Patents by Inventor Tadashi Terazawa

Tadashi Terazawa 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: 7104612
    Abstract: A brake hydraulic pressure generator is proposed which is simple in structure and can suppress fluctuations in the brake pedal operating amount due to fluctuations in the amount of brake fluid consumed in the brake circuit. The brake hydraulic pressure generator includes an input shaft operated by a brake pedal, a stroke simulator for imparting a stroke and a reaction force corresponding to the brake pedal operating amount to the input shaft, a master cylinder for generating brake hydraulic pressure, and a pressure detector member for applying a reaction force corresponding to the hydraulic pressure in the master cylinder to a valve member of the control valve. The reaction force is transmitted through the pressure detector member to the control member. The input to the brake pedal is transmitted to the control valve through the stroke simulator so as to oppose the reaction force. The control valve operates to balance the reaction force and the input.
    Type: Grant
    Filed: July 30, 2004
    Date of Patent: September 12, 2006
    Assignee: Advics Co., Ltd.
    Inventors: Tadashi Terazawa, Yoji Inoue
  • Publication number: 20050023891
    Abstract: A brake hydraulic pressure generator is proposed which is simple in structure and can suppress fluctuations in the brake pedal operating amount due to fluctuations in the amount of brake fluid consumed in the brake circuit. The brake hydraulic pressure generator includes an input shaft operated by a brake pedal, a stroke simulator for imparting a stroke and a reaction force corresponding to the brake pedal operating amount to the input shaft, a master cylinder for generating brake hydraulic pressure, and a pressure detector member for applying a reaction force corresponding to the hydraulic pressure in the master cylinder to a valve member of the control valve. The reaction force is transmitted through the pressure detector member to the control member. The input to the brake pedal is transmitted to the control valve through the stroke simulator so as to oppose the reaction force. The control valve operates to balance the reaction force and the input.
    Type: Application
    Filed: July 30, 2004
    Publication date: February 3, 2005
    Inventors: Tadashi Terazawa, Yoji Inoue
  • Patent number: 6679564
    Abstract: An auxiliary vehicle hydraulic pressure source device includes a hydraulic pressure pump pressurizing and discharging fluid, an accumulator accumulating fluid pressurized and discharged by the hydraulic pressure pump, a hydraulic pressure detector continuously detecting the accumulator hydraulic pressure, and a controller controlling operation of the hydraulic pressure pump based on a comparison of the detection result of the hydraulic pressure detector with a predetermined target pressure.
    Type: Grant
    Filed: December 21, 2001
    Date of Patent: January 20, 2004
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Hirofumi Nitta, Michiharu Nishii, Tadashi Terazawa, Masaki Oishi, Kenichi Suzuki
  • Patent number: 6619762
    Abstract: A hydraulic brake apparatus for a vehicle includes a supplementary hydraulic pressure source outputting a pressurized output hydraulic pressure and an electronic control apparatus that controls a hydraulic pump in the supplementary hydraulic pressure source. The electronic control apparatus judges whether the hydraulic pump satisfies a predetermined operating condition based on the output hydraulic pressure of the supplementary hydraulic pressure source or not. The electronic control apparatus compares the output hydraulic pressure with a minimum standard hydraulic pressure, detects a drop in the output hydraulic pressure when the output hydraulic pressure is less than a standard hydraulic pressure and determines that the hydraulic pump does not satisfy the predetermined operating condition.
    Type: Grant
    Filed: August 30, 2001
    Date of Patent: September 16, 2003
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Hirofumi Nitta, Michiharu Nishii, Tadashi Terazawa, Masaki Oishi
  • Publication number: 20020093243
    Abstract: An auxiliary vehicle hydraulic pressure source device includes a hydraulic pressure pump pressurizing and discharging fluid, an accumulator accumulating fluid pressurized and discharged by the hydraulic pressure pump, a hydraulic pressure detector continuously detecting the accumulator hydraulic pressure, and a controller controlling operation of the hydraulic pressure pump based on a comparison of the detection result of the hydraulic pressure detector with a predetermined target pressure.
