DE102009008650A1 - Bearing surface in e.g. engine connecting rod, includes lubrication micro-pockets in closely-spaced pattern of rows formed by picosecond-pulsed laser beam around bearing surface - Google Patents

Abstract

The micro-pockets (10) have an extent of less than 0.5 mm, preferably less than 0.1 mm in the direction of the surface normal, when seen in cross section. The pockets have an approximately elliptical, lengthy or circular cross section. They have an inward conical form in the workpiece, with a depth less than 20 mu m, preferably less than 10 mu m. Their depth is a multiple of the surface roughness R. They are arranged in adjacent rows close to each other, or on a helix. Less than 20%, preferably less than 12% of the entire bearing surface (8) is formed by micro-pockets. The bearing surface is an internal cylindrical surface, an external cylindrical surface or an annular surface. The surface is on a connecting rod or crankshaft. It is an internal cylindrical- or annular surface and the micro-pockets are elongated in the circumferential direction. They are formed by overlapping smaller pockets. The pockets are laser-formed, the workpiece being moved relative to the laser. The laser pulse width is measured in picoseconds and its energy is less than 300 mu J. The pulse frequency exceeds 100 kHz, being preferably 400 kHz. The beam is inclined and the micro-pocket is formed by a sequence of pulses, maintaining relative movement. Preferably 5 pulses are used, i.e. more than 3 and less than 10. The frequency of pulse succession is less than 20 kHz. The laser-processing unit includes a picosecond laser with optics directed onto the bearing surface and equipment causing relative movement. The laser optics rotate about an axis. A scanner or deflection unit is included. The workpiece rotates about the axis of a spindle and is guided adjustably along the axis of rotation. The laser beam is positioned by the scanner to lead, lag or equal the rotary speed of the workpiece. Independent claims are included for the following: (A) the method of forming the micro-pockets; (B) and the processing equipment required.

Description

The The invention relates to a workpiece with a sliding or Guide surface according to the preamble of Claim 1, a method for producing micro-lubricating pockets such a workpiece and a processing unit to carry out the process.

Especially For heavily loaded plain bearings, it is always necessary for adequate lubrication through an oil film between to ensure the mutually sliding surface sections. Particularly high demands are placed on friction bearings of internal combustion engines posed. Such slide bearings are for example in the field the crank bearing of a crankshaft or in the area of a small Connecting rod eye of a connecting rod mounted piston pin.

To stabilize the oil film on such sliding / guiding surfaces is in the EP 1 275 864 B1 stimulated to form in the respective sliding surface a plurality of pockets, which then form chambers for receiving oil / lubricant. In the known solution, these oil lubrication pockets are formed by first the sliding surface is pre-processed by honing, turning, rough grinding and then, for example by laser processing, said pockets are formed. Due to the comparatively high energy input in these known methods, pimples or burrs are created in the edge region of the pockets, which are removed by brushing or deburring in a further production processing step. In a final operation, then a fine machining of the sliding surfaces by honing, grinding or polishing.

adversely with this approach is that due to the large number of process steps - pre-processing, Texturing (pocket design), deburring and finishing - a considerable manufacturing effort is required.

In the DE 10 2004 041 847 A1 a device for laser processing is described, which in principle for the training in the aforementioned EP 1 275 864 B1 shown, relatively bulky and having an elongated cross-section pockets is suitable. In this known solution, the laser beam is guided over a beam deflection device, so that different pocket geometries can be formed without changing the relative position of laser optics and workpiece by adjusting this beam deflection device.

Across from The above-mentioned prior art is the present Invention, the object of a workpiece with a Sliding or guide surface with low production costs produce and thereby a sufficient lubrication of the sliding / guide surfaces to ensure. The invention is further the Task, a method for producing such Workpiece and a processing unit for implementation of such a procedure.

This object is with respect to the workpiece by the feature combination of claim 1 , in terms of the method by the features of the independent claim 10 and with respect to the processing unit by the feature combination of the independent claim 15 solved.

other advantageous developments of the invention are the subject of the dependent claims.

