RU2790993C1 - Metod for adjusting ring discs - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: invention concerns the adjustment of low-rigid parts such as ring discs by reducing the no-flatness and dishing of the shape. The disc is mounted on the lower conical rollers forming a common support surface. During installation, the disc is centered along the axis of rotation from above by conical rollers. The disc is rotated due to the lower drive rollers. At the same time, the angular rotation speeds of the conical rollers for alternating bending can be mismatched with the angular rotation speeds of the conical rollers for compression, compensating for the advance and lag of the disc movement in the zone of alternating bending of the web. During the rotation of the disc, the upper conical rollers overlap the lower conical rollers and are arranged relative to each other in a staggered manner, by the amount of deflection of the disc web. Bending stresses occur in the disc material above the elastic limit. At the same time, with the help of oppositely positioned rollers, the disc is compressed to the level of relative deformation of the disc web within 0.5-2% with alternating bending. The adjustment process is carried out according to the loading cyclogram until the geometric dimensions of the disc are stabilized, namely, deviations from flatness, within the tolerance of the shape.

EFFECT: improving the quality of adjustment by reducing the non-flatness, eliminating the dishing of the shape by creating an equidistant state during adjusting.

3 cl, 5 dwg

Description

The invention relates to the processing of metals by pressure and can be used when dressing parts such as ring discs in order to improve the quality of dressing by reducing the non-flatness of their surface.

A device for straightening discs is known (AS 1779431, B21D 3/00 USSR / Stepanenko A.V. et al., declared 08.01.1990 (No. 4798257/27); publ. 07.12.1992. Bull. No. 45) [ 1]. Editing of the discs is carried out by applying a dressing force perpendicular to the straightened surface of the disc located between concentric annular supports in combination with simultaneous deformation of the disc web by twisting in the tangential direction. With this straightening method, a fractional deformation of the disk surface occurs in the thickness direction, and due to the shift of the annular supports, torsion deformations occur in the tangential direction of the disk web.

However, such dressing method for discs having a small annular web width is limited due to the impossibility of dividing the deformation zone into even narrower annular zones during dressing.

Closest to the claimed invention is a method for straightening ring discs (AS 1792763, B21D 1/02 USSR / Antonyuk V.E. et al., declared 03/29/1991 (No. 4940788/27); publ. 02/07/1993. Bull No. 5) [2].

Dressing is carried out between staggered tapered rollers, the axes of which are located at an angle. During the dressing process, the disc rotates between the upper and lower tapered roller cassettes. The forming surfaces of the tapered rollers overlap, the disk annular sheet is loaded and a traveling wave of bending deformation occurs. The damping nature of the action of alternating bending stresses is achieved due to the displacement of the cassettes relative to each other. The deformation of the disk bending between the tapered rollers during the straightening process is characterized by unevenness from the inner to the outer diameter of the disk. Changing the angle between the axes of the tapered rollers and the plane of the disc by one or more turns of the rollers causes a turn of the plane of the disc itself under the action of the editing force transmitted through the tapered rollers. During the straightening process, due to such a turn, under the action of conical bending rollers, the disk takes on a plate shape, which is retained after straightening. This is typical for bending deformation of annular disks (for more details, see Methodological fundamentals of software calculation of power parameters of dynamic stabilization of friction disks / Antonyuk V.E., Skorokhodova A.S., Alexandrova B.C. - Minsk.: Topical issues of mechanical engineering. Joint Institute of Mechanical Engineering of the National Academy of Sciences of Belarus , volume 7, 2018 - 400 pp.) [3, pp. 256-260].

Existing known dressing methods have these disadvantages and do not allow to obtain high quality dressing and provide acceptable minimum non-flatness values of 0.1-0.15 mm, depending on the size of the discs.

The aim of the invention is to improve the quality of the straightening process by reducing the level of non-flatness and technologically inherited disc shape in the manufacture of disks, eliminating the effect of strengthening the plate shape during the straightening process, by creating an equally stressed state during straightening.

This goal is achieved by a joint combination of bending deformations and compression deformations of the disk web, which makes it possible to create a uniform stress state in the radial and tangential directions of the annular disk. Bending deformation is created by staggered conical rollers, and compression deformation - by applying compressive forces directed perpendicular to the plane of the disk web, by compressing it between a pair of oppositely located conical rollers. Such loading contributes to the reduction of disc shape errors.

When implementing the proposed straightening method, the annular blade of the disc during rotation experiences alternating stresses of alternating bending and compressive stresses.

Simultaneous action of alternating bending stresses and compressive stresses creates an increased uniformity of deformations. During rotation, the disk, passing through the conical rollers for crimping, is forced into a position in which there is no disc-shaped, since the plane of contact of the conical rollers for crimping with the surface of the disk is parallel. The compressive stresses during the dressing process ensure the accuracy of the disk in flatness, which is the end result of the dressing process.

