METHOD FOR SURFACE PROCESSING OF A COMPONENT BY FLOW GRINDING

Abstract

The invention relates to a method for the surface processing of a component by flow grinding, comprising the following steps: (a) providing a blank (1), (b) flooding at least one surface of the blank (1) with a fluid carrier material containing grinding particles,
wherein the blank (1) is rounded at positions at which, during flooding, the flow direction (25) of the fluid carrier material containing the grinding particles changes and, at positions at which a flow separation occurs on the finished component, additional material (5) is attached such that a flow separation at the beginning of the flooding operation is prevented.

Claims

1-15. (canceled)

16. A method for the surface processing of a component by flow grinding, comprising the following steps: (a) providing a blank, (b) flooding at least one surface of the blank with a fluid carrier material containing grinding particles, wherein the blank is rounded at positions at which, during flooding, the flow direction of the fluid carrier material containing the grinding particles changes and, at positions at which a flow separation occurs on the finished component, additional material is attached such that a flow separation at the beginning of the flooding operation is prevented.

17. The method as claimed in claim 16, wherein the blank is rounded at the positions at which, during flooding, the flow direction of the fluid carrier material containing the grinding particles changes with a radius which corresponds to 0.1 to 2.5 times the mean spacing between the surface over which flow passes and the opposite wall of the duct through which the fluid carrier material containing the grinding particles flows.

18. The method as claimed in claim 16, wherein the additional material, which is attached at positions at which a flow separation occurs on the finished component, on the side facing the flow, in the case of a component having a rotationally symmetrical projection surface exposed to the flow, has a surface which is inclined and runs concavely in the flow direction with respect to a central axis of a duct in which the fluid carrier material containing the grinding particles flows.

19. The method as claimed in claim 18, wherein the inclined and concavely running surface has a curvature with a radius in the range of from 1 to 5 times the diameter of the rotationally symmetrical projection surface.

20. The method as claimed in claim 16, wherein the additional material, which is attached at positions at which a flow separation occurs on the finished component, on the side facing the flow, in the case of a component having a non-rotationally symmetrical projection surface exposed to the flow, has a surface which is inclined and runs concavely in the flow direction with respect to a central plane running parallel to the flow direction of the fluid carrier material containing the grinding particles.

21. The method as claimed in claim 20, wherein the inclined and concavely running surface has a curvature with a radius in the range of from 2 to 10 times the maximum perpendicular spacing from the central plane running parallel to the flow direction of the fluid carrier material containing the grinding particles to the edge of the non-rotationally symmetrical projection surface.

22. The method as claimed in claim 16, wherein, in the case of a surface over which flow passes that forms a wall of a duct, in which the duct comprises a change in direction, material which has in the center a convexly running surface and outwardly a concavely running surface is applied to the wall of the duct which is exposed to the flow of the fluid carrier material containing the grinding particles on account of the change in direction of the duct.

23. The method as claimed in claim 22, wherein the convexly running surface has a curvature with a radius in the range of from 0.5 to 5 times the hydraulic diameter of the duct.

24. The method as claimed in claim 22, wherein the applied material has a maximum thickness which corresponds to 0.1 to 0.75 times the hydraulic diameter of the duct.

25. The method as claimed in one of claims 7 to 9, wherein the concavely running surface has a curvature with a radius in the range of from 0.5 to 5 times the hydraulic diameter of the duct.

26. The method as claimed in claim 1, wherein, in the case of a surface over which flow passes that forms a wall of a duct, in which the duct has a widening in which the duct is widened from a region with a first hydraulic diameter to a region with a second hydraulic diameter, in which a transition portion of the wall of the duct between the region with the first hydraulic diameter and the region with the second hydraulic diameter has an angle of between 7° and 90° with respect to the main flow direction, in which the surface over which flow passes runs convexly at the transition from the region with the first hydraulic diameter to the transition portion.