    Type: Application
    Filed: December 21, 2001
    Publication date: July 18, 2002
    Inventors: Hirofumi Nitta, Michiharu Nishii, Tadashi Terazawa, Masaki Oishi, Kenichi Suzuki
  • Publication number: 20020038977
    Abstract: A vehicle hydraulic brake system includes a hydraulic pressure generator which pressurizes brake fluid supplied from a reservoir to apply brake pressure to a wheel cylinder in response to operation of a brake member, an auxiliary hydraulic pressure source having an accumulator and a hydraulic pump that pressurizes brake fluid supplied from the reservoir to a predetermined level for generating power hydraulic pressure, and an output hydraulic pressure detector for continuously detecting an output hydraulic pressure of the accumulator. A vehicle condition detector continuously detects an operating condition of the vehicle and a driving condition setting device sets a driving condition of the hydraulic pump based on the detected operating condition of the vehicle. A driving control device controls the hydraulic pump based on the driving condition of the hydraulic pump set by the driving condition setting device and the output hydraulic pressure of the accumulator.
    Type: Application
    Filed: September 27, 2001
    Publication date: April 4, 2002
    Inventors: Hirofumi Nitta, Michiharu Nishii, Tadashi Terazawa, Masaki Oishi
  • Publication number: 20020030404
    Abstract: A hydraulic brake apparatus for a vehicle includes a supplementary hydraulic pressure source outputting a pressurized output hydraulic pressure and an electronic control apparatus that controls a hydraulic pump in the supplementary hydraulic pressure source. The electronic control apparatus judges whether the hydraulic pump satisfies a predetermined operating condition based on the output hydraulic pressure of the supplementary hydraulic pressure source or not. The electronic control apparatus compares the output hydraulic pressure with a minimum standard hydraulic pressure, detects a drop in the output hydraulic pressure when the output hydraulic pressure is less than a standard hydraulic pressure and determines that the hydraulic pump does not satisfy the predetermined operating condition.
    Type: Application
    Filed: August 30, 2001
    Publication date: March 14, 2002
    Inventors: Hirofumi Nitta, Michiharu Nishii, Tadashi Terazawa, Masaki Oishi
  • Patent number: 6244674
    Abstract: The present invention is directed to a brake control system for an electrically operated vehicle, which is adapted to reduce a regenerative braking torque and add a hydraulic braking force. A motor control unit is provided for controlling an electric motor to apply a rotating force to a wheel and apply the regenerative braking torque to the wheel. A pressure control device is provided for controlling a hydraulic braking pressure generated by a pressure generator in response to operation of a manually operated braking member, and supplied to a wheel brake cylinder, which is operatively mounted on the wheel for applying a hydraulic braking force to the wheel. The regenerative braking torque is reduced in response to a braking condition monitored by a monitor. A pressure difference is detected between the hydraulic braking pressure of the brake fluid discharged from the pressure generator and the hydraulic braking pressure in the wheel brake cylinder.
    Type: Grant
    Filed: September 16, 1998
    Date of Patent: June 12, 2001
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Tetsuya Kuno, Tadashi Terazawa, Yoshinori Suzuki, Harumi Ohori, Shingo Urababa
  • Patent number: 6216808
    Abstract: The present invention is directed to a brake control system for an electrically operated vehicle which is adapted to reduce a regenerative braking torque and add a hydraulic braking force to compensate for lack of the regenerative braking torque, when voltage of a battery exceeds an upper limit. A motor control unit is provided for controlling an electric motor to apply a rotating force to a wheel and apply the regenerative braking torque to the wheel. A pressure control device is provided for supplying pressurized brake fluid to a wheel brake cylinder in response to operation of a manually operated braking member to apply the hydraulic braking force to the wheel. A reducing device is provided for reducing the regenerative braking torque when the voltage of the battery exceeds a predetermined upper limit.
    Type: Grant
    Filed: July 29, 1998
    Date of Patent: April 17, 2001
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Tetsuya Kuno, Tadashi Terazawa, Shingo Urababa, Harumi Ohori, Kenji Asano
  • Patent number: 6070954
    Abstract: In an electrically operated vehicle in which a regenerative braking operation is performed to apply a regenerative braking torque to a wheel, if the regenerative braking torque reaches its maximum value and is insufficient to brake the wheel, a static hydraulic pressure outputted from a master cylinder is supplied to the wheel brake cylinder mounted on the wheel until the brake pedal reaches a retained position. Thereafter, a dynamic hydraulic pressure is supplied to the wheel brake cylinder. While the brake pedal is in movement from the rest position to the retained position, the wheel brake cylinder is supplied with only the static hydraulic pressure and while the brake pedal is being retained at the retained position the wheel brake cylinder is supplied with the static hydraulic pressure and the dynamic hydraulic pressure.
