DE10106335A1 - Method for monitoring a production process and for ascertaining the number of manufactured products, requires automatically determining the presence of a tool of the production machine in a first or in a second state - Google Patents

Abstract

Monitoring of production process can be carried out more accurately by equipping each production machine with sensors indicating the status of the machine e.g. tool open, tool closed, machine in fully automatic operation, machine in manual operation, and assigning a code to the various tools, and detecting an identification code for the actual tool in the machine etc, and by eliminating errors when ascertaining the number of manufactured parts.

Description

Technical field

The present invention relates to a method for monitoring the Production process and to record the number of products manufactured during operation a system with automatic production machines, which by exchanging a the machine associated tool or the like for the production of different products are convertible.

The invention further relates to a device for monitoring the Production process and to record the number of products manufactured in one System with automatic production machines.

Underlying state of the art

In the manufacturing industry it often happens that a larger number of different Tools can be used for a group of machines. These tools can be used in different machines, so that the production by the current demand of different parts can be controlled. An example is a Plastic company that produces plastic parts by injection molding. The  Machinery can, for example, 50 injection molding machines in different sizes and 250 tools for manufacturing various parts. A majority of these Alternatively, tools can be used in several of the injection molding machines, the choice of the injection molding machine in which the tool is inserted depends on which one is free when manufacturing starts.

Examples of other types of manufacture, under which corresponding conditions can rule, are injection molding of rubber parts, punching or pressing of Sheet metal parts, vacuum forming, hot pressing, press casting etc.

If a production unit in this way consists of a larger number of machines and Tools, there is an administrative problem, namely the entire one Information about the type of manufacture carried out on a Warehouse management program to be transferred in a simple manner. The desired The primary information to be transmitted is which parts have been manufactured and in what number. Usually one is on the reports of the Operator instructed on completed production. However, this leads to Risks due to incorrect reading of counters and incorrect Type specification of the part specified, manufactured, etc. in the report. Errors of this kind can easily arise because the operator, who can have the task Monitoring a number of injection molding machines forgets to read a counter and reset to zero, for example when changing tools, or forgets indicate that a new part is being manufactured.

Disclosure of the invention

An object of the invention is to provide a method and an apparatus for To create monitoring of production machines, which u. a. the above Sources of error by creating an operator independent Eliminate monitoring and detection of manufactured parts.  

Another object of the invention is to provide a new identification technique of manufacturing tools and thus of manufactured parts using To create signal codes of the tool without the tool being an energy source must contain.

According to the invention, these objects are achieved by means of methods of the type mentioned in the introduction in that

• a) with respect to each current machine and regularly with a frequency which greater than the cycle time of the respective machine, the presence of the Tool of the machine in a first or a second of two States are automatically detected, which are chosen so that a change from going through the first state to the second state Manufacturing cycle means
• b) operating the machine in an automatic position, a manual position or a semi-automatic position is detected,
• c) an identification code for the current tool is recorded in the machine, and
• d) electrical signals corresponding to the condition and code detected to collect information regarding the number when operating the machine in the automatic position of manufactured products of a certain type become.

When using this method, an automatic reporting and recording of the Type of part produced and the number of parts produced, the Risks of operator error are eliminated.  

In a preferred use of the method, the tool of the machine guides one electrical tool-identifying code via a coupling arrangement, which contains two contact elements, which allow automatic operation of the Machine must be interconnected. So it cannot be automatic Manufacture take place without information regarding the number of parts manufactured and correct type of part.

Multipole contact members are preferably used and one Signal voltage is interconnected by the machine and the tool Contact members supplied and on contact elements in the contact member of the tool distributed in a manner that forms a unique tool code. This is on the contact elements in the contact member of the machine and one Analog-to-digital converter for converting to a digital identification code fed. This ensures that the tool has a code in the form of can give electrical signals without the tool itself an energy source must contain.

Further features of this method and a device according to the invention are Subject of the further claims.

