WO2012038491A1 - Method for checking a saved production sequence for one or more machines having a cyclical machine operation sequence - Google Patents

Abstract

The invention relates to a method for checking a saved production sequence for one or more machines having a cyclical machine operation sequence, wherein a production sequence is saved for a cycle using command functions, wherein all necessary production parameters and target values are prescribed, a chronological actuation profile having a starting point and a time duration is created, in particular calculated, for each of the driven machine components from the command functions, the production parameters, and the target values, and the chronological actuation profiles corresponding to the production sequence are placed in chronological correlation to each other. In order to avoid incorrect programming and thus a malfunction during operation of the machine or machines, the production sequence is run for at least one cycle in a simulation mode of the machine(s) and a check is made according to saved collision rules as to whether the chronological correlation of the chronological sequence of the command functions is correct over the entirety of the chronological actuation profiles, and whether a collision of two or more machine components takes place.

Description

 description

title

 Method for checking a stored production sequence for one or more machines with a cyclical machine operating sequence

The present invention relates to a method for checking a stored production sequence for one or more machines with a cyclical machine operating sequence, in particular an injection molding machine, according to the preamble of claim 1.

In modern machine tools, for example injection molding machines, machine processes, for example the production process, can often be graphically displayed and modeled on a screen device. With the help of such graphical modeling, it is possible, in particular, to visualize the dependencies between the individual command functions and to make the cyclic process comprehensible to the operator overall. The individual process steps during the running machine operation are partially also animated graphically, so that you can track and follow the program steps just performed on a screen device.

The possibilities of such a modeling help on the one hand with the establishment or reprogramming of a machine tool, for example an injection molding machine. On the other hand, a fully modeled sequence also shows the sequence rules very well. In particular, it is often possible for an operator to detect collisions in the time sequence, for example, of two or more machine components. However, the detection of collisions "with the naked eye" proves to be difficult when a complex production process is due to an interaction of a plurality of machine components or the collision can not be easily recognized by the eye, for example, due to only a slight temporal overlap of actuation profiles of machine components.

With regard to the general background technologies of the prior art, reference is made to the documents DE 102 469 25 A1, EP 573 912 B1 and WO 2006/089451. In all the aforementioned cases, it is possible to graphically specify the sequence in an injection molding machine and to define it as a function of the individual process steps.

A known representation of a production process is also explained with reference to FIGS 2-4.

2 shows a flow diagram on a screen device 10, in which command functions for machine components to be executed by means of "icons" are represented in the programmed sequence and the control flow (also branches) is indicated by means of arrows In addition, possibly parallel or possibly overlapping processes can be recognized, but an exact temporal relationship can not be seen from the illustration in Fig. 2. Thus, in the flow diagram of Fig. 2, the impression is made suggests that the functions denoted A and B will occur simultaneously and in parallel, but such a temporal relation between process steps A and B is not given.

If the cyclical sequence is represented in the form of a so-called KO function (KO comes from cathode-ray oscilloscope), then in FIG. 3 for the machine components "positive connection", "injection axis", "nozzle", "ejector" and "nozzle However, in this representation, the structural structure (the control flow) of the sequence program is not recognizable, nor is the reference of the lines to the associated process step immediately apparent. From the so-called sequence graph (also called cycle time diagram) in Fig. 4 Although the timing of the individual process steps (commands), but again not the structural structure (the control flow) of the process and the dependencies between the individual process steps visible.

Currently, the review of a fully programmed machine sequence in various ways known. It is possible to have a visual check on the screen or to step through the programmed production process as a drying cycle, whereby no production material or all production materials are fed in during the drying cycle. Of course, the start of productive operation after programming the control of a machine is also possible.

However, a so-called dry run alone usually does not help the operator; For example, it can not usually check the logical process or the setup of the correct synchronizations. The possibility of a so-called "step mode" with a step-by-step execution of the production process, possibly with reduced speeds, also helps the operator only to a limited extent, thus possibly opening the possibility to stop the movement of a machine component before an actual collision However, correct interaction of all machine components is not possible and, in particular, the immediate start of the production sequence after programming can have devastating consequences for the machine or machine components, the handling device and the tool.

Object of the present invention is to provide a method which allows a review of a programmed production process, in particular, whether a machine sequence is programmed correctly, logically, collision and trouble-free.

This object is achieved by the features mentioned in claim 1. Accordingly, an idea of the present invention is to run in a simulation mode of the machine or machines (ie without the actual operation of the machine itself) the production process for at least one cycle and thereby the production process on the basis of time-scale assignments and in particular taking into account Collision rules to check whether the temporal sequence of the command functions is correct for the totality of the temporal actuation profiles in their temporal correlation and a collision of two or more machine components, in particular of two or more machine components of a (single) machine. The check is thus carried out before the first productive operation of a machine with a newly stored or a changed production process. Even the true-to-scale representation of the production process based on model data enables the operator to detect collisions.

