Abstract: A process for producing a skin material-laminated hollow molded article of thermoplastic resin, using a mold having, in any one or both of its fixed and movable parts, at least one fluid-ejecting pin which can be slid in a clamping direction and which has a fluid-ejecting hole at its pointed end. The process consists of fixing two sheets of a skin material having a tensile modulus at ambient temperature of 50-1,000 kg/cm.sup.2 and a tensile modulus at 80.degree. C. of 5 to 100 kg/cm.sup.2 on the parting surfaces of both the mold parts which are in the open state. A molten thermoplastic resin is fed between the skin materials in an amount of 5 to 50% by volume of the cavity volume. The fluid-ejecting pin is thrusted so that its pointed end penetrates one of the skin material sheets and comes between the skin material sheets. The mold parts are closed to wrap the molten thermoplastic resin in between the skin material sheets.

Abstract: A process for producing a concrete form made of thermoplastic resin by a press-molding process by feeding a reinforcing material-containing thermoplastic resin heated to a temperature not lower than the melting temperature of the resin into the cavity between male and female halves of a die, clamping the die and cooling the die, wherein the press-molding is carried out under the conditions that the period of time from completion of feeding the melted resin to completion of clamping is not longer than 6 seconds and flow length L of the fed resin and thickness T of the molded product satisfy the formula 190.ltoreq.L/T.

Abstract: A fiber reinforced thermoplastic resin shaped article is prepared by supplying a preheated fiber reinforced thermoplastic resin sheet between upper and lower molds, positioning the upper and lower molds so that a clearance between the upper and lower molds at the time of the completion of mold clamping is larger than a thickness of the unpreheated fiber reinforced thermoplastic resin sheet, and supplying a molten thermoplastic resin in a recess provided in at least one of the upper and lower molds through a resin passage provided in the mold so that a portion formed from the molten thermoplastic resin in the recess is integrated by fusion with a portion formed from the fiber reinforced thermoplastic resin sheet. The article is light-weight and also has a rib, a boss or any other projection.

Abstract: A concrete form a part of which is made of a fiber-reinforced thermoplastic resin, said fiber-reinforced thermoplastic resin satisfying the following conditions:Tt(C).gtoreq.Tt(M)-1.5.alpha.15.ltoreq.Tt(c)wherein Tt(C) (%) is total transmittance of the fiber-reinforced thermoplastic resin measured at the thickness of top board, .alpha. (% by weight) is fiber weight fraction of the fiber-reinforced thermoplastic resin, and Tt(M) (%) is total transmittance of the matrix resin measured at the same thickness as above.

Abstract: A fiber reinforced thermoplastic resin shaped article is prepared by supplying a preheated fiber reinforced thermoplastic resin sheet between upper and lower molds, positioning the upper and lower molds so that a clearance between the upper and lower molds at the time of the completion of mold clamping is larger than a thickness of the unpreheated fiber reinforced thermoplastic resin sheet, and supplying a molten thermoplastic resin in a recess provided in at least one of the upper and lower molds through a resin passage provided in the mold so that a portion formed from the molten thermoplastic resin in the recess is integrated by fusion with a portion formed from the fiber reinforced thermoplastic resin sheet.

Abstract: A multicylinder engine whose working cylinders are variably controlled in number to suit operating requirements, with an air fuel mixture fed from a single throttle valve to the working cylinder or cylinders through an intake manifold, includes at least one normally closed control valve installed in at least one intake pipe of the intake manifold. When the throttle valve has opened to a prescribed degree, the control valve instantly opens fully or almost fully or to a prescribed degree, independently of the throttle valve.

Abstract: A multicylinder engine whose working cylinders are variably controlled in number to suit operating requirements, with an air fuel mixture fed from a single throttle valve to the working cylinder or cylinders through an intake manifold, includes at least one normally closed control valve installed in at least one intake pipe of the intake manifold. When the throttle valve has opened to a prescribed degree, the control valve instantly opens fully or almost fully or to a prescribed degree, independently of the throttle valve.

Abstract: A multicylinder engine whose working cylinders are variably controlled in number to suit operating requirements, with an air fuel mixture fed from a single throttle valve to the working cylinder or cylinders through an intake manifold, includes at least one normally closed control valve installed in at least one intake pipe of the intake manifold. When the throttle valve has opened to a prescribed degree, the control valve instantly opens fully or almost fully or to a prescribed degree, independently of the throttle valve.