DE3537009A1 - METHOD, HONING MACHINE AND HONING TOOL FOR HONING WORKPIECES - Google Patents

Description

The invention relates to a method, a honing machine and a Honing tool for honing workpieces.

DE-OS 24 60 997 describes a method according to the preamble of Claim 1 became known. For most machining areas of workpieces, in particular through holes and holes with In this case, this method works extremely well and advantageously arrested. However, it is difficult to use blind holes, drilling inward projecting frets or processing areas in which it is difficult to carry out the tool with a zone in the tool.

For machining blind holes, it is from DE-PS 25 06 243 already became known to make honing stones in such a way that you Machining diameter at the tool end, i.e. in the area of the floor of the blind hole, is slightly larger than in the rest of the area. This However, like conventional honing tools, tool works with oscillation axial drive. The greater expansion in the lower area should compensate for the missing overflow of the honing tool. At This honing tool can be used for two different groups of honing stones be provided, which are turned on by a rotating mechanism can be put. The optional expansion of various groups Pen of honing stones can according to DE-PS 24 50 686 also by axial Displacement of an expanding body in two different directions  (back and forth).

The object of the invention is a method, a honing machine and to create a honing tool with which blind holes or abge set bores machined with just one or a few honing strokes can be.

This object is achieved by the features of claims 1, 11 and 19 solved.

For workpiece bores where the machining area is the Boh the tool is drawn into the hole Honing pads retracted, then widening to the finished size taken and then the working stroke in the form of a return stroke leads. The vast majority of material removal is in this single stroke, in the area of one widening cutting zone on which a finishing or calibration zone that ensures the final dimension. These Calibration zone can be quite short.

The invention is also for honing other than Bohrungsbe work usable, for example when honing outside. Also for them The process can be advantageous for machining through holes be because the guide of the pulling driven during the working stroke Tool in the hole is very good. In this case it would Tool at least with the largest part, i.e. with the calibration and Cutting zone through the hole and advantageously from this be driven out, then the expansion and then in Return stroke processing can be carried out to the final quality. It is however also possible with largely unchanged tool setting lifts, if e.g. a certain waiter surface structure (cross-cut) is desired. The use of a before, i.e. the cutting on the side facing the machine spindle zone, arranged guide section is advantageous, but by good self-management is not absolutely necessary. Could also be slightly conical, which makes it even better self-centering works. One downstream of the calibration zone in the working direction Leading zone, which would then lie towards the end of the tool  be provided, but is particularly not necessary if the tool leaves the hole after the working stroke and into it not returning. This post-lead zone, if featured can be seen in the manner known from DE-AS 24 60 997 continuously Connect to the calibration zone to re-enter the To facilitate drilling after the calibration zone has been removed from it was driving. When processing the tool with the potash brierzone pulled completely over the processing area.

The results regarding the surface quality, dimensional and shape retention speed, tool wear and the need for aftermath position of the tool are just as good as with the tool DE-OS 24 60 997, to which reference is also made in particular in this regard men will. It can be with a fairly substantial processing allowance up to a few hundredths or tenths of a millimeter accuracy surface, size and shape, especially in straight lines can be achieved that are less than one µm. The same applies here essential advantage that bore edges, for example in the area of webs, no funnel-shaped widenings.

These and other features of preferred developments of the Invention also arise from the subclaims and the description and drawing, the individual features for yourself, alone or in groups of three in the form of sub-combinations Embodiments of the invention and also in other fields can be partially realized. Execution and application Games of the invention are shown in the drawing and are explained in more detail below. Show it:

Fig. 1 is a central longitudinal sectional view of a honing tool during the machining of a dashed line indicated bore, right next to the profile of the greatly exaggerated Honbeläge is indicated,

Fig. 2 is a longitudinal section through a strip honing tool with guide surfaces,

Fig. 3 is a cross section along the line III in Fig. 2,

Fig. 4 is a schematic longitudinal section and

Fig. 5 shows a cross section along line V through parts of a honing tool and a honing machine with two groups of honing pads.

