US 10,329,737 B2Granted

Hybrid construction machine

AssigneeHitachi Construction Machinery Co., Ltd.

InventorsMasafumi Hita, Shinya Imura, Shinji Nishikawa

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Abstract

An output command calculating section (40) of an HCU (36) restricts a battery discharge power from an electricity storage device (31) based upon a battery electricity storage rate (SOC) and a current square integrating rate (Risc) of the electricity storage device (31). Thereby, the HCU (36) transfers from a normal mode (NMODE) to a low speed mode (LSMODE) to lower a movement speed of a hydraulic actuator. A monitor display amount calculating section (50) of the HCU (36) calculates a maximum speed reduction rate (DRs) based upon a battery discharge power limit value (Plim0) and an engine output upper limit value (Pemax) from the output command calculating section (40). A monitor device (39) displays a reduction rate of the movement speed of the hydraulic actuator in the low speed mode (LSMODE) based on the maximum speed reduction rate (DRs).

Claims3

Dependent claims

A hybrid construction machine comprising:

an engine;
a motor-generator that is connected mechanically to said engine;
an electricity storage device that is connected electrically to said motor-generator;
a hydraulic pump that is driven by torque of said engine and/or said motor-generator;
a plurality of hydraulic actuators that are driven by pressurized oil from said hydraulic pump;
a controller that controls output of said electricity storage device;
and
a monitor device that is connected to said controller, wherein said controller:
detects a plurality of state-amounts indicative of a state of said electricity storage device, and, when any one of the plurality of state-amounts detected surpasses a given threshold, executes a low speed mode for reducing a movement speed of said hydraulic actuator in accordance with the surpassing degree,
calculates a speed reduction degree of a speed of said hydraulic actuator in said low speed mode, and
converts into a common scale a region of not transferring in said low speed mode to each of said plurality of state-amounts indicative of the state of said electricity storage device, and thereby converts the present value of each of said plurality of state-amounts into a value of said common scale to specify any one of these values as a representative value, and wherein said monitor device:
displays the speed reduction degree of the speed of said hydraulic actuator, and
displays said representative value.

10 more elements

Dependencies are inferred from the claim text.