RU2421320C2 - Electrically driven vibration head for rolling - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming, particularly, to surface pulsed impact plastic deformation. Female head comprises body with central bore, deforming elements, plate-like master cam with central hole rigidly fitted on body face, and hollow-shaft rotor. Rotor hole surface is provided with splines. Master cam central bore surface has ledges and recesses. Said body is made up of three-phase induction squirrel-cage motor with rotor running in antifriction bearing there inside. V-shaped bent flat plate springs are fitted into rotor bore. Deforming element are secured at the center of plate springs. Plate springs have their one end secured rigidly on rotor face and opposite end fitted in master cam central hole for them to be acted on by said ledges and recesses. Deforming elements are arranged to embrace the workpiece.

EFFECT: expanded performances, higher efficiency.

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Description

The invention relates to the processing of metals by pressure, in particular to the manufacture of tooling for processing by impulse-impact surface plastic deformation (PPD), and can be used for finishing and hardening of cylindrical, screw and complex profiles, for example, screw pump pumps, screw surfaces with rounded -sinusoidal profile, eccentric shaft necks, cam surfaces and PK profiles.

Known three-roller device, mounted on a support of a lathe, consisting of a housing and a holder pivotally connected to it with three deforming elements - rollers, allowing to unload the machine components from unilaterally applied force and processing non-rigid parts such as shafts [1]. The hinged connection of the holder with the housing allows to increase the accuracy of the shaft processing and to eliminate the influence of the beating of the shaft surface acquired in previous operations.

The disadvantages of the known device are the narrow technological capabilities in which the finishing by surface plastic deformation (PPD) of screw and other complex external surfaces after appropriate modernization is very difficult, and in some cases impossible, while low productivity and complicated long-term setup increase the cost of processing.

A device is known that comprises a housing with an individual high-speed drive, covering a workpiece with a ring with deforming elements located on the treadmill on the inner surface, the housing ring being installed in a crank, also having an individual drive, due to which additional planetary rotation is transmitted about an axis passing through the center workpieces parallel and offset relative to the axis of the body-ring by the amount of eccentricity [2, 3].

The disadvantages of the known device are the narrow technological capabilities in which the finishing by surface plastic deformation of the screw outer surfaces after appropriate modernization is very difficult, and in some cases impossible. In addition, a structurally complex drive, consisting of two individual drives, increases the cost of processing, reduces productivity, degrades the quality of the processing surface, requires complex and lengthy settings.

The objective of the invention is to expand the technological capabilities of equipment for PPD of complex surfaces by using a covering tool with deforming elements mounted on flat leaf springs and located on the inner surface of the rotor of the electric motor, which allows to improve the quality of the machined surface, increase productivity and reduce processing costs.

The problem is solved using the proposed enclosing head for surface plastic deformation of cylindrical and helical surfaces, comprising a housing with a Central hole and deforming elements, and it is equipped with a copier in the form of a disk with a Central hole, rigidly mounted on the end of the housing, and a rotor in the form of a hollow shaft, on the surface of the opening of which slotted grooves are made, while on the surface of the central hole of the copier protrusions and depressions are made, the body is made in the form of a stat A socket of a three-phase asynchronous squirrel-cage electric motor, inside of which the aforementioned rotor is mounted on rolling bearings, V-shaped curved flat leaf springs of steel cold-rolled heat-treated tape are installed in the hole of the latter, made with the possibility of creating an interference fit, which provides the force of surface plastic deformation, the deforming elements are fixed in the middle part leaf springs, which at one end are rigidly fixed to the end of the rotor, and the other end is located enes in the central opening of the copier, with exposure to said projections and depressions of the copier, and the deformation elements are arranged to grasp the workpiece to form the inner diameter passing through their vertices, when the plate spring in a free condition, a smaller diameter preform by an amount of interference.

Design features and operation of the head are illustrated by drawings.

Figure 1 shows a diagram of an implementation of the proposed head for rolling in and hardening a helical surface, a partial longitudinal section; figure 2 is a view from one end along A in figure 1; figure 3 is a section along BB in figure 1; in Fig.4 is a view from the other end along B in Fig.1, flat springs with deforming elements in the rolling position; in Fig.5 is a view from the other end along B in Fig.1, flat springs with deforming elements in the impact position.

