WO2017149037A1

WO2017149037A1 - Method and device for the rolling of bushings

Info

Publication number: WO2017149037A1
Application number: PCT/EP2017/054821
Authority: WO
Inventors: Wolfgang RÖMPP; Siegfried Gruhler; Joachim Klein; Andreas Josef FRIES
Original assignee: Mauser-Werke Oberndorf Maschinenbau Gmbh
Priority date: 2016-03-02
Filing date: 2017-03-01
Publication date: 2017-09-08

Abstract

Disclosed are a device and a method for the rolling of bushings (28) using a rolling tool (24), wherein said rolling tool has an adjustable rolling circle diameter and can be introduced linearly into the bushing (28) along a NC axis. The rolling is carried out in a position- and/or torque- and/or force- and/or time-controlled manner. An angle-dependent control is also possible.

Description

Method and device for rolling bushes

description

The invention relates to a method and a device for rolling in

Jacks.

From WO 2013/064655 A1, the rolling of bushes in a bearing eye, for example, in a small connecting rod eye is known. In this case, the bearing bush is inserted via a press-fit into the bearing eye, this insertion can be done with clearance or with a small interference fit. This surface compression is significantly lower than with a press fit, which is necessary to secure the bearing bush against rotation in the bearing eye during operation. In a next process step, the bearing bush is widened by plastic deformation in the radial direction and rolled onto the inner periphery of the bearing eye via a rolling tool with cylindrical, circumferentially distributed rolling elements - in contrast to the conventional method, the interference fit is thus produced by a forming step the advantage that the bearing bush can be prefabricated with much lower dimensional accuracy than in conventional methods, with lower requirements than in the prior art also with regard to the surface finish and surface coating and on the bearing bush material.

As described in the Applicant's WO 2014/195500 A2, the receptacle, for example the small connecting rod eye, can be designed as a shaped bore in order to improve the contact pattern for the bearing bush and to ensure optimum prestressing.

The security against rotation can be increased if a structuring is formed on the inner circumference of the bearing eye, as described, for example, in DE 103 25 910 B4 of the Applicant.

Furthermore, it is advantageous to form structures for improving the oil-holding capacity in the bearing surface of a bearing (WO 2015/185451 A1).

Page 1/27 A problem with conventional methods is that the bushings used in the above-described Einwalzprozessen vary in wall thickness. The wall thickness differences can be up to 4/10 mm, so that the inner diameter of the bushing can have differences in diameter of 8/10 mm. As a result, a socket with a large wall thickness has a comparatively small inside diameter and a socket with a small wall thickness has a comparatively large inside diameter. With the conventional methods, the rolling-in process can be designed only with regard to a middle sleeve wall thickness or a middle inner diameter, so that the retaining force with which the sleeve is secured against rotation in the bearing seat varies.

Accordingly, there is a certain need for optimization with regard to improving the bushing adhesion and the associated security against rotation.

Accordingly, the invention has for its object to provide a method and a device for rolling of sockets, through which the twisting security of the socket is improved with little effort.

This object is achieved by a method for rolling bushes according to

A device for rolling in bushes according to claim 9 or solved.

Advantageous developments of the invention are the subject of the dependent claims.

According to the rolling of the bushes takes place in a receptacle, for example a bearing bush in a small connecting rod eye of a connecting rod, by means of a rolling spindle driven by a rolling tool, which has one or more radially adjustable rolling elements, which bear against an inner peripheral surface of the socket inserted into the receptacle can be brought. The rolling tool is first retracted with a rapid feed in the direction of a feed axis in the socket. The rolling circle diameter of the rolling tool is set so that it is slightly smaller or at most equal to the inner diameter of the bushing used.

Page 2/27 After retraction of the rolling tool, the feed is reduced to a rolling feed or the rolling tool is switched to a rolling mode, thereby increasing the rolling circle diameter of the rolling tool to widen the sleeve in the radial direction. The widening is in the tenth of a millimeter range, for example in the range of less than 0.5 mm, preferably in the range of 0.3 mm. In conventional connecting rods, this expansion can be, for example, 0.1 mm. This rolling is carried out according to the invention position-controlled and / or force-controlled and / or torque-controlled and / or time-controlled until the final rolling diameter is reached. The aforementioned control processes can also be combined, so that, for example, first a position control, then a time control and then a torque control takes place.

Under a rolling mode while the control of the rolling tool is understood so that increases the size of the active rolling circle diameter for forming the sleeve. This can be done by retracting an axially adjustable tool part (for example, a cone) or by radial adjustment by means of radial actuators.

The advantage of a torque control is that the torque acting on the rolling tool is relatively easy to detect, so that the torque range is fully utilized and thus the resolution, d. h., The machining precision is optimized.

It was found that this procedure and appropriate choice of process parameters, the resistance to rotation of bushings used in stock recordings over conventional solutions can be significantly improved.

