Patents by Inventor Mitsuaki Hirakawa

Mitsuaki Hirakawa 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: 20090289751
    Abstract: A composite transformer, having first and second inductors and a transformer, includes a transformer core that has a core leg around which portions of first and second windings are wound, and a base fixing the core leg, a first inductor core that has a core leg around which a portion of the first winding is wound and a base fixing the core leg, and a second inductor core that has a core leg around which a portion of the second winding is wound and a base fixing the core leg. The first and second windings are wound in a manner that flux are cancelled with each other, and are wound around the core leg of the transformer core in a manner alternately overlapping with each other, and are wound around respective core legs of the first and second inductor cores so as to be apart from each other to suppress any interference of magnetic fluxes.
    Type: Application
    Filed: May 22, 2009
    Publication date: November 26, 2009
    Inventors: Masao Nagano, Mitsuaki Hirakawa
  • Publication number: 20090289589
    Abstract: A power supply system includes a fuel cell, a capacitor connected in parallel to the fuel cell, a voltage boost means for boosting output voltages from the fuel cell and the capacitor to supply the electric motor with electric power resulting from the boosted voltages, a voltage control means for further boosting an output voltage from the voltage boost means, a secondary battery connected to the voltage control means, an external power source connecting means connected to the one end of the voltage boost means and in parallel with the fuel cell and for receiving supply of electric power from an external power source, and an electronic control unit which charges the secondary battery from the external power source by controlling step-up ratios of the voltage boost means and the voltage control means such that a voltage applied to the secondary battery during the charging becomes a desired voltage.
    Type: Application
    Filed: May 19, 2009
    Publication date: November 26, 2009
    Inventors: Takeshi Fujino, Minoru Noguchi, Eisuke Komazawa, Mitsuaki Hirakawa
  • Publication number: 20090267718
    Abstract: A magnetic-filed cancellation type transformer includes a primary winding wire and a secondary winding wire which generate magnetic flux when energized, and a core constituted by a magnetic leg portion about which the primary winding wire and the secondary winding wire are wound, and a base for fixing the magnetic leg portion. The primary winding wire and the secondary winding wire are alternately piled and wound on the magnetic leg portion, so that the direction of magnetic flux generated from the primary winding wire and the secondary winding wire are opposite to each other in any couple selected from among the pieces of magnetic flux, and the magnetic flux is cancelled out with each other.
    Type: Application
    Filed: April 22, 2009
    Publication date: October 29, 2009
    Inventors: Masao Nagano, Mitsuaki Hirakawa
  • Patent number: 7602165
    Abstract: A phase control device for use with a voltage-boosting DC/DC converter includes a current sensor for detecting a current flowing through at least one of the primary and secondary windings of a transformer of the DC/DC converter, a ripple determining section for, on the basis of a current signal detected by the current sensor, determining an amount of current ripple occurring when a first switching element or second switching element switches to an ON state, and a phase regulating section for, on the basis of the amount of current ripple determined by the ripple determining section, regulating a phase related to an ON time of each of the first and second switching elements such that the amount of current ripple is reduced to zero.
    Type: Grant
    Filed: August 8, 2007
    Date of Patent: October 13, 2009
    Assignee: Honda Motor Co., Ltd.
    Inventors: Yasuto Watanabe, Mitsuaki Hirakawa, Keigo Andou
  • Patent number: 7583064
    Abstract: A booster circuit according to an embodiment of the present invention comprises: an input terminal; an output terminal; a common terminal; a transformation unit including first, the second, and the third windings, the windings wound in the same direction and connected in series; a first rectifier unit provided between the input terminal and a connection point of the first and the second windings; a second rectifier unit provided between the input terminal and a connection point of the second and the third windings; a first switching unit provided between one end of the transformation unit and the common terminal; a second switching unit provided between other end of the transformation unit and the common terminal; a third rectifier unit provided between a connection point of one end of the transformation unit and the first switching element and the output terminal; and a fourth rectifier unit provided between a connection point of other end of the transformation unit and the second switching element and the o
    Type: Grant
    Filed: March 28, 2007
    Date of Patent: September 1, 2009
    Assignee: Honda Motor Co., Ltd.
