Abstract: Method of depositing an Fe.sub.x O comprising coating onto a light metal substrate by use of wire-arc thermal spraying that propels atomized droplets by use of atomizing gases, comprising: preparing at least one surface of the light metal substrate to present an exposed essentially non-oxidized substrate surface; and thermally spraying melted droplets of a steel feedstock wire onto the prepared surface by use of propellant gases to deposit a composite coating, the gases being controlled as to content to regulate the exposure of the droplets to oxygen so that Fe.sub.x O is substantially the only iron oxide formed during spraying, x being 0.5-1.5.

Abstract: Sliding contact-making structures of an internal combustion engine, which comprise (a) a cylinder unit having an inner plating coating containing a dispersoid substance such as a plating coating of Ni-P-SiC or Ni-SiC; and (b) a piston provided with at least one piston ring, fitted into the inside of the cylinder in the axial direction so as to freely slide upon the inside surface thereof, are characterized in that the piston ring has a surface in sliding contact with the inside surface, which surface is covered with a vapor deposition layer such as a physical vapor deposition layer of TiN or CrN, whereby resistance to friction abrasion and seize, and the friction coefficient can be effectively improved.

Abstract: The combustion chamber of an engine is formed in a double insulation structure where partially stabilized zirconia (PSZ) material having a low thermal conductivity is disposed between two walls for thermal installation. The double insulation structure has a head liner made of a silicon nitride material and an outer tubing which are separated by a space. A plurality of gaskets, i.e. the PSZ materials, are arranged in the space, with each having a PSZ thermal insulator 31 sandwiched between two contact claddings made of stainless steel or copper. The escape of heat from the head liner is minimized by the PSZ material, having a lower thermal conductivity, thereby increasing a thermal insulation quality of the combustion chamber.

Abstract: Heat engine piston and combustion chamber construction enclosing a gas combustion zone, comprising: a piston body having a crown facing said gas combustion zone; combustion chamber surfaces cooperating with said piston to complete enclosure of said zone; and a thermal diffusivity coating on said crown and combustion chamber surfaces having an effective thickness to operate as a thermal diode to restrict heat transfer to said piston body and combustion chamber and to restrict heat transfer to said combustible charge prior to combustion.

Abstract: An aluminum alloy cylinder block for an internal combustion engine includes a pair of liners fit within a pair of symmetrically disposed grooves which are formed on an inner peripheral surface of each of a plurality of piston cylinders and not overlapping a connector joining adjacent ones of the plurality of piston cylinders whereby the cylinder block can be reduced in weight, size and length thereof and its durability extended.

Abstract: An engine block with one or more anti-friction coated cylinder bores, comprising an oil-attracting coating of grains fused to each other and to the bore wall, the grains comprising agglomerates of solid lubricant particles and hardened, fused particles, the solid lubricant particles being selected from the group consisting of graphite molybdenum disulfide, boron nitride, lithium fluoride, and calcium fluoride, the coating having been finish-honed to expose certain margins of the fused particles.

Abstract: A split cycle internal combustion engine having located wholly within the combustion chamber (13) of the firing cylinder (10) and spaced from the walls thereof a hollow dome (14) with the closed head of the dome (14) adjacent to the head (11) of the firing cylinder (10) and the open base of the dome (14) nearer to the power piston (12), a nozzle (24) directing air from a compressor around the interior wall of the dome (14), nozzle (24) directing fuel into the dome (14) after all the air has entered the dome (14) and a nozzle (25) for igniting the fuel/air mixture when the temperature of the dome (14) is insufficiently high for ignition. An inwardly directed flange (17) extends around the open base of the dome (14) to form a channel (18). It is preferred that the engine operates at very high pressures, the compressor is multi-stage.

Abstract: An engine block having one or more anti-friction coated cylinder bore walls, comprising: a coating of grains fused to the cylinder bore wall, the grains being comprised of solid lubricant particles encapsulated within a soft metal shell, the shells being fused together to form a network with limited porosity, the solid lubricant comprising at least graphite and MoS.sub.2 ; and wet oil lubrication retained within the porosity of the coating.

