Abstract: A solid propellant rocket motor devised so as to temporarily increase its thrust at a desired stage of its operation. The motor has a first propellant grain which is fixedly disposed in the combustion chamber and is formed with a hole that intersects an inital burning surface of the grain and a second propellant grain which is slidably and gastightly fitted in the hole of the first grain and is shorter in length than this hole. Initially, the second grain is prevented from moving relative to the first grain by a restraining mechanism including, for example, a plunger protruding into an aft end portion of the aforementioned hole to come into abutment with an end face of the second grain.

Abstract: A governor sleeve is axially displaceable on a stationary governor shaft and has an inner space which is defined by one end of the governor shaft and which communicates with the inner chamber of a pump housing charged with fuel. The inner space varies in volume drawing thereinto and discharging therefrom fuel in response to axial displacement of the governor sleeve.

Abstract: A weft detaining device of a shuttleless loom, including a drum having a frustoconical section and a cylindrical section, a first catching member for catching the weft yarn on the drum in the vicinity of the border between the frustoconical and cylindrical sections for at least a period of weft pickings, a second catching member for catching the weft yarn on the drum for at least a period of the first time weft picking in sequential twice weft pickings and releasing its catching action to the weft yarn for at least a period of the second time weft picking of the sequential twice weft pickings, and a third catching member for catching the weft yarn on the drum cylindrical section for at least a period wherein the detaining of the weft yarn for the succeeding twice sequential weft pickings is completed, thereby enabling a so-called dual-pick pass weft insertion though the weft detaining device is of the drum type.

Abstract: A material for reinforcing a panel includes a resin material and a expandable material. The expandable material is centered onto the resin material in such a manner that the edges of the resin material are exposed and can adhere to the panel. The expandable material includes an easy-bending portion in a position corresponding to a bent portion of the panel. The easy-bending portion is formed by a groove or by perforations in the expandable material.

Abstract: The turbine rotor unit comprises a ceramic rotor and a ceramic shaft. Connection or bonding of the rotor and the shaft is made by applying a slip of ceramic material to engaging sections of the rotor and the shaft and baking them for solidification of the slip. If metal-silicone is used as a material for the rotor and the shaft, the connection or bonding of them can be made without the slip.

Abstract: In preparing a resin coated sand for use in sand mold casting processes by a hot-melt process using an unsaturated polyester which is solid at room temperature as the coating material, a solution of an organic peroxide as a polymerization initiator for the unsaturated polyester is introduced into the mixture of heated foundary sand and the unsaturated polyester while the polyester is in the state of liquid coating on the sand particles, and stirring is continued to uniformly mix the solution with the unsaturated polyester and evaporate and dissipate the solvent before solidification of the polyester coating as the result of cooling of the mixture. The polyester coating contains no liquid cross-linking agent, so that the resin coated sand is untacky and high in fluidity at room temperature and, therefore, can be filled into a die cavity to shape a sand mold or core with sufficiently high bulk density.

Abstract: The invention relates to a swirl-chamber Diesel engine. A swirl-chamber Diesel engine is disclosed which has a main combustion chamber, a swirl chamber, and a communicating passage for connecting them. The problem encountered is that, when the engine runs at low speeds, fuel droplets within the swirl chamber will gather and flow along the communicating passage into the main combustion chamber. To prevent this unfavorable fuel flow, a depression is formed within the swirl chamber to collect the fuel droplets. The depression is disposed adjacent to and communicating with the communicating passage via a rounded lip to provide an arrangement which will make it easy for the combustion gases flow to draw the collected fuel from the depression. Since the fuel is drawn from the depression by the combustion gases flow, carbonization of fuel on the depression wall will not take place.

Abstract: A plasma jet ignition plug comprises an electric insulator formed with a discharge cavity and a plurality of electrodes communicating with the discharge cavity to form, within the discharge cavity, a spark gap. The plurality of electrodes include a central electrode connected to a high voltage electric source and a low voltage electric source, and a peripheral electrode which is grounded. The peripheral electrode substantially closes the discharge cavity and is formed with a jet opening. At least that part of at least one of the plurality of electrodes which communicates with the discharge cavity is made of a material selected from a group consisting of ferrite, a nickel alloy containing at least one of silicon, aluminum and magnesium, and electrically conductive ceramic.

