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).

  • Publication number: 20240102263
    Abstract: A working machine includes a machine body, a working device provided on the machine body movably up and down with respect to the machine body, a protector provided on the machine body to protect an operator's seat on the machine body, a detector provided on the protector to detect an obstacle higher than the protector, and a controller configured or programmed to, when the detector detects the obstacle, perform at least one process to prevent the working device from contacting the obstacle.
    Type: Application
    Filed: September 27, 2022
    Publication date: March 28, 2024
    Inventors: Ryota HAMAMOTO, Hiroaki NAKAGAWA, Yuji FUKUDA
  • Publication number: 20240102265
    Abstract: A working machine includes a machine body, a left traveling device located left on the machine body, a right traveling device located right on the machine body, and a controller configured or programmed to perform automatic deceleration to automatically reduce a first rotation speed of a left traveling motor and a second rotation speed of a right traveling motor by shifting a speed stage of each of the left and right traveling motors from a second speed stage to a first speed stage that is lower than the second speed stage. The controller is configured or programmed to: not perform the automatic deceleration when the first rotation speed or the second rotation speed is equal to or higher than a predetermined rotation speed; and perform the automatic deceleration when the first rotation speed and the second rotation speed are less than the predetermined rotation speed.
    Type: Application
    Filed: December 6, 2023
    Publication date: March 28, 2024
    Applicant: KUBOTA CORPORATION
    Inventors: Yuji FUKUDA, Kohei NAGAO
  • Publication number: 20240076466
    Abstract: In a thermal decomposition extruder, a hopper has an upper end closed. A sidewall of the hopper is provided with an emission hole for emission of decomposition gas produced during thermal decomposition of a polymer, to the outside of the hopper.
    Type: Application
    Filed: December 9, 2021
    Publication date: March 7, 2024
    Inventors: Yuji FUKUDA, Kenji INAGAWA, Yoshitaka KIMURA
  • Publication number: 20240060273
    Abstract: A hydraulic system for a working machine includes a variable displacement hydraulic pump, a plurality of hydraulic actuators, and a plurality of control valves. Each of the control valves includes an input port, an output port, and a flowrate reduction section. At least one of the control valves includes a flowrate increase section. The hydraulic actuators are a boom cylinder, a working tool cylinder, and an auxiliary actuator. The control valves are a boom control valve for controlling the boom cylinder, a working tool control valve for controlling the working tool cylinder, and a first auxiliary control valve for controlling the auxiliary actuator. The boom control valve and the working tool control valve each include the flowrate reduction section, and the first auxiliary control valve includes the flowrate reduction section and the flowrate increase section.
    Type: Application
    Filed: November 1, 2023
    Publication date: February 22, 2024
    Applicant: KUBOTA CORPORATION
    Inventor: Yuji FUKUDA
  • Publication number: 20240060271
    Abstract: A hydraulic system for a working vehicle includes a first hydraulic pump to deliver pilot fluid to a control valve for a hydraulic actuator whose highest load pressure acts on a first fluid passage, and a second hydraulic pump to deliver hydraulic fluid whose pressure acts on a second fluid passage. A hydraulic controller is operable to control a load-sensing (LS) differential pressure between the highest load pressure and a delivery pressure of the hydraulic fluid from the second hydraulic pump. A third fluid passage to which the second hydraulic pump delivers the hydraulic fluid branches to a fourth fluid passage for flow of the pilot fluid. A solenoid valve is operable to change a pilot pressure of the pilot fluid for the hydraulic controller, and a controller is configured or programmed to control the solenoid valve to adjust the pilot pressure to change the LS differential pressure.
    Type: Application
    Filed: November 1, 2023
    Publication date: February 22, 2024
    Inventors: Yuji FUKUDA, Toshihiko TAKEMURA
  • Patent number: 11905683
    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: Grant
    Filed: December 15, 2021
    Date of Patent: February 20, 2024
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Ryosuke Kinugawa, Ryota Hamamoto, Jun Tomita
  • Publication number: 20240052597
    Abstract: A hydraulic system for a working machine includes first and second hydraulic actuators actuated by hydraulic fluid delivered by a hydraulic pump, a first flow rate controller to control a first supply flow rate of hydraulic fluid supplied to the first hydraulic actuator to match a first required flow rate, a second flow rate controller to control a second supply flow rate of hydraulic fluid supplied to the second hydraulic actuator to match a second required flow rate, and a special flow rate control system to, if a sum of the first and second required flow rates is greater than a maximum delivery flow rate of the hydraulic pump, reduce the first supply flow rate to allow the second supply flow rate to approach the second required flow rate.
    Type: Application
    Filed: August 9, 2023
    Publication date: February 15, 2024
    Inventors: Kohei NAGAO, Yuji FUKUDA, Ryuki NISHIMOTO
  • Patent number: 11898327
    Abstract: A hydraulic system for a working machine includes a hydraulic pump to output a hydraulic fluid, an operation device operable to supply a pilot fluid in accordance with an amount by which the operation device is operated, a hydraulic actuator to be operated by the hydraulic fluid, a pilot fluid passage connected to the operation device, a first control valve connected to the pilot fluid passage and to be operated by the pilot fluid to control a flow of the hydraulic fluid, a second control valve to be operated by the pilot fluid to control a flow of the hydraulic fluid, a proportional valve to change a pressure of the pilot fluid to operate the second control valve, a pressure detector provided in the pilot fluid passage to detect a pressure in the pilot fluid passage, and a controller to control the proportional valve based on the pressure.
