METHOD FOR TRACKING FORGED PARTS THROUGH THE ENTIRE MANUFACTURING PROCESS, IN PARTICULAR FROM THE FORGING PROCESS, THROUGH SANDBLASTING AND HEAT TREATMENT TO MECHANICAL MACHINING

Description

[0001] The invention relates to a method for tracing forged parts throughout the entire manufacturing process, in particular from the forging process, through sandblasting and heat treatment to mechanical processing.

[0002] Traceability of workpieces offers numerous advantages. For example, if quality problems arise with one workpiece, other workpieces manufactured under comparable conditions can be identified for inspection, sorting, or replacement. This is particularly beneficial for automotive components, as it eliminates the need to replace all components from the same production batch, potentially leading to a costly recall. Instead, only those components manufactured under similar conditions need to be replaced. However, this requires traceability of the components (forged parts) throughout the entire manufacturing process. Workpiece traceability also includes access to the process parameters of each step in the manufacturing process.

[0003] Traceability of forgings throughout the entire manufacturing process requires continuous marking of the workpieces from forging, through sandblasting and heat treatment, to machining and the final use of the finished forging. However, the environmental conditions and circumstances prevailing during the forging process, combined with the requirements for the finished forging, prevent continuous marking of the workpieces from forging, through sandblasting and heat treatment, to machining and the final use of the finished forging. During and immediately after the forging process, there is an extremely high thermal stress from the hot workpiece and the corresponding heat radiation. Furthermore, the workpiece exhibits surface scaling after forging, which prevents direct access to the workpiece surface.In addition, there are contaminants from spray agents such as graphite. In the following process steps, the scale is removed using methods for the mechanical and / or thermal removal of material, for example, by sandblasting or shot blasting, and the surface of the workpiece is treated by heat treatment such as case hardening, carbonitriding, or tempering, resulting in high mechanical stress. Consistent marking must be maintained under these conditions; however, the requirements for the final workpiece (forged part) preclude the use of markings that negatively affect the workpiece's mechanical properties. This prevents damage to the workpiece surface (notch effect), deterioration of corrosion resistance, or negative impacts on the assembly process.

[0004] Furthermore, the individual process steps of the entire manufacturing process are not usually carried out directly sequentially, but rather the workpieces are temporarily stored between individual process steps. Additionally, in some process steps, several workpieces are processed in parallel, as is the case, for example, in shot blasting or heat treatment. Continuous optical tracking of the workpieces throughout the entire manufacturing process is therefore not possible. LIEWALD MATHIAS ET AL: "On the tracking of individual workpieces in hot forging plants", August 2018, addresses the tracking of workpieces in a forging process.

[0005] The invention is therefore based on the objective of providing a method for tracing forged parts throughout the entire manufacturing process, in particular from the forging process, through sandblasting and heat treatment to mechanical processing, which meets all the aforementioned requirements.

[0006] The problem is solved according to the invention by a method according to claim 1. Advantageous embodiments of the method are defined in the dependent claims.

[0007] According to the inventive method, the relevant process parameters are recorded in all process steps of the manufacturing process of the forged part. This is achieved, for example, through process automation of the respective manufacturing process. To ensure that the recorded process parameters can be assigned to the manufactured workpiece at any time along the process chain or in subsequent use, the workpiece produced by the forging process is provided with a first identifier using a mechanical indentation method. The first identifier and the recorded process parameters are stored in a database for later traceability. The process parameters of the forging process can be retrieved from the database at a later time using the first identifier.

[0008] According to the invention, the step of acquiring process parameters of the forging process can include acquiring parameters before, during, and after the forging process. For example, raw material data is acquired before the forging process; during the forging process, parameters of the forging operation, such as forces, temperatures, etc., are acquired; and after the forging process, parameters of the produced workpiece, such as dimensions, can be acquired.

[0009] The mechanical indentation method for generating the initial marking has the advantage that the brittle scale layer in the area of ​​the initial marking is automatically removed, as it flakes off. Furthermore, any impurities do not negatively affect the initial marking, since it is created by mechanical penetration into the workpiece surface. Because the workpiece still has a very high temperature of up to 1250°C after the forging process, the mechanical means for generating the initial marking can penetrate the workpiece surface more easily. These mechanical means for generating the initial marking can also be designed using simple mechanical devices that can withstand the thermal and mechanical stresses after the forging process.

