EP1475185A1 - Method and apparatus for abrasively working surfaces of revolution - Google Patents

Abstract

Process for abrasive cylindrical machining of a workpiece (18) comprises placing a first abrasive tool (20) rotating about a first tool axis against the workpiece to machine a first workpiece surface in a first abrasive process. A second abrasive tool (54) rotating about a second tool axis (56) is placed against the workpiece to machine a second workpiece surface in a second abrasive process. The two workpiece surfaces are rotationally symmetrical with regard to the workpiece axis and are arranged adjacently to each other. A circular transition edge is formed between the two workpiece surfaces. The two abrasive processes end at the same time. An independent claim is also included for an abrasive device (10) for abrasive cylindrical machining of a workpiece.

Description

Technical area

The invention relates to a method for abrasive round machining of a workpiece and a device for carrying out the abrasive round machining process according to the Preambles of the independent claims.

State of the art

For many applications, workpieces are needed that are at least partially rotationally symmetric are formed and a workpiece axis defining the axis of symmetry have as well as two adjacent surfaces, with respect to the workpiece axis are formed rotationally symmetrical and between which a circular Transition edge is formed. Such workpieces are e.g. as valve or nozzle needles typically one of the two faces is a sealing seat and the other the two surfaces forms a guide surface of the valve or nozzle needle. With such Valve or nozzle needles also for high pressure applications such as Fuel injection systems suitable for modern gasoline or diesel engines, where partial pressures be controlled from well over 1000 bar, are high requirements in terms to comply with the compliance of manufacturing tolerances. In particular, the transitional edge must between the seat and the guide surface sharp as possible and burr-free be educated.

For the machining of workpieces of the above type are chip-forming processes with geometrically indeterminate cutting edges (also known as abrasive machining processes applied), in particular grinding and honing. A method for abrasive rounding can thus e.g. a cylindrical grinding process or a round honing process be. Accordingly, both a cylindrical grinding machine and a Rundhonmaschine as a device for carrying out an abrasive round machining process to watch.

From document WO 01/60565 (Robert Bosch GmbH) are a grinding method and a grinding machine is known, which is the manufacture of a valve needle for a fuel injection valve allow by means of cylindrical grinding. The grinder is with a Abrasive wheel and arranged with respect to the workpiece relative to the grinding wheel Provided deburring mandrel. If the grinding wheel is an abrasive surface of the As the workpiece grinds, a burr forms over the surface between the grinding surface and one adjacent edge formed in the region of the adjacent transition area Projecting surface. The deburring mandrel is arranged and formed such that the burr due to the rotation of the workpiece rotating about its axis from the deburring mandrel the grinding surface pressed back and ground on the next contact with the grinding wheel becomes.

It has been found that the grinding method and the grinding machine according to the Document WO 0 1/60565 is disadvantageous for the mass production of large workpiece series. It happens over and over again that the burr formation by the deburring mandrel not reliably prevented. Therefore, a time consuming review of the Workpieces required to ensure the desired production quality.

Presentation of the invention

The object of the invention is to specify a method and a device for abrasive Round machining, which ensures reliable and precise machining of workpieces with a sharp and burr-free transition edge between two rotationally symmetric Allow surfaces in large-scale production.

The solution of the problem is defined by the features of the independent claims. According to the invention, for machining a workpiece, which is a workpiece axis has performed an abrasive round machining process. While performing of the round machining process, the workpiece rotates about the workpiece axis, while simultaneously a first abrasive tool (in particular a grinding tool or a honing tool) rotating about a first tool axis and the workpiece be delivered against each other, in a first Abrasivvorgang (in particular a Grinding or honing process) to process a first workpiece surface. The inventive Processing method is characterized in that a second abrasive tool (In particular, a grinding tool or a honing tool), which is a second tool axis rotates, is delivered against the workpiece, in a second Abrasivvorgang a second workpiece surface to edit. The two workpiece surfaces are rotationally symmetrical with respect to the workpiece axis and each other arranged so adjacent that between them a sharp, burr-free, circular Transition edge is formed. The two abrasive processes are controlled in this way, that they will be finished at the same time.

In other words, this means that the two Abrasivvorgänge at least to be performed simultaneously and ended at the same time against their end the workpiece rotates around the workpiece axis.

