JP2669035B2 - Press punching method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] A press punching method for removing an unnecessary portion of a plate material, for the purpose of improving product accuracy, the inside of the unnecessary portion of the plate material to be removed by the press punching is opposed to the unnecessary portion. Using a first punch having a cutting edge to perform half-punching in a direction opposite to the unnecessary part punching direction, and then using a second punch having a cutting edge facing the unnecessary part, in the punching direction. It is characterized by punching out unnecessary parts.

[Industrial applications]

The present invention relates to a press punching method for removing unnecessary portions of a plate material, and more particularly to a press punching method for forming a product having a width relatively small with respect to the thickness of the plate material with high precision.

[Conventional technology]

In the conventional press punching process that uses a punch to remove unnecessary parts of a plate material, a punch with a cutting edge facing the unnecessary part shears the unnecessary part and corresponds to the inside of the unnecessary part A processing method of performing pre-processing (preliminary punching) with a first punch having a cutting edge to perform shaving with a second punch having a cutting edge corresponding to an unnecessary portion is widely used.

FIG. 7 is an explanatory diagram of the most common press punching method of a punch, and FIG. 8 is an explanatory diagram of the shaving method.

In FIG. 7, a plate material 1 is sandwiched between a die 3 having a through hole 4 facing the punch 2 and a stripper 5 having a through hole 6 through which the punch 2 can penetrate, and the plate material 1 is inserted from above the die 3.
The punch 2 is lowered until the cutting edge is inserted into the through hole 4 because the cutting edge facing the unnecessary portion is formed and generally has a clearance of about 4 to 8% with respect to the through hole 4. , The chip 7 of the unnecessary portion sheared from the plate material 1 through hole 4
It drops more and is removed from the equipment.

In FIG. 8 (a), a die 13 having a through hole 14 facing a punch 12 having a cutting edge facing an unnecessary portion is provided.
Before the punching of the through hole 11 by the first punch (not shown) having a cutting edge formed inside the unnecessary portion between the stripper 15 having the through hole 16 through which the punch 12 can freely penetrate. The processed plate material 1 is sandwiched.

Next, as shown in FIG. 8 (b), the punch 12 whose clearance between the cutting edge portion and the through hole 14 is generally about 1 to 2% is moved downward, and the cutting edge portion of the punch 12 is moved into the through hole 14. When it is inserted, the outside of the through hole 11 is cut off along the contour of the unnecessary portion, and the chip 16 falls and is removed outside the apparatus.

[Problems to be solved by the invention]

In the conventional general press punching method,
Unnecessary portions are removed, and the product 9 formed on the plate material 1 is subjected to a punch 11 or a punch 11 by a shearing force for removing chips (unnecessary portions) 7.
In particular, a product having a width w smaller than the plate thickness t is deformed into a substantially pentagonal cross section as shown in FIG. 7 due to a phenomenon commonly called Korogari.
There is a problem that a shearing force larger than the shaving method shown in FIG. 8 is required.

In the conventional shaving method, the shearing force required for each of the pre-processing and the shaving may be smaller than that of the processing method shown in FIG. 7, and the shaving die clearance is smaller than that of the die to be punched at one time. Product accuracy is improved. However, the chips 16 generated during the shaving process are fine and extremely lightweight,
Since it is easy to adhere to etc. and is difficult to remove, there is a possibility that a product defect may occur or the press working device may be damaged, and in the product 9 having a width dimension w smaller than the plate thickness t, the deformation due to the roller slip cannot be ignored. was there.

[Means for solving the problem]

In FIG. 1, which is a basic explanatory view of the method of the present invention, there is a cutting edge corresponding to the contour of a region inside the contour of the unnecessary portion A of the plate material 1 to be removed by press punching over the entire circumference of the contour. A second punch having a cutting edge corresponding to the contour of the unnecessary part A after half-punching the inside of the contour of the unnecessary part A in the first direction (upward direction) using the first punch 21
22, the unnecessary portion A is punched in a second direction (downward) opposite to the first direction.

In FIG. 1, reference numeral 18 denotes a die having a through hole facing the punch 21, reference numeral 19 denotes a die having a through hole facing the punch 22, and reference numeral 20 denotes a chip obtained by removing the unnecessary portion A.

[Action]

According to the above means, after the inside of the unnecessary portion is half-punched in the direction opposite to the unnecessary portion punching direction, the unnecessary portion is punched in the punching direction.

Therefore, at the time of punching, the clearance of the mold, that is, the clearance between the punch 22 and the punching through hole of the die 19,
It is possible to set the value to approximately the same value (about 1 to 2% of the plate thickness) as the shaving process in the prior art,
Moreover, since the chips are solid unlike the chips obtained by shaving, the force for pulling the product portion of the plate material is reduced. As a result, the product part is less deformed and high precision is guaranteed.

Further, since the half-punching and the punching are performed separately, there is an advantage that the shearing force required for each processing can be smaller than the method of removing unnecessary portions at once.

〔Example〕

Examples of the press punching method according to the present invention will be described below.

2 (a) to 2 (d) are explanatory views of one embodiment of the method of the present invention, FIG. 3 is a side sectional view showing a main part of a half blanking apparatus in another embodiment of the method of the present invention, and FIG. FIG. 5 is a diagram for explaining the operation of the half-punching machine, FIG. 5 is a schematic diagram of the cross-sectional shape of a product according to the embodiment of the present invention and the prior art, and FIG. 6 is a schematic diagram for evaluating the cross-sectional shape.

