Honda Giken Kogyo Kabushiki Kaisha

Honda Motor Co., Ltd.

Dowa Thermotech Co., Ltd.

Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Susumu Maeda

Shinichi Kubota

Eiji Mutoh

Atsushi Kobayashi

Yuichiro Shimizu

Kiyotaka Akimoto

Masao Kanayama

Shuji Nagatani

Masato Yuya

Hideki Imataka

Yuya Gyotoku

Suguru Asakura

Tsuyoshi Baba

Shigeru Ibaraki

Akira Nagai

Takashi Kawachi

Akihisa Sato

Kazuya Yokayama

A first nitriding process step is performed in which a steel member is subjected to a nitriding process in a nitriding gas atmosphere having a nitriding potential with which a nitride compound layer having a &#x3b3;' phase or an &#x3b5; phase is generated, and thereafter a second nitriding process step is performed in which the steel member is subjected to a nitriding process in a nitriding gas atmosphere having a nitriding potential lower than the nitriding potential in the first nitriding process step, to thereby precipitate the &#x3b3;&#x2032; phase in the nitride compound layer. It is possible to generate the nitride compound layer having a desired phase mode uniformly all over a component to be treated and to manufacture a nitrided steel member high in pitting resistance and bending fatigue strength.

Nitriding process method of steel member

A nitrided component has a chemical composition consisting of, by mass percent, C: 0.07-0.14%, Si: 0.10-0.30%, Mn: 0.4-1.0%, S: 0.005-0.030%, Cr: 1.0-1.5%, Mo: &#x2264;0.05% (including 0%), Al: 0.010% or more to less than 0.10%, V: 0.10-0.25%, optionally at least one element selected from Cu: &#x2264;0.30% and Ni: &#x2264;0.25%, [0.61Mn+1.11Cr+0.35Mo+0.47V&#x2264;2.30], and the balance of Fe and impurities. P, N, Ti and O among the impurities are P: &#x2264;0.030%, N: &#x2264;0.008%, Ti: &#x2264;0.005%, and O: &#x2264;0.0030%. The nitrided composition is suitable for use as an automobile ring gear. The nitrided component has a surface hardness of 650-900 HV, core hardness being &#x2265;150 HV, effective case depth of &#x2265;0.15 mm, has excellent bending fatigue strength and surface fatigue strength although the content of Mo is as low as &#x2264;0.05% and has a small amount of expansion caused by nitriding.

Nitrided component

A manufacturing method of a nitrided steel member and the nitrided steel member include: performing a nitriding treatment on a steel member made of a carbon steel or an alloy steel in an atmosphere of a nitriding treatment gas in which when the total pressure is set to 1, a partial pressure ratio of NHgas is set to 0.08 to 0.34, a partial pressure ratio of Hgas is set to 0.54 to 0.82, and a partial pressure ratio of Ngas is set to 0.09 to 0.18, at a flow speed of the nitriding treatment gas set to 1 m/s or more, at 500 to 620&#xb0; C.; and thereby, forming an iron nitride compound layer having a thickness of 2 to 17 &#x3bc;m on a surface of the steel member.

Manufacturing method of nitrided steel member

A nitrided steel member including an iron nitride compound layer formed on a surface of a steel member having predetermined components, wherein: in X-ray diffraction peak intensity IFeN (111) of a (111) crystal plane of FeN and X-ray diffraction peak intensity IFeN (111) of a (111) crystal plane of FeN, which are measured on a surface of the nitrided steel member by X-ray diffraction, an intensity ratio expressed by IFeN (111)/{IFeN (111)+IFeN (111)} is 0.5 or more; Vickers hardness of the iron nitride compound layer is 900 or less, Vickers hardness of a base metal immediately under the iron nitride compound layer is 700 or more, and a difference between the Vickers hardness of the iron nitride compound layer and the Vickers hardness of the base metal is 150 or less; and a thickness of the iron nitride compound layer is 2 to 17 &#x3bc;m.

Nitrided steel member and manufacturing method thereof

The present invention provides a nitrided steel member and manufacturing method thereof. the nitrided steel member including: an iron nitride compound layer formed on a surface of a steel member made of carbon steel for machine structural use or alloy steel for machine structural use, in which with regard to X-ray diffraction peak intensity IFeN (111) of the (111) crystal plane of FeN and X-ray diffraction peak intensity IFeN (111) of the (111) crystal plane of FeN obtained by measuring a surface of the nitrided steel member by X-ray diffraction, an intensity ratio represented by IFeN(111)/{IFeN (111)+IFeN (111)} is 0.5 or more, and a thickness of the iron nitride compound layer is 2 to 17 &#x3bc;m.

Evaporator temperature control means (U) that, in order to make the temperature of steam generated by heating water using exhaust gas of an engine coincide with a target temperature, controls the amount of water supplied to the evaporator based on the flow rate of the exhaust gas, the temperature of the exhaust gas, the temperature of the water, and the temperature of the steam. Calculating an exhaust gas flow rate (Gmix) based on a fuel injection quantity, an air/fuel ratio, and a rotational speed of the engine improves the precision and the responsiveness of the calculation. Controlling the amount of water supplied to the evaporator based on this exhaust gas flow rate (Gmix) therefore improves the accuracy with which the steam temperature is controlled so as to make it coincide with the target temperature.

