Abstract: A fan assembly which has an air inlet that combines the function of absorbing fan noise and the function of streamlining air intake. A continuous strip of sound absorbing material is mounted on a perforated support and is wrapped in an overlapping manner which, when placed with the fan, dampens fan noises, as well as allows acceleration and uniformity of distribution of incoming airflow.

Abstract: A muffler for work vehicle V-type internal combustion engines is disclosed, which is mounted in a horizontal sideway position, with its axis placed perpendicularly with the longitudinal vehicle axis, kept a proper distance from the chassis or vehicle body so that it is disposed in full exposure to the atmosphere for proper cooling. A pair of spaced inlet ports are provided in the muffler, at locations adjacent to opposite ends thereof for receiving the exhaust gases from the engine through a pair of parallely extending, parallel exhaust pipes directly interconnected between the combustion chambers of the two cylinders and the muffler inlet ports, without using the conventional intermediate flexible corrugated connectors.

Abstract: Disclosed herein is an engine noise control device for use in automobiles or the like comprising a noise control member which is attached to an opening of an engine room of an automobile or the like. The noise control member has a plurality of hollow conduit passages penetrating from one of surfaces to the other surface thereof. The hollow conduit passages are so arranged that the length of the conduit passages becomes shorter from the central portion to the peripheral portion of the noise control member. Thereby, a noise-propagating direction is changed by controlling the noise to reduce the energy of sounds radiated and/or diffracted to the outside.

Abstract: The invention relates to an adhesive insulating system that is non-destructively removable, e.g. for the purpose of repair, for sound insulation of partition walls, particularly in motor vehicles. To overcome the disadvantages associated with the previous systems in mounting and also in repair a layer of material of a highly under-cross-linked polyurethane is now applied between the substrate and the overlying layers. This polyurethane layer has, owing to its under-cross-linking, a great adhesive effect and thus enables the substrate and the insulating layers to be joined in a force-locked manner. The adhesive material layer can be prefabricated or is prepared by spraying on a highly under-cross-linked 2-component mixture of the polyurethane former.

Abstract: An acoustical enclosure for a marine engine generator set includes a squirrel cage fan powered mechanically by the engine and mounted over a large opening in an end of the enclosure. Air inlets are provided to admit external air into the enclosure. A large air flow results, allowing the generator to be operated at full capacity, even at elevated ambient temperatures. Noise is prevented from escaping out of the opening in the end of the enclosure by having the fan placed directly over the opening, where the solid plate of the squirrel cage fan reflects a portion of the noise back into the enclosure where it is absorbed by sound absorbing material lining the inside of the enclosure. A fan duct surrounds the fan and a cover is placed over the duct. The cover is also lined with sound absorbing material to further attenuate any noise not reflected back by the fan.

Abstract: A portable engine unit is provided. The unit comprises an engine including a clutch, a crankcase enclosing a crank shaft, an engine cylinder enclosing a piston and a piston rod, a carburetor, an air filter, a recoil starter, and a muffler; and a housing for enclosing the engine, comprising at least two portions which are assembled and disassembled along a plane including the axis of rotation of an output shaft of the engine to enclose and expose the engine.

Abstract: A base structure of a motor saw forms fuel and oil tanks (16,17) and a crankcase bottom in one piece. This piece is injection moulded in plastics with closed tank cavities obtained by means of cores in the mould which are made of a metal having a melting temperature lower than the softening temperature of the plastic material. After moulding the cores are melted by heat treatment and the metal runs out through filling holes (18,19) of the tanks. Armouring pieces are moulded in the plastics to reinforce the attachments of crankshaft bearings and the guide bar.

Abstract: A partition (4) for separating the engine compartment (2) from the passenger compartment (3) of a motor vehicle comprises a wall (5) and a covering (6) of noise-insulating material on the engine compartment side of the wall. The partition (4) has convex or concave deformations (8, 9, 11) in one or several areas of the high noise occurrence.

Abstract: An engine compartment sound and water shield pad fabricated of a material which provides sound and vibration control and which has an integrally formed waterproof drain tray portion. The pad is particularly suited to be carried on the underside of a vehicle hood panel which is provided with louvers to facilitate the flow of air through an engine compartment enclosed by the hood.

