Abstract: The present invention relates to a segment component in high-temperature casting material for an annular combustion chamber of an aircraft engine, characterized by a combustion-chamber wall which in operation shields a fuel flame extending along a burner axis from the environment, with the combustion-chamber wall having a bulge which points in a direction facing away from the burner axis. The invention furthermore relates to an annular combustion chamber, an aircraft engine with an annular combustion chamber as well as a method for the manufacture of an annular combustion chamber.

Abstract: A cylinder liner for an engine includes a hollow cylindrical sleeve, with an inner surface and an outer surface, that extends from a first end to a second end along a longitudinal axis. The cylinder liner may also include an annular cuff-ring groove, with a radiused fillet region, on the inner surface proximate the first end. The cylinder liner may further include a hardened case formed on the inner surface of the sleeve. The case may extend under a base of the fillet region of the cuff-ring groove.

Abstract: There is provided a method for manufacturing a cast iron member in which the production of gas defects such as blowholes or pinholes in a clad layer formed on the surface of a cast iron material can be reduced, and the generation of bead cracks in the clad layer can be restrained. In the method for manufacturing a cast iron member, including a step of forming the clad layer by melting a material for cladding by means of irradiation of a laser emitted from a laser irradiation device and by depositing the melted material on the surface of a part of the cast iron material, the step of forming the clad layer is performed by using a material the main ingredient of which is a copper element as the material for cladding so that when the clad layer is formed, a hardened layer having a thickness of 0.01 to 2.0 mm is formed on the surface of the cast iron material.

Abstract: A solid portion having a first opening, a second opening, and a third opening, leading to a chamber. The first, second, and third openings may be located at a top, bottom, and periphery of the solid portion, wherein the periphery is substantially perpendicular to the top and the bottom of the solid portion. A plurality of gear teeth may be located nearer the top of the solid portion than the bottom of the solid portion. One or more magnets may be located nearer the top of the solid portion than the bottom of the solid portion. A first plurality of ball bearings may be located nearer the top of the solid portion than the bottom of the solid portion. The solid portion may be mounted in a cylindrical cavity of an internal combustion engine so that the solid portion can rotate within the cylindrical cavity.

Abstract: A method of remanufacturing a cylinder assembly that has a shaft body and a slidable cylinder assembly extending thereover. A plurality of seals extend between the shaft body and the slidable cylinder to provide a plurality of fluid-tight chambers. The shaft body has opposing ends with a first end cap positioned at a first end and a second end cap positioned at a second end thereof. The shaft body is permanently coupled to the end caps to preclude removal thereof. The method requires cutting the shaft body to remove the end caps, and subsequent reattachment.

Abstract: A cylinder block of a piston-type compressor includes a main cylinder block, a shaft hole formed through the main cylinder block, a plurality of cylinder bores formed in the main cylinder block around the shaft hole, a separation wall formed integrally with the main cylinder block and closing one end of the cylinder bore, a first hole formed through the separation wall and a second hole formed linearly and connecting the cylinder bore and the shaft hole. The first hole is formed so that the first hole is located on an extended line of axis Q of the second hole and the diameter of the first hole is equal to or more than that of the second hole.

Abstract: A cooling jacket casting core for the production of a cylinder head of an internal combustion engine. The cooling jacket casting core has a slot running at least in part substantially in the direction of a crankshaft longitudinal axis and separating the cooling jacket casting core in at least one section. The slot can run at least in part in an impression of the cooling jacket and can have at least one elevation arranged perpendicular to the longitudinal axis of the cooling jacket casting core.

Abstract: A method of detecting a gap extending along a longitudinal axis and defined between a shoulder of a seat formed around a port in a cylinder head and an inboard axial end of a valve seat insert disposed in the seat includes disposing a distance sensor within the port, and moving one of the distance sensor and the cylinder head relative to the other of the distance sensor and the cylinder head along the longitudinal axis to generate relative movement between the distance sensor and the cylinder head. A radial distance is sensed perpendicular to the longitudinal axis during the relative movement between the distance sensor and the cylinder head to detect a change in the radial distance at an interface between the inboard axial end of the valve seat insert and the shoulder of the seat, thereby indicating an undesirable gap therebetween.

Abstract: A core portion (47) that is used to hold an upper water jacket-forming core (45) and a lower water jacket-forming core (46) with a predetermined distance maintained therebetween includes holding core portions (48) and distance maintaining core portions (50). The upper water jacket-forming core (45) and the lower water jacket-forming core (46) are split from each other at the holding core portions (48). Communication passages that provide communication between an upper water jacket and a lower water jacket are formed by the distance maintaining core portions (50).