During the simultaneous execution of the two Abrasivvorgänge is a possible by the first abrasive tool formed during abrasive machining of the first workpiece surface Burr that extends beyond the transition edge into the area of the second workpiece surface and thus projects into the area machined by the second abrasive tool, according to the Rotation of the workpiece around the workpiece axis within less than one full revolution of the workpiece on the next contact with the second abrasive tool abraded. In the same way is a possibly due to the second abrasive tool formed during abrasive machining of the second workpiece surface burr, on the Transitional edge out into the area of the first workpiece surface and thus in the first abrasive tool machined area protrudes, within less than one full revolution of the workpiece on the next contact with the first Abrasive tool ground. For simultaneous abrasive machining of the two workpiece surfaces Thus, any burrs on the transition edge to the outset effectively prevented.

Further, in simultaneous abrasive machining of the two workpiece surfaces as well Any burrs ground off at the transitional edge, previously during a non-Muslim abrasive machining of the workpiece surfaces have been formed. For the Burr-free formation of the transition edge after the completion of the inventive It is therefore irrelevant if the procedure is completed for a certain period of time one of the two Abrasivvorgänge carried out alone and thereby a burr at the transition edge is formed. By the simultaneous execution of the two abrasive processes shortly before the completion and the simultaneous termination of the two abrasive processes in the Completion of the inventive processing method are also possible burrs, which were previously formed in the transitional edge, ground away.

By the two abrasive operations at least at the end of the inventive machining process simultaneously executed and terminated at the same time, nothing remains Burr left over at the transition edge. Simultaneity in the present context means that a possible time difference between the end of the first and the second Abrasive action is too short for burr formation, even if during one of these Time difference corresponding period of only one of the two abrasive tools in (grinding) contact with the workpiece is. In case of grinding of tungsten carbide manufactured workpieces by means of grinding wheels, which are suitable for grinding carbide are suitable and with common grinding speeds of the order of magnitude between about 20 and 60 m / sec with respect to the workpiece, means Simultaneity in the sense mentioned above, that the time difference between the end of both grinding operations less than about 0.5 seconds, preferably less than is about 0.3 seconds, in particular even less than about 0.2 seconds.

For carrying out the first abrasive process according to the invention It is possible to process the workpiece by one during the first abrasion process stationary workpiece axis is rotated and the first abrasive tool against the workpiece is delivered. Such abrasive operations are typically on cylindrical grinding machines executed, in which an elongated workpiece between a a workpiece spindle mounted during the first abrading process and one at a stationary during the first grinding tailstock arranged quill is added. Alternatively, it is also possible that the workpiece rotating about the workpiece axis against one at a time during the first grinding operation stationary first tool axis rotating first abrasive tool is delivered. Such abrasive processes are usually of cylindrical grinding machines designed for centerless cylindrical grinding (that is for cylindrical grinding without quill) are formed. In principle, it is also possible that during the implementation the first Abrasovvorgangs both the first abrasive tool and the Wekrstückachse (or a workpiece axis defining Wekrstückspindel) simultaneously be moved.

Compared to the grinding process described in WO 01/60565, the inventive Processing method further has the advantage that the two adjacent Work piece surfaces between which the transition edge is formed, at least partially simultaneously (i.e., simultaneously), thereby reducing the processing time for Production of the workpiece is considerably shortened. This is especially for the grossserielle Production of workpieces a significant advantage.

In the course of the inventive method, it is possible that both Abrasiworgänge only time-controlled. That is, both abrasions are respectively while performed at the outset, so for the two Surfaces depending on the respective time period corresponding removal is removed by machining. In this case, for carrying out the inventive method, the Start times for the two Abrasivvorgänge the time difference between the for the both periods of abrasion are set offset. The two Abrasive processes then become the start times offset by this time difference started, so that after the completion of the two Abrasivvorgänge this at the same time to be ended.

