WO1990002980A1

WO1990002980A1 - Machining station and process for operating it

Info

Publication number: WO1990002980A1
Application number: PCT/CH1989/000161
Authority: WO
Inventors: Paul Fricker; Herbert Russbuelt; Roland Sauter
Original assignee: Agie Management Ag
Priority date: 1988-09-06
Filing date: 1989-09-04
Publication date: 1990-03-22
Also published as: JPH03502143A; EP0389587A1

Abstract

The machining station has integrated therein a machine (1) for performing the machining, an NC or CNC control (3) comprising a process computer (6) assigned thereto, a CAM station (4) comprising a process computer (7) assigned thereto, a single console (5) for providing man-machine interaction with the control (3) as well as the CAM station (4), and a link (8) for bidirectional data transmission ('bus') between the two process computers (6, 7). During the operation of the machine (1), the two process computers (6, 7) are permanently connected with each other and with the console (5). The link (8) can be constructed as a data transmission network to which additional processors (6', 6'') and/or an additional computer (9) can be connected. The machine (1) for performing the machining can be a machine-tool, preferably for machining workpieces by means of electroerosion (spark erosion). The link (8) can be activated to transmit information pertaining to the machine for performing the machining, to a tool used therein and/or to a workpiece used therein, from the control (3) to the CAM station. During operation, the process computer (6) of the control (3) processes in real time at least part of the time-critical process parameters, and the process computer (7) of the CAM station (4) processes all computing-intensive but not time-critical process quantities and optionally also part of the time-critical process parameters.

Description

Processing station and method for its operation

The invention relates to a processing station with a processing machine such as e.g. a machine tool, and a method for its operation.

For controlling processing machines such as Nowadays, machine tools are generally used with numerical controls (NC = "numerical control"), mostly computer-controlled numerical controls (CNC = "computerized numerical control"). The purpose of these controls is to generate a movement of the machine axes on the basis of commands and data which are entered via a keyboard, a data carrier (for example punch tape reader, diskette) or a data channel (for example chaining with serial transmission) and the To ensure implementation and control of the machining process.

The determination of the input parameters for the NC or CNC control can be very complex, depending on the geometric and technological requirements of the machining process. For this reason, computer-aided manufacturing (CAM - "computer-aided manufacturing") is used for the calculation of the input parameters. CAM stations use problem- and process-oriented application program languages to generate the required data, which is generally sent to the NC or CNC via data carriers ("off-line") or via a data connection ("on-line") - Control are transmitted, usually in the form of coded language elements (ISO or EIA code). NC or CNC controls are designed to control or regulate time-critical process variables and machine movements. As a result of a lack of ability to carry out computationally intensive tasks, as well as a lack of screen resolution, a lack of problem-oriented application program languages, and a lack of expressing the workpiece and machining geometry Data structures etc. are generally limited in the possibilities of changing the machining geometry during the machining process by intervening in the NC or CNC controls. For their part, CAM stations are not well suited to controlling time-critical process variables and machine movements because they do not react quickly enough to the large number of process-dependent program interruption requirements ("interrupts") that occur during the machining process.

From "VDI-Z" 128/22 (1986) 875-878 and from "wt Werkstattechnik ¹¹ 77/3 (1987) 129-133 it is known to provide a CAM station with a programming system for an NC or CNC control With this state of the art, this programming system creates NC control information standardized according to DIN 66025, which is somehow to be fed to the NC or CNC control, so that there is no direct connection between the CAM station and the NC or CNC control Since under these circumstances it makes no sense to transfer any data from the programming system back to the CAM station, the connection between the CAM station and the programming system is only for unidirectional data transmission, exclusively in the direction of the CAM station used for the programming station, which can also be seen from the arrow directions in the illustrations of these publications. In addition, these two publications teach to largely increase the autonomy of the individual systems to universally couple old and existing conventional structures (cf. "VDI-Z", page 878, left column, second paragraph, and "wt Werkstattechnik", page 131, point 4). Otherwise, in "wt Werkstattechnik", page 131, point 4, interfaces of the IGES or APT type are proposed, with which no interactive process control in real time is possible.

