Secondary air supply apparatus and control method for the same

• US 20070137185A1
• Filed: 08/15/2005
• Published: 06/21/2007
• Est. Priority Date: 08/30/2004
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Muraguchi, Tomokazu
• Granted Patent: US 8,015,804 B2
• Time in Patent Office: Days
• US Class Current: 60/289
• CPC Class Codes: F01N 11/00 Monitoring or diagnostic devices for exhaust-gas treatment apparatus , e.g. for catalytic activity safety, indicating or supervising devices for internal combustion engines F02B77/08; testing of machines G01M13/00
• CPC Class Codes: F01N 13/011 having two or more purifying devices arranged in parallel
• CPC Class Codes: F01N 13/107 More than one exhaust manifold or exhaust collector
• CPC Class Codes: F01N 2550/14 Systems for adding secondary air into exhaust
• CPC Class Codes: F01N 3/22 Control of additional air supply only, e.g. using by-passes or variable air pump drives
• CPC Class Codes: F01N 3/32 using air pump using jet air pumps F01N3/34; pumps in general F04
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 41/0002 Controlling intake air
• CPC Class Codes: F02D 41/062 for starting F02D41/061 takes precedence
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

An ECU executes (300) a program including a step (S202) of opening an electromagnetic ASV (232) while a vacuum pressure ASV (1) and a vacuum pressure ASV (2) are controlled so as to be closed, and an air pump (200) is controlled so as to be stopped in a case where an air amount GA that is an amount of air introduced into an engine (100) is equal to or larger than a predetermined air amount GA (0), and a coolant temperature TW at the starting time of the engine is equal to or higher than a predetermined coolant temperature TW (0) (“YES” in step S200); a step (S204) of detecting a pressure; a step (S206) of closing the electromagnetic ASV; and a step (S402) of determining that failure has occurred in at least one of the vacuum pressure ASV (1) and the vacuum pressure ASV (2), that is, one of the vacuum pressure ASV (1) and the vacuum pressure ASV (2) remains in an opened state and cannot be closed when there is a pulsation of the pressure that is detected while the electromagnetic ASV is opened (“YES” in step S400).

Claims

1. A secondary air supply apparatus for an internal combustion engine provided with plural cylinders, which supplies secondary air to a portion upstream of an exhaust gas control device, the apparatus comprising:

an air pump which supplies air under pressure;

a first air passage through which the air delivered under pressure from the air pump flows;

a first opening/closing valve which opens/closes the first air passage;

a second air passage one end of which is connected to the first air passage at a portion downstream of the first opening/closing valve, and the other end of which is connected to an exhaust passage leading to a predetermined cylinder among the plural cylinders;

a second opening/closing valve which opens/closes the second air passage;

a third air passage one end of which is connected to the first air passage at a portion downstream of the first opening/closing valve, and the other end of which is connected to an exhaust passage leading to a cylinder different from the predetermined cylinder to which the exhaust passage connected to the second air passage leads;

a third opening/closing valve which opens/closes the third air passage;

a pressure detector that performs detection of a pressure in the first air passage, the pressure detector being provided between the air pump and the first opening/closing valve; and

a failure determining device that determines whether failure has occurred in the secondary air supply apparatus based on a result of the detection that is performed by the pressure detector while the first opening/closing valve is controlled so as to be opened, the second opening/closing valve and the third opening/closing valve are controlled so as to be closed, and the air pump is controlled so as to be stopped.

2. The secondary air supply apparatus according to claim 1, wherein the failure determining device determines whether failure has occurred in the secondary air supply apparatus when an amount of air introduced into the internal combustion engine is larger than a predetermined amount.

3. The secondary air supply apparatus according to claim 1, wherein the failure determining device determines that failure has occurred in the secondary air supply apparatus when a change in the pressure is detected by the pressure detector.

4. The secondary air supply apparatus according to claim 1, wherein the failure determining device determines whether failure has occurred in at least one of the second opening/closing valve and the third opening/closing valve.

5. A secondary air supply apparatus for an internal combustion engine installed in a vehicle, which supplies secondary air to a portion upstream of an exhaust gas control device, the apparatus comprising:

a pressure detector that performs detection of a pressure of secondary air delivered under pressure from an air pump to a passage connecting to an exhaust gas passage;

an information obtaining device that obtains information relating to noise heard by an occupant of the vehicle;

a pump operating device that operates the air pump when a magnitude of the noise is larger than a predetermined value; and

a failure determining device that determines whether failure has occurred in the secondary air supply apparatus based on a result of the detection that is performed by the pressure detector while the air pump is controlled so as to be operated.

6. The secondary air supply apparatus according to claim 5, wherein the information relating to the noise includes at least one of a vehicle speed, a rotational speed of the internal combustion engine, and an opening amount of a throttle valve provided in the internal combustion engine.

7. The secondary air supply apparatus according to claim 5, wherein the internal combustion engine is provided with plural cylinders, and wherein

the secondary air supply apparatus includes i) a first air passage through which the air delivered under pressure from the air pump flows, ii) a first opening/closing valve which opens/closes the first air passage, iii) a second air passage which is connected to the first air passage at a portion downstream of the first opening/closing valve, and which is connected to an exhaust passage leading to a predetermined cylinder among the plural cylinders, iv) a second opening/closing valve which opens/closes the second air passage, v) a third air passage which is connected to the first air passage at a portion downstream of the first opening/closing valve, and which is connected to an exhaust passage leading to a cylinder different from the predetermined cylinder to which the exhaust passage connected to the second air passage leads, and vi) a third opening/closing valve which opens/closes the third air passage;

and

the failure determining device determines whether failure has occurred in the secondary air supply apparatus based on a result of the detection that is performed by the pressure detector while the first opening/closing valve, the second opening/closing valve, and the third opening/closing valve are controlled so as to be closed.

8. The secondary air supply apparatus according to claim 7, wherein the failure determining device determines that failure has occurred in the secondary air supply apparatus when an increase in the pressure is not detected by the pressure detector.

9. The secondary air supply apparatus according to claim 5, wherein the failure determining device determines whether failure has occurred in at least one of the pressure detector and the air pump.

10. A secondary air supply method for controlling secondary air supplied to a portion upstream of an exhaust gas control device, the method comprising:

providing an air pump which supplies air under pressure;

a first opening/closing valve which opens/closes the first air passage through which the air delivered under pressure from the air pump flows;

a second opening/closing valve which opens/closes the second air passage which is connected to the first air passage at a portion downstream of the first opening/closing valve, and which is connected to an exhaust passage leading to a predetermined cylinder among the plural cylinders; and

a third opening/closing valve which opens/closes the third air passage which is connected to the first air passage at a portion downstream of the first opening/closing valve, and which is connected to an exhaust passage leading to a cylinder different from the predetermined cylinder to which the exhaust passage connected to the second air passage leads;

detecting a pressure in the first air passage between the air pump and the first opening/closing valve; and

determining whether failure has occurred in the secondary air supply apparatus based on a result of the detection that is performed by the pressure detector while the first opening/closing valve is controlled so as to be opened, the second opening/closing valve and the third opening/closing valve are controlled so as to be closed, and the air pump is controlled so as to be stopped.

11. A secondary air supply method for controlling secondary air supplied to a portion upstream of an exhaust gas control device, comprising:

detecting a pressure of air delivered under pressure from an air pump;

obtaining information relating to noise heard by an occupant of the vehicle;

operating the air pump when a magnitude of the noise is larger than a predetermined value; and

determining whether failure has occurred in the secondary air supply apparatus based on the detected pressure while the air pump is controlled so as to be operated.