The honing tool 11 shown in FIG. 1 has a substantially tubular tool body 12 with a bayonet mounting device 13 for a machine spindle 14 of a honing machine 15, indicated by dash-dotted lines. The spindle is rotatably and displaceably mounted in the axial direction and contains an adjusting device 16 in the form of an expandable rod axially displaceable in the spindle 14 and relative thereto.

The tool body has from its lower end 17 outgoing, in the longitudinal direction of the tool parallel surface slots 18 which are broken through in the area of the tool end to the central bore 19 of the tool body. In these slots, of which, for example, six are provided on the circumference, honing stones 20 are guided, which are provided at their lower end adjacent to the tool end 17 with very wear-resistant honing pads 21 , for example with diamond honing pads. From the upper end of the honing layer, the honing stone extends upwards over a large length range of the tool body and has an outwardly open recess 22 at its upper end, so that a hook-shaped head is formed which is suspended in a bolt 23 projecting through the slot and thus the honing stone 20 is articulated at its upper end.

The honing stones, which are held together by a tube spring 24 running around their circumference, can be turned on by an adjusting mechanism 25 , ie expanded. This consists of a bolt-like adjusting body 26 with an adjusting cone 27 at its end and leads into the central bore 19 . A screwed bolt 28 screwed into it and loaded by a return spring 29 creates the connection to the adjusting device 16 .

The adjustment cone 27 acts on inclined adjustment surfaces 30 on the honing stones and can thus pivot the honing stones outwards about the hinge pin 13 . It can be seen that the adjustment not only radially expands the honing stones, but also swivels them diagonally by a small amount, so that they are expanded more in their lower region than in the upper region.

From the right next to Fig. 1 drawn profile contour 31 of the honing layer 21 it can be seen that the honing layer has a front (upper) guide section 32 , which lies on a circle of smaller circumference, a subsequent one, which widens towards the tool end 17 , ie has a bevelled cutting zone 33 and a subsequent finishing or calibration zone 34 . The sections or zones 32 , 34 can be essentially cylindrical. Depending on the use of the tool, they can be relatively short, and the front guide section 32 may be completely absent or consist of a section of slightly less taper than the cutting zone 33 . The slope of the sections changes with the expansion. Since the wear of the honing pads 21 is usually extremely low, there are very constant conditions.

The tool according to FIG. 1 is particularly suitable for machining blind holes 40 . This bore has a recess 37 near its base 36 .

The method according to the invention works as follows:

The tool of FIG. 1 is retracted in the retracted Anstellmechanis mechanism in the bore. Thus, the diameter swept by the Honbelä gene diameter is less than the diameter of the dashed line in the drawing on a half of the drawing Boh tion 40 in the workpiece 38th The retraction can take place at an increased lifting speed, since no processing takes place when retracting. When the tool is inserted into the bore, ie the tool end 17 is short of the bottom 36 of the bore, the honing pads 21 are adjusted to a fixed value. In contrast to conventional honing tools, the tool is adjusted by axially downward displacement of the adjusting device 16 and the adjusting mechanism 25 and the effect of the adjusting cone 27 on the adjusting surfaces 30 in that the honing stones 20 are pressed outwards in their lower region with pivoting about the bolts 23 . In contrast to conventional honing tools, this setting takes place practically before the start of machining, that is, before the working stroke, ie the return stroke in the direction of arrow 39 , begins. The position of the tool remains essentially unchanged during the working stroke. The peripheral speed of the honing pads is in the range of normal cutting speeds for honing, for example in the range of 20 to 30 m / min. However, the lifting speed is considerably lower and is approximately one tenth to one thirtieth of the peripheral speed.