Abstract: A method of forming a cylinder head may include machining an upper surface of a cam tower of the cylinder head to form a generally planar surface. An oil passage may be drilled in the upper surface to provide an oil feed. A bearing bore may be formed in the upper surface of the cam tower. The bearing bore may include a recess having first and second circumferential ends. The oil passage may intersect the first circumferential end.

Abstract: A method of forming a cylinder head includes casting the cylinder head to include an integral cast-in exhaust manifold. The integral cast-in exhaust manifold defines an intermediate exhaust gas passage in fluid communication with exhaust ports and an exhaust gas outlet passage in fluid communication with the intermediate exhaust gas passage. The cast cylinder head includes a coolant cavity to receive a cooling fluid. The coolant cavity includes first and second portions extending around an outer circumference of the exhaust gas outlet passage separated from one another by a first cast-in wall. The method further includes machining the first cast-in wall to provide fluid communication between the first and second portions of the coolant cavity. Machining the first cast-in wall forms a first coolant passage created by the first and second portions of the coolant cavity and the machined passage around the outer circumference of the exhaust gas outlet passage.

Abstract: A motorcycle includes an engine configured to expel an exhaust from combustion chambers of cylinders in a cylinder head through exhaust ports. Each of the cylinders is provided with a recessed portion provided in an exhaust passage wall surface in a central portion of an exhaust passage of a corresponding exhaust port. This makes it possible to maintain flow rate and flow velocity of the exhaust gas, and to decrease exhaust loss. As a result, it is possible to increase engine torque by use of a simple structure. In addition, no restriction is imposed on the layout of parts around the engine, because the recessed portions are provided in the exhaust ports.

Abstract: A cylinder (2) for a combustion engine has a cylinder bore (42) and a cylinder wall (43). At least one channel is formed in the cylinder wall (43). At least one cover (19), which at least partially closes the channel on the side facing away from the cylinder bore (42), is arranged on the cylinder (2). A very precise channel geometry which can be easily manufactured is achieved in that a first stop (25) is formed in the longitudinal direction of the cylinder between the cylinder (2) and the cover (19) and a second stop (33) is formed in the tangential direction with respect to the cylinder bore (42), with the cover (19) resting on the cylinder (2) at the first stop (25) and at the second stop (33).

Abstract: A cylinder block includes a scavenging passage, which extends between a combustion chamber and a crankcase chamber to communicate them together and has a scavenging port defined in the cylinder block so as to open at an inner peripheral surface of the cylinder block. An intake passage or exhaust passage, the scavenging passage including the scavenging port and a throughhole defined therebetween are formed by the use of a molding piece movable in a direction towards the fuel intake passage or exhaust passage and the throughhole is closed by a lid.

Abstract: An unfinished cylinder head casting for producing a cylinder head for internal combustion engines powered with diesel fuel includes a sealing surface, intended for mounting in a finished state on a corresponding sealing surface of an engine block, and designed on a sealing surface section of the unfinished cylinder head casting. A thickness of the sealing surface section in a casting state exhibits a machining allowance in relation to its set thickness, obtained after a material-removing finishing of the sealing surface. The sealing surface includes a combustion chamber region, associated with a combustion chamber formed in the engine block. In the case of such a cylinder head, an optimum load-bearing capacity is achieved in a simple manner in that a combustion chamber region sealing surface section machining allowance amounts to a maximum of 15% of the machining allowance of the sealing surface section in the remaining region of the sealing surface.

Abstract: A method includes coupling a cylinder head to a cylinder block. A valve member is then moved into a valve pocket defined by the cylinder head such that a first stem portion of the valve member engages an actuator. A first portion of the biasing member is then disposed against a second stem portion of the valve member, the second stem portion being opposite the first stem portion. An end plate is then coupled to the cylinder head such that a second portion of the biasing member engages the end plate.

Abstract: A method of manufacturing a cylinder block for a multi-cylinder engine is disclosed herein. The cylinder block includes a crankcase and cylinder bores disposed therein separated by cylinder walls. The crankcase is adapted to receive a crankshaft and includes crank chambers disposed therein separated by partition walls. Each of the crank chambers of the crankcase corresponds to one of the cylinder bores of the cylinder block. The cylinder bore side of each partition wall has a honing runoff portion thinner in section than the crankshaft side thereof such that a step face results in the partition walls. Further, a runoff groove is formed in the partition walls of the crank chambers, and also a communication hole is formed at least partially within the runoff groove in at least one of the partition walls to enable communication between crank chambers.