Abstract: A ceramic coating for a metal article includes a metallic bond coat deposited on the metal article, at least one MCrAlY/ceramic layer deposited on the bond coat, and a ceramic composite top layer deposited on the MCrAlY/ceramic layer. The M in MCrAlY stands for Fe, Ni, Co, or a mixture of Ni and Co. The ceramic in the MCrAlY/ceramic layer comprises mullite, alumina, zircon, sillimanite, sodium zirconium phosphate, fused silica, cordierite, aluminum titanate, or zirconia. The ceramic composite top layer comprises a ceramic matrix and at least one secondary phase. A method of making the coating includes sequentially depositing a metallic bond coat on the metal article, at least one MCrAlY/ceramic layer on the bond coat, and a ceramic composite top layer on the MCrAlY/ceramic layer.

Abstract: Ceramic materials to be insert-cast are disclosed, which each contain not less than 65% by volume of aluminum titanate as a crystalline phase, and have an average particle diameter of crystals thereof being not less than 10 .mu.m, Young's modulus of 50 to 2,000 kgf/mm.sup.2, compression strength of 5 to 40 kgf/mm.sup.2, and porosity of 5 to 35%. Ceramic port liners are also disclosed, which are free from cracking due to compression force during insert-casting, peeling-off during use, and facilitate insert-casting. To attain this, a reinforcement which meets either one or both of requirements that differences in coefficient of thermal expansion at 800.degree. C. and Young's modulus between the reinforcement and a material constituting the port liner body are in a range of .+-.0.1% and in a range of .+-.1,000 kgf/mm.sup.2, respectively, is filled into a depressed portion at an outer peripheral surface of the port liner body to form an integrated structure with a flat or swelled surface.

Abstract: A method of producing a cylinder head of an internal combustion engine, comprising a cylinder head housing made of an aluminum material and having a base plate fitted into the combustion-chamber-side base wall of the cylinder head housing and made of a highly heat-resistant material. The combustion chamber plate is connected to the base wall of the cylinder head housing by friction welding.

Abstract: The present invention relates to a two-cycle internal combustion gasoline engine cylinder. The two-cycle engine cylinder according to this invention is characterized in that a smooth hard chromium plated layer is formed on a combustion chamber top inner surface of the cylinder.

Abstract: An internal combustion engine is described as having a unique angular relationship between the longitudinal axis of each piston cylinder, the center axis of any associated intake ports through which fluid enters the cylinder, and the longitudinal axis of any associated intake passageway for channeling fluid to the communicating intake port, to induce the fluid entering the cylinder to swirl about an axis which is angularly disposed to the longitudinal axis of the cylinder, rather than conventionally swirling about the longitudinal axis of the cylinder. The initial velocity of swirl is then accelerated by the principle of conservation of angular momentum to a more rapid and robust velocity during the compression stroke, thereby allowing the use of a much leaner fuel to air mixture.

Abstract: A cylinder liner is fitted in a cylinder bore of a cylinder block of a multiple-cylinder engine. The cylinder liner has an outer circumferential surface having a plurality of annular grooves and a plurality of longitudinal grooves connected thereto, in which a cooling liquid is flowed in the grooves. A part in an axial direction of a crankshaft of a bottom of at least one of the annular grooves is coated with a sprayed coating of metal, and a sectional area of the annular groove provided with the sprayed coating varies in a circumferential direction.

Abstract: A cylinder liner comprises an alloy plating film of Ni-B or Ni-P or Ni-Co-P formed on at least a part contacting with cooling liquid in an outer peripheral surface and further a nitrided layer formed on an inner peripheral surface to improve an anti-cavitation characteristic, a sliding characteristic and an anti-corrosion characteristic and facilitate a manufacturing of the cylinder liner.

Abstract: In a cast linerless single cylinder or multicylinder block made of an aluminum alloy and intended for use in internal combustion engines, the aluminum matrix contains embedded silicon particles, which protrude from the sliding surface of the cylinder. In order to distinctly reduce the cost of the mechanical machining of the entire surface of the single cylinder or multicylinder block, only the sliding surface of the cylinder is constituted by a fibrous body which contains interspersed silicon particles and infiltrated aluminum alloy.

Abstract: A wet sleeve from a diesel engine is coated with Teflon in the area which will be in contact with the water from the cooling system. The Teflon coating will prevent the sleeves from being pitted from the boiling of the water against the sleeve.

