Abstract: A piston has a top surface composed of porous alumina. Top surface includes a first region and a second region. The first region includes a part or all of a region connecting to an outer periphery of the top surface. The second region is adjacent to the first region. The second region includes some or all of the region inside the top surface. The porous alumina formed on the second region is thinner than that formed on the first region. In a manufacturing method of a piston, first, a casting piston made of aluminum alloy is prepared. Then, a casting surface in a first region is removed, thereby a material surface is exposed. Then, anodization of the casting piston is performed, whereby a porous alumina is formed on the first and second regions.

Abstract: A piston for an internal combustion engine includes a piston having a bowl surface forming a combustion bowl, a rim surface forming an annular rim, and a gallery surface exposed to a backside cooling gallery of the piston. The bowl surface forms a bowl profile varied circumferentially around a piston center axis, and the gallery surface forms a gallery profile that is varied circumferentially around the piston center axis and is congruous with the bowl profile. The gallery surface is concave to the combustion bowl, convex to the backside cooling gallery, and forms no edges exposed within the backside cooling gallery. A wall formed between the combustion bowl and the backside cooling gallery has a heat-dissipation wall thickness defined by the varied bowl profile and the varied gallery profile.

Abstract: A piston-slipper assembly and method for assembling a piston-slipper assembly for use in a hydraulic apparatus such as a piston motor or piston pump. The assembly contains a piston and a slipper, and at least one of the piston or the slipper includes a ball and the other includes a socket. The ball is retained in the socket without crimping, swaging or bending of the socket.

Abstract: A method for the production of a piston made of steel, for an internal combustion engine, in which the upper piston part is produced using the forging method, and the lower piston part is produced using the forging or casting method, and they are subsequently welded to one another. To simplify the production method and make it cheaper, the upper piston part is forged using the method of hot forming and of cold calibration, to finish it to such an extent that further processing of the combustion bowl and of the upper cooling channel regions can be eliminated.

Abstract: A method of making an aluminum piston is described. In one embodiment, the method includes placing a oil gallery core in a mold, the oil gallery core comprising a metal tube connected to a hollow inlet tube and a hollow outlet tube; introducing liquid aluminum into the mold around the oil gallery core; and allowing the liquid aluminum to solidify, the oil gallery core forming a channel in the piston. Aluminum pistons are also described.

Abstract: A piston with a cast bi-metallic dome feature and a method of making the piston. In one form, the piston is for use in a diesel engine, while in another, the piston is for use in a gasoline engine. The dome feature may include a laminate of a relatively high-temperature material (such as stainless steel) and a relatively low temperature material (such as aluminum or aluminum alloys) such that the portion of the dome made from the relatively high-temperature material is directly exposed to combustion within a cylinder into which the piston is placed. In another form, an aluminum coated stainless steel layer is used to form the dome. In one form, an ablation casting process may be used to manufacture the dome.

Abstract: A diesel piston with a cast bi-metallic dome and a method of making the piston. In one form, the dome may include a laminate of a relatively high-temperature material, for example, stainless steel, and a relatively low temperature material, for example, aluminum or aluminum alloys, such that the portion of the dome made from the relatively high-temperature material is directly exposed to combustion within a cylinder into which the piston is placed. In another form, an aluminum coated stainless steel ring is used to form the dome. In one form, an ablation casting process may be used to manufacture the dome.

Abstract: A method and a manufacturing line allow for the manufacture of piston blanks of dimensions close to the final dimensions, which in the course of subsequent finish-machining need only be machined with removal of material to a small degree. A piston shaft of the piston blank is produced by backward extrusion. At least one hollow throat element is already produced at the piston blank by an upset-forging operation. For this purpose, a special forging tool is provided, which, after the manufacture of the piston shaft, takes effect on the piston blank in such a way that at least one hollow throat element is formed at the latest at subsequent forming of the piston base. In this way, a perceptible reduction is achieved in the weight of a piston in relation to conventionally manufactured forging pistons.

Abstract: A method for the production of a piston (1) made of steel, for an internal combustion engine, in which the upper piston part (3) is produced using the forging method, and the lower piston part (4) is produced using the forging or casting method, and they are subsequently welded to one another. To simplify the production method and make it cheaper, the upper piston part is forged using the method of semi-hot forming, to finish it to such an extent that further processing of the combustion bowl and of the upper cooling channel regions can be eliminated.

