Patents by Inventor Hisasi Kawai

Hisasi Kawai 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: 4437345
    Abstract: A gas flow measuring device has a measuring circuit for measuring the flow of gas based on the output signals of an electric heater and a first and a second temperature dependent resistor. In the measuring circuit, the first and the second temperature dependent resistors, together with first and second reference resistors, form a bridge and a constant voltage is applied to a voltage at one diametrical point of the bridge. The difference between the other voltage of the diametrical point of the bridge and the output of the constant voltage adding circuit is amplified, and the output voltage of the amplifier circuit is further amplified so that the voltage applied to the electric heater and the bridge is feed-back controlled.
    Type: Grant
    Filed: March 30, 1982
    Date of Patent: March 20, 1984
    Assignee: Nippon Soken, Inc.
    Inventors: Tsuneyuki Egami, Hisasi Kawai, Tokio Kohama, Hideki Obayashi
  • Patent number: 4434767
    Abstract: In the range where the fuel efficiency may be improved by relatively increasing the load of working cylinders at the time of partial loading of a multicylinder internal combustion engine, the intake pressure of the engine is maintained at a fixed optimum value. Also, the number of working cylinders is controlled, so that a torque actually required by the driver is obtained, and under any load, the maximum improvement of fuel efficiency may be attained at a saving of fuel consumption.
    Type: Grant
    Filed: December 23, 1981
    Date of Patent: March 6, 1984
    Assignee: Nippon Soken, Inc.
    Inventors: Tokio Kohama, Seizi Huzino, Hideki Obayashi, Hisasi Kawai, Tsuneyuki Egami
  • Patent number: 4433665
    Abstract: The degree of opening of the choke valve in a carburetor for an internal combustion engine is controlled in accordance with the temperature of at least one predetermined position of temperature adjustment devices in the air intake manifold portion of the engine, whereby emission of harmful exhaust gas is reduced and the rated fuel consumption of the engine is maintained.
    Type: Grant
    Filed: March 23, 1982
    Date of Patent: February 28, 1984
    Assignees: Nippon Soken, Inc., Toyota Jidosha Kogyo Kabushiki Kaisha
    Inventors: Seiko Abe, Toshihiko Igashira, Hisasi Kawai, Toshikazu Ina, Masayoshi Tokoro
  • Patent number: 4428558
    Abstract: A proportional solenoid comprises a rotary magnet for causing a rotational displacement within an angle of 180 degrees in proportion to a current supplied to a coil, a torsion bar for damping the rotation of the rotary magnet and a rotary valve driven by the rotation of the rotary magnet.
    Type: Grant
    Filed: February 13, 1981
    Date of Patent: January 31, 1984
    Assignees: Nippon Soken, Inc., Toyota Jidosha Kogyo Kabushiki Kaisha
    Inventors: Takaharu Odogaki, Hisasi Kawai, Takeshi Matsui, Kyo Hattori, Kazuhiro Sakurai
  • Patent number: 4425792
    Abstract: In a fluid flow rate measuring apparatus having a sensor including an electric heater resistance wire and first and second temperature dependent resistance wires and a measuring circuit, each of the resistance wires is wound to be held firmly in place on a supporting member made of an electrical insulating material, and the electric heater resistance wire and the first temperature dependent resistance wire, which is responsive to the temperature of the fluid under measurement heated by the electric heater resistance wire, are wound on the same supporting member alternately and close to each other so that the winding direction thereof makes an angle from 60.degree. to 120.degree. to the direction of the flow of the fluid under measurement. Further, each of the supporting members is constructed and arranged so as to minimize the influence of the heat capacity thereof and also to avoid the occurrence of turbulence in the flow of the fluid which is detrimental to the flow rate measurement.
    Type: Grant
    Filed: May 7, 1982
    Date of Patent: January 17, 1984
    Assignee: Nippon Soken, Inc.
