Abstract: A post injection is utilized in a more effective manner. In an internal combustion engine which is provided with a fuel injection valve for injecting fuel into a cylinder of the internal combustion engine, in cases where a post injection is carried out after a main injection of fuel from the fuel injection valve, when a rotation speed of the internal combustion engine is equal to or more than a first predetermined speed, a penetration force of fuel in the post injection is made larger than a penetration force of fuel in the main injection, whereas when the rotation speed of the internal combustion engine is less than a second predetermined speed which is equal to or less than the first predetermined speed, the penetration force of fuel in the post injection is made smaller than the penetration force of fuel in the main injection.

Abstract: A gas engine is provided that suppresses fluctuation of the actual air-fuel ratio even when a load fluctuates. A gas engine (1) in which at least one opening degree (D) selected from the opening degree of an air supply valve (5a) and the opening degree of a bypass valve (5b) is corrected so that an adequate target air-fuel ratio (?t) is achieved, wherein a target gas pressure (Pgt) and a target gas-jetting time (Tt) of a fuel gas are calculated on the basis of fluctuations of an actual load (L), the gas pressure is corrected on the basis of the target gas pressure (Pgt), and at least one opening degree selected from the opening degree of the air supply valve and the opening degree of the bypass valve is corrected on the basis of the amounts of change in the target gas pressure (Pgt) and the target gas-jetting time.

Abstract: A method and system for dealing with a change of mind event during an automatic shut-down of an engine 6 having a dual mass flywheel 8 is provided that reduces or eliminates the risk of excessive dual mass resonance during a restart of the engine 6 is disclosed.

Abstract: An intake system is provided. The intake system including an intake manifold coupled to an engine and a vacuum port located in said intake manifold and in an air flow path downstream of a throttle body, the vacuum port including a molded flow disruptor including a cross-beam traversing an outlet of the vacuum port. The intake system may further include a vacuum passage coupling the vacuum port to a vehicle subsystem.

Abstract: An engine system and method for improving engine starting are disclosed. In one example, engine port throttles are adjusted to improve fuel vaporization of a fuel that includes alcohol. The system and method may improve engine starting and emissions.

Abstract: It is intended to provide an air-fuel ratio control device for a carburetor, which is capable of variably inject fuel by opening and closing a choke valve in accordance with an opening degree of a throttle valve and the load and which is capable of achieving low cost, clean emission and fuel saving by attaining a desired air-fuel ratio in an entire operational range (rotation speed, load) of the internal combustion engine.

Abstract: An air-balanced engine assembly is configured to operate efficiently while producing a reduced level of harmful emissions. The engine assembly includes a two-stroke internal combustion engine with multiple power cylinders and intake and exhaust manifolds that fluidly communicate with the cylinders. The engine assembly also includes an air balancing assembly with valves that control intake air flow from the intake manifold to the cylinders. The valves cooperate to balance intake air flow among the cylinders and are configured to substantially equalize trapped equivalence ratios among the cylinders.

Abstract: A fuel injection apparatus including a plurality of throttle bodies, a fuel supply pipe to supply fuel to upstream and downstream side injectors; connecting pipes to connect the fuel supply pipe to the upstream side injectors and the downstream side injectors; upstream side branch passages to supply fuel branched from the fuel supply pipe to the respective upstream side injectors; downstream side branch passages to supply fuel branched from the fuel supply pipe to the respective downstream side injectors; a nip angle of the upstream side injectors is larger than a nip angle of the downstream side branch passages against the intake flow direction of the intake passage; and the nip angle of the downstream side branch passages is larger than a nip angle of the downstream side injectors against the intake flow direction of the intake passage.

Abstract: An ECU controls an adjusting mechanism adjusting an output of an engine, such as a throttle valve, a swirl control valve, an ignition plug, an intake valve, and an ACIS (Acoustic Control Induction System) changing the length of an intake manifold, in accordance with a ratio between a maximum value KL(MAX) of load factor and the load factor required of the engine by the driver and by the system mounted on the vehicle at current engine speed NE.

Abstract: Engine synchronization apparatus and system for multi-engine vehicles such as boats and aircraft providing limited authority throttle cable trim effected by an apparatus interposed between the throttle plate and throttle cable of a slave engine and mounted in a floating configuration. An actuator is mounted to the apparatus to trim the distance between the throttle plate and throttle cable attachment thereby trimming the throttle cable. A system is provided in which a difference signal derived from master and slave engine tachometer signals is used to control the actuator and synchronize the engines within a predetermined range.

