RU2492032C2 - Method of combined processing - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to machine building and can be used for making and hardening tools intended for finishing axially symmetric parts, for example, fine-module hard-alloy shaping cutters. Proposed method comprises making the electrode tool from easy-to-machine alloy with axially-symmetric profile by piercing at appropriate die and applying ultrasound oscillations thereto with simultaneous circular and radial displacement of piercing tool. Thereafter made electrode tool is used for spark erosion machining of axially symmetric part. Note here the amplitude of ultrasound oscillation makes double electrode gap of spark erosion machining.

EFFECT: higher finishing precision.

4 dwg

Description

The method relates to the field of mechanical engineering and can be used to make tools for finishing machining axisymmetric parts, for example, small-module hard-alloy cutters.

Known methods for finishing the profile of cutters, grooves, gears by grinding. The disadvantages of the method include the high consumption and cost of an abrasive tool, especially in the manufacture of small-modal cutters [1, p. 388].

A known method of combined electroerosive and chemical treatment with an abrasive tool, which allows to reduce tool consumption, but requiring high costs for the manufacture of conductive abrasive wheels and their editing [2, p. 68].

A known method of intensifying processing processes by applying bending ultrasonic vibrations to the tool. The disadvantages of the method include obtaining a different amplitude of oscillation in the processing of involute and other axisymmetric products [3, p.268].

There are known cylindrical (circular) waves, the use of which allows you to adjust the distance between the mating surfaces in axisymmetric parts when they are processed with anodic dissolution of the material [4, p.178].

Closest to the application is a method [3]. The essence of the method is that when performing traditional blade processing of axisymmetric parts, ultrasonic vibrations are superimposed on the processing tool, which increase the removal rate of the material layer due to the appearance of additional cutting forces. The disadvantages of the method include the unstable amplitude of the vibrations when processing involute and other axisymmetric products, which leads to a decrease in the accuracy of the machined surfaces and additional costs for fine-tuning the accuracy of the profile during subsequent finishing operations.

The invention is aimed at improving the accuracy of finishing, reducing the cost of abrasive tools in the manufacture of axisymmetric gear, especially small module products, such as cutters with carbide cutting elements.

This is achieved by the fact that the method of combined processing of a workpiece of an axisymmetric part with cutting elements includes the manufacture of an electrode-tool from an easily machined alloy with an axisymmetric part profile by flashing with a flashing tool with superposition of ultrasonic vibrations and with simultaneous circular and radial movement of the flashing tool, after which made electrode-tool carry out electroerosive-chemical processing of the workpiece axisymmetric parts, with the amplitude of trazvukovyh oscillations is largest lateral double electroerosion electrode gap-chemical treatment.

In the electrode tool designed for finishing, the work profile processed earlier is flashed with plastic deformation, while the parts are provided with circular and radial movement around the axis with the amplitude of ultrasonic vibrations equal to twice the interelectrode gaps during erosion-chemical finishing of the working profile of axisymmetric parts, for example dolbyakov. Figure 1 shows the location of the electrode tool relative to the firmware tool, figure 2 shows the essence of the method of manufacturing the working profile of the electrode tool; figure 3 shows the installation of the electrode tool relative to the cutting part of the axisymmetric part, such as a dolby; figure 4 - the position of the electrodes during electroerosive-chemical combined processing.

The method is implemented as follows. From the easy-to-work alloy recommended in [4] for the manufacture of tool electrodes for electroerosive-chemical sizing (for example, copper alloys of the brass type), an electrode tool blank 1 is made (Fig. 1) with a diameter "d" equal to the diameter of the initial circle axisymmetric firmware tool with the external profile of the part. The thickness "H" of the workpiece must be at least the length of the working section of the manufactured part. As a firmware tool 2 (Fig. 1), a carbide working element of a conditional cutter mounted on the mandrel 3 in the position opposite to the working one when chiseling can be used.

The billet of the electrode-tool 1 is installed on the plate 4 of the table of the machine with a mechanical feed of the tool (figure 2). The plate 4 has lateral protrusions 5 and 6, on which the ultrasonic concentrators 7 and 8 are fixedly fixed, abutting at an angle α (α = 45 ° ± 10 °) in the side surface of the electrode-tool 1 mounted on the plate 4 through an elastic element 9 (for example rubber).