A particular application arises in injection molding machines or systems with injection molding machines. An injection molding machine has several driven or drivable machine components, such as:

 Closing unit with at least one movable platen,

- Formhäflten,

 - core trains,

 - one or more ejectors,

 - reciprocating plasticizing and injection unit,

 - Rotary and linearly driven plasticizing screw.

The temporal actuation profiles or the movement profiles of the individual axes of an injection molding machine, for example the actuation profiles of the abovementioned machine components, must be coordinated with one another in the productive operation of the injection molding machine in a specific manner. This requires the correct chronological sequence of command functions in order to avoid a collision of two or more driven machine components during their movement. For example, the advance of the plasticizing screw and thus the injection into a mold may only take place when the mold halves are closed and the plasticizing and injection unit is docked to the sprue bush of the mold is. Another example is the ejector, which may only be operated when the mold is open. So it depends on the right operating profile of this machine component with the right starting point and the correct time extension of the operation for each driven machine component. Moreover, it is important to set these actuation profiles in a temporal correlation with each other.

In order to be able to check the production process as a whole, the temporal behavior of the individual machine components and their temporal correlation must be known. In this respect, in a first step for each driven machine component from the command functions, the production parameters and the setpoints, a temporal actuation profile with a starting point and a temporal extent is created (in particular calculated); Furthermore, the temporal actuation profiles are set according to the production process in a temporal correlation with each other. It is based on the fact that the actuation profiles with their temporal sequences from the command functions, the production parameters and the setpoints on the basis of a stored model (also model calculation) determine - in particular calculate - leave. For example, the actuation profiles for individual machine components can be determined by means of controller models for the existing controllers of the individual machine components.

If it should not be possible to calculate an actuation profile for a machine component, which may be the case for some auxiliary components (eg for core pullers in molds of injection molding machines), then a query would have to be started, via which the operator will need necessary values for the actuation profile (eg time extension) the actuation) for this machine component.

The aforementioned creation of actuation profiles and their temporal correlation are the prerequisites for checking whether the various process steps are started at the right time and are finished at the right time. All in all, it is necessary to completely store and program a sequence or partial sequence, because only then can knowledge of the corresponding entirety of the command functions, their time extension and their influence on one another be determined for the entire machine operating sequence. For this purpose, the necessary production parameters and setpoints, in particular those which have a temporal influence on the machine operating sequence, must be specified.

Preferably, the simulation and verification of the production process for the operator is made visible on a screen. This visualization is preferably carried out in the time scale representation of a production process.

Thus, the command functions can be scaled according to the time extent and displayed in a time-correct length. This can be done, for example, such that at the beginning of a command function shown in particular bar graphically indicated with a starting point in the form of a command icon, which indicates the function and then continues until reaching the correct time end and then ends. As a result, it is possible to extract from the diagram and the illustration on the screen an extension in time and in particular also the temporal correlation of the command functions with one another. During a simulated run through a production cycle, the operator can see which process steps are being performed in parallel and which process steps are being carried out sequentially.

In this case, incorrect time sequences or collisions of machine components are preferably displayed on the screen, so that the operator can recognize the problematic timing in the production process as well as the problem itself; It can then be seen which machine components interfere with each other. Also, in a preferred embodiment on the screen buffer times that are not directly in the cycle time, thus are not relevant cycle time and remain with regard to the cycle time as unused time, be displayed separately.

In addition, it may be useful for the operator if the command sequences determining the cycle time are represented overall as a critical path. He then sees which functions and commands are critical for the cycle time resulting from the process and which effect it would have if certain command functions were to be changed or alternatively implemented.

If a progress line is displayed for the diagram on the screen, which indicates the position at which the machine is currently present during the execution of the sequence program, the operator can immediately see, with regard to the screen, in which working position the machine is currently located and which Time since the beginning of the cycle has already expired. Furthermore, he can recognize which further commands and functions still have to be carried out during the remaining cycle. This type of view is called progress mode. In particular, he can also recognize which commands would run parallel in time or overlap in time. From this, the machine can - if the necessary knowledge has been deposited (for example in the form of collision rules) - or the operator can detect possible collisions.

A separate view option is to realize a so-called roll mode, in which the current flow position is locally fixed on the screen. Under the fixed marking, the sequence program, as it were, rolls in accordance with the processing, for example in the form of a band which runs from one side to the other side over the screen. This type of representation is helpful in continuous operation of the machine. Of course, it can also be provided to switch between the different types of views. The present invention will be explained in more detail below with reference to the accompanying drawings with reference to a concrete embodiment. The drawings show in

1 is a schematic representation of a screen with a flowchart with exact temporal correlation of the programmed command functions according to an embodiment of the invention,

2 shows a flow chart with dependencies of the command functions without temporal correlation according to the prior art,

Fig. 3 is a flowchart in the manner of a KO display according to the prior art and

4 is a diagram in the manner of a sequence graphic according to the prior art

 Technique showing the timing, but not the structural structure and dependencies between the individual process steps.