Accordingly, the device according to the invention for rolling in bushings has a rolling tool driven by a roller spindle drive, which has at least one roller body that can be adjusted in the radial direction, which can be brought into contact with the inner peripheral surface of the bushing inserted into the receptacle. The device has a control unit with corresponding drive units which are designed in such a way that the rotating rolling tool can be moved into the socket inserted into the receptacle with rapid feed in the direction of a feed axis. In this case, the rolling circle diameter of the rolling tool is set so that it is less or at most equal to the inner diameter of the bushing used. The control unit is further designed so that

Page 3/27 the feed after retracting to a roll feed is reduced and the rolling circle diameter of the rolling die is increased to radially widen (roll in) the sleeve.

The control takes place in such a way that the widening of the bearing bush is in the range of a few tenths of a millimeter. Thus, the expansion may be in the range of less than 0.5 mm, preferably less than 0.3 mm. For automobile connecting rods, a widening in the range of 0.1 mm is sufficient.

Depending on the geometry of the pairing (bushing / receiving), the rolling is carried out position-controlled and / or torque-controlled (roller spindle drive) and / or force-controlled (feed) and / or time-controlled. D. h, the control unit and the drive units of the device are designed so that the rolling process is selectively controllable according to the above specifications.

In a particularly preferred embodiment, it is provided that the rapid feed is switched over to the roll feed, when the rolling tool runs up onto a workpiece-side drive-on bushing with a rolling tool-side stop body (docking).

The rolling process may be terminated upon reaching a predetermined force or torque setpoint or an averaged force or torque setpoint.

According to a variant of the invention, a proper rolling operation can be concluded when a threshold value and a final value of torque and / or force lie within a path / position window of the rolling tool.

Alternatively, a proper rolling operation can be concluded if, during a torque monitoring, the rolling tool remains at a predetermined position for a predetermined dwell time.

The process monitoring can, for example, by random sampling of the press-in position of the sleeve before and after rolling to assess an axial Ver

Page 4/27 displacement of bush material or by continuous control of an axial projection of the bushing by means of a sensor or the like, or else by detecting the parallelism of the rolling. This measurement can be done, for example, as a post-process measurement at an external measuring station or - preferably - in the process, wherein the rolling station is designed with a corresponding sensor that detects the diameter of the bushing during the rolling process and accordingly a response to the Machine control generated.

In principle, monitoring of the tool with regard to wear of the rolling elements is also possible - such monitoring is preferably carried out as a post-process measurement.

In one embodiment of the invention, the receptacle has a chamfer at least in the pressing-in direction of the bushing, the bushing overlapping or projecting over the chamfer in the axial direction. The rolling process is preferably controlled so that

Bushing material is displaced during rolling in the chamfer, so that the socket is positively secured in the radial direction.

This projection can also arise at least partially by elongation of the bush during rolling.

The inventive method requires that the device according to the invention with suitable pickups, devices for detecting the position of the torque, the forces occurring during rolling, etc. is executed.

Furthermore, according to an embodiment of the invention, a sensor for detecting an axial projection of the socket can be provided.

As described above, the bush can be a bearing bush for a cylindrical connecting rod eye of a connecting rod or for a connecting rod with a trapezoidal or handle-shaped connecting rod eye.

Page 5/27 The rolling bodies are cylindrical or can also be designed as shaped bodies adapted to the shape of the receptacle or the bushing.

As stated, the device may additionally be designed with a station for forming oil retention and oil transfer micro-spaces.

Preferred embodiments of the invention are explained in more detail below with reference to schematic drawings. Show it:

Figure 1 is a three-dimensional view of the basic structure of a rotary transfer machine, which is designed with a station according to the invention for pressing and rolling of bearing bushes in a small connecting rod eye of a connecting rod;

Figure 2 is a detail view of a device for pressing / joining and rolling of bushings of the station shown in Figure 1;

Figure 3 is a partial view of the device according to Figure 2;

Figure 4 is a sectional view of the device or station according to Figures 2 and 3;

FIG. 5 shows individual views of a rolling tool of the station according to FIGS. 2, 3 and 4;

FIG. 6a shows a three-dimensional sectional illustration of the device according to FIG. 4 with the tool according to FIG. 5;

FIG. 6b shows a detailed representation of the arrangement according to FIG. 6a;

FIG. 7a shows the joining and rolling station according to FIG. 1 with a feed device for bearing bushes;

Figure 7b is a schematic diagram to illustrate the orientation of the bushings in the supply and

Figure 8 path, force and torque curves during the rolling process.

FIG. 1 shows the basic structure of a rotary indexing machine 1 designed as a cracking and assembly machine. This has a rotatable ring table 2, are stretched on the connecting rod 22, the large connecting rod eye fracture on the cracking machine and in the small connecting rod a bushing is pressed. In the illustration according to FIG. 1, only the station is shown in which the insertion / joining and rolling in of the bearing

Page 6/27 socket - in the following socket 28 called iin the small connecting rod eye takes place. This station is referred to below as the joining and rolling station 4. The stations for feeding / discharging the connecting rods, for introducing fracture separation notches by means of laser radiation, for fracture separation by means of a Crackdorns, for screwing the fracture-separated bearing cap with the rod side of the connecting rod, etc. are not shown in Figure 1. For each of these stations, a tensioning device or cassette 20 for a connecting rod 22 is provided on the ring table 2.