Abstract: A process for remanufacturing a cylinder head that includes a worn or damaged rocker arm stand adapted to receive a rocker shaft to which at least one rocker arm is mounted, the steps including machining a channel in a surface of the worn or damaged rocker arm stand, securing an insert into the channel, and machining the insert to form a remanufactured inner facing surface. The remanufactured cylinder head includes at least one rocker arm stand that has a machined channel with a remanufactured insert secured therein, the rocker shaft being disposed adjacent the inner facing surface, not the rocker arm stand.

Abstract: Provided is a cylinder block which includes a liner and a water jacket having a closed-deck structure in a simple configuration and which has a structure providing high rigidity and enabling easy formation at low cost. A cylinder block of the present invention includes a liner arranged on an inner circumference surface of a bored hole and a water jacket arranged on the outside of the liner in the radial direction. By a bending process of folding back an end portion of a cylinder-shaped member, a hollow portion capable of forming the water jacket is formed integrally in one end portion or both end portions of a liner portion forming the liner, and the cylinder-shaped member is enclosed with a cylinder block forming material by casting.

Abstract: A downhole pump for a well has a barrel and a plunger. The barrel has a passage extending along the length of the barrel, with the passage having an inside diameter. The plunger has an outside diameter and is received by the barrel passage for relative reciprocal movement. One of the barrel or the plunger is equipped with wear rings, with a wear ring at one or at each end. The wear rings are made of a material that is harder than the material of the respective plunger or barrel. The wear rings provide protection from abrasion, particularly in a sandy well.

Abstract: This disclosure provides a method of adjusting capacities of combustion chambers of a multi-cylinder engine having a cylinder head with recessed parts that partially form the combustion chambers and a mating surface for mating with a cylinder block, which includes casting a cylinder head material having flat reference surfaces on top of the recessed parts of the cylinder head, machining the cylinder head material to form the mating surface, measuring distances in a height direction from the mating surface to the reference surfaces, respectively, and adjusting machining margins of machining portions of the reference surfaces of the recessed parts based on the measured height direction distances.

Abstract: A linear actuator includes an actuator wall, and the actuator wall includes a first wall layer having an inner surface that defines an actuator chamber. The actuator chamber is configured to accommodate an actuator fluid. The first wall layer is also subjected to a pre-load such that the first wall layer is compressively pre-stressed. The actuator wall further includes a second wall layer disposed outwardly from the first wall layer. The linear actuator further includes a piston supported within the actuator chamber, and the piston is movable in response to the actuator fluid entering and exiting the actuator chamber.

Abstract: A cylinder head modification method includes the steps of selecting a cylinder head for an internal combustion engine having a plurality of combustion chambers and the cylinder head having a plurality of combustion chamber faces on the top of each combustion chamber. An elongated cylinder head insert is selected having a generally T-shaped cross-section and then forming an elongated slot in the selected cylinder head between a pair of combustion chamber faces. The elongated slot is shaped to receive the elongated cylinder head insert therein. A method includes press fitting the elongated cylinder head insert into the elongated slot and the cylinder head to thereby reduce localized high temperature deformations in the cylinder head. The method includes the step of heating the cylinder head to expand the slot for pressure fitting the cylinder head insert thereinto.

Abstract: A central direct injection (DI) cylinder head is configured with an intake valvetrain and an exhaust valvetrain separated by an uncovered central DI valley. The uncovered central DI valley limits oil flow from the high side chamber to the low side chamber and PCV transfer. Oil drainage and additional PCV transfer between the intake and exhaust chambers is provided by drain/vent passages integrally cast into the casting of the cylinder head. The drain/vent passages may be of varying configuration, and may be located between an injector port of a first cylinder set and a spark plug port of an adjacent cylinder set, or at either or both ends of the cylinder head. A method is provided to form a casting of the cylinder head as described herein, including casting of a plurality of drain/vent passages between the first chamber and the second chamber of the cylinder head.

Abstract: A jig for used in performing a finish processing of a cylinder bore 3 comprises a jig body 10 that comes close to and disengages from a cylinder head mounting surface 2, bolt member 16 that forms a tapered bore portion 20 by a internal surface 21 of a plurality of blot pieces 18 having a threaded portion 19 engageable to a female threaded portion 8 of a head bolt hole 7 and that expands the diameter thereof by a wedge action receiving through the tapered bore portion 20, a tapered shaft member 17 having a tapered surface portion 22 inserted into the tapered bore portion 20 so as to add the wedge action to it, and a piston member 24 having a pressing surface 23 contacting a given surface portion on the cylinder head mounting surface 2.

