Abstract: Fluid flow grooves (11) with a flat cross section being formed between the back surface of a metal mold (2) for blow molding and a back-up member (4) which adheres tightly to this back surface. A plurality of these fluid flow grooves (11) are provided, and these fluid flow grooves are disposed densely in parallel with partition walls (21) interposed between the grooves. Fluid inlets (12) and outlets (13) are formed in the respective fluid flow grooves (11). A heating fluid or cooling fluid enters the respective fluid flow grooves (11) via the inlets (12) from a fluid supply manifold (14). The fluid flows out of the outlets (13), enters a fluid discharge manifold (15), and is discharged to the outside. Rapid heating and rapid cooling of the metal mold (2) are performed, no irregularity occurs in temperature, and the cycle time can be shortened, so that a metal mold device for blow molding in which the energy consumption is small can be obtained.

Abstract: Fluid flow grooves (11) with a flat cross section being formed between the back surface of a metal mold (2) for blow molding and a back-up member (4) which adheres tightly to this back surface. A plurality of these fluid flow grooves (11) are provided, and these fluid flow grooves are disposed densely in parallel with partition walls (21) interposed between the grooves. Fluid inlets (12) and outlets (13) are formed in the respective fluid flow grooves (11). A heating fluid or cooling fluid enters the respective fluid flow grooves (11) via the inlets (12) from a fluid supply manifold (14). The fluid flows out of the outlets (13), enters a fluid discharge manifold (15), and is discharged to the outside. Rapid heating and rapid cooling of the metal mold (2) are performed, no irregularity occurs in temperature, and the cycle time can be shortened, so that a metal mold device for blow molding in which the energy consumption is small can be obtained.

Abstract: A blow formed, one-piece, hollow bumper includes a bumper body member, and a reinforcing frame member for connection with the vehicle frame. The frame member projects into the hollow inside of the body member from the backside of the body member. The frame member is formed in one piece with the body member attached to a vehicle frame attachment portion of the body member. In one embodiment, the frame member is closed off with a metallic plate member so as to form a box cross section. A method of making the bumper is also disclosed and includes the steps of setting the frame member in a mold and blow forming a bumper member integral with the frame.

Abstract: A plastic bumper for use in an automobile includes a front wall member generally having a U-shape cross-section, and a rear wall member having a mid portion intermittently indented to form a plurality of pyramid frustum shaped recesses. An outer end face of each pyramid frustum recess is adhered to an inside face of said front wall member. Thus, the bumper is reinforced with respect to vertical and horizontal impacts.