Abstract: A tape recorder includes an auto-reverse system comprising an actuator incorporated with a tape driving means for switching driving direction from forward to reverse direction or from reverse to forward direction and a circuit for switching the actuator between operative and inoperative conditions. The switching circuit cooperates with a manual reversing switch and a tape end detecting means, used for auto-reverse operation. The switching circuit includes a manually operative switching means for selectively switching the auto-reverse system between operative and inoperative.

Abstract: A welding wire for automatic arc welding, which is particularly suitable for use in build-up welding operation for the purpose of providing hard surface to a metal die. The welding wire consists of a continuous tubular metal casing and a core composition charged in the interior of the casing and comprises such amounts of Ni, Si, B, Nb and C as essential alloying elements that the deposited metal contains at least 40% of Ni, 3-8% of Si, 0.1-0.4% of B, 0.3-1.8% of Nb and 0.2-1.5% of C, all by weight. Preferably, either a practically pure Ni strip or an Fe-Ni alloy strip is used as the material of the casing, and the core composition in the form of a powder mixture contains necessary amounts of Ni, Si, B, Nb and C, optionally with the addition of a small amount of Zr. The deposited metal given by this welding wire has high wear resistance and good antifrictional property and seldom suffers from weld cracks.

Abstract: An electronic fuel supply control system for internal combustion engines which carries out the engine fuel cutoff while the engine is decelerated either with a predetermined delay or immediately depending on engine driving conditions, and preferably on the state of the transmission, thus reducing the jolt produced when the fuel cutoff is carried out.

Abstract: A rotary vane type compressor having a rotor (8) mounted with a number of vanes (10) each accommodated in a vane groove (11) of a liner (12) made of anti-abrasive material and a boss (13) for fixing the liners (12) and the liners are fixed in position with respect to the boss by integrally casting the liners and the boss by placing them in the predetermined position using light weight alloy.

Abstract: A heating apparatus for a passenger compartment of a motor vehicle including a heater is provided with a bypass passage which bypasses an engine water jacket and an engine driven water pump, and a thermostat valve disposed between a feed passage from the engine water jacket and the heater so that the liquid from the engine water jacket is prevented from flowing into the heating circuit until the liquid temperature reaches to a predetermined level. A rapid warming up of the passenger compartment is enabled by forming a heating circuit with small water capacity through the bypass passage.

Abstract: A cylinder block for an automotive in-line multiple-cylinder internal combustion engine, comprising an outer wall structure, an elongate cylinder row structure spacedly located within the outer wall structure including a plurality of cylinder sections whose neighboring cylinder sections are integrally connected with each other, and first and second connecting wall portions which integrally connect the cylinder sections at the extremities of the cylinder row structure with the outer wall structure so as to define independent coolant passages at the opposite sides of the cylinder row structure, thereby improving flexural and tortional rigidities though produced by die-casting.

Abstract: A fuel injector valve comprises a main magnetic pole securely disposed within a casing and provided with an electromagnetic coil wound thereon, a valve seat member securely connected to the casing so as to be located opposite to the main magnetic pole tip section, a spherical valve member movably disposed within a valve chamber which is to be filled with fuel, and defined between the main magnetic pole tip section and the valve seat member, and an adapter member securely interposed between the main magnetic pole and the casing to secure the locational relationship therebetween, thereby securely achieving the locating and centering of the main magnetic pole.

Abstract: An industrial detergent useful for degreasing and cleansing of metal parts, which is in the form of an aqueous solution and comprises 3 to 20 parts by weight of a fatty acid sucrose ester as a nonionic surfactant, 3 to 15 parts by weight of polyoxyethylene alkyl ether also as a nonionic surfactant, 1 to 10 parts by weight of a chelating agent for metal ions typified by EDTA, 1 to 5 parts by weight of a petroleum sulfonic acid salt, preferably an alkanolamine salt, as a rust-inhibiting agent and 3 to 10 parts by weight of propylene glycol. Optionally small amounts of sorbitol and/or CMC may be added. This detergent is weak in alkalinity but strong in deterging power, and the organic surfactants are harmless to the human body and can be decomposed by microorganisms.

Abstract: Automatic speed control system is provided which has circuitry responsive to the turning off of the system's restart switch. This circuitry activates the control upon detection of a control signal, generated as a function of the difference between the actual vehicle speed and the set speed, when the restart switch switches off. In the system according to the present invention, the vehicle is effectively prevented from unexpected acceleration caused by the misoperation of the restart switch or damage thereof.