Abstract: An air cleaner for an engine is provided according to the invention. Said air cleaner comprises openings for communicating with atmosphere provided along a peripheral portion surrounding a suction chamber communicating with a suction port of a carburetor, a filter to cover said openings, a suction path formed along the inside of said openings, a partition wall provided to separate said suction path and said suction chamber, and a communicating path to provide communication between said suction path and said suction chamber so that the suction sound of the engine is prevented by said partition wall from propagating directly to atmosphere and reduced due to interference caused when passing through the long suction path which is located inside the filter, without reducing the area of the path through which suction air passes.

Abstract: A soundproof engine-operated machine or generator includes a floor having first and second air discharge hole, wall members cooperating with the floor in defining a container, at least one wall member having an air inlet for introducing air into the container, a water-cooled engine disposed in the container, a first cooling fan disposed in front of said engine for delivering air from said air inlet toward said engine to cool the engine, a machine unit such as a generator operable by the water-cooled engine, a radiator attached to the engine, a second cooling fan disposed in front of the radiator for drawing air from behind the radiator therethrough, an exhaust pipe connected to the engine and extending below the floor, a muffler connected to a downstream portion of the exhaust pipe and disposed below the floor, a duct for guiding air from the engine around the exhaust pipe to cool the exhaust pipe and for discharging the air through the first air discharge hole, and a scroll-shaped fan cover for discharging a

Abstract: A water-cooled internal combustion engine powering the vehicle is mounted in an engine compartment comprising a sound-insulating capsule. Independent of and additionally to any possible blower ventilation of the capsule at least one separate inlet opening into the capsule is connected to an intake opening situated in an area which is exposed to dynamic pressure when the vehicle is in motion. The front cross-member may be provided with an intake opening open in the direction of motion as well as with a sound-absorbing lining, and the inflowing cooling air may be fed into the capsule via the adjacent longitudinal beams of the vehicle frame.

Abstract: In a motor vehicle a water-cooled internal combustion engine serving as the driving engine is enclosed by a sound-absorbing capsule partly formed by the surrounding parts of the vehicle. At the front wall of this capsule a housing is provided to receive the air flowing off from the radiator, from which housing a closed air duct passes through the capsule, leading into the outside at one of the other capsule walls.

Abstract: An improved induction system silencing device for an outboard motor having an engine and a surrounding protective cowling comprising a baffle plate positioned within the protective cowling for forming a resonance chamber.

Abstract: An internal combustion engine powering a motor vehicle is provided with a separate exhaust casing which is located within an engine compartment developed into a sound-insulating capsule, and is designed as a roof-type cover without a bottom shielding at least those parts of the exhaust system close to the cylinder head of the engine. This cover is connected with an outlet opening in an outer wall of the vehicle, which opening is positioned in an area where the heated air rises from the exhaust system, such that ventilation of the capsule and the exhaust system is ensured even after the engine has been turned off.

Abstract: A longitudinal housing wall for an internal combustion engine is formed with an elongate channel defined by two confronting parallel surfaces. A rod extends in said channel over at least two-thirds of the length of said channel and is coupled to said wall so as to be resiliently movable relative to said wall and capable of absorbing energy of flexural vibration at a predetermined frequency from said wall.

Abstract: A board having improved thermal and/or acoustical properties is disclosed, together with a method and apparatus for producing same. The board is of finite thickness and has a graduated density, the two opposing major surfaces have the greatest density and the intermediate portion has the least density with the board density gradually decreasing in the region between the major surfaces toward the intermediate portion thereof. The board is produced by a molding process, wherein blankets of loosely gathered fibers and containing a suitable binder, are utilized to form the board. The blankets are preferably high compressible and have interposed therebetween an initially relatively highly incompressible air filled member. These laminates are pressed together between a pair of heated mold halves. As the temperature of the laminate increases, the interposed member softens and is rapidly reduced in thickness due to the escape of air as it softens and melts.

