Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
  • B23P9/00—Treating or finishing surfaces mechanically, with or without calibrating, primarily to resist wear or impact, e.g. smoothing or roughening turbine blades or bearings; Features of such surfaces not otherwise provided for, their treatment being unspecified
  • B23P9/02—Treating or finishing by applying pressure, e.g. knurling
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B39/00—Burnishing machines or devices, i.e. requiring pressure members for compacting the surface zone; Accessories therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B39/00—Burnishing machines or devices, i.e. requiring pressure members for compacting the surface zone; Accessories therefor
  • B24B39/003—Burnishing machines or devices, i.e. requiring pressure members for compacting the surface zone; Accessories therefor the working tool being composed of a plurality of working rolls or balls
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B39/00—Burnishing machines or devices, i.e. requiring pressure members for compacting the surface zone; Accessories therefor
  • B24B39/02—Burnishing machines or devices, i.e. requiring pressure members for compacting the surface zone; Accessories therefor designed for working internal surfaces of revolution
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D7/00—Modifying the physical properties of iron or steel by deformation
  • C21D7/02—Modifying the physical properties of iron or steel by deformation by cold working
  • C21D7/04—Modifying the physical properties of iron or steel by deformation by cold working of the surface
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/47—Burnishing
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/47—Burnishing
  • Y10T29/476—Continuous feed
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/47—Burnishing
  • Y10T29/479—Burnishing by shot peening or blasting

