SU1361186A1 - Method of machining articles and device for effecting same - Google Patents

Abstract

The invention relates to the treatment of products by vibration and can be used to remove residual voltages of parts and structures of various electrically conductive materials. The purpose of the invention is to improve the quality by uniformly relieving the residual stresses of the products and reducing the processing time. The essence of the invention is that the workpiece 4 is positioned free (L its Oi 00 05 FIG.

Description

but on the support rollers 6, 7 of the base 3, in the recess of which the inductor 1 is positioned so that its working surface is at a distance of 0.5-2 mm from the workpiece 4. When a current pulse passes through the inductor in the part of the part located above the inductor , eddy currents are induced. The interaction of the magnetic fields of the inductor and eddy currents leads to the emergence of an electromagnetic local contactless impact on the part area. The part is separated from the support rollers and the part of the part that is subjected to electromagnetics. The invention relates to the processing of products by vibration and can be used to relieve residual stresses of parts and structures of various electrical conductive materials.

The purpose of the invention is to improve the quality by uniformly removing residual stresses in the entire product and reducing the processing time.

FIG. 1 shows a device for carrying out the method for processing large-sized parts, in FIG. 2 - the same when processing small parts.

The vibration exciter in the form of a flat inductor 1 with a winding 2, which is made solid or hollow, preferably from a copper bus, is located in the groove of the base 3. Parts 4 are located in the cells of cassette 5 or part 4 lies on support rollers 6 and 7, the part 4 and the working surface of the inductor 1 have a mm gap to eliminate mechanical and electrical contact between the inductor and the part. The role of the rollers 6 and 7 can be performed by ball bearings, or part 4 can lie on an air cushion. The sensors 8 respond to the occurrence of the part 4 on the support rollers. This can be piezoelectric or piezometric pressure sensors or proximity sensors inductive, etc.

to a knock shock, it makes free bending oscillations that relieve residual stresses. Each subsequent impact on the part is applied at the moment of contact of the part of the support rollers after the next jump, for which the support rollers from different sides of the inductor are equipped with sensors 8, which through the switch 9 start the current pulse generator 10. To process the entire surface of the part, the latter is moved relative to the inductor, for which part of the support rollers is equipped with a drive 12. 2 s, and 2 3.p.f-ly, 2 ill.

The sensors 8, for example, the pressures are under the supports of the rollers 8. These rollers will be called measuring. The sensors 8 are placed on opposite sides around the inductor, can work in parallel, jointly or one by one when processing the ends of the part 4. Sensors 8 are connected to a switch 9, which serves as a trigger circuit for

generator 10 current pulses. Switch 9 may be a mechanical starting scheme, ignatron, trigatron or other type. All electrical components of the device are connected to the power supply 11. The actuator 12, such as a reversible motor, rotates the rollers 6 to move the part 4.

Example. Install free work piece 4 over

the working surface of the vibration exciter - inductor 1 on the support rollers 6 and 7, then excite vibrations of parts on its own frequencies by a non-contact electromagnetic shock by passing a current pulse through the winding 2 of inductor 1. Parts 4 are scanned relative to inductor 1 and cause each subsequent electromagnetic shock

on part 4 at the moment of returning the part to the working surface of inductor 1, i.e. on support rollers 6 and 7.

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Small parts 4 are oriented in the cells of the cassette 5 plane 10

20

25

The smallest stiffness is perpendicular to the working surface of the inductor 1 and limit the vertical movements of the parts by the top cover of the cassette 5.

The device that implements the method works as follows.

The workpiece 4 is placed on the support rollers 6 and 7. Under the action of the part 4, the sensors 8, located under the measuring rollers 7, give a signal. This signal triggers. the switch 9, which, in turn, triggers the generator 10 15 current pulses, and a current pulse passes through the winding 2 of the inductor 1. When a current pulse passes through the inductor winding, eddy currents are induced in the part above the inductor into the parts.

The interaction of the magnetic fields of the inductor current and eddy currents in the parts creates significant mechanical repulsive forces, which are perceived by the part 4 as a mechanical shock. Under the action of this impact, the part 4 is separated from the support rollers 6 and 7, and in the part of the part on which the impact occurred, bending oscillations occur at natural frequencies, because the part is free and is not connected mechanically with anything.

The part, oscillating, moves upward, then under the force of gravity is lowered onto rollers 6 and 7. Sensors 8 are triggered, a generator of 10 current pulses is triggered again through switch 9 and a current pulse passes through winding 2 again. the item is experiencing the next blow, etc. During the entire flight, part 4 performs bending oscillations at the natural frequencies of the sections. To process the entire part 4, the latter moves on the rollers 6 and 7 due to the rotation of the rollers 6 from the actuator 12 or otherwise the part performs scanning movements over the inductor.

The pressure experienced by the part is determined by the formula

thirty

35

40

45

50

gg

P B2

i-o VsiT

where P is pressure, MPa;

B - magnetic field induction, Gs.

When the magnitude of the induction of magnetic fields of the order of 300 kGs, you can get a pulse pressure of about 350 MPa,

0

0

five

five

0

five

0

five

0

and when the field is 1 MGS, the pulse pressure is 3500-4000 MPa. The force that occurs when a current pulse passes through an inductor acts on the part as an impact without mechanical contact between the inductor and the part. Moreover, the impact affects the area of the part located directly above the inductor. Under the action of the impact, the part above the inductor, on which the impact occurred, will oscillate at the natural frequency, and there will be bending oscillations.

