JP4858471B2 - Vehicle control apparatus and control method - Google Patents

Description

  The present invention relates to a control of a vehicle equipped with an internal combustion engine having a fuel injection device that directly injects fuel into a cylinder and a blow-by gas reduction device that reduces blow-by gas generated in the cylinder to an intake passage. The present invention relates to control of a reduction amount of blow-by gas during execution of fuel cut control.

  In an internal combustion engine mounted on a vehicle or the like, a mixture of fuel and air is burned in a cylinder, and power is obtained by reciprocating a piston based on energy generated by the combustion. Normally, in this type of internal combustion engine, a blow-by gas reduction device that reduces and burns the unburned mixture (blow-by gas) into the cylinder of the internal combustion engine again via the intake passage without releasing it into the atmosphere. Is provided.

  As an engine provided with such a blow-by gas reduction device, for example, Japanese Utility Model Publication No. 1-179112 (Patent Document 1) avoids the occurrence of an over-lean state at the time of fuel return from a state where fuel supply is stopped at the time of deceleration. Disclosed is an intake device for an engine. The engine intake device includes a blow-by gas passage communicating the intake passage and the inside of the engine, a fuel supply means for supplying fuel to the intake passage, a deceleration detection means for detecting a deceleration state of the engine, and a signal of the deceleration detection means When the fuel supply is returned from the deceleration fuel cut by the deceleration fuel cut means, the blowby gas control valve that opens and closes the blowby gas passage, and the deceleration fuel cut means, Blow-by gas control means for controlling the operation of the blow-by gas control flight so as to limit the supply of gas is provided.

According to this engine intake device, when the fuel returns from the deceleration fuel cut state, the supply of blowby gas is restricted for a predetermined period by controlling the blowby gas control valve, so that it adheres to the intake passage wall surface in the deceleration fuel cut state. In addition to the supply delay of the return fuel corresponding to the disappearance of the lost fuel, the air-fuel ratio becomes overlean due to the increase in air due to the supply of the auxiliary fluid of the blowby gas. It is possible to limit the supply and prevent the occurrence of an overlean state without causing a decrease in fuel efficiency due to an increase in the fuel supply amount.
Japanese Utility Model Publication No. 1-179112

  By the way, in an internal combustion engine of a type in which fuel is directly injected into a cylinder, the fuel is difficult to atomize when it is cold, so that the directly injected fuel in the cylinder adheres to the cylinder wall surface. The fuel adhering to the wall surface in the cylinder is scraped into the crankcase by the piston ring and mixed with the engine oil, so that fuel dilution occurs in the engine oil. Further, after the internal combustion engine is warmed up, if the fuel for diluting the engine oil evaporates, it is returned to the intake passage as blow-by gas. When the fuel cut control of the internal combustion engine is being executed, the blow-by gas reduced to the intake passage is not burned in the combustion chamber, and the unburned gas in the blow-by gas is purified by the catalyst provided in the middle of the exhaust passage. Will be.

  However, when the inside of the catalyst is in a reducing atmosphere or when the temperature of the catalyst is low, there is a problem that the ability to purify unburned gas is reduced. Therefore, the exhaust performance may be deteriorated. In the above-mentioned publication, only unburned gas is burned with a catalyst, and no consideration is given to such a problem.

  The present invention has been made to solve the above-described problems, and its object is to perform blow-by at an appropriate reduction amount at an appropriate time according to the state of the catalyst during execution of fuel cut control of the internal combustion engine. It is an object of the present invention to provide a vehicle control device and a control method that reduce a gas to an intake passage to suppress a decrease in exhaust gas purification performance.

  A vehicle control device according to a first aspect of the present invention is a vehicle control device on which an internal combustion engine is mounted. The internal combustion engine is provided in a cylinder, an intake passage for introducing air into the cylinder, a blow-by gas passage for reducing blow-by gas generated in the cylinder to the intake passage, and a blow-by gas passage, and the flow rate of the blow-by gas to the intake passage is It includes a control valve that is restricted according to the state of the internal combustion engine, an exhaust passage that circulates exhaust gas discharged from the cylinder, and a catalyst that is provided in the middle of the exhaust passage and purifies the exhaust gas by an oxidation reaction. The control device includes a detecting means for detecting the degree of purification capability of the catalyst, a means for detecting the concentration of the fuel component in the blow-by gas flowing through the blow-by gas passage, and execution of fuel cut control of the internal combustion engine. Means for detecting a running state of the vehicle as a condition, and means for controlling the control valve so as to be limited according to the state of the internal combustion engine when at least the execution condition is not satisfied, and When it is determined that the fuel concentration is higher than a predetermined concentration, the vehicle running state satisfies the execution conditions, and the detected purification capacity is high, the flow rate of the blow-by gas is limited. Control means for controlling the control valve so as to relax the restriction rather than the degree of restriction according to the state of the internal combustion engine. A vehicle control method according to a tenth aspect of the invention has the same configuration as the vehicle control apparatus according to the first aspect of the invention.

  According to the first invention, when it is determined that the fuel concentration is higher than a predetermined concentration, the execution condition of the fuel cut control of the internal combustion engine is satisfied, and the degree of purification capability is high, the internal combustion engine By controlling the control valve so as to relax the restriction rather than the degree of restriction according to the state (for example, suction negative pressure), the reduction amount of the blowby gas to the intake passage may be increased from the normal reduction amount. it can. Since the catalyst has a high degree of purification capability, a large amount of blow-by gas can be purified. As a result, more fuel diluted in engine oil can be purified. Further, when it is determined that the degree of purification capacity is high, the amount of blow-by gas reduced to the intake passage is increased, so that an appropriate amount of blow-by gas can be purified at an appropriate time. Therefore, during the execution of the fuel cut control of the internal combustion engine, the control of the vehicle that suppresses the deterioration of the exhaust gas purification performance by reducing an appropriate reduction amount of blowby gas to the intake passage at an appropriate time according to the state of the catalyst. An apparatus and a control method can be provided.

  In the vehicle control apparatus according to the second invention, in addition to the configuration of the first invention, the detection means detects the oxygen concentration of the exhaust gas that has passed through the catalyst. The control device further includes means for determining that the purification capacity of the catalyst is high when the detected oxygen concentration is greater than a predetermined concentration. The vehicle control method according to the eleventh invention has the same configuration as the vehicle control device according to the second invention.

  According to the second invention, when the detected oxygen concentration is larger than a predetermined concentration, the catalyst is in an oxidizing atmosphere, so that hydrocarbon (HC) or carbon monoxide (CO) in the blow-by gas is removed. The ability to purify is high. In such a case, the flow rate of the blowby gas to the intake passage is increased by controlling the control valve so as to relax the restriction rather than the degree of restriction according to the state of the internal combustion engine. Can be purified.

  In addition to the configuration of the second invention, the vehicle control apparatus according to the third invention is such that the detected fuel concentration is greater than a predetermined concentration, satisfies the execution condition, and is detected. The control valve further includes means for controlling the control valve so that the restriction of the flow rate of the blow-by gas becomes stronger than the degree of restriction according to the state of the internal combustion engine. A vehicle control method according to a twelfth aspect of the invention has the same configuration as the vehicle control apparatus according to the third aspect of the invention.

