Method for the Additive Manufacture of a Plurality of Motor Vehicle Components

Abstract

A method for additive manufacture of a plurality of motor vehicle components specifies a target geometry for the plurality of motor vehicle components, specifies a production geometry associated with a production position within a tool for additive manufacture according to the specified target geometry, and produces the plurality of motor vehicle components by additive manufacture according to the production geometry in the tool. An actual geometry of the plurality of motor vehicle components associated with a production position is determined, the actual geometry is compared with the target geometry, and the production geometry is adapted according to the comparison.

Claims

1.-5. (canceled)

6. A method for additive production of a plurality of motor vehicle components, comprising: predefining a setpoint geometry for the plurality of motor vehicle components; in a manner dependent on the predefined setpoint geometry, predefining a production geometry assigned to a respective production position within a tool for additive manufacturing; and additively manufacturing the plurality of motor vehicle components in the tool in a manner dependent on the production geometry, wherein an actual geometry, assigned to a respective production position, of the plurality of motor vehicle components is determined, the actual geometry is compared with the setpoint geometry, and the production geometry is adapted in a manner dependent on the comparison.

7. The method according to claim 6, wherein the actual geometry is, after at least one further method step, determined in a manner assigned to the respective production position.

8. The method according to claim 7, wherein the plurality of motor vehicle components is, in the at least one further method step, heat-treated, separated from the tool, and/or subjected to mechanical postprocessing, chemical postprocessing r electrochemical postprocessing.

9. The method according to claim 6, wherein the production geometry is adapted in a manner dependent on a raw material of the motor vehicle components.

10. The method according to claim 6, wherein the production geometry is adapted in a manner dependent on production parameters of the additive manufacturing process.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 is a side view of a tool for additive manufacturing, with a plurality of additively produced motor vehicle components, wherein each of the motor vehicle components is assigned a defined production position; and

[0019] FIG. 2 shows a method diagram for a systematic compensation of distortion of the motor vehicle components during the additive production thereof.

DETAILED DESCRIPTION OF THE DRAWINGS

[0020] FIG. 1 illustrates a plurality of motor vehicle components 1 which have been produced additively or generatively in a tool 2. In particular, the motor vehicle components 1 have been built up in layers on a bottom plate 3 of the tool 2. For the motor vehicle components 1, a setpoint geometry is predefined which the motor vehicle components 1 are intended to have after the additive manufacturing 7 thereof. During the manufacturing 7 of the motor vehicle components 1, a varying heat distribution may arise in the tool 2 and in particular on the bottom plate 3, which may in turn lead to a distortion of individual motor vehicle components 1.

[0021] In order to be able to keep finish machining required as a result of the distortion particularly low, a systematic compensation of the distortion is provided, wherein a method diagram for the systematic compensation is illustrated in FIG. 2. In a first method step 4, the setpoint geometry for the motor vehicle components 1 is predefined. Subsequently, the predefined setpoint geometry is, in a second method step 5, resolved with respect to respective production positions of the motor vehicle components 1 in the tool 2.

[0022] In a third method step 6, respective production geometries resolved with respect to production position, which may also be referred to as respective manufacturing geometries, are ascertained for the motor vehicle components 1. Subsequently, the additive manufacturing 7 of the motor vehicle components 1 is performed in the tool 2 in a manner dependent on the respective production position of the motor vehicle components 1 and on the production geometry assigned to the respective production position.

[0023] In a fourth method step 8, an actual geometry, assigned to the respective production positions, of the motor vehicle components 1 is ascertained by means of a detection device. Subsequently, in a comparison 9, the respective actual geometry is compared with the setpoint geometry in a production-position-related manner, and in a fifth method step 10, a deviation between the setpoint geometry and the actual geometry is determined. The respective deviation between the setpoint geometry and the actual geometry is assigned to the respective production position in a respective systematic data processing operation 11.

[0024] In a sixth method step 12, a compensation of the deviation between the setpoint geometry and the actual geometry is performed. The compensation of the deviation between the setpoint geometry and the actual geometry results in an adaptation 13 of the production geometry in a manner dependent on the compensation. Here, the adaptation 13 of the production geometry is performed in each case in a production-position-related manner. Subsequently, by means of the tool 2, a further plurality of motor vehicle components 1 is additively manufactured in a manner dependent on the adapted production geometries assigned to the production positions.

[0025] Alternatively or in addition, the actual geometries of the motor vehicle components 1 can be, after at least one further method step, ascertained and assigned to the respective production position of the respective motor vehicle component 1 during the additive manufacturing 7 thereof in the tool 2. The at least one further method step may be a heat treatment and/or a separation of the respective motor vehicle component 1 from the tool 2 and/or blasting, in particular sand-blasting, and/or washing of the motor vehicle components 1. Here, the respective production geometries may be adapted in a production-position-related manner in a manner dependent on the comparison 9 of the actual geometries after the at least one further method step with the setpoint geometry.

