A first cylinder and a second cylinder are provided. A first exhaust pipe is connected to the first cylinder and a second exhaust pipe is connected to the second cylinder. A communicating pipe connects together an intermediate portion of the first exhaust pipe with an intermediate portion of the second exhaust pipe. An exhaust gas control catalyst is arranged in the second exhaust pipe downstream of the portion to which the communicating pipe is connected. Exhaust gas amount reducing devices are provided which reduce the amount of exhaust gas that flows from the first exhaust pipe into the second exhaust pipe through the communicating pipe during execution of rich/lean burn control which performs combustion with an air-fuel ratio of an air-fuel mixture that is richer than the stoichiometric air-fuel ratio in one of the first cylinder and second cylinder and performs combustion with an air-fuel ratio of an air-fuel mixture that is leaner than the stoichiometric air-fuel ratio in the other cylinder.

Exhaust Gas Control Apparatus for Internal Combustion Engine

Methods and systems are provided for selecting a group of cylinders for selective deactivation, in a variable displacement engine system, based at least on a regeneration state of an exhaust catalyst. The position of one or more valves and throttles may be adjusted based on the selective deactivation to reduce back-flow through the disabled cylinders while also maintaining conditions of a downstream exhaust catalyst. Pre-ignition and knock detection windows and thresholds may also be adjusted based on the deactivation to improve the efficiency of knock and pre-ignition detection.

Methods and Systems for Variable Displacement Engine Control

Various systems and methods are disclosed for carrying out combustion in a fuel-cut operation in some or all of the engine cylinders of a vehicle. Further, various subsystems are considered, such as fuel vapor purging, air-fuel ratio control, engine torque control, catalyst design, and exhaust system design.

System and method for controlling valve timing of an engine with cylinder deactivation

The exhaust sound and emission control system is a system for reducing sound and noxious emissions from an automotive exhaust. The system may have an exhaust resonator (34) having one or more catalytic converter elements (24) in combination therewith in a single device (10). Alternatively, the system may have multiple angularly disposed chambers therein, with a series of V-shaped baffles or guides in one of the chambers, thereby combining resonator and muffler functions in a single device. In another alternative, the system has a series of longitudinal tubes therein, in combination with a series of V-shaped guides or vanes, combining catalytic converter, muffler, and resonator functions in a single device. The various elements of the different embodiments, e.g. catalytic converter element(s), double wall shell, perforated tubes and multiple flow paths, interconnecting crossover tubes, etc., may be combined with one another as practicable.

Exhaust sound and emission control systems

Emission control device

The exhaust gases of a two-bank internal-combustion engine are guided, by way of exhaust gas collectors, to a central expansion chamber of a housing. From there, they flow through main catalysts arranged on opposite ends of the housing, before they are guided into the open air by way of end mufflers. This exhaust system provides a space-saving arrangement of all components required for an optimal emission control, and low exhaust gas back pressure, and meets all acoustic requirements.

Exhaust system of an internal-combustion engine

The air intake system of a two-bank internal-combustion engine has one resonance receptacle for each cylinder bank and an additional receptacle in the respective center. Via suction pipes, the resonance receptacles are connected to the cylinders and are mutually provided with connecting pipes, fresh air entering into one of these connecting pipes. Suction pipe extensions are connected to the other receptacle which partially extend inside the resonance receptacles and are arranged in them at a distance in an alignment with the admission funnels of the suction pipes. The combination of the connecting pipes acting as resonance pipes and the suction pipe extensions acting as swing pipes causes an increase of the mean pressure which raises the torque as well as the performance of the internal-combustion engine.

Air intake system of an internal-combustion engine

The invention relates to a multiple cylinder internal combustion engine, comprising at least one cylinder line which has a cylinder head housing (24) in which inlet and outlet valves (26, 28) are arranged, said valves supplying combustion air to the cylinders and removing combustion waste gases via an exhaust system (36). According to the invention, means (44') are provided for executing different outlet valve stroke courses of at least two cylinders located in a cylinder line and said means reduce the overlapping opening phases of these outlet valves (28), in which the inlet valve (26) and the outlet valve (28) of one of the two cylinders are themselves in an overlapping opening phase. This enables the cylinders of a V8 engine with a crankshaft that is cranked with 90° to be filled with fresh gas uniformly.

Multiple cylinder internal combustion engine

A multi-cylinder internal combustion engine is provided with a group of constantly operated cylinders and a group of cylinders that can be switched off. An exhaust line having a catalytic converter is associated with each group of cylinders. A shutoff element is disposed downstream of the catalytic converter of the constantly operated cylinder subassembly. In addition, the two exhaust lines or the two catalytic converters are connected to each other via a bypass line. Maintaining the temperature of the second catalytic converter is made possible via the bypass line, even when the cylinders of the second group are not operated and when the exhaust line is closed.

Exhaust system for a multi-cylinder internal combustion engine

The exhaust gases of both cylinder banks of a multi-cylinder reciprocating engine first flow through a catalyst situated along the respective cylinder bank and then, in a cross countercurrent, flow through a horizontally situated muffler arranged transversely to the cylinder banks.

Erwin Rutschmann

Papers

Exhaust system of an internal-combustion engine

Air intake system of an internal-combustion engine

Multiple cylinder internal combustion engine

Exhaust system for a multi-cylinder internal combustion engine

Exhaust system of a multi-cylinder reciprocating engine