The application of the invention is based on the fact that each manufacturing machine to be monitored is provided with sensors which can decode signals which correspond to the following states:

• - tool open,
• - tool closed,
• - tool code,
• - machine in the state of fully automatic operation,
• - machine in manual mode,
• - Machine in the state of semi-automatic operation (not with all machine types available).

All sensors are connected via an analog-digital converter to a computer which records all sensors, for example twice a second. The following information can be automatically recorded and forwarded to a warehouse management system:

• - the number of manufacturing cycles, each change of a tool, for example from closed to open state, corresponds to one cycle,
• - The code of the tool, which provides clear information about the part manufactured supplies,
• - If the machine is in the state of fully automatic operation, both the Number of parts produced as well as the amount of raw material consumed recorded (every tool has a known material consumption),
• - If the machine is in manual or semi-automatic mode, then this usually means that trimming or a test run is taking place no faultless parts are produced (the information is only used to record the Material consumption used without any manufactured parts in the warehouse be fed).

In addition to information regarding warehouse management and raw material consumption, this can System also valuable information for a statistical description of it provide how every machine and tool has been used, degree of exploitation, Cycle times, business interruption, etc.

The invention is described below with reference to that in the accompanying Drawings shown as an exemplary embodiment of the tool identification system explained.  

Brief description of the drawings

Fig. 1 is a schematic block diagram of a system identification tool.

Fig. 2 shows the detection of the production cycles of the tool.

Preferred embodiment of the invention

The block diagram in FIG. 1 schematically shows a monitoring system for a production machine, which can be used together with a plurality of different tools, e.g. B. an injection molding machine for plastic parts. In this case, 20 denotes a contact element arranged on the machine, in this example provided with ten poles, which can be interconnected with a second contact element 30 arranged on a tool. The contact member 20 is preferably designed as a father contact and the contact member 30 as a mother contact. A plug made of insulating material is designated by 40 , which can be inserted into one or the other of two further two-pole mother contacts 50 and 60 arranged on the contact member 30 in order to mechanically influence the contact elements therein. The contacts 50 and 60 are only shown schematically in order to clarify the function.

The contact element 30 is set up to emit a tool-identifying signal code, which is fed via the contact element 20 and a multiple conductor 70 to an analog-digital converter 80 , the output 81 of which is connected to a computer (not shown) for collecting, recording and sorting incoming data. The contact element 30 does not have its own energy source, but is fed by means of a signal which is supplied to the contact element 30 from a connection 71 , the conductor 70 and the contact element 20 .

The analog-digital converter 80 is also provided with two inputs 82 and 83 , to which information about the state of the tool is fed.

90 schematically denotes a switch with two positions in this case, which correspond to manual operation or automatic operation of the production machine. When the switch 90 is in the right position, shown by a broken line, the input 91 is directly connected to an output 92 , which means that the entire monitoring equipment with the contact members 20 and 30 is bridged and the machine is operated manually can. Alternatively, a third position for semi-automatic operation can also be provided.

If the switch 90 is in the left position, there is no direct connection between the input 91 and an output 93 for automatic operation, but this connection runs via the contacts 4 and 9 of the contact members 20 and 30 . This means that the machine cannot be operated in automatic mode without the contact members 20 and 30 being connected together, which in turn means that the code of the contact member 30 is automatically transmitted to the analog-to-digital converter 80 via the mother contact member 20 . The machine cannot be operated in automatic mode without the current tool being identified.

In the illustrated embodiment, the contact member 30 is provided with the additional mother contacts 50 , 60 in order to enable identification of one or the other of two possible options of the tool. In plastic injection molding, for example, this can affect the color of a manufactured part if the part can be produced in one or the other of two colors in the same tool. The option must also have been selected so that the machine can be operated in automatic mode. This is done by inserting the plug 20 into one of the contacts 50 or 60 .

Functional description

The embodiment shown uses contact members with ten contacts, apart from the two option contacts mentioned. The contacts and the corresponding connections have been numbered 1-10. Of course, both more and fewer contacts can be used to change the number of possible tool codes. With the seven inputs of the analog-digital converter shown, 2 ⁷ = 128 different tool codes can be taken into account. With another input, the number 256, etc.

