Method for making an acoustic panel for the air intake lip of a nacelle
View Patent ↗The invention relates to a method for making an acoustic panel ( 12 ) for an air intake lip ( 2 ) of a nacelle ( 1 ) that includes the steps of obtaining a perforated de-icing assembly ( 14 ) including at least one array of conducting members obtained by a photolithographic method, said de-icing member ( 14 ) being secured to a structure with a cellular web ( 13 ). The invention also relates to an air intake lip and to a nacelle.
1. A method for making an acoustic panel of an air intake lip of a nacelle comprising:
A. producing an outer skin reproducing an aerodynamic line of the air intake lip;
B. fastening a conductive layer on said outer skin, said conductive layer including conducting members;
C. fastening a photosensitive layer on said conductive layer, said photosensitive layer including at least one photosensitive member;
D. piercing the material thus formed using a piercing means to form acoustic holes;
E. applying a mask on the photosensitive layer of material at the end of step D so as to form an array of conducting members not obstructing the holes resulting from step D;
F. revealing said array using a photolithography method;
G. electrically isolating the surface of the array resulting from step F;
H. fastening a cellular core structure on the de-icing assembly obtained at the end of step G;
I. applying a second skin on the de-icing assembly thus obtained at the end of step H, thereby forming an acoustic panel.
2. The method according to claim 1 , wherein in step G, the electric isolation is done by depositing an oxide layer.
3. The method according to claim 1 , wherein in step H, the de-icing assembly obtained at the end of step G is fastened on the cellular core structure by adhesion.
4. The method according to claim 1 , wherein the cellular core structure is a honeycomb structure.
5. The method according to claim 1 , wherein the glue is applied on the array of conducting members by blowing compressed air in through the acoustic holes.
6. The method according to claim 1 , wherein the conducting members comprise at least one of copper, aluminum, or an alloy of copper and nickel.
7. The method according to claim 1 , wherein the mask is a xylene-based films.
8. The method according to claim 1 , wherein the conductive layer is applied on a flexible substrate capable of substantially fitting the shape of the outer skin at least locally.
9. The method according to claim 8 , wherein the substrate includes glass fibers.
10. The method according to claim 1 , wherein before step E, a plurality of centering means is applied on the material resulting from step D to position the mask durably and precisely.
11. The method according to claim 1 , wherein a diameter of the acoustic holes made in step D is between 0.2 mm and 0.5 mm.
12. The method according to claim 1 , wherein a metal web is applied on the outer skin.
13. The method according to claim 1 , wherein a diameter of the acoustic holes made in step D is between 1.5 mm and 2 mm.