The workpiece according to the invention has a sliding or guide surface, in which a variety of micro-lubrication pockets is trained. According to the invention, these lubrication pockets executed as micro-pockets, by the surface normal seen, one - preferably approximately circular, elliptical or oblong - have cross-section, the maximum extent being less than 0.5 mm, preferably is less than 0.1 mm. Such small micro pockets require one comparatively low energy input for training, so that the emergence of irregularities in the peripheral wall of the individual micro-lubrication pockets can be prevented. Through this burr-free formation of the micro-pockets can on the elaborate post-processing by deburring and finishing (honing, polishing, grinding) be dispensed with, so that the production engineering effort considerably less than in the solutions mentioned above.

It showed surprisingly that the lubricating film training when using such small micro-pockets the solutions with large-volume pockets is not inferior; at certain Requirements even improved wear behavior As it is at a large Hertzian pressure in the Area of large-scale pockets for scrapping or shabby effects. Due to the comparatively small Micro-pockets is in the solution according to the invention this effect of the Hertzian pressure (surface pressure) reduces and thus minimize such Abschabeffekte.

at In a particularly preferred embodiment, the Micro pockets are approximately circular in shape, with irregularities of course, due to the melting of the material are.

In a variant of the invention extend the micro-pockets inwardly in the workpiece in approximately conical, the maximum depth is less than 20 microns, preferably less than 10 microns, but a multiple of the roughness of the adjacent surface areas.

According to the invention it is preferred if the micro-pockets in a row above each other and lying side by side or arranged on a spiral, so that the sliding / guiding surface evenly provided with micro pockets.

at an embodiment is the totaled Area of the micro-pockets less than 20%, preferably about 12% of the total area.

These For example, an area may be an inner cylinder, an outer cylinder or a ring surface. Of course are also other surface geometries, such as plane sliding surfaces, etc. executable in the manner according to the invention.

The inventive concept is particularly advantageous for inner cylinder and outer cylinder surfaces as with connecting rods or crankshafts.

at In a variant of the invention, the micro-pockets are cylindrical Sliding or guide surfaces in the circumferential direction seen elongated. This elongated For example, geometry can overlap by overlapping of circular or elliptical (oblique Coupling) cross sections come, each by individual laser pulses getting produced.

to Production of such a workpiece is preferred a manufacturing process used in which the laser optics and workpiece are movable relative to each other to the above-described micro-pocket pattern to be able to train. The driving of the laser is done with a pulse width in picosecond range and low pulse energy, z. B. less than 250 μJ.

at A laser with such low energy input can emerge from jarring in the peripheral area of the micro-pockets reliably be avoided.

According to the invention it is preferred if the pulse frequency is more than 100 kHz, preferably about 400 kHz. Such a fast laser allows it, the above-described surface pattern in the shortest possible time Form time so that the cycle times for machining the workpiece are minimal.

there it is preferred if the pulse width is less than 10 ps.

In the case where the sliding or guiding surface is an inner cylindrical surface or annular surface, the laser beam can be obliquely coupled. Due to this oblique coupling, it is not necessary, the laser optics pinolenartig - as in the DE 10 2004 041 847 A1 described - to immerse in the bore forming the sliding surface. A disadvantage of such oblique coupling is that the micro-pocket is then elliptical in cross-section. This disadvantage can be overcome according to the invention in that the micro pocket is formed by a multiplicity of pulse trains, during which the relative movement between the workpiece and the laser optics is maintained, so that a somewhat rounder or even elongated cross section of the micro pocket due to the "sanding" can be generated.

to Minimization of energy input is preferred when training a circular micro-pocket less than 10, preferably about 5 pulse sequences are used.

The Pulse train frequency - also called burst frequency - is preferably less than 20 kHz, and is dependent on the maximum pulse repetition frequency of the laser and the number of consecutive following impulses.

The inventive processing unit for implementation of the method has a so-called picosecond laser whose Laser optics with reference to the machining sliding or guiding surface of the Workpiece is aligned. The processing device also has a facility for workpiece and laser optics to move relative to each other.

