EP1080833A2 - Method and apparatus for inclined centerless plunge-cut grinding - Google Patents

Abstract

The method involves rotating a work piece (34) about an axis inclined by a given angle at a conical grinding wheel (16), to engage at least part of its surface. The grinding wheel and the work piece are advanced through a given overmeasure (A) in at least two steps. In a first step, they are advanced in a radial direction (74/1) to grind a cylindrical section (50,52) and in the second step they are advanced in an axial direction to grind a conical shoulder section (52). An Independent claim is included for a grinding machine for implementing the method.

Description

The invention relates to a method for centerless oblique plunge grinding on a workpiece rotatable about a first axis with essentially cylindrical sections different Diameter and at least one between the sections lying shoulder, one of which is conical on its circumference trained grinding wheel around their, to the workpiece axis axis rotated by a predetermined angle and with at least one surface line of the circumference engages with the Workpiece is brought, and while still the grinding wheel and the workpiece by a predetermined allowance relative to each other be delivered.

The invention further relates to a grinding machine for centerless Oblique plunge grinding on one around a first axis rotatable workpiece with essentially cylindrical sections of different diameters and at least one between the sections lying on the shoulder, one on her Scope of conical grinding wheel around its, to the workpiece axis axis rotatable by a predetermined angle arranged and with at least one surface line of the circumference in Engagement with the workpiece can be brought, and while still the grinding wheel and the workpiece by a predetermined allowance are deliverable relative to each other.

A method and a grinder of the above Kind are known.

As is known, centerless grinding becomes a rotatable one Workpiece on a support between a grinding wheel and positioned a regulating wheel. The grinding wheel will be there engaged on a peripheral surface of the workpiece, while this is supported by the regulating wheel at the same time becomes.

In this context, it is also known to work through Machining oblique plunge grinding. For oblique plunge grinding is the grinding wheel axis to the longitudinal axis of the workpiece inclined by a predetermined angle. The outer circumference the grinding wheel is conical in this case, such that the surface line of the conical section of the grinding wheel e.g. runs parallel to the axis of the workpiece and thus grinding cylindrical circumferences is possible.

It is also known in this connection, such workpieces to grind the axial sections different Have diameter. Are located between these sections shoulders that are either ring shoulders with one in one Radial plane surface or inclined shoulders, whose surface is a cone and in this way the cylindrical Sections of different diameters with each other connects.

In the case of oblique plunge grinding of such workpieces, it is known to store the workpieces axially on the support rail, i.e. for angular plunge grinding against an axial stop to press.

With conventional centerless helical plunge grinding for removing a predetermined allowance on the circumference of the workpiece the grinding wheel in a direction oblique to the workpiece axis delivered. It is known in this context the workpiece itself with the support around it oblique angle of the infeed inclined to the longitudinal median plane of the Arrange grinding machine on a sled that is movable perpendicular to the workpiece axis. The control wheel in turn is arranged on a second carriage which is on the mentioned first carriage arranged and parallel to it Feed direction can also be advanced to the regulating wheel to the workpiece in a radial direction to the workpiece axis to be able to press. In these known grinding machines the grinding spindle is firmly connected to the machine bed. The axis of rotation of the grinding wheel runs parallel to the longitudinal center plane the grinding machine. The grinding wheel is on hers Tapered circumference, the cone angle straight the angle of inclination of the workpiece to the longitudinal median plane of the Corresponds to grinding machine.

With this known procedure there is a risk that the Grinding wheel initially only with the allowance in the area of Shoulder engages and therefore removes this oversize, while with the cylindrical part of the workpiece allowance does not come into contact yet. Then there can be between the workpiece, Regulating wheel, grinding wheel and support rail an undefined Position result that under the acting against the shoulder Grinding pressure to deflect the workpiece and thus leads to unwanted movements. In addition, the Drive the rotation of the workpiece through the regulating wheel in this case because of the low radial force that over the Grinding wheel contact only on the shoulder of the workpiece is not guaranteed.

