Shigeru Oho

US Patent:

6453739, Sep 24, 2002

Filed:

Sep 10, 1999

Appl. No.:

09/393395

Inventors:

George Saikalis - West Bloomfield MI
Shigeru Oho - Farmington Hills MI
Marco diPierro - Karisruhe, DE

Assignee:

Hitachi America, Ltd. - Tarrytown NY

International Classification:

G01F 168

US Classification:

7320414, 7320423

Abstract:

A time domain measurement and control system for a hot wire air flow sensor is disclosed in which the air flow sensor is of the type having a resistive heating element with an input end and an output end. The control system includes a fixed frequency variable width pulse generator which generates a pulse train through the heating element. This pulse train, furthermore, has a first predetermined voltage amplitude. The output voltage amplitude of the pulse train is determined at the outlet end of the heating element while a control circuit varies the duty cycle of the pulse train to maintain the output voltage amplitude at a second predetermined voltage level. The duty cycle of the pulse train is proportional to the air flow rate through the air flow sensor. In a modification of the invention, a fixed width variable frequency pulse train is generated through the resistive heating element and the frequency of the pulse train is varied to maintain the output voltage amplitude of the pulse train at the outlet end of the resistive heating element at a second predetermined voltage level. In this modification, the frequency of the pulse train is proportional to the air flow rate through the air flow sensor.

US Patent:

6568261, May 27, 2003

Filed:

Oct 16, 2000

Appl. No.:

09/688585

Inventors:

George Saikalis - West Bloomfield MI
Shigeru Oho - Farmington Hills MI
Takashi Kadohiro - Livonia MI

Assignee:

Hitachi America, Ltd. - Tarrytown NY

International Classification:

G01E 168

US Classification:

7320427

Abstract:

An improved hot wire gas flow sensor is disclosed having a housing with a passageway in series with a passageway through which the gas flow is measured. The housing includes both a hot wire and cold wire disposed within the passageway. A current circuit maintains the temperature differential between the hot wire and cold wire preferably in the range of 30Â C. to 100Â C. by varying the current flow through the hot wire. Current limiting circuitry is then utilized to limit the current flow through the hot wire and thus the temperature of the hot wire in order to prevent possible combustion of the gas in the passageway. Additionally, a current augmenting circuit augments the current flow through the hot wire for a limited period of time following the electrical energization of the flow sensor in order to provide rapid heat up of the hot wire in the hot wire sensor. Improvements are also disclosed for fluidly sealing the electrical leads to both the hot wire and cold wire to prevent gas leakage from the sensor.

US Patent:

6640626, Nov 4, 2003

Filed:

Jan 18, 2002

Appl. No.:

10/051318

Inventors:

George Saikalis - West Bloomfield MI
Shigeru Oho - Farmington Hills MI
Takashi Kadohiro - Livonia MI

Assignee:

Hitachi, Ltd. - Tokyo

International Classification:

G01F 168

US Classification:

7320411

Abstract:

A method and a system are disclosed for identifying a gas type. The system includes a first sensor in contact with the gas and which produces a first electrical output signal indicative of a first condition of the gas. Similarly, a second sensor is also in contact with the gas and produces a second electrical output signal indicative of a second condition of the gas. A processor receives the output signals as input signals from the first and second sensors and determines the type of gas by calculation or from lookup tables stored in memory accessible to the processor. The first and second conditions of the gas are selected from the group of temperature, mass flow rate, temperature and pressure.

US Patent:

6736103, May 18, 2004

Filed:

Oct 21, 2002

Appl. No.:

10/274682

Inventors:

Frank Warren Hunt - West Bloomfield MI
Shigeru Oho - Farmington Hills MI
Ayumu Miyajima - Farmington Hills MI

Assignee:

Hitachi Ltd. - Tokyo

International Classification:

F02B 300

US Classification:

123299, 12317912, 12317915, 123480, 123491

Abstract:

A system for the management of fuel and fuel vapors in the cold start fuel passageway of an internal combustion engine which has a cold start fuel injector which, when activated, introduces fuel into the cold start fuel passageway. The system includes an engine control unit (ECU) which determines the probability of fuel within the cold start passageway. Different procedures programmed in the ECU are then utilized to dissipate the fuel from the cold start passageway. These procedures include delaying the initiation of the spark ignition for the engine, maintaining the heater associated with the cold start fuel injector activated for a period of time following deactivation of the cold start fuel injector, maintaining revolution of the internal combustion engine for a predetermined time period, as well as other strategies.

