WO2006002862A1

WO2006002862A1 - Tool and device for machining workpieces

Info

Publication number: WO2006002862A1
Application number: PCT/EP2005/006924
Authority: WO
Inventors: Michael Grimm; Gregory Aaron Hyatt
Original assignee: Kennametal Inc.
Priority date: 2004-07-06
Filing date: 2005-06-28
Publication date: 2006-01-12
Also published as: DE202004015343U1

Abstract

The invention relates to a tool for machining a workpiece (6) comprising bearing surfaces (22, 23) that are rotationally symmetrical about a main bearing axis (21) and are eccentric in relation to said axis, in particular the main bearing and the lifting bearing of a crankshaft or camshaft. The invention provides a tool (1) comprising a disc-type tool carrier (2), around the periphery of which various machining bits (3 to 6) are arranged, a number of identical first machining bits (3, 4 or 5) and a number of identical second machining bits (4, 5) being provided. A corresponding machining device (20) comprises displaceable headstocks (25) in a machine bed (24) for clamping and rotatively bearing the workpiece (6), in addition to at least one tool support (27) that is combined with a tool (1).

Description

description

Tool and device for machining workpieces

The invention relates to a tool for machining workpieces with about a main bearing axis rotationally symmetrical and eccentric for this purpose bearing surfaces, in particular main and stroke bearings of crankshafts or camshafts, with a disc-shaped tool carrier with arranged on the periphery processing inserts. It further relates to a corresponding apparatus for machining such workpieces.

Crankshafts and camshafts of motor vehicles, in particular passenger cars, are typical workpieces that have both centrally and eccentrically to a workpiece or main bearing axis lying, at least approximately rotationally symmetric surfaces. Particularly in the case of crankshaft production, the machining of the main bearings, which are centered relative to the main bearing axis, must be distinguished from the machining of the eccentric stroke bearings with respect to the main bearing axis.

In the machining itself is basically a distinction between the turning, broaching, in particular the turning or rotating lathe, grinding and milling, which in turn can be distinguished in the so-called internal milling and external milling or especially high-speed external milling. Although hereby processing methods are available, with which the machining of both the central main bearing - and in particular the center bearing of a crankshaft - and the eccentric stroke bearing and end faces of cheeks surfaces is possible, often processing with different methods is performed.

Thus, in particular the rotary lathe has prevailed for the machining of the main bearing and the center bearing, while the eccentric stroke bearings are machined with disc-shaped outer cutters. For this purpose, the rotational shaft is clamped between the crankshaft of a tool support clamped crankshaft to the 1000 revolutions per minute, whereby the rotational speed determines the cutting speed.

The spaced apart on or on the circumference of a disc-shaped tool carrier spaced cutting or processing inserts for rotational spacing increase in distance to the center of the rotatable disc-shaped tool carrier, which rotates about an axis parallel to the main bearing axis of the crankshaft axis. In this case, material is removed from the circumferential surface of the main bearings by pivoting the rotary cutting edges along the circumference of the crankshaft rotating much faster. In the event that the cutting inserts are arranged for the rotational clearances with the same distance from the center of the tool carrier, this is delivered at a predetermined feed rate radially to the respective main bearing of the crankshaft. For turning and turning, the turning room is preceded by a piercing turning process with additional cutting inserts. During the Einstechdrehens rotates only the crankshaft and thus the tool piece, while the stationary tool carrier is moved at a certain feed rate radially against the workpiece.

In particular, provided for the crank bearings of the crankshaft external milling a usually separate disc-shaped external milling cutter is used with a large number of Fräseinsetzen. In external milling, the external cutter, i. the disk-shaped tool carrier carrying the milling inserts is moved about an axis parallel to the main bearing axis of the crankshaft at the cutting speed, while the tool carrier is tracked by slowly rotating the crankshaft about the main bearing axis. In external milling, the cutting speed results primarily from the rotation of the tool, i. of the outer cutter, while the workpiece, namely the crankshaft rotates only very slowly until at least one complete revolution of the tool about the rotating surface of the workpiece to be machined, i. the crank bearing of the crankshaft is completed.

