SU1419869A2 - Method of producing microrelief by impact vibro-rolling - Google Patents

Abstract

The invention relates to the processing of metals by pressure and can be used to remove heat at the boiling point of a heat transfer medium and for shock vibration rolling. The method of obtaining the microrelief consists in sequential exposure of the surface to three conveying machines: wedge, with a conical working surface and with a working surface in the form of a reverse cone. The wedge indenter is installed with an offset along the axis of rotation, NIN. Details and angular displacement. After the annular groove is formed from the wedge indenter udaff, an indenter 4 blows into its trail, and then the indenter 5, which makes it possible to increase the heat transfer coefficient. 9 il. I (L

Description

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Fig.G

11 the invention relates to the processing of metals by pressure and can be used to remove heat during the boiling of the coolant, as well as for shock vibration.

The aim of the invention is to reduce energy consumption by increasing heat transfer during boiling of the heat transfer medium.

FIG. 1--3 is a diagram of the interaction of the work surface and tools; in fig. 4 wedge indenter; in fig. 5 and 6 — indenters with conic surfaces; Figs. 7, 8 show the heat exchange surface with microrelief; FIG. 9 is a graph of heat transfer coefficient versus heat flux density.

The method of shock vibration rolling of the microrelief is carried out as follows.

The cylindrical part - pipe I 0 50 mm - is rotated on a lathe. At the same time, the pipe is perpendicularly perpendicular to its surface by a wedge indenter 2 and tool 3, making an oscillation motion using separate electromagnets connected synchronously to an AC network (not shown). In the tool 3, the indenter 4 is fixed (Fig. 4) with a conical working surface and parallel to it an indenter 5 (Fig. 5) with a working surface in the form of a reverse cone. The angle of the cone of the indenter is 4 -, the indenter is 5 -. The diameter of the base of the cone is 4–, 15 mm for the indenter, 5–5 mm for the indenter.

The wedge indenter 2 (Fig. 6) has an angular displacement and a displacement along the axis of rotation of the pipe 1 relative to the tool 3. The angle of the wedge of the wedge indenter 2 (, wedge length, 5 mm.

The oscillation movement of all indenters is carried out with a frequency at which the fractional part {ij of its ratio to the number of revolutions of the pipe is zero. At an oscillation frequency of 3000, the tube is rotated at a speed of 5 rpm (, 0;). Indenter feedrate

expressions, where S is the feed rate; D is the diameter of the pipe; n is the speed of rotation of the pipe; f is the oscillation frequency; k - coefficient equal to one at {i} 0.

Based on this expression, at 1 (, 5 rpm) the feed rate S is 0.65 mm / rev. The distance between the indenters 4, 5 is set by a multiple of the feed rate S and is equal to 9.75 mm.

The angular change of the indenter 2 relative to tool 3 is taken as 90. The choice of the angle θ depends on the design dimensions of the electromagnet and the indenter 2 and can be in the range of 90-180 °. The most convenient way to calculate is to take two values of the angular displacements and.

The offset of the indenter 2 along the axis of rotation of the pipe relative to the tool 3 op0

 ;

0

five

0

five

0

f. ;

is determined from the expression sH-c,

where rn is a positive integer to, i. 2, 3 ...); at and offset is 65,163 mm.

After forming a ridge groove from the impact of the wedge indenter 2, the indentor 4 strikes it in its wake and a conical cavity in the center of the radial groove is squeezed, and then the indenter 5 strikes the upper edge of the hollow. As a result, depressions with a depth of 0.5 mm are formed on the surface of the pipe (Figs. 7, 8) with a base 6 of conical shape (cone angle 20 °) and; tapered inlet 7 diameter. 0.15 mm, strictly concentric cavities annular grooves 8 with a diameter. 0.5 mm and radial grooves 9 (length 1.5 mm, depth 0.45 mm) connecting the conical parts of the depressions with the surface 10 between them.

The graph (Fig. 9) shows the dependence of the heat transfer coefficient (a) on the heat flux density (q) during boiling of P-113 freon for the surface with the obtained microrelief (curve 11) and the surface in the main image (curve 12). As can be seen from the graph, the heat transfer coefficient of the proposed surface in the entire range of heat flux is higher than that of the surface according to the basic invention.

Claims (1)

Invention Formula The method of obtaining the microrelief by shock injection by auth. St. No. 1227,250 according to claim 2, characterized in that, in order to reduce energy intensity by increasing heat transfer during boiling of the heat transfer fluid, before impact vibration vibrating with an instrument with a conical working part, an additional impact is made by the wedge indenter and form radial grooves, while the wedge indenter yctaaF is applied with a compound relative to the tool with a conical working part along the axis of rotation of the part and an angular displacement related by the relation where a is D,; 1. S + displacement along the axis of rotation of the part, mm; Fie.2 FIG. Ф - angular displacement, hail; m is a positive integer, and the length of the wedge wedge indenter is chosen larger than the diameter of the annular groove. Fi.Z FIG. five 6 7 V 9 iO OS ten YU 8 9 12 10 Phage. 9 d, Bm / fi