Abstract: A particulate trap for use with a diesel engine is high in particulate trapping capacity and regenerating capacity and low in pressure drop, and yet is compact and inexpensive. This trap has a filter element made up of a plurality of tapered filter members formed from a fabric of heat-resistant metal fibers. The filter members have different diameters from each other and are nested concentrically one inside the other so that the adjacent filter members are positioned inversely. Each filter member is connected at its large-diameter end to the small-diameter end of the immediately outer filter member to alternately close the exhaust inlet and outlet ends of the gaps between the adjacent filter members. The filter element thus formed is mounted in a metal case provided in an exhaust line and used as a particulate trap. With this arrangement, it is possible to increase the particulate trapping area of the filter and the exhaust inlet openings without increasing the size of the entire trap.

Abstract: An exhaust gas purification device of a compression-ignition combustion engine comprises exhaust branch passages each being connected to a corresponding cylinder of the engine at one end thereof and connected to a common exhaust passage at the other end thereof, and a filter arranged in at least one of the exhaust branch passages to trap particulates in the exhaust gas discharged from the engine. Pressure in the exhaust branch passage upstream of the filter is controlled to continuously make the pressure equal to or greater than a pressure in the exhaust branch passage downstream of the filter.

Abstract: A particulate trap for use in a diesel engine which is inexpensive, and which is high in particulate trapping efficiency, regeneration properties and durability, and low in pressure loss due to particulates trapped. An even number of flat filters made from a non-woven fabric of heat-resistant metallic fiber are laminated alternately with the same number of corrugated sheets made of a heat-resistant metal. The laminate thus formed are rolled into a columnar shape. Each space between the adjacent flat filters in which every other corrugated sheet is inserted is closed at one end of the filter element by a closure member. The other spaces between the adjacent flat filters are closed at the other end of the filter element.

Abstract: A particulate trap for a diesel engine use which is less likely to vibrate or deform under exhaust pressures and achieves good results in all of the particulate trapping properties, pressure drop, durability and regenerating properties. This trap has a filter element made of plurality of flat or cylindrical filters. Longitudinally extending exhaust incoming and outgoing spaces are defined alternately between the adjacent filters by alternately closing the inlet and outlet ends of the spaces between the adjacent filters. Gas permeable reinforcing members are inserted in the exhaust outgoing spaces to prevent the filter from being deformed due to the difference between the pressure upstream and downstream of each filter produced when exhausts pass through the filters. Similar gas permeable reinforcing members may also be inserted in the exhaust incoming spaces or at both ends of the filter element to more positively prevent vibration of the filters.

Abstract: A particulate trap for a diesel engine in which at least two nonwoven sheets made of heat-durable metallic fibers and at least two corrugated plates made of heat-durable metal having a width smaller than that of the nonwoven sheets are alternately overlaid in the thicknesswise direction with each other in a spiral manner, and one surface of one of the nonwoven sheets and one surface of the other of the nonwoven sheets are in close contact and are continuously welded to each other along the upstream edges thereof as seen from the flowing direction of the exhaust gas so that a first space closed along the upstream edges and opened along the downstream edges is formed between the nonwoven sheets via one of the corrugated plates, and the other surface of the one nonwoven sheet and the other surface of the other nonwoven sheet are in close contact and are continuously welded to each other along the down stream edges thereof as seen from the flowing direction of the exhaust gas so that a second space closed along t

Abstract: A compression ignition type engine comprising an NO.sub.x arranged in its exhaust passage. This NO.sub.x absorbent absorbs NO.sub.x when the air-fuel ratio of the inflowing exhaust gas is lean and releases the absorbed NO.sub.x when the air-fuel ratio of the exhaust gas is rich. When NO.sub.x should be released from the NO.sub.x absorbent, the mean value of the air-fuel ratio in the combustion chamber is changed from lean to rich. At least at this time, use is made of fuel containing oxygen as the injected fuel.

