Patents by Inventor Takato Ogiwara

Takato Ogiwara 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: 9056601
    Abstract: A controller controls a hydraulic control device to generate a target braking force corresponding to the stroke of a brake pedal by adjusting a controlled hydraulic braking force portion generated by the hydraulic control device on the basis of the relationship with a master hydraulic braking force portion generated from the brake hydraulic pressure in a master cylinder and a regenerative braking force portion generated by a regenerative brake device. The regenerative brake device maximizes the regenerative braking force portion before the stroke of the brake pedal reaches an idle stroke, and thereafter, the hydraulic control device 5 starts braking by the controlled hydraulic braking force portion. When the stroke of the brake pedal reaches the idle stroke, the master cylinder starts braking by the master hydraulic braking force portion.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: June 16, 2015
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Takato Ogiwara, Mitsuhiro Endo, Naganori Koshimizu
  • Patent number: 8807668
    Abstract: Provided are a vehicle braking system and a master cylinder which are capable of providing a good pedal feel. A valve-opening pressure for a pressure-reducing valve of the master cylinder is set higher than a hydraulic pressure which is obtained with a pressing force on a brake pedal being 500 N and lower than a hydraulic pressure obtained at a time when a booster reaches a full-load point in case of failure of the booster so as to be specialized for improving pedal feel. Required performance in case of failure of the booster is realized by a pressure-intensifying unit.
    Type: Grant
    Filed: March 24, 2010
    Date of Patent: August 19, 2014
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Naganori Koshimizu, Takato Ogiwara
  • Patent number: 8578711
    Abstract: A master cylinder includes a cylinder body which an operating fluid is introduced from a reservoir, a piston which is slidably fitted in the cylinder body and defines a pressure chamber inside the cylinder body, a supply pathway which is formed in the cylinder body and supplies the operating fluid from the reservoir to the pressure chamber, a bypass pathway which bypasses the supply pathway and allows the reservoir to communicate with the pressure chamber, and a check valve which is installed in the bypass pathway and opens a valve when the pressure inside the pressure chamber is lower than the pressure of the reservoir.
    Type: Grant
    Filed: August 27, 2010
    Date of Patent: November 12, 2013
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Ryoichi Yagi, Naganori Koshimizu, Takato Ogiwara
  • Publication number: 20130257140
    Abstract: A controller controls a hydraulic control device to generate a target braking force corresponding to the stroke of a brake pedal by adjusting a controlled hydraulic braking force portion generated by the hydraulic control device on the basis of the relationship with a master hydraulic braking force portion generated from the brake hydraulic pressure in a master cylinder and a regenerative braking force portion generated by a regenerative brake device. The regenerative brake device maximizes the regenerative braking force portion before the stroke of the brake pedal reaches an idle stroke, and thereafter, the hydraulic control device 5 starts braking by the controlled hydraulic braking force portion. When the stroke of the brake pedal reaches the idle stroke, the master cylinder starts braking by the master hydraulic braking force portion.
    Type: Application
    Filed: March 15, 2013
    Publication date: October 3, 2013
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Takato OGIWARA, Mitsuhiro ENDO, Naganori KOSHIMIZU
  • Patent number: 8347622
    Abstract: A master cylinder includes a bottomed cylindrical cylinder body, a piston formed into a bottomed cylindrical shape by a forging method and slidably disposed in the cylinder body, and a spring assembly including a spring urging the piston toward an opening side of the cylinder body. A length of a spring of the spring assembly is determined by a retainer which can abut against an inner bottom portion of the piston. An annular groove is formed on the outermost side of the inner bottom portion of the piston by the forging method.
    Type: Grant
    Filed: March 23, 2009
    Date of Patent: January 8, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Takato Ogiwara, Takayuki Kinoshita
  • Patent number: 8286427
    Abstract: In a master cylinder, a supply passage for supplying operating liquid from a reservoir (2) to a pressure chamber (6) is provided in a cylinder body (3) coupled with the reservoir. A bypass passage (37) for bypassing the supply passage and connecting the reservoir and the pressure chamber is further provided, and a check valve (34) adapted to open when a pressure in the pressure chamber is lower than that in the reservoir is disposed in the bypass passage. A valve case (38) containing a valve body (41) of the check valve includes a valve seat (40) and a cylindrical wall (45) for slidably guiding the valve body which are integrally formed as a single member.
