CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority from Japanese Patent Application No. 2019-202027, filed Nov. 7, 2019, the entire content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to an automatic lay-up device that lays up a long sheet-shaped thermosetting prepreg on a layer surface by moving, in a lay-up direction, a lay-up head including a raw-cloth roller around which the thermosetting prepreg is wound, a cutting device that cuts the thermosetting prepreg drawn from the raw-cloth roller at a cutting angle forming an angle with respect to a longitudinal direction and a width direction thereof, and a pressing device that presses the thermosetting prepreg against the layer surface.

Background Art

A fiber reinforced composite material such as carbon-fiber-reinforced plastic (CFRP) is produced from a prepreg lay-up body formed by laying up prepregs formed by impregnating reinforcing fibers (carbon fibers or the like) with a matrix resin. That is, the prepreg lay-up body has a multilayer structure in which a plurality of prepregs are laid up, and when manufacturing a fiber reinforced composite material, the prepregs are first laid up. As the prepreg, a woven material obtained by impregnating a woven fabric having reinforcing fibers as warps and wefts with a matrix resin, or a so-called UD material in which the reinforcing fibers are aligned in one direction, impregnated with a matrix resin, and converged. As the matrix resin, there are a thermosetting resin and a thermoplastic resin.

When laying up the prepregs, by laying up the prepregs in a state where the orientation directions of the reinforcing fibers in each layer of the prepreg lay-up body are different from each other, the fiber reinforced composite material produced thereby is superior in rigidity and strength as compared with those obtained by laying up the prepregs in a state where the orientation directions of the reinforcing fibers are aligned.

Then, such laying up the prepregs may be performed by an automatic lay-up device. The automatic lay-up device generally includes a lay-up head provided with a raw-cloth roller around which a long sheet-shaped prepreg (prepreg sheet) is wound, a cutting device that cuts the prepreg sheet for cutting out a prepreg piece to be laid up from the prepreg sheet drawn from the raw-cloth roller, and a pressing device that presses the prepreg sheet (prepreg piece) against a layer surface. Then, the automatic lay-up device moves the lay-up head in the lay-up direction on a table to pull out the prepreg sheet from the raw-cloth roller, and presses the prepreg sheet against the layer surface by the pressing device to lay up the prepreg piece. Further, the lay-up direction (moving direction of the lay-up head) is determined based on the orientation direction of the reinforcing fibers, and the lay-up is performed in any direction of a plurality of predetermined angles with respect to a reference direction (for example, a front and rear direction of the table) in a range in which the prepreg pieces defined on the table are laid up (hereinafter, referred to as “lay-up range”).

Incidentally, in a general automatic lay-up device, the cutting device is configured to cut the prepreg sheet in a direction parallel to the width direction thereof. Therefore, in laying up the prepreg pieces by such an automatic lay-up device, the cutting end of the prepreg piece may be in a state of protruding from the lay-up range depending on the lay-up direction. On the other hand, the automatic lay-up device disclosed in JP-A-2018-020409 includes a cutting device configured to cut the prepreg sheet at a cutting angle that forms an angle with the longitudinal direction and the width direction thereof. Further, according to the automatic lay-up device disclosed in JP-A-2018-020409, the cutting end of the prepreg piece may not be in a state of protruding from the lay-up range as described above by setting the cutting angle as an angle corresponding to the lay-up direction.

SUMMARY OF THE INVENTION

In general, the above-described pressing device is provided in the automatic lay-up device so as to press the prepreg sheet (prepreg piece) at the same position in the longitudinal direction across the width direction, and sequentially press the prepreg sheet (prepreg piece) along with the movement of the lay-up head in the longitudinal direction. On the other hand, in a case where the prepreg sheet is cut at a cutting angle that forms an angle with respect to the longitudinal direction and the width direction as in the automatic lay-up device disclosed in JP-A-2018-020409 described above, the cutting end (rear end) the prepreg piece to be laid up is cut at the cut portion and the cutting end (front end) of the prepreg sheet that is continuous with the raw-cloth roller are overlapped at the same position of the prepreg sheet in the longitudinal direction.

