Abstract: An air-fuel ratio control device comprising a memory which stores the relationship between the degree of opening of the throttle valve and the absolute pressure in the intake passage, which pressure is produced when the engine is in a cruising state. When a difference between the blunt value of the actual absolute pressure in the intake passage and the absolute pressure stored in the memory exceeds a fixed value, the air-fuel mixture is changed from the mixture for the stoichiometric air-fuel ratio to a lean mixture.

Abstract: A slip control system for a vehicle provided with an internal combustion engine having a knocking control system for controlling an ignition timing retarding amount in accordance with a degree of knocking detected by a knocking sensor mounted on a body of the engine. The slip control system controls the torque applied to drive wheels of the vehicle in accordance with a degree of slip generated at the drive wheels. A circuit is provided for cancelling the operation of the knocking control system during the operation of the slip control system.

Abstract: A lean burn internal combustion engine wherein a basic fuel amount is calculated from a map based on the intake pressure and the engine speed, and a lean correction factor, which is multiplied by the basic fuel amount, is calculated from a lean map based on the intake pressure and engine speed. A second lean map based on the throttle opening and engine speed is provided for obtaining a lean correction factor when the degree of opening of the throttle valve is larger than a predetermined value. A lean sensor is provided for obtaining a signal indicating the air fuel ratio for carrying out a feedback control. The lean sensor is provided with a heater for controlling the temperature of the sensing element of the heater.

Abstract: In an internal combustion engine, a vibration period and a vibration amplitude are measured and the detected vibration period is compared with a natural vibration period prestored in accordance with a driving condition of the vehicle. If the detected vibration period is equal to the natural vibration period under the driving condition at which the vibration period is detected, it is determined that surging due to a torque variation of the engine is occurring. In this condition, the torque variation is controlled to be a predetermined value by increasing an air-fuel ratio or decreasing an amount of EGR when the detected vibration amplitude is smaller than a predetermined value, and the torque variation is controlled to a predetermined value by decreasing an air-fuel ratio or increasing an amount of EGR when the detected vibration amplitude is larger than a predetermined value, and accordingly, the driveability and emission rate are improved.

Abstract: A device for determining an activated condition of the oxygen sensor of a lean sensor for an electric-controlled fuel injection internal combustion engine. When the engine is under a fuel cut operation, the output level from the oxygen sensor is compared with a first predetermined threshold level or with a second predetermined threshold level which is lower than the first threshold level. A determination of the activated condition of the oxygen sensor is obtained when the output level from the oxygen once exceeds the higher first level, or when the output level from the oxygen sensor consecutively exceeds the higher first level twice, whereby a positive and quick determination of the activated condition of the oxygen sensor can be obtained.

Abstract: A method for economically manufacturing an iron-boron-silicon alloy through simple steps, which comprises the steps of: adding a boron raw material and a carbonaceous reducing agent to a molten iron received in a vessel; blowing oxygen gas into the molten iron to reduce the boron raw material in the molten iron by means of the carbonaceous reducing agent to prepare a boron-containing molten iron; continuing the blowing of oxygen gas to decarburize the boron-containing molten iron until the carbon content in the boron-containing molten iron decreases to up to 0.2 wt. %; and adding at least one of silicon and ferrosilicon to the boron-containing molten iron while stirring the boron-containing molten iron, thereby manufacturing an iron-boron-silicon alloy.

Abstract: A method for smelting reduction of Ni ore comprises charging Ni ore and carbonaceous material into a converter type smelting reduction furnace having bottom-blow tuyeres and a top-blow lance, the smelting reduction furnace holding a molten metal, blowing oxygen gas from the top-blow lance and a stirring gas from the bottom-blow tuyeres into the furnace, and discharging slag so that a relation represented with a formulaVo>0.4 Ws+1.0can be satisfied, Vo (m.sup.3 per ton of molten metal) being a specific volume of the smelting reduction furnace per ton of molten metal and Ws (ton per ton of molten metal) being 2 specific weight of slag per ton of molten metal.

Abstract: A traction control device comprising a fuel supply control device for controlling the supply of fuel fed into the engine cylinders. When the temperature of the engine is high, if the speed difference between the rotating speed of the free running wheel and the rotating speed of the driven wheel exceeds a predetermined value, the supply of fuel fed into some of the cylinders or all of the cylinders is stopped. Conversely, when the temperature of the engine is low, even if the speed difference exceeds the predetermined value, the feeding of fuel to all of the cylinders is continued.

Abstract: A method for manufacturing molten metal containing Ni and Cr comprises a process of smelting and reducing Ni ore, and a process of smelting and reducing Cr ore.The process of smelting and reducing Ni ore comprises the steps of charging molten iron into a smelting reduction furnace having a top-blow oxygen lance and tuyeres for blowing stirring gas, charging Ni ore, carbonaceous material and flux into the smelting reduction furnace, blowing decarbonization oxygen and post-combustion oxygen from the top-blow oxygen lance into the smelting reduction furnace, blowing stirring gas for stirring the molten metal and slag inside the smelting reduction furnace from the tuyeres, and controlling post-combustion ratio [(H.sub.2 O+CO.sub.2)/(H.sub.2 +H.sub.2 O+CO+CO.sub.2)] at 0.3 or more.

Abstract: A traction control device comprising a subthrottle valve arranged upstream of the main throttle valve. When the speed difference between the rotating speed of the free running wheel and the rotating speed of the driven wheel exceeds a predetermined value, the subthrottle valve is closed to reduce the output torque of the engine, and the supply of EGR gas into the intake passage and the supply of fuel vapor from the charcoal canister into the intake passage are stopped when the subthrottle valve is closed.

Abstract: In an internal combustion engine, a vibration period and a vibration amplitude are measured when the surging of a vehicle is detected and the detected vibration period is compared with a natural vibration period prestored in accordance with a driving condition of the vehicle when the detected vibration amplitude is larger than a predetermined value, and if the detected vibration period is equal to the natural vibration period under the driving condition at which the vibration period is detected, surging due to variations of a combustion cycle of the engine is determined to be occurring, and accordingly, a surging reducing process is activated.

Abstract: A method for smelting reduction of Ni ore comprises charging Ni ore, carbonaceous material and flux into a converter type smelting reduction furnace holding molten iron therein and controlling a post-combustion ratio [(H.sub.2 O+CO.sub.2)/(H.sub.2 +H.sub.2 O+CO+CO.sub.2)] inside the smelting reduction furnace at 0.3 or more by blowing oxygen from a top-blow oxygen lance and stirring gas from a bottom-blow tuyere arranged in the bottom of the smelting reduction furnace into the smelting reduction furnace.A relation between a content of carbon [C] (%) in molten metal and an amount of slag produced per ton of molten metal is represented with a formula:[C].gtoreq.