49results about How to "Deterioration in fuel economy" patented technology

A hydraulic control apparatus includes a continuously-variable transmission; a line-pressure control section configured to produce a line pressure by adjusting a discharge pressure of an oil pump; a first hydraulic-pressure control section configured to adjust a first hydraulic pressure based on the line pressure, the first hydraulic pressure being supplied to the drive pulleys; and a second hydraulic-pressure control section configured to adjust a second hydraulic pressure based on the line pressure, the second hydraulic pressure being supplied to the driven pulleys. The continuously-variable transmission includes a pair of drive pulleys including a first movable pulley and a first fixed pulley; a pair of driven pulleys including a second movable pulley and a second fixed pulley; and a belt wound between the pair of drive pulleys and the pair of driven pulleys. The line-pressure control section is configured to adjust the line pressure to a value set by adding a margin pressure to higher one of the first hydraulic pressure and the second hydraulic-pressure, and configured to reduce the margin pressure when the first hydraulic pressure is higher than the second hydraulic pressure.

The evaluation system for vehicle operating conditions comprises an automatic control device (10, 27) for setting target vehicle operating conditions and controlling the vehicle so as to achieve the target operating conditions, and a display device (4) mounted on the vehicle. The system determines whether operation that worsens fuel economy has been performed or not on the basis of the operating conditions of the vehicle; determines the operating state of the automatic control device (10, 27) based on the operating conditions of the vehicle; computes the excess fuel consumption, which is the fuel amount consumed in excess by operation that worsens the fuel economy, based on operating conditions of the vehicle and the operating state of the automatic control device (10, 27); and displays the computed excess fuel consumption to the display device (4).

The evaluation system for vehicle operating conditions comprises an automatic control device (10, 27) for setting target vehicle operating conditions and controlling the vehicle so as to achieve the target operating conditions, and a display device (4) mounted on the vehicle. The system determines whether operation that worsens fuel economy has been performed or not on the basis of the operating conditions of the vehicle; determines the operating state of the automatic control device (10, 27) based on the operating conditions of the vehicle; computes the excess fuel consumption, which is the fuel amount consumed in excess by operation that worsens the fuel economy, based on operating conditions of the vehicle and the operating state of the automatic control device (10, 27); and displays the computed excess fuel consumption to the display device (4).

In a motor vehicle of the invention, when an intake air temperature Ta is not lower than a preset reference temperature Tref, warm-up drive control selectively uses an evaporated fuel processing acceleration operation curve, which gives a high level of a negative pressure in an intake manifold, to set a target drive point of an engine and controls the operation of the engine. This ensures good emission of the engine. When the intake air temperature Ta is lower than the preset reference temperature Tref and when the setting of a heating demand Hq requires heating, on the other hand, the warm-up drive control increases an EGR quantity from an ordinary level and switches over an operation mode of a cooling system for the engine to a warm-up circulation mode for making the flow of a cooling medium bypass a radiator. This introduces a greater amount of heat of exhaust into a heat exchanger to enable quick supply of the warm air to a passenger compartment. The warm-up drive control selectively uses a negative pressure reduction operation curve, which gives a lower level of the negative pressure in the intake manifold than the level of the negative pressure set on the evaporated fuel processing acceleration operation curve, to set the target drive point of the engine and controls the operation of the engine. This enhances the operation efficiency of the engine and improves the fuel economy during the warm-up time of the engine.

A control apparatus for a vehicular 4-wheel drive system provided with: primary drive wheels to which a drive force is transmitted from a drive power source; auxiliary drive wheels to which the drive force is selectively transmitted; a first clutch configured to selectively place a first power transmitting path in a power transmitting state and a power cutoff state; and a second clutch disposed in a second power transmitting path to selectively place the second power transmitting path in a power transmitting state and a power cutoff state. The first and second clutches are placed in fully released states to establish a 2-wheel drive mode. The control apparatus includes a first-clutch control portion configured to bring the first clutch into a partially engaged state when a predetermined condition in which the vehicular 4-wheel drive system generates or is considered to generate a noise is satisfied in the 2-wheel drive mode.

A fuel cell system in which fuel gas and oxidizing gas are supplied to a fuel cell stack and power generation is performed by electrochemical reaction between the fuel gas and the oxidizing gas, and a control method thereof are provided. This fuel cell system includes a fuel gas supply manifold which is extended in a unit cell stacking direction and which distributes the fuel gas to a fuel gas passage; a switching device which is provided inside the fuel gas supply manifold, and which switches between permission and prohibition of distribution of the fuel gas to the fuel gas passage of each of the unit cells; a load disconnect device which disconnects an output terminal of the stack from a load; a short-circuit device which short-circuits a positive electrode and a negative electrode of the output terminal of the stack; and a control device which short-circuits the positive electrode and the negative electrode of the output terminal by the short-circuit device after distribution of the fuel gas to the fuel gas passage of each of the unit cells is prohibited by the switching device when the output terminal is disconnected from the load by the load disconnect device.

