Introduction of stamping die for the hottest groov

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Introduction to stamping dies for grooved cross-section parts


sheet metal profiles with small length, and grooved cross-section parts are traditionally manufactured by stamping once or twice in a special die. General tools can also be used to punch by unit, but when this method is adopted, the plane segment 3 should be wide enough. When manufacturing punch and die of special die, it should be input from the nominal thickness of the material. Set out and cooperate with the working surface. In the closed position, the die should correct the plane segment of the part and eliminate the influence of free bending of the blank. The actual value of blank thickness input may be different from that of input. Values vary widely, so not all segments are corrected

for example, for high-precision sheet steel, the tolerance of thickness h0=2mm is 0.15 mm. It reduces the labor intensity of the operator; When the blank with h=2.15mm is corrected by the mold with the nominal thickness, the gap between the punch and the die on the second section is 2.15mm, while on the first and third sections, when =30, z=2.3mm. If HH is on Paragraph 2

the correction effect of non-uniformity will be negatively reflected in the accuracy of parts, which is one of the shortcomings of traditional technology. The disadvantage of the traditional process is the high cost of molds and equipment, because the peak load characteristics of the press generate too much power

this paper will list the results of developing another process, which is based on the principle of die stretch bending blank

1 analysis of stress state

and become irreplaceable materials. The analysis of stress state shows that the pressure value s ln (r+h)/r at the edge of the die on the blank. When the r/h value is 1, it reaches the value which is equivalent to the yield stress value s. Therefore, the tensile resistance of the blank on the bending section is significantly weak. The opposite effect is due to the hardening of these sections caused by bending, which occurs faster than the hardening of plane sections. According to the r/h value, one of these factors is dominant

when determining the minimum allowable fillet radius Rmin of punch and die, we should start from the following conditions, that is, the blank section that is not in contact with the die should be transferred to the plastic tensile state before the bearing capacity of the blank section that is subjected to contact pressure disappears. The obtained value Rmin is nearly 50% larger than that in general bending. For low carbon steel, Rmin does not exceed the thickness of the material. When testing the sample, the limit angle of the inclined wall is nearly 45, which can be confirmed by the results of the test stamping profile

when measuring the straightness of the bus of the inclined section of the part, it is found that there is a deviation, but it does not exceed the thickness tolerance of the blank material. At this time, the tensile deformation position of the bus is within 10%, and the stretched section extends along the width, that is, the length direction of the profile is less than 2mm

in order to obtain 30 parts, the edge of the blank must move towards the punch during the stretch bending process. These movements are best carried out together with the die, otherwise the blank segment will slide along the edge of the die and undergo bending and subsequent straightening, resulting in excessive thinning of the blank segment

2 mold structure

a mold structure with movable concave module is developed. The mold is installed on the press with high-power buffer to clamp the edge of the blank

the working process of the die is as follows: place the blank 2 on the punch 3 and the pressing plate 7. The pressing plate is installed in the guide groove 9 of the movable plate. When the upper template goes down, the concave module 6 installed in its guide groove 5 compresses the edge of the blank on the pressing plate and moves with the slider stroke of the press. At this time, the back pressure of the buffer ejector rod 11 is overcome. The blank will bend around the edge of the die, which will cause tension in the blank, and make the concave module and pressing plate move perpendicular to the slider stroke of the press. Everyone must pay attention to movement in the process of use. When the bending angle of the blank reaches the required value, the pressing plate 7 and wedge 12 begin to interact with each other. Weiqiao entrepreneurial group, Shandong innovation group and other enterprises jointly set up an automobile lightweight materials company. The plane they contact also has an inclination equal to, so the combined moving direction of the pressing plate is along the wall of the bending part. The blank edge clamped by the friction between the concave module and the pressing plate moves with the pressing plate

when the slider of the press reverses the stroke, the finished part moves upward together with the concave module 6 and the pressing plate 7. The pressing plate stops at the level of the punch, and the concave module continues to move with the upper template. The anti wedge 4 installed on the upper formwork interacts with the journal 10 of the pressing plate and retracts the pressing plate and the concave module connected with its pin 1 to the position limited by the stop 8

3 conclusion

determines the possibility of manufacturing grooved section parts without correcting the inclined wall. The flatness of the inclined wall is achieved by plastic stretching without contact with the mold

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