DE2207718C2 - Copy machine tool - Google Patents

Description

The invention relates to a copying machine tool as specified in the preamble of claim 1 Genus.

The production of complex shaped workpieces, for example the production of shaped electrodes Graphite for EDM and ECivl processing Copying machine tools is complex and tedious, since the machined surfaces are usually smooth Workpieces are required that could previously only be achieved by manual finishing within the specified tolerances. Significant problems with the production of three-dimensional, more complicated molding tools for injection molding technology or electrical discharge machining, for example, provided the very precise three-dimensional detection of Model forms and the error-free transfer of the recorded values to servomotors for controlling the corresponding tool or workpiece movements.

From CH-PS 3 54 002 a mechanical-electrical curve scanning system is known, which in connection can be used with a machine tool of the specified type and its measured values, if necessary, according to a deformation can control the movements of a suitable tool. A feeler is made by one servomotor drive system in two coordinates

directions shifted iind rotated around a shaft and generates a fault chip that controls the drive system as soon as its key element, which is attached to a curve template, is deflected from a target saw. ^: When changes in direction of Schablönenkurve a sensor member of a second probe 'is an error generated panhiing ^, depart the perpendicular to the two Koofdinatenrichtungen carrier wave correspondingly rotated and a computer trigoncmetrischen activated; This computer converts the movement variables of the first sensor into control signals that are sent to the two drives for the coordinate shifts. The two sensing fingers are pressed against the surface of the cam track by spring force and allow scanning of arbitrarily extending,; possibly. closed Kuryehbahneri without tracking errors. By using only two tactile fingers, however, this system can only detect two-dimensional curves and is therefore only suitable to a limited extent for scanning three-dimensional model shapes

From US-FS 34 57 484 a Kopiervsferkzeugmaschine is known which scanner is the three-dimensional Capture the form of a template and are coupled with pulse generators, which the analog Convert output signals from the scanner into digital control signals for stepper motors. Because of the training however, the scanner with only one feeler element in each case can be used with this known copying machine tool only inadequate copying accuracy, especially when processing complex shapes Models or workpieces are adhered to.

The object of the invention is to create a copying machine tool of the type specified, which is used in When machining even complex workpieces, an exact scanning of the model, error-free «reproducibility and enables a correspondingly precise shaping of the workpiece to be machined without excessive work

This object is achieved according to the invention in connection with the features of the preamble the characterizing features of claim 1 solved

The use according to the invention of at least three scanning fingers in one scanner leads to the preservation of a correspondingly large number of different position signals that show the exact course of a flat or curved Mark the area. The digital implementation of the various analog scanners and The measured values given enable extremely sensitive and delay-free positioning control of the tool or workpiece movements with the desired effect of a very precise match the movements of these machine parts with the movements of the scanner. The constant accurate Alignment of the tool axis perpendicular to the surface of the tool to be machined finally causes an optimal tool attack on the workpiece and enables the maintenance of a high surface quality.

In an advantageous embodiment of the invention according to claim 2, the two degrees of swiveling freedom of the tool holder in the circuit of the scanner provided an analog analyzer, the establishes a trigonometric relationship between position increments and swivel angle.

In a further embodiment of the invention according to claim 4, by providing one of outer. Sensing fingers surrounding the central sensing element the size and sign of a Plächenkrümmuhg can be detected. The ^ sampler can depend on

for those of the outer touch fingers every complex

Topography of a model shape in convex and concave Dissolve areas and the tool accordingly

iThe copy machine tool according to the invention

can be used for finishing and surface finishing

ίο by fluid honing one on the same machine previously machined workpiece can be used. This surface treatment is done behind the use of Abrasives in a liquid or gas jet

■■■ or by electrochemical material removal by means of an electrolyte. While up to now a time of 16 hours was required for manual surface finishing of a steel workpiece up to a surface quality of 25 μm Hm «, a significantly better surface quality of 3 μm Hoax can be achieved in only about 45 minutes with the copying machine tool according to the invention.

Other embodiments of the invention are the subject of further subclaims.

In the following, exemplary embodiments of the invention are explained in more detail with reference to the drawing shows

F i g. 1 schematically shows an axial section of a scanning head,

, F i g. 1A shows a cross section IA-IA in FIG. 1,
'F i g. 1B shows a scanning element of the scanning head according to FIG

F i g. FIG. 2 shows a side view of a copying machine with a scanner according to FIG. 1,1A and 1B,

F i g. 3 another scanning head in a schematic **> axial section,

F i g. 3A is an end view of the scan head of FIG. 3,

F i g. 4 and 5 different positions of certain points of the scanning head according to FIG. 1,

6 movements of a tool in a schematic side view,

7 i g. 7 the circuit diagram of a device for derivation the output signals of the scanners of the heads of FIG. 1 and 3,

F i g. 7A is a circuit diagram showing the operation of the readheads; 8 shows a block diagram to explain other features of the circuit according to the invention,

9 shows a block diagram with the transfer or Transfer functions of some elements of the scanner circuits,

Figure 10 is a vertical end view of a device for the direct formation of a model,

F i g. 11 is a side view of the device according to FIG. 10,

FIG. 12 shows the scanning head of the device according to FIG. 10,

13 shows a partially sectioned side view of a further machine with additional degrees of freedom for the operation of a scanning head or tool,

F i g. 14 is a front view of the machine according to FIG.