Abstract: An NO.sub.x absorbent (18) is disposed in an exhaust passage of an internal combustion engine and the exhaust gas is constantly made to circulate through the NO.sub.x absorbent (18) during the operation of the engine. The NO.sub.x absorbent (18) absorbs the NO.sub.x when the air-fuel ratio of the exhaust gas flowing into the NO.sub.x absorbent (18) is lean and releases the absorbed NO.sub.x when the air-fuel ratio of the exhaust gas flowing into the NO.sub.x absorbent (18) becomes the stoichiometric air-fuel ratio or rich. In the majority of the engine operation region, the lean air-fuel mixture is burned in the combustion chamber (3), and the NO.sub.x generated at this time is absorbed into the NO.sub.x absorbent (18). The air-fuel ratio of the exhaust gas flowing into the NO.sub.x absorbent (18) is periodically made the stoichiometric air-fuel ratio or rich, and the NO.sub.x absorbed in the NO.sub.x absorbent (18) is released, and simultaneously reduced.

Abstract: A NO.sub.x absorbent which absorbs NO.sub.x in exhaust gas when the air-fuel ratio of the exhaust gas is lean and releases absorbed NO.sub.x when the oxygen concentration of the exhaust gas is lowered, is disposed in an exhaust passage of an engine. When the amount of the NO.sub.x absorbed by the NO.sub.x absorbent is increased, the regenerating process of the NO.sub.x absorbent is performed by supplying a reducing agent to the NO.sub.x absorbent so that the NO.sub.x absorbed by the NO.sub.x absorbent is released and reduced by the reducing agent. Usually, to reduce the amount of the reducing agent required for the regenerating process, the inflowing exhaust gas into the NO.sub.x absorbent is shut off. In the present invention, even in the regenerating process of NO.sub.x absorbent, a small amount of the exhaust gas (carrier gas) is introduced to the NO.sub.x absorbent to carry the supplied reducing agent through the NO.sub.

Abstract: An exhaust emission gas control device having a first filter trapping particulates contained in an exhaust gas, and a second filter removing offensive odor components in the exhaust gas. The first filter is a honeycomb type having a cordierite substrate on which .tau.-alumina is coated. The second filter is provided downstream of the first filter, and is formed by an ion-exchange of copper on a synthetic zeolite rich in silica to form copper ions thereon.

Abstract: An exhaust gas purifying apparatus comprising a first and a second casings having expansion chambers, respectively, a third casing arranged between the first and second casings to form a passage therebetween, an inlet pipe introducing the exhaust gas into the first expansion chamber, and an outlet pipe discharging the exhaust gas from the second expansion chamber, whereby a muffler is constituted. The apparatus also comprises a filter arranged in the third casing to trap particulates in the exhaust gas, and a heater arranged adjacent to the filter on the side of the second expansion chamber to burn the particulates deposited on the filter, to regenerate the filter. A flow control unit, comprising a bypass and a valve therein, is arranged such that the exhaust gas normally flows through the filter and the heater, and when the filter is regenerated, at least a part of the exhaust gas flows in reverse through the heater and the filter. This exhaust gas purifying apparatus is built-in to the muffler.

Abstract: An exhaust gas emission control device comprising a filter provided in the exhaust passage, a heater provided near the filter, first and second passage bypassing the filter and the heater, a single first valve upstream of the filter a single second valve downstream of the filter, and a controller controlling the first and the second valve. When trapping particles, one of or both of the first and second valves closes the first and second passages, and the first and second valves open the exhaust passage, whereby exhaust gas flows through the filter and the heater. On the other hand, when regenerating the filter, the heater is switched ON, the first valve shuts the exhaust passage and the second valve is open to a predetermined degree, so that exhaust gas flows into the first passage, and a part of the exhaust gas flowing via the first passage flows through the heater, the filter, and the second passage.

Abstract: An exhaust-gas purifying apparatus according to the present invention comprises an exhaust-gas filter for trapping particulates in exhaust gas from an engine, and a heating device located on the upper-course side of the filter, with respect to the flowing direction of the exhaust gas, the heating device including one or more conductive-ceramic heater elements, capable of heating and burning the particulates caught by the filter, and a heater case for holding the heater elements in position, so that the caught particulates are heated and burned by the heater elements when the flow resistance of the exhaust gas, flowing through the filter, is increased by the caught particulates, whereby the flow resistance is reduced. The heater element includes a fixed electrode portion, immovably fixed to the heater case, and a slidable electrode portion held slidably.

Abstract: A ceramic heater for regenerating a fine particle collecting filter which is exposed to exhaust gases at elevated temperatures. This ceramic heater comprises two electrode potions, a heat generation portion connected to the two electrode portions and a holding projection portion of a ceramic heater connected to the side of the heat generating portion. The two electrode portions, the heat generating portion and the holding projection portion are formed integrally.