Furthermore, the known procedure has the disadvantage that the Removal of the nominal size in the area of the cylindrical sections and depends on each other in the area of the shoulder, namely over the oblique angle at which the grinding wheel and the workpiece are delivered relative to each other.

The invention is based on the object of a method and a grinding machine of the aforementioned type to further develop the disadvantages mentioned above be avoided.

In particular, a secure location, condition should be available at all times and system of the workpiece can be guaranteed so that only one defined movement of the workpiece is possible. Also supposed to be ensured be that the workpiece by an appropriate Sufficient radial force is applied to the regulating wheel and therefore the drive of the workpiece is guaranteed. After all, it should be possible to remove the material in the area of cylindrical sections of the workpiece and the shoulder separately adjusted according to the respective circumstances.

In a method of the type mentioned at the outset, this task solved according to the invention in that in a first Step essentially in the radial direction and in a second Step delivered essentially in the axial direction is such that in the first step, the oversize in the area of the cylindrical sections and in the second step essentially the measurement of the shoulder is removed.

In a grinding machine of the type mentioned in the introduction Object achieved according to the invention in that means for delivery are provided in at least two steps, one in first step essentially in the radial direction and in delivered in a second step essentially in the axial direction is such that in the first step essentially that Measurement in the area of the cylindrical sections and in the second Step essentially removed the measurement of the shoulder becomes.

The object on which the invention is based is achieved in this way completely solved.

By dividing the delivery movement into two steps achieved that initially essentially in the radial direction is delivered so that the problems described above an undefined location and undefined movement of the Workpiece relative to the grinding wheel, support and regulating wheel cannot occur. You can also do this the removal in the area of the cylindrical sections separately from Adjust the removal in the shoulder area, since these two removals can be effected in successive steps.

However, it is in a preferred embodiment of the invention possible, the delivery movement in the second step an additional to superimpose radial movement component, such that also in second step an oversize in the area of the cylindrical sections is removed.

This measure has the advantage that a second step Radial force is exerted on the workpiece, so that also in the second step is to securely place the workpiece on the regulating wheel is guaranteed.

In a further variant of the invention, the first Step a first intermediate step is carried out, in which the Grinding wheel again in a substantially radial direction Workpiece is moved away, and after the second step a second intermediate step in which the grinding wheel in a substantially radial direction again on the Workpiece is moved.

This measure has the advantage of further differentiation the delivery movement different areas of the The workpiece is approached in a defined manner and the measurement in these areas in different steps and therefore different is adjustable adjustable.

In preferred embodiments of the invention, the Angle between 10 ° and 30 °.

This dimensioning range has proven to be optimal in practice proven.

In further preferred embodiments of the invention the workpiece axis is kept stationary and the grinding wheel in moved radially and in the axial direction relative to the workpiece axis.

This measure has the advantage that a simple constructive Design of the required grinding machine is possible, in which the movement processes by means of a cross slide or the like the grinding wheel and thus all movement processes between grinding wheel and workpiece. can.

The infeed movement is preferably by overlaying Sledge movements generated, all possible combinatorial Swap directions are possible.

Further advantages result from the description and the attached one Drawing.

It is understood that the above and those below Features to be explained not only in each case specified combination, but also in other combinations or can be used alone, without the scope of to leave the present invention.

Fig. 1

eine äußerst schematisierte Draufsicht auf ein Ausführungsbeispiel einer erfindungsgemäßen Schleifmaschine;

Fig. 2A

einen Ausschnitt aus Fig. 1 in stark vergrößertem Maßstab;

Fig. 2b

ein Vektordiagramm zur Erläuterung der Anordnung gemäß Fig. 2A;

Fig. 3A und 3B

eine weitere Schemazeichnung zur Verdeutlichung des erfindungsgemäßen Verfahrens in zwei unterschiedlichen Verfahrenschritten;

Fig. 4A und 4B

die Vorgehensweise gemäß Fig. 3A und 3B in weiter schematisierter Darstellung;

Fig. 5A bis 5D

eine Darstellung ähnlich Fig. 4A und 4B zur Erläuterung einer Variante des dort dargestellten Verfahrens.

