Patents by Inventor Yuji Fukuda

Yuji Fukuda has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11448244
    Abstract: A hydraulic system includes a first output fluid tube connecting between a hydraulic pump to output operation fluid and a first operation valve to change a first pilot pressure of the operation fluid, a second output fluid tube connected between the hydraulic pump and a second operation valve to change a second pilot pressure of the operation fluid, a switching valve provided in the second output fluid tube, and a warm-up fluid tube connected between the first operation valve and the switching valve, wherein the switching valve is switched between a first position allowing the operation fluid to be drained through the first output fluid tube, the first operation valve, the warm-up fluid tube and the switching valve, and a second position allowing the operation fluid to be supplied through second output fluid tube to the second operation valve.
    Type: Grant
    Filed: January 28, 2021
    Date of Patent: September 20, 2022
    Assignee: KUBOTA CORPORATION
    Inventor: Yuji Fukuda
  • Publication number: 20220259826
    Abstract: A working machine includes a traveling motor that is shifted between a first speed and a second speed faster than the first speed, a traveling pump that supplies hydraulic fluid to the traveling motor, a traveling operation member operable to operate the traveling pump, and a controller including an automatic speed reduction unit that performs automatic speed reduction in which the traveling motor having been shifted to the second speed is automatically shifted from the second speed to the first speed based on the operation amount of the traveling operation member. The controller includes an automatic speed reduction restraining unit configured or programmed to restrain the automatic speed reduction from being performed when the traveling operation member is operated to steeply change the operation amount from a first operation amount to a second operation amount.
    Type: Application
    Filed: December 14, 2021
    Publication date: August 18, 2022
    Applicant: KUBOTA CORPORATION
    Inventors: Kohei NAGAO, Yuji FUKUDA
  • Patent number: 11414835
    Abstract: 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.
    Type: Grant
    Filed: October 21, 2020
    Date of Patent: August 16, 2022
    Assignee: KUBOTA CORPORATION
    Inventors: Masahiro Toyama, Ryuki Nishimoto, Yuji Fukuda, Kohei Nagao, Ryota Hamamoto, Hiroaki Nakagawa
  • Patent number: 11396738
    Abstract: A hydraulic system includes a first hydraulic device to be operated by an operation fluid, a second hydraulic device, the second hydraulic device being configured to be operated by the operation fluid, a first control valve to control the first hydraulic device, a second control valve disposed on a downstream side of the first control valve and configured to control the second hydraulic device, a communication tube connecting the first hydraulic device to the first control valve, the communication tube being configured to supply a return fluid that returns from the first hydraulic device to the first control valve, a supply fluid tube connecting the first control valve to the second control valve and being configured to supply the return fluid to the second control valve, and a connection fluid tube disposed on the first control valve, the connection fluid tube connecting the communication tube to the supply fluid tube.
    Type: Grant
    Filed: May 14, 2018
    Date of Patent: July 26, 2022
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Keigo Honda, Yoshimitsu Tanaka
  • Patent number: 11391018
    Abstract: A working machine includes a pair of traveling devices, a pair of traveling motors having a first speed and a second speed higher than the first speed, a pair of traveling pumps to supply operation fluid to the traveling motors, a connector fluid tube connecting the traveling motors and the traveling pumps, a traveling-pump pressure detector to detect a traveling-pump pressure that is pressure generated in the connector fluid tube, a revolving speed detector to detect a prime-mover revolving speed, a third storage to store a second decelerating judgment table representing a relation between the prime-mover revolving speed and a second decelerating judgment pressure, and a controller having: an automatic decelerator portion to perform an automatic deceleration process for reducing a speed of the traveling motor, and a differential pressure calculator portion to calculate a traveling differential pressure between one traveling pump pressure and another traveling pump pressure.
    Type: Grant
    Filed: April 2, 2020
    Date of Patent: July 19, 2022
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Jun Tomita, Ryota Hamamoto, Ryosuke Kinugawa, Yoshimitsu Tanaka
  • Patent number: 11371214
    Abstract: 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.