Fixing a part of the disk surface between the compressing rollers creates the effect of flowing plastic compression deformation. The angular speeds of rotation of the conical rollers for alternating bending can be mismatched with the angular speeds of rotation of the conical rollers for compression, while bending and tensile stresses are created in the disk web, evenly distributed over the thickness of the disk itself. The bending zone is characterized by the occurrence of tensile and compressive stresses from different sides of the disk web. In the compression zone, between the compressing rollers, there is a turn of the platelet bending plane of the annular disk into the compression plane, in which the platelet of the disk is close to zero. Between the compression and bending zones, the disk web is stretched over its entire thickness, due to the appearance of membrane stresses, the magnitude of which depends on the magnitude of the compression force.

Qualitative changes that occur with this method of straightening annular disks are determined by the appearance of additional tensile (membrane) stresses in the tangential direction. The deformation zone is characterized by various types of plastic deformations, which vary depending on the position of the dressing disk relative to the tapered rollers. Additional stretching of the disk material in the tangential direction creates conditions for the occurrence of plastic deformations in the plane stressed and plane deformed states, which corresponds to shear deformation in two perpendicular directions: radial and tangential. As one moves away from the conical rollers for compression and approaches the conical rollers for bending, the deformation pattern changes and plastic bending deformation occurs. The manifestation of the total action of compressive forces and bending forces with this method of straightening annular disks between tapered rollers for various purposes leads to the fact that the disk deflection required for plastic deformation will be less. the values of all stresses are summarized: compression, tension and bending. Under the action of tensile stresses, the surface of the disk is leveled, and the alternating nature of the action of bending stresses caused by the rotation of the disk, with a change in the compression force and bending force during the straightening process, contributes to the "annihilation" of stresses in the web. The subsequent relaxation of stresses, due to their insignificant magnitude and the balance of the stress state in the disk at the end of the straightening process, does not lead to an increase in the effect of the plate shape, which contributes to obtaining a geometrically even surface.

On FIG. 1 shows an axonometric projection of a device for implementing the proposed method for straightening an annular disk 1 by rotating the disk web between staggered conical rollers 2 and 3 for bending. Between them, along the ring of disk 1, there are pairs of opposed tapered rollers 4.1 and 4.2 (for its crimping during straightening). Figure 2 - scheme editing the disk. On FIG. 3 shows the cross section A-A of disk 1 (270° - 90°). On the right is a block of opposite rollers 4.1 and 4.2, between which the disk web is compressed, on the left is the upper roller 2 for bending. On FIG. 4 shows a scan of disk 1 (210° - 90°), which shows tapered rollers 2 and 3 along the ring of curved disk 1. arranged in a checkerboard pattern, alternating with opposite rollers 4.1 and 4.2. On FIG. 5 - cyclograms of changes in the bending forces P _n and compression P _c when editing the disk.

The process of editing the annular disks according to the invention is as follows. Disc 1 is mounted on rollers 2 and 4.1, located perpendicular to the axis of rotation of the disc, forming a support surface. When installed, disk 1 is centered on the axis of rotation. During the rotation of the disk 1, the rollers 3 overlap the rollers 2 by the value of the web deflection f, at which bending stresses arise in the disk material. Simultaneously opposed rollers 4.1 and 4.2 are brought into contact with the surface of the disk 1. When loaded with a compressive force transmitted through the rollers, the disk web is compressed to a level of relative deformation of the disk web within 0.5-2%. The level of compressive stresses arising at such values of the deformation of the web is sufficient for the plastic deformation of the web itself to occur throughout its entire thickness in order to straighten the surface of the disk during the straightening process in combination with its plastic deformation during the bending process. Moreover, depending on the magnitude of the compression force, the magnitude of the tensile stresses of the disk web depends. At the beginning of the process, it is necessary that the maximum value of the compression force be characterized by the value at which the tensile stresses behind the compression zone in the disk web reach the yield strength, which ensures the straightening of low-rigid parts.

This nature of the disk loading during the dressing process is characterized by the presence of tensile stresses in the tangential direction along the disk, since when the disk is compressed between rollers 4.1 and 4.2 and rollers 3 and 2, an additional tension of the disk web occurs. The total action of tensile stresses and bending stresses qualitatively changes the process of plastic deformation and leads to the appearance of plastic deformation in the material of the straightened disk at lower values of disk deflection. This leads to the straightening of the original local irregularities of the web, which were determined to a certain extent by residual stresses before straightening.

The manifestation of all factors of the combined loading of compression and bending allows the straightening process according to the invention to be carried out with a 20-30% lower deflection of the disk, creates an equally stressed state in the radial and tangential directions of the disk during straightening. The rotation of the disc web at the end of editing under the action of a compression force is excluded, which ensures the creation of a more even (correct shape) surface of the disc, which remains after the release of the straightened disc. During unloading, secondary plastic deformations do not occur and there is no twisting of the disk web (increasing the effect of the disc shape of the disk), after alternating bending.