Abstract: A fluid flow valve in a cylinder head comprises a first valve end and an axially disposed second shaft end connected by a valve shaft. A first valve member is located at the first valve end and a second valve member is located axially from, and in fixed relationship to, the first valve member along the valve shaft. A valve support extends axially between and connects the first valve member and the second valve member; the valve support including an axially extending wall portion having circumferentially spaced support struts extending radially between the valve shaft and the wall portion. Fluid flow passages extend axially through the wall portion, between the circumferentially spaced support struts, wherein fluid flows simultaneously about the exterior of the wall portion and through the fluid flow passages in the wall portion when the valve member is biased to an open position.

Abstract: A method of forming a gearbox includes the use of hollow structural steel.

Abstract: A chromium-iron alloy comprises in weight %, 1 to 3% C, 1 to 3% Si, up to 3% Ni, 25 to 35% Cr, 1.5 to 3% Mo, up to 2% W, 2.0 to 4.0% Nb, up to 3.0% V, up to 3.0% Ta, up to 1.2% B, up to 1% Mn and 43 to 64% Fe. In a preferred embodiment, the chromium-iron alloy comprises in weight %, 1.5 to 2.3% C, 1.6 to 2.3% Si, 0.2 to 2.2% Ni, 27 to 34% Cr, 1.7 to 2.5% Mo, 0.04 to 2% W, 2.2 to 3.6% Nb, up to 1% V, up to 3.0% Ta, up to 0.7% B, 0.1 to 0.6% Mn and 43 to 64% Fe. The chromium-iron alloy is useful for valve seat inserts for internal combustion engines such as diesel or natural gas engines.

Abstract: A block casting for an internal combustion engine and method of its manufacture provide reduced engine block size and weight, and/or increased engine displacement, through cylinder-forming walls that decrease in thickness from minimal explosion-resistant thicknesses at their combustion chamber ends to reduced thicknesses at their other ends.

Abstract: A cylinder head assembly for an internal combustion engine and its method of manufacture is disclosed. The cylinder head assembly includes a cylinder head having a combustion chamber and a port opening into the combustion chamber. An insert pocket is circumferentially disposed about the port and is configured to receive a valve seat therein and to define a seam therebetween. A seal, comprising displaced cylinder head material disposed across the seam, seals the seam against the ingress of contaminants.

Abstract: A method of inoculating magnesium (Mg) on compacted graphite iron (CGI) comprises: providing a partition having a predetermined height on the bottom of a radle so as to divide the interior of the radle into a first space and a second space; laminating an Mg inoculant and a cover in order in the second space; and tapping liquid CGI cast iron onto the first space, whereby the Mg inoculant becomes in contact with the liquid CGI iron after the liquid CGI tapped onto the first space goes over the partition toward the second space and after the cover is melted by the liquid CGI. According to the method, the deviation of density of Mg is minimized, and a secondary inoculating process can thus be omitted.

Abstract: A cast cylinder head 1 of an internal combustion engine to be mounted on a vehicle has an intake-side side wall 2i, an exhaust-side side wall 2e, and opposite end walls 3r and 3f. The walls 2i, 2e, 3r and 3f define a water jacket 8. A first cooling water exit part 11 and a second cooling water exit part 21 both having a solid structure are formed by casting integrally with one of the intake-side side wall 2i and the exhaust-side side wall 2e and with one of the end walls 3r and 3f, respectively. Cooling water exit openings 15,16 or 25,26 opening into the water jacket 8 are drilled selectively in either of the first cooling water exit part 11 and the second cooling water exit part 21 depending on the engine mounting position on the vehicle. Thus the same cylinder head can be used independently of the mounting orientation of the engine on the vehicle.

Abstract: Embodiments of the invention use a gas flow to prevent adherence of a coating to portions of an engine block adjacent to a cylinder bore being coated with the coating. Embodiments may be particularly useful for applying a coating on the inner surface of the cylinder bores in one cylinder bank while protecting cylinder bores in an opposing cylinder bank, e.g., in a V-type engine. One method of applying a coating to an engine block comprises spraying the coating on an inner surface of a first cylinder bore of the engine block. The method further comprises shielding a second cylinder bore of the engine block from the sprayed a coating with a gas flow while spraying the coating on the inner surface of the first cylinder bore.