The embodiment of the present invention will be explained with reference to FIG. In this case, a screen device 10 is shown in Fig. 1, on which the operation and production process is shown in the injection molding machine.

First, a production process in an injection molding machine is completely entered into the control thereof. This can be done by programming or by reading a known production process and its modification. Complete programming requires the knowledge of all production parameters and setpoints. With regard to the programming itself, reference is made to WO 2006/089451.

On the basis of a model stored in the control of the machine - for example, the controller models for those involved in the production process To machine components operated in the course of the production process - the actuation profiles for all machine components included in the production process are now calculated. The actuation profiles include the starting points as well as the time extension of the operation.

Should it not be possible to create an actuation profile for certain machine components, such as tool subcomponents (e.g., core pulls), the missing values for their creation must be manually retrieved and manually entered by an operator by means of an input device. In addition, the synchronization and interlocks are determined from the programming.

The actuation profiles of the machine components involved in the production process are then set in temporal correlation with each other according to the programmed production sequence, whereby the entire production process with the respective starting point for an actuation of a machine component and its time extension is known. In addition, it is then clear which machine components overlap in their operation or otherwise correlate in time.

Now it is possible to change to a simulation mode in which at least one cycle is completed in terms of control. This means that while the controller acts as if it were going through the production cycle, no machine component actually operates.

During the simulation, it is checked on the basis of stored collision rules whether the time sequence, in particular with regard to its logic, is correct and whether there is a collision of two or more machine components.

A logically correct chronological sequence is not given, for example, if the injection of a melt material takes place in an injection molding machine without the mold having been closed. Also, it must not be that an ejector is actuated when the plastic melt injected in an injection molding machine, but the tool is not yet open.

Of course, there may also be applications where exactly the ejector must be operated with the tool closed.

The simulation process can be displayed in a corresponding graphic on a screen. The commands preferably run in the time provided and calculated for this purpose.

With reference to FIG. 1, the icon 50 indicates the start of an injection molding cycle. The icon 52 indicates the end of an injection molding cycle. Once this process has been completed, the process starts again at the beginning of the cycle (icon 50). Between these two markings (icons 50 and 52), the entire sequence of a cycle is modeled in temporally correct correlations of the command functions with each other. The associated actuation profiles are calculated and stored in the control.

In the present case, the individual process steps are shown in the form of the command functions. Each individual command function has a bar, at the beginning of which there is a command icon indicating the function, and which is extended by means of a bar until the (temporal) end of the process step.

Thus, it can be seen from the upper contiguous line representation that during operation of the injection molding machine, the injection mold is first closed (icon with reference numeral 54). Subsequently, the plasticizing and injection unit is moved up to the tool (icon with reference numeral 56) and the injection and Nachdruckvorgang performed (icon with reference numeral 58). Next, a cooling operation is performed (icon with reference numeral 60) extending to a time when the tool is opened (icon with reference numeral 62). Parallel (and shown in Fig. 1 below) are still (not specifically designated by reference numerals) further steps such as Screw retraction, opening the plasticizing, the metering of a plastic melt, the lifting of the plasticizing and injecting the tool and the operation of the ejector carried out. These steps are displayed in parallel with a corresponding dependency branch. Attention is paid to the correct temporal correlation of the individual command functions, which are displayed in the correct way and stored in the machine control, which can be recognized by the time axis (in the picture below).

In the step shown in FIG. 1, the cooling time in the mold is taking place after the holding pressure and at the same time the plasticizing and injection unit (see lower bar) is again metering plastic melt. Depending on progress, the progress line 26 travels either via the screen setup (progress mode) or alternatively it remains fixed and the other display moves under the progress marker from right to left (roll mode).

When performing the simulation, a progress line 26 now travels over the cycle shown on the screen. At the same time, the controller uses the stored collision rules to check the correct chronological sequence and a possible collision of two or more machine components.

If an error, e.g. If a wrong logical sequence or a collision of machine components is detected, the simulation stops and thus the progress line and the conflicting command functions are displayed graphically.

From FIG. 1, indication 22 indicates the time extent of the entire cycle, the cycle time being determined by the so-called (time-) critical path 20, which contains the cycle sequence determining command sequence. This critical path allows the operator to recognize those command functions that determine cycle time. By changing these command functions, he can change the cycle time. Further, in the figure, reference numeral 28 indicates a period serving as a buffer. In the present case exists between the end of the command function shown and the step in which this function must be completed before another command function, for example, the start of bringing the plasticizing and injection device to the tool (reference numeral 56), a free time phase 28, the does not affect the cycle time and thus represents a buffer period.