[0010] The initial identifier created by the mechanical indentation process is retained even in the subsequent process steps of shot blasting and heat treatment. This means that the process parameters recorded in these steps, along with the forging process parameters, are stored in the database as the initial identifier. During subsequent machining of the workpiece, such as turning, milling, grinding, or similar processes, the initial identifier is removed and can no longer be read from the machined workpiece for traceability. Therefore, the workpiece processed in this step is subsequently marked with a further identifier, generated using a laser or a printing process. The process parameters recorded during the corresponding process step are then assigned to the first identifier of the corresponding workpiece in the database, along with the additional identifier.Thus, the corresponding first identifier can be retrieved from the database via the additional identifier, and the workpiece can be traced back through the entire manufacturing process, and all process parameters of all process steps stored in the database can also be accessed.

[0011] Theoretically, it is also possible that during further processing of the workpiece a new identifier is applied using a surface marking process, if the previous additional identifier is not retained during this further processing.

[0012] According to the invention, the first identifier is generated in an area of ​​the workpiece produced in the forging process, which is removed in one of the subsequent process steps. The area with the first identifier is removed, for example, mechanically by subsequent machining. Due to the subsequent removal of the first identifier, this first identifier, generated by the mechanical indentation method, has no negative impact on the workpiece (forged part) produced in the overall manufacturing process.

[0013] According to an advantageous embodiment of the invention, the additional identifier is applied in an area of ​​the workpiece that is subject to minimal stress during use. Preferably, the additional identifier is applied in an area of ​​the workpiece that is not subject to any stress during use. Thus, the additional identifier has no negative impact on the workpiece's properties. Due to the minimal or non-existent stress on the area bearing the additional identifier, its legibility is maintained, which is also advantageous for subsequent traceability.

[0014] For traceability, subsequent readability of the further identifier is not absolutely necessary, provided that it is documented where which workpieces with their further identifiers were used / assembled.

[0015] In a further embodiment of the invention, in addition to the process parameters, quality data is at least partially recorded during the process steps and stored in the database together with the first identifier and / or the subsequent identifier. The quality data is determined, for example, as part of an automatic and / or manual quality inspection and / or final inspection. Automatic determination is preferred, if possible. By determining and storing the quality data, the individual process steps or any subsequent processing or assembly can access the stored quality data. Quality standards can thus be checked and ensured. Furthermore, it may be unnecessary to perform separate incoming inspections of workpieces.

[0016] According to one embodiment of the invention, the first identifier is generated in an area of ​​the workpiece that is not deformed by the forging process or that has already received its final shape through the forging process. In this area of ​​the workpiece, the first identifier can theoretically be generated before or during the forging process, since the forging process no longer has any influence on this area and the first identifier thus remains legible.

[0017] According to an advantageous embodiment of the invention, the first identifier is produced by means of a dot peen printing process or an embossing process.

[0018] In an advantageous variant, the embossing tools (e.g., needles) are made of hot-work steel, carbide, or the like and / or feature active cooling. This extends the service life of the needle for the dot matrix printing or dot peening process.

[0019] According to a further preferred embodiment of the invention, the device for generating the first identifier comprises a passive and / or active thermal protection device. A passive thermal protection device is, for example, thermal insulation, and an active thermal protection device is, for example, cooling. This reduces the negative heat influence of the forging process or the forged workpiece on the device for generating the first identifier, thereby extending its service life and reducing failures.

[0020] According to the invention, the additional identifier is generated using a laser or a printing process. A printing process generates the identifier on the surface of the workpiece and thus has no influence on the mechanical properties of the workpiece. However, a printed additional identifier is usually less durable than additional identifiers integrated into the surface. A laser generates the additional identifier in the surface of the workpiece and could therefore theoretically influence the mechanical properties of the workpiece. However, the identifier is only generated in the uppermost layer, so the influence should be very small. The additional identifier generated by a laser is usually more durable than a printed additional identifier.

[0021] In one embodiment of the invention, the first identifier and / or the further identifier comprises a data matrix code, a QR code, a barcode, one or more numbers and / or digits, or other characters or symbols, in particular for indicating a part or drawing number, a supplier identifier, an order number, or the like.

