RU2319594C1 - Apparatus for static-pulse working of shaped surfaces - Google Patents

Abstract

FIELD: manufacturing processes in machine engineering, namely apparatuses for static-pulse working of blanks having shaped surface and joined with said surface part of blank.

SUBSTANCE: apparatus includes deforming tool for acting upon blank with interference, attachment for mounting blank, hydraulic cylinder and arranged in it striker and wave-guide. Deforming tool has working inner surface whose cross section form is identical and reciprocal to that of cross section of worked blank. Working surface of deforming tool has intake lip for entering blank and sizing portion for outlet of worked blank. Striker is made with possibility of acting upon wave-guide. Deforming sleeve is mounted according to condition of performing feed motion in direction normal to lengthwise axis of blank and it is fastened in wave-guide. The last is made with possibility of applying to deforming sleeve static load and cyclic pulse load by means of striker.

EFFECT: enlarged manufacturing possibilities of apparatus, improved efficiency, quality and accuracy of working.

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Description

The invention relates to mechanical engineering technology, in particular to methods and devices for calibrating, deforming pulling and hardening of metal shaped surfaces of parts such as bodies of revolution from steels and alloys by surface plastic deformation (PPD).

A device for static-pulse processing of workpieces having a contoured surface and a part of the workpiece associated with it, containing a deforming tool for acting on the workpiece with an interference fit [1].

The known device has limited technological capabilities, low efficiency, high energy consumption, a small depth of the hardened layer and a small degree of hardening of the treated surface, while the device does not allow to obtain a high-quality processed surface.

A known method and tool for processing incomplete spherical surfaces of parts of the PPD, in which the workpiece and the deforming tool are notified of rotational motion, and the deforming tool is informed of rotation in a circle lying in a plane offset from the center of the processed spherical surface, while the angular velocity of the deforming tool is associated with the angular speed of the workpiece by the ratio ω _in >> ω _d , in addition, a mathematical relationship between the force loading and rolling force [2].

The method and tool is characterized by limited technological capabilities, low efficiency, high energy intensity, small depth of the hardened layer and a small degree of hardening of the machined surface, while the non-self-aligning tool used does not allow to obtain a high-quality machined surface.

There is a method and a double-row percussion tool implementing it for processing external cylindrical surfaces, in which the first row of rollers is mounted on an elastic "floating" self-aligning mandrel in the radial direction, and the second row of rollers is mounted on a rigid mandrel [3].

The method and tool is characterized by limited technological capabilities and is used only for processing external cylindrical surfaces, low efficiency and productivity, a small depth of the hardened layer and a low degree of hardening of the treated surface, complexity, high energy and metal consumption of the structure, as well as overall dimensions.

The objective of the invention is to increase the productivity, quality and accuracy of processing the shaped surface of the workpiece, as well as expanding the technological capabilities of PPD through the use of static-pulse loading of a deforming tool of the original design, which allows you to control the depth of the hardened layer, the degree of hardening and the microrelief of the machined shaped surface.

The problem is solved with the help of the proposed device for static-pulse processing of workpieces having a shaped surface and a part of the workpiece associated with it, containing a deforming tool for impacting the workpiece with an interference fit, and it is equipped with a device for installing, basing and securing the workpiece with the possibility of rotation relative to the longitudinal axis, a hydraulic pulse generator for generating a pulse load, which is connected to the hydraulic cylinder and placed in the last spike and a waveguide made in the form of rods of the same diameter, the deforming tool is made in the form of a deforming sleeve with a longitudinal groove for free passage of a part of the workpiece mated to its shaped surface, and with a working inner surface having a cross-sectional shape identical and reciprocal to the shape of the longitudinal section the processed workpiece, and made in the form of a fence cone for the entrance of the workpiece and the calibrating part for the output of the processed workpiece, ene to act on the waveguide, deforming the sleeve is installed from the condition of the feed motion in a direction perpendicular to the longitudinal axis of the workpiece, and is fixed to a waveguide which is configured to communicate static load deforming the sleeve and pin through periodic pulse loading.

The essence of the proposed device is illustrated by drawings.