Abstract: An intake controller includes a casing defining an intake passage that communicates with a combustion chamber of an engine, a valve received in the casing to open/close the passage, a rotational shaft that changes an opening degree of the valve, an actuator having a gear that drives the valve through the shaft, a gear retaining member retaining the gear, a sensor including a magnet that rotates according to rotation of the shaft and a magnetic detection element that detects magnetic flux generated from the magnet, and a sensor retaining member retaining the sensor. The sensor detects the opening degree of the valve based on a change of density of the magnetic flux passing through the element. One of the gear and the gear retaining member, and one of the sensor and the sensor retaining member are separately fixed on the shaft.

Abstract: In line carburetor (104) is mounted to a manifold (140) over the engine (800). The barrels of the carburetor deliver air/fuel suspensions to concentrated positions (152) of the manifold, with the concentrated positions being at opposite ends of the engine. The ports leading from the manifold to the runners are equally positioned about the concentrated positions (152) so that the runners are of substantially equal length and resistance, thereby providing more uniform delivery of the air/fuel suspension to the cylinders.

Abstract: A cross-sectional shape of a first intake passage is formed in a circular shape and a cross-sectional shape of a second intake passage is formed in a rectangular shape. Thus, an opening area of a second intake throttle portion can be made larger than an opening area of a first intake throttle portion even when the opening area of the first intake throttle portion is narrow and an intake air quantity supplied into a combustion chamber of an engine is small as in the case of engine start-up or engine idling operation. Accordingly, an intended strong tumble flow in accordance with a demand for improving a combustion efficiency in the combustion chamber can be generated in the combustion chamber while achieving the intake air quantity necessary during the engine start-up or the engine idling operation.

Abstract: A method for controlling an engine airflow, the engine having at least one cylinder, the engine also having an intake manifold and an outlet control device for controlling flow from the intake manifold into the cylinder, comprising of generating a desired engine torque, generating a desired cylinder air charge amount based on said desired engine torque and changing the outlet control device to provide said desired cylinder air charge amount and thereby provide said desired engine torque.

Abstract: An intake structure for internal combustion engine includes an intake passage which is communicated with a combustion chamber of the internal combustion engine and through which air to be supplied to the combustion chamber flows; and a valve which is provided in the intake passage and which controls the airflow in the intake passage. The intake passage has a recess which is formed in the inner wall face of the intake passage and in which the valve is arranged; and a groove that is connected to the recess, at a substantially center position of the recess in a width direction of the recess, and that extends from the recess toward the downstream side of the intake passage.

Abstract: The invention relates to an internal combustion engine which is provided with a manifold from which an intake tube extends to an intake of a cylinder of the internal combustion engine, with a gas inlet valve, disposed at the intake of the cylinder, an intermittent charge valve, disposed upstream of the gas inlet valve in the intake tube and releasing or closing the intake tube subject to a switching position of the intake tube, and in injection valve for metering fuel. The temporal position of the duration of injection of the fuel is adjusted subject to a point in time at which the switching position of the intermittent charge valve is changed. In this manner, it can be ensured that the air has a high velocity of flow during injection, thereby obtaining a good mixture preparation in a simple manner.

Abstract: In order to protect a rotating portion of an intermediate link lever support pin, an intake air control apparatus provided with main and sub throttle valves is structured such that a wire bracket (6) supporting valve opening and closing wires (Wa, Wb) is screwed to an outer end surface (1a) at a throttle drum side of a throttle body (1), an intermediate link lever support pin (23) is provided toward the throttle body (1) side on an inner end surface (6d) facing to the throttle body (1) of the wire bracket (6), an intermediate link lever (20) rotatably borne to the intermediate link lever support pin (23) is arranged at the throttle body (1) side from the inner end surface (6d), and a rotating portion (R) of the intermediate link lever support pin (23) and the intermediate link lever (20) is arranged to face to the inner end surface (6d).

Abstract: A choke device for an intake system of an internal combustion engine; the choke device has at least one choke body fitted movably inside an intake conduit, and an actuating device for moving the choke body to and from a work position in which the choke body reduces the cross section of the intake conduit; and the actuating device has a filiform actuating member made of a shape-memory material that changes shape when subjected to physical external stress, and having a first portion embedded in the choke body, and a second portion located outside the choke body and secured mechanically to a fixed part.