15 shows a model duplicating machine, the scanning head of which is coupled to the tool head turret is,

F i g. 15A shows a section XVA-XVA in FIG. 15,
15B shows a side view of the coupling of the scanning head with the tool head according to FIG. 15,

16A is a schematic side view of another model copying machine, the heads of which have several

Have degrees of freedom and are coupled with each other,

16B shows a front view of the machine according to FIG. 16A,

17 is a front view of another connecting structure;

F i g. 17A shows a view XVIIA-XVIIA in FIG. 17,

18 is a side view of a head in a machine in which the workpiece or model is rotatable,

18A is a front view of the machine according to FIG. 18,

18B is a side view of a machining head for the machine according to Fig. 18,

18C is a front view of the machining head according to Fig. 18

F i g. 18D is a side view of another head; F i g. 18E a front view of the further head,

F i κ. 19 is a plan view of a device with Crank to explain the movement of the scanning head or the tool,

F i g. 20 a side view of a further copying machine tool;

F i g. 20A is a front view of the machine according to FIG. 20,

F i g. 21 is a partially sectioned side view of a finishing or surface finishing device;

21A shows another apparatus for finishing and

22 shows a block diagram to explain various functional features.

The scanning head according to FIG. 1 and 1A is used in Copy machine tools used to control the position of the tool or the workpiece, the Tool is always held with its axis perpendicular to the workpiece surface, perpendicular to a tangent to the surface in Point of intersection of the tool axis with the workpiece surface. This makes it very accurate and smooth Preserved surface that is practically free of tool marks and scratches. To do this, be the tools with multiple degrees of freedom of movement regardless of the shape of the workpiece automatically aligned to follow the shape of the model.

A signal for aligning the tool therefore has several, at least three components that correspond to the Cartesian coordinates x, y, ζ or three polar coordinates with r (radius) and two angles Φ and θ. These coordinates define a tangent for each location in space and its normal for aligning the tool. Accordingly, at least five degrees of freedom for the tool and correspondingly at least five signals for these degrees of freedom must be generated and derived from the scanner. In some cases it is useful to link the signals for the various degrees of freedom in such a way that hybrid signals for controlling the tool or workpiece result from the coordinate signals.

The output signals of the scanner can be used as part a program of an NC control can be stored, so that a program-controlled machine can be operated subsequently, simultaneously or with any desired time delay. The signals received from the scanner can also be compared with signals that characterize a soflform or have been taken from a model, to check the postform quality and to indicate errors. The scanner of FIG. 1 has a housing 101, from one end of which a pin 102 protrudes, which supports the armature 103 of a pin shown schematically in FIG. IB illustrated linear differential transformer 103a forms. The pin 102 is displaceable in a bore in the housing and can have a sliding piece 102a in order to reduce the play. The pin 102 presses on a scanning plate 104, which is always pressed tangentially against a convex surface S. A spherical segment-shaped projection 105a of the plate 104 is acted upon by the pin 102.

Four sensing fingers 105a through 105d are in cylinders 105e displaceable by piston 105 / ". The cylinders are stationary via a line 105g- with a pressurized fluid source in Connection to press the fingers down with constant force. The linear differential transformers

is 105 /, 105Λ are coupled to these scanning fingers and work with the coils and armatures according to Fig. IB together. Each sensing finger and pin 102 is on a corresponding upwardly acting tension spring iG6 hewn.

According to FIG. 4 and 5, the plate 104 is held perpendicular to the axis A of the scanning head on the surface 5 of the model and only touches it at a point Pi which is separated from a point P ₂ . This point Pi marks the intersection of the axis A with the Surface 5 and point P _{1 is} a pivot point. The finger 105a exerts a downward force F parallel to the axis A at a point a distance Lj from the point P \ . Similarly, the force F of the finger 1056 acts on the plate 104 at a distance L] from point Pt. The moment M \ in the counterclockwise direction exceeds the moment M ₂ in the clockwise direction by Fx (L \ - L ₂ ), so that the plate 104 is pivoted about the point P \ in the counterclockwise direction up to the position according to FIG Mi and M _{2 the} same are.

The finger 105a is raised from its starting position according to FIG. 4 and the finger 1056 is lowered which generates output signals from the corresponding linear differential transformers. are those indicating the orientation of the plate 104. Since four receive such output signals the orientation of the plate 104 tangent to the surface is positively determined and a tool becomes controlled accordingly Da the center of curvature of the extension 104a is exactly centered at the intersection of the axis A with the underside of the plate 104, when the latter is perpendicular to the fingers 105a to 105d and the pin 102, the piaite can pivot on the surface without axial displacement of the center c ken. In general, however, the movement will cause a displacement from point P \ to point P, which corresponds to a vertical displacement ΔΖ. This axial displacement is detected by the pin 102 and its differential transformer

The composite signal characterizes the swiveling of the normal / V to the axis A and can be expressed in signals of the Cartesian coordinate system, in geometric signals obtained from it, in polar signals or in any synthesis or hybrid combination. link. The position of the normal N is converted, together with the shift ΔΖ, into a similar normal deviation shift of a tool 107 in its holder 108 in order to shape the workpiece surface W τα (FIG. 6). If that The input signal of the tool is a Cartesian coordinate signal], a slide can move the axis T \ to the left in T ₂ by a distance AX , the pivot point of the tool 107 by a distance ΔΖ

Lower the tool and rotate or swivel the tool around the axis Cum by an angle ΔΘ in order to position it in alignment with the normal to the workpiece surface W. Of course, in the case of a three-dimensional shape, a rotation about the axis D by the angle ΔΘ 'is also necessary. The distance Ϊ of the center point C or the axis D from the workpiece is contained in the output signal of the differential transformer of the pin 102. Four to five signals are sufficient to align the tool perpendicular to the workpiece surface.

The scanning head according to FIG. 3 differs from the scanning head according to FIG. 1 by eliminating the plate 104 to define the tangential surface. The sensing fingers 205a, 205c, 205c / are arranged closely adjacent at the corners of a square and form a cage for the central pin 202. The sensing fingers 205a to 205c / are curved outwards and upwards and carry magnet armatures 203a, 2036, which with the coils of the linear differential transformers 203a ', 203b' , etc. cooperate. The sensing fingers are suspended from coil springs 206a, 2066. The pin 202 carries the armature 203, which works together with the linear differential transformer 203 ', and is suspended from the spring 206. In the embodiment according to FIG. 1, the plate 104 is tangential only at one point on the surface, and the output signals of the linear differential transformers exclusively determine the normal to the tangential plane at this point. In the case of complex shapes, the plate 104 can bridge two or more peaks, so that their position does not correspond to the tangential plane at a peak. In this case the system of FIG. 3 and 3A can be used, in which the fingers 205a to 205c / are sufficiently closely adjacent and define a fictitious tangential plane from which the normal position can be derived.