Zones 32 , 33 , 34 of honing coating 21 pass through the bore in succession in a single stroke and are processed simultaneously, but in succession in the axial direction from start to finish. Here, the oblique cutting zone is made spanungsarbeitet the main cerium in the range 33, while the calibration zone 34, the Kali-calibration for the exact final dimensions and the desired surface quality manages.

In the case of blind bores with a very small turn at the end of the bore, the honing pads with the three successive zones would have to be very short, which could result in the cutting and calibration zones 33 , 34 being too short despite the excellent self-guidance of the tool. In this case, it would also be possible to adjust the honing linings in such a way that the calibration zone 34 is not immediately set to the exact finished dimension when the machining begins. In this case, the lower edge 41 of the processing surface 40 of the bore 40 would be in a central region of the cutting zone or possibly even in the region of the calibration zone 34 . However, the final adjustment would then take place in such a way that the expansion to the final finished dimension has ended before the calibration zone 34 has swept over the edge 41 . There too, the condition is met that the adjustment to the finished dimension and the blocking of this dimension takes place by the adjusting mechanism before the tool with the calibration zone 34 which is decisive for the finished dimension is completely moved in the working direction 39 into the working surface 40 .

When machining is carried out with sufficient supply of cutting fluids, for example honing oils, excellent dimensional and shape retention and surface quality are achieved in a single pass. The tool leaves the machining area 35 at the upper bore end 42 . Since the rigid supports and the blocked setting do not have the tendency to "press in" elastically, the bore in the area of the upper bore end is not widened more than in the rest of the processing area, so that the shape accuracy extends over the entire processing area. In this case, it is not necessary to connect a further guide zone down to the calibration zone 34 . However, it could be provided and have a profile as indicated by dashed line 43 . It should connect continuously to the calibration zone 34 and makes it possible, if necessary, to retract the tool into the bore for a leveling stroke following the working stroke, without the bore edge 42 or the tool being damaged. This leveling stroke can be important, for example, to create certain surface properties, for example for cross grinding on the surface, ie a surface with intersecting machining marks.

At the lower end of the tool, a stop 44 in the form of an adjusting screw is also indicated, with which the downward movement of the adjusting mechanism can be blocked. It could be set according to the finished size and ensures that regardless of the exact setting of the adjusting device in the Honma machine, the expansion of the honing pads takes place exactly to the finished size. There, wear-dependent adjustment can then take place, but this is usually only necessary after several hundred workpieces. Such a readjustable finished dimension stop could, however, also be provided in the honing machine or the spindle and, if necessary, could be automatically readjusted step by step.

The tool shown in Fig. 2 corresponds in its basic construction to that of FIG. 1, to the description of which reference is made. The same reference numerals designate the same or comparable parts.

The honing stones 20 a are not pivotable with this tool, but are guided in a radially displaceable manner and are supported with two spaced-apart contact surfaces 30 on axially successive adjusting cones 27 a , which are provided on two adjusting bodies 26 a which are arranged one behind the other. These are inhibited and possibly against each other adjustable in their spacing, so that thereby the axial parallelism of the honing bars can be adjusted by a connecting bolt 50 together ver. The honing stones 20 are guided in slots 18 and are resiliently loaded inwards with upper and lower hose springs 24 . The receptacle 13 and the rest of the adjustment mechanism 25 are comparable to FIG. 1.

In Fig. 2 left and in Fig. 3 it can be seen that between the total of six honing stones 20 a guide bar 51 is fixedly arranged on the tool body 12 a . The guide pad 52 of the guide bar 51 has approximately the same length as the honing pad 21 of the honing bar 20 a . The guide pad 52 , which was also known as Panzerungsbe or wear protection coating, consists, like the honing pad 21 , of particles of great hardness and wear resistance, for example diamond particles or similar materials, which are, for example, galvanically bonded. However, the grain size is much smaller here, so that there is no significant cutting effect and, accordingly, no wear on the coating.

