The method of assembly of parts with tension
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.
FIELD: machine engineering, possibly manufacture of sealing envelopes of corrosion resistant steels of metal-plastic high-pressure bottles.
SUBSTANCE: method comprises steps of separately making metallic convex bottoms with cylindrical collar and backing ring. Thermal expansion factor of backing ring exceeds that of bottoms; outer diameter of backing ring provides close fit of bottoms onto it at 20°C; cooling preliminarily assembled backing ring with bottoms until cryogenic temperature; sliding bottoms on backing ring in cooled state until mutual touch of cylindrical collars of bottoms; heating assembly up to 20°C in order to provide close fit of backing ring in cylindrical collars of bottoms; welding bottoms along butt of assembly and then removing backing ring by chemical milling.
EFFECT: simplified process of making envelopes with enhanced mass characteristics.
2 cl, 4 dwg, 1 ex
FIELD: machine engineering, namely equipment for dismounting press-fit joints, possibly restoration of electric machines.
SUBSTANCE: apparatus includes housing with platforms for horizontal and vertical motions. Part to be dismounted is placed on horizontal motion platform and it is fed to stripping mechanism. The last is joined with vertical motion platform by means of fastening members and it is provided with adjusted grips supporting heating members with possibility of their axial movement. Heating members are in the form of nozzles for alternating feed of hot and cooled air.
EFFECT: reduced axial errors between dismounted part and stripping mechanism, lowered efforts for stripping parts.
5 cl, 5 dwg
FIELD: machine engineering, possibly restoration of articles operating at large cyclical loads and high temperature values.
SUBSTANCE: method comprises steps of cooling male part in liquefied nitrogen and introducing it into female part. Male part is made of refractory nickel alloy similar to that of female part. After equalizing temperature of assembly, it is heated till recrystallization temperature and subjected to isothermic soaking. It causes creation of structural and phase conversions in assembled parts.
EFFECT: improved quality of joints of parts.
1 ex, 1 tbl
FIELD: mechanical engineering.
SUBSTANCE: invention can be used in shaft-bushing interference. According to invention, shaft and bushing are made of material with similar physical and mechanical properties with projections in form of laser hardened paths. Pitch of parts is twice as great as their width. Paths are arranged at angle of 0-90° to axis of joint. Opposite paths of shaft and bushing are displaced relative to each other by width of part. In particular cases, paths can be arranged along ring lines lying in planes square to axis of joint, in starting lines parallel to axis of joint, or helical lines.
EFFECT: increased load-carrying capacity of joint.
4 cl, 4 dwg
FIELD: measuring technique.
SUBSTANCE: device comprises flexible measuring member mounted concentrically with respect to the bearing race and having strain gauges covered with casing and set on its surface. The device also has split bushing with conical outer side mounted for permitting cooperation of the inner side of the flexible member with the outer side of the bearing race to be tested. The flexible member is sectional and composed of two step thick-walled races provided with strain gauges, mounted on the bushing, and interconnected by means of a thread joint. The bushing has ring cylindrical recess centered in its outer surface. The inner surfaces of the smaller steps of the thick-walled races are conical, with cone bases arranged from the side of the large steps.
EFFECT: enhanced convenience of testing and reduced metal consumption.
FIELD: plastic working of metals, namely processes for forming butt welded seams on tubes at making tube studs of U-shaped tube bundles using effect of localized hot plastic deforming of welded seam and near-seam zones.
SUBSTANCE: method comprises steps of preliminarily working tube ends by expanding them from cylinder to cylinder; assembling tubes with use of mandrel and placing intermediate member of additive material between joined end surfaces of end portions of tubes sized by expansion and end surfaces of step ring. Welded seams are formed by argon-arc welding due to melting material of intermediate member at its both sides adjacent to tube ends. The intermediate member is heated up and it is subjected to hot radial squeezing while concentrating its initial deformation in surface layers according to position of ring steps, welded seams and near-seam zones on mandrel for providing size of their outer diameter equal to initial outer diameter of tubes.
EFFECT: improved quality of welded seams.
FIELD: railway transport; repair of rolling stock.
SUBSTANCE: invention relates to repair of load-bearing parts of vehicles, particularly, to repair of overspring beams of car bogies with inserts press-fitted into step bearings. According to proposed method, step bearing of overspring beam is heated, together with insert, to temperature exceeding 250°C. Inner surfaces of insert are cooled by blowing at velocity 1.1 times higher than velocity of heat exchange through surfaces in contact with step bearing to eliminate negative allowance between insert and outer bead of step bearing. To extract insert, it is expanded from inside by applying force. Device for implementing the method has body in form of disk to be arranged in step bearing with slots on side surface in which bellcranks 9 are fitted being driven by pneumatic cylinder, with claws for gripping the insert, central hole through which rod 16 of pneumatic cylinder passes to extract insert 40, with inner space designed for distribution of cooling compressed air among nozzles pointed to surfaces of insert.
EFFECT: increased efficiency when repair overspring beams, reduced energy consumption and labor input in process of repair.
3 cl, 4 dwg
FIELD: processes and apparatuses for assembling parts at tightness, possibly production and restoration of sleeves of sealing unit of turbo-compressor.
SUBSTANCE: method comprises steps of placing sleeve into embracing part at technological tightness; performing electric-contact heating of inner surface of sleeve and then deforming it by drifting for creating mounting tightness of sleeve and embracing part joint; smoothing roughness of inner surface of sleeve. Electric-contact heating and drifting of inner surface of sleeve are realized with use of duplex tool in the form of contact- heating tool and arranged behind it deforming- calibrating tool. Contact-heating tool provides heating of inner surface of sleeve in annular zone of contact with said contact-heating tool. Deforming- calibrating tool is mounted at tightness equal to 0.8 mm. In the result during one operation sleeve is pressed-in to embracing part, roughness of inner surface of sleeve is smoothed and inner surface of sleeve is strengthened at hardness 48 - 54 HRC3.
EFFECT: enhanced efficiency of assembling parts.
FIELD: machine building.
SUBSTANCE: invention is related to machine building and instrument making, and may be used in performance of machine assembly works. Method for interference fit of parts by means of press fitting with application of material that strengthens the joint includes partial press fitting of parts with measurement of press fitting force and their further additional press fitting. According to method partial press fitting of parts is carried out. Then material that strengthens joint is applied on free sections of joined surfaces of one or both parts. After that their further additional press fitting is realised.
EFFECT: simplification of assembly process and reduction of costs for joint strengthening.
FIELD: process engineering.
SUBSTANCE: external part inner surface is furnished with 2 to 5 mm-pitch teeth. Assembly is carried out to make a clearance between external and internal parts. Internal part is subjected to upsetting.
EFFECT: higher quality and strength of joint, simplified assembly.
4 dwg, 1 ex