Patents by Inventor Jun TOMITA

Jun TOMITA 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: 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
  • Publication number: 20220049465
    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: Application
    Filed: August 9, 2021
    Publication date: February 17, 2022
    Applicant: KUBOTA CORPORATION
    Inventors: Yuji FUKUDA, Ryota HAMAMOTO, Jun TOMITA, Yuya KONISHI, Kazuki UEDA
  • Publication number: 20220049460
    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: Application
    Filed: July 29, 2021
    Publication date: February 17, 2022
    Applicant: KUBOTA CORPORATION
    Inventors: Yuji FUKUDA, Kohei NAGAO, Ryota HAMAMOTO, Hiroaki NAKAGAWA, Jun TOMITA
  • Publication number: 20220049727
    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: Application
    Filed: August 9, 2021
    Publication date: February 17, 2022
    Applicant: KUBOTA CORPORATION
    Inventors: Yuji FUKUDA, Jun TOMITA, Yuya KONISHI, Fumitaka FUJISAWA, Daiki ABE, Kohei KURACHI, Yudai KOGA, Yuya TANABE
  • Patent number: 11236491
    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: February 18, 2020
    Date of Patent: February 1, 2022
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Ryosuke Kinugawa, Ryota Hamamoto, Jun Tomita
  • Publication number: 20210404150
    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: Application
    Filed: June 28, 2021
    Publication date: December 30, 2021
    Applicant: KUBOTA CORPORATION
    Inventors: Yuji FUKUDA, Ryota HAMAMOTO, Jun TOMITA, Daiki ABE
  • Patent number: 11168462
    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.
    Type: Grant
    Filed: April 15, 2020
    Date of Patent: November 9, 2021
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Daiki Abe, Jun Tomita, Yuya Konishi, Ryosuke Kinugawa
  • Patent number: 11118609
    Abstract: A hydraulic system includes a control device to reduce a first movement speed to be lower than a second movement speed, the first movement speed being a speed at which a spool of a first control valve moves from a first supply position to a first stop position under a state where a second control valve is in the second supply position, the second movement speed being a speed at which the spool moves from the first supply position to the first stop position under a state where the second control valve is in the second stop position. The first supply position allows operation fluid to be supplied to a hydraulic actuator. The first stop position prevents the operation fluid from being supplied to the hydraulic actuator. The second stop position prevents the operation fluid from being supplied to a first fluid tube coupling a hydraulic pump to the hydraulic actuator.
    Type: Grant
    Filed: June 5, 2019
    Date of Patent: September 14, 2021
    Assignee: KUBOTA CORPORATION
    Inventors: Ryuki Nishimoto, Yuji Fukuda, Jun Tomita
  • Patent number: 11067103
    Abstract: A hydraulic system for a working machine, includes a hydraulic device to change a flow rate of an operation fluid. The hydraulic device includes a first hydraulic receiver to which the operation fluid is applied, a second hydraulic receiver to which the operation fluid is applied, and a movable portion to be moved by the operation fluid applied to any one of the first hydraulic receiver and the second hydraulic portion. A hydraulic system further includes a differential pressure regulator to supply the operation fluid to the first hydraulic receiver and the second hydraulic receiver, the differential pressure regulator being configured to regulate a differential pressure between a first pressure that is a pressure of the operation fluid applied to the first hydraulic receiver and a second pressure that is a pressure of the operation fluid applied to the second hydraulic receiver.
    Type: Grant
    Filed: October 2, 2018
    Date of Patent: July 20, 2021
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Tsuyoshi Matsumoto, Ryosuke Kinugawa, Jun Tomita, Nozomu Minagawa
  • Publication number: 20210123215
    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: Application
    Filed: October 21, 2020
    Publication date: April 29, 2021
    Applicant: KUBOTA CORPORATION
    Inventors: Yuji FUKUDA, Ryota HAMAMOTO, Jun TOMITA
  • Publication number: 20210123214
    Abstract: 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.
