Kobe Steel, Ltd.

Kobelco Construction Machinery Co., Ltd.

Kabushiki Kaisha Kobe Seiko Sho

Toshihiro Nogi

Satoshi Maekawa

Sho Fujiwara

Kenichi Inoue

Akira Tsutsui

Masashi Hamaguchi

A hydraulic drive apparatus includes a boom flow rate control valve, a target boom cylinder speed calculation part, a pressing force calculation part, a correction part, and a boom flow rate operation part. The target boom cylinder speed calculation part calculates a target boom cylinder speed for making the construction surface by the bucket closer to the target construction surface. The pressing force calculation part calculates the pressing force by which the bucket is pressed against the construction surface, based on the cylinder thrust of the boom cylinder and the center-of-gravity position information on the center-of-gravity position of the work device. The correction part corrects the target boom cylinder speed to make the deviation between the target pressing force and the calculated pressing force closer to 0. The boom flow rate operation part operates the boom flow rate control valve to provide the corrected target boom cylinder speed.

Hydraulic drive device for excavation work machines

A hydraulic drive apparatus includes a boom flow rate control valve, a target boom cylinder speed calculation part calculating a target boom cylinder speed for making a construction surface by a bucket closer to a target construction surface based on the cylinder speed of a boom cylinder and the like, and a boom flow rate operation part. The boom flow rate operation part operates the boom flow rate control valve to make a boom cylinder supply flow rate be a target supply flow rate corresponding to the target boom cylinder speed when the target boom cylinder speed direction coincides with a cylinder thrust direction, and operates the boom flow rate control valve to make the boom cylinder discharge flow rate be a target discharge flow rate corresponding to the target boom cylinder speed when the target boom cylinder speed direction is opposite to the cylinder thrust direction.

Hydraulic actuator for excavation work machine

A motor drive device and motor drive system according to the present invention comprise: a power source terminal; a charging and discharging unit connected in series with the power source terminal; connection terminals to be connected to each of primary and secondary excitation coils for an anti-symmetric two phase motor; and a drive control unit which has a plurality of switching elements and respectively forms first and second paths by turning these switching elements on and off. The first path is used for independently supplying power to the respective primary and secondary excitation coils from the power source terminal via the connection terminals, and the second path is used for independent regeneration of each residual energy remaining in the primary and secondary excitation coils from the respective primary and secondary excitation coils into the charging and discharging unit via the connection terminals.

Motor drive device and motor drive system

Growing community of inventors

Kobe, Japan

Toshihiro Nogi