Title:
クレーン
Document Type and Number:
Japanese Patent JP6740684
Kind Code:
B2
Abstract:
Provided is a crane that is capable of protecting a hydraulic cylinder by suppressing operation of the hydraulic cylinder when the hydraulic cylinder is in poor connection with a hydraulic circuit. A crane (1) provided with a derricking cylinder (15) configured as a detachable hydraulic cylinder is configured in such a manner that: a head side hydraulic sensor (32) and a rod side hydraulic sensor (33) are provided to the derricking cylinder (15); and when the hydraulic pressure Pr of a rod side oil chamber (15F) becomes equal to or higher than the hydraulic pressure Ph of a head side oil chamber (15E) before a prescribed time T elapses after power supply to the head side hydraulic sensor (32) and to the rod side hydraulic sensor (33) is started, and a derricking direct-acting switching valve (28) is switched, by a derricking operation tool (22B), to a state of supplying hydraulic oil to the head side oil chamber (15E), it is determined that the rod side oil chamber (15F) and the derricking direct-acting switching valve (28) are not coupled to each other via a one-side joint (16A).
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Inventors:
Toshihiko Okamoto
Maeda Yasuhiro
Naoto Kawabuchi
Maeda Yasuhiro
Naoto Kawabuchi
Application Number:
JP2016077669A
Publication Date:
August 19, 2020
Filing Date:
April 07, 2016
Export Citation:
Assignee:
Tadano Co., Ltd.
International Classes:
B66C13/20; F15B11/028; F15B20/00
Domestic Patent References:
| JP8282978A | ||||
| JP2002005122A | ||||
| JP2013542386A | ||||
| JP2014163464A |
Foreign References:
| US20130276516 | ||||
| US20140360349 |
Attorney, Agent or Firm:
Yanouchi Foreign Patent Office