GB2084909A

GB2084909A - Equipment for machining workpieces

Info

Publication number: GB2084909A
Application number: GB8123307A
Authority: GB
Original assignee: Deutsche Industrieanlagen Werk Hermann Kolb Maschinenfabrik GmbH
Current assignee: Deutsche Industrieanlagen Werk Hermann Kolb Maschinenfabrik GmbH
Priority date: 1980-07-29
Filing date: 1981-07-30
Publication date: 1982-04-21
Also published as: JPS57107713A; DD206955A1; FR2487720A1; GB2084909B; HU184092B; DE3028685A1

Abstract

The equipment comprises two units, one unit having a workpiece or pallet holder 22, the other unit 4 having at least one tool 6 acting on a respective workpiece. The workpiece unit comprises a base with a slide movable transversely to the unit 4. At least one column 21 is slidable on the slide to or from the unit 4. The holder is provided with guiding members 27, 28 for the pallet 15, 16 and is connected to a drive 7 arranged on the column for vertical working movements. The holder may have a part for tilting about a horizontal axis. The holder may be fed by a rotatable transfer device 14. The tool unit is fixed or is slidable on a base transversely to the workpiece unit. The tool unit may have side-by-side separate tool carriers each movable to or from the workpiece unit. <IMAGE>

Description

SPECIFICATION Equipment for machining workpieces, such as drilling, boring, milling etc, typically in the form of a multi-spindle machining centre This invention relates to equipment for machining of workpieces, such as drilling, boring, milling etc., typically in the form of a multi-spindle machining centre, consisting of at least two units of which the one unit has at least one pallet accommodating the respective workpieces and the other unit has at least one tool acting on a respective workpiece and of which at least the one unit is arranged movably in a structure supporting it, this unit being typically provided with drives permitting working motions in the directions of the various axes and the other unit being typically formed in the manner of a fixable block and the movable unit having a bed with at least one column arranged vertically on it.

Equipment in the nature of so-called machining centres is increasingly used for machining of workpieces, an essential feature being that the workpiece secured on the clamping unit remains clamped in place until completion or at least until a number of machining operations have been carried out.

A known piece of equipment of this type is essentially formed by two units of which the one is fixed and the other is movable. The fixed unit, frequently made in the form of a fixed block, is provided with a clamping unit, e.g. a clamping table, onto which a workpiece to be machined can be clamped. The movable unit which is capable of performing working motions in the directions of the axes, i.e. X, Y and Z is fitted with the tools to machine the respective workpiece, the tools being accommodated in a spindle of a headstock arranged to move upwards and downwards in machining the workpiece. This movable unit is formed by a column, a cross-slide supporting the column and a bed supporting and guiding these two parts. The cross-slide is mounted on the bed at right angles and is capable of being moved to and fro along the bed.The column, which in turn is mounted on the cross-slide, is capable of being moved to and fro in the longitudinal direction of the crossslide, this motion being at a right angle to the movement of the cross-slide on the bed.

These different motions of the cross-slide, column and headstock permit the workpiece to be approached at several positions and corresponding machining operations to be carried out on this workpiece. As a result, it is not necessary for the clamping of the workpiece to change in order to machine it with a complement of tools fitted to a tool changer of known type, but the workpiece may need to be unclamped only after several and/or all tools have been applied.Admittedly, it is possible with equipment of this type to effect several operations without changing the clamping of the workpiece and, by adding a pallet changing system, a sequence of workpieces can be loaded and unloaded automatically, but this type of equipment and/or machining centres is limited to an arrangement where only one workpiece is accepted and machined and, as a rule, unless multi-spindle heads are used, only one tools can be accommodated in a working spindle and driven by a main drive (cf, German Preliminary Patent Specification 24 14 615).

On this basis, it is the objective of the present invention to provide further developments of such equipment so that a plurality of machining operations, also on a plurality of workpieces, can be carried out simultaneously without the need to change the clamping and, moreover, that the machining times can be substantially reduced without the quality of the machining being affected or the tools being excessively heated during the machining operation and where removal of the chips is considerably facilitated and accurate guidance of the tools is ensured even where complex workpieces and hard materials are involved.