Abstract: An automotive vehicle seat belt is attached to a slide mechanism attached to the vehicle body or door adjacent the occupant seat. The belt is connected to a slide element which slides on a rail between a forward released position (door open) and a rearward retaining position (door closed) in response to a door switch. A control mechanism overrides the effect of the door switch under certain conditions so that the belt does not release automatically when the door is opened. Examples of such conditions include specified criteria, ignition switch, transmission shift position, clutch position, and hand brake position.

Abstract: A covered electrode for shielded metal arc welding, which is particularly suitable for use in build-up welding operation for the purpose of providing hard surface to a metal die. The covered electrode comprises such amounts of Ni, Si, B, Nb, C and Zr as essential alloying elements that the deposited metal contains at least 40% of Ni, 3-8% of Si, 0.1-0.5% of B, 0.3-2.0% of Nb, 0.2-1.5% of C and 0.01-0.20% of Zr, all by weight. In a preferred form, either Ni wire or Fe--Ni wire is used as the core wire, and the covering contains necessary amounts of all the essential alloying elements except Ni. The deposited metal has high wear resistance and good antifrictional property, and the presence of Zr is highly effective for preventing the occurrence of weld cracks.

Abstract: A fluid passing through a nozzle operative on the principle of wall effect of fluidic devices is variously deflected. A pair of control valves are provided at control fluid passages for supplying control jets into the throat portion of the nozzle in order to control the deflection of fluid flowing therethrough. A continuous straightforward flow is generated by simultaneous opening of said control valves.

Abstract: A fluid outlet structure includes cavities formed in both inner sidewalls of the outlet having control fluid passages from which control fluid is jetted toward a center of the outlet to deflect fluid flowing through the outlet. According to the invention, the fluid outlet structure comprises one or more supplementary fluid control members including supplementary cavities having respective supplementary control fluid passages, and communicating pipes for communicating the cavities in the sidewalls and supplementary cavities of the supplementary fluid control members having the fluid passages opening in the same directions, thereby obtaining deflected fluid flows with great deflecting angles.

Abstract: An ignition spark timing control system for an internal combustion engine capable of controlling the ignition spark advance angle corresponding to a knocking condition of the engine. The spark timing control system includes a means for retarding spark timing in response to an engine knocking condition and a means for detecting unstable driving condition of the engine and interrupting the retarding of the spark timing when the engine driving condition is unstable in order to maximize the engine output characteristics and improve fuel economy.

Abstract: A method and system for controlling the air-fuel ratio for a carburetor for an internal combustion engine having an intake passage, an exhaust passage, a throttle valve, a detector for detecting the concentration of a constituent of the exhaust gases, an on-off type electro-magnetic valve for correcting the air-fuel ratio of the air-fuel mixture supplied by an air-fuel mixture supplier and an electronic controller. The electronic controller comprises a comparing circuit for comparing the output signal of the detector with a stoichiometric reference signal, for driving the on-off electro-magnetic valve for controlling the air-fuel ratio to a value approximating the stoichiometric air-fuel ratio.

Abstract: An abnormality treatment device for an automatic transmission control device according to the invention comprises in input portions of signals from an engine load sensor, a vehicle speed sensor and a pressure sensor, abnormal value detection circuits for detecting any abnormal value of at least one of the signals from the sensors to generate an abnormality detection signal, and a speed range selection judgement circuit and a hydraulic control judgement circuit for generating respective abnormality treatment signals when receiving the abnormal detection signal, thereby maintaining a predetermined speed range and a predetermined high line pressure.

Abstract: A two-shift automatic assembling apparatus for selectively assembling a component member or members to an incomplete work of one model or a component member or members to an incomplete work of another model during each cycle of operation, comprising a base structure rotatable about a horizontal axis and having two opposite faces parallel with the axis. Two sets of assembling fixtures are mounted respectively on the two faces of the base structure so that one of the two sets of fixtures can be moved into operative position by turning the base structure into one of two diametrically opposed angular positions about the axis thereof.

