# US 2020/0003149 A1 · Internal combustion engine having a cylinder head and a secondary air system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0003149 A1 - Document ID: US20200003149A1 - Status: Published application - Kind: A1 - Application number: 16/465,450 - Filed: 2017-11-23 - Published: 2020-01-02 - Earliest claimed: 2016-12-02 - Assignees: Volkswagen Aktiengesellschaft - Applicants: Volkswagen Aktiengesellschaft - Inventors: Peter KAWELKE - Web page: https://patentgrep.com/patent/US20200003149A1 ## CPC - F02F 1/243: {Cylinder heads and inlet or exhaust manifolds integrally cast together} - F01N 3/34: using air conduits or jet air pumps, e.g. near the engine exhaust port - F01N 13/105: {having the form of a chamber directly connected to the cylinder head, e.g. without having tubes connected between cylinder head and chamber} - F01N 2270/00: Mixing air with exhaust gases - F02F 2001/4278: {Exhaust collectors} - Y02A 50/20: Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters - Y02T 10/12: Improving ICE efficiencies - F02F: CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES - F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16) - Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An internal combustion engine has a cylinder head having an integrated exhaust manifold which has multiple exhaust ducts; and a secondary air system for supplying ambient air that is additionally supplied through an inlet as secondary air into the exhaust manifold into the exhaust gas flow downstream from the exhaust valves of the internal combustion engine during the cold-start phase. For fresh air supply, the secondary air system has a plurality of supply ducts that connect a distributor block of the secondary air system to an exhaust duct and are arranged in the integrated exhaust manifold and each provided with a valve assembly. Each valve assembly has a blocking means in the form of a closure flap that is pivotable about a pivot axis at a distance from the center of mass of the blocking means. According to the installation position of the internal combustion engine in a motor vehicle, and owing to this eccentric arrangement of the pivot axis, the blocking means assumes a defined closed position under the influence of gravity when there is no pressure difference between the exhaust manifold and the secondary air system and opens automatically under the influence of a relative overpressure in the gas pressure on the side of the secondary air system in relation to the gas pressure on the side of the exhaust manifold. ## Claims ### Claim 1 An internal combustion engine, comprising: a cylinder head having an integrated exhaust manifold which has multiple exhaust ducts, and a secondary air system, at least one valve assembly for restricting a fluid flow of the exhaust gas from the exhaust manifold to the secondary air system, wherein the exhaust manifold and the secondary air system are designed as integral components of the cylinder head, and wherein the secondary air system has a plurality of supply ducts that are connected to a respective exhaust duct in the integrated exhaust manifold with at least one valve assembly. ### Claim 2 (depends on 1) The internal combustion engine as set forth in claim 1, wherein each supply duct is equipped with a valve assembly. ### Claim 3 (depends on 1) The internal combustion engine as set forth in claim 1, wherein the valve assembly has a movable blocking means, particularly a closing flap. ### Claim 4 (depends on 1) The internal combustion engine as set forth in claim 1, wherein the blocking means is arranged so as to be pivotable about a pivot axis from the center of mass of the blocking means. ### Claim 5 (depends on 1) The internal combustion engine as set forth in claim 1, wherein, apart from the acting compressive forces, the blocking means is acted upon exclusively by gravity. ### Claim 6 (depends on 1) The internal combustion engine as set forth in claim 1, wherein the blocking means has a closed position that is configured so as to be inclined relative to the cross-sectional plane of the supply duct, and wherein the cross-sectional shape of the blocking means deviates from the cross-sectional area on the cross-sectional plane of the supply duct. ### Claim 7 (depends on 1) The internal combustion engine as set forth claim 1, wherein, in the absence of pressure difference, the blocking means assumes a parallel orientation relative to the main extension of the supply duct in a portion enclosing the blocking means. ### Claim 8 (depends on 1) The internal combustion engine as set forth in claim 1, wherein the blocking means is adjustable. ### Claim 9 (depends on 1) The internal combustion engine as set forth in claim 1, wherein the valve assembly is arranged within the internal combustion engine below a plane of the exhaust manifold. ### Claim 10 (depends on 1) A cylinder head for such an internal combustion engine as set forth in claim 1. ### Claim 11 (depends on 8) The internal combustion engine as set forth in claim 8, wherein the blocking means is adjustable by means of an actuator.