Abstract: A cylinder crankcase for a four-stroke engine is disclosed. The cylinder crankcase includes a cylinder head, cylinder block, and crankcase which are monolithic. A half-crank crankshaft bears in a crank arm, which is included in the crankcase. The cylinder crankcase includes a belt driven valve train and crank arm that includes a pocket containing a crank gear attached to the crankshaft for driving the belt.

Abstract: A method of forming a cylinder head may include machining an upper surface of a cam tower of the cylinder head to form a generally planar surface. An oil passage may be drilled in the upper surface to provide an oil feed. A bearing bore may be formed in the upper surface of the cam tower. The bearing bore may include a recess having first and second circumferential ends. The oil passage may intersect the first circumferential end.

Abstract: Disclosed is an internal combustion engine component (1) which is made of an aluminum alloy and comprises at least one area (2) that is subjected to a great thermal load during operation of the internal combustion engine. Said area (2) that is subjected to a great thermal load is small compared to the entire component (1) and is provided with an alloy composition which is modified in relation to the entire component (1) in such a way that the area (2) that is subjected to a great thermal load has a greater breaking elongation than the entire component (1).

Abstract: An intake duct cast as a recess in a combustion engine cylinder head that opens into a combustion chamber thereof at its lower end via an annular valve-seat housing. The intake duct, over part of its length, includes a substantially planar underside connected to the housing via a transition region that defines a shrinkage void of rounded shape within the mass of the cylinder head.

Abstract: A method for machining a cylinder head including a cooling jacket, wherein the fire deck of the cylinder head which is in a raw state is machined by material removal in relation to a reference mark of the cylinder head. The position of the cooling jacket is used as a reference mark.

Abstract: A cylinder head (3) for an axial flow rotary valve (1). The head comprises a bore (2) having an axis and adapted to house an axial flow rotary valve (1), a window (8) in the bore through which at least one port (12, 13) in the valve periodically communicates with a combustion chamber (9) as the valve rotates, at least two axially extending slots (21) in the bore, adjacent opposite sides of the window, each of the slots being adapted to locate a floating elongate gas sealing element (20), and at least one spark plug hole (7) adjacent to the bore and adapted for mounting a spark plug associated with the valve. The head further comprises at least one elongate axially extending cooling passage (24, 25 26) disposed between the bore and the spark plug hole, adjacent to one of the slots, the passage having a substantially constant cross section and extending axially at least over the length of the slots.

Abstract: The tubular die of a centrifugal casting device of GNo.30 or above is employed suitably and powder is introduced while rotating, and an outer tubular body composed of that powder is provided. Subsequently, molten is introduced to the inner circumferential wall side of the outer tubular body while sustaining rotation of the tubular die thus forming an inner tubular body. The outer tubular body functions as a cooling metal (chiller) when the molten is cooled and solidified. In place of the outer tubular body composed of the powder, molten may be used for forming an outer tubular body or an outer tubular molding molded previously into tubular shape may be employed.

Abstract: In an internal combustion engine, a lubricated camshaft assembly is in a cam chamber formed between a cylinder head and a cylinder head cover. The cylinder head includes outer bolt-receiving holes in which selected head bolts are inserted, and which are outside of the cam chamber. An oil discharge passage in the cylinder head has an inlet opened into the cam chamber, and an outlet opened into an outer bolt-receiving hole. The inlet of the oil discharge passage is disposed on one lateral side of the cam chamber. An opening part of a timing chamber is on the other lateral side of the cam chamber. An endless loop timing chain or belt is disposed inside of the timing cover, for transmitting the power of a crankshaft to the camshaft. A vehicle, which may be a four-wheeled all-terrain vehicle, may incorporate the engine and cylinder head as described.

Abstract: A speed pick-up ring includes a main body having a plurality of targets and defining a plurality of notches. Each notch is disposed between adjacent targets. Each notch includes a base wall, a first sidewall and an oppositely disposed second sidewall. The base wall includes a convex portion. A fluid device includes a housing and a variable reluctance speed sensor engaged to the housing. The fluid device further includes a speed pick-up ring disposed within the housing. The speed pick-up ring includes a main body having a plurality of targets and defining a plurality of notches. Each notch is disposed between adjacent targets. Each notch includes a base wall, a first sidewall that is generally concave and an oppositely disposed second sidewall that is generally concave. The base wall includes a convex portion.

