Patent EP-2286982-A1 (EP)
Inventor: FOCKELE MATTHIAS
IPC: B22F3/105
Filed: 2010-08-19
Abstract: The device for the production of form body through layer-wise application of material powder through location-selective hardening of powder to related areas according to the standard of geometry description data of the form body, comprises a process area (9) with a process area base (11) that has a base plain (51) and a height adjustable building platform (13) controlled by a controllable drive unit along a vertical building platform axis, for the form body, a device for preparing a powder layer to be hardened on the building platform, and a powder hardening device. The device for the production of form body through layer-wise application of material powder through location-selective hardening of powder to related areas according to the standard of geometry description data of the form body, comprises a process area (9) with a process area base (11) that has a base plain (51) and a height adjustable building platform (13) controlled by a controllable drive unit along a vertical building platform axis, for the form body, a device for preparing a powder layer to be hardened on the building platform, and a powder hardening device that is activatable for location-selective hardening of powder of the powder layer preparing on the building platform. The powder layer preparing device comprises a powder supply device for providing powder in the process area, and a smoothing slider with a powder smoothing strip (47) for the distribution and smoothing of the powder provided by the powder supply device in the process area on the building platform. The smoothing slider is moved with its building platform between two reversing locations in the process area in back- and forth manner in order to move the powder layer location-selectively hardened in an interval corresponding to the desired powder layer thickness on the building platform. The powder supply device comprises a powder supply channel connected to a powder supply container equipped external of the process area, and a conveyor for conveying powder in the powder supply channel during the phase, in which the powder hardening device is activated for location-selective hardening of powder on the building platform. The powder supply channel ends to a powder inlet position lying between the building platform and one of the reversing location of the powder smoothing strip in the process area in order to guide the powder directly to the process area base. The powder smoothing strip is height adjustable in its movement between the reversing locations relative to the process area base in controlled manner. The powder supply channel ends to the powder inlet position lying between the building platform and one of the reversing location of the powder smoothing strip towards bottom into the process area base. The powder smoothing strip is height adjustable so that it is lifted during the movement over the powder inlet position from the base plain of the process area base and is tightly aligned to the base plain of the process area base. The smoothing slider comprises arms movably guided between the reversing locations and is controllable by a control device in such a way that the powder smoothing strip has a pre-determined movement profile for the height adjustable movement between the reversing locations. The smoothing slider comprises a further powder smoothing strip that passes in horizontal interval to the first powder smoothing strip so that the powder smoothing strip limits an intermediate area opening to process area base. The smoothing slider is positioned with its powder smoothing strip in a powder refilling condition near to the building platform so that the powder inlet position ends in the intermediate area. The further powder smoothing strip is height adjustable in its movement between the reversing locations relative to the process area base in controlled manner. The powder smoothing strips are height adjustable to each other in independent manner. The smoothing slider is controllable by a control device in such a way that the powder smoothing strip is raised or lowered in the movement between the reversing locations, where the powder smoothing strip running in the movement direction is raised during the other powder smoothing strip is lowered. The conveyor is screw conveyor that has conveyor screws equipped in the powder supply channels. The powder hardening device comprises a radiation device with a laser radiation source, whose radiation is directed to the building platform in order to melt or sinter the powder of the powder layer to be prepared to related areas. The building platform is lowered relative to the base plain of the process area base to the measurement of the desired powder layer thickness in a new lowered position in order to receive a new powder layer. The lower side of the powder smoothing strip is arranged at the height of the base plain of the process area base. The powder smoothing strip has the form of an arch in top view, where the arch is convex in the powder refilling position of the smoothing slider in the direction to the building platform axis. The conveyor is controllable in order to bring a pre-determined quantity of powder for preparing the powder layer to be hardened in the process area. A mechanical actuator is provided, which diverts the height adjustment of the powder smoothing strip from movement drive for the translation movement between the reversing locations.