    Type: Grant
    Filed: October 21, 2020
    Date of Patent: June 28, 2022
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Ryota Hamamoto, Jun Tomita
  • Patent number: 11371215
    Abstract: A working machine includes a first traveling fluid line through which operation fluid applied to a first pressure receiving portion when a traveling operation member is operated, a second traveling fluid line through which operation fluid applied to a second pressure receiving portion when the traveling operation member is operated, a third traveling fluid line through which operation fluid applied to a third pressure receiving portion when the traveling operation member is operated, a fourth traveling fluid line through which operation fluid applied to a fourth pressure receiving portion when the traveling operation member is operated, and a controller configured or programed to judge, first, second, third and fourth pilot pressures, whether the traveling operation member is operated in a direction corresponding to any of spin-turn, pivotal-turn and straight-traveling.
    Type: Grant
    Filed: August 9, 2021
    Date of Patent: June 28, 2022
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Kohei Nagao, Ryota Hamamoto, Hiroaki Nakagawa, Yoshimitsu Tanaka
  • Patent number: 11353047
    Abstract: A hydraulic system for a work machine includes a tank to store an operation fluid, a hydraulic device to be operated by the operation fluid, a control valve to control the hydraulic device, a first fluid tube connecting the hydraulic device and the control valve, the first fluid tube being to supply the operation fluid from the control valve to the hydraulic device, a second fluid tube branching from the first fluid tube and connected to the tank, a switch valve provided to the second fluid tube, the switch valve being to control a flow rate of the operation fluid, and an oil cooler provided to the second fluid tube between the switch valve and the tank.
    Type: Grant
    Filed: April 14, 2020
    Date of Patent: June 7, 2022
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Kazuyoshi Arii, Hiroaki Nakagawa
  • Patent number: 11353048
    Abstract: A working machine includes a fan motor driven with hydraulic fluid, the fan motor including a first port and a second port, a bypass fluid passage connecting the first port of the fan motor and the second port to each other, a flow rate control valve provided on the bypass fluid passage to control a flow rate of the hydraulic fluid flowing in the bypass fluid passage, a drain passage configured to drain the hydraulic fluid upstream of the flow rate control valve, and an unloading valve shiftable between a full-closing position to close the drain passage and a full-opening position to open the drain passage.
    Type: Grant
    Filed: August 6, 2021
    Date of Patent: June 7, 2022
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Daiki Abe, Ryota Hamamoto, Kazuki Ueda, Kohei Kurachi, Yuya Konishi, Masaki Inaoka, Yasushi Otagaki, Yuya Tanabe
  • Patent number: 11346076
    Abstract: A hydraulic system includes a hydraulic pump, a first hydraulic actuator, a second hydraulic actuator, a first control valve to control the first hydraulic actuator, a second control valve connected to a downstream side of the first control valve and configured to control the second hydraulic actuator, a return fluid tube in which return fluid discharged from the first hydraulic actuator flows, the return fluid tube coupling the first control valve and the first hydraulic actuator, an internal fluid tube arranged in the first control valve and connected to the return fluid tube, an external fluid tube connected to the internal fluid tube, the external fluid tube coupling the first control valve and the second control valve, a branched fluid tube branched from the external fluid tube and connected to a discharge fluid tube, and a pressurizing portion provided to the discharge fluid tube.
    Type: Grant
    Filed: November 8, 2019
    Date of Patent: May 31, 2022
    Assignee: KUBOTA CORPORATION
    Inventor: Yuji Fukuda
  • Publication number: 20220154428
    Abstract: A hydraulic system in a work machine includes a travel operation device provided in a pilot oil path between a hydraulic pump a travel pump and including an operation member and configured to generate a pilot pressure supplied via the pilot oil path and an additional pilot pressure in accordance with an operation amount of the operation member. The travel pump is to control a flow direction of hydraulic oil supplied to a travel motor based on the pilot pressure and the additional pilot pressure. A pressure selection valve is provided in a first coupling oil path to select a selected pressure from the pilot pressure and the additional pilot pressure to apply the selected pressure to the pilot hydraulic oil in the second coupling oil path. A pressure adjustment valve is provided in a second coupling oil path to control the selected pressure to be an adjusted pilot pressure.