From Figure 1, one can further recognize the time (see reference numeral 30) that has elapsed between the start of the cycle and the current expiration position. It is also possible with the present invention, the time of a particular command, for example, the cooling command 60 with the temporal extension 24, read. Alternatively, it is possible to determine a period between two points by two markers in the diagram.

Overall, in the simulation mode, the operator can check the programming of a production process and recognize an incorrect programming of the production process without the machine actually being operated and being in danger of being damaged in case of incorrect programming in production mode.

Of course, it is still possible to speed up the simulation process compared to the normal real-time process (time-lapse operation), to slow down (slow-motion operation), to stop altogether or to select a so-called step mode in which the production process is carried out step by step. Furthermore, the display can be enlarged or reduced on the screen (zoom functions). Another preferred function is the representation of all machine components that are active in the current simulation time. In this way you can see collisions very well. Other processes, such as the previous cycle, a reference cycle, etc., can also be displayed. Furthermore, it is possible to change the configuration of the graphic, for example to select whether only the current cycle or the current as well as the previous cycle or parallel reference cycle should be displayed.

It is also possible to export, import or store the sequences of the sequences - possibly including predetermined setpoint and parameter values and a reference cycle. For example, external analyzes can be carried out or a proven production process can be saved for later use.

List of Reference Screen

Critical path (cycle time determining command sequence) Cycle length

command length

Scoreboard

slack

Expired cycle time

Claims

claims 1 . Method for checking a stored production sequence for one or more machines with a cyclical machine operating sequence,  in which  a production sequence for one cycle is stored using command functions in the control of the machines or of the machines, whereby all necessary production parameters and set values are specified,  for each driven machine component, from the command functions, the production parameters and the setpoints, a temporal actuation profile is created, in particular calculated, with a starting point and a temporal extent,  the actuation profiles are set in temporal correlation with one another according to the production process,  characterized in that  in a simulation mode of the machine or of the machines, the production process is run through for at least one cycle and is checked on the basis of time-scale-accurate assignments, in particular corresponding stored collision rules, whether for the entirety of the temporal actuation profiles in their temporal correlation  the timing of the command functions is correct, in particular logically correct, and  - There is a collision of two or more machine components. 2. The method according to claim 1,  characterized,  that the collision rules specifications  - the logic of the program flow and / or  - to check the synchronizations and / or  - To check the lock commands and / or - to check the correct parameterization of the individual command functions. 3. The method according to claim 1 or 2,  characterized,  that for machine components such as tool auxiliary controls for which no time actuation profile can be created from the command functions, the production parameters or the setpoint values, a query for inputting the necessary values for the temporal behavior is initiated, the actuation profile is determined taking into account the entered values. 4. The method according to any one of claims 1 to 3,  characterized,  the simulation mode is displayed on the screen when running through a cycle. 5. The method according to claim 4,  characterized,  that incorrect chronological sequences or collisions of two or more machine components are indicated on the screen. 6. The method according to any one of claims 4 or 5,  characterized,  that the display is done on the screen in real time. 7. The method according to any one of claims 4 to 6,  characterized,  that the command functions on the screen by a representation of the command with a start time and an extension to be displayed until the timely correct end. 8. The method according to any one of the preceding claims 4 to 7,  characterized,  that a buffer time that does not enter into the cycle time is displayed separately. 9. The method according to any one of the preceding claims 4 to 8, characterized, that a cycle time determining command sequence is displayed as a critical path. 10. The method according to any one of the preceding claims 4 to 9,  characterized,  a progress line indicating the position at which the machine is currently executing the sequence program is displayed. 1 1. Method according to one of the preceding claims 4 to 10,  characterized,  that the elapsed time between a cycle start and the current position in the sequence program is displayed. 12. The method according to any one of the preceding claims 4 to 1 1,  characterized,  a view mode is displayed on the screen in a scrolling mode, in which the current sequence position is locally displayed on the screen and the programmed sequence runs according to the processing of the production process in the form of a band on the screen. 13. The method according to any one of the preceding claims 4 to 12,  characterized,  in a progress mode, a view is displayed on the screen, which indicates which command functions have already been performed and / or which are currently being performed and / or which others are still to be carried out in the remaining cycle. 14. The method according to any one of the preceding claims 4 to 13,  characterized,  that from two points marked on the screen in the process, the time in between is determined. 15. The method according to any one of the preceding claims 4 to 14, characterized, that a cycle cycle preceded by the current cycle or a Reference cycle is displayed. Method according to one of the preceding claims, characterized, the continuous display is halted upon detecting an incorrect timing or a collision of two or more machine components.