[0022] According to a variant of the invention, the workpiece is provided with several first identifiers when it is divided in one of the subsequent manufacturing steps, the several first identifiers preferably being arranged such that each divided workpiece has a first identifier. If the workpiece is divided at the end of the manufacturing process, the individual parts can each be provided with a further identifier by means of the surface marking process and can each access the process data and the first identifier together.

[0023] According to one embodiment of the invention, the recorded process parameters include target and actual values ​​of plant automation systems for the forging process or other process steps, machine data, process data, measurement logs, carbon emissions, or the like, preferably process temperatures, workpiece temperatures, especially at different times, process times, cycle times, spraying times, residence times, process forces, forming and reaction forces, machine data, motor current consumption of main and auxiliary drives, springback of the press body, unplanned process events, tool failure, especially cracking, forging of end pieces, double loaders, or the like. The carbon emissions as process parameters include, in particular, the carbon emissions generated in the respective process step.

[0024] In an advantageous embodiment of the invention, the process parameters are stored in the database together with the first identifier and / or the subsequent identifier when predefined limits or thresholds are exceeded and / or fallen below. Thus, not all process parameters from all process steps of the manufacturing process are necessarily stored, but only those process parameters that exceed predefined thresholds or limits are stored. This significantly reduces the amount of data to be stored.

[0025] According to a particularly preferred embodiment, the method according to the invention comprises analyzing the process data stored in the database to identify defective or faulty products, in particular based on subsequently discovered defective or faulty products, and comparing the process data of the defective or faulty product with the process data in the database and identifying the corresponding product based on the first identifier and / or the further identifier.

[0026] According to an advantageous embodiment of the invention, a process step in which the first identifier is retained comprises sandblasting, shot peening, a heat treatment such as case hardening, carbonitriding, tempering or the like of the workpiece.

[0027] In one embodiment of the invention, a process step in which the first identifier is not retained comprises a mechanical machining of the workpiece such as turning, milling, grinding, or the like.

[0028] According to a practical embodiment of the invention, the first identifier is generated by one or more marking units arranged directly in front of, inside, or behind the forging device. This direct arrangement allows the process parameters of the forging process to be unambiguously assigned to the first identifier applied immediately before, immediately after, or in parallel with the forging device. There is no risk of confusion between the forging device and the marking unit. If this is not possible, a clear assignment must be ensured, for example, by optical or logical tracking of the workpieces between the forging device and the marking unit.If the forging process is faster than the generation of the initial identifier, several marking units are preferably assigned to a forging device so that the generation of the initial identifier does not reduce the throughput of the manufacturing process. In this case, the assignment of the workpieces to the individual marking units, along with the associated process parameters, must be ensured.

[0029] The invention is described below with reference to a work in the Figure 1 The illustrated embodiment is explained in more detail. It shows: Fig. 1 shows a flow chart of an embodiment of a method according to the invention for tracing forged parts throughout the entire manufacturing process, in particular from the forging process, through sandblasting and heat treatment to mechanical processing.

[0030] Fig. 1shows a flow chart of an exemplary embodiment of a method according to the invention for tracing forged parts throughout the entire manufacturing process, in particular from the forging process, through sandblasting and heat treatment to mechanical processing.

[0031] According to the flow chart of the inventive method from Fig. 1 The manufacturing process begins with a forging process. The process parameters of the forging process are recorded according to the invention.

[0032] During or after the forging process, the workpiece produced is marked with an initial identifier. This initial identifier is created using a mechanical indentation process, particularly a needle-punch or embossing process. The corresponding marking materials, such as needles, are made of hot-work steel, cemented carbide, or similar materials. Furthermore, the marking materials or needles may incorporate active cooling. This extends the service life of the marking materials or needles.

[0033] To better protect the device for generating the first identifier from the temperatures of the forging process and / or the workpiece, it preferably has a passive and / or active thermal protection device. This could be, for example, thermal insulation or a cooling device.

[0034] The initial marking is created in an area of ​​the workpiece produced during the forging process, which is mechanically removed in one of the subsequent process steps. Therefore, the initial marking has no negative impact on the workpiece / product manufactured in the overall production process.