When the switch 90 is in the left position according to automatic operation, the input 91 is connected to the contact 4 in the contact member 20 , while the output 93 is connected to the contact 9. To close the circuit between the contacts 4 and 9 in the contact member 20 , the contact member 30 must be interconnected with the contact member 20 . Furthermore, the plug 40 must be inserted into the contact 50 or 60 in the contact member 30 . When the plug 40 is inserted into the contact 50 , a current path is created in the contact member 30 from the contact 4 via the right contact element 51 in the contact 50 to the contact 9. This enables automatic operation. The corresponding function is achieved when the plug 40 is inserted into the contact 60 , which is easy to see.

In the illustrated embodiment, the contact 3 in the contact member 30 is connected to the contacts 2, 6 and 7, which forms the unique code for this particular tool. Via a corresponding contact in the contact member 20 , the contact 3 is fed from the connection 71 with a signal voltage, which can preferably be 0 volts, and which is distributed to the other contacts 2, 6 and 7. This code is received by the analog-to-digital converter 80 as a unique identification of the current tool.

When inserting the plug 40 into an option contact, for. B. the contact 50 , the signal voltage at the contact 3 via the left contact element 52 of the contact 50, the contact 5 is supplied. This signal is also fed to the analog-to-digital converter, which identifies the selected option, for example the one of two possible colors. If plug 40 is instead inserted into contact 60 , the signal voltage is applied to contact 10, indicating that the other option has been selected. In this embodiment, an option choice must be made, because otherwise no connection is obtained between contacts 4 and 9, which is necessary for automatic operation.

In summary, for automatic operation it is necessary that both the contact members 20 and 30 are interconnected, as a result of which the analog-digital converter is forced to receive information regarding the tool used, that is to say that an option is selected by inserting the plug 40 into the contact 50 or 60 , whereby the analog-to-digital converter also forcibly receives information regarding the valid option.

Of course, the option contacts can be completely omitted if this option is not desired, or alternatively, more than two Options are provided.

The technique described allows u. a. the advantage that the tool has a can provide easily identifiable code to an analog-to-digital converter without that the tool itself must contain an energy source.

The system described above is complete from the operator's reports independent, since the information is automatically fed to the analog-digital converter becomes. The machine cannot be operated in automatic mode without that the contacts are interconnected, and as soon as this happens, that is Tool identified and a possible option identified. The whole Manufacturing is assigned to the correct part.  

According to the number of parts produced is counted in that the Presence of the tool of the machine in a first or a second of two states are detected, which are selected so that a change from the first State to the second state means going through a manufacturing cycle. At an injection molding tool, the first state can be a shot tool correspond, during which material is pressed into the tool and shaped there while the second state may correspond to an open tool, i. H. Demoulding the manufactured part.

In Fig. 2, the time changes of a voltage U at a limit switch connected to a production tool is shown with a solid line. In an injection molding tool, the low voltage level can correspond to a closed tool, while the high voltage level corresponds to an open tool. Because demolding takes much less time than inserting material into the tool, the high tension is present for a much shorter time than the low tension. Since the transition from high to low voltage is a manufactured product, the frequency with which the voltage is sampled must be so high that none of the high voltage pulses in the diagram is missed. In systems with a large number of machines and in which at least one of the states for one of the tools is relatively short, problems can arise due to very high demands on the computer capacity.

This problem can be reduced by extending the short voltage pulses, as shown in broken lines in FIG. 2, so that they essentially correspond to half the period. This can be achieved, for example, by means of a switching-delayed time relay, which maintains the high pulse voltage even for a short time after the tool changes state.

Accordingly, the transition from high to low voltage, for example, can be a Change of state of the tool represents the manufacture of a part.  

Corresponding voltage signals are fed to the analog-digital converter via inputs 82 and 83 .

The converter 80 thus receives information regarding both the type of the part produced, possibly with the option selected, and the number of parts produced. This information can be fed to a warehouse management program which records the number of manufactured parts in the warehouse, the raw material consumption and the remaining raw material quantity.