Abstract: A vehicle body structure, comprises: a pair of rear wheel housing each having inner and outer housing half portions, and inner and outer flange portions respectively extending radially outwardly from the outer circumferences of said housing half portions, said inner and outer flange portions being integral with said housing half portions and connected to each other for forming in combination said rear wheel housing; said outer flange portion being bent in a lateral direction of said rear wheel housing; a pair of rear pillar inner panels each having a lower end portion connected to each of said outer flange portions; and a pair of side sills extending in parallel with each other and projecting forwardly from said rear wheel housings, respectively, each of said side sills having inner and outer side sill half portions, and inner and outer flange portions respectively extending upwardly from the upper ends of said side sill half portions, said inner and outer flange portions being integral with said side sill ha

Abstract: A switch arrangement comprises a movable switch member movable corresponding to shifting of transmission gear position and a stationary switch member including a plurality of contacts housed in a single member. The contacts are arranged to be adapted to respective transmission gear position and connectable with the movable switch member for electrical communication.

Abstract: A vibration absorber for an automotive vehicle which can prevent the shuddering phenomenon even while the vehicle is gradually accelerated or decelerated. The rubber member thereof is provided with multistep elasticity characteristics such that a first shearing portion of the rubber member is first deformed in shear, a second shearing portion thereof is next deformed in shear, and the other portion thereof is lastly deformed under compression. To achieve the above-mentioned elasticity characteristics, some appropriately sized slots, cavities, or gaps are provided within the rubber member at appropriate positions within the rubber member.

Abstract: A diesel engine has a first lubrication system, containing conventional engine oil, used to lubricate that section of the engine subjected to excessive wear--the valve train including the cam shaft, valve lifters, rocker arm, valve stems, etc., and a second lubricant system, utilizing diesel fuel, for lubricating the remaining section of the engine--the crankshaft and associated parts, pistons, connecting rods, etc. By being exposed to crankcase blowby exhaust gases, diesel fuel used to lubricate the crankshaft, etc. absorbs pollutants and contaminants contained therein and recirculates these contaminants through the fuel system to be burned and exhausted. By constantly being lubricated with fresh lubricant, wear on these specific parts is reduced. Frequent lubrication changes have been eliminated because the diesel fuel/lubricant is continuously changed and circulated through fuel system.

Abstract: In an air jet loom of the type wherein a weft yarn projected from a weft inserting nozzle is carried through a weft guide channel to pick the weft yarn into a shed of warp yarns by air jets from a plurality of auxiliary nozzles, weft picking is carried out by controlling the ejection of air jets from the auxiliary nozzles in a manner to simultaneously commence the air jet ejections from all the auxiliary nozzles prior to the time the weft yarn from the weft inserting nozzle reaches the auxiliary nozzle closest to the weft inserting nozzle, thereby producing a steady state air steam within the weft guide channel to stably complete a weft insertion into the shed of warp yarns.

Abstract: A weft picking device of an air jet type weaving loom including a weft inserting nozzle, a plurality of air guide members which form an air guide channel through which a weft yarn from the weft inserting nozzle is picked into the shed of warp yarns, and an auxiliary nozzle disposed between a pair of adjacent air guide members and formed with a small nozzle opening through which auxiliary air is ejected, the nozzle opening being so located that the extension of the axis thereof intersects the axis of the air guide channel at an angle lying within a plane containing the axes of the nozzle opening and the air guide channel, thereby achieving effective weft picking and overcoming the drawbacks encountered in various conventional weft picking devices.

Abstract: A system for detecting the operation of the throttle valve of an internal combustion engine for an emission control system for internal combustion engines. The emission control system has a three-way catalyst convertor, a detector, such as an oxygen sensor for detecting the concentration of oxygen in the exhaust gases, an on-off type electromagnetic valve for correcting the air-fuel ratio of the air-fuel mixture and an electronic controller. The system comprises a transducer, such as a potentiometer and a pair of sample-and-hold circuits, in which each gate thereof is periodically operated by pulse trains for sampling and holding the output voltage of the transducer, which pulse trains have a 180 degrees phase difference with respect to each other. Both sample-and-hold circuits are connected to an operational amplifier type comparator through relay switches.

Abstract: Disclosed is a method and apparatus for controlling application and release of brake pressure in automotive vehicle brakes in order to prevent the vehicle from skidding. The system has a component for determining the coefficient of friction between the road surface and a tire tread, operative to determine that coefficient as a function of the wheel acceleration, wheel load and brake torque. Additionally there is provided a circuit for detecting a peak of the friction coefficient during a control cycle, as well as circuitry for determining wheel r.p.m. and for determining target wheel r.p.m. The latter function is performed on the detected wheel r.p.m. responsively to detection of the peak of the friction coefficient. Additionally, a control device is provided for controlling applying and releasing of fluid pressure to wheel cylinders for skid controlling the rate of wheel deceleration. The target wheel r.p.m. determining circuit determines a deceleration coefficient of wheel r.p.m.

