Diesel Kiki Co., Ltd.

Keiichi Yamada

Masayoshi Kobayashi

Toru Sakuranaka

Takeo Kushida

Shinya Nozaki

Tadashi Kobayashi

Tsuneyuki Chiyoda

Nobuyuki Nakajima

Tatsuhiko Abe

Sachio Nakagawa

Ryuichi Komori

Kohki Iwata

Hideyuki Kimura

Masayasu Hayakawa

Tadao Gonda

A fuel injection timing control method for a diesel engine, wherein engine rotational speed and fuel injection quantity as a parameter value indicative of the engine load magnitude are detected. A desired value of the fuel injection timing based upon the detected engine rotational speed and fuel injection quantity is calculated by means of an electronic control unit. An injection timing control device operatively connected to the fuel injection pump of the engine is driven according to the calculated desired fuel injection timing value, so as to minimize the difference between the calculated desired fuel injection timing value and an actual value of the fuel injection timing, by means of the electronic control unit. The fuel injection quantity is detected from the output of an oxygen concentration sensor indicative of oxygen concentration in engine exhaust gases, to thereby precisely detect the engine load magnitude and enable accurate control of the fuel injection timing.

Fuel injection timing control method for diesel engines

In a solenoid valve with ON/OFF switch arranged by a valve member and the associated valve seat defined in an electrically conductive body, the solenoid valve has a stopper connected to the valve member for setting the stroke of the valve member and is guided by an insulating guide member mounted on the body in such a way that the stopper comes in contact with only one of the end portions of the guide member when the solenoid actuator is in the de-energized state and this end portion is acting as an electrically insulating stopping member for the stopper.

Solenoid valve

An electromagnetic actuator in which a stator and an armature are opposed to move relatively. A plurality of coils are provided on the stator in the radial direction. A slit is formed on the armature in a radial direction and the flow of the eddy current in the circumferential direction is prevented.

Electromagnetic actuators

In a fuel injection nozzle unit, a piezo-electric element is provided about a central plunger for controlling the lift of the nozzle needle to selectively inhibit and allow lifting of the central plunger by having its inner diameter decreased or increased in response to electrical energization or deenergization thereof, thereby adjusting the fuel injection rate characteristic.

Fuel injection nozzle unit for internal combustion engines

A fuel injection apparatus comprises a first storing device for temporarily storing cut-off fuel drained after the termination of a fuel injection, a second storing device of changeable volume for temporarily storing fuel for intake, the second storing device having a movable member which is movable in response to the quantity of fuel introduced therein, a detector for producing a detection signal showing an actural position of the movable member and a clamping device responsive to an electric signal for clamping the movable member. The clamping device is actuated to clamp the movable member in response to the detection signal when the desired amount of fuel is stored therein. The adjusted quantity of fuel stored in the second storing device is supplied to a high pressure chamber together with the cut-off fuel stored in the first storing device during the next fuel intake stroke of a fuel injection pump. As a result, extremely high accuracy control of fuel quantity can be realized.

Fuel injection apparatus for internal combustion engines

A fuel injection system for in internal combustion engine includes a solenoid valve disposed across a fuel passage defined in a fuel injection pump and actuatable under the control of a control circuit for controlling the fuel injection quantity and the fuel injection timing. The actual fuel injection quantity is detected by a sensor disposed in the solenoid valve and fed back to the electric circuit where it is compared with the objective fuel injection quantity determined on the basis of engine operating conditions. If there is a difference, the fuel injection quantity supplied to the internal combustion engine through the solenoid valve is changed by the control circuit in a measured manner which will tend to make this difference disappear. The control of the fuel injection timing can be achieved by the system substantially the same manner as described above. The sensor comprises an electric on-off switch defined jointly by a valve seat and a valve element of the solenoid valve.

