JP2000257452A - Exhaust valve failure diagnosis device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration of drivability caused by diagnosis by diagnosing an exhaust valve by controlling opening of the valve, when an internal combustion engine is operating and fuel injection is stopped. SOLUTION: An adsorption mechanism 15, which is disposed in an exhaust pipe 11 has ring-shaped adsorbent 152 interposed between an outer tube 150 with a major diameter and an intermediate tube 151 with a minor diameter. An upstream exhaust pipe 11a is connected to the outer tube 150, and a downstream exhaust pipe 11b is inserted into the intermediate tube 151. A valve system 160 is disposed at the end portion on upstream of the intermediate tube 151 as an exhaust valve, to control exhaust air flow rate. In diagnosing the valve system 160, collection of data to be used as a parameter for diagnosing is started, when charging condition of a battery is satisfactory at vehicle start and when vehicle is decelerating or braking. If the change rate of intake air amount is less than a standard change rate, when the condition of the valve system 160 is controlled from a fully open state to a fully closed state, the valve system 160 is decided as being abnormal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a technique for diagnosing a failure of a valve mechanism provided in an exhaust passage of an internal combustion engine.

[0002]

2. Description of the Related Art With respect to an internal combustion engine mounted on an automobile, there has been proposed a technique of providing a valve mechanism for various purposes in an exhaust passage in an exhaust purification system, a supercharging system, an exhaust brake system, or the like.

As a valve mechanism used in an exhaust gas purification system, for example, a bypass passage bypassing a part of an exhaust passage, and a three-way catalyst, an unburned fuel component adsorbent, a storage reduction NO _In an exhaust gas purification system provided with an exhaust gas purification mechanism such as an _X catalyst or a diesel particulate filter (DPF), an exhaust valve provided to switch the flow of exhaust gas to an exhaust passage and a bypass passage is known. I have.

The valve mechanism used in the supercharging system is, for example, a turbine housing provided in an exhaust passage of an internal combustion engine and containing a turbine wheel that rotates by the pressure of exhaust gas, and a valve mechanism provided in an intake passage of the internal combustion engine. In a turbocharger system including a compressor housing containing a compressor wheel that rotates integrally with a turbine wheel and a bypass passage communicating an exhaust passage upstream of the turbine wheel and an exhaust passage downstream of the turbine wheel, the bypass passage is opened and closed. A wastegate valve provided for the purpose is known.

[0005] As a valve mechanism used in an exhaust brake system, for example, an exhaust throttle valve provided in an exhaust passage to reduce an exhaust flow rate in an exhaust passage during braking of a vehicle is known.

Incidentally, in the various valve mechanisms as described above, there is a risk that unburned fuel components and carbon contained in the exhaust gas adhere to each other, or exhaust gas leaks due to deformation and wear of the valve element due to heat of the exhaust gas. Therefore, it is also important to accurately determine the failure of the valve mechanism.

In response to such a demand, a diagnostic device for an exhaust gas purifying device described in Japanese Patent Application Laid-Open No. 8-334014 is conventionally known. This diagnostic apparatus is configured such that a passage having a higher exhaust resistance of the exhaust passage and the bypass passage is fully closed from a fully closed state, in other words, a passage having a lower exhaust resistance of the exhaust passage and the bypass passage is fully opened from a fully opened state. The exhaust valve is operated to be closed, and a failure of the exhaust valve is diagnosed based on a change in the intake pipe pressure at that time.

That is, in the above-described diagnostic apparatus, when the exhaust valve is normal, the back pressure increases due to the opening / closing operation of the exhaust valve, whereby the intake pipe pressure changes to the atmosphere side.
This is based on the finding that when the exhaust valve is out of order, the change in the back pressure is reduced even if control is performed to open and close the exhaust valve, and the change in the intake pipe pressure is reduced accordingly.

[0009]

By the way, in the diagnostic apparatus described in the above-mentioned Japanese Patent Application Laid-Open No. 8-334014, the torque output from the internal combustion engine during the operation of the internal combustion engine, that is, the driving force of the vehicle is reduced. When the internal combustion engine is used as an engine, the operating state of the internal combustion engine fluctuates due to the change in back pressure caused by the opening / closing operation of the exhaust valve. This may have an adverse effect on driving stability.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has been made in consideration of the above-described problems. In a vehicle equipped with an internal combustion engine having a valve mechanism in an exhaust passage, failure diagnosis of the valve mechanism is performed without affecting the running state of the vehicle. An object of the present invention is to provide a technology capable of performing the above-mentioned, thereby preventing deterioration of drivability caused by a failure diagnosis.

[0011]

The present invention employs the following means in order to solve the above-mentioned problems. That is,
An exhaust valve failure diagnosis device for an internal combustion engine according to the present invention includes an exhaust valve provided in an exhaust passage of the internal combustion engine for adjusting an exhaust flow rate in the exhaust passage, wherein the internal combustion engine is in an engine rotation state and a fuel injection stopped state. A failure diagnosis means for performing a failure diagnosis of the exhaust valve by controlling the opening and closing of the exhaust valve.

[0012] In the exhaust valve failure diagnosing apparatus configured as described above, the failure diagnosing means outputs the torque when the internal combustion engine is in the engine rotation state and the fuel injection is stopped, that is, the internal combustion engine substantially outputs torque. When it is not, the exhaust valve is opened and closed to perform a failure diagnosis of the exhaust valve.

In this case, even if the pressure in the exhaust passage changes due to the opening / closing operation of the exhaust valve related to the failure diagnosis, and the change in the exhaust pressure acts on the internal combustion engine as a change in the back pressure, the internal combustion engine substantially reduces the torque. , The opening and closing operation of the exhaust valve does not affect the running state of the vehicle.

The case where the internal combustion engine is in the engine rotation state and the fuel injection stopped state, that is, the case where the internal combustion engine does not substantially output torque is exemplified by the time of fuel cut control such as the time of vehicle deceleration. be able to.

Next, an exhaust valve failure diagnosis apparatus for an internal combustion engine according to the present invention includes a hybrid mechanism for selectively driving the power of the internal combustion engine and the power of an electric motor to drive a vehicle, and an exhaust passage of the internal combustion engine. An exhaust valve for adjusting an exhaust flow rate in the exhaust passage; and, when the internal combustion engine is in an engine rotation state and a fuel injection stopped state, controls opening and closing of the exhaust valve to diagnose a failure of the exhaust valve. And a failure diagnosing means to be executed.

This is because, in a hybrid vehicle having an auxiliary power source capable of driving the vehicle in addition to the internal combustion engine, when the vehicle is running only with the power of the auxiliary power source, the internal combustion engine is in an engine rotation state. In such a case, it is assumed that the fuel injection is stopped. In such a case, the exhaust valve failure diagnosis affects the traveling state of the vehicle by performing the exhaust valve failure diagnosis by controlling the opening and closing of the exhaust valve. This is because things are gone.