The embodiment according to FIG. 3 can also be used to control the tool, using the fingers 205a to 205c / are driven by servomotors into which a control signal is fed from a scanner and which will position a floating housing 201 around an in place of the pin 202 Align the tool in a normal to the surface. The tool can have an electrode for electrical discharge machining or electrochemical machining or a cutting tool, e.g. B. a milling cutter.

The device according to FIG. 2 to reproduce a model shape can be used to manufacture electrodes for EDM or ECM systems. The device has a scanning head 301 with externally arranged fingers 305a, 3056 etc. and a central pin 305, as in the scanner according to FIG. 1 and 3. The scanning head 301 can be displaced on a rail 310 in the horizontal direction 301a and is displaceable by columns 310 'on a base part 310 ″ above a cross slide 311 and a table 3116 slidable parallel to the rail 310 The columns 310 * can be provided with lead screws to raise and lower the scanning head 301. The carriage and head positioning devices allow the head to be positioned at any point on the model S. Such a positioning device uses the three Cartesian x, y and z coordinates. A polar coordinate system can also be used to position the scanner at any point. The movements of the model are controlled by a programmer 320 which controls the position of the model coordinated with that of the workpiece W and by a timer, e.g. en clock pulse generator 320a, is activated. The output signals from the scanning head 301 are transmitted to a signal discriminator at 301a, e.g. B. an analyzer 321, which converts the signals of the individual scanning fingers into movements of a tool T to the tool in a normal to

ίο to align the surface in the appropriate point. The analyzer 321 has three outputs 321a, 3216 and 321c corresponding to the three orientation coordinates of the tool T.

The tool, a milling cutter, is rotated about its axis T ₁ by a motor 322 in the head, which is supplied with electrical energy through lines not shown. The head can be pivoted about an axis Ha perpendicular to the plane of the drawing, namely by means of a pinion 322a which meshes with an arcuate rack 3226 which rotates on the axis Ha. In addition, the rack / pinion / head system 322, 322a and 3226 can be shifted vertically in the direction of the arrow V in the x or y coordinate. For this purpose, the slide 322c is mounted on a vertical guide column 322c /. The vertical drive can be controlled by a signal from analyzer 321. Another signal from the analyzer J? L controls a lead screw 322e around the. To move the holder 322 / to the column 322c / and thereby move the tool and the workpiece relative in the z-coordinate. The twist; The ng of the head about the axis Ha is controlled by an on-Signalr.l of the analyzer 321, while a further signal rotates the head assembly about a vertical axis in the direction of arrow Hb .

The workpiece W is fastened to a compound slide 323, the parts 323a and 3206 of which can be displaced in the x or / coordinate; the compound slide can have a diameter if a rotary movement is desired.

• Signals generated by the scanner can move the tool Tin to a position in which its axis T is perpendicular to the fictitious tangential plane of the workpiece surface (see Fig. 6).

Fig. 7 shows part of a signal analyzer for a scanner with a linear interference amplifier 403a which cooperates with the armature 4C3 of one of the fingers 105a- d . The linear differential amplifier 403a has an input coil 403a 'and two output coils 403a "and 403a'". An alternating current source 421 a of the analyzer 421 is connected to the coil 403 a ′ and supplies electrical current for the center tap of the differential transformer via an isolating transformer 4216.

Each coil 403a "and 403a '" is connected in series with the secondary winding of the isolation transformer 4216 with rectifier diodes 421c and resistors 421 d 421 e capacitors are connected to the output resistances. The analyzer 421 after

so F i g. 7 is a phase discriminator which generates an output signal corresponding to the change in position of armature 403 from its central position. and 403 "decreases. A phase shift signal is integrated via the network 42Ie, 421d and fed into the amplifier 424 as an analog signal of the shift

the armature 403 moves in the opposite direction moves, an analog signal is fed to the other input of amplifier 424, which is a common Analog servo amplifier can be. The amplified signal is fed to a servomotor 424a, which is a Pneumatic system shut-off member 424b controls the finger pressing against the model. The servomotor 424a is part of a feedback loop that according to the principles of local servo control ensures that the output signal always reflects the position of the Indicates scanner. Another output signal is derived at 424c and can be fed into the servomotor fed in to control the tool.

In Fig. 7A shows a modification of the basic circuit of FIG. 7, with each of the output signals of resistors 421c / for a pair of samplers resp. whose armature 503a and 503b is fed into a comparator amplifier 524 in order to achieve a relative displacement of the two scanners and thus the inclination of a line that connects the tips of the scanners with the central position connects, to define. Here, too, the output signal is fed into the servomotor 524a and thus into a feedback path 524b to the samplers. The control signal for rotating the head according to the inclination the tangential plane can then be turned into one of the servomotors of the head at 524c, as described above, be fed in. The systems according to FIG. 7 and 7A are in the block diagram according to FIG. 8 shown where the Sampler position is derived at a block 603, the output signal as a phase difference in a Phase discriminator 621 is fed, the analog output signal is amplified at 624. That The analog signal is converted into a digital signal by an analog-to-digital converter 624c / and the controller of the scanner is carried out by a pulse-modulated servomotor 624a. The digital pulse train also controls a tool stepper motor 624c. The servomotor 624a is fed back at 6246.

