JPH0399728A - Shearing die - Google Patents

Abstract

PURPOSE:To improve shearing quality and to reduce working cost by providing a relief of a specified angle on a die to shear a plate member in cooperation with a punch. CONSTITUTION:In an operation shearing a plate member 16 carried out in cooperation with the punch 11 and the die 12, the relief 15 of an inclined angle 4-12 deg. is given to the die. On one hand, the clearance C between the punch 11 and the die 12 is set to 0-20% of the plate thickness of the plate member 16. Consequently, when the plate member 16 is set on the die 12 and the punch 11 is moved downward to perform blanking, stress is concentrated on a part of the plate member 16 corresponding to the cutting edge 14 of the die 12, after completion of blanking most of the cut area is a fracture surface, burrs are free from generation, shearing quality is improved, the tool life is prolonged and the working cost can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a new type of sheathing that performs processing such as punching or punching holes on a plate material, and particularly relates to a new type of sheathing that suppresses the occurrence of burrs.

(Prior Art) In shear processing, how to suppress the occurrence of burrs has become an important issue, and various countermeasures have been taken in the past. For example, in the upper and lower punching method shown in FIGS. 4(a) to (C), first the plate material 3 is half punched using the punch 1 and the die 2 [(a)], and then the process is transferred and a new punch 4 is used.
Insert the plate material 3 between the die and the die 5 [(b)]
, then move the punch 4 upward and pull it out in the opposite direction < [(c
)], and in the flat pressing method shown in FIGS. 5(a) to (C), first the punch 1 is
Cut the plate material 3 in half using the die 2 and die 2 (a)], then move the process and set the plate material 3 between the pair of flat dies 6 and 7 [(b)], and then cut out one of the flat dies 6. It is moved relatively and pulled out in the opposite direction as well.

In addition, as a special example, for example, JP-A-61-1995
As shown in Japanese Patent No. 28, there is a countermeasure in which a hole is punched from one side of the plate using a small-diameter punch, and then a hole is punched from the other side of the plate using a punch of the finished size to remove the holes as well.

(Problem to be solved by the invention) However, according to the countermeasures using the above-mentioned top and bottom punching method and flat pressing method, the number of man-hours and equipment costs increase due to two-step processing (in this case, a special press or die is required). (requires a set) is unavoidable, which significantly increases processing costs.
There was a problem with removing the mold. Furthermore, according to these countermeasures, if a crack occurs in the plate material 3 when it is half-cut, the cut surface will change in a complicated manner during shearing in the subsequent process. It is necessary to select a ductile material that does not contain ions, which limits the scope of application. Moreover, according to these countermeasures, if the clearance changes substantially due to wear of the mold, the effect of preventing burrs is weakened, and it becomes difficult to obtain stable machining accuracy. Note that the countermeasures indicated in the "Mold Temperature Bulletin" do not change the basics of two-step processing, so an increase in processing costs is unavoidable as described above, and on top of that, the bottom of the punch is hit by burrs, which increases the wear of the punch. There is a problem in that there is a lot of damage, and corrections and replacements must be carried out frequently.

The present invention was made to solve the above-mentioned conventional problems, and its purpose is to significantly suppress the occurrence of burrs by specifying the size of the relief provided in the die. Our aim is to provide new and innovative products.

It should be noted that providing relief in dies has been done in the past (for example, Hiroshi Suzuki ed. "Plastic Processing" published by Shokabo in 1966, pp. 154-155; This is provided to make it easier to remove scraps or blanks from the die, and the angle of inclination (gap angle) is 5.
It was said to be between 3 minutes and 3 degrees. A breakout of this size does not have any effect on the occurrence of burrs, and there has never been any idea that there is a relationship between this breakout and burrs. By the way, the reason why the upper limit of the clearance angle is 3 degrees is because
This is to prevent the clearance from increasing when the die surface is repeatedly polished due to wear of the cutting edge.

(Means for Solving the Problems) In order to achieve the above object, the present invention has a configuration in which a relief with an inclination angle of 4 to 12 degrees is provided in a die that cooperates with a punch to shear a plate material. Features.

In the present invention, the angle of inclination of the relief is set to 4 to 120.If it is less than 4 degrees, the effect of suppressing the occurrence of burrs will be small, and if it exceeds 12 degrees, the cutting edge of the die will become weak and the life of the die will be shortened. Depends on the reason. Further, the present invention has an inclination angle of 4
Any value can be selected as the relief size within the range of ~12 degrees, but experiments have shown that burrs almost disappear when the inclination angle is around 8 degrees, so burrs do not occur. For mild steel (low carbon steel), it is desirable to set the inclination angle in the range of 6 to 100 around 8°.