From DE 197 49 939 C2 it is known for the machining of workpieces with about a main bearing axis rotationally symmetrical and eccentric bearing surfaces, in particular for machining the main and stroke bearings of crank or Camshaft, a disc-shaped rotary Drehräumer and additionally provide a disc-shaped outer cutter in the same machine. This is to be achieved, the two processing methods for turning-turning chambers of the main bearing of the crankshaft on the one hand and the external milling of the stroke bearings on the other hand to use the same machine. The aim is to reduce set-up times and non-productive times, and in particular to avoid re-clamping the workpiece, in particular the crankshaft, to another machine. The known machine thus has two processing units, one of which takes the turning, turning or rotating lathe and the other the external milling or turn milling, especially at high speed, takes over. These at least two

Machining units with the two separate disk-shaped tool carriers are arranged on separately controllable supports, which can be displaced at least in the X direction, preferably also in the Y direction, and, if appropriate, are rotatable about the B axis.

The invention has for its object to provide a tool for machining workpieces of the type mentioned above, which allows the highest possible machine utilization. In particular, a 100% division between a main or center bearing machining and a Hublagerbearbeitung to various machines or tool support should be possible with a suitable device.

This object is achieved by a combined tool with on a tool carrier a number of the same first processing inserts and a number of identical second processing inserts. On the tool carrier expediently two different machining inserts for milling, grinding, turning or turning lathe are arranged so that a combination tool for milling and turning or turning lathe, or a combination tool for milling and grinding, or a combination - Nationwide tool for turning or rotary twisting and grinding is provided. This allows a redistribution of the processing load. Thus, for example, a machine or support utilization of 60% for one processing and 100% for the other processing can be changed in a simple manner such that a respective 80% utilization results on both machines or supports. This is ultimately achieved in that each tool carrier used can be used both as an external milling cutter and as a rotary Drehräumer or grinder or both as a rotary Drehräumer and as a grinder without tool change.

In an advantageous embodiment, the respective same machining inserts on the tool carrier are circumferentially arranged on spaced segments. In the combined milling and turning or rotary Drehräumwerkzeug the milling inserts are arranged such that their cutting edges project beyond the cutting and / or Einstechkanten the cutting inserts for turning latitudes or rotational rotation relative to the center of the tool carrier in the radial direction. This also applies to the combined rotary or rotary Drehräum- and grinding tool, in which then extend the inserts for grinding or rotary lathe the inserts for grinding relative to the center of the tool carrier in the radial direction. The lying between the segments of the same processing inserts for milling or for turning or rotary lathe segments of each other same machining inserts then serve to accommodate the other inserts for turning, turning-rotating spaces or for grinding.

Are provided to provide a preferred combined milling and turning lathe tool only milling inserts and cutting inserts for rotary lathe, they are arranged alternately on the circumference of the tool carrier. The respective segment size for rotary lathe is then selected such that adjacent milling inserts do not collide during machining of the workpiece due to rotational latitudes on the tool carrier. In particular, when machining a crankshaft while the segment size is essentially predetermined or determined by the allowance of the crankshaft. In order to achieve the largest possible number of teeth of the combined milling and turning Drehräumwerkzeugs, whose disc diameter should be as large as possible, with a tooth a milling segment and corresponds to a rotary Drehräumsegment. Advantageously, therefore, a disc diameter is greater than or equal to 500mm, z. B. 800mm.

The milling inserts are advantageously formed by detachably held on the circumference of the tool holder s cassettes with releasably held cutting plates, wherein each disk cartridge in particular four indexable inserts are provided in pairs on opposite sides of the tool carrier. Similarly, the cutting inserts for turning or rotating lathe and the inserts are held for grinding in cassettes or formed by such. An alternating arrangement of the o different machining inserts is also particularly advantageous in the combined milling and Drehräum- or grinding tool and in the combined rotary or rotary Drehräum- and grinding tool.

A corresponding device for machining such a workpiece has a machine bed with axially displaceable therein (in the Z direction) headstocks, between which the workpiece is clamped and rotatably mounted about a main bearing axis (C-axis). Each of preferably two tool supports carries such a combined disc-shaped tool carrier with peripherally different machining inserts, namely milling inserts and o this alternating rotary Drehräum inserts or grinding inserts or

Cutting inserts for clearing, in particular turning rooms or rotary lathe and this alternating inserts for grinding. The tool supports, with which the combined tools are rotatably driven about a B-axis extending parallel to the main bearing axis, are displaceable parallel to the main bearing axis in the Z-direction and transversely in the X-direction. Also, only one tool support or more, preferably similar supports can be provided.

