Zexel Gmbh

Diesel Kiki Co., Ltd.

Mitsubishi Jidosha Kogyo Kabushiki Kaisha

Hiroshi Ishiwata

Jun Matsubara

Takashi Ohishi

Susumu Yamaguchi

Kenichi Kubo

Tohru Yokota

Noriyuki Abe

Nobuhiro Kitahara

Mitsuaki Kobayashi

Toru Yokota

Toshiaki Kasahara

Hisashi Nakamura

Atsushi Ueda

Ken-ichi Kubo

Tsutomu Katori

Katsuhiro Shimokoshikimachi

Hiroshi Tai

Naotake Ohi

Ken'ichi Kubo

Toru Yamakawa

Teruo Ohsawa

In a spill control apparatus for a fuel injection system in which a sleeve is externally fitted to a rotor, and the position of the sleeve relative to the rotor is used to adjust the communication timing between a port on the rotor and a port on the sleeve, the port formed at the rotor is constituted of a first indented portion formed over a specific angle of rotation and a second indented portion formed to achieve specific spill characteristics. The second indented portion is formed continuous to the front end of the first indented portion in the direction of rotation and the contour of the second indented portion is continuous to the contour of the first indented portion which is constituted of oblique sides which extend toward the front relative to the direction of rotation. The length of the rotor port in the axial direction may be set smaller than the length of the port formed on the sleeve in the axial direction. Thus, it is possible to inhibit the entry of dust particles into the area between the rotor and the sleeve, reducing the incidence of scarring induced on the sliding contact surfaces of the rotor and sleeve, and preventing the seizure of the rotor and the sleeve.

Spill control apparatus for fuel injection system

The movement of a control sleeve in the circumferential direction is made to interlock with the movement of a timer piston to ensure that the control sleeve has a function of pre-stroke control. In order to interlock the movements of the timer piston and the control sleeve, they are linked with first through third link members and the control sleeve is caused to rotate in the circumferential direction at a specific ratio relative to the quantity of movement of the timer piston. In a fuel injection system provided with an actuator for adjusting the fuel force feed end by moving the control sleeve in the direction of the axis and an actuator for controlling the timing with which the cam lift begins, pre-stroke control can be achieved without requiring a separate actuator, with a simple mechanical structure.

Fuel injection system

Inflow/outflow ports are provided in either one of a distribution member for distributing compressed fuel or a control sleeve which is externally fitted around the distribution member. Each of the ports includes a slit extending therefrom. At the other one of the distribution member and the control sleeve, an intake-cutoff hole that communicates sequentially with the inflow/outflow ports and a pilot port which communicates with the slits during part of the force feed period are provided. Since the fuel flows out through the slits during part of the force feed period, pilot injection can be more easily achieved prior to the main injection during low speed rotation and fuel is less likely to be diverted through the slits due to the constricting effect during high speed rotation so that only the main injection is performed. As a result, a distributor type fuel injection pump which achieves pilot injection in the idling range and in the no-load range, and cancels the pilot injection in the full-load range is provided.

Distributor type fuel injection pump

A prestroke controller 31 for an engine fuel injection pump 30 utilizes a magnetic coupling 26 and, by taking advantage of the fact that the secondary side (driven side internal magnet) of the magnetic coupling can be controlled to a desired position without being driven by force from a flyweight 11 on the primary side (driving side external magnet), not only secures speed timer characteristics but also provides a greater degree of freedom in determining the injection timing advance characteristic. The prestroke controller 31 includes the magnetic coupling 26 as a member of a displacement transfer section provided between the flyweight 11 and the timing control rod 6 and also includes an add-on device 36 for injection timing advance adjustment which can be engaged with or disengaged from the timing control rod 6 and is capable of controlling the prestroke independently of the magnetic coupling 26.

Prestroke controller for engine fuel injection pump

A pilot injection controller and a method of controlling pilot injection quantity enable the quantity of fuel pilot-injected fuel by an internal combustion engine fuel injection system of the type in which the fuel delivery stroke for pilot injection is fixed to be maintained substantially constant irrespective of engine speed by controlling prestroke such that the utilized portion of a cam is shifted to a lower delivery velocity region thereof with increasing engine speed, the principle involved being that the quantity of fuel pilot-injected by a fuel injection system is proportional to the actual plunger delivery velocity and the fact that since the actual delivery velocity is proportional to the product of the cam velocity constant and the cam rotational speed the actual delivery velocity can be maintained substantially constant by increasing the cam velocity constant in the low speed region and decreasing the cam velocity constant in the high speed region.