    Type: Grant
    Filed: July 25, 2008
    Date of Patent: October 16, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Takato Ogiwara, Takayuki Kinoshita
  • Publication number: 20110048226
    Abstract: A master cylinder includes a cylinder body which an operating fluid is introduced from a reservoir, a piston which is slidably fitted in the cylinder body and defines a pressure chamber inside the cylinder body, a supply pathway which is formed in the cylinder body and supplies the operating fluid from the reservoir to the pressure chamber, a bypass pathway which bypasses the supply pathway and allows the reservoir to communicate with the pressure chamber, and a check valve which is installed in the bypass pathway and opens a valve when the pressure inside the pressure chamber is lower than the pressure of the reservoir.
    Type: Application
    Filed: August 27, 2010
    Publication date: March 3, 2011
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Ryoichi YAGI, Naganori KOSHIMIZU, Takato OGIWARA
  • Publication number: 20100244549
    Abstract: Provided are a vehicle braking system and a master cylinder which are capable of providing a good pedal feel. A valve-opening pressure for a pressure-reducing valve of the master cylinder is set higher than a hydraulic pressure which is obtained with a pressing force on a brake pedal being 500 N and lower than a hydraulic pressure obtained at a time when a booster reaches a full-load point in case of failure of the booster so as to be specialized for improving pedal feel. Required performance in case of failure of the booster is realized by a pressure-intensifying unit.
    Type: Application
    Filed: March 24, 2010
    Publication date: September 30, 2010
    Inventors: Naganori KOSHIMIZU, Takato Ogiwara
  • Patent number: 7694517
    Abstract: A master cylinder designed to facilitate an operation of assembling and adjusting a check valve is provided. A supply passage for supplying operating fluid from a reservoir 2 to a pressure chamber 6 is formed in a cylinder body 3 connected to the reservoir 2. A bypass 37 for bypassing the supply passage connecting the reservoir 2 and the pressure chamber 6 is formed and provided with a check valve system 34 adapted to open when a pressure in the pressure chamber 6 is lower than that in the reservoir 2. A valve case 38 and a covering member 32 constitute a cartridge 39, which accommodates a valve body 41 and an urging spring 42, so as to form a check valve system 34. The cartridge 39 is placed in a valve chamber 33 of the bypass 37.
    Type: Grant
    Filed: August 28, 2007
    Date of Patent: April 13, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Takato Ogiwara, Takayuki Kinoshita, Naganori Koshimizu, Tomonori Mouri
  • Publication number: 20090241768
    Abstract: A master cylinder comprises a bottomed cylindrical cylinder body, a piston formed into a bottomed cylindrical shape by the forging method and slidably disposed in the cylinder body, and a spring assembly comprising a spring urging the piston toward an opening side of the cylinder body. A length of a spring of the spring assembly is determined by a retainer which can abut against an inner bottom portion of the piston. An annular groove is formed on the most outer side of the inner bottom portion of the piston by the forging method.
    Type: Application
    Filed: March 23, 2009
    Publication date: October 1, 2009
    Inventors: Takato Ogiwara, Takayuki Kinoshita
  • Patent number: 7516617
    Abstract: A master cylinder including a cylinder body having a tubular shape with a closed end; and a piston having one side slidably inserted into the cylinder body and another side that projects from the cylinder body. The piston and the cylinder body define a pressure chamber for generating hydraulic pressure. The master cylinder also includes a protecting member for covering the side of the piston projects from the cylinder body. The protecting member is adapted to extend and contract, and limit backward movement of the piston.