The Laser optics can be performed with a beam deflector (scanner) be so that by controlling this beam deflection of the on the Laser optics on the workpiece directed laser during the relative movement between workpiece and laser optics in a predetermined relative position can be maintained. So is For example, it is possible with a rotating workpiece the laser beam by suitable control of the beam deflecting device leading, d. H. faster than the workpiece rotation, lagging, d. H. slower than the workpiece rotation, or stopped with respect to a surface segment become. For example, in the latter alternative to drill a hole with several pulse trains. For indoor or Outer cylinder surfaces is to be noted that the Surface segment within which the laser beam is held is curved, so that the laser spot during the relative movement in the surface segment to be refocused got to.

A Such control unit for a beam deflecting device This is the case, for example, with today's marking lasers known with autofocusing. It can be done by scripting a possible oblique coupling of the laser beam equalizes become.

The Laser optics is preferably designed so that the focusing point is adjustable to easily adapt to different Workpiece geometries or the above-described focusing during the relative movement of the laser beam in the surface segment allow the workpiece.

at In one variant, the relative movement takes place in that the laser optics about an axis of rotation with respect to the sliding or guide surface is movable. In such a solution with rotating Laser optics is a refocusing of the laser beam during processing of internal cylinder surfaces not required, as long as the Laser optics is arranged coaxially to the inner cylinder surface.

at an alternative solution, the workpiece is relative guided to stationary laser optics movable. In the Machining of cylindrical surfaces can be at this solution the axial feed by adjusting the workpiece or the laser optics take place. If provided with a beam deflector is the axial feed - as stated above - preferably over the beam deflector, which then again refocusing is required.

at Inner cylinder surfaces, it is preferred if the workpiece rotatably mounted about the cylinder axis and in the direction of the axis of rotation is designed to be adjustable, so that the micro-pockets on one spiral track lie.

preferred Embodiments of the invention are described below explained in more detail with reference to schematic drawings. Show it:

1 a schematic representation of a connecting rod according to the invention;

2 a settlement of a peripheral surface of a small connecting rod eye of the connecting rod 1 ;

3 a single view of a micro-pocket;

4 the depth extension of the micro pocket according to 3 ;

5 a processing unit for processing a connecting rod according to 1 and 2 ;

6 a schematic representation of a processing unit according to 3 with two parallel processing stations

7 a schematic representation of a unit 5 in a side view and

8th an alternative variant of a processing unit with rotatable laser optics.

The invention is explained below with reference to the machining of a connecting rod of an internal combustion engine - as described above, the invention is not limited to the use of connecting rods, but generally applicable to all tribologically stressed surfaces. The construction of such connecting rod 1 is known, so that only the components required for understanding the invention are described here. The connecting rod shown has a large connecting rod eye 2 , a small connecting rod eye 4 as well as a connecting rod 6 holding the two connecting rod eyes 2 . 4 connects with each other.

The big connecting rod eye 2 is separated by fracture separation and is screwed 4-fold in the illustrated embodiment, the screws in the illustration according to 1 are not visible. The small connecting rod eye 4 serves to accommodate a piston pin. According to the invention are in an approximately cylindrical peripheral surface 8th the small connecting eye 4 a variety of micro pockets 10 executed. 2 shows a greatly simplified handling of this peripheral surface 8th the small connecting eye 4 with the micro pockets 10 in the illustrated embodiment, an approximately circular cross-section (view 2 ) exhibit. 3 shows such a micro-pocket 10 on an enlarged scale. It can be seen that the peripheral surface of the micro-pocket 10 not strictly geometrically circular, but is designed due to the formation by means of laser pulse trains and energy setting with certain irregularities, with a slightly elliptical shape is permissible. The mean diameter D of the micro-pocket 10 is about 50 to 100 microns in the illustrated embodiment.

4 shows the geometry of the micro pocket 10 in a section perpendicular to the plane in the 2 and 3 , Accordingly, the micro-pocket extends 10 approximately conical in the interior of Pleuelaugenwandung inside, the depth T of the micro-pocket in the illustrated embodiment is between 2 to 12 microns. According to the invention, the depth T and the diameter D of the micro-pocket 10 depending on the positioning in the peripheral surface 8th vary. So it is conceivable, for example, seen in the axial direction outside and inside areas (top and bottom in 2 ) of the peripheral wall 8th with flatter micro pockets 10 (even less than 3 microns) run while the micro-pockets 10 deeper in the middle area, as in Be rich from 2 to 12 microns are formed.

