Pre-impregnated fiber deposition head with laser heating adjustment device

A deposition head for automated fiber layup of pre-impregnated fibers on a deposition surface comprising:

• an application roller rotating around a rotation axis carried by the deposition head, the application roller being removable and positioned relative to the deposition head by reference surfaces;
• pressure means configured to applying an application pressure of the application roller to the deposition surface;
• a heating laser for heating the pre-impregnated fibers and the deposition surface during automated layup;
• an optical device configured for focusing a laser beam and to project a laser spot with a power distribution at a working distance, the optical device being connected to the deposition head by an adjustable polyarticulated linkage, configured to adjust a relative position of the optical device with respect to the deposition head;
• a pilot laser of reduced power as compared with the heating laser, configured to be conveyed by the optical device;
• the deposition head further comprising:
• an adjustment device configured to be installed on the deposition head in place of the application roller and positioned in relation to the deposition head by the reference surfaces;
• a translucent screen connected to the adjustment device by a lockable pivot link around a pivot axis and configured to receive the laser of the pilot laser projected by the optical device on a face exposed to the optical device;
• a camera oriented towards a face opposite the exposed face of the translucent screen and configured to acquire an image of the translucent screen;
• and
• a control monitor configured for displaying the image acquired by the camera.

A method for adjusting a deposition head for automated fiber layup of pre-impregnated fibers on a deposition surface with an adjustment system comprising computer means comprising calculation means configured to analyze the image acquired by a camera, the deposition head comprising:

• an application roller rotating around a rotation axis carried by the deposition head, the application roller being removable and positioned relative to the deposition head by reference surfaces;
• pressure means configured to applying an application pressure of the application roller to the deposition surface;
• a heating laser for heating the pre-impregnated fibers and the deposition surface during automated layup;
• an optical device configured for focusing a laser beam and to project a laser spot with a power distribution at a working distance, the optical device being connected to the deposition head by an adjustable polyarticulated linkage, configured to adjust a relative position of the optical device with respect to the deposition head;
• a pilot laser of reduced power as compared with the heating laser, configured to be conveyed by the optical device;
• an adjustment device configured to be installed on the deposition head in place of the application roller and positioned in relation to the deposition head by the reference surfaces;
• a translucent screen connected to the adjustment device by a lockable pivot link around a pivot axis and configured to receive the laser of the pilot laser projected by the optical device on a face exposed to the optical device;
• a camera oriented towards a face opposite the exposed face of the translucent screen and configured to acquire an image of the translucent screen and to transmit the image to the computer means;
• a control monitor configured for displaying the image acquired by the camera;
• the method comprising the steps of:
• I) calculating a position relative to the reference surfaces of a nip line of the application roller on the deposition surface when the application roller is applied to the deposition surface with the application pressure;
• II) obtaining target conditions for heating, by the heating laser, the deposition surface and the pre-impregnated fibers during the layup operation;
• III) determining from a result of step II) an orientation angle α of the heating laser and a theoretical relative position of a center of the laser spot with respect to the nip line at the working distance;
• IV) installing the adjustment device in place of the application roller and positioning the translucent screen relative to the reference surfaces according to a result of steps I) to III), V) orienting the translucent screen by its lockable pivot link according to the orientation angle α determined in step III;
• V) projecting the laser spot onto the translucent screen with the pilot laser;
• VI) acquiring the image of the laser spot with the camera and displaying it on the control monitor,
• VII) displaying on the control monitor the theoretical position of the center of the laser spot obtained in step III;
• and
• VIII) acting on the adjustable polyarticulated linkage to make the center of the image of the laser spot coincide with the theoretical position of the center of the laser spot displayed on the control monitor.