METHOD AND DEVICE FOR IDENTIFYING WORKPIECES

Description

Technical field

[0001] The invention relates to a method and a device for identifying workpieces during a machining process, wherein the workpieces consist of wood, wood-based materials or the like. State of the art

[0002] In general, workpieces made of wood, wood-based materials, or similar materials must be detected and marked during a processing step. In the furniture and construction component industries, the processes for marking workpieces of the type mentioned above often involve the use of identification media such as barcodes, transponders (RFID), and microchips.

[0003] The marking usually serves to uniquely identify a workpiece during production. Additionally, workpiece properties such as dimensions, color, and material can be stored on the marking carrier. By linking the information on the marking carrier with corresponding routines in the machining process, workpiece processing can be largely automated.

[0004] However, if marking carriers are applied superficially to a workpiece, there is a risk that they will be lost or damaged during subsequent processing. Furthermore, the marking carriers often have to be removed after the processing, as they can be disruptive, for example, from an aesthetic or production-technical perspective. Furthermore, the application and detection of the marking carriers require additional equipment.

[0005] EP2230626 discloses a method for marking solid panel workpieces by attaching an RFID tag, particularly in a recess to be produced in the workpiece, wherein the inserted RFID tag is provided with a coating for environmental protection. DE102014208746 discloses another method for marking workpieces, comprising the steps of applying a codable coating, particularly a film, edge, and / or adhesive, to a surface of the workpiece, as well as reversibly or irreversibly coding the coating by a coding unit such that the coding can be read again by a reading unit.

[0006] When machining workpieces made of wood, wood-based materials, or similar materials, problems continue to arise when, for example, external influences such as temperature change the dimensions of the workpieces, resulting in the workpieces being inaccurately positioned in a processing machine, resulting in the processing step being performed improperly. However, with the help of electronic recording devices, workpiece properties can be recorded upstream of the processing machine, and the processing step can be adjusted accordingly.

[0007] EP2308659 discloses a device for processing workpieces, which device comprises a conveyor for conveying the workpieces and an electronic detection device for detecting a position of an optical and / or three-dimensional structure of the workpieces conveyed on the conveyor.

[0008] If a processing step is carried out improperly, the subsequent processing step may be adversely affected or the incorrectly processed workpiece may leave the processing process unnoticed.

[0009] Another example of a previously known method for identifying workpieces can be found in DE 10 2017 207 992 A1. Description of the invention

[0010] The invention is based on the object of providing a method and a device for identifying workpieces, which enable control and quality control of the workpieces in the machining process, whereby the necessary equipment expenditure is to be kept low.

[0011] According to the invention, this object is achieved by a method for identifying workpieces having the features of patent claim 1 and by a device for carrying out the method according to patent claim 10. Advantageous embodiments and improvements of the invention can be found in the subclaims.

[0012] The invention is based in particular on the finding that synergistic effects can be used in the identification and quality control of workpieces in a machining process, which reduces the equipment expenditure originally required for this purpose. Furthermore, it was recognized that in order to control and monitor a machining process with different workpieces, it is not necessarily necessary to individually mark each workpiece. For this purpose, the present method identifies the workpieces based on their workpiece properties. If the workpiece properties for workpiece identification correspond to the workpiece properties for workpiece testing, both processes can be carried out with the same detection system. The detection of geometric and / or physical workpiece properties has proven particularly suitable in this context.

[0013] Using these findings, the invention provides a method for identifying workpieces according to claim 1.

[0014] The invention thus ensures that the workpiece can be identified exclusively based on its properties. The workpiece's identification data are thus inextricably linked to the workpiece. The workpiece can thus be identified at any time during the machining process. Additional attachment of identification carriers is therefore unnecessary.

[0015] Furthermore, this results in a dynamic machining process, since a machining step is adapted to the situation according to the existing workpiece properties of the workpiece to be machined and is not limited to defined data of a marking carrier.

[0016] Another advantage is that the recorded workpiece properties used to assign a workpiece to a corresponding category are also the properties of a workpiece 35 that are to be tested for possible deviations from a standard. The synergistic effect is therefore that the recorded workpiece properties for workpiece identification and the workpiece properties to be tested match. The equipment required for recording workpiece properties for workpiece identification and workpiece testing can be limited to the same recording system.

[0017] Preferably, the method according to the invention is implemented such that at least one workpiece property to be changed is detected after the machining step, and a next process step is determined on this basis. This ensures that the workpiece is properly machined according to the machining step. It is advantageous that the next process step depends on the machining result of the previous machining step.