    Type: Grant
    Filed: June 10, 2022
    Date of Patent: February 13, 2024
    Assignee: KUBOTA CORPORATION
    Inventors: Kohei Nagao, Yuji Fukuda
  • Patent number: 11891780
    Abstract: A working machine includes a prime mover, a traveling pump configured to deliver hydraulic fluid at a flow rate corresponding to an angle of the swashplate, a traveling motor configured to be rotated by the hydraulic fluid delivered from the traveling pump so as to have a rotation speed shiftable between a first speed and a second speed higher than the first speed, a traveling change-over valve shiftable between a first state to set the rotation speed of the traveling motor to the first speed and a second state to set the rotation speed of the traveling motor to the second speed, an operation device, an operation valve configured to change the angle of the swashplate of the traveling pump according to operation of the operation device, an actuation valve provided upstream or downstream of the operation valve and fluidly connected to the operation valve, and a controller configured or programmed to output a control signal to control the actuation valve in such a way that, when the traveling change-over valve i
    Type: Grant
    Filed: August 9, 2021
    Date of Patent: February 6, 2024
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Ryota Hamamoto, Jun Tomita, Yuya Konishi, Kazuki Ueda
  • Publication number: 20240026648
    Abstract: A working machine includes a prime mover, a traveling device, a traveling motor, a traveling pump, a circulation fluid passage, a traveling switching valve shiftable between a first state corresponding to a first speed of a hydraulic motor and a second state corresponding to a second speed of the hydraulic motor, a brake, an actuation valve configured to output the hydraulic pressure applied to the traveling pump, and change the hydraulic pressure output therefrom, and a controller configured or programmed to control the traveling switching valve, the brake and the actuation valve, and being capable of activating a first mode. The controller is configured or programmed to, when activating the first mode, shift the brake into a braking state, shift the traveling switching valve into the second state, and control the actuation valve so as to set the hydraulic pressure output from the actuation valve to a predetermined pressure.
    Type: Application
    Filed: September 29, 2023
    Publication date: January 25, 2024
    Applicant: KUBOTA CORPORATION
    Inventors: Yuji FUKUDA, Kohei NAGAO, Hiroaki NAKAGAWA, Ryota HAMAMOTO
  • Patent number: 11873624
    Abstract: A working machine includes a controller to perform automatic deceleration to automatically reduce a first rotation speed of a left traveling motor to output a power to a left traveling device on a left portion of a machine body and a second rotation speed of a right traveling motor to output a power to a right traveling device on a right portion of the machine body by shifting a speed stage of each of the left and right traveling motors from a second speed to a first speed that is lower than the second speed. The controller is configured or programmed to determine, based on the second rotation speed, a left threshold for judging whether to perform the automatic deceleration in left pivot turn of the machine body, and to determine, based on the first rotation speed, a right threshold for judging whether to perform the automatic deceleration in right pivot turn of the machine body.
    Type: Grant
    Filed: July 29, 2021
    Date of Patent: January 16, 2024
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Kohei Nagao
  • Patent number: 11873894
    Abstract: A working machine includes a first traveling fluid passage connected to a first pressure-receiving portion, a second traveling fluid passage connected to a second pressure-receiving portion, a third traveling fluid passage connected to a third pressure-receiving portion, a fourth traveling fluid passage fluidly connected to a fourth pressure-receiving portion, and a connection fluid passage connecting at least two of the first, second, third and fourth pressure-receiving portions to each other. When a traveling operation member is operated, operation fluid flows to the first pressure receiving portion through the first traveling fluid passage, to the second pressure receiving portion through the second traveling fluid passage, to the third pressure receiving portion through the third traveling fluid passage, and to the fourth pressure receiving portion through the fourth traveling fluid passage.
    Type: Grant
    Filed: August 9, 2021
    Date of Patent: January 16, 2024
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Jun Tomita, Yuya Konishi, Fumitaka Fujisawa, Daiki Abe, Kohei Kurachi, Yudai Koga, Yuya Tanabe
  • Patent number: 11866911
    Abstract: A control method for a fan of a work vehicle includes supplying, when an engine is started, a first current to a solenoid of a variable relief valve such that the hydraulic fluid flows by a first flow rate, supplying, when a rotational speed of the engine becomes larger than a first rotational speed threshold value, a second current larger than the first current to the solenoid such that the hydraulic fluid flows by a second flow rate smaller than the first flow rate to reduce the rotational speed of the fan, and supplying, when the rotational speed of the engine becomes larger than a second rotational speed threshold value that is larger than the first rotational speed threshold value, a current to the solenoid to change the rotational speed of the fan, the current corresponding to a temperature of liquid flowing in the work vehicle.