Abstract: The invention relates to a combustion air supply arrangement, including an air intake duct of an internal combustion engine, and a compressor arranged in the air intake duct, and a first throttle located downstream the compressor and upstream the internal combustion engine and arranged to change the flow area of the air intake duct between the compressor and the internal combustion engine, the same furthermore including a second throttle, which is located upstream the compressor and which is arranged to change the flow area of the air intake duct upstream the compressor. Furthermore, the compressor is a centrifugal compressor, the rotational speed of which is directly dependent on the rotational speed of the internal combustion engine, and that the combustion air supply arrangement is arranged in such a way that the sucked-in air is compressed once between the second throttle and the internal combustion engine.

Abstract: The invention relates to an internal combustion engine comprising a manifold, from which an induction pipe leads to an intake of a cylinder of the internal combustion engine. A gas intake valve is located at the intake of the cylinder. A pulse charging valve is positioned upstream of the gas intake valve in the induction pipe, the latter being released or sealed depending on the selected position of the pulse charging valve. The internal combustion engine is also provided with a pressure sensor, which is located in the induction tract and detects an induction pipe pressure. The progression of the detected induction pipe pressure is compared to that of a reference induction pipe pressure, which characterizes a predetermined operating state of the pulse charging valve. A malfunction of the pulse charging valve is detected depending on said comparison, thus guaranteeing a reliable monitoring of the pulse charging valve.

Abstract: A carburetor automatic control system in an engine includes, a temperature-sensitive operating device for operating a choke valve so that the choke valve is opened with a temperature increase of the engine and a governor for opening and closing a throttle valve to maintain a preset rotational speed of the engine. The governor device includes, a stepping motor opening and closing the throttle valve over a range from an idling opening degree to a fully opening degree, and an electronic control unit driving the stepping motor so that the rotational speed of the engine is maintained the preset speed. A relief mechanism is interposed between the choke valve and the temperature-sensitive operating device, the relief mechanism opening the choke valve in response to an intake vacuum pressure within the intake passage when the engine is in a cold state and the choke valve is in a fully closed state.

Abstract: A regulating device for regulating the air intake of an internal combustion engine, and comprising at least one throttled body having at least one air feed conduit connectable to the engine, and a first and second throttle housed in said at least one feed conduit to regulate air intake of the engine on command; the regulating device comprises a manually operated accelerator control device connected mechanically to the first throttle to rotate the first throttle about a first axis of rotation into an operating angular position related to the engine torque demanded by the user operating the accelerator control device; and electric control means for rotating the second throttle about a second axis of rotation into a target angular position determined as a function of the operating angular position of the first throttle.

Abstract: A variable flow control method and device between an air intake and a throttle comprise at least one one-way valve with suitable restoring function between the air intake and the throttle, especially for a car. Corresponding functions can be generated among the one-way valve, an air intake manifold and the throttle to adjust and control an engine so that the engine can rapidly get various rotating rates corresponding to various degrees of vacuum respectively as natural or original air taking can be effectively and rapidly accelerated when the accelerator is trampled rapidly, and reflect the improvement on performances responding to torsion and acceleration of the various rotating rates.

Abstract: An intake control valve of an intake device of an internal combustion engine comprises a given portion defined by an air intake passage that leads to a combustion chamber of the engine through an intake valve; a pivot shaft passing through the given portion; and a valve plate secured to the pivot shaft to pivot therewith within the given portion. The valve plate is pivotal between a close position to close the air intake passage and an open position to open the air intake passage. When the valve plate assumes the close position, the interior of the air intake passage downstream the valve plate is formed with mutually isolated first and second air flows that are separated and oriented to enhance a flow of air/fuel mixture in the combustion chamber.

Abstract: An excess oxygen reduction system includes a fuel cut-off condition module, an injector module, and a valve module. The fuel cut-off condition module determines whether a fuel cut-off condition exists. The injector module prevents a fuel injector from fueling a cylinder when said fuel cut-off condition exists. The valve module closes an impulse charging valve when said fuel cut-off condition exists.

Abstract: Disclosed is a subunit having a hollow cylinder which is provided with an opening on at least one face and in which a spring bearing is arranged on the inside of the face and a first valve spring resting against said spring bearing. A shaft that is guided within the spring bearing is disposed in the first valve spring so as to be reversibly movable in the direction of the longitudinal axis of the hollow cylinder. A thrust bearing for the first valve spring is located at the end of the shaft, which faces away from said face of the hollow cylinder, the thrust bearing being connected to the shaft. A second valve spring is placed between the thrust bearing and the interior on the opposite face of the hollow cylinder.