According to the invention, this objective is achieved in equipment of the type initially referred to by a combination of the following features: a) the movable unit is equipped with a clamping unit for a pallet accommodating at least one workpiece, b) the clamping unit is provided with guiding members for the pallet and the movable unit is provided with further guiding means for its column, c) the clamping unit is connected to a drive arranged on the column for vertical working movements (in the direction of the axis Y) of the clamping unit, d) the column is typically mounted indirectly on a bed and guided there movably for a working movement (in the direction of axis Z) at right angles to the vertical working movement (in the direcion of axis X) of the clamping unit, e) the typically immovably formed unit is typically separated from the bed and column, arranged on a separate supporting body and consists of at least one drive unit and typically of a plurality of working spindles mounted on this unit to accommodate tools, f) the bed is provided with a cross-slide and this cross-slide is arranged on the bed for a working movement (in the direction of axis X) at right angles to the horizontal working movement (in the direction of axis Z) of the column, g) the tools (working spindles) are arranged horizontally and a chip removal system is provided between the units.

These features not only provide an advanta geous solution in terms of the objective underlying the invention, but there are additonal benefits accrueing. For instance, it is possible by coupling several movable or fixed units to essentially increase the productivity of the equipment. Also this arrangement of the equipment with horizontal working spindles and a chip conveyor between the units is considered to afford a considerable advantage in that the removal of the chips obtaining is facilitated and that the chips will not remain at the workpiece where they will not only cause appreciable heating of the workpiece and the tools themselves but also obstruct the supply of coolant and lubricant.

A further advantageous development of the invention is distinguished by the fact that the clamping unit is equipped with parts of a pallet changer and that mating parts cooperating with these parts as well as clamping means for the workpiece are arranged on the pallet.

This feature offers an advantage in that the workpiece is clamped on a pallet and can be transferred with this to the respective machining operation whereby inaccuracies caused by changing the clamping several times can be obviated.

In order to facilitate clamping of the workpiece on the respective pallet and of the pallet on the clamping unit, it is a further feature of the invention that each pallet is an integral part of the clamping unit and that this pallet is capable of being loaded and unloaded into the parts of the pallet changer at right angles to the vertical movement of the clamping unit.

Another feature of the invention for the prupose of simplifying clamping consists in each pallet being an integral part of the clamping unit and in the pallets being capable of being loaded into and unloaded from the parts of the pallet changer parallel to the vertical motion of the clamping unit.

Another advantageous development of the invention consists in the clamping unit having pivot bearings on its sides extending parallel to its axis of movement and in a pallet carrier having at least two bearings trunnions to engage the pivot bearings as well as in this pallet carrier being equipped with parts of a pallet changer for which mating parts are fitted to the pallet supporting the workpieces and in the pallets together with the pallet carrier being supported on the pivot bearing in a manner permitting tilting about an axis through the pivot bearings.

This latter feature enables the workpieces to be pivotted through a large angle so that other sides of the workpieces can also be covered by the tools or tool without changing the clamping, whereby machining times can be reduced even further.

A number of typical embodiments of the invention are schematically shown in the accompanying drawings in which: Figure 1 is a side view of equipment according to the invention consisting of a movable unit and a fixed unit, Figure 2 is a plan view of the equipment shown in Fig. 1, Figure 3 is a side view of equipment according to the invention with the changing device for workpieces clamped onto pallets, Figure 4 is a plan view of the equipment shown in Fig. 2, Figure 5 is a side view of equipment according to the invention with movable units and a changing device for workpieces clamped onto pallets, Figure 6 is a plan view of the equipment shown in Fig. 5, Figure 7 is a side view of equipment having a pallet fitted to the clamping unit in a manner permitting tilting about an axis, Figure 8 is a plan view of the equipment shown in Fig. 7, Figure 9 is an end view showing specifically the non-moving unit with four slide units arranged side by side in one horizontal plane on it with tools and working spindles fitted to the slide units and a tools magazine revolving over the tools and working spindles respectively, Figure 10 is a side view of the equipment with both units shown.