An exhaust gas purification system includes an oxygen mass flow rate detecting unit for detecting or calculating a mass flow rate of oxygen fed to a filter and a regeneration end determining unit for determining a regeneration end of the filter in accordance with information provided from the oxygen mass flow rate detecting-unit and upon arrival of an integrated value of the oxygen mass flow rate at a predetermined value during regeneration of the filter.

In control apparatus and method for an internal combustion engine, a first cylinder group in which both of intake and exhaust valves of each of engine cylinders thereof are controllably stopped is provided, second cylinder group in which a lift of the intake valve of each of the engine cylinders thereof is variably controlled is provided, and the lift of the intake valve of each of the engine cylinders of the second cylinder group is controlled n order for an engine torque when the intake and exhaust valves of each of the cylinders of the first cylinder group are controlled to be stopped to be approximately equal to the engine torque by means of the first cylinder group and the second cylinder group before the intake and exhaust valves of each of the cylinders of the first cylinder group are controlled to be stopped.

There is provided a driving force control apparatus for an automotive vehicle, including an internal combustion engine to rotate main drive wheels of the vehicle by engine torque, a generator driven by the engine; a motor powered by the generator to rotate subsidiary drive wheels of the vehicle by motor torque in a four-wheel drive state, a detecting section to detect a vehicle start failure under which the vehicle has failed to make a start in response to a vehicle starting operation in the four-wheel drive state, and a motor torque characteristic changing section to change a target torque characteristic of the motor to a higher level so as to increase the motor torque upon detection of the vehicle start failure.

Provided is an exhaust emission control device for an internal combustion engine capable of preventing NOx purification performance from degrading according to the operating condition. The exhaust emission control device comprises a NOx purification catalyst, a catalytic converter for continuously reducing the NOx in the exhaust emissions, a fuel reformer for reforming fuel to manufacture a reformed gas and supplying the reformed gas as the reducing gas from the upstream side of the NOx purification catalyst and the catalytic converter of the exhaust pipe, an operating condition detecting means for detecting the operating condition of an engine, and an enriching means for enriching the exhaust air-fuel ratio. The enriching means enriches the exhaust air-fuel ratio by supplying the reducing gas into the exhaust pipe by using the fuel reformer when the operating condition detected by the operating condition detecting means is a high-load operating condition.

A control system for a hybrid vehicle includes an engine and a motor as driving sources, and a controller. The controller reduces at least one of the engine driving force and the motor driving force in response to a request for deceleration of the vehicle, such that the proportion of the amount of reduction of the engine driving force and the amount of reduction of the motor driving force is changed, according to a request for re-acceleration of the vehicle.

An operation point of the engine where the fuel economy is optimal is obtained based on an iso-fuel-economy curve which is defined by engine speed and engine torque. Each of the operation points is connected to each other to form an efficiency characteristic line on which the demand operation point is computed. When the operation point of the engine is moved in a direction in which the fuel economy is improved, the moving speed of the operation point is increased so that the operation point rapidly moves to the point of high fuel economy as soon as possible. Contrary, when the operation point moves in a direction where the fuel economy is deteriorated, the moving speed of the operation point of the engine is decreased so that the operation point can be moved toward the point of low fuel economy as slow as possible.

To determine whether an exhaust gas purification catalyst (42) of an engine (1) has deteriorated, a characteristic of exhaust gas on an upstream side of the catalyst (42) is detected, a characteristic of the exhaust gas on a downstream side of the catalyst (42) is detected, and when the engine (1) operates at a lean air-fuel ratio, a value expressing a difference in the oxygen concentration on the upstream side and downstream side of the catalyst (42) (an average excess air ratio difference) is calculated from the two detected values. When the value expressing the difference in the oxygen concentration is smaller than a deterioration determination threshold calculated in accordance with a quantity of state of the catalyst (42), the catalyst (42) is determined to have deteriorated.

An operation point of the engine where the fuel economy is optimal is obtained based on an iso-fuel-economy curve which is defined by engine speed and engine torque. Each of the operation points is connected to each other to form an efficiency characteristic line on which the demand operation point is computed. When the operation point of the engine is moved in a direction in which the fuel economy is improved, the moving speed of the operation point is increased so that the operation point rapidly moves to the point of high fuel economy as soon as possible. Contrary, when the operation point moves in a direction where the fuel economy is deteriorated, the moving speed of the operation point of the engine is decreased so that the operation point can be moved toward the point of low fuel economy as slow as possible.

