RU2275289C1 - Method of surface plastic deformation of embracing rings - Google Patents

Abstract

FIELD: metal working.

SUBSTANCE: method comprises setting the deforming tool for permitting longitudinal feed and setting the blank to be worked in rotation. The deforming tool is made of at least two freely mounted embracing rings mounted in the bearings in the central openings of the holders movably mounted in the housing of the deforming tool by means of tension members made of compression springs mounted between the disks provided with the central openings for free passing of the blank to be worked. One disk is rigidly connected with the housing, and the other disk is secured to the face of the first disk by means of spacing bushings and screws.

EFFECT: expanded functional capabilities.

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Description

The invention relates to the processing of metals by pressure, in particular to methods for processing surface plastic deformation (PPD) of shafts, screws and other bodies of revolution.

A known method, implemented by a three-roller device for rolling in non-rigid shafts, consisting of a holder with rollers, pivotally connected to the housing, which is mounted on a machine support [1].

The disadvantage of this method is the limited application, narrow specialization (only for cylindrical surfaces) and low productivity, while to obtain high quality it is necessary to create large working forces, and this requires the use of rollers with a large radius of the profile, which negatively affects the overall dimensions and not always feasible. At the same time, a significant amount of the plastic wave traveling in front of the deforming elements in the form of rollers or balls increases the likelihood of cracking and peeling of the processed surface layer.

The objective of the invention is the expansion of technological capabilities by providing the processing of PPD of conventional and eccentric shafts, screw surfaces of screws and other bodies of revolution, as well as reducing costs, increasing productivity and improving manufacturing quality through the use of deforming elements in the form of spanning rings that significantly reduce the amount of plastic wave, going before the deforming elements and the likelihood of cracking and peeling of the processed surface layer, thanks to the use of the same machine on which the pre-process workpiece.

The problem is solved by the proposed method of surface plastic deformation of non-rigid shafts, screws and other bodies of revolution with a deforming tool installed with the possibility of longitudinal feed when communicating the workpiece with rotational movement, and surface plastic deformation is carried out by freely rotating covering rings of the deforming tool, in an amount of at least two, mounted in bearings in central holes of holders movably mounted in the case of the deforming tool using stretch marks in the form of compression springs between two disks with central holes for free passage of the workpiece, one of which is rigidly connected to the body and the other to the end of the first disk with spacer sleeves and screws, while the necessary rolling force is created by two compression springs common to all holders and located in peripheral diametrically opposite grooves of the holders.

The essence of the method is illustrated by drawings.

Figure 1 presents the processing scheme according to the proposed method of surface plastic deformation of a non-rigid screw of an oil producing screw pump with a deforming tool with female rings on a lathe, a longitudinal section along AA in figure 2; figure 2 - deforming tool, a General view from the right along B (rotated) in figure 3; figure 3 - deforming tool, section bb in figure 2; figure 4 is a General side view of the block (consisting of two) holders of the deforming tool in the working position when rolling the screw; figure 5 is a General side view of a block (consisting of two) holders of a deforming tool in a free state, without a workpiece; in Fig.6 is a block (consisting of two) holders of the deforming tool indicating the direction and place of action of the rolling forces, left view in Fig.4; in Fig.7 - block holders indicating the direction and place of action of the rolling forces, a longitudinal section along G-G in Fig.6; Fig.8 is a deforming tool, a section DD in Fig.3.

The proposed method relates to surface plastic deformation (PPD) processing - rolling in conventional, eccentric and other varieties of non-rigid shafts, screws mainly with a large pitch, for example, oil pump screws, and other bodies of revolution of shaft varieties, screws with a large pitch, for example, oil producing screws pumps, and other bodies of revolution with a multi-element deforming tool in the form of spanning rings.

The deforming tool comprises a body 1 of a welded structure, with which the tool is mounted, for example, on a support of a lathe. In the housing you can distinguish: half disk 2, located vertically, two mutually perpendicular horizontal strips 3 for fixing the housing in the tool holder of the caliper (not shown) and stiffeners 4.

Surface plastic deformation is carried out by freely rotating deforming elements in the form of covering rings 5, in an amount of not less than two, which are mounted on bearings 6 in the central holes of the holders 7. The holders 7 (in the amount equal to the number of deforming rings - block holders) freely contact each other with their end surfaces, while in the peripheral diametrically opposite grooves 8 of the holders are two compression springs 9 common to all the holders, creating the necessary force e rolling in P _about . Compression springs 9 are installed in the grooves 8 on the strips 10, which are the supporting platforms for the springs and at the same time limiters of the lateral movements of the holders 7, made under the action of the springs 9, when changing the workpieces and removing them from the rolling zone of the deforming tool (Fig. 5).