Figure 1 presents a diagram of the PPD using the proposed device shaped surface on the example of a spherical automobile finger, which shows (in thin lines) the initial position of the workpiece, conventionally transferred below; figure 2 is an example of a toroidal design of the workpiece, which can be processed using the proposed device; figure 3 - view And figure 1, the deforming tool is conventionally shown without a waveguide; figure 4 is an example of a shaped design of the workpiece having convex and concave surfaces, which can be processed using the proposed device.

The proposed device is used for static-pulse PPD, calibration, deforming pulling and hardening of metal shaped, for example, spherical surfaces, spherical automobile fingers 1, racetracks of cone bits, toroidal (figure 2), complex shaped convex and concave surfaces of bodies of revolution ( 4) and other parts with a central axis of rotation of steels and alloys by surface plastic deformation (PPD). The device consists of a device 2 for installing, basing and securing the workpiece 1 with the possibility of rotation relative to the longitudinal axis and the deforming tool 3.

The deforming tool 3, which is a sleeve, is rigidly fixed to the waveguide 4 located in the hydraulic cylinder 5, which in turn is fixed in the cartridge 6, for example, a vertical broaching machine (not shown).

The cartridge 6 and the deforming sleeve 3 perform under the action of a static force P _st developed by the machine drive, the feed motion S _pr in the direction perpendicular to the longitudinal axis of the workpiece 1, while the workpiece rotates V _z relative to its longitudinal axis.

The deforming tool - the sleeve 3 has a longitudinal groove 3 ′ for free passage of part 1 ′ of the workpiece 1, mating with the machined shaped surface. The inner surface of the hole of the deforming sleeve 3 is a working and identical and reciprocal shape of the longitudinal section of the workpiece 1, and in the longitudinal section from the end side (Fig. 1, below), where the workpiece enters, the hole of the sleeve has an intake cone with an angle φ = 3. ..5 ° and the calibrating surface, where the processed workpiece comes from.

The deforming sleeve 3 translationally (from top to bottom, according to FIG. 1) moves under the action of a static force P _article and is subjected to additional impact of a periodic impulse load P _them through the hammer 7 and waveguide 4, made in the form of rods of the same diameter and located in the cylinder 5. Impulse load produced by a hydraulic pulse generator (GGI) [4-6], which (not shown) is connected to the hydraulic cylinder 5.

Impulse loading P by _{him is} carried out by hitting the striker 7 at the end of the waveguide 4, on which the tool 3 is installed. As a result of the shock, shock and oppositely directed pulses of the same amplitude and duration arise in the striker and waveguide, each of which will affect the surface to be treated with a cycle equal to double pulse duration. Having reached the surface to be treated, the shock pulse is distributed on the passing and reflecting. The passing pulse forms the dynamic component of the strain force.

The shock pulse introduces the deformation sleeve into the surface to be machined by a large amount and in a significantly short time than with traditional processing using only static load.

The depth of the hardened layer reaches 1.5 ... 2.5 mm, which is significantly (3 ... 4 times) more than with traditional static hardening. The greatest degree of hardening is 15 ... 30%. As a result of static-pulse processing according to the proposed method, the effective depth of the layer hardened by 20% or more increases by 1.8 ... 2.7 times, and the depth of the layer hardened by 10% or more, by 1.7. ..2.2 times compared with traditional hardening.

Axial shock pulses applied to the deformation sleeve 3 with a frequency, for example, of the order of 20 Hz and an amplitude of 0.3 ... 1.5 mm, significantly reduce the axial force.

The height of the intake conical part of the deforming sleeve is determined by the formula:

l _to > 10z / tgφ,

where l _to - the height of the intake conical part of the deforming sleeve, mm;

z is a value equal to half the interference, mm;

φ is the angle of the intake conical part, deg.

The main technological parameter of the process is an interference fit, which is determined, for example, for a spherical workpiece, by the formula

i = D _o -d _in ,

where D _o is the diameter of the spherical surface before processing (arithmetic mean value taking into account the deviations of the shape in the cross section);

d _in - the diameter of the cylindrical part of the hole of the deforming sleeve.

When processing with an interference fit i up to 0.5 mm, the deviations of the shape in the cross section (deviation from roundness) are reduced, the accuracy of the size is increased by 30 ... 35%, and the parameters of surface roughness are reduced. With such interference, workpieces are also treated after heat treatment.

The total interference is limited by the ductility of the workpiece material. Billets made of brittle materials are processed with small interference, as with high interference, their destruction can occur.

