Komatsu Corporation

Masami Naruse

Masatake Tamaru

Kenzo Kimoto

Naritoshi Ohtsukasa

Tetsuyuki Hirano

Sadao Nunotani

Jun Maruyama

Hiroyuki Inoue

Kenji Kanemaru

Junsei Tanaka

Tatsuya Futami

Seiya Haga

To provide a hydraulic drive device for a work machine that is capable of ensuring reduction in fuel consumption even in actual work where an operating condition changes every moment. Operating condition identifying unit () for identifying the operating condition and hydraulic pump control system () for controlling absorption torque of hydraulic pump () are provided. When the operating condition identified by operating condition identifying unit () is a specific operating condition, hydraulic pump control system () controls the absorption torque of hydraulic pump () to achieve hydraulic pump absorption torque characteristic line (PLb) matching the absorption torque of hydraulic pump () with output torque of engine () at engine output torque point Mb at which a fuel consumption rate is substantially minimum.

Hydraulic drive device for work machine

A primary object is to provide a hydraulic drive device for a work machine that is capable of optimum control of pump absorption horsepower according to a change of working condition, thereby reducing fuel consumption, and a secondary object is to provide a hydraulic drive device for a work machine that is based on this primary object and capable of restraining variations in the pump absorption horsepower. When working condition identifying unit () determines that, for example, a working condition has changed from working condition (a) to (b), engine control system () changes engine output torque characteristic line from engine output torque characteristic line (ELa) to (ELb), and hydraulic pump control system () changes hydraulic pump absorption torque characteristic line from hydraulic pump absorption torque characteristic line (PLa) to (PLb). At output torque points (Ma), (Mb) at which output of engine () reaches a maximum, output torque of engine () is matched with absorption torque of hydraulic pump ().

A device arrangement structure for hybrid construction equipment capable of reducing devices of a charging system in size is provided. For this purpose, in the device arrangement structure: a hydraulic pump () is connected to an engine () via a first power take-off (); and a regenerative motor (), which is regenerated by return oil from hydraulic actuators (), and a generator motor (), which assists an engine as an electric motor to drive hydraulic pump and generates power with surplus torque of the regenerative motor, are provided in parallel with the hydraulic pump via the first power take-off.

Device arrangement structure for hybrid construction equipment

Hybrid powered construction equipment is capable of making effective use of the output energy of an engine; increasing operating speed while keeping noise level low, and assuring operation power more than the performance of the engine. To this end, the hybrid powered construction equipment has a hydraulic pump powered by the engine; hydraulic actuators activated by discharge oil from the hydraulic pump; a motor-generator working in conjunction with the engine; and a battery for storing electric power generated by the electric motor-generator, the construction equipment further comprising a power-up switch disposed in an operating lever or operation panel and a controller which inputs a signal released from the power-up switch, wherein the controller constantly controls the revolution speed of the engine in response to a signal from the power-up switch and controls the output torque of the electric motor-generator such that torque for assisting powering of the hydraulic pump is output.

Hybrid powered construction equipment

Compact, low-cost construction equipment capable of effectively recovering energy from a plurality of hydraulic actuators is provided. To this end, the construction equipment comprises: a hydraulic recovery circuit for recovering return oil from the hydraulic actuators, the circuit being equipped with a pump motor rotatably driven by the recovered return oil; oil guide passages each of which is for guiding return oil from the meter-out side of its corresponding hydraulic actuator to the hydraulic recovery circuit; switches for switching the respective oil guide passages between their opened and closed states; pressure sensors for detecting the back pressure of each hydraulic pressure actuator; and a dynamo-electric generator for generating electric power from the rotary force of the pump motor.

Construction equipment

Hybrid construction equipment leveling an engine load and effectively performing regeneration of energy is provided. For this purpose, the construction equipment includes a hydraulic pump ( ) and a first electric motor ( ) driven by an engine ( ), a battery ( ) for charging electric power generated by the first electric motor, a second electric motor ( ) driven by electric power of the battery and functioning as a generator at a time of braking revolution, a swash plate angel sensor and a pressure sensor for the hydraulic pump, and a controller ( ) for controlling the first electric motor as a generator by surplus torque when absorption torque is smaller than predetermined output torque of the engine and controlling the first electric motor as a motor to generate an amount of shortage of torque when the absorption torque is larger than the predetermined torque.

Hybrid construction equipment

A hybrid construction equipment capable of sufficiently exhibiting performance of a battery with strategic arrangement of the apparatuses being carried out is provided. For this purpose, the hybrid construction equipment includes, on an upper revolving superstructure ( ) rotatably placed on a lower traveling unit, an engine ( ), a generator ( ) driven by the engine ( ), a battery ( ) charged with electric power generated by the generator ( ), an electric motor ( ) driven by electric power of the battery ( ), an inverter ( ) for controlling drive of the electric motor ( ) and a driver's cab ( ), and the battery ( ) is placed to be isolated from the engine ( ) and the generator ( ).

A hydraulic shovel is provided which comprises a pair of left and right running/rotation pedals ( L and R) for running or rotating a vehicle, and a single running/rotation lever which is installed separately from the pedals for similarly running or rotating the vehicle. The shovel allows the operator to run or rotate the vehicle by operating on the running/rotation pedals L and R, as well as by manipulating the running/rotation lever Moreover, because the running/rotation lever consists of a single lever, the operator can easily manipulate it by one hand, being relieved of complicated operations and inconveniencies encountered with the conventional machine, which ensures the improved operability.

Hydraulic shovel

A hydraulic pipe arrangement of a working machine is not in contact with an obstacle and no torsion and no bending are generated. Accordingly, in a hydraulically driven type working machine provided with a boom ( ) having a vertical swing supporting point supported at a base end side by a machine frame and a joint connection supporting point in a front end side, an arm ( ) connected in a base end side to the joint connection supporting point, a boom driving hydraulic cylinder ( a) hoisting around a hoist supporting point provided in the machine frame so as to drive the boom, an arm driving hydraulic cylinder ( ), and a working tool driving hydraulic cylinder ( ), a swivel joint mechanism relaying a hydraulic pipe arrangement from a side of the machine frame is provided at a center of at least one of the vertical swing supporting point, the joint connection supporting point and the boom driving hydraulic cylinder hoist supporting point.

Growing community of inventors

Hirakata, Japan

Masami Naruse