[0035] If the first identifier is created during the forging process, this occurs in an area of ​​the workpiece that is either not deformed by the forging process or that has already received its final shape through forging. This ensures that the forging process does not impair the legibility of the first identifier.

[0036] If the forging process is faster than the generation of the first identifier, several devices for generating the first identifier can be provided to avoid negatively impacting the throughput of the manufacturing process. The at least one device for generating the first identifier is preferably arranged directly before, within, or after the forging device.

[0037] After the workpiece has been assigned its first identifier, the recorded process parameters of the forging process are stored in a database along with the first identifier of the manufactured workpiece.

[0038] In the subsequent process steps, the identifier of the workpiece produced in the previous process step, for example, the first identifier of the workpiece produced in the forging process, is read out. Furthermore, the process parameters are recorded in the subsequent process step.

[0039] Basically, a distinction is made in subsequent process steps as to whether the readability of the identifier of the workpiece produced in the previous process step is maintained by the subsequent process step or not.

[0040] If the identifier of the workpiece produced in the previous process step remains readable, the sequence between reading the workpiece identifier and recording the process parameters of the subsequent process step is irrelevant and freely selectable. In this case, the recorded process parameters of the subsequent (current) process step are captured and stored in the database along with the read identifier. The next process step then follows.

[0041] Process steps in which the readability of the first identifier is maintained include, in particular, sandblasting, shot peening, heat treatment such as case hardening, carbonitriding, tempering or the like of the workpiece.

[0042] If the identifier of the workpiece produced in the previous process step becomes unreadable, the identifier of the workpiece produced in the previous process step is first read, and then the process parameters of the subsequent (current) process step are recorded, since the identifier of the workpiece produced in the previous process step is lost during this step. In this case, the workpiece is marked with a further identifier using a laser or a printing process.

[0043] The recorded process parameters are then stored in the database with the further identifier corresponding to the identifier of the workpiece produced in the previous process step, in particular the associated first identifier of the corresponding workpiece.

[0044] The additional identifier is applied in particular to an area of ​​the workpiece which is subject to little or no stress during use of the workpiece.

[0045] A process step in which the identifier of the workpiece produced in the previous process step is not retained includes, in particular, mechanical processing of the workpiece such as turning, milling, grinding, or the like.

[0046] A further process step can then follow, or the manufacturing process is complete.

[0047] The recorded process parameters of the forging process and / or subsequent process steps include, for example, target and actual values ​​from the automation of the forging process or the subsequent process step, machine data, process data, measurement logs, carbon emissions, and the like. These preferably include process temperatures, workpiece temperatures (especially at different times), process times, cycle times, spraying times, residence times, process forces, forming and reaction forces, machine data, motor current consumption of main and auxiliary drives, press body deflection, unplanned process events, tool failure (especially cracking), forging of end pieces, double loading, and the like. Advantageously, the carbon emissions generated in each process step are recorded as process parameters for that step.

[0048] In addition to the process parameters, according to a variant of the invention, quality data can be recorded at least partially in the process steps, which are stored in the database together with the first identifier and / or the further identifier.

[0049] The first identifier and / or the subsequent identifier may include, for example, a data matrix code, a QR code, a barcode, one or more numbers and / or digits, or other characters or symbols, particularly for indicating a part or drawing number, a supplier identifier, an order number, or the like. Since the first identifier is created by a mechanical indentation process, it preferably consists of a simple numeric or alphanumeric string or a dot matrix. In contrast, the subsequent identifier, produced by a laser or a printing process, may be more complex and contain additional information, for example, in the form of a QR code.

[0050] According to a variant of the invention, the workpiece is provided with several first identifiers when it is divided in one of the subsequent manufacturing steps, the several first identifiers preferably being arranged such that each divided workpiece has a first identifier. If the workpiece is divided at the end of the manufacturing process, the individual parts can each be provided with a further identifier by means of the surface marking process and can each access the process data and the first identifier together.

[0051] In an advantageous embodiment of the invention, the process parameters are stored in the database together with the first identifier and / or the subsequent identifier when predefined limits or thresholds are exceeded and / or fallen below. Thus, not all process parameters from all process steps of the manufacturing process are necessarily stored, but only those process parameters that exceed predefined thresholds or limits are stored. This significantly reduces the amount of data to be stored.