From the right as indicated in Fig. 2 profile 31 of the Honbelages 21 and the axially parallel substantially, ie zylinderabschnittsför-shaped contour 53 of the guide pad can be seen that due to the (increasingly drawn) superposition of the two contours of the guide pad 52, the front guide zone 32 forms, while the adjustable honing stone 20 a then takes over the cutting work in the area of the cutting zone 33 and the calibration zone 34 is formed by flattening this stone. At this time, as well as in Fig. 1, the inclination of the cutting zone 33, either through a profile of the Honbelages ation on the strip be formed or reciprocal of the oblique position of the bar, which automatically results in Fig. 1 and Fig. 2 by the Adjustment of the adjusting body 26 a can be achieved. In this case, the calibration zone 34 would be formed as a rear bevel, which in turn results in an essentially cylindrical contour when the honing stone is placed at an angle. Since this always grinds itself during operation, the wear adjustment could also be carried out by mutual adjustment of the two adjusting bodies 26 , 26 a . The contours 31 , 53 indicated in FIGS. 1 and 2 are idealized. In practice, there are rounded transitions, especially when you consider that the diameter differences shown in the drawing, which are greatly exaggerated, are in practice in the range of hundreds and thousandths of a millimeter. Also in Fig. 2 is indicated by a dashed line 43 that a rear guide zone could be provided, which connects essentially continuously to the calibration zone 34 and possibly leads back to the level of the guide pad 52 , which then protects the rear guide with its wear-resistant coating for a possible reintroduction of the honing tool.

The honing process to be carried out with FIG. 2 is the same as that described with reference to FIG. 1, with the difference that the management tasks are partially taken over by the guide strips 51 . It should be noted, however, that this tool, like the one shown in FIG. 1, is also suitable for through holes, the tool preferably being driven through the hole so far that the lower end of the machining area is in the area the guide zone 32 is located and then the processing takes place in the return stroke after the employment.

In Fig. 4 a honing tool is shown, which corresponds to that of Fig. 1 except for the changes described in the fol lowing. The pivotable in slots 18 of the tool body 12 honing stones form two groups, namely honing stones 20 b with a honing coating 21 , which extends longer from the tool end 17 upwards than a honing coating 61 of short-stroke honing stones 60 , each alternating with the honing stones 20 b are arranged on the tool body. Except for the other type of honing pads, the honing stones 20 b and 60 correspond. The short-stroke honing pad 61 is substantially shorter and has a substantially cylindrical shape or a shape that widens slightly downwards when the finished dimension is used, while the honing pad 21 of the honing stones 20 b can be profiled in accordance with FIG. 1. In the example shown, a pronounced front guide zone 32 is missing, which is possible in many applications by the good self-centering of the tool drawn during the working stroke.

The adjusting body 26 b is a cylindrical body, in which the setting bevels 27 b , 27 c are incorporated in the form of axially extending grooves with an oblique groove base. Such designs of adjusting bodies are described in principle in DE-OS 24 50 686 and 25 06 242, to which reference is made here. In the present embodiment, however, the inclined surfaces 27 c , 27 d run for the two different groups of honing stones 20 b , 60 , each in the same direction, so that with a downward axial movement of the adjusting body 26 b, both groups of strips are employed, however according to the shape of the slopes at the beginning of the expansion one after the other. For this purpose, the inclined surface 27 b is offset by starting in its near-end area with an incline-free section, then has a steeper incline and finally changes to the same incline that the inclined surface 27 c has over the entire length.

