Abstract: A device is provided for discharging two gases from a vehicle to ambient air, one gas having pressure pulsation of a first magnitude. The device includes an elongated body connected with the vehicle and having a first inlet connected with a first gas source, a second inlet connected with a second gas source, an outlet fluidly communicable with ambient air, and an interior mixing chamber, the two inlets being fluidly communicable with the chamber such that the two gases flow into the chamber. The body combines the two gases within the mixing chamber to form a combined gas having pressure pulsation of a lesser, second magnitude and to discharge the combined gas to ambient air. Preferably, the body includes an outer tubular member having the first inlet and the outlet and an inner tubular member disposed within the outer member and including the second inlet and a plurality of ports.

Abstract: A heat shield for an internal combustion engine exhaust system for supporting a first heat shield plate and a second heat shield plate on a U-shaped exhaust pipe extending from an exhaust port of an engine, via a support member such as band members, and heat shield plate attachment fixtures. The first heat shield plate covers all around a curved section of the U-shaped exhaust pipe in the vicinity of the exhaust port. The second heat shield plate covers an upper part of a straight section of the U-shaped exhaust pipe and extends rearwardly from the curved section. Further, since the exhaust pipe is formed as one piece, the first heat shield plate may be formed as a simple two-part structure using the band members. With this configuration, an effective heat shielding effect can be exhibited, and cost can be reduced.

Abstract: An exhaust gas purifying device of the present invention comprises NOx trap catalyst including NOx trap material, catalytic metal and O2 storage material, NOx sensor, section for releasing NOx when NOx absorbed amount of the NOx trap catalyst reaches a specified amount, section for determining diagnosis conditions of the NOx trap catalyst, section for detecting termination of O2 release from the O2 storage material, and section for diagnosing O2 storage capacity according to output value (NO1) of the NOx sensor during a term from beginning of the oxygen concentration lowering by the NOx release section until termination of the O2 release and for diagnosing NOx reduction capacity of the catalytic metal according to output value (NO2) of the NOx sensor after termination of O2 release, wherein a speed of lowering oxygen concentration during the diagnosis is set so as to be slower than that during non-diagnosis.

Abstract: An exhaust system having an exhaust manifold that comprises a plurality of single-shell discrete exhaust pipes connected to an engine, a double-shell collective chambered pipe joined to the discrete exhaust pipes and comprising an internal pipe shell into which exhaust gas streams passing through the discrete exhaust pipes are introduced and merge together and an external pipe shell surrounding the internal pipe shell, and a spherical joint connecting the collective chambered pipe to the exhaust pipe. The discrete exhaust pipe has a bent portion and a straight portion continuously extending from the bent portion to the collective chambered pipe. The bent portions of the respective discrete exhaust pipes are oriented toward a center of a straight row of cylinders so as to lay the straight portions of the discrete exhaust pipes nearly parallel to one another.

Abstract: An exhaust processor includes a soot filter and a filter regenerator. The filter regenerator is configured to burn off particulate matter collected in the soot filter to regenerate the soot filter.

Abstract: An exhaust gas system for an internal combustion engine, in particular, of a motor vehicle has two mufflers through which the exhaust gas is able to flow in a parallel fashion. A switching unit makes it possible to selectively convey the exhaust gas flow of the internal combustion engine only or almost exclusively through the first muffler, or only or almost exclusively through the second muffler, or through both mufflers in a parallel fashion. The two mufflers are realized differently with respect to their muffling effect and/or flow resistance.

Abstract: A catalytic oxidation system and method for the treatment of volatile organic compounds in which VOC-containing gas is preheated in a heat exchanger for raising its temperature before oxidation in a catalytic oxidizer without use of a burner. A reduced portion of the VOC-containing gas is diverted into an internal combustion engine with the exhaust mixed with the preheated VOC-containing gas to further raise the temperature of the mixed gas to a required reaction temperature for oxidation of the VOC-containing gas in the catalyst bed of the catalytic oxidizer. Heat from the catalytic reaction is recovered to assist preheating the VOC-containing gas in the heat exchanger.