Abstract: A noise reducing cover for use with an internal combustion engine, taking the form of a cylinder head cover, an oil pan, a valley cover, a valve lifter cover or the like, is constructed of a main body portion of a resilient porous material, and an inner skin layer of a resilient non-porous material, securely connected to the inside of the main body portion. The noise reducing cover excludes a hard layer made of metal or hard plastic, thereby suppressing vibration of the noise reducing cover itself even when engine vibration is transmitted thereto.

Abstract: A method and apparatus for suppressing sound generated by engines or other noise sources, by utilizing at least two acoustical encasements separated by an air channel with air being drawn through the air channel to provide intake air to the noise source. Sound leaks through the intake vent are attenuated by the air channel. Entrainment devices or an auxillary fan may be used to compensate for loss of air intake due to pressure losses through the air channel. Also, the use of entrainment allows for a smaller exhaust vent which reduces the opening ratio in the encasement, thus reducing sound leaks through the exhaust vent. Additionally, sound absorbing or attenuating materials are placed inside the intake air channel, thus suppressing the sound emanating from the noise source. Also, the exhaust vent is lined with proper absorbing materials to further reduce sound coming from the noise source. Furthermore, the inside encasement is substantially isolated from the outside encasement.

Abstract: An axial fan, preferably for the cooling systems of water-cooled internal combustion engines, comprises an impeller and an air duct housing provided with a fan guard which is separated by an annular gap from the tips of the impeller blades and is centered on the impeller axis by a support comprising radial arms attached to the fan guard. For noise reduction, the radial arms are supported on the hub of the impeller, on the side facing the fan shaft, by means of a roller bearing held by a mounting plate, and the mounting plate is made independent of the impeller bearing.

Abstract: A sealing device for a timing belt cover and an engine mount bracket comprises a rib formed on said engine mount bracket and a gasket having a lip of C-shaped section and a fixed portion continuous from said lip. The fixed portion of the gasket is attached to a portion of the timing belt cover surrounding an opening provided in said timing belt cover and said lip of C-shaped section of the gasket is contact with said rib of the engine mount bracket. Since the gasket is made of an elastic material other than sponge, e.g. rubber, it does not undergo a permanent deformation and causes no gap between said lip and said rib. Besides, since said lip of C-shaped section is easily deformed, there is no likelihood of an excessive load being applied to said timing belt cover.

Abstract: A closed enclosure for a vehicle engine has an air inlet and an air outlet formed at its front and rear ends. Both air inlet and air outlet have sets of sound absorber blades for noiselessly admitting ambient cooling air into the enclosure and for noiselessly exhausting the air therefrom. Disposed horizontally within the enclosure, a first heat insulating partition divides its interior into an engine compartment accommodating the engine and, thereover, a muffler and air cleaner compartment. A second heat insulating partition is mounted vertically on the first partition to subdivide the muffler and air cleaner compartment into a muffler compartment receiving an exhaust muffler assembly and an air cleaner compartment receiving an air cleaner assembly. The engine compartment is open both forwardly and rearwardly for the passage of the cooling air therethrough.

Abstract: A member adjacent to an engine, as an engine cover such as an engine head cover and oil pan and an air cleaner, is made of fiber layers by shaping organic or inorganic fibers mixed with a resin and its crosslinking agent while heating so as to cause a crosslinking reaction, thereby absorbing vibrations transmitted from an engine and remarkably decreasing noises resulting from surface vibrations of the member with the aid of the damping capacity of the fiber layers.

Abstract: The apparatus is enclosed in thermally and acoustically insulating panels supported by a framework. Each panel has a peripheral gasket which seals against adjacent surfaces of the framework to provide improved thermal and acoustic insulation.

Abstract: A circumferentially extending structure 30 for containing particles having an axial component of velocity and a radial component of velocity is disclosed. The structure includes an inner casing, such as the first casing 48, and an outer casing, such as the second casing 50. The outer casing is flexible. The outer casing is formed of a plurality of layers of fabric and a means for applying a load to the fabric such as a plurality of bars 80, 82 and turnbuckles 74. A method of forming the structure is disclosed. The method includes the step of wrapping a fabric having a first length about the inner casing and the step of stretching the fabric to a second length to affect the operative response of the fabric to the impact of a particle.