In FIG. 2 (a), a lower mold plate 23 into which a punch 21 having a cutting edge corresponding to an area located inside the contour of the unnecessary portion of the plate material 1 is vertically movably fitted from below, When the plate material 1 is sandwiched between the punch 24 and the die 24 having the through hole 25 facing the upper side, and the punch 21 is pushed up in the first direction (upward in the figure) with a stroke that does not exceed the thickness t of the plate material 1. The portion 26 of the plate 1 that is inner than the unnecessary portion is extruded upward without leaving the plate 1.

In FIG. 2B, a punch 22 having a cutting edge corresponding to the contour of the unnecessary portion of the plate material 1 has a stripper 27 having a through hole into which the punch 22 is vertically movably fitted from above, and a transparent member facing the punch 22. The plate material 1 is sandwiched between the die 28 having the hole 29 and the punch 22 so as to face the unnecessary inner portion 26, and the punch 22 is moved in the second direction (downward direction) opposite to the first direction. Then, the unnecessary inner extruded portion 26 is pushed back into the plate 1 by the punch 22.

Therefore, when the punch 22 is further moved downward, as shown in FIG. 2C, the pushing portion 26 and the portion 30 along the unnecessary portion A on the outside thereof are pushed down together and finally shown in FIG. As shown in ()), the sheet material 1 is sheared and removed outside the apparatus.

In FIG. 3, a half punching punch 21 stands upright on a die backing plate 32 fixed on a die holder 31, and a pair of pins 33,
A support plate 34 supporting the pin 33 and a compression coil spring 35 supporting the support plate 34 are constantly urged upward by a punch at the center.
The upper surface of the knockout 36 through which the 21 slidably penetrates is formed by a stop block 37 that locks a part of the knockout 36.
During non-operation, the upper surface of the punch 21 is aligned with the upper surface of the punch 21, and the upper surface of the punch 21 projects by an appropriate amount from the die plate 38 fixed on the die backing plate 32.

Stripper plate facing above die plate 38
A die 40 has a through hole facing the upper side of the punch 21 and having a through hole in which the punch 21 is fitted.
Accommodates 41, stop block 42 and adjustment plate
The eject 41, which can be moved up and down by an appropriate amount by 43, passes through the adjustment plate 43, and can be moved up and down by pins 44 and 4
A support plate 45 fixed to the upper end of 4 and a plate member 47 fixed to the upper surface of the stripper backing plate 46 that supports the stripper plate 39 and a compression coil spring 48 inserted between the support plate 45 always attaches downward. It is energized.

In the drawing, reference numeral 52 denotes an adjustment plate for adjusting the operation amount of the knockout 36.

In the pre-processing apparatus thus configured, the plate material 1 is placed on the knockout 36, and the punch plate 51 fixed to the punch holder 50 is lowered from above the stripper backing plate 46 via the punch backing plate 49. Then, as shown in FIG. 4, the upper surface of the plate 1 is ejected.
By the descending motion after the lower surface of 41 is in contact, the eject 41 is pushed up and the knockout 36 is pushed down,
The extruded portion 26 of the plate material 1 is formed.

In FIG. 5, (a) is a cross-sectional view of a product formed by the method of the present invention, and (b) is a cross-sectional view of a product formed by the conventional method shown in FIG. The deformation of the cross section of the product 9b by the conventional method is larger than that of the cross section.

In FIG. 6, the sectional shape of the pentagonal product 9 is defined as a thickness (height) t, a maximum width W, a minimum width w, and a V-shaped deformation amount u, and the evaluation value of deformation B = (W−w) / When t, C ＝ u / t, product 9
The evaluation values Bb and Cb of the conventional product 9b are 20
It was confirmed by actual measurement that the value increased by 30% to 30%.
However, the sample used was a phosphor bronze plate having a thickness of 0.4 mm and a product width of 0.3 mm.

〔The invention's effect〕

As described above, according to the method of the present invention, the inside of the unnecessary portion is half-punched in the direction opposite to the unnecessary portion punching direction, and then the unnecessary portion is punched in the punching direction.

Therefore, the product according to the method of the present invention has a smaller tensile force due to the shearing of the chips to reduce the deformation, and the clearance of the mold used for the main processing can be the same as that of the conventional shaving mold. The accuracy of
In addition, the present invention has the effect of reducing the damage to the device by solving the difficulty of removing chips by conventional shaving.

[Brief description of the drawings]

FIG. 1 is a basic view of the method of the present invention, FIG. 2 is an explanatory view of an embodiment of the method of the present invention, FIG. 3 is a sectional side view showing a configuration example of a main part of a half-blanking apparatus in the method of the present invention. FIG. 4 is an explanatory view of the operation of the half blanking apparatus shown in FIG. 3, FIG. 5 is a schematic view of a cross-sectional shape of a product according to the method of the present invention and a conventional technique, and FIG. FIG. 7 is an explanatory diagram of the most common press punching method of the prior art, and FIG. 8 is an explanatory diagram of a shaving method of the prior art. Reference numeral 1 denotes a plate material, 21 denotes a first punch, 22 denotes a second punch, and A denotes a plate material unnecessary portion.

Claims (1)

(57) [Claims] 1. A first punch having a cutting edge corresponding to the contour of a region inside the contour of the unnecessary portion of the plate material to be removed by press punching is used, and the unnecessary portion is used. After half blanking the inside of the contour in the first direction, a second punch having a cutting edge corresponding to the contour of the unnecessary portion is used, and a second direction opposite to the first direction is used. A press punching method, wherein the unnecessary portion is punched.