Abstract: A method of producing a hollow casting is provided, by which the joinability of a cast base material and a hollow-forming member to each other can be enhanced while suppressing the generation of oxides of or blow holes on a casting base material. The method of producing the hollow casting comprises enveloping a hollow-forming member in a molten base-metal cast material. Specifically, the method comprises the steps of: producing a hollow-forming member with a material having a melting point higher than that of a base-metal cast material such that air-gap layers are formed within the surface layers of contact surfaces with which the molten metal comes into contact; coating the contact surfaces with a layer of the same metal as that of the base-metal cast material; and enveloping the hollow-forming member in the base-metal cast material by disposing the coated hollow-forming member within a mold and then pouring the molten base-metal cast material into the mold.

Abstract: An internal combustion piston comprises a modified layer produced by a surface treatment including injecting injection powders having a diameter of 20 ?m to 400 ?m and containing a reinforcing element to be collided with a surface of the internal combustion piston obtained by casting and forging by injecting at an injection speed of 80 m/s or more or at an injection pressure of 0.3 MPa or more, the reinforcing element improving a strength of an alloy comprising the piston when being diffused and penetrated in the alloy, wherein by the surface treatment, oxides generated on the surface of the piston by the casting and forging are removed, and surface flaws generated on the surface are repaired, whereby the modified layer is formed to have a uniformly fine-grained metal microstructure which contains the reinforcing element in the injection powders diffused and penetrated in the vicinity of the surface of the piston and an alloy element of the alloy comprising the piston.

Abstract: A method for surface treatment capable of easily improving a mechanical strength of an internal combustion piston at a reasonable cost is provided. A modified surface layer is formed by injecting injection powders containing a reinforcing element to be collided with an Al—Si alloy-based piston obtained by casting and forging by injecting under predetermined conditions, the reinforcing element being diffused and penetrated in the piston to improve the strength thereof. When a function, such as fuel modification, is imparted to the modified surface layer, an element exhibiting a photocatalytic function by oxidation, such as Ti, Sn, Zn, Zr, or W, is selected as the reinforcing element.

Abstract: A piston 1 which is to be movably supported in a cylinder 11 of a pump 10 to be reciprocally driven is formed by a fluororesin so that it is not impaired by a corrosive liquid. A cylindrical outer peripheral portion 2 of the piston 1 has a thickness of 1 mm or less, and is flexible. The outer peripheral portion has a flange portion 7 in an open end portion via an approximately 180-degree folded-back portion 3. The flange portion 7 is attached to the cylinder 11. When the pump 10 is driven, the cylindrical outer peripheral portion 2 of the piston 1 smoothly rolls without producing deflections or bends in a gap between the outer peripheral face of a piston support member 15 and the inner peripheral face of the cylinder 11, while being in close contact with the two faces.

Abstract: A piston for an internal combustion engine has annular cooling passage arranged in the vicinity of the piston crown and radially on the outside, which, in those regions of the pin bosses which lie close to the boss holes, has boss cooling passages which are connected to the cooling passage and are intended for improved cooling of the pin bosses.

Abstract: A method is provided for efficiently manufacturing a high quality internal combustion engine piston having an annular cavity allowing for good circulation of cooling fluid. An annular groove is formed at the circumferential edge of the top face of a piston crown, or at the top of the exterior circumferential face of the crown, and an annular protruding strip is formed as a continuation of an edge of the opening of the annular groove. The protruding strip is bent in the direction of the opening of the annular groove by bringing to bear a pressure roller 11, while rotating the main piston body. Consequently, the opening of the annular groove is closed, whereby an annular cavity for circulating cooling fluid is formed so as to surround a pressure receiving recess.

Abstract: A piston for internal combustion engine has both fatigue strength and wear resistance without increased production cost. At least one of a combustion chamber surface, a skirt rib, a pin boss rib which connects a pin boss and a crown, a lower portion of the pin boss casting surface, and a surface layer including the casting surface is a first eutectic structure in which primary crystal Si does not crystallize. A top ring groove and a pin holing of a piston pin are finished surfaces obtained by eliminating the surface layer by means of machining. The layer including the finished surface is a second eutectic structure in which the primary crystal Si crystallizes.