US Patent:

6756571, Jun 29, 2004

Filed:

Oct 17, 2002

Appl. No.:

10/273050

Inventors:

George Saikalis - West Bloomfield MI
Shigeru Oho - Farmington Hills MI

Assignee:

Hitachi, Ltd. - Tokyo

International Classification:

H05B 102

US Classification:

219497, 731182, 7320418, 219205

Abstract:

A system for compensation of contamination of a heated element in a heated element gas flow system in which the heated element becomes heated from an ambient temperature to an elevated temperature upon the application of electrical power to the heated element during a startup time period. The system includes a processing circuit having an input and an output. A voltage signal from the heated element is connected to the input of the processing circuit. The processing circuit reads a plurality of temporally spaced input signals as data from the processing circuit input during the startup time period. The processing circuit then computes the parameters of a transfer function corresponding to the data on its input. The processing circuit then calculates a contamination correction factor as a function of at least one parameter of the transfer function. The processing circuit then utilizes the correction factor to modify a measured gas flow rate by the gas flow meter after the heated element attains the elevated steady state temperature to compensate for contamination of the heated element.

US Patent:

6843238, Jan 18, 2005

Filed:

Mar 8, 2002

Appl. No.:

10/094188

Inventors:

Frank Warren Hunt - West Bloomfield MI, US
Shigeru Oho - Farmington Hills MI, US
Ayumu Miyajima - Farmington Hills MI, US

Assignee:

Hitachi, Ltd. - Tokyo

International Classification:

F02M 2300

US Classification:

123531, 12319717

Abstract:

A cold start fuel control system is disclosed for use with an internal combustion engine having at least one combustion chamber, a source of fuel and a primary intake manifold having an inlet and an outlet and fluidly connected between the fuel source and the combustion chamber. The system includes a cold start fuel injector assembly having an inlet and an outlet with the inlet being fluidly connected to the fuel source. An auxiliary intake manifold has an interior chamber which is fluidly connected with each combustion chamber. The outlet from the cold start fuel injector is then fluidly connected to the auxiliary intake manifold so that, upon activation of the cold start fuel injector assembly, a fuel/air is inducted from the cold start fuel injector, through the auxiliary intake manifold and into the engine combustion chambers. Optionally, the cold start fuel injector assembly as well as the auxiliary intake manifold is heated to enhance the vaporization of the fuel prior to induction into the combustion chambers.

US Patent:

6874467, Apr 5, 2005

Filed:

Aug 7, 2002

Appl. No.:

10/213794

Inventors:

Frank Warren Hunt - West Bloomfield MI, US
Shigeru Oho - Farmington Hills MI, US
Ayumu Miyajima - Farmington Hills MI, US

Assignee:

Hitachi, Ltd. - Tokyo

International Classification:

F02D041/06
F02D009/00

US Classification:

12333927, 123399, 123442, 12356821, 123491

Abstract:

A fuel delivery system having an electronically controlled throttle valve operatively disposed in an intake manifold. An idle speed control valve is operatively disposed within a bypass gas flow passageway. A control system controls the actuation of both the throttle valve and idle speed control valve to control the delivery of a combustible charge to the internal combustion engine to maximize engine efficiency and minimize noxious emissions.

US Patent:

6918383, Jul 19, 2005

Filed:

Jul 8, 2003

Appl. No.:

10/614881

Inventors:

Frank Warren Hunt - West Bloomfield MI, US
Ayumu Miyajima - Farmington Hills MI, US
George Saikalis - West Bloomfield MI, US
Jonathan Borg - Livonia MI, US
Shigeru Oho - Farmington Hills MI, US

Assignee:

Hitachi, Ltd. - Tokyo

International Classification:

F02M023/00

US Classification:

123531, 12317917

Abstract:

A cold start fuel control system is disclosed for use with an internal combustion engine having a plurality of combustion chambers, a source of fuel and an intake manifold having an inlet and an outlet port connected to each combustion chamber. The system includes a cold start fuel injector assembly having an inlet and an outlet to provide a vapor fuel charge during a cold start engine condition. The cold start fuel injector assembly inlet is fluidly connected to the source of fuel. An auxiliary intake manifold has an internal chamber and the cold start fuel injector assembly outlet is fluidly connected to the auxiliary intake manifold chamber. The auxiliary intake manifold chamber is then fluidly connected through a control orifice to each of the combustion chambers at a position downstream from the inlet of the primary intake manifold. A control circuit optionally controls the area of the control orifice to minimize noxious emissions from the engine and a shroud is optionally associated with each control orifice to enhance mixing of the vapor fuel with the inducted airflow to also minimize noxious emissions from the engine.