    Type: Application
    Filed: February 9, 2022
    Publication date: May 19, 2022
    Applicant: Kubota Corporation
    Inventor: Yuji FUKUDA
  • Publication number: 20220120057
    Abstract: A working machine includes a prime mover, a traveling pump to be driven by the prime mover to output operation fluid, a traveling motor to be driven by the operation fluid outputted from the traveling pump and to change a motor speed between a first speed and a second speed higher than the first speed, a machine body on which the prime mover, the traveling pump, and the traveling motor are arranged, a traveling switching valve to be switched between a first state allowing the traveling motor to rotate at the first speed and a second state allowing the traveling motor to rotate at the second speed, and a controller to reduce a revolving speed of the prime mover based on a traveling condition of the machine body in switching the traveling switching valve between an accelerating state to switch the traveling switching valve from the first state to the second state and a decelerating state to switch the traveling switching valve from the second state to the first state.
    Type: Application
    Filed: December 15, 2021
    Publication date: April 21, 2022
    Applicant: KUBOTA CORPORATION
    Inventors: Yuji FUKUDA, Ryosuke KINUGAWA, Ryota HAMAMOTO, Jun TOMITA
  • Patent number: 11306746
    Abstract: A hydraulic system for a working machine includes a hydraulic actuator having a first fluid chamber and a second fluid chamber, an accumulator, an outputting fluid tube to output an operation fluid, and a switching valve to be switched between a first position and a second position. The first position allows the first fluid chamber and the second fluid chamber to be communicated with the outputting fluid tube and thereby allowing a floating operation. The second position allows the first fluid chamber and the accumulator to be communicated with each other, allows the second fluid chamber and the outputting fluid tube to be communicated with each other, and thereby allows an anti-vibration operation.
    Type: Grant
    Filed: August 7, 2020
    Date of Patent: April 19, 2022
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Keigo Honda, Ryosuke Kinugawa, Ryuki Nishimoto, Yuji Yamashita, Daisuke Sakurai
  • Publication number: 20220112687
    Abstract: A hydraulic system for a working machine includes a hydraulic actuator configured to be operated by operation fluid, a control valve connected to the hydraulic actuator, and a communication fluid line for fluid communication between the hydraulic actuator and the control valve. The control valve includes a first supply path to guide the operation fluid toward the hydraulic actuator; a regeneration path to guide the operation fluid having been returned to the control valve from the hydraulic actuator, to the first supply path; and a branched path that branches from the regeneration path and supplies operation fluid to outside of the control valve.
    Type: Application
    Filed: October 12, 2021
    Publication date: April 14, 2022
    Applicant: KUBOTA CORPORATION
    Inventor: Yuji FUKUDA
  • Publication number: 20220098833
    Abstract: A hydraulic system for a working machine includes hydraulic actuators actuated with hydraulic fluid delivered from a hydraulic pump, and control valves each of which is shiftable among shift positions to control a flowrate of hydraulic fluid flowing to the corresponding hydraulic actuator. Each control valve includes an input port, an output port, and a flowrate reduction section. When the control valve is shifted to a reduction position, the flowrate reduction section reduces a flowrate of the hydraulic fluid entering the input port and outputs the flowrate-reduced hydraulic fluid to the output port. At least one of the control valves includes a flowrate increase section. When the control valve is shifted to an increase position, the flowrate increase section outputs the hydraulic fluid having entered the input port to the output port at a flowrate larger than that of hydraulic fluid output by the flowrate reduction section.
    Type: Application
    Filed: September 28, 2021
    Publication date: March 31, 2022
    Applicant: KUBOTA CORPORATION
    Inventor: Yuji FUKUDA
  • Publication number: 20220090611
    Abstract: A hydraulic system includes a hydraulic pump, a first hydraulic actuator, a second hydraulic actuator, a first control valve to control the first hydraulic actuator, a second control valve to control the second hydraulic actuator, a pressure increasing portion to increasing a pressure of the operation fluid, a first discharge fluid tube connected to any one of the first control valve and the second control valve and connected to the pressure increasing portion, a second discharge fluid tube connected to the first discharge fluid tube and configured to discharge the operation fluid, a float switching valve having an allowance position, a prevention position, and a float position, the allowance position blocking the second discharge fluid tube and allowing the operation fluid to flow to the pressure increasing portion, the prevention position unblocking the second discharge fluid tube and preventing the operation fluid from flowing to the pressure increasing portion.
