Fuji Jukogyo Kabushiki Kaisha

Nippon Piston Ring Co., Ltd.

Other

Kabushiki Kaisha Koyama

Fuji Jugogyo K.k.

Teruyuki Oda

Hiroshi Takiguchi

Shigeru Koyama

Tsuyoshi Nozawa

Kazuo Koyama

Hiroshi Nippon Piston Ring Co Ltd Takiguchi

A preform main body of an iron species preform for forming a metal matrix composite inserted in an aluminum species alloy base material to be cast-in is bored with a first to fourth through holes communicating an inner peripheral face and an outer peripheral face. In a cast-in step, shrinkage in a peripheral direction of the inner peripheral face and the outer peripheral face of the iron species preform in accordance with solidification of the melted aluminum species alloy is uniformly received by shrinkage in accordance with solidification of the melted aluminum species alloy invading the through holes, movement thereof in the peripheral direction is restrained, a clearance can be prevented from being brought about at an interface, a cast-in performance is excellent and a stable bonding strength of the interface is achieved.

Iron species preform

An iron species preform for forming a metal matrix composite is inserted in an aluminum species alloy member to be cast-in. The aluminum species alloy member has bearing faces having a section in a semicircular arc shape. An inner peripheral face of the iron species preform is provided with a plurality of inner side grooves. The inner side groove includes flat portions and groove bottom portions continuous to two end edges continuous to the inner peripheral face and opposed to each other. In a cast-in step, shrinkage in a peripheral direction accompanied by solidifying a melted aluminum species alloy is uniformly received by the respective inner side grooves, movement in the peripheral direction is restrained, a clearance at an interface can be prevented from being brought about, so that a cast-in performance is excellent, and stable bonding strength and close contact of the interface can be ensured.

A cast iron cylinder liner of the present invention includes a plurality of grooves formed on an outer surface of the cylinder liner. Each of the grooves extends in a circumferential direction of the cylinder liner in a ring or spiral shape, and the grooves divide the outer surface of the cylinder liner into a plurality of ring or spiral sections. The outer surfaces of the ring sections have a uniform distance from the central axis of the cylinder liner over the entire area of the outer surfaces, and the grooves being arranged symmetrically with respect to the center of the cylinder liner in an axial direction thereof. Each of the grooves has a J-shaped longitudinal cross-section including a first inclination part and a groove bottom part. The first inclination part extends from the outer surface of one of the ring sections or of one turn of the spiral sections toward the center of the cylinder liner in an axial direction thereof. The groove bottom part has a longitudinal cross-section approximately in the form of a circular arc, and extends from the first inclination part in a direction away from the center of the cylinder liner in an axial direction thereof.

Cylinder liner and cylinder block

The object of the invention is to provide an iron based sintered body suitable for being enveloped in light metal alloy such as an aluminum alloy by casting, and a method for producing the same. A mixed powder is prepared by mixing an iron based powder, a copper powder and a graphite powder blended so that the Cu content and the C content are 5 to 40% by mass and 0.5 to 2.5% by mass, respectively, in the mixed powder. A lubricant powder and a fine particle powder for improving machinability may be further added in the mixed powder. Then, the mixed powder is filled into a mold formed to a green compact, and is sintered into a sintered body so that the sintered body has a desired average thermal expansion coefficient. The surface of the sintered body may be adjusted to have a surface roughness Rz of 10 to 100 &#x3bc;m optionally by applying a shot blast treatment or by a shot blast treatment and an additional steam treatment. This process permits the sintered body to be enhanced in an adhesive property and bonding strength while being improved in enveloping casting property when the sintered body is enveloped in the light metal alloy by casting. A martesitic stainless steel powder or ferritic stainless steel powder may be used instead of the pure iron powder, or Cr, Mo and W powders may be further blended.

Iron based sintered body excellent in enveloped casting property in light metal alloy and method for producing the same

The cylinder liner is capable of being tightly adhered to an aluminium block. The cylinder liner is made of cast iron and formed into a cylindrical shape. In the cylinder liner, slender section is provided in a middle portion, and outer diameter of the cylinder liner is gradually made greater toward both end sections from the slender section. A plurality of projected lines are formed on an outer circumferential face of the cylinder liner with regular separations and extended in the axial direction thereof. With this structure, the cylinder liner can securely stay in a cylinder block even if an external force in the axial direction works to the cylinder liner. In the cylinder block of the present invention, a plurality of the cylinder liners are enclosed with casted aluminium.

Growing community of inventors

Tokyo, Japan

Teruyuki Oda