When an automatic transmission is in a manual mode, a transmission ECU calculates a speed sftrng manually requested by the driver and a speed sftrngmap set by a shift map and then performs a shift prohibition procedure. In this procedure, if the engine coolant temperature is equal to or lower than a predetermined coolant temperature or the AT fluid temperature is equal to or lower than a predetermined fluid temperature, a prohibition, determination flag xthlow is set to “on”, and if the engine coolant temperature is higher than the predetermined coolant temperature and the AT fluid temperature is higher than the predetermined fluid temperature, the prohibition determination flag xthlow is set to “off”. When the prohibitions determination flag xthlow is “on”, the speed sftrngmap is set as the upper limit of the speed sftrng.

In a motor vehicle, when an intake air temperature Ta is not lower than a preset reference temperature Tref, warm-up drive control selectively uses an evaporated fuel processing acceleration operation curve, which gives a high level of a negative pressure in an intake manifold, to set a target drive point of an engine and controls the operation of the engine. This ensures good emission of the engine. When the intake air temperature Ta is lower than the preset reference temperature Tref and when the setting of a heating demand Hq requires heating, on the other hand, the warm-up drive control increases an EGR quantity from an ordinary level and switches over an operation mode of a cooling system for the engine to a warm-up circulation mode for making the flow of a cooling medium bypass a radiator.

To determine whether an exhaust gas purification catalyst (42) of an engine (1) has deteriorated, a characteristic of exhaust gas on an upstream side of the catalyst (42) is detected, a characteristic of the exhaust gas on a downstream side of the catalyst (42) is detected, and when the engine (1) operates at a lean air-fuel ratio, a value expressing a difference in the oxygen concentration on the upstream side and downstream side of the catalyst (42) (an average excess air ratio difference) is calculated from the two detected values. When the value expressing the difference in the oxygen concentration is smaller than a deterioration determination threshold calculated in accordance with a quantity of state of the catalyst (42), the catalyst (42) is determined to have deteriorated.

The internal combustion engine control apparatus of the invention starts gradually delaying an ignition timing θ for catalyst warm-up, immediately after a start of an internal combustion engine. When the ignition timing θ is delayed to or below a preset reference timing θref, a fuel amount increase flag F1 is set to 1 to start increase correction of a fuel injection amount. The internal combustion engine control apparatus then starts gradually increasing a throttle opening TH to a preset target opening THset. The increase correction of the fuel injection amount is terminated after elapse of a preset time t3 since the increase of the throttle opening TH to the preset target opening THset. This arrangement enables the increase correction of the fuel injection amount according to the requirement, thus improving the fuel economy and the emission.

A fuel cell system in which fuel gas and oxidizing gas are supplied to a fuel cell stack and power generation is performed by electrochemical reaction between the fuel gas and the oxidizing gas, and a control method thereof are provided. This fuel cell system includes a fuel gas supply manifold which is extended in a unit cell stacking direction and which distributes the fuel gas to a fuel gas passage; a switching device which is provided inside the fuel gas supply manifold, and which switches between permission and prohibition of distribution of the fuel gas to the fuel gas passage of each of the unit cells; a load disconnect device which disconnects an output terminal of the stack from a load; a short-circuit device which short-circuits a positive electrode and a negative electrode of the output terminal of the stack; and a control device which short-circuits the positive electrode and the negative electrode of the output terminal by the short-circuit device after distribution of the fuel gas to the fuel gas passage of each of the unit cells is prohibited by the switching device when the output terminal is disconnected from the load by the load disconnect device.

An automatic transmission includes a first planetary gear set; a second planetary gear set; a third planetary gear set; an input shaft; an output shaft; and five friction elements. A second ring gear is constantly locked. A first carrier is connected with a third carrier to define a first rotating member, and a second sun gear is connected with a third sun gear to define a second rotating member. The input shaft is constantly connected with a first sun gear, and the output shaft is constantly connected with the first rotating member. The five friction elements include a first friction element adapted to selectively connect a first ring gear with a second carrier, a second friction element adapted to selectively connect the first ring gear with the second rotating member, a third friction element adapted to selectively connect the second carrier with a third ring gear, a fourth friction element adapted to selectively stop a rotation of the third ring gear, and a fifth friction element adapted to selectively connect the first sun gear with the second carrier. Each of at least seven forward speed-ratios and one reverse speed-ratio is achieved by an engaged state of two friction elements selected from the five friction elements.