The basic structure of such cracking and assembly machines 1 is described, for example, in DE 101 35 233 B4, so that reference can be made to this document with regard to further details.

The joining / rolling station 4 has a device 6 for joining / rolling the bushing 28 into the small connecting-rod eye. This device 6 is attached to a carriage 8 which is movable along a Z-axis 10 on a stand 12. This in turn is on a frame 14 along a Y-axis 16 in the radial direction and an X-axis 18 in the tangential direction with respect to the ring table 2 adjustable. For example, the X, Y and Z axes are each designed as linear axes, so that the device 6 can be aligned with the connecting rod 22 with reference to the workpiece to be machined in each case.

FIG. 2 shows an individual view of the joining / rolling station 4. It has a housing 23 which is fixed on the above-mentioned carriage 8 and on which a rolling tool 24 and a joining tool 26 are arranged. The term "joining tool" has been chosen deliberately, since the bushings 28 to be processed according to the invention are used only with comparatively little force and no press-fitting takes place, as is the case in conventional solutions Station, in which, for example, a screwing of the bearing cap with the connecting rod, aligned with respect to the joining / rolling station 4. Initially, the joining tool 26 is aligned with respect to the small connecting rod eye via the X, Y guide 16, 18 Socket 28 was transferred to the joining tool 26 via a feed device explained in more detail below. This joining tool 26 is in a manner known per se

Page 7/27 not carried out with a conventional clamping device for the sleeve 28 - this is held only by an internal form of spring, the holding force is sufficient to hold the sleeve 28 when joining in the predetermined position on the joining tool 26. The bushing 28 (also called mold bushing) is then inserted (joined) by moving the joining tool 26 in the Z direction into the small connecting rod eye so that it is received in the connecting rod eye with a small holding force. However, this holding force is sufficient to hold the sleeve 28 in the connecting rod, while the joining tool 26 is pulled out with the form spring. The use of such a shaped spring has the advantage that in case of damage during the assembly, a replacement of the form spring is very easily possible. When using a complex clamping device, this exchange, which is usually associated with a prolonged machine downtime, much more complex.

The drive provided with the reference numeral 30 in Figure 2 is used for the rotary drive of the joining tool 26: This drive 30 acts via a toothed belt drive 31 which is encapsulated in the representation of Figure 3, the joining tool 26, so that this for aligning the sleeve 28 with Can be rotated relative to the connecting rod eye. This alignment is required, for example, in a Henkelkorbpleuel or a slotted socket 28 to bring the contour or the slot in the desired position in the connecting rod.

According to the invention it is preferred if slotted bushes 28 are used.

Figure 2 shows a detail of the unit with the rolling tool 24 and a part of the Buchseneinpress- / joining device. This unit is guided on the NC vertical axis (Z axis), so that the unit can be moved in the vertical direction.

In FIG. 2, next to an NC straightening drive 32 of the rolling tool 24, a rotary leadthrough 34 for minimum quantity lubrication (MQL) of the rolling tool 24 is provided, so that this is lubricated on the one hand and cooled on the other hand.

As will be explained in more detail below, the NC straightening drive 32 is connected via a toothed belt drive to a rolling spindle 62 in order to drive it.

Page 8/27 FIG. 3 shows the device 6 according to FIG. 2 in the mounting position on the carriage 8, which can be moved along the Z-axis 10, which is designed as an NC vertical axis, on the stand 12. The device 6 is associated with a hold-down device 36, via which the connecting rod to be machined is held down during the joining and the rolling.

The hold-down device 36 has a hold-down slide 38, which in turn is adjustably guided along a vertical guide 40 on the stand 12 in the vertical direction. The method of the hold-down carriage 38 along the vertical guide 40 is preferably carried out by means of a hydraulic cylinder 71 (see Figure 4). Of course, a linear drive or a pneumatic cylinder can be used. This hold-down carriage 38 has a base 42 on which a Auffahrbuchse 44 and a guide bush 46 for the rolling tool 24 and the joining tool 26 are held so that they precisely during the respective step with respect to the in the clamping device 20 (also called cassette) held connecting rod 22 are aligned. An additional centering of the bushing 28 inserted by means of the joining tool 26 also takes place when the rolling tool 24 is dipped into the connecting rod eye.

FIG. 4 shows a section in the radial direction with respect to the ring table 2, wherein the sectional plane takes place through the axis of the rolling tool 24. D. h., The view of Figure 4 shows a part of the arrangement of Figure 3 seen from the left. The sectional view is greatly simplified, so as not to overload the figure with unnecessary details.

As stated, the connecting rod 22 is held in a cassette / clamping device 20 of the ring table 2 of the rotary transfer machine, wherein in the small connecting rod 48 of the connecting rod 22, the sleeve 28 is inserted. This small connecting rod 48 is formed handle basket-shaped in the illustrated embodiment.

