Method for manufacturing a composite material connecting rod having reinforced ends
View Patent ↗In the field of aviation, a method of fabricating a composite-material rod. The method comprises a first step of fabricating a mandrel comprising a sleeve of composite material and solid inserts of composite material secured to the ends of said sleeve to constitute a rigid whole. Then, one or more layers of braided fibers are applied around the mandrel by using a fiber-braiding machine. Next, a resin is injected into the layers of braided fibers so as to establish cohesion rigidly bonding the braided fiber layers and at least the ends of the mandrel in order to form a rod body out of composite material having reinforced ends. Finally, respective holes are drilled at each end of the rod body, each hole passing through the layers of braided fibers and also through the corresponding insert.
1. A method of fabricating a composite-material rod having reinforced ends, the method comprising the steps of:
fabricating a mandrel comprising a sleeve extending longitudinally and reinforcing inserts secured to the ends of said sleeve in order to constitute a rigid whole;
applying one or more layers of braided fibers around the mandrel by moving it longitudinally into a machine for braiding reinforcing fibers surrounding it all along its length;
injecting and polymerizing resin into the one or more layers(s) of braided fibers in order to establish cohesion rigidly bonding the layers of braided fibers and at least the ends of the mandrel-together in order to form a rod body having reinforced ends; and
drilling to make a through orifice at each end of the rod body, each orifice passing through the layers of braided fibers and through the corresponding insert.
2. A method according to claim 1 , wherein the sleeve and the inserts are fabricated out of a composite material comprising a resin of the same type as the resin injected into the layers surrounding the mandrel.
3. A method according to claim 1 , wherein the sleeve and the inserts are made of a composite material comprising fibers of the same type as the fibers of the layers surrounding the mandrel.
4. A method according to claim 1 , wherein the inserts extend at least in part inside the ends of the sleeve.
5. A method according to claim 4 , wherein each insert or each insert portion is fabricated together with all or part of the sleeve to provide optimum cohesion between the inserts and the sleeve.
6. A method according to claim 4 , wherein first and second ends of the mandrel are fabricated, each comprising an insert and a portion of sleeve, and the two ends are assembled together to form the mandrel.
7. A method according to claim 6 , wherein each end of the mandrel is obtained by fabricating a first insert half and a first shell together in order to constitute a first half of an end, and by fabricating a second insert half and a second shell together in order to constitute a second half of an end, before assembling the two halves together in order to form an end of the mandrel.