Roller unit for feeding tapes, fiber placement apparatus and method of molding composite material
A roller unit aligns tapes in a width direction and feeds the tapes in a length direction while pressing the tapes in a thickness direction. The tapes are made of fibers which have not been impregnated with resin or have been impregnated with the resin. The roller unit includes rollers and a support shaft. The rollers rotate by friction force between the tapes and the rollers. The rollers are aligned so that rotation axes lie on a same straight line. Maximum diameters of the rollers are same as each other. The support shaft supports the rollers rotatably at rotational speeds independent from each other. Each of the rollers includes springs and thereby has elasticity. Length directions of the springs as well as expansion and contraction directions of the springs are radial directions of the each of the rollers. The springs are radially disposed inside the each of the rollers.
1 . A roller unit for aligning tapes in a width direction and feeding the aligned tapes in a length direction while pressing the aligned tapes in a thickness direction, the tapes being made of fibers which have not been impregnated with resin or have been impregnated with the resin,
the roller unit comprising:
rollers rotating by friction force between the tapes and the rollers when the rollers contact with the tapes, the rollers being aligned so that rotation axes of the rollers lie on a same straight line, maximum diameters of the rollers being same as each other; and
a support shaft supporting the rollers rotatably at rotational speeds independent from each other,
wherein each of the rollers includes springs and thereby has elasticity, length directions of the springs being radial directions of the each of the rollers, expansion and contraction directions of the springs being radial directions of the each of the rollers, the springs being radially disposed inside the each of the rollers, and
wherein the each of the rollers includes a ring forming an outer surface of the each of the rollers, the springs being disposed inside the ring, the ring consisting of a corrugated spring of which a phase direction is circular and of which amplitude directions are in radial directions of the each of the rollers.
2 . The roller unit according to claim 1 , wherein the ring is made of an elastic body which deforms the ring so as to fit a surface having unevenness when the ring is pressed against the surface having the unevenness, the elastic body restoring a deformed shape of the ring to an original undeformed shape when the ring is pulled away from the surface having the unevenness.
3 . A fiber placement apparatus comprising:
the roller unit according to claim 2 .
4 . A method of molding a composite material comprising:
laminating the tapes by feeding the tapes using the roller unit according to claim 2 ; and
curing the resin with which the tapes have been impregnated.
5 . A fiber placement apparatus comprising:
the roller unit according to claim 1 .
6 . A method of molding a composite material comprising:
laminating the tapes by feeding the tapes using the roller unit according to claim 1 ; and
curing the resin with which the tapes have been impregnated.
7 . The roller unit according to claim 1 , wherein each roller further includes at least one radial step formed in the outer ring so that the thickness of each outer ring decreases in a radial out to radial inward direction.
8 . The roller unit according to claim 1 , wherein each roller includes an inner ring forming an interior surface supported by said support shaft, and wherein the springs having radial length directions are circumferentially spaced apart from each other as to define circumferential gaps between adjacent springs having radial length directions, and which circumferential gaps each extend radially for a full radial length between the inner ring and the outer ring.
9 . A roller unit for aligning tapes in a width direction and feeding the aligned tapes in a length direction while pressing the aligned tapes in a thickness direction, the tapes being made of fibers which have not been impregnated with resin or have been impregnated with the resin,
the roller unit comprising:
rollers rotating by friction force between the tapes and the rollers when the rollers contact with the tapes, the rollers being aligned so that rotation axes of the rollers lie on a same straight line, maximum diameters of the rollers being same as each other; and
a support shaft supporting the rollers rotatably at rotational speeds independent from each other,
wherein each of the rollers includes springs and thereby has elasticity, length directions of the springs being radial directions of the each of the rollers, expansion and contraction directions of the springs being radial directions of the each of the rollers, the springs being radially disposed inside the each of the rollers,
wherein the springs having radial length directions are each comprised of a one-dimensional wavy spring whose phase direction is a radial direction of the roller, while amplitude direction of the wavy spring is perpendicular to both the radial direction and the rotation axis direction of the roller, and
wherein the springs having radial length directions each have amplitudes that increase in moving radially away from the rotation axis of the roller.
10 . The roller unit according to claim 9 , wherein each roller includes an outer ring forming an outer surface, the springs having radial length directions are disposed inside the outer ring, and wherein the outer ring is a wave shaped corrugated spring of which a phase direction is circular, the corrugated spring being integrated with the springs having radial length directions.