The in the 2 and 3 illustrated comparatively regular circular cross-sectional area of the micro-pockets 10 can be relatively simple in principle, if a pinolenartige laser optics is used, as in the aforementioned prior art according to the DE 10 2004 041 847 A1 is used. However, such a laser optics with a beam deflection device and pinolenartiger design is comparatively expensive and therefore expensive, so that - as will be explained in more detail below - to reduce the device complexity, an oblique coupling of the laser beam is provided. In such a variant, the laser optics can be made comparatively simple, since it is arranged outside the connecting rod eye. Due to the oblique coupling of the per se circular laser spot forms no circular micro pocket but an in

3 dashed lines indicated elliptical pocket 12 whose width b corresponds approximately to the diameter of the laser spot (for example 30 μm) and whose longer axis c depends on the coupling-in angle. An approximately circular micro-pocket 10 You get that if several of the bags 12 overlapping side by side to be roughly the microstructure 10 according to 3 train. These five, overlapping sections of pockets 12 are in 3 indicated. In the same way it is then possible to move in the circumferential direction (horizontally in 2 ) extending elongated holes or elliptical pockets, if necessary to adapt the lubricating film. In this case, then more would be the bags 12 be placed side by side.

In the illustrated embodiment, each bag 12 formed by a pulse train, wherein the pulse duration is less than 10 ps and the pulse frequency in about 400 kHz. Ie. the five, then a micro-pocket 10 training bags 12 are formed by a plurality of pulse trains which are offset relative to each other in the circumferential direction. The frequency of these pulse trains (burst frequency) is approximately in the range of 8 to 12 kHz, for example about 11 kHz. The burst frequency and the pulse frequency of the picosecond laser determines the process speed, while the depth T of the micro pocket 10 is essentially determined by the pulse energy which, as mentioned above, is less than 250 μJ in order to avoid the occurrence of revaluations.

As in particular from 4 As can be seen, the other roughness depth R of the circumferential surface after pre-machining (honing, smoothing or fine boring, etc.) is substantially less than the depth T of the micro-pocket 10 ,

In the illustrated embodiment, the total area of the micro-pockets is 10 about 15% of the area of the peripheral surface 8th , so that the Hertzian pressure due to the comparatively high, not with micro pockets 10 provided area remains low.

At the in 2 illustrated embodiment are the micro-pockets 10 arranged in a pattern in which they are arranged one behind the other in the circumferential direction and in the axial direction, so that in the illustration according to FIG 2 a plurality of vertically and horizontally in succession or juxtaposed micro-pockets 10 results, wherein in the horizontal or vertical direction adjacent pockets are each equally spaced. As will be explained in more detail below, the micro-pockets 10 However, also be arranged on a circumferentially extending spiral, wherein the slope of this spiral in about the distance of two horizontal rows according to 2 equivalent.

3 shows the highly schematic basic structure of a processing unit for forming the above-described micro-pocket structure. In the 3 illustrated processing unit 14 shows two ways to hold the connecting rod 1 , In the alternative 1 is the processing unit 14 with a stand 16 executed on the vertical guide 18 vertically adjustable spindle unit 20 is guided. This spindle unit 20 is via a spindle motor 22 and a transmission, such as a belt transmission 24 driven and carries at its free end portion a clamping unit 26 at the connecting rod 1 can be determined. Clamping the connecting rod 1 takes place such that the small connecting rod eye 4 coaxial with the spindle axis 28 is aligned. When controlling the spindle unit 20 thus rotates the connecting rod 1 around the axis of the small connecting rod 4 (indicated by dashed lines in FIG 5 ).