Abstract: A method for surface treatment capable of easily improving a mechanical strength of an internal combustion piston at a reasonable cost is provided. A modified surface layer is formed by injecting injection powders containing a reinforcing element to be collided with an Al—Si alloy-based piston obtained by casting and forging by injecting under predetermined conditions, the reinforcing element being diffused and penetrated in the piston to improve the strength thereof. When a function, such as fuel modification, is imparted to the modified surface layer, an element exhibiting a photocatalytic function by oxidation, such as Ti, Sn, Zn, Zr, or W, is selected as the reinforcing element.

Abstract: A piston includes a piston structure being unitarily formed in a powder metallurgy process, the piston structure having a crown assembly and a skirt assembly, at least a partial combustion chamber being formed intersecting a piston crown surface during the powder metallurgy process, the skirt assembly depending from the crown assembly and having two spaced apart pin bosses, each pin boss having a pin bore defined therein, a pair of opposed semi-circular skirt members, each skirt member extending outwardly from and being integrally joined to both of the pin bosses. The piston may be formed by executing a powder metallurgy process on at least two different metallic constituents to define a non-homogenous piston structure. A method of forming a piston is further included.

Abstract: The present invention provides a composite magnetic body containing metallic magnetic powder and thermosetting resin and having a packing ratio of the metallic magnetic powder of 65 vol % to 90 vol % and an electrical resistivity of at least 104 ?·cm. When a coil is embedded in this composite magnetic body, a miniature magnetic element can be obtained that has a high inductance value and is excellent in DC bias characteristics.

Abstract: The invention relates to a piston (1), which is comprised of an approximately circular cylindrical upper area (5) and of a lower area (6), having two hubs (7), which are set back toward the piston central axis (8) so that, in the upper area (5), recesses (12, 12?) can be made, which are open toward the lower area (6), in the vicinity of the hubs (7). In order to make relief cuts (13, 13?) in the area between the hubs (7) and the upper area (5), a salt mold part (15) is placed on the respective window insert (14). The salt mold part (15) serves to produce the recesses (12, 12?) as well as the relief cuts (13, 13?) when casting the piston (1) and is washed out after the piston (1) has been cast.

Abstract: The invention relates to a piston for a piston-cylinder arrangement, especially a shock absorber piston, comprising a piston body that is fitted with at least one peripheral web on its peripheral surface, wherein a collar-shaped sealing element made of thermoformable plastic material is also formed on the peripheral surface of the piston body in such a way that the web is only formed in part of the height of the material of the collar-shaped sealing element.

Abstract: A piston includes a piston structure being unitarily formed in a powder metallurgy process, the piston structure having a crown assembly and a skirt assembly, at least a partial combustion chamber being formed intersecting a piston crown surface during the powder metallurgy process, the skirt assembly depending from the crown assembly and having two spaced apart pin bosses, each pin boss having a pin bore defined therein, a pair of opposed semi-circular skirt members, each skirt member extending outwardly from and being integrally joined to both of the pin bosses. The piston may be formed by executing a powder metallurgy process on at least two different metallic constituents to define a non-homogenous piston structure. A method of forming a piston is further included.

Abstract: A process for producing pistons for a reciprocating internal combustion engine by casting, the process including the steps of determining for at least a first piston of a casting process batch, a volume Vactual formed by a surface of the piston that faces a combustion chamber of the engine, comparing the volume Vactual with a desired nominal volume Vnominal, and, based on this comparison, fixing a compression height KH so that its deviation from a set point ensures that, subsequently Vactual=Vnominal within tolerance limits.

Abstract: A method of producing a piston for a swash plate type compressor including a head portion which is slidably fitted in a cylinder bore of the compressor, and an engaging section which engages a swash plate of the compressor, wherein a blank including a hollow cylindrical head section corresponding to the head portion and an engaging section corresponding to the engaging portion is formed by a pore-free die-casting method, such that the head section and the engaging section are formed integrally with each other at the closed end by the head section, and wherein a closing member is fixed to the hollow cylindrical head section so as to close its open end, for thereby providing the head portion of the piston.