Abstract: Sound damping apparatus for internal combustion engines, especially for public works or agricultural machines, and machines provided with such an apparatus.This sound damping device is intended for machines or engines mounted within a bonnet (1) and provided with a blower (3) discharging cooling air to the outside through a radiator (4). It is constituted by a sound damping element (9, 21) such as a block of expanded foam material having one or more central openings (14) oriented in the direction of flow of the air discharged by the blower and peripheral openings (16) inclined or specially shaped so as to direct the air towards the central flow passing through the central opening or openings downstream of the device. Means are provided for forming an expansion chamber (13) between the radiator and the sound damping element.

Abstract: An engine block includes a crankshaft, and is enclosed by a sheath. Sealing elements connect the sheath to the engine block and insulate against structure-borne sound. A flywheel is non-rotatably connected to the crankshaft at one end of the engine block. A power train housing is disposed at that end of the engine block and includes a flywheel housing which accommodates the flywheel. The flywheel housing is rigid with the engine block and forms a unit therewith. The sheath encloses the engine block on all sides and defines an oil chamber around the engine block. The sealing elements consist of rings provided at opposite ends of the engine block. The unit is carried by and connected to a support by elastic elements which insulate against structure-borne sound.

Abstract: A circumferentially extending apparatus 46 for containing particles having an axial component and a radial component of velocity is disclosed. The apparatus is comprised of a support structure 48 and a flexible casing 50 formed of a fabric 78. The external surface of the support structure has a first diameter and a second diameter not equal to the first diameter at a location spaced axially from the location of the first diameter. The fabric is preloaded to increase the length of the fabric and is wrapped under tension about the surface of the support structure such that the installed length of the fabric is greater than the free length of the fabric. A method for forming the circumferentially extending structure is disclosed which includes the steps of forming a support structure and wrapping a preloaded fabric about the support structure to cause an elongation of the fabric and tension in the fabric in the installed condition, which varies depending on the diameter of the support structure.

Abstract: It should be possible to manufacture, in a simple manner, a sound-absorbing wall-lining (3) consisting of a material to be applied to the wall which needs lining, and a resilient layer (4, 5) of foam, e.g. foam rubber, felt, or similar material, having locally distinctive sound-absorbing capacities, and whose thickness will possibly remain uniform, provided the resilient layer (4, 5) contains a filler with locally distinctive degrees of cross-linking--corresponding to distinctive sound-absorbing capacities.

Abstract: In order to avoid the danger of overheating the separate exhaust jacket of a water-cooled internal combustion engine with a sound-absorbing cover whose enclosed space contains air inlet and outlet openings sealed against the penetration of sound, and is ventilated by cooling air during operation of the engine, and which has a separate exhaust jacket with air ducts of its own-with a radiator cooling fan being placed outside of the cover in the vicinity of a cover wall serving as a radial deflector for the outgoing air from the fan, and with the exhaust jacket leading substantially upwards from its outlet to its inlet opening-after the engine has been switched off and the forced ventilation has thus come to a standstill, the air inlet opening leading into the exhaust jacket is connected to the topmost part of this jacket and is positioned such as to be exposed to the flow of outgoing air from the fan.

Abstract: A noise-shielding panel comprises a flat section spacedly disposed from the surface of an engine body and formed of a fibrous composite, and a contacting section integral with the flat section and formed of the same fibrous composite as in the flat section. The contacting section is in direct contact with the engine body surface and lower in density of the fibrous composite than the flat section, thereby facilitating production thereof and exhibiting a high noise-shielding effect.

Abstract: A circumferentially extending structure 30 for containing particles having an axial component of velocity and a radial component of velocity is disclosed. The structure includes an inner casing 48 and an outer casing 50. The outer casing is formed of a plurality of layers of flexible fabric and includes layers having differing masses per unit length in the fabric. The layers of fabric extend about the inner casing. A means for applying a load to the fabric engages the fabric to place the fabric in tension. One such means is a plurality of bars 80, 82 and turnbuckles 74. In one embodiment, the fabric has a greater mass per unit length in the leading edge region and a greater tension is applied to the leading edge region than other regions of the fabric. A method of forming the structures is disclosed.

