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Patent Searching and Data

Document Type and Number:
WIPO Patent Application WO/2018/025439
Kind Code:
Provided is an exhaust gas purification system for a construction machine with which it is possible to prevent urea water (remaining in the piping of a urea water replenishment circuit after replenishment of urea water in a urea water tank) from being affected by heat from an engine, operating oil tank, or the like, and deteriorating. A first return pipe 9 connecting a urea water injection device 4 to a urea water tank 6 and a second return pipe 10 connecting the urea water injection device 4 to a pipe 11 in a urea water replenishment circuit 201 are provided in a urea water return circuit 202, which returns to the urea water tank 6 excess urea water that has not been injected into exhaust gas from the urea water injection device 4. The valve-opening pressure of a first check valve 15 provided in the first return pipe 9 is set so as to be higher than the valve-opening pressure of a second check valve 16 provided in the second return pipe 10.

SAKURAI Masatoshi (Hitachi Construction Machinery Co. Ltd., 650, Kandatsumachi, Tsuchiura-sh, Ibaraki 13, 〒3000013, JP)
Application Number:
Publication Date:
February 08, 2018
Filing Date:
March 10, 2017
Export Citation:
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HITACHI CONSTRUCTION MACHINERY CO., LTD. (16-1, Higashiueno 2-chome Taito-k, Tokyo 15, 〒1100015, JP)
International Classes:
F01N3/08; B01D53/94; E02F9/00
Attorney, Agent or Firm:
KAICHI IP (3-16, Nihonbashi-muromachi 4-chome Chuo-k, Tokyo 22, 〒1030022, JP)
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