As the above-mentioned exhaust valve, for example, in an exhaust passage having a main exhaust passage communicating with an internal combustion engine and a bypass passage bypassing the main exhaust passage, exhaust gas to the main exhaust passage and the bypass passage is provided. An exhaust valve for switching the flow of the exhaust gas can be exemplified.

The failure diagnosing means may diagnose a failure of the exhaust valve based on a pressure change in the intake passage when the exhaust valve is controlled to open and close. Diagnosis of a failure of the exhaust valve may be based on a change in pressure in the exhaust passage, or diagnosis of a failure of the exhaust valve based on a change in temperature in the exhaust passage when the exhaust valve is controlled to open and close. It may be.

In a cold region, it is assumed that the exhaust valve freezes and sticks. In such a case, if the failure diagnosis of the exhaust valve is performed, it is determined that the exhaust valve is malfunctioning although it is normal. There is a risk of erroneous diagnosis. For this reason, the failure diagnosis means may execute the failure diagnosis of the exhaust valve a plurality of times in one traveling process from when the ignition is turned on to when it is turned off.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a specific embodiment of an exhaust valve failure diagnosis apparatus for an internal combustion engine according to the present invention will be described with reference to the drawings.

In this embodiment, a case where the present invention is applied to an internal combustion engine mounted on a hybrid vehicle will be described as an example. FIG. 1 is a diagram illustrating a schematic configuration of a hybrid mechanism mounted on a hybrid vehicle. The hybrid mechanism includes two driving sources, an internal combustion engine 100 and an electric motor (electric motor) 200.

The internal combustion engine 100 is a four-cycle four-cylinder gasoline engine. The internal combustion engine 100 includes an ignition plug 3 for igniting an air-fuel mixture in a combustion chamber of each cylinder 2.

An intake branch pipe 4 is connected to the internal combustion engine 100, and each branch pipe of the intake branch pipe 4 communicates with a combustion chamber of each cylinder 2 via an intake port (not shown). A fuel injection valve 9 having an injection hole facing an intake port is attached to each branch pipe of the intake branch pipe 4.

The intake branch pipe 4 is connected to a surge tank 5, and the surge tank 5 is connected to an intake pipe 6. In the middle of the intake pipe 6, a throttle valve 7 for adjusting the flow rate of intake air flowing through the intake pipe 6 is provided.

The throttle valve 7 is composed of a stepper motor or the like. The actuator 8 drives the opening and closing of the throttle valve 7 according to the magnitude of the applied current, and outputs an electric signal corresponding to the opening of the throttle valve 7. And a throttle position sensor 33 to be mounted.

The intake pipe 6 upstream of the throttle valve 7 is provided with an air flow meter 32 for outputting an electric signal corresponding to the mass of fresh air flowing through the intake pipe 6. On the other hand, an exhaust branch pipe 10 is connected to the internal combustion engine 100, and each branch pipe of the exhaust branch pipe 10 communicates with a combustion chamber of each cylinder 2 via an exhaust port (not shown). The exhaust branch pipe 10
Is connected to an exhaust pipe 11, and the exhaust pipe 11 is connected downstream to a muffler (not shown).

In the middle of the exhaust pipe 11, a three-way catalyst 12 is provided.
Is provided. The three-way catalyst 12 includes a ceramic carrier made of cordierite formed in a lattice shape having a plurality of through-holes along the flow direction of exhaust gas, and a catalyst layer coated on the surface of the ceramic carrier.

The catalyst layer is formed, for example, by supporting a platinum-rhodium (Pt-Rh) -based noble metal catalyst material on the surface of porous alumina (Al ₂ O ₃ ) having a large number of pores. .

The three-way catalyst 12 configured as described above is activated when the temperature is equal to or higher than a predetermined temperature (for example, 300 ° C.), and the air-fuel ratio of the inflowing exhaust gas is within a predetermined range (catalyst purification window) near the stoichiometric air-fuel ratio. , The hydrocarbons (H
C) and carbon monoxide (CO) react with oxygen (O ₂ ) in the exhaust gas to oxidize them into water (H ₂ O) and carbon dioxide (CO ₂ ), and at the same time, nitrogen oxides (NO _X ) in the exhaust gas. Reacts with hydrocarbons (HC) and carbon monoxide (CO) in the exhaust gas to reduce them to water (H ₂ O), carbon dioxide (CO ₂ ), and nitrogen (N ₂ ).

When the internal combustion engine 100 is a lean-burn internal combustion engine or a direct injection internal combustion engine capable of burning an air-fuel mixture in an excess oxygen state, or a diesel engine, the three-way catalyst 12 is replaced with NO. _X storage reduction catalyst and NO _X
A selective reduction catalyst or the like may be used.

An upstream air-fuel ratio sensor 13 for outputting an electric signal corresponding to the air-fuel ratio of the exhaust gas flowing into the three-way catalyst 12 is attached to the exhaust pipe 11 upstream of the three-way catalyst 12. A downstream air-fuel ratio sensor 14 that outputs an electric signal corresponding to the air-fuel ratio of the exhaust flowing out of the three-way catalyst 12 is attached to the exhaust pipe 11 downstream of the exhaust pipe 11.

The upstream air-fuel ratio sensor 13 and the downstream air-fuel ratio sensor 14 are, for example, zirconia (Zr
O ₂ ) is formed of a solid electrolyte portion fired into a cylindrical shape, an outer platinum electrode covering the outer surface of the solid electrolyte portion, and an inner platinum electrode covering the inner surface of the solid electrolyte portion, and a voltage is applied between the electrodes. In this case, the sensor outputs a current having a value proportional to the oxygen concentration in the exhaust gas (the concentration of the unburned fuel component when the ratio is richer than the stoichiometric air-fuel ratio) as the oxygen ions move.

The exhaust pipe 11 upstream of the upstream air-fuel ratio sensor 13 is provided with an adsorption mechanism 15. As shown in FIG. 2, the suction mechanism 15 has an outer cylinder 150 having an inner diameter larger than the outer diameter of the exhaust pipe 11, and an outer cylinder 150 having an inner diameter larger than the outer diameter of the exhaust pipe 11 and smaller than the inner diameter of the outer pipe 150. A middle cylinder 151 having a diameter, and an annular adsorbent 152 disposed between the middle cylinder 151 and the outer cylinder 150.
And

The exhaust pipe 11 is isolated in the outer cylinder 150 into an upstream exhaust pipe 11a and a downstream exhaust pipe 11b. The upstream exhaust pipe 11a and the downstream exhaust pipe 11
b is connected via the outer cylinder 150.