    Inventors: Kouya Kimura, Masao Nagano, Mitsuaki Hirakawa
  • Publication number: 20090191451
    Abstract: A battery assembling body capable of preventing a temperature rise of a battery while preventing an inflow of foreign matters. The battery assembling body (12) includes a housing (15) which contains batteries (2a, 2b, 6), a side frame (17) which is used to detachably fit the housing (15) to a lower frame of a vehicle, a ventilation hole (18c) located upper part of the housing (15), and a ventilation space (24a, 24b) which is formed between the housing (15) and the batteries, and the ventilation space (24, 24b) is in communication with the ventilation hole (18c).
    Type: Application
    Filed: January 22, 2009
    Publication date: July 30, 2009
    Inventors: Kazuo Sato, Eisuke Komazawa, Takeshi Fujino, Mitsuaki Hirakawa
  • Publication number: 20090186247
    Abstract: A fuel cell power supply includes a fuel cell voltage detection means which detects a terminal-to-terminal voltage of the fuel cell; an internal resistance calculation means which supplies electric power from a battery to a motor via a second DC-DC converter and calculates a resistance value of an internal resistance of the fuel cell on the basis of a detection voltage of the fuel cell in a state where a current output of the fuel cell is stopped, a detection voltage of a terminal-to-terminal voltage of the fuel cell in a state where the output current of the fuel cell is adjusted to a value, and the value; and a deterioration level determination means which determines a deterioration level of the fuel cell on the basis of a change in the resistance value of the internal resistance of the fuel cell.
    Type: Application
    Filed: January 21, 2009
    Publication date: July 23, 2009
    Inventors: Mitsuaki Hirakawa, Minoru Noguchi
  • Publication number: 20090180305
    Abstract: A multi-parallel magnetic-filed cancellation type transformer includes a plurality of coils which generate magnetic flux during energization and a core having a plurality of magnetic leg portions on which the coils are wound, and bases for fixing the magnetic leg portions. The plurality of coils are wound on the magnetic leg portions in such a manner that the magnetic flux generated from the coils are formed in the directions opposite to each other. A plurality of closed magnetic circuits of the magnetic flux are formed at the magnetic leg portions and the bases. The magnetic resistance of the closed magnetic circuits is homogeneous. Accordingly, the transformer can reduce the size thereof, and prevent the deterioration of electric power conversion efficiency.
    Type: Application
    Filed: January 16, 2009
    Publication date: July 16, 2009
    Inventors: Satoshi Hashino, Masao Nagano, Mitsuaki Hirakawa
  • Publication number: 20090146493
    Abstract: A vehicle power supply device which prevents a lack of power supply to the motor and insufficient recovery of regenerative electric power of the motor at the time of switching between power running and regeneration. First input-output sections (3a, 3b) of a first DC-DC converter (3) are connected to second input-output sections (4d, 4e) of a PDU (4), second input-output sections (3c, 3d) of the first DC-DC converter (3) are connected to a fuel cell (1) and a capacitor (2), first input-output sections (20a, 20b) of a second DC-DC converter (20) are connected to second input-output sections (4d, 4e) of the PDU (4), and second input-output sections (20c, 20d) of the second DC-DC converter (20) are connected to a lithium-ion battery (21).
    Type: Application
    Filed: December 5, 2008
    Publication date: June 11, 2009
    Inventors: Takeshi Fujino, Minoru Noguchi, Eisuke Komazawa, Mitsuaki Hirakawa
  • Publication number: 20090142634
    Abstract: It is an object of the present invention to provide a fuel cell power supply device that can realize a reduction in size and improvement of durability of an accumulating unit while maintaining output performance that is applicable when large output is requested.