Abstract: The disclosure relates to a novel arrangement of a combustion chamber for diesel engines, which is defined by an inner wall including a fuel-impinging area formed of a metallic material, and a remaining area which at least partly is formed of a ceramic material or a like heat-resisting material. The arrangement serves to achieve an effective exhaust gas clarification, including the minimization of NOx emission, and to realize increased power output and reduced fuel consumption of the engine.

Abstract: This four-cycle head insulating engine has combustion chambers which consist of cylinder head lower surface portions and cylinder liner upper portions, and which are formed in a heat insulating manner; exhaust valves provided in exhaust ports formed in the cylinder head; suction ports formed in cylinder liner lower portion so as to be spaced in the circumferential direction thereof and opened in the positions before the lower dead points; guide scrolls communicating with the suction ports and formed on the outer circumferential surface of a cylinder block; and a supercharger joined to suction passages communicating with the guide scrolls. Accordingly, this heat insulating engine renders it unnecessary to provide, especially, check valves in the suction system, and enables the degree of freedom of designing the guide scrolls to be improved, and the guide scrolls to be formed to such a shape that allows the suction air to be swirled in a large curve and sucked easily into the cylinders.

Abstract: In this ceramic engine, the cylinder liners are formed out of a ceramic material, and bearings consisting of a ceramic material are installed in the rotary sliding portions of a crankshaft and larger- and smaller-diameter parts of connecting rods, suction ports being formed in the cylinder liner lower portions so as to be spaced in the circumferential direction thereof, these suction ports and crank chambers communicating via first suction passages, fuel alcohol supply means being provided in second suction passages through which suction air is introduced into the crank chambers. Accordingly, lubricating films of ungasified components of the fuel alcohol are formed on the sliding surfaces of the pistons and cylinder liners and those of the above-mentioned rotary sliding portions, and these sliding surfaces and rotary sliding portions are kept in an excellently lubricated condition owing to such lubricating films.

Abstract: In order to improve the suction efficiency and the cycle efficiency, a heat-insulating engine structure of the invention has a planar and thin-walled piston head surface portion of a ceramics material to be exposed to combustion gases. A combustion chamber is formed not on the side of the piston head but on the side of a cylinder head. Namely, the piston head is defined by the cooperation of a cylinder head bottom wall portion having a lowered central portion and a raised outer peripheral portion and a cylinder liner upper portion including an upper tubular part of a substantially square cross-section and a lower cylindrical part. The cylinder head bottom wall portion has an inclined surface radially upwardly extending from the central portion to the outer peripheral portion. Intake and exhaust valves are associated with valve seats formed in the inclined surface. A fuel injection nozzle is disposed substantially centrally of the cylinder head bottom wall portion.

Abstract: A heat-insulated four-cycle engine includes a heat-insulated main combustion chamber, a prechamber having an ejection port communicating with the main combustion chamber and associated with an exhaust valve, a projection mounted on the piston head surface of a piston and movable into the ejection port in the vicinity of the top dead center, a recess defined in the piston head surface around the projection, and intake ports defined in the cylindrical wall of a cylinder which defines the main combustion chamber. Combustion gases produced as a result of combustion of fuel in the prechamber are held in the prechamber by the projection in a high-temperature condition for a certain period of time. Thereafter, as the piston is lowered from the top dead center, the combustion gases are discharged from the prechamber into the main combustion chamber, thus lowering the pressure in the prechamber.

Abstract: A fuel ignition products adhesive coating is disposed on the surface of an internal combustion engine piston. The coating protects the surface from corrosion and wear caused by the combustion of fuel in the cylinder.

Abstract: A cylinder liner unit comprises a plurality of cylinder liners made of a non-aluminum alloy for use in an internal combustion engine and uniformly covered with a layer of an aluminum series alloy around the plurality of cylinder liners so as to be integrally combined by the layer of aluminum series alloy layer in unity. Thereafter, the integrally combined cylinder liner unit is casted in a cylinder block made of an aluminum alloy.

Abstract: A cylinder liner and method for forming it for a reciprocating machine including a sleeve having one or more port openings that have stepped diameters so as to form a shoulder. The shoulder lies approximately at the finished outer diameter of the sleeve and a resist or stop layer is positioned on the larger diameter portion of the port opening and the sleeve is plated so that the plating layer will extend only over the inner surface, first portion of the port opening and the shoulder. As a result, removal of the outer sleeve periphery will not upset the plating layer nor will it leave edges of the plating layer exposed to flow through the port as might cause erosion.

