Abstract: A partitioning portion partitions a fuel chamber into a first space, which receives a pressurizing chamber forming portion and is communicated with an inflow pipe, and a second space, which is communicated with an outflow pipe. A flow passage forming portion extends from the partitioning portion toward the first space side and forms a communicating flow passage, which communicates between the first space and the second space. Thereby, vapor contained in the fuel, which is returned from a pressurizing chamber to the fuel chamber, is accumulated as bubbles in the first space, which receives the pressurizing chamber forming portion. The first space is communicated with the outside through the communicating flow passage and the second space. Therefore, outputting of air bubbles of the first space to the outside can be effectively limited in comparison to a case where the fuel chamber is directly communicated with the outside.

Abstract: A partitioning portion partitions a fuel chamber into a first space, which receives a pressurizing chamber forming portion and is communicated with an inflow pipe, and a second space, which is communicated with an outflow pipe. A flow passage forming portion extends from the partitioning portion toward the first space side and forms a communicating flow passage, which communicates between the first space and the second space. Thereby, vapor contained in the fuel, which is returned from a pressurizing chamber to the fuel chamber, is accumulated as bubbles in the first space, which receives the pressurizing chamber forming portion. The first space is communicated with the outside through the communicating flow passage and the second space. Therefore, outputting of air bubbles of the first space to the outside can be effectively limited in comparison to a case where the fuel chamber is directly communicated with the outside.

Abstract: A fuel injection valve includes a valve body having a valve seat, a nozzle plate arranged on an injection side of the valve body, a valve plug for intermitting fuel injection through the nozzle hole, and a sleeve