Definitions

• the invention relates to a fluidostatic rolling device for surface processing, in particular for smooth rolling and / or deep rolling, with (a) at least one rolling element, (b) at least one fluid-axial bearing, by means of which the at least one rolling element is mounted, and (c) at least one Pressure fluid supply, which is designed for supplying a pressurized fluid for storage, wherein (d) the bearing is formed so that the rolling body can be pressed by means of the pressurized fluid against a workpiece surface to be machined.
• the invention relates to a method for boundary layer forming with the steps of (i) applying a rolling body of a rolling tool with a pressurized fluid, (ii) contacting the rolling element with a workpiece surface of a workpiece so that the rolling element exerts a force on the surface and (iii) moving the rolling element relative to the workpiece.
• Hydrostatic rolling mills are used for surface layer forming of workpieces, in particular of metallic workpieces. They comprise a rolling tool provided with one or more rolling elements which are pressed against the workpiece surface with high force, while the tool and the workpiece move relative to one another, for example rotate. The rolling force is generated by a pressurized fluid behind the rolling elements.
• the pressurized fluid used is usually an oil which has a double function, namely, on the one hand, to apply the hydrostatic pressure to the rolling element and, on the other hand, to lubricate the rolling element with respect to its bearing.
• a disadvantage of known rolling devices is that the achievable processing speed is limited in free-form surfaces or non-cylindrical workpieces by the hysteresis of the rolling element movement.
• the processing takes place only in exceptional cases along a feed axis of the machine tool used. Therefore, during the movement of the rolling tool of the rolling device along the contour to be machined, the rolling tool must be tracked.
• the tracking takes place in discrete steps, so that the supernatant, by which the rolling element projects beyond its bearing, changes with each step and additionally with every change in distance to the workpiece. The faster the supernatant changes, the stronger the pressure fluid, for example the hydraulic oil, dampens the movement of the rolling element. This limits the maximum achievable processing speed.
• the invention has for its object to enable higher processing speeds.
• the invention solves the problem by a generic hydrostatic rolling apparatus in which the pressurized fluid is a gas.
• the invention solves the problem also by a machine tool with such a rolling device.
• the invention solves the problem by a generic method in which a pressurized gas is used as the pressurized fluid.
• the invention is based on the finding that the rolling elements can also be stored hydrostatically by a gas. This is surprising because the viscosity of gases increases with temperature, but decreases with liquids. As the pressure increases, the viscosity of gases generally increases, whereas with liquids it remains almost unchanged. If one relaxes a high-pressure gas, its viscosity drops very sharply. However, since a high viscosity is a prerequisite for safe hydrostatic storage, it would have been expected that gas would not be suitable.
• Another advantage is that the changes in edge zone properties caused by rolling are retained for some materials, such as certain steels, for a longer time.
• the background to this is that the temperature and pressure of the lubricating-particle-containing gas can be selected so that the lubricating-particle-containing gas cools when it is expanded near the rolling body. In the workpiece edge zone, cold forming takes place, which particularly improves the material surface in a sustainable manner.
• the rolling element is understood in particular to mean a body which, like the bearing, is part of a rolling tool, which in turn is part of the rolling device and can be acted upon by the pressurized fluid supply with pressurized fluid.
• the rolling element is designed and arranged such that it rotates when moving the rolling tool along the workpiece surface and so on the workpiece edge zone acts.
• the rolling body is a ball.
• the fluid-static bearing is understood in particular to mean a device by means of which the position of the rolling element is kept the same relative to the rest of the rolling tool.
• it is a fluidostatic guide, is in particular understood that the rolling elements is held during operation on a gas cushion from the compressed gas, so that in particular no solid friction of the rolling element with the storage or other component of the rolling tool.
• the gas is, for example, air, nitrogen, carbon dioxide or mixtures thereof. In principle, however, all gases can be used. It is advantageous if the inversion temperature of the gas is above 0 ° C.
• a gas is understood to mean, in particular, a substance which is gaseous at room temperature of 22 ° C. and atmospheric pressure of 1013 hPa. In particular, the gas is understood as meaning a substance which is gaseous at room temperature even at 200 bar (20 MPa).
• the rolling device comprises a plurality of rolling tools. It is independently possible that the rolling tool or the rolling tools each have one, two, three or more rolling elements, or have.
• the rolling tool has a plurality of rolling elements, they can be arranged in along a straight line or a curve, in particular a circle. It is also possible that the rolling elements are arranged along a plane or along a curved surface, in particular a cylindrical surface or a barrel-like surface.
• the pressurized fluid is a pressurized lubricating particulate matter. tiger gas. It is then an advantage that the consumption of cooling lubricant can be significantly reduced.
• the concentration of lubricating particles in the gas can be chosen so small that only a thin film of lubricant particles, for example of oil, remains on the workpiece, which does not have to be removed. Since, in known fluidostatic rolling devices, the pressurized fluid simultaneously serves for lubrication and thus requires a significantly increased throughput of lubricant compared to the invention, it is surprising that a small amount of lubricant particles is sufficient.
• the lubricating particle-containing gas is a lubricant mist.
• the lubricant-containing gas is a smoke, that is to say contains solid particles, it is particularly favorable if the lubricant containing the lubricant particles is an aerosol of gas and lubricant droplets.
• the lubricant droplets in the lubricant mist have a droplet size of at most 10 micrometers, more preferably at most 1 micrometer.
• the pressurized fluid supply is arranged to dispense a pressurized fluid which delivers at most 50 milliliters of lubricant per hour of operation. It is then a minimal-quantity-lubricated rolling tool.