The large connecting rod 50 is acted upon by a pneumatic clamping cylinder 52 which on the one hand biases the connecting rod 22 in the direction of a support and on the other hand prevents rotation of the connecting rod 22 during rolling. This clamping cylinder 52 is in the along the vertical guide 40 movable hold down

Page 9/27 pour 38 added. At this further the Auffahrbuchse 44 is held, which also forms a stop for the rolling tool 24, which passes through a through hole 54 of the Auffahrbuchse 44. This passage opening 54 is arranged coaxially with the small bearing eye 48. The illustrated rolling tool 24 has, as explained below, for example, three rolling elements 72, which are uniformly distributed on the circumference and whose axial length is at least as large as the axial length of the bush 28.

The rolling tool 24 is provided with a HSK chuck 58 which is inserted into a corresponding HSK receptacle 60 of the rolling spindle 62. In the illustrated embodiment, a roller spindle drive, as explained, executed with the NC straightening drive 32 and the toothed belt drive 64. The entire unit with the NC straightening drive 32 and the rolling tool 24 can be moved with the carriage 8 guided along the aforementioned Z axis. Accordingly, the rotary drive of the roller spindle 62 via the NC straightening drive 32. The feed (rapid feed, roller feed) in the Z direction of the rolling tool 24 is effected by moving the carriage 8 by means of the NC linear drive (Z-axis 10).

The entire unit 6 with the rolling tool 24 and the joining device 26 is furthermore, as explained, adjustable along a horizontal axis in order to align the rolling tool 24 or the joining tool 26 with respect to the small connecting-rod eye 48.

In the illustrated embodiment, an optical sensor 66 is further provided, which detects the bushing elongation and / or the book diameter during the Einwalzprozesses.

The clamping cylinder 52 has a clamping plate 66 which is actuated by a differential piston 68 which is guided in a cylinder 69, the annular space or in the Absenkrichtung acting pressure chamber with a pneumatic pressure accumulator are connected to lower the clamping plate 66 in the clamping direction or to raise in the release direction , The pneumatic connections are indicated by the reference numeral 70. Of course, a hydraulic actuation can be provided.

Page 10/27 When fitting clamping plate 66 (presser), the connecting rod 22, more precisely, the large connecting rod 50 is secured against rotation. A centering of the large connecting rod 50 by means of a centering mandrel is preferably not carried out to ensure an exact coaxial alignment of the sleeve 28 with respect to the small connecting rod 48.

In the illustration according to FIG. 4, the hydraulic cylinder 71 is also visible, via which the hold-down carriage 38 can be adjusted along the vertical guide 40.

Figure 5 shows detailed views of the rolling tool 24. Accordingly, the rolling tool 24 - as already explained - three circumferentially distributed cylindrical roller body 72, the head radially adjustable on a tool 74 (sleeve) are mounted. The rolling elements 72 project radially outwards and can be brought into contact with the inner circumference of the bushing 28. Within the tool head 74, the rolling elements 72 abut against a cone 76, which is adjustable relative to the rolling elements 72 by means of the NC vertical axis (Z-axis 10), so that with a corresponding adjustment of the cone 76, the rolling elements 72 are adjustable in the radial direction to to set the rolling circle diameter.

On the outer circumference of the tool head 74, a stop body 78 is formed, which is guided on the outer circumference of the sleeve of the tool head 74, wherein the sleeve of the tool head 74 is rotatable relative to the stop body 78. The cone 76 is held on an axially adjustable middle part 80, which is supported via a biasing spring 82 on an extended part of the sleeve. The back of the aforementioned HSK chuck 58 is arranged.

When retracting the rolling tool 24 in rapid traverse the flange-extended end face of the stopper body 78 comes into abutment against the Auffahrbuchse 44 of the hold-down carriage 38. When further feed along the NC vertical axis (Z-axis 10) remains the stop body 78 due to friction - the middle part 80 with the cone 76 is further adjusted in the vertical direction against the force of the biasing spring 82, so that the rolling bodies 72 extend correspondingly in the radial direction and the rolling circle diameter is increased. The stopper body 78 does not rotate with the tool head (rolling element) 74 in the docking position. In this case, the feed and, for example, the torque applied via the roller spindle drive are controlled via the control explained in the introduction

Page 11/27 adjusted so that sets a predetermined torque, force curve within a predetermined time window. Depending on this process, the quality of the rolling process can then be influenced and assessed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGS. 6a and 6b, detailed views of the section according to FIG. 4 are shown, which, however, are considerably simplified in comparison with the illustration according to FIG. It can be seen in this three-dimensional sectional view extending in the radial direction, in the sleeve (tool head 74) mounted rolling elements 72. The cone 76 with the central part 80 is not shown explicitly.

In the retracted position of the rolling tool 24 is also also only hinted and slightly different than constructed in Figure 5 stop body 78 of the rolling tool 24 on a corresponding bottom end face 84 of the cup-shaped Auffahrbuchse 44, so that the retraction position of the rolling tool 24 or more precisely, the rolling body 72 in the small connecting rod 48 is predetermined - a deeper retraction of the stop body 78 is not possible. The rolling position is correspondingly reached only when the stopper body 78 abuts the Auffahrbuchse 44.

