Komatsu Corporation

Kabushiki Kaisha Komatsu Seisakusho

Kawasaki Steel Corporation

Jiro Akagi

Shigeru Yamamoto

Nobuki Hasegawa

Takao Nagai

Taku Murakami

Kazunori Kuromoto

Kunihiko Imanishi

Hiroki Sato

Sadachika Akiyama

Daisuke Yoshida

Godo Ozawa

Takashi Sakasai

Masaki Takahashi

Norifumi Abe

Koichi Okaya

Hiroki Satow

Noriaki Nakane

The present invention provides a wide range injection timing, small dispersion, good response and simple structure. In order to obtain this, in a fuel injection device for a diesel engine comprising a cylindrical body ( ), an upper plunger ( ) inserted thereto and capable of sliding in a vertical direction in response to a cam, an intermediate plunger forming a pressure chamber ( ) with respect to the upper plunger, a lower plunger ( ) brought into contact with the intermediate plunger, and an injection chamber ( ) provided in a lower end portion of the body plunger, in which a fuel in the injection chamber is injected by the lower plunger being subject to a force from the upper plunger, the improvement comprises a passage, having a large cross-sectional area, formed in the body for supplying a pressurized oil to the pressure chamber, the intermediate plunger ( ) being vertically movable in response to an oil pressure so as to make it possible to change a volume of the pressure chamber, and a timing spring ( ) having an end being brought into via contact with the intermediate plunger and the other end being brought into contact with the lower plunger and vertically moving the intermediate plunger in response to the pressure.

Fuel injection device for diesel engine

Only snapshot data necessary for monitoring faults are collected from machine such as vehicles, allowing faults to be more accurately monitored, and the amount of data and the memory storage volume at a monitoring station to be reduced. The values of a plurality of (A), (B), (C), and (D) operating parameters (engine rotational speed, lever operating position, vehicle speed, and tractive force) which change during the operation of the machine are sequentially detected for each machine. The fault detection history data are thus updated every time a fault (drop in engine oil pressure, overheating) is detected during the operation of the machine. Thus, when a fault (drop in engine oil pressure) is detected during the operation of the machine, it is determined on the basis of the history data whether or not to send to the monitoring station the sequential values of the operating parameters ((A) engine rotational speed, (B) lever operating position, (C) vehicle speed, (D) tractive force) from within a prescribed period of time (from 10 min. before to 5 min. after) around the point in time t0 at which the fault was detected. When it is determined that they should be sent, the type of detected fault (0001 (drop in engine oil pressure)), the values detected ((A) 2, (B) 3, (C) 3, (D) 2) at the time the fault was detected, as well as the sequential values of the operating parameters from within a prescribed period of time (from 10 min. before to 5 min. after) around the time the fault was detected are transmitted to the monitoring station. When it is determined that they should not be sent, on the other hand, the type of detected fault (0001 (drop in engine oil pressure)) and the values detected ((A) 2, (B) 3, (C) 3, (D) 2) at the time the fault was detected are sent to the monitoring station.

Machine fault monitoring apparatus and method

An inductive load driving device in which the rise of load current at an initial stage of driving can be executed at high speed includes a plurality of step-up circuits (,), for alternately applying a high voltage to the same inductive load within a predetermined period of time, to thereby allow each load current to rise at a high speed; a holding current output circuit (,), for applying a predetermined voltage to the same inductive load after the load current has risen, to thereby hold the load current at a predetermined value; a plurality of switching means (,), adapted to be switched in such a manner that the respective outputs of the plurality of step-up circuits (,) and the holding current output circuit (,) can be alternately connected to the same inductive load; and a control logic circuit (,), for switching the plurality of switching means (,) in a predetermined sequence.

Inductive load driving device and driving method

Maintenance due times of components of a machine are determined according to the status of user-performed in-house maintenance and according to the occurrence of abnormalities during machine operation. A subtraction point (20 points) associated with an abnormality (overheating) detected during machine operation is subtracted from the score (80 points) of a corresponding component (engine) in the machine. An addition point (50 points) associated with the type of maintenance (overhaul performed by in-house maintenance) indicated in maintenance information is added to the score (80 points). Thus, at the time where the value resulting from subtractions from and additions to the score for that component (engine) reaches a prescribed value (10 points) indicating maintenance due time, it is determined that the maintenance due time for that component (engine) has been reached.

Method and apparatus for determining machine maintenance due times

Method of controlling fuel injection apparatus for internal combustion

Fuel injection system for internal combustion engine

A fuel injection nozzle assembly for the injection of fuel under pressure into a combustion chamber of an internal combustion engine. A nozzle body has formed therein a fuel inlet, a storage chamber and spray orifices for discharging pressurized fuel from the storage chamber. Disposed in the storage chamber is a needle valve for opening and closing the spray orifices and a check valve for admitting a metered amount of pressurized fuel into the storage chamber. The needle valve has formed therein a blind hole in which is slidably mounted a stem extending from a cylindrical section of a check valve and an axial passageway is formed through the stem.

Fuel injection nozzle assembly

A diesel fuel injection nozzle and holder assembly includes a tubular nozzle holder carrying a nozzle on one end and defining, in combination therewith, a storage chamber for receiving successive charges of fuel under pressure via a check valve mounted therein. A needle valve, complete with a stem, mounted in the storage chamber is urged by a first spring toward a position for closing spray orifices in the nozzle. Disposed opposite to the end of the needle valve stem, a yieldable abutment is biased by a second spring toward the stem and normally retained a preassigned distance away therefrom. When acted upon by each pressurized fuel charge trapped in the storage chamber, the needle valve is unseated to open the spray orifices against the force of the first spring if the fuel pressure is relatively low, and against the resultant of the forces of the first and second springs if the fuel pressure is higher.

Fuel injection nozzle and holder assembly for internal combustion engines

An injection valve assembly for spraying fuel into a diesel engine by receiving accurately metered charges of the fuel under pressure from an engine-driven jerk pump. The fuel inlet of the valve assembly communicates via a check valve with a storage chamber, where each incoming charge of pressurized fuel is stored temporarily. The fuel outlet of the valve assembly, in communication with the storage chamber, is normally closed by a spring-biased needle valve member. Upon full accumulation of each fuel charge in the storage chamber the check valve automatically closes the fuel inlet thereby causing the needle valve member to be displaced under the fuel pressure against the bias of the spring and hence to open the fuel outlet. Another embodiment employs two needle valve members, one for the on-off control of communication between the storage chamber and the fuel outlet, and the other for the on-off control of the fuel outlet.

Fuel injection valve assembly for internal combustion engines

A fuel injection apparatus for a diesel engine comprising a holder body having an accumulator chamber and a spring chamber, a nozzle body detachably connected to the holder body, the nozzle body having formed therein a stepped longitudinal bore, a pressure chamber intermediate the stepped longitudinal bore and an injection orifice communicating with the longitudinal bore, a check valve disposed in a passage communicating a fuel injection pump with the accumulator chamber, a solenoid-operated spool valve mounted in the accumulator chamber, a communication passage having an upper end selectively connectible with the accumulator chamber through the spool valve and a lower end being in constant communication with the pressure chamber, a needle valve fitted in the stepped longitudinal bore and movable therein, and a spring accommodated in the spring chamber for biasing the needle valve toward closing the injection orifice.

Growing community of inventors

Oyama, Japan

Jiro Akagi