    Type: Grant
    Filed: September 16, 2022
    Date of Patent: January 9, 2024
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Hiroaki Nakagawa, Ryota Hamamoto, Yasuhiro Nishida, Daiki Abe
  • Patent number: 11846087
    Abstract: A working machine includes a controller configured to determine a first deceleration threshold corresponding to each of a first traveling pressure, a second traveling pressure, a third traveling pressure, and a fourth traveling pressure, to perform automatic deceleration to reduce rotation speeds of a left traveling motor and a right traveling motor, and to judge whether to perform the automatic deceleration based on the determined first deceleration threshold, the first traveling pressure, the second traveling pressure, the third traveling pressure, and the fourth traveling pressure.
    Type: Grant
    Filed: July 29, 2021
    Date of Patent: December 19, 2023
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Kohei Nagao, Ryota Hamamoto, Hiroaki Nakagawa, Jun Tomita
  • Patent number: 11846090
    Abstract: A hydraulic system for a working machine includes hydraulic actuators actuated with hydraulic fluid delivered from a hydraulic pump, control valves each of which is shiftable among shift positions to control a flowrate of hydraulic fluid flowing to the corresponding hydraulic actuator, a detection fluid passage, an interlocking control valve, and a pressure detection unit. Each control valve includes an input port, an output port, and a flowrate reduction section. One of the control valves includes a flowrate increase section. The interlocking control valve is configured to be shifted in accordance with a shift of the one of the control valves among the shift positions and to be shifted to a blocking position to block a pilot fluid introduced into the interlocking control valve from the detection fluid passage when the one of the control valves is shifted to the increase position.
    Type: Grant
    Filed: January 20, 2023
    Date of Patent: December 19, 2023
    Assignee: KUBOTA CORPORATION
    Inventor: Yuji Fukuda
  • Patent number: 11840825
    Abstract: A hydraulic system for a working vehicle includes a first hydraulic pump to deliver pilot fluid to a control valve for a hydraulic actuator whose highest load pressure acts on a first fluid passage, and a second hydraulic pump to deliver hydraulic fluid whose pressure acts on a second fluid passage. A hydraulic controller is operable to control a load-sensing (LS) differential pressure between the highest load pressure and a delivery pressure of the hydraulic fluid from the second hydraulic pump. A third fluid passage to which the second hydraulic pump delivers the hydraulic fluid branches to a fourth fluid passage for flow of the pilot fluid. A solenoid valve is operable to change a pilot pressure of the pilot fluid for the hydraulic controller, and a controller is configured or programmed to control the solenoid valve to adjust the pilot pressure to change the LS differential pressure.
    Type: Grant
    Filed: June 16, 2022
    Date of Patent: December 12, 2023
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Kazuyoshi Arii, Toshihiko Takemura
  • Publication number: 20230383499
    Abstract: A working machine is provided, which includes a machine body, a prime mover, a pair of traveling devices, a pair of traveling motors to be switched between a first speed and a second speed higher than the first speed, a pair of traveling pumps driven by the prime mover to supply operation fluid to the pair of traveling motors, respectively, a controller configured to automatically shift down the pair of traveling motors from the second speed to the first speed, a mode switch configured for an operator to select an ON position allowing the controller to automatically shift down the first traveling motor from the second speed to the first speed and an OFF position preventing the controller to automatically shift down the first traveling motor from the second speed to the first speed, and a display to display that the operator selects the ON position of the mode switch.
    Type: Application
    Filed: August 11, 2023
    Publication date: November 30, 2023
    Applicant: KUBOTA CORPORATION
    Inventors: Yuji FUKUDA, Jun TOMITA, Ryota HAMAMOTO, Ryosuke KINUGAWA, Yoshimitsu TANAKA
  • Patent number: 11814815
    Abstract: A working machine includes a prime mover, a traveling motor a speed shifting valve configured to shift an output speed of the traveling motor between a first speed and a second speed faster than the first speed, an actuation valve to change a hydraulic pressure applied to the speed shifting valve, a brake shiftable between a braking state to brake the traveling motor and a braking releasing state to release the braking, and a controller configured or programmed to control the actuation valve and the brake, and being capable of activate a warm-up mode. The controller, when activating the warm-up mode, shifts the brake into the braking state, and controls the actuation valve so as to make the hydraulic pressure applied to the speed shifting valve equal to or greater than a value corresponding to the second speed.
    Type: Grant
    Filed: August 5, 2021
    Date of Patent: November 14, 2023
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Kohei Nagao, Hiroaki Nakagawa, Ryota Hamamoto, Kazuki Ueda, Yudai Koga, Kohei Kurachi
  • Patent number: 11788255
    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.
    Type: Grant
    Filed: June 28, 2021
    Date of Patent: October 17, 2023
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Ryota Hamamoto, Jun Tomita, Daiki Abe
  • Patent number: 11781572
    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.
    Type: Grant
    Filed: August 6, 2021
    Date of Patent: October 10, 2023
    Assignee: KUBOTA CORPORATION
    Inventors: Daiki Abe, Yuji Fukuda, Hiroaki Nakagawa, Ryota Hamamoto