Lay-up-position correcting method for automatic lay-up machine

1. A lay-up-position correcting method for an automatic lay-up machine including

a head device including

a sheet supplying unit in which a raw-cloth roller having a long prepreg sheet wound therearound is mounted and that supplies the prepreg sheet from the raw-cloth roller, the prepreg sheet including sheet-shaped prepreg and release paper bonded to a surface of the prepreg,

a lay-up unit that lays up the prepreg on a receiving surface by pressing the prepreg sheet supplied by the sheet supplying unit against the receiving surface with a lay-up head, and

a sheet take-up unit that takes up the release paper separated from the prepreg when the prepreg is laid up, and

a support mechanism that supports the head device and includes a mechanism for moving the head device at least in a lay-up direction of the prepreg and a width direction of the prepreg sheet,

wherein the lay-up-position correcting method corrects a position of the prepreg sheet in the width direction at a start of a lay-up operation performed by the automatic lay-up machine, and

wherein the lay-up-position correcting method comprises:

a first step of establishing a state in which a position of the raw-cloth roller coincides with a lay-up position in the width direction by moving the head device to a starting point of the lay-up position while the head device is in a state in which an end portion of the prepreg sheet fed from the raw-cloth roller is below the lay-up head and in which a predetermined tension is applied to the prepreg sheet;

a second step of determining a deviation between a position of an edge of the prepreg sheet and the lay-up position in the width direction;

a third step of establishing a state in which the position of the edge of the prepreg sheet coincides with the lay-up position in the width direction by moving the head device by a movement amount corresponding to the deviation in a movement direction along the width direction for cancelling the deviation;

a fourth step of establishing a state in which the end portion of the prepreg sheet is pressed against the receiving surface at the starting point of the lay-up position by moving the head device or the lay-up head downward; and

a fifth step of reestablishing the state in which the position of the raw-cloth roller coincides with the lay-up position in the width direction by moving the head device in a direction along the width direction opposite to the movement direction in the third step by an amount equal to the movement amount in the third step.

2. The lay-up-position correcting method according to claim 1 , further comprising:

a tension reducing step of reducing a tension of the prepreg sheet, the tension reducing step being performed between the fourth step and the fifth step; and

a tension returning step of reestablishing the state in which the predetermined tension is applied to the prepreg sheet, the tension returning step being performed after the fifth step.

3. The lay-up-position correcting method according to claim 2 , wherein the tension reducing step is a step of rotating the raw-cloth roller in a direction for feeding the prepreg sheet, and the tension returning step is a step of rotating the raw-cloth roller in a direction for rewinding the prepreg sheet.