Patents by Inventor Masaki Yoshikawa

Masaki Yoshikawa 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: 9383002
    Abstract: To provide a travel control device for a working vehicle, including a speed change lever that is applicable even when a transmission in which speed stages are set to be larger by one stage is applied, the travel control device comprises a switching device (41) that switches speed changed by a transmission (3) either manually or automatically, a speed stage selecting device (30b) that selects a speed stage out of a plurality of speed stages of the transmission (3), and a first speed selecting device (40) that changes the speed stage manually down to a first speed separately from the speed stage selecting device (30b), regardless of a switching state of the switching device (41), wherein the speed stage selecting device (30b) selects the speed stages including a second speed or more but excluding the first speed, and a control device (10) is further provided, which controls the transmission (3) based on instructions sent from the switching device (41), the speed stage selecting device (30b), and the first speed
    Type: Grant
    Filed: October 11, 2013
    Date of Patent: July 5, 2016
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Tetsuji Tanaka, Masaki Yoshikawa, Nobuyuki Hidaka, Isamu Aoki, Keigo Kikuchi
  • Publication number: 20160178095
    Abstract: A premium threaded joint has a pin-side shoulder angle ?1, a box-side shoulder angle ?2, a seal interference quantity ? and a seal point distance xp satisfying ?2??1=?×?/xp, ?=7 to 14, and a pin distal end thickness tp1 defined by a difference Re?Ri between a radius Re of a pin most distal end portion and an inner radius Ri of a pin distal end portion is 0.25 times or more as large as a pin raw pipe thickness tp0.
    Type: Application
    Filed: July 29, 2014
    Publication date: June 23, 2016
    Inventors: Takamasa Kawai, Kazunari Takahashi, Hiroshi Chikatsune, Masaki Yoshikawa, Jun Takano, Takuya Nagahama, Masateru Ueta, Hideo Sato, Haruhiko Seki, Tsuyoshi Yoneyama
  • Publication number: 20160130884
    Abstract: In a joint for oil country tubular goods, a pitch change is made such that an internally-thread pitch has the same value as an externally-thread pitch from a thread end portion on a box end side to a pitch change position taken on a box center side with respect to a position away from the thread end portion by ½ of an entire length of the threaded portion, and the internally-thread pitch is changed to a value less than the externally-thread pitch at the pitch change position so that a thread gap is gradually decreased from the pitch change position to a position of the thread end portion on the box center side, and the thread gap is eventually set to a value which is 0.2 to 0.8 times as large as the thread gap before the pitch change is made.
    Type: Application
    Filed: June 9, 2014
    Publication date: May 12, 2016
    Applicant: JFE STEEL CORPORATION
    Inventors: Takamasa Kawai, Kazunari Takahashi, Hiroshi Chikatsune, Masaki Yoshikawa, Jun Takano, Takuya Nagahama, Masateru Ueta, Hideo Sato, Haruhiko Seki, Tsuyoshi Yoneyama
  • Publication number: 20160123091
    Abstract: A threaded joint for an oil country tubular goods includes pins each of which occupies a pipe end portion of a steel pipe for an oil country tubular goods, and includes an externally-threaded portion, a nose extending toward a pipe end side from the externally-threaded portion, and a shoulder forming a distal end of the nose; and a box including internally-threaded portions each forming a threaded portion by being threadedly joined with the externally-threaded portion, and shoulders brought into contact with the shoulders of the pins, wherein the pins and the box being joined to each other by the threaded joining so that portions between the threaded portions and the shoulders are brought into metal-to-metal contact with each other to thereby form seal portions at the contact portions, and the shoulders of the pins and the shoulders of the box forming shoulder faces are brought into contact with each other at the time of make-up of the threaded joint, and a ratio of a chamfer length of pin thread to a thread
    Type: Application
    Filed: June 9, 2014
    Publication date: May 5, 2016
    Inventors: Takamasa Kawai, Kazunari Takahashi, Hiroshi Chikatsune, Masaki Yoshikawa, Jun Takano, Takuya Nagahama, Masateru Ueta
  • Publication number: 20150377391
    Abstract: A threaded joint for pipes including a pin and a box, characterized in that the relationship 0.05 degrees??sb??sp?2.0 degrees is satisfied, where ?sb is an angle of an insertion surface of the female thread on the box side relative to a plane perpendicular to an axis of pipe, and ?sp is an angle of an insertion surface of the male thread, which faces the insertion surface of the female thread, on the pin side relative to the plane perpendicular to the axis of pipe.