At this time, the downstream exhaust pipe 11b is held in the outer cylinder 150 such that the upstream open end protrudes into the outer cylinder 150, and the distal end thereof is a non-fixed end.
Corresponding to this, the middle cylinder 151 has one end of the middle cylinder 151, the outer cylinder 150, the exhaust pipe 11, or the valve device 16 described later.
0, and the other end of the middle cylinder 151 is not fixed to any of the outer cylinder 150, the exhaust pipe 11, and the valve device 160, and the upstream end of the middle cylinder 151 has the downstream exhaust. The outer cylinder 15 extends upstream from the upstream end of the pipe 11b.
It shall be kept within 0.

Since the temperature of the outer cylinder 150 tends to be lower than that of the middle cylinder 151 and the downstream exhaust pipe 11b, the outer cylinder 150 is fixed to the upstream exhaust pipe 11a and the downstream exhaust pipe 11b. In addition, both ends of the middle cylinder 151 or the upstream end of the downstream exhaust pipe 11b are directly connected to the outer cylinder 150 or the valve device 16.
0, the outer cylinder 150, the middle cylinder 15
This is because there is a possibility that the main suction mechanism 15 may be damaged due to a difference in thermal expansion between the first and the downstream exhaust pipes 11b, and this leads to a decrease in durability.

The adsorbent 152 comprises an outer cylinder 150 and a middle cylinder 1
51, so that a difference in thermal expansion between the outer cylinder 150 and the middle cylinder 151 due to a temperature difference between the outer cylinder 150 and the middle cylinder 151 can be allowed.

The middle cylinder 151 and the downstream exhaust pipe 11b
The holding members 153 are arranged at a plurality of places in the space 155 between them to improve the earthquake resistance of the downstream side exhaust pipe 11b.

The holding member 153 is fixed to only one of the inner wall of the middle cylinder 151 and the outer wall of the downstream exhaust pipe 11b, so that the middle cylinder 151 and the downstream exhaust pipe 11b are not fixed to each other. This makes it possible to absorb a difference in thermal expansion between the downstream exhaust pipe 11b and the middle cylinder 151 in the axial direction.

A valve device 160 for opening and closing the upstream end of the middle cylinder 151 is provided at the upstream end. The valve device 160 realizes the exhaust valve according to the present invention, and is configured by a butterfly type two-way valve as shown in FIG.

Specifically, the valve device 160 is provided with the middle cylinder 1
A housing 161 fitted to an upstream open end of the housing 51;
A passage 164 extending axially through the housing 161;
A valve body 162 for opening and closing the passage 164; and a shaft 163 attached to the valve body 162.

One end of the shaft 163 is rotatably supported by the housing 161.
Is connected to a bearing 1 provided on an outer wall of the outer cylinder 150.
65 rotatably supported.

The other end of the shaft 163 is connected to an actuator 166 via a link mechanism or the like. The actuator 166 includes a stepper motor or the like, and can open and close the shaft 163 and the valve body 162 according to the magnitude of the applied current.

In the suction mechanism 15 configured as described above,
When the three-way catalyst 12 is in the inactive state, the actuator 166 is controlled so that the valve element 162 of the valve device 160 is fully closed as shown in FIG.

In this case, the passage 1 is connected to the upstream exhaust pipe 11a.
Since the exhaust flow passage (main exhaust passage) communicating with the downstream exhaust pipe 11b via the pipe 64 becomes non-conductive, all of the exhaust flowing into the adsorption mechanism 15 from the upstream exhaust pipe 11a is Annular space 1 formed between outer cylinder 150
It is guided to 54 and passes through the adsorbent 152.

The exhaust gas passing through the adsorbent 152 collides with the inner wall of the outer cylinder 150 and changes its flow direction.
Annular space 1 formed between the air and the downstream exhaust pipe 11b
55.

The exhaust gas guided to the space 155 flows from the downstream side of the suction mechanism 15 to the upstream side in the space 155. The exhaust gas flowing through the space 155 is supplied to the valve device 16.
Thus, the gas flows into the downstream side exhaust pipe 11b by colliding with zero. Hereinafter, an exhaust passage communicating from the upstream exhaust pipe 11a to the downstream exhaust pipe 11b via the space 154 and the space 155 will be referred to as a bypass passage.

After the three-way catalyst 12 is activated, the actuator 166 is controlled so that the valve body 162 of the valve device 160 is fully closed as shown in FIG. In this case, in the adsorption mechanism 15, the main exhaust passage communicating from the upstream exhaust pipe 11a to the downstream exhaust pipe 11b via the passage 164 becomes conductive, and the space 154 extends from the upstream exhaust pipe 11a to the space 154.
In addition, the bypass passage communicating with the downstream exhaust pipe 11b via the space 155 becomes conductive.

Here, the suction mechanism 15 shown in this embodiment is used.
Is configured such that the exhaust resistance of the bypass passage is larger than the exhaust resistance of the main exhaust passage, so that the upstream exhaust pipe 11a
Most of the exhaust gas flowing into the adsorption mechanism 15 flows through the main exhaust passage, and the remaining exhaust gas flows through the bypass passage.

Returning now to FIG. 1, the internal combustion engine 100
A crank position sensor 17 that outputs a pulse signal every time the crankshaft 100a, which is the engine output shaft, rotates by a predetermined angle (for example, 30 degrees), and the temperature of cooling water flowing through a water jacket formed inside the internal combustion engine 100 And a water temperature sensor 18 for outputting an electric signal corresponding to the above.

Next, the crankshaft 100 a of the internal combustion engine 100 is connected to a power split device 19.
The power split mechanism 19 includes a generator 20 and an electric motor 2.
The rotation shaft (motor rotation shaft) 200a is mechanically connected to the rotation shaft 200a.

The power split mechanism 19 includes, for example, a planetary carrier that rotatably supports a pinion gear, a ring gear disposed outside the planetary carrier, and a sun gear disposed inside the planetary carrier. It is composed of gears (planetary gears)
The rotation shaft of the planetary carrier is an engine output shaft 100a.
And the rotating shaft of the ring gear is a motor rotating shaft 2
00a, and the rotation shaft of the sun gear is connected to the generator 20
Is linked to

The motor rotating shaft 20 of the electric motor 200
A speed reducer 21 is connected to Oa, and wheels 24 and 25 as drive wheels are connected to the speed reducer 21 via drive shafts 22 and 23. The reduction gear 21 is configured by combining a plurality of gears, and
00a, the drive shaft 22, 2
3

The generator 20 is electrically connected to an inverter 26, and the inverter 26 is electrically connected to a battery 27 and an electric motor 200. The generator 20 is constituted by an AC synchronous motor, and when an exciting current is applied, kinetic energy input from the internal combustion engine 100 via the power split device 19 is converted into electric energy to generate electric power. Do. In addition, the generator 2
When the driving power from the battery 27 is applied at the time of starting the internal combustion engine 100, the reference numeral 0 functions as a starter motor of the internal combustion engine 100.

The battery 27 is configured by connecting a plurality of nickel-metal hydride batteries in series. The battery 27 has a charge state (State Of Cha) based on the integrated value of the discharge current and the charge current of the battery 27.
rge) is attached.