The equipment 1 according to the invention for machining workpieces 2 such as for drilling, boring and milling of same is formed in the fashion of a multi-spindle machining centre and comprises essentially two units 3, 4 of which at least one unit is preferably immovable on a so-called foundation block 5 and the other unit is arranged movably on a sub-base. The units 3, 4 of which the one movable unit 3 serves for clamping workpieces 2 to be machined and the other preferably immovable unit 4 serves to accommodate and operate tools 6 for machining the workpieces are arranged relative to each other so that they mutually act upon the workpiece or workpieces respectively. To this end, the units 3, 4 are provided with drives 7, 8, 9 which move them and their tools 6 or other working means 14 and which are not always shown in the drawings and the movable units and/or their parts are guided on guiding means 10, 11 which due to their high stability and accurate machining not only afford exact guidance of the units and/or parts thereof, but also permit relative feeding of the workpiece or workpieces 2 in respect of the tool or tools 6 and viceversa. Analogously to the individual machining operations, one of the units 4, specifically the one which has the tools 6 is equipped with at least one tools and this unit can also be provided with a plurality of tools corresponding to the number of machining operations as well as at least one tool changing device consisting of a tool magazine 12 and tools changer 13 in a manner known per se.As a result of this configuration of the equipment 1 and the arrangement of its units 3, 4, the latter are capable of performing working motions conjointly or at least one of them alone in the three known directions of the axes X, Y, Z it being a matter of discretion depending on the application and the concept of the equipment to assign only specific working motions in the directions of the aforementioned axes to the individual units or to all units. According to the configuration of the equipment 1 and, analagously to this, according to the work sequences to be performed by this equipment, which frequently depend on the size of the workpiece 2 and the machining cycles applied to it, the unit 3 accommodating the workpiece or workpieces may also be equipped with a changing device 14 for pallets 1 5, 16.In such a case, the workpieces 6 can be clamped by means of appropriate holders 17, 18 onto the respective pallet 15, 16 where they remain clamped until they have been machined on the unit 1 or subsequently, are transferred with this pallet to further machining operations in order to be unclamped from the pallet again on completion of the machining. The use of the pallets 15, 16 which eliminate the usual repetition of clamping operations, also affords time-saving clamping and adjustment of the workpieces 2 relative to the tool 6 working spindle respectively so that set-up times can also substantially be reduced.

In the configuration of the equipment 1 according to Figs. 1 and 2, the movable unit 3 serves for the clamping of the workpiece or workpieces 2 and it is essentially formed by a bed 19, a cross-slide 20 mounted and movable on it at right angles to the bed, as well as a column 21 mounted and movable at right angles on the cross-slide. A clamping unit 22 on which the work-pieces 2 are directly mounted is arranged here on the column 21 in a manner permitting it to move up and down. In this configuration, the unit 4 mounting the tools 6 is arranged in the fashion of a fixed block preferably stationary on a foundation block 5 so that all working movements in the directions of the axes X, Y and Z are solely performed by the workpiece 2, i.e.

its cross-slide 20, column 21 and clamping unit 22. All parts of this unit to be moved are guided in exactly formed guiding means 10, 11 of which the guiding means on the bed 19 and cross-slide 290 may, for instance, take the form of rails and the guiding means on the column 21 may, for instance, take the form of a slotted guide. In addition to these guides, these parts are provided with drives 7, 8 which perform the individual motions according to the degee of necessary feed of the workpiece 2 relative to the tools 6.The unit 4, which is stationary here, with the tool or tools 6 fitted to it is provided with one or a plurality of revolving tools magazines which in known manner contain appropriate tools for the respective machining sequence for the work-piece 2 and from which the appropriate tool is picked up by a tool changer 13 to transfer it to the respective working spindle and back again to the tool magazine. In the case of the arrangement of the clamping unit 22 adopted here for the workpieces 2 which are only schematically shown by dash-dot lines in Fig. 3 of the drawing, the workpieces are not machined from the top but from the sides by the tools 6 so that the chips obtaining during the machining do not remain on the workpiece but drop down.For this purpose, a chip conveyor 24 is provided underneath the tools 6 to remove the chips, a possible configuration of the chip discharge being a shaft in the machine foundation and/ or floor and a discharge trough 23 arranged underneath. This is schematically shown in the drawing by dash-dot lines.

