RU213617U1 - DORN FOR ELECTROMECHANICAL HOLING - Google Patents

Abstract

The utility model relates to mechanical engineering and can be used for finishing and hardening holes. The mandrel for electromechanical processing of holes includes a mandrel with an external thread in the tail section, on which coupling nuts and a current-insulating sleeve are installed. In the front part on the mandrel, a reinforcing tooth and a calibrating tooth, isolated from the mandrel and reinforcing tooth, are fixed with a nut. On the opposite side of the mandrel, a blind hole is made, hermetically plugged. In the middle part of the mandrel there is a radial blind hole in which a fitting for supplying coolant is installed. In the front part of the mandrel there are two channels symmetrical to each other for supplying coolant. The calibrating part is made with a wear-resistant coating based on titanium-silicon nitride. The technical result is to increase the resistance of the calibrating part. 3 ill.

Description

The utility model relates to mechanical engineering and repair production, in particular to tooling for finishing and hardening holes.

Known mandrel with a duplex tool [Patent RU No. 178535, publ. 04/06/2018, bul. No. 10], includes a mandrel with an external thread in the tail section, on which coupling nuts and a current-insulating sleeve are installed, in the front part, a reinforcing tooth and a calibrating tooth are fixed on the mandrel, isolated from the mandrel and reinforcing tooth by an insulating sleeve and insulating rings, with the opposite on the side of the mandrel, an axial blind hole is made, hermetically plugged with a screw plug, in the middle part of the mandrel there is a radial blind hole communicated with an axial blind hole, in which a fitting for supplying coolant is installed, and in the front part of the mandrel on the outer side, two channels symmetrical to each other are made for supplying coolant to the mating surfaces of the hardening tooth and the hole being machined from the axial blind hole in the mandrel.

Known mandrel has the following disadvantages - the low resistance of the calibrating tooth and the unstable quality of the finishing and hardening of the holes.

EFFECT: increased durability of the calibrating tooth and quality assurance of the finishing and hardening processing of the holes.

The specified technical result is achieved by the fact that the calibrating tooth is made with a wear-resistant coating based on titanium-silicon nitride.

In FIG. 1 shows a general view of the mandrel for hardening the surface of the hole of the part, in Fig. 2 - section along the line A-A.

The mandrel for hardening the surface of the hole in the part includes a mandrel with an external thread in the tail section 1, a nut 2, two coupling nuts 3, a current-insulating sleeve 4, a calibrating tooth 5, a reinforcing tooth 6, an insulating sleeve 7, and insulating rings 8. In the upper end part of the mandrel an axial blind hole 9 is made, hermetically plugged with a screw plug 10. In the middle part of the mandrel, below the coupling nuts, a radial blind hole is made communicating with the axial hole and a fitting 11 is installed. In the lower part of the mandrel on the outer side, two channels 12 symmetrical to each other are made for process fluid supply to the mating surfaces of the reinforcing element and the machined surfaces of the hole. A wear-resistant ion-plasma coating based on titanium-silicon nitride is applied to the calibrating tooth 5.

The coatings were applied by the CIB method (condensation from the plasma phase in a vacuum with ion bombardment). A calibrating tooth, preliminarily cleaned of impurities, made of VK8 hard alloy, was placed in the chamber of the Bulat-6T installation with electric arc evaporators installed in it, the cathode materials of which include coating elements.

Work mandrel for electromechanical processing of holes as follows. The reinforcing tooth is brought to the hole being processed and a tight contact is created. A current with a density of 250...300 A/mm ² is passed through the place of contact of the hardening tooth with the treated surface of the hole. As a result of the subsequent axial movement of the mandrel relative to the axis of the hole being processed, the annular region of the hardening tooth with the inner surface of the hole is heated up to a temperature of 900 ... mandrel and two radial holes on the outer side of the mandrel, there is an instantaneous heat removal and the formation of a hardened layer. The gauge tooth following the hardening tooth smooths out the roughness and forms the final dimensions of the hole.

The use of a calibrating tooth with an ion-plasma coating based on titanium-silicon nitride makes it possible to increase the tool life (calibrating tooth) by 1.2–1.4 times and ensure the quality of the finishing and hardening processing of holes in terms of surface layer hardness and roughness.

Claims (1)

Mandrel for electromechanical processing of holes, containing a mandrel with an external thread in the tail part, on which coupling nuts and a current-insulating sleeve are installed, in the front part, a reinforcing tooth and a calibrating tooth are fixed on the mandrel, isolated from the mandrel and reinforcing tooth by an insulating sleeve and insulating rings, on the opposite side of the mandrel, an axial blind hole is made, hermetically plugged with a screw plug, in the middle part of the mandrel, a radial blind hole is made, connected with the axial blind hole, in which a fitting for supplying coolant is installed, and in the front part of the mandrel on the outer side there are two symmetrical another channel for supplying coolant to the mating surfaces of the hardening tooth and the hole being machined from the axial blind hole in the mandrel, characterized in that the calibrating tooth is made with a wear-resistant coating based on titanium-silicon nitride.

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