    Type: Application
    Filed: December 18, 2013
    Publication date: December 31, 2015
    Inventors: Takuya NAGAHAMA, Hiroshi CHIKATSUNE, Kazunari TAKAHASHI, Masaki YOSHIKAWA, Jun TAKANO, Masateru UETA, Takamasa KAWAI
  • Publication number: 20150368987
    Abstract: A threaded joint in which the outer peripheral face of the pin nose has a single tapered shape, the seal face of the box has an outwardly convex curved shape, and a seal point xp defined by equation (1) is greater than or equal to 0.2 inches, x p = ? x 1 x 2 ? px ? ? x F ? ? F = ? x 1 x 2 ? p ? ? x ( 1 ) where p is a contact face pressure, x is a distance from an end of the pin in a pipe axis direction, and x1 and x2 are respectively a lower limit and an upper limit of a domain of x corresponding to the seal portion.
    Type: Application
    Filed: January 28, 2013
    Publication date: December 24, 2015
    Inventors: Takuya Nagahama, Osamu Sonobe, Masaki Yoshikawa, Jun Takano, Takamasa Kawai
  • Patent number: 9194190
    Abstract: A threaded joint for a pipe is disclosed in which scalability, compression resistance, and galling resistance are enhanced. The threaded joint includes a pin nose outer peripheral surface that forms an outward convex curve in an axial cross-sectional view; the convex curve is such that a composite R curve, in which a plurality of outward convex arcs having different radiuses of curvature are connected in sequence to a generating line of a cylindrical portion next to a male member, is curved such that the radiuses of curvature increase with distance from the male member and tangents on connection points of the arcs are aligned with those of corresponding arcs connected thereto; and the inner peripheral surface of a box component facing the pin nose is a tapered surface that interferes with the pin nose outer peripheral surface when connected to a pin component.
    Type: Grant
    Filed: June 22, 2011
    Date of Patent: November 24, 2015
    Assignee: JFE STEEL CORPORATION
    Inventors: Osamu Sonobe, Takuya Nagahama, Masaki Yoshikawa, Jun Takano, Takamasa Kawai, Kazunari Takahashi
  • Publication number: 20150226316
    Abstract: To provide a travel control device for a working vehicle, including a speed change lever that is applicable even when a transmission in which speed stages are set to be larger by one stage is applied, the travel control device comprises a switching device (41) that switches speed changed by a transmission (3) either manually or automatically, a speed stage selecting device (30b) that selects a speed stage out of a plurality of speed stages of the transmission (3), and a first speed selecting device (40) that changes the speed stage manually down to a first speed separately from the speed stage selecting device (30b), regardless of a switching state of the switching device (41), wherein the speed stage selecting device (30b) selects the speed stages including a second speed or more but excluding the first speed, and a control device (10) is further provided, which controls the transmission (3) based on instructions sent from the switching device (41), the speed stage selecting device (30b), and the first speed
    Type: Application
    Filed: October 11, 2013
    Publication date: August 13, 2015
    Applicant: Hitachi Construction Machinery Co., Ltd.
    Inventors: Tetsuji Tanaka, Masaki Yoshikawa, Nobuyuki Hidaka, Isamu Aoki, Keigo Kikuchi
  • Patent number: 9091221
    Abstract: An engine speed control device for an industrial vehicle includes an approach detector that detects an approach of the industrial vehicle to an object to be approached; and an engine speed controller that restricts an upper limit of a rotation speed of an engine when the approach detector detects an approach of the industrial vehicle to an object to be approached.
    Type: Grant
    Filed: June 16, 2010
    Date of Patent: July 28, 2015
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Koji Hyodo, Masaki Yoshikawa, Tadayoshi Aoki, Katsutaka Hara
  • Publication number: 20150198270
    Abstract: A threaded joint for pipes is provided in which a box-side lip length L, which is the axial distance between a pin-nose-end corresponding point P of the box component 1 and a load surface 18b of a lip-side internal thread ridge 50 closest to the pin-nose-end corresponding point P, is 300 or more times as long as an insertion surface interval ?, which is the axial interval between an insertion surface 19b of an internal thread ridge at a position two or more ridges backwards from the lip-side internal thread ridge 50 and an insertion surface 19a of an external thread ridge facing the insertion surface 19b when tightened, that is, L?300×?.