The hubs 7 and 8 work with the displacement of the ultrasonic pulse from the generator (not shown in FIG. 2) by ¼ of the period to ensure the angular movement of the tool electrode 1 to obtain the calculated interelectrode lateral gap S (FIG. 3) during subsequent combined processing.

The processing of the working profile in the electrode-tool 1 is performed by the firmware-firmware 2 during ultrasonic vibrations of the electrode-tool 2 by the concentrators 7 and 8 in the circumferential direction (shown in Fig. 2 by arrows) with an amplitude of A _to .

The amplitude of the ultrasonic circular vibrations is established by adjusting the axial clearances of the concentric elements symmetrical with respect to the axis of the diametrical action, working with a shift in time of the action of the pulses by half the half-wave period of the pulse.

After the firmware is completed, the electrode-tool 1 is installed on the machine for combined processing (not shown in Fig. 4) and the cutting part of the working profile of the axisymmetric part 10 is finally processed (polished) in the design mode with the selected feed "V".

An example of the method

It is necessary to make the working part of an axisymmetric part - a hard-alloy cutter with a module of 1 mm and a cutting part length of 0.5 mm.

The outer diameter of the cutter is 30 mm.

The blank 1 is made of a sheet of brass LS - 1 with a thickness of 5 mm, an outer diameter of 40 mm, an inner diameter of 35.6 + 0.05 mm.

Side clearance A _k = 0.08 mm. To obtain a working gap equal to the lateral And _p = And _{to the} gap "h" set 0.05 mm

Processing sequence

1. The blank of the electrode-tool 1 is installed on the tabletop of the machine table with a mechanical feed of the tool (drilling machine 2A15). The plate has lateral protrusions on which ultrasonic concentrators are fixedly fixed, abutting at an angle α (α = 45 ° ± 10 °) against the side surface of the electrode-tool 1 mounted on the plate through an elastic element (rubber).

Hubs of ultrasonic vibrations work with the displacement of the ultrasonic pulse from the generator of ultrasonic vibrations by ¼ period, in order to ensure the angular movement of the electrode-tool 1 to obtain the estimated interelectrode lateral gap S = 0.04 mm. The amplitude of the ultrasonic vibrations is 0.08 mm. The amplitude of ultrasonic circular vibrations is set by adjusting the axial clearances symmetric about the axis of the diametrical effect of the concentrators of ultrasonic vibrations.

Processing time 50 seconds.

Thus obtained electrode tool is used in the operation of combined processing.

2. The combined processing of the working part of the carbide cutter was carried out on a special machine with the following conditions:

- voltage 45 V,

- working environment - industrial water,

- processing time of the cutting part of the cutter 3 seconds,

- the size of the working gap was set two times greater than the value of the set amplitude of ultrasonic vibrations, non-compliance with this condition leads to the fact that the process of electroerosive-chemical processing is impossible due to non-compliance with the size of the working gaps.

Measurements showed that the cutter on the working profile meets the requirements of the drawing for accuracy. The complexity of manufacturing a cutter is reduced by 18 times compared to the previously used process of grinding with diamond wheels. At the same time, the diamond wheel consumption was 1 cup wheel per dolby with the indicated dimensions.

INFORMATION SOURCES

1. Chetverinov S.S. Metal-cutting tools M: Higher school, 1965-732 p.

2. Smolentsev EV Design of electrical and combined processing methods M: Mechanical Engineering, 2005-511 p.

3. Grigoriev S.N. Processing technology with concentrated energy flows S.N. Grigoriev, E.V. Smolentsev, M.A. Volosova St. Oskol: TNT, 2009-280 s.

4. Electrophysical and electrochemical methods of processing materials. B2T, T1 Ed. V.P. Smolentseva M: Higher school 1983-247 p.

Claims (1)

A method for the combined processing of a workpiece of an axisymmetric part with carbide cutting elements, including the manufacture of an electrode-tool from an easily machined alloy with the profile of the axisymmetric part by flashing with a firmware tool with the application of ultrasonic vibrations and with simultaneous circular and radial movement of the firmware tool, followed by a manufactured electrode tool conduct electroerosive-chemical processing of the workpiece of an axisymmetric part, with an amplitude of trazvukovyh oscillations is set equal to twice the side of the interelectrode gap with EDM-chemical treatment.

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