公开(公告)号：US20230193596A1

公开(公告)日：2023-06-22

申请号：US18074725

申请日：2022-12-05

申请人： KUBOTA CORPORATION

发明人： Kazuki UEDA ,  Yuji FUKUDA ,  Ryota HAMAMOTO

IPC分类号： E02F9/22

CPC分类号： E02F9/2253 ,  E02F9/2296

摘要： In a working machine, a controller decreases a supply amount of a hydraulic fluid from a travel pump to a travel motor based on a travel state of a machine body when a speed-change instruction of increasing or decreasing speed is output by operating a switch, and a pressure detector detects a travel pressure that is a pressure of a hydraulic fluid delivered by the travel pump to the travel motor. In accordance with the travel pressure detected by the travel pressure detector, the controller changes a delay period lasting up to a switching timing of the travel switching valve from an output timing of the speed-change instruction of the switch.

公开(公告)号：US20220307229A1

公开(公告)日：2022-09-29

申请号：US17839019

申请日：2022-06-13

申请人： KUBOTA CORPORATION

发明人： Yuji FUKUDA ,  Jun TOMITA ,  Ryota HAMAMOTO ,  Ryosuke KINUGAWA ,  Yoshimitsu TANAKA

IPC分类号： E02F9/22 ,  E02F9/02 ,  E02F9/24 ,  F16H61/456 ,  B62D55/06

摘要： A working machine is provided, which includes a prime mover, a first traveling pump driven by power of the prime mover to supply operation fluid through a connector fluid tube, a traveling motor including first and second ports connected to the connector fluid tube, the traveling motor configured to be switched in a first speed and a second speed higher than the first speed, a first pressure detector to detect first traveling-pump pressure near the first port, a second pressure detector to detect second traveling-pump pressure near the second port, and a controller configured, with the traveling motor switched in the second speed, to automatically shift down the traveling motor from the second speed to the first speed, when a differential pressure between the first traveling-pump pressure and the second traveling-pump is equal to or more than a deceleration threshold.

公开(公告)号：US20210404150A1

公开(公告)日：2021-12-30

申请号：US17360398

申请日：2021-06-28

申请人： KUBOTA CORPORATION

发明人： Yuji FUKUDA ,  Ryota HAMAMOTO ,  Jun TOMITA ,  Daiki ABE

IPC分类号： E02F9/22

摘要： A working machine includes a prime mover, a traveling pump driven by a power of the prime mover to deliver operation fluid, a traveling motor rotated by the operation fluid delivered from the traveling pump to have a rotation speed stage shiftable between a first speed stage and a second speed stage higher than the first speed stage, a traveling switching valve shiftable between a first state where the rotation speed stage of the traveling motor is set to the first speed stage and a second state where the rotation speed stage of the traveling motor is set to the second speed stage, an actuation valve configured to change a pilot pressure of a pilot fluid to control a flow of operation fluid delivered from the traveling pump, and a controller configured to control the pilot pressure of the pilot fluid output from the actuation valve so that a value of the pilot pressure differs depending on whether the set rotation speed stage of the traveling motor is the first speed stage or the second speed stage.

公开(公告)号：US20210123215A1

公开(公告)日：2021-04-29

申请号：US17076361

申请日：2020-10-21

申请人： KUBOTA CORPORATION

发明人： Yuji FUKUDA ,  Ryota HAMAMOTO ,  Jun TOMITA

IPC分类号： E02F9/22 ,  E02F9/02 ,  F16H61/16 ,  F16H59/02 ,  F16H61/4035

摘要： A working machine includes a machine body, a prime mover, a traveling device mounted on the machine body, a traveling motor to provide a power to the traveling device and to switch between a first speed and a second speed higher than the first speed, a traveling pump to be driven by the prime mover and to supply operation fluid to the traveling motor, and a controller device including an automatic shifter to automatically shift the traveling motor to the first speed or to the second speed, a timer to count an elapsed time from the automatically shifting, and a shift prohibitor to prohibit the automatically shifting by the automatic shifter when the elapsed time counted by the timer is less than a threshold.

公开(公告)号：US20210123212A1

公开(公告)日：2021-04-29

申请号：US17076282

申请日：2020-10-21

申请人： KUBOTA CORPORATION

发明人： Masahiro TOYAMA ,  Ryuki NISHIMOTO ,  Yuji FUKUDA ,  Kohei NAGAO ,  Ryota HAMAMOTO ,  Hiroaki NAKAGAWA

IPC分类号： E02F9/22 ,  E02F9/20

摘要： A working machine includes a hydraulic device, an operation valve to supply operation fluid to operate the hydraulic device and to vary the operation fluid to be supplied to the hydraulic device, an operation device having an operation member supported swingably, the operation device being configured to output an operation signal in accordance with an operation amount of the operation member, and a controller including a swing calculator to calculate an evaluation value representing a degree of swinging of the operation member, and a control signal generator to generate a control signal based on the evaluation value and the operation signal.