The holder block 7 is movably mounted in the housing 1 using two disks 11 and 12. The disks 11 and 12 have central openings for free passage of the workpiece. The disk 11 is rigidly connected to the half-disk 2 of the housing 1 by screws 13, and the other disk 12 is rigidly attached to the end of the disk 11 with the spacer sleeves 14 and screws 15. Between the disks 11 and 12, a holder block is freely mounted with a clearance along the sliding fit (H7 / h6) with a gap 7 by means of extensions in the form of tension springs 16. The springs 16 are fixed at one end to the holders 7 and the other are fixed to the spacer sleeves 14. Spring extensions can be installed on either each holder or on one, due to the fact that all holders are combined into a block by compression springs 9.

Assembly of a deforming tool that implements the proposed method is carried out in the following sequence.

To the housing 1, welded from separate elements: half-disk 2, straps 3 and stiffeners 4, screws 13 are attached with screws 13. The holder block 7 is separately assembled. The assembly of the holder 7 assembly consists in installing a bearing 6 and a deforming element - rings 5 in each holder 7. and connecting them to the unit by installing compression springs 9, which are compressed into the peripheral grooves 8 of the holders 7, and securing the stretch marks - springs 16.

The general assembly of the deforming tool ends by installing the disk 12 and fastening it with the help of the rollers 14 with screws 15, with the preliminary installation between the disks 11 and 12 of the holder block 7 assembly, the tension is made, the springs 16 are fixed on the rollers 14 and the bars 25 with the screws 24 are set .

At the end of the assembly, a check is made and, if necessary, adjustment of the gaps between the disks 11 and 12 and the holder block 7 by installing washers (not shown) between the rollers 14 and the disk 11 or 12 for the purpose of free transverse displacement of the holder block 7 relative to the disks 11 and 12 without backlash.

Work on the proposed method is carried out in the following sequence.

When finishing with surface plastic deformation - rolling in a shaft with a variable cross-section 17 (for example, a screw of a screw pump having a profile and dimensions D, D ₁ , t, e, e ₁ , shown in Fig. 1) with a deforming tool, a screw stock that has passed preliminary, for example, turning is fixed in the chuck 18 of the spindle 19 of the headstock 20, the tool is brought in and the free end of the screw blank is inserted into the hole of the tool, and the center 21 of the tailstock 22 is pressed in. The introduction of blanks is a certain difficulty hole tool. Since the hole formed by the deforming rings of adjacent free-standing holders will be smaller than the workpiece diameter to be machined, it is necessary to radially spread the holders, overcoming the resistance of the compression springs 9. The holders 7 can be pulled apart in several ways: due to the longitudinal feed and forced separation of the holders due to the chamfer 23, available on the workpiece, with a special lever tool in the form of scissors (not shown) or the method shown in Fig. 8, in which the lateral displacement is held c 7 is performed by adjusting screws 24 set against the respective holders, by screwing them into strips 25 which are secured in the slots 11 and the disc 12.

A rotational motion V _{s is} reported to the machined screw. The speed of rotation of the workpiece is set depending on the required performance, design features of the workpiece and equipment. Usually the speed is 30 ... 150 m / min.

The deforming tool is informed of a longitudinal feed S _pr in one direction of not more than 0.1 ... 3.0 mm / rev. The optimal supply S _pr ^about is determined by the formula:

where k is the number of deforming elements;

S _e - supply to one deforming element, is adopted for deforming covering rings, which are in cross section a torus with a radius R on the inner surface (Fig.7), not more than 0.1 ... 0.5 mm / rev.

When switching to processing another screw or shaft size in the tool, it is enough to replace the holder block and deforming elements.