Execution example.

As an example of the proposed method for straightening ring disks, disks with an outer diameter of 390 mm, an inner diameter of 285 mm, and a web thickness of 4 mm are considered. The discs have an internal crown with 58 teeth. Disc material - steel 65G. Discs are used in steering clutches.

Disc 1 to be dressed is mounted on rollers 3 and 4.1, which are perpendicular to the axis of rotation. In this position, rollers 2 and 4.2 are lowered perpendicular to the axis of rotation of the disk. The rollers for crimping the disc 4.2 (3 pcs. ) are opposite to the rollers 4.1 (3 pcs.), and the rollers for bending 2 (3 pcs. ) are in a checkerboard pattern relative to the rollers 3 (6 pcs.). The mechanisms of movement and loading of the disc by the forces of compression and bending are separate. All compression rollers 4.1 and bending rollers 3 have separate rotation drives.

As an example of the implementation of the method, the following characteristics were taken: the angular speed of rotation of the disk - 200 min ^-1 , the bending force of the disk web on the roller - 5000 N, the compression force of the disk web on the roller, maximum - 5000 N, the maximum deflection of the disk web - 2.5 mm, the number of disk loading cycles in alternating bending - 700, straightening time - 3.5 min.

The disc rotates due to friction forces between the disc web and rollers 3 and 4.1, which form the supporting surface. By lowering the rollers 2 onto the disc web, it is loaded with a bending force. In this case, there is a displacement of the disk web relative to the rollers 3 until the specified deflection value is reached. A traveling wave of alternating bending deformation arises in the disk web under the action of tensile stresses in the convex surface of the disk and compressive stresses in the concave part of the disk. At the same time, compressive stresses appear in the disk web, which is in contact with rollers 4.1 and 4.2, under the action of a compression force, evenly distributed over the entire width of the ring and its thickness. In the area of the disk surface between the compression rollers 4.1, 4.2 and the bending rollers 2 and 3, tensile stresses occur in the tangential direction, evenly distributed over the thickness of the disk. Changing the compressive force during the implementation of the method allows you to change the magnitude of the compressive and tensile stresses in the center of plastic deformation of the disk to ensure an equally stressed state in combination with the simultaneous appearance of various types of compressive, tensile and bending deformations. With a minimum compression force, only the disk surface is fixed in a flat plane, and all irregularities are forced out into the tension zone and then into the zone of alternating bending. In the tension zone, the irregularities straighten out, and in the bending zone, a traveling wave of alternating tension and compression stresses "absorbs" the stresses caused by the fixation of the disk between the rollers in the compression zone. The final stage of straightening is keeping the disc under the action of only compression forces, with a simultaneous decrease in the deflection of the disc and capping its surface in a plane without the disc shape that exists during bending.

The straightening method is carried out according to loading sequence diagrams, when at the beginning the bending force and deflection increase, the compression force changes cyclically and remains constant for some time when the disk is unloaded.

After the end of the straightening process, measurements of the error in the geometric shape of a batch of annular disks were carried out and it was found that the deviation from flatness is within the tolerance range of 0.05 mm - 0.15 mm. those. within tolerance.

Information sources

1. A.S. 1779431, V21D 3/00 USSR / Stepanenko A.V., Petrenko V.Sh., Dobrovolsky I.G., Formansky S.S. Claimed 01/08/1990 (No. 4798257/27); publ. 12/07/1992. Bull. No. 45.

2. A.s. 1792763, B21 D 1/02 USSR / Antonyuk V.E., Igudesman R.E., Samoseiko A.P., Sosonkin A.L. Claimed 03/29/1991 (No. 4940788/27); publ. 02/07/1993. Bull. No. 5.

3. Antonyuk V.E., Skorokhodova A.S., Aleksandrova V.C. - Minsk: Topical issues of mechanical engineering. Joint Institute of Mechanical Engineering of the National Academy of Sciences of Belarus, volume 7, pp. 256-260, 2018 - 400 p.

Claims (3)

1. A method for straightening annular disks, in which the disk is repeatedly deformed by alternating bending during its rotation between conical rollers arranged in a checkerboard pattern, characterized in that during the straightening process, a compression force is simultaneously applied to the disk directed perpendicular to the plane of the disk web due to the oppositely located pairs of tapered crimping rollers evenly spaced around the disc ring. 2. The dressing method according to claim 1, characterized in that during the dressing period the compressive force of the disc, transmitted by oppositely located tapered rollers, is cyclically reduced from the maximum value at which the relative deformation of the disc web is achieved within 0.5-2%, and at the end of the editing process, the compression force is kept constant with a decrease to zero when the disk is completely unloaded. 3. The straightening method according to claim 1, characterized in that the angular speeds of rotation of the conical rollers for alternating bending are mismatched with the angular speeds of rotation of the conical rollers that perform compression to create tensile stresses in the disk web.

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