  According to the third invention, when the detected oxygen concentration is equal to or lower than a predetermined concentration, the catalyst is in a reducing atmosphere, so hydrocarbon (HC) or carbon monoxide (CO) in the blow-by gas is removed. The ability to purify is lower than that in an oxidizing atmosphere. In such a case, the amount of reduction of the blow-by gas to the intake passage is reduced from the normal amount of reduction by controlling the control valve so as to make the restriction stronger than the degree of restriction according to the state of the internal combustion engine. Can do. For this reason, the amount of blow-by gas corresponding to the purification capacity of the catalyst can be reduced to the intake passage, so that release of the blow-by gas into the atmosphere can be suppressed.

  In the vehicle control apparatus according to the fourth aspect of the invention, in addition to the configuration of the first aspect of the invention, the detection means relates to the means for detecting the oxygen concentration of the exhaust gas that has passed through the catalyst, and the temperature of the catalyst. Means for detecting a physical quantity. When the oxygen concentration is higher than the predetermined concentration and the temperature of the catalyst based on the detected physical quantity is equal to or higher than the predetermined temperature, the control device has a catalyst purification capability. Further comprising means for determining high. A vehicle control method according to a thirteenth aspect of the invention has the same configuration as the vehicle control apparatus according to the fourth aspect of the invention.

  According to the fourth invention, when the detected oxygen concentration is larger than the predetermined concentration and the temperature of the catalyst based on the detected physical quantity is equal to or higher than the predetermined temperature, the catalyst is in an oxidizing atmosphere. Moreover, since the temperature is high, the ability to purify hydrocarbons (HC) and carbon monoxide (CO) in blow-by gas is in a high state. In such a case, by controlling the control valve so as to relax the restriction rather than the degree of restriction according to the state of the internal combustion engine, the amount of reduction of blow-by gas to the intake passage is increased from the normal amount of reduction. be able to. Therefore, a large amount of blow-by gas can be purified.

  In addition to the configuration of the fourth invention, the vehicle control apparatus according to the fifth invention is such that the detected fuel concentration is greater than a predetermined concentration, satisfies the execution condition, and the oxygen concentration is predetermined. When it is determined that the temperature of the catalyst is equal to or lower than the concentration and the temperature of the catalyst based on the detected physical quantity is equal to or higher than a predetermined temperature, the restriction on the flow rate of the blow-by gas is restricted according to the state of the internal combustion engine. It further includes means for controlling the control valve to increase the limit beyond the degree. The vehicle control method according to the fourteenth invention has the same configuration as the vehicle control device according to the fifth invention.

  According to the fifth invention, when the detected oxygen concentration is equal to or lower than a predetermined concentration, the catalyst is in a reducing atmosphere, so that hydrocarbon (HC) or carbon monoxide (CO) in the blow-by gas is removed. The ability to purify is lower than that in an oxidizing atmosphere. In such a case, the amount of reduction of the blow-by gas to the intake passage is reduced from the normal amount of reduction by controlling the control valve so as to make the restriction stronger than the degree of restriction according to the state of the internal combustion engine. Can do. For this reason, the amount of blow-by gas corresponding to the purification capacity of the catalyst can be reduced to the intake passage, so that release of the blow-by gas into the atmosphere can be suppressed.

  In addition to the structure of the fifth invention, the vehicle control device according to the sixth invention responds to the state of the internal combustion engine when the temperature of the catalyst based on the detected physical quantity is lower than a predetermined temperature. Means are further included for controlling the control valve to a degree of restriction. The vehicle control method according to the fifteenth aspect of the invention has the same configuration as the vehicle control apparatus according to the sixth aspect of the invention.

  According to the sixth invention, when the temperature of the catalyst is lower than the predetermined temperature, the blow-by gas purifying ability in the catalyst is lower than that in the case where the temperature of the catalyst is equal to or higher than the predetermined temperature. It is. In such a case, the amount of reduction of blow-by gas to the intake passage can be reduced from the normal amount of reduction by controlling the control valve so that the degree of restriction is in accordance with the state of the internal combustion engine. For this reason, the amount of blow-by gas corresponding to the purification capacity of the catalyst can be reduced to the intake passage, so that release of the blow-by gas into the atmosphere can be suppressed.

  According to a seventh aspect of the present invention, there is provided a control apparatus for a vehicle according to the state of the internal combustion engine when the detected fuel concentration is equal to or lower than a predetermined concentration in addition to the configuration of any one of the first to sixth aspects. And further includes means for controlling the control valve to achieve a limited degree. A vehicle control method according to a sixteenth aspect of the invention has the same configuration as the vehicle control device according to the seventh aspect of the invention.

  According to the seventh invention, when the detected fuel concentration is equal to or lower than a predetermined concentration, the degree of blow-by gas generation is low. Further, when the running state of the vehicle does not satisfy the fuel cut control execution condition, combustion is performed in the cylinder, so that the blow-by gas is purified in the cylinder. Therefore, in such a case, the blow-by gas can be appropriately purified by controlling the control valve that has a degree of restriction according to the state of the internal combustion engine.

  In the vehicle control apparatus according to the eighth invention, in addition to the configuration of any one of the first to seventh inventions, the internal combustion engine is provided with a fuel injection device that injects fuel directly into at least the cylinder. A vehicle control method according to a seventeenth invention has the same configuration as the vehicle control device according to the eighth invention.

  According to the eighth aspect of the invention, the present invention is applied to an internal combustion engine provided with a fuel injection device that directly injects fuel into at least a cylinder, and the fuel cut control of the internal combustion engine is appropriately performed according to the state of the catalyst. By reducing the blow-by gas to the intake passage at a suitable time and at an appropriate reduction amount, it is possible to suppress a reduction in exhaust gas purification performance.

  In the vehicle control apparatus according to the ninth aspect of the invention, in addition to the configuration of any one of the first to eighth aspects, the internal combustion engine is operated by a fuel containing at least one of alcohol and gasoline. A vehicle control method according to an eighteenth aspect of the invention has the same configuration as the vehicle control apparatus according to the ninth aspect of the invention.

  According to the ninth aspect, by applying the present invention to an internal combustion engine that operates with a fuel containing at least one of alcohol and gasoline, the fuel cut control of the internal combustion engine is performed according to the state of the catalyst. Therefore, it is possible to reduce the exhaust gas purification performance by reducing the blow-by gas to the intake passage at an appropriate time and at an appropriate reduction amount.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

<First Embodiment>
As shown in FIG. 1, a vehicle equipped with the vehicle control device according to the present embodiment includes an internal combustion engine (hereinafter referred to as an engine) 150, an intake system 152, an exhaust system 154, an ECU (Electronic Control Unit) 100.

  The engine 150 includes a cylinder block 124, cylinders 162 formed in the cylinder block 124 corresponding to the number of cylinders, a piston 128 slidably provided in the cylinder 162, and one end connected to the piston 128. Piston rod 122, crankshaft 130 connected to the other end of piston rod 122, crankcase 132 that rotatably supports crankshaft 130, crank position sensor 156 that detects the rotational position of crankshaft 130, intake air An intake port 158 for introducing air circulated from the system 152 into the cylinder 162, an intake valve 172 provided at a connection portion between the intake port 158 and the cylinder 162, a fuel injection device 126 for directly injecting fuel into the cylinder 162, , Exhaust gas exhausted from cylinder 162 An exhaust port 160 that circulates in the exhaust system 154, an exhaust valve 174 provided at the connection between the exhaust port 160 and the cylinder 162, an ignition plug 176 provided at the top of the cylinder 162, and a blow-by gas reduction device (described later). including.