    Type: Application
    Filed: July 1, 2013
    Publication date: July 16, 2015
    Applicant: JFE STEEL CORPORATION
    Inventors: Takuya Nagahama, Kazunari Takahashi, Hiroshi Chikatsune, Masaki Yoshikawa, Jun Takano, Takamasa Kawai, Masateru Ueta
  • Publication number: 20150091782
    Abstract: A display device includes: a display unit that displays a physical quantity; and a display control unit that causes the display unit to display the physical quantity. The display unit includes a numerical value display part that displays a numerical value of a plurality of digits and a unit display part, in which a plurality of units representing the physical quantity coexist; the numerical value display part has a numerical character segment group representing a numerical character in each of the digits; the unit display part has a plurality of symbol segments representing symbols making up the units; and the display control unit selects one of the units, causes symbol segments that represent a selected unit to be displayed in the unit display part, and causes a numerical value representing the physical quantity corresponding to the selected unit to be displayed in the numerical value display part.
    Type: Application
    Filed: September 29, 2014
    Publication date: April 2, 2015
    Inventors: Yasuo YAMAZAKI, Masaki YOSHIKAWA, Kazuyuki ITO
  • Patent number: 8991875
    Abstract: Provided is a threaded joint for steel pipes having high sealability even under a bending load. In the threaded joint, when a pin 3 and a box 1 are threadedly connected with each other, the outer peripheral face of a nose 8 of the pin and the inner peripheral face of a nose of the box are in metal-to-metal contact with each other at a contact portion and the contact portion serves as a seal portion 20. A threaded portion, at which the externally threaded portion 7 and the internally threaded portion 5 are threadedly connected with each other, has a negative load flank angle ?, shoulder portions 12 and 14 have a negative torque shoulder angle ?, and the ratio L/d0 of a length L of the nose and a pipe outside diameter d0 is equal to or higher than 0.08.
    Type: Grant
    Filed: February 24, 2012
    Date of Patent: March 31, 2015
    Assignee: JFE Steel Corporation
    Inventors: Masaki Yoshikawa, Takuya Nagahama, Hiroshi Chikatsune, Jun Takano, Takamasa Kawai, Kazunari Takahashi, Masateru Ueta, Osamu Sonobe
  • Publication number: 20150061287
    Abstract: In the threaded joint for pipes, a coating having a Vickers hardness greater than or equal to 310 is formed on a threaded portion of the box and an inner face of the box corresponding to a seal portion. The seal interference amount ratio ?/D of the seal portion in a pipe circumferential direction is greater than or equal to 0.002, where D is a seal diameter defined as an outside diameter of the pin at a seal point that is a point on the outer peripheral face of the nose of the pin at which the outer peripheral face first comes into contact with the inner peripheral face of the nose of the box and ? is an interference amount defined as an amount by which the outside diameter at the seal point is reduced by the box when the pin and the box are threadedly connected with each other.
    Type: Application
    Filed: October 16, 2012
    Publication date: March 5, 2015
    Applicant: JFE Steel Corporation
    Inventors: Masaki Yoshikawa, Takuya Nagahama, Hiroshi Chikatsune, Jun Takano, Takamasa Kawai, Masateru Ueta, Kazunari Takahashi, Nobuhiko Morioka
  • Publication number: 20140303879
    Abstract: An engine control device for a work vehicle decides that an idling stop condition is established when the front device is in the unengaged slate, the steering device is in the engaged state, the accelerator pedal is in the non-operation state, either the transmission is in the neutral state or the parking brake device is in the engaged state or the transmission is in the neutral state and also the parking brake device is in the engaged state, and the service brake device is in the unengaged state, and stops an engine when it is decided that it passes the predetermined length of time since it was decided that the idling stop condition was established.
    Type: Application
    Filed: November 15, 2012
    Publication date: October 9, 2014
    Inventors: Koji Hyodo, Masaki Yoshikawa, Isamu Aoki, Tetsuji Tanaka
  • Patent number: 8744702
    Abstract: A work vehicle control device includes: a rotation speed control unit that controls an engine rotation speed in correspondence to an accelerator pedal operation quantity indicating an operating extent of an accelerator pedal; a speed ratio detection unit that detects a ratio of speed at an input shaft and at an output shaft of a torque converter, which is disposed between the engine and wheels; a decision-making unit that makes a decision that a fuel efficiency deteriorating condition exists if the torque converter speed ratio is less than a predetermined value or if the torque converter speed ratio is equal to or greater than the predetermined value and a target engine rotation speed corresponding to an operation of the accelerator pedal is greater than a preset value; and an informing unit that informs results of the decision made by the decision-making unit.