9 shows the tool control according to the invention as a block diagram. The input signal from the circuit 7, 7a or 8 is a position signal shown as block 703 in the form of an analog voltage or an analog current a * This position signal is processed in a circuit 725 with a suitable transfer function to determine the angle of inclination Q _u from the relative displacement of the two scanning fingers and to calculate from their distance L as the difference to the original angular position θ ,, ο. The result is an analog output signal which represents the angle of inclination of the tangential plane and which is fed via the analog-digital converter 724c / the servomotor 725a, which controls one of the positioning movements of the tool.The feedback path 725b creates the initial condition for the next control process. The input signal L is a coefficient input signal z. B. a coefficient potentiometer, which characterizes a constant of the system, such as. B. the distance between two scanners, or a variable from which the angle of inclination can be derived (see Fig. 6). In order to acidify the workpiece positions, the angle of inclination is converted into output signals A _x and A _z using trigonometric relationships in block 725c, which in turn are converted into pulse sequences by analog-to-digital converters 725t / and 725e, which control servomotors 725 / and 725 ^, which position the chutes so that the processing location is set according to the degree of inclination.

In Fi g. '0,11 and 12 is a copy tool machine

ne is shown which has a frame 830 with a stand 830a and a dovetail guide 830b for a horizontal cross slide 830c, which is in the K direction by a lead screw mechanism with a Servomotor 830c / is displaceable (see Fig. H). This compound slide 830c carries a table 831, which is shown in A "direction (Fig. 10) by a lead screw arrangement (not shown) and a servomotor 831a is displaceable. The table guide 831b corresponds to the guide 830b. The workpiece t / and the model 5 are on the table 831 stretched.

A stand 83Oe extends upward from the frame (Fig. 10) and forms a vertical guide in the a scanner carriage 832 is vertically displaceable in the Z direction by a lead screw 832a, which is by a Servomotor 832b is driven. The carriage 832 carries a cranked arm 832c (Fig. 12), of which the Pickup 801 hangs down. The scanning fingers 801a, 801b, 801c etc. can be pivoted on a plate 804 hinged, which rests tangentially on the concave surface of the model 5. If convex surfaces occur or shape changes in the surface are to be detected, the head 801 is by the scanning head 201 according to FIG. 3 replaced. The output signals from the differential transformers can be fed into those in the rack arranged control circuit can be inputted through the arm 832c.

In parallel to the stand 830e, the stand 830a for the tool head is provided with a vertical slide 833 which can be displaced in the Z direction by a lead screw 833a and a motor 833b (FIG. 10). Like F i g. 11 shows, the slide 833 forms a guide 833c for a cross slide 834 which is driven in the V direction by a lead screw 834a and a motor 834b. The cross slide 834 forms the base body of a turntable 835, which is rotatable about a horizontal axis H _c (FIG. 11) and is driven by a servomotor 835a, the pinion of which engages in a toothed ring rack on the turntable 885. The turntable also carries a horizontal arm 836 which carries a guide 836a for a slide 836b which can be moved in the X direction by a lead screw 836c and a servomotor 836c / (FIG. 11).

The slide 836b forms a base for a turntable 837 with external toothing, which is driven by a pinion of a motor 837a about the horizontal axis Hd . As from ^P i g. 11, the tool head 808 can be pivoted with the drive motor rotating the milling cutter R about the axis V ₃ about the axis H _d in the drawing line of FIG. 11, ie in the plane of the axis V ₃ . By moving the slide <s36b on the arm 836 and by raising and lowering the arm over the slide 833, three degrees of freedom of movement are given to position the tool at any point on the surface of the workpiece JV and also to position the tool axis perpendicular to a tangent to pivot the surface in this plane. By rotating the arm 836, the axis V ₁ can also be seen in the drawing plane of FIG. 10, ie about an axis perpendicular to the axes V ₃ and Ha, pivot. The horizontal movement is brought about by the slide 834. The two additional degrees of freedom ensure that the axis V _{3 is} perpendicular to a tangent to the workpiece surface. The axis V. is thus perpendicular to two mutually perpendicular and intersecting tangents at the processing location, so that it is perpendicular to the imaginary tangential plane. The input signals

for the servomotors 8336, 8346, 8364, 835a and 837a are obtained from the scanner and, as above (Figs. 7 and 9), processed.

In another embodiment with at least five degrees of freedom for machining a workpiece according to FIGS. 13, 14, a frame 930 forms a horizontal guide 9306 for a table 930c, which is moved by a motor 93Od. This table in turn forms a guide 9316 for a platform 931, which can be displaced horizontally and perpendicular to the table 930c by a servomotor 931a via a lead screw. The frame 930 forms a vertical guide 930a for a vertical slide 933, which is driven by a servomotor 933e via a worm 9336 'and a worm wheel 9336 ", which represents the nut for the stationary lead screw 933a. The vertical slide 933 forms a housing for an arcuate one Toothed rack 938, the fulcrum of which is centered on the tip of the tool T and which can be slid about a horizontal axis perpendicular to the plane of the drawing in Fig. 13. The toothed rack 938 is guided by rollers 938a and 9386 and driven by a pinion 938c of a servomotor 938d The rack carries a bearing bushing 938e in which a shaft 936a of a crank arm 936 is mounted about an axis H _c which intersects at a right angle with the tip of the tool T. A servomotor 935 rotates the arm 936, which the tool head 908 with The axis of the tool T is represented by Vb In this embodiment there are five degrees of freedom obtained by moving the rack 938 and pivoting the axis Vj, through an angle θ in the plane of the drawing of FIG. 14, by rotating the shaft 936a and pivoting the axis Vj, through an angle Φ, by moving the carriage 932 vertically and through the two horizontal movements of the table 930c and the platform 931 guaranteed. The servomotors for this drive can be operated according to a recorded program, namely by a scanning arrangement according to FIGS. 1, 3 and 10 to 12. By simply interchanging the tool head and the workpiece with the scanning head and the model, the construction according to FIGS. 13 and 14 can form a model scanning arrangement as an alternative to the previously described exemplary embodiments. In addition, the machining head of FIGS. 10-12 can optionally be driven by the head and control system of FIG. 13 and 14 are replaced.