  The crankshaft 130 is connected to the other end of the piston rod 122 connected to the piston 128 of each cylinder via a crank mechanism. The force to the piston 128 acting by the combustion in each cylinder is converted into the force in the rotation direction of the crankshaft 130 by the crank mechanism.

  The intake valve 172 operates in conjunction with the rotation of the crankshaft 130 to block or communicate the intake port 158 and the cylinder 162. The exhaust valve 174 operates in conjunction with the rotation of the crankshaft 130 to block or communicate the exhaust port 160 and the cylinder 162.

  The crank position sensor 156 transmits a signal indicating the detected rotational position of the crankshaft 130 to the ECU 100. ECU 100 calculates the rotational position and rotational speed of crankshaft 130 (ie, engine rotational speed) based on the received signal indicating the rotational position of crankshaft 130.

  The fuel injection device 126 directly injects fuel into the cylinder 162 based on a control signal received from the ECU 100. In the present embodiment, engine 150 may be an engine provided with a fuel injection device that injects at least fuel directly into the cylinder. Engine 150 may be, for example, an engine equipped with a port injector that injects fuel into intake port 158 in addition to fuel injection device 126 that directly injects fuel into cylinder 162. The engine 150 may be an engine that operates with fuel containing at least one of gasoline and alcohol.

  Further, the ECU 100 detects the traveling state of the vehicle that is the execution condition of the fuel cut control, and executes the fuel cut control when the execution condition of the fuel cut control is satisfied. That is, ECU 100 controls fuel injection device 126 so as to stop fuel injection when a predetermined fuel cut control execution condition is satisfied.

  In the present embodiment, the conditions for executing fuel cut control are determined in advance as a condition that the vehicle is decelerating (for example, a condition that the opening degree of throttle valve 112 is substantially zero) and the rotational speed of engine 150. And the condition that the rotation speed is equal to or higher than that. The execution condition of the fuel cut control may further include a vehicle speed condition and a cooling water temperature condition.

  The intake system 152 includes an intake pipe 110 connected to the intake port 158, an air cleaner 118 provided in the middle of the intake pipe 110, and a position in the middle of the intake pipe 110 between the air cleaner 118 and the intake port 158. A throttle valve 112 provided, a throttle motor 114 that operates the throttle valve 112, a throttle position sensor 116 that detects the opening of the throttle valve 112, and the intake pipe 110, between the air cleaner 118 and the throttle valve 112. An intake air temperature sensor 104 provided at the position of FIG. 1, a surge tank 148 provided in the middle of the intake pipe 110 between the throttle valve 112 and the intake port 158, and a vacuum sensor 190 for detecting the pressure in the intake pipe 110 including. The “intake passage” includes the intake port 158 and the intake pipe 110.

  The throttle position sensor 116 transmits a signal indicating the detected opening of the throttle valve 112 to the ECU 100. The intake air temperature sensor 104 transmits a signal indicating the detected intake air temperature to the ECU 100. The vacuum sensor 180 transmits a signal indicating the detected pressure in the intake pipe 110 to the ECU 100.

The exhaust system 154 includes an exhaust pipe (1) 108 connected to the exhaust port 160, a three-way catalyst 120 provided in the middle of the exhaust pipe (1) 108, and a middle part of the exhaust pipe (1) 108. In the middle of the air-fuel ratio sensor 200 provided at a position closer to the exhaust port 160 than the original catalyst 120, the exhaust pipe (2) 164 connected to the exhaust pipe (1) 108, and the exhaust pipe (1) 108, An O ₂ sensor 102 provided at a position closer to the exhaust pipe (2) 164 than the three-way catalyst 120 and a three-way catalyst 166 provided in the middle of the exhaust pipe (2) 164 are included. The “exhaust passage” includes an exhaust port 160, an exhaust pipe (1) 108 and an exhaust pipe (2) 164.

  The air-fuel ratio sensor 200 detects the oxygen concentration in the exhaust gas closer to the exhaust port 160 than the three-way catalyst 120. The air-fuel ratio sensor 200 transmits a signal indicating the detected oxygen concentration in the exhaust gas to the ECU 100. Specifically, the air-fuel ratio sensor 200 outputs an output voltage signal that changes linearly with respect to the oxygen concentration to the ECU 100. ECU 100 calculates the air-fuel ratio based on the output voltage signal received from air-fuel ratio sensor 200.

The O ₂ sensor 102 detects the oxygen concentration in the exhaust gas closer to the exhaust pipe (2) 164 than the three-way catalyst 120. The O ₂ sensor 102 transmits a signal indicating the detected oxygen concentration in the exhaust gas to the ECU 100. Specifically, the O ₂ sensor 102 outputs to the ECU 100 an output voltage signal that greatly changes the degree of the output voltage before and after the theoretical air-fuel ratio with respect to the oxygen concentration. Based on the output voltage signal received from the O ₂ sensor 102, the ECU 100 determines whether the air-fuel ratio is a rich air-fuel ratio or a lean air-fuel ratio with respect to the stoichiometric air-fuel ratio. An air-fuel ratio sensor may be used in place of the O ₂ sensor 102.

  When the engine 150 is operated, air is taken into the intake pipe 110. The air drawn into the intake pipe 110 flows toward the intake port 158 via the air cleaner 118. The flow rate of the air flowing through the intake port 158 is limited according to the opening degree of the throttle valve 112.

  The air flowing from the intake port 158 into the cylinder 162 is mixed with the fuel injected from the fuel injection device 126. The air-fuel mixture in which fuel and air are mixed is burned by the ignition plug 176 igniting the air-fuel mixture before and after the piston 128 reaches top dead center after the intake valve 172 and the exhaust valve 174 are closed. . When combustion occurs, the piston 128 is pushed down to the bottom dead center side by the combustion pressure. The linear motion between the top dead center and the bottom dead center of the piston 128 is converted into the rotational motion of the crankshaft 130 by the crank mechanism, and power is generated in the engine 150.

  Exhaust gas generated by combustion of the air-fuel mixture in the cylinder 162 flows from the exhaust port 160 to the exhaust pipe (1) 108 and flows into the three-way catalyst 120. Nitrogen oxide (NOx) contained in the inflowing exhaust gas is reduced in the three-way catalyst 120. In addition, HC, CO or contained in the inflowing exhaust gas is oxidized in the three-way catalyst 120. In the present embodiment, the three-way catalyst 120 is a catalyst that reduces NOx and oxidizes HC and CO, but may be any catalyst that purifies exhaust gas by at least an oxidation reaction.

  During the operation of the engine 150, the air-fuel mixture compressed by the piston 128 in the cylinder 162 leaks from the gap between the piston ring and the wall surface of the cylinder 162, and unburned gas flows into the crankcase 132.