Visible in the sectional view according to FIG. 6a is also a part of a central lubricant channel 86, through which the coolant / lubricant (MMS) supplied via the rotary feedthrough 34 is guided towards the rolling bodies 72 in order to cool the forming area and to feed the rolling bodies 72 lubricate.

Visible in Figure 6a is also a sensor 86, via which the elongation of the bushing 28 or the inner diameter of the bushing can be detected. The signals detected by the sensor 86 are then guided to the machine control, so that according to the rolling process by changing the feed, the torque, the position, etc., during the machining process is adjustable to achieve an optimum rolling result. In this way, even comparatively large manufacturing tolerances in the manufacture of the sockets 28 can be compensated. Accordingly, it is possible to process sockets 28 with very thin wall thicknesses while ensuring the best possible quality of the storage area.

Page 12/27 FIG. 6b shows a detailed representation of the arrangement according to FIG. 6a. Well visible in this partial view of the retracted into the small connecting rod 48 tool head 74, in which the rolling elements 72 (only one visible) are received adjustably in the radial direction. The Z-direction adjustable cone is not shown. In the immersion position of the stop body 78 of the rolling tool 24 runs on the bottom-side end face 84 of the cup-shaped Auffahrbuchse 44. As indicated by dashed lines in Figure 6b, the stopper body 78 is not rotatably connected to the tool head 74, so that - as already stated - the stop body 78 stops. The tool head 74 with the rolling elements 72 remains in the Z-position (feed direction in the Z direction) that is predetermined on the end face 84 when the stop body 78 comes to rest (but continues to rotate). However, the cone 76, not shown, is moved further on the NC feed in the Z direction, so that the rolling elements 72 extend in the radial direction corresponding to the Z feed. This rolling feed, during which the rolling bodies 72 are adjusted in the radial direction, can be regulated as a function of the sensor signal. Accordingly, it is possible to retract the rolling tool 24 with a comparatively fast rapid feed and radially retracted roller body 72 in the small connecting rod 48 and then switch after emergence of the stopper body 78 on the Auffahrbuchse 44 to a much slower roller feed, which then regulated according to the above-mentioned specifications becomes. The above-described sensor 86 can also monitor the parallelism of the rolling process.

Figure 7a shows the basic structure of the socket feed to the joining / rolling station 4. In the illustrated embodiment, the small connecting rod 48 is - as explained - handle basket-shaped. Accordingly, the socket to be used 28 (see Figure 7b) with a short shell portion 88 and a contrast extended shell portion 90 is formed.

Such bushings 28 provided for Henkelkorbpleuel are made of comparatively thin sheet metal material and have a slot 92 which extends in the vertical direction along the shorter central portion 88. When feeding these bushes 28 then care must be taken that they are fed to the predetermined orientation of the joining / rolling station 4. FIG. 7b shows various "malpositions" which may occur in the case of such a supply and which are correspondingly corrected.

Page 13/27 have to be gassed. Shown on the left in FIG. 7b is a misorientation in which a right flank 94 (seen from the slot 92) leads in the feed direction. In the middle of Figure 7b, a position is shown, in which the left flank 96 leads in the feed direction (see arrow). On the right in FIG. 7b, the optimum, desired feed position is shown. Positional orientation can be achieved, for example, by rotating the respective bush 28 into the position shown on the right via an alignment element 98 of the bushing feed. In principle, it should also be ensured that the bushes are supplied with the predetermined vertical orientation. For example, it may happen that the peripheral edge 100 located at the bottom in FIG. 7b is fed in an oriented upward direction. In the illustrated socket 28, however, this plays no or only a minor role. However, instead of an alignment element 98 in the feed, the orientation can also be compensated for via the drive 30 of the joining tool 26, since this drive makes it possible to turn the joining tool so that the bearing bush 28 assumes the predetermined position in the small connecting-rod eye 48. This position can also be monitored relatively easily, since it is possible with relatively little effort at the position of the slot 92 or the above flanks 94, 96 oriented. For cylinder liners in which an additional orientation on the contour of the flanks 94, 96 is not possible, it is preferable to orientate oneself at the position of the slot 92.

As explained, FIG. 7 a shows the above-described joining / rolling station 4 in a view approximately from the ring table 2. In this illustration, the overall structure of the arrangement is again clearly visible. One sees the frame 14, on which the stand 12 is adjustably guided over the Y and X-axes 16, 18. D. h., The stand 12 is moved over an X, Y guide and carries according to Figure 7a counter-holders 102, 104, the respective tool and or the connecting rod 22 from below lead / support during the joining process and during the rolling process , On the stand 12, the device 6 described above for joining and rolling of the sockets 28 via the Z-axis 10 is movable. The drive 30 of the joining tool 26 and the NC straightening drive 32 are also visible. The bushes 28 are automatically fed from a bushing store 106, from which the bushes 28 are taken in isolated fashion via a singulation and feed 108 and then oriented in orientation via an orientation station 1 10 Be fed to the conveyor 1 12, of which the position-oriented sockets the Fügewerk-

Page 14/27 26 will be handed over. This orientation station 1 10 may be provided with a control station, are sorted out over the non-compliant sockets 28. As mentioned, can be carried out by appropriate control of the drive 30, a position positioning of the bushing 28 before the actual joining process.