Exemplary embodiments of the invention are shown in the drawing and are explained in more detail in the following description. Show it:

Fig. 1

an extremely schematic plan view of an embodiment of a grinding machine according to the invention;

Figure 2A

a section of Figure 1 in a greatly enlarged scale.

Fig. 2b

a vector diagram for explaining the arrangement of FIG. 2A;

3A and 3B

a further schematic drawing to illustrate the method according to the invention in two different method steps;

4A and 4B

3A and 3B in a further schematic representation;

5A to 5D

4A and 4B to explain a variant of the method shown there.

In Fig. 1, 10 designates as a whole a grinding machine for centerless oblique plunge grinding.

The grinding machine 10 comprises a first carriage 12 which designed as a cross slide. The first carriage 12 is thus linearly adjustable along the axes indicated at 14, namely the so-called Z-axis and the so-called X-axis.

A grinding wheel 16 with associated drive 18 is on the first carriage 12 attached. An axis 20 of the drive 16 is inclined to the Z axis by an angle α. The angle α is preferably in the range between 10 ° and 30 °.

The grinder 10 further includes a second carriage 22, which is also designed as a cross slide and thus along the axes indicated at 24, namely the Z axis and the X axis is movable. As in Fig. 1 with X 'and a dashed line Indicated by a double arrow, the first carriage 12 insofar as can also be moved along the axis, which is not under at a right angle to the longitudinal axis of the grinding machine 10 runs. The second carriage 22 carries a regulating disk 26 with drive 28. The axis of the regulating wheel 26 is designated 30.

There is a support 32 between the slides 12 and 22 for a workpiece 34. The workpiece 34 is rotationally symmetrical Shape and has a longitudinal axis 35. The workpiece 34 lies in the axial direction at the upper end in FIG. 1 at one axial stop 36. The stop 36 can be used for this purpose a spherical or rotatable contact surface for the workpiece 34 exhibit.

It is also important that the workpiece 34 has a shoulder 38, which can be radial or oblique.

Finally, FIG. 1 also shows a dressing device 40 a first dressing tool 42 for the grinding wheel 16 and a second dressing tool 44 for dressing the regulating wheel 26.

The dressing device is located in the illustrated embodiment 40 on the edition 32 and is therefore fixed in space. By Movement of carriages 12 and 22 along axes 14 and 24, respectively a dressing process can be carried out. In Fig. 1 is in solid lines that the grinding wheel 16th by moving along the axes 14 with their circumference to the first dressing tool 42 was brought in to there in itself perform a dressing process in a known manner. 1 is with dash-dotted lines shown the state in which the grinding wheel 16 is in engagement with the workpiece 34 or is just being fed towards the workpiece 34.

In Fig. 1, 46 is also a longitudinal median plane, the runs parallel to the Z axis and on both sides of it Carriages 12 and 22 are arranged. The workpiece 34 is located on the support 32 essentially in the longitudinal median plane 46.

2A, the conditions are at Workpiece 34 shown again in further details.

It can first be seen that the workpiece 34 is a thin cylindrical Section 50, a conical transition section 52 and has a thicker cylindrical portion 54. The conical section 52 thus forms a shoulder between the cylindrical sections 50 and 54. The conical section 52 is only to be understood as an example, because in its place a radial ring shoulder could also be provided. The The transition between sections 50 and 52 is denoted by 56.

The regulating disk 26 is correspondingly larger cylindrical section 60 and a smaller cylindrical Section 62 provided. Sections 60 and 62 are in contact the cylindrical portions 50 and 54 of the workpiece 34.

