SU1514583A1 - Method of burnishing holes and tool for making same - Google Patents

Description

The invention relates to mechanical engineering, in particular to the processing of parts by surface plastic deformation. The purpose of the invention is to improve the quality of processing deep holes due to the increase of the vibration resistance of the technological system. A tool for smoothing holes provide a prismatic insert with an axis, the invention relates to the treatment of metals by surface plastic deformation.

The aim of the invention is to improve the quality of processing deep holes by increasing the vibration resistance of the technological system.

Figure 1 shows the layout of the part and tool with smoother when implementing method 2

poured in the housing can be rotated around its axis, perpendicular to the axis of the tool body.

The ends of the insert are made along a radius equal to the distance between its end and the axis. Smoothers are placed on the specified insert. The tool is supplied with elastic mounting elements, and a diametrical groove is made in the body, between which walls and the ends of the insert are placed elastic elements. When machining, the main and additional screw grooves are applied to the surface of the part. An additional groove is placed between adjacent turns of the main a

grooves at a distance equal to half of its pitch. The frequency of the angular displacements of the smoothers is chosen to be equal to the frequency of rotation of the part and not coinciding with the oscillation frequency of the tool itself. This allows the treatment of large surfaces with high quality.

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ba; figure 2 - scheme of the deformation of the surface layer under the action of the smoother, filled in the form of Rferra; FIG. 3 shows a deformation scheme using the proposed method; FIG. 4 shows a diagram of deformation traces of the surface of a hole of a part at the moment of equilibrium of forces acting on smoothers; figure 5 is a tool for implementing the method, a general view; figure 6 - section aa in figure 5.

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with vyglazhnvate 3 and 4 inquiries about the situation with τ in d i with I have eaten u! ¹ obviously way.

When rotating part 1 around the axis of the spindle (figure 1) and the longitudinal feed 5 of the tool 2

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The full sphere of the first smoother 3, located in the direction of the supply 5, creates on the surface a microstructure representing sinusoidal traces by character and density. The variation in the shape, size and density of these traces is achieved both by changing the processing modes: the rotational speed of the part, the tool feed, the pressing force of the smoother to the part, the radius of the spherical surface of the smoother, and by changing the rigidity of the position of the insert 5 on the stem part of the tool 2 a "relative sharpoz 6. The second smoother 4, the center of the sphere" a ”which is set with an offset" e "in the direction of movement of the feed 2 tool 2 and in the area between the plastically deformed traces tons of the previous first smoother, provides a permanent change in the existing smoothing forces. This is due to the fact that a track is formed in front of the sphere “a” of the smoother 4, into which it periodically runs due to the execution of smoothers on a single insert 5 and the possibility of an angular rotation cp relative to the hinge 6 in the diametral plane of the main motion. At the same time, the change in the operating smoothing forces on the first sphere of the smoother 3 occurs to a lesser extent than on the subsequent sphere due to the angular rotation insert 5 and move the sphere in the direction of an existing track. The effect of the smoother forces, smaller in magnitude, is due to the fact that when the second trace is pressed, the extrusion of the material sphere occurs both ways from the center of its touch with the surface of the workpiece and some of the influxes received from both sides are commensurate with the height of the previously formed trace. As a result, there is a general raising of the metal by a certain amount, which is especially important in the manufacture of parts of precise joints, in which such influxes are unacceptable.

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we and to eliminate them in the process introduce an additional operation to remove them.

In the considered scheme for implementing the method, the insert is placed on elastic elements 7, having a stiffness value lower than that of the stem part of the tool. The fixed insert 5, by means of the compliance of the elastic elements 7 and the hinge 6, oscillates according to the arrows (c) indicated in Fig. 1. The stiffness of the elastic elements located along the ends of the insert 5 is selected from the conditions necessary to create angular oscillations of the smoothers relative to the hinge 6, and due to the smallness of the amplitudes of the angular oscillations compared to the diameter of the spheres, an arc is moving, determined by the distance from the center of the hinge 6 to the filling spheres "a" smoothers, which is equivalent to the simultaneous movement along the surface of the hole and in its depth. When performing the stiffness of the elastic elements 7, providing the resonant frequency of the angular displacements of the eG of the insert 5 close to the frequency η of the rotation of the part 1, smoothers

4 and 3 make forced oscillations, which by the nature of the creation is continuous. Maintaining an oscillatory insertion process

5 with installed smoothers occurs through the so-called feedback, which regulates the transfer of energy from the source to the oscillatory subsystem. Feedback oscillating insert - smoother with a source of energy - through the friction force between the spherical surface of the smoother and the treated surface. The frictional force depends on the relative velocity of the sphere and the part. The frequency of the angular oscillations of the smoothing spheres is selected in magnitude, which does not coincide with the frequency of the stem part of the instrument.