    Inventors: Tokio Kohama, Hideki Obayashi, Hisasi Kawai, Tsuneyuki Egami
  • Patent number: 4421091
    Abstract: In an ignition system for an internal combustion engine in which the flow of a primary winding energizing current is switched on and off in synchronism with the rotation of the engine and a high voltage is induced in the secondary winding upon switching off of the energizing current, an energizing current is supplied again at around the top dead center of each cylinder and then decreased gradually and interrupted in accordance with a sawtooth waveform whose voltage attains a predetermined potential at around the top dead center and then decreases gradually.
    Type: Grant
    Filed: March 25, 1982
    Date of Patent: December 20, 1983
    Assignee: Nippon Soken, Inc.
    Inventors: Hisasi Kawai, Hiroshi Sada, Toshihiko Igashira, Toru Yoshinaga
  • Patent number: 4417471
    Abstract: A first temperature dependent resistor and a second temperature dependent resistor are disposed within a single gas passage defined by a branch pipe extending into a conduit for a gas whose flow rate is to be measured. An electric heater is located between these temperature dependent resistors and is heated for the purpose of measurement of the flow rate of the gas. A first reference resistor and a second reference resistor constitute a bridge circuit together with the first and second temperature dependent resistors, and the difference between the potentials at the terminals of the bridge circuit is amplified by a first differential amplifier circuit. The difference between the output voltage of the first differential amplifier circuit and a predetermined reference voltage is then amplified by a second differential amplifier circuit.
    Type: Grant
    Filed: November 23, 1981
    Date of Patent: November 29, 1983
    Assignee: Nippon Soken, Inc.
    Inventors: Hisasi Kawai, Tsuneyuki Egami, Tokio Kohama, Hideki Obayashi
  • Patent number: 4414847
    Abstract: A gas flow rate measuring apparatus for measuring the intake air flow rate of an automobile engine or the like is disclosed, which comprises a flow rate measuring tube containing an electric heater resistance wire and two temperature-dependent resistance wires, one subject to the effect of heat of the electric heater and the other free from the effect. An output signal of a voltage divider circuit including the series-connected temperature-dependent resistance wires is used to measure the gas flow rate. The electric heater resistance wire and the temperature-dependent resistance wire thermally affected thereby are wound side by side but avoiding occurrence of any short-circuit therebetween on a single support member of an electrically insulating material.
    Type: Grant
    Filed: July 23, 1981
    Date of Patent: November 15, 1983
    Assignee: Nippon Soken, Inc.
    Inventors: Tokio Kohama, Hisasi Kawai, Hideki Obayashi, Tsuneyuki Egami
  • Patent number: 4409828
    Abstract: An electric heater connected between first and second temperature dependent resistors provided inside a pipe through which the gas the flow of which is to be measured is heated for the measurement of the gas flow. A voltage control circuit controls the voltage applied to or current through the electric heater such as to maintain a constant potential difference between diagonal points of a bridge circuit which is formed by the first and second temperature dependent resistors and first and second reference resistors. An output computing circuit which receives a signal proportional to the voltage across the electric heater and also to the current therethrough produces an output signal representing the rate of flow of gas being measured.
    Type: Grant
    Filed: April 7, 1981
    Date of Patent: October 18, 1983
    Assignee: Nippon Soken, Inc.
    Inventors: Tokio Kohama, Hideki Obayashi, Hisasi Kawai, Tsuneyuki Egami
  • Patent number: 4408592
    Abstract: An ignition system for internal combustion engines of the type in which after the energizing current flow to the primary winding of an ignition coil has been interrupted and an ignition spark generating high voltage has been produced in the secondary winding, the primary winding is energized again to interrupt the ignition spark. The ignition spark is interrupted at around the TDC only when the engine is at high speed operating conditions and the deenergizing current in the primary winding is not interrupted in a moment but decreased gradually. Also, the ignition spark is interrupted only when the ignition spark is to continue beyond the top dead center.
    Type: Grant
    Filed: May 18, 1981
    Date of Patent: October 11, 1983
    Assignee: Nippon Soken, Inc.