    Type: Application
    Filed: November 26, 2008
    Publication date: June 4, 2009
    Inventors: Takeshi Fujino, Minoru Noguchi, Eisuke Komazawa, Mitsuaki Hirakawa
  • Publication number: 20090133943
    Abstract: It is an object of the present invention to provide a vehicle that can efficiently cool or heat a group of the components, in view of appropriate operating temperature ranges of respective components configuring a fuel cell power supply system, while realizing saving of a mounting space in the vehicle and cost of the vehicle. A vehicle 11 mounted with a fuel cell power supply system includes at least a fuel cell 1, an accumulating unit 12 including a capacitor 2 and a secondary battery 6 connected to the fuel cell 1, a motor 5 serving as a power source for the vehicle 11 to which output sections of the fuel cell 1 and the accumulating unit 12 are connected, and a PDU 4 provided between the output sections and the motor 5, wherein a component group of the power supply system including the fuel cell 1, the accumulating unit 12, and the PDU is arranged so as to be cooled by a cooling medium which flows inside the vehicle 11, in order from one having a smallest heating generation amount.
    Type: Application
    Filed: November 25, 2008
    Publication date: May 28, 2009
    Inventors: Minoru Noguchi, Mitsuaki Hirakawa, Takeshi Fujino, Eisuke Komazawa
  • Patent number: 7504811
    Abstract: A boost DC/DC includes an inductor connected at one end to the positive-pole terminal of a low-voltage-side port, a transformer of a magnetic-field cancellation type including a primary winding and a secondary winding interconnected in an oppositely-wound configuration, a common terminal of the primary winding and the secondary winding being connected to another end of the inductor. A switching element controls an energizing current of the primary winding flowing to a common reference terminal, and another switching element controls an energizing current of the secondary winding flowing to the common reference terminal. A diode allows current to flow in only one direction from the primary winding to the positive-pole terminal of a high-voltage-side port, and another diode allows current to flow in only one direction from the secondary winding to the positive-pole terminal of the high-voltage-side port.
    Type: Grant
    Filed: October 16, 2007
    Date of Patent: March 17, 2009
    Assignee: Honda Motor Co., Ltd.
    Inventors: Yasuto Watanabe, Mitsuaki Hirakawa
  • Publication number: 20090039839
    Abstract: A fuel cell power supply device capable of externally supplying electric power in a stable manner is provided.
    Type: Application
    Filed: August 6, 2008
    Publication date: February 12, 2009
    Inventors: Minoru Noguchi, Mitsuaki Hirakawa, Takeshi Fujino, Eisuke Komazawa
  • Publication number: 20090039815
    Abstract: A power supply device for vehicles, output units (10a, 10b) thereof are connected to a motor (5), includes a fuel cell (1) which is connected to the output units (10a, 10b), a capacitor (2) which is connected in parallel to the fuel cell (1), a lithium ion battery (21) which is connected in parallel to the capacitor (2) through a DC/DC converter (20), and a current control means (32) which limits an output current of the lithium ion battery (21) to at most an output upper-limit current (Ibout_lmt) when power is supplied to the motor (5) from the lithium ion battery (21) during a power running operation of the motor (5), and limits an input current into the lithium ion battery (21) to at most an input upper-limit current smaller than the output upper-limit current (Ibin_lmt) through the DC/DC converter (20) when regenerative power of the motor (5) is recovered into the lithium ion battery (21) during a regenerative operation of the motor (5).
    Type: Application
    Filed: July 31, 2008
    Publication date: February 12, 2009
    Inventors: Takeshi Fujino, Mitsuaki Hirakawa, Minoru Noguchi, Eisuke Komazawa
  • Publication number: 20080297126
    Abstract: Combined type transformer includes: a transformer core; first and second coils provided with respect to the transformer core; first and second inductor cores provided around the first coil; and third and fourth inductor cores provided around the second coil. The transformer core and the first and second coils constitute a transformer, the first coil and the first and second inductor cores constitute a first inductor, and the second coil and the third and fourth inductor cores constitute a second inductor.
    Type: Application
    Filed: February 5, 2008
    Publication date: December 4, 2008
    Inventors: Masao Nagano, Mitsuaki Hirakawa, Toshihisa Shimizu
  • Publication number: 20080238383
    Abstract: The DC/DC converter is that which is constituted so as to have a failure detecting circuit in which a first capacitor and a second capacitor are connected in series, a plurality of switches are switched according to a predetermined operating mode to select an inductor, the first capacitor and the second capacitor, allowing them to function, thereby performing any one of the boost, buck, and conducting operations of input voltage.