The electric motor 200 is constituted by an AC synchronous motor, and when the electric power generated by the generator 20 and / or the electric power of the battery 27 is applied, the electric motor 200 generates a torque corresponding to the magnitude of the applied electric power. The motor rotation shaft 200a is driven to rotate. Further, when the vehicle is decelerated, the rotational torque of the wheels 24 and 25
2 and 23 and the motor rotation shaft 200a via the reduction gear 21
The regenerative power generation is performed by utilizing the information transmitted to

The inverter 26 is a power converter composed of a combination of a plurality of power transistors. The inverter 26 applies the power generated by the generator 20 to the battery 27 and controls the power generated by the generator 20. Motor 200
, The electric power stored in the battery 27 to the electric motor 200, and the electric power regenerated by the electric motor 200 to the battery 27 are selectively switched.

Here, since the generator 20 and the electric motor 200 are constituted by AC synchronous motors, the inverter 26 operates when the power generated by the generator 20 is applied to the battery 27. After converting the AC voltage generated at 20 into a DC voltage, it is applied to the battery 27,
When the electric power of the battery 27 is applied to the electric motor 200, the DC voltage of the battery 27 is converted into an AC voltage and then applied to the electric motor 200, and when the electric power regenerated by the electric motor 200 is applied to the battery 27, the electric power is applied. The AC voltage regenerated by the motor 200 is converted into a DC voltage and then applied to the battery 27.

The hybrid mechanism as described above has an electronic control unit (E-E) for controlling the internal combustion engine 100.
An ECU (ECU) 29 and an electronic control unit (H-ECU) 30 for comprehensively controlling the entire hybrid mechanism are provided.

The H-ECU 30 includes an accelerator position sensor 31 for outputting an electric signal corresponding to the operation amount of an accelerator pedal (not shown), and an SOC controller 28.
And an electrical wiring, and it is possible to input an output signal (accelerator opening signal) of the accelerator position sensor 31 and an output signal (a signal indicating the state of charge of the battery 27) of the SOC controller 28. .

The H-ECU 30 is connected to the generator 20, the inverter 26, and the electric motor 200 via electric wiring, and can control the generator 20, the inverter 26, and the electric motor 200. ing.
Further, the H-ECU 30 is connected to the E-ECU 29 by a communication line, and can transmit and receive signals to and from the E-ECU 29.

For example, the H-ECU 30 starts the internal combustion engine 100 when the ignition switch is switched from off to on. Specifically, the H-ECU 30
Controls the inverter 26 to apply the driving power from the battery 27 to the generator 20 to operate the generator 20 as a starter motor, and to operate the ignition plug 3, the throttle valve 7, and the fuel injection valve 9. E-EC
It controls U29.

In this case, in the power split device 19, while the sun gear connected to the generator 20 rotates, the wheels 2
Since the ring gears 4 and 25 are stopped, substantially all of the rotational torque of the sun gear is transmitted to the planetary carrier. Since the planetary carrier is connected to the crankshaft 100a of the internal combustion engine 100, when the planetary carrier rotates by receiving the rotational torque of the sun gear, the crankshaft 1
00a rotates. At that time, the cranking of the internal combustion engine 100 is realized by the E-ECU 29 operating the ignition plug 3, the throttle valve 7, and the fuel injection valve 9,
The internal combustion engine 100 is started.

When the temperature of the cooling water rises to a predetermined temperature or higher after the internal combustion engine 100 is started, the H-ECU 30
Deems that the warm-up of the internal combustion engine 100 has been completed, and
The operation of the internal combustion engine 100 is stopped via the CU 29.

When the vehicle is stopped with the ignition switch turned on, the H-ECU 30 controls the E-ECU 29 to stop the operation of the internal combustion engine 100 and stops the rotation of the electric motor 200. The inverter 26 is controlled in order to achieve this.

However, when the vehicle is stopped, an output signal of SOC controller 28 (a signal indicating the state of charge of battery 27).
Is less than a predetermined standard, when it is necessary to operate accessories that are driven by using a part of the torque output from the internal combustion engine 100, such as a compressor of an indoor air conditioner, Alternatively, when it is necessary to warm up the internal combustion engine 100 and the exhaust purification system, the internal combustion engine 100 is started.

When the vehicle starts, the HE
The CU 30 controls the inverter 26 to apply driving power from the battery 27 to the electric motor 200. When the driving power is supplied from the battery 27 to the electric motor 200, the motor rotating shaft 200a of the electric motor 200 rotates, and then the rotating torque of the motor rotating shaft 200a is reduced via the speed reducer 21 and the drive shafts 22 and 23 to the wheels 2.
4 and 25, and the vehicle starts.

In this case, in the power split device 19, the ring gear connected to the motor rotation shaft 200a is rotated, and the rotation torque of the ring gear is distributed to the sun gear and the planetary carrier.

The rotation torque transmitted from the ring gear to the planetary carrier is transmitted to a crankshaft 100a connected to the planetary carrier, and the internal combustion engine 100 rotates the crankshaft 100a when fuel injection is stopped. It becomes a ring state.

When the vehicle 27 starts moving, the state of charge of the battery 27 is not good, when it is necessary to operate auxiliary equipment such as an air conditioner compressor, or when the inner engine 1 or the exhaust purification system is warmed up. Is required, the H-ECU 30 starts the internal combustion engine 100.

When the internal combustion engine 100 is started when the vehicle starts, the H-ECU 30 controls the inverter 26 to apply an exciting current from the battery 27 to the generator 20.
The generator 20 is operated as a generator.

In this case, the crankshaft 100a is rotated by the torque output from the internal combustion engine 100.
The rotational torque of the crankshaft 100a is transmitted to the planetary carrier of the power split device 19, and is distributed from the planetary carrier to the sun gear and the ring gear.

The rotational torque distributed from the planetary carrier to the sun gear is transmitted to a generator 20 connected to the sun gear, and the generator 20 converts kinetic energy transmitted from the sun gear to electric energy. This generates electricity. The power generated by the generator 20 is distributed by the inverter 26 to the battery 27 and the electric motor 200.

The rotation torque distributed from the planetary carrier to the ring gear is transmitted to a motor rotation shaft 200a connected to the ring gear. As a result, the motor rotation shaft 200a rotates with a torque obtained by adding the torque output from the electric motor 200 and the rotation torque transmitted from the ring gear. The rotation torque of the motor rotation shaft 200a is transmitted to the wheels 24 and 25 via the reduction gear 21 and the drive shafts 22 and 23.

When the vehicle is in a normal running state,
The H-ECU 30 controls the E-ECU 29 so that the torque output from the internal combustion engine 100 becomes a desired target torque, stops the supply of drive power from the battery 27 to the electric motor 200, and generates power from the battery 27. Machine 2
The inverter 26 is controlled so as to apply the exciting current to zero.