Abstract: In a two-cycle heat-insulating engine of the present invention, each of combustion chambers defined by the lower surface of a cylinder head and a cylinder line has an adiabatic structure, each of exhaust valves is disposed in each exhaust port formed in the cylinder head, an intake valve for preventing the backflow of an exhaust gas is disposed in each intake port formed at the lower part of a cylinder, each of these valves is actuated for opening and closing by electromagnetic force of each electromagnetic valve driving device, and a controller controls the opening/closing timing of the intake and exhaust valves, the valve opening/closing time, etc, in response to detection signals from detection means for detecting the operational conditions of the engine.

Abstract: In this heat insulating engine, an auxiliary combustion chamber which is formed by a block consisting of a material of a low heat transfer rate and provided on the inner surface thereof with a thin member composed of a high-density ceramic material, and which is provided with a fuel injection nozzle in the wall thereof, is communicated with a main combustion chamber fitted in a cylinder head via a heat insulating member and formed by a thin member consisting of a high-density ceramic material. Accordingly, the thermal capacity of the inner surface of the auxiliary combustion chamber becomes small, and the mixing of the atomized fuel with air is effected speedily. Consequently, the combustion temperature increases in a short period of time, and the generation of smoke is suppressed.

Abstract: Method of bonding cylinder liners to cylinder bore walls, comprising: (a) inserting a cylindrical work hardenable liner into a complementary sized cylindrical bore wall of the block, with a uniform annular radial spacing therebetween of about 0.005 inch; and (b) forcing a nondeformable mandrel throughout the interior length of the cylindrical liner to uniformly circumferentially expand the radially outer surface of the liner into full annular surface-to-surface heat exchange relationship with the interior surface of the bore wall, the mandrel having a cross-sectional radius greater than the interior radius of the liner by a dimension which is at least 0.001 inch in excess of such radial spacing. Preferably, the cylindrical liner is comprised of steel having a ductility of at least 30%, a hardness of at least 35 HRB, and a wall thickness in the range of 0.050-0.250.

Abstract: A piston head for an internal combustion engine is provided containing a polished nickel plated layer formed in the piston top and an anodized layer formed on at least the lower part of the uppermost piston ring groove in order to reduce the adverse affects of excessive thermal conditions on the member.

Abstract: An igniting device for an engine has a glow plug disposed in a combustion chamber which is constructed of a thermally insulating material. When a temperature of the combustion chamber wall is lower than a predetermined temperature, the glow plug is supplied with electric power at a timing which is determined dependent upon the rotational speed of the engine and the top dead center position of a piston.

Abstract: Cylinder liners for internal combustion engines, particularly diesel engines, are described the liners comprising a metal outer sleeve having therein an inner sleeve comprising a ceramic material which is held by compressive hoop stresses under all normal engine operating conditions, the inner sleeve extending over at least a part of the axial length of the liner. In a preferred embodiment the inner sleeve comprises a composite material of two different ceramic materials. For example an inner sleeve is described having a silicon nitride working surface with a layer of partially stabilized zirconia thereon.

Abstract: The upper parts of the cylinder liners and the cylinder head are formed integral in one piece, and a water jacket is provided around the outer peripheries of the upper parts of the cylinder walls, with no water jacket provided to the cylinder body. This eliminates the use of the core for the water jacket in molding the cylinder body, which in turn reduces the engine weight, brings about a significant cost reduction and makes machining operations easy. Because the piston head is made of a heat insulating material and a water jacket is not provided to the cylinder body, the heat is prevented from flowing down to the cylinder liners. Furthermore, the cylinder liners are made of a ceramic material to improve an anti-galling characteristic during sliding motions at high temperatures. Also, since the water jacket is provided only to the cylinder head, the water jacket can be made simple and small in structure, reducing the cooling water flow resistance.

Abstract: The heat insulating combustion chamber according to the present invention is provided with a surface layer, which faces a combustion chamber, of a head liner consisting of an integrated structure of a lower surface portion of a head and an upper portion of a cylinder liner and made of a thin ceramic layer of the smallest possible thickness, and a heat insulating member, i.e.