In addition to injection molding machines, the technique described can also be used for a number of other manufacturing machines are used, instead of "open" and "closed" position different positions of a movable tool part, such as For example, a movable molding table can be used in a press.

Common for different applications of the invention is the fact that a computer connected to the analog-to-digital converter 80 can provide accurate and reliable information regarding both the type and the number of products manufactured and thus also regarding the material consumption, since the quantity of material is known for each part.

Claims (10)

1. A method for monitoring the production process and for recording the number of products produced when operating a system with automatic production machines, which can be converted to produce different products by exchanging a tool or the like assigned to the machine, characterized in that

• a) with respect to each current machine and regularly with a frequency that is greater than the cycle time of the respective machine, the presence of the tool of the machine is automatically detected in a first or in a second of two states, which are selected so that a change from the first state to the second state means going through a manufacturing cycle,
• b) the operation of the machine is detected in an automatic position, a manual position or a semi-automatic position,
• c) an identification code for the current tool is detected in the machine, and
• d) electrical signals corresponding to the detected condition and the detected code are used to detect information regarding the number of products of a certain type produced when the machine is operating in the automatic position.

2. The method according to claim 1, characterized in that only the at Operation of the machine in the automatic position as manufactured products be viewed properly and that the number of these products one Warehouse management system are fed. 3. The method according to claim 1 or 2, characterized in that the entire Material consumption is determined by the number of tools continuous cycles can be summed regardless of whether it is in automatic Position, manual position or semi-automatic position, and this number is multiplied by the material consumption in each cycle. 4. The method according to any one of claims 1-3, characterized in that it for Manufacture of plastic products by injection molding is used. 5. The method according to any one of claims 1-4, characterized in that the Machine using an electrical tool-identifying code supplies a coupling arrangement which contains two contact members which interconnected to allow automatic operation of the machine Need to become. 6. The method according to claim 5, characterized in that multi-pole Contact elements are used and a signal voltage from the machine Tool supplied via the interconnected contact links and on a Number of contact elements in the contact member of the tool in one way is distributed, which forms a unique tool code, which the Conveyed contact elements in the contact member of the machine and an analog Digital converter for converting to a digital identification code is fed. 7. Device for monitoring the production process and for recording the number of products produced in a system with automatic production machines, which can be converted to produce different products by exchanging a tool or the like assigned to the machine, characterized by

• a) means by which, with respect to each current machine and regularly at a frequency which is greater than the cycle time of the respective machine, the presence of the tool of the machine is automatically detected in a first or in a second of two states, which is so are chosen such that a change from the first state to the second state means going through a manufacturing cycle,
• b) means for detecting the operation of the machine in an automatic position, a manual position or a semi-automatic position,
• c) means ( 30 ) for identifying the current tool in the machine by means of a unique code, and
• d) means ( 80 ) for transmitting electrical signals corresponding to the detected condition and the code to means for detecting information relating to the number of products of a certain type produced when the machine is operating in the automatic position.

8. The device according to claim 7, characterized by a coupling arrangement which contains two contact members ( 20 , 30 ) for transmitting an electrical tool-identifying code from the tool to the machine, the contact members ( 20 , 30 ) being interconnected to allow the operation of the machine have to. 9. The device according to claim 8, characterized in that the contact members ( 20 , 30 ) are multi-pole, the arrangement contains means for supplying a signal voltage from the machine to the tool via the interconnected contact members, and means for distributing the signal voltage to a number of Contact elements (2, 6, 7) in the contact element ( 30 ) of the tool in a manner which forms a unique tool code which mediates the contact elements in the contact element ( 20 ) of the machine, and analog-digital converter means for converting the tool code into a digital identification code. 10. The device according to claim 9, characterized in that it is set up for producing similar products in different variants and that the contact member ( 30 ) of the tool has at least two further contacts ( 50 , 60 ), each with a contact element (5, 10th ) are connected in the contact member ( 30 ) of the tool to convey a variant code to the contact elements (5, 10) in the contact member ( 20 ) of the machine.