The proposed head is designed for plastic deformation of screw, cylindrical and other complex surfaces (for example, screw pump pumps, screw surfaces with a rounded sinusoidal profile, cylindrical shafts, eccentric shaft necks, cam surfaces and RC profiles), the work of which is that workpiece and deforming tool report rotational movements V _W and V _and accordingly, the head by deforming tool reported continued movement hydrochloric feed S _PR. The head has deforming elements that inflict numerous blows on the surface of the workpiece, plastically deforming and hardening the outer surface.

For surface pulsed-impact deformation of the workpiece’s work surface, for example, screw pump screw 1 (see Fig. 1), pretreated, for example, by turning, it is fixed in a fixture, for example, in a three-jaw self-centering cartridge with a center tailstock (not shown) , and the rotational movement V _{З is} reported around its own central axis, and the longitudinal feed S _{PR is} provided to the pulse-impact deforming tool 2.

The head consists of a housing 3 made in the form of a stator of a three-phase asynchronous squirrel-cage motor, taken, for example, according to GOST 19523-74, with poles 4 and made of gray cast iron. Inside the stator housing 3, on the rolling bearings 5, a rotor 6 is mounted in the form of a hollow steel shaft.

In the spline hole of the rotor 6, V-shaped curved flat leaf springs 7 are installed, made of cold-rolled steel heat-treated tape. In the middle part of the leaf springs 7 are fixed deforming elements 8, for example balls, rollers, etc.

The leaf springs 7 are located in the spline grooves 9 of the rotor hole and are bolted to one end of the rotor 6 at one end of the rotor 6 with bolts 10. The spline grooves in the rotor hole are designed to transmit rotor torque to the deforming elements and prevent longitudinal twisting of the flat springs, so the latter are tightly seated in the spline grooves .

The other end of the leaf springs 7 is free, located in the slotted grooves of the rotor hole, extends beyond its dimensions and is located in the central hole of the copier 11, made in the form of a disk and rigidly fixed to the end of the housing 3. The central hole of the copier 11 is made in the form of protrusions 12 and depressions 13 Thus, the protrusions 12 and depressions 13 of the copier 11 act on the free end of the flat spring 7 when the rotor 6 rotates, turning free rolling into a pulse-impact surface plastic deformation (PPD) with a strengthening effect.

The number of deforming elements 8 is chosen for structural reasons and taking into account that they cover the workpiece 1.

The inner diameter "d" at the tops of the deforming elements 8, mounted on leaf springs 7, which are in a free state without a workpiece, is less than the workpiece diameter D _{1 to be} processed by the amount of interference that determines the rolling force when the end of the leaf spring is in the hollow of the copier. The force P of the pulse-impact action of the deforming elements 8 on the workpiece surface 1 is set by the difference "K" of the protrusion 12 over the cavity 13 and the stiffness of the springs (see figure 5).

The proposed design of the head and the fastening of the deforming tool 2 in the hole of the shaft of the rotor 6 of the electric motor mounted, for example, on the transverse support of the lathe (not shown), allows oscillatory movements of the deforming elements 8 mounted on leaf springs 7, realizing a pulse-impact plastic deformation of the surface blank layer.

The kinematic transmission of the rotational motion of V _{And the} rotor shaft 6 with deforming elements 8 is carried out using electric forces induced in the stator housing of the electric motor, and is minimal in length and complexity and eliminates the use of intermediate belt, gear and other gears and reducers, therefore, the proposed device has high efficiency.

In order to create a force P for a pulse-impact surface plastic deformation, a copier is installed that exerts pressure on the leaf springs and, accordingly, on the deforming elements 8 in the transverse direction. The movable fastening of the deforming elements 8 on the leaf springs 7 is carried out by known methods.

The hardness of the surface layer, the depth of hardening and surface roughness obtained using the proposed head, depend on the impact force and the number of strokes per 1 mm ² surface. These parameters, in turn, depend on the peripheral speed of the rotor shaft with deforming elements 8, interference, the size of the deforming elements, their number, rotation speed of the workpiece, the magnitude of the longitudinal feed of the tool and the number of passes.