    Type: Grant
    Filed: November 28, 2006
    Date of Patent: April 14, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Yasutoshi Nagatsuyu, Tomonori Mouri, Takato Ogiwara, Naganori Koshimizu
  • Publication number: 20090025385
    Abstract: An object of the present invention is to make it possible to easily improve precision with which the valve body is seated on the valve seat of the check valve, and provide a master cylinder which can be easily manufactured and in which high precision is realized. In a master cylinder, a supply passage for supplying operating liquid from a reservoir 2 to a pressure chamber 6 is provided in a cylinder body 3 coupled with the reservoir 2. A bypass passage 37 for bypassing the supply passage and connecting the reservoir 2 and the pressure chamber 6 is further provided, and a check valve 34 adapted to open when a pressure in the pressure chamber 6 is lower than that in the reservoir 2 is disposed in the bypass passage 37. A valve case 38 containing a valve body 41 of the check valve 34 comprises a valve seat 40 which the valve body 41 is seated on and moves away from, and a cylindrical wall 45 for slidably guiding the valve body 41 which are integrally formed as a single member.
    Type: Application
    Filed: July 25, 2008
    Publication date: January 29, 2009
    Inventors: Takato Ogiwara, Takayuki Kinoshita
  • Publication number: 20080173015
    Abstract: A master cylinder designed to facilitate an operation of assembling and adjusting a check valve is provided. A supply passage for supplying operating fluid from a reservoir 2 to a pressure chamber 6 is formed in a cylinder body 3 connected to the reservoir 2. A bypass 37 for bypassing the supply passage connecting the reservoir 2 and the pressure chamber 6 is formed and provided with a check valve system 34 adapted to open when a pressure in the pressure chamber 6 is lower than that in the reservoir 2. A valve case 38 and a covering member 32 constitute a cartridge 39, which accommodates a valve body 41 and an urging spring 42, so as to form a check valve system 34. The cartridge 39 is placed in a valve chamber 33 of the bypass 37.
    Type: Application
    Filed: August 28, 2007
    Publication date: July 24, 2008
    Inventors: Takato Ogiwara, Takayuki Kinoshita, Naganori Koshimizu, Tomonori Mouri
  • Publication number: 20070119167
    Abstract: A master cylinder comprising: a cylinder body having a tubular shape with a closed end; a piston having one side thereof slidably inserted into the cylinder body and another side thereof projecting from the cylinder body, the piston and the cylinder body defining a pressure chamber for generating hydraulic pressure; and a protecting member for covering said another side of the piston projecting from the cylinder body, the protecting member being adapted to extend and contract, and limit a backward movement of the piston.
    Type: Application
    Filed: November 28, 2006
    Publication date: May 31, 2007
    Inventors: Yasutoshi Nagatsuyu, Tomonori Mouri, Takato Ogiwara, Naganori Koshimizu
  • Patent number: 7032982
    Abstract: A master cylinder apparatus for a BBW system is provided, which enables accurate detection of a piston stroke without substantial increase in the size of a master cylinder. A master cylinder apparatus includes a master cylinder adapted to be connected to wheel cylinders through fail-safe valves, a stroke simulator for ensuring a desired stroke of a brake pedal upon receiving a brake fluid introduced from a fluid pressure chamber in the master cylinder through a simulator passage, and an opening/closing device for opening and closing the simulator passage. A stroke sensor for detecting a stroke of a primary piston is formed by a rotation angle detector, a sensor arm having one end connected to a rotary shaft of the rotation angle detector and a sensor pin extending from the primary piston. Linear motion of the primary piston is converted to rotational motion through engagement between the sensor pin and the sensor arm and is transmitted to the rotation angle detector.
    Type: Grant
    Filed: August 25, 2004
    Date of Patent: April 25, 2006
    Assignee: Kabushiki Kaisha Hitachi Seisakusho
    Inventors: Takato Ogiwara, Toshio Takayama
  • Patent number: 7003952
    Abstract: A master cylinder has a cylinder member in the shape of a cylinder, one end of which is closed, and a piston inserted in the cylinder member to form a pressure chamber in the cylinder member. The cylinder member is formed with a port for providing communication between the pressure chamber and a reservoir. The port is formed during casting of the cylinder member, thereby eliminating the need to form the port by boring, and forming the port into an elongated-hole shaped sectional configuration.
