公开(公告)号：US20170159265A1

公开(公告)日：2017-06-08

申请号：US15371102

申请日：2016-12-06

Applicant: KUBOTA CORPORATION

Inventor： Jun TOMITA ,  Yuji FUKUDA ,  Yuya KONISHI

IPC: E02F3/42 ,  E02F9/22 ,  F15B1/02 ,  F15B13/06 ,  F15B11/16 ,  F15B1/04

CPC classification number: E02F3/422 ,  E02F3/3414 ,  E02F3/432 ,  E02F9/2203 ,  E02F9/2217 ,  E02F9/2267 ,  E02F9/2282 ,  F15B1/021 ,  F15B2211/30565 ,  F15B2211/3059 ,  F15B2211/30595 ,  F15B2211/625 ,  F15B2211/6658 ,  F15B2211/71

Abstract: A hydraulic system for a work machine includes a first control valve to control a first hydraulic actuator, a second control valve to control a second hydraulic actuator, a first fluid tube connecting the first hydraulic actuator to the first control valve, and a second fluid tube connecting the second hydraulic actuator to the second control valve. A level control valve apparatus is connected to the first fluid tube and the second fluid tube. The level control valve apparatus is configured to control a leveling operation for the second hydraulic actuator. An accumulator apparatus is connected to the first hydraulic actuator. The accumulator apparatus communicates with the first fluid tube between the level control valve apparatus and the first control valve. Circuitry is configured to control the level control valve apparatus to stop the leveling operation when the accumulator apparatus is in operation.

公开(公告)号：US20220389680A1

公开(公告)日：2022-12-08

申请号：US17830473

申请日：2022-06-02

Applicant: KUBOTA CORPORATION

Inventor： Yuji FUKUDA ,  Jun TOMITA ,  Yuya KONISHI ,  Toshiya TANI ,  Daisuke SAKURAI

IPC: E02F9/22 ,  F15B13/02

Abstract: A hydraulic system of a working machine includes a hydraulic pump to output a hydraulic fluid, at least one proportional valve to deliver the hydraulic fluid to a supply target, a valve body including the proportional valve, a heat-up fluid passage in the valve body and into which the hydraulic fluid flows, a switching valve switchable between an open position in which the hydraulic fluid passing through the heat-up fluid passage is supplied to a hydraulic device and a closed position in which the hydraulic fluid is not supplied thereto and the hydraulic fluid from the hydraulic device is to be returned, a controller to operate the switching and proportional valves, and a return circuit through which the hydraulic fluid flowing into the heat-up fluid passage is returned as a result of at least one of the switching and proportional valves being operated by the controller.

公开(公告)号：US20200048859A1

公开(公告)日：2020-02-13

申请号：US16430969

申请日：2019-06-04

Applicant: KUBOTA CORPORATION

Inventor： Daiki ABE ,  Yuji FUKUDA ,  Yuya KONISHI ,  Keigo HONDA ,  Hiroya HANANO ,  Jun TOMITA

IPC: E02F3/34 ,  E02F9/22

Abstract: A hydraulic system for a working machine, includes an operation member, an operation valve to change an output pressure of an operation fluid in accordance with operation of the operation member, a hydraulic device to be activated by the operation fluid outputted from the operation valve, a first fluid tube coupling the operation valve to the hydraulic device, and a bleed circuit connected to the first fluid tube and configured to output the operation fluid in the first fluid tube. The first fluid tube includes a first section fluid tube arranged in a section between the operation valve and a coupling portion coupling the first fluid tube to the bleed circuit, and a second section fluid tube arranged in a section between the coupling portion and the hydraulic device, the second section fluid tube having an inner diameter different from an inner diameter of the first section fluid tube.

公开(公告)号：US20200002922A1

公开(公告)日：2020-01-02

申请号：US16449862

申请日：2019-06-24

Applicant: KUBOTA CORPORATION

Inventor： Yuji FUKUDA ,  Daiki ABE ,  Jun TOMITA ,  Yuya KONISHI ,  Fumitaka FUJISAWA ,  Yudai KOGA

IPC: E02F9/22 ,  F16H39/10 ,  F16H61/4157 ,  F16H61/423 ,  B60T1/00

Abstract: A hydraulic device includes a braking device to brake a traveling device and release braking of the traveling device, a traveling pump to drive the traveling device with pressure of operation fluid, a brake-operation valve to control operation fluid flowing to the brake device, a traveling operation valve to control operation fluid flowing to the traveling pump, a first discharge fluid tube to discharge operation fluid flowing through the brake-operation valve, the first discharge fluid tube being connected to the brake operation valve, and a second discharge fluid tube to discharge operation fluid flowing through the traveling operation valve, the second discharge fluid tube being connected to the traveling operation valve. The traveling operation valve has a set pressure that is set to be higher than a brake set pressure set by the brake operation valve.

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：US20190249390A1

公开(公告)日：2019-08-15

申请号：US16393966

申请日：2019-04-25

Applicant: KUBOTA CORPORATION

Inventor： Jun TOMITA ,  Yuji FUKUDA ,  Yuya KONISHI

IPC: E02F3/42 ,  E02F9/22 ,  F15B1/02 ,  E02F3/43

CPC classification number: E02F3/422 ,  E02F3/3414 ,  E02F3/432 ,  E02F9/2203 ,  E02F9/2217 ,  E02F9/2267 ,  E02F9/2282 ,  F15B1/021 ,  F15B2211/30565 ,  F15B2211/3059 ,  F15B2211/30595 ,  F15B2211/625 ,  F15B2211/6658 ,  F15B2211/71

Abstract: A hydraulic system for a work machine includes a first control cylinder to move a boom and a second control cylinder to move a bucket. A body of the first control cylinder has a first fluid chamber and a second fluid chamber. A first control valve is connected to the first fluid chamber via a first fluid path and connected to the second fluid chamber via a second fluid path to control the first hydraulic cylinder. A bucket positioning valve is connected to the second fluid path and a third fluid path to control a second hydraulic cylinder so as to rotate the bucket. A discharge fluid path is connected to the second fluid path between the bucket positioning valve and the first control valve. A discharge control valve is provided in the discharge fluid path to be opened and closed.

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：US20230092677A1

公开(公告)日：2023-03-23

申请号：US17840680

申请日：2022-06-15

Applicant: KUBOTA CORPORATION

Inventor： Yuji FUKUDA ,  Ryota HAMAMOTO ,  Jun TOMITA ,  Yuya KONISHI

IPC: E02F9/22

Abstract: In a hydraulic system for a working machine, a controller is configured or programmed to increase an output-port pressure of one activation valve for one hydraulic device and an output-port pressure of another activation valve for another hydraulic device to a normal pressure higher than a preloading pressure from a state where the output-port pressure of the one activation valve is equal to the preloading pressure and the output-port pressure of the other activation valve is lower than the preloading pressure, by causing the output-port pressure of the one activation valve to be lower than the preloading pressure and increasing the output-port pressure of the other activation valve to the normal pressure.

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.