    Type: Grant
    Filed: August 27, 1998
    Date of Patent: June 6, 2000
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Shingo Urababa, Harumi Ohori, Tetsuya Kuno, Tadashi Terazawa
  • Patent number: 6065815
    Abstract: An auxiliary hydraulic pressure source device for use with an antilock brake system in a vehicle includes an accumulator that can be reduced in size without deteriorating the performance of the vehicle brakes. The auxiliary hydraulic pressure source device also includes a hydraulic pump for delivering brake fluid into a high-pressure brake fluid output line. A first one-way valve connects this output line with the accumulator only when the hydraulic pressure inside the output line exceeds the hydraulic pressure inside the accumulator by more than a given value .DELTA.P. A second one-way valve connects the accumulator with the output line only when the hydraulic pressure inside the output line is lower than the hydraulic pressure inside the accumulator.
    Type: Grant
    Filed: April 27, 1998
    Date of Patent: May 23, 2000
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Tadashi Terazawa, Michiharu Nishii
  • Patent number: 5897175
    Abstract: The invention is directed to a brake pressure control system which includes a brake pedal, a wheel brake operatively mounted on a wheel, and a pressure generator which generates a first brake pressure of a first pressure characteristic according to a stroke of the brake pedal, and which generates a second brake pressure of a second pressure characteristic according to the stroke of the brake pedal. The pressure generator is adapted to generate the second brake pressure to be higher than the first brake pressure, with a smaller stroke of the brake pedal than the stroke of the brake pedal for generating the first brake pressure. The system further includes a detector for detecting an emergency brake operation of the brake pedal, and a pressure selecting device which selects one of the first brake pressure and the second brake pressure to be supplied into the wheel brake.
    Type: Grant
    Filed: July 11, 1996
    Date of Patent: April 27, 1999
    Inventors: Tadashi Terazawa, Michiharu Nishii
  • Patent number: 5851057
    Abstract: A vehicle brake control unit includes a cylinder body (2); a spool member (18) which is slidably provided in the cylinder body (2), and has one end portion confronted with a pressure chamber (10) and the other end portion confronted with a regulator pressure chamber (24) in the cylinder body, the spool member being axially moved by both the pressure in the pressure chamber and the pressure in the regulator pressure chamber, thus adjusting the pressure of a pressure source (26) which is applied to a regulator port (2a) formed in the cylinder body. The pressure provided at the regulator port is led into the regulator pressure chamber and supplied to the wheel cylinders (33, 34, 35 and 36).
    Type: Grant
    Filed: June 26, 1996
    Date of Patent: December 22, 1998
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Tadashi Terazawa, Michiharu Nishii
  • Patent number: 5845974
    Abstract: The present invention is directed to an anti-skid control system which includes a return passage provided for communicating a wheel brake cylinder with an actuator. A pressure pump is disposed in the return passage, and a reservoir is disposed in the return passage at the inlet port's side of the pump. The reservoir stores the brake fluid in the wheel brake cylinder through the actuator to decrease the wheel cylinder pressure. The pump discharges the brake fluid stored in the reservoir into the return passage thereby to gradually increase the wheel cylinder pressure. The amount of brake fluid stored in the reservoir is estimated on the basis of the amount of brake fluid fed into the reservoir and the amount of brake fluid discharged therefrom. The amount of brake fluid fed into the reservoir is estimated on the basis of the wheel cylinder pressure provided when the pressure decreasing operation starts, and in response to the pressure decreasing time.
    Type: Grant
    Filed: September 6, 1995
    Date of Patent: December 8, 1998
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Masaru Kamikado, Tadashi Terazawa, Hiroyuki Ichikawa, Yasuhiro Abe
  • Patent number: 5779327
    Abstract: The invention is directed to a pressure supply system which has a fluid pump, an electric motor for driving the fluid pump to supply a hydraulic pressure in proportion to a current fed to the motor, and an accumulator for accumulating the hydraulic pressure supplied from the fluid pump. The pressure supply system includes a current detection device which detects the current fed to the motor, and a malfunction detection device which detects a malfunction of the pressure supply system on the basis of the output of the current detection device. The malfunction detection device is adapted to determine that the malfunction occurs when an increasing rate of the current fed to the motor is less than a predetermined rate, preferably after a predetermined time elapsed from the time when the current initially fed to the motor. The pressure supply system may further include such a warning device as a lamp or a buzzer, which will be activated when the malfunction detection device detects the malfunction of the system.
