Patents by Inventor Yu Motoyama

Yu Motoyama 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: 6109223
    Abstract: A two cycle crankcase compression internal combustion engine wherein a single fuel injector is mounted in the cylinder block and can inject either directly into the combustion chamber or into the induction system through the crankcase chamber through a window in the piston. A control strategy is disclosed wherein the injection occurs primarily into the induction system during either or both of startup and low temperature.
    Type: Grant
    Filed: August 19, 1999
    Date of Patent: August 29, 2000
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Yu Motoyama, Hidehiro Nishimura, Kousei Maebashi
  • Patent number: 6085733
    Abstract: A direct cylinder injected engine in several different embodiments which are specifically illustrated as two-cycle engines but which can also be used in four-cycle engines. The fuel injector is positioned so as to minimize escape of fuel from the exhaust port in the two-cycle engine applications. In addition, multiple or extended spark plug firing is accomplished under difficult running conditions and wherein fuel vaporization may be incomplete. This will ensure complete combustion. Various control routines and strategies are disclosed that control the number or time of injection depending upon such factors as engine speed, load, speed variation, air fuel ratio variations and pressure variations.
    Type: Grant
    Filed: July 14, 1998
    Date of Patent: July 11, 2000
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Yu Motoyama, Miyoshi Ishibashi, Akihiko Ohokubo, Yoshihiko Moriya
  • Patent number: 6039012
    Abstract: An exhaust control system for a two-cycle, crankcase compression, direct injection engine wherein an exhaust control valve modifies the effective cross-sectional area of the exhaust system in response to engine speed and operator demand to provide optimum charging and scavenging conditions. The exhaust control system is modified in response to other than normal steady state operating conditions such as during starting, warm up, and during rapid changes in engine speed and/or load and/or operator demand so as to improve performance during these conditions.
    Type: Grant
    Filed: September 17, 1997
    Date of Patent: March 21, 2000
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventor: Yu Motoyama
  • Patent number: 5946908
    Abstract: A number of embodiments of exhaust temperature sensors that cooperate with an exhaust control for maintaining optimum engine performance by controlling the exhaust temperature to maintain the desired pulse back effect on the exhaust system.
    Type: Grant
    Filed: January 14, 1997
    Date of Patent: September 7, 1999
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Yu Motoyama, Yoshihiko Moriya
  • Patent number: 5826557
    Abstract: A number of embodiments of two-cycle crankcase compression direct injected internal combustion engines wherein engine speed is controlled under at least some running conditions by cylinder disabling. Exhaust systems including exhaust control valves for precluding the passage of cooler gasses from the disabled cylinders to the operating cylinders through their exhaust ports are illustrated in varying forms and for various types of engines.
    Type: Grant
    Filed: September 22, 1997
    Date of Patent: October 27, 1998
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Yu Motoyama, Akihiko Ohokubo
  • Patent number: 5732674
    Abstract: An improved method of operating a direct cylinder-injected engine wherein adequate fuel and scavenging can be achieved at mid and high-mid range by injecting the fuel in two increments. Various control strategies are disclosed, and they all particularly lend themselves for use with two-cycle crankcase compression engines.
    Type: Grant
    Filed: May 13, 1996
    Date of Patent: March 31, 1998
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Yu Motoyama, Michihisa Nakamura, Yoshihiko Moriya
  • Patent number: 5690063
    Abstract: A fuel injection and ignition control system for a two-cycle crankcase compression engine wherein both fuel injection and ignition timing are controlled by sensed engine running characteristics at a predetermined crankshaft position. The timing of the ignition is controlled by the same parameter at which the fuel injection was controlled, so that the timing of ignition and amount and duration of fuel injection will be optimized for the same engine running condition.
    Type: Grant
    Filed: July 12, 1996
    Date of Patent: November 25, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Yu Motoyama, Takeru Ibara
  • Patent number: 5682870
    Abstract: A number of embodiments of combustion controls for two-cycle internal combustion engines wherein a sensor chamber is provided in which a combustion condition sensor is located. The sensor chamber communicates with the combustion chamber in such a way that only combustion products can flow from the combustion chamber into the sensor chamber. Various valving and control arrangements for achieving this purpose are disclosed.
    Type: Grant
    Filed: December 28, 1995
    Date of Patent: November 4, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventor: Yu Motoyama
  • Patent number: 5613468
    Abstract: A fuel injection system for an engine having a reed type valve in the induction system. The injection system is designed and controlled so that the fuel that is injected is injected substantially entirely before the reed type valve is closed. The time of closing of the reed type valve is determined either by measuring the pressure differential or by recording data indicative of the valve closing in response to various engine running conditions such as speed and/or load.
    Type: Grant
    Filed: April 19, 1996
    Date of Patent: March 25, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Takeru Ibara, Yoshihiko Moriya, Yu Motoyama
  • Patent number: 5211145
    Abstract: Several embodiments of fuel injected engines wherein stability and running is achieved by maintaining an injection velocity that is greater than the velocity of the charge in the chamber including that component contributed by the squish action in the engine and at least equal to 40 meters per second so as to ensure effective stratification and the existence of a stoichiometric charge at the spark plugs at the time of ignition, even under low load and speed conditions such as idle.
    Type: Grant
    Filed: January 22, 1992
    Date of Patent: May 18, 1993
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Ryuichi Ichikawa, Yu Motoyama
  • Patent number: 5193508
    Abstract: Two embodiments of fuel injection systems for two cycle crankcase compression internal combustion engines that employ two fuel injectors. One fuel injector injects into the combustion chamber while another injects into the induction system of the engine. A simplified regulating system is incorporated so that the first injector receives fuel under a higher pressure than the second injector.
