Patents by Inventor Mitsuo Sasaki

Mitsuo Sasaki 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: 7558662
    Abstract: In vehicular driving control apparatus and method, a steering assistance force provided for steerable road wheels of the vehicle in a direction at which a sideslip angle is decreased when a vehicular sideslip angle which is a difference between a forwarding direction of the vehicle and a steering direction of a steering wheel of the vehicle is detected and a vehicular oversteer state is detected, and thereafter, each of road wheels of the vehicle is controlled to decrease the sideslip angle when the steering assistance force is provided in a direction at which the vehicular sideslip angle is decreased and when the sideslip angle is equal to or larger than a predetermined value.
    Type: Grant
    Filed: July 19, 2006
    Date of Patent: July 7, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Naoshi Yamaguchi, Mitsuo Sasaki, Kazuya Yamano, Toru Takahashi, Motohiro Higuma
  • Patent number: 7552978
    Abstract: A brake system that provides a good pedal feel, that assists stepping force of a driver by a small motor, and that can control braking force of wheels individually. The brake system comprises a first actuator (5) for increasing a liquid pressure in a master cylinder (2) by driving torque of a motor (51), and a second actuator (6) capable of driving a brake generating mechanism (3) without transmitting power to the master cylinder (2), wherein the actuators (5, 6) to be driven are switched depending on the operation of a brake pedal (1). The first and second actuators (5, 6) are connected to hydraulic piping (4f, 4r), and a pressurized oil is supplied to the brake generating mechanism (3) through hydraulic valve means (63f, 63r, . . . 65rr).
    Type: Grant
    Filed: October 29, 2004
    Date of Patent: June 30, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Atsushi Yokoyama, Taisetsu Tanimichi, Satoru Kuragaki, Yukihiro Osawa, Jun Kubo, Yukihiko Inoue, Katsuya Iwasaki, Mitsuo Sasaki, Tsutomu Hibi
  • Publication number: 20090125190
    Abstract: A power steering apparatus includes a power cylinder including first and second pressure chambers; a reversible pump including a first outlet port and a second outlet port; a first hydraulic passage including a portion made from an elastomer; a second hydraulic passage including a portion made from an elastomer; a motor arranged to drive the reversible pump; a motor control section; a pump reverse rotation judging section configured to judge a reverse rotation state of the reversible pump when an actual rotation direction of the reversible pump does not correspond to a direction in which the motor is rotated by the driving signal from the motor control section; and a damping torque adding section configured to damp a torque generated in the reversible pump when the pump reverse rotation judging section determines the reverse rotation state of the reversible pump.
    Type: Application
    Filed: November 12, 2008
    Publication date: May 14, 2009
    Inventors: Tatsuo Matsumura, Mitsuo Sasaki, Toru Takahashi, Kohei Ono, Eiji Kasai, Takatoshi Saito
  • Publication number: 20090125189
    Abstract: A power steering apparatus includes: a steering mechanism connected with a steering wheel; a transmitting mechanism connecting the steering mechanism and a steered wheels; a motor arranged to drive the transmitting mechanism based on a torque inputted to the steering mechanism to provide a steering assist force to the steered wheels; a motor control section configured to output a drive signal to the motor in accordance with the steering assist force; a motor reverse rotation judging section configured to judge a reverse rotation state of the motor when an actual rotation direction of the motor does not correspond to a direction in which the motor is rotated by the driving signal from the motor control section; and a damping torque adding section configured to damp a torque generated in the motor when the motor reverse rotation judging section determines the reverse rotation state of the motor.
    Type: Application
    Filed: November 12, 2008
    Publication date: May 14, 2009
    Inventors: Tatsuo Matsumura, Mitsuo Sasaki, Toru Takahashi
  • Publication number: 20090125191
    Abstract: A power steering apparatus includes a power cylinder; a reversible pump; first and second hydraulic passages; a reservoir tank; a first supply passage arranged to supply the hydraulic fluid through the reversible pump to the second hydraulic passage; a first one-way valve provided in the first supply passage; a second supply passage arranged to supply the hydraulic fluid through the reversible pump to the first hydraulic passage; and a second one-way valve provided in the second supply passage. A Reynolds number of a flow in the first one-way valve is equal to or smaller than 2300 when a flow rate per unit time of the flow in the first one-way valve is maximum. A Reynolds number of a flow in the second one-way valve is equal to or smaller than 2300 when a flow rate per unit time of the flow in the second one-way valve is maximum.