By suitable design of the feed, it is ensured that the bushes are respectively fed in the predetermined relative position of the press-in device (automatic averaging).

The bushings 28 are then - as explained - used by means of a press-in punch of the joining tool 26 in the small connecting rod 48, the insertion can be done with a small press fit or even with play - the actual fixation is done by rolling. In the illustration of Figure 7a is also a

Control unit 1 12 shown, over which the above and described below control processes of the station 4 are controlled.

For clarification, an example of a production sequence is explained by way of example.

In a station, not shown, the small connecting rod 48 is made by means of a Aussteuerwerkzeugs, which is adjustable in the radial direction, for example by means of a membrane head or a Piezoan- drive to measure. In this case, the bore can be designed as a shaped bore. It is essential that a torsionally rigid receiving bore for the sockets 28 is formed with a defined cutting edge.

In a subsequent operation, the bushing 28 is then inserted into the small connecting rod 48 and rolled at the above-described station 6.

In a third operation, the finish is then made with a surface design, are formed in the microspaces for oil maintenance and oil transport. Furthermore, retraction grooves with a secondary cutting edge and subsequent rolling can also be formed.

Page 15/27 A coaxial or eccentric arrangement of the microspaces allows a uniform projectable oil distribution. This design is possible in principle with and without sockets 28.

In one embodiment, the oil grooves (oil transport / oil containment microspaces) are performed eccentrically in a pre-drilling and a subsequent back-boring. The applicant reserves the right to make a separate patent application for this eccentric configuration of the microspaces.

In the illustrated embodiment, the rolling tool 24 has a

Roll diameter range, which allows the rolling tool 24 in the small

Insert connecting rod 48 and then expand in the radial direction. That is, the

Roll diameter range is adapted to the bush diameter. Thus, the rolling diameter range for a connecting rod 22 may be in the range between 18 and 20 mm, while the bushing diameter before rolling is about 19.5 mm - thereby an expansion of the bushing diameter is possible and required.

The small connecting rod 48 can be executed at least in the insertion direction with a Einführfase 1 14 (15 °). This Einführfase 1 14 may be formed on one side and is advantageous for the press-fitting of the bushing 28 into the connecting rod to avoid damage to the connecting rod eye. The projection of the bushing 28 can be adjusted on the one hand by the axial length of the bush 28 before the rolling process. In principle, it is also possible that this supernatant is also caused by elongation in the rolling process or a proportion of the supernatant resulting from this elongation.

This supernatant can be utilized in the rolling process to a volume displacement of the bushing material in the direction of the bevel 1 14. In a cylindrical bushing 28 then results in a positive engagement against axial displacement and also an improvement in Verdrehsteif ig speed due to the increased holding power by the circumferential extension.

In the case of a shaped connecting rod (trapezoid or handle basket), a shape-adapted chamfer 14 also results in volume displacement during the rolling process

Page 16/27 In addition, an improved rotation by the associated with the volume displacement positive locking.

Through the use of rollforming bodies, a strong pressure can be formed in the region of the chamfer 14 in the case of a cylindrical bush 28. In addition, a chamfer 14 can be rolled up with such rollforming bodies.

As explained above, via the vertical NC axis (Z-axis 10), the docking of the stopper body 78 to the drive-up bush 44 and the NC positioning of the roller tool 24 in the bushing diameter are controlled. The modulation of the feed and the rotation of the rolling spindle drive 62 can be position-controlled and / or angle-controlled and / or force-controlled and / or torque-controlled.

In the Crackmaschine after insertion of the sleeve 28, first the rolling tool 24 is retracted by means of the NC-Z-axis 10 in rapid traverse. The rolling circle diameter is set, for example, to a diameter which is smaller than the inner diameter of the bushing 28. During this rapid traverse, the rolling spindle 62 rotates at a speed of, for example, 200 revolutions / minute.

When the stopper body 78 of the rolling tool 24 runs onto the drive-on bushing 44, the rolling circle diameter is then increased until it corresponds to the bushing diameter.

Subsequently, the fast rapid feed is switched over to a slow roller feed, which is, for example, in the tenth of a millimeter range per revolution. By this rolling feed, the axial relative position between the rolling elements 72 and the aforementioned cone 76 is adjusted, so that the rolling bodies 72 extend. It is sufficient in a car connecting rod, for example, that the rolling circle diameter is increased during the rolling feed by about 1/10 mm. This final roll diameter is position-controlled and / or torque-controlled and / or time-controlled. When the final roll diameter is reached, it may be possible to set a dwell time - there is a time control in this interval.