определяли по формуле

и принимали

где k=2 - количество деформирующих колец в инструменте, высота деформирующих колец - 7,94 мм, следовательно R=3,97 мм. Усилие обкатывания составляло около ≈1700 Н, глубина наклепанного слоя находилась в пределах 0,15...0,20 мм; величина, на которую изменился размер после обкатки - 0,01...0,02 мм; смазывающе-охлаждающей жидкостью при обкатывании служил сульфофрезол (5%-ная эмульсия).Example. The left screw N41.1016.01.001 of the screw oil pump ЭВН5-25-1500, which had the following dimensions, was processed by rolling in: the total length was 1282 mm, the length of the screw part was 1208 mm, and the cross-section diameter of the screw was D ₁ = 27 ^-0.05 mm , D = 30.3 mm, eccentricity e ₁ = 1.65 mm, e = 3.3 mm, pitch t = 28 ^{± 0.01} mm, roughness R _a = 0.4 μm; single-helical screw surface, left direction; material - steel 18HGT GOST 4543-74, hardness HB 207 ... 228, weight - 5.8 kg. Preliminary processing by turning and finishing processing by rolling was carried out on a mod screw-cutting lathe. 16K20, the peripheral speed of the workpiece - v _s = 84.78 m / min (1.41 m / s), n _s = 1000 rpm, longitudinal feed

determined by the formula

and took

where k = 2 is the number of deforming rings in the tool, the height of the deforming rings is 7.94 mm, and therefore R = 3.97 mm. The breaking-in force was about ≈1700 N, the depth of the riveted layer was in the range 0.15 ... 0.20 mm; the size by which the size has changed after running-in - 0.01 ... 0.02 mm; Sulfofresol (5% emulsion) served as a lubricant-cooling fluid during the run-in.

мин по базовому варианту при традиционном шлифовании с помощью шлифовальной головки, с последующим полированием абразивной лентой ЛВТ 2200×55 Э4, 5-8-10 ГОСТ 12439-79 на токарном станке 1К62 на АО "Ливгидромаш"). Контроль проводился скобой индикаторной с индикатором ИЧ 10 Б кл. 1 ГОСТ 577-68. Накопленная погрешность между любыми не соседними шагами была не более 0,1 мм, просвет при контроле лекальной линейкой образующих по диаметру выступов - не более 0,07 мм, что допустимо по ТУ.The required roughness and accuracy of the helical surface was achieved after T _m = 3.15 min (against

min according to the basic version with traditional grinding using a grinding head, followed by polishing with an abrasive belt ЛВТ 2200 × 55 Э4, 5-8-10 GOST 12439-79 on a lathe 1K62 at JSC "Livhydromash"). 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.

The advantages of the proposed method of rolling in non-rigid bodies of revolution with a floating multi-element tool with deforming enclosing rings are:

- the ability to run in non-rigid workpieces with an increase in machining accuracy (by 10 ... 20%) due to the rigid design of the holder (shape deviation not more than 10 ... 30 microns);

- run in at maximum feeds in comparison with the known single-element devices;

- ensuring a constant contact force of the deforming elements and the work surface;

- reduction of the error of the previous processing;

- the multi-element tool allows for multi-pass processing, due to which a higher quality of processing is achieved;

- unloading of machine components from unilateral application of force and the possibility of processing non-rigid workpieces;

- the ability to form certain macro- and microgeometric shapes of the treated surface, reduce the roughness parameters - smooth surfaces, change the structure of the material - surface hardening and create a certain stress state, favorably affecting wear resistance.

Thanks to the use of enveloping rings as deforming elements, the magnitude of the plastic wave traveling in front of the deforming elements is significantly reduced, and the likelihood of cracking and peeling of the surface layer being treated is negated, and the use of the same machine on which the helical surface of the workpiece was pre-treated extends the processing capabilities PPD of eccentric shafts, screw surfaces of non-rigid screws with large pitch, and also reduces bestoimost treatment improves productivity and improves the manufacturing quality.

The proposed method of processing surface plastic deformation of non-rigid blanks of bodies of revolution is easy to implement, and the deforming tool is simple in design and reliable in operation. The structural layer obtained on the surface of the workpiece has increased hardness and, accordingly, wear resistance and resistance to fatigue failure.

Using the proposed method allows to increase the processing productivity of 1.5 ... 2.0 times and to ensure high accuracy.

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 .: Engineering, 1985, p. 387, Fig. 6 - prototype.

Claims (1)

A method of surface plastic deformation of non-rigid shafts, screws and other bodies of revolution with a deforming tool installed with the possibility of longitudinal feeding when the workpiece is rotationally informed, characterized in that the surface plastic deformation is carried out by freely rotating covering rings of the deforming tool in an amount of at least two mounted in bearings in the central holes of the holders, movably mounted in the body of the deforming tool umment using stretch marks in the form of compression springs between two disks with central holes for free passage of the workpiece, one of which is rigidly connected to the body, and the other to the end of the first disk with spacer sleeves and screws, while the necessary rolling force is created by two compression springs common to all holders and located in peripheral diametrically opposed grooves of the holders.

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