In Fig. 15, 15A and 15B, a further embodiment of a copying machine tool is shown, which basically has the same structure as that according to FIGS. 13 and 14 / is displaceable A platform 1031 is displaceable on this table horizontally and perpendicular to the displacement direction of the table 1030c by means of a motor 1031a. Both the model 5 and the workpiece W can be mounted on the platform 1031. A slide 1033 is vertically displaceable in a guide 1030a by a lead screw arrangement 1033a and a motor 10336 and carries both the tool T and the scanner 1001, both of which have the structure according to FIG. 3 can have. For this purpose, the bent rack 1038 is held in the slide 1033 (that of FIGS. 13 and 14 can be provided as a holder) and is driven by a pinion 1038c of a motor 1038tf. The rack 1038 defines an axis of rotation at the cutting edge of the tool T and is provided with a horizontal support rail 1038e, which forms bearings for two rods 1036 and 1032, which are rotatable in corresponding bearing bushes of the carrier 1038e, as indicated by an arrow 1036a. The drive motor for diet «; Rotational motion at 1035a is similar to FIG. 13 and 14 shown.

In this embodiment, however, each has over heads 1040 and 1041 for the scanner and da *

ίο workpiece a rotary or turret head 1040a or 1041a, which is rotatable about an axis T ₃ or Tt , which is at an angle to the tool or scanner axis, but is thus coplanar. A stepper motor 10406 or 10416 is provided to rotate the turrets, which have chucks 1040c and 1041c to accommodate scanners of different sensitivities and dimensions, and cutters of different diameters and fineness. The drive motor for the two devices can be provided at 1008.

In the embodiment of Figures 15, 15A and 15B, the scanner can be electronically coupled to the tool head, as previously described, to rotate arm 1038 or arm 1036 as needed. The electronic equipment provided for this has already been explained. However, many of these electronic components can be saved by coupling arms 1032 and 1036 for common rotation by a link 1042 that is pivotally connected to each arm as shown at 1042a. Since the horizontal X and Y coordinates are determined by the joint movement of the value piece W and the model S on a common table, the rotation of the

J5 tool and the scanner by the angle θ through the common coupling of the scanner and the tool with the curved rack 1038, the common angle of rotation Φ through the connection 1042 and the common lift Z through the use of a single carriage 1033, it can be seen that the The scanner need only be servo-controlled to maintain its own perpendicular position with respect to the model, thereby ensuring the perpendicular position of the tool. In this case, the in F i g. 7, 7A and 8 with the tool servomotors shown can be omitted.

A similar mechanical coupling can be seen in FIGS. 16A and 16B, where a single model is used as a template or pattern for several workpieces Wi and Wz ...

is used. In this system, a frame 1130 forms a single horizontal table 1130c which is positioned in the horizontal Y direction by a servomotor 113Od. A platform of sufficient length to support all workpieces and the model is on the table for movement in the X direction 1130c stored, as shown at 1131. A servomotor 1131a for moving this platform can also be seen. The scanner 1101 and the tools 1108 are connected by a parallelogram linkage for a common inclination in the plane of the axes of the tool and scanning heads. The scanning head 1101Λ is hinged to two coupling rods 1143 and 1144 at separate locations 1143a and 11436 on the scanning axis. Referring to FIG. 16A, similar pairs of rods can be provided on either side of each head. Joints or pins 1143a ', 1143a "and 11446', 11446" similarly connect the parallel rods 1143, 1144 with the tool heads 11084 which are equipped with electrical

motors can be provided to drive the tools. When the rod 1143 is shifted to the right relative to the rod 1144, the heads are pivoted clockwise by an identical angle θ. A common vertical movement of all heads is "guaranteed by a carriage 1133, which can be shifted in the vertical direction by a motor 11336, e.g. Servomotor 1135, which acts on a connecting member 1145, which is connected by levers 1145a and 11456 of the rods 1142 and 1144 in a knee joint which is biased by a spring 1145c into the center position shown. When the motor 1135 is actuated, the Heads together inclined to one side or the other hen the arm of the fork 1133ί in the axis Hf is rotatably mounted so that the entire unit can be pivoted through the angle θ clockwise or counterclockwise, as shown in Fig. 16B In this embodiment as well as in that of Figs 15A the servo control of the position of the scanner is sufficient. to position the tool.

In the arrangement of FIGS. 17 and 18A, the scanning head 1201 is mounted on an arm 1232 which is rotatably received by a rod 1246 and is driven by its servomotor, as already described. The scan head 1201 is also connected by a link 1243 to heads 1208 of a plurality of processing stations, each supported by its own arm 1236. Pivoting the scanner about the axis of its rod 1232 clockwise or counterclockwise to adjust the angle of inclination Φ therefore leads to a corresponding inclination of the machining heads.

The rod 1246 is also supported for rotation about the horizontal axis H _e in stands 1233 at each end of the machine, the latter being arranged vertically slidable on respective carriages which can be driven by the motor 1233Z>. The uprights 1233 thus ensure a vertical displacement Z. As in the previously described embodiments, the model S and the workpieces Wi, W ₁ etc. are supported by a platform 1231 which is displaceable in the K direction by a servomotor 1231a, while a table 1230c located underneath can be displaced in the direction of arrow X via another servomotor (not shown). However, the individual heads may be rotatable about respective axes Hi , as shown in Figure 7A, if so desired, in which case a further link couples the heads together separately from the link 1243 which pivots the respective arms on (e.g. 16A, 16B, 17 and 17A can replace those of FIGS. 13 to 15 and vice versa if mechanically controlled copying is desired. Further, the links of Figures 15 and 17A can be omitted if independent but electronically controlled copying is required in accordance with the features set forth for Figures 10-14.

