Hollow structure plate, manufacturing method thereof, manufacturing device thereof, and sound absorbing structure plate

A method for manufacturing a hollow structure plate comprising:

• introducing, using a pair of sheet-introduction plates, two thermoplastic resin sheets into a pressure-reduced chamber;
• attracting and attaching the thermoplastic resin sheets respectively to a circumferential surface of each of a pair of upper and lower emboss rollers that are arranged rotatably in said pressure-reduced chamber to form a multitude of hollow protrusions on each of the thermoplastic resin sheets in accordance with a shape of a plurality of pins projected from each of the emboss rollers;
• and
• thermally fusing, using a heater that is disposed between the pair of sheet-introduction plates, the end faces of said hollow protrusions in a position of a contact point of the emboss rollers continuously;
• wherein the pair of sheet-introduction plates are inclined in a direction toward the contact point;
• and
• wherein the emboss rollers satisfy the following conditions:
• each of said pins is truncated cone-shaped;
• a ratio between a total area of lower base portions of the pins and a surface area of said emboss rollers on which the pins are not formed, is in a range from 0.3 to 0.58;
• and
• a rising angle of a side face of each of the pins in a vertical plane including a central axis of the pin is in a range from 50 degrees to 70 degrees.

An apparatus for manufacturing a hollow structure plate comprising:

• a pressure-reduced chamber that is evacuated to reduce a pressure inside;
• a pair of upper and lower emboss rollers that are supported with bearings rotatably in said pressure-reduced chamber in a state in which circumferential surfaces of the emboss rollers face a front opening portion of said pressure-reduced chamber, wherein a plurality of pins provided on one of the emboss rollers is brought into contact with a plurality of pins provided on the other of the rollers via two thermoplastic resin sheets in a position of a contact point;
• a pair of sheet-introduction plates for introducing the two thermoplastic resin sheets into the pressure-reduced chamber, the pair of sheet-introduction plates being inclined in a direction toward the contact point;
• and
• a heater for heating that is arranged at said front opening portion of said pressure-reduced chamber between the pair of sheet-introduction plates;
• wherein each of said pins of said emboss rollers is truncated cone-shaped;
• wherein a ratio between a total area of lower base portions of the pins and a surface area of said emboss rollers on which the pins are not formed, is in a range from 0.3 to 0.58;
• and
• wherein a rising angle of a side face of each of the pins in a vertical plane including a central axis of the pin is in a range from 50 degrees to 70 degrees.