OBRABOTKAMETALLOV Vol. 25 No. 4 2023 technology Research methodology We studied the design of the device for angular multichannel pressing (fig. 1), consisting of the following structural components: a punch 1, a container 2, a flange 3, bolts 4 and a bottom plate 6. The container 2 is connected to the plate 6 by means of the flange 3 and the bolts 4. At the bottom of the container 2 (fig. 1, a) there is a rectangular groove located at an angle of 90° relative to the axis of the container 2 with diameter D. The die 5 is mounted in the groove, which in this case has three channels of an equiaxed shape. The shape of the channels of the die 5 is shown in fig. 1, b. The axes of these channels are located at an angle of 90° to the axis of the container and along the axis of the rectangular groove. It should be noted that the channels can be placed in another way, namely, along the radius of the container. At that, in the first positioning variant, the bars flow out of the dies in parallel rows; when implementing the second variant, the symmetry of the metal flow of the pressed rods relative to the center of the circumference of the container cavity is ensured. In this case, the channels have a circular shape in its cross-section. It should be noted that the channels can have a different cross-section, for example, a square, depending on the requirements of the consumer of the pressed products. Thus, the presence of a device for angular multichannel pressing among the structural elements ensures a change in the configuration of the cross section of the pressed product to the shape of the openings present in the die. The use of a die with the number of channels n > 2 makes it possible to bring the pressing force values closer to the minimum possible values. From the theory of pressing it is known that the force is proportional to the natural logarithm of the elongation ratio, and with a larger number of channels the overall elongation ratio decreases. This becomes an important factor if it is planned to press metals with high strain resistance without heating. However, it should be taken into account that as the number of channels increases, the area of the contact surface at the level of the parallel lands of the die increases. The situation is complicated by the fact that this area is considered in the pressing force equation by introducing an elongation ratio as a co-multiplier, which is a significant value in pressing. Therefore, we have to apply the rule of minimizing the lengths of die parallel bands. Its length should provide the strength conditions with a small safety factor. When setting the problem, the length of the die parallel bands was assigned to 4 mm. It should be specially noted that, unlike the conventional pressing, the axes of the die channels in this case are in a plane located at an angle of 90° to the axis of the container. This makes it possible to reduce the size of discard, which, in turn, leads to an increase in the product yield value. a b Fig. 1. The structure diagram of the device for angular pressing of bars round cross–section in the amount three: a – the beginning of the process is reflected on the left half, the stationary stage of the process is reflected on the right half; b – the cross section A-A: on the left shows a matrix with the axes of the channels at an angle of 90° to the axis of the container and along the axis of the rectangular groove, with the display on the right of the same with the location of the bars
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