  In addition, when the fuel is directly injected into the cylinder 162 by the fuel injection device 126 at a cold time such as immediately after the engine 150 is started, atomization becomes difficult. Therefore, the injected fuel adheres to the wall surface of the cylinder 162. The fuel adhering to the wall surface is scraped off to the crankcase 132 by a piston ring (not shown) provided on the piston 128 when the piston 128 reciprocates. The fuel leaking into the crankcase 132 is mixed with the engine oil in the crankcase 132 or an oil pan (not shown), and fuel dilution occurs in which the engine oil is diluted with fuel.

  When the water temperature of the engine 150 rises and the warm-up is completed, the temperature of the engine oil also rises, so that the fuel that dilutes the engine oil evaporates and vaporizes. The gas generated in this way is called blow-by gas, and is reduced to the intake system 152 by the blow-by gas reduction device, so that the fuel component in the blow-by gas is burned and purified, and release to the atmosphere is prevented. The

  As shown in FIG. 2, the blow-by gas reduction device 170 includes an electronic PCV (Positive Crankcase Ventilation) valve 168, a PCV pipe (1) 142, and a PCV pipe (2) 146.

  The PCV pipe (1) 142 communicates the inside of the cylinder head cover 136 with the inside of the intake pipe 110 at a position closer to the air cleaner 118 than the throttle valve 112. The PCV pipe (2) 146 communicates the inside of the cylinder head cover 136 and the inside of the surge tank 148 via the PCV valve 168.

  The electronic PCV valve 168 is an electromagnetic control valve whose opening degree is controlled by a control duty signal from the ECU 100, and blow-by gas flowing through the PCV pipe (2) 146 according to the opening degree of the electronic PCV valve 168. The flow rate is limited. That is, the opening degree of the electronic PCV valve 168 indicates the degree of restriction of the flow rate of blow-by gas flowing through the PCV pipe (2) 146.

  The ECU 100 controls the opening degree of the electronic PCV valve 168 based on, for example, a physical quantity related to the suction negative pressure of the engine 150. For example, the ECU 100 may control the opening degree of the electronic PCV valve 168 based on the opening degree of the throttle valve 112, or may open the electronic PCV valve 168 based on the suction negative pressure detected by the vacuum sensor 190. The degree may be controlled. Alternatively, the ECU 100 may control the opening degree of the electronic PCV valve 168 based on the differential pressure between the suction negative pressure of the engine 150 and the pressure inside the cylinder head cover 136. Alternatively, the ECU 100 may control the opening degree of the electronic PCV valve 168 based on the opening degree of the throttle valve and the intake air amount.

  The ECU 100 prevents the backflow of blow-by gas based on the intake negative pressure of the engine 150, or the flow rate is predetermined according to the intake negative pressure so that the amount of reduction to the intake system 152 does not become excessive. The degree of restriction of the flow rate in the electronic PCV valve 168 is controlled. For example, ECU 100 controls electronic PCV valve 168 so that the flow rate is set based on the intake negative pressure of engine 150, a map, and the like.

  The blow-by gas uses the negative pressure of the intake manifold to circulate through the PCV pipe (2) 146 when the engine 150 is lightly loaded and through the PCV pipe (1) 142 when the engine 150 is heavily loaded. Thus, the air is forcibly returned to the intake system 152.

  When the engine 150 is lightly loaded, the throttle valve 112 is controlled so that the opening degree becomes small. Therefore, the negative pressure on the downstream side of the throttle valve 112 is large. Fresh air upstream of the throttle valve 112 flows through the PCV pipe (1) 142 and is introduced into the cylinder head cover 136. Fresh air and blow-by gas are mixed in the cylinder head cover 136, distributed through the PCV pipe (2) 146, and returned to the surge tank 148. The blow-by gas reduced to the surge tank 148 flows through the intake pipe 110 and the intake port 158 and burns in the combustion chamber.

  On the other hand, when engine 150 is at a high load, throttle valve 112 is controlled so that the opening degree becomes large. At this time, since the magnitude of the negative pressure in the intake pipe 110 increases, the blow-by gas in the cylinder head cover 136 flows through the PCV pipe (1) 142 and the PCV pipe (2) 146 and is reduced to the upstream side of the throttle valve 112. The The blow-by gas reduced to the upstream side of the throttle valve 112 is mixed with fresh air flowing from the air cleaner 118, flows through the intake pipe 110 and the intake port 158, and burns in the cylinder 162.

  The vehicle control apparatus according to the present embodiment further includes a fuel concentration sensor 163 that detects the concentration of the fuel component in the blowby gas. In the present embodiment, the fuel concentration sensor 163 is provided in the middle of the PCV pipe (2) 146. The fuel concentration sensor 163 is not particularly limited to be provided in the middle of the PCV pipe (2) 146. For example, the fuel concentration sensor 163 may be provided in the cylinder head cover 136 or more than the throttle valve 112. It may be provided in the intake passage on the cylinder 162 side. The fuel concentration sensor 163 transmits a signal indicating the concentration of the fuel component in the blowby gas flowing through the PCV pipe (2) 146 to the ECU 100.

  The blow-by gas inside the engine 150 flows through the oil pan 138, the crankcase 132, the cylinder block 124, the cylinder head 134 or the timing chain cover 140 and reaches the cylinder head cover 136.

  In the configuration as described above, the present invention enables the ECU 100 to detect the detected fuel concentration higher than a predetermined concentration, the vehicle running state satisfies the execution condition of the fuel cut control of the engine 150, and the detection. The electronic PCV valve 168 is controlled so that the restriction of the flow rate of the blow-by gas is relaxed rather than the degree of restriction according to the state of the engine 150 when it is determined that the degree of the purified purification capacity is high. Has characteristics.

  In the present embodiment, the ECU 100 is used when the three-way catalyst 120 is in an oxidizing atmosphere, that is, when the detected oxygen concentration is larger than a predetermined concentration and the air-fuel ratio is the lean air-fuel ratio. Then, it is determined that the purification capacity of the three-way catalyst 120 is high. That is, the ECU 100 determines that the detected fuel concentration is greater than a predetermined concentration, the detected running condition satisfies the fuel cut control execution condition, and the air-fuel ratio is the lean-side air-fuel ratio. If so, the electronic PCV valve 168 is controlled so that the flow rate of the blow-by gas is set to an opening larger than the opening according to the state of the engine 150.

  Further, ECU 100 controls electronic PCV valve 168 so that the opening degree corresponds to the state of engine 150 (that is, the suction negative pressure) when at least the fuel cut control execution condition is not satisfied.

  FIG. 3 shows a functional block diagram of ECU 100 that is the vehicle control apparatus according to the present embodiment.

  ECU 100 includes an input interface (hereinafter referred to as an input I / F) 300, an arithmetic processing unit 400, a storage unit 500, and an output interface (hereinafter referred to as an output I / F) 600.

The input I / F 300 includes an oxygen concentration signal from the O ₂ sensor 102, a throttle opening signal from the throttle position sensor 116, a crank position signal from the crank position sensor 156, and a fuel concentration signal from the fuel concentration sensor 163. Is transmitted to the arithmetic processing unit 400.

  Arithmetic processing unit 400 includes a fuel concentration detection unit 402, a concentration determination unit 404, a fuel cut determination unit 406, a lean determination unit 408, and a PCV control unit 410.