The following method is thus possible: The tool 11 c is inserted into a blind hole, and by moving the adjusting body 26 b downward, only the group of the short-stroke honing rollers 60 is started first. This is shown in the schematically indicated profile A. The honing pads 21 of the groin group 20 b do not come into engagement. However, it can be seen that the short-stroke honing 61 would have approximately the length of the calibration zone 34 . With these short stroke honing bars, a short stroke honing movement is carried out in several strokes in the area of the bottom of the blind hole. This is used to sufficiently work off very close to the bottom of the section of the machining area, which would not be possible due to the lack of space during the actual working stroke. A measuring device can be connected to the tool, for example a pneumatic measuring device 68 with a measuring nozzle 65 in the tool body. When the finished dimension is reached, the adjusting body 26 b , which is advanced axially in this part of the machining in accordance with the machining progress, has already been advanced so far that the honing pads 21 have already been turned on by the adjusting surfaces 30 b from the slope-free area have moved over the steep slope into the main setting area 66 . The honing pads 21 and 61 lie on a common circumferential line in the calibration zone 34 , so they work synchronously. When Errei chen of the finished dimension, possibly controlled by the measuring device, the actual working stroke is initiated, with the short strokes interrupted and the tool is pulled through the hole in one operation.

It is therefore an upstream short-stroke honing that blends in well with the other honing work carried out in one operation and can be carried out with an integrated tool. The two honing stone groups can also be employed in other ways. For example, each group can work for itself in the usual way for two-group honing tools, in which case the short-stroke honing bars would not be engaged during the main processing. In the embodiment according to FIG. 4, however, the honing pads 21 , 61 can always be ground in the same way during the main work stroke carried out jointly, so that reproducible conditions are always present. In the case of different wear for both tool groups, a corresponding adjustment between the two groups could be provided. The upstream short stroke honing can also be carried out with the honing stones 20 b alone, the calibration zone then being effective during the short stroke honing and replacing special short stroke honing pads. Other adjusting devices, for example the employment described in DE-PS 25 06 243 by means of a rotatable adjusting body, can be provided.

Depending on the workpiece shapes to be machined, a change in the relative lengths of the short-stroke and main honing pads 61 , 21 to one another is also possible. It is advantageous when the two groups work together that the calibration zone 44 , which is important for good dimensional stability, has a larger proportion of the grinding surface on the circumference than the other zones. This could also be provided for tools with only one group of honing pads by making the grinding pads wider in the area of the calibration zone. This is particularly advantageous in the case of workpieces that come close to the bottom or shoulder of a bore with correspondingly very short calibration zones.

The invention has been described above with the aid of strip tools been used. You can also use tools with yourself perform expandable tool body.

Fig. 4 also shows in schematic form the measuring device 68 assigned to the honing machine 15, which ends the short stroke honing when the finished dimension is reached by blocking the adjusting device 16 and the spindle lifting device 69 , both of which are shown schematically as hydraulic cylinders, from the oscillating short stroke switches the working stroke in the direction of 39 .

Claims (22)

