RU2317885C1 - Arrangement for surface plastic deformation of the spherical surfaces of ball pins - Google Patents

Abstract

FIELD: the invention refers to technology of machine building namely to arrangements for surface plastic deforming of spherical ball pins.

SUBSTANCE: the arrangement has a deforming element for impacting on the blank with tension and a jig for installation of the blank with possibility of its rotation relatively to the longitudinal axis. The deforming element is fulfilled in the shape of a bushing with a longitudinal groove for free passing of the blank of the ball pin conjugated with its spherical surface. The working inner surface of the deforming element is fulfilled in the shape of a truncated cone at an angle of φ=3...5^o and connected with its smaller foundation of the cylindrical calibrating part. The mentioned bushing is firmly fixed in the chuck of the machine fulfilled with possibility of making feeding movements in the direction perpendicular to the longitudinal axis of the blank.

EFFECT: expands technological possibilities.

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Description

The invention relates to mechanical engineering technology, in particular to devices and methods for calibrating, deforming pulling and hardening of metal spherical surfaces of parts made of steels and alloys by surface plastic deformation (PPD), for example, automobile ball fingers.

A known tool and method for processing incomplete spherical surfaces of PPD parts, in which the workpiece and the deforming tool are given rotational movement, and the deforming tool is told to rotate around 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 the speed of the workpiece by the ratio ω _in >> ω _d , in addition, a mathematical relationship between the load guns and rolling force [1].

The tool and method is characterized by low efficiency, high energy consumption, a small depth of the hardened layer and a small degree of hardening of the treated surface, while the applied non-self-aligning tool does not allow to obtain a high-quality processed surface.

Known double-row percussion tool for processing the outer 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 mounted on a rigid mandrel [2].

The tool is characterized by limited 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 processed surface, complexity, high energy and metal consumption of the structure, as well as overall dimensions.

The objective of the invention is to expand the technological capabilities of PPD through the use of the original design of the deforming tool, which allows you to control the depth of the hardened layer, the degree of hardening and the microrelief of the processed spherical surface, as well as improving productivity, quality and accuracy of processing the workpiece.

The problem is solved using the proposed device for processing on the machines the spherical surfaces of ball fingers, containing a deforming element for acting on the workpiece with interference and a device for installing, basing and securing the workpiece with the possibility of rotation relative to the longitudinal axis, and the deforming element is made in the form of a sleeve with a longitudinal groove for free passage of a part of the ball pin preform paired with its spherical surface and with the working inner surface в in the form of a truncated cone with an angle of φ = 3 ... 5 ° for the input of the workpiece from the side of the larger base of the latter and the cylindrical calibrating part connected to its smaller base for the output of the processed workpiece, while the said sleeve is rigidly fixed in the machine cartridge made with the possibility of making a feed movement in a direction perpendicular to the longitudinal axis of the workpiece, and the inner surface of the sleeve in the form of a truncated cone is made of height l _to , mm:

l _to > 10z / tgφ,

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

φ is the angle of the inner surface of the sleeve in the form of a truncated cone, deg.

The essence of the proposed device is illustrated by drawings.

Figure 1 presents a diagram of the surface plastic deformation (PPD) of the spherical surface of a spherical automobile finger, which shows (in thin lines) the initial position of the workpiece, conventionally transferred below; figure 2 is a view of figure 1.

The proposed device is intended for calibration, deforming pulling and hardening of metal spherical surfaces, for example, automobile spherical fingers 1 and other parts of steel and alloys by surface plastic deformation (PPD). The device includes a device 2 for installing, basing and securing the workpiece with the possibility of rotation relative to the longitudinal axis and a deforming tool 3.

Deforming tool 3 is a sleeve rigidly mounted in a cartridge, for example, a vertical broaching machine (not shown). The threaded holes 4 are used to secure the deformation sleeve 3 in the cartridge with screws (not shown).

