Abstract: A gas ventilation system for an internal combustion engine is provided which includes a downstream intake pipe communicating with cylinders of the engine, an upstream intake pipe communicating with the downstream intake pipe through a throttle valve, and a gas ventilation pipe for recirculating a given gas to the engine. The system also has an inner hollow cylinder connected to the upstream intake pipe, disposed within the downstream intake pipe to define a gas passage between the periphery of the inner cylinder and an inner wall of the downstream intake pipe. The gas passage communicates with the gas ventilation pipe and serves as an isolating member for isolating flow of the gas entering the downstream intake pipe through the gas ventilation pipe from swirls produced by intake air flowing downstream of the throttle valve from the upstream intake pipe.

Abstract: The present disclosure concerns a soil or ground quality stabilizer comprising a mixture formed by mixing a burned sewage sludge ash the main contents of which are CaO, SiO.sub.2 and Al.sub.2 O.sub.3 with a lime of calcium hydroxide to reduce hydraulicity and a fine Fe oxides mixture powder byproduced in steel production the main content of which is iron oxide. The soil or ground quality stabilizer is added into a pavement material containing crushed stones, natural soil, etc. to improve the strength and viscoelasticity of the natural soil and can give a desired CBR strength to the soil having an increased moisture content. The preferable adding ratio of the fine Fe oxides mixture powder into the mixture of the burned sewage sludge ash and the lime of calcium hydroxide is within the range of 15-35 weight %.

Abstract: A soil or ground reinforcing material consisting of Al--Fe oxides mixture the main contents of which are iron oxide made from fine iron oxide powder byproduced in steel production and Aluminum oxide made from red mud by-produced in Aluminum smeltering and lime added therein is mixed into a soil containing crushed stones, natural soil, etc., and further Titanium oxide is mixed into the above soil or ground reinforcing material to make Al--Fe--Ti oxides mixture in which lime is added and mix this material into a soil or ground containing crushed stones, natural soil, etc. to enhance the strength and viscoelasticity thereof. The content of the Titanium oxide in the soil or ground reinforcing material is within the range of 0.5-2.0% by weight.

Abstract: A method of and apparatus for controlling a fuel injection quantity for an internal combustion engine wherein the fuel injection quantity is controlled on the basis of both an intake-pipe pressure and a rotational speed of the engine. The output of a pressure sensor for detecting the intake-pipe pressure is processed by a CR filter having a time constant which enables removal of a pulsating component of the intake-pipe pressure. The output of the CR filter is relaxed to calculate a first weighted mean value with a relatively low degree of relaxation and a second weighted mean value with a relatively high degree of relaxation. The second weighted mean value is subtracted from the first weighted mean value, and an incremental/decremental quantity is determined on the basis of the result of the subtraction.

Abstract: Disclosed is a suction pipe pressure detection apparatus for detecting suction pipe pressure of a multi-cylinder type internal combustion engine provided with a throttle valve in the suction pipe of each of the cylinders, or a so-called independent suction type internal combustion engine. The apparatus detects the suction pipe pressure for just a few cylinders out of the total number of cylinders, makes proper corrections to the detected data in accordance with the throttle valve opening, engine speed of the internal combustion engine, etc., and, during the period before the next detection of the suction pipe pressure is made, accurately computes, using the above data, the suction pipe pressure for the cylinders, under the suction stroke, for which the pressure is not actually detected.

Abstract: An air valve type carburetor of the kind in which a throttle valve is disposed in the downstream portion of a barrel interconnected to an engine via an intake manifold; a main nozzle is disposed upstream of the barrel and is connected to a jet of a float chamber; an air horn disposed on the barrel is connected to an air cleaner via an air connector; an air valve is disposed at the upper part of the main nozzle, faces at its tip the nozzle and is connected to the base end of a metering needle which is inserted into a through-hole of the air horn for free vertical movement therein; and a shield plate is fixed to the shank of the metering needle so as to prevent pressure pulsations inside the air connector from entering the through-hole and being applied to the surface of the fuel.

Abstract: An air valve type two-stage twin compound carburetor for an internal combustion engine comprises a carburetor body including a primary bore and a secondary bore, a primary throttle valve which is arranged in the primary bore so that it can be opened and closed, a secondary throttle valve which is arranged in the secondary throttle bore so that it can be opened and closed co-operatively with the opening and closing of the primary throttle valve after the primary throttle valve has been opened beyond a certain degree, and an air valve which is arranged in the secondary bore upstream of a secondary fuel nozzle disposed upstream of the secondary throttle valve, so that the air valve is opened and closed. The degree of opening of the air valve is regulated so as to be opened when the primary throttle valve is in the idle closing position or in the initial opening position.

Abstract: An internal combustion engine includes an intake system and an exhaaust system, and an exhaust gas recirculation conduit leads from the exhaust system to the intake system for recirculating exhaust gas. An exhaust gas recirculation control valve at an intermediate part of the exhaust gas recirculation passage controls the flow of exhaust gases therein, and is operated by supply of actuating vacuum. The supply of actuating vacuum to the exhaust gas recirculation control valve is furnished according to engine operational conditions. A vacuum tank accumulates vacuum while the engine is running. A vacuum conduit joins the vacuum tank to the exhaust gas recirculation control valve, and is controlled by a vacuum valve which is closed when the ignition system of the engine is being supplied with electrical power, and is open when the ignition system is not being supplied with electrical power.

Abstract: An altitude compensation device for an internal combustion engine having a vacuum-operated ignition timing advancer and a carburetor has an atmospheric pressure variation responsive valve operative to control the air bleed of the carburetor and the vacuum fed to the vacuum advancer such that, as the atmospheric air pressure is lowered due to increase of the altitude, the air flow into the advancer vacuum chamber is decreased to advance the ignition timing while the air flow into the carburetor air bleed passage is increased to increase the air-fuel ratio of the air-fuel mixture produced by the carburetor.

Abstract: An atmospheric pressure responsive and vacuum actuated control valve applied to a fluid control system for maintaining the same absolute ratio of air rate by fuel rate in a combustible mixture in an intake manifold of a vehicle engine regardless of whether the vehicle engine is moved to higher altitudes. The valve has a succesive changing ability of a superimposed corrective quantity of air on the intake manifold in accordance with the altitude of the engine.

Abstract: A carburetor in a fuel system in a motor vehicle including a fuel tank, a fuel pump for delivering fuel from the fuel tank to the carburetor under pressure and the return line which returns fuel from the carburetor to the fuel tank when an excess amount of fuel is delivered to the carburetor by the fuel pump. The carburetor further includes a check valve means in the return line for preventing the flow of fuel in the return line in a direction from the fuel tank to the carburetor whereby leaking out of fuel from the carburetor of fuel flowing backwards through the return line is prevented when the vehicle is turned upside down in an accident.

Abstract: A variable Venturi carburetor having a Venturi portion defined by movable members which are linked with and driven by an accelerating pedal so as to vary the area of its throat opening in accordance with a required engine output power thereby establishing air flow through the Venturi throat at the acoustic speed for the most part of the engine operational region. In high load operation wherein the acoustic speed is not maintained at the Venturi throat, fuel pressure is modified to compensate therefor.