Fuel injection system for internal combustion engine

A suction space is disposed to selectively communicate with a pump working chamber defined at one end of a plunger via a first communication passageway in which a solenoid valve is arranged, or with suction ports formed in the plunger and communicating with the pump working chamber via a second communication passageway having a restriction therein. The solenoid valve alternately opens and closes for ordinary fuel injection during operation of the engine other than at the start thereof. A selector valve keeps the first communication passageway closed and simultaneously keeps the second communication passageway opened for fuel injection through collaboration of the suction ports with the second communication passageway, in place of the alternate opening and closing of the solenoid valve.

Electronically controlled distributor type fuel injection pump for

A pair of cut-off ports are formed in a plunger and a plunger barrel at a predetermined axial location and registrable with each other to spill pressurized fuel into a zone under lower pressure. A communication passageway communicates a pump working chamber defined by the plunger at one end thereof with the zone under lower pressure. A solenoid valve is arranged across the communication passageway for blocking same. Control means controls the solenoid valve to cause same to selectively assume an open position and a closed position. While the plunger moves toward the pump working chamber, the solenoid valve is closed by the control means to start injection of fuel present in the pump working chamber, and upon registration of the cut-off ports with each other, the fuel injection is terminated.

Electronically controlled distributor type fuel injection pump

A fuel injection valve for internal combustion engines wherein a nozzle needle is slidably fitted in a nozzle body so as to alternately close and open nozzle holes formed therein. A selector valve is axially slidably fitted through the nozzle needle to selectively close or open second nozzle holes formed in the nozzle body. While the nozzle needle has a predetermined valve opening pressure set by a nozzle spring, the selector valve is controlled to operate in response to operating conditions of the engine by control means such that the second nozzle holes are opened in predetermined operating regions of the engine. Thus, the overall discharge area of the nozzle holes can be controlled to values appropriate to operating conditions of the engine. Preferably, the selector valve comprises a spool valve which can assume a seated position wherein its spool is fitted in an axial through hole formed in the tip of the nozzle body to close the second nozzle holes opening in the peripheral wall of the axial through hole, and a lifted position wherein the spool is disengaged from the axial through hole to open the second nozzle holes.

Fuel injection valve with variable discharge area of nozzle holes

In a distributor type fuel injection pump in which fuel is sucked and pressurized by a reciprocating and rotating plunger, and the pressurized fuel is fed under pressure to each fuel injection nozzle from a distribution port by means of a distribution path, the improvement constituted by a delivery valve to be provided in the distribution path is omitted or a delivery valve having a large suction return quantity is provided, and an auxiliary port is provided in the plunger, and a groove for taking out the pressure when it is aligned with the auxiliary port is formed in the plunger barrel, and a uniform pressure slit is formed on the plunger which is at an identical position with that of the distribution port and being circumferentially offset by a proper angle, and the uniform pressure slit is communicated with the groove for taking out the pressure by means of a communicating path, and a pressure equalizing valve is provided in the communicating path, whereby non-continuous injection in a low speed zone can be prevented while the residual pressure before the injection can be set at high pressure, and also, the generation of a secondary injection can be curbed on account of the pressure after the injection being zero or the pressure after the injection being lowered to near zero.

Distribution type fuel injection pump

The nozzle body has a main nozzle hole and a sub nozzle hole formed therein, the latter being directed at a predetermined angle with the former and smaller in discharge area than the former. The nozzle needle slidably received in the nozzle body is disposed such that its tip is fitted in the main nozzle hole when the nozzle needle is in a seated position thereof, and the tip substantially remains in the main nozzle hole during lifting of the nozzle needle before the nozzle needle lifts through a predetermined stroke, whereby fuel is injected substantially solely through the sub nozzle hole in a first predetermined direction, while the tip of the nozzle needle substantially comes out of the main nozzle hole after the nozzle needle has lifted through the predetermined stroke, whereby fuel is injected mainly through the main nozzle hole in a second predetermined direction different from the first predetermined direction by the above predetermined angle. Control means is responsive to operating conditions of the engine to allow the nozzle needle to lift only through the above predetermined stroke in a low speed/low load region of the engine, while allowing the nozzle needle to lift beyond the predetermined stroke in a high speed/high load region of the engine.