    Type: Application
    Filed: November 12, 2008
    Publication date: May 14, 2009
    Inventors: Masakazu KURATA, Toshimitsu Sakaki, Mitsuo Sasaki, Tamotsu Yamaura, Mitsuaki Nakada, Kohei Ono, Eiji Kasai, Takatoshi Saito
  • Publication number: 20090038876
    Abstract: A steering system, comprising: an input cylinder having a first hydraulic chamber and a second hydraulic chamber; a transmission mechanism, wherein a transmission efficiency for converting and transmitting a linear motion of the input cylinder to a rotary motion of a steering wheel is less than a transmission efficiency for converting and transmitting the rotary motion of the steering wheel to the linear motion of the input cylinder; an output cylinder connected to a steerable vehicle wheel and having a third hydraulic chamber and a fourth hydraulic chamber; a first hydraulic passage for connecting the first hydraulic chamber to the third hydraulic chamber; a second hydraulic passage for connecting the second hydraulic chamber to the fourth hydraulic chamber; a flow rate control mechanism for exchanging hydraulic oil with: a first hydraulic circuit including the first and third hydraulic chambers and the first hydraulic passage; and a second hydraulic circuit including the second and fourth hydraulic chambers
    Type: Application
    Filed: October 11, 2007
    Publication date: February 12, 2009
    Applicant: Hitachi, Ltd.
    Inventors: Takahiro ITO, Atsushi Yokoyama, Mitsuo Sasaki
  • Publication number: 20080265809
    Abstract: A motor control apparatus which controls an output voltage reference for an inverter driving a permanent magnet synchronous motor based on d-axis and q-axis current references, d-axis and q-axis current detected values, and a computed frequency value. When a torque reference specifying torque greater than maximum torque that the motor can output is input, a limit value for a phase angle that is a deviation between a rotation phase reference of control and a rotation phase value of the motor is varied depending on a quantity of the predetermined state.
    Type: Application
    Filed: April 24, 2008
    Publication date: October 30, 2008
    Inventors: Kentaro Ol, Kazuaki Tobari, Yoshitaka Iwaji, Mitsuo Sasaki, Tatsuo Matsumura
  • Publication number: 20080145259
    Abstract: An oil pump including a first housing having a rotation shaft insertion hole, a cam ring, a pump element, a rotation shaft rotatably extending through the rotation shaft insertion hole, a second housing disposed on the cam ring, wherein the cam ring is placed in a position relative to the rotation shaft insertion hole of the first housing by using a jig, and the cam ring includes a clamped portion that is clamped by a cam ring holding device, while the first housing and the second housing are fixed to each other after placing the cam ring in the position relative to the rotation shaft insertion hole by using the jig. Alternatively, the oil pump including a fixing means for fixing the cam ring to the pump body instead of the clamped portion.
    Type: Application
    Filed: December 12, 2007
    Publication date: June 19, 2008
    Applicant: Hitachi, Ltd.
    Inventors: Yasuhito NAKAKUKI, Kaname Kidokoro, Tetsuo Abe, Toshimitsu Sakaki, Mitsuo Sasaki, Masakazu Kurata
  • Publication number: 20080116740
    Abstract: A brake system that provides a good pedal feel, that assists stepping force of a driver by a small motor, and that can control braking force of wheels individually. The brake system comprises a first actuator (5) for increasing a liquid pressure in a master cylinder (2) by driving torque of a motor (51), and a second actuator (6) capable of driving a brake generating mechanism (3) without transmitting power to the master cylinder (2), wherein the actuators (5, 6) to be driven are switched depending on the operation of a brake pedal (1). The first and second actuators (5, 6) are connected to hydraulic piping (4f, 4r), and a pressurized oil is supplied to the brake generating mechanism (3) through hydraulic valve means (63f, 63r, . . . 65rr).
    Type: Application
    Filed: October 29, 2004
    Publication date: May 22, 2008
    Applicant: Hitachi, Lld.
