Kayaba Industry Company, Ltd.

Kyb Corporation

Masahiro Egawa

Haruhiko Kawasaki

Yasuhiro Yonehara

A control system for a hybrid construction machine includes first and second main pumps for supplying working oil, a boom cylinder extending by supply of the working oil to a piston-side chamber and raising a boom and contracting by discharge of the working oil from the piston-side chamber and lowering the boom, a regenerative spool valve controlled by a pressure of pilot pressure oil and adjusting a flow rate of the working oil discharged from the piston-side chamber, a regenerative motor for regeneration rotating by the working oil discharged from the piston-side chamber, a rotary electric machine connected to the regenerative motor, and a failsafe switching valve switching with a pressure of a regenerative passage between the regenerative control spool valve and the regenerative motor as a pilot pressure and lowering the pressure of the pilot pressure oil to the regenerative control spool valve so that a flow rate of the working oil discharged from the piston-side chamber is narrowed if the pressure of the regenerative passage is less than a set pressure.

Control system for hybrid construction machine

A control system of a hybrid construction machine includes a regeneration passage switching valve having a normal position where flow of working fluid is blocked, and a regeneration position allowing for the working fluid to flow from main passages to a regeneration motor when a working fluid pressure of the main passages reaches a set pressure during operation of the actuators, and an assist switching valve having a normal position proportionally dividing the working fluid of an assist passage into a regeneration passages, a first switching position supplying more working fluid of the assist passage to one of the main passages when that the one has a higher working fluid pressure, and a second switching position supplying more working fluid of the assist passage to the other one of the main passages when that the other one has a higher working fluid pressure.

Control system of hybrid construction machine

A control system for hybrid construction machine includes a regeneration motor configured to be rotated by working fluid introduced from a turning circuit, a pressure detector configured to detect a turning pressure during a turning operation of the turning motor or a braking pressure during a braking operation of the turning motor, a switching valve for turning regeneration configured to perform turning regeneration by introducing the working fluid from the turning circuit to the regeneration motor when being switched to an open position by a pressure of pilot fluid, an electromagnetic proportional pressure reducing valve configured to be switched to an open position and generate a pilot secondary pressure for switching the switching valve for turning regeneration to the open position when a pressure detected by the pressure detector reaches a first set pressure, and a pilot switching valve configured to allow the passage of the pilot fluid for switching the switching valve for turning regeneration to the open position by being switched to an open position when the pressure of the turning circuit reaches a second set pressure.

A control system for a hybrid construction machine includes a turning-regeneration-use switching valve that opens when a pressure detected by a pressure detector reaches a turning-regeneration starting pressure, so as to introduce the working fluid from a turning circuit to a regenerative motor, an operating-state detector that detects an operating state of a fluid pressure cylinder; and a cylinder-regeneration-use switching valve that opens based on a detection result of the operating-state detector, so as to introduce the working fluid from the fluid pressure cylinder to the regenerative motor. When the turning regeneration is performed alone, the working fluid from the turning circuit is introduced into the regenerative motor without pressure reduction, When the turning regeneration and the cylinder regeneration are simultaneously performed, the working fluid from the turning circuit is reduced in pressure, joins the working fluid from the fluid pressure cylinder, and is introduced into the regenerative motor.

A control system for a construction machine includes: a boom cylinder; a boom switching valve; a fluid pressure motor adapted to drive a motor generator by being rotated by means of a return fluid guided from a piston side chamber; a regeneration control valve adapted to adjust a first supply amount serving as a supply amount of a working fluid supplied from the piston side chamber to the boom switching valve, and a second supply amount serving as a supply amount of the working fluid supplied from the piston side chamber to the fluid pressure motor; and a controller adapted to control the regeneration control valve so that the second supply amount becomes smaller than the first supply amount in a case where a stroke amount of a spool becomes an upper limit value or more.

Control system for construction machine

A control system for hybrid construction machine includes: an operation valve for operating a boom; a variable displacement type fluid pressure motor; a distribution mechanism adapted to adjust a flow to be distributed to the fluid pressure motor; a motor generator adapted to be rotated integrally with the fluid pressure motor; a variable displacement type assist pump adapted to be rotated integrally with the motor generator; a distribution mechanism control unit adapted to control the distribution mechanism; a tilt angle control unit adapted to control tilt angles of the fluid pressure motor and the assist pump; and a motor generator control unit adapted to maintain a rotation speed of the motor generator at a target rotation speed. The target rotation speed at the time of boom regeneration control is set to higher than the target rotation speed in a case where only an assist control is carried out.

