US 12,221,915 B2
Air supply to an internal combustion engine and method and device for diagnosing an air supply to an internal combustion engine
Benedikt Graf, Ludwigsburg (DE); Christian Disch, Wimsheim (DE); Conrad Bubeck, Esslingen (DE); and Stefan Bauer, Gerlingen (DE)
Assigned to ROBERT BOSCH GMBH, Stuttgart (DE)
Filed by Robert Bosch GmbH, Stuttgart (DE)
Filed on Dec. 12, 2023, as Appl. No. 18/536,406.
Claims priority of application No. 10 2022 213 545.8 (DE), filed on Dec. 13, 2022.
Prior Publication US 2024/0191644 A1, Jun. 13, 2024
Int. Cl. F01N 3/30 (2006.01); F01N 3/22 (2006.01); F01N 11/00 (2006.01)
CPC F01N 3/30 (2013.01) [F01N 3/22 (2013.01); F01N 11/007 (2013.01); F01N 2900/1402 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A method for an air supply, the air supply including (a) a first air duct configured to supply air to at least one cylinder of an internal combustion engine for operating the internal combustion engine, (b) a second air duct configured to supply air to a heater for heating an exhaust system of the internal combustion engine, and (c) a third air duct by which the first and second air ducts are connected to an air filter for providing filtered ambient air to the internal combustion engine, wherein each air duct of the first and second air ducts has at least one control element configured to control an amount of air flowing through the respective air duct, and each air duct of the second and third air ducts has a mass flow sensor configured to measure a mass of air flowing through the air duct, the method comprising, in an operating phase of the air supply:
closing the control element in the first air duct so that no air flows through the first air duct;
controlling the control element in the second air duct such that air for operation of the heater flows through the second air duct; and
diagnosing the air supply;
wherein the method includes at least one of the following two features (I)-(II):
(I) the diagnosing is performed by comparing mass flows through the second and third air ducts to each other; and
(II) the control includes switching on an air pump of the control element in the second air duct and opening a valve of the control element in the second air duct, and the diagnosing is performed by one of:
(i) comparing the mass flow through the second air duct or a pressure signal of the second air duct to an expected value that results from the control of the air pump and the opening of the valve; and
(ii) measuring an oxygen content in exhaust gas of the heater downstream of the heater, and comparing the measured oxygen content to an expected value.