27. The method as claimed in claim 26, wherein the surface running convexly at the transition from the region with the first hydraulic diameter to the transition portion has a curvature with a radius in the range of from 0.05 to 2.5 times the hydraulic diameter of the duct upstream of the widening.

28. The method as claimed in claim 26, wherein the surface over which flow passes runs concavely at the transition from the transition portion to the region with the second hydraulic diameter.

29. The method as claimed in claim 28, wherein the surface running concavely at the transition from the transition portion to the region with the second hydraulic diameter has a curvature with a radius in the range of from 0.05 to 2.5 times the hydraulic diameter of the duct upstream of the widening.

30. The method as claimed in claim 16, wherein the fluid carrier material is water, oil or a highly viscous grease.

Description

[0041] Examples of the invention are illustrated in the figures and explained in more detail in the following description.

[0042] In the figures:

[0043] FIG. 1 shows a blank with a circular cross section and material attached thereto, in order to prevent a flow separation,

[0044] FIG. 2 shows a duct through which flow passes, the walls of which duct are processed by flow grinding and which duct comprises a change in direction,

[0045] FIG. 3 shows a duct through which flow passes and which has a widening.

[0046] FIG. 1 shows a blank with a circular cross section and material attached thereto, in order to prevent a flow separation.

[0047] A blank 1 having a surface 3, which is intended to be processed by flow grinding, is introduced for this purpose into a suitable duct, through which a fluid carrier material containing grinding particles flows. In order to prevent a flow separation, additional material 5 is attached to the blank 1 on the side facing away from the flow. The additional material 5 has on the side 7 facing the flow a surface 11 which is inclined and runs concavely in the flow direction with respect to a central plane 9, which runs parallel to the flow direction 25 of the fluid carrier material containing the grinding particles.

[0048] The blank 1 illustrated in FIG. 1 has a circular cross section, such as for example a cylinder or a sphere. When the blank 1 is a cylinder, it has a non-rotationally symmetrical projection surface exposed to the flow, specifically a rectangular projection surface. The central plane 9, which runs parallel to the flow direction 25 of the fluid carrier material containing the grinding particles, forms with the rectangular projection surface an intersecting line which runs in the center of the projection surface, with the result that the spacing from the intersecting line to the edge of the projection surface corresponds to the radius of the cylinder.

[0049] When the blank is not a cylinder but rather is a sphere, it has a rotationally symmetrical projection surface, in this case the additional material on the side facing the flow having a surface which runs concavely and in an inclined manner in the flow direction 25 with respect to a central axis. The central axis runs in this case in a manner corresponding to the central plane 9 through the center point of the sphere and parallel to the flow direction 25 of the fluid carrier material containing the grinding particles.

[0050] In the case of a cylindrical blank 1, the surface 11 which is inclined and runs concavely with respect to the central plane 9 preferably has a curvature with a radius 13 which corresponds to 2 to 10 times the maximum perpendicular spacing from the central plane 9 to the edge of the non-rotationally symmetrical projection surface, that is to say it corresponds to 2 to 10 times the radius 15 of the cylindrical blank 1. Correspondingly, in the case of a spherical blank 1, the surface which is inclined and runs concavely with respect to the central axis has a curvature with a radius 13 which corresponds to 1 to 5 times the diameter of the spherical blank 1, that is to say 2 to 10 times the radius of the spherical blank 1.

[0051] The radius 13 of the curvature of the surface 11 which runs concavely and in an inclined manner particularly preferably amounts to 3 to 6 times the maximum perpendicular spacing from the central plane 9 to the edge of the non-rotationally symmetrical projection surface and/or the radius 15 of the rotationally symmetrical projection surface, for example, as illustrated in FIG. 1, 4 times the radius 15 of the rotationally symmetrical projection surface or the cylinder and/or two times the radius 15 of the rotationally symmetrical projection surface or the cylinder.

