RU2545983C2 - Multielectrode outfit with independent suspension of electrodes and inertia vibration exciter - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention relates to electrospark doping of a metal surface with a complex geometry. The invention proposes a multielectorde outfit for electrospark doping, which contains a multielectrode cassette that can be mounted in a support of a mill with adjustment of its inclination angle. The cassette housing is made from dielectric material and combines two or more electrode holders for rod electrodes; with that, on electrode holders there fixed are individual inertia vibration exciters providing independent movement of each rod electrode in the direction perpendicular to the processed surface, and springs are installed between the lower part of the cassette housing and cartridges of the above electrode holders.

EFFECT: invention allows improving efficiency of electrospark doping of surfaces with complex geometry and quality of the obtained coating due to stable contact of an electrode with the processed surface and exclusion of influence of possible uneven consumption of electrodes at mechanical tracing of relief of the treated surface with each electrode separately at different cassette inclination angles.

3 dwg

Description

The invention relates to electrical processing methods and can be used to harden the surfaces of various metal parts of machines and tools. An increase in the efficiency of the process of electrospark alloying is ensured by the use of a multi-electrode tooling design, and the uniformity of properties and the quality of the resulting coatings is achieved by freely adjusting the angle of inclination of the rod independently fixed electrode, whose vibration in the axial direction is provided by an inertial vibrator. An independent electrode suspension allows mechanical “tracking” of changes in the surface topography of the workpiece, and an inertial vibrator provides separation and the necessary mechanical impact for forging the treated surface in the process of electrospark alloying.

Known versions of the technological tooling, in which the coating on the surface of the part is applied with a rod electrode by vibration-free alloying by maintaining the tracking system with a given value of the erosion gap [1, 2, 3].

The presence of a special tracking system in [1 and 3], associated with a source of technological pulses, greatly complicates the design of the equipment and increases its overall dimensions. In addition, taking into account the absence of the mechanical effect of the electrode during the electric spark treatment [1, 2, 3], it becomes necessary to carry out an additional smoothing-deforming effect, which significantly increases the complexity of the process and can lead to the formation of tensile residual stresses in the surface layer of the part and deterioration of mechanical characteristics of the resulting coatings.

Known methods of electroerosive coating with a vibrating rod electrode-tool, in which it is rotated around its axis and placed at an angle to the surface of the workpiece [4 and 5]. In these methods, the rod electrode-tool is rotated around its axis and placed at an angle from 8-45 ° to the surface of the workpiece, while the end of the electrode-tool can be sharpened at an angle of 60-90 °. A constant interelectrode gap is maintained using an automatic tracking system.

The disadvantage of this embodiment is the limitation of the angle of the electrode-tool to 45 ° and the complexity of the system for maintaining the interelectrode gap, which does not allow the processing of open surfaces with grooves with a non-linear generatrix (for example, round streams on dies or rolling rolls). Non-uniformity of the properties of the resulting coatings may also occur due to changes in the parameters of mechanical and thermal effects due to changes in the area of the working surface of the electrode during its consumption [5]. The simultaneous rotation and vibration of the electrode-tool in [4] complicates the alloying process.

A significant drawback of most technological equipment with mechanical or automatic tracking systems designed for electric-spark machining of bodies with complex surface topography is the need to coordinate the movement of the positioning mechanism with the frequency of technological current pulses, which makes it impossible to use the circuit with an independent pulse generator and significantly complicates the technological equipment and equipment. The bulkiness of the tracking system limits the possibility of using a multi-electrode circuit of technological equipment when processing surfaces of a large area.

Also known is a method of implementing a stable process of spark spark alloying, selected as a prototype, based on the periodic contacting of the working electrode with the part using electromagnetic vibration exciters [6, 7]. This method, which is based on tooling with a vibrating rod electrode-tool, has ample opportunity to adjust the coating process depending on the power of the pulse source and the nature of the electrode materials by providing the necessary relationship between the duration of contact of the electrode with the treated surface and the pause between contacts. This embodiment of technological equipment can be used in a technological process in which the vibration parameters of the tool are not related to the parameters of the pulse generator (circuit with an independent pulse generator). It is important that in the process implementation scheme using a vibrating rod electrode-tool, the temporary lag of plastic deformation caused by the mechanical action of the electrode does not exceed the solidification time of the transported particles of the electrode material. This allows you to increase the hardness, continuity, reduce the roughness of the resulting coating, increase the processing performance, which allows to increase the efficiency of the alloying process.

Technological equipment for processing parts with complex surface geometry, made according to the scheme with a vibrating rod electrode, today is performed either in the form of a hand tool or in the form of a manipulator machine. In the first case, there is a need for training personnel and the risk of violating the stability of the process increases, and in the second case, the complexity and bulkiness of the equipment increases. In both cases, mainly used single-electrode tool. The main disadvantage of such a tool is the tight connection of the tool vibrator body with the supporting surface of the machine (caliper) or manipulator.

The technical problem solved by the invention is to increase the efficiency of the process of electrospark alloying of surfaces with complex geometry and the quality of the resulting coating due to the use of a multi-electrode circuit and independent suspension of the tool electrodes in the cassette, which allow mechanical tracking of the surface relief of the processed surface independently by each tool electrode individually. Moreover, the stability of the mechanical effect of the electrode on the treated area is ensured by an individual electromagnetic vibrator.