The tool for the implementation of this method is presented in figure 5 and 6, consists of a long stem part of the tool 2, a prismatic insert 5 installed in the radial groove of the stem part, and smoothers 4, 3, tucked in the form of a sphere "a". Insert 5 in box 5

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here are at least two ironers in the center plane of the tool. The insert 5 was located at the ends with radii "b", the portion of which is located in the central zone of the groove along the longitudinal axis of the tool, which provides it with the possibility of angular rotation in the longitudinal groove of the stem part about the axis 8, which is installed perpendicular to the support surfaces of the groove and insert '. radius "in" the ends of the pilot the possibility of contacting g elastic; elements 7, which are both locking the position of the insert in the groove, and the adjusting elements. The elastic elements 7 are pints, the middle part of which has a rectangular cross-section, and at the end of its elastic part formed in this way, the conical surface "g" is made. The conical surface "g" of element 7 is in contact with the flats of the "e" of the insert 5.

The elastic elements 7 are placed on the stem part of the tool 2 along its ends, which ensures the regulation of the radial position of the smoothers 3 and 4, and when the rectangular section of the element 7 is rotated

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relatively groove allows you to change the stiffness of the angular displacement of the insert 5 in this groove. The fastening of the smoothers 4 n 3 pas box 5 can 35 be made different. 11a 6 they are pressed into the holes of the holder. The centers of the filling areas "a" of the smoothers are shifted; in the direction of feed 3 at a distance of ^ 0 0, which ensures that each successive smoother 4 is placed in the zone between the plastically deformed traces of the previous smoother 3. This distance is determined for each song of the next smoother,

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where hl - the serial number was smoothed by me;

5 - axial tool feed on one turn of the part ’1;

k is an integer determined by the design of the tool itself.

Before machining the holes, adjusting the pressing force of the smoothers 3 and 4 to the surface of the machined hole is carried out using the set screws, which is carried out by changing the position of the smoothers in the diametrical plane of the tool.

In the process of processing this tool, the residual compressive stresses are 2–2.5 times greater than when smoothing without vibrations in the same modes. This is due to a sharp increase in the deforming effect of the spheres "a" of the smoothers 3 and 4, which, with the specified method and use of the tool, is due to the complication of the kinematics process! Vibro shaker in comparison with traditionally used methods. When using the specified tool, the track width increases, the speed of interaction between the spheres of smoothers and the direction of compaction of the deformable layer of the surface of the workpiece 1 (fng.1) constantly changes. This explains the increase in the compression planes, since in case of angular oscillations of the insert 5 with ironing agents 3 and 4 relative to the axis of 6 spheres!; "a" affect the material simultaneously both tangentially and towards the material, i.e. compress the material of the machined surface of the part 1. The depth of penetration into the material of part 1 when deformed by the sphere "a" directed to the surface of the hole is carried out at a more significant length of the path of movement of the spheres than when using reciprocating movements of the same sphere with other things being equal .

Compared to other methods of surface plastic deformation, the proposed method has significant advantages due to the use of a kinematic pattern of motion of smoothers in tools, which allows machining surfaces of greater length from high-strength materials. Surface treatment is accompanied by low pressure forces on each smoother (50 350 I!) By distributing them evenly among several spheres.

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“a” of smoothers, which allows to handle low-stiff and unequally-stiff lengthy parts. The ease of processing without vibration devices and significant machine upgrades and the ability to use universal machines should also be attributed to the advantages of the proposed method and tool.

Claims (2)

Claim 1. A method of smoothing holes, in which parts communicate rotation with a certain frequency, and tool smoothers are displaced relative to each other in the axial directions and are set with the possibility of angular displacements and vibrations, moreover, the tool is informed of the feed movement with obtaining a helical groove, characterized by that, in order to improve the quality of processing deep holes due to the increase in the vibration resistance of the technological system, an additional helical groove is placed on the surface of the part w between adjacent turns of the helical groove at a distance equal to half its pitch, the angular movements smoother frequency selected equal parts speed and not coinciding with the oscillation frequency of the tool itself. 2. Tool for smoothing holes, comprising a body with smoothers installed in it, elements for fixing and adjusting the radial position, characterized in that the tool is equipped with a prismatic insert with an axis and elastic mounting elements, with a diametrical groove in the body, and the insert is installed in it can be rotated around its axis, perpendicular to the axis of the tool body, and smoothers are placed on this insert, the ends of which are made along a radius equal to the distance between its orTsom and the axis, and elastic members disposed between the ends of the insert and the housing walls of the groove. 1514583