  The fuel concentration detector 402 detects the concentration of the fuel component in the blow-by gas flowing through the PCV pipe (2) 146 based on the fuel concentration signal received from the input I / F 300. The concentration determination unit 404 determines whether or not the concentration of the fuel component detected by the fuel concentration detection unit 402 is higher than a predetermined concentration. The “predetermined concentration” is not particularly limited as long as it is experimentally adapted. For example, the concentration determination unit 404 may turn on the concentration determination flag when the concentration of the fuel component in the blow-by gas flowing through the PCV pipe (2) 146 is higher than a predetermined concentration.

  The fuel cut determination unit 406 determines whether or not an execution condition for fuel cut control of the engine 150 is satisfied. That is, the fuel cut determination unit 406 determines whether or not the fuel cut control of the engine 150 is being executed.

  For example, fuel cut determination unit 406 determines that the conditions for executing fuel cut control are satisfied when the vehicle is decelerating and the rotational speed of engine 150 is equal to or higher than a predetermined rotational speed.

  For example, when the concentration determination flag is turned on, the fuel cut determination unit 406 determines whether or not the execution condition of the fuel cut control is satisfied, and determines that the execution condition of the fuel cut control is satisfied. The fuel cut execution determination flag may be turned on.

When the fuel cut determination unit 406 determines that the fuel cut control execution condition of the engine 150 is satisfied, the lean determination unit 408 determines the air / fuel ratio of the engine 150 based on the oxygen concentration signal received from the O ₂ sensor 102. It is determined whether or not is the lean air-fuel ratio. The lean determination unit 408 determines that the air-fuel ratio of the engine 150 is the lean air-fuel ratio when the oxygen concentration detected by the O2 sensor 102 is greater than a predetermined concentration. Note that, for example, when the fuel cut execution determination flag is turned on, the lean determination unit 408 determines whether the air-fuel ratio of the engine 150 is the lean-side air-fuel ratio, and may be the lean-side air-fuel ratio. If determined, the lean determination flag may be turned on.

  The PCV control unit 410 is in a state where the concentration of the fuel component in the blow-by gas flowing through the PCV pipe (2) 146 is larger than a predetermined concentration, satisfies the execution condition of the fuel cut control, and When the air-fuel ratio is a lean-side air-fuel ratio (that is, when the oxygen concentration is larger than a predetermined concentration), the opening degree that restricts the flow rate of the blowby gas is larger than the opening degree corresponding to the suction negative pressure The electronic PCV valve 168 is controlled so that

  As described above, the opening degree of the electronic PCV valve 168 is set based on the suction negative pressure and the map. The PCV control unit 410 is in a state where the concentration of the fuel component in the blow-by gas flowing through the PCV pipe (2) 146 is larger than a predetermined concentration, satisfies the execution condition of the fuel cut control, and When the air-fuel ratio is the lean-side air-fuel ratio, the electronic PCV valve 168 is controlled so as to increase from the intake negative pressure and the flow rate set by the map, that is, to increase the opening. The PCV control unit 410 relaxes the restriction more than the degree of restriction of the flow rate according to the state of the engine 150, for example, by increasing the intake negative pressure and the opening set by the map by a predetermined value. Thus, the electronic PCV valve 168 is controlled. The predetermined value may be increased as the air-fuel ratio becomes leaner, for example. The PCV control unit 410 generates a control signal for the electronic PCV valve 168 and transmits the generated control signal to the electronic PCV valve 168 via the output I / F 600.

  Furthermore, the PCV control unit 410 has a fuel component concentration in the blow-by gas flowing through the PCV pipe (2) 146 that is greater than a predetermined concentration, satisfies the fuel cut control execution condition, and has an air-fuel ratio. Is the rich side air-fuel ratio (that is, when the oxygen concentration is equal to or lower than a predetermined concentration), the restriction of the flow rate of the blow-by gas is restricted more than the degree of restriction according to the state of the engine 150. The electronic PCV valve 168 is controlled to be strengthened.

  The PCV control unit 410 is in a state where the concentration of the fuel component in the blow-by gas flowing through the PCV pipe (2) 146 is larger than a predetermined concentration, satisfies the execution condition of the fuel cut control, and When the air-fuel ratio is the lean-side air-fuel ratio, the electronic pressure is reduced so that the flow rate is set lower than the intake negative pressure and the flow rate set by the map, that is, the opening is smaller than the opening corresponding to the intake negative pressure. The PCV valve 168 is controlled. For example, the PCV control unit 410 makes the restriction stronger than the degree of restriction of the flow rate according to the state of the engine 150 by making it smaller by a predetermined value than the opening set by the suction negative pressure and the map. The electronic PCV valve 168 is controlled. For example, the predetermined value may be increased as the air-fuel ratio becomes richer.

  Further, the PCV control unit 410 determines that the concentration of the fuel component in the blow-by gas flowing through the PCV pipe (2) 146 is equal to or lower than a predetermined concentration or does not satisfy the execution condition of the fuel cut control. The electronic PCV valve 168 is controlled so as to be limited to a degree according to the state of the engine 150. That is, the PCV control unit 410 controls the electronic PCV valve 168 so as to have an opening set by the suction negative pressure and the map, for example.

  In the present embodiment, the fuel concentration detection unit 402, the concentration determination unit 404, the fuel cut determination unit 406, the lean determination unit 408, and the PCV control unit 410 are all CPUs (Central Processing Units) that are arithmetic processing units 400. May be realized by executing a program stored in the storage unit 500. Such a program is recorded on a recording medium and mounted on the vehicle.

  The storage unit 500 stores various information, programs, threshold values, maps, and the like, and is read out by the arithmetic processing unit 400 as necessary.

  Hereinafter, with reference to FIG. 4, a control structure of a program executed by ECU 100 that is the control device for the vehicle according to the present embodiment will be described.

  In step (hereinafter, step is referred to as S) 100, ECU 100 detects the concentration of the fuel component in the blow-by gas flowing through PCV pipe (2) 146.

  In S102, ECU 100 determines whether or not the detected concentration is higher than a predetermined concentration. If the detected concentration is higher than the predetermined concentration (YES in S102), the process proceeds to S104. If not (NO in S102), the process proceeds to S112.

  In S104, ECU 100 determines whether or not an execution condition for fuel cut control is satisfied. If the fuel cut control execution condition is satisfied (YES in S104), the process proceeds to S106. If not (NO in S104), the process proceeds to S112.

In S106, ECU 100 determines whether or not the air-fuel ratio is a lean-side air-fuel ratio based on the oxygen concentration detected by O ₂ sensor 102. If the air-fuel ratio is the lean air-fuel ratio (YES in S106), the process proceeds to S108. If not (NO in S106), the process proceeds to S110.

  In S108, the ECU 100 controls the electronic PCV valve 168 so that the opening set based on the suction negative pressure and the map is increased by a predetermined value (hereinafter, such control is performed at a flow rate). (Increase control).

  In S110, ECU 100 controls electronic PCV valve 168 so that the opening is reduced by a predetermined value from the opening set based on the suction negative pressure and the map (hereinafter, such control is performed at a flow rate). Called weight loss control).

  In S112, ECU 100 controls electronic PCV valve 168 based on the suction negative pressure and the map (hereinafter, such control is referred to as normal flow rate control).