[0018] Furthermore, it is advantageous that information about the machining success of the workpiece is generated and associated with it. With the help of the additionally acquired information about the machining success of the workpieces, the machining process can be controlled more effectively. The method according to the invention is particularly preferred, according to which the workpiece is further machined in the next process step or is removed from the machining process. This has the advantage that only properly machined workpieces remain in the machining process and subsequent machining steps are not influenced by improperly machined workpieces. Workpieces with irreversible machining errors do not remain undetected in the machining process and are removed. In contrast, workpieces with reversible machining errors can be subjected to additional machining in a further machining step.

[0019] In a further advantageous embodiment of the method of the invention, the at least one workpiece property to be changed is additionally detected before the machining step, and the workpiece is machined according to the assigned workpiece category and the additionally detected workpiece property to be changed.

[0020] By recording at least one workpiece property to be changed before the machining step, it is possible for a workpiece to undergo a machining step multiple times. This has the advantage that when a machining step is repeated, different workpiece properties can be changed each time, rather than the same machining step being performed repeatedly.

[0021] The present method of the invention is characterized in particular in that the workpiece is assigned to a workpiece category by combining a plurality of the same and / or different workpiece properties.

[0022] Consequently, depending on the number of recorded identical and / or different workpiece properties, a corresponding number of definable workpiece categories is available into which the workpieces can be assigned. The advantage of this is that by increasing the number of recorded workpiece properties, the number of assignable workpiece categories can be increased accordingly.

[0023] In a further preferred embodiment of the method, physical and / or geometric workpiece properties are recorded. These can be, for example, weight information, dimensions, colors, or three-dimensional structures of the workpieces.

[0024] The physical and / or geometric workpiece properties offer a multitude of different sets of values ​​to be recorded. This makes it possible to provide a data pool with a variety of workpiece properties and combine them into a variety of different workpiece categories, based on which the workpieces are identified.

[0025] In a further preferred embodiment, the workpiece properties to be recorded and the workpiece categories are defined in a data pool.

[0026] This creates a data pool of workpiece properties and workpiece categories from a multitude of workpiece properties and workpiece categories. This has the advantage that different data pools of workpiece properties and workpiece categories can be flexibly defined for different machining processes with different workpieces, on the basis of which different workpieces can be identified.

[0027] It is particularly preferred in the present method that the workpiece properties recorded during the machining process are additionally stored in the data pool.

[0028] In this way, a data pool of workpiece properties is generated that corresponds to the workpieces currently in the machining process. This has the advantage of providing real-time data on the workpieces in the machining process and their properties.

[0029] It is also preferred that a process control system accesses the data pool and controls the processing process.

[0030] This allows individual processing steps to be coordinated with each other and the processing process to be utilized optimally. Furthermore, the process control system provides the user with an overview of the workpieces currently being processed and enables the flexible design of a higher-level production process.

[0031] The present invention further provides a device for carrying out the method, comprising: at least one detection system arranged upstream of a workpiece processing unit to detect workpiece properties necessary for assigning a workpiece category and at least one workpiece processing unit arranged to process the workpiece according to an assigned workpiece category.

[0032] The invention thus ensures that, upstream of the processing unit, the processing step to be performed is determined based on the assigned workpiece category. This has the advantage that a marking carrier is no longer required. In addition to recording the workpiece properties for identification, the detection system also enables the inspection of these workpiece properties. This has the advantage that the equipment required is limited to one detection system.

[0033] A machining process with individual machining steps can also be carried out dynamically, since a machining step is adapted to the situation according to the recorded workpiece properties and is not dependent on the data of a marking carrier.

[0034] In a preferred embodiment of the device, at least one detection system is set up after the workpiece processing unit in order to detect the workpiece property to be changed.

[0035] This ensures that the workpiece is machined correctly according to the machining step and additional information about the machining success of the workpiece is generated.

[0036] In an advantageous embodiment of the device, at least one detection system is arranged in front of the processing unit in order to detect the workpiece property to be changed.

[0037] This determines whether machining needs to be performed in the machining unit according to the assigned workpiece category. This has the advantage that a machining unit can perform different machining steps on a workpiece.

[0038] Furthermore, in a preferred embodiment of the device, the detection system comprises one and / or more active and / or passive sensors, in particular mechanical, thermoelectric, resistive, piezoelectric, capacitive, inductive, optical, acoustic, or magnetic sensors. This allows a variety of geometric and / or physical workpiece properties to be detected. It is advantageous that the sensors can be individually selected according to the properties of the workpieces to be machined.

