SU1759549A1 - Press-mold for molding powder products - Google Patents

Abstract

Essence: the conical segments of the die 5 are installed in the opening of the sleeve 3 and are pressed against the washer 7 by fixing the coil springs 6 on the brackets 4. Then the lower punch 2 is installed and the press powder is poured, after which the upper movable punch 1 is placed, to which a force is applied and compacted press powder. At the end of the pressing cycle, the lower fixed punch 2 is removed, a stand is placed under the brackets 4, force is applied to the upper movable punch 1. Under the action of friction forces between the surface of the product and the die, the conical segments move down and press the washer 7, which is held by the springs 6. The washer 7, together with the die, the conical segments are lowered, moving along the conical hole of the sleeve 3, is consumed and the compact is released. Products have the exact geometrical sizes and high degree of purity of a surface. 3 il. with

Description

The invention relates to mold designs for pressing articles from powder.

A known mold containing punches and a die with a cylindrical hole for filling and pressing the press powder,

The disadvantages of this mold are high cost due to the use of high-quality steels with high wear resistance and the occurrence of cracked cracks in the extruded products.

The closest to the technical essence of the present invention is a mold containing the upper and lower punches, a split matrix consisting of individual elements, and a yoke.

The disadvantages of this mold are the low accuracy of the geometrical dimensions of the finished product due to the decrease in the diameter of the die hole with increasing pressing pressure, the appearance of burrs on the side surface of the product, as well as the appearance of longitudinal cracks in the finished product due to the appearance of large elastic expansion forces. at the moment of relieving pressure.

The purpose of the invention is to improve the accuracy of the geometric dimensions and strength of the finished product.

For this, the mold is equipped with a washer with guides and cylindrical springs placed on the guides, the yoke is made with brackets,

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the sockets for the runners, the split matrix is made as a set of conical segments, the angle of inclination of the forming tapered bore of the sleeve to the axis of the upper punch is 100-175 °, and the lower punch is placed in the opening of the washer and is made with a diameter equal to the sum of the diameter of the upper punch and wall thickness of the matrix at the base.

Fig, 1 shows the proposed mold; in fig. 2 is a section A-A in FIG. 1; in fig. 3 - the moment of pushing the pressed product.

The mold contains movable punch 1 and lower stationary: / punch 2, ferrule 3 with brackets 4, die 5, which is a set of horse segments, cylindrical springs b, washer 7 with guides 8 and a support 9.

The mold works as follows. .

The conical segments of the die 5 are installed in the opening of the sleeve 3 and are pressed against the washer 7 by fixing the coil springs 6 on the brackets 4. Then the lower punch 2 is installed and the press powder is poured, after which the upper movable punch 1 is applied. compacted press powder. At the end of the pressing cycle, the lower fixed punch 2 is removed, a stand 9 is installed under the brackets 4. Then a force is applied to the upper movable punch 1. Under the action of the friction between the surface of the product and the rim 5, the conical segments move down and press the washer 7, which is held by the springs . The washer 7, together with the die 5, lowers the conical segments, moving along the conical opening of the sleeve 3, is consumed and the pressing is released.

It should be noted that the proposed device allows to obtain articles from press powders with higher elastic expansion coefficients than indicated in the prototype. In this case, the products have exact geometric dimensions, a higher degree of surface cleanliness due to the absence of burrs and

surface cracks. In addition, the optimum angle of inclination of the generatrix of the conical hole to the axis of the upper punch lies in the range of 100-175 ° and depends on the magnitude of the elastic expansion coefficient of the press powders used. When ug- Lachas smaller than 100 °, the ferrule expands by the elastic forces of the extruded product immediately after relieving the pressing pressure, due to which cracks appear loosened. At angles greater than 175 °, the dimensions of the mold increase dramatically, which leads to an increase in metal intensity and inefficiency of its operation.

The optimum diameter of the lower punch is equal to the sum of the diameter of the upper punch plus the thickness of the die wall at the base. This value is optimal to prevent the press powder from being pressed into the gaps between the washer and

fixed punch.

Claims (1)

Invention Formula A mold for pressing products from powder, containing upper movable and lower fixed punches, a holder with a tapered bore and a detachable matrix placed in the cage, characterized in that, in order to improve the accuracy of the geometric dimensions and strength of the finished product, it is equipped with a washer with the guides and cylindrical springs placed on the guides, the yoke is made with brackets having sockets for the tapping of the guides, the detachable matrix is molded in the form of a set of conic segments, and the angle it is thus formed Tsey conical opening to zerhnego punch holder axis is 100-175 °, and shzhny punch disposed in the bore and adapted iayby diameter equal to the sum of the diameter of the upper punch and the die wall thickness at the base, BUT FIG. Fie.2 Fig.Z