Patents by Inventor Tomoo Tadokoro

Tomoo Tadokoro 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: 4926636
    Abstract: Disclosed is an engine-control apparatus in which an exhaust passageway of the engine is provided with plural sound deadening passages. A portion of the plural sound deadening passages is designed to be opened or closed by a shift valve on the basis of a predetermined switching characteristic, and the pressure of the exhaust gases is changed upon the switching of the shift valve. In order to prevent torque shock to the driven wheels which may occur attendant upon operation of the shift valve to open or close or in order to reduce probability that torque shock would occur, there is provided a torque regulating apparatus which permits an adjustment of torque generator by the engine, of a transmission efficiency of power to the driven wheel, or of a switching speed at which the shift valve is switched to open or close, or a change in the switching characteristic.
    Type: Grant
    Filed: February 14, 1989
    Date of Patent: May 22, 1990
    Assignee: Mazda Motor Corporation
    Inventors: Tomoo Tadokoro, Seiji Tashima, Haruo Okimoto, Toshimichi Akagi, Masami Nakao, Ikuo Matsuda, Einosuke Suekuni
  • Patent number: 4909035
    Abstract: A turbo-supercharger for an engine includes a turbine casing formed with two scrolls. A shut-off valve is provided for closing one of the scrolls in a low speed engine operation. The shut-off valve is operated by a pneumatic actuator which is normally biased to force the shut-off valve to the open position. Under a low speed engine operation, the intake suction pressure is applied to the actuator to move the shut-off valve to the closed position.
    Type: Grant
    Filed: February 2, 1988
    Date of Patent: March 20, 1990
    Assignee: Mazda Motor Corporation
    Inventors: Tomoo Tadokoro, Ikuo Matsuda
  • Patent number: 4745753
    Abstract: An engine turbo-supercharger including an exhaust gas turbine provided in the exhaust gas passage of an engine, a compressor provided in the intake passage of the engine and adapted to be driven by the turbine, a variable nozzle being provided in the exhaust gas passage upstream the turbine for changing an effective area of the exhaust gas passage leading to the turbine. The variable nozzle has a first position wherein a smaller effective passage area is provided and a second position wherein a larger effective passage area is provided, a bypass passage being provided in the exhaust gas passage and bypassing the turbine, a bypass valve for opening the bypass passage when the intake pressure of the engine increases beyond a predetermined value so that the intake pressure is maintained below the predetermined value.
    Type: Grant
    Filed: May 28, 1986
    Date of Patent: May 24, 1988
    Assignee: Mazda Motor Corporation
    Inventors: Tomoo Tadokoro, Ikuo Matsuda, Masami Nakao
  • Patent number: 4730456
    Abstract: A turbo-supercharger for an engine including a turbine casing of which scroll is formed with two exhaust gas inlet passages. The turbine casing has an inlet end surface connected with the outlet end surface of an engine exhaust pipe. The inlet passages are opened to the inlet end surface of the turbine casing respectively through inlet ports which are arranged in side-by-side relationship. A valve mechanism is provided to close one of the inlet ports under a low speed engine operation. The valve mechanism has a valve member adapted to seat on the inlet end surface and a swingable arm mounted on the exhaust pipe for moving the valve member. The exhaust pipe is formed with a sidewardly bulged portion where the swingable arm is supported. The swingable arm and the valve member are substantially received in the bulged portion in the open position.
    Type: Grant
    Filed: March 19, 1986
    Date of Patent: March 15, 1988
    Assignee: Mazda Motor Corporation
    Inventors: Tomoo Tadokoro, Ikuo Matsuda
  • Patent number: 4702219
    Abstract: In a supercharged engine, a part of the pressurized air pressurized by a supercharger is introduced into the exhaust system as secondary air in a predetermined operating range of the engine. The supercharging pressure is controlled to be lower when introduction of secondary air is effected than when it is not effected.
