Patents by Inventor Takahisa Oasa

Takahisa Oasa 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: 20200158235
    Abstract: When the vehicle speed increases and reaches a predetermined switching threshold, the controller reduces the displacement of the first travel motor and controls the flow rate control device to offset a flow rate excess in the hydraulic circuit in accordance with the reduction in the displacement of the first travel motor. After the vehicle speed has reached the switching threshold, the controller executes switching control to switch the clutch from an engaged state to a disengaged state.
    Type: Application
    Filed: January 21, 2019
    Publication date: May 21, 2020
    Inventor: Takahisa OASA
  • Publication number: 20200123740
    Abstract: A controller determines a compensation factor from an operating amount of an accelerator operating member and a hydraulic pressure of at least one of a first circuit and a second circuit. The controller determines a target vehicle speed from the operating amount of the accelerator operating member. The controller determines at least one of a target displacement of a travel pump and a target displacement of a travel motor from the target vehicle speed and the compensation factor.
    Type: Application
    Filed: January 21, 2019
    Publication date: April 23, 2020
    Inventor: Takahisa OASA
  • Publication number: 20200102719
    Abstract: A controller determines a target rotation speed of an engine from an operation amount of an accelerator operating member. The controller determines whether a vehicle is in coasting deceleration. The controller decreases a differential pressure between a first circuit and a second circuit of a hydraulic circuit according to a deviation between an actual rotation speed of the engine and the target rotation speed, or the operation amount of the accelerator operating member when the vehicle is in the coasting deceleration.
    Type: Application
    Filed: January 21, 2019
    Publication date: April 2, 2020
    Inventor: Takahisa OASA
  • Publication number: 20200056354
    Abstract: A work vehicle includes a vehicle body, a work implement including a boom attached to the vehicle body and an attachment attached to a tip end part of the boom, a first actuator configured to rotate the boom up and down, and a controller configured to execute an automatic lowering control in order to automatically rotate and lower the boom. The controller is further configured to set the first actuator to a floating state when it is detected that the attachment has reached a predetermined position during an execution of the automatic lowering control.
    Type: Application
    Filed: September 28, 2018
    Publication date: February 20, 2020
    Inventors: Takahisa OASA, Kiyotaka NINOMIYA
  • Publication number: 20190352881
    Abstract: A work vehicle includes an engine, a hydrostatic transmission, and a controller. The hydrostatic transmission includes a traveling pump driven by the engine, a hydraulic circuit connected to the traveling pump, and a traveling motor connected to the traveling pump via the hydraulic circuit. The controller is configured to control the traveling motor and the traveling pump, determine a target flow rate of the traveling motor or the traveling pump, determine a correction amount of the target flow rate from a hydraulic pressure of the hydraulic circuit, and determine a target displacement of the traveling motor or the traveling pump from the target flow rate and the correction amount.
    Type: Application
    Filed: May 29, 2018
    Publication date: November 21, 2019
    Inventor: Takahisa OASA
  • Patent number: 9074546
    Abstract: A work vehicle includes a controller. The controller is configured to determine whether low-load conditions indicating that the work vehicle is in a low-load state are satisfied. The controller is configured to control an engine so that an upper limit value of an output torque of the engine when the low-load conditions are satisfied is made less than when the low-load conditions are not satisfied. Also, the controller is configured to vary a reduction amount of the upper limit value of the output torque of the engine when the low-load conditions are satisfied, in accordance with variation in at least one of vehicle speed, vehicle acceleration, and engine-rotation-speed acceleration, and in accordance with variation in engine rotation speed.
    Type: Grant
    Filed: February 16, 2011
    Date of Patent: July 7, 2015
    Assignee: KOMATSU LTD.
    Inventors: Satoshi Asami, Jun Koizumi, Shotaro Ishii, Takahisa Oasa, Ai Haginiwa, Masahiro Minato
  • Patent number: 8769945
    Abstract: A pump displacement control cylinder is configured to control the displacement of a hydraulic pump according to pressure of hydraulic fluid and switches the discharge direction of the hydraulic fluid from the hydraulic pump according to the supply direction of the hydraulic fluid to the pump displacement control cylinder. A forward and backward progression switching valve is configured to switch the supply direction of the hydraulic fluid to the pump displacement control cylinder. A pressure control valve is configured to control the pressure of the hydraulic fluid supplied to the pump displacement control cylinder according to a command value input to the pressure control valve. A control section is configured to execute pump shuttle control which reduces the command value to the pressure control valve when switching between forward and backward progression using a forward and backward progression operation member.
    Type: Grant
    Filed: September 4, 2012
    Date of Patent: July 8, 2014
    Assignee: Komatsu Ltd.
    Inventors: Atsushi Shirao, Takahisa Oasa, Shinichi Kitao
  • Publication number: 20140144129
    Abstract: A pump displacement control cylinder is configured to control the displacement of a hydraulic pump according to pressure of hydraulic fluid and switches the discharge direction of the hydraulic fluid from the hydraulic pump according to the supply direction of the hydraulic fluid to the pump displacement control cylinder. A forward and backward progression switching valve is configured to switch the supply direction of the hydraulic fluid to the pump displacement control cylinder. A pressure control valve is configured to control the pressure of the hydraulic fluid supplied to the pump displacement control cylinder according to a command value input to the pressure control valve. A control section is configured to execute pump shuttle control which reduces the command value to the pressure control valve when switching between forward and backward progression using a forward and backward progression operation member.
    Type: Application
    Filed: September 4, 2012
    Publication date: May 29, 2014
    Inventors: Atsushi Shirao, Takahisa Oasa, Shinichi Kitao
  • Publication number: 20130041561
    Abstract: A work vehicle includes a controller. The controller is configured to determine whether low-load conditions indicating that the work vehicle is in a low-load state are satisfied. The controller is configured to control an engine so that an upper limit value of an output torque of the engine when the low-load conditions are satisfied is made less than when the low-load conditions are not satisfied. Also, the controller is configured to vary a reduction amount of the upper limit value of the output torque of the engine when the low-load conditions are satisfied, in accordance with variation in at least one of vehicle speed, vehicle acceleration, and engine-rotation-speed acceleration, and in accordance with variation in engine rotation speed.
    Type: Application
    Filed: February 16, 2011
    Publication date: February 14, 2013
    Applicant: KOMATSU LTD.
    Inventors: Satoshi Asami, Jun Koizumi, Shotaro Ishii, Takahisa Oasa, Ai Haginiwa, Masahiro Minato