    Type: Grant
    Filed: February 26, 2003
    Date of Patent: February 28, 2006
    Assignee: Kabushiki Kaisha Hitachi Seiksakusho
    Inventors: Tomonori Mouri, Takato Ogiwara, Yasuhiko Amari, Naganori Koshimizu
  • Patent number: 7003954
    Abstract: A master cylinder apparatus for a BBW system is provided, which eliminates a risk of brake delay, even with the use of a plunger-type master cylinder, and which therefore is able to achieve a reduction in size of a master cylinder. The master cylinder apparatus comprises a tandem-type master cylinder connected to wheel cylinders through fail-safe valves and a stroke simulator for ensuring a desired stroke of a brake pedal upon receiving a brake fluid introduced from a fluid pressure chamber in the master cylinder. The master cylinder is arranged in the form of a plunger-type master cylinder in which cup seals are provided on an inner surface of a bore of the cylinder body. A spring force of a second return spring for a secondary piston is set to be larger than that of a first return spring for a primary piston. A retracted position of the secondary piston is limited by a stopper pin extending through an oblong hole formed in the secondary piston.
    Type: Grant
    Filed: August 25, 2004
    Date of Patent: February 28, 2006
    Assignee: Kabushiki Kaisha Hitachi Seisakusho
    Inventors: Takato Ogiwara, Toshio Takayama
  • Publication number: 20050067891
    Abstract: A master cylinder apparatus for a BBW system is provided, which enables a simulator passage for communication between a stroke simulator and a fluid pressure chamber in a master cylinder to be smoothly and reliably closed, without risk of damage to a stop valve provided in the simulator passage, without requiring an increase in size of the master cylinder. The master cylinder apparatus comprises a tandem-type master cylinder including a cylinder body adapted to be connected to wheel cylinders through fail-safe valves and a stroke simulator for ensuring a desired stroke of a brake pedal upon receiving a brake fluid introduced from a first fluid pressure chamber in the master cylinder through a simulator passage. In the event of failure of the BBW system, an opening/closing means closes the simulator passage in accordance with movement of a secondary piston.
    Type: Application
    Filed: August 25, 2004
    Publication date: March 31, 2005
    Inventors: Takato Ogiwara, Toshio Takayama
  • Publication number: 20050067885
    Abstract: A master cylinder apparatus for a BBW system is provided, which enables accurate detection of a piston stroke without substantial increase in the size of a master cylinder. A master cylinder apparatus comprises a master cylinder adapted to be connected to wheel cylinders through fail-safe valves, a stroke simulator for ensuring a desired stroke of a brake pedal upon receiving a brake fluid introduced from a fluid pressure chamber in the master cylinder through a simulator passage, and an opening/closing means for opening and closing the simulator passage. A stroke sensor for detecting a stroke of a primary piston is formed by a rotation angle detector, a sensor arm having one end connected to a rotary shaft of the rotation angle detector and a sensor pin extending from the primary piston. A linear motion of the primary piston is converted to a rotational motion through engagement between the sensor pin and the sensor arm and is transmitted to the rotation angle detector.
    Type: Application
    Filed: August 25, 2004
    Publication date: March 31, 2005
    Inventors: Takato Ogiwara, Toshio Takayama
  • Patent number: RE40573
    Abstract: A master cylinder of the invention supplies a brake fluid from a large diameter pressurizing chamber 56 to a small diameter hydraulic chamber 49 by opening a reverse flow checking opening and closing portion 61 by sliding movement of a stepped piston 16 forwardly, that is, fast fill and when the hydraulic pressure of the large diameter pressurizing chamber 56 rises, a control valve 86 escapes the hydraulic pressure of the large diameter pressurizing chamber 56 to a reservoir 12 to gradually lower in accordance with rise of the hydraulic pressure of the small diameter hydraulic chamber 49, thereby capable of reducing a strange feeling in a pedal feeling caused by sudden pressure release of the large diameter pressurizing chamber 56.
    Type: Grant
    Filed: March 2, 2006
    Date of Patent: November 18, 2008
    Assignee: Kabushiki Kaisha Hitachi Seisakusho
    Inventors: Takato Ogiwara, Kenji Sano, Naganori Koshimizu, Hiromi Ando