About one in 5 only indicated laser optics 46 becomes a laser beam 82 coupled with a predetermined Einkopplungswinkel α and on the peripheral surface 8th focused. In the illustrated embodiment, the laser unit 30 designed as a picosecond laser and operates at a pulse frequency of 200 to 800 kHz. The focal length is usually in the range between 100 and 200 mm, wherein the focus is chosen so that there is a laser spot with a diameter of about 30 microns. The diameter of the laser spot can be varied by appropriate focusing due to the conical laser beam. In such a coupling and the formation of the micro-pockets 10 by a plurality of pulse sequences, for example, at five Impulsfol gene a micro-pocket with a diameter of about 50 microns can be achieved, in which case the laser is operated at a pulse frequency of 400 kHz, the spindle rotates at a speed of about 750 revolutions per minute and a burst frequency of about 11 kHz is set. The center distance between the first bag 12 and the fifth bag according to 3 is then about 20 microns. Of course, by varying the above parameters, for example, the number of pulse trains, the burst frequency and the speed of the spindle 20 also other Mikrotaschengeometrien be formed. The extension of the micro pocket 10 in the axial direction (vertically in 3 ) depends - as mentioned - essentially from the coupling angle α.

By feeding in the vertical direction (Y in 5 ) along the vertical guide 18 and the rotation of the small connecting rod eye 4 around the spindle axis 28 is correspondingly a helical structure of the micro-pockets 10 formed, wherein the distance between adjacent micro pockets 10 essentially depends on the aforementioned pulse frequency and the spindle speed. In the case where the laser optics 46 . 48 each with a beam deflector (scanner) are provided, the laser beam - in the manner described above - within a predetermined area segment of the small connecting rod 2 being held.

Instead of the above-described hanging arrangement of the connecting rod 1 can this - as in 5 indicated below - be stored upright. In this variant, the spindle unit 20 ' on the bed of the processing unit 14 stored and the connecting rod 1' placed on a corresponding clamping unit. The laser optics 46 is in this case advantageously above the connecting rod 1' arranged so that the laser beam from above into the small connecting rod eye 4 is coupled.

The loading and unloading of the connecting rods 1 via a workpiece changer 32 , for example, via a swivel arm (see the following comments on 6 ) to be processed connecting rod from a feed belt 34 removes and by pivoting the clamping unit 26 feeds or in the reverse manner an already processed connecting rod 1 removes and deposits on a unloading tape. This workpiece changer 32 is also adjustable in the Y-direction, so that the connecting rod of the clamping unit 26 deducted and the next station can be supplied by pivoting and corresponding vertical feed.

6 shows a possible layout of a processing unit 14 with two parallel processing stations 36 . 38 in which the connecting rods 1 hanging or resting can be edited. Each of the processing stations 36 . 38 has a spindle unit 20a . 20b with the associated drive (spindle motor 22 , Transmission 24 ) and the in 6 not shown clamping unit 26 in which the respective connecting rod 1a . 1b is curious. As explained above, this clamping takes place in such a way that the small connecting rod eye 4 coaxial with the spindle axis, so that the connecting rod 1 upon activation of the respective spindle unit, a rotation about the axis of the small connecting rod eye 4 performs. The inflow and outflow of the connecting rods 1a . 1b takes place alternately via an associated workpiece changer 32a . 32b , where the timing is such that in each case a connecting rod on a station 36 is processed while the other station 38 loaded and brought to speed - in this way, the main time of the processing station is not adversely affected. The spindle units 20a . 20b are along the vertical guidance 18a . 18b in the Y direction (perpendicular to the plane in 6 ) adjustable to the micro pockets 10 in the axial direction of the small connecting rod eyes 4 to be able to position. Even with these solutions, the optics 46 . 48 be provided with beam deflection of the type described above, the laser beam in a predetermined area segment of the small connecting rod 4 to keep. In the case where the laser is carried out without beam deflection means, the focusing optics can 48 . 48 also be designed with a displaceable lens for focusing the laser spot with respect to the workpiece surface (surface segment).

Both processing stations 36 . 38 is a common laser unit 30 assigned to the laser beam 40 via a beam switch 42 , a deflecting mirror 44 and an optic 46 . 48 on one of the processing stations 36 . 38 cocked connecting rods 1a . 1b can be focused. The beam switch 42 is adjustable so that it's the laser beam 40 either to the laser optics 46 deflected or to the deflection mirror 44 pass through. In the latter case, then the laser beam on the deflection mirror 44 towards the second laser optics 48 diverted. In this variant, the entire laser unit 30 with the beam switch 42 , the deflection mirror 44 and the laser optics 46 . 48 fixedly arranged while the respective connecting rod 1 for forming the spiral structure via the spindle unit 20 and the vertical guide 18 is moved according to the trainee structure. It is understood - as stated above - the pulse rate, the burst frequency and the pulse width and the maximum pulse energy adapted to each task in order to form the desired geometry of the micro-pocket can. About the optics 46 and the corresponding associated beam switch 42 . 44 becomes the laser beam 40 then into the small connecting rod eye 4 coupled.