  The operation of ECU 100, which is the vehicle control apparatus according to the present embodiment, based on the above-described structure and flowchart will be described with reference to FIG. In FIG. 5, for convenience of description of the present invention, the operation of the ECU 100 will be described as an example in which the opening degree of the electronic PCV valve 168 set based on the suction negative pressure and the map is constant.

  As shown in FIG. 5, for example, the engine speed remains constant, the concentration of the fuel component in the blow-by gas is smaller than a predetermined concentration, and the fuel cut control execution condition is satisfied. Assume no state.

  At time T (0), the fuel concentration sensor 163 detects the concentration of the fuel component in the blow-by gas flowing through the PCV pipe (2) 146 (S100), and the detected concentration is lower than the predetermined concentration. If it is larger (YES in S102), it is determined whether or not the execution condition of fuel cut control is satisfied (S104).

  If the fuel cut control execution condition is not satisfied (NO in S104), normal flow control of electronic PCV valve 168 is performed (S112).

  At time T (1), for example, the driver releases the depression of the accelerator pedal, the vehicle is decelerated, and the engine speed (the speed of the crankshaft 130) is a predetermined speed NE. If it is (0) or more, the fuel cut control execution condition is satisfied (YES in S104), and the fuel cut control is executed.

When the air-fuel ratio based on the oxygen concentration detected by the O ₂ sensor 102 is the rich-side air-fuel ratio (NO in S106), the flow rate reduction control of the electronic PCV valve 168 is performed (S110).

  Note that until the air-fuel ratio is determined to be the lean air-fuel ratio after the fuel cut control execution condition is satisfied, the flow rate reduction control is prohibited and the intake negative pressure and the map are displayed. The electronic PCV valve 168 may be controlled so that the opening degree is set based on the opening degree.

At time T (2), the concentration of the fuel component in the blow-by gas flowing through the PCV pipe (2) 146 is greater than the predetermined concentration (YES in S102), and the fuel cut control execution condition is satisfied. If the air-fuel ratio based on the oxygen concentration detected by the O ₂ sensor 102 becomes the lean air-fuel ratio (YES in S106), the flow rate increase control of the electronic PCV valve 168 is controlled. Implemented (S108).

When the air-fuel ratio based on the oxygen concentration detected by the O ₂ sensor 102 becomes the rich air-fuel ratio again at time T (3) (NO in S106), the flow reduction control of the electronic PCV valve 168 is performed. (S110).

Furthermore, when the air-fuel ratio based on the oxygen concentration detected by the O ₂ sensor 102 becomes the lean side air-fuel ratio again at time T (4) (YES in S106), the flow rate increase control of the electronic PCV valve 168 is performed. (S108).

  At time T (5), if the engine speed falls below a predetermined speed NE (0), the fuel cut control execution condition is not satisfied (NO in S104), so that the electronic PCV valve 168 is turned off. Normal flow control is performed (S112).

  As described above, according to the vehicle control apparatus of the present embodiment, the fuel concentration is larger than the predetermined concentration, satisfies the fuel cut control execution condition, and the purification capability of the three-way catalyst is improved. When it is determined that the degree is high, the reduction amount of the blow-by gas to the intake system is controlled by controlling the electronic PCV valve so as to relax the restriction rather than the restriction degree according to the state of the engine. Can be increased. Since the three-way catalyst has a high degree of purification capability, a large amount of HC or CO in the blow-by gas can be purified. As a result, more fuel diluted in engine oil can be purified. Further, when it is determined that the degree of purification capacity is high, the amount of blow-by gas reduced to the intake system is increased, so that the appropriate amount of blow-by gas can be purified at an appropriate time. Therefore, during the execution of the fuel cut control of the internal combustion engine, the control of the vehicle that suppresses the deterioration of the exhaust gas purification performance by reducing an appropriate reduction amount of blowby gas to the intake passage at an appropriate time according to the state of the catalyst. An apparatus and a control method can be provided.

  In particular, in an engine that operates with a fuel containing alcohol, since the fuel injection time is longer than an engine that operates with gasoline, the degree of fuel dilution tends to be large. Therefore, by applying the present invention to such an engine, a large amount of blow-by gas generated by the diluted fuel can be purified.

<Second Embodiment>
Hereinafter, the vehicle control apparatus according to the second embodiment will be described. The vehicle control device according to the present embodiment is different in the control structure of the program executed by ECU 100 as compared with the configuration of the vehicle on which the vehicle control device according to the first embodiment described above is mounted. The other configuration is the same as the configuration of the vehicle on which the vehicle control device according to the first embodiment described above is mounted. They are given the same reference numerals. Their functions are the same. Therefore, detailed description thereof will not be repeated here.

In the present embodiment, the ECU 100 calculates an estimated value of the temperature of the three-way catalyst 120, and the calculated estimated value of the temperature of the three-way catalyst 120 is equal to or higher than a predetermined temperature, and is calculated by the O ₂ sensor 102. When the air-fuel ratio based on the detected oxygen concentration is the lean air-fuel ratio, it is determined that the purification capacity of the three-way catalyst 120 is high.

  ECU 100 calculates an estimated value of the temperature of three-way catalyst 120 based on a physical quantity related to the temperature of three-way catalyst 120. For example, the ECU 100 may calculate the estimated value of the temperature of the three-way catalyst 120 based on the history of the load of the engine 150 (intake air amount based on the intake negative pressure detected by the vacuum sensor 190). Alternatively, the ECU 100 receives the temperature signal from the temperature sensor provided in the three-way catalyst 120 instead of calculating the estimated value of the temperature of the three-way catalyst 120 and directly detects the temperature of the three-way catalyst 120. You may make it do.

  The ECU 100 determines that the concentration of the fuel component in the blow-by gas flowing through the PCV pipe (2) 146 is greater than a predetermined concentration, satisfies the fuel cut control execution condition, and the oxygen concentration is higher than the predetermined concentration. When the temperature of the catalyst is larger and the temperature of the catalyst is equal to or higher than a predetermined temperature, the restriction of the flow rate of the blow-by gas is less than the degree of restriction according to the state of the engine 150 (for example, intake negative pressure). Thus, the electronic PCV valve 168 is controlled.

  FIG. 6 shows a functional block diagram of ECU 100 that is the vehicle control apparatus according to the present embodiment. In addition, the same code | symbol is attached | subjected to the structure which has the same function as the functional block of ECU100 which is the control apparatus of the vehicle which concerns on the above-mentioned 1st Embodiment, The detailed description is not repeated.

  The catalyst temperature calculation unit 412 calculates an estimated value of the temperature of the three-way catalyst 120 based on the load history of the engine 150. The catalyst temperature determination unit 414 determines whether or not the calculated estimated value of the temperature of the three-way catalyst 120 is equal to or higher than a predetermined temperature. The “predetermined temperature” is not particularly limited as long as it is adapted by experiments or the like.

  For example, when the catalyst temperature determination unit 414 determines that the fuel cut determination unit 406 satisfies the execution condition of the fuel cut control, is the estimated value of the temperature of the three-way catalyst 120 equal to or higher than a predetermined temperature? The catalyst temperature determination flag may be turned on when the estimated value of the temperature of the three-way catalyst 120 is equal to or higher than a predetermined temperature.