According to a preferred embodiment of the invention, however, at least one of carried out messgesteuert both abrasive operations. In the present context is understood by the messgesteuerte performing a Abrasiworgangs that the in an abrasive process machined workpiece surface during the implementation of the Abrasivvorgangs is measured and the Abrasivvorgang is terminated as soon as a desired target size is reached. For carrying out the inventive Method according to this embodiment of the invention is initially after a first Measurement of the workpiece surface based on the measurement result, a first estimate of the determines the completion of the measurement-controlled abrasion process required time. This estimate is then used for a completion value the time required for the other abrasive process, the time difference between the estimate for completion of the gauged abrasive process and the time value for the completion of the other Abrasivvorgangs is determined. Is it? If the other abrasive process is a timed process, then the time value be determined due to the time already spent for this Abrasivvorgang. If, on the other hand, the other abrasive process is also a measurement-controlled one Process, the time value can be analogous to the estimated value for the first measuring process are estimated. Subsequently, that Abrasivvorgang, for which a shorter time has been determined until the completion of the operation, delayed according to the time difference. The determination of the time difference and the subsequent deceleration of one abrasive process can occur several times during the Implementation of the inventive method are made to the temporal To increase precision for the simultaneous termination of the two abrasive operations.

For the implementation of the inventive method, one of the two processed Workpiece surfaces conical, while the other machined workpiece surface can be either conical or cylindrical.

The inventive method is particularly good for external cylindrical grinding suitable, i. for cylindrical grinding of a workpiece whose one workpiece surface to be machined outwardly conical and its other workpiece surface to be machined either is also designed ausenkonisch or cylindrical. For external cylindrical grinding Grinding wheels are typically used whose diameter is much larger are the diameter of the workpiece in the area to be ground. In this case the advantage is particularly large, since the burr formation in the use of comparatively large grinding wheels is a significant problem.

In principle, however, the inventive method is also for a combined External and internal cylindrical grinding (i.e., for grinding an internal conical workpiece surface and one to this adjacent another workpiece surface, either outwardly conical or cylindrical) or even for internal cylindrical grinding of two applicable adjacent conical workpiece surfaces. In these cases, the Grinding the inner conical workpiece surfaces each grinding wheels with a comparatively small diameter used.

One for carrying out the inventive method for abrasive round machining a workpiece trained abrasive device may in particular a grinding machine or honing machine, which rotates about a workpiece spindle axis Workpiece spindle comprises, which with a trained for receiving the workpiece Workpiece holder is provided. The Abrasivvorichtung further includes a to a first Tool axis rotating first abrasive tool and a first feed device to deliver the first abrasive tool and the workpiece against each other. The first Delivery device is designed such that by means of the first feed device either the first abrasive tool against the workpiece or the workpiece together the workpiece spindle against the first abrasive tool is deliverable. But it can at the same time both the first abrasive tool and the workpiece together with the Workpiece spindle be moved relative to a stationary base to the first Abrasivwerkzeug and deliver the workpiece against each other. The inventive Abrasivvorichtung further comprises a rotating about a second tool axis second Abrasivwerkzeug, a second feed device, for feeding the second abrasive tool is formed against the workpiece, and a control device for Control of the abrasive device. The controller is for controlling the first one Delivery device designed such that by means of the first delivery device, the first Abrasivwerkzeug and the workpiece against each other be delivered to a first Abrasivvorgang a first workpiece surface to edit. The control device is further configured to control the second feed device such that the second Abrasivwerkzeug delivered by means of the second feed device against the workpiece is used to process a second workpiece surface in a second abrasion process, wherein the two workpiece surfaces with respect to the workpiece spindle axis rotationally symmetrical are formed and arranged adjacent to each other such that between them a circular transitional edge is formed. In addition, the Control device for controlling the two feed devices is designed such that the two Abrasivvorgänge be terminated at the same time.

The first feed device may comprise a first carriage by means of either soft the workpiece together with the workpiece spindle or the first abrasive tool along a first straight linear guide obliquely or at right angles to the workpiece spindle axis is movable to the first abrasive tool and the workpiece against each other to send. In the case of a rectangular delivery of the first abrasive tool against the workpiece is referred to as a straight line engraving, in the case of one of a right Angle deviating delivery as an oblique engraving.

As an alternative to a first carriage which can be moved along a first linear guide the first delivery device may also comprise other suitable delivery means, e.g. a Platform pivotable about a pivot axis.

In addition, a further translational movement axis between the first abrasive tool and the Wekrstückspindel be provided to between the workpiece and the first abrasive tool a plane relative movement with two translational degrees of freedom to enable.