The typical embodiment of the equipment 1 shown in Figs. 3 and 4 is essentially similar to that in Figs. 1 and 2 from which it differs mainly in that a changing device 14 for pallets 15, 16 is added at the side of the movable unit 3. The changing device 14 is formed by two slotted guides 25, 26 of which each is offset against the other by an angle of 90 . This arrangement of the slotted guides 25, 26 relative to each other permits loading of the one slotted guide, e.g. 25 of the changing device with the one pallet 15 plus workpieces 2 with the pallets in a horizontal position at the time when the other slotted guide 26 of the changing device 14 is in the process of transferring another pallet 16 from or to the pallet carrier or holder 17 of the clamping unit 22 of the column 21.In order to hold the respective pallet 15 or 16 on the pallet carrier of the clamping unit 22 on the column 21, this clamping unit is also provided with slotted guides 27, 28 for the mating parts existing on the pallet. The arrangement of the workpieces 2 on the respective pallet 15 or 16 can be selected to suit the workpiece complement as on a conventional fixed unit, the machining in the case of a multiple arrangement of workpieces on such a pallet being preferably in a manner that the forces of the tools 6 acting on the workpieces balancing out to the maximum extent possible. In the case of the changing device 14 shown in this representation, only the pivoting drive 9 for the pallet change is indicated.In order to be able to move the respective pallet 15, 16 from the slotted guide 25, 26 of this pallet changer to the slotted guide 27, 28 of the pallet carrier of the clamping unit 22 or viceversa, a push-pull link, which is not shown in the drawing, is provided which, when appropriately operated, effects the change of the pallets 15, 16. The drive 7 for the upwards and downwards movement of the clamping unit 22 on the column 21 may be arranged on top of the column, with a crosshead 34 of the clamping unit guided on the column in guiding means 11, cf. Fig. 2, being moved, for instance, by means of a screw spindle.

Figs. 5 and 6 show a unit 1 where, in addition to the movability of unit 3 accommodating workpiece 2, the unit 4 accommodating tool or tools 6 is arranged to be movable at least in the direction of one axis (e.g. X).

Movability of the unit 4 mounting the tool or tools 6 appears to be desirable in this case in so far as the clamping unit 22 can be loaded with an oblong workpiece 2 or several workpieces arranged end to end in the longitudinal direction and for whose changing device 14 free space is provided at the side of the column 21.

The arrangement of the equipment 1 illustrated in Figs. 7 and 8 differs from the preceding arrangements only in that the clamping unit 22 mounted on the column 21 comprises pivot bearings 29, 30 in which the bearing trunnions 31, 32 provided on the carriers on which the pallets 15, 16 are mounted can be rotatably inserted and locked in position. In this manner, a pallet 15, 16 supporting the workpiece 2 can be tilted about an axis 33 extending through the pivot bearing 29, 30 both ways towards the column 21 permitting the side faces of the workpiece 2 to be reached also up to a degree corresponding to the tilted position by the tool or tools 6.

In the typical embodiment depicted in Figs.

9 and 10, the concept of the equipment 1 as described in the earlier embodiments has been largely retained, except that the unit 4 which preferably is arranged to be stationary is formed with a greater length and there are 4 tools 6, i.e. working spindles 8 arranged in line side by side. In conformity with the previously discussed configurations, the tools 6 and working spindles 8 respectively are preferably arranged in line in one horizontal plane, but this does not preclude the adoption of alternative arrangements especially where different positions on the workpiece 2 are to be approached. In order to facilitate approach of the tools 6 to the respective workpiece 2, the tools may each be arranged on a separate slide unit 37 which is axially slidably mounted on unit 4.Axial slidability of this slide unit 37 is preferably in the direction of axis z, a separate sliding drive being assigned to it to move it. The slide unit 37 is provided with a separate adjusting axis which is not shown in the drawing and which extends in parallel to the working spindle 8. Each slide unit 37 would be mounted on the unit 4 by means of a separate guide 38 each.

The present invention is not limited to the typical embodiments illustrated here. It is possible, for instance, to provide the loading of the clamping unit 22 with the respective pallet 15, 16 from the top instead of from the side. Also it is possible instead of the tool magazines 12 shown, for example, with a square shape, to use oval, ablong or round tools magazines and to arrange these on top of unit 4 supporting the tools 6 instead of at its side. Alternatively, it is possible with such equipment to arrange the unit 4 mounting the tools 6 so as to permit working motions also in the direction of axis X so that the column 21, which performs working motions in the direction of axis Z, could be provided with changing devices 14 on both sides. This would permit pallets 15, 16 to be pushed through, whereby linking up of units 1 would be simpler.