The modes of pulse-impact deformation for the proposed head, equipped with, for example, balls with a diameter of 5 ... 10 mm, and steel billets are as follows: the peripheral speed of the rotor shaft is V _And ≈0.05 ... 1.5 m / s, the peripheral speed of the workpiece is V _З ≈20 ... 40 m / s, the number of passes - 2 ... 3, the interference - 1.1 ... 2.5 mm.

As a result of pulse-impact plastic deformation of microroughnesses and the surface layer of the proposed head, the surface roughness parameter increases to Ra = 0.08 ... 0.4 μm with the initial value Ra = 0.8 ... 3.2 μm. The hardness of the treated surface increases by 25 ... 75% with a riveted layer depth of 0.25 ... 2.5 mm. The residual compressive stresses reach 350 ... 750 MPa on the surface.

Pre-treatment of the workpiece: grinding to a roughness parameter value Ra = 0.4 ... 1.6 μm, as well as finishing turning of surfaces with a roughness Ra = 3.2 μm.

The head for pulse-impact deformation allows you to create a regular microrelief on the machined complex profile, including the helical surface, which can hold lubricants and extend the life of parts during operation.

The head for pulse-impact deformation is used in the manufacture of blanks from non-ferrous metals and alloys, cast iron and steel with hardness up to HRC 58 ... 64.

In industrial tests, the head mounted in the cartridge with an electromechanical drive lathe mod. 16K20F3 processed the screw blank of the left H41.1016.01.001 screw pump of the EVN5-25-1500 brand, which had the following dimensions: total length - 1282 mm, length of the screw part 1208 mm, screw cross-section diameter - 27 ^-0.05 mm, eccentricity - 1.65 mm, pitch - 28 ^{± 0.01} mm, roughness R _a = 0.4 μm; single-helical screw surface, left direction; material - steel 40X, hardness HB 270-280, weight - 5.8 kg. The processing was carried out using the developed head, based on the IM5010 electric motor having a shaft rotation speed of the rotor n = 750 min ^-1 ; the outer diameter of the rotor shaft is 157.3 mm; the diameter of the hole bored under the tool and the workpiece from 54 mm to 115 mm; length of the housing - stator - 253 mm; the outer diameter of the housing - stator is 261 mm.

Impulse-impact PPD were conducted in the following modes: peripheral speed of the instrument - V _And ≈1.2 m / s; the peripheral speed of the workpiece is V _З ≈15 m / s, the number of passes is 3, the interference fit is 1.2 mm, the longitudinal S _PR feed is 1.5 ... 2.0 mm / rev, the hardening force is 170 ... 175 N; the screw diameter changed after processing by 0.03 mm (0.015 mm per side); the depth of the hardened riveted layer was in the range of 0.15 ... 0.20 mm; hardness increase by 25 ... 30%; during processing, the deforming elements were lubricated with a mixture of industrial oil (60%) and kerosene (40%), the surface of the workpiece with kerosene. The values of technological factors (impact frequency, feed rate) were chosen in such a way as to ensure the multiplicity of impact on the elementary area of the treated surface in the range of 6 ... 10. A further increase in the multiplicity of the deforming effect leads to softening.

The initial roughness parameter Ra = 3.2 μm, achieved Ra = 0.32 μm; deforming tool - balls with a diameter of 7 mm from steel ШХ 15, hardness HRC 63 ... 65.

The depth of the hardened by pulse-shock processing of the layer is 3 ... 4 times higher than with traditional rolling. The hardened layer in the traditional static rolling is formed under long-term action of large static forces.

The proposed head with a similar depth of the hardened layer is achieved as a result of a short-term pulse-impact impact on the deformation zone of the energy pulse.

The required roughness and accuracy of the screw surface was achieved after T _m = 3.45 min (against T _m ^bases = 10.6 min according to the basic version with traditional rolling of screws on a 1K62 lathe at OAO Livhydromash).

To ensure the required quality and dimensional accuracy of the processing, the main time was 3 times less than when rolling in with a traditional obkatnik. In this case, the depth and microhardness of the hardened layer (white zone) were 0.20 ... 0.25 mm and 8 ... 9 GPa, respectively, with a gradual decrease in microhardness in depth to the initial state - 2.0 ... 2.5 GPa.

