Kawasaki Jukogyo Kabushiki Kaisha

Kabushiki Kaisha Kawasaki Precision Machinery

Hideyasu Muraoka

Akihiro Kondo

Nobuyuki Kinoshita

Tomomichi Nose

Yoshiyuki Tode

Hayato Kawasaki

Kazuya Iwabe

Yoji Yudate

Hiroshi Itoh

Ryo Yamamoto

Takashi Okashiro

Hiroaki Shimizu

Kazuto Fujiyama

Jun Umekawa

Masahiro Yamada

Makoto Ito

Hideki Tanaka

Hirohide Matsushima

Naoki Hata

Hiroaki Fujimoto

Takehisa Kato

Yuki Nakayama

Hitoshi Nakagawa

Moriyuki Sakamoto

Makoto Itoh

Takuya Fukumoto

Toshio Akashi

Yoshihiko Hata

A hydraulic-pump flow-rate calibration system includes: a variable capacitance type hydraulic pump that supplies an operating fluid to a hydraulic actuator; a regulator that changes the dispense flow rate of the hydraulic pump according to a flow rate command signal; a flow rate detection device that detects the flow rate of the operating fluid; a control device that outputs the flow rate command signal to the regulator to control the regulator; and a calibration device that calculates an actual measurement characteristic of the dispense flow rate for the flow rate command signal, and performs, on a preset reference characteristic, calibration based on the actual measurement characteristic. The actual measurement characteristic is calculated as a result of the flow rate of the operating fluid being detected by the flow rate detection device during output of a predetermined flow rate command signal from the control device to the regulator.

Hydraulic-pump flow-rate calibration system

This hydraulic drive system includes: a hydraulic pump that supplies a working fluid to a hydraulic actuator; a meter-in control valve that controls a flow rate of the working fluid flowing from the hydraulic pump to the hydraulic actuator; a meter-out control valve that controls a flow rate of the working fluid being drained from the hydraulic actuator into a tank; and a regeneration valve that supplies, to the hydraulic actuator, the working fluid drained from the hydraulic actuator. The meter-out control valve is connected to the hydraulic actuator in parallel with the regeneration valve.

Hydraulic drive system

This hydraulic drive system includes: a hydraulic pump capable of changing a discharge flow rate of a working fluid; a meter-in control valve that controls a meter-in flow rate of the working fluid flowing from the hydraulic pump to a hydraulic actuator; a meter-out control valve that is provided separately from the meter-in control valve and controls a meter-out flow rate of the working fluid being drained from the hydraulic actuator into a tank; an operation device that outputs an operation command; a first pressure sensor that detects a drainage pressure of the hydraulic actuator; and a control device that sets a target meter-out flow rate according to the operation command from the operation device and controls an opening degree of the meter-out control valve on the basis of the drainage pressure detected by the first pressure sensor and the target meter-out flow rate.

This control device controls movement of a valve body of a valve device included in a hydraulic system and includes: a stroke command calculator that calculates a stroke command for the valve body on the basis of an opening command that is input to the stroke command calculator; an observer that estimates, on the basis of the stroke command, a dynamic deviation of a stroke of the valve body that corresponds to the stroke command; and a flow force estimator that estimates, on the basis of the stroke command and the dynamic deviation, a flow force acting on the valve body. The stroke command calculator calculates the stroke command on the basis of the flow force in addition to the opening command.

Control device and hydraulic system including the same

A directional and flow control valve includes: a housing with a pump port, a first supply/discharge port, a second supply/discharge port, and a tank port, the housing including therein a first pilot chamber, a second pilot chamber, and a third pilot chamber; and a first spool and a second spool, which are independent of each other. The first spool includes a first end surface facing the first pilot chamber and a second end surface facing the third pilot chamber. The second spool includes a first end surface facing the second pilot chamber and a second end surface facing the third pilot chamber. The first spool brings the first supply/discharge port into one of the pump port or the tank port, and the second spool brings the second supply/discharge port into the other one of the pump port or the tank port.

Directional and flow control valve and hydraulic system

This hydraulic pump system includes: a hydraulic pump having a discharge flow rate that is changeable; a regulator device that adjusts the discharge flow rate of the hydraulic pump; an operation device including an operation tool; a lock switching input unit that unlocks the operation tool; an unloader valve that adjusts a discharge pressure of the hydraulic pump by changing the opening area of the unloader valve; and a control device that controls movement of the unloader valve. When a predetermined actuation condition is satisfied, the control device causes the unloader valve to reduce the opening area to increase the discharge pressure of the hydraulic pump. The regulator device increases the discharge flow rate after the control device causes an increase in the discharge pressure of the hydraulic pump. The actuation condition includes a condition that the lock switching input unit has unlocked the operation tool.