Abstract: A throttle body configured to supply air to an air-intake port of an engine is disclosed. The throttle body typically includes an air-intake passage through which air flows. The air-intake passage at least partially has a non-perfect circle portion with a cross-section of a non-perfect circle shape in a direction substantially perpendicular to a direction of an air flow of air taken in from outside. The non-perfect circle shape typically has long and short axes. At least one of a first throttle valve and a second throttle valve typically is mounted within the non-perfect circle portion of the air-intake passage. The first throttle valve and second throttle valve may include throttle valve members each having a shape conforming to the non-perfect circle shape of the cross-section of the non-perfect circle portion of the air-intake passage. Typically, the first throttle valve and the second throttle valve are each configured to control an amount of the air flow.

Abstract: In a multi-cylinder internal combustion engine having throttle valves to be opened and closed by electric motors, output control is enabled in various ways according to the state of usage of an object to be driven by the multi-cylinder internal combustion engine with a simple structure with the scope of application of shared components being expanded to reduce the cost. In addition, a throttle body assembly is downsized in the direction of the arrangement of the cylinders. A multi-cylinder internal combustion engine includes a predetermined number of cylinders, a throttle body assembly including the throttle bodies formed with intake-air channels and throttle valves. The respective throttle valves are opened and closed by the electric motors provided independently for each throttle valve. Air-intake ports of the first and fourth cylinders are formed so as to approach a center plane in the direction of the arrangement as they approach entrances.

Abstract: A method for controlling an engine having at least one cylinder is provided. The engine includes an intake manifold and an outlet control device for controlling flow from the intake manifold into the cylinder. The method includes generating an operator command. The method further includes controlling flow into the cylinder by changing the outlet control device to control flow into the cylinder based on the operator command.

Abstract: A valve control and diagnostic system uses physical stops to determine whether a connection between the valve motor and the valves has become degraded. The method can detect degradation in both the opening and closing direction, as well as in multi-valve systems, such as used on internal combustion engines.

Abstract: In a fuel gas mixer 1 including a throttle valve 4 provided in an air intake passage 2 connected to an engine for opening and closing the air intake passage 2 and a fuel gas supply passage 6 connected to the air intake passage 2 upstream of the throttle valve 4. A fuel gas control valve 5 is provided in the air intake passage 2 upstream of the connecting part of the fuel gas supply passage 6 for opening and closing the air intake passage 2, and a fuel gas control value controlling means 11 is provided for varying the degree of the opening of the fuel gas control value 5 depending upon the operating state of the engine.

Abstract: A fuel delivery system having an electronically controlled throttle valve operatively disposed in an intake manifold. An idle speed control valve is operatively disposed within a bypass gas flow passageway. A control system controls the actuation of both the throttle valve and idle speed control valve to control the delivery of a combustible charge to the internal combustion engine to maximize engine efficiency and minimize noxious emissions.

Abstract: An internal combustion engine includes at least two intake valves per cylinder, and at least two intake ports leading to the intake valves, a first intake port preferably being configured as unthrottled tangential passage and the flow through a second intake port being controlled by means of a first throttle element (11) actuated in dependence of at least one engine parameter, and at least one fuel injector per cylinder injecting fuel into at least two intake ports, wherein in the closed position of the first throttle element at least one leakage aperture will permit a defined minimum flow through the second intake port.

Abstract: To improve freedom of mounting to a motor cycle, a tandem valve type throttle body is provided with a throttle valve (4) in the downstream side of an intake passage (2) and a sub throttle valve (9) in the upstream side thereof, a sub throttle valve shaft (8) is rotated by a motor (M), a sub throttle valve lever (10) and a throttle valve lever (5) are connected by a transmission member, the shaft (8) and a sensor rotor (TA) of an opening degree sensor (T) are energized in the opening direction of the shaft (9) by a rotor spring (TC), a link lever spring (14) pressing the transmission member (12) in one direction is energized in the closing direction of the valve (9), and torque is set so as to cancel spring forces applied to the shaft (8) by both the springs (TC), (14).