    Inventors: Atsushi Yokoyama, Taisetsu Tanimichi, Satoru Kuragaki, Yukihiro Osawa, Jun Kubo, Yukihiko Inoue, Katsuya Iwasaki, Mitsuo Sasaki, Tsutomu Hibi
  • Publication number: 20080006469
    Abstract: A steering system includes a hydraulic power cylinder 5 that assists a steering force of a rack-and-pinion mechanism 4, and a first hydraulic pressure supply mechanism 8 having a first trochoid pump 23 selectively supplying hydraulic pressure to two hydraulic pressure chambers 15a and 15b of the hydraulic power cylinder via first and second fluid passages 6 and 7, and a first electric motor 24 for the first trochoid pump. When the first hydraulic pressure supply mechanism becomes failed, a second hydraulic pressure supply mechanism 11 is operated responsively to a command signal from a control unit 14 to selectively supply hydraulic pressure via third and fourth fluid passages to either one of the hydraulic pressure chambers. Thus, it is possible to positively apply a steering assist force by means of the second hydraulic pressure supply mechanism 11, thereby reducing a driver's operating force applied to a steering wheel.
    Type: Application
    Filed: August 9, 2004
    Publication date: January 10, 2008
    Inventors: Mitsuo Sasaki, Tadaharu Yokota, Toshimitsu Sakaki, Michiya Hiramoto
  • Publication number: 20070253855
    Abstract: In order to realize cost reduction in a gear pump apparatus by reducing form accuracy of a gear while securing pump performance, a running-in coating is provided on a tooth sliding contact portion when forming a confinement area in at least one of gears of the gear pump apparatus. By this feature, the running-in coating is gradually worn away and deformed according to rotary drive of the pump, and thus it is possible to obtain an optimal gear form in meshing combinations of the gears. Further, it is possible to reduce leakage inside the pump to secure the pump performance even if the form accuracy of the gear is reduced for the sake of the cost reduction.
    Type: Application
    Filed: March 9, 2007
    Publication date: November 1, 2007
    Applicant: Hitachi, Ltd.
    Inventors: Isamu TSUBONO, Mitsuo Sasaki, Toru Takahashi, Masaaki Busujima, Masakazu Kurata, Yasuhito Nakakuki
  • Publication number: 20070209859
    Abstract: In a power steering system comprising a power cylinder for assisting a steering power of a steering mechanism, a hydraulic pump for supplying a hydraulic pressure to the power cylinder, a first oil passage and a second oil passage connecting the power cylinder and the hydraulic pump respectively, a motor for driving the hydraulic pump, and power steering control means for calculating a command value to the motor based on the steering torque, a flow rate of the working oil supplied from a high-pressure side oil passage to a low-pressure side oil passage is restrained at the transition from the end of the steering state (lock end) of the steering mechanism to the returning. The flow-rate restraint increasingly corrects a driving current of the motor in the steering direction or limits the flow rate of the working oil.
    Type: Application
    Filed: January 18, 2007
    Publication date: September 13, 2007
    Applicant: Hitachi, Ltd.
    Inventors: Ayumu Miyajima, Isamu Tsubono, Takaomi Nishigaito, Toru Takahashi, Mitsuo Sasaki, Toshimitsu Sakaki, Tatsuo Matsumura
  • Patent number: 7174988
    Abstract: A power steering system includes a reversible-type oil pump supplying hydraulic fluid to first and second pressure chambers of a hydraulic power cylinder through first and second passages and having first and second discharge ports, and a branch passage conveying part of hydraulic fluid discharged from the discharge ports of the oil pump to the outside of the pressure chambers of the power cylinder, wherein the branch passage has a passage sectional area greater than a total leak sectional area of the oil pump.
    Type: Grant
    Filed: July 28, 2004
    Date of Patent: February 13, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Mitsuo Sasaki, Yuji Torizawa
  • Publication number: 20070028606
    Abstract: In a power-cylinder equipped power steering device, under a first condition where a first directional control valve disposed in a first pressure line receives fluid pressure supplied into a second pressure line by a reversible pump, the first directional control valve intercommunicates a reservoir and a first-pressure-line downstream passage section, and blocks fluid communication of the first-pressure-line upstream and downstream passage sections. Under a second condition where a second directional control valve receives fluid pressure supplied into the first pressure line by the pump, the first directional control valve intercommunicates the first-pressure-line upstream and downstream passage sections. Under the second condition, the second directional control valve intercommunicates the reservoir and the second-pressure-line downstream passage section, and blocks fluid communication of the second-pressure-line upstream and downstream passage sections.