In the illustrated embodiment, the Einkoppelwinkel of the laser beam is in the small connecting rod 4a . 4b chosen at about 45 °.

6 schematically shows a way, the connecting rod 1 to rest on a lying or hanging position. In this variant, the spindle unit 20 with a hollow shaft 50 running, via a rolling bearing assembly 52 is stored. The hollow shaft 50 carries the clamping unit 26 in the illustrated embodiment, the large connecting rod 2 (not visible) or on the connecting rod 6 attacks. The hollow shaft 50 is from a suction tube 54 permeated, which is connected to a suction, so that in the laser processing resulting melt or other processing residues can be sucked. In the embodiment according to 6 is the spindle unit 20 standing taken up, of course, a corresponding construction can be installed hanging.

In the embodiments described above, the workpiece, ie in the present case, the connecting rod 1 Relative to the fixed laser optics 46 emotional. 8th shows the basic principle of a variant in which the connecting rod is tensioned hanging or resting and does not change its position during processing. The relative movement is effected by the laser optics 46 , in turn, via a bearing assembly 56 to an optical spindle head 58 is stored. This has a housing in the illustrated embodiment 60 , about that, for example by means of the beam switches 42 or the deflection mirror 44 the laser beam 40 coaxial with the axis of rotation 62 is coupled through a central beam guide. This in the vertical direction into the housing 60 entering laser beam 40 then hits one in the axis of rotation 62 lying deflection mirror 65 and is deflected by the latter by 90 ° in the horizontal direction and then encounters a focusing and reflective off-axis mirror 66 from which he points to another deflecting mirror 68 is reflected and over the outlet opening 70 focused exit. The outlet opening 70 , the further deflecting mirror 68 and the off-axis mirror 66 are in a beam guiding component 72 recorded, whose geometry is designed according to the beam path and the via a guide 74 on the housing 60 transverse to the axis of rotation 62 is adjustable. The nominal position of this precision-guided beam-guiding component 72 can be finely adjusted and fixed via a set screw so that the beam guiding component 72 adjustable with high accuracy to the workpiece diameter to be machined. In principle, the off-axis mirror 66 be replaced by a deflecting mirror and a subsequent lens. The optical spindle head 58 is so led that in addition to the rotation of the optics 46 also allows their vertical movement in the Y direction. To avoid imbalances is in the case 60 a balance weight 80 provided that the weight of the beam-guiding component 72 balances.

Instead of using 8th described rotation optics - as stated at the beginning - a pilonenartig in the small connecting rod eye 4 dipping optics are used, as for example in the EP 1 464 436 is described. When using such an optic may in certain circumstances on the in 3 indicated multiple pulse sequence are omitted, since due to the coupling at an angle α of 90 ° substantially circular micro-pockets can be generated. With a pinolenartigen laser optics according to the cited document DE 10 2004 041 847 Even more complex geometries can be produced with comparatively little effort. In this case, the relative movement of the laser beam 40 within the aforementioned area segment by the rotation of the quill-like laser optics and the movement of the laser beam 40 be controlled by the beam deflector (scanner). An essential feature of the procedure according to the invention is that comparatively small, burr-free micro-pockets are formed, with picosecond lasers being used, as marketed, for example, by the company Trumpf with the product name TruMikro 5000.

Disclosed is a workpiece with a sliding or guiding surface, which improve lubrication with a variety of micro-pockets is executed. These micro-pockets are made by means of a processing unit formed in which a picosecond laser with low energy input is used. The geometry of the micro-pockets can be increased by several Pulse trains are changed, these pulse trains staggered with respect to the workpiece to be machined.