According to a preferred variant of the invention, the second delivery device comprises a second carriage, by means of which the second abrasive tool along a second straight linear guide obliquely or at right angles to the workpiece spindle axis is movable, wherein the second linear guide is arranged such that the second Abrasivwerkzeug from one with respect to the workpiece the first abrasive tool opposite side against the workpiece is deliverable. Like the first one Delivery device may also be the second feed device in the manner of a Schrägeinstichs or be arranged in the manner of a straight line engraving.

In this case, the second linear guide comprises at least two leading the second carriage and the direction of travel of the second carriage defining elongated guide elements, define the two parallel geometric axes. The guide elements can e.g. Be rails or guide rods. The guide elements are like this arranged that the (geometric) workpiece spindle axis between the through the Guide elements defined axes leads. The arrangement of Guide elements such that the axes defined by these axes on both sides of the workpiece spindle axis Run by, ensures a high rigidity of Abrasivvorichtung for workpiece machining by means of the second abrasive tool and thus a high precision in the processing.

Preferably, the guide elements of the second feed device are even such arranged that the workpiece spindle axis even between the guide elements even through, not just between their extensions. This will achieves a particularly high rigidity of the abrasive device.

Instead of a movable along a second linear guide second carriage can the second delivery means in turn comprise other suitable delivery means, e.g. a Platform pivotable about a pivot axis.

The second abrasive tool may in particular be a grinding wheel. In case of above-mentioned variant of the invention with a movable along a second linear guide The second carriage then preferably further comprises the abrasive device Dressing tool for dressing the grinding wheel. The dressing tool can be used on the Workpiece spindle axis opposite side of the grinding wheel arranged such be that the grinding wheel by means of the second carriage either against the Workpiece or against the dressing tool is movable. This will be a compact and space-saving structure of Abrasivvorichtung achieved.

Preferably, the second feed device comprises a third carriage, by means of which the second abrasive tool along a third straight linear guide parallel to Workpiece spindle axis is movable. In this case, the third linear guide comprises at least three the third carriage and the direction of movement of the third carriage defining elongate guide elements, each one parallel to each other geometric Define axis. The guide elements may e.g. Be rails or guide rods.

The guide elements are arranged such that the workpiece spindle axis within a space which is of an imaginary envelope (i.e., an envelope in the geometric sense) around the at least three infinitely long axes of the third Linear guide is limited. In other words, the guide elements the third linear guide arranged such that the workpiece spindle axis a polygon penetrates, which lies in a plane normal to the workpiece spindle axis and whose Corners through the guide elements associated axes of the third linear guide are defined. This arrangement of the guide elements in turn ensures a high Stiffness of Abrasivvorichtung for workpiece machining by means of the second Abrasivwerkzeugs and thus a high machining accuracy.

If the second feed device obliquely both along the second linear guide or at right angles to the workpiece spindle axis movable second carriage as well a movable along the third linear guide parallel to the workpiece spindle axis third carriage, is preferably the second carriage by means of the second Linear guide on the third carriage arranged movable, so that the second carriage in Sense of a serial kinematics is the third carriage downstream. This will be a obtained comparatively simple and rigid construction of the second feed device. In principle, however, for certain applications, the reverse is serially kinematic Arrangement possible, i. the arrangement of the carriage such that the third Carriage is arranged movable by means of the third linear guide on the second carriage.

The abrasive device may further comprise a tailstock provided with a quill for Stabilizing a longitudinal end of the workpiece during workpiece machining is provided. In this case, preferably the second feed device on the tailstock is arranged. This is a particularly simple and rigid construction of Abrasivvorrichtung achieved.

In the case of an equipped with a tailstock and quill abrasive device whose second feed device further comprises a third carriage, which parallel to Workpiece spindle axis along a third linear guide is movable, is the third Linear guide advantageously arranged on the tailstock. The third sled is then movable relative to the tailstock along the third linear guide. Next is Advantageously, the quill in through a formed in the third carriage passage leading assembly connected to the tailstock such that the third Slide independently of the quill along the quill is movable. The quill can turn be provided with an adjustment, which for adjusting or Method of sleeve with respect to the tailstock parallel to the workpiece spindle axis is trained. The third slide and quill are then independent movable parallel to the workpiece spindle axis with respect to the tailstock.

From the following detailed description and the totality of the claims result in further advantageous embodiments and feature combinations of Invention.