The grinding wheel 16 is in its shape to the shape of the workpiece 34 adapted. Depending on the angle α points the grinding wheel 16 has a first conical section 66, one second conical section 68 and a third conical Section 70 on. These sections are designed so that they just abut against sections 50, 52 and 54 of the workpiece 34 can be brought by the generatrices of the Lay sections 50/66, 52/68 and 54/70 together. In the Grinding wheel 16 is the transition between sections 66 and 68 at 72.

In order to grind the workpiece 34, the grinding wheel 16 would have to from the position shown in Fig. 2A along an arrow 74 approach the workpiece 34 and then around the desired one Allowances are delivered.

The arrow 74 shows that the approach and infeed direction runs inclined to the longitudinal center plane 46. As Fig. 2B shows, the arrow 74 thus decays into a radial component 74x along the X axis as well as in an axial component 74z the Z axis.

According to the invention, the infeed movement is now carried out in several Steps performed, with predominance during each step or is delivered completely axially or radially.

This is illustrated in more detail in FIGS. 3A and 3B.

It can be seen in FIG. 3A that the workpiece 34 has an overall oversize A has, according to the invention divided into two partial measurements A1 and A2 becomes.

In a first infeed step, the grinding wheel 16 is now delivered in the radial direction to the workpiece 34, as in 3A indicated by an arrow 74/1. So get there first substantially engaging sections 66 and 70 Measurement areas 80 and 82 at sections 50 and 54. In one The second method step according to FIG. 3B is now essentially axially delivered, as indicated by an arrow 74/2. This feed movement can run exactly axially, but it can still include some radial component, as in Fig. 3B shown. In this way, an oversize 84 is essentially Section 52 of the workpiece 34 removed and, if a radial Component is provided, further measurements 86 and 88 in areas 50 and 54.

In this way it is achieved that according to the first step 3A, the workpiece 34 is initially essentially radial Direction is loaded, so that a defined position and movement of the workpiece 34 on its support 32 also ensured is like a secure system on the regulating wheel 26.

The above process is illustrated in Figures 4A and 4B shown again schematically. With P72 and P72 / 1 is symbolically the movement of the grinding wheel in the area of the transition 72 shown. The movement is as shown in Fig. 4A strictly radial and leads to P72 / 1. In the second step according to 3B and 4B, the grinding wheel 16 is essentially Travel axially from P72 / 1 to P72 / 2.

A refined variant is shown in FIGS. 5A to 5B in one Representation similar to FIGS. 4A and 4B.

Then the grinding wheel 16 or the circumference 72 remains unchanged in the first step in the radial direction from P72 to P72 / 1 delivered. Now, however, an intermediate step according to FIG. 5B inserted, in which the grinding wheel of P72 / 1 by a small The amount is withdrawn again according to P73, i.e. from workpiece 34 is driven away. From this withdrawn position 5C an axial infeed from P73 to P74 is carried out, while then in a further intermediate step Fig. 5D again in the radial direction from P74 to P75 becomes.

In this way it is possible to measure in the area of the transitions between the ranges 50 and 52 as well as 52 and 54 exactly grind out.

Claims (19)