公开(公告)号：US20240052598A1

公开(公告)日：2024-02-15

申请号：US18362961

申请日：2023-08-01

申请人： KUBOTA CORPORATION

发明人： Kohei NAGAO ,  Daiki ABE ,  Ryota HAMAMOTO

IPC分类号： E02F9/22 ,  F15B15/18 ,  F15B13/04

CPC分类号： E02F9/2228 ,  E02F9/2292 ,  E02F9/2285 ,  E02F9/2246 ,  F15B15/18 ,  F15B13/0401 ,  E02F9/2296

摘要： A work vehicle includes a primary pressure control valve configured to control a pilot primary pressure of pilot oil. A secondary pressure control valve is configured to control a pilot secondary pressure of the pilot oil. Control circuitry is configured to control a rotation speed of an engine according to a target rotation speed. The control circuitry is configured to control the primary pressure control valve and the secondary pressure control valve based on a first target value of the pilot primary pressure and a second target value of the pilot secondary pressure. The control circuitry is configured to reduce the first target value and the second target value such that the second target value is higher than the first target value when the rotation speed of the engine detected by a rotation speed sensor becomes lower than the target rotation speed by a predetermined speed difference or more.

公开(公告)号：US20240003119A1

公开(公告)日：2024-01-04

申请号：US18192641

申请日：2023-03-30

申请人： KUBOTA CORPORATION

发明人： Daiki ABE ,  Ryota HAMAMOTO

IPC分类号： E02F9/22 ,  G05D1/02

CPC分类号： E02F9/2253 ,  E02F9/2246 ,  G05D1/021 ,  G05D2201/0202

摘要： A control method for a work vehicle includes acquiring an upper limit speed in a creep mode in which the work vehicle travels at the upper limit speed or less regardless of an operation amount of at least one operation device, detecting a hydraulic pressure in an oil passage between a hydraulic motor to move the work vehicle and a hydraulic pump to actuate the hydraulic motor, determining a traveling primary pressure of pilot oil supplied to an operation valve operated by a first operation device out of the at least one operation device based on a first relationship among the upper limit speed, the hydraulic pressure, and the traveling primary pressure, and controlling a control valve via which the pilot oil is supplied to the operation valve such that a pressure of the pilot oil supplied to the operation valve approaches the traveling primary pressure.

公开(公告)号：US20230287654A1

公开(公告)日：2023-09-14

申请号：US18073705

申请日：2022-12-02

申请人： KUBOTA CORPORATION

发明人： Daiki ABE ,  Ryota HAMAMOTO ,  Jun TOMITA ,  Fumiya KOZONO

IPC分类号： E02F9/22

CPC分类号： E02F9/2253 ,  E02F9/2285 ,  E02F9/2267 ,  E02F9/2296 ,  E02F9/2292

摘要： A working machine includes a traveling pump to be operated by power of a prime mover and deliver a hydraulic fluid; a traveling motor that rotates using the delivered hydraulic fluid; an operation valve that changes pilot pressure of a pilot fluid outputted to the traveling pump in response to operation of an operation member; an actuation valve that operates based on a control signal and changes primary pressure that is the pilot pressure of the pilot fluid supplied to the operation valve; a controller that controls opening of the actuation valve by outputting the control signal to the actuation valve; and a first detector that detects an actual number of revolutions of the traveling motor. The controller includes a changer that changes setting of the control signal such that the opening of the actuation valve increases as the actual number of revolutions of the traveling motor decreases.

公开(公告)号：US20230203786A1

公开(公告)日：2023-06-29

申请号：US17994682

申请日：2022-11-28

申请人： KUBOTA CORPORATION

发明人： Daiki ABE ,  Ryota HAMAMOTO ,  Yuya TANABE

IPC分类号： E02F9/22 ,  E02F9/26 ,  E02F9/20 ,  F15B15/18 ,  F15B13/02

CPC分类号： E02F9/2228 ,  E02F9/2285 ,  E02F9/26 ,  E02F9/2004 ,  E02F9/2203 ,  F15B15/18 ,  F15B13/02 ,  E02F9/2292 ,  E02F9/2296

摘要： A working machine includes a prime mover, a rotation-speed operation actuator, a rotation detector, a hydraulic pump, a hydraulic unit, an operation valve capable of changing a pilot pressure of a pilot fluid supplied from the hydraulic pump to the hydraulic unit in accordance with an operation of an operation member, an actuation valve operating in accordance with a control signal and capable of changing a primary pressure as the pilot pressure of the pilot fluid supplied from the hydraulic pump to the operation valve, and a controller that outputs the control signal based on a difference between target and actual rotation speeds to the actuation valve to control an opening thereof. The controller has a mode including calculating the control signal based on the difference, correcting the calculated control signal, and increasing or decreasing a target primary pressure value set in accordance with the control signal.

公开(公告)号：US20210123214A1

公开(公告)日：2021-04-29

申请号：US17077341

申请日：2020-10-22

申请人： KUBOTA CORPORATION

发明人： Yuji FUKUDA ,  Ryota HAMAMOTO ,  Jun TOMITA

IPC分类号： E02F9/22

摘要： A working machine includes a switching valve to switch between a first state and a second state, the first state allowing a revolving speed of a traveling motor to be a first speed, the second state allowing the revolving speed of the traveling motor to be a second speed, and a controller device to reduce the revolving speed of the prime mover in either acceleration to switch from the first state to the second state or deceleration to switch from the second state to the first state. The controller device associates a return timing with a switch timing in either the acceleration or deceleration, the return timing allowing an actual revolving speed of a prime mover to start returning toward a first target revolving speed after the actual revolving speed is reduced, the switch timing allowing the switching valve to switch to either an acceleration side or a deceleration side.