Brief description of the drawings

Fig. 1

in einer vereinfachten Teilansicht von oben eine Abrasivvorichtung gemäss einer ersten bevorzugten Ausführungsart der Erfindung, in einer ersten Arbeitsstellung;

Fig. 2

in einer der Fig. 1 entsprechenden Darstellung die Abrasivvorrichtung aus Fig. 1 in einer zweiten Arbeitsstellung;

Fig. 3

die Abrasivvorrichtung aus Fig. 1 in einer vereinfachten perspektivischen Teilansicht.

The drawings used to explain the embodiment show:

Fig. 1

in a simplified partial view from above a Abrasivvorichtung according to a first preferred embodiment of the invention, in a first working position;

Fig. 2

in a representation corresponding to FIG. 1, the abrasive device from FIG. 1 in a second working position; FIG.

Fig. 3

the abrasive device of Fig. 1 in a simplified perspective partial view.

Basically, the same parts are provided with the same reference numerals in the figures.

Ways to carry out the invention

In the figures 1-3 an external cylindrical grinding machine 10 is shown, which is a stable stationary machine bed (not shown). On the machine bed is a straight linear guide (not shown) arranged below as the fourth Linear guide is called. A carriage (not shown), then fourth Carriage referred to, is linearly movable on the fourth linear guide, as in the Figures are indicated by the double arrow 62.

On the fourth carriage, a workpiece headstock (not shown) is fixed, in which a workpiece spindle 12 about a substantially horizontal workpiece spindle axis 14 is rotatably mounted, wherein the workpiece spindle axis 14th extends parallel to the direction of travel of the fourth carriage on the fourth linear guide. At a flying end of the workpiece spindle is a workpiece clamping device 16 arranged in which a longitudinal end of an elongate workpiece 18 is clamped. The Workpiece spindle 12 is driven by a motor (not shown) such that it when grinding with a number of revolutions of about 800 rpm around the workpiece spindle axis 14 turns.

Die erste Schleifscheibe 20 ist zum Schleifen einer zylindrischen Fläche des Werkstücks 18 ausgebildet, wobei das Werkstück 18 im Bereich dieser zylindrischen Fläche einen Durchmesser von ungefähr 4 mm hat. Die erste Schleifscheibe 20 hat einen Scheibendurchmesser von ungefähr 500 mm und wird von einem Motor (nicht dargestellt) derart angetrieben, dass sie sich beim Schleifen mit einer Tourenzahl von ungefähr 1750 U/min um die erste Werkzeugachse dreht.

On the machine bed, another straight linear guide (not shown) is arranged, which is referred to below as the first linear guide. A carriage (not shown), hereinafter referred to as the first carriage, can be moved obliquely to the workpiece spindle axis 14 along the first linear guide. The first carriage carries the main spindle (not shown) of the external cylindrical grinding machine 10, wherein in the main spindle a main grinding wheel 20 designated first grinding wheel 20 about a first substantially horizontal tool axis (not shown) is rotatably mounted. The first carriage and the first linear guide are part of a first feed device, which serves to deliver the first grinding wheel 20 against the workpiece 18 and to drive away from it again, as indicated in the figures by the double arrow 22:

The first grinding wheel 20 is designed to grind a cylindrical surface of the workpiece 18, the workpiece 18 having a diameter of approximately 4 mm in the region of this cylindrical surface. The first grinding wheel 20 has a pulley diameter of approximately 500 mm and is driven by a motor (not shown) to rotate about the first tool axis during a grinding operation with a turning number of approximately 1750 rpm.

Next is on the fourth carriage relative to the workpiece headstock a tailstock 30 firmly mounted. At the workpiece headstock facing end of the Tailstock 30 is a sleeve 32 projecting toward the workpiece spindle arranged, said quill by means of a hydraulic drive with respect Tailstock 30 parallel to the workpiece spindle axis 14 is movable.

The workpiece spindle 12 and the sleeve 32 are arranged such that at a Longitudinal end in the workpiece clamping device 16 clamped workpiece 18 between the workpiece spindle 12 and the sleeve 32 is received, during which it Rotation about the workpiece spindle axis 14 at the other longitudinal end of the Pinolenspitze is stabilized. In addition, the tailstock 30, the workpiece headstock and on the first linear guide movable main spindle relative to each other arranged in such a way that the main grinding wheel 20 by means of the first feed device between the Workpiece spindle 12 and the Pinolenspitze against the workpiece 18 is deliverable.