Temperature control device of evaporator

In order to control an actual temperature of a vapor generated by en evaporator ( ) for heating water by an exhaust gas from an engine ( ) to a target vapor temperature by varying the amount of water supplied from a supplied-water amount control injector ( ), a control unit ( ) controls the amount of water supplied in a feedforward manner in accordance to an engine rotational speed and an intake negative pressure and controls the amount of water supplied in a feedback manner based on a difference between the actual vapor temperature and the target vapor temperature. It is possible to control the actual temperature of the vapor generated by the evaporator ( ) to the target vapor temperature with a high accuracy even in a transient state of the engine ( ) by correcting a feedforward control value using at least one of a fuel-cut control signal, an ignition-retarding control signal, an EGR control signal and an air fuel ratio control signal which are parameters indicating a burned state of the engine ( ).

Steam temperature control system for evaporator

The fuel injection valve controller steadily detects the completion of opening of the fuel injection valve or the completion of the needle valve lifting movement. A current flowing through the electromagnetic coil 4 which drives the fuel infection valve, is measured based on the voltage difference V across the resistor R6 connected in series with the coil 4. The circuit 21 emphasizes changes in the coil current. The signal V2 representative of emphasized coil current is supplied to the current change detecting circuit 22 which generates the output signal V3 when the coil current or voltage signal V2 temporarily decreases. The signal V3 is compared with the reference voltage Vref to issue the signal S3 showing the full opening of the fuel injection valve.

Fuel injection valve controller apparatus

A second operation mode without a hold period is used for starting up an engine when the ambient temperature is extremely low so that an electromagnetic coil remains fed with the current until the valve opening is completed, thus ensuring elimination of an injection valve cling up. A full opening of the injection valve is recognized by detecting a decrease of a coil current in the electromagnetic coil. The lower the temperature where the cling up is hardly eliminated in a short period, the longer the energizing period for the coil is provided. Consequently, such an event as failing to eliminate the cling up due to too short of the energizing period will be prevented.

A vehicle anti-theft system in which, only when the ID signal is obtained from a right ignition key and when the vehicle anti-theft function is halted by the failure of an anti-theft circuit or theft detection unit itself, the start-up of the engine is permitted. The system comprises a unit for generating a start-up enable signal in response to a verification signal representing a right ID signal, and an engine control unit for performing the start-up control of the engine in response to the start-up enable signal and disabling the engine in response to a theft signal. The start-up enable signal generating unit generates a start-up enable signal in response to the fault signal. A dummy line for detecting a breakage is wired along various signal lines wired on the substrate of an immobilizer, which, if intentionally broken by an ill-intentioned third party, could cause a fault signal similar to that for the failure of the immobilizer to be outputted from a determination signal output terminal. If a break in the dummy line is detected, the engine control is inhibited even if the fault signal is detected.

Vehicle anti-theft system

An engine control device exhibiting a unique vehicle anti-theft function which prevents a vehicle from being stolen when equipped physically on a vehicle in place of an engine control device with vehicle anti-theft function. The antenna unit detection circuit in an ECU 30b' instructs engine ECU 16 to inhibit engine control when it is detected that an antenna unit 29 which should not originally be connected to ECU 30b' has been connected to ECU 30b', that is, the ECU 30b' without anti-theft function is attached to a vehicle to which an ECU 30a with anti-theft function is to be attached.

Simplified vehicle engine control device for mounting on a vehicle

An engine control system in which control of an engine can be performed after there has been a momentary power disconnection of a power supply, such as the vechicle battery, from an engine control unit of an electronic circuit which executes an anti-theft function. A power supply detecting circuit detect a connecting of the power supply to the engine control unit. A further circuit determines on the basis of the vehicle speed and the RPM whether or not the vehicle is running. When a connecting of the power supply to the engine control unit is dectected, a determination is made whether or not the power supply connecting has occured after a preceding momentary power disconnection if the further circuit determines that the vehicle is running. The anit-theft function of the electronic circuit is disable when it is determined that there has been a preceding momentary power desconnection.

Engine control system with vehicle anti-theft function

Ribs 9'a to 9'd provided in a connector 50b on the terminal device side are coincident with grooves 8'a to 8'd provided in a connector 40b on the ECU 30b side, but are not coincident with grooves 8a to 8d provided in a connector 40a in position, size and shape. Even if the connector 40b of the ECU 30b without the immobilizer CPU 13 is attempted to be engaged the connector 50a which should originally be connected to the ECU 30a with the immobilizer CPU 13, it cannot be engaged or right electrical connections between input/output terminals in the ECU 30a and corresponding terminal devices cannot be achieved. Accordingly, the theft of the vehicle by replacing the ECU 30a with the ECU 30b is prevented.

A method and apparatus for vehicular data processing which enable quick, efficient input of first serial data entered from an external device and comparison of the first and second data with prestored second serial data. First serial data is repeatedly sent out asynchronously. The prestored second serial data is sent out in response to a request. Storing of the second serial data is performed until distinctive leading pulse of the first serial data is detected, at which time storing of the second serial data is suspended to permit storing of the first serial data in an interrupt mode.

Data processing method and apparatus for vehicle

A data processing apparatus for a vehicle which permits accurate and reliable registration of a key ID code in a vehicle. ID code detecting means detects an ID code received in succession from outside. The ID code detected previously is registered in the memory 132 for previous ID code; the ID code detected this time is registered in the memory 133 for the present ID code. First comparing means compares the previous ID code with the present ID code and if the two ID codes match, then the ID code is registered as a reference ID code in an EEPROM. Second comparing means compares the present ID code with the reference ID code and if the two ID codes match, then it issues an engine control enable (OK) signal to an engine CPU.

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Wako, Japan

Susumu Maeda