Abstract: An outboard engine has an internal combustion engine as a prime mover, a throttle valve device including a valve element and a valve shaft supporting the valve element, and combined with the internal combustion engine, a driven unit combined with the throttle valve device, and a drive unit for driving the driven unit. The drive unit is capable of smoothly transmitting an external throttle-operating force to the driven unit regardless of its position. A throttle valve operating mechanism connects an operating lever included in the driven unit, and a throttle-operating Bowden cable included in the drive unit. The throttle valve operating mechanism is a linkage including plural links. Joints joining the adjacent joining parts of those links are ball-and-socket joints, respectively. The valve shaft has one end connected to the operating lever and the other end connected to a throttle position sensor. The valve shaft is inclined to a horizontal plane.

Abstract: A throttle valve is opened after stopping an engine to prevent the valve from sticking. Then, when a temperature of the valve has become lower than the polymerization temperature, the valve is closed to seal the vapor of the HCs in a surge tank downstream. Changes in the temperature of the valve are, for example, estimated based on a temperature of an intake air detected by an intake temperature sensor.

Abstract: A diaphragm carburetor for an internal combustion engine that operates with scavenging is provided, especially for the two-cycle engine in a manually guided implement. The carburetor has a housing in which is formed an intake channel portion in which is disposed a butterfly valve that is rotatably held via a butterfly valve shaft. The carburetor has at least one air channel that supplies additional combustion air and that is provided with an air valve that is rotatably held via an air valve shaft. The air valve is, at least in one angular range, coupled to the movement of the butterfly valve, whereby the coupling includes a butterfly valve lever that is fixedly connected with the butterfly valve shaft, and an air valve lever that is fixedly connected with the air valve shaft. Disposed on one of the levers is a driver member that at least in one angular range slides upon the other lever between an outer contact point and an inner contact point.

Abstract: In a control system of an internal combustion engine including an intake flow control valve disposed downstream of a throttle valve, a controller controls opening and closing of the intake flow control valve, depending upon an operating state of the internal combustion engine. Upon detection of a failure in the intake flow control valve, the controller controls an intake air amount or flow rate to a different value.

Abstract: A fuel delivery system for an internal combustion engine of the type having an intake manifold selectively fluidly connected to a combustion chamber and a bypass gas flow passageway having an inlet open to the intake manifold and an outlet open to the intake manifold downstream for the inlet is disclosed. The system includes an electronically controlled throttle valve operatively disposed in the intake manifold and movable between an open and a closed position to control air flow through the intake manifold. An idle speed control valve is operatively disposed within the bypass gas flow passageway, and the idle speed control valve is also movable between an open and a closed position to control air flow through the bypass gas flow passageway. A control system controls the actuation of both the throttle valve and idle speed control valve to control the delivery of a combustible charge to the internal combustion engine to maximize engine efficiency and minimize noxious emissions.

Abstract: A sub collector is connected to a main collector disposed downstream of a throttle valve in an intake passage and a control valve for collector capacity disposed between the two collectors controls connection therebetween. A difference in pressure between the two collectors is reduced when a condition that pressure in the sub collector is lower than a predetermined value in relation to pressure in the main collector occurs. Namely, the control valve is forcibly opened at a point from a fully closed position of the throttle valve to acceleration operation thereof.

Abstract: A diaphragm carburetor for an internal combustion engine that operates with scavenging is provided, especially for the two-cycle engine in a manually guided implement. The carburetor has a housing in which is formed an intake channel portion in which is disposed a butterfly valve that is rotatably held via a butterfly valve shaft. The carburetor has at least one air channel that supplies additional combustion air and that is provided with an air valve that is rotatably held via an air valve shaft. The air valve is, at least in one angular range, coupled to the movement of the butterfly valve, whereby the coupling includes a butterfly valve lever that is fixedly connected with the butterfly valve shaft, and an air valve lever that is fixedly connected with the air valve shaft. Disposed on one of the levers is a driver member that at least in one angular range slides upon the other lever between an outer contact point and an inner contact point.

Abstract: A method for controlling an engine having both an electronically controlled inlet device, such as an electronic throttle unite, and an electronically controlled outlet device, such as a variable cam timing system is disclosed. The method of the present invention achieves cylinder air charge control that is faster than possible by using an inlet device alone. In other words, the method of the present invention controls cylinder air charge faster than manifold dynamics by coordination of the inlet and outlet device. This improved control is used to improve various engine control functions.