With this device, two or more workpiece bearings can be processed simultaneously. In this case, both a main bearing and a crank bearing of a crankshaft o and with respect to the main bearing, the different processing steps of the rotary Drehräumens be processed simultaneously with one and the same combined milling and turning Drehräumwerkzeug. Similarly, the machining steps of milling and grinding and those of the rotary or rotary Drehräumens and be made of grinding. As a result, a particularly high utilization of the existing supports due to the high utilization of the individual processing steps or procedures is achieved.

Embodiments of the invention will be explained in more detail with reference to a drawing. Show:

Fig. 1 in perspective detail of a combined milling and

FIG. 2 is a sectional view of a bearing profile produced by the combination tool according to FIG. 1; FIG.

3 shows a representation according to FIG. 1 of a combined milling and turning lathe tool, FIG.

4 in a representation according to FIG. 2 a bearing profile produced by the combination tool according to FIG. 2, FIG.

5 in a representation according to Figures 1 and 3, a combined rotary

Turning and grinding tool,

6 shows a representation according to FIGS. 2 and 4 of a bearing profile produced by the combination tool according to FIG. 5, and FIG. 7 shows a device according to the invention for machining workpieces with two combined tools according to FIGS. 1, 3 and / or 5 ,

Corresponding parts are provided in all figures with the same reference numerals.

The tool 1 shown in Figures 1, 3 and 5 comprises a disc-shaped tool carrier 2, which is peripherally provided with machining inserts 3, 4, 5. 1 shows in detail a combined milling and grinding tool with milling inserts 3 and grinding inserts 5. FIG. 3 shows a combined milling and turning (rotary) spaceinwerkzeug with milling inserts 3 and rotary or rotary Drehräumeinsätzen 4. Fig. FIG. 5 shows a combined rotary lathe and grinding tool with rotary lathe inserts 4 and with grinding inserts 5. A workpiece 6 to be machined shown in FIG. 7 may be a crankshaft or a camshaft. Fig. 1 shows a detail of the combined milling and grinding tool 1 with a corresponding tool carrier 2, wherein only a few segments Si and S2 of the tool 1 are shown. Each segment Si is associated with a milling insert 3, while each alternating segment S _{2 is assigned} a grinding insert 5. The milling inserts 3 are formed by detachably held on the circumference of the tool carrier 2 cartridges 7 with therein in turn releasably held indexable inserts 8. In this case, on both sides of the tool carrier 1 each two indexable inserts 8 are arranged in pairs opposite each other and offset from each other. Likewise, the grinding inserts 5 are formed by on the circumference of the tool carrier 2 releasably held cartridges 9 held therein grinding elements 10. The alternating placement of the tool carrier 2 with the different processing inserts 3, 5 is expediently carried out with the cutting plates 8 and the grinding elements 10 already contained cassettes 7 and 9 respectively.

FIG. 2 shows the combined milling and grinding tool 1 in machining engagement of one of the grinding inserts 5 in a bearing profile 11 of the workpiece or the crankshaft 6. The bearing profile 11 is thereby produced by milling by means of the respective milling insert 3 of the tool 1. The cutting speed results from the rotating disk-shaped tool 1, wherein the crankshaft rotates slowly in the feed direction. The profile of the grinding inserts 5 (grinding profile) is smaller in diameter than the profile of the milling inserts 3 (milling profile). In width, the segments S ₂ can be calibrated with the grinding inserts 5 to finished or narrower to then, for. B. via CNC to produce the bearing width of the bearing profile or the bearing 11. The rotating crankshaft 6 generates the cutting speed during grinding, wherein the grinding segment S ₂ is brought to the respective abrasive insert 5 drehräumartig by the feed rotation of the tool holder 2 or -mäßig engaged and a ground and surface-precise finishing, for example, a mirror surfaces of the bearing 11 and thus a Passport bearing generated.

Similarly, Fig. 3 shows a detail of the combined milling and turning (rotary) - Räumwerkzeug 1 with a corresponding tool carrier 2, with only a few Segments Si and S _{2 of} the tool 1 are shown. Each segment Si is associated with a milling insert 3, while each alternate segment S _{2 is associated with} a rotary Drehräumeinsatz 4. The alternating between the segments

5 _{1 of} the milling inserts 3 lying segments S _{2 of} the rotary (rotary) spaceinsätze 4 are chosen in terms of their size such that the rotary lathe, in contrast to the milling tool 1 and the corresponding main bearing of the crankshaft 6 with high Rotates rotational speed, the adjacent milling inserts 3 do not collide, ie just not also with the workpiece 6 are engaged.