    Type: Grant
    Filed: August 27, 1985
    Date of Patent: October 27, 1987
    Assignee: Mazda Motor Corporation
    Inventors: Tomoo Tadokoro, Haruo Okimoto, Toshimichi Akagi
  • Patent number: 4627395
    Abstract: A two rotor type rotary piston engine includes an intake system comprised of including individual intake ports provided in at least one of the intermediate and side housings to open to the respective rotor cavities and adapted to be cyclically closed by the rotors as the rotors rotate, an intake passage including individual passages leading respectively to the intake ports and opened to a surge tank through openings which are opposed to each other with a spacing therebetween. The overall length of the individual passages and the spacing between the openings is determined with respect to the intake port timings so that a compression wave produced in one individual passage in opening timing of one intake port is transmitted to the other intake port just before the other intake port is closed to obtain an additional charge under a specific engine speed range.
    Type: Grant
    Filed: April 17, 1985
    Date of Patent: December 9, 1986
    Assignee: Madza Motor Corporation
    Inventors: Tomoo Tadokoro, Haruo Okimoto, Ikuo Matsuda
  • Patent number: 4612904
    Abstract: A fuel injection device for internal combustion engines, provided with a light load fuel injection valve and a heavy load injection valve for each cylinder of the engine. The light load fuel injection valve and the heavy load fuel injection valve are provided in an intake passage. The light load fuel injection valve is positioned close to the combustion chamber of the engine whereas the heavy load fuel injection valve is located further from the combustion chamber than the light load fuel injection valve. The fuel injection device is also provided with a control circuit which controls the light load fuel injection valve to provide additional supply of fuel during engine accelerating operation so that the increased fuel is rapidly introduced into the combustion chamber at the time of engine acceleration.
    Type: Grant
    Filed: February 14, 1984
    Date of Patent: September 23, 1986
    Assignee: Mazda Motor Corporation
    Inventors: Tomoo Tadokoro, Haruo Okimoto
  • Patent number: 4612770
    Abstract: A control system for an automobile engine having intake and exhaust systems for respectively conducting intake gases to and exhaust gases from the engine comprises a turbocharger including a turbine disposed in the exhaust system and a blower disposed in the intake system and drivingly connected with the turbine, an exhaust purifying device disposed in the exhaust system downstream of the turbine with respect to the direction of flow of the exhaust gases, a choke valve for varying the effective cross-section of a portion of the exhaust system leading to the turbine, a control device for controlling the choke valve in dependence on an operating condition of the engine, and a correcting unit for controlling the choke valve to increase the effective cross-section during a particular engine operating condition associated with a cold start of the exhaust purifying device.
    Type: Grant
    Filed: July 26, 1985
    Date of Patent: September 23, 1986
    Assignee: Mazda Motor Corporation
    Inventors: Tomoo Tadokoro, Ikuo Matsuda, Haruo Okimoto
  • Patent number: 4566422
    Abstract: For a supercharged internal combustion engine having at least one engine cylinder, a fuel intake system comprises a primary intake passage for supplying a combustible air-fuel mixture to the engine cylinder, and an auxiliary intake passage including a supercharger for supplying at least supercharged air to the engine cylinder, said supercharger being constituted by a displacement air pump and adapted to be driven by the engine such as to produce and supply the supercharged air into the engine cylinder at least during the period in which the engine cylinder is held under the compression stroke.
    Type: Grant
    Filed: November 19, 1984
    Date of Patent: January 28, 1986
    Assignee: Mazda Motor Corporation
    Inventors: Tomoo Tadokoro, Haruo Okimoto, Ikuo Matsuda
  • Patent number: 4566412
    Abstract: A two rotor type rotary piston engine includes an intake system comprised of individual intake ports provided in at least one of the intermediate and side housings to open to the respective rotor cavities and adapted to be cyclically closed by the rotors as the rotor rotate, an intake passage including a throttle valve and individual passages leading respectively to the intake ports and communicated with each other by communicating passages downstream of the throttle valve. The intake port includes a main port having an opening period of 230.degree. to 290.degree. in terms of angle of rotation of the eccentric shaft and an auxiliary port having an opening period of 270.degree. to 320.degree. in terms of the angle of rotation of the eccentric shaft. The auxiliary port is normally closed but opened in heavy load operation by a control valve and has a closing timing later than that of the main port.