From EP-A-0109742 it is known to process data from a to transfer the programming station for an NC or CNC control to this NC or CNC control. With this state of the art, the data is transferred exclusively in the direction from the programming station to the NC or CNC control. Incidentally, this programming station is in no way a CAM station because it can change the input parameters for the NC or CNC control depending on the geometric requirements of the machining process, but in no way on the technological requirements of the Bear ¬ determine the processing process. _

It is known from EP-A-0109742 and from EP-A-0086843 to use connections for data transmission between the programming station and the NC or CNC control which also act as bidirectionally activatable connections (bidirectional connections , "bus") can be used. In this prior art according to EP-A-0109742 and EP-A-0086843, however, the bidirectional connections are in no way used to create a real bidirectional data exchange between the process computer of the programming station and the process computer of the NC or CNC control , but only to allow the data flow in one direction or the other as required between each individual process computer and an input / output device leading to a data memory ("input / output controller"). The data transmission between the process computer of the programming station and the process computer of the NC or CNC control takes place in the prior art according to EP-A-0109742 and EP-A-0086843 - always only unidirectionally, from the programming station to

NC or CNC control.

In addition, EP-A-0109742 and EP-A-0086843 for data transmission between the programming station and the NC or CNC control show connections which only temporarily block the data flow between the process computer of the programming station and the process computer of the NC or CNC Ensure control, but do not allow data flow at certain times, ie the connection between the process computer of the programming station and the process computer of the NC or CNC control is then interrupted.

The prior art therefore lacks any suggestion for a reciprocal process-interactive data exchange between the process computer of the NC or CNC control and the process computer upstream of it of the programming station or the CAM station.

With regard to the keyboard and the screen, EP-A-0109742 also shows connections that only lead to the programming station and to the NC or CNC control either selectively but not at the same time. It would therefore contradict the prior art to direct the data flow between the CAM station and the NC or CNC control differently than essentially only in the direction from the CAM station to the NC or CNC control . In other words, the state of the art only teaches to use a CAM station before starting the machining process, while the process-interactive use of a CAM station in cooperation with an NC or CNC control contradicts the state of the art ¬ would speak. All the more, it would contradict the state of the art to have any conditions currently prevailing in the processing machine relating to the processing geometry and / or the processing technology of the ongoing processing process reported back from the NC or CNC control to the CAM station. As already mentioned, the CAM station cannot process the resulting values quickly enough to be able to deliver them to the NC or CNC control in time for a meaningful use in the ongoing machining process. In the prior art, it is therefore impossible to process tasks of a conventional CAM station. tion and of tasks of a conventional NC or CNC control to the respective process computer of the CAM station and the NC or CNC control in a different way than in the conventional way, in which all tasks of the CAM -Station from your own process computer

CAM station and all tasks of the NC or CNC control can be done by the own process computer of the NC or CNC control.

In any case, it is not possible to move the processing of a conventional CAM station entirely into a conventional NC or CNC control, because a conventional NC or CNC control is at least incapable of looking at the amount of data. to cope with the tasks of a conventional CAM station. In any case, it is also not possible to move the processing of the tasks of a conventional NC or CNC control entirely into a conventional CAM station, because a conventional CAM station cannot react sufficiently quickly, at least to process-related time-critical events . The object of the invention is to combine the advantageous properties of a conventional NC or CNC control and a conventional CAM station in an integrated solution in such a way that conditions currently prevailing in the processing machine regarding the machining geometry and / or the Machining technology of the current machining process from the NC or CNC control to the CAM station reported back, processed in the CAM station, and the NC or CNC control still in time the data and necessary for the continuation of the machining process / or commands can be delivered.

To achieve this object, a processing station according to the invention is characterized by the combination of features specified in claim 1. Advantageous designs of the processing station result from claims 2 to 6. A method for operating the processing Processing station results from claim 7. Advantageous further developments of the method result from claims 8 to 10.