Page 17/27 After reaching the Endwalzdurchmessers then the rolling tool 24 is extended in rapid traverse.

The force control of the Z-axis 10 and the torque control of the rolling spindle 62 can be made directly in response to the actual force or torque value or in dependence on an averaged force / torque instantaneous actual value.

This averaged value may be determined, for example, during a predetermined sampling time. This can be, for example, 2 ms, with a total sampling time of 40 ms for a number of revolutions n = 20. Thereafter, it is considered that the finish rolling state is achieved.

If a force or torque maximum value is exceeded, an alarm deactivation can be carried out.

During the rolling feed and the concomitant increase in the rolling circle diameter, the threshold value and the end value of torque (rolling spindle 62) and force (Z-axis) can be monitored. As long as this threshold and end value lie within a predetermined path window, it can be assumed that a proper rolling process is carried out.

For example, the rolling tool 24 can be moved into a defined position window. The shutdown then takes place upon reaching an averaged torque, which sets at a predetermined number of revolutions and a predetermined speed of the rolling tool.

Another possibility is that the rolling tool 24 moves to a position with a predetermined dwell time while an active torque monitoring takes place. The rolling process is stopped when a certain torque is exceeded.

In all these control concepts, a distance and torque controlled operation takes place.

Page 18/27 The process monitoring can also be done by monitoring the parallelism of the rolling. It should be noted that a tool life parameter or wear parameters during rolling are unparallel the rolling elements 72.

Alternatively, a random sample of the press-in position of the bushing 28 before and after rolling to assess the axial displacement.

This control can also be carried out continuously by means of a sensor, preferably of the initially described - preferably optical - sensor 86, which is particularly easy to implement in the case of a protruding sleeve 28, since then the sensor can detect the supernatant from the side.

Also in the continuous control, a comparison of the press-in position before and after the rolling can be performed.

After the rolling of the bush 28, a retaining seat test can still be performed. This holding seat test can be done, for example, that the force is measured, which is required to squeeze the bushing 28 from the small connecting rod eye (Auspresshalteprüfung). However, this test is relatively inaccurate. A better check is feasible, in which a hexagon is fitted and glued into the rolled bushing 28. This hexagon is then - for example by means of a torque wrench - applied with a torque, wherein the torque is detected, which is required to rotate the sleeve 28 within the connecting rod 48. This test can also be done in a warmed up oil.

A problem with Henkelkorbpleueln is that in conventional bushes 28, which generally have a very low surface quality and are not flat, forms a hollow layer that significantly reduces the security against rotation. The formation of such a hollow layer is not to be feared during rolling, so that a much better holding force than in conventionally pressed bushes can be realized by the rolling process.

The socket 28 may be rolled from a sheet metal blank.

Page 19/27 The applicant reserves the right to make independent claims on each of the regulatory and control strategies described above.

FIG. 8 shows a diagram in which the path, force and torque characteristics during the rolling process over time are shown. The wavy, sharply rising curve in the starting area represents the current for controlling the roller spindle 62 again - this current is directly proportional to the torque which is applied via the roller spindle 62. This torque increases sharply with increasing rolling.

The overhead (violet) curve indicates the current for driving the Z axis. This current is directly proportional to the force applied across the NC-Z axis during rapid traverse and roll feed.

The lower curve (blue) represents the path of the rolling tool 62 again. Accordingly, in a relatively short time interval, the rolling tool 62 with the rapid traverse (high feed) is retracted into the socket 28. Since during this rapid traverse the rolling elements 72 are not in operative engagement, accordingly, the torque is approximately equal to zero. Also, the force for adjusting the rolling tool 62 in the Z direction is minimal.

After a predetermined stroke / time interval, the stop body 78 docks onto the drive-on bushing 44 - this can be recognized by the short horizontal stage of the route and the peaks in the force / torque curve. Subsequently, then, the rapid feed switches over to the roller feed, so that the rolling tool 24 or, more precisely, its cone 76 and the roller spindle 62 perform only a comparatively short stroke (in the range of 1 mm) - during this stroke the rolling circle diameter is increased - Accordingly, the torque that must be applied by the roller spindle drive increases steeply. The increase of the force required for the axial displacement of the rolling tool 62 also increases. However, the slope is significantly less than the increase in torque.

After reaching the finish rolling position (maximum rolling circle diameter), a predetermined residence time may be provided to complete the rolling process.

Page 20/27 After fulfilling the criteria described above, the rolling is then terminated and the rolling tool 24 extended in rapid traverse - for this extension, only a very small force from the Z axis is applied. The torque goes back to zero accordingly.

Disclosed are a device and a method for rolling bushes with a rolling tool whose rolling circle diameter is adjustable and which is linearly retractable along an NC axis in the socket. The rolling takes place position and / or torque and / or force and / or time-controlled. Also an angle dependent

Control is possible.