Abstract: A throttle valve has or cooperates with a metering wall or walls which function to limit the amount of air permitted to flow past the edge of the throttle valve when it is initially moved from its closed position. The amount of rotation of the throttle valve for a given change of air flow is thus increased enabling the output of a sensor such as a variable resistor to vary sufficiently to enable an accurate indication of the amount of air passing to the engine especially at frequently used relatively low throttle settings.

Abstract: An electromagnetic clutch includes a mechanism which is responsive to a first short energization of an electromagnet thereof to cause a spring arrangement therein to snap to a reverse configuration wherein it holds the clutch engaged until a second short energization with a current larger than that used for the first energization, whereupon the mechanism again reverses the configuration of the spring and subsequently causes the clutch to disengage.

Abstract: A solenoid valve is arranged in a bypass passage of an engine cooling water circuit to selectively open and close the bypass passage. A temperature sensor is arranged in a vehicle cabin heating water circuit to monitor water temperature therein. A control unit is designed so that when the temperature sensor senses that the temperature of water in the vehicle cabin heating water circuit is below a predetermined level, the solenoid valve is closed, thereby increasing the flow rate of water in the vehicle cabin heating water circuit.

Abstract: An internal combustion engine is disclosed which includes an active cylinder unit always active and an inactive cylinder unit being inactive when the engine load is below a predetermined value. The engine has an intake passage divided into first and second branches leading to the active and inactive cylinder units, respectively. The second intake passage branch is connected through an EGR passage to the exhaust passage of the engine. The second intake passage branch has therein a stop valve and the EGR passage having therein an EGR valve. Means are provided for closing the stop valve and opening the EGR valve at a predetermined time after a low engine load condition occurs.

Abstract: First and second waste gates respectively control the supercharging pressure of an engine supercharger and the pressure fed to an auxiliary turbine from the engine turbo-charger turbine. The scroll of the auxiliary turbine is divided by a partition into first and second passages which respectively receive the exhaust gases by-passed by the first waste gate and the exhaust gases from the turbo-charger turbine. The first waste gate prevents over pressurization of the engine cylinders while the second prevents the build up of excessive back pressure downstream of the turbo-charger turbine, thus maintaining the efficiency and torque output of the engine while still deriving benefit from the operation of the auxiliary turbine.

Abstract: In a gas turbine engine having a diffuser provided downstream of the power section and composed of inner and outer diffuser wall members forming therebetween a diffuser chamber which is open into an exhaust gas collector chamber, the outer diffuser wall member is provided with at least one flow guide member which extends on the generally frustoconical outer peripheral surface of the outer diffuser wall member and which is curved arcuately or circularly about the common center axis of the inner and outer diffuser wall members for thereby suppressing formation of vortices in the flow of the combustion gases being exhausted through the collector chamber.

Abstract: A head lamp washing system is disclosed which comprises a solenoid valve having an inlet and first and second outlets, the solenoid valve operable in its first position where the inlet is connected only to the first outlet when energized and in its second position where the inlet is connected only to the second outlet when deenergized, first and second injectors each having at least one injection nozzle, the injection nozzle of the first injector connected to the first inlet, the injection nozzle of the second injector connected to the second inlet, a detergent cistern containing a liquid detergent, the cistern connected to the inlet of the solenoid valve, a pressurizer for pressurizing the liquid detergent supplied to the solenoid valve, and a control circuit for alternatively allowing and cutting off power to the solenoid valve on a periodic basis.

Abstract: A navigation instrument comprises a first counter for counting travelling distance from a start point, a second counter for counting travelling time from starting, a means for setting a scheduled average vehicle speed, an arithmetic means for calculating average vehicle speed, the deviation of travelling distance from the scheduled distance and the deviation of travelling time from the scheduled time, and a display means for displaying the result of calculation. The first counter is capable of subtractively counting travelling distance in response to switching operation of a switching means which is incorporated to the first counter. The first counter is also incorporated with a means for stopping navigating operation which is operative when the first counter counts down the travelling distance until a given value.

