Thermoplastic component repair
AssigneeGM Global Technology Operations LLC
InventorsHamid G. Kia, Xiaosong Huang
Life of this patent
Estimating the term…
Abstract
Thermoplastic components may experience local damage, including cracks and decohesion of fiber reinforcements, among others. Such thermoplastics may be repaired by heating them to a suitable softening/melting temperature under pressure and maintaining them under pressure and at elevated temperature until the damage is healed. This may be done in-place using custom-fabricated, suitably-shaped die portions maintained under pressure by magnetic attraction. Various heating methods and die portion fabrication methods are described.
Claims20
A method of repairing damage, localized in a damage zone, in a shaped thermoplastic sheet component with a thickness, the component having an undamaged shape, the shaped thermoplastic sheet component having opposing surfaces, the damage zone comprising only a portion of the shaped thermoplastic sheet component, the damage zone having an extent and a center, the method comprising:
- fabricating opposing die portions, each having forming surfaces complementary in shape to a portion of one of the opposing surfaces of the shaped thermoplastic sheet component in its undamaged shape, the forming surfaces being adapted for centering on the damage zone center, the forming surfaces extending outwardly beyond the extent of the damage zone, the die portions comprising a magnetic system comprising a first and a second magnetic element, the magnetic elements being adapted to develop an attractive magnetic force between the elements, the magnetic elements being so positioned that the magnetic force urges the die portions together;
- placing the die portions on the opposing component surfaces and using the magnetic elements to urge the forming surfaces of the die portions into forcible engagement with the surfaces of the component by application of the magnetic force, the force applying sufficient pressure to the component surfaces to reshape the component to substantially its undamaged shape;
- selectively heating the reshaped thermoplastic sheet component at the damage zone to a temperature sufficient to soften and/or melt the thermoplastic, the sheet being heated either directly, or by contact with at least one heated die portion, the forming surfaces extending outwardly beyond the extent of the damage zone and being supported on unheated portions of the component to assure that the spacing between the opposing die forming surfaces corresponds to the thickness of the undamaged component at the damage location;
- maintaining the heated shaped thermoplastic sheet component damage zone at about its softening/melting temperature for a time sufficient to heal the damage in the damage zone;
- and,
- discontinuing heating while maintaining pressure on the component damage zone until the component damage zone cools sufficiently to maintain its shape and thereby restore the damage zone to its original shape and thickness.
An in-place method of repairing damage, localized in a damage zone, in a shaped thermoplastic sheet component with a thickness while the shaped thermoplastic sheet component is assembled into an article of manufacture and attached to other components for cooperative interaction with the other components, the shaped thermoplastic sheet component having an undamaged shape, the shaped thermoplastic sheet component having opposing surfaces, the damage zone comprising only a portion of the component, the damage zone having an extent and a center, the method comprising:
- fabricating durable opposing die portions with forming surfaces, each forming surface being complementary in shape to a portion of one of the opposing surfaces of the undamaged shaped thermoplastic sheet component, the forming surfaces being centered on the damage zone center and extending outwardly beyond the extent of the damage zone, the die portions comprising a magnetic system comprising first and second magnetic elements adapted to develop an attractive magnetic force between the elements, the elements being positioned so that the magnetic force urges the die portions together;
- aligning the forming surface of each die portion with its complementary component surface portion in the damage zone, and, optionally, after preheating the damage zone;
- urging each of the die portions into forcible engagement with one of the opposing shaped thermoplastic sheet component surfaces by application of the magnetic force, the force applying pressure to the component surfaces sufficient to reshape the component to substantially its undamaged shape;
- then,
- selectively heating the reshaped thermoplastic sheet component at the damage zone to a temperature sufficient to soften and/or melt the thermoplastic, the sheet being heated either directly or by contact with at least one heated die portion, the forming surfaces extending outwardly beyond the extent of the damage zone and being supported on unheated portions of the component to assure that the spacing between the opposing die forming surfaces corresponds to the thickness of the undamaged component at the damage location;
- maintaining the heated shaped thermoplastic sheet component damage zone at about its softening/melting temperature for a time sufficient to heal the damage in the damage zone;
- cooling the shaped thermoplastic sheet component damage zone while maintaining pressure on the component damage zone until the component damage zone cools sufficiently to maintain its shape and thereby restore the damage zone to its original shape and thickness, then, discontinuing the application of magnetic force;
- and
- removing the magnetic system and die portions.
Dependencies are inferred from the claim text.