[0039] In a particularly preferred embodiment of the device, a switch element is arranged downstream of the processing unit in order to discharge the workpiece or to feed it to a further processing step.

[0040] The diverter element allows improperly machined workpieces to be either removed from the machining process or re-entered into a machining step. This has the advantage that these workpieces do not have to be immediately removed by hand or relocated to another point in the machining process. This prevents improperly machined workpieces from consuming the capacity of subsequent machining steps.

[0041] Further preferably, the device comprises a process control system to control the machining process based on the stored data pool of the recorded workpiece properties and the assigned workpiece categories.

[0042] This allows individual processing steps to be coordinated with one another, thus ensuring optimal utilization of the entire process. Furthermore, the process control system provides the user with an overview of the workpieces currently being processed, thus enabling the flexible design of a higher-level production process. Short description of the drawings

[0043] Further features and advantages of a device, a use, and / or a method will become apparent from the following description of embodiments with reference to the accompanying drawings. These drawings show: Figure 1 : a schematic drawing of a device for identifying workpieces in a machining process; Figure 2: a schematic drawing of a device for identifying a door and a table top in a processing process which includes, for example, the processing steps of painting and edge banding. Description of embodiments

[0044] Figure 1 shows a schematic drawing of a device 100 for identifying workpieces 3 in a machining process according to a first embodiment of the invention.

[0045] The workpieces consist of wood, wood-based materials, plastics, metal, or the like. The workpieces 3 are known in particular from furniture manufacturing, commercial furnishing, vehicle and ship construction, house construction and interior fittings, and the like.

[0046] Device 100 has one or more processing units for processing the workpieces. Processing units include, for example, processing and coating machines known from practice, such as formatting and edge banding machines, painting machines, wide belt sanders, planers, drilling and dowel driving machines, panel dividing saws, and the like.

[0047] In particular, the device shown is such that two detection systems 1, 4 are arranged before and one detection system 5 after the processing unit 2.

[0048] The detection systems 1, 4, 5 are equipped with different sensors such as mechanical, thermoelectric, resistive, piezoelectric, capacitive, inductive, optical, acoustic or magnetic sensors.

[0049] In the present embodiment, a conveyor device 9 is configured to enable a closed conveying circuit of a workpiece 3.

[0050] The conveying device 9 for conveying the workpieces 3 is configured, for example, in the form of conveyor belts, conveyor belts, conveyor chains, driverless transport systems (FTS), autonomous handling systems, robots and the like.

[0051] The workpieces 3 are reintroduced into the conveyor circuit at a point S, and with the aid of a switch element 7, it can be controlled that they either remain in the conveyor circuit, are discharged to an external storage unit 11, or are transported to another processing machine 10. The switch element 7 is preferably arranged directly after the third detection system 5.

[0052] Furthermore, the device 100 is designed such that the point S at which the workpieces 3 are transported back to the processing unit 2 via the switch element 7 and at which unprocessed workpieces 3 are introduced into the processing process is located in front of the first 1 and second detection system 1, 4.

[0053] The device 100 is in particular configured such that a central process control system 8, for example via a wireless connection, controls the individual units (1, 2, 4, 5, 6, 7, 9, 11) of the device 100. The Figure 1 The device 100 described can be considered a separate process unit. The process control system 8 can access a data pool 20 to control the machining process.

[0054] In further embodiments not shown, it is provided that an overall process consists of process units connected in series and / or in parallel, whereby a continuous and seamless machining process of a workpiece 3 is enabled.

[0055] The following is an example of the procedure based on the Figure 1 shown device 100 will be described.

[0056] In a first step of the claimed method, the workpiece properties of the workpiece 3, which are defined for identification purposes and which are introduced into the machining process at the point S and transported via the conveyor device 9 to the first detection system 1, are first detected with the aid of a sensor 6 of the detection system 1.

[0057] The workpiece properties suitable for identification are, in particular, geometric and / or physical properties. Depending on the geometric and physical properties of the workpiece 3 to be machined, a multitude of different workpiece properties arise that can be recorded in the current machining process. The workpiece properties to be recorded are defined in a data pool 20.

[0058] In the second method step, the workpiece 3 is uniquely assigned to a workpiece category based on the recorded workpiece properties and is thereby identified. A workpiece category is defined in the data pool 20 by one or more workpiece properties according to the combinatorics principle. According to the invention, a workpiece category is defined by a surface pattern in combination with a weight specification. In particular, instead of an individual value for the weight specification, a set of values ​​for the weight specification can also be defined.

