SU931300A1 - Method of working non-rigid hollow parts - Google Patents

Description

(54) METHOD OF MECHANICAL TREATMENT OF UNRULTIER EMPTY PARTS

one

The invention relates to mechanical engineering technology and can be used for turning or grinding by grinding in centers of non-rigid hollow parts.

A known method of machining black hollow parts involves stretching the part in the cutting process within the elasticity of the material being processed simultaneously in axial and radial directions by means of a deforming element placed inside the part with a linear expansion coefficient, a large linear expansion coefficient of the material of the workpiece, and the cutting process, the part and the deforming element are heated 1

The disadvantage of this method is the low efficiency of stretching in the axial direction due to the fact that stretching begins at the moment of elimination of the gap between the workpiece and the mandrel with a joint

THEIR HEATED. During this time, the workpiece and the mandrel have time to be extended to a significant extent, therefore, after the appearance of thermal tension between them, further axial stretching occurs to a lesser extent (up to 2% of the total elongation of the workpiece).

The purpose of the invention is to increase the efficiency of the process of stretching the part in the axial direction.

to

The goal is achieved by the fact that in the method of machining non-rigid hollow parts, including the simultaneous stretching of the part in axial and radial directions when

15 by heating on a mandrel having a linear expansion coefficient greater than the corresponding coefficient of the part, the heating process is carried out simultaneously at the end of the part until it reaches the required temperature in the middle of the part.

Claims (1)

FIG. 1 shows the scheme of the implementation of the proposed method for the mechanical treatment of non-rigid hollow parts; Fig. 2 is a diagram of axial and radial deformations during heating. The circuit contains a part 1, mounted on a mandrel 2 fixed in cartridge 3, a turn 4 of an HDTV indicator, the protrusions of which are in close proximity to the ends of the part 1, at an erasure of D depending on the required heating temperature of the part. The processing is carried out by a cutter 5J mounted in the tool holder 6. The part is pressed by the axially movable center 7. The processing method is carried out as follows. The part 1 with the minimum clearance is mounted on the mandrel 2 and fixed with it in the chuck 3. At the ends of the part, an HDTV indicator coil is applied to its parts and the mandrel 2 is heated together with the part 1. At the initial heating moment in the cross sections parts located in close proximity to its ends, the part and mandrel expand intensively in these places between the part and the support & This is followed by guaranteed tension. When the part and mandrel are further heated, a joint elongation of the mandrel and the part occurs, and since the linear expansion coefficient of the mandrel is greater than the corresponding coefficient of the part, the mandrel lengthens to a greater extent, stretching the part. Heat is stopped when the desired temperature is reached in the middle of the part. 04 FIG. 2 shows a diagram of the temperature deformations of a non-rigid part 1 by the magnitude lR in the axial direction, i.e., the change in its length from P. to the mandrel 2 from P (to. Also presented is a diagram of the radial expansion of the part and mandrel — increasing the diameters cf and di to d. + d (j4dd (j with tension. Part 1 is machined with a cutter 5 fixed in the tool holder 6. After the cutting process is completed, part 1 with the mandrel 2 is removed from the machine and as the joint cools down to 2 0-50 ° C, they are separated. processing of non-rigid hollow parts., including simultaneous stretching of the part in the axial and radial directions when heated on a mandrel having a linear spreading coefficient greater than the corresponding part coefficient, in order to increase the efficiency of the process of part elution in the axial direction, the heating process is carried out simultaneously at both ends of the part until reaching the required temperature in the middle of the part. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 614893, cl. B 23 B 1/00, 1977.