[0052] The surface running concavely and in an inclined manner of the additionally applied material is preferably inclined such that the central plane 9, in the case of a blank 1 with a non-rotationally symmetrical projection surface in the flow direction 25, or the central axis, in the case of a blank 1 with a rotationally symmetrical projection surface in the flow direction, is a tangent of the inclined and concavely running surface 11.

[0053] In the case of a blank 1 in which the central plane 9 is a plane of symmetry, the additional material 5 is also attached symmetrically with respect to the central plane 9, with the result that the additional material 5 on both sides of the central plane 9 has an inclined and concavely running surface 11 which ends tangentially with respect to the central plane 9. In the case of a blank 1 with a projection surface which is rotationally symmetrical in the flow direction, the additional material 5 is preferably likewise rotationally symmetrically attached to the blank 1. In the case of a non-rotationally symmetrical projection surface, which in the flow direction 25 is also not axially symmetrical with respect to the intersecting line with the central plane 9, the additional material is preferably applied such that the radius of the curvature on both sides of the central plane 9 is different, such that the central plane 9 on both sides and at the same position in the flow direction of the fluid carrier material containing the grinding particles forms a tangent to the surface running in a curved and inclined manner.

[0054] FIG. 2 shows a duct through which flow passes, the walls of which duct are processed by flow grinding and which duct comprises a change in direction.

[0055] The duct 17 illustrated in FIG. 2 has a first portion with a first hydraulic diameter 19 and a second portion with a second hydraulic diameter 21. The second portion adjoins the first portion downstream of a change in direction.

[0056] Additional material 5, which has in the center a convexly running surface 27 and outwardly a concavely running surface 29, is applied to the wall 23 of the duct 17 which is exposed to the flow of the fluid carrier material containing the grinding particles, the flow direction of which is labeled by an arrow 25, on account of the change in direction of the duct.

[0057] The convexly running surface 27 preferably has a curvature with a radius 31 which is in the range of from 0.5 to 5 times the hydraulic diameter. The radius 31 of the curvature of the convexly running surface 27 particularly preferably amounts to 0.5 to 2 times the hydraulic diameter of the duct 17. When, as illustrated here, the duct 17 has a first hydraulic diameter 19 upstream of the change in direction and a second hydraulic diameter 21 downstream of the change in direction, the hydraulic diameter on which the size of the radius 31 is based is the second hydraulic diameter 21. The radius 31 of the curvature of the convexly running surface particularly preferably amounts to one times the second hydraulic diameter 21, as illustrated here.

[0058] The concavely running surface 29 preferably has a curvature with a radius 33 which is in the range of from 0.5 to 5 times the hydraulic diameter of the duct 17. The radius 33 particularly preferably amounts to 1 to 3 times the hydraulic diameter of the duct 17. Like for the radius 31 of the curvature of the convexly running surface 27, the hydraulic diameter on which the radius 33 of the curvature of the concavely running surface 29 is based is the second hydraulic diameter 21. The radius 33 of the curvature of the convexly running surface 27 in particular amounts to two times the second hydraulic diameter 21, as illustrated here.

[0059] The thickness of the applied additional material 5 has a maximum thickness, which corresponds to 0.2 to 0.75 times the hydraulic diameter of the duct 17. The thickness of the applied additional material 5 particularly preferably corresponds to 0.5 times the hydraulic diameter of the duct 17, the hydraulic diameter on which the thickness of the applied additional material 5 is based also being the second hydraulic diameter here.

[0060] The wall 37 is rounded on the side which is opposite the wall which is exposed to the flow of the fluid carrier material containing the grinding particles on account of the change in direction of the duct and at which a flow separation can result on account of the change in direction of the duct 17. The radius 39 with which the wall 37 is rounded preferably corresponds to 0.1 to 2.5 times the hydraulic diameter of the duct 17, in which the hydraulic diameter of the duct 17 in the case of a duct with a first hydraulic diameter 19 upstream of the change in direction and a second hydraulic diameter 21 downstream of the change in direction the average hydraulic diameter is used. In this respect, the arithmetic mean value is used, that is to say the average hydraulic diameter is calculated from the sum of the first hydraulic diameter 19 and the second hydraulic diameter 21 divided by 2. The radius 39 particularly preferably corresponds to 0.25 to one times the average hydraulic diameter and in particular 0.5 times the average hydraulic diameter.