Therefore, when trying to press the portion on the rear end side of the prepreg piece by the pressing device at the cut portion, the pressing by the pressing device is not only performed on the portion on the rear end side of the prepreg piece, but also on the portion on the front end side of the prepreg sheet. Then, in a case where the prepreg is a thermosetting prepreg, the thermosetting resin as the matrix resin has high viscosity, and thus if the portion on the front end side of the prepreg sheet is also pressed in such a manner, in the outside of the lay-up range, there is a case where the portion on the front end side is stuck to the table, which causes a problem in the subsequent lay-up.

Therefore, when laying up by using a thermosetting prepreg, in a case where the prepreg sheet is cut at a cutting angle according to the lay-up direction as described above, which is a case where the lay-up direction forms an angle with respect to the reference direction, the pressing of the prepreg piece by the pressing device may not be performed at the portion on the rear end side. Specifically, when the pressing device reaches the rear end of the prepreg piece being laid-up (pressed), by moving the pressing device upward, the cut portion including a portion on the front end side of the prepreg sheet may not be pressed by the pressing device.

Accordingly, the portion of the prepreg sheet on the front end side is prevented from being stuck to the table. However, in that case, since the portion on the rear end side of the prepreg piece to be laid up is not pressed by the pressing device, the portion on the rear end side is simply laid without being pressed against the layer surface. As a result, wrinkles may occur in the portion on the rear end side of the prepreg piece, or air (air bubbles) may remain between the portion on the rear end side and the layer surface, and in that case, the produced fiber reinforced composite material does not meet the desired quality.

Therefore, an object of the present invention to provide an automatic lay-up device capable of preventing poor quality of the fiber reinforced composite material to be produced by pressing the portion on the rear end side of the prepreg piece against the layer surface without pressing the portion on the front end side of the prepreg sheet.

The present invention is premised on an automatic lay-up device that lays up a long sheet-shaped thermosetting prepreg on a layer surface by moving, in a lay-up direction, a lay-up head including a raw-cloth roller around which the thermosetting prepreg is wound, a cutting device that cuts the thermosetting prepreg drawn from the raw-cloth roller at a cutting angle forming an angle with respect to a longitudinal direction and a width direction thereof, and a pressing device that presses the thermosetting prepreg against the layer surface.

Then, in order to achieve the above-described object, according to the present invention, the automatic lay-up device on which the invention is premised includes a driving mechanism provided in the lay-up head for moving the pressing device in a direction parallel to the width direction, and a drive controller that controls the driving of the driving mechanism to start moving the pressing device when a cutting end of the thermosetting prepreg reaches a position of the pressing device.

According to the automatic lay-up device of the present invention, a driving mechanism for moving the pressing device in a direction parallel to the width direction (hereinafter, simply referred to as “width direction”) is provided, and when the driving mechanism moves the pressing device in the state where the lay-up head moves in the lay-up direction, the pressing device moves relative to the prepreg sheet (prepreg piece) in a direction that forms an angle (hereinafter, referred to as “angle direction”) with the longitudinal direction and the width direction of the prepreg sheet (prepreg piece). The angle direction corresponds to movement speed of the pressing device with respect to movement speed of the lay-up head. Therefore, when the pressing device reaches the rear end of the prepreg piece being laid up (pressed), if the driving mechanism is controlled by the drive controller so that the pressing device is moved at a speed determined based on the cutting angle and the movement speed of the lay-up head, the pressing device moves in a direction that forms the same angle as the cutting angle with respect to the lay-up direction.

With this, in the cut portion, the portion on the front end side of the prepreg sheet is not pressed by the pressing device, and the portion on the rear end side of the prepreg piece is pressed against the layer surface by the pressing device. Therefore, while avoiding the occurrence of the problem caused by pressing the portion on the front end side of the prepreg sheet as described above, the occurrence of the problem caused when the portion on the rear end side of the prepreg piece is not pressed against the layer surface can be prevented, and as a result, poor quality of the fiber reinforced composite material to be produced can be prevented.