    Inventors: Toru Yoshinaga, Toshihiko Igashira, Kouichi Mori, Hisasi Kawai, Seiji Morino
  • Patent number: 4406273
    Abstract: An ignition system for the internal combustion engine comprising a high voltage circuit for generating a spark, having the primary and secondary windings. In response to a first signal, the current in the primary winding is cut off thereby to generate a high voltage at the secondary winding. In response to a subsequent second signal, the primary winding is shorted thereby to cut off the high voltage thus far generated in the secondary winding, thus properly regulating the duration of the spark generated.
    Type: Grant
    Filed: May 21, 1981
    Date of Patent: September 27, 1983
    Assignee: Nippon Soken, Inc.
    Inventors: Toru Yoshinaga, Toshihiko Igashira, Kouichi Mori, Hisasi Kawai, Seiji Morino
  • Patent number: 4400944
    Abstract: The temperature and air-fuel ratio of the exhaust gases of an internal combustion engine are sensed to generate signals indicative thereof and the amount of fuel to be injected into the engine is determined in accordance with the signals, thus controlling the air-fuel ratio at a predetermined value and thereby decreasing the abnormal temperature rise in the exhaust system.
    Type: Grant
    Filed: December 2, 1980
    Date of Patent: August 30, 1983
    Assignees: Nippon Soken, Inc., Toyota Jidosha Kogyo Kabushiki Kaisha
    Inventors: Kenzi Iwamoto, Makoto Kuroyanagi, Hisasi Kawai, Kunimasa Yoshimura, Hidetaka Nohira, Mitsuyuki Ugajin, Hisashi Ohki
  • Patent number: 4399697
    Abstract: A gas flow measuring apparatus for measuring intake air flow for an automobile engine having an electrical heater resistive member, and first and second temperature dependent resistive members. The first resistive member is located so as to be well influenced by heat from the heater resistive member, while the second resistive member is located so as to be little influenced by the same. The measuring apparatus measures a gas flow rate by using an output signal from a voltage dividing circuit as a series circuit of the first and second resistive members. In the gas flow measuring apparatus, a heater film resistive member is deposited on a first support member by an evaporation depositing or printing process, and is further covered with electric insulating material such as glass.
    Type: Grant
    Filed: March 24, 1981
    Date of Patent: August 23, 1983
    Assignee: Nippon Soken, Inc.
    Inventors: Tokio Kohama, Hideki Obayashi, Hisasi Kawai, Tsuneyuki Egami
  • Patent number: 4393702
    Abstract: A first temperature dependent resistor, an electric heater and a second temperature dependent resistor are arranged in this order within and from the downstream to the upstream of a pipe in which flows a gas whose flow rate is to be measured. A bridge circuit is formed by the first and second temperature dependent resistors along with first and second reference resistors. In response to the output of the bridge circuit, a measuring circuit regulates the supply of power to the electric heater and generates a signal indicative of the flow rate of the gas. Each of the first and second reference resistors is in the form of a film resistor formed on an insulating base. The insulating base having the film resistors formed thereon is placed for example in the flow of the gas to be measured.
    Type: Grant
    Filed: March 11, 1981
    Date of Patent: July 19, 1983
    Assignee: Nippon Soken, Inc.
    Inventors: Tokio Kohama, Hideki Obayashi, Hisasi Kawai, Tsuneyuki Egami
  • Patent number: 4391132
    Abstract: A gas flow measuring apparatus includes first and second temperature dependent resistors located in a gas tube respectively downstream and upstream of an electric heater which is also located in the gas tube. The first and second temperature dependent resistors are connected to form a bridge circuit together with first and second reference resistors. Between a pair of diagonal junctions of the bridge circuit, a potential difference is produced depending on the flow rate of the gas and the power supplied to the electric heater, and a measuring circuit controls the power supplied to the electric heater so that the potential difference is maintained at a predetermined value irrespective of a change in flow rate of the gas.
    Type: Grant
    Filed: September 11, 1981
    Date of Patent: July 5, 1983
    Assignee: Nippon Soken, Inc.