  The PCV control unit 410 is in a state where the concentration of the fuel component in the blow-by gas flowing through the PCV pipe (2) 146 is larger than a predetermined concentration, satisfies the execution condition of the fuel cut control, and When the temperature of the three-way catalyst 120 is equal to or higher than a predetermined temperature and the air-fuel ratio is a lean side air-fuel ratio, a value that is determined in advance from the suction negative pressure and the opening set by the map By making it larger, the electronic PCV valve 168 is controlled so as to relax the restriction rather than the normal flow restriction.

  Further, the PCV control unit 410 is in a state where the concentration of the fuel component in the blow-by gas flowing through the PCV pipe (2) 146 is larger than a predetermined concentration, and satisfies the execution condition of the fuel cut control, In addition, when the temperature of the three-way catalyst 120 is equal to or higher than a predetermined temperature and the air-fuel ratio is the rich air-fuel ratio, the opening set by the suction negative pressure and the map is reduced. The electronic PCV valve 168 is controlled.

  Further, the PCV control unit 410 may be configured such that the concentration of the fuel component in the blow-by gas flowing through the PCV pipe (2) 146 is not more than a predetermined concentration, does not satisfy the fuel cut control execution condition, or When the estimated value of the temperature of the three-way catalyst 120 is lower than a predetermined temperature, the electronic PCV valve 168 is controlled so that the opening is set by the suction negative pressure and the map.

  In the present embodiment, the fuel concentration detection unit 402, the concentration determination unit 404, the fuel cut determination unit 406, the lean determination unit 408, the PCV control unit 410, the catalyst temperature calculation unit 412, and the catalyst temperature determination unit 414 are all included. It may be realized by a CPU (Central Processing Unit) which is the arithmetic processing unit 400 executing a program stored in the storage unit 500. Such a program is recorded on a recording medium and mounted on the vehicle.

  Hereinafter, with reference to FIG. 7, a control structure of a program executed by ECU 100 which is the vehicle control apparatus according to the present embodiment will be described.

  In the flowchart shown in FIG. 7, the same steps as those in the flowchart shown in FIG. 4 are given the same step numbers. The processing for them is the same. Therefore, detailed description thereof will not be repeated here.

  When the fuel cut control execution condition is satisfied (YES in S104), ECU 100 calculates an estimated value of temperature of three-way catalyst 120 in S200. In S202, ECU 100 determines whether or not the calculated estimated value of temperature of three-way catalyst 120 is equal to or greater than a predetermined value. If the estimated value of temperature of three-way catalyst 120 is equal to or greater than a predetermined value (YES in S202), the process proceeds to S106. If not (NO in S202), the process proceeds to S112.

  The operation of ECU 100 as the vehicle control apparatus according to the present embodiment based on the structure and flowchart as described above will be described with reference to FIG.

  As shown in FIG. 8, for example, the engine speed remains constant, the concentration of the fuel component in the blow-by gas is smaller than a predetermined concentration, and the fuel cut control execution condition is satisfied. Assume no state.

  At time T ′ (0), the fuel concentration sensor 163 detects the concentration of the fuel component in the blow-by gas flowing through the PCV pipe (2) 146 (S100), and the detected concentration is determined from a predetermined concentration. Is larger (YES in S102), it is determined whether or not the execution condition of the fuel cut control is satisfied (S104).

  If the fuel cut control execution condition is not satisfied (NO in S104), normal flow control of electronic PCV valve 168 is performed (S112).

  At time T ′ (1), for example, when the driver releases the depression of the accelerator pedal, the vehicle is decelerated, and the engine speed is equal to or higher than a predetermined speed NE (0). When the fuel cut control execution condition is satisfied (YES in S104), the fuel cut control is executed.

  Even if the fuel concentration is higher than the predetermined concentration (YES in S102) and the fuel cut control execution condition is satisfied (YES in S104), the calculated estimated temperature of the three-way catalyst 120 is previously determined. When the temperature is lower than the predetermined temperature (NO in S200 and S202), electronic PCV valve 168 is controlled to have a flow rate set using the state of engine 150 and the map (S112).

At time T ′ (2), the concentration of the fuel component in the blow-by gas flowing through the PCV pipe (2) 146 is larger than the predetermined concentration (YES in S102), and the execution condition of the fuel cut control is set. Satisfied (YES in S104), the calculated estimated value of the temperature of the three-way catalyst 120 is equal to or greater than a predetermined value (YES in S200, S200), and is detected by the O ₂ sensor 102. When the air-fuel ratio based on the oxygen concentration becomes the lean-side air-fuel ratio (YES in S106), the flow rate increase control of electronic PCV valve 168 is performed (S108).

When the air-fuel ratio based on the oxygen concentration detected by the O ₂ sensor 102 becomes the rich-side air-fuel ratio at time T ′ (3) (NO in S106), the flow reduction control of the electronic PCV valve 168 is performed. (S110).

Further, when the air-fuel ratio based on the oxygen concentration detected by the O ₂ sensor 102 becomes the lean side air-fuel ratio again at time T ′ (4) (YES in S106), the flow rate increase control of the electronic PCV valve 168 is controlled. Implemented (S108).

  At time T ′ (5), if the engine speed falls below a predetermined speed NE (0), the fuel cut control execution condition is not satisfied (NO in S104), and therefore normal flow rate control is performed. Implemented (S112).

  As described above, according to the vehicle control device according to the present embodiment, in addition to the same effects as those produced by the vehicle control device according to the first embodiment, the temperature of the three-way catalyst is previously set. When the temperature is lower than the predetermined temperature, the ability of the three-way catalyst to purify the blow-by gas is lower than when the temperature of the three-way catalyst is equal to or higher than the predetermined temperature. In such a case, the blow-by gas returned to the intake system can be appropriately purified by controlling the electronic PCV valve so as to be limited to a degree according to the state of the engine.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure which shows the structure of the engine mounted in a vehicle. It is a figure which shows schematic structure of a blow-by gas reduction apparatus. It is a functional block diagram of ECU which is a control device of vehicles concerning a 1st embodiment. It is a flowchart which shows the control structure of the program performed with ECU which is the control apparatus of the vehicle which concerns on 1st Embodiment. It is a timing chart which shows operation of ECU which is a control device of vehicles concerning a 1st embodiment. It is a functional block diagram of ECU which is a control device of vehicles concerning a 2nd embodiment. It is a flowchart which shows the control structure of the program performed with ECU which is the control apparatus of the vehicle which concerns on 2nd Embodiment. It is a timing chart which shows operation of ECU which is a control device of vehicles concerning a 2nd embodiment.

Explanation of symbols

102 O ₂ sensor, 104 Intake temperature sensor, 110 Intake pipe, 112 Throttle valve, 114 Throttle motor, 116 Throttle position sensor, 118 Air cleaner, 120 Three-way catalyst, 122 Piston rod, 124 Cylinder block, 126 Fuel injection device, 128 Piston , 130 Crankshaft, 132 Crankcase, 136 Cylinder head cover, 138 Oil pan, 140 Timing chain cover, 148 Surge tank, 150 Engine, 152 Intake system, 154 Exhaust system, 156 Crank position sensor, 158 Intake port, 160 Exhaust port, 162 cylinder, 163 fuel concentration sensor, 166 three-way catalyst, 168 electronic PCV valve, 170 blow-by gas reduction device, 172 intake valve, 174 Exhaust valve, 176 spark plug, 190 vacuum sensor, 200 air-fuel ratio sensor, 300 input I / F, 400 arithmetic processing unit, 402 fuel concentration detection unit, 404 concentration determination unit, 406 fuel cut determination unit, 408 lean determination unit, 410 PCV control unit, 412 catalyst temperature calculation unit, 414 catalyst temperature determination unit, 500 storage unit, 600 output I / F.