Abstract: In a gas turbine power generator, a compressor rotor and a junction boss are assembled by fitting a convex faucet joint provided on the compressor rotor and a concave faucet joint provided on the junction boss, in a freely releasable manner, and the compressor rotor and a rotor shaft are assembled by fitting the convex faucet joint provided on the compressor rotor and a concave faucet joint provided on the rotor shaft, in a freely releasable manner, and those compressor rotor, the rotor shaft and a generator core are combined in series and fastened by using a tie bolt and a nut, which is connected to the junction boss of the turbine rotor.

Abstract: An exhaust manifold for a vehicle engine constructed of two stamped halves joined together along a longitudinal weld seam to form a compactly configured manifold. The assembled manifold includes exhaust tubes in communication with the combustion chambers of the engine and a collector chamber for directing exhaust from the tubes to the exhaust system. The individual exhaust tubes are configured for a compact installation and the collection chamber facilitates efficient flow of exhaust through the manifold.

Abstract: A heat shield provides thermal insulation and reduced noise transmission for under-the-hood vehicular engine components, such as exhaust manifolds. The structure is formed in three layers: an outer metal layer to provide structural integrity, a center insulation layer to isolate heat and dampen noise, and an inner metal layer directly adjacent the shielded component for reflecting heat back to the shielded component. As disclosed, the insulation layer is sandwiched between the two metal layers. The heat shield is formed in two integral mating halves to define a unitary structure containing grommets. The grommets incorporate capscrews rotatably secured in respective halves of the structure for attachment to mounting bosses on the component. Finally, the edges of the two metal layers of the heat shield are folded over to prevent injury to installers, and to reinforce the heat shield structure for enhancing its useful life under severe conditions of vibration and heat.

Abstract: An exhaust pipe has a manifold; one end of the manifold is connected to a distal end of a connecting tube. Another ends of the manifold are extended with a left branch tube and a right branch tube. The left branch tube is connected to a first muffler tube and the right branch tube is connected to a second muffler tube. The feature is that an interior of a middle section of the manifold has a valve which is controlled by a controller. The valve controls the area of the opening of the left branch tube communicated with the first muffler tube and the area of the opening of the right branch tube communicated with the second muffler tube. The driver may control the variation of exhaust gas without needing to adjust the exhaust pipe. The noise may be reduced easily and the performance of acceleration is enhanced.

Abstract: An exhaust manifold is disclosed that enhances the purification efficiency and lifetime of the catalyst in a catalytic converter. The manifold includes: a mixing chamber of a spheroidal shape having runners, each runner having one end connected to an exhaust port and the other end to the mixing chamber along the outer circumference thereof at an angle that causes rotation of the entering exhaust; and a diffuser to induce exhaust gas to diffuse widely before passing through the catalytic converter.

Abstract: A vehicle front structure which is partitioned into an engine compartment and a passenger compartment with a dashboard. An exhaust pipe is extended from a rear part of an engine accommodated in the engine compartment to a rear part of the vehicle, beneath the passenger compartment. Between the engine and the dashboard, a steering gearbox, a harness and a plurality of pipes extending transversely of the vehicle are arranged. A heat shielding plate is interposed between the steering gearbox, harness and pipes as a group, and the exhaust pipe. The heat shielding plate blocks heat emitted from the engine and the exhaust pipe from affecting the steering gearbox, harness and pipes.

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: Heat shielding panels are attached to exhaust pipes and a silencer by using small set springs and large set springs. Distortion on a heat shielded panel, which would be caused when attaching a heat shielding panel through welding, is not caused. A process for positioning a bracket, which would be required when welding a bracket to an exhaust pipe, can be omitted. Moreover, as no bolt and nut is used, the number of parts can be reduced. As a result, productivity can be improved and an increase in the cost can be suppressed.

Abstract: An exhaust equipment member having an exhaust gas path portion at least partially having a thickness of 5 mm or less is made of a heat-resistant, high-Cr, high-Ni, austenitic cast steel having weight ratios of Cr/Ni of 1.0-1.5 and Mn/S of 5 or more a composition by weight of 0.2-1.0% of C, 2% or less of Si, 2% or less of Mn, 0.04% or less of P, 0.05-0.25% of 5, 20-30% of Cr, and 16-30% of Ni, the balance being substantially Fe and inevitable impurities, with a weight loss by oxidation of 50 mg/cm2 or less when kept in the air at 10100 C. for 200 hours.