Page 21/27 reference numeral

1 rotary transfer machine / cracking machine

2 ring table

4 joining / rolling station

6 device

8 sleds

10 Z axis

12 stands

14 frame

16 Y-axis

8 X axis

20 clamping device

22 connecting rods

23 housing

24 rolling tool

26 joining tool

28 socket

30 drive

31 belt drive

32 NC straightening drive

34 rotary feedthrough

36 hold-down device

38 hold-downs

40 vertical guide

42 base

44 lifting bush

46 guide bush

48 small connecting rod eye

50 large connecting rod eye

52 clamping cylinder

54 passage opening

58 HSK chucks

Page 22/27 HSK holder

roller spindle

Zahnriementheb

chipboard

differential piston

cylinder

connections

hydraulic cylinders

roller body

Tool head

cone

stop body

midsection

biasing spring

face

sensor

short coat section

long coat section

slot

right flank

left flank

aligning

peripheral edge

backstop

jack storage

feed

Orientation station

control unit

chamfer

Page 23/27

Claims

claims

1 . A method for rolling bushes (28) into a receptacle, in particular into a bearing receptacle of a workpiece, with a rolling tool (24) which is held by a roller spindle (62) driven by a roller spindle drive and which has one or more radially adjustable rolling elements (72 ) engageable with an inner circumferential surface of the bush (28) for expanding by rolling in a radial direction, comprising the steps of:

Inserting the bush (28) into the bearing receptacle,

- Retraction of the rolling tool (24) with a rapid feed along a feed axis in the socket (28), wherein

a rolling circle diameter of the rolling tool (24) is set to be less than or equal to the inner diameter of the bushing (28),

- subsequently reducing the rapid feed to a roll feed or reversing the rolling tool into a rolling mode and

- Increasing the rolling circle diameter of the rolling tool (24) to the

Widen bushing (28) in the radial direction,

the expansion being in the range of less than 0.5 mm, preferably less than 0.3 mm,

- This rolling is optionally position-controlled and / or force-controlled and / or torque-controlled and / or time-controlled and / or angle-controlled or by combining these control processes.

2. The method according to claim 1, wherein the rapid feed is terminated when a rolling tool side stop body (78) runs onto a Auffahrbuchse (44).

3. The method according to claim 1 or 2, wherein the rolling process is terminated upon reaching a force or torque setpoint or an average force or torque setpoint.

4. The method according to any one of the preceding claims, wherein it is concluded that a proper rolling, when a threshold value and a final value

Page 24/27 torque and / or force are within a path / position window of the rolling tool position.

5. The method according to any one of the preceding claims, wherein it is concluded that a proper rolling operation, when during a torque monitoring or force monitoring, the rolling tool (24) during a predetermined residence time remains at a predetermined position.

6. A method according to any one of the preceding claims, wherein a process control by random checking the press-in position of the bushing (28) before and after rolling to assess an axial displacement of bushing material or by continuous control of an axial projection of the bush (28) by means of a sensor (86 ) or the like, or by detecting the parallelism of the bushing (28).

7. The method according to any one of the preceding claims, wherein the bearing receptacle at least in the pressing direction of the bushing (28) has a chamfer (1 14) and the sleeve (28) in the axial direction, the chamfer (1 14) overlaps or projects beyond this, wherein the rolling process is controlled so that bushing material is displaced into the chamfer (1 14).

8. The method according to claim 7, wherein at least a portion of the supernatant by elongation of the bushing (28) during rolling is formed.

9. A device for rolling bushes (28) into a receptacle of a workpiece, comprising a roller tool driven by a roller spindle drive (24), which has one or more radially adjustable rolling elements (72) in abutment against an inner peripheral surface of the receiving Inserted bushing (28) can be brought to expand them by rolling in the radial direction, with a control unit (1 12), which is designed to retract the rotary rolling tool (24) in the direction of a feed axis with a rapid feed into the socket (28) a rolling circle diameter of the rolling tool (24) is set to less than or equal to the inner diameter of the bush (28) and wherein the control unit (1 12) is designed to reduce the feed to a rolling feed or to switch the rolling tool to a rolling mode and

Page 25/27 at the rolling circle diameter of the rolling tool (24) to widen the bushing (28) in the radial direction, said widening being in the range of less than 0.5 mm, preferably less than 0.3 mm, and this rolling being selectively position controlled and / or torque controlled and / or or force-controlled and / or time-controlled and / or angle-controlled feasible.

10. Device according to claim 9, with a rolling tool-side stop member (78), which runs at the end of the rapid feed on a Auffahrbuchse (44).

1 1. Device according to claim 9 or 10, comprising a sensor (86) for detecting an axial projection of the socket (28) or other socket parameters.

12. Device according to one of the claims 9 to 1 1, wherein the bushing (28) is a bearing bush for a cylindrical connecting rod eye of a connecting rod (22) or for a Formpleuel with trapezoidal or Henkelkorbförmigem connecting rod.

13. Device according to one of the claims 9 to 12, wherein the rolling elements (72) are cylindrical or to the shape of the receptacle or the bush (28) adapted shaped body.

14. Device according to one of the claims 9 to 13, with a station for forming Ölhalte- and Öltransportmikroräumen.

Page 26/27