The following elements are integrated in the processing station according to the invention: a processing machine; an NC or CNC control which comprises a process computer assigned to it; a CAM station which comprises a process computer assigned to it; a single console with a screen, keyboard and, if applicable, a printer for human-machine interaction both with the NC or CNC control and with the CAM station, and a connection for bidirectional data transmission (bidirectional connection, "bus") between the two process computers. It is advantageous that the inventive

The design of the processing station enables all functions that do not relate to time-critical process variables and movements of the processing machine to be transferred to the CAM station. This is more efficient and reduces the effort, because the NC or CNC control only deals with a part of the functions of a conventional NC or CNC control and can accordingly be designed more easily. The multiple input of the same or similar data, for example the recoding of the data from the CAM format to the NC or CNC format, for example in accordance with DIN 66025, and the associated ambiguities and sources of errors are avoided. In addition, the user interface and the operating language are standardized, which improves the user friendliness.

In short, there have been two separate "worlds", namely the "CAM world" on the one hand and the "NC or CNC world" on the other, while the invention enables larger elements of the "NC or CNC World "in the" CAM world "and thus in their user interface and language. The inventive Training of the processing station now includes a bidirectional coupling with real-time behavior between the CAM station and the NC or CNC control. The actual NC or CNC control is reduced to a fuselage control, because parts of the classic task of an NC or CNC control are taken over by the CAMτStation, whereby a considerable rationalization effect is achieved.

Preferably, at least during the operation of the processing machine, the two process computers are constantly connected to one another and the console is permanently connected to both process computers.

The advantage here is that the data to be displayed of the CAM station and the NC or CNC control can both be displayed on the single screen at the same time using the known window technology. In the prior art, the operator takes the other hand, at the same time on two screens look, of which respectively one each ^'of the CAM station .. the N - or CNC control is assigned, or the operator takes up from

State of the art according to EP-A-0109742 derivable assign the screen either the data of the CAM station or the data of the NC or CNC control and dispense with the display of the unassigned data. Such a machining station can preferably be used in connection with a machine tool and in particular for machining workpieces by electrical discharge machining (spark erosion).

The connection for bidirectional data transmission is preferably designed as a data network to which additional processors and / or an external computer can be connected.

The advantage here is that the external computer can carry out administrative tasks and, for example, can obtain its data from the manufacturing plant without an operator being interposed. The external computer It can also be connected very easily to the processing station according to the invention, because the data network can be designed (and correspondingly designed in accordance with the basic rules of modern network topology)

5 is).

The processing machine is preferably a machine tool, in particular a machine tool for processing workpieces by electroerosion (spark erosion). 10. The connection for bidirectional data transmission is preferably in the direction of at least during the operation of the processing machine for transmitting information about the processing machine, a tool used therein and / or a workpiece used therein

15 of the NC or CNC control to the CAM station can be activated. The method according to the invention for operating such a machining station according to the invention is characterized in that the process computer of the NC or CNC control operates in real time and at least

20 processes part of the time-critical process variables, while the process computer of the CAM station processes all computation-intensive, non-time-critical process variables.

The advantage here is that the laying of all

25 functions in the CAM station which do not relate to time-critical process variables and movements of the processing machine, the multiple input of the same or similar data, for example the recoding of the data from the CAM format to the NC or CNC format, for example

30 according to DIN 66025, which, among other things, avoids double ambiguities and sources of error. In addition, the user interface and the operating language are standardized, which improves the ease of use.

35 The process computer of the CAM station preferably also processes part of the time-critical process variables. In other words, if the process computer of the CAM station works very quickly, the type of integration and coupling means that the CAM station can also be used to process the process computer of the NC or CNC control when calculating Support real-time problems.

It is advantageous that the process computer of the CAM station receives the latest information about the current machining geometrical and technological conditions of the current machining process. The process computer of the CAM station processes a large amount of data from the machining process, which allows it to intervene in the ongoing machining process. For example, the process computer of the CAM station, in particular if the processing machine is intended for machining a workpiece by electroerosion (spark erosion), can adapt the machining process when the parameters of the generator are changed, or it can change it by changing the geometry data when cutting radii or else by changing the so-called escape strategy with precarious stability of the machining process and especially with precarious rinsing conditions.

If the processing machine is a machine tool and in particular a machine tool for processing workpieces by electroerosion (spark erosion), the connection for bidirectional data transmission in a preferred development of the method can at least temporarily provide information about the processing machine, a tool used therein and / or transfer a workpiece used in the direction from the NC or CNC control to the CAM station. This information essentially represents the current machining-geometric and technological conditions of the current machining process, and their feedback to the CAM station takes place in addition to the conventional transmission of data and / or commands between the NC or CNC control to the CAM Station that before the start of the Machining process takes place.

