摘要:
In the production of a metallic honeycomb body for use as a metallic carrier, for supporting a catalyst, in the purification of an exhaust gas from automobiles or the like, a desired joint site for each layer constituting the metallic honeycomb body is preset, and, when a portion of contact between a metallic corrugated foil and a metallic flat foil for forming the metallic honeycomb body has reached the joint site, a brazing foil which has been cut into a predetermined length is inserted and enfolded in the contact portion.
摘要:
In an electrically heated catalyst support, when necessary, reinforcing layers are formed on the inner circumference and the outer circumference of a honeycomb body. On an end surface of the honeycomb body on the downstream side of exhaust gas, there are provided a plurality of insulating ceramic bars on the outer circumferential layer and/or the inner circumferential layer in such a manner that the insulating ceramic bars cross a non-reinforcing layer of the honeycomb body. End portions of the ceramic bars are held on the reinforcing layer by pins or a ring-shaped holding member joined to an external metallic cylinder. Due to the foregoing arrangement, telescoping of the honeycomb body in the direction of gas flow and damage of the metallic foil can be prevented without obstructing the generation of heat when electricity is supplied. Accordingly, durability of the catalyst support can be remarkably enhanced.
摘要:
An electrically heatable catalytic converter for converting pollutant materials from an engine, such as carbon monoxide, unburned hydrocarbons, nitrogen oxides, etc., to carbon dioxide, nitrogen and water. A catalytic core has a rod center electrode, metal strips, such as corrugated strips and plane strips, and insulation layers spirally wound together about the center electrode to form a spiral electrical path. The central region adjacent to the center electrode and the peripheral region of the catalytic core are wound without intervening of the insulation layer and contact metal to metal. The intermediate region of the core is mainly heated, and there is almost no heat generation in the central and peripheral regions of the catalytic core.
摘要:
The electrically heated catalytic converter of the present invention includes a catalyst substrate, which is formed as a scroll-like cylindrical laminated assembly. The assembly is formed by laminating a thin corrugated and plain metal sheets and winding the metal sheets together around a center electrode. The outermost layer of the laminated assembly is connected to an outer electrode. The corrugated metal sheet has an insulating coating made of an alumina, and the plain metal sheet is uninsulated. Local conductive connections form between the thin metal sheets by soldering strips of zirconium solder foils between the layers of the thin metal sheets. Since zirconium has a larger reducing capability than aluminum, the alumina in the insulating coating is reduced by zirconium and precipitates at the local conductive connections. Therefore, the plain and corrugated metal sheet are electrically connected to each other at the local conductive connections. The solder foils in the respective layers are arranged in a configuration where a strip of solder foil in one layer overlaps with strips of solder foils in adjoining layers only at its ends, and does not overlap with strips of solder foils in the adjacent layers when viewed radially. Since the solder foils overlap only by a small area, electric current flowing through the local conductive connections concentrates in the overlap area and produces hot spots. The overall resistance of the electric paths can be adjusted by varying the solder strip length.
摘要:
An engine has a plurality of the cylinders. The cylinders are divided into a first cylinder group and a second cylinder group, and each cylinder group is connected, via a corresponding branch exhaust passage, to a common interconnecting exhaust passage. In the interconnecting exhaust passage, an exhaust gas purifying catalyst is arranged. The air-fuel ratio of the exhaust gas of the first cylinder group is made lean to feed oxygen to the exhaust gas purifying catalyst, and the air-fuel ratio of the second cylinder group is made rich to feed fuel for heating to the exhaust gas purifying catalyst, so that the oxygen and the fuel for heating react with each other to heat the exhaust gas purifying catalyst to reactivate the exhaust gas purifying catalyst when the reactivation of the exhaust gas purifying catalyst is must be performed. In each branch exhaust passage, a start catalyst is arranged.
摘要:
An electrically heating catalytic apparatus that quickly heats catalyst to an activation temperature even when the engine is started at a low temperature below the catalyst activation temperature. The apparatus employs an electrically conductive catalyst carrier that is electrically heated. The carrier is provided with local hot spots to be energized. Since the heat is locally generated, the heat capacity of the catalyst carrier is small to shorten a temperature increasing time.
摘要:
An electrically heating catalytic apparatus that quickly heats catalyst to an activation temperature even when the engine is started at a low temperature below the catalyst activation temperature. The apparatus employs an electrically conductive catalyst carrier that is electrically heated. The carrier is provided with local hot spots to be energized. Since the heat is locally generated, the heat capacity of the catalyst carrier is small to shorten a temperature increasing time.
摘要:
Cylinders of a diesel engine 1 are provided with cylinder pressure sensors 29a to 29d for detecting combustion chamber pressures. An electronic control unit (ECU) 20 of the engine selects optimum combustion parameters in accordance with a fuel injection mode of fuel injectors 10a to 10d of the engine and a combustion mode determined by the amount of EGR gas supplied from the EGR valve 35 from among a plurality of types of combustion parameters expressing the combustion state of the engine calculated based on the cylinder pressure sensor output and feedback controls the fuel injection amount and fuel injection timing so that the values of the combustion parameters match target values determined in accordance with the engine operating conditions. Due to this, the engine combustion state is controlled to the optimum state at all times regardless of the fuel injection mode or combustion mode.
摘要:
An internal combustion engine has an EGR passage provided with an EGR control valve and a catalyst for purifying the EGR gas. When the internal combustion engine operates in a low-temperature combustion mode in which the amount of EGR gas supplied to a combustion chamber is larger than that of EGR gas with which the amount of soot produced reaches a peak, and almost no soot is produced, a controller reduces an opening amount of the exhaust gas recirculation control valve so as to increase an exhaust gas temperature, and reduces an opening amount of the throttle valve so as to suppress an increase in the amount of the EGR gas, thereby to reduce reductions in the temperature of the EGR gas and the temperature of the catalyst.
摘要:
A stable combustion without generating smoke or misfire is performed by selectively conducting a first combustion mode and a second combustion mode. In the first combustion mode, an amount of an inert gas, e.g., EGR gas, provided to a combustion chamber is made to be larger than an amount of the inert gas that causes the generation amount of soot to become a peak amount. This causes substantially no soot to be generated. In the second combustion mode, the amount of the inert gas provided to the combustion chamber is made to be smaller than the amount that causes the generation amount of soot to become a peak amount. The injection timing is quickened if the injection amount is increased in the first combustion mode, and the injection timing is delayed if the injection amount is reduced.