Aisin Seiki Kabushiki Kaisha

Toyota Jidosha Kabushiki Kaisha

Aisin Seiki Kabushiki

Soichi Hara

Yasuhiro Kawabata

Hiroshi Kageyama

Shirou Machida

Motoichi Murakami

Toshiaki Konomi

Naoki Minamoto

Akinari Ishikawa

Takanori Kamiya

Tomohiro Sawada

Hiromi Niimi

Tomohiro Aikawa

An aluminum alloy for internal-combustion engine pistons has good high-temperature strength and good abrasion resistance. It comprises from 2 to 5% by weight of copper, from 13 to 16% by weight of silicon, from 0.2 to 1.3% by weight of magnesium, from 1.0 to 2.5% by weight of nickel from 0.05 to 0.2% by weight of vanadium and from 0.004 to 0.02% by weight of phosphorus, with the balance of aluminum. To produce the piston, a melt of the aluminum alloy having the defined composition is cast and then aged under heat at 220 to 260.degree. C. for 3 to 5 hours (T5 treatment) or, after having been cast, heated at 480 to 510.degree. C. for 3 to 10 hours for solution treatment and then aged under heat at 240 to 260.degree. C. for 3 to 5 hours (T6 or T7 treatment).

Aluminum alloy for internal-combustion piston, and aluminum alloy piston

The method of making a piston unit for an internal combustion engine incorporates the steps of pinching a melting core in a mold cavity of a piston mold wherein the melting core includes an inner ring that forms a ring shaped passage within a piston body, an outer ring and a plurality of coupling portions connected with between the inner ring and the outer ring. The method further includes pouring molten metallic alloy into the cavity and solidifying therein, removing the outer ring of the melting core, filling the space left by removal of the outer ring with reinforced material, and then melting the inner ring and the coupling portions of the melting core.

Method of making a piston unit for an internal combustion engine

Disclosed is a piston for an internal combustion engine, which includes a land portion, and a skirt portion including a non-coated portion which is formed in an arbitrary shape on a sliding portion thereof and a coated portion which is formed on a sliding portion thereof other than the sliding portion on which the non-coated portion is formed. When the piston is descending, an oil which has adhered on a cylinder bore is introduced into the non-coated portion and accordingly an oil film is established in the non-coated portion. Since the advantageous effects of the coated portion and the oil film are combined in the piston, the sliding resistance can be reduced remarkably. Hence, the coated portion can be inhibited from wearing out, and its function of the sliding resistance reduction can be maintained for a long period of time. In addition, since the non-coated portion does not work as a sliding surface, there arises a reduced sliding surface area which also results in the reduction of the sliding resistance. The non-coated portion and the coated portion can be formed with a resin by printing. If such is the case, they can be formed with ease and at a less production cost.

Piston for an internal combustion engine

A piston comprises a crown part, a piston under part, a first shoulder at a thrust side formed between the crown part and the piston under part, a second shoulder at an anti-thrust side formed between the crown part and the piston under part, a first in-low part at the thrust side formed in the piston under part, and a second in-low part at the anti-thrust side formed in the piston under part, wherein a thickness of the first shoulder is formed thinner than a thickness of the second shoulder, and a height of the first in-low part is formed smaller than a height of the second in-low part.

Piston for internal combustion engine

A piston installed into a cylinder of an engine includes annular projections formed in axially spaced relation on a top land facing a cylinder inner wall and having a saw-toothed cross-section in which the external diameter of the projections are such that, when cold, that adjacent the lower end of the top land is greater than that adjacent the upper end thereof. Thereby the effective clearance between the top land face and the cylinder inner wall is reduced. This causes a reduction in the hydrocarbon content of the incompletely consumed combustion gas, and prevents the temperature from rising in the top ring groove and thus prevents the wearing of the groove.

Internal combustion engine piston with top-land circumferential

A piston is formed with a cooling channel in its crown by dissolving a fusible core cast into the crown. The fusible core is supported prior to casting by a strut which is itself supported on a plurality of cores which help to find the piston cavity. The plurality of cores are configured so as to be removable from the strut, after casting, in a downward direction. The fusible core is dissolved by introducing a dissolving liquid to the fusible core via inlet or outlet passages cut between the cavity and the fusible core.

Piston assembly having a fusible core to form a cooling channel and a

A manufacturing method of a piston in used for an internal combustion engine. The method comprises a step of reinforcing a circumference of a top ring groove by an inorganic fiber assembly, a step of forming an oil cooking gallery by a soluble core, a step of fixing the soluble core by projections formed in a strut preventing a thermal expansion of the piston, a step of setting the soluble core in a position supported by a punch mold, and step of setting the inorganic fiber assembly in an annular groove of a lower mold.

Manufacturing method of a piston for an internal combustion engine

A method for manufacturing a piston of an internal combustion engine, especially for forming a piston gallery portion provided in the piston head for cooling the engine. A gallery member made of a metal pipe having a high thermal conductivity or a salt-core having a shape corresponding to the piston gallery is fixed to a fixing member having a peripheral rim and a plurality of fixing legs extended from the rim. The gallery member or the salt-core fixed to the fixing member is cast in the piston, body, and then, the fixing member is cut off from the piston body. The salt-core is melted away by pouring water. By this method, a piston of light weight and having high cooling efficiency can be manufactured.

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Soichi Hara