Ryobi Limited

Other

Tatsuya Manabe

Shin Nitta

Hirotake Usui

Toru Komazaki

Yasuyuki Mizukusa

Fumiyuki Ogawa

Hiroshi Furusawa

A closed deck type cylinder block providing an optimum area ratio of opening at a top deck side, and a method for producing such cylinder block having the reduced area ratio of the opening at a reduced energy cost and with reduced labor, yet exhibiting smooth discharge of waste sand converted from a water jacket core through the opening in spite of the reduced area ratio of the opening. The cylinder block is formed with a plurality of cylinders juxtaposedly arranged to each other and a water jacket portion surrounding the cylinders. An upper end of the water jacket portion is open at a top deck and is partly covered with bridge portions. The opening has an area ratio of from 10 to 30% of a projection area of the water jacket portion at the top deck surface.

Closed deck type cylinder block and method for producing the same

A metal mold arrangement for producing a closed deck type cylinder block in which a plurality of bridge portions partly cover an open end of a water jacket at a top deck side of the cylinder block. A water jacket die provides a configuration of a water jacket. A plurality of recesses are formed in the water jacket die, and each separate core having a shape complementary to the recess is insetted in each recess. Each separate core has a top deck side end face and a crank case side end face opposite thereto. The two faces are slanted in a direction opposite to each other for serving as drafts. A bottom of each recess is also slanted coincident with the slant of the top deck side end face, and each bridge portion is formed adjacent the bottom of the recess. Upon solidification of a molten metal, the water jacket die is removed from the casted product while each separate core remains in a resultant water jacket. Each of the separate core can be moved toward a direction to increase a distance between the end faces within the water jacket and can be offset from each bridge portion, thereby removing the separate core from the water jacket.

Metal mold arrangement for producing cylinder block

A combination of a device for producing a closed deck type cylinder block and a sand core to be used in the device, the combination being capable of producing the block having high dimensional accuracy and eliminating precise dimensional control to the end face portion of the sand core. The sand core has a configuration identical with a water jacket formed in the engine block. Holding projections extending in an axial direction of a cylinder liner integrally protrude from a slide core of a movable die, and complementary holding bores are formed in the sand core, the bores being open at a top deck end face of the sand core. In one preferred embodiment, the top deck end face of the sand core is of a planner arrangement, and an end face of the slide core is formed with recesses for forming bridge portions therein. Casting is performed while maintaining a surface contact between the planner end face and the end face of the slide core. The contacting areas will become windows of the water jacket.

Casting device for producing closed deck type cylinder block and sand

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Fuchu, Japan

Tatsuya Manabe