Such vibrations at natural frequencies effectively remove internal residual stresses in the parts. The magnitude of the blow, i.e. the magnitude of the current pulse in the inductor can be calculated so that during the movement of the part from the inductor and back, several free oscillations of the part region, i.e. the time spent in flight must be equal to several periods (on the order of 3-6) of natural oscillations.

The magnitude of the impact can also be adjusted by the size of the gap between the surface of the part and the working surface of the inductor. Here, the minimum gap (on the order of 0.5 mm) is determined by the precision of the surface treatment of the part and the inductor and the need to avoid mechanical and electrical contact between the inductor and the part. The maximum gap (on the order of 2 mm) is determined by energy considerations.

In addition to the reduction of residual stresses due to oscillations in parts of the part experiencing a pulsed magnetic field, other positive effects arise. For example; a pulsed magnetic field contributes to a phase transition in the structure of the material of the part, the electrodynamic and thermomechanical forces that appear equalize the structure of the part, compact the crystallites of the structure.

When processing small parts (Fig. 2), the latter are oriented with the planes of least rigidity gg perpendicular to the working surface of the inductor and limit their vertical movement. When a current pulse is passed through the inductor winding due to the effect of shock mag5136

Part 4 forces push up, begin to move and oscillate at their own frequencies. When the upper base of the cassette 5 is reached, the parts 4 receive an additional mechanical shock and begin to move downward, continuing to oscillate at their own frequencies. The current pulses into the inductor come periodically or the parts themselves 4, coming into contact with the working surface, cause another current pulse. Cassette 5 is made of dielectric.

The shape of the current pulse in the inductor can be damped oscillatory or aperiodic, in any case, the force acting on the part has one direction (repulsion from the inductor), since the force is proportional to the square of the magnetic field induction, i.e. the square of the current in the inductor and does not change direction.

The duration of the current pulse must be less than a quarter of the period of natural oscillations, parts of the part. The shorter the current pulse through the inductor, the closer the nature of the influence of magnetic forces on the part to the shock effect. The duration of the current pulse through the inductor during the magnetic-pulse processing of the material is 4

riyals for about 10 s. Such an impulse is perceived by the part as an instant hit. At frequencies of natural oscillations of parts of a part up to 10 Hz, such a pulse duration is satisfactory.

The magnitude of the current pulse and the parameters of the inductor are calculated depending on the mass of the part and the electrical conductivity of the material of the part according to the well-known method for calculating flat inductors for magnetic-pulse processing, for example, stamping.

The implementation of the proposed method allows processing the part without direct mechanical contact between the inducer and the part. It is not necessary to fix the part to the inductor. The item does not experience contact mechanical shock. In addition, the use of the method makes it possible to subject individual parts of the part to bending vibrations at natural frequencies, which, as is well known, is most effective for removing residual stresses.

6

The scientific research institute allows to achieve high quality machining of parts, i. E. more complete removal of residual stresses, to process the part in automatic mode, i.e. the part itself, when dropped on the support rollers, triggers the current pulse generator, i.e. the next blow

which reduces part processing time, i.e. increases labor productivity, as well as to process the entire part of any configuration in one installation due to scanning movements of the part over the inductor.

Continuously automatically excited bending vibrations at eigenfrequencies lead to almost complete elimination of residual stresses, i.e. Increase processing quality. Free location of the part, scanning of the part above the exciter and bending oscillations at natural frequencies, shorten the time of processing the part, i.e. increase labor productivity.

Claims (4)

1. Method of processing products, including the installation of the product and the vibrator on the supports, pulsed vibration of individual sections at a natural frequency creating a mode of free oscillation of the product between pulses and moving the part relative to the surface of the vibrator, characterized in that, in order to improve quality by uniformly removing residual stresses in the product and reducing the processing time, the product is set above the surface of the vibrator at a distance of 0, 5-2.0 mm, the vibration is carried out by a non-contact electromagnetic shock, each stroke being carried out at the moment of contact of the product with the support, and the movement of the product is carried out continuously. 2. Method POP1, characterized in that, in order to expand the technological capabilities by processing small-sized products, when installing the product, the planes of the least rigidity are additionally oriented perpendicularly to the surface of the vibrator and limit their vertical movement, 3. A device for machining products containing supports and a vibrator. characterized in that, in order to improve the quality of the product by uniformly processing the whole and reducing the processing time, it further comprises a current pulse generator, a switch, pressure sensors mechanically fixed with supports and electrically connected to the current pulse generator, the supports are in the form of rollers, and vibration torus - in the form of an electromagnetic inductor, which is electrically connected to a current pulse generator, 4. The device according to claim 3, characterized in that, in order to expand the technological capabilities by treating products with a curved surface, the surface of the inductor is made curved. Editor C, Baker Compiled by A, Kulemin Tehred M. Margental Order 6198/30 Circulation 550Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab ,, d, 4/5 Production and printing company, Uzhgorod, st. Project, 4 FIG. 2 Proofreader V. But ha