    Type: Grant
    Filed: June 18, 2010
    Date of Patent: June 3, 2014
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Koji Hyodo, Masaki Yoshikawa, Ei Takahashi, Katsutaka Hara
  • Publication number: 20140116560
    Abstract: Radial seal type threaded joints for steel pipes have still room for improvement in ensuring sealability in terms of the rigidity of the pin nose. Specifically, the outer circumferential surface of the nose of the pin has an outward convex curved shape, and the sealing surface of the box has a tapered shape; and the cross-sectional area of the pin at a seal point that is a portion on the outer circumferential surface of the nose of the pin, the portion first coming into contact with the sealing surface of the box when threaded-joined, is 35% or more of the cross-sectional area of an original pipe portion corresponding to an unprocessed portion.
    Type: Application
    Filed: February 24, 2012
    Publication date: May 1, 2014
    Applicant: JFE STEEL CORPORATION
    Inventors: Takamasa Kawai, Kazunari Takahashi, Hiroshi Chikatsune, Masaki Yoshikawa, Jun Takano, Takuya Nagahama, Masateru Ueta, Osamu Sonobe
  • Patent number: 8671673
    Abstract: There are provided: a first circuit for traveling HC1, formed through a closed circuit connection of a variable displacement hydraulic pump 2 and a variable displacement hydraulic motor 3, that includes a motor control unit 10, 11 that controls a displacement of the hydraulic motor 3; a second circuit for working HC2 that drives a work hydraulic actuator 114, 115 by pressure oil from a work hydraulic pump 4; and a maximum value control unit that controls a maximum displacement of the hydraulic motor 3 in accordance with load pressure Pf in the second circuit HC2. The maximum value control unit decreases the maximum displacement to a minimum limit q1 corresponding to a maximum load pressure Pr in the second circuit when load pressure Pf in the second circuit exceeds a predetermined value Ps.
    Type: Grant
    Filed: March 12, 2008
    Date of Patent: March 18, 2014
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Koji Hyodo, Kazuo Chonan, Yasuo Yamazaki, Nobuhiro Suzuki, Koji Takano, Genichiro Ishimaru, Nobuyuki Hidaka, Masaki Yoshikawa
  • Patent number: 8668624
    Abstract: A motor control device for a working vehicle includes: a travel drive device that transmits rotation of a motor to wheels through a torque converter; a first selection device to be operated so as to select one of a power mode and an economy mode; a second selection device that is different from the first selection device; a mode switching device that switches from the economy mode to the power mode if the second selection device is operated in a state where the economy mode has been selected by the first selection device; and a speed restriction device that, when the economy mode is set, restricts a maximum rotational speed of the motor to a lower speed side than that when the power mode is set.
    Type: Grant
    Filed: June 21, 2010
    Date of Patent: March 11, 2014
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Koji Hyodo, Masaki Yoshikawa, Kazuo Chounan
  • Publication number: 20140049045
    Abstract: Provided is a threaded joint for steel pipes having high sealability even under a bending load. In the threaded joint, when a pin 3 and a box 1 are threadedly connected with each other, the outer peripheral face of a nose 8 of the pin and the inner peripheral face of a nose of the box are in metal-to-metal contact with each other at a contact portion and the contact portion serves as a seal portion 20. A threaded portion, at which the externally threaded portion 7 and the internally threaded portion 5 are threadedly connected with each other, has a negative load flank angle ?, shoulder portions 12 and 14 have a negative torque shoulder angle ?, and the ratio L/d0 of a length L of the nose and a pipe outside diameter d0 is equal to or higher than 0.08.
    Type: Application
    Filed: February 24, 2012
    Publication date: February 20, 2014
    Applicant: JFE Steel Corporation
    Inventors: Masaki Yoshikawa, Takuya Nagahama, Hiroshi Chikatsune, Jun Takano, Takamasa Kawai, Kazunari Takahashi, Masateru Ueta, Osamu Sonobe
  • Patent number: 8655557
    Abstract: A working vehicle motor control device includes: a rotational speed control device that controls a motor rotational speed in accordance with an operation amount of an accelerator pedal; a travel drive device that transmits rotation of the motor to wheels through a torque converter and a transmission; a speed ratio detection device that detects a speed ratio of an input shaft and an output shaft of the torque converter; and a speed restriction device that restricts a maximum rotational speed of the motor in accordance with a speed ratio detected by the speed ratio detection device. In the working vehicle motor control device, the speed restriction device restricts the maximum rotational speed when a detected speed ratio is in an acceleration region of the motor rotational speed to less than the maximum rotational speed when a detected speed ratio is in a non-acceleration region.
    Type: Grant
    Filed: June 17, 2010
    Date of Patent: February 18, 2014
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Koji Hyodo, Hiroki Nakazono, Masaki Yoshikawa, Tadayoshi Aoki, Isamu Aoki