The rotary Drehräumeinsätze 4 have detachably held cutting plates 12 and

Einstechplatten 13, from rotary Drehräumsegment S ₂ to rotary Drehräumsegment

5 ₂ alternately on the one or the other side of the tool carrier 2 protrude beyond the respective support surface or plane. The cutting plates 12 on the one hand and the puncture plates 13 on the other hand are in turn releasably held in the circumference of the tool carrier 2 releasably held cartridges 14 to form the respective rotary Drehräumeinsatzes 4.

Fig. 4 shows a by rotary (rotary) clearing by means of the respective rotary (rotary) spatial use 4 of the combined milling and turning (rotary) Räumwerkzeug 1 generated bearing profile 11 of the crankshaft 6. Fig. 4 also shows a by milling by means of the respective milling insert 3 generated cheek profile 15 of the crankshaft. 6

Fig. 5 shows a detail of the combined rotary (rotary) space and grinding tool 1 with a corresponding tool carrier 2, again only a few segments Si and S _{2 of} the tool 1 are shown. Each segment Si is associated with a rotary (rotary) space insert 4, while each alternating segment S _{2 is assigned} a grinding insert 5. The rotary (rotary) space inserts 4 are in turn formed by detachably held on the circumference of the tool carrier 2 cartridges 14 therein in turn releasably held cutting or Einstecheinplatten 12 and 13 respectively. Likewise, in turn, the grinding inserts 5 are formed by detachably held on the circumference of the tool carrier 2 cartridges 9 held therein grinding elements 10. Fig. 6 shows again by a rotary (rotary) clearing by means of the respective rotary (rotary) space insert 4 of the combined milling and turning (rotary) Räumwerkzeugs 1 generated bearing profile 11 of the crankshaft 6. Fig. 6 also shows the combined Rotary (rotary) spatial and grinding tool 1 in the machining engagement of the respective s grinding insert 5 in the bearing section 11 of the crankshaft. 6

The cutting speed results from the rotating crankshaft 6, wherein the disk-shaped tool carrier 2 rotates slowly in feed rate. The profile of the grinding inserts 5 and the grinding cassettes 9 (grinding profile) is in o diameter above the profile of the rotary (rotary) space inserts 4 (Drehräumprofil) before. In width, the segments Si can be calibrated with the rotary (rotary) space inserts 4 to finished or narrower, to then, for. B. via CNC ₁ to produce the bearing width of the bearing profile of the bearing 11. The rotating crankshaft 6 generates the cutting speed during grinding while the crankshaft 6 rotates slowly at its feed speed. The abrasive segments S ₂ with the respective

Grinding inserts 5 produce a dimensional and surface precision finishing, for example, a bearing journal cylinder of the bearing 11th

To form the combined milling and grinding tool 1 or the combined o milling and rotating (rotary) raumeinwerkzeugs 1 or the combined rotary (rotary) spatial and grinding tool 1 with the milling inserts 3 and the rotary or rotary Drehräumeinsätzen. 4 and / or the grinding inserts 5 may suitably be used similar tool carrier 2. For this purpose, it is equipped accordingly with the respective cassettes 7, 14 and 9 alternately. 5

In the combined milling and grinding tool 1 shown in FIG. 1 and in the combined milling and turning (rotary) raumeinwerkzeug 1 shown in FIG. 3, the milling inserts 3 are arranged such that their cutting edges 16, the cutting edges 17 of the cutting inserts 4 for Turning spaces or rotary turning spaces o or the inserts 5 project radially for grinding relative to the center of the tool carrier 2. Similarly, in the combined rotary (rotary) spatial and grinding tool 1 of FIG. 5, the cutting inserts 4 are arranged for rotation (rotation) space such that their cutting edges 17 radially project beyond the inserts 5 for grinding, relative to the center of the tool carrier 2.

7 schematically shows a device or machine 20 for machining the workpiece 6 with about a main bearing axis 21 rotationally symmetrical and eccentric bearing surfaces, in particular the main bearing 22 and the lifting bearing 23 of the crankshaft 6. The device 20 includes a machine bed 24 with therein in Z- Direction slidably arranged headstocks 25a, 25b. Between these, the crankshaft 6 is clamped and thereby rotatably supported in the direction of the arrow 26 about the main bearing axis or C-axis 21.