Fuel injection valve for internal combustion engines

A fuel injection pump assembly comprises a plunger rotatably and telescopically mounted in a pump cylinder and having a plurality of fuel supply slots which are as many as the engine cylinders and movable in response to rotation of the plunger for selective communication with a pair of fuel inlet ports in the pump cylinder. The fuel supply slots are half as many as the engine cylinders and angularly equally spaced at a first angle. The fuel inlet ports are angularly spaced from each other at a second angle which is equal to the product of the first angle and [(1/2)+n (n=0 or a positive integer)]. The plunger is rotatable about its own axis in response to rotation of the engine and reciprocable in strokes which are as many as the engine cylinders per rotation of the engine for selectively supplying fuel from the fuel inlet ports through the fuel supply slots, through a pressurization chamber in the pump cylinder, and through a passageway in the plunger to fuel distribution ports in the pump cylinder which are connected to the engine cylinders via delivery valves. The fuel inlet ports are selectively opened and closed by solenoid-operated valves to disable selected engine cylinders by cutting off fuel supply thereto.

Fuel injection pump assembly

A distributive type fuel injection apparatus including a fuel distribution plunger mounted for rotary and reciprocating motion in a cylinder that defines a fuel pressure chamber, an inlet passage communicating with a fuel reservoir, and a plurality of discharge ports each providing communication between the pressure chamber and a different one of an engine's power cylinders. The plunger defines discharge passages for sequentially registering with the discharge ports and an overflow passage providing communication between the pressure chamber and the fuel reservoir. A control valve automatically closes the overflow passage during certain engine operating conditions and selectively opens the overflow passage during other engine operating conditions in synchronism with the registration between the discharge passages and only predetermined ones of the discharge ports.

Distribution type fuel injection apparatus

In a distribution type fuel injection system, the fuel injection advance angle, or the relative angular position at which fuel injection begins, is controlled by a first spring loaded piston (44). The spring force is opposed by pressurized fuel from a pump (14), the pressure increasing with engine speed. A second spring loaded piston (49) moves the first piston (44) to an advanced position for starting the engine and is retracted when the fuel pressure reaches a certain value to subsequently retard the advance angle in an idling speed range. The fuel pressure moves the first piston (44) to progressively advance the angle in a higher speed range. An electromagnetic valve (62) is controlled to trap fuel and apply a hydraulic lock to the second piston (49) during starting of the engine to prevent retarding of the advance angle until the engine speed or coolant temperature reaches a predetermined value.

Fuel injection advance angle control apparatus

A fuel injection pump in which a relief channel is formed which communicates with the pump working chamber and is arranged to be blocked by a valve means, associated with a valve actuating means responsive to a pressure varying with engine r.p.m., during starting of the engine so that the fuel injection quantity is increased. Thus, improved starting characteristics of the engine can be obtained. Said relief channel may comprise a first channel communicating with the pump working chamber, and a second relief channel which has a portion thereof extending in the pump plunger to terminate in an outer periphery of the bottom end of said plunger and is so disposed as to communicate with the pump suction chamber after a predetermined delivery stroke length or prestroke has been executed. Communication between said first and second relief channels is adapted to be interrupted by said valve means at less than a predetermined engine r.p.m. As another advantagenous arrangement, the relief channel may comprise a first relief channel which consists of a port having one end communicating with the pump working chamber and the other end terminating in an outer periphery of the plunger and a communication channel having one end terminating in an inner periphery of the plunger barrel and the other end arranged for communication with a lower pressure zone, and a second relief channel allowing a restricted flow rate and communicating with the pump working chamber. The port and communication channel of said first relief channel are so disposed as to communicate with each other at the beginning of the delivery stroke of the plunger. Said first and second relief channels are arranged to be simultaneously blocked by said valve means during starting of the engine.

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Higashimatsuyama, Japan

Keiichi Yamada