The method of assembly of parts with tension

 

(57) Abstract:

The invention relates to mechanical engineering and can be used in the Assembly with interference fit parts like nut - case, in particular thin-walled parts. Covered in detail with a gap set in the hole covering, after which the hole is covered items are donovani. Then the mandrel is moved in the direction opposite to the working course, while imposing a radial ultrasonic vibrations with amplitude equal 18-22 microns, and the frequency equal to 10-22 kHz. The result is the expansion of the scope of the method while maintaining the high quality of the obtained compound.

The invention relates to the field of engineering, and in particular to methods of Assembly parts type sleeve - body tensed by burnishing, in particular, thin-walled parts.

There is a method of Assembly of the cylinder head of an internal combustion engine, including connection details the installation of the glass nozzle at the top and bottom of the nest with the formation of the annular gap, centering and fixation of the Cup with donovania internal surface of a glass nozzle (see and.with. NO. 1717857, IPC5F 02 I 1/24, publ. 1992).

Naib is tightness, including connection details, burnishing superimposed on the mandrel ultrasonic vibrations (ultrasonic testing), while the first mating surface covering details create residual compressive stress by means of burnishing superimposed on the mandrel UT with amplitude equal 20-22 microns, to form the Assembly clearance between the parts, then join them, followed by the sample Assembly gap due to the residual compression stress (see and.with. NO. 1199557, IPC423 R 11/02, publ. 1985).

The disadvantage of these methods is limited scope due to the provision of an Assembly of parts with tension by means of burnishing through-hole of the workpiece on the passage of the mandrel. The inability of the parts with tension by donovania blind holes due to the difficulty of moving the mandrel in the direction opposite to the working course, after the end of burnishing because of an elastic residual stresses on the inner surface of the machined workpiece, which leads to deterioration of surface quality and reduce the density of the connection details.

The invention aims to expand the scope of the method while maintaining a high quality connection is with her tightness by means of burnishing through or blind hole parts by providing after burnishing movement of the mandrel in the direction reverse course work.

To achieve the mentioned technical result in the method of Assembly of parts with tension first establishes connection parts installation covered in detail in the hole covering the items with the formation of the Assembly gap between them, then subjected to dorneanu hole covered in detail, after which the mandrel is moved in the direction opposite to the working course, while imposing a radial ultrasonic vibrations with amplitude equal 18-22 microns, and the frequency equal to 20-22 kHz.

The movement of the mandrel in the direction opposite to the working course, is provided by increasing the diameter of the hole covered in detail after the burnishing superimposed on the mandrel radial ultrasonic vibrations with amplitude equal 18-22 microns, and the frequency equal to 20-22 kHz. This allows to extend the scope of application of the method while maintaining the high quality of Assembly and processing of the inner surface parts donovania due to the possibility of the parts with tension as with end-to-end, and with a blind hole by means of burnishing.

When the amplitude of the ultrasonic inspection imposed on the mandrel below 18 microns is an increase in the frictional forces impeding the movement of the mandrel in the opposite direction of working the Le ultrasonic waves, that leads to the weakening of the surface layer holes covered items.

When the frequency of ultrasonic testing more than 22 kHz deteriorates the surface quality of machined donovania holes covered parts, namely the deviation from the form.

This method is used for the Assembly of parts with tension by means of burnishing, where as covered items can be used a thin-walled part with a ratio of outer diameter to inner not more than 1.2 mm

The method of Assembly of parts with tension as follows.

First establishes connection details the installation of covered items, such as thin-walled sleeve into the hole covering details such as housing, education Assembly gap between planting f7 and f8. Then subjected to dorneanu the inner surface of the sleeve. This select Assembly gap and provide a high quality press-fit connection, creating a planting density due after burnishing elastic stresses acting on the part of the body on the sleeve and the sleeve on the body. Then the mandrel is moved in the direction opposite to the working course, while imposing a radial ultrasonic inspection amplitudine the diameter of the sleeve becomes smaller than the diameter of the mandrel, that makes it impossible for removing the mandrel in the direction opposite to the working course, without compromising the quality of the processed surface and the quality of the obtained compound. To temporarily increase the diameter of the sleeve to provide movement of the mandrel in the direction opposite to the working course, after the burnishing on the mandrel impose radial ultrasonic inspection with amplitude equal 18-22 microns, and the frequency equal to 20-22 kHz.

The imposition of radial ultrasonic inspection on the mandrel allows, firstly, to reduce the elastic stresses acting on the part of the sleeve and the housing on the mandrel, secondly, to create temporary elastic stresses acting on the sleeve from the mandrel, in order to reduce the diameter of the inner bore of the sleeve, thirdly, to improve the quality of the inner surface of the sleeve in the high-frequency radial vibrations of the mandrel, in which there are crushing smoothing irregularities on the inner surface of the sleeve, fourthly, to increase the effectiveness of lubricant that reduces friction of the mandrel on the sleeve.

An example of a specific implementation of the proposed method.

Assemble the stationary press-fit connection of the sleeve with an outer diameter 24,9 mm and the inner is tulki in the housing bore with the formation of the Assembly gap between them. Then subjected to the inner surface of the sleeve donovani mandrel, the diameter of which is equal to 21.3 mm, the width of the cylindrical ribbon 2 mm and chamfer angle 14. The burnishing is carried out on a hydraulic press equipped with a device for ultrasonic processing, and ultrasonic generator. Using the mandrel of the resonant diameter, which converts the longitudinal ultrasonic inspection in the radial. In the process of burnishing choose Assembly gap and get a fixed connection with simultaneously high-quality processing of the inner surface of the sleeve hole.

Thus, the use of the proposed method contributes to the expansion of applications while maintaining a high quality due to the ability to assemble parts with tension by means of burnishing as deaf, and through holes covered parts due to the possibility of relocation of the mandrel after the burnishing in the direction opposite to the working course.

The method of Assembly of parts with tension, including connection details, burnishing superimposed on the mandrel radial ultrasonic vibrations, wherein the first establishes connection parts installation covered in detail in the hole covering the details of the Le which the mandrel is moved in the direction reverse course work, while imposing a radial ultrasonic vibrations with amplitude equal 18-22 microns, and the frequency equal to 20-22 kHz.

 

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