Abstract:
The invention relates to a method for producing an internal combustion engine piston which is provided with at least one cooling channel (12) and at least one reinforced piston ring groove (14) consisting in producing a piston blank (1), in forming a groove (10) provided with a cooling channel (12) and an external ring (11) in said piston blank (1), in filling the cooling channel (12) with are movable material (2), in filling the external ring with a reinforcing material (3) in removing the removable material (2) and in finish-machining the piston. A piston made of aluminum alloy and produced according to the inventive method is also disclosed.
Abstract:
The invention relates to a method of producing a piston (1) with a combustion chamber recess (2) for an internal combustion engine, in which at least one region of the combustion chamber recess (2) comprising at least one recess base (20) is melt-treated in order to re-melt a material in the melt-treated region, so that a buildup of the material in the melt-treated region is changed in a layer with a definable depth, and relates to such a piston (1).
Abstract:
The invention relates to a method for producing an internal combustion engine piston which is provided with at least one cooling channel (12) and at least one reinforced piston ring groove (14) consisting in producing a piston blank (1), in forming a groove (10) provided with a cooling channel (12) and an external ring (11) in said piston blank (1), in filling the cooling channel (12) with are movable material (2), in filling the external ring with a reinforcing material (3) in removing the removable material (2) and in finish-machining the piston. A piston made of aluminium alloy and produced according to the inventive method is also disclosed.
Abstract:
The invention relates to a piston for an internal combustion engine, which consists of a copper alloy. According to the method for producing such a piston, said piston is produced from a copper alloy. According to the invention, a copper alloy is used in the production of a piston for an internal combustion engine.
Abstract:
Exhaust gas to be cleaned is introduced into a conversion and mixing duct and the exhaust gas flows through the duct along a predetermined longitudinal direction. A reducing agent, such as aqueous urea solution, is injected into the exhaust gas stream in the conversion and mixing duct. The exhaust gas stream is then deflected into a reaction duct which extends parallel to or coaxially around the conversion and mixing duct. The exhaust gas then flows in the opposite direction through the reaction duct. A reduction catalyst is disposed in the reaction duct, where the reducible components of the exhaust gas are reduced. The exhaust gas cleaned in this manner is then discharged from the reaction duct.
Abstract:
A method and a device for decomposing nitrogen oxides in an exhaust gas of an internal combustion engine, include feeding the exhaust gas and a reactant which is sprayed into the exhaust gas through the use of compressed air, to a catalytic converter. A compressor for supplying compressed air is associated with the internal combustion engine, and part of the compressed air is diverted and used as the compressed air for injecting the reactant. The sprayed reactant is fed to the catalytic converter, together with the exhaust gas to be purified, which ensures the decomposition of the nitrogen oxides, in particular according to the method of selective catalytic reaction.
Abstract:
A metering system in a combustion unit having an exhaust-gas chamber and a reducing agent reservoir includes an electrically controllable valve for introducing the reducing agent into the exhaust-gas chamber without using compressed air. The valve has an outlet opening that opens directly into the exhaust-gas chamber. The outlet opening is fluidically connected to the reservoir through the valve. The metering system can be produced with only little technical outlay. The metering system includes a recirculating circuit, and the valve has a holding chamber for the reducing agent. The holding chamber is disposed downstream of the outlet opening in a reducing agent flow direction, and is fluidically connected into the recirculating circuit. The metering system includes a coolant circuit for cooling the valve. The valve and its outlet opening is disposed in the exhaust-gas chamber to position the principal axis of the valve at an angle of less than 90° with respect to a principal direction of flow of exhaust gas in the exhaust-gas chamber. The metering system includes a baffle disposed in the exhaust-gas chamber to cause a change in direction of reducing agent introduced therein. The combustion unit can be a diesel engine, and the reducing agent can be a urea solution.
Abstract:
When determining the amount of a reducing agent solution to be introduced into the exhaust gas of a combustion system, in particular of a diesel engine, for catalytically reducing the nitrogen oxides by the SCR process, the concentration of the reducing agent in the reducing agent solution as well as the parameters characterizing the operating state of the combustion system, the exhaust gas and/or the catalyst are taken into consideration. As a result, the safety margin with respect to a theoretically optimum amount to be introduced that is required to avoid a leakage of reducing agent can be reduced, whereby the conversion rate of the nitrogen oxides is improved.
Abstract:
A static mixer in the exhaust emission control system of an excess-air-operated combustion engine is formed of an expanded grid with a plurality of openings formed between crossbars. Using an expanded grid achieves both good mixing of the exhaust gas with a reducing agent in a short mixing path and properly aligns the exhaust flow.
Abstract:
A device for introducing a liquid reducing agent into an exhaust gas purification system includes a gas line for receiving and carrying a gas, a reducing agent line for receiving and carrying a liquid reducing agent, a mixing chamber for mixing the reducing agent with the gas, the mixing chamber fluidically connected to the gas line and to the aid reducing agent line, a metering valve disposed in the reducing agent line; and a control device for controlling a pressure in the reducing agent line dependent upon a gas pressure in the gas line. The control device can also be used for controlling the reducing agent throughput in the reducing agent line in dependence on the gas pressure in the gas line.