    Type: Grant
    Filed: April 27, 1990
    Date of Patent: March 16, 1993
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Yu Motoyama, Ryusuke Kato, Yoshihiko Moriya
  • Patent number: 5190006
    Abstract: A fuel injection system for engines for improving performance and fuel economy. The fuel injector controlled along with an exhaust port timing control mechanism so that fuel injected into the engine will not pass out of the exhaust port under most engine running conditions. The invention is disclosed particularly in conjunction with a two cycle crankcase compression engine wherein it has particular utility. The timing of the opening and closing of the exhaust port is changed by means of an exhaust control valve that obstructs the exhaust port under certain running conditions so as to delay its opening and closing.
    Type: Grant
    Filed: March 22, 1991
    Date of Patent: March 2, 1993
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Yu Motoyama, Ryusuke Kato
  • Patent number: 5181493
    Abstract: A fuel injection system and method of operating it for a two-stroke crankcase compression internal combustion engine. The engine is provided with a main fuel injector that injects fuel directly into the combustion chamber and an auxiliary fuel injector that injects fuel into the inductions system. A throttle valve controls the flow through the induction system. The system includes a detector for detecting an abnormality in the operation of the main fuel injector and shuts the main fuel injector down when this occurs and increases the amount of fuel supplied by the auxiliary fuel injection. When this abnormal operating condition occurs, the degree of opening of the throttle valve is also reduced.
    Type: Grant
    Filed: May 24, 1991
    Date of Patent: January 26, 1993
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Yu Motoyama, Ryusuke Katoh
  • Patent number: 5136990
    Abstract: A fuel injection system for a two cycle crankcase compression internal combustion engine including a first injector that supplies fuel directly to the combustion chamber of the engine. An induction system is provided for inducting air into the crankcase chamber of the engine and in a multiple cylinder engine this includes a manifold having a single inlet. A throttle body having a throttle valve controls the flow of air through the inlet and a second fuel injector sprays fuel into the throttle body upstream of the throttle valve and against the throttle valve in certain positions of the throttle valve. In accordance with one disclosed embodiment of the invention, the second fuel injector supplies the fuel requirements for maximum power while the first fuel injector supplies the fuel requirements for low and mid range performance, but does not have adequate capacity to supply all of the fuel for high range performance.
    Type: Grant
    Filed: October 2, 1990
    Date of Patent: August 11, 1992
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Yu Motoyama, Toshikazu Ozawa, Junichi Kaku
  • Patent number: 5123399
    Abstract: A fuel air injection system for a multiple cylinder engine wherein an air manifold is rigidly affixed to all of the fuel air injectors so as to form a unitary assembly that can be removed from the engine as a unit.
    Type: Grant
    Filed: October 2, 1990
    Date of Patent: June 23, 1992
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Yu Motoyama, Junichi Kaku
  • Patent number: 5113829
    Abstract: A two cycle crankcase compression internal combustion engine having a main air/fuel injection system for injecting fuel and air directly into the combustion chamber and an auxiliary injection system for injecting fuel into the engine upstream of the combustion chamber for cooling the piston. A variety of arrangements of control strategies and auxiliary injection nozzle positions are illustrated and described.
    Type: Grant
    Filed: April 12, 1990
    Date of Patent: May 19, 1992
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventor: Yu Motoyama
  • Patent number: 5105792
    Abstract: An embodiment of air/fuel injection system for a two-cycle, crankcase compression, internal combustion engine wherein the air/fuel injector is provided with at least a pair of fuel injectors, one of which operates under low speed conditions and the other of which operates under high speed conditions so that adequate fuel can be injected under all running conditions before cylinder pressure reaches its maximum.
    Type: Grant
    Filed: October 2, 1990
    Date of Patent: April 21, 1992
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Ryuichi Ichikawa, Yu Motoyama, Takahiro Suzuki
  • Patent number: 5095873
    Abstract: A fuel injection system and control for a two cycle crankcase compression internal combustion engine wherein air and fuel are directly injected into the combustion chamber of the engine and the idle speed is maintained constant by varying the timing of fuel injection. Fine tuning of the idle speed is further accomplished by changing the duration of fuel injection under certain conditions.
    Type: Grant
    Filed: September 10, 1990
    Date of Patent: March 17, 1992
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Yu Motoyama, Ryusuke Kato
  • Patent number: 5092287
    Abstract: A fuel injection system for a two cycle engine having main fuel injectors that inject directly into the engine combustion chambers and a sub or auxiliary fuel injector that injects into the induction system only under high load conditions to effect better piston cooling. Once the sub fuel injector begin to inject, then the amount of fuel per cycle injected by the main fuel injectors is decreased. The sub injector injects into a common manifold for a multiple cylinder engine and injects only one per crankshaft revolution.
    Type: Grant
    Filed: April 10, 1991
    Date of Patent: March 3, 1992
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Yu Motoyama, Masaki Ohsako, Keiichi Harada
  • Patent number: 5063887
    Abstract: An exhaust control valve arrangement for an in-line, two-cycle, crankcase compression engine which permits the porting arrangement to be rotated relative to the cylinder bore axis to achieve a compact configuration and wherein all of the exhaust control valves are operated by a single shaft assembly that extends parallel to a plane containing the cylinder bore axes. As a result of this orientation, the exhaust control valves provide an asymmetric exhaust port opening under at least some operative positions of the valves when the valves are in a flow obstructing position. A number of embodiments are disclosed which configure the exhaust control valves so that the port is symmetric in at least some operative obstructing positions of the valves. Also, several embodiments using curved valve configurations are disclosed.
    Type: Grant
    Filed: August 13, 1990
    Date of Patent: November 12, 1991
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Toshikazu Ozawa, Yu Motoyama