公开(公告)号：US20230323636A1

公开(公告)日：2023-10-12

申请号：US18122847

申请日：2023-03-17

Applicant: KUBOTA CORPORATION

Inventor： Masaki INAOKA ,  Daiki ABE ,  Takumi USUI

IPC: E02F9/22

CPC classification number: E02F9/2292 ,  E02F9/2217 ,  E02F9/2285 ,  E02F3/3414

Abstract: A hydraulic system for a working machine includes: a first hydraulic pump; a first hydraulic device; a hydraulic fluid tank; a first discharge fluid passage to allow hydraulic fluid discharged from the first hydraulic device to flow into the tank; a second hydraulic pump to suck fluid from the tank through a suction fluid passage; a second hydraulic device in which difference between flow rate of fluid from the second hydraulic pump device and that of discharged fluid changes according to actuation; a second discharge fluid passage connected to a suction port of the first hydraulic pump and allowing fluid discharged from the second hydraulic device to flow into the first hydraulic pump; a connecting fluid passage branching from the second discharge fluid passage and connected to the suction fluid passage between the tank and the second hydraulic pump; a supplier to supply fluid to the second discharge fluid passage.

公开(公告)号：US20210404150A1

公开(公告)日：2021-12-30

申请号：US17360398

申请日：2021-06-28

Applicant: KUBOTA CORPORATION

Inventor： Yuji FUKUDA ,  Ryota HAMAMOTO ,  Jun TOMITA ,  Daiki ABE

IPC: E02F9/22

Abstract: 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：US20230228062A1

公开(公告)日：2023-07-20

申请号：US18075917

申请日：2022-12-06

Applicant: KUBOTA CORPORATION

Inventor： Ryota HAMAMOTO ,  Kazuki UEDA ,  Daiki ABE

IPC: E02F9/22 ,  E02F9/20

CPC classification number: E02F9/2228 ,  E02F9/2004 ,  E02F9/2246 ,  E02F9/2253 ,  E02F9/2267 ,  E02F9/2285 ,  E02F9/2292

Abstract: A working machine includes a controller that performs shift shock reduction control when shift-down switching from a second state to a first state, in which a motor speed can be increased up to a first maximum speed lower than a second maximum speed available in the second state, is performed. The controller includes a first processor configured to, based on a drop amount that is a difference between target and actual numbers of revolutions of a prime mover, compute a first reduction amount for reducing an amount of hydraulic fluid supply from a traveling pump to a traveling motor, a second processor configured to compute a second reduction amount based on a degree of straight traveling of a machine body, and a reduction controller configured to, based on the first or second reduction amount, whichever is larger in absolute value, perform the shift shock reduction control.

公开(公告)号：US20230044116A1

公开(公告)日：2023-02-09

申请号：US17844071

申请日：2022-06-20

Applicant: Kubota Corporation

Inventor： Daiki ABE ,  Ryota HAMAMOTO ,  Yuki BUNRYO

IPC: E02F9/22 ,  B62D11/00 ,  B62D11/04 ,  E02F9/26

Abstract: A method for controlling a work vehicle includes driving a first hydraulic pump and a second hydraulic pump by an engine to supply hydraulic fluid to a first hydraulic motor and a second hydraulic motor, respectively, to drive a first traveling device and a second traveling device, respectively. An operation state of a direction input device to operate a traveling direction of the work vehicle is detected. Based on the operation state detected, whether or not a traveling state of the work vehicle is a turning state. When it is determined that the traveling state is the turning state, a rotation command to decrease a target rotational speed of the engine from a first rotational speed to a second rotational speed is output.

公开(公告)号：US20200240113A1

公开(公告)日：2020-07-30

申请号：US16848849

申请日：2020-04-15

Applicant: KUBOTA CORPORATION

Inventor： Yuji FUKUDA ,  Daiki ABE ,  Jun TOMITA ,  Yuya KONISHI ,  Ryosuke KINUGAWA

IPC: E02F9/22 ,  F15B11/16 ,  F15B13/044

Abstract: A hydraulic system for a work machine includes a travel hydraulic device which changes a travel speed in accordance with switching positions of a hydraulic switch valve. A controller controls a proportional valve so as to change a pressure of an operation fluid at an increasing rate over a time while the hydraulic switch valve is switched from a first switching position to a second switching position to increase the travel speed from a first speed to a second speed, and at a decreasing rate over the time while the hydraulic switch valve is switched from the second switching position to the first switching position to decrease the travel speed from the second speed to the first speed. A magnitude of the increasing rate is different from one of the decreasing rate to output an operation fluid.

公开(公告)号：US20250154744A1

公开(公告)日：2025-05-15

申请号：US19026509

申请日：2025-01-17

Applicant: KUBOTA CORPORATION

Inventor： Kohei NAGAO ,  Daiki ABE ,  Ryota HAMAMOTO

IPC: E02F9/22

Abstract: 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.