[0059] The assignment of workpiece 3 to a workpiece category is carried out in particular by the process control system 8 by accessing the data pool 20. In doing so, the process control system 8 compares the values ​​of the workpiece properties of workpiece 3 acquired with the aid of the acquisition system 1 with the defined values ​​of the workpiece properties of the defined workpiece categories. If the acquired values ​​of the workpiece properties of workpiece 3 match the defined values ​​of the workpiece properties of a workpiece category, the process control system 8 assigns the workpiece 3 to this workpiece category, thereby identifying it.

[0060] Furthermore, the process control system 8 checks the recorded values ​​of the workpiece properties of the workpiece 3, for example, for possible deviations from a defined standard. Figure 1it is not shown that a further switch element can be installed in front of the processing unit 2, which ejects the workpiece 3 from the processing process if it does not comply with a standard.

[0061] After the workpiece 3 has been clearly assigned to a workpiece category and the workpiece properties have been positively tested for compliance with a standard, the third process step is initiated. In this step, the workpiece 3 is machined in the machining unit 2 according to the assigned workpiece category. In particular, one or more work processes for the machining unit 2 are stored in the process control system 8 for each workpiece category. The process control system 8 determines the machining to be performed on the workpiece 3 in the machining unit based on the workpiece category.

[0062] After machining the workpiece 3 in the machining unit 2, a third detection system 5 uses a sensor 6 to detect the changed workpiece properties of the workpiece 3. These are transmitted to the process control system 8 and stored in the data pool 20. Depending on the machining result of the machining unit 2, the process control system 8 controls the conveyance of the workpiece 3 with the conveyor unit 9 via the switch element 7 either again to the first machining unit 2, or to a storage unit 11, or to another machining unit 10.

[0063] The workpiece 3 is repeatedly fed to the first processing unit 2, for example, if the workpiece 3 was not machined properly, the error is reversible, and the machining can be performed again. A further machining step can also be performed with the same processing unit 2 at a different and / or the same location on the workpiece 3, thereby changing another workpiece property. In particular, the processing unit 2 is designed so that the workpiece 3 can be realigned in the processing machine 2.

[0064] If the machining result is improper and the error is irreversible or the machining is completed, the workpiece 3 is stored in the storage unit 11 of the device.

[0065] If the workpiece 3 is repeatedly fed to the processing unit 2, at least one second detection system can be provided upstream of the processing unit 2 to detect the changed workpiece properties of the workpiece 3. The work step in the processing unit 2 is determined and executed by the process control system based on the assigned workpiece category and / or changed workpiece properties of the workpiece 3.

[0066] All data relating to the recorded workpiece properties of the workpieces 3 during the machining process are stored in the data pool 20. By accessing the data pool 20, the process control system 8 can use a visualization to determine the location of a workpiece 3 of a specific category in the machining process and its current machining status. If different workpieces 3 are in the machining process, the process control system 8 can regulate the individual units 1, 2, 4, 5, 6, 7, 9, 10, and 11 based on the data from the data pool 8 and dynamically control the entire process.

[0067] Figure 2 shows a schematic drawing of a device 100 for identifying a door 12 and a table top 13 in a processing process according to a second embodiment of the invention, which includes, for example, the processing steps of painting and edge banding.

[0068] With the help of the Figure 2 In the following, the claimed method will be described using a possible processing process from practice.

[0069] At location S of device 100, two rectangular workpieces to be machined, which in the example presented here are a semi-finished cabinet door 12 and a semi-finished tabletop 13, are introduced into the machining process. Using a camera of a first optical detection system 1, the length and height of door 12 (X door , Y door ) and tabletop 13 (X table , Y table ) are recorded. Data pool 20 stores that for a combination of a specific value range [x 1 ,...,xn ] regarding the length with a specific value range [y 1 ,...,yn ] regarding the height of a workpiece, either the workpiece category "door" or "table" is defined.The process control system 8 accesses the data pool 20 and assigns the "door" category to the workpiece, for which a door length X and a door height Y were recorded using the optical detection system 1, if the recorded values ​​each correspond to a value in the corresponding value range defined for the length and height of the "door" category. The described process is carried out analogously for the tabletop 13. The "door" and "table" categories can then be clearly distinguished using the two value ranges for length and height if at least one of the two value ranges for length and height does not overlap. In the process described here, the value ranges are selected so narrowly that they simultaneously fulfill the function of checking the tabletop (12) and the door for deviations from a standard.The value range defined for assigning a workpiece to a category then corresponds to the permissible value range for a standard dimension.