    Type: Application
    Filed: July 27, 2006
    Publication date: February 8, 2007
    Inventors: Masaki Misunou, Masakazu Kurata, Mitsuo Sasaki, Masaaki Busujima, Yoshimori Kondo
  • Publication number: 20070032937
    Abstract: In vehicular driving control apparatus and method, a steering assistance force provided for steerable road wheels of the vehicle in a direction at which a sideslip angle is decreased when a vehicular sideslip angle which is a difference between a forwarding direction of the vehicle and a steering direction of a steering wheel of the vehicle is detected and a vehicular oversteer state is detected, and thereafter, each of road wheels of the vehicle is controlled to decrease the sideslip angle when the steering assistance force is provided in a direction at which the vehicular sideslip angle is decreased and when the sideslip angle is equal to or larger than a predetermined value.
    Type: Application
    Filed: July 19, 2006
    Publication date: February 8, 2007
    Inventors: Naoshi Yamaguchi, Mitsuo Sasaki, Kazuya Yamano, Toru Takahashi, Motohiro Higuma
  • Publication number: 20060237256
    Abstract: A power steering apparatus includes a hydraulic power cylinder, and a reversible pump driven by a motor and connected by left and right fluid passages with left and right pressure chambers of the power cylinder. The first and second fluid passages are so arranged that pressure losses in the first and second passages are substantially equal to each other.
    Type: Application
    Filed: April 10, 2006
    Publication date: October 26, 2006
    Inventors: Mitsuo Sasaki, Toru Takahashi
  • Publication number: 20060185296
    Abstract: A prefabricated solid structure provided with a frame including struts arranged in a rectangular shape as viewed on a plane, side beams and upper side beams horizontally extending to couple the struts together, and inner side beams coupling the side beams. The frame is constituted by detachably fastening the struts, side beams and upper side beams, and side beams and inner side beams together all by using bolts and internally threaded members.
    Type: Application
    Filed: April 8, 2004
    Publication date: August 24, 2006
    Inventor: Mitsuo Sasaki
  • Patent number: 6990136
    Abstract: A laser beam transmission apparatus comprises a light-incidence optical system (22) converging and focusing a laser beam emitted from a solid-state laser apparatus (1), and an optical fiber (8) which transmits the laser beam that has been converged and focused by the light-incidence optical system. The light-incidence optical system (22) has at least first and second lenses (13, 14) disposed on the same optical path. A first distance (a) between an output end of the solid-state laser apparatus and the first lens or a second distance (b) between the second lens and a light-incidence end of the optical fiber is freely set according to a relational formula based on a focal distance (f1, f2) of each of the first and second lenses.
    Type: Grant
    Filed: September 5, 2002
    Date of Patent: January 24, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yasuhiro Akiyama, Naotada Okada, Mitsuo Sasaki, Takashi Obara
  • Patent number: 6941779
    Abstract: In a steerage locking system for a vehicle, including a control knob mounted to a rotor capable of being turned from a LOCK position via an ACC position and an ON position to a START position, the control knob is detachably fastened to a front end of the rotor by a screw member from axially outside the rotor. Thus, the maintenance such as exchange of the control knob is facilitated.
    Type: Grant
    Filed: July 29, 2003
    Date of Patent: September 13, 2005
    Assignees: Kabushiki Kaisha Honda Lock, Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Katsuyoshi Shigeyama, Takeshi Taniguchi, Mitsuo Sasaki, Kentaro Yoshimura, Tomoaki Nakai, Kenichi Takizawa, Masashi Suzuki
  • Publication number: 20050023073
    Abstract: A power steering system includes a reversible-type oil pump supplying hydraulic fluid to first and second pressure chambers of a hydraulic power cylinder through first and second passages and having first and second discharge ports, and a branch passage conveying part of hydraulic fluid discharged from the discharge ports of the oil pump to the outside of the pressure chambers of the power cylinder, wherein the branch passage has a passage sectional area greater than a total leak sectional area of the oil pump.
    Type: Application
    Filed: July 28, 2004
    Publication date: February 3, 2005
    Inventors: Mitsuo Sasaki, Yuji Torizawa