More specifically, the H-ECU 30 determines a driving torque (hereinafter referred to as required driving) required by the driver from an output signal (accelerator opening) of an accelerator position sensor 31 and an output signal (vehicle speed) of a vehicle speed sensor (not shown). (Referred to as torque)
Is calculated to satisfy the required driving torque.
To be output (hereinafter referred to as required engine torque)
And a torque to be output by the electric motor 200 (hereinafter referred to as a required motor torque).

Subsequently, the H-ECU 30 transmits the required engine torque to the E-ECU 29 and controls the inverter 26 according to the required motor torque. At that time, H-
The ECU 30 controls the number of revolutions of the generator 20 by adjusting the magnitude of the exciting current applied to the generator 20,
Thereby, the engine speed of the internal combustion engine 100 is controlled.

Here, the H-ECU 30 to the E-ECU 2
The request engine torque transmitted to the internal combustion engine 1
It is a value using the intake air amount of 00 and the engine speed as parameters. In that case, the H-ECU 30 has a map indicating the relationship between the intake air amount, the engine speed, and the engine torque, and specifies the intake air amount and the engine speed corresponding to the desired engine torque from this map, The specified intake air amount and the engine speed are transmitted to the E-ECU 29 as the required engine torque.

The E-ECU 29 having received the required engine torque from the H-ECU 30 determines the throttle opening, the fuel injection amount, the fuel injection timing, and the ignition timing according to the required engine torque, and determines the actuator 8, the fuel injection valve, and the like. 2
6 and the spark plug 3 are controlled.

When the battery 27 needs to be charged during normal running of the vehicle, the H-ECU 30
E-ECU 29 to increase the torque output from
And the inverter 26 is controlled to increase the exciting current applied from the battery 27 to the generator 20, thereby increasing the amount of power generation while securing the required driving torque.

When the vehicle is accelerating, H-
The ECU 30 calculates the required driving torque, the required engine torque, and the required motor torque in the same manner as in the normal driving described above, then controls the internal combustion engine 100 via the E-ECU 29, and also controls the electric motor 2 via the inverter 26.
00 is controlled.

When controlling the inverter 26, the H-ECU 30 performs control so as to apply the electric power of the battery 27 to the electric motor 200 in addition to the electric power generated by the generator 20. Increased torque.

When the vehicle is in a decelerating state or a braking state, the H-ECU 30 controls the E-ECU 29 so as to stop the operation of the internal combustion engine 100 (stop the fuel injection control and the ignition control). , Generator 2
The inverter 26 is controlled to stop the operation of the electric motor 200 and the operation of the electric motor 200.

At this time, since the motor rotating shaft 200a is connected to the motor rotating shaft 200a via the drive shafts 22, 23 and the speed reducer 21, the motor rotating shaft 200a
0a rotates by receiving the rotational torque of the wheels 24 and 25. Therefore, the H-ECU 30
7 controls the inverter 26 to apply an exciting current to the electric motor 200, thereby causing the electric motor 200 to act as a generator to perform regenerative power generation. The electric power regenerated by the electric motor 200 is charged in the battery 27 via the inverter 26.

In this case, in the power split mechanism 19, the ring gear connected to the motor rotation shaft 200a rotates, and the rotation torque of the ring gear is distributed to the sun gear and the planetary carrier. The rotation torque transmitted from the ring gear to the planetary carrier is transmitted to the crankshaft 100a connected to the planetary carrier, so that the internal combustion engine 100 enters a motoring state.

Next, the E-ECU 29 includes an upstream air-fuel ratio sensor 13, a downstream air-fuel ratio sensor 14, a crank position sensor 17, a water temperature sensor 18, an air flow meter 32, and a throttle position sensor 33 via electric wiring. The output signals of the various sensors described above are input to the E-ECU 29.

The E-ECU 29 is connected to the ignition plug 3, the actuator 8, the fuel injection valve 9, and the valve device 160 (actuator 166) of the adsorption mechanism 15 via electric wiring. It is possible to transmit a control signal to

The E-ECU 29 determines the operating state of the internal combustion engine 100 using the output signals of the various sensors as parameters, and, based on the determined engine operating state, ignition control, throttle control, fuel injection control, and adsorption mechanism. 15 and the failure diagnosis control of the valve device 160 which is the gist of the present invention.

For example, in the fuel injection control, the E-ECU 2
9 determines the fuel injection amount (TAU) according to a fuel injection amount calculation formula as shown below. TAU = TP * FWL * (FAF + FG) * [FASE + FAE + FOTP + FDE (D)] * FFC + TAU
V (TP: basic injection amount, FWL: warm-up increase, FAF: air-fuel ratio feedback correction coefficient, FG: air-fuel ratio learning coefficient, FASE: increase after start, FAE: acceleration increase, FOTP: OTP increase, FDE (D): Deceleration increase (decrease), FFC: Fuel cut return correction coefficient, T
(AUV: invalid injection time) At that time, the E-ECU 29 determines the operating state of the internal combustion engine 100 using the output signal values of various sensors as parameters,
Based on the determined engine operation state and a map previously stored in a ROM or the like in the E-ECU 29, the above-described basic injection amount (TP), warm-up increase (FWL), and post-start increase (FA)
SE), acceleration increase (FAE), OTP increase (FOT)
P), deceleration increase (FDE (D)), fuel cut return correction coefficient (FFC), invalid injection time (TAUV), etc. are calculated.

The E-ECU 29 calculates the air-fuel ratio feedback correction coefficient (FAF) according to the following procedure. That is, the E-ECU 29 first determines whether the air-fuel ratio feedback control condition is satisfied.

The above-mentioned air-fuel ratio feedback control conditions include, for example, that the coolant temperature is equal to or higher than a predetermined temperature, that the internal combustion engine 100 is in a non-start state, that the fuel injection amount is not increased after start-up correction, The fuel injection amount warm-up increase correction is not executed, the fuel injection amount acceleration increase correction is not executed, and the OTP increase correction for preventing heating of exhaust system components such as the three-way catalyst 12 is not executed. Conditions such as a state, a state in which the fuel cut control is not executed, and the like can be exemplified.

If the above-described air-fuel ratio feedback control condition is not satisfied, the E-ECU 29 calculates the fuel injection amount (TAU) with the air-fuel ratio feedback correction coefficient (FAF) set to “1.0”.

On the other hand, when the above-described air-fuel ratio feedback control condition is satisfied, the E-ECU 29 inputs the output signal of the upstream air-fuel ratio sensor 13 and outputs the input output signal and the upstream air-fuel ratio sensor. It is determined whether the actual air-fuel ratio of the exhaust gas is leaner or richer than the stoichiometric air-fuel ratio based on the response delay time of No. 13.