1

pleuel

2

great connecting rod

4

small connecting rod

6

connecting rod

8th

peripheral surface

10

micro pocket

12

bag

14

processing unit

16

machine stand

18

vertical guide

20

Spindles

22

spindle motor

24

transmission

26

clamping unit

28

spindle axis

30

laser unit

32

Workpiece changer

34

To-, Discharge Conveyor

36

processing station

38

processing station

40

laser beam

42

beam switch

44

deflecting

46

laser optics

48

laser optics

50

hollow shaft

52

roller bearing assembly

54

suction tube

56

bearing arrangement

58

Optics spindle head

60

casing

62

axis of rotation

64

beamline

65

deflecting

66

Off-axis mirror

68

Another deflecting

70

outlet opening

72

Beam guidance component

74

guide

76

screw

80

counterweight

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 1275864 B1 [0003, 0005]
• DE 102004041847 A1 [0005, 0022, 0044]
• - EP 1464436 [0060]
• - DE 102004041847 [0060]

Claims (20)

Workpiece with a sliding or guide surface ( 8th ) along which a plurality of lubricating pockets are formed for improving the lubrication by energy radiation, characterized in that the lubricating pockets are designed as micro-pockets ( 10 ) are executed, seen in the direction of a surface normal cross section has a maximum extent of less than 0.5 mm, preferably less than 0.1 mm. Workpiece according to claim 1, wherein the micro-pockets ( 10 ) have an approximately elliptical, elongated or circular cross-section. Workpiece according to claim 1 or 2, wherein the micro-pockets ( 10 ) to the inside, in the workpiece in about conical, with a depth (T) of less than 20 microns, preferably less than 10 microns, executed, but which is a multiple of the roughness (R) of the adjacent surface areas. Workpiece according to one of the preceding claims, wherein the micro-pockets ( 10 ) are arranged in a row next to and above one another or lie on a spiral. Workpiece according to one of the preceding claims, wherein less than 20%, preferably about 12% of the total guide surface ( 8th ) through the micro-pockets ( 10 ) is trained. Workpiece according to one of the preceding claims, wherein the guide surface is an inner cylinder surface, an outer cylinder surface or an annular surface is. Workpiece according to one of the preceding claims, this being a connecting rod ( 1 ) or a crankshaft. Workpiece according to one of the preceding claims, wherein the peripheral surface ( 8th ) is an inner cylinder or annular surface and the micro-pockets ( 10 ) in the circumferential direction of the peripheral surface ( 8th ) are elongated. Workpiece according to claim 8, wherein the micro-pockets ( 10 ) by overlapping smaller pockets ( 12 ) are formed. Process for the production of micro-pockets ( 10 ) of a workpiece with the steps: setting a relative movement between the workpiece ( 1 ) and a laser optics ( 46 ) and driving the laser with a pulse width in the picosecond range and an energy of less than 300 μJ. The method of claim 10, wherein the pulse frequency of the laser greater than 100 kHz, preferably 400 kHz is. Method according to claim 10 or 11, wherein the laser beam ( 40 ) is coupled at an angle and the micro-pocket ( 10 ) is formed by a plurality of pulse sequences, during which the relative movement between the workpiece ( 1 ) and laser optics ( 46 ) is maintained. Method according to claim 12, wherein for the formation of the micro-pocket ( 10 ) more than 3 and less than 10, preferably 5 pulse sequences are used. Method according to claim 13, wherein the pulse repetition frequency less than 20 kHz. Processing unit for carrying out the method according to one of the claims 10 to 14, having a picosecond laser ( 30 ), whose laser optics ( 46 ) with respect to the sliding or guiding surface ( 8th ) of a workpiece ( 1 ) and with a device via which the laser optics ( 46 ) and the workpiece ( 1 ) are movable relative to each other. Machining unit according to claim 15, wherein the laser optics ( 46 ) about a rotation axis ( 62 ) is rotatably mounted. Machining unit according to claim 15 or 16, wherein the laser optics ( 46 ) is performed with a beam deflection unit (scanner). Processing unit according to one of the claims 15 to 17, wherein the workpiece ( 1 ) is movable relative to the optics. Machining unit according to claim 18, wherein the workpiece ( 1 ) about a spindle axis ( 28 ) is rotatably guided and adjustable in the direction of the axis of rotation (Y). Processing unit according to one of the claims 15 to 19, wherein the laser beam through the scanner with respect to the rotating workpiece ( 1 ) leading, lagging or resting positionable.