In other words, the connection is used as usual before the start of the machining process to transfer data about the workpiece geometry and machining geometry as well as technological data from the CAM station to the NC or CNC control. In addition, the connection is also used during the machining process to reload data of the above-mentioned type during the machining process, if this is necessary, for example, due to the limited storage capacity in the NC or CNC controller for cost reasons, and by Exchanging machining geometrical and technological data between the NC or CNC control and the CAM station, which opens up the possibility of optimizing the use of the capabilities of the process computer and thus the data exchanged itself.

The advantage of this solution according to the invention is that the same screen, the same keyboard, both for the part of the processing station which corresponds to the CAM station and for the part of the processing station which corresponds to the NC or CNC control, the same application program language and generally the same style of human-machine interaction can be used. Among the many other advantages of the processing station according to the invention, the following can be mentioned, among others:

- The always possible access to the complete data structure for describing the three-dimensional shape of workpiece, tool and machining path as well as to the technological database for describing planetary movements and retraction strategies for the tool, etc., and the resulting possibility or improvement optimization of the technology of the machining process, the geometric path specification and the sequence of steps during the machining process; the possibility of connecting the processing machine itself to a local high-performance network (LAN = "local area network") and the resultant possibility of intelligent operating data acquisition and of data transmission from a central operating computer to the processing machine;

- The possibility of measuring the workpiece and machining geometry during the machining process, among other things, for the determination of geometry errors, and the possibility of a subsequent correction processing to compensate or correct the geometry errors by changing geometric and technological parameters;

- the possibility of using more powerful data structures than those of the conventional ISO or EIA codes for machining processes; and (but not exhaustively)

- the possibility of using the ^{'Leistungsfä¬} capability of the CAM Systemtrukturen for adaptive control of the machining process.

An embodiment of the invention is described in more detail below with reference to the drawing.

The figure shows a processing station according to the invention in a block-schematic representation. Since it is not the machining process itself that is important, but rather its interrelationships with the NC or CNC control and the CAM station, the invention can be described below with reference to training the machine tool for cutting a workpiece by means of electrical discharge machining can be described with a wire electrode as a tool.

In this embodiment, given as an example, the machining station according to the invention includes, among other things: a wire tool spark erosion machine 1,

a generator 2 for spark erosion, - a CNC control 3 for the tool and the workpiece,

a CAM station 4,

a first processor 6 of the CNC control 3, which works in real time and processes time-critical process variables,

a second processor 7 of the CAM station 4, which processes all computation-intensive but predominantly not time-critical process variables, and

a console 5 with a screen, keyboard and printer, the screen of which is connected to the first processor 6 and the keyboard and printer of which is connected to the second processor 7, a high-performance bidirectional connection 8 which acts as a data network and the first processor 6 connects to each other with the second processor 7. If necessary, the first processor 6 can be supported by additional processors 6 ¹ , 6 ″.

The machining station according to the invention can be connected to an external computer 9, which in the present example is a central operating computer of the machining workshop. This connection can take place either in a conventional manner via a local high-performance network (LAN) or, as shown in dashed lines and designated by 10, directly via the data network 8 of the processing station. Thanks to the computing power of the processor 7 of the CAM station 4 and thanks to the feedback of values or data from the NC or CNC control 3 to the CAM station 4, the central operating computer 9 is able to detect and operate the processing station For example, to keep statistics of downtimes and operational incidents. Appropriate programming of the two process computers 6 and 7 means that time-critical process Process variables 6 of the NC or CNC control 3 and the computationally intensive but not time-critical process variables are processed by the process computer 7. This division of the work is made possible by the fact that all the data required for both process computers are available on the data network 8.

The following can be mentioned as time-critical process variables that are processed by the first processor:

- interpolation,

- control of the servo drives,

- control of the generator,

- control of the tool drive, ^• - control of the machining process,

adaptive optimization of the parameters of the workpiece and machining geometry and the technological parameters of the machining process on the basis of data measured during the machining process,

- Selection of the optimal withdrawal strategy for the

Tool depending on the workpiece and machining geometry and on the geometric and technological requirements of the machining process.