Abstract: An exhaust treatment system is provided for use with an internal combustion engine of a motor vehicle. The exhaust treatment system includes a parallel plate, monolithic plasma reactor for reducing nitrogen oxides in the exhaust gas from the engine, an electric power source for providing an electrical signal to the electrodes of the plasma reactor, and a controller interconnected between the electric power source and the plasma reactor for modulating the electrical signal to the plasma reactor. More specifically, the electric power source provides an alternating current electrical signal and the controller modulates the electrical signal off in accordance with a predetermined duty cycle, thereby achieving uniform barrier discharge in the plasma reactor.

Abstract: An in-cylinder injection type internal combustion engine, which includes a main fuel injection control unit that drives a fuel injector to inject fuel directly into a combustion chamber, is provided so that premixed combustion or stratified charge combustion takes place depending upon operating conditions of the engine. The engine further includes an additional fuel injection control unit that drives the fuel injector to inject additional fuel during an expansion stroke after the fuel injector is driven by the main fuel injection control unit, when it is necessary to increase the temperature of a catalyst provided in an exhaust passage for purifying exhaust gas. An exhaust manifold includes an exhaust chamber, in which the exhaust gas remains, and the additional fuel that is left unburned is re-burned in the exhaust chamber.

Abstract: An emission control system especially for light duty diesel engines has a first catalyst, 2, positioned upstream of a second catalyst, 3. The first catalyst converts NO to NO2 and the second catalyst oxidises HC, CO and VOF. The tendency of the second catalyst to collect soot particles is reduced by combustion of the soot particles by NO2 from the first catalyst.

Abstract: A combination recessed port of an internal combustion engine having a depth and inside diameter dimensions, and an adapter tube of a length exceeding the depth dimension of the recessed port, and an exhaust pipe having an inside diameter at least as large as the inside diameter of the recessed port and an outside diameter dimension greater than the inside diameter dimension of the recessed port provides improved engine efficiency and operation. The adapter tube is formed as an open ended cylinder providing an outer cylindrical surface having an annular lip formed medially, and a tapered annular surface at a distal end for mating with the exhaust pipe. The adapter inside diameter is smaller than the diameter of the exhaust port and is of such length as to enable exhaust flow to pass completely through the adapter prior to the next discharge.

Abstract: An exhaust gas dilution apparatus 10-2 is the same form multi-venturi type comprising a rectifier 11, divider 12, exhaust chamber 14, dilution tunnel 15, and a divider pipes 13t on the dilution side of a tunnel 15 side. All divider pipes 13 are provided with a venturi 21 having the same performance inserted in the same position, to measure the flow rate in the dilution tunnel and the flow rate on the exhaust pipe side. The opening of the shutter 19 provided in the exit of the exhaust chamber 14 is controlled so that the two flow rates are equivalent.

Abstract: An exhaust passage control valve has a valve element of a spiral shape mounted on a valve seat portion of a housing through which exhaust gases from an engine pass. The valve element is urged by a valve spring in a direction of closing the valve. A spring constant of the valve spring is kept low without enlarging the valve spring, and there can be obtained opening and closing characteristics in that the valve opens at a stretch when an exhaust-gas pressure has reached a predetermined value. As the valve spring, a helical torsion spring having a coiled cylindrical body portion is used. Arm portions on both ends of a coiled cylindrical body portion are engaged with a pair of spring receiving members. The spring receiving members are disposed in the housing on circumferentially opposite sides of the valve seat portions. The arm portion are engaged with the spring receiving members so as to be slidable in a longitudinal direction of the arm portions.

Abstract: An exhaust gas cooling system for a vehicle includes a cooling fin system retrofit and a side exhaust pipe retrofit having an exhaust gas exit pipe having a first portion having a plurality of mixing portions which are either bends or internal mixing fins configured to mix vehicle exhaust gas, but not to restrict exhaust gas flow, a second portion fastened to the first portion and a chrome coated third portion fastened to the second portion and extending along the side of the vehicle. The cooling fin system retrofit includes an adjustable clamp and one or more cooling fins, each cooling fin having a base having a pair of upstanding arms, with one arm of the pair having a lip for engaging an arm of another cooling fin. An exhaust gas cooling system kit, a side exhaust pipe retrofit kit, a cooling fin kit are included.