On tailstock 30 four straight guide rods 34, 36, 38, 40 are arranged, each are arranged parallel to the workpiece spindle axis 14 and of the workpiece headstock facing end face of the tailstock 30 in the direction of the workpiece headstock protrude. The four guide rods 34, 36, 38, 40 are part of another straight Linear guide, which is referred to below as the third linear guide. Just before the end of the tailstock 30 facing the workpiece spindle is another Carriage 42, hereinafter referred to as third carriage 42, arranged, with four Guide bushing is provided, through which the four guide rods 34, 36, 38, 40 of the lead third linear guide through. The third carriage 42 is in one area between the tailstock 30 and the workpiece headstock along the third linear guide movable relative to the workpiece spindle axis 14 with respect to the tailstock 30, such as it is indicated in Figures 1-3 by the double arrow 44.

The four guide rods 34, 36, 38, 40 of the third linear guide are arranged such that they form the corners of a rectangle which approximates the cross section of the Tailstock 30 corresponds. Further, the four guide rods 34, 36, 38, 40 with respect to the workpiece spindle axis 14 is arranged such that the workpiece spindle axis 14 by that of the four guide rods 34, 36, 38, 40 of the third linear guide spanned rectangle leads through.

In the third carriage 42 is a coaxial with the workpiece spindle axis 14 extending Pinole passage formed. The projecting from the front side of the tailstock 30 Quill 32 extends through this passage, so that the third carriage 42nd independently of the sleeve 32 along the third linear guide is movable.

On the tailstock 30 remote and facing the workpiece headstock Front of the third carriage 42 are two straight guide rods 46, 48 arranged, each extending transversely to the workpiece spindle axis 14 and substantially horizontally. These two guide rods 46, 48 are part of another straight linear guide, the hereinafter referred to as a second linear guide. Immediately in front of the workpiece headstock facing front side of the third carriage 42 is another Carriage 50, hereinafter referred to as second carriage 50, arranged, with two Guide bushing is provided, through which the two guide rods 46, 48 of the second Guide linear guide through. The second carriage 50 is in a range between the third carriage 42 and the workpiece headstock along the second linear guide transverse to the workpiece spindle axis 14 and substantially horizontal with respect to the third Carriage 42 movable, as indicated in the figures by the double arrow 52.

The guide rods 46, 48 of the second linear guide are substantially vertically one above the other arranged on the third carriage 42 such that the third carriage in the 42nd formed Pinolendurchgang (and thus to this substantially coaxial Work spindle axis 14) approximately halfway between the two guide rods 46, 48 of the second linear guide passes.

On the remote from the third carriage 42 and facing the workpiece headstock Front side of the second carriage 50 is a second designated as auxiliary grinding wheel 54 Grinding wheel 54 arranged around a substantially horizontal and parallel to the Workpiece spindle axis 14 arranged second tool axis 56 with respect to the second Carriage 50 is rotatably mounted. The second carriage 50 and the third carriage 42 as well the second and the third linear guide are part of a second feed device, which serves to the second grinding wheel 54 in the manner of a cross slide in a in Deliver substantially horizontal plane against the workpiece 18 and again from him to drive away. In this case, the second delivery device is designed and arranged in such a way that the second grinding wheel 54 on the with respect to the workpiece spindle axis 14 and the workpiece 18 of the first grinding wheel 20 opposite side of the workpiece Arranged 18 and fed from this side against the workpiece 18 and again from this way is mobile.

The second grinding wheel 54 is for grinding an external surface of the workpiece Formed 18, wherein this aussenkonische workpiece surface so to that of the first grinding wheel 20 ground cylindrical workpiece surface is adjacent to that between them a sharp circular transition edge is formed. The second grinding wheel 54 has a disc diameter of about 100 mm and is of a Motor (not shown) driven so that they are when grinding with a number of turns about 6000 rpm about the second tool axis 56 rotates.