Claims (18)

A control device for a vehicle equipped with an internal combustion engine, wherein the internal combustion engine includes a cylinder, an intake passage for introducing air into the cylinder, and a blow-by gas passage for reducing blow-by gas generated in the cylinder to the intake passage. A control valve that is provided in the blow-by gas passage and restricts the flow rate of the blow-by gas to the intake passage according to the state of the internal combustion engine; and an exhaust passage through which the exhaust gas discharged from the cylinder flows. A catalyst provided in the middle of the exhaust passage and purifying the exhaust gas by an oxidation reaction;
Detection means for detecting the degree of purification capacity of the catalyst;
Means for detecting the concentration of the fuel component in the blow-by gas flowing through the blow-by gas passage;
Means for detecting a running state of the vehicle as an execution condition of fuel cut control of the internal combustion engine;
Means for controlling the control valve so as to have a degree of restriction according to the state of the internal combustion engine when at least the execution condition is not satisfied;
When it is determined that the detected fuel concentration is higher than a predetermined concentration, the running state of the vehicle satisfies the execution condition, and the degree of the detected purification capacity is high, the blow-by And a control means for controlling the control valve so that the restriction of the gas flow rate is less than the degree of restriction according to the state of the internal combustion engine. The detection means detects the oxygen concentration of the exhaust gas that has passed through the catalyst,
The vehicle control according to claim 1, wherein the control device further includes means for determining that the purification capacity of the catalyst is high when the detected oxygen concentration is higher than a predetermined concentration. apparatus.   When the detected fuel concentration is larger than a predetermined concentration, satisfies the execution condition, and the detected oxygen concentration is equal to or lower than a predetermined concentration, the control device The vehicle control device according to claim 2, further comprising means for controlling the control valve such that the restriction of the gas flow rate is made stronger than the degree of restriction according to the state of the internal combustion engine. The detection means includes
Means for detecting the oxygen concentration of the exhaust gas that has passed through the catalyst;
Means for detecting a physical quantity related to the temperature of the catalyst,
When the oxygen concentration is higher than a predetermined concentration and the temperature of the catalyst based on the detected physical quantity is equal to or higher than a predetermined temperature, the control device The vehicle control device according to claim 1, further comprising means for determining that the purification capacity of the catalyst is high.   The control device is configured such that the detected fuel concentration is larger than a predetermined concentration, satisfies the execution condition, the oxygen concentration is equal to or lower than a predetermined concentration, and is equal to the detected physical quantity. When it is determined that the temperature of the catalyst based on the temperature is equal to or higher than a predetermined temperature, the control of the restriction of the flow rate of the blow-by gas is made to be stronger than the degree of restriction according to the state of the internal combustion engine. The vehicle control apparatus according to claim 4, further comprising means for controlling the valve.   When the temperature of the catalyst based on the detected physical quantity is lower than the predetermined temperature, the control device controls the control valve so as to be limited according to the state of the internal combustion engine. The vehicle control device according to claim 5, further comprising means for   The control device further includes means for controlling the control valve so as to be limited to a degree according to the state of the internal combustion engine when the detected fuel concentration is equal to or lower than the predetermined concentration. The vehicle control device according to any one of claims 1 to 6.   The vehicle control device according to claim 1, wherein the internal combustion engine is provided with a fuel injection device that injects fuel directly into at least the cylinder.   The vehicle control device according to any one of claims 1 to 8, wherein the internal combustion engine is operated by a fuel including at least one of alcohol and gasoline. A control method for a vehicle equipped with an internal combustion engine, wherein the internal combustion engine includes a cylinder, an intake passage for introducing air into the cylinder, and a blow-by gas passage for reducing blow-by gas generated in the cylinder to the intake passage. A control valve that is provided in the blow-by gas passage and restricts the flow rate of the blow-by gas to the intake passage according to the state of the internal combustion engine; and an exhaust passage through which the exhaust gas discharged from the cylinder flows. A catalyst provided in the middle of the exhaust passage and purifying the exhaust gas by an oxidation reaction;
A detection step for detecting the degree of purification capacity of the catalyst;
Detecting the concentration of the fuel component in the blow-by gas flowing through the blow-by gas passage;
Detecting a running state of the vehicle that is an execution condition of fuel cut control of the internal combustion engine;
Controlling the control valve so as to have a degree of restriction according to the state of the internal combustion engine when at least the execution condition is not satisfied;
When it is determined that the detected fuel concentration is higher than a predetermined concentration, the running state of the vehicle satisfies the execution condition, and the degree of the detected purification capacity is high, the blow-by And a control step of controlling the control valve so that the restriction of the gas flow rate is less than the degree of restriction according to the state of the internal combustion engine. The detection step detects an oxygen concentration of exhaust gas that has passed through the catalyst,
The vehicle control method according to claim 10, wherein the control method further includes a step of determining that the purification capacity of the catalyst is high when the detected oxygen concentration is higher than a predetermined concentration.   When the detected fuel concentration is greater than a predetermined concentration, the execution condition is satisfied, and the detected oxygen concentration is equal to or lower than a predetermined concentration, the blow-by is performed. The vehicle control method according to claim 11, further comprising a step of controlling the control valve so that the restriction of the gas flow rate is made stronger than the degree of restriction according to the state of the internal combustion engine. The detecting step includes
Detecting the oxygen concentration of the exhaust gas that has passed through the catalyst;
Detecting a physical quantity related to the temperature of the catalyst,
In the control method, when the oxygen concentration is higher than a predetermined concentration and the temperature of the catalyst based on the detected physical quantity is equal to or higher than a predetermined temperature, The vehicle control method according to claim 10, further comprising a step of determining that the purification capacity of the catalyst is high.   In the control method, the detected fuel concentration is greater than a predetermined concentration, satisfies the execution condition, the oxygen concentration is equal to or lower than a predetermined concentration, and is equal to the detected physical quantity. When it is determined that the temperature of the catalyst based on the temperature is equal to or higher than a predetermined temperature, the control of the restriction of the flow rate of the blow-by gas is made to be stronger than the degree of restriction according to the state of the internal combustion engine. The vehicle control method according to claim 13, further comprising a step of controlling the valve.   In the control method, the control valve is controlled so as to be limited according to the state of the internal combustion engine when the temperature of the catalyst based on the detected physical quantity is lower than the predetermined temperature. The vehicle control method according to claim 14, further comprising a step.   The control method further includes a step of controlling the control valve so as to be limited to a degree according to a state of the internal combustion engine when the detected fuel concentration is equal to or less than the predetermined concentration. The vehicle control method according to claim 10.   The vehicle control method according to claim 10, wherein the internal combustion engine is provided with a fuel injection device that injects fuel directly into at least the cylinder.   The vehicle control method according to claim 10, wherein the internal combustion engine is operated by a fuel containing at least one of alcohol and gasoline.

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