公开(公告)号：US20240117879A1

公开(公告)日：2024-04-11

申请号：US18529312

申请日：2023-12-05

Applicant: KUBOTA CORPORATION

Inventor： Daiki ABE ,  Kohei KURACHI ,  Yudai KOGA ,  Yuya KONISHI ,  Yuya TANABE

IPC: F16H61/47 ,  E02F9/22 ,  F15B11/17 ,  F16H61/431

CPC classification number: F16H61/47 ,  E02F9/2235 ,  E02F9/2253 ,  E02F9/2282 ,  E02F9/2285 ,  E02F9/2289 ,  E02F9/2292 ,  E02F9/2296 ,  F15B11/17 ,  F16H61/431 ,  F15B2211/7135 ,  F16H61/456

Abstract: A working machine includes: a first fluid passage fluidly connecting a traveling operation device to an actuation valve; a first traveling fluid passage; a second traveling fluid passage; a third traveling fluid passage; a fourth traveling fluid passage; a second fluid passage fluidly connecting the first fluid passage to the first traveling fluid passage; and a third fluid passage fluidly connecting the first fluid passage to the third traveling fluid passage. Each of the first, second, third, and fourth traveling fluid passages is configured so that operation fluid to be applied to a first, second, third, and fourth pressure-receiving portions flows through the first, second, third, and fourth traveling fluid passages, respectively, when a traveling operation member is operated.

公开(公告)号：US20230349402A1

公开(公告)日：2023-11-02

申请号：US18221055

申请日：2023-07-12

Applicant: KUBOTA CORPORATION

Inventor： Daiki ABE ,  Ryota HAMAMOTO ,  Hiroaki NAKAGAWA

IPC: F15B21/0423 ,  F01P7/04 ,  E02F9/22

CPC classification number: F15B21/0423 ,  F01P7/044 ,  E02F9/226 ,  F15B2211/62 ,  F15B21/02

Abstract: A working machine includes a prime mover, a hydraulic pump driven by power of the prime mover, a cooler including a cooling fan rotated by either the power of the prime mover or hydraulic fluid delivered from the hydraulic pump, and a controller configured or programmed to perform a reduction control for reducing a target fan rotation speed that is a target rotation speed of the cooling fan in response to reduction of an actual prime mover rotation speed that is an actual rotation speed of the prime mover, and to perform, after the reduction control, a restoration control for restoring the target fan rotation speed. The controller is configured or programmed to make a difference between a reduction rate of the target fan rotation speed in the reduction control and an increase rate of the target fan rotation speed in the restoration control.

公开(公告)号：US20170284063A1

公开(公告)日：2017-10-05

申请号：US15473632

申请日：2017-03-30

Applicant: KUBOTA CORPORATION

Inventor： Yuji FUKUDA ,  Daiki ABE ,  Jun TOMITA ,  Yuya KONISHI ,  Ryosuke KINUGAWA

IPC: E02F9/22 ,  F15B11/16 ,  F15B13/044

CPC classification number: E02F9/22 ,  E02F3/3414 ,  E02F9/2235 ,  E02F9/2246 ,  E02F9/225 ,  E02F9/2253 ,  E02F9/2267 ,  E02F9/2285 ,  E02F9/2289 ,  E02F9/2292 ,  E02F9/2296 ,  F15B11/163 ,  F15B13/0442 ,  F16H61/40

Abstract: A hydraulic system for a work machine includes a hydraulic bump to output an operation fluid, a hydraulic switch valve to be switched among switching positions in accordance with a pressure of the operation fluid, a proportional valve to change the pressure of the operation fluid applied to the hydraulic switch valve, a travel hydraulic device to change a thrust power in accordance with the switching positions of the hydraulic switch valve. And, the hydraulic system includes a controller to control the proportional valve in accordance with a state of the travel hydraulic device.

公开(公告)号：US20250109573A1

公开(公告)日：2025-04-03

申请号：US18900252

申请日：2024-09-27

Applicant: Kubota Corporation

Inventor： Daiki ABE ,  Yuki BUNRYO ,  Ryuki NISHIMOTO

IPC: E02F9/22

Abstract: A working machine includes a pump actuated by power from a prime mover to deliver hydraulic fluid, a working unit including a working device and an attachment to perform work upon actuation, by hydraulic fluid, of actuator(s) included in the working device and/or the attachment, a solenoid valve to change a flow rate of hydraulic fluid to the actuator(s) based on a control signal, a controller to input the control signal into the valve, an accelerator to input a target rotation speed of the prime mover, and a rotation speed sensor to detect an actual rotation speed of the prime mover. The controller is configured or programmed to, during high-load work, if a decrease in actual rotation speed relative to the target rotation speed reaches a threshold or greater, change the control signal based on the actual rotation speed to limit the flow rate of hydraulic fluid to the actuator(s).