Abstract: A siamese-type cylinder block blank which is composed so that upon the pouring a molten metal under a pressure, a sleeve of cast iron is cast in each cylinder barrel of a siamese-type cylinder barrel made of an aluminum alloy and consisting of a plurality of cylinder barrels connected in series. The cylinder block blank is characterized in that each sleeve cast presents a substantially oval configuration in section with the lengthwise axis parallel to the direction of cylinder barrels arranged, as a result of the reception of the solidification shrinkage force of each cylinder barrel.

Abstract: The invention relates to a cylinder head for an internal combustion engine in which each combustion chamber has a prechamber. A cast metal body of the cylinder head has recesses each of which provides a prechamber, and a hollow and, for example, bell-shaped member of a porous ceramics is cast-inserted in the inner surface defining each recess. Use is made of a ceramics low in thermal expansion coefficient and heat conductivity, such as aluminum titanate or cordierite, and the porosity of the ceramics is 5 to 50%. Because of its porousness the cast-inserted ceramics member is easily machine-finished. After that, for enhancement of strength and durability, the cast-inserted member of the porous ceramics is impregnated with an inorganic refractory material by using either a solution of, for example, sodium silicate or aluminum phosphate or an aqueous suspension of a ceramics powder, or a mixture of the solution and the suspension.

Abstract: In a heat insulating engine of this invention, the piston head is made up of a retainer body, a heat insulating member mounted on the retainer body, and a thin ceramic member formed over the upper surface of the heat insulating member exposed to the burning gas and over the circumference of the former two members. The retainer body is mounted to a piston skirt through a heat insulating gasket. The cylinder is so constructed that the piston head does not contact the cylinder liner upper portion of the head-liner but can contact the cylinder liner lower portion. When the piston is situated close to the top dead center, the heat insulating structure of the combustion chamber prevents heat from being released from the piston head.

Abstract: A finish for a cylinder liner is provided by first treating the entire inner surface area of the cylinder liner to form a base porosity. An abrasive media is then applied only to portions of the inner surface area to create an extremely light break-in surface, preferably in a pattern such that at any axial location of a piston ring in the cylinder, its periphery is in contact with both the areas of the break-in surface as well as the areas of base porosity to which the break-in surface has not been applied.

Abstract: A cylinder block made of fiber-reinforced light alloy for an internal combustion engine comprises a cylinder barrel having a fiber-reinforced part formed around a cylinder bore, and a cylinder block outer wall surrounding the cylinder barrel and defining a water jacket between itself and the barrel, wherein a reinforcing deck part is provided to connect between the outer wall and an end portion of the barrel adjacent the cylinder head joining surface, the deck part having a thickness in the direction of barrel axis set to be not less than 7% of a piston stroke.

Abstract: Thin thermal barrier coating of a specified thickness of 0.002 to 0.009 inch to insulate the combustion chamber of an internal combustion engine to achieve optimum reduction of transient head flow. The coating is of an optimum thickness to reduce in-cylinder heat loss in the combustion chamber during combustion, thus increasing engine efficiency, specific power output, and reducing emissions. However, the temperature increase is not so great as to adversely affect engine lubricant life or volumetric efficiency. The invention is particularly suitable for gasoline engines as it does not cause preignition or knocking that is generally caused by insulating coatings of greater thickness. In addition, the invention is particulalry suitable for aluminum combustion chamber components. The thinner coating also results in improved reliability and durability by reducing chipping and cracking failure tendencies associated with ceramic coatings.

Abstract: Ceramic cylinder assemblies for internal combustion engines, particularly diesels, are described. The assemblies comprise at least two portions including at least one main cylinder portion and at least one combustion region portion, the at least two portions being contained within a metal sleeve and wherein the at least one combustion region portion has a generally axially directed slit therein, the slit passing through the whole thickness of the ceramic material.

Abstract: A two-cycle, internal combustion engine designed for operation in conjunction with high pressure supercharging for high temperature, high pressure combustion in one or more piston cylinders, the combustion chamber including a porous, floating liner displaced from the cylinder walls of the combustion chamber, the pistons having a concentric groove for receiving the floating liner on the compression stroke for insulating the wall of the piston cylinder from the hot gases of combustion.

