Abstract: An apparatus for cleaning an exhaust gas containing nitrogen oxide and particulate matter and discharged from a diesel engine, wherein the apparatus comprises a porous ceramic honeycomb filter and an SCR catalytic converter in this order from upstream, wherein the honeycomb filter has pluralities of flow paths partitioned by porous cell walls and a catalyst supported by the porous cell walls, with desired flow paths sealed by plugs, and wherein at least one plug on the side of an exhaust gas inlet is separate inward from an exhaust gas inlet end. A ratio D/V of the diameter D (mm) of the honeycomb filter to the displacement V (liter) of the diesel engine is preferably 15 mm/liter or more. The honeycomb filter and an SCR catalytic converter are preferably contained in one case.

Abstract: Sensing accuracy of a temperature sensor is enhanced so as to accurately conduct regeneration control of a particulate filter. Disclosed is an exhaust emission control device wherein a pair of dispersion plates 10 and 11 with a number of communicating holes 10a and 11a are arranged in a filter casing 7 incorporated in an exhaust pipe such that the plates are opposed to each other in a direction of flows of exhaust gas 3, catalytic regenerative particulate filter 6 being received in a reception chamber 12 defined by and between the dispersion plates 10 and 11. A temperature sensor 14 is arranged in the filter casing 7 so as to detect exhaust temperature in the reception chamber 12, a sensing element 15 of the temperature sensor 14 being adapted to be in one of flows of the exhaust gas 3.

Abstract: Sensing accuracy of a temperature sensor is enhanced so as to accurately conduct regeneration control of a particulate filter. Disclosed is an exhaust emission control device wherein a pair of dispersion plates 10 and 11 with a number of communicating holes 10a and 11a are arranged in a filter casing 7 incorporated in an exhaust pipe such that the plates are opposed to each other in a direction of flows of exhaust gas 3, catalytic regenerative particulate filter 6 being received in a reception chamber 12 defined by and between the dispersion plates 10 and 11. A temperature sensor 14 is arranged in the filter casing 7 so as to detect exhaust temperature in the reception chamber 12, a sensing element 15 of the temperature sensor 14 being adapted to be in one of flows of the exhaust gas 3.

Abstract: Provided is an exhaust emission control device which makes it possible to arbitrarily effect forcible regeneration of a particulate filter by a driver's will. A catalytic regenerative particulate filter 6 is incorporated in an exhaust pipe 4 through which exhaust gas 3 flows. Provided are control and fuel injection devices 12 and 13 for forcibly burning off particulates captured by the particulate filter to regenerate the particulate filter 6 as well as a regeneration button 17 in a driver's cabin for arbitrarily actuating the devices.

Abstract: An apparatus for cleaning an exhaust gas containing nitrogen oxide and particulate matter and discharged from a diesel engine, wherein the apparatus comprises a porous ceramic honeycomb filter and an SCR catalytic converter in this order from upstream, wherein the honeycomb filter has pluralities of flow paths partitioned by porous cell walls and a catalyst supported by the porous cell walls, with desired flow paths sealed by plugs, and wherein at least one plug on the side of an exhaust gas inlet is separate inward from an exhaust gas inlet end. A ratio D/V of the diameter D (mm) of the honeycomb filter to the displacement V (liter) of the diesel engine is preferably 15 mm/liter or more. The honeycomb filter and an SCR catalytic converter are preferably contained in one case.

Abstract: A ceramic honeycomb filter comprising a ceramic honeycomb structure having porous partition walls defining a plurality of flow paths, and plugs disposed inside the flow paths such that an exhaust gas passes through pores of the porous partition walls, thereby removing particulates from the exhaust gas; a catalyst being carried at least partially on the partition walls and/or the plugs; and at least one of plugs on the side of exhaust gas inlets being disposed at a position separate from the inlet-side opening ends of the flow paths. Particulates are removed from the exhaust gas by injecting unburned fuel and/or hydrocarbon in a gaseous state upstream of the inlet-side plugs to maintain at least part of the inlet-side plugs and their downstream regions at a temperature substantially equal to or higher than the lowest activation temperature of the catalyst.

Abstract: A particulate filter integrally carrying an oxidation catalyst is arranged in an exhaust pipe through which exhaust gas from a diesel engine flows. A NOx-absorption reduction catalyst is arranged in the exhaust pipe and downstream of the particulate filter. A bypass line is branched from a portion of the exhaust pipe between the particulate filter and the reduction catalyst and is connected to a portion of the exhaust pipe downstream of the reduction catalyst. A selector valve is arranged at the branch point of the bypass line and may be switched over to guide the exhaust gas either to the reduction catalyst or to the bypass line. As a result, without difficultly controlling the operation of the diesel engine, the reduction catalyst is prevented from being poisoned and deteriorated by sulfate, the lowering of the ratio of NOx purification through the NOx-absorption reduction catalyst is averted and prolongation of its life is attained.