Pilot injection controller in fuel injection system and method of

In a solenoid valve, a gap is formed between a solenoid, which includes a stator housed within a resin mold, and a retainer that secures the solenoid on a housing. The gap communicates with a armature chamber that houses the armature mounted on a front end of a plug valve. High-pressure fuel is charged from the fluid passage into the armature chamber and flows into the gap around the solenoid to apply even pressure to the periphery of the resin mold as well as to the intake end surface of the solenoid. This prevents deformation of the resin mold and, consequently, distortion of the intake end surface. Such distortion can also be prevented by internally fitting a protective plate made of a non magnetic body in the opening ends of the coil grooves formed in the intake end surface of the stator.

Solenoid valve

A pilot injection control system for an internal combustion engine comprises a plurality of fuel injection nozzles, the valve-opening pressure of one of which (the reference nozzle) is set slightly higher than that of the other nozzles, means for detecting the pilot injection of the reference nozzle, and means for feedback controlling the pilot injection quantity of the reference nozzle based on the detected pilot injection. The system is able to effectively control the pilot injection of all nozzles by actually controlling the pilot injection of only one nozzle and can therefore be implemented at low cost.

Pilot injection control system

A fuel injection pump for an engine comprises a magnetic coupling 37 straddling a partition 36 for connecting a timing control rod 6 and a displacement transfer section 34 of a governor so as to enable efficient transfer of rotational force from the displacement transfer section to the timing control rod without need for an oil seal therebetween, and a prestroke controller for the fuel injection pump 131 includes an injection advance adjustment add-on device 136 for conducting prestroke control independently of the magnetic coupling and thereby provide greater freedom in establishing injection timing advance characteristics by enabling injection timing control in response to temperature or load and/or a safety mechanism 237 for ensuring operation of a governor mechanism 20 based on movement of a flyweight 11 even if the magnetic coupling should stick.

Fuel injection pump and prestroke controller therefor

A solenoid valve unit is provided in the middle of fuel supply path that leads to a compression space in an injection pump main body, and the fuel injection quantity is adjusted through the open and close control of the solenoid valve unit. In this fuel injection system, the plug valve is moved until it is seated on the valve seat during the preliminary injection that is performed prior to the main injection. An arrangement for leaking the fuel from within the compression space is provided in the injection pump main body and the time period during which the fuel in the compression space is leaked via the arrangement for leaking and the time period during which the fuel supply path is restricted with the plug valve being seated on the valve seat are combined to stabilize the movement of the plug valve. Consequently, an optimal small quantity is achieved for the preliminary injection that is nearly constant regardless of the rate of rotation of the engine. Also, if a drive pulse that closes the fuel supply path over the period during which the fuel is leaked is supplied to the solenoid valve unit, the solenoid valve unit needs to be operated only once and stable injection characteristics are achieved from the pilot injection through the main injection.

ABSTRACT A solenoid valve is provided in a fuel injection pump fuel supply path. A communication path communicates with each other an armature chamber, which accommodates an armature, and a spill chamber, which accommodates a head of a valve body and is connected to a lower pressure side. When high pressure fuel is spilt to the low pressure side, an orifice in the communication path reduces a high frequency pressure wave propagated from the spill chamber to the armature chamber, thus reducing deformation or corrosion of the solenoid in over a long period of use.

Fuel injection device

A prestroke control device for a fuel injection pump includes at least one control sleeve slidably fitted on at least one plunger, a control rod engaging the control sleeve, the control rod extending perpendicularly to the plunger and rotatable about an axis thereof for varying an axial position of the control sleeve relative to the plunger to thereby control the prestroke of the plunger, and an actuator for rotatively driving the control rod about its own axis. A counterweight is movable in unison with rotation of the control rod for cancelling a rotating force generated by axial movement of the control sleeve and acting upon the control rod.

Prestroke control device for fuel injection pumps

A fuel injection pump includes a reciprocating plunger and a control sleeve slidably fitted over the plunger, the prestroke of which is varied by vertical movement of the control sleeve. The control sleeve is provided at its upper end with a fuel discharge groove, through which the fuel contained in a fuel-pressurizing chamber is discharged after the end of injection. The control sleeve also has to pressure escape passage. A variation in the effective stroke allows the pressure of fuel contained in the fuel-pressurizing chamber to be selectively regulated by the pressure escape passage, thereby controlling the pressure of fuel to be injected.

Fuel injection pump having variable prestroke mechanism

In a fuel injection apparatus for an internal combustion engine which has a fuel injection pump having a plunger and one control sleeve fitted on the plunger and capable of regulating both the fuel injection quantity and the timing of the beginning of fuel injection by the adjustment of the relative positional relationship therebetween, and a control unit for controlling the positional relationship in order to obtain the optimum fuel injection rate and fuel injection quantity, the apparatus comprises a detector for detecting any trouble occurring in the control system for regulating the position of the control sleeve and a limiting circuit for limiting the control operation by the control unit so that an excessive rise in the inner pressure of the cylinders in the internal combustion engine is prevented when the occurrence of the trouble is detected by the detector.

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Higashimatsuyama, Japan

Hiroshi Ishiwata