[0052] According to a particularly preferred embodiment, the method according to the invention comprises analyzing the process data stored in the database to identify defective or faulty products, in particular based on subsequently discovered defective or faulty products, and comparing the process data of the defective or faulty product with the process data in the database and identifying the corresponding product based on the first identifier and / or the further identifier.

Claims

1. Method of tracking forged parts over the entire production process, particularly from the forging process, via sandblasting and heat treatment, to mechanical processing, comprising the steps: detecting process parameters of a forging process; identifying the workpiece, which is produced in the forging process, by a first identification by means of a mechanical penetration method; storing the detected process parameters of the forging process together with the first identification of the produced workpiece in a databank; reading out the identification from the workpiece produced in the preceding process step; detecting process parameters during subsequent process steps of the production process; storing the process parameters of the subsequent process steps in the databank with respect to the read-out identification insofar as the legibility of the first identification of the workpiece is maintained by the following process step of the production process; identifying the workpiece, which is produced in the following process step, by a further identification by means of a laser or by a printing method insofar as the legibility of the first identification of the workpiece is not maintained by the following process step of the production process; and storing the process parameters of the following process step together with the further identification together with the process parameters of the previous process steps and the first identification in the databank, wherein the first identification is produced in a region, which is removed in one of the subsequent process steps, of the workpiece produced in the forging process.

2. Method according to claim 1, wherein the further identification is applied in a region, which is exposed to low loadings in use of the workpiece, of the workpiece.

3. Method according to one of claims 1 and 2, wherein in addition to the process parameters there is detection in the process steps of at least partial quality data which are stored together with the first identification and / or the further identification in the databank.

4. Method according to any one of claims 1 to 3, wherein the first identification is produced in a region, which does not experience any deformation by the forging process or which has already received its final form by the forging process, of the workpiece.

5. Method according to any one of claims 1 to 4, wherein the first identification is produced by means of a needle pressure method or needle stamping method.

6. Method according to claim 5, wherein the needles consist of hot-work steel, hard metal or the like and / or have active cooling.

7. Method according to any one of claims 1 to 6, wherein the device for producing the first identification comprises a passive and / or active thermal protection device.

8. Method according to any one of claims 1 to 7, wherein the first identification and / or the further identification comprises or comprise a data-matrix code, a QR code, a barcode, one or more numbers and / or numerals or other marks or symbols, particularly for statement of a part number or drawing number, a supplier identification, an order number or the like.

9. Method according to any one of claims 1 to 8, wherein the workpiece is provided with a plurality of first identifications if the workpiece is divided in one of the subsequent production steps, wherein the plurality of first identifications is preferably so arranged that each divided workpiece has a first identification.

10. Method according to any one of claims 1 to 9, wherein the detected process parameters comprise target and actual values of plant automations of the forging process or of the other process steps, machine data, process data, measurement protocols or the like, preferably process temperatures, workpiece temperatures, particularly at different points in time, process times, cycle times, spray times, dwell times, process forces, reshaping and reaction forces, machine data, motor current consumption by main and auxiliary drives, spring-back of the press body, unplanned process events, tool failures, particularly crack formation, forging of end pieces, wire pairs or the like.

11. Method according to any one of claims 1 to 10, wherein the process parameters in the case of exceeding and / or falling below predetermined limits or threshold values are stored in the databank together with the first identification and / or the further identification.

12. Method according to any one of claims 1 to 11, comprising analysing process data, which is stored in the databank, for identification of deficient or faulty products, particularly on the basis of subsequently discovered deficient or faulty products and comparison of the process data of the deficient or faulty product with the process data in the databank, and identifying the corresponding product by way of the first identification and / or the further identification.

13. Method according to any one of claims 1 to 12, wherein a process step in which the first identification is maintained comprises sandblasting, bead blasting, heat treatment such as, for example, use hardening, carbonitriding, hardening / tempering or the like of the workpiece.

14. Method according to any one of claims 1 to 13, wherein a process step in which the first identification is not maintained comprises a mechanical processing of the workpiece such as, for example, turning, milling, grinding or the like.

15. Method according to any one of claims 1 to 14, wherein the first identification is produced by one or more marking units which is or are arranged directly in front of, in or behind the forging device.