A multi-electrode tooling for electrospark alloying is proposed, comprising a multi-electrode cartridge made with the possibility of mounting and adjusting the angle of inclination on the machine support and having a body of dielectric material that combines two or more electrode holders for rod electrodes, while individual inertial vibration exciters are fixed on the electrode holders, providing independent the movement of each rod electrode perpendicular to the relative processing aemoy surface direction, and between the lower part of the cassette housing and said electrode arms cartridges installed spring.

The means to achieve this goal is that the design of the snap allows you to position two or more rod electrodes with their independent movement from each other in the direction perpendicular to the surface being machined. Moreover, such a system allows each electrode to independently "track" the change in surface topography along the height, and ensures the stability of electric pulse and mechanical action.

Vibration of the electrode in the direction perpendicular to the surface provides forging and compaction of the applied layer. At the same time, when machining parts with a complex surface topography, a multi-electrode cassette, combining two or more electrode holders, must be fixed in the support of a turning or milling machine perpendicular to the surface being machined.

A diagram of the suspension of electrodes in a multi-electrode cassette is presented in Figure 1.

The housing of the cassette 1 is assembled from a dielectric heat-resistant material. The electrode holders 2 are located in the guide bushings 3 and have a degree of freedom along the axis of the electrode. An electromagnetic vibrator 4 of directional action is attached to each electrode holder. An inertial load is fixed on the moving part of the vibrator, providing the energy necessary for mechanical action. The vibrator generates vibrations along the axis of the electrode 5, which allows the process of spark doping with forging.

The independent suspension system shown in Figure 1 allows for stable contact of the electrode with the work surface and eliminates the effect of possible uneven consumption of electrodes. When the angle of inclination of the cartridge to the vertical is less than 45 °, the mass of inertial load fixed on the vibrator ensures the electrode is clamped to the treated surface. At large angles of inclination, up to negative, the electrode clamp is provided by a spring 6 installed between the electrode holder 7 and the lower part of the cassette 1.

The vibration displacement parameters and the amount of mechanical energy realized when the electrode strikes the surface to be treated can be controlled by changing the current and voltage parameters of the electromagnetic vibrator, as well as by selecting the mass of the inertial load.

The figure 2 presents a schematic diagram of a mechanical tooling that allows you to conduct an electric spark treatment of bodies of revolution with a complex shape of the side generatrix (stream of the rolling roll) simultaneously with several electrodes.

The calipers of the mechanical multi-electrode tooling 9 are made in the form of arcs on which radial guides 10 are mounted, allowing the multi-electrode cartridge 11 to be moved in the direction of the radius of the barrel of the work roll. The movement of the multielectrode cartridge along the axis of rotation of the roll is provided by axial guides 12. The guide of the cartridge 14 is mounted on the axial guide using a rotary sleeve 13 and has two degrees of freedom: rotation about the axis of the axial guide and tangential movement to the surface of the axial guide. Thus, the mechanical equipment provides a sufficient number of degrees of freedom for adjustment under any stream rolling mill.

Pilot tests of a four-electrode modular snap made on the basis of two two-electrode cassettes with an independent suspension of electrodes with an inertial vibration exciter were carried out (Figure 3).

Tests of tooling in the electric spark machining of a roll calibrated to produce a profile of a circle with a diameter of 18 mm showed that the proposed version of the tooling allows continuous coating without gaps. The parameters of electrode vibration when changing the angle of inclination of the tool to the axis of symmetry of the caliber from 0 to 180 ° change negligibly. The coatings obtained using various electrode materials are characterized by a roughness corresponding to the roughness obtained using a hand tool with a vibrating rod electrode at similar energy conditions. The use of the device allows to obtain high-quality coatings without defects in the surface layer in the form of tearing and caring of the metal.

The use of this type of multi-electrode tool with an independent suspension of electrodes and an inertial vibration exciter reduces the processing time of bodies with complex surface topography in proportion to the number of simultaneously working electrodes while ensuring uniformity of the properties of the resulting coatings.

Information sources

1. Hardening of surfaces of parts in combined ways. A.G. Boytsov, V.N. Mashkov, V.A. Smolentsev, L.A. Twig. - M.: Mechanical Engineering, 1991, 127-134 p.

2. Mikhaylyuk A.I., Rapoport L.S., Gitlevich A.E., Ivanov A.N., Fomicheva E.I. The effect of surface plastic deformation on the characteristics of iron-based electrospark coatings. Communication 2. The formation of the relief - Electronic processing of materials, 1991, No. 2, p.17-20.

3. Patent number: 2175594.

4. Auto USSR 1362577, class B23H 9/00, publ. 12/30/87, bull. 48.

5. Patent RU 2196665.

6. Gitlevich A.E., Mikhailov VV, Parkansky N.Ya. and other Electrospark alloying of metal surfaces // Chisinau: Shtiintsa, 1985, 195 p.

7. Auto USSR No. 629036. Cl. B23P 1/18, 1978.

Claims (1)

A multi-electrode tooling for electrospark alloying, comprising a multi-electrode cartridge made with the possibility of mounting in a machine support with an adjustment of the angle of its inclination, the housing of which is made of dielectric material and combines two or more electrode holders for rod electrodes, while individual inertial vibration exciters are fixed on the electrode holders, providing independent movement of each rod electrode perpendicular to the processing the direction of the surface, and springs are installed between the lower part of the cartridge case and the cartridges of said electrode holders.

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