If the E-ECU 29 determines that the actual exhaust air-fuel ratio is richer than the stoichiometric air-fuel ratio, the E-ECU 29 changes the value of the air-fuel ratio feedback correction coefficient (FAF) to reduce the fuel injection amount (TAU). If it is determined that the actual exhaust air-fuel ratio is leaner than the stoichiometric air-fuel ratio, the value of the air-fuel ratio feedback correction coefficient (FAF) is corrected to increase the fuel injection amount (TAU).

Subsequently, the E-ECU 29 performs an upper limit guard process and a lower limit guard process on the air-fuel ratio feedback correction coefficient (FAF) calculated in the above-described procedure, and outputs the air-fuel ratio feedback correction coefficient (FAF) after the guard process. The fuel injection amount (TAU) is calculated by substituting into the fuel injection amount calculation formula.

The E-ECU 29 controls the downstream air-fuel ratio sensor 14 in parallel with the air-fuel ratio feedback control (first air-fuel ratio feedback control) based on the output signal of the upstream air-fuel ratio sensor 13 as described above. The air-fuel ratio feedback control (second air-fuel ratio feedback control) may be executed based on the output signal.

In the second air-fuel ratio feedback control, for example, the E-ECU 29 compares the output signal value of the downstream air-fuel ratio sensor 14 with a predetermined reference voltage, and
It is determined whether the air-fuel ratio of the exhaust flowing out of the engine is lean or rich, and based on the result of the determination, a lean / rich determination reference value or an air-fuel ratio feedback correction coefficient in the first air-fuel ratio feedback control. (FAF)
Of the output characteristics of the upstream air-fuel ratio sensor 13 and the deterioration of the exhaust emission characteristics due to the change over time of the output characteristics of the upstream air-fuel ratio sensor 13 due to individual differences of the upstream air-fuel ratio sensor 13 are suppressed. I do.

Next, when controlling the valve device 160, the E-ECU 29 inputs an output signal (cooling water temperature) of the water temperature sensor 21 when the internal combustion engine 100 is started, and displays the output signal and a predetermined map. Based on the time required from the start of the internal combustion engine 100 to the activation of the three-way catalyst 12,
(Referred to as catalyst activation time).

The E-ECU 29 determines that the valve device 1 is in operation while the elapsed time from the start of the internal combustion engine 100 is shorter than the catalyst activation time, that is, while the three-way catalyst 12 is in the inactive state.
A control signal is output to the actuator 166 so as to bring the 60 valve bodies 162 into the fully closed state (the main exhaust passage in the suction mechanism 15 is in a non-conductive state).

At this time, all of the exhaust gas discharged from the internal combustion engine 100 flows into the three-way catalyst 12 via the bypass passage in the adsorption mechanism 15 and the adsorbent 152.
As a result, the unburned fuel components contained in the exhaust gas are adsorbed by the adsorbent 152 without being released to the atmosphere.

When the elapsed time from the start of the internal combustion engine 100 reaches the catalyst activation time or longer, that is, when the three-way catalyst 12 is activated, the E-ECU 29 sets the valve device 16
A control signal is output to the actuator 166 so as to bring the zero valve body 162 into a fully opened state (the main exhaust passage in the suction mechanism 15 is in a conducting state).

At this time, since both the main exhaust passage and the bypass passage are in a conductive state in the adsorption mechanism 15, the exhaust gas discharged from the internal combustion engine 100 passes through both the main exhaust passage and the bypass passage to be three-way. The harmful gas components in the exhaust gas flowing into the catalyst 12 are purified by the three-way catalyst 12.

In the suction mechanism 15 shown in the present embodiment, the exhaust inflow portion and the exhaust outflow portion of the bypass passage are arranged at close positions, so that the exhaust pressure near the exhaust inflow portion and the exhaust outflow portion The difference between the pulsation of the exhaust gas flowing through the main exhaust passage near the exhaust inflow portion and the pulsation of the exhaust gas flowing through the main exhaust passage near the exhaust outflow portion becomes small, as a result. Only a trace amount of the exhaust gas discharged from the internal combustion engine 100 flows into the three-way catalyst 12 through the bypass passage, and most of the other exhaust gas flows into the three-way catalyst 12 through the main exhaust passage. Will do.

As described above, when the flow rate in the bypass passage becomes extremely small, the amount of exhaust gas passing through the adsorbent 152 becomes correspondingly minimal, so that the rate of temperature rise of the adsorbent 152 becomes gentle, and The adsorbed unburned fuel component gradually desorbs little by little.

As a result, the amount of unburned fuel component introduced into the exhaust pipe 11 upstream of the three-way catalyst 12 from the adsorbent 152 via the bypass passage becomes extremely small, and the air-fuel ratio of the exhaust gas flowing into the three-way catalyst 12 is reduced. There is no excessive rich state that deviates from the catalyst purification window.

Therefore, the air-fuel ratio of the exhaust gas flowing into the three-way catalyst 12 is such that the three-way catalyst 12 can purify hydrocarbons (HC), carbon monoxide (CO) and nitrogen oxides (NO _x ). Without deviating from the window, the three-way catalyst 12
The unburned fuel components in the exhaust (unburned HC), carbon monoxide (CO), and it is possible to reliably purify nitrogen oxide (NO _X).

Hereinafter, the failure diagnosis control of the valve device 160, which is the gist of the present invention, will be described. In the present embodiment, E-
The ECU 29 controls the crankshaft 10 of the internal combustion engine 100.
0a is in a rotating state and the fuel injection from the fuel injection valve 9 is stopped, in other words, although the crankshaft 100a is rotating, the internal combustion engine 100 does not substantially output torque. At times, a failure diagnosis of the valve device 160 is performed.

Here, in the hybrid mechanism according to the present embodiment, when the vehicle starts moving, the operation of internal combustion engine 100 is stopped, and wheels 24 and 25 are driven only by the torque output from electric motor 200. At this time, since the rotational torque of the motor rotation shaft 200a is transmitted to the crankshaft 100a of the internal combustion engine 100 via the power split device 19, the internal combustion engine 100 enters a motoring state.

Further, in the hybrid mechanism according to the present embodiment, when the vehicle decelerates or brakes,
00 is stopped, and regenerative power generation in which the kinetic energy of the wheels 24 and 25 is converted into electric energy by the electric motor 200 is performed. At this time, since the rotation torque of the motor rotation shaft 200a is transmitted to the crankshaft 100a of the internal combustion engine 100 via the power split mechanism 19, the internal combustion engine 10
0 indicates a motoring state.

Therefore, in this embodiment, the E-ECU 2
Reference numeral 9 indicates that the failure diagnosis of the valve device 160 is performed when the vehicle starts and the state of charge of the battery 27 is good, and when the vehicle decelerates / brakes.

The failure diagnosis of the valve device 160 is performed by the E-ECU 2
9 is realized by executing a failure diagnosis control routine as shown in FIG. The failure diagnosis control routine includes:
This is an application program stored in advance in a ROM or the like (not shown) of the E-ECU 29, and is a routine that is repeatedly executed at predetermined time intervals when the ignition switch is on.