The control was carried out by an indicator bracket with an indicator ICh 10 B cells. 1 GOST 577-68. The cumulative error between any non-adjacent steps was not more than 0.1 mm, the clearance when controlling the straightedge of the protrusions forming in diameter was not more than 0.07 mm, which is permissible according to the technical specifications.

Studies of the stress state of the hardened surface layer by pulse-shock processing showed that the maximum residual stresses are close to the surface, as when chasing, which is favorable for most of the interfaced parts of mechanisms and machines. A comparison of the depth of the stressed and hardened layer, the stress gradient and the hardening gradient shows that the depth of the stressed layer is 1.1 ... 1.3 times greater than the depth of the riveted layer, which is consistent with the theory of surface plastic deformation.

The ultimate roughness value achieved during processing by the proposed head is R _a = 0.08 μm, a 5-fold decrease in the initial roughness is possible.

Impulse-impact deformation in the process favorably affects the working conditions of the head. It leads to a more uniform distribution of the load on the deforming elements, facilitates the formation of a hardened surface.

Impulse-impact deformation contributes to better penetration of cutting fluid (coolant) into the treatment area. When applying a pulsed load, the deforming elements and the deforming surface periodically “rest”, which helps to increase its resistance. Processing under conditions of pulse-impact deformation sharply increases the cooling, dispersing and plasticizing effect of the coolant due to the facilitation of its access to the contact zone of the deforming elements and the workpiece.

The proposed head extends the technological capabilities of pulse-impact treatment by surface plastic deformation, allows you to control the depth of the hardened layer, the degree of hardening and the surface microrelief. At the same time, a structurally simple drive reduces the cost of processing, increases productivity, improves the quality of the machined surface, does not require complex and lengthy settings.

The movable connection and installation of deforming elements on such leaf springs, such as a rest, centers the workpiece, improves the accuracy of machining of non-rigid workpieces and eliminates the influence of beating of the surface of the workpieces acquired in previous operations.

Information sources

1. Reference technologist-machine builder. In 2 vols. T 2 / Ed. A.G. Kosilova and R.K. Meshcheryakova. - 4th ed., Revised. and add. - M.: Mechanical Engineering, 1985. S.386-388. Fig. 7 is a prototype.

2. RF patent 2276005, IPC V24V 39/04. The method of running in incomplete spherical surfaces. Stepanov Yu.S., Kirichek A.V., Samoilov N.N., Gavrilin A.M., Afanasyev B.I., Katunin A.A., Fomin D.S. 2004129399/02; 10/05/2004; 05/10/2006. Bull. No. 13.

3. RF patent 2276006, IPC V24V 39/04. Device for pulse-impact deformation of spherical surfaces. Stepanov Yu.S., Kirichek A.V., Samoilov N.N., Afanasyev B.I., Katunin A.A., Katunin A.V. Fomin D.S. 2004136428/02; 12/14/2004; 05/10/2006. Bull. No. 13.

Claims (1)

A female head for surface plastic deformation of cylindrical and helical surfaces, comprising a housing with a central hole and deforming elements, characterized in that it is provided with a copier in the form of a disk with a central hole rigidly fixed to the end of the housing and a rotor in the form of a hollow shaft on the surface of the hole which is made of slotted grooves, while on the surface of the central hole of the copier protrusions and depressions are made, the housing is made in the form of a stator of a three-phase asynchronous short-circuit of an enclosed electric motor, inside of which the aforementioned rotor is mounted on rolling bearings, V-shaped curved flat leaf springs made of cold-rolled steel heat-treated tape are installed in the hole of the latter, made with the possibility of creating an interference fit, providing surface plastic deformation force, deforming elements are fixed in the middle part of the leaf springs, which at one end are rigidly fixed at the end of the rotor, and at the other end are located in the central hole of the copier with the possibility of exposure to the said protrusions and depressions of the copier, and the deforming elements are arranged to seize the workpiece with the formation of an inner diameter passing through their tops when the leaf springs are in a free state, less than the diameter of the workpiece by the tightness.

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