    Type: Application
    Filed: March 19, 2008
    Publication date: October 2, 2008
    Inventors: Yasuto Watanabe, Mitsuaki Hirakawa
  • Publication number: 20080230290
    Abstract: A vehicle suitable in consideration of each of an electric power supply amount to a motor and a mounting space of a fuel cell or the like is provided. The outputs of a fuel cell (11) and a battery (12) are raised in voltage by a voltage raising device (13), and electric power of these raised voltages is supplied to a motor (15). Therefore, a total output voltage of the fuel cell (11) and the battery (12), and thus, their total volume can be correspondingly reduced. Namely, it is possible to reduce the total volume of a designated article group including the fuel cell (11), the battery (12) and the voltage raising device (13), and thus, a mounting space of the designated article group in the vehicle (1). Further, a space of a frame (22) arranged on the upper side of a floor panel (20) and the lower side of a seat (24) in a vehicle interior space can be utilized effectively as the mounting space of the designated article group as it is without enlarging this space of the frame.
    Type: Application
    Filed: March 20, 2008
    Publication date: September 25, 2008
    Inventors: Mitsuaki Hirakawa, Takeshi Fujino, Minoru Noguchi, Eisuke Komazawa
  • Publication number: 20080211316
    Abstract: The invention provides an optimal electric power converter for a DC/DC converter which variably steps up a voltage successively with an optional magnification of one to two times or more and/or step down a voltage successively with a step-down ratio of one time or less. The converter includes a first input-output part, an inductor connected with a positive or a negative electrode side of the first input-output part, plural switches, plural capacitors, a second input-output part connected with plural capacitors, and a control circuit, wherein the control circuit controls the plural switches with operation mode and makes the inductor and plural capacitors selectively functional, wherein the electric power converter is of a switched capacitance type that performs any operation out of step-up, step-down, regeneration, and continuity, and wherein the control circuit controls to have a period for which two switches out of the plural switches are simultaneously turned ON.
    Type: Application
    Filed: November 30, 2007
    Publication date: September 4, 2008
    Applicant: HONDA MOTOR CO., LTD.
    Inventors: Yasuto Watanabe, Mitsuaki Hirakawa, Satoshi Hashino
  • Patent number: 7400116
    Abstract: When a control means turns on a pre-charging contactor, an AC current from an AC power source is converted into a DC current by a switching circuit to charge a smoothing capacitor. However, the smoothing capacitor cannot be charged completely due to the operation of a capacitor of an LC filter. Therefore, when the voltage of the smoothing capacitor detected by a voltage detecting means exceeds a predetermined value, the smoothing capacitor is further charged by bringing the switching circuit into a boosting operation. Thus, even if an LC relay required in the prior art for invalidating the capacitor of the LC filter is not provided, it is possible to completely charge the smoothing capacitor, thereby providing a decrease in the number of parts and an enhancement in reliability of the pre-charging circuit, and preventing a reduction in performance of the LC filter due to a loss in the LC relay.
    Type: Grant
    Filed: March 21, 2005
    Date of Patent: July 15, 2008
    Assignee: Honda Motor Co., Ltd.
    Inventors: Takeshi Kato, Yoshiki Tatsutomi, Mitsuaki Hirakawa
  • Patent number: 7388353
    Abstract: In discharging a smoothing capacitor connected to DC sides of first and second switching circuits, a DC-DC converter is first turned on to charge a battery for an auxiliary, thereby discharging the smoothing capacitor. Therefore, an electric charge of the smoothing capacitor can be effectively utilized to the maximum. When the voltage of the smoothing capacitor detected by a voltage detector is reduced to a predetermined value or less, and as a result the DC-DC converter is brought into an inoperable state, electric charge of the smoothing capacitor is consumed by at least one of a motor/generator and an LC filter connected to AC sides of the first and second switching circuits by driving at least one of the first and second switching circuits. Therefore, the smoothing capacitor can be completely discharged without need for a special discharging circuit.
    Type: Grant
    Filed: March 21, 2005
    Date of Patent: June 17, 2008
    Assignee: Honda Motor Co., Ltd.
    Inventors: Takeshi Kato, Yoshiki Tatsutomi, Mitsuaki Hirakawa