In the failure diagnosis control routine, E-EC
U29 first determines in S501 whether or not the vehicle is in a starting state. The E-ECU 29 performs the processing in S501
When it is determined that the vehicle is in the starting state in S50,
The process proceeds to S3, and if it is determined in S501 that the vehicle is not in the starting state, the process proceeds to S502.

In S502, the E-ECU 29 determines whether the vehicle is in a deceleration state or a braking state,
If it is determined that the vehicle is in the deceleration state or the braking state, the process proceeds to S503, and if it is determined that the vehicle is not in the deceleration state or the braking state, the execution of this routine is temporarily ended.

In S503, the E-ECU 29 determines whether the internal combustion engine 100 is in a motoring state.
That is, the E-ECU 29 determines whether it is necessary to charge the battery 27 using the torque of the internal combustion engine 100 when the vehicle is in the starting state or the deceleration / braking state,
Using the torque of the internal combustion engine 100, it is determined whether it is necessary to operate accessories such as an air conditioner compressor, and whether it is necessary to warm up the internal combustion engine 100.

When the vehicle is in the starting state or the deceleration / braking state in S503, it is necessary to charge the battery 27 using the torque of the internal combustion engine 100. If it is determined that it is necessary to operate auxiliary equipment such as a compressor for a conditioner, or that it is necessary to warm up the internal combustion engine 100, the E-ECU 29 determines that the internal combustion engine 100 is not in the motoring state. It is assumed that the execution of this routine is temporarily terminated.

On the other hand, when the vehicle is in the starting state or the deceleration / braking state in S503, it is not necessary to charge the battery 27 using the torque of the internal combustion engine 100, and the torque of the internal combustion engine 100 is used. If it is determined that there is no need to operate auxiliary equipment such as a compressor for an air conditioner and it is not necessary to warm up the internal combustion engine 100, the E-ECU 29
Is in the motoring state, and the process proceeds to S504.

In S504, the E-ECU 29 starts collecting data serving as parameters for failure diagnosis. The above-mentioned data includes, for example, the mass of air sucked into the internal combustion engine 100 during the intake stroke of one cycle: GA (= value obtained by dividing the output signal value of the air flow meter 32 by the engine speed), the engine speed : NE (a value calculated based on a time interval at which the crank position sensor 17 outputs a pulse signal), and a throttle opening degree: TA (an output signal of the throttle position sensor 33).

In S505, the E-ECU 29 controls the actuator 166 to return the valve element 162 of the valve device 160 from the fully opened state to the fully closed state and then back to the fully opened state. In S506, the E-ECU 29 ends the data collection processing started in S504.

In S507, the E-ECU 29 determines whether the S
Referring to the data collected from step 504 to step S506, the internal combustion engine 10 during the control of returning the valve device 160 from the fully open state to the fully closed state and then back to the fully open state is performed.
It is determined whether the state of 0 is stable.

More specifically, the E-ECU 29 refers to the collected data to change the engine speed during the control to return the valve device 160 from the fully open state to the fully closed state and then to the fully opened state. Is a predetermined amount: STTE, and the throttle opening change amount: ΔTA is a predetermined amount:
It is determined whether it is less than STTA.

If it is determined in S507 that the change amount of the engine speed: △ NE is a predetermined amount: STTE or more, or that the change amount of the throttle opening: △ TA is a predetermined amount: STTA or more, E− The ECU 29 controls the valve device 1
It is considered that the state of the internal combustion engine 100 has not been stabilized while the control is performed to return to the fully open state after the state of the internal combustion engine 100 is changed from the fully open state to the fully closed state, and the process proceeds to S512.

In step S512, the E-ECU 29 determines whether the S
The data collected from 504 to S506 is deleted, and the execution of this routine is temporarily terminated. On the other hand, the S
At 507, the change amount of the engine speed: △ NE is less than a predetermined amount: STTE, and the change amount of the throttle opening:
If it is determined that ΔTA is smaller than the predetermined amount: STTA, the E-ECU 29 switches the valve device 160 from the fully open state to the fully closed state and then controls the internal combustion engine 100 during the control to return to the fully open state. Assuming that the state was stable, S5
Proceed to 08.

In step S508, the E-ECU 29 determines that the S
From the data collected from S 504 to S 506, the amount of change in intake air amount: ΔGA when the valve device 160 is controlled from the fully open state to the fully closed state is calculated, and the change amount of the intake air amount is calculated. : It is determined whether or not GA is equal to or greater than a predetermined reference intake air change amount: CHECKGA.

Here, since the exhaust resistance of the bypass passage in the adsorption mechanism 15 is larger than the exhaust resistance of the main exhaust passage,
When the valve device 160 is normal, the pressure in the exhaust passage increases by operating the valve body 162 from the fully open state to the fully closed state.

On the other hand, the internal combustion engine 100 in the motoring state
Since the crankshaft 100a is rotating in a state where the fuel injection control and the ignition control are stopped, only air in the intake passage is taken into the cylinder during the intake stroke, and the air taken into the cylinder is discharged during the exhaust stroke. It will be discharged to the exhaust passage.

At this time, when the pressure in the exhaust passage increases due to the operation of the valve device 160 as described above, the increased pressure acts on the internal combustion engine 100 as a back pressure. That is, the exhaust pressure increased by the operation of the valve device 160 becomes a resistance of the air exhaust operation in the cylinder during the exhaust stroke, thereby hindering the air intake operation in the next intake stroke, and the intake air amount of the internal combustion engine 100. : GA is reduced.

Therefore, the E-ECU 29 sets the valve device 160
Of the intake air amount when the control for changing the intake air from the fully open state to the fully closed state is performed: ΔGA is the reference intake air change amount: CHE
If it is not less than CKGA, it is determined that the valve device 160 is normal. If the change amount of the intake air amount: ΔGA is smaller than the reference intake air change amount: CHECKGA, it is determined that the valve device 160 is abnormal. It is possible to determine.

The internal combustion engine 10 in the motoring state
Since the intake air amount of 0 changes according to the rotational speed (engine speed) of the crankshaft 100a, the intake air temperature, and the like, the reference intake air change amount: CHECKGA and the relationship between the engine speed and the intake air temperature are determined in advance. The relationship may be determined experimentally, and the relationship may be mapped and stored in the ROM or the like of the E-ECU 29.

When the internal combustion engine 100 is provided with a variable valve timing mechanism for varying the opening / closing timing of the intake valve and / or the exhaust valve, the valve overlap amount between the intake valve and the exhaust valve when performing a failure diagnosis. May be increased to increase the degree of influence of the change in the back pressure on the intake system.

Here, returning to the failure diagnosis control routine of FIG. 5, the change in intake air amount when the valve device 160 is controlled from the fully opened state to the fully closed state in S508: ΔGA is the reference intake If it is determined that the air change amount is equal to or more than CHECKGA, the E-ECU 29 proceeds to S509.
Then, it is determined that the valve device 160 is normal, and the execution of this routine ends.