[0026] In order to incorporate respective material-specific characteristics, it is possible in the third method step 6 for the respective production geometry of the motor vehicle components 1 to be predefined in a manner dependent on a raw material of the motor vehicle components 1. Alternatively or in addition, the respective production geometry of the motor vehicle components 1 may, in the sixth method step 12, be adapted in a manner dependent on the raw material of the motor vehicle components 1.

[0027] It is furthermore possible for the respective production geometry of the motor vehicle components 1 to be adapted in a manner dependent on production parameters of the additive manufacturing process. Here, installation-specific parameters of the tool 2 and/or production-specific parameters of the additive manufacturing process are incorporated in the adaptation of the production geometries.

[0028] The described method is based on the recognition that, for automobile production, relatively small metal parts are already produced by additive manufacturing 7. For this purpose, firstly, a CAD model of the metal part to be manufactured is created by computer. For the manufacturing 7, a metal powder is used in a selective laser melting process. The metal powder is applied in layers during the additive manufacturing 7, wherein, in each layer, regions which form the respective metal part are fused in targeted fashion by means of a laser beam.

[0029] In the case of production of series parts, that is to say in the case of production of large unit quantities, the metal parts are manufactured closely adjacent to one another on the bottom plate 3, as can be seen in FIG. 1. As a result of the same motor vehicle component 1 being manufactured in large unit quantities directly adjacent to one another, or in a manner nested with one another on the bottom plate 3, which can also be referred to as building plate, a varying heat distribution may arise at different locations on the bottom plate 3. The varying heat distribution may lead to varying stress states in the motor vehicle components 1, which can in turn lead to distortion and thus to low dimensional accuracy. The distortion may be dependent inter alia on a size and/or geometry of the motor vehicle component 1 and/or on a packing density of the motor vehicle component 1 in a structural space of the tool 2 and/or on laser parameters during the additive manufacturing process. Predicting dimensional deviations that arise during the additive manufacturing 7 of the plurality of motor vehicle components 1 by simulation is extremely challenging, and such a prediction is highly dependent on a quality of a respective simulation model that is used, in particular on material and process input variables, and calculation methods used. A topology-optimized design of the respective motor vehicle components 1 may furthermore have the effect that, for a simulation-based prediction, the new material models would have to be generated, which involves high outlay.

[0030] The method for distortion compensation as described in conjunction with the figures overcomes these disadvantages. Owing to varying distortion of the respective motor vehicle components 1 on the bottom plate 3, each motor vehicle component 1 is considered in conjunction with its production position. Firstly, the motor vehicle components 1 can be additively manufactured in a manner dependent on the predefined setpoint geometry. Subsequently, the motor vehicle components 1 produced, which may have a respective distortion, can be compared with the setpoint geometry in a spatially resolved manner, that is to say in a production-position-related manner. In a further step, the respective production geometries of each individual motor vehicle component 1 on the bottom plate 3 can be compensated in a location-dependent and thus production-position-related manner. The systematic compensation is repeated until the motor vehicle components 1 that are actually manufactured correspond to the predefined setpoint geometry within defined specified tolerances.

[0031] This method is advantageous specifically for production of large unit quantities of motor vehicle components 1. The method leads to particularly fast and particularly straightforward production of the motor vehicle components 1 in the course of the additive production process, whereby production costs can be kept particularly low. During an ongoing series, that is to say in the case of the additive manufacturing of the plurality of motor vehicle components 1 being performed multiple times in succession, it is possible, upon every measurement of the actual geometry, for any process variations that arise to be corrected by virtue of the respective compensation being recalculated. With continuous monitoring of the actual geometry of the motor vehicle components 1, the systematic compensation can be used as a closed-loop geometry controller which ensures constant quality of the motor vehicle components 1 with regard to the dimensional accuracy thereof. Since the systematic compensation is based on the comparison 9 of the actual geometry with the setpoint geometry, dimensional deviations of the further method steps can be taken into consideration in the creation of the respective production-position-related production geometries without increased outlay. Processing times for the geometry-based systematic compensation are particularly short in relation to a physical process simulation.

[0032] The described method has the advantage that a respective distortion of the motor vehicle components 1 can be compensated, such that a dimensional deviation of the motor vehicle components 1 with respect to the setpoint geometry can be kept particularly low. Moreover, it is possible to avoid the use of complex mathematical models for predicting the respective distortions of the motor vehicle components 1. The method is moreover a systematic approach which can be applied without prior knowledge. Respective distortion-compensated production of further motor vehicle components 1 with the production-position-related adapted production geometries can be implemented with particularly short development times. With regular measurement of the respective actual geometry of the motor vehicle components 1, the compensation can be used, in an ongoing series, as a closed-loop geometry controller in order to correct process variations such as fluctuations in the raw material and/or ageing or wear of installation equipment, in particular of the tool 2, etc.

LIST OF REFERENCE DESIGNATIONS

[0033] 1 Motor vehicle component [0034] 2 Tool [0035] 3 Bottom plate [0036] 4 First method step [0037] 5 Second method step [0038] 6 Third method step [0039] 7 Manufacturing [0040] 8 Fourth method step [0041] 9 Comparison [0042] 10 Fifth method step [0043] 11 Systematic data processing [0044] 12 Sixth method step [0045] 13 Adaptation