Claims

1. Equipment for the machining of workpieces, such as drilling, boring, milling etc., typically in the form of a multi-spindle machining centre, consisting of at least two units of which the one unit has at least one pallet accommodating the respective workpieces and the other unit has at least one tool acting on a respective workpiece and of which at least the one unit is arranged movably in a structure supporting it, this unit being typically provided with drives permitting working motions in the directions of the various axes and the other unit being typically formed in the manner of a fixable block and the movable unit having a bed with at least one column arranged vertically on it, characterized by the combination of the following, partly known, features:: a) the movable unit (3) is equipped with a clamping unit (22) for a pallet (15, 16) accommodating at least one workpiece (2), b) the clamping unit (22) is provided with guiding members (27, 28) for the pallet (15, 16), and the movable unit (3) is provided with further guiding means (10, 11) for its column (21), c) the clamping unit (22) is connected to a drive (7) arranged on the column (21) for vertical working movements (in the direction of axis Y) of the clamping unit, d) the column (21) is typically mounted indirectly on a bed (19) and guided there movably for a working movement (in the direction of axis Z) at right angle to the vertical working movement (in the direction of axis X) of the clamping unit (22), e) the typically immovably formed unit (4) is typically separated from the bed (19) and the column (21), arranged on a separate supporting body (foundation block 5) and consists of at least one drive unit (8) and typically of a plurality of working spindles mounted on this unit to accommodate tools (6), f) the bed (19) is provided with a cross-slide (2) and this cross-slide is arranged on the bed (19) for a working movement (in the direction of axis X) at right angles to the horizontal working movement (in the direction of axis Z) of the column (21), g) the tools (working spindles) are arranged horizontally and a chip removal system is provided between the units.

2. Equipment as in Claim 1, characterized in that the clamping unit (22) is provided with parts (27, 29) of a pallet changer (14) and in that mating parts (25, 26) cooperating with those parts as well as clamping means for workpieces (2) are provided on the pallet (15, 16).

3. Equipment as in Claim 2, characterized in that each pallet (15, 16) is an integral part of the clamping unit (22) and in that this pallet is capable of being loaded into and unloaded from the parts (25, 26) of the pallet changer (14) at right angles to the vertical movement of the clamping unit.

4. Equipment as in Claim 2, characterized in that each pallet (15, 16) is an integral part of the clamping unit (22) and in that this pallet is capable of being loaded into and unloaded from the parts of the pallet changer (14) in a direction parallel to the vertical movement of the clamping unit.

5. Equipment as in Claim 1, characterized in that the clamping unit (22) is formed with pivot bearings (29, 30) on the sides extending parallel to its moving direction and that at least two trunnions (31, 32) are provided on a pallet carrier to engage in the pivot bearings and in that this pallet carrier is provided with parts of a pallet changer (14) for which mating parts (26) are provided on a pallet (15, 16) supporting the workpieces (2) and in that the pallet (15, 16) is tiltably supported together with the pallet carrier about an axis (33) of the pivot bearings.

6. Equipment as in Claim 1, characterized in that the tools (working spindles 6, 8) mounted on the typically immovably formed unit (4) are arranged horizontally in line in one plane.

7. Equipment as in Claim 6, characterized in that each tool (working spindle 6, 8) is provided on a separate slide unit (37) and that each slide unit has a separate adjusting axis in parallel to its working spindle.

8. Equipment as in Claim 7, characterized in that a guide (38) extending in the direction of the adjusting axis of the slide unit (37) and, consequently, also in the direction of the axis (z) is provided for each slide unit (37) on the typically immovably formed unit (4).

9. Equipment as in Claim 6, characterized in that a tool magazine (12) running over the unit (4) is provided for all tools (working spindles 6, 8) on the unit (4) and in that the working spindles are capable of being supplied with tools from the tool magazine (12).

10. Equipment for the machining of workpieces, substantially as described with reference to any of the accompanying drawings.