The cartridge with the deforming sleeve 3 makes the feed movement S _CR in the direction perpendicular to the longitudinal axis of the workpiece 1, while the workpiece makes a rotational movement V _s 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 a spherical surface.

The inner surface of the hole of the deforming sleeve 3 is working and has a shape consisting of a truncated conical part with an angle φ = 3 ... 5 °, where the workpiece enters from the side of the larger base, and a cylindrical calibrating surface connected to the smaller base of the conical part, from where machined workpiece, in addition, the height of the conical part is determined by the formula:

l _to > 10z / tgφ,

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

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

φ is the angle of the inner surface of the sleeve in the form of a truncated cone, deg.

The main process parameter is interference

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 and 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. The billet from brittle materials is processed with small tightnesses, since with high tightness it can break.

Processing with a deforming sleeve provides optimal conditions for deformation - the tool has the maximum dimensional, durability. Depending on the size of the workpiece surface to be treated, one-piece deforming bushings are used (see Figs. 1-2) or prefabricated (not shown).

The deforming sleeve on the side of the conical part has a guiding chamfer providing mutual orientation of the workpiece and the tool.

The material of the whole deforming sleeve and the working part of the prefabricated sleeve 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 made symmetrical (from each end there is a conical intake part, and in the middle a cylindrical part) in order to work with feeds down (according to Fig. 1) and up or turn 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 made of high alloy, heat-resistant and corrosion-resistant steels and alloys, the following SOTS should be used: АСМ-1, АСМ-4, АСМ-5, АСМ-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 the material of the workpiece, the processing mode used by the COTS and the angle of the working 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 the sphere after roughing and finishing turning (initial parameter Ra = 6.3 ... 1.6 μm), surfaces with Ra = 0.8 ... 0.1 μm 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 of the proposed device will be the lower, the less the interference at which the processing of the sphere. 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 Uz 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. We processed the PPD blank of the ball upper finger 2101-2904187, installed in a special electromechanical device on a vertical-broaching machine mod. 7B65, the proposed device. 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 made of VK8 hard alloy 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; Sulfofresol (5% emulsion) served as the cutting fluid.

The required roughness and accuracy of the spherical surface was achieved with one pass in T _m = 0.5 min (against T _m ^bases = 2.75 min according to the basic version with the traditional rolling treatment at the Oryol steel mill OSPAZ). The control was carried out with an indicator bracket with an indicator ICh 10 B class 1 GOST 577-68 and on a profilometer mod.283 type AN GOST 19360-86. In the processed batch (equal to 100 pieces), no defective parts were found. 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 running in. The energy intensity of the process decreased by 2.2 times.

The proposed device extends the technological capabilities of PPD through the use of the original design of the deforming tool and allows you to control the depth of the hardened layer, the degree of hardening and the microrelief of the machined spherical surface, and also increases the productivity, quality and accuracy of processing the workpiece.

Information sources

1. RF patent 2031770, MKP 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.

2. 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.

Claims (1)

A device for processing on the machines the spherical surfaces of the ball fingers, containing a deforming element for acting on the workpiece with an interference fit and a device for installing, basing and securing the workpiece with the possibility of rotation relative to the longitudinal axis, characterized in that the deforming element is made in the form of a sleeve with a longitudinal groove for the free passage of the part of the workpiece of the spherical finger, conjugated with its spherical surface, and with the working inner surface in the form of a truncated cone with an angle φ = 3 ... 5 ° to enter the workpiece from the side of the larger base of the latter and connected to its smaller base, a cylindrical calibrating part for the output of the processed workpiece, while the said sleeve is rigidly fixed in the machine chuck made with the possibility of making a feed movement in a direction perpendicular to the longitudinal axis of the workpiece, and the inner the surface of the sleeve in the form of a truncated cone is made with a height l _to , mm: l _to > 10z / tgφ, where z is a value equal to half the interference, mm; φ is the angle of the inner surface of the sleeve in the form of a truncated cone, deg.

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