    Type: Grant
    Filed: November 28, 1983
    Date of Patent: January 28, 1986
    Assignee: Mazda Motor Corporation
    Inventors: Tomoo Tadokoro, Hideo Shiraishi, Haruo Okimoto
  • Patent number: 4562805
    Abstract: A two rotor type rotary piston engine includes an intake system comprised of light load intake ports provided in the intermediate housing and heavy load intake ports provided in side housings to open to the respective rotor cavities and being cyclically closed by the rotors as the rotor rotates, an intake passage including a throttle valve and individual passages leading respectively to the intake ports. The passages leading to the light load ports are communicated with each other by a communicating passage downstream of the throttle valve. The heavy load intake port includes a main port and an auxiliary port. The auxiliary port is normally closed but opened in high speed, heavy load operation by a control valve and has a closing timing later than that of the main port.
    Type: Grant
    Filed: December 1, 1983
    Date of Patent: January 7, 1986
    Assignee: Mazda Motor Corporation
    Inventors: Tomoo Tadokoro, Haruo Okimoto, Hideo Shiraishi
  • Patent number: 4562803
    Abstract: A two rotor type rotary piston engine includes an intake system comprised of individual light load intake ports and heavy load intake ports provided in at least one of the intermediate and side housings to open to the respective rotor cavities and adapted to be cyclically closed by the rotors as the rotor rotate, an intake passage including a throttle valve and individual light load and heavy load passages leading respectively to the light load and heavy load intake ports. The light load passages are communicated with each other by a communicating passage downstream of the throttle valve and the heavy load passages are also communicated each other by a further communication passage. The intake port timings and the passage lengths are so determined that pressure resonance effects can be obtained at both medium and high speed engine operations.
    Type: Grant
    Filed: December 1, 1983
    Date of Patent: January 7, 1986
    Assignee: Mazda Motor Corporation
    Inventors: Tomoo Tadokoro, Haruo Okimoto, Hideo Shiraishi, Toshimichi Akagi
  • Patent number: 4562804
    Abstract: A two rotor type rotary piston engine includes an intake system including individual intake ports provided in at least one of the intermediate and side housings to open to the respective rotor cavities and adapted to be cyclically closed by the rotors as the rotors rotate, an intake passage including a throttle valve and individual passages leading respectively to the intake ports and communicated with each other by communicating passages downstream of the throttle valve. The intake port has an opening period of 270.degree. to 320.degree. in terms of the angle of rotation of the eccentric shaft, the communication passages and the individual passages leading to the respective rotor cavities having overall length between 0.57 and 1.37 m so that a compression wave produced in one individual passage in opening timing of one intake port is transmitted to the other intake port just before the other intake port is closed to obtain an additional charge under an engine speed range of 5000 to 7000 rpm.
    Type: Grant
    Filed: October 17, 1983
    Date of Patent: January 7, 1986
    Assignee: Mazda Motor Corporation
    Inventors: Tomoo Tadokoro, Haruo Okimoto, Ikuo Matsuda
  • Patent number: 4513707
    Abstract: A rotary piston engine including a casing comprised of a rotor housing and a pair of side housings attached to the opposite sides of the rotor housing to define a rotor cavity. A substantially triangular rotor is disposed in the rotor cavity. The intake system includes a light load intake port formed in one of the side housings so as to open to the rotor cavity, a medium load and heavy load intake ports formed in the other side housing. The light load and medium load intake ports are formed so that they are opened to a working chamber before the chamber is disconnected from the exhaust port. The heavy load intake port is associated with a control valve which is closed under light and medium load operations. The medium load intake port has an effective area smaller than that of the light load intake port and is closed earlier than the light load intake port.
    Type: Grant
    Filed: April 21, 1983
    Date of Patent: April 30, 1985
    Assignee: Toyo Kogyo Co., Ltd.
    Inventors: Tomoo Tadokoro, Haruo Okimoto, Ikuo Matsuda
  • Patent number: 4502435
    Abstract: Intake system for a multiple cylinder internal combustion engine having primary and secondary passages leading to each cylinder and respectively provided with throttle valves. The primary passages for the respective cylinders are connected together through a first communicating passage of relatively large cross-sectional area and a second communicating passage of a relatively small cross-sectional area which is downstream of the first passage. One of the primary passages is provided with a shut-off valve which is located close to but downstream of the second communicating passage and adapted to be closed in idling operation or deceleration of the engine for directing the mixture totally toward the cylinder associated with the other primary passage. The primary and secondary passages leading to the same cylinder are connected together by a connecting passage downstream of the throttle valve.
