摘要:
Provided is a molten metal discharge nozzle capable of suppressing turbulence in a molten metal stream passing through an inner bore thereof, with a simple structure. A cross-sectional shape of a wall surface of the inner bore, taken along an axis of the inner bore, comprises a part or an entirety of a curved line expressed by the following formula: log(r(z))=(1/n)×log((Hc+L)/(Hc+z))+log(r(L)) (1), where: 6≧n≧1.5; L is a length of the nozzle; Hc is a calculative hydrostatic head; and r(z) is a radius of the inner bore at a position located a distance z downward from an upper end of the nozzle, wherein, in a graph where the distance z is plotted with respect to a horizontal axis (X-axis) thereof, and a pressure of molten metal at a center of the inner bore in horizontal cross-section at a position located the distance z is plotted with respect to a vertical axis (Y-axis) thereof, an approximation formula of a line on the graph is established without simultaneously including two or more coefficients having opposite signs, and wherein, on an assumption that the line is derived from an approximation formula based on a linear regression, an absolute value of a correlation coefficient of the line is 0.95 or more.
摘要:
Provided is a molten metal discharge nozzle capable of suppressing turbulence in a molten metal stream passing through an inner bore thereof, with a simple structure. A cross-sectional shape of a wall surface of the inner bore, taken along an axis of the inner bore, comprises a part or an entirety of a curved line expressed by the following formula: log(r(z))=(1/n)×log((Hc+L)/(Hc+z))+log(r(L)) (1), where: 6≧n≧1.5; L is a length of the nozzle; Hc is a calculative hydrostatic head; and r(z) is a radius of the inner bore at a position located a distance z downward from an upper end of the nozzle, wherein, in a graph where the distance z is plotted with respect to a horizontal axis (X-axis) thereof, and a pressure of molten metal at a center of the inner bore in horizontal cross-section at a position located the distance z is plotted with respect to a vertical axis (Y-axis) thereof, an approximation formula of a line on the graph is established without simultaneously including two or more coefficients having opposite signs, and wherein, on an assumption that the line is derived from an approximation formula based on a linear regression, an absolute value of a correlation coefficient of the line is 0.95 or more.
摘要:
A single cylinder engine includes an engine body having a combustion chamber, an intake opening and an exhaust opening which face toward the combustion chamber, an intake passage in communication with the combustion chamber through the intake opening, and an exhaust passage in communication with the combustion chamber through the exhaust opening, an intake valve that opens and closes the intake opening, an exhaust valve that opens and closes the exhaust opening, an injector that injects a fuel toward the intake opening and into the intake passage, a ternary catalyst provided in the exhaust passage, and an engine control unit (ECU) that performs a decelerated operation to selectively execute a cycle for injection of a fuel from the injector, a quantity of which makes an air-fuel ratio in the combustion chamber substantially equal to a theoretical air fuel ratio, and a cycle for inhibition of fuel injection from the injector.
摘要:
A single cylinder engine includes an engine body having a cylinder and a combustion chamber, an intake opening that faces the combustion chamber, and an intake passage in communication with the combustion chamber through the intake opening, a piston provided in the cylinder, an ignition plug arranged in a position within about 5% of a bore diameter of the cylinder from an axis of the cylinder, a throttle valve provided in the intake passage, a sensor that detects an opening degree of the throttle valve, and an ECU that causes the ignition plug to lag in ignition timing during two or three cycles when the throttle valve is increased in opening degree from an idling state.
摘要:
The present invention is intended to provide a heat-insulating refractory material, which does not contain environmentally and hygienically undesirable ceramic heat-insulating fibers, but only contains organic fibers to the extent necessary to improve adhesive rate upon spraying, and which can nevertheless achieve a specified heat-insulating effect. The heat-insulating refractory material includes a mixture containing 2-50 wt % of a foaming raw material foamed by heat at a temperature from 400.degree. to 1500.degree. C. and 50-98 wt % of a refractory powder, and a liquid binder which is added to the mixture in an amount of 20-250 wt % on the basis of the weight of the mixture.
摘要:
An internal combustion engine includes a cylinder having a cylinder inner surface, a cylinder head that cooperates with the cylinder inner surface to define a combustion chamber and has a head inner surface including an intake opening through which an intake gas is introduced into the combustion chamber, an intake valve that opens and closes the intake opening, an ignition plug provided on the cylinder head, and an intake drifting mechanism that causes the intake gas to drift toward an axis of the cylinder in the intake opening and generates a vortex flow in the combustion chamber. When the intake valve is opened, a minimum gap between the intake valve and the head inner surface is equal to or larger than a gap between the intake valve and the cylinder inner surface in a diametrical direction of the cylinder.
摘要:
An internal combustion engine includes a cylinder head, a cylinder having an opposed surface opposed to the cylinder head and including a water jacket, which is concave in an axial direction of the cylinder, and a piston provided in the cylinder. An oil ring is provided on the piston on a side that is farthest from the cylinder head. At least a portion between a cylinder inner surface and the water jacket in the cylinder is made of a material having a higher thermal conductivity than that of iron. A bottom wall of the water jacket is positioned in the cylinder axial direction between the opposed surface of the cylinder and a lower end of the oil ring when the piston is disposed at a top dead center position.
摘要:
An internal combustion engine includes a cylinder head, a cylinder having an opposed surface opposed to the cylinder head and including a water jacket, which is concave in an axial direction of the cylinder, and apiston provided in the cylinder. An oil ring is provided on the piston on a side that is farthest from the cylinder head. At least a portion between a cylinder inner surface and the water jacket in the cylinder is made of a material having a higher thermal conductivity than that of iron. A bottom wall of the water jacket is positioned in the cylinder axial direction between the opposed surface of the cylinder and a lower end of the oil ring when the piston is disposed at a top dead center position.
摘要:
A single cylinder engine includes an engine body having a combustion chamber, an intake opening and an exhaust opening which face toward the combustion chamber, an intake passage in communication with the combustion chamber through the intake opening, and an exhaust passage in communication with the combustion chamber through the exhaust opening, an intake valve that opens and closes the intake opening, an exhaust valve that opens and closes the exhaust opening, an injector that injects a fuel toward the intake opening and into the intake passage, a ternary catalyst provided in the exhaust passage, and an engine control unit (ECU) that performs a decelerated operation to selectively execute a cycle for injection of a fuel from the injector, a quantity of which makes an air-fuel ratio in the combustion chamber substantially equal to a theoretical air fuel ratio, and a cycle for inhibition of fuel injection from the injector.
摘要:
An internal combustion engine includes an engine body including a cylinder that defines a combustion chamber, an intake opening that faces the combustion chamber, and an intake passage in communication with the combustion chamber through the intake opening, a piston provided in the cylinder, an intake valve that opens and closes the intake opening, a throttle valve provided in the intake passage, and an injector that injects fuel between the throttle valve in the intake passage and the intake opening. A ratio of a volume of the portion that extends from the throttle valve in the intake passage to the intake opening, to a stroke volume of the cylinder is at most approximately 0.61. The time period in which fuel injection from the injector is terminated during an idling operation is set within a period of time after one intake stroke has been completed and before the next intake stroke is begun.