    Type: Application
    Filed: October 22, 2020
    Publication date: April 29, 2021
    Applicant: KUBOTA CORPORATION
    Inventors: Yuji FUKUDA, Ryota HAMAMOTO, Jun TOMITA
  • Patent number: 10920881
    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.
    Type: Grant
    Filed: June 24, 2019
    Date of Patent: February 16, 2021
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Daiki Abe, Jun Tomita, Yuya Konishi, Fumitaka Fujisawa, Yudai Koga
  • Patent number: 10837157
    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.
    Type: Grant
    Filed: April 25, 2019
    Date of Patent: November 17, 2020
    Assignee: KUBOTA CORPORATION
    Inventors: Jun Tomita, Yuji Fukuda, Yuya Konishi
  • Publication number: 20200318320
    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: Application
    Filed: April 2, 2020
    Publication date: October 8, 2020
    Applicant: KUBOTA CORPORATION
    Inventors: Yuji FUKUDA, Jun TOMITA, Ryota HAMAMOTO, Ryosuke KINUGAWA, Yoshimitsu TANAKA
  • Patent number: 10787787
    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.
    Type: Grant
    Filed: June 4, 2019
    Date of Patent: September 29, 2020
    Assignee: KUBOTA CORPORATION
    Inventors: Daiki Abe, Yuji Fukuda, Yuya Konishi, Keigo Honda, Hiroya Hanano, Jun Tomita
  • Publication number: 20200270425
    Abstract: [Problem ] The present invention addresses the problem of providing a novelnanocarbon composite which is used to achieve a stable and uniform mechanical strength improvement effect in a carbon fiber-reinforced plastic or carbon fiber-reinforced composite material impregnated with a nanocarbon-containing resin. [Solution] A novel nanocarbon composite containing nanocarbon and nano-cellulose modified with a functional group(s) or a novel nanocarbon composite containing nanocarbon, nano-cellulose modified with a functional group(s), and a affinitive binding agent is constituted by incorporating a resin serving as a matrix in a carbon fiber-reinforced plastic or carbon fiber-reinforced composite material.
    Type: Application
    Filed: December 12, 2016
    Publication date: August 27, 2020
    Applicants: Nano Summit Co., Ltd., The University of Tokyo
    Inventors: Ichiro SAKATA, Bunshi FUGETSU, Kotaro KUMAGAI, Jun TOMITA, Shoichi MANABE
  • Publication number: 20200263393
    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: February 18, 2020
    Publication date: August 20, 2020
    Applicant: KUBOTA CORPORATION
    Inventors: Yuji FUKUDA, Ryosuke KINUGAWA, Ryota HAMAMOTO, Jun TOMITA
  • Publication number: 20200240113
    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.
    Type: Application
    Filed: April 15, 2020
    Publication date: July 30, 2020
    Applicant: KUBOTA CORPORATION
    Inventors: Yuji FUKUDA, Daiki ABE, Jun TOMITA, Yuya KONISHI, Ryosuke KINUGAWA
  • Patent number: 10648156
    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.
    Type: Grant
    Filed: March 30, 2017
    Date of Patent: May 12, 2020
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Daiki Abe, Jun Tomita, Yuya Konishi, Ryosuke Kinugawa
  • Publication number: 20200048868
    Abstract: A hydraulic system includes a control device to reduce a first movement speed to be lower than a second movement speed, the first movement speed being a speed at which a spool of a first control valve moves from a first supply position to a first stop position under a state where a second control valve is in the second supply position, the second movement speed being a speed at which the spool moves from the first supply position to the first stop position under a state where the second control valve is in the second stop position. The first supply position allows operation fluid to be supplied to a hydraulic actuator. The first stop position prevents the operation fluid from being supplied to the hydraulic actuator. The second stop position prevents the operation fluid from being supplied to a first fluid tube coupling a hydraulic pump to the hydraulic actuator.
    Type: Application
    Filed: June 5, 2019
    Publication date: February 13, 2020
    Applicant: KUBOTA CORPORATION
    Inventors: Ryuki NISHIMOTO, Yuji FUKUDA, Jun TOMITA