A control apparatus for a power unit equipped with an internal combustion engine and outputs a power. The control apparatus according to the invention starts engine operation when the required power becomes equal to or larger than an engine start threshold during engine stop, and stops engine operation when the required power becomes equal to or smaller than an engine stop threshold during engine operation. The internal combustion engine is equipped with a catalyst. When the purification capacity of the catalyst is lower than a start threshold correction threshold, a value smaller than a reference engine start threshold is set as the engine start threshold. When the purification capacity of the catalyst is equal to or higher than the start threshold correction threshold, a value equal to the reference engine start threshold or a value larger than the reference engine start threshold is set as the engine start threshold.

An engine is stopped after a battery is charged by a first motor-generator driven by the engine when a condition in which freezing of condensed water in an exhaust pipe is expected to occur is satisfied after an ignition switch is turned OFF. By the engine operated during the charging of the battery, the condensed water accumulated in the exhaust pipe can be discharged to the outside of the exhaust pipe by the exhaust pressure of the exhaust gas. Accordingly, the condensed water is unlikely to remain in the exhaust pipe, and the freezing of the condensed water in the exhaust pipe can be suppressed even when parking continues for long under a low temperature atmosphere. The battery is charged by the first motor-generator, and thus the electric power of the battery can be used for traveling of a vehicle and fuel economy deterioration can be suppressed.

In a control apparatus for an internal combustion engine, The ignition timing in a rich-cylinder is corrected toward a retardation side from a theoretical-MBT such that the torque generated in the rich-cylinder exceeds a torque generated in the rich-cylinder at the theoretical-MBT, and the ignition timing in a lean-cylinder is corrected toward an advancement side from the theoretical-MBT such that the torque generated in the lean-cylinder exceeds a torque generated in the lean-cylinder at the theoretical-MBT, when a temperature raising process is being executed, and the ignition timing in the rich-cylinder is corrected further toward the retardation side such that the torque generated in the rich-cylinder becomes equal to or smaller than a maximum theoretical generated torque and equal to or larger than the torque generated in the lean-cylinder at the theoretical-MBT, when the temperature raising process is being executed and the engine is in a low-load operating state.

When an automatic transmission is in a manual mode, a transmission ECU calculates a speed sftrng manually requested by the driver and a speed sftrngmap set by a shift map and then performs a shift prohibition procedure. In this procedure, if the engine coolant temperature is equal to or lower than a predetermined coolant temperature or the AT fluid temperature is equal to or lower than a predetermined fluid temperature, a prohibition, determination flag xthlow is set to “on”, and if the engine coolant temperature is higher than the predetermined coolant temperature and the AT fluid temperature is higher than the predetermined fluid temperature, the prohibition determination flag xthlow is set to “off”. When the prohibitions determination flag xthlow is “on”, the speed sftrngmap is set as the upper limit of the speed sftrng.

To determine whether an exhaust gas purification catalyst (42) of an engine (1) has deteriorated, first deterioration of the catalyst (42) is determined on the basis of an excess air ratio difference, which is a value expressing a difference in the oxygen concentration on the upstream side and downstream side of the catalyst (42). When the catalyst (42) is determined to have deteriorated on the basis of the excess air ratio difference, the air-fuel ratio of the engine (1) is feedback-controlled to a stoichiometric air-fuel ratio, and deterioration of the catalyst (42) is determined again on the basis of a value expressing a difference in the air-fuel ratio variation on the upstream side and downstream side of the catalyst (42) at that time.

An automatic transmission includes a first planetary gear set; a second planetary gear set; a third planetary gear set; an input shaft; an output shaft; and five friction elements. A first ring gear is constantly locked. A third sun gear is connected with a first sun gear to define a first rotating member, and a second sun gear is connected with a first carrier to define a second rotating member. The input shaft is constantly connected with the first rotating member, and the output shaft is constantly connected with a third carrier. The five friction elements include a first friction element adapted to selectively connect a second ring gear with a third ring gear, a second friction element adapted to stop a rotation of a second carrier, a third friction element adapted to selectively connect the second carrier with the third ring gear, a fourth friction element adapted to selectively connect the second ring gear with the third carrier, and a fifth friction element adapted to selectively connect the first rotating member with the second carrier. Each of at least seven forward speed-ratios and one reverse speed-ratio is achieved by an engaged state of two friction elements selected from the five friction elements.

A controller controls a continuously variable transmission including a variator with a primary pulley, a secondary pulley, and a power transmission member mounted therebetween. A torque converter is provided with a rotational speed detector detecting the rotational speed of a rotor located closer to drive wheels than the torque converter, a rotational speed change amount calculator calculating a change amount in the rotational speed per unit time, a limit setting unit that sets a higher absolute value of a limiter for the change amount as a rotational speed difference between an input shaft and an output shaft of the torque converter increases, a final change amount setting unit setting the smaller of the absolute value of the change amount and of the limiter as a final change amount, and a hydraulic controller controlling a hydraulic pressure to the variator based on the final change amount.