In Fig. 18 to 18E are a number of modifications

for holding the tool head according to the Invention shown. For example, in FIG. 18, a Frame i330 a table 1330c, with the cleaning direction Z Slidable by a servomotor 133Od. Of the Table 1330c in turn carries a horizontally displaceable platform 1331 which can be displaced in the direction of arrow X via a servomotor 1331a. In this system, however, the platform 1331 supports a turntable 1349 which is driven by a motor 1349a so that the

ίο workpiece Wum the vertical axis V / is rotatable Stand 1330a of the frame supports a carriage 1333 which is driven in the vertical direction by a motor 1336 and A horizontal cross slide 1334 is slidable by a suitable lead screw assembly

is powered by engine 1334a. An upwardly inclined arm 13346 carries a bearing unit 1334c in which a shaft 13346 of a further turntable arrangement 1335 is rotatably received. The turntable 1335 can be driven about the inclined axis I \ , which is the vertical Axis Vr intersects at the machining location. The slide, which is rotated by the StelbiKXcr 1335a, is provided with a curved toothed rack Ϊ336 through which the machining head 1308 can be tilted via a servomotor 1336a. In other words, two degrees of freedom the rotation in mutually perpendicular planes are also provided in this head. The system of Fig. 18B differs from that of Fig. 18 in that a carriage 1434 carries a horizontal arm 14346 which is rotated about the axis H _{e by a servomotor 1434a} is rotatable The arm 1436, which extends from the arm 14346, is rotatable by a servomotor 1436a in order to pivot the cutting head 1408 by the angle θ about its axis H _k . The workpiece W is rotatable about the vertical axis Vg on a rotary table 1449.

Figs. 18D and 18E show another embodiment S; example according to the invention, the features of FIG. 18 and 18A along with some features of 18B and 18C can be used. In the embodiment of FIGS. 18D and 18E, the workpiece is Wauf a turntable 1549 which can be driven by a motor 1549a, the turntable 1549 on a longitudinal feed platform and a cross feed table in the one in the preceding Figures indicated manner is stored and wherein

This X- K unit is denoted by 1531. An arm 15346 is supported here in a bearing 1535a for rotation about the inclined axis h by a motor 1535a '. The arm 15346 is also cranked, as shown in FIG. 18E shows and carries a crank-like arm 1536, which is rotatable by a servomotor 1536a and carries a head 1508. To make a vertical movement too allow, the bearing bush 1535a is mounted on a vertically displaceable slide 1533, which in turn of a horizontally slidable slide 1534 is worn. Although the systems of Figs. 18 through 18E can have the same corresponding servomotors that are controlled by electronic pulses, as shown, for example, by the circuits of FIG. 7 to 9 can be generated mechanically with coupled to the corresponding scanner or for one Be connected synchronously on a workpiece support table, as described in connection with FIGS. 17 and I7A is described. Fig. 19 shows a further modification of the work tool or electrode holder according to the invention. In this case a head 1608 is mounted on a shaft 1636 which is rotatable about an axis / 3 through a Servomotor 1636a or a link that is a

A number of such units connects with one another (cf. Figli5, 15A and 15B). En camp 1635a, in which one Shaft 1636 is supported by a cranked arm 1635 cantilevered, the "fm, one; vertical sliding column 1633. is mounted, and; to the Axis fim pivotable by a SteÜmotqr 1635Ö. In addition, the. Construction of a compound table 1631, the m the Λ "- and Y-direction by servomotors 1631a and 1630J is drivable It will be understood that the The head of FIG. 19 has the same possibilities of movement and can be actuated in the same way as that in FIG Fig. 18 to 18E illustrated systems.

20 and 20A show a further system for achieving two degrees of freedom for a tool head 1708 containing a motor, which is adjacent to the workpiece W. In this case, the tool head 1708 is cantilevered at the end of a cranked arm 1736, the axis of rotation H _{n of} which is the tool axis 7} cuts at the machining point P ₄ on the workpiece surface The crank 1736 can be pivoted by a servomotor 173Sa and is mounted in a bearing 1735a of a vertically displaceable column 1733, which is movable in the Z-direction by a servomotor 1733a Vertically displaceable supports 1733 are carried by a swivel arm 1735, which can be swiveled about the workpiece axis on a shaft 1749 by a servomotor 17356. The arm 1735 can be swiveled about a vertical axis and is mounted in a support 1730 below the work table. The latter consists of at least one table 173Oq by a position motor 173Od is displaceable in the Y-direction, and carries a platform 1731, which is displaceable in the '-direction by a servomotor 1731a. Here too, the tool has two degrees of freedom of rotation and translational movement on the Z-axis.

As already mentioned, an important aspect of the invention is the use of the system for the finishing or surface finishing of a workpiece having a predetermined shape. Apparatus for this purpose is shown in Figures 21 and 21A. In Figure 21 a housing 50 can be seen which is connected to a suction pump via a line 150 from which a high pressure fluid and particles or gases are evacuated. The "tool" in this case is a nozzle 58 which is provided on a holder 57 with a device, for example an actuator or a manual control 56, for setting the distance between the nozzle 58 and the workpiece W , which is here schematically as an electrode for electrical discharge machining or electrochemical machining. The nozzle is preferably oriented perpendicular to the surface to be finished and for this purpose one of the methods previously shown in FIG. 1 to 20 can be used. A simplified head mount and scanner arrangement is shown here to highlight the fundamental differences between copy finishing apparatus and apparatus using other mechanical de-materialing techniques. The housing 50 is covered with a hinged transparent flap 50a and is provided with bushing insulators SOb and 50c through which wires 55 lead to the workpiece wound to the nozzle 58 from an electrochemical machining source 54. The latter can have the circuitry of any of the common ECM power supplies. A pump 53, driven by a motor 52, presses an electrolyte under high pressure through a hose 59 in; this, nozzle; 58 ^ which is also with an air jet over a. RohrTeO ^ yonieinem a suitable compressor is applied winLÖie abrasion particles can be dosed into the air flow from a funnel 61 via a dosing shut-off element 62 or into the liquid line from a funnel 63 and a dosing shut-off element 64. In the embodiment of FIG. 21 is the pattern or model 5 on a table i70

ίο stored, which can be moved in ^ - and Y-direction

kanin ^ as explained above. A scanner or Probe 69 is directed downward to the surface of the model via a rack and pinion drive 68

- Most, where a servomotor is formed by the dgr In the circuits of Fig. 7 or 7A can be actuated in this case the nozzle 58 is over with the scanner 69 a rod 67 coupled for common movement with the scanner although also independent servomotors can be provided for the nozzle, as has been described with reference to FIGS. The cross feed of the scanner 69 is reached by two rails 66 which have a rack in which a pinion of a cross-feed servomotor 65 engages. The servomotor 65 enables movement of the scanner and the nozzle in the. ^ - direction. The movement in the The Y direction is ensured by two rails 71 which run perpendicular to the plane of the drawing, but with a servomotor 72 work together to the scanner and the nozzle also in this direction move.