Abstract: A disc having first and second sets of markers thereon is rotated in sychronism with the crankshaft of an engine so that pickups associated with the disc produce pulse trains of two and three pulses per revolution of the crankshaft respectively. A circuit responsive to either the speed or load of the engine selectively connects one of the pulse trains to a fuel injection control circuit to induce the fuel injector to inject in synchronism with the pulses of the selected pulse train. Alternatively the pulses outputted by the ignition system are frequency divided and fed to the fuel injection control circuit.

Abstract: A voice warning system for an automobile vehicle provided with an automatic speed control device, by which the driver is informed of the vehicle speed, in voice form, when operating a set switch for controlling the vehicle with the device. The volume level of the voice form signal is determined in accordance with a volume setting of a radio in the vehicle. The voice warning system comprises a vehicle speed sensor, a component for generating a signal representative of the volume of the radio, an interface, a voice synthesizing system, and an electronic volume control for the synthesized message, in addition to the automatic speed control device and a set switch therefor.

Abstract: A fuel injection timing control system for a Diesel engine, having a fuel injection pump supplying fuel to the engine periodically according to the rotation of the engine crankshaft, and a device connected to the fuel injection pump to vary the fuel injection timing in terms of crank angle. The engine is equipped with an exhaust gas recirculation arrangement. A control unit is connected to the device and the arrangement to drive them in such a manner that when the arrangement is operative to effect the exhaust gas recirculation, the fuel injection timing is advanced compared to that under the condition where the exhaust gas recirculation arrangement is at rest suspending the exhaust gas recirculation.

Abstract: In a line pressure control device of an automatic transmission for vehicle a circuit is provided for generating a target line pressure signal corresponding an actually measured load signal obtained from an engine load sensor. A line pressure sensor generates an actually measured line pressure signal corresponding to the line pressure. A converter converts the target line pressure signal and the actually measured line pressure signal into upper limit line pressure signals and lower limit line pressure signals which are set given amounts above and below the target signal and the actually measured signal respectively. A decision circuit compares the upper and lower limit line pressure signals drives and properly driving and controls the hydraulic pressure adjusting valve in accordance with the result of the comparison.

Abstract: A passage leads from a high pressure discharge zone of a vane pump to an interface defined between the surface of the rotor of the pump and an arcuate contact surface formed in the inner wall of the pump housing to supply fluid under pressure to the interface for lubricating same.

Abstract: A system for rapidly warming up a catalytic converter provided to an automotive internal combustion engine to purify the exhaust gas. The system includes a vacuum-operated device to increase the opening degree of the throttle valve by a predetermined degree to thereby increase the quantity of the exhaust gas and another vacuum-operated device to retard the ignition timing of the engine to a predetermined extent to thereby raise the temperature of the exhaust gas. The two devices are connected by a vacuum passage to the intake passage of the engine at a section downstream of the throttle valve in series, and an electromagnetic valve renders the vacuum passage effective to thereby actuate the vacuum-operated devices only when the engine is idling under cold condition. Because of the series connection of the two devices, an intake vacuum is applied to the two devices in desirable sequence.

Abstract: A series of airfoil cross-section equidistantly spaced normally parallel vanes are disposed linearly across the mouth of an induction housing port which lies on an essentially flat plane non-intersecting with the axis of rotation of a turbo compressor wheel. A control mechanism moves the vanes upon the compressor tending to surge so that each of the vanes is moved through an angle different from the preceeding one, whereby the air flows passing between the vanes are deflected and converge upstream of the compressor wheel and swirl theretoward in the form of a single flow to impinge on the blades of the wheel with a uniform and reduced angle of incidence.

Abstract: A noiseless cover such as an oil pan, front cover, cylinder head cover and the like for an engine comprises elastic bodies fixed to an engine body of the engine and resiliently abutting against a mid-portion of the cover, thereby preventing surface vibrations of the cover without any troublesome operation for mounting the cover and without any sealing problem.

Abstract: A system for controlling the air-fuel ratio for a carburetor for an internal combustion engine having an intake passage, an exhaust passage, a throttle valve, a detector for detecting the concentration of a constituent of the exhaust gases, an on-off type electromagnetic valve for correcting the air-fuel ratio of the air-fuel mixture supplied by an air-fuel mixture supplier and an electronic controller. The electronic controller comprises a judging circuit for comparing the output signal of the detector with a stoichiometric reference signal, for driving the on-off electromagnetic valve for controlling the air-fuel ratio to a value approximating the stoichiometric air-fuel ratio. A load sensor and an engine temperature sensor are provided respectively.