Abstract: A circumferentially extending structure 30 for containing particles having an axial component and a radial component of velocity is disclosed. The apparatus is comprised of a hollow annular beam 48 and a fabric 46 wrapped under tension about the annular beam such that the installed length of the fabric is greater than the free length of the fabric. In one particular embodiment the fabric is coated with a layer 116 of epoxy resin such that the resin penetrates only the top layer of the fabric to form a shield. The shield layer protects the containment fabric from injury.

Abstract: A constrained-layer construction comprising a stiff layer or substrate and a layer of a viscoelastic polymer which is the reaction product of (a) 25 to 75 weight percent of an acryloyl or methacryloyl derivative of at least one oligomer, said oligomer having a glass transition temperature of less than 25.degree. C. and a molecular weight per oligomer of 600 to 20,000, and (b) 75 to 25 weight percent of a copolymerizable monomer whose homopolymer has a glass transition temperature of at least 50.degree. C., the copolymer being suitable for damping vibrations at relatively high temperatures, e.g., 50.degree.-150.degree. C., is disclosed. Also included is a process for damping vibrations in component parts of devices used in automotive, aerospace, and computer industries.

Abstract: A motor vehicle comprising a power unit including an internal combustion engine, a radiator and a transmission, a sound insulating cover located below the power unit, and connecting plate members which securely connect the sound insulating cover to the body of the motor vehicle, thereby forming a noise insulating duct in which the engine is located, so that the engine noise is effectively prevented from being directly emitted outside the vehicle.

Abstract: A reed type valve is operatively secured on the outer surface of the casing of an engine air filter assembly to supply the exhaust system of an engine with secondary air. The reed valve is fluidly connected to an air induction passage formed inside the casing of the air filter assembly. A resonance chamber is also formed inside of the casing and communicates through a communication passage with the air induction passage so as to attenuate a relatively low frequency component of exhaust noise transmitted through the reed valve. The air induction passage, resonance chamber and communication passage are formed as follows: ##EQU1## where, S.sub.o (cm.sup.2)=the cross-sectional area of the air induction passageS(cm.sup.2)=the cross-sectional area of the communication passagel(cm)=the length of the communication passageV(cm.sup.3)=the volume of the resonance chamberM=the number of the engine cylinders of the engine.

Abstract: Disclosed is an air cooled internal combustion engine which comprises a cooling fan formed unitarily on a flywheel fixed to one end of an engine crank shaft, a cooling fan case covering the cooling fan and adapted to guide the flow of cooling air generated by the cooling fan toward the engine body, an air cleaner connected to the suction port of the engine, and a silencer connected to the exhaust port of the engine, wherein the suction port is located at the same side of the engine body as the flywheel while the other exhaust port is located at the opposite side of the engine body to the flywheel, and wherein the air cleaner is formed integrally with the cooling fan case.

Abstract: A noise reducing cover for an internal combustion engine, comprising a layer formed of a material which is high in damping capacity, and metal fibers contained in the high damping capacity material, thereby effectively preventing engine noise emission, maintaining good heat conductivity therethrough.

Abstract: An internal combustion engine whose engine unit support, comprising such sound-generating parts as cylinders, cylinder head, piston rods, crankshaft bearings, crankshaft, is provided with a bracket of at least two arms at least at its output end. This bracket is attached to the bearing seats of the crankshaft and is provided with at least one sound-insulating element at each end of its arms for connecting said engine unit support to the crankcase. This will reduce any relative movements between the crankshaft and the crankcase in a simple manner.

Abstract: An engine, preferably of the heavy duty diesel internal combustion type, is provided with a crankcase having downwardly extending side walls interconnected by a stiffening bridge member. The bridge member includes integral mounting means for an oil pump and its drive shaft and supports a drive gear that directly engages a driving gear on the engine crankshaft immediately above the assembly.