Hydraulic pump system and control device

This hydraulic drive system includes: first and second circuit systems; first and second hydraulic pumps; a merge valve that opens and closes a merge passage connecting the hydraulic pumps; an operation device that outputs an operation command corresponding to an amount of operation specifying an amount of actuation of first and second hydraulic actuators; and a control device that controls the merge valve according to the operation command from the operation device. The first circuit system includes: a first meter-in control valve that controls a meter-in flow rate of the working fluid that flows to the first hydraulic actuator; and a first meter-out control valve that controls a meter-out flow rate of the working fluid that is drained from the first hydraulic actuator into a tank. The control device controls an opening degree of the first meter-in control valve and an opening degree of the first meter-out control valve.

A hydraulic excavator drive system includes: a first pump connected to a head-side chamber of a boom cylinder; and a second pump that supplies hydraulic oil to one of, or both, an arm cylinder and a bucket cylinder. The first pump is driven by an electric motor. The drive system further includes a switching valve that is in a first position at a boom raising operation and in a second position at a vehicle body lifting operation. The first position is a position in which the switching valve brings a rod-side chamber of the boom cylinder into communication with a tank, and the second position is a position in which the switching valve brings the rod-side chamber into communication with the second pump.

Hydraulic excavator drive system

A hydraulic excavator drive system includes: a first pump that is connected to a head-side chamber of a boom cylinder by a head-side line and to a rod-side chamber of the boom cylinder by a rod-side line to form a closed circuit; and a second pump that supplies hydraulic oil to at least one of an arm cylinder or a bucket cylinder. The hydraulic excavator drive system further includes a switching valve located on a relay line that connects a supply line extending from the second pump to the rod-side line. The switching valve opens the relay line at a boom raising operation and blocks the relay line except at the boom raising operation.

A hydraulic excavator drive system () includes an arm control valve () and an arm switching valve (). The arm switching valve () is connected to an arm pushing supply line () by a rod-side line () and to an arm crowding supply line () by a head-side line (). The arm switching valve () is switched between a neutral position, a recycling position in which the arm switching valve () allows the rod-side line () to communicate with the head-side line () and a second tank line (), and a meter-out control position in which the arm switching valve () allows the head-side line () to communicate with the tank line (). The arm switching valve () incorporates therein a check valve () that allows a flow from the rod-side line () toward the head-side line () when the arm switching valve () is in the recycling position.

A housing of a multi-control valve includes an arm parallel passage, an arm crowding supply passage, an arm pushing supply passage, a boom parallel passage, a boom raising supply passage, and a boom lowering supply passage. The housing further includes: a slide hole; a head-side passage that is branched off from the boom raising supply passage and extends to the slide hole; a rod-side passage that is branched off from the boom lowering supply passage and extends to the slide hole; and a regeneration passage that extends from the slide hole to the arm parallel passage. The slide hole receives a boom sub spool therein. The boom sub spool is either a boom recycling spool or a boom regeneration spool.

Multi-control valve

A control device controls movement of a valve body of a valve device and estimates a flow rate of the valve device; determines, on the basis of an input target flow rate value and the flow rate estimate, whether or not the flow of an operating fluid in the valve device is in a transient flow state; calculates an opening command on the basis of the target flow rate value and an upstream-downstream pressure difference of the valve device; and controls the movement of the valve body. When the control device determines that the flow is not in the transient flow state, it controls the movement of the valve body on the basis of the opening command, and when the control determines that the flow is in the transient flow state, it controls the movement of the valve body on the basis of the target flow rate value.

A hydraulic excavator drive system includes: a first pump connected to a head-side chamber of a boom cylinder; and a second pump that supplies hydraulic oil to at least one of an arm cylinder or a bucket cylinder. The first pump is driven by an electric motor. The drive system further includes: a first switching valve located on a rod-side line; and a second switching valve located on a relay line. The first switching valve opens the rod-side line at a boom raising operation, but blocks the rod-side line except at the boom raising operation. The second switching valve blocks the relay line at the boom raising operation, but opens the relay line at a vehicle body lifting operation.

A regeneration device includes: a regeneration valve that controls the flow rate of an operating fluid being drained from one port of a cylinder; a non-return valve that allows a regenerative flow of the operating fluid from the regeneration valve to the other port of the cylinder and blocks an opposite flow of the operating fluid; and an exhaust valve that controls the flow rate of the operating fluid output from the regeneration valve being drained to a tank. The regeneration valve controls the flow rate independently of the exhaust valve.

Regeneration device, hydraulic drive system equipped with same, and control device therefor

A hydraulic system of a construction machine includes: control valves interposed between a main pump and hydraulic actuators; and first solenoid proportional valves connected to pilot ports of the control valves. The hydraulic system further includes: a brake for a slewing motor; and a second solenoid proportional valve connected to a brake release port of the brake by a secondary pressure line and connected to an auxiliary pump by a primary pressure line. A switching valve including a pilot port connected to the secondary pressure line by a pilot line is interposed between the auxiliary pump and the first solenoid proportional valves.

Growing community of inventors

Akashi, Japan

Hideyasu Muraoka