Processing with a deforming sleeve ensures optimal deformation conditions, and the tool has maximum dimensional stability. The resistance of a hard alloy deformation sleeve when processing steel billets is 100 ... 150 km of the total processing length.

Depending on the size of the workpiece surface to be treated, deforming bushings are used whole (not shown) or prefabricated (see figures 1, 3). Prefabricated deformation sleeve consists of a sleeve body 3, carbide liner 8, mounting plates 9 and a supporting ring 10.

The deforming sleeve on the side of the intake cone has a guide chamfer that provides mutual orientation of the workpiece and the tool.

The material of the integral deforming sleeve and the working part of the prefabricated sleeve: of the insert is VK8 hard alloy.

The radial runout of the working surface of the sleeve bore should not exceed 0.02 ... 0.05 mm.

The deforming sleeve can be symmetrical (from each end the intake cone, and in the middle the calibrating part) in order to work with downward feeds (according to Fig. 1) and rotate the sleeve when it is worn.

When processing the proposed device, it is necessary to use a lubricating-cooling technological agent (COTS), which prevents the setting of the deforming sleeve with the metal being treated. The absence of COTS leads to the rejection of processed workpieces and often to the destruction of the tool. For parts made of carbon and low alloy steels are recommended: sulfofresol, MP-1, MP-2, emulsions. The same liquids should be used in the processing of blanks from non-ferrous metals (bronze, brass, aluminum alloys). For parts of highly alloyed, heat-resistant and corrosion-resistant steels and alloys, the following SOTS should be used: ASM-1, ASM-4, ASM-5, ASM-6. When machining billets of hardened steels, ASF-3 grease is used.

The roughness of the surface treated by the proposed device depends on the initial roughness and material of the workpiece, the processing mode used by the COTS and the angle of the working intake cone of the tool. The roughness of the treated surface does not depend on the processing speed (within the range of applied speeds).

To obtain small values of the roughness parameters, it is advisable to pre-treat the outer spherical surface with a carbide tool, for example, a cutter having small angles in plan (φ = 30 ... 40 °), at cutting speeds that exclude the formation of growth.

When processing spheres and other shaped surfaces after roughing and finishing turning (initial parameter Ra = 6.3 ... 1; 6 microns), surfaces with Ra = 0.8 ... 0.1 microns are obtained if the workpiece material is steel; Ra = 0.4 ... 0.1 μm when processing billets of bronze and Ra = 1.6 ... 0.4 μm when processing billets of cast iron.

The surface roughness after plastic deformation by the proposed device will be the lower, the less the interference at which the shaped surface is processed.

So, when processing a workpiece made of steel 45 with an initial roughness of Ra = 4 ... 8 μm, we obtained the following roughness with interference on a deforming tool:

Preload i, mm ... 0.05 0.10 0.20 0.40 0.80 Parameter Ra, μm ... 0.06 0,07 0.4 1.3 3.0

Hardening of the metal is a consequence of the occurring deformations. The hardening, expressed by a change in hardness, decreases with the transition from the machined surface to the depth of the billet sphere.

The thickness of the texture layer with increased hardness is greater, the greater the interference and the less, the higher the initial hardness of the processed metal. The increase in hardness depends on the metal being processed and is 130 ... 260%.

The longitudinal feed speed S _pr deforming tool during processing by the proposed device is associated with the rotation speed of the workpiece V _{s the} following ratio:

S _CR = 0.01 · V _s ,

where S _CR - the speed of the longitudinal feed of the deforming tool, m / min;

V _s - the speed of the rotational movement of the workpiece, m / min.

The speed of the rotational movement of the workpiece V _{s is} assigned within 2 ... 25 m / min.

To achieve accuracy in 11 ... 13th qualifications, processing is carried out with great interference. To achieve accuracy in the 8 ... 11th qualifications, medium tightness (0.2 ... 0.5 mm) should be applied. To obtain accuracy according to the 5 ... 6th qualifications, preliminary precise machining is necessary, after which the deformation is carried out with small tightnesses (0.02 ... 0.2 mm). For the last group of workpieces, a deformation - cutting - thin deformation scheme is advisable.

Example. The PPD was processed with a blank of a ball of the upper ball 2101-2904187 installed in an electromechanical device on a modernized vertical broaching machine mod.7B65 using a special GGI. The modernization concerned the installation on a machine on the cartridge of the hydraulic cylinder body with a waveguide and a striker, performing additional periodic pulsed loading of the deforming sleeve.