    Type: Application
    Filed: December 1, 2021
    Publication date: March 24, 2022
    Applicant: KUBOTA CORPORATION
    Inventors: Yuji FUKUDA, Keigo HONDA
  • Patent number: 11280064
    Abstract: A hydraulic system in a work machine includes a hydraulic pump to supply pilot hydraulic oil. A work hydraulic actuator is to move a work device of the work machine. A control valve is to control the work hydraulic actuator based on a pilot pressure of the pilot hydraulic oil. A target pilot pressure of the pilot hydraulic oil is input through the work operation device to control, according to the target pilot pressure, the pilot pressure supplied from the hydraulic pump to the control valve. A pilot oil path connects the work operation device and the control valve to supply the pilot pressure to the control valve. A drain oil path is divided from the pilot oil path. A pressure adjustment valve is provided in the drain oil path to adjust the pilot pressure to be less than the target pilot pressure when a condition is satisfied.
    Type: Grant
    Filed: April 17, 2020
    Date of Patent: March 22, 2022
    Assignee: KUBOTA CORPORATION
    Inventor: Yuji Fukuda
  • Patent number: 11255353
    Abstract: A hydraulic system includes a hydraulic pump to output an operation fluid, first and second hydraulic devices to be operated by the operation fluid, first and second control valves to control the first and second hydraulic device, respectively, first and second communication tubes connecting the first hydraulic device to the first control valve, a supply fluid tube connecting the first control valve to the second control valve, the supply fluid tube being configured to supply the return fluid to the second control valve, first and second connection fluid tubes disposed on the first control valve, a discharge fluid tube connected to the first control valve, first and second branching fluid tubes branched from the first and second connection fluid tubes, respectively, first and second throttles disposed on the first and second branching fluid tubes, respectively, the second throttle being smaller than the first throttle.
    Type: Grant
    Filed: February 25, 2021
    Date of Patent: February 22, 2022
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Keigo Honda
  • Publication number: 20220049461
    Abstract: A working machine includes a first pressure detector configured to detect a first pilot pressure that is a pressure of operation fluid passed through a first traveling fluid line, a second pressure detector configured to detect a second pilot pressure that is a pressure of operation fluid passed through a second traveling fluid line, a third pressure detector configured to detect a third pilot pressure that is a pressure of operation fluid passed through a third traveling fluid line, a fourth pressure detector configured to detect a fourth pilot pressure that is a pressure of operation fluid passed through a fourth traveling fluid line, and a controller configured or programed to judge in which of the left-front, right-front, left-rear and right-rear operation areas an operational position of the traveling operation member exists.
    Type: Application
    Filed: August 6, 2021
    Publication date: February 17, 2022
    Applicant: KUBOTA CORPORATION
    Inventors: Kohei NAGAO, Yuji FUKUDA, Hiroaki NAKAGAWA, Ryota HAMAMOTO, Tomoyuki NOGUCHI
  • Publication number: 20220049472
    Abstract: A working machine includes a machine body, a traveling device provided on the machine body, an operation member operable to activate the traveling device, a camera device to capture an image of surroundings of the machine body, a display unit to display the image captured by the camera device, a notification unit to notify a traveling direction of the traveling device, and a controller to control the display unit and the notification unit so that when the operation member is operated to activate the traveling device, the display unit is controlled to display the captured image and the notification unit is controlled to notify the traveling direction. The controller delays either one of a first timing when the display unit starts to display the captured image and a second timing when the notification unit starts to notify the traveling direction later than the other.
    Type: Application
    Filed: June 25, 2021
    Publication date: February 17, 2022
    Applicant: KUBOTA CORPORATION
    Inventors: Yuji FUKUDA, Kohei NAGAO, Ryota HAMAMOTO, Tomoyuki NOGUCHI