摘要:
According to the invention, there is provided an exhaust gas purification device for purifying an exhaust gas discharged from an engine having cylinders including first and second cylinders. An exhaust stroke in the first cylinder is carried out next to an exhaust stroke in the second cylinder. The exhaust gas purification device comprises exhaust branch passages which are connected to the cylinders, respectively. The exhaust branch passages include first and second exhaust branch passages which are connected to the first and second cylinders, respectively. The exhaust gas purification device comprises a common exhaust passage connected to the exhaust branch passages, a catalyst positioned in the common exhaust passage for purifying an exhaust gas, and an exhaust gas recirculation passage connected to the first exhaust branch passage. The exhaust gas recirculation passage introduces the exhaust gas from the first exhaust branch passage into an intake passage which is connected to the cylinders. According to the invention, a reducing agent is fed to only the second cylinder during the power or the exhaust stroke in the second cylinder to promote the purifying operation of the catalyst when the exhaust gas is introduced into the intake passage via the exhaust gas recirculation passage.
摘要:
In a fuel injection control system, a throttle valve is provided on the intake air passage of a diesel engine and an EGR control valve is provided for recycling a part of the engine exhaust gas to the intake air system of the engine. An engine control unit (ECU) controls the intake air amount of the engine to a value corresponding to the engine operating condition by adjusting the throttle valve and the EGR control valve. Further, the ECU detects the actual intake air amount by an airflow meter disposed at the inlet of the intake air passage and determines the maximum fuel injection amount based on the engine speed and the actual intake air amount. The maximum fuel injection amount is the maximum amount of the fuel which does not generate the exhaust smoke. By restricting the actual fuel injection amount so that the actual fuel injection amount does not exceed the maximum fuel injection amount, the generation of the exhaust smoke is prevented in transient operating conditions of the engine regardless of a delay in the response of the EGR control valve.
摘要:
According to the present invention, there is provided a fuel injecting device for injecting fuel into a cylinder of an engine. A fuel injector injects a main fuel charge into the cylinder at a predetermined first timing, and the fuel injector injects additional fuel into the cylinder at a predetermined second timing which is different from the predetermined first timing. It is judged if an amount of fuel adhering to an inner wall of the cylinder is larger than a predetermined fuel amount when the fuel injector injects the additional fuel. The fuel injector inject the additional fuel such that an amount of fuel adhering to the inner wall of the cylinder becomes smaller than the predetermined fuel amount when it is judged that an amount of fuel adhering to the inner wall of the cylinder is larger than the predetermined fuel amount.
摘要:
A fuel injection control device for a direct injection type engine having an exhaust passage and a NO.sub.x catalyst arranged therein to purify NO.sub.x in exhaust gas discharged from the engine comprises fuel injectors for injecting fuel into a cylinder. The injecting operation of the fuel injectors is controlled to carry out a main fuel injection at the latest at the beginning of a power stroke of the engine. The injecting operation of the fuel injectors is controlled to carry out a sub fuel injection at one of a power stroke and an exhaust stroke of the engine after the main fuel injection is completed to increase an amount of hydrocarbon in the exhaust gas. The injecting operation of the fuel injectors is controlled to carry out an additional sub fuel injection after the main fuel injection is completed and before the sub fuel injection is carried out.
摘要:
According to the present invention, there is provided an exhaust gas purification device for an engine having an exhaust passage, the device comprising a catalyst arranged in the exhaust passage and having an upstream end and a downstream end, a purification ratio of exhaust gas by the catalyst becoming more than a predetermined ratio when a temperature of the catalyst is within a predetermined temperature range, cooling means for cooling the upstream end of the catalyst, heating means for heating the downstream end of the catalyst, and control means for controlling the cooling means and the heating means to maintain the temperature of a portion of the catalyst, which portion is positioned between the upstream end and the downstream end, in the predetermined temperature range.
摘要:
An exhaust gas purifying device, for an engine performing a lean operation and having an EGR system capable of controlling an EGR ratio, comprises a NO.sub.X catalyst arranged in the exhaust passage capable of selectively reducing NO.sub.X in the inflowing exhaust gas, in the oxidizing atmosphere including a reducing agent, and a reducing agent injector arranged in the exhaust passage of the engine for secondarily supplying a reducing agent to the exhaust passage upstream of the NO.sub.X catalyst. The EGR system has an EGR passage connecting the exhaust passage and the intake passage of the engine, an EGR control valve arranged in the EGR passage, and an intake air control valve arranged in the intake passage upstream of an inlet of the EGR passage. The openings of the EGR control valve and the intake air control valve are controlled to control the temperature of the exhaust gas to make the temperature of the NO.sub.X catalyst within the optimum temperature range or equal to the optimum temperature. The amount of the reducing agent injected by the reducing agent injector is made smaller as the EGR ratio becomes higher.
摘要:
An exhaust gas purification device, for an engine having an exhaust passage, said device comprising a catalyst arranged in the exhaust passage for purifying NO.sub.x with a reducing agent. A purification ratio of the NO.sub.x by said catalyst becomes more than a predetermined ratio when a temperature of said catalyst is within a predetermined temperature range. A predetermined amount of a reducing agent is fed to said catalyst. An amount of the reducing agent to be fed is increased with respect to the predetermined amount when a temperature of an upstream end of the catalyst is lower than a lowest value of the predetermined temperature range and a temperature of a downstream end of the catalyst is higher than the lowest value.
摘要:
According to the present invention, there is provided an exhaust gas purification device for an engine having an exhaust passage, the device comprising a catalyst arranged in the exhaust passage and having an upstream end and a downstream end, a purification ratio of exhaust gas by the catalyst becoming more than a predetermined ratio when a temperature of the catalyst is within a predetermined temperature range, cooling means for cooling the upstream end of the catalyst, heating means for heating the downstream end of the catalyst, and control means for controlling the cooling means and the heating means to maintain the temperature of a portion of the catalyst, which portion is positioned between the upstream end and the downstream end, in the predetermined temperature range.
摘要:
A hexagonal cell honeycomb structure body has a plurality of hexagonal cells. Each hexagonal cell is surrounded by six cell walls in a hexagonal lattice shape. A R-shaped corner part of an approximate circular-arc shape is alternately formed at interior angle parts of the six cell walls forming each hexagonal cell. The three R-shaped corner parts are at the alternate internal corners of each hexagonal cell observed from a cross section of the axis direction of the hexagonal cell honeycomb structure body. A radius of curvature of each R-shaped corner part is larger than that of the interior corner part having no R-shaped corner part. The minimum radius of curvature of the R-shaped corner part is 2.8 to 5 times of a thickness of each hexagonal cell wall, namely within a range of 0.25 mm to 0.45 mm.
摘要:
A honeycomb-shaped substrate for catalyst is made from ceramic, has a straight-flow structure, and includes cellular walls exhibiting pore volumes, which differ partially, and a large number of cellular passages demarcated by the cellular walls. A catalyst for purifying exhaust gases is produced by providing the cellular walls of the honeycomb-shaped substrate with a catalytic coating layer.