The blank is made of steel 20X GOST 1050-74.

Processed a sphere with a diameter of 32.7 ± 0.1; the initial roughness parameter Ra = 3.2 μm, achieved - Ra = 0.63; a deforming tool in the form of a sleeve of VK8 carbide in the following modes: workpiece rotation speed V _s = 20 m / min (n _s = 200 min ^-1 ); the speed of the longitudinal feed of the deforming tool S _CR = 0.2 m / min; total tightness on diameter - 0.2 mm (0.1 mm per side); the depth of the layer of high hardness was 0.15 ... 0.20 mm; SOTS served as sulfofresol (5% emulsion). Are axial shock pulses with a frequency of 15 Hz and an amplitude of 1.0 ... 1.5 mm applied to the deformation sleeve?

The required roughness and accuracy of the spherical surface were achieved with one pass in T _m = 0.45 min (against T _m ^bases = 2.8 min in the base case with the traditional rolling treatment at the Oryol Steel Mill OSPAZ).

The control was carried out by an indicator bracket with an indicator ICh 10 B cells. 1 GOST 577-68 and on the profilometer mod. 283 type AII GOST 19300-86. No defective parts were found in the processed batch (100 pieces). The deviation of the treated surface from sphericity was not more than 0.02 mm, which is acceptable TU.

The processing showed that the roughness parameter of the treated spherical surfaces decreased to Ra = 0.32 ... 0.63 μm with the initial value Ra = 3.2 ... 6.3 μm, the productivity increased by more than five times compared to traditional run-in. The energy intensity of the process decreased by 2.2 times.

The proposed device improves the productivity, quality and accuracy of processing shaped surfaces of workpieces, and also expands the technological capabilities of PPD through the use of the original design of the deforming tool and its static-pulse loading, which allows you to control the depth of the hardened layer, the degree of hardening, and the microrelief of the machined shaped surface.

Information sources

1. A.S. SU 1567361 A1, B24B 39/04, 05/30/1990 - prototype.

2. RF patent 2031770, MKG ⁶ V24V 39/04, 39/00. A method of processing incomplete spherical surfaces of parts by surface deformation. Gavrilin A.M., Samoilov N.N. 5045958/27; 04/14/92; 03/27/95. Bull. No. 9.

3. Reference technologist-machine builder. In 2 vols. T.2 / Ed. A.G. Kosilova and R.K. Meshcheryakova. - 4th ed. reslave. and add. - M.: Mechanical Engineering, 1986. P.392, Fig. 14, b.

4. RF patent 2098259, MKI ⁶ V24V 39/00. Lazutkin A.G., Kirichek A.V., Soloviev D.L. Method of pulse treatment by surface plastic reforming. No. 96110476/02, 05.23.96; 12/10/97. Bull. Number 34.

5. Kirichek A.V., Lazutkin A.G., Soloviev D.L. Static-pulse processing and equipment for its implementation // STIN, 1999, No. 6. - S.20-24.

6. RF patent 2090342. Lazutkin A.G., Kirichek A.V., Soloviev D.L. Water hammer device for processing parts by surface plastic deformation. 1997. Bull. Number 34.

Claims (1)

A device for static-pulse processing of workpieces having a shaped surface and a part of the workpiece associated with it, containing a deforming tool for impacting the workpiece with an interference fit, characterized in that it is equipped with a device for installing, basing and securing the workpiece with the possibility of its rotation relative to the longitudinal axis, hydraulic pulse generator for generating a pulse load, which is connected to the hydraulic cylinder and placed in the last spike and waveguide, made in the form of of the same diameter, the deforming tool is made in the form of a deforming sleeve with a longitudinal groove for free passage of the part of the workpiece mated to its shaped surface, and with a working inner surface having a cross-sectional shape identical to and corresponding to the longitudinal section of the workpiece being machined, and made in in the form of an intake cone for the entrance of the workpiece and the calibrating part for the output of the processed workpiece, while the hammer is made with the possibility of impact on the wave the novode, the deforming sleeve is installed from the condition of the feed movement in the direction perpendicular to the longitudinal axis of the workpiece, and is mounted on the waveguide, which is configured to communicate to the deforming sleeve a static load and by means of a striking periodic pulse load.

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