1. A method for honing workpieces, in particular special workpiece bores with a honing tool, which has expandable honing pads, of which material is removed from a machining area in an expanding cutting zone and which, prior to the start of machining, places the finished dimension of the workpiece in a finishing zone are characterized in that the tool is retracted into the machining area with the honed linings retracted, the honing linings are adjusted there according to the finished size and are held in this position during the machining and the rotatingly driven tool is moved through the machining area in a working stroke. 2. The method according to claim 1, characterized in that that the tool with no machining intervention entering the machining area in the essentially through the entire length to be machined  the processing area is driven and the ar beitshub in a return movement of the tool to be led. 3. The method according to claim 1 or 2, characterized records that the tool for the working stroke is slower is moved axially than when retracting. 4. The method according to any one of the preceding claims, characterized in that the tool at least a second time with according to the finished dimension employed honing layer through the processing area moved and, if necessary, the honing pads at the end of processing is drawn in again. 5. The method according to any one of the preceding claims, characterized in that the tool on drive from guide covers that cannot be issued on Workpiece is guided. 6. The method according to any one of the preceding claims, characterized in that the tool before the start of the working stroke performs some short strokes. 7. The method according to claim 6, characterized in that that the short strokes at the far end of the Bear processing area. 8. The method according to claim 6 or 7, characterized records that the short strokes from another honbe lag to be executed as the working stroke. 9. The method according to any one of claims 6 to 8, characterized characterized that the short strokes under the machining adjusted progress and  then, if necessary, under control, the initiation of the Fixed dimension setting of the working stroke leads. 10. The method according to any one of the preceding claims, characterized in that the expansion of the Calibration zone to the finished dimension in the machining area is made. 11. Honing tool, in particular for carrying out the method according to one of the preceding claims, with at least one honing coating ( 21 ) which, at least in the employed state, has an expanding cutting zone and a calibration zone which can be set by a setting mechanism ( 25 ) and which can be determined in accordance with the finished dimension ( 34 ), characterized in that the adjusting mechanism ( 25 ) the honing coating ( 2 ) after the first time, without substantial processing passed through the processing area ( 35 ), but before the working stroke traveled in the opposite direction ( 39 ) to a finished dimension corresponding employment notes. 12. Honing tool according to claim 11, characterized in that it has guide linings ( 52 ) which are preferably made of a wear protection material before running as a tool axis direction, between the honing linings ( 21 ) arranged on the tool body ( 12 ) attached strips ( 51 ) are. 13. Honing tool according to claim 11 or 12, characterized in that it has two separately adjustable honing pad groups ( 20 b , 60 ), of which a short-stroke honing group ( 60 ) can be employed for performing short honing strokes and the other Group ( 20 b) is provided with the cutting and calibration zone ( 33 , 34 ). 14. Honing tool according to claim 13, characterized in that the short-stroke honing pads ( 61 ) for performing the working stroke together with the other group ( 20 b) can be determined in cutting engagement, wherein they are preferably arranged in the region of the calibration zone ( 34 ). 15. Honing tool according to one of claims 11 to 14, characterized in that the expansion of the cutting zone ( 33 ) when changing the honing pads ( 21 ) is changeable. 16. Honing tool according to one of claims 11 to 15, characterized in that it is designed as a ingot tool and that the honing coating ( 21 ) accordingly the cutting and calibration zones ( 33 , 34 ) and possibly one in the working direction ( 39 ) before Cutting zone ( 33 ) arranged guide section and a guide zone arranged behind the calibration zone ( 34 ) is profiled. 17. Honing tool according to one of claims 11 to 16, characterized in that the honing stones ( 20 ) are pivotably mounted on the tool body ( 12 ) in the manner of a one-armed lever, the pivot axis preferably being at the drive-side end of the honing stone ( 20 ). 18. Honing tool according to one of claims 11 to 17, characterized in that the adjusting mechanism ( 25 ) contains a pre-adjustable stop ( 44 ) corresponding to the finished dimension. 19. Honing machine, in particular for performing the method according to one of claims 1 to 10, characterized in that it has at least one honing tool ( 11 , 11 b ) receiving, rotatable and axially movable in one run-in stroke through the machining area ( 35 ) ( 14 ), which at least partially has an adjusting device ( 16 ) for adjusting the honing pads ( 21 , 61 ) of the honing tool ( 11 , 11 b ) to a finished dimension after the retracting stroke through the processing area ( 35 ) and Blocking this employment during the subsequent work return stroke ( 39 ). 20. Honing machine according to claim 19, characterized in that the adjusting device ( 16 ) is designed for employing two different groups of honing pads ( 21 , 61 ). 21. Honing machine according to claim 19 or 20, characterized in that the spindle ( 14 ) during the working return stroke ( 39 ) is preferably movable at a lower Axialhubge speed than in the retracting stroke, the working axial stroke speed being about a tenth to a thirtieth Circumferential speed of the honing tool ( 11 , 11 b ). 22. Honing machine according to one of claims 19 to 21, characterized in that a measuring device ( 65 , 68 ) measuring during machining is provided, which has a blocking device for the adjusting device ( 16 ) and possibly a triggering of the lifting device ( 69 ) controls to carry out the working return stroke ( 39 ).