On the other hand, in S508, the valve device 160
Of the intake air amount when control is performed to change the intake air amount from the fully open state to the fully closed state: ΔGA is the reference intake air change amount: CH
If it is determined that the value is less than ECKGA, the E-ECU2
In step S510, it is determined that an abnormality has occurred in the valve device 160.

Subsequently, the E-ECU 29 proceeds to S511, and performs processing for outputting warning information indicating that an abnormality has occurred in the valve device 160, such as turning on an indicator lamp provided in the vehicle interior. Then, the execution of this routine ends.

As described above, the failure diagnosis means according to the present invention is realized by the E-ECU executing the failure diagnosis control routine. In the embodiment described above, the internal combustion engine 1
00 is in the motoring state, that is, when the internal combustion engine 100 is not outputting torque substantially, the failure diagnosis of the valve device 160 is executed. This does not affect the running state of the vehicle, and the deterioration of the driver's driveability is prevented.

In the above-described embodiment, the valve device 16
Although the example in which the failure diagnosis is performed based on the amount of change in the intake air amount when the opening / closing control of the valve device 160 is performed has been described, the present invention is not limited to this. The failure diagnosis may be performed based on a change in the pressure in the exhaust pipe 11 on the upstream side or a change in the temperature in the exhaust pipe 11 on the upstream side of the valve device 160. Further, the intake air amount may be determined based on the intake pipe pressure and the engine speed. In the case of a speed-density internal combustion engine that is indirectly detected from the above, a failure diagnosis may be performed based on a change in intake pipe pressure when the valve device 160 is controlled to open and close.

Further, in the above-described embodiment, a hybrid vehicle has been described as an example of a vehicle to which the present invention is applied. However, it is needless to say that a vehicle running only with the power of an internal combustion engine may be used. In this case, the failure diagnosis of the valve device is performed at the time of so-called fuel cut control when the crankshaft is in a rotating state and fuel injection is stopped, such as when the vehicle is decelerated.

[0136]

According to the exhaust valve failure diagnosis apparatus of the present invention,
When the internal combustion engine is in the engine rotation state and the fuel injection is stopped, that is, when the internal combustion engine is not outputting torque substantially, the failure diagnosis of the exhaust valve is performed by controlling the opening and closing of the exhaust valve. Therefore, even if the opening / closing operation of the exhaust valve affects the internal combustion engine, it does not affect the running state of the vehicle.

Therefore, according to the exhaust valve failure diagnosis device of the present invention, it is possible to diagnose the failure of the exhaust valve without deteriorating the drivability of the vehicle. Further, when the present invention is applied to a hybrid vehicle having an auxiliary power source capable of driving the vehicle in addition to the internal combustion engine, the failure diagnosis device may operate as if the vehicle is running only with the power of the auxiliary power source. When the power of the internal combustion engine is not used as the driving force of the vehicle, the opening and closing operation of the exhaust valve affects the running state of the vehicle by controlling the opening and closing of the exhaust valve to perform failure diagnosis of the exhaust valve. Therefore, deterioration of drivability due to the failure diagnosis is prevented.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a hybrid vehicle to which the present invention is applied;

FIG. 2 is a diagram (1) showing an internal configuration of a suction mechanism.

FIG. 3 is a diagram (2) showing an internal configuration of a suction mechanism.

FIG. 4 is a diagram illustrating the operation of the suction mechanism.

FIG. 5 is a flowchart showing a failure diagnosis control routine.

[Explanation of symbols]

 4 ··· Intake branch 5 ··· Surge tank 6 ··· Intake pipe 7 ··· Throttle valve 8 ··· Actuator 9 ··· Fuel injection valve 10 ··· Exhaust branch Reference Signs List 11 exhaust pipe 11a upstream exhaust pipe 11b downstream exhaust pipe 12 three-way catalyst 15 adsorption mechanism 150 outer cylinder 151 middle cylinder 152 adsorbent 17 ··· Crank position sensor 18 ··· Water temperature sensor 29 ··· E-ECU 32 ··· Airflow meter 33 ··· Throttle position sensor 160 ··· Valve device 162 ··· Valve body 166 ··· Actuator

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F01N 7/08 B60K 9/00 Z F02D 45/00 345 F-term (Reference) 3G004 AA01 BA00 DA02 DA12 DA24 3G065 AA04 AA10 BA06 CA34 CA38 DA06 EA05 GA05 GA09 GA10 GA27 GA41 KA02 3G084 AA03 BA05 BA13 BA19 CA06 DA31 DA33 EB22 FA02 FA07 FA10 FA20 FA33 3G091 AA02 AA14 AA17 AA28 AB03 AB10 BA31 CA13 CB02 CB07 EA01 EA05 EA07 EA07

Claims (6)

[Claims] An exhaust valve provided in an exhaust passage of an internal combustion engine for adjusting an exhaust flow rate in the exhaust passage; and opening and closing the exhaust valve when the internal combustion engine is in an engine rotation state and a fuel injection stopped state. And a failure diagnosis means for controlling and performing a failure diagnosis of the exhaust valve. 2. A hybrid mechanism for selectively driving the power of an internal combustion engine and the power of an electric motor to drive a vehicle, and an exhaust provided in an exhaust passage of the internal combustion engine and adjusting an exhaust flow rate in the exhaust passage. A valve; and a failure diagnosis unit configured to perform a failure diagnosis of the exhaust valve by controlling opening and closing of the exhaust valve when the internal combustion engine is in an engine rotation state and a fuel injection stopped state. Engine exhaust valve failure diagnostic device. 3. The exhaust passage includes a main exhaust passage communicating with the internal combustion engine, and a bypass passage bypassing the main exhaust passage. The exhaust valve is connected to the main exhaust passage and the bypass passage. The exhaust valve failure diagnostic device for an internal combustion engine according to claim 1 or 2, wherein the flow of exhaust gas is switched. 4. The failure diagnosis means diagnoses a failure of the exhaust valve based on a pressure change in an intake passage of the internal combustion engine when the opening and closing of the exhaust valve is controlled. An exhaust valve failure diagnosis apparatus for an internal combustion engine according to claim 1 or 2. 5. The apparatus according to claim 1, wherein the failure diagnosis unit diagnoses a failure of the exhaust valve based on a change in pressure in the exhaust passage when the opening and closing of the exhaust valve is controlled.
An exhaust valve failure diagnosis apparatus for an internal combustion engine according to claim 2 or 3. 6. The failure diagnosis device according to claim 1, wherein the failure diagnosis device diagnoses a failure of the exhaust valve based on a change in a temperature in the exhaust passage when the opening and closing of the exhaust valve is controlled.
An exhaust valve failure diagnosis apparatus for an internal combustion engine according to claim 2 or 3.