Komatsu Corporation

Tomoya Watanabe

Mitsuo Yabe

Masahiro Ikeda

Seiichi Fuchita

Yasuhiro Kusuyama

Teruyuki Matsuki

Hiroki Shinoda

Atsushi Kawano

Hiroaki Inoue

Noboru Kanayama

Satoru Nishimura

Kazuya Imamura

Kuniaki Nakada

Teruyuki Hosoya

A cooling device includes: a cooling fan; a shroud provided at an outer circumferential side of the cooling fan; and a ring having an inner circumferential wall and an outer circumferential wall. The inner circumferential wall is provided on the shroud and adjacent to an outer circumference of the cooling fan. The outer circumferential wall surrounds the inner circumferential wall, and an air-flow-direction downstream side end of the outer circumferential wall is positioned at a further downstream position in an air flow direction than an air-flow-direction downstream side end of the inner circumferential wall. An air-flow-direction downstream side end of an outer circumferential edge of the cooling fan is positioned at a further downstream position in the air flow direction than the air-flow-direction downstream side end of the inner circumferential wall.

Cooling device and construction machine or working machine equipped with the same

A cooling device includes: a cooling fan; a shroud provided at an outer circumferential side of the cooling fan; an inner circumferential wall provided on the shroud and adjacent to the outer circumference of the cooling fan so as to surround the cooling fan; an outer circumferential wall provided to surround the inner circumferential wall. An air-flow-direction downstream side end of the outer circumferential wall is positioned at a further downstream position in an air flow direction than an air-flow-direction downstream side end of the inner circumferential wall. The cooling fan is rotatable within a space provided on a radially inner side of the inner circumferential wall. The air-flow-direction downstream side end of the outer circumferential wall is provided at a further upstream position in the air flow direction than an air-flow-direction downstream side end of the cooling fan.

A cooling device includes: a cooling fan; a shroud provided at an outer circumferential side of the cooling fan; an inner circumferential wall provided on the shroud and adjacent to the outer circumference of the cooling fan; and an outer circumferential wall provided to surround the inner circumferential wall. An air-flow-direction downstream side end of the outer circumferential wall is positioned at a further downstream position in an air flow direction than an air-flow-direction downstream side end of the inner circumferential wall. An air-flow-direction downstream side end of the cooling fan is positioned at a further downstream position than the air-flow-direction downstream side end of the inner circumferential wall. A ratio between a length of the outer circumferential wall and a length of the inner circumferential wall in the air flow direction is 1.07 or more and 1.81 or less, and a width between the outer circumferential wall and the inner circumferential wall is 15 mm or more and 55 mm or less.

A cooling device includes: a cooling fan; a shroud provided at an outer circumferential side of the cooling fan; an inner circumferential wall provided on the shroud and adjacent to the outer circumference of the cooling fan; and an outer circumferential wall provided to surround the inner circumferential wall. An air-flow-direction downstream side end of an outer circumferential edge of the cooling fan is positioned at a further downstream position in an air flow direction than an air-flow-direction downstream side end of the inner circumferential wall. An angle between: an line connecting the air-flow-direction downstream side end of the inner circumferential wall to the air-flow-direction downstream side end of the outer circumferential wall in cross section along the air flow direction of the inner circumferential wall and the outer circumferential wall; and a line orthogonal to the air flow direction, is 9 degrees or more and 45 degrees or less.

A pressure-receiving face plateis mounted on one end face of a piston, and a support memberis raised on the end face of the piston. Disposed on the support memberwith an allowance are, from the pressure-receiving faceplaterespectively, a disk spring, a plate, and a plunger. A flangeprevents these members from slipping off the support member. When the pistonapproaches a stroke end, the plungeris inserted in an oil passageand applies a cushioning effect to the piston. In addition, a gap between the pressure-receiving faceplateand the platebrought into contact with a cylinder bottombecomes narrow, and produces a squeeze effect such that oil escapes from the narrow gap. This makes it possible to provide a hydraulic cylinder that produces a sufficient impact force at the stroke end of the piston and also reduces noise emitted by the impact force, without increasing a length of the hydraulic cylinder.

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Hiratsuka, Japan

Tomoya Watanabe