Abstract: The heat-insulating engine structure according to the invention comprises fitting a ceramic head liner for which a cylinder liner top and a head lower surface portion are unified structurally in a cylinder head, coating an outer surface of the cylinder liner top of the head liner with a heat insulating laminate with a metallic sheet and a heat insulating material with potassium titanate as a principal component wound spirally by turns with a compressive force exerted thereon, thus enhancing strength or pressure resistance, forming a wall of the head liner as thin as possible to minimize a thermal capacity of the head liner, thereby enhancing suction efficiency and cycle efficiency. Further, heat insulation efficiency is enhanced all the more by disposing the heat insulating laminate having air layers between the head liner and the cylinder head.

Abstract: An assembly for an internal combustion engine comprises a unitary cylinder head having at least one opening extending therethrough and at least one combustion chamber housing removably associated with the unitary cylinder head and received at least in part in the one opening. The chamber is formed for cooling fluid within a part of the opening within the cylinder head such that cooling fluid circulates about the combustion chamber housing. A method is provided for assembling the combustion chamber housing within the cylinder head and for assembling the composite structure to an internal combustion engine.

Abstract: An internal combustion engine having a cylinder block made of a light-alloy with a cylinder wall around a cylinder bore including a cylindrical fiber-reinforced portion which is formed of a mixture of an alumina-based fiber and a carbon fiber with a light-alloy matrix. The alumina-based fiber has a fiber volume fraction set in a range of 8 to 20%, and the carbon fiber has a fiber volume fraction set in a range of 0.3 to 15%. The alumina-based fiber contains 25% or less, by weight, of silica, has an average aspect ratio of 20 to 150, and an alpha rate of 2 to 60%. The carbon fiber has an average aspect ratio set in a range of 10 to 100 and a Young's modulus set in a range of 20 to 30 t/mm.sup.2. The piston for the cylinder bore has an iron-plated layer covered by a tin-plated layer. The piston rings for the piston may be of austenitic stainless steel to provide thermal expansion characterics similar to the cylinder wall and may be provided with a nitride or chromium-plated layer.

Abstract: A two- or four-stroke internal combustion engine is provided having individual features and combinations of features not heretofore known which provide enhanced power, efficiency and braking performance compared to known engines.

Abstract: In an adiabatic internal combustion engine with a piston movably disposed in a cylinder to which air and fuel are admitted for combustion therein and from which the gases generated during combustion are discharged after extraction of energy therefrom, the cylinder includes a piston guide and seal structure having piston seal rings associated therewith and has a wall structure of heat resistant material and the piston has a guided section adapted to move back and forth through the guide and seal structure and a cap of heat resistant material disposed on top of the guided piston section and having a cylindrical side wall slightly spaced from the heat resistant cylinder wall.

Abstract: An uncooled (adiabatic) engine having an insulator sleeve in each cylinder o retard heat flow into the engine wall structure. Each sleeve is yieldably (springably) mounted in an engine bore, such that the sleeve can experience thermal growth in the axial direction without excessive stress or mechanical failure.

Abstract: In a two cycle internal combustion engine (2) having a cylinder liner (14), a fuel-air flow passage (52) is provided from the crankcase (8) to the exhaust bridge (38) in the cylinder liner (14) and the exhaust bridge (39) in the cylinder block (12) along the interface between the cylinder liner (14) and the cylinder block (12). A plurality of apertures (57-60) are provided through the cylinder liner (14) communicating with the fuel-air flow passage (52). A second fuel-air flow passage (56) is provided between the piston (4) and the cylinder liner (14) and in communication with the apertures (57-60) to facilitate fuel-air mixture flow through the exhaust bridge (38) to improve lubrication and cooling thereof.

Abstract: In an uncooled engine, it is propose to form insulator coatings on the combustion chamber surfaces, and to mechanically protect such coatings against erosion or cracking by means of outer protective layers applied over the insulator coatings. The insulator coatings can be zirconium oxide applied to a thickness of approximately 0.15 inch. The protective layers can be formed of various materials resistant to high temperatures in the vicinity of 2000.degree. F., e.g. silicon nitride, steel or cast iron.

Abstract: A cylinder liner with a ring-shaped insert. Such inserts ensure that the carbon deposited on the fire land of the piston cannot contact the cylinder surfaces below the insert. The task to be solved by the invention is to simplify and improve the securing of such an insert, on the one hand to facilitate installation and removal and, on the other hand, to ensure greater reliability. Also, the insert is intended to be suitable for retrofitting. Essentially, this is achieved in that the ring-shaped insert is provided at its upper end with a flange that extends over the entire top cross-sectional area of the cylinder liner.