• the pressurized fluid supply is configured to dispense a lubricant mist containing lubricant droplets of an oil-free lubricant.
• the lubricant mist contains lubricant drops from an oil, that is an oil-aerosol, or contains both oil-free and oil-containing components.
• the bearing is designed so that the at least one rolling element can be pressed with a time-uniform force against a workpiece surface to be machined. This is particularly advantageous for burnishing.
• Surfacing tools are known in which impact balls are held on a circular path by means of compressed air, the impact balls striking contact balls at regular intervals, which abut the workpiece surface.
• the bearing is formed so that the at least one rolling element applies a force to the workpiece during machining, which varies with a fundamental frequency of at most 1 Hertz.
• the pressurized fluid supply is designed to dispense a pressurized fluid under a working pressure, the working pressure being at least 20 bar (2 MPa), in particular at least 50 bar (5 MPa). It has been shown that the lubrication of the rolling element is reliably ensured at a working pressure of at least 20 bar. This is due to the current state of knowledge due to the fact that the pressurized gas expands in the vicinity of the rolling body, thereby cooling and thereby increases the viscosity of the lubricant droplets.
• lubricant adheres better to the rolling element and so, in spite of the low lubricant concentration in the pressurized fluid, reliable lubrication of the rolling element is ensured.
• the lubricant particles, in particular the lubricant droplets then experience their cooling when they are between the bearing and the rolling element.
• the flow velocity is highest there and, according to the law of Bernoulli, the pressure is particularly low and thus the temperature is low.
• the lubricant droplets have a high viscosity in the gap between the bearing and the rolling element, they hinder the passage of the gas and thus reduce the consumption of pressurized fluid or lubricant mist.
• the bearing has a Wälzianuitz by means of which the rolling element is trapped. That is, the rolling element can not be pushed out of the rolling tool by the pressurized fluid because it is restrained by the rolling element seat.
• the rolling tool preferably has a sleeve which prevents the rolling element from coming off when the rolling element is not prevented from being exited by an opposing workpiece surface.
• the fluidostatic bearing has a Wälzianuitz, wherein the Wälzianuitz is formed so that it is at least substantially fluid-tightly closed by the rolling body, so that substantially no pressure fluid escapes when the rolling elements is not engaged with the workpiece.
• the WälzSystemitz is formed so that a
• Pressure fluid cushion between the WälzConsequently and the rolling element is formed when the rolling element is pressed against a workpiece.
• the rolling tool has a temperature control and / or regulation for controlling and / or regulating a gas temperature of the lubricant-containing gas.
• the cooling of the gas caused by the expansion plays a role.
• At constant pressure can be adjusted by adjusting the temperature of the gas, the temperature of the rolling elements, so that the conditions under which rolled, are definable.
• the gas temperature of the lubricant-containing gas before, but also after the introduction of the lubricant particles, in particular the lubricant particles can be realized.
• the pressurized fluid supply includes a compressor for compressing air.
• a temperature control is provided, which may in particular comprise a heat exchanger.
• the heat generated by the compression can be dissipated.
• a method according to the invention is carried out in particular in such a way that pressurized fluid is supplied to the rolling element in such a way that it flows around the rolling elements, lubricates lubricating particles, in particular lubricating liquid droplets, the rolling element and causes expansion of the pressurized fluid as it exits the rolling tool to reduce the temperature of the rolling element
• Pressure fluid of more than 10 Kelvin, in particular more than 20 Kelvin leads. As stated above, this increases the viscosity of droplets of lubricating liquid.
• the higher the working pressure of the pressure fluid the greater the temperature reduction is usually. For example, it may be advantageous if the working pressure is at least 150 bar, since then it can lead to a temperature drop of more than 30 Kelvin.
• the gas temperatures and / or the fluid pressure of the lubricant-containing gas are chosen so that the temperature of the pressure fluid after exiting the rolling body, ie in the vicinity of the workpiece surface, below 20 ° C, preferably below 10 ° C, in particular below 5 ° C. ,
• the method comprises adjusting the gas temperature of the lubricant-containing gas to a gas temperature which is less than 50 °, in particular less than 40 °.
• the pressurized fluid is a
• a lubricant mist comprising lubricating fluid droplets from a lubricating fluid, wherein the lubricating fluid has a temperature-dependent viscosity.
• the rolling element is acted upon by lubricant mist with a working pressure such that the viscosity of the lubricant increases at least twice as much due to the temperature reduction during expansion of the lubricant mist in the region of the rolling body.
• a combined peeling rolling tool in addition to the above features for a fluidostatic rolling tool has a cutting tool, in particular at least one geometrically determined cutting edge.
• the method is carried out so that the Druckfluid id when exiting the rolling die has a temperature of less than 15 ° C, in particular less than 10 ° C.
• FIG. 1 shows a cross section through a rolling tool of a rolling device according to the invention at the height of the rolling elements, a perspective view of a rolling device according to the invention, a second embodiment of a rolling device, a third embodiment of a rolling device, a fourth embodiment of a rolling device according to the invention, a detailed drawing of the thermodynamic conditions on the rolling elements and a cross section through an inventive Walzvor direction.
• FIG. 1 shows a cross section through a head 10 of a rolling tool 12 according to the invention.
• the rolling tool 12 has a rolling element 14.1 and a second rolling element 14.2, which are mounted here in the form of a bore by means of a bearing 16.
• the rolling elements 14 (numerals without Zählsuffix denote the object as such) have a diameter which is smaller by a small amount than a diameter of the bore 16 so that they are slidably and rotatably received in the bore 16.
• a pressurized gas 20 is supplied, so that the rolling elements 14 radially outward against a to be machined Workpiece surface 22 are pressed.
• the rolling elements 14 then exert a force on the workpiece surface 22 and deform it.