    Type: Grant
    Filed: September 6, 1983
    Date of Patent: March 5, 1985
    Assignee: Mazda Motor Corporation
    Inventors: Tomoo Tadokoro, Toshimichi Akagi
  • Patent number: 4488531
    Abstract: A fuel intake system for a supercharged automotive engine having at least one engine cylinder with first and second fuel intake ports and exhaust port comprises first fuel intake passage communicated at one end to the first fuel intake port and at the other end to the supercharger through a first throttle valve, and a second fuel intake passage communicated at one end to the second fuel intake port and at the other end to the supercharger through a second throttle valve. These intake and exhaust ports are adapted such that the first fuel intake port opens at a timing preceding the closure of the exhaust port and the second fuel intake port opens after the opening of the first fuel intake port.
    Type: Grant
    Filed: March 31, 1982
    Date of Patent: December 18, 1984
    Assignee: Mazda Motor Corporation
    Inventors: Tomoo Tadokoro, Haruo Okimoto, Masami Nakao, Masato Iwaki
  • Patent number: 4470394
    Abstract: A supercharged internal combustion engine comprising a combustion chamber of which volume cyclically changes in response to a rotation of the engine to conduct engine operating strokes including an intake and compression strokes, an intake system for supplying intake gas to the combustion chamber.
    Type: Grant
    Filed: January 7, 1983
    Date of Patent: September 11, 1984
    Assignee: Toyo Kogyo Co., Ltd.
    Inventors: Tomoo Tadokoro, Ikuo Matsuda, Haruo Okimoto
  • Patent number: 4459809
    Abstract: An engine having a turbo-supercharger comprised of a blower in the intake passage and an exhaust gas turbine in the exhaust passage. A charging pressure limiting device includes a pressure relief passage in the intake system or a turbine bypass passage in the exhaust system which is provided with a control valve. A control circuit is provided for limiting the peak charging pressure. The control circuit includes a limit signal generating circuit for providing a limit signal which decreases in response to an increase in the engine speed under a high speed range, a comparator for comparing the limit signal with the actual charging pressure signal and producing a control signal when the charging pressure signal reaches or exceeds the limit signal so that the charging pressure does not exceed the limit value which decreases in response to an increase in the engine speed under a high speed range.
    Type: Grant
    Filed: February 23, 1982
    Date of Patent: July 17, 1984
    Assignee: Toyo Kogyo Co., Ltd.
    Inventors: Tomoo Tadokoro, Masami Nakao, Haruo Okimoto, Masato Iwaki
  • Patent number: 4425883
    Abstract: A two rotor type rotary piston engine including a casing comprised of a pair of rotor housings connected together with an intermediate housing interposed therebetween and side housings attached to the outer sides of the rotor housings to define rotor cavities. A substantially triangular rotor is disposed in each rotor cavity. The intake system includes a light load intake port formed in the intermediate housing so as to open to each rotor cavity, a medium load and heavy load intake ports formed in each side housing. The light load and medium load intake ports are formed so that they are opened to a working chamber after the chamber is disconnected from the exhaust port and closed substantially simultaneously. The heavy load intake port is associated with a control valve which is closed under light and medium load operations.
    Type: Grant
    Filed: July 15, 1981
    Date of Patent: January 17, 1984
    Assignee: Toyo Kogyo Co., Ltd.
    Inventors: Tomoo Tadokoro, Nobuhiro Hayama, Toshimichi Akagi
  • Patent number: 4423711
    Abstract: A rotary piston engine including a casing comprised of a rotor housing and a pair of side housings attached to the opposite sides of the rotor housing to define a rotor cavity. A substantially triangular rotor is disposed in the rotor cavity. The intake system includes a light load intake port formed in one of the side housings so as to open to the rotor cavity, a medium load and heavy load intake ports formed in the other side housing. The light load and medium load intake ports are formed so that they are opened to a working chamber after the chamber is disconnected from the exhaust port and closed substantially simultaneously. The heavy load intake port is associated with a control valve which is closed under light and medium load operations.
    Type: Grant
    Filed: July 15, 1981
    Date of Patent: January 3, 1984
    Assignee: Toyo Kogyo Co., Ltd.
    Inventors: Tomoo Tadokoro, Nobuhiro Hayama, Toshimichi Akagi