A boom driving device comprises a boom control valve causing a boom cylinder to elongate and contract. The boom control valve returns a hydraulic fluid discharged from an working chamber of the boom cylinder to a tank in a boom descending position A part of the discharged hydraulic fluid is branched in the upstream of the boom control valve and is supplied to a generator through a regenerative passage for power generation. The regenerative passage is provided with a regenerative control spool valve. The regenerative control spool valve is opened when a flow cross-sectional area of the hydraulic fluid flowing from the working chamber to the tank reaches a predetermined area while the boom control valve is in the descending position. According to this construction, it is possible to alleviate a shock that may be generated at the start of power generation by the generator.

Boom driving device

A control system for a hybrid construction machine includes: a turning motor provided in a turning circuit; a pressure detector for detecting a turning pressure of the turning motor; a variable displacement type of fluid pressure motor for regeneration which is rotated by means of pressurized fluid guided from the turning motor; a motor generator adapted to be rotated integrally with the fluid pressure motor; and a controller adapted to predict a turning regeneration flow from the turning motor on the basis of the turning pressure detected by pressure detector to control a tilt angle of the fluid pressure motor on the basis of the predicted turning regeneration flow.

A control system for construction machine includes a main pump; a circuit system which includes a plurality of operation valves; a boom cylinder which is connected to a specific valve; one passage which allows communication between the specific operation valve and a piston-side chamber; another passage which allows communication between the specific operation valve and a rod-side chamber; a hydraulic motor which rotates by the action of return oil from the piston-side chamber; a generator; and a valve mechanism which is provided in the one passage communicating with the piston-side chamber of the boom cylinder, introduces the return oil from the piston-side at the time of descent as a regeneration flow to the hydraulic motor and introduces the return oil as a recovery flow to the rod-side chamber if necessary by causing the return oil to flow into the other passage.

A control system for hybrid construction machine includes an engine, a main pump to be driven by the engine, a rotary shaft linking an assist pump, a regenerative hydraulic motor and a motor generator, and a clutch for linking the engine and the rotary shaft.

A control system for construction machine includes a pair of first and second main pumps which are variable-displacement pumps, first and second circuit systems connected to the first and second main pumps and including a plurality of control valves, main switching valves provided between the first and second circuit systems and the first and second main pumps, a hydraulic motor for power generation connected to the first and second main pumps via the main switching valves, a generator coupled to the hydraulic motor for power generation, and a battery for storing power generated by the generator. When at least the main switching valve connected to one circuit system is at a position to cause one main pump connected thereto to communicate with the hydraulic motor for power generation, the main switching valve connected to the other circuit system causes the other main pump to communicate with the other circuit system.

A charging apparatus includes a diode, a switch, a high-voltage conversion circuit, and a controller which determines whether a charge capacity of a low-voltage battery is above a threshold and outputs a signal for supplying power of a generator to the low-voltage battery when the charge capacity is equal to or below the threshold while outputs a signal for charging the high-voltage battery when the charge capacity is above the threshold value.

Charging apparatus for construction machine

A control device for a hybrid construction machine includes a regulator that performs control such that a tilt angle of a variable volume pump increases as an exerted pilot pressure decreases. A controller switches a main switch valve such that an oil discharged from the variable volume pump is led to a regenerative hydraulic motor and switches a pilot selection valve such that a second pilot flow passage provided with a solenoid variable pressure reducing valve communicates with the regulator when all of a plurality of operation valves are determined to be in a neutral position.

Control device for hybrid construction machine

A regeneration switching valve which communicates with a neutral flow path and a tank at a normal position and cuts off communication between the neutral flow path and the tank to cause the neutral flow path to communicate with a hydraulic motor for power generation at a switched position is provided in at least one of first and second circuit systems including a plurality of control valves.

A controller determines whether or not a control valve for controlling the supply of pressure fluid from a main pump to an actuator is at a neutral position, detects input power of a hydraulic motor rotated by return oil from the actuator, and narrows the opening of a proportional electromagnetic throttle valve when the control valve is at the neutral position and the input power of the hydraulic motor is in excess of a first threshold value.

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Kawaguchi, Japan

Masahiro Egawa