Abstract: All of NOx, PM, HC and CO concentrations necessary for realization of OBD are determined by utilization of an in-vehicle existing NOx sensor. A NOx sensor arranged in an exhaust pipe detects the NOx concentration in the exhaust gas. On the basis of O2 concentration detected in a course of detection of the NOx concentration, PM, HC and CO concentrations are determined in conversion through mutual correspondences of the concentrations.

Abstract: A particulate filter integrally carrying an oxidation catalyst is arranged in an exhaust pipe through which exhaust gas from a diesel engine flows. A NOx-absorption reduction catalyst is arranged in the exhaust pipe and downstream of the particulate filter. A bypass line is branched from a portion of the exhaust pipe between the particulate filter and the reduction catalyst and is connected to a portion of the exhaust pipe downstream of the reduction catalyst. A selector valve is arranged at the branch point of the bypass line and may be switched over to guide the exhaust gas either to the reduction catalyst or to the bypass line. As a result, without difficultly controlling the operation of the diesel engine, the reduction catalyst is prevented from being poisoned and deteriorated by sulfate, the lowering of the ratio of NOx purification through the NOx-absorption reduction catalyst is averted and prolongation of its life is attained.

Abstract: A ceramic honeycomb filter comprising a ceramic honeycomb structure having porous partition walls defining a plurality of flow paths for flowing an exhaust gas through the porous partition walls to remove particulates from the exhaust gas, the predetermined flow paths among the flow paths being sealed at their ends, a catalyst being carried by the porous partition walls, the porous partition walls having a porosity of 60-75% and an average pore diameter of 15-25 &mgr;m when measured according to a mercury penetration method, and the maximum of a slope Sn of a cumulative pore volume curve of the porous partition walls relative to a pore diameter obtained at an n-th measurement point being 0.

Abstract: A ceramic honeycomb filter comprising a ceramic honeycomb structure having porous partition walls defining a plurality of flow paths, and plugs disposed inside the flow paths such that an exhaust gas passes through pores of the porous partition walls, thereby removing particulates from the exhaust gas; a catalyst being carried at least partially on the partition walls and/or the plugs; and at least one of plugs on the side of exhaust gas inlets being disposed at a position separate from the inlet-side opening ends of the flow paths. Particulates are removed from the exhaust gas by injecting unburned fuel and/or hydrocarbon in a gaseous state upstream of the inlet-side plugs to maintain at least part of the inlet-side plugs and their downstream regions at a temperature substantially equal to or higher than the lowest activation temperature of the catalyst.

Abstract: A ceramic honeycomb filter comprising a ceramic honeycomb structure having porous partition walls defining a plurality of flow paths for flowing an exhaust gas through the porous partition walls to remove particulates from the exhaust gas, the predetermined flow paths among the flow paths being sealed at their ends, a catalyst being carried by the porous partition walls, the porous partition walls having a porosity of 60-75% and an average pore diameter of 15-25 &mgr;m when measured according to a mercury penetration method, and the maximum of a slope Sn of a cumulative pore volume curve of the porous partition walls relative to a pore diameter obtained at an n-th measurement point being 0.

Abstract: A muffler includes an outer box fitted over and attached to an exhaust pipe. The muffler also has a connecting member of a noncircular cross section fixed to said exhaust pipe and interposed between the exhaust pipe and the outer box.

Abstract: An exhaust muffler for use with an internal combustion engine has at least one internal suppression chamber, at least one inlet pipe for receiving exhaust gases from the internal combustion engine, and at least one outlet pipe vented to atmosphere. The exhaust muffler comprises a plurailty of component units connected in series with each other and each having the internal suppression chamber. Each of the component units has a casing having an inner layer of a sound-absorbing material which defines the internal suppression chamber, and a connector pipe connected to and extending through the casing, the connector pipe having upstream and downstream ends projecting out of the casing, the connector pipe having at least one opening which opens into the internal suppression chamber.

Abstract: A muffler for an internal combustion engine includes an outer box composed of a plurality of separate bodies made of a formed sound insulation material and having portions joined by an adhesive, the outer box having an inlet for introducing an exhaust gas from the internal combustion engine and an outlet for discharging the exhaust gas, and a reinforcing member mounted on the joined portions to seal and reinforce the same. The muffler is simple in construction, has a good sound insulation capability, is lightweight, and sufficiently mechanically strong.