Process for centerless oblique plunge grinding a workpiece (34) rotatable about a first axis (35) with essentially cylindrical sections (50, 54) of different diameters and at least one between the sections (50, 54) lying shoulder (52), one of which is conical in size Grinding wheel (16) around its, to the workpiece axis (35) rotated a predetermined angle (α) inclined axis (20) and engages with at least one generatrix of the circumference is brought with the workpiece (34), and wherein furthermore the grinding wheel (16) and the workpiece (34) by a predetermined oversize (A) relative to each other are characterized in that in at least two steps are delivered, with a first Step (74/1) essentially in the radial direction (X) and in a second step (74/2) essentially in axial direction (Z) is delivered such that in the first Step essentially the oversize (80, 82) in the area of the cylindrical sections (50, 54) and in the second Step essentially the measurement (84) of the shoulder (52) is removed. A method according to claim 1, characterized in that the infeed movement in the second step (74/2) additionally a radial component of motion is superimposed, that in the second step, an oversize (86, 88) in the area of the cylindrical sections (50, 54) removed becomes. A method according to claim 1 or 2, characterized in that that after the first step, a first intermediate step is carried out in which the grinding wheel (16) in substantially radial direction again from the workpiece (34) is driven away and that after the second step second intermediate step is carried out in which the Grinding wheel (16) in a substantially radial direction is driven back to the workpiece (34). Method according to one or more of claims 1 to 3, characterized in that the angle (α) is between 10 ° and dimensioned 30 °. Method according to one or more of claims 1 to 4, characterized in that the workpiece axis (35) is spatially fixed held and the grinding wheel (16) in radial (X) and in the axial (Z) direction relative to the workpiece axis (35) is moved. Method according to one or more of claims 1 to 5, characterized in that the infeed movement the grinding wheel (16) relative to the workpiece (34) Overlay of slide movements is generated. A method according to claim 6, characterized in that a first carriage movement (X) at a right angle to the workpiece axis (35). A method according to claim 6, characterized in that a first carriage movement (X ') under a sharp one Angle to the workpiece axis (35). Method according to one or more of claims 6 to 8, characterized in that a second carriage movement (Z) parallel to the workpiece axis (35). Grinding machine for centerless oblique plunge grinding on a workpiece rotatable about a first axis (35) (34) with essentially cylindrical sections (50, 54) of different diameters and at least one shoulder lying between the sections (50, 54) (52), one of which is conical in circumference Grinding wheel (16) around its, to the workpiece axis (35) rotatable a predetermined angle (a) inclined axis (20) arranged and with at least one surface line of the circumference can be brought into engagement with the workpiece (34), and wherein further the grinding wheel (16) and the workpiece (34) by a predetermined allowance (A) relative to each other are deliverable, characterized in that means intended for delivery in at least two steps are, in a first step (74/1) essentially in the radial direction (X) and in a second Step (74/2) essentially in the axial direction (Z) is delivered in such a way that in the first step essentially the allowance (80, 82) in the area of the cylindrical Sections (50, 54) and in the second step essentially the measurement (84) of the shoulder (52) is removed. Grinding machine according to claim 10, characterized in that the feed movement in the second step (74/2) additionally a radial movement component can be superimposed, such that an oversize (86, 88) removed in the area of the cylindrical sections (50, 54) becomes. Grinding machine according to claim 10 or 11, characterized in that that after the first step, a first intermediate step is executable in which the grinding wheel (16) again in a substantially radial direction from Workpiece (34) is moved away and that after the second Step a second intermediate step is executable in which the grinding wheel (16) in substantially radial Towards the workpiece (34) again. Grinding machine according to one or more of claims 10 to 12, characterized in that the angle (α) between Is 10 ° and 30 °. Grinding machine according to one or more of claims 10 to 13, characterized in that the workpiece axis (35) fixed in space and the grinding wheel (16) in radial (X) and in the axial (Z) direction relative to the workpiece axis (35) is movable. Grinding machine according to one or more of the claims 10 to 14, characterized in that the grinding wheel (16) and the workpiece (34) relative to each other can be moved by superimposing slide movements are. Grinding machine according to claim 15, characterized in that a carriage (18) along a first axis (X) under can be moved at a right angle to the workpiece axis (35) is. Grinding machine according to claim 15, characterized in that a slide along a first axis (X ') under can be moved at an acute angle to the workpiece axis (35) is. Grinding machine according to one or more of claims 15 to 17, characterized in that a carriage (18) along a second axis (Z) parallel to the workpiece axis (35) is movable. Grinding machine according to one or more of claims 16 to 18, characterized in that the carriage (18) the grinding wheel (16) carries.

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