On the tailstock 30 a dressing unit is further arranged, the one about a vertical Swivel axis with respect to the tailstock 30 pivotally adjustable dressing headstock 58, in which a dressing spindle is mounted, which is a substantially horizontal Abrichtspindelachse is rotatable. There is a dressing wheel on the dressing spindle 60, which is designed to dress the second grinding wheel 54. The Dressing unit is on the workpiece spindle axis 14 opposite side of the second grinding wheel 54 arranged such that the second grinding wheel 54 by means of the second carriage 50 either against the workpiece 18 or against the Dressing wheel 60 is movable. The grinding wheel 54 may also be translational with two Degrees of freedom in a plane with respect to the dressing wheel 60 and / or the Workpiece 18 are moved by the second carriage 50 and the third carriage 42nd at the same time each along their associated linear guides are moved (also as interpolating movement of the grinding wheel 54).

In FIGS. 1 and 2, the external cylindrical grinding machine 10 is in a working position in which both the first grinding wheel 20 and the second grinding wheel 54 are delivered against the workpiece 18 and the workpiece 18 of the two Grinding wheels 20, 54 is ground simultaneously. In Fig. 3 are the sake of clarity the first grinding wheel 20 and the workpiece headstock are not shown. In the figure 2 the external cylindrical grinding machine 10 is shown in a working position, in which the second Grinding wheel 54 along the second linear guide from the workpiece 18 away to the dressing wheel 60 is moved towards and in the first grinding wheel 20 from the workpiece 18th is gone.

Furthermore, the external cylindrical grinding machine 10 shown in FIGS. 1-3 comprises one the fourth carriage arranged first measuring device (not shown), the Measuring the abrasion caused by grinding with the first grinding wheel 20 Workpiece 18 is formed, arranged on the fourth carriage second Measuring device (not shown) for measuring when grinding with the second Grinding wheel 54 caused erosion of the workpiece 18 is formed, and a Control means (not shown) for controlling the first and second Delivery device is formed.

In another, not shown in the figures 1-3 variant of an inventive External cylindrical grinding machine is the second measuring device not on the fourth slide, but arranged on the quill.

In an external cylindrical grinding machine according to another not in the figures illustrated variant of the invention are the workpiece headstock, the tailstock and the first measuring device stationarily arranged on the machine bed. In order between the Workpiece and the main grinding wheel nevertheless a plane relative movement with two to allow translational degrees of freedom for the main grinding wheel on arranged a cross slide, which with respect to the machine bed with two translational degrees of freedom in a plane is movable.

By means of the external cylindrical grinding machine 10 shown in FIGS cylindrical and the outer-conical surfaces of the workpiece 18 to grind such that between them a sharp, burr-free circular transition edge is formed first by means of the first removal measuring device in a first grinding process Measured by the first grinding wheel 20 from the workpiece 18 abraded Abtrag. The measurement result of the first removal measuring device is sent to the machine control which, from this, the required for the completion of the first grinding process first time period determined. At the same time by means of the second removal measuring device in a second grinding operation by means of the second grinding wheel 54 from the workpiece 18 abraded Abtrag measured. The measurement result of the second removal measuring device is also transmitted to the machine control, which therefrom for the Completion of the second grinding operation required second period determined. Thereafter, the engine controller determines the difference between the first and the second second time span. Subsequently, the two grinding operations are started, the Machine control, the first and the second feed device controls such that the grinding process for which the shorter time to completion of the Grinding process has been determined according to the time difference after the start of the another grinding process is started. This causes the two Grinding operations are completed at the same time.

According to another variant of the invention, the time difference is not automatically by the Machine control determined. Instead, first, by means of the first and the second Abtragsmesseinrichtung the two ablated from a workpiece ablations measured, after which an operator from these abductions the periods of completion of the two grinding operations and the time difference between these periods. Then the operator programs the machine control for the processing of a Series of substantially identical to each other formed workpieces, wherein the Starting times for the two grinding operations that take place on each workpiece are set to be offset by the time difference that is needed to carry out the Grinding operations have been calculated over certain periods of time. Then it will Series of workpieces to be machined with fixed time switching points processed.

In summary, it should be noted that a method and a Device for abrasive round machining can be specified, which is a reliable and precise machining of workpieces with a sharp and burr-free Transition edge between two rotationally symmetrical surfaces also in the grossseriellen Enable production.