[0061] FIG. 3 shows a duct through which flow passes and which has a widening.

[0062] A duct 41 through which flow passes and which has a widening 43 has a first region 45 with a first hydraulic diameter 47 and a second region 49 with a second hydraulic diameter 51. In this case, the second hydraulic diameter 51 is greater than the first hydraulic diameter 47. At the widening 43, the duct 41 through which flow passes has a transition portion 53, in which the wall of the duct 41 has an angle of between 45° and 90° with respect to the flow direction 25. In the embodiment illustrated here, the wall of the duct 41 transition portion has an angle of 90° with respect to the flow direction 25.

[0063] In order to prevent a flow separation at the widening 43, that surface of the duct 41 over which flow passes runs convexly at the transition from the first region 45 to the transition portion 53.

[0064] The surface 55, which runs convexly at the transition from the first region 45 to the transition portion 53, preferably has a curvature with a radius 57 in the range of from 0.05 to 2.5 times the hydraulic diameter of the duct upstream of the widening 43, that is to say of the first hydraulic diameter 47 in the first region 45. The surface 55, which runs convexly at the transition from the first region 45 to the transition portion 53, particularly preferably has a curvature with a radius 57 which corresponds to 0.25 to 1 times the first hydraulic diameter, for example, as illustrated here, 0.375 times the first hydraulic diameter 47 in the first region 45.

[0065] The transition from the transition portion 53 to the second region 49 can have an angle, for example a right angle in the case of a wall of the transition portion 53 which has an angle of 90° with respect to the flow direction 25, or else, as illustrated here, can run concavely.

[0066] When the surface in the transition from the transition portion 53 to the second region 49 runs concavely, said surface preferably has a curvature with a radius 59, which corresponds to 0.05 to 2.5 times the first hydraulic diameter 47 in the first region 45, that is to say the hydraulic diameter upstream of the widening 43. The curvature at the transition from the transition portion 53 particularly preferably has a radius 59 which corresponds to 0.25 to 1 times the first hydraulic diameter 47, for example, as illustrated here, 0.375 times the first hydraulic diameter, that is to say the hydraulic diameter upstream of the widening 43 in the first region 45.

[0067] As a result of the convex transition from the first region 45 to the transition portion 53 and the concave transition from the transition portion 53 to the second region 49, a flow separation at the widening 43 is prevented and in addition the occurrence of an undesired backflow, which can lead to cavitation and thus uncontrolled removal of material, is prevented.

LIST OF REFERENCE SIGNS

[0068] 1 Blank [0069] 3 Surface [0070] 5 Additional material [0071] 7 Side facing the flow [0072] 9 Central plane [0073] 11 Inclined and concavely running surface [0074] 13 Radius of the surface 11 which runs concavely and in an inclined manner [0075] 15 Radius of the blank 1 [0076] 17 Duct [0077] 19 First hydraulic diameter [0078] 21 Second hydraulic diameter [0079] 23 Wall [0080] 25 Flow direction [0081] 27 Convexly running surface [0082] 29 Concavely running surface [0083] 31 Radius of the convexly running surface [0084] 33 Radius of the concavely running surface [0085] 35 Thickness of the additional material [0086] 37 Wall [0087] 39 Radius [0088] 41 Duct through which flow passes [0089] 43 Widening [0090] 45 First region [0091] 47 First hydraulic diameter [0092] 49 Second region [0093] 51 Second hydraulic diameter [0094] 53 Transition portion [0095] 55 Convexly running surface [0096] 57 Radius [0097] 59 Radius