• the bearing as provided in the present embodiment, retaining structures 24.1, 24.2, by means of which it is prevented that the rolling elements 14 can leave the rolling tool 12.
• the retention structures also largely prevent leakage of gas 20 when the rolling element 4 is not in contact with a workpiece. As soon as the rolling element 14 is deflected by a workpiece surface, a gap opens and an air cushion, which guides the rolling element 14, forms.
• FIG. 2 shows a schematic view of a rolling device 25 according to the invention with the rolling tool 12 and a pressurized fluid supply 26.
• the pressurized fluid supply 26 comprises a pressurized gas source 28, from which gas 20 can be removed through a pressure line 30. Via a valve 32, the gas flow can be interrupted, so that, for example, the compressed gas source 28 can be changed. Via a pressure regulator 34, a fluid pressure pi is adjusted, with which the pressurized fluid gas 20 is conducted into a nebulization chamber 36.
• a nozzle 38 is arranged, which nebulizes lubricating fluid 40, which is provided with a lubricating fluid pressure p s from a lubricating fluid line 42.
• the lubricating fluid line 42 is fed by a lubricant metering unit 44, which has a lubricant reservoir 46 for liquid lubricant and a
• Lubricant pump 48 includes.
• the lubricating fluid pressure ps is usually higher than the fluid pressure in the misting chamber 36, a lubricant mist 50 is formed, which is passed via a pressure line 52 at a working pressure p A to the rolling tool 12, on which the head 10 is formed.
• the components from the compressed gas source 28 up to and including the pressure Line 52 and a pressure port 56 are part of the Druckfluidversor- supply 26.
• the tool 12 has a tool shank 54, via which a rotational movement of a spindle can be introduced. About an anti-rotation 58 co-rotation of the housing is prevented, so that only the head 10 rotates.
• a method according to the invention is carried out by first of all subjecting the rolling elements 14 of the rolling tool 12 to gas in particular from the pressurized fluid supply 26 containing lubricant particles. Thereafter, or before, the rolling bodies 14 are brought into contact with a workpiece surface, not shown in FIG. 2, of a workpiece, so that the rolling bodies 14 exert a force on the material surface. The rolling tool 12 is then moved relative to the workpiece, in the present case with a rotating head along a bore, so that the rolling body or the rolling elements influence the edge zone of the workpiece.
• gas 20 is removed from the compressed gas cylinder 28, brought to a leading pressure pi by means of the pressure regulator 34 and directed to the misting chamber 36, where, for example, the lubricating liquid 40 is nebulized by means of a Venturi nozzle.
• the resulting schnnierpumble® gas under a working pressure p A is then passed to the rolling tool 12.
• the lubricant pump 48 is driven by a control, not shown, so that the content of lubricating particles in the lubricant-containing gas, which is discharged through the pressure line 52, is constant.
• FIG. 3 shows an alternative embodiment of a pressurized fluid supply 26 of a rolling device 25 according to the invention, in which the pressurized gas Source 28 comprises a compressor 60 which sucks and compresses ambient air.
• the pressurized gas 20 thus produced reaches a temperature control 62, which comprises a heat exchanger and controls or regulates the pressurized gas 20 to a predetermined gas temperature TG.
• a pressure gauge 64 is arranged to control the pressure.
• both the pressure regulator 34 and the pressure gauge are not necessary if, for example, the compressor 60 is designed accordingly.
• FIG. 4 shows a further embodiment of a pressurized fluid supply 26, in which the lubricant reservoir 46 is under the fluid pressure pi, in that a stub line 66 ensures the corresponding pressure equalization.
• the nozzle 38 is designed as a Venturi nozzle and the lubricating fluid line 42 opens in a point high flow rate and thus low pressure in the nozzle 38. As a result, lubricating fluid 40 is sucked from the lubricating fluid tank 42 and atomized, so that the
• FIG. 5 shows a further embodiment of the pressurized fluid supply 26 for a rolling device 58 according to the invention, in which the pressurized gas source 28 comprises compressed gas cylinders 68 which are filled by the compressor 60 as required.
• a check valve 70 ensures that compressed gas 20 does not leave the compressed gas cylinders 68 in the direction of the compressor 60.
• Via a pressure switch 72 the compressor 60 is activated when a pressure in the compressed gas cylinders 68 falls below a predetermined threshold.
• FIG. 6 shows schematically the situation in the tool 12 during operation.
• the lubricating particle-containing gas in the form of the lubricant mist 50 flows at a flow rate v ⁇ the working pressure PA and the temperature Ti to the rolling body 14.
• the lubricant droplets 74.1, 74.2, 74.3, ... consist of lubricant with a viscosity
• the flow velocity increases to the value v 2
• the pressure drops to the value p 2 and as a result the temperature drops to the value T 2 .
• the viscosity v of the lubricant droplets increases due to the lower temperature to the value v 2 . Due to the reduced viscosity, some of the lubricant droplets adhere to and lubricate the roller 14, for example, when the roller 14 is disengaged or re-engaged with the roller 78.
• FIG. 7 shows a rolling device 25 according to the invention which comprises a plurality of rolling tools 12, of which the rolling tools 12.1, 12.2, 12.3 can be seen in FIG. If the rolling tools 12 are not in contact with the workpiece 78, then the ball centers of the rolling elements 14 lie in a surface which may be a plane. But it is also possible that the surface is curved in one dimension or in two dimensions.
• the rolling tools 12 are connected via a common pressure line 52 to the pressurized fluid supply 58 (see FIGS. 2 to 5).

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Rolling Contact Bearings (AREA)
• Lubricants (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

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ID=46196954

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Citations (3)

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• 2011
  • 2011-02-11 DE DE102011011276A patent/DE102011011276A1/de not_active Withdrawn
• 2012
  • 2012-02-08 JP JP2013552839A patent/JP6034806B2/ja not_active Expired - Fee Related
  • 2012-02-08 CN CN201280008391.0A patent/CN103347648B/zh not_active Expired - Fee Related
  • 2012-02-08 EP EP12724544.7A patent/EP2673112B1/de not_active Not-in-force
  • 2012-02-08 WO PCT/DE2012/000143 patent/WO2012107028A1/de not_active Ceased
  • 2012-02-08 US US13/982,572 patent/US9321135B2/en active Active
  • 2012-02-08 KR KR1020137023964A patent/KR20140018259A/ko not_active Withdrawn

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