Abstract: A sliding surface 4A of a shoe 4 undergoes laser radiation in a shape of a large number of parallel lines to form a large number of swollen portions 6 and to form concave portions 7 in adjacent positions thereof. The swollen portions 6 and the inner side thereof become direct hardening portions 11 with high hardness and the concave portions 7 and the inner side thereof become double hardening portions 12, which are lower in hardness than the swollen portions 6. After the laser hardening, the sliding surface 4A undergoes wrapping up to a position of an imaginary line 15 to delete relief to form a flat and smooth plane. Thereafter the sliding surface 4A undergoes buffing. Thereby, portions with low hardness are chipped off more largely than portions with high hardness to form a large number of minute irregularities on the sliding surface 4A (see FIG. 6). A large number of minute irregularities is formed uniformly on the sliding surface 4A of the shoe 4 and lubrication oil will be introduced thereinto.

Abstract: A new method for internal combustion engine cylinder finishing is proposed. Techniques for engine bore out, cylinder finish, and metal sleeve replacement have been developed for internal combustion engines. Separately, mandrel pull-through cold-working methods for fatigue life improvement have existed for holes with cracks. However, despite the decades old technology, mandrel pull-through cold-working has not been applied as the critical step in engine cylinder finishing. The first filing for the invention was provisional patent application 60883908 for “Cold-working application in combustion engines” submitted by the inventor on 8 Jan. 2007. This invention provides multiple techniques for applying mandrel pull through technology to cylinders that experience the hot, high cycle environment found in internal combustion engine cylinders. The method of employing cold-working as a critical step in engine cylinder finishing forms the basis for all claims listed.

Abstract: A cylinder block has at least two cylinder banks each having cylinder bores arranged in at least two directions relative to an axis for a crankshaft. A rotator on which the cylinder block is securely disposed has a convex rounded surface. When the rotator rotates, the convex rounded surface moves along a concave rounded surface of a rotator-holding base. As a result of the rotation, the cylinder bores of the first bank or the cylinder bores of the second bank face upward in the vertical direction. Accordingly, with a single spray gun, sprayed coatings can be formed on inner surfaces of the cylinder bores of the first and second banks without having to change a mounting position of the cylinder block.

Abstract: A core portion (47) that is used to hold an upper water jacket-forming core (45) and a lower water jacket-forming core (46) with a predetermined distance maintained therebetween includes holding core portions (48) and distance maintaining core portions (50). The upper water jacket-forming core (45) and the lower water jacket-forming core (46) are split from each other at the holding core portions (48). Communication passages that provide communication between an upper water jacket and a lower water jacket are formed by the distance maintaining core portions (50).

Abstract: An internal combustion engine component is composed of an aluminum alloy containing silicon, and includes a plurality of silicon crystal grains located on a slide surface. The slide surface has a ten point-average roughness RzJIS of about 0.54 ?m or more, and a load length ratio Rmr(30) at a cut level of about 30% of the slide surface is about 20% or more.

Abstract: There is provided a method for manufacturing a cast iron member in which the production of gas defects such as blowholes or pinholes in a clad layer formed on the surface of a cast iron material can be reduced, and the generation of bead cracks in the clad layer can be restrained. In the method for manufacturing a cast iron member, including a step of forming the clad layer by melting a material for cladding by means of irradiation of a laser emitted from a laser irradiation device and by depositing the melted material on the surface of a part of the cast iron material, the step of forming the clad layer is performed by using a material the main ingredient of which is a copper element as the material for cladding so that when the clad layer is formed, a hardened layer having a thickness of 0.01 to 2.0 mm is formed on the surface of the cast iron material.

Abstract: To form the housing of a double-screw extrude, the housing body or a segment thereof is provided with auxiliary bores along a segment of the housing at which the hardening material is to be thicker or a hardening material is to be provided. The screw-receiving bores are then formed and overlap each other and the auxiliary bores and the hardening material is provided at least in the auxiliary bores by a division process, preferably a hot isostatic pressing (HIP) process.

Abstract: A cylinder block includes a scavenging passage, which extends between a combustion chamber and a crankcase chamber to communicate them together and has a scavenging port defined in the cylinder block so as to open at an inner peripheral surface of the cylinder block. An intake passage or exhaust passage, the scavenging passage including the scavenging port and a throughhole defined therebetween are formed by the use of a molding piece movable in a direction towards the fuel intake passage or exhaust passage and the throughhole is closed by a lid.