A metering pump 73, which is driven by a motor 74, sucks fluid from a container basin 75 below the workpiece Wab and conveys it into a pump 53. The operation of the system of FIG.

In Fig. 21A there is a modification of the system of 21 with a workpiece housing 150 mounted on a platform 131 which is in the .Y direction is displaceable by a lead screw assembly driven by a servomotor 131a The pattern or model Sund the workpiece W are thus carried by the same table, and a number of nozzle heads and Workpieces can be coupled in the same direction, as described in connection with FIGS. 17 and 17λ.

A main body 130 of the device has a

Fixed lead screw 133a (see. Fi g. 13 and 14), on the a slide 133 is vertically displaceable (in the Z direction) by a servomotor 1336. The carriage 133 carries

such a curved rack 138, with a cross bar 138e with bearings for corresponding cranked arms 136 and 132 which carry a scanner or probe 101 and a nozzle 108, respectively. As shown in FIG. 15,15A and 15B, the arms 136 and 132 are connected by a rod 142 and the usual hinges. the The tool nozzle and the scanner can therefore perform the same types of movements as in connection with F i g. 13, 14, 15 and 15A.

The platform 131 is supported by a table 130c which is perpendicular to the direction of the in the horizontal direction Displacement of the platform 131 is displaceable by the servomotor 13Od. The scanner 101 has that here Structure of F i g. 1 or 3 and is related to the circuits of FIG. 7 to 9 provided for the orthogonality between the nozzle 108 and the workpiece.

A drain 175 from the housing 150 directs the liquid into a foreline pump 173 operated by a motor 174

. ■■ ".. ■ '. · ■''F'.'^;: ■ '■■ ". ^{J is} driven and feeds a high pressure pump 153. The latter is driven by its motor 152 in order to introduce the liquid into the nozzle via a line 159. Air is supplied via εΐηέ Leitüngl60; and filling devices 61 to 64 'can be used to add in the tray -to the system. The pivoting of the Zaiiristange 138 is carried out by a servomotor 138d. The housing 150 has an outlet 151 for sucking off exhaust gases, solid surfaces and drops from the system.

In Fi %. 22 shows a system for producing copies or duplicates, in particular a molding tool or a plurality of molding tools, wherein the features of the invention are applied. In a first stage 1 a drawing of the desired product is made in the usual way, and a negative model of it can be made of any suitable material, for example wood, plaster or any other material which is not very suitable as an electrode material a copy milling machine 2 of the type described in connection with FIGS. 1 to 20 is clamped to which, at Wg, a block of electrode material, for example graphite, is supplied as a workpiece. In this stage, the electrode block is expediently first roughly shaped using a suitable cutting edge of the milling cutter to copy the model in the usual three-dimensional manner, and then finished with a finishing tool, the tool axis always being kept perpendicular to the surface, as previously explained in detail so that the resulting surface is practically free of any scratches which otherwise usually had to be removed by hand in time consuming finishing.

When the model has been reproduced from the electrode material, the electrode is automatically (under the control of a programmer 7) through a conveyor 11a to an electrode control station 3 transported in which the electrode and the model are compared and the dimensions in a computer 8 to reject the electrode or to continue the program or the Sequence control can allow. The rejected electrode can be finished by hand, if it is possible and data of the machining parameters that led to the rejected electrode become then advantageously used to correct the machining parameters. The shape of the model is then of course saved in the computer for subsequent use

An electrode of satisfactory dimensions is automatically advanced at 116 to, for example, an electrical coarse forming device, shown schematically at 4 and of the ECM or EDM type. Workpiece material, which is indicated by a block 10 and which can consist of steel or the like, is transported to the device or to stage 4 at 11 f. A further electrical processing stage 5 of the EDM finishing type can then pick up the workpiece, a conveyor 11c being provided for the workpiece feed from stage 4 to stage 5. Before electrical machining, the workpiece can be roughly machined and then hardened. After the finishing stage 5 the product is automatically d in a further step at 11 5a to a Kopierfertigbearbeitungs- or Fluidhonvorrichtung

transported, in which a surface of high quality underneath. Control by the "output model or computer-stored information" is generated, while manual processing was previously provided for this. The workpiece is then transported at Hd 'to a product control station 3' Here the dimensions and shape of the product are compared with the information stored in the computer 8, and if desired, the model is used again or the information for controlling the system is changed in a feedback loop. The product is then automatically removed by a conveyor He and received at 6 as a molding tool complementary to the original model and to the electrode

The electrical machining stages 4 and 5 require _; a> number of electrodes, namely a rough machining electrode, a finishing electrode, an intermediate machining electrode, etc. It can be seen that such electrodes with either identical or different dimensions can easily be used with the copy milling machine 2 according to a common model or a common drawing or according to separate similar models or Drawings can be made, after which a control in stage 3 takes place

Electrical processing levels 4 and 5 can can expediently be carried out with a common device «for example with one EDM device, especially of the type that is very versatile in its machining capabilities is and preferably an automatic parameter switching system and an automatic electrode changer so that once a workpiece block has been received, the apparatus has several Can carry out processing steps automatically or essentially without operator intervention and a correspondingly electrically processed workpiece ejects

If the electrode, which is required for the electrical forming of a molding tool in stages ί and 5, has a concave surface, which does not allow satisfactory shaping by a corresponding cutting tool or by corresponding λ 5 cutting tools with the copy milling machine according to the invention in stage 2 the model is divided into suitable sections, which are separated by essentially convex Hacher. _{e e} formed, each of the electrode portions being made from the corresponding section of the divided models by using the milling machine in the same manner as described above. Copy-formed electrode parts can then be installed in a magazine or storage unit of an automatic tool changing unit of the EDM or ECM device as previously mentioned and used in the device in a suitable sequence in order to progressively machine the workpiece into a required shape, complementary to the model that the subdivided electrodes together form.

