Abstract: A cylinder head of an engine is provided, which includes first and second intake ports that open to a common cylinder. The first intake port opens to the cylinder to generate a swirl flow. The second intake port has a tumble flow generating part configured to cause intake air to become a tumble flow in the same direction as the swirl flow. The tumble flow generating part includes a helical part having an inner wall surface curving on a centerline perpendicular to an opening surface of the second port and continuing from a first port side to the opening of the second intake port toward at an opposite side from the first port. The opening of the second intake port has an edge part having an opening angle with respect to the centerline of the second port, the opening angle being smaller at an upstream side of the swirl flow.

Abstract: A cylinder head of an engine is provided, which includes first and second intake ports that open to a common cylinder. The first intake port opens to the cylinder to generate a swirl flow. The second intake port has a tumble flow generating part configured to cause intake air to become a tumble flow in the same direction as the swirl flow. The tumble flow generating part includes a helical part having an inner wall surface curving on a centerline perpendicular to an opening surface of the second port and continuing from a first port side to the opening of the second intake port toward at an opposite side from the first port. The opening of the second intake port has an edge part having an opening angle with respect to the centerline of the second port, the opening angle being smaller at an upstream side of the swirl flow.

Abstract: A structure of a combustion chamber is provided. The structure includes a cavity formed in a central part of a crown surface of a piston and a wall surface constituting the cavity. The wall surface has a central ridge portion bulging farther toward a bottom surface of a cylinder head toward a center of the cavity, a periphery concave portion formed radially outward of the central ridge portion to concave radially outward, and a lip portion formed between the periphery concave portion and an opening edge of the cavity to convex radially inward. An outer circumferential part of the crown surface has a first portion and a second portion located radially outward of the first portion. A stepped portion is formed between the first and second portions. A stepped portion volume ratio of a stepped portion volume to a top dead center volume is set to 0.1 or smaller.

Abstract: According to a method of the present invention for producing a CPVC resin, the method includes the steps of: introducing chlorine into a slurry of a PVC resin in a first tank; transferring, from the first tank to a second tank, the slurry into which chlorine has been introduced; and irradiating, with UV light, the slurry in the second tank. This method improves an amount of chlorine dissolved into the slurry of the PVC resin and consequently, improves production efficiency of the CPVC resin.

Abstract: A structure of a combustion chamber is provided. The structure includes a cavity formed in a central part of a crown surface of a piston and a wall surface constituting the cavity. The wall surface has a central ridge portion bulging farther toward a bottom surface of a cylinder head toward a center of the cavity, a periphery concave portion formed radially outward of the central ridge portion to concave radially outward, and a lip portion formed between the periphery concave portion and an opening edge of the cavity to convex radially inward. An outer circumferential part of the crown surface has a first portion and a second portion located radially outward of the first portion. A stepped portion is formed between the first and second portions. A stepped portion volume ratio of a stepped portion volume to a top dead center volume is set to 0.1 or smaller.

Abstract: According to a method of the present invention for producing a CPVC resin, the method includes the steps of: introducing chlorine into a slurry of a PVC resin in a first tank; transferring, from the first tank to a second tank, the slurry into which chlorine has been introduced; and irradiating, with UV light, the slurry in the second tank. This method improves an amount of chlorine dissolved into the slurry of the PVC resin and consequently, improves production efficiency of the CPVC resin.

Abstract: A chlorinated vinyl chloride resin composition comprising 100 parts by weight of chlorinated vinyl chloride resin and a hydroxypolycarboxylic acid salt, e.g., sodium tartrate, and/or 0.2 to 1.5 parts by weight of zeolite. The composition exhibits improved thermal stability and is particularly suited to pipe extrusion.

Abstract: A chlorinated vinyl chloride resin composition comprising 100 parts by weight of chlorinated vinyl chloride resin and a hydroxypolycarboxylic acid salt, e.g., sodium tartrate, and/or 0.2 to 1.5 parts by weight of zeolite. The composition exhibits improved thermal stability and is particularly suited to pipe extrusion.

Abstract: A polyvinyl chloride resin having an average particle diameter of not less than 150 &mgr;m and porosity at 31-1,011 psi of not less than 0.15 cc/g is suspended in an aqueous medium and chlorinated by blowing gaseous chlorine into the aqueous suspension. In this way, the floating resin formation during chlorination can be prevented and a chlorinated polyvinyl chloride resin excellent in free flow property and showing good resistance to initial discoloration and good thermal stability in heating and molding processes can be produced.

Abstract: A polyvinyl chloride resin having an average particle diameter of not less than 150 &mgr;m and porosity at 31-1,011 psi of not less than 0.15 cc/g is suspended in an aqueous medium and chlorinated by blowing gaseous chlorine into the aqueous suspension. In this way, the floating resin formation during chlorination can be prevented and a chlorinated polyvinyl chloride resin excellent in free flow property and showing good resistance to initial discoloration and good thermal stability in heating and molding processes can be produced.

Abstract: A polyvinyl chloride resin having an average particle diameter of not less than 150 &mgr;m and porosity at 31-1,011 psi of not less than 0.15 cc/g is suspended in an aqueous medium and chlorinated by blowing gaseous chlorine into the aqueous suspension. In this way, floating resin formation during chlorination can be prevented and a chlorinated polyvinyl chloride resin excellent in free flow property and showing good resistance to initial discoloration and good thermal stability in heating and molding processes can be produced.