Two tool supports 27a, 27b of the processing device or machine 20 each carry a combined tool 1 according to FIGS. 1, 3 and / or 5, referred to below as a combination tool, for example a combined milling and turning tool 1 according to FIG to

Processing of the stroke bearing 23 or the main bearing 22 of the crankshaft 6 delivered against this. The combination tools 1 are rotatably driven drivable on the respective support 27a, 27b in the direction of the arrow 28 about the B-axis 29 offset parallel to the main bearing axis 21. The tool supports 27a, 27b are also in the direction of the arrow 30, i. displaceable in X-direction. Furthermore, the

Tool supports 27a, 27b in the direction of the arrows 31, i. displaceable in the Z direction.

When machining the crankshaft 6, depending on the processing method, the tool 1 is driven about the center or center point in a rotational movement. For external milling, the milling inserts 3 with the workpiece 6 to be machined, i. in particular a stroke bearing 23 of the crankshaft 6, delivered in the feed direction. The cutting speed then results from the number of revolutions of z. B. 1000rpm of tool 1.

With this device 20 and in particular due to the use of two combination tools, eg. B. of two combined milling and turning Drehräum¬ tools 1 can simultaneously two bearings 22, 23 of the crankshaft 6 by machining to be edited. Depending on the combination tool 1 used, for example, two bearings 22, 23 can be machined by milling, by turning-turning chambers or by grinding. Also, with the same device 20, the one bearing 23 can be machined by milling or grinding, while the other bearing 22 is machined by turning lathe or grinding, without a tool change must be made. In this case, the utilization of the machine or device 20 can be optimized, in which the load on the two tool supports 27a, 27b is distributed as evenly as possible.

Claims

claims

1. tool (1) for machining a workpiece (6) about a Hauptlager- axis (21) rotationally symmetrical and eccentric for this purpose bearing surfaces (22,

23), in particular main and lifting bearings of a crankshaft or camshaft, with a disc-shaped tool carrier (2) with angeord¬ Neten machining inserts (3 to 5), characterized in that o on the tool carrier (2) different processing inserts (3 to

6) are arranged, wherein a number of identical first processing inserts (3, 4 or 5) and a number of like second processing inserts (4, 5) are provided.

s

2. Tool according to claim 1, characterized in that the different processing inserts (3 to 5) are arranged alternately on Um¬ catch of the tool carrier (2).

0 3. Tool according to claim 1 or 2, characterized in that the respective same first processing inserts (3, 4 or 5) along the circumference of the tool carrier (2) spaced-apart segments (Si) are arranged between which segments (S ₂ ) are provided for each of the same 5 second processing inserts (4, 5).

4. Tool according to one of claims 1 to 3, characterized in that on the tool carrier (2) in addition to a number of milling inserts 0 (3) a number of cutting inserts (4) for rotating spaces or rotary Dreh¬ spaces are arranged.

5. Tool according to one of claims 1 to 3, characterized in that on the tool carrier (2) in addition to a number of milling inserts s (3) a number of inserts (5) are arranged for grinding.

6. Tool according to claim 4 or 5, characterized in that the milling inserts (3) are arranged such that their cutting edges o (16) those of the cutting inserts (4) for turning or rotating

Rotary chambers or the inserts (5) for grinding relative to the center of the tool carrier (2) protrude radially.

7. Tool according to one of claims 1 to 3, 5 characterized in that on the tool carrier (2) in addition to a number of cutting inserts (4) for turning or turning lathe rotation a number of inserts (5) are arranged for grinding.

0 8. A tool according to claim 7, characterized in that the cutting inserts (4) are arranged to rotate or rotary lathe so that their cutting edges (17) the inserts (5) for grinding relative to the center of the tool carrier (2) radially overtop. 5

9. Tool according to one of claims 1 to 8, characterized in that the machining inserts (3 to 5) as on the circumference of the tool carrier (2) releasably held cartridges (7, 9, 14) are executed.

10. Device for machining workpieces (6) with a main bearing axis (21) rotationally symmetrical and eccentric Lager¬ surfaces (22, 23), in particular main and stroke bearings of crankshaft or camshafts,

- With a machine bed (24) with axially displaceable headstocks (25) for clamping and for rotary mounting of the workpiece (6), and

- With at least one tool support (27) carrying a combined tool (1) according to one of claims 1 to 9. 0

11. The device according to claim 10, characterized in that the combined tool (1) by means of the respective tool support (27) about a parallel to the main bearing axis (21) extending axis (29) 5 is rotatably driven.

12. The apparatus of claim 10 or 11, characterized in that the respective tool support (27) parallel and / or transversely to the main bearing o axis (21) is displaceable.