Method and apparatus for continuous shaping of carbon-fiber-reinforced plastic tubes

Claim 1

A method for continuous shaping of carbon-fiber-reinforced plastic tubes having a wall thickness of 0.5 mm or less, which comprises steps of: (a) supporting a rod-like mandrel for forming a tube so as to be movable in its longitudinal direction; (b) laminating carbon fiber prepreg in tape form impregnated with a thermosetting resin on and around said mandrel; (c) preheating said laminate provided on said mandrel; (d) providing a hot die having an insertion part through which said mandrel having said preheated laminate is passed; and (e) pulling said preheated laminate in and through said hot die together with said mandrel, during which it is gelled, cured, and shaped into the carbon-fiber-reinforced plastic tubes, said pulling operation being done continuously by alternate operations of a first grasping means and a second grasping means, wherein said first and second grasping means, which respectively have gripping members for gripping or releasing said mandrel with said laminate of the prepreg of tape form and are disposed so as to be movable in the axial direction of said mandrel, carry out said pulling step by the movement in the axial direction while said mandrel is gripped by said gripping member, and wherein the pulling force of the second grasping means is generated, while the pulling force of the first grasping means still remains, and completing gellation of said laminate at the former half part of said hot die.

Claim 2

A method for continuous shaping of carbon-fiber-reinforced plastic tubes having a wall thickness of 0.5 mm or less, which comprises steps of: (a) supporting a rod-like mandrel for forming a tube so as to be movable in its longitudinal direction; (b) laminating carbon fiber prepreg in tape form impregnated with a thermosetting resin on and around said mandrel; (c) preheating said laminate provided on said mandrel; (d) providing a hot die having an insertion part through which said mandrel having said preheated laminate is passed; and (e) pulling said preheated laminate in and through said hot die together with said mandrel, during which it is gelled, cured, and shaped into the carbon-fiber-reinforced plastic tubes, said pulling operation being done continuously by alternate operations of a first grasping means and a second grasping means, wherein said first and second grasping means, which respectively have gripping members for gripping or releasing said mandrel with said laminate of the prepreg of tape form and are disposed so as to be movable in the axial direction of said mandrel, carry out said pulling step by the movement in the axial direction while said mandrel is gripped by said gripping member, and wherein the pulling force of the second grasping means is generated, while the pulling force of the first grasping means still remains, and completing gellation of said laminate at the former half part of said hot die.

Claim 11

An apparatus for continuous shaping of carbon-fiber-reinforced plastic tubes having a wall thickness of 0.5 mm or less, which comprises in combination: (a) a rod-like mandrel for forming tube, which is supported being movable in its axial direction; (b) means for laminating carbon fiber prepreg in tape form impregnated with a thermosetting resin in synchronism with a moving speed of said mandrel; (c) means for preheating said prepreg laminated on and around said mandrel; (d) a hot die for gelling and curing said preheated prepreg forwarded thereinto together with said mandrel, and for shaping the same into the carbon-fiber-reinforced plastic tubes, said hot die being constructed with a resin squeezing zone, a resin gelling zone, and a resin curing zone, each of said zones being temperature-controlled individually and separately; (e) first and second grasping means for gripping and pulling said shaped product from said hot die together with said mandrel; (f) first and second detectors for detecting the pulling force of each of said grasping means; and (g) pull-out drive means having a controller for generating the pulling force of said second grasping means, while said first grasping means still retains its pulling force, on the basis of the pulling force as detected by said first and second detectors.

Claim 12

An apparatus for continuous shaping of carbon-fiber-reinforced plastic tubes having a wall thickness of 0.5 mm or less, which comprises in combination: (a) a rod-like mandrel for forming tube, which is supported being movable in its axial direction; (b) means for laminating carbon fiber prepreg in tape form impregnated with a thermosetting resin in synchronism with a moving speed of said mandrel; (c) means for preheating said prepreg laminated on and around said mandrel; (d) a hot die for gelling and curing said preheated prepreg forwarded thereinto together with said mandrel, and for shaping the same into the carbon-fiber-reinforced plastic tubes, said hot die being constructed with a resin squeezing zone, a resin gelling zone, and a resin curing zone, each of said zones being temperature-controlled individually and separately; (e) first and second grasping means for gripping and pulling said shaped product from said hot die together with said mandrel; (f) first and second detectors for detecting the pulling force of each of said grasping means; and (g) pull-out drive means having a controller for generating the pulling force of said second grasping means, while said first grasping means still retains its pulling force, on the basis of the pulling force as detected by said first and second detectors.