Abstract: A flexible line element, particularly for exhaust pipes of internal combustion engines of motor vehicles, is disclosed having a screw thread-like or annularly corrugated bellows provided with cylindrical connection ends and a metal netting directly surrounding the bellows. The metal netting is inherently stable and has at least one plastic deformation for acoustic or mechanical damping of the bellows. Consequently, the metal netting has both a protective and a damping function.

Abstract: A two cycle engine comprising an induction system to induct fuel and air into said two cycle engine, at least one cylinder arrangement to combust the fuel and air mixture of said two cycle engine, and a piston arrangement disposed in said at least one cylinder arrangement. The at least one cylinder arrangement is configured to combust the fuel and air mixture of the two cycle engine during each two cycle movement of said piston arrangement. The engine also has an ignition system disposed to combust the fuel and air mixture in the at least one cylinder during each two cycle movement of the piston arrangement and an exhaust system to exhaust gases from the at least one cylinder. The exhaust system comprises a reactor and a precombustion chamber, the precombustion chamber is disposed between the at least one cylinder and the reactor. The engine also includes a heat exchanger configured and disposed to transfer heat from exhaust gases from the reactor to the precombustion chamber.

Abstract: A pipe assembly includes an inner pipe and an outer laminated pipe disposed around the inner pipe for use in conveying exhaust gases from an internal combustion engine. The outer pipe is formed from two or more laminated layers to reduce noise emission. The outer pipe surrounds the inner pipe to protect the inner pipe, and muffle the inner pipe, while the inner pipe provides support for the outer pipe, either consistently contacting the outer pipe at the upstream inlet portion, or contacting the outer pipe at three areas spaced from each other on the outer pipe at the downstream outlet portion. The three contacting areas at the downstream outlet portion create an air-filled space at least partially separating the inner pipe and the outer laminated pipe. The air-filled space insulates the inner pipe so that exhaust gases moving through the inner pipe do not cool significantly as a result of heat dissipating by conduction or convection to the outer pipe.

Abstract: A knuckle joint 18 for the exhaust system of an internal combustion engine comprises first and second pipe segments 20, 22, the second pipe segment having an outwardly deformed end portion 24 which enters with clearance into a flared end portion 26 of the first pipe segment. There is a flange 32 on the first pipe segment and a flange 34 on the second pipe segment. A plurality of circumferentially spaced bolts 36 pass through corresponding holes in the flanges, there being a nut 40 on each of the bolts. On each bolt there is a coil spring 38 between the flanges, and a coil spring 42 between the flange 32 and the nut.

Abstract: An exhaust system for an internal combustion engine includes an enclosure with a top wall having an opening. An exhaust pipe includes an exhaust outlet and an outlet flange which is attached to the pipe at the exhaust outlet. The outlet flange is disposed adjacent to the opening in the enclosure. An exhaust muffler includes an exhaust inlet and an inlet flange which is attached to the muffler at the exhaust inlet. A rain skirt is interposed between and attached to each of the outlet flange of the exhaust pipe and the inlet flange of the exhaust muffler. The rain skirt has a hole therein allowing fluid communication between the exhaust pipe and the exhaust muffler. The rain skirt extends outwardly from the outlet flange and prevents water from entering into the enclosure through the opening.

Abstract: An improved apparatus for withstanding the high temperatures in the exhaust assembly of an internal combustion engine. A quilted insulating element is extended about a liner of a manifold or port liner. The liner in this invention is preferably ceramic. After assembling the insulating element about the liner, a metallic ring is installed for support during casting. A metallic housing, preferably cast iron, can then be cast around the liner, insulating element, and metallic ring.

Abstract: An exhaust gas cooling system for a vehicle includes a cooling fin system retrofit and a side exhaust pipe retrofit having an exhaust gas exit pipe having a first portion having a plurality of mixing portions which are either bends or internal mixing fins configured to mix vehicle exhaust gas, but not to restrict exhaust gas flow, a second portion fastened to the first portion and a chrome coated third portion fastened to the second portion and extending along the side of the vehicle. The cooling fin system retrofit includes an adjustable clamp and one or more cooling fins, each cooling fin having a base having a pair of upstanding arms, with one arm of the pair having a lip for engaging an arm of another cooling fin. An exhaust gas cooling system kit, a side exhaust pipe retrofit kit, a cooling fin kit are included.