(Function) In the shearing type having the configuration described in item 1, the cutting edge of the die is at an acute angle, so stress concentrates on the part of the plate material corresponding to this cutting edge side, and cracks occur in the stress concentrated part at the initial stage of shearing. Occur. As a result, the fracture progresses from this crack as a starting point, and the fracture surface occupies most of the cut.
The occurrence of burrs is suppressed.

(Example) Hereinafter, an example of the present invention will be described based on the accompanying drawings.

FIG. 1 shows the structure of the new type of plunger according to the present invention and how it is used. In the same figure, 11 is a punch,
12 is a die, and a cutting edge 1 is provided in the through hole 13 of the die 12.
A see-through 15 is provided directly connected to 4. In this embodiment, the inclination angle θd of the relief 15 is set to 4 to 12 degrees, while the clearance C between the punch 11 and the die 12 is set to 0 to 20% of the thickness of the plate 16. There is.

In the case of a shedding type having a circular structure, the plate material 1 is placed on the die 12.
6 and move the punch 11 downward to remove it,
Stress is concentrated in the portion of the plate material 16 corresponding to the cutting edge 14 of the die 12, and cracks occur in the stress concentrated portion at the initial stage of shearing. As a result, the fracture progresses from the crack as a starting point, generating a large rack 17. After punching is completed, most of the cut surface is occupied by the fracture surface, and almost no burrs occur.

Here, the mold clearance C is fixed at 20JL11,
The inclination angle θd of the relief 15 of the die 12 is varied to perform punching, and the inclination angle θd affecting the burr height Bh is
We conducted an experiment on the influence of In addition, the diameter of the punch 11 is 2
．． 5mm and plate material 16-c JIS G31
41, with a plate thickness of 0.4 mm was selected. Figure 2 shows
The results are shown below.

From this, the burr height Bh is 1″O when #7 remainder angle θd is 60, and even when Od is 4° or 12°, I
It was about gm. On the other hand, when no relief 15 is provided (Od=0), the burr height B t+ is 10p.
Lm or more, and on the other hand, even when Od is 16°, the burr height Bh reaches nearly 5 gm, and setting the inclination angle Od in the range of 4 to 12° is extremely effective in suppressing the occurrence of burrs. It became clear that.

Next, set the inclination angle Od of the relief 15 of the die 12 to O and 8°.
For each setting, the mold clearance C was changed variously and punching was performed, and the burr height B was
An experiment was conducted to examine the effect of clearance C on h. Note that the punch 11 and plate material 16 used were the same as in the experiment described in 1- above. FIG. 3 shows the results.

From this, it can be seen that when no relief 15 is provided (Od-O), the burr height Bh increases linearly as the clearance C increases, but when the inclined angle θd is set to 8 degrees, , even if the clearance C increases, the burr height Bh
It was found that there was almost no change. This means that the mold of the present invention is less susceptible to the influence of the clearance C, in other words, the degree of freedom in setting the clearance is increased and the allowable range for wear of the mold is increased.

(Effects of the Invention) As explained in detail, according to the new model of the present invention, the die is provided with a relief of a predetermined size, so that it can be pressurized by about 1 inch. However, it is possible to suppress the occurrence of burrs to an extremely small level, and the effect of significantly reducing the pressurization cost I can be obtained. In addition, even non-ductile materials can be sheared, expanding the range of application, and even if the clearance changes, the accuracy of the cut is maintained, resulting in the effect of stabilizing full-face pressure.

[Brief explanation of drawings]

Figure 1 shows the structure and use of the new model according to the present invention.
Figure 2 is a correlation diagram showing the influence of the inclination angle of the die relief on the burr height, No. 31) 4 is a correlation diagram showing the influence of die clearance on the burr height, and 4th Figures (a) to (C) are one of the conventional burr countermeasures.
1--A sectional view showing the undercutting method. FIGS. 5(a) to 5(c) are sectional views showing the flat pressing method, which is another example of conventional burr countermeasures. 11 ... Punch 12 ... Dice 15 ... Escape 16 ... Plate material Od ... Slope angle 4 yen 1 t 1 person in distress I. Yota Auto 11 Town Stock Association 1
.

Claims (1)

[Claims] (1) Inside the die that cooperates with the punch to shear the plate material,
A shearing type characterized by having a relief with an inclination angle of 4 to 12 degrees.