    Type: Grant
    Filed: August 27, 1996
    Date of Patent: July 14, 1998
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Hiroshi Nakashima, Toshiaki Hamada, Tadashi Terazawa, Yuichiro Sakakibara
  • Patent number: 5733017
    Abstract: The invention is directed to a pressure accumulating control system for use in a pressure supply apparatus which has a fluid pump, an electric motor for driving the fluid pump to supply a hydraulic pressure, and an accumulator for accumulating the hydraulic pressure supplied from the fluid pump. The system includes a pressure detection device for detecting the hydraulic pressure accumulated in the accumulator, and a continuous control device for feeding a current to the motor continuously. The continuous control device is adapted to feed the current to the motor continuously, when the pressure detected by the pressure detection device becomes less than a predetermined lower limit, and is adapted to terminate the continuous feeding of the current to the motor, when the pressure detected by the pressure detection device exceeds a predetermined upper limit. The system further includes an intermittent control device for feeding a current to the motor intermittently by a predetermined cycle of time.
    Type: Grant
    Filed: August 27, 1996
    Date of Patent: March 31, 1998
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Hiroshi Nakashima, Toshiaki Hamada, Tadashi Terazawa, Yuichiro Sakakibara
  • Patent number: 5664850
    Abstract: The present invention is directed to an anti-skid control system for controlling a braking force applied to road wheels including driven wheels of an electrically operated vehicle which has an electrical motor for driving the driven wheels. A hydraulic braking pressure is supplied to each wheel brake cylinder through an actuator. The actuator is controlled by a braking force controller into which output signals of wheel speed sensors are fed. A band-pass filter is provided for passing the wheel speeds of the driven wheels having an oscillation property within a predetermined band of frequencies, out of the wheel speeds detected by the wheel speed sensors. And, a coefficient of friction of a road is estimated to be relatively low when the output of the band-pass filter is in a predetermined range of frequencies.
    Type: Grant
    Filed: September 11, 1996
    Date of Patent: September 9, 1997
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Tetsuya Kuno, Toshiaki Hamada, Tadashi Terazawa
  • Patent number: 5631632
    Abstract: The invention is directed to a pressure monitoring system for monitoring a hydraulic pressure which is supplied from a fluid pump and accumulated in an accumulator. The pressure monitoring system includes an electric motor which drives the fluid pump to supply the hydraulic pressure in substantially linear proportion to a current fed to the motor, a current detection device which detects the current fed to the motor, and a pressure estimation device which estimates the hydraulic pressure accumulated in the accumulator in response to the current detected by the current detection device. A malfunction detection device may be provided for detecting a malfunction on the basis of the output of the pressure estimation device.
    Type: Grant
    Filed: August 27, 1996
    Date of Patent: May 20, 1997
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Hiroshi Nakashima, Toshiaki Hamada, Tadashi Terazawa, Yuichiro Sakakibara
  • Patent number: 5549366
    Abstract: In a hydraulic brake system for a vehicle, the brake fluid in a first wheel brake and the brake fluid in a second wheel brake which are hydraulically connected to a pressure generating chamber of a master cylinder are individually caused to flow into a low back pressure reservoir with the aid of an electromagnetic change-over valve and first and second electromagnetic cut-off valves; and with a pump driven by an electric motor, the brake fluid flowing in the low back pressure reservoir in the above-described manner is caused to flow through a first check valve and a first orifice to the first wheel brake, and through a second check valve and a second orifice to the second wheel brake. With the pump operated, the first and second electromagnetic cut-off valves are individually operated, so that the first and second wheel brakes are individually decreased or reincreased in hydraulic pressure. For traction control, electromagnetic change-over valves provided in bypass passages are operated.
    Type: Grant
    Filed: May 25, 1995
    Date of Patent: August 27, 1996
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Hiroshi Toda, Michiharu Nishii, Akihito Kusano, Yoshiki Noda, Hiromu Kuromitsu, Tadashi Terazawa, Seiichi Kojima
  • Patent number: 5540488
    Abstract: The present invention is directed to a hydraulic braking system having a hydraulic braking pressure circuit for braking each wheel of an automotive vehicle with brake fluid fed to a wheel cylinder operatively mounted on the wheel. The system includes an auxiliary pressure source which has an inlet for introducing the brake fluid and an outlet connected to the pressure circuit for discharging thereinto the pressurized brake fluid. A circulation passage is disposed between the outlet and the inlet for communicating with each other. An auxiliary valve is disposed in the circulation passage so as to open or close the passage. An auxiliary reservoir is connected to the circulation passage between the valve and the inlet of the source. The auxiliary reservoir has a capacity for storing a predetermined amount of brake fluid. And, a controller is provided for driving the source and actuating the valve so as to open or close the circulation passage.
    Type: Grant
    Filed: July 14, 1995
    Date of Patent: July 30, 1996
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Tadashi Terazawa, Michiharu Nishii