Diesel Kiki Co., Ltd.

Zexel Gmbh

Ken-ichi Kubo

Hisashi Nakamura

Jun Matsubara

Toshiro Hirakawa

Hiroshi Ishiwata

Xin-he Li

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

A servo valve type timer for controlling a fuel injection timing on the basis of the difference in pressure between a high-pressure chamber and a low-pressure chamber, including a timer piston for adjustment of a fuel injection timing which is disposed between the high-pressure chamber and the low-pressure chamber so as to be slidable between the high-pressure chamber and the low-pressure chamber and is operated in accordance with a fuel pressure introduced into the high-pressure chamber and/or the low-pressure chamber, a servo valve for controlling the operation of the timer piston, and a pressure control member for adjusting the fuel pressure of the low-pressure chamber.

Servo valve type timer for fuel injection pump

An electromagnetic valve includes a tubular valve member fitted on a cylindrical guide member for sliding movement therealong. The guide member has an axial introduction passage leading to a valve seat of the valve member via a communication passage. When the valve member is disengaged from the valve seat, a high-pressure fluid in the introduction passage is spilled into a low pressure chamber provided around the guide member. The electromagnetic valve is incorporated in a unit fuel injector so as to control the spilling of the fuel pressurized by a pump mechanism. In the unit fuel injector, the pump mechanism, the electromagnetic valve and an injection nozzle mechanism are mounted on a linearly-extending body and disposed on the axis of said body. A plunger of the pump mechanism and a nozzle of the injection nozzle mechanism extend along the axis of the body. The electromagnetic valve is disposed between the pump mechanism and the injection nozzle mechanism.

Electromagnetic valve and unit fuel injector with electromagnetic valve

In a distribution-type fuel injection pump, a fuel supply passageway, through which a feed pump and a fuel pressurizing chamber communicate with each other, is isolated from a cam chamber and bypasses the same. In order to simplify the construction, the fuel supply passageway is formed in a peripheral wall portion of a housing. On the other hand, a cam mechanism comprises a spring assembly including at least one spring, first and second annular spring seats and an engaging member. The first spring seat has an annular base section and an extension extending from a peripheral edge of the base section toward the second spring seat. The engaging member is fixedly mounted to a forward end of the extension. Prior to incorporation the spring assembly into a hollow body of the housing, the spring assembly is in a state in which the peripheral edge of the second spring seat is engaged with the engaging member under elastic force of the spring. After the spring assembly has been incorporated into the body through an opening at one end thereof, bolts are employed to fixedly mount the head to the body against the spring to close the opening of the body.

Distribution-type fuel injection pump

A fuel injection pump of the type wherein the fuel injection timing is controlled by a timer and a solenoid-operated timing control valve. The timer has a high-pressure chamber and a low-pressure chamber which are defined at both sides, respectively, of a timer piston. The high-pressure chamber communicates with a high-pressure groove formed in the timing control valve through a passage. The low-pressure chamber communicates with the suction side of a feed pump through a low-pressure passage and also communicates with a low-pressure hole formed in the timing control valve through a passage. The timer piston is not provided with a passage mechanism which provides communication between a pump chamber and the high-pressure chamber. The pump chamber communicates directly with the high-pressure groove in the timing control valve through a fixed orifice disposed in the wall of the pump housing and a passage leading to the orifice. This structure enables a reduction in the dead volume of the passage required to activate the timer piston.

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Higashimatsuyama, Japan

Ken-ichi Kubo