    Inventors: Tsuneyuki Egami, Hisasi Kawai, Tokio Kohama, Hideki Obayashi
  • Patent number: 4384484
    Abstract: A first temperature dependent resistor and a second temperature dependent resistor are disposed within a pipe for flowing a gas whose flow rate is to be measured. An electric heater is located between these temperature dependent resistors and is heated for the purpose of measurement of the flow rate of the gas. A first reference resistor and a second reference resistor constitute a bridge circuit together with the first and second temperature dependent resistors. A measuring circuit controls the current or voltage applied to the electric heater in accordance with the voltage between the terminals of the bridge circuit, so as to generate an output signal representing the flow rate of the gas. The temperature coefficient resistance of the electric heater is smaller than that of the temperature dependent resistors.
    Type: Grant
    Filed: March 12, 1981
    Date of Patent: May 24, 1983
    Assignee: Nippon Soken, Inc.
    Inventors: Tokio Kohama, Hideki Obayashi, Hisasi Kawai, Tsuneyuki Egami
  • Patent number: 4381757
    Abstract: A pair of power transistors in a push-pull connection are connected with a pair of primary coils of a transformer acting as an ignition coil. Between the neutral point of the pair of the primary coils and a power source at least one diode is connected. The paired power transistors are turned on and off with a high frequency to generate in the secondary coil of the transformer high voltage trigger pulses and substantially continuous discharge voltages which last over a long period during each ignition period.
    Type: Grant
    Filed: July 24, 1980
    Date of Patent: May 3, 1983
    Assignee: Nippon Soken, Inc.
    Inventors: Seiji Morino, Hisasi Kawai, Norihito Tokura
  • Patent number: 4363210
    Abstract: An exhaust gas purifying system for internal combustion engines includes a three-way catalyst disposed in the exhaust system of the engine, and secondary air is supplied to the exhaust system through an air control valve under the control of an air-fuel ratio control circuit. The air-fuel ratio control circuit produces a control signal which increases or decreases stepwisely at every reception of a clock signal depending on whether the air-fuel ratio in the exhaust system is above or below a stoichiometric air-fuel ratio. The air control valve is of the proportional electromagnetic type and controls the secondary air passing therethrough in proportion to the control signal.
    Type: Grant
    Filed: June 8, 1981
    Date of Patent: December 14, 1982
    Assignees: Nippon Soken, Inc., Toyota Jidosha Kogyo Kabushiki Kaisha
    Inventors: Hisasi Kawai, Kazuhiro Sakurai, Muneaki Matsumoto
  • Patent number: 4361164
    Abstract: A method of driving a solenoid-operated proportional control valve is disclosed. The solenoid-operated proportional control valve is of the kind in which a valve member is displaced in proportional relation to current supplied to a solenoid under control of a control signal, and the method comprises adding a predetermined value to the control signal when the valve member starts to move to open the solenoid-operated proportional control valve from its full-closed position or subtracting a predetermined value from the control signal when the valve member starts to move to close the solenoid-operated proportional control valve from its full-open position.
    Type: Grant
    Filed: August 25, 1980
    Date of Patent: November 30, 1982
    Assignees: Nippon Soken, Inc., Toyota Jidosha Kogyo Kabushiki Kaisha
    Inventors: Yasuyuki Sakakibara, Hisasi Kawai, Kazuhiro Sakurai, Kyo Hattori
  • Patent number: 4357830
    Abstract: A gas flow measuring apparatus of the type which measures for example, the amount of air flow to the engine of an automotive vehicle, includes a flow measuring tube, an electric heater wire and two temperature dependent resistance wires which are all positioned in the flow measuring tube such that one of the temperature dependent resistance wires is subjected to the effect of the heat of the electric heater and the other is not subjected to the same effect, whereby the flow rate of gas is measured in accordance with the output signal of a voltage divider including a series-connection of the temperature dependent resistance wires. The electric heater wire and the temperature dependent resistance wire subjected to the effect of the heat from the former are wound closely and alternately on the same support made from an electrical insulating material.
    Type: Grant
    Filed: September 17, 1980
    Date of Patent: November 9, 1982
    Assignee: Nippon Soken, Inc.
    Inventors: Tokio Kohama, Hisasi Kawai, Hideki Obayashi, Tsuneyuki Egami