The following can be mentioned as non-time-critical process variables that are processed by the second processor:

- Calculations of the machining paths (e.g. geo-electrical support points),

- calculation of processing orders,

Selection of the correct processing technology on the basis of information stored in a database, selection of the optimal processing algorithms and strategies, - Selection of the correct machining geometrical

Sequences depending on the degree of difficulty of the machining geometry, for example for determining planetary movements of the tool electrode,

- Measurement of the workpiece geometry and determination of the corresponding correction processes for the compensation or correction of errors in the workpiece geometry by changing geometric and technological parameters.

The console includes a single screen and keyboard, and a printer. It forms the only interface between the operating personnel and the programmers on the one hand and the processing machine on the other. Your tasks include:

Input of data on the workpiece and machining geometry and of technological data,

- input of instructions to the machine tool in manual operation,

- Display of data relevant to the machining process, such as workpiece and machining geometry, technological data, operating data, etc. It is a great advantage that only one console is required to operate the entire machining station: in particular if any operating problem arises , the operating personnel does not have to run back and forth between different command stations in order to read or enter data here and there. This advantage has so far not been achievable in such an integral and consistent form and in particular with the simultaneity of monitoring and standardization of operation that is now guaranteed.

Claims

1. Processing station in which the following elements are integrated:

- a processing machine (1),

- An NC or CNC control (3) which comprises a process computer (6) assigned to it,

a CAM station (4) which comprises a process computer (7) assigned to it,

- a single console (5) provided with a screen, keyboard and optionally a printer for human-machine interaction both with the NC or CNC control (3) and with the CAM station (4), and

- A connection (8). for bidirectional data transmission (two-way connection, "bus") between the two process computers (6, 7).

2. Processing station according to claim 1, characterized in that, at least during the operation of the processing machine (1), the two process computers (6, 7) are constantly connected to one another and the console (5) is constantly connected to both process computers (6, 7) ) connected is.

3. Processing station according to claim 2, characterized by an embodiment of the connection (8) for bidirectional data transmission as a data network to which additional processors (6 ', 6 ") and / or an external computer (9) can be connected .

4. Processing station according to claim 1, characterized in that the processing machine (1) is a machine tool.

5. Processing station according to claim 4, characterized in that the processing machine (1) is a machine tool for processing workpieces by electro-erosion (spark erosion).

6. Processing station according to claims 2 and 4, characterized in that the connection (8) for bidirectional data transmission at least during the operation of the processing machine (1) for transmitting information about the processing machine, a tool used therein and / or a workpiece used therein can be activated in the direction from the NC or CNC control to the CAM station.

7. Method for operating a processing station with a processing machine (1), an NC or CNC control (3) which comprises a process computer (6) assigned to it, a CAM station (4) which assigns one to it ¬ th process computer (7) comprises a single console (5), permanently connected to both process computers (6, 7) and provided with a screen, keyboard and optionally a printer, for human-machine interaction both with the NC or CNC control (3) as well as with the CAM station (4) and a permanent connection (8) for bidirectional data transmission (bidirectional connection, "bus") for data exchange between the two process computers (6,7), characterized in that the process computer (6) of the NC or CNC control (3) works in real time and processes at least some of the time-critical process variables, while the process computer (7) of the CAM station (4) processes all of them not time-critical, compute-intensive process variable processed.

8. The method according to claim 7, characterized in that the process computer (7) of the CAM station (4) also processes a part of the time-critical process variables.

9. The method according to claim 7 or 8, in which the processing machine (1) is a machine tool, characterized in that the connection (8) for bidirectional data transmission, at least temporarily, provides information about the processing machine, one therein transferred tool and / or a workpiece used therein in the direction from the NC or CNC control to the CAM station.

10. The method according to claim 7 or 8, in which the processing machine (1) is a machine tool for machining workpieces by electroerosion (spark erosion), characterized in that the connection (8) for bidirectional data transmission is at least temporarily one Transmits information about the processing machine, a tool used therein and / or a workpiece used in the direction from the NC or CNC control to the CAM station.