Between a movable core chamber and a fuel supply passage, a needle guide slidably supports a needle fixed to a movable core. The needle guide has a communication hole which fluidly connects the movable core chamber and the fuel supply passage. An opening sectional area of the communication hole is defined in such a manner that a fuel discharged amount decreases as an energization start time of a coil is delayed. In a suction stroke, it is restricted that the movable core and the needle bounce toward the fixed core after the needle biases a suction valve toward a stopper by means of a biasing force of a second spring. A relationship between the energization start time of the coil and the fuel discharged amount is properly maintained, so that the fuel discharged amount of the high-pressure pump can be controlled correctly.

High pressure pump

A fuel supply system for a direct injection engine which has a variable capacity single cylinder plunger pump and two fuel rails. There are disposed orifices at the upstream side inlets of the both fuel rails, respectively. At the opposite sides to the inlet sides, the fuel rails are interconnected with each other by a connecting pipe. By the fuel supply system, it is capable of increasing a characteristic frequency of the fuel columns, and of stabilizing, suppressing, and smoothing out pressure pulsation in the fuel rails, thereby reducing uneven fuel injections into the cylinders. The system may have a cam which drives a plunger of a high pressure fuel pump to reciprocate once for every two combustion in two engine cylinders.

Fuel supply system

In a high pressure fuel supply pump for transmitting rotation of a cam to a reciprocating plunger via a tappet and a retainer, a diametric force acting on the plunger is reduced. The pump includes the retainer disposed on the plunger and a return spring exerting an urging force on the retainer in a direction of the tappet. A clearance between a plunger leading end and a tappet bottom surface opposed thereto is set to be greater than a clearance between a retainer bottom surface and the tappet bottom surface opposed thereto, and a clearance between a retainer inside diameter section and a plunger peripheral surface section opposed thereto is set to be greater than a clearance between a retainer outside diameter section and a tappet inner wall opposed thereto.

High-pressure fuel supply pump

Methods and systems are provided for restarting an engine in response to a driver's change-of-mind. In one embodiment, the engine is shutdown during an idle stop with the transmission in a higher gear or with the transmission tied-up to a transmission case. In response to a driver change-of-mind restart request, the transmission is downshifted, or released from the tie-up, to return driveline torque.

Method and system for engine control

A fuel supply system includes a fuel pump having a bottom inlet end configured to pick up fuel and a top discharge end configured to discharge fuel at a pressure higher than that of the inlet end. A housing defines a pressure vessel in fluid communication with the discharge end of the fuel pump. The fuel pump is secured with respect to the housing so that the pressure vessel is laterally adjacent the fuel pump and the pressure vessel and the fuel pump have overlapping heights. Exactly one check valve is positioned between the discharge end of the fuel pump and the pressure vessel, and the check valve is spaced laterally away from the discharge end of the fuel pump at an inlet to the pressure vessel.

In a high pressure fuel injection system, fuel is pumped up from a fuel tank by a low pressure pump and further pressurized by a high pressure pump. Pressurized fuel is accumulated in a common rail connected to injectors which inject fuel into an engine. A high pressure regulator is connected to the common rail to mechanically relieve excessive fuel pressure in the common rail or to electronically reduce the fuel pressure when required. An electronic control unit controls operation of the high pressure pump, the high pressure regulator and the injectors according to engine operating conditions which are fed to the unit from various sensors. The fuel pressure in the common rail is decreased by operation of the high pressure pump and the high pressure regulator either rapidly or gradually according to engine operating conditions. Vapor, including fuel and air, accumulated in the common rail under high ambient temperature is purged out quickly before the engine is stared by driving only the low pressure pump under command from the electronic control unit. The system is also provided with a "limp-home" function under which a car is driven back home even when some portions of the system fail or malfunction.

High pressure fuel injection system for internal combustion engine

A fuel supply apparatus having a cross sectional
area S 0 of a first low pressure fuel passage (3) which is
connected to a high pressure pump (5) and which has a pressure
regulator (7), a cross sectional area S 1 of an orifice (20)
formed between the first low pressure fuel passage (3) and
a second low pressure fuel passage (2), and a cross sectional
area S 2 of the second low pressure fuel passage (2) for
supplying the low pressure fuel to the first low pressure
fuel passage (3) Those cross sectional areas are set to
satisfy a relationship of S 1 < S 0 < S 2 such that the pressure
pulsation generated at the pressure regulator (7) is reduced,
and the noise produced by the fuel supply apparatus is
reduced

Fuel supply apparatus

A common rail delivers fuel to a fuel injection valve for injecting fuel directly into each combustion chamber of a direct injection type gasoline engine. A connected accumulator incorporates a gas-sealed type damper. A body portion of the damper can stretch and shrink by being constructed of a metallic bellows, and gas is sealed in the metallic bellows. The pressure at which the gas is initially sealed within the damper is set for 4 Mpa or more, more preferably, for 8 Mpa or more. Further, to secure suppression of a variation in normal operation fuel pressure (for example, 10-12 Mpa), the pressure at which the gas is initially sealed within the damper is set to be lower than the normal operation fuel pressure, more preferably, lower than the normal operation fuel pressure by 1 Mpa or more.

Fuel supply apparatus for direct injection type gasoline engine

An apparatus and method for applying constant pressure to a plurality of pressure demanding mechanisms is disclosed. The apparatus includes a common rail, a plurality of pressure demanding mechanisms, a pressure supply source, and a plurality of branching paths. The lengths of the pressure supply path Lp, the pressure propagation path in the common rail, Lc, and the pressure branching paths, Li, are chosen so as to satisfy the following formulae, which leads to reductions in pressure fluctuations: (2n+0.5)Lp≦Lc≦(2n+1.5)Lp (2n+1.5)Lp≦Li≦(2n+2.5)Lp, where (n=0, 1, 2, . . .).

Pressure supply device

PROBLEM TO BE SOLVED: To early transfer a common-rail internal pressure to a desired reduced pressure, when an operating condition of an engine is placed in a pressure reduction required condition of the commonrail internal pressure. SOLUTION: An electromagnetic and mechanical high pressure regulator 10 is provided, which can reduce a fuel pressure of a fuel supply system supplying fuel to an injector 106 via a common-rail 105 from a high pressure fuel supply pump 104. When an operating condition of an engine is placed in a pressure reduction required condition of a common-rail internal pressure, by an input of an electric signal, the high pressure regulator 10 is placed electromagnetically in an opening condition, partly high pressure fuel in the common-rail is forcedly opened to a low pressure side, so as to early transfer the common- rail internal pressure to a desired reduced pressure.

Tsutomu Furuhashi

Papers

High pressure fuel injection system for internal combustion engine

Fuel supply apparatus

Fuel supply apparatus for direct injection type gasoline engine

Pressure supply device

Accumulator type fuel supply device for engine