[0070] After the unprocessed table top and the door have been clearly assigned to the category "door" and "table", the processing step stored in the process control system 8 for the respective workpiece category is carried out in the painting machine 2.

[0071] The second optical detection system 5 uses a camera 6 to detect the painting area and the pattern of the paintwork on the door and table top and stores the information in the data pool 20. Based on this information, the process control system 8, by controlling the switch 7, causes the partially painted door 15 to be transported back to the painting machine 2, a table top 17 to be diverted to a storage area 11 due to faulty painting, and a properly painted door 16 to be transported to the edge banding machine 10.

[0072] The second optical detection system 4 upstream of the painting machine 2 detects the partially painted part of the door 15. The process control system 8 assigns the door (15) to the "door" category with the help of the first optical detection system 1, which detects the height and length of the door. Based on the additional information about the painting status of the door 15, the process control system 8 initiates a further painting process on the door by the painting machine 2 for the "door" category.

[0073] The process for identifying the door 16 and the table top 14 before the edge banding machine 10 is analogous to the process described above. The edge banding machine 10 provides a door 19 and the table top 18 with an edge according to the workpiece category. List of reference symbols

[0074] 1 Detection system, optical detection system 2 Processing device, painting machine 3 Workpieces, 4 Detection system, optical detection system 5 Detection system, optical detection system 6 Sensor, camera 7 Switch element 8 Process control system 9 Conveyor device 10 Processing device, edge banding machine 11 Storage unit 12 Door 13 Table top 14 Painted table top 15 Partially painted door 16 Painted door 17 Incorrectly painted table top 18 Painted table top with edge 19 Painted door with edge 20 Data pool 21 Optical detection system

Claims

1. Method for identifying workpieces (3), consisting at least in part of wood, wood-based materials or the like, in a machining process (100) with machine tools and / or coating machines, said method comprising the steps of: detecting workpiece properties before a machining step by means of a detection system having different sensors, uniquely assigning the workpiece (3) to a workpiece category based on the detected workpiece properties, and machining the workpiece (3) in the machining step, which is determined by the assigned workpiece category of the workpiece (3), characterised in that the workpiece category is defined by the detected workpiece properties, namely a surface pattern in combination with an indication of weight.

2. Method according to claim 1, wherein at least one workpiece property to be changed is detected after the machining step and a subsequent process step is determined on this basis.

3. Method according to claim 2, wherein the workpiece (3) is machined further in the subsequent process step or is ejected from the machining process (100).

4. Method according to claim 1, wherein the at least one workpiece property to be changed is additionally detected before the machining step and the workpiece (3) is machined according to the assigned workpiece category and the additionally detected workpiece property to be changed.

5. Method according to any of the preceding claims, wherein the workpiece (3) is assigned to a workpiece category by combining a plurality of the same and / or different workpiece properties.

6. Method according to any of the preceding claims, wherein physical and / or geometric workpiece properties are detected, in particular indications of weight, dimensions, colours or three-dimensional structures.

7. Method according to claim 1, wherein the workpiece properties to be detectd and the workpiece categories are defined in a data pool (20).

8. Method according to claim 7, wherein the workpiece properties detected during the machining process are additionally stored in the data pool (20).

9. Method according to claim 8, wherein a process control system (8) accesses the data pool (20) and controls the machining process (100).

10. Device, configured to carry out the method according to claims 1 to 9, comprising: at least one detection system (1) which is configured upstream of a workpiece machining unit (2) to detect workpiece properties that are required for assignment to a workpiece category, and at least one workpiece machining unit (2) which is configured to machine the workpiece (3) according to an assigned workpiece category.

11. Device according to claim 10, wherein at least one detection system (4) upstream of the workpiece machining unit (2) is configured to detect the workpiece properties to be changed.

12. Device according to claim 10 or 11, wherein, furthermore, at least one detection system (5) downstream of the machining unit (2) is configured to detect the changed workpiece properties.

13. Device according to any of the preceding claims, wherein the detection system (1, 4, 5) has one and / or more active and / or passive sensors (6), in particular mechanical, thermoelectric, resistive, piezoelectric, capacitive, inductive, optical, acoustic or magnetic sensors.

14. Device according to any of claims 11 to 13, wherein a switch element (7) downstream of the detection system (5) and machining unit (2) is configured to eject the workpiece (3) or to supply same to a further machining step.

15. Device according to any of the preceding claims, wherein the process control system (8) is configured to control the machining process based on the data pool (20).