Abstract: A method for controlling an engine having both an electronically controlled inlet device, such as an electronic throttle unite, and an electronically controlled outlet device, such as a variable cam timing system is disclosed. The method of the present invention achieves cylinder air charge control that is faster than possible by using an inlet device alone. In other words, the method of the present invention controls cylinder air charge faster than manifold dynamics by coordination of the inlet and outlet device. This improved control is used to improve various engine control functions.

Abstract: A method for controlling a powertrain of a vehicle is described. The method determines a desired vehicle condition based on three driver actuated elements. In a preferred embodiment the first element can be pedal position, the second element can be a brake actuator or, more specifically, brake actuation duration, and the third element can be a gear selection lever. Further, the desired vehicle condition can be desired powertrain output, vehicle acceleration, or various other parameters.

Abstract: In an air intake control device of a fuel injection engine, a throttle body includes a cam lever rotatably mounted on a sub-throttle valve, a stopper cam for rotating a main throttle pulley, and a link mechanism for linking the cam lever and the stopper cam. When the sub-throttle valve is fully opened while a main throttle valve is closed, the rotation of the cam lever is transmitted to the stopper cam by the link mechanism, and the main throttle valve is opened at the angle required for the first idling by the rotation of the stopper cam.

Abstract: In a multi-port fuel injection system for a lean burn engine, the attaching of fuel particles from the fuel spray onto a wall surface, which is a problem in atomizing injected fuel, is reduced, and the quality and shape of the mixed gas in the cylinders of the engine is improved. The engine has a fuel injector 1; an intake valve 6 for opening and closing an intake port; and an intake air flow control device 10. The injected fuel is shaped to provide a low penetration fuel spray when the engine is operated in a low load state and at a low rotation speed, and the injected fuel is shaped to provide a high penetration fuel spray when the engine is operated in a high load state and at a high rotation speed. The fuel is injected in synchronism with the intake stroke of the engine, and it is transported by the air flow flowing through the intake air flow control device 10 to suppress the attaching of fuel particles from the fuel spray onto a wall surface of the intake manifold.

Abstract: A method for controlling an engine having both an electronically controlled inlet device, such as an electronic throttle unite, and an electronically controlled outlet device, such as a variable cam timing system is disclosed. The method of the present invention achieves cylinder air charge control that is faster than possible by using an inlet device alone. In other words, the method of the present invention controls cylinder air charge faster than manifold dynamics by coordination of the inlet and outlet device. This improved control is used to improve various engine control functions.

Abstract: In a tandem valve type throttle body in which a sub throttle valve lever and a throttle valve lever are connected by a transmission member, a freedom of mounting characteristic to a motor cycle is improved by making a motor for driving a sub throttle valve shaft compact. The tandem valve type throttle body is provided with a throttle valve 4 in a downstream side of an intake passage 2, and with a sub throttle valve 9 in an upstream side thereof. The sub throttle valve shaft 8 is rotated and controlled by a motor M, and a sub throttle valve lever 10 and a throttle valve lever 5 are connected to each other by a transmission member. The sub throttle valve shaft 8 and a sensor rotor TA of an opening degree sensor Tare energized in an opening direction of the sub throttle valve shaft 9 by a rotor spring TC, and a link lever spring 14 which presses the transmission member 12 to one direction is energized in a closing direction of the sub throttle valve 9.

Abstract: To provide a tandem valve type throttle body in which a closing direction of a second throttle valve is not restricted to one side, can an intake efficiency can be improved, and an entire length of a throttle body can be reduced, a butterfly type first throttle valve (3) is attached to a first throttle valve shaft (4) and operated by an accelerator, a butterfly type second throttle valve (5) is disposed in an upstream side of the first throttle valve (3) and attached to a second throttle valve shaft (6), the second throttle valve (5) is formed in an always open type and operated so as to be closed by an electromagnetic actuator, an axial pitch (P) between the first throttle valve shaft (4) and the second throttle valve shaft (6) is twice a radius (R) of the throttle valve (3) or less, and a notch portion (5B) is formed in the second throttle valve (5) in correspondence to an interference portion on planes of both the throttle valves (3, 5) at a time of fully opening both the throttle valves (3, 5).

Abstract: A throttle valve is opened after stopping an engine to prevent the valve from sticking. Then, when a temperature of the valve has become lower than the polymerization temperature, the valve is closed to seal the vapor of the HCs in a surge tank downstream. Changes in the temperature of the valve are, for example, estimated based on a temperature of an intake air detected by an intake temperature sensor.