Abstract: An exhaust particle cleaning device for a diesel engine includes a trap case provided in a passage way of exhaust gas. A filter material is disposed in the trap case so that carbon particles or other exhaust particles contained in the exhaust gas can be caught within the filter material during the time the exhaust gas is passed through the filter material. A plurality of electric heater elements are spread or dispersed on the upstream end face of the filter material, so that the exhaust gas passes through the areas defined between the plurality of heater elements. The electric heater element may be coated with a ceramic material.

Abstract: An exhaust gas cleaning device comprises at least one exhaust gas flowing passage, at least one particulates collecting member composed of two filter elements having different heat capacity, which is disposed within the exhaust gas flowing passage and heating means which is interposed between the filter elements so as to be closely contacted therewith. The filter element having smaller heat capacity is disposed on the upper stream side of the heating means and the filter element having larger heat capacity is disposed on the downstream side thereof. The filter element having smaller heat capacity is rapidly heated by the heating means and the heat of the filter element having smaller heat capacity is transmitted to the filter element having larger heat capacity. All of the particulates collected by the particulates collecting member can be burnt off with excellent heat efficiency.

Abstract: A diesel engine is provided with a soot particle catcher. When the soot particle catcher is heavy with accumulation of soot, while the engine is operating a combustion chamber thereof is supplied with a purging supply of diesel fuel at a timing point at which heat produced by combustion of this diesel fuel within the combustion chamber is not substantially converted into mechanical work, but is vented to the exhaust system in the exhaust gases substantially completely. Thus the soot catcher is heated up, and is purged by combusting the accumulation of soot particles in it. This timing point may be the later part of the expansion stroke of the piston of the combustion chamber. The amount of this purging fuel supply may be arranged to be just enough completely to use up by combustion all excess oxygen in the combustion chamber at the timing point.

Abstract: This invention provides improvements in method of and apparatus for reducing an emitted amount of particulates by collecting the particulates contained in the exhaust gas from a diesel engine by a trapper. According to the invention, firstly, an excess amount of the particulates which have adhered to the trapper is detected, and thereafter, temperature of the trapper being within a range of self-burning temperature of the particulates is detected. When necessity for regenerating the trapper is ascertained based on the both detections described above, the inlet side of the trapper is heated to a range of igniting temperature of the particulates, whereby a large igniting energy required for propagating combustion is accumulated. Thereafter, secondary air is supplied to the trapper to ignite the particulates, and combustion is propagated to the particulates being within the range of self-burning temperature thereof by the secondary air continuously supplied, to thereby regenerate the trapper.

Abstract: An exhaust gas cleaning device for an internal combustion engine comprises a housing provided with an inlet port which is communicated with an exhaust pipe of an internal combustion engine and an outlet port, two particulates collecting members disposed in two independent exhaust gas flowing passages which are communicated with the inlet port through an inlet chamber and with the outlet port through an outlet chamber, a butterfly valve provided in the inlet chamber for alternately directing the exhaust gases into either one of the exhaust gas flowing passages and a heated air supplying means for burning off the particulates collected by the particulates collecting members, which is provided with a heated air outlet port opening into the inlet chamber so as to be opposed to the inlet port with the butterfly valve therebetween.

Abstract: An exhaust gas cleaning device comprises a casing provided with an inlet port which is communicated with an exhaust pipe of an internal combustion engine and an outlet port, two particulates collecting members disposed in two independent exhaust gas flowing passages which are communicated with the inlet port and the outlet port of the casing, a valve means provided on the downstream side of the two exhaust gas flowing passages for selectively passing the exhaust gases into either one of the exhaust gas flowing passages and a heated air supplying means provided on the downstream side of the collecting members for selectively supplying heated air into either one of the particulates collecting members.

Abstract: An exhaust gas recirculation system comprises a speed detector for generating an engine rotational speed signal and a reference rotational position detection signal, a pressure sensor for detecting the negative pressure in the intake pipe of an engine to generate a negative pressure signal, a microcomputer responsive to the negative pressure signal and the rotational speed signal generated at the reference rotational position of the engine to compute an amount of exhaust gas recirculation in synchronism with the reference rotational position detection signal, and an electronic control circuit for controlling the opening of an exhaust gas recirculation control valve in accordance with the computed amount.