Hitachi Construction Machinery Co., Ltd.

Hitoshi Nishiguchi

Toshihiro Abe

Hidefumi Hiramatsu

Tomoyuki Saito

Toshinori Fujii

Daiwa Sato

Tetsuya Matsumoto

Kazuya Kusano

Kunihiko Ikeda

Masaharu Imi

Tsuyoshi Onozaki

Kenichi Hano

A construction machine includes a centrifugal fan, and a bell mouth arranged on the suction side of the centrifugal fan. The centrifugal fan has a rotatable hub, an annular shroud arranged so as to face the hub and having a suction port, and multiple blades provided between the hub and the shroud. An outlet of the bell mouth is arranged on the radially inner side of the suction port of the shroud. Each blade is formed such that: a leading edge has a convex shape protruding toward a suction surface relative to a line segment linking a connection of the leading edge with the hub and a connection of the leading edge with the shroud; and a vertex of the convex shape of the leading edge is positioned on a radially inner side of a wall surface of the outlet of the bell mouth when the suction side of the centrifugal fan is seen in an axis direction.

Construction machine

There is provided a urea water supply device () that is disposed in a urea water pipe line () to supply urea water toward a urea water injection valve () from a urea water tank (). A bracket () for attaching the urea water supply device () is attached to a revolving frame () of an upper revolving structure (). A cover () for covering the urea water supply device () is attached to the bracket (). On top of that, a urea water filter () that is disposed in the urea water pipe line () and traps foreign objects mixed into the urea water is attached to the cover ().

A bypass line () having one end side connected to a pilot delivery line () between a pilot pump () and a throttle () and the other end side connected to the pilot delivery line () between a check valve () and a pressure reducing valve type pilot valve () so as to bypass the throttle (), a gate lock valve (), and the check valve () provided in order from a pilot pump () is provided in the pilot delivery line (). A lock switching valve () shutting down a flow of a pilot pressure oil from the pilot pump () through the bypass line () at a normal time and allowing the flow of the pilot pressure oil through the bypass line () when a pressure generated in the pilot delivery line () exceeds a predetermined pressure between the gate lock valve () and the check valve () is provided in the bypass line ().

An expansion tank, while maintaining gas-liquid separation performance of coolant circulating through an engine cooling apparatus, can absorb pressure variations occurring with volume change of the coolant even when an excessive amount of coolant is supplied. A bulkheadpartitions an expansion tankinto separate chambers Rto Rthat communicate with each other via a first communication holepositioned lower than a FULL line. The separate chambers Rto Rthat constitute a separate chamber group X communicate with each other via a third communication holepositioned higher than the FULL line. The separate chambers Rto Rthat constitute a separate chamber group Y communicate with each other via a fourth communication holepositioned higher than the FULL line. The separate chamber Rand the separate chamber Rcommunicate with each other via a second communication holedisposed at the height of the FULL line.

Expansion tank

A construction machine includes a cooling fan () and a shroud (). The cooling fan () sends air drawn in via a radiator () to an engine. The shroud () is disposed on an outer peripheral side of the cooling fan and forms a passage for air to be drawn in via the radiator. The construction machine includes a tank () and a cover (B). The tank () is disposed superior to an upper end portion of the radiator and stores cooling water to be supplied to the radiator and the engine. The cover (B) is disposed openably in an opening (A) formed in a top surface plate (B) of the shroud. The tank () is disposed at a position adjacent to the shroud () on a side closer to the engine side than the cover (B) is.

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Tsuchiura, Japan

Hitoshi Nishiguchi