Claims (10)

Method for abrasive round machining of a workpiece (18), which has a workpiece axis and rotates about the workpiece axis during the execution of the method, while at the same time a first abrasive tool (20) rotating about a first tool axis and the workpiece (18) are opposed to each other, in order to process a first workpiece surface in a first abrasive process, characterized in that a second abrasive tool (54) rotating about a second tool axis (56) is delivered against the workpiece (18) in order to process a second workpiece surface in a second abrasive process, wherein the two workpiece surfaces are rotationally symmetrical with respect to the workpiece axis and arranged adjacent to each other so that between them a circular transition edge is formed, and wherein the two Abrasivvorgänge be terminated at the same time. A method according to claim 1, characterized in that at least one of the two Abrasivvorgänge is performed messgesteuert. A method according to claim 1 or 2, characterized in that at least one of the two workpiece surfaces is conical. Abrasive device (10) for abrasive round machining of a workpiece (18) with a workpiece spindle axis (14) rotating workpiece spindle (12) which is provided with a workpiece holder (16) for receiving the workpiece holder (16), one around a first tool axis rotating first abrasive tool (20), and a first feed device to deliver the first abrasive tool (20) and the workpiece (18) against each other, characterized in that the device (10) further comprises a second abrasive tool (56) rotating about a second tool axis (56). 54), a second feed device for feeding the second abrasive tool (54) against the workpiece (18), and a control device for controlling the abrasive device (10) such that by means of the first feed device the first abrasive tool (20) and the workpiece (18 ) are delivered against each other to edit a first workpiece surface in a first abrasive, and the second abrasive tool (54) is delivered against the workpiece (18) by means of the second feed device in order to machine a second workpiece surface in a second abrasive process, wherein the two workpiece surfaces are rotationally symmetrical with respect to the workpiece spindle axis (14) and adjacent to each other, in that a circular transition edge is formed between them, and wherein the control device for controlling the two feed devices is designed such that the two abrasive processes are terminated at the same time. Abrasivvorrichtung (10) according to claim 4, characterized in that the first feed device comprises a first carriage, by means of which either the workpiece (18) together with the workpiece spindle (12) or the first abrasive tool (20) along a first straight linear guide obliquely or at right angles to Workpiece spindle axis (14) is movable to deliver the first abrasive tool (20) and the workpiece (18) against each other. Abrasivvorrichtung (10) according to claim 5, characterized in that the second feed device comprises a second carriage (50) by means of which the second abrasive tool along a second straight linear guide obliquely or perpendicular to the workpiece spindle axis is movable to the second abrasive tool (54) of a with respect to the workpiece (18) to the first abrasive tool (20) opposite side against the workpiece (18), wherein the second linear guide at least two the second carriage (50) leading and the direction of movement of the second carriage (50) defining elongated guide elements (46, 48) defining two mutually parallel axes and arranged such that the workpiece spindle axis (14) passes between the two axes. The abrasive device (10) of claim 6, characterized in that the second abrasive tool (54) is a grinding wheel (54) and the abrasive device (10) further comprises a dressing tool (60) for dressing the grinding wheel (54), the dressing tool (60 ) is arranged on the side opposite the workpiece spindle axis (14) side of the grinding wheel (54) such that the grinding wheel (54) by means of the second carriage (50) selectively either against the workpiece (18) or against the dressing tool (60) is movable. Abrasivvorichtung (10) according to any one of claims 5 to 7, characterized in that the second feed device comprises a third carriage (42) by means of which the second abrasive tool (54) along a third linear linear guide parallel to the workpiece spindle axis (14) is movable, wherein the third linear guide comprises at least three elongated guide elements (34, 36, 38, 40) guiding the third carriage (42) and defining the travel direction of the third carriage (42), each defining an axis parallel to the workpiece spindle axis (14) and arranged in such a way in that the workpiece spindle axis (14) lies within a space bounded by an envelope around the at least three axes of the third linear guide. An abrasive device (10) according to any one of claims 5 to 8, characterized in that it further comprises a tailstock (30) provided with a quill (32) for stabilizing a longitudinal end of the workpiece (18) during workpiece machining, the second Delivery device on the tailstock (30) is arranged. Abrasive device (10) according to claim 8 and claim 9, characterized in that the third linear guide on the tailstock (30) is arranged such that the third carriage (42) with respect to the tailstock (30) along the third linear guide is movable, wherein the quill (32) is connected to the tailstock (30) in an arrangement passing through a passage formed in the third carriage (42).

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