minute scraps that occur during conventional shaving processing do not occur.

Fig. 2 shows the configuration of a processing device that realizes the C (C-1, C-2) process in Fig. 1, and the parts explained in Fig. 1 are given the same numbers as in Fig. 1. .

In FIG. 2, 20 represents a plate material.

Further, a half-blanking bunch 5 is fixed upright on a die backing plate 32 fixed on the die holder 31, and a lower part is provided with a through hole approximately in the center into which the punch 5 fits. The template 6 is attached to the die backing plate 32 with the punch 5 slidably assembled in the through hole.
A pair of bins 33. It is always urged upward by a support plate 34 that supports the bin 33 and a compression coil spring 35 that elastically supports the support plate 34, and in particular, its upper surface is provided with a stop block that locks a part of the lower mold plate 6. 36 so that it is aligned with the upper surface of the punch 5 when not in operation.

The upper surface of the punch 5 is designed to protrude by an appropriate amount from the upper surface of the die plate i.37 fixed on the die banking plate 32.

Therefore, when the lower mold plate 6 is pressed down against the compression coil spring 35, the fixed punch 5 is moved relative to the lower mold plate 6.
It will stand out from the

On the other hand, at a position corresponding to the punch 5 of the stripper plate 38 facing above the die plate 37, a diamond having a through hole into which the punch 5 fits is arranged, and a through hole of the diamond is arranged. The portion accommodates a knockout 25 that is movable up and down within the through hole.

In particular, the knockout 25, which can be moved up and down by an appropriate amount by a stop block 39 and an adjustment plate 40 that adjusts the amount of movement, is connected to a pin 41 that passes through the adjustment plate 40 and can be moved up and down. It is connected to a compression coil spring 44 via an extrusion punch 42 fixed to the upper end of the bin 41 and a bin 43 fixed to the extrusion punch 42, and is constantly urged downward by the compression coil spring 44. .

In the figure, 45 is a support plate that holds the stripper plate 38, 46 is a punch plate that guides the extrusion punch 42, and 47 is a punch holder that holds the punch plate 46 via a punch backing plate 48.

In the processing apparatus configured in this way, when the plate material 20 is placed on the lower mold plate 6 and the punch holder 47 is lowered from above the support plate 45 via the punch backing plate 48, the upper surface of the plate material 20 is first The lower surface of the knockout 25 comes into contact with the punch holder 47, but when the punch holder 47 descends, the knockout 25 is pushed up against the compression coil spring 44 while remaining in contact with the upper surface of the plate 20, and the lower surface of the diamond is pushed up through the plate 20. Press the upper surface of the lower mold plate 6.

Therefore, the lower mold plate 6 is pushed down, and as a result, the punch 5 protrudes to the state shown in FIG. 1 (C-1), thereby forming the half-punched protrusion 20b.

At this point, the knockout 25 is pressing the upper surface of the half-punched protrusion 20b with the pressing force of the compression coil spring 44.

Therefore, when the punch holder 47 is raised, the lower mold plate 6 is raised and the punch 5 is relatively lowered.

Therefore, the half-punched protrusion 20b pressed downward by the knockout 25 can be pushed into the plate material 20 to be in the state shown in FIG. 1 (C-2).

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a press punching method that can form products with a relatively small width relative to the thickness of the plate material or products with small pitch intervals with high precision.

[Brief Description of the Drawings] Fig. 1 is a process diagram illustrating the press punching method of the present invention, Fig. 2 is a cross-sectional view of the structure of a processing device that realizes the second step (C) of the present invention, FIG. 3 is a diagram explaining a conventional shaving processing method, FIG. 4 is a process diagram showing an example of a recent shaving press punching method, and FIG. 5 is a diagram explaining problems. In the figure, 58.21 is a punch, 6 is a lower template, 7.10.
23 is a die, 9 and 22 are strippers, 20 is a plate material, 20a is a preliminary punching hole, 20b is a half punching protrusion, 23a is a through hole, 25 is a knockout,
31 is a die holder, 32 is a die backing plate, 33.41.43 is a pin, 34.45 is a support plate,
35.44 is a compression coil spring, 36.39 is a stop block, 37 is a gui plate, 38
is a stripper plate, 40 is an adjustment plate, 42 is an extrusion punch, 46
47 represents a punch plate, 47 represents a punch holder, and 48 represents a standard punch backing plate. This month's calendar 1-9 Robushu Sukigo Nuki 3 Caloe way Husband name V Monthly work 1 Presentation figure 35 Compression carp 1 and C Gone water plane Hu's 2nd C 2nd layer and the processing equipment to be realized Diagram of the composition of the book, Figure (a).

Claims (1)

[Claims] A press punching method for removing an unnecessary part of a plate material, comprising: a first punch (20) having cutting edges facing inside the unnecessary part along the outline of the unnecessary part of the plate material (20); In step 21), a preliminary punching hole (20a) is formed in the plate material (20), and a second hole having cutting edges larger than the preliminary punching hole (20a) and facing along the outline of the unnecessary portion inside the unnecessary portion. 2 punch (
5), half punch out the protruding part (
20b) is formed, and the half-punched protrusion (20b) is pushed into the plate material (20) using a knockout (25), and then a third punch (20b) having opposing cutting edges corresponding to the unnecessary part is inserted
8) A press punching method characterized in that the unnecessary portion is punched out in the punching direction.