Abstract: A heat-resistant, thermally insulative, ductile port liner for a head of an internal combustion (IC) engine having a tube-shaped structure formed from at least one layer of fiber reinforced ceramic matrix composite (FRCMC) material. The FRCMC material includes a polymer-derived ceramic resin in its ceramic form and fibers. In a first embodiment of the port liner, the tube-shaped structure has one FRCMC layer forming the sole, solid wall of the structure. Whereas, in a second embodiment, the tube-shaped structure has two FRCMC layers forming inner and outer walls of the structure, respectively, with an intervening space separating the inner and outer walls. The intervening space is sealed at both ends It can be filled with a thermally insulating material, evacuated and held at substantially a vacuum pressure, or filled with a gas. Once the port liner has been formed, it is preferably cast-in-place when the metal head of the IC engine is formed.

Abstract: An exhaust manifold comprising a plurality of exhaust pipes and a merging portion applies exhaust gas from each cylinder uniformly to an oxygen sensor in a merging portion at low speed thereby improving the durability of the oxygen sensor. A downstream forward end of each exhaust pipe of the exhaust manifold, when connected to an inlet wall of a merging case having the oxygen sensor mounted on a side thereof, is formed in the shape of a bell mouth for leading the exhaust gas to the oxygen sensor. Each exhaust pipe is fixedly welded to the merging case at a position upstream of the forward end of the bell mouth. An angle formed by lines perpendicular to tangential lines at starting and ending points of a curved portion of the bell mouth at the forward end of the exhaust pipe is set in the range of 45.degree. to 75.degree.. As a result, the bell mouth spreads over the whole interior of the merging case and reduces a flow rate of the exhaust gas, and part of the exhaust gas flows toward the oxygen sensor.

Abstract: An exhaust manifold seal arrangement to eliminate oil slobber comprises a counter bore in cylinder head exhaust ducts, a spiral wound gasket with chevron shaped ends and a barrel shaped portion disposed between the chevron shaped ends being disposed in the counter bore to form a leak proof seal between the cylinder head and the exhaust manifold and a thermal liner between the exhaust gases and the counter bore, the exhaust manifold being made in three parts with a spiral wound gasket being disposed between the parts to form a leak proof seal between the parts.

Abstract: An exhaust manifold assembly including a one-point junction type exhaust manifold, whereby the occurrence of exhaust interference is prevented by a large capacity portion formed at a junction of the branch pipes. The large capacity portion has a capacity larger than the capacity of each branch pipe. Both torque and output can be improved, the size of the exhaust manifold can be reduced, and layout restrictions can be eliminated. The exhaust manifold assembly includes an exhaust manifold attached to the internal combustion engine, the internal combustion engine having a plurality of cylinders, and a manifold cover disposed to shut out heat and sound from the exhaust manifold.

Abstract: An exhaust after-treatment system for treating an exhaust stream from an internal combustion engine of an automotive vehicle includes first and second exhaust treatment devices in a parallel path, continuous flow, flow rate sensitive exhaust temperature modification circuit for conducting exhaust gases from the first treatment device to the second exhaust treatment device.

Abstract: A heat shield for an exhaust system of a vehicle includes a resinified spaced layer fabric having at least one inner layer, at least one outer layer, and at least one spacer between the inner layer or layers and the outer layer or layers to form one or more insulative spaces. The heat shield includes an emissivity reducing material. The insulative space is between about one and about eight millimeters thick, to reduce convective heat transfer.

Abstract: An ionization field is produced across the pumped air flow to a fuel combustion process to increase the content of oxygen in the stream, and the stream reactivity. This ionization field may be produced between a sharp electrode and a grid or sheet, positioned in a shielded structure like the filter housing on the engine intake. Alternatively, an ultraviolet light source may be used to ionize the oxygen in the air stream. In either form the air stream may be compressed before its ionization and then may be injected into the exhaust products of the combustion process. The ionization power may be modulated along with the demand. Thus the throttleposition may be sensed to modulate the voltage multiplier levels across the electrodes straddling the air stream, in accordance with the demand.