Some measured values will now be reproduced by way of example, which during the practical testing of the invention won:

A workpiece consisting of 0.55% carbon steel (S55C) was placed with an EDM graphite electrode machined using kerosene as a machining fluid. The EDM switch-on time was 240 με and the switch-off time 12 με. The peak of the

Machining current was 40 A. The surface roughness of the product was 11 µm. Hm «- The roughness dimensions used here indicate the maximum height in µm of sections of the surface adjacent to low points. A similar body formed by hand had a roughness of 25 µm HoT _3x and required 16 hours of manual processing to reduce the roughness to 3 μm Hmax.

After machining to a roughness of 11 µm Hn «* by EDM, as above mentioned, the surface of the body was sandblasted using air pressure of 5.5 bar and of silicon carbide particles with dimensions corresponding to a US sieve number of 180 (approximately 0.084 mm in diameter). The surface roughness

This was reduced to 4 to 8 in the best of cases when using the device shown in FIG of water with 15% sodium nitrate and a pressure of 35 bar, the surface roughness avf was reduced by 3.5 µm. With a system that used ECM current of 2 A and a potential of 40 V as well as silicon carbide and air, the surface roughness could be reduced to 1.5 pm Hoax . When the nozzle was pivoted from the vertical on the surface by 2 °, the roughness increased threefold.

In addition 17 sheets of drawings

Claims (14)

Patent claims: 1. Copy tool machine with a scanner for scanning a model with the delivery of several position signals, with a workpiece holder, with a tool holder and with a drive for the workpiece and / or tool holder controlled by the scanner for the relative movement of workpiece and tool along several axes, the The scanner has a plurality of fingers pretensioned in the direction of the model and associated mechano-electrical measuring transducers for the delivery of electrical analog signals corresponding to the finger position, which act on servomotors, characterized in that the scanner has at least three fingers (102,105a-d ; 202, 205a-d ) has that the fingers (102,105a- d ~, 202, 205a- d) are arranged in relation to the model (S) in such a way that they have a tangent plane to the surface of the model (S) and the direction of curvature of its surface Define the respective scanning point, and that the servomotors belonging to the drive for the workpiece and / or tool holder ü The transducers are connected via analog-digital converters and control the relative movement of workpiece (W) and tool (T) in such a way that tool (T) is held with its axis perpendicular to the workpiece surface to be machined 2. A copying machine tool according to claim 1 with a trigonometric transmission element ¹ connected downstream of the transducers, characterized in that the tool holder has a tool carrier which can be pivoted about an axis by one of the servomotors, and that the network forming the trigonometric transmission element (FIG. 9 ) at least two of the transducers are connected downstream and an assigned servomotor is connected upstream 3. A copying machine tool according to claim 1 or 2, characterized in that a plate (104) engages the fingers (105a to \ 05d) and rests tangentially on the model (5j. 4. Copy machine tool according to one of Claims 1 to 3, characterized in that the fingers (105a— d; 205a— d) surround a central scanning element (102, 202), the output signal of which characterizes the curvature of the model surface. 5. copying machine tool according to one of claims 1 to 4, characterized in that a device (105e, 105 /; 105gJ for pneumatic biasing of each finger (105a- iO5d) in the direction of the model (S) is provided. 6. copying machine tool according to one of claims 1 to 5, characterized in that the tool holder has a slide (833, 933, 1033, 1133, 1233, 1333, 1434; 1433, 1533; 1534) which is linear in one direction relative to the Workpiece (W) is displaceable, a first arm (836, 938; 938e, 1038; 1038e, 1146, 1236, 1334Λ + 1334c + 1334d + 1335, 1434Λ, 1534 /?; Which is attached to the slide about an axis (Hc, ed , Hj, Ii, 12, Hm) is rotatable perpendicular to its displacement axis (Z) , and a second arm (808, 936, 1036, 1145,1208,1336,1436,1536) on the first arm for rotation by one Axis (Hd, Hc, Hf, Hi, Hk, 13) mounted perpendicular to the axis of rotation of the first arm is, wherein the tool (T) is mounted on the second Ann with its axis coaxial to the axis of rotation of the second Anns ■ 7. copying machine tool according to claim 6, characterized in that the axis of rotation of the first arm and the axis of rotation of the second arm with the tool in the machining area cut. . 8. Copy tool machine according to claim 6, characterized by rigid links (1042) interposed between the scanner and the Tool holders are articulated for their common displacement. 9. copying machine according to one of claims 1 to 8, characterized in that the workpiece holder has a table (1031) which carries both the model (S) and the workpiece (W) , and a device for shifting the model in two on top of one another perpendicular linear directions. 10. Copy machine tool according to one of claims 1 to 9, characterized by a drive for the rotation of the workpiece f H ^ about the axis of the tool (T) 11. Copy machine tool according to one of the Claims up to 10, characterized in that the tool is a milling cutter 12. Copying machine tool according to one of claims 1 to 10, characterized in that the tool is ein.Düse (58) for directing a fluid or hydro-honing jet onto the workpiece (W) 13. Copy machine tool according to claim 12, characterized by a power source (54) for electrochemical processing connected between the workpiece (W) and the nozzle (58). 14. Copy machine tool according to claim 13, characterized by a device (60) for Forced throughput of compressed air through the nozzle (58).