Abstract: An automotive vehicle noise reduction device comprises an under-cover structure fixedly disposed directly under an engine and including a plate member securely connected to a vehicle body, a plurality of covering members which are spaced from each other and fixedly disposed between the plate member and the engine, and a sound absorbing material securely attached on each covering member and located opposite to the plate member, thereby effectively improving noise insulation effect while preventing vehicle fire.

Abstract: An internal combustion engine includes an engine block, an oil pan, a sound insulating capsule and a sealing gasket connecting the oil pan to an underside of the engine block. The sealing gasket has folds for permitting a relative displacement between the engine block and the oil pan during operation of the engine. The sealing gasket is supported on a lower portion of the capsule as a component thereof, while the capsule is supported externally of the engine. A closure plate is sealingly secured to the engine block for covering an underside of the engine block. The plate has an oil return opening whose dimensions are small relative to length and width dimensions of the closure plate and the oil pan. The closure plate and the oil pan carry nipples which are in alignment with one another and to which the sealing gasket is secured.

Abstract: An endless ridge extends along the peripheral portion of each of opposed sides of a cylinder block in a manner to enclose the major portion of the side a soundproof board is sealingly mounted to the ridge in a manner to cover at least the major portion enclosed by the ridge and to define a considerable air space (t) between the outer surface of the major portion and the inner surface of the soundproof board. The soundproof board is constructed of a material having high vibration damping effect and high thermal conductivity.

Abstract: A noise-reducing casing member for oil-containing elements of interval combustion engines. The walls of the casing member are converging stepped plates containing inward depressions and/or grooves for frequency detuning.

Abstract: An engine oil pan is mounted in noise reducing vibration isolation from the associated engine by a mounting arrangement including a unitary resilient seal having lips that extend under the oil pan flange to retain the seal in assembly with the pan both during and after assembly of the pan to the engine block. Separate support members interconnect spacer sleeves that extend through gripping openings in the seal and limit compression of the seal by oil pan attaching bolts so as to maintain the vibration isolating qualities of the seal in assembly.

Abstract: A silent-running motor power unit with an internal combustion motor (3) enclosed in a sound absorption chamber formed by a casing, having at least two walls (24, 22a, 23) arranged one (24) inside the other (22a, 23). The walls form part of a labyrinthine channel (6, 1) lined with sound absorption material. To make access and service to the motor (3) easy said walls (22a, 23, 24) include inner (24) and outer (22a, 23) door sections hinged at one of their ends whereat an inner section (24) may be swung outwards through the opening of an outer section (22a, 23). This is achieved by making the sections as a smaller part of a channel wall and as a light plane wall section instead of previously used heavy channel volume type sections.

Abstract: A sound absorber comprises a layer of a composition of a heat resistant binder and a low temperature oxidizing catalyst which is coated on a porous metal substrate in the hardened form.

Abstract: A tractor vehicle (10) is provided with segregated engine (45) and heat exchanger compartments (64). The heat exchanger compartment (64) is supplied with ambient air from an intake grille (24) above the heat exchanger compartment. The process air from the heat exchanger compartment is exhausted forwardly through a front grille (40) location on the tractor. The engine compartment is ventilated by a forced air system induced by the heat exchanger compartment exhaust fan (80). Engine compartment process air is drawn to the downstream side of the primary heat exchanger (76) and is discharged along with the heat exchanger compartment process air, through the front grille of the tractor.

Abstract: A sound absorber comprises a layer of a composition of a heat resistant binder and an acidic solid catalyst which is coated on a porous metal substrate in the hardened form.

Abstract: In an internal combustion engine with an engine unit support (1) comprising parts directly affected by body resonance as, e.g., cylinder block (2), cylinderhead (3), crankshaft (7) and crankshaft bearings (6), the engine unit support is connected to the crankcase (8) by means of several vibration absorbing and power transmitting elements (29) whereby the crankcase is insulated against body resonance. A sealing element (40; 44) is arranged between the engine unit support (1) for the crankcase (8) and sealing a lower oil-wetted part (15) of the engine oil-tightly against an upper dry part. The vibration absorbing elements (29) are mounted on the one side at the walls (25, 26) of the crankcase (8) and on the other side at the main bearing walls (20, 21) of the engine unit support in the region of the crankshaft axis (22).