Abstract: A corrosion-resistant, thermally insulative riser elbow for a marine engine. The riser elbow has an exhaust gas conduit made of fiber reinforced ceramic matrix composite (FRCMC) material formed from a polymer-derived ceramic resin in its ceramic state and fibers. Employing a FRCMC material results in a low-cost, light-weight, corrosion-resistant exhaust gas conduit not available with existing riser elbows. In addition, a FRCMC exhaust gas conduit is thermally insulative and so more of the heat of the exhaust is retained rather than being transferred to the conduit. This allows the cooling requirements for the riser elbow to be lowered, while still maintaining a touch temperature below prescribed levels. FRCMC can also be formed into practically any shape and size desired and can be very ductile thereby making the exhaust gas conduit fracture resistant and capable of withstanding thermally-induced strains typical of the environment of a marine engine's exhaust system.

Abstract: A method for detection of the performance reduction of an exhaust gas purification catalyst used for reducing the concentration(s) of combustible components or (and) nitrogen oxides all present in an exhaust gas, which method detects a reduction in the heat amount E.sub.g generated from the exhaust gas by the reaction of the exhaust gas catalyzed by the catalyst, or a reduction in the cumulative heat amount generated from the exhaust gas by said reaction in a predetermined temperature range taken by the catalyst during its temperature increase. This method can detect the performance reduction of the catalyst accurately without conducting constant-speed vehicle running for a long time.

Abstract: A heat-resistant, thermally insulative, ductile port liner for a head of an internal combustion (IC) engine having a tube-shaped structure formed from at least one layer of fiber reinforced ceramic matrix composite (FRCMC) material. The FRCMC material includes a polymer-derived ceramic resin in its ceramic form and fibers. In a first embodiment of the port liner, the tube-shaped structure has one FRCMC layer forming the sole, solid wall of the structure. Whereas, in a second embodiment, the tube-shaped structure has two FRCMC layers forming inner and outer walls of the structure, respectively, with an intervening space separating the inner and outer walls. The intervening space is sealed at both ends. It can be filled with a thermally insulating material, evacuated and held at substantially a vacuum pressure, or filled with a gas. Once the port liner has been formed, it is preferably cast-in-place when the metal head of the IC engine is formed.

Abstract: A hot pipe from an automobile manifold is shielded from other components in the engine compartment by attaching a two part shield around the pipe and clamping it in place. Each part is formed of two sheets of metallic material sandwiching therebetween a fibrous layer of heat insulating material. The layers of each of the shield parts are formed to a shape to conform to the shape of the hot pipe to be shielded prior to installation.

Abstract: A method of forming a breakage resistant, erosion resistant ceramic liner for a part comprising the steps of, forming a liner of a ceramic material containing pores; filling the pores with a pre-ceramic polymer resin; and, firing the liner saturated with a pre-ceramic polymer resin at a temperature and for a time which converts the resin into a ceramic within the pores. The liner can be mechanically attached, adhesively bonded or, a metal part can be cast onto the liner by placing the liner within the metal casting mold for the part as a sidewall or integral element thereof. The invention also includes method for producing parts and liners of fiber reinforced ceramic matrix composite by a resin transfer molding process or the like wherein fiber preforms are saturated with liquid pre-ceramic polymer resin. The preforms are then polymerized in a mold, the part removed from the mold, and then fired to transform the polymer to ceramic. The process can also be employed to form hollow parts such as manifolds.

Abstract: The invention relates especially to an exhaust piping for a catalytic gas exhaust system including a gas manifold and a catalyzer, said piping (4) being situated between said manifold and said catalyzer and provided with a composite tube (8) which consists of an internal tube and of an external tube defining between them a substantially annular space.Advantageously, said composite tube (8) is housed inside said exhaust piping (4), the external tube coming substantially into contact with said piping, and said internal tube (10) and external tube (11) exhibit thin walls (10A, 11A), the thickness of which is less than 0.3 millimeter.

Abstract: In order to prevent a catalyst for an internal combustion engine from experiencing decreased efficiency by deterioration after long time use of the catalyst, the decreased efficiency of the catalyst is determined, and the internal engine is controlled based on results of the determination so as to maintain high efficiency of the catalyst. The catalyst is installed in an exhaust pipe of the engine. Sensors for detecting conditions of exhaust gas both at a upstream side and a downstream side of the catalyst are provided, respectively. As for the sensor, for example, an oxygen sensor whose output varies stepwise at .lambda.=1, or a sensor whose output varies in proportion to air-fuel ratio can be used. Detected values of the sensors are taken into a control unit, catalyst efficiency and deteriorating degree of the catalyst are estimated by comparison of the detected values, and the engine is controlled so that the catalyst efficiency is maximized.

Abstract: An exhaust manifold for an internal combustion engine with at least two cylinders includes at least two adjacent connection branches which are interconnected by collection pipe sections having an expansion compensating bellows for accommodating differential thermal expansion therebetween and a gas flow guide pipe structure which extends into the bellows. At least one of the collection pipe sections comprises a multi-layered pipe wall with which the expansion compensating bellows is integrally formed.

Abstract: An exhaust manifold for an internal combustion engine includes an inner duct with flanges for connection to an engine. The inner duct is enclosed by an envelope consisting of two shells which are interconnected at their edges by seams. Between the inlet flanges, the seams are disposed at a substantially greater distance from the inner duct than in other areas such that, in a cross-sectional plane disposed between, and extending normal to, the flanges, the envelope has drop-like shape.

Abstract: The design and construction of past exhaust port liners with heat insulation capabilities have had to become more simple in order to reduce costs. However, less costly exhaust port liners may have inferior heat insulation capabilities. The present invention overcomes this and other problems with a means for encapsulating an insulating layer of material. The encapsulating means is composed of fiberglass cloth with the ability to withstand high temperatures. A blanket is formed when the fiberglass cloth encapsulates the insulating layer. The blanket is stitched in a quilted pattern to form a plurality of individual pockets. The blanket is wrapped around a ceramic body of a port liner. The quilted stitching pattern, due to separating the insulating layer into the plurality of individual pockets, protects the pockets individually. If damage should occur to one of the plurality of pockets, the insulating layer would remain intact within the remaining plurality of pockets.

Abstract: A damped heat shield for a high temperature portion of a vehicle exhaust system. The heat shield has inner and outer metal layers of substantially different thicknesses and substantially different resonant frequencies, which causes the shield to damp vibrational energy and reduce radiated sound energy and noise. Between the metal layers is a layer of sound and heat shielding material such as aluminum foil or ceramic fiber paper. The metal layers are preferably stainless steel, cold rolled steel, aluminized steel, aluminum-clad steel, or aluminum. If cold rolled steel is used, the exterior of the shield is preferably coated with a corrosion-resistant coating.

Abstract: A method of controlling the operation of heaters for an exhaust gas oxygen sensor as function exhaust gas temperature as compared to a first exhaust gas temperature to turn on the heaters and a second exhaust gas oxygen sensor temperature to turn off the heaters.

Abstract: A portable, work prooducing apparatus is powered by a single cylinder, two-stroke, internal combustion engine made substantially from aluminum. An exhaust port defined through a wall of the cylinder has inserted therein a steel sleeve with dimensions smaller than the exhaust port to create an air gap between the sleeve and the walls of the exhaust port. A muffler is fastened directly to the cylinder at the exhaust port. Fastening of the muffler acts to press the flange of the sleeve against the exterior of the cylinder, thereby retaining the sleeve within the exhaust port without additional fasteners and creating a good seal with the muffler. The steel and air insulate very hot exhaust gases from the cylinder to prevent overheating of the air-cooled cylinder in the area around the exhaust port that causes premature failure of lubricant and wear of the engine components.

Abstract: A hanger for use with a conveyor in a garment making plant or the like for holding limp sheet material includes a hanger rod for attachment to a conveyor trolley and a hanger body carrying, and forming in part, a plurality of grippers, each capable of holding a workpiece unit to the body. Each gripper is made up of a stationary gripping face on part of the hanger body and a grip elememnt supported for movement along a path giving it a wedging action on a work unit inserted in the gripper when the grip element is urged downwardly by the weight of the work unit and its engagement therewith.