RU2503538C1 - Method of processing caprolon blanks - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to machining and may be used for machining of plastic articles, mainly of Caprolon. In compliance with proposed method, blank and cutting tool are displaced relative to each other for shaping purposes. Note here that along with cutting the blank is irradiated by nanosecond electromagnetic pulses. Note here the electrodes to emit nano-second electromagnetic pulses are composed of cutting tool and slider in contact with Caprolon blank and are isolated from machine tool metal parts.

EFFECT: higher efficiency of processing and physical-mechanical properties.

2 cl, 1 dwg, 1 ex

Description

The invention relates to the processing of materials by cutting and can be used in the machining of plastic blanks, mainly from caprolon.

There is a method of mechanical processing, for example, turning, of plastic blanks, for the implementation of which a special cutting tool equipped with hard alloys is used (V.N. Poduraev. Cutting of hard-to-work materials: Textbook for universities. - M.: Higher School, 1974, p. .574).

However, the implementation of this method does not provide a high-quality surface after processing due to the presence of significant differences in the physicochemical properties of metals and plastics. In this case, a significant surface roughness is formed, the elements of which create stress concentrators, which negatively affect the strength characteristics of the finished part as a whole.

The closest analogue is the method of processing blanks from caprolon, in which the relative motion of forming is reported to the blank and the cutting tool, and the feeding is carried out discretely (RF patent No. 2317196, B29C 37/00, BI No. 6, 2008).

However, the known method does not allow to provide high performance and to obtain high physico-mechanical properties of products (tensile strength, hardness, strength under static bending).

The technical problem to which the invention is directed is to increase the productivity of processing the workpiece and the physicomechanical properties of the products.

This problem is solved by the fact that in a method involving the processing of workpieces from caprolon, in which the workpiece and the cutting tool are informed of the relative motion of the shaping, and the feed is carried out discretely, according to the invention, simultaneously the workpiece is irradiated with nanosecond electromagnetic pulses, while the electrodes are for irradiation with nanosecond electromagnetic pulses, a cutter and a sliding element are used, which are in contact with the workpiece of caprolon and insulators Ana from metal parts of the machine. In addition, nanosecond electromagnetic pulses with a duration of 1 ns, an amplitude of 8 to 12 kV, a power in a single pulse of 1 to 2 MW, and a pulse repetition rate of 1000 Hz are used.

In this case, the simultaneous processing of the workpiece by cutting and nanosecond electromagnetic pulses contributes to the excitation of polymer chains, which causes a decrease in its binding energy. This effect leads to a decrease in the mechanical stability of the loaded polymer network and thus contributes to the breaking of the chain, the occurrence of fracture or crack propagation, and the increase in defective tests, i.e. its loosening and embrittlement and, consequently, to reduce the mechanical strength of the material.

The proposed modes of preparation processing nanosecond electromagnetic pulses are optimal for processing caprolon.

To implement the method of processing blanks from caprolon use the following equipment.

The blank 1 of caprolon is installed in a lathe with a cutting tool 2 (cutter). To rotate the workpiece, there is a drive 3 and a feed device 4 of the cutting tool 2. The lathe is equipped with a generator 5 for irradiating the workpiece 1. In this case, the cutting tool 2 (cutter) and sliding element 6, which are in contact with blank 1 and insulated using insulation 7 from the metal parts of the machine.

To implement the method, a generator of 5 nanosecond electromagnetic pulses (GNI-01-1-6) manufactured by the South Ural State University with the following parameters is used:

- pulse polarity is positive;

- pulse amplitude of more than 8 kV;

- pulse duration - 1 ns;

- power of one pulse is more than 1 MW;

- the maximum permissible repetition rate of the generating pulses -1000 Hz;

- the maximum current consumed by the generator in the entire range of supply voltages, not more than 1.7 A at a frequency of 61 kHz.

An example implementation of the method.

The blank 1 of caprolon is fixed in a lathe in a known manner. Then, a generator of 5 nanosecond electromagnetic pulses is connected to the cutting tool 2 and to the sliding element 6 using electrodes and processed by pulses of 1 ns duration, an amplitude of 8 to 12 kV, a power of 1 to 2 MW per pulse, and a pulse repetition rate of 1000 Hz. At the same time, the workpiece 1 is machined with a cutting tool 2 to form chips. Modes of turning are established experimentally.

In this case, treatment with nanosecond electromagnetic pulses promotes the excitation of polymer chains, which causes a decrease in its binding energy. This effect leads to a decrease in the mechanical stability of the loaded polymer network and thus contributes to the breaking of the chain, the occurrence of fracture or crack propagation, and the increase in defective tests, i.e. its loosening and embrittlement and, consequently, to reduce the mechanical strength of the material.

This allows you to increase the cutting speed and feed rate, to increase the processing productivity of the polymer. The quality of the processed surface is significantly improved, in addition, high physical and mechanical properties of the products (tensile strength, hardness, strength under static bending) are obtained, which are fixed and confirmed by long-term operational tests.

Unlike analogues, the proposed method provides an increase in processing productivity, as well as strength, stiffness, modulus of elasticity of products based on caprolon during operation by improving the quality of the surface zone of the material processed by nanosecond electromagnetic pulses and conventional turning operations.

Claims (2)

1. A method of processing workpieces from caprolon, in which the relative motion of forming is reported to the workpiece and cutting tool, and the feed is carried out discretely, characterized in that simultaneously with the cutting, the workpiece is irradiated with nanosecond electromagnetic pulses, while using electrodes for irradiation with nanosecond electromagnetic pulses a cutter and a sliding element that are in contact with the caprolon blank and are isolated from the metal parts of the machine. 2. The method of processing blanks from caprolon according to claim 1, characterized in that they use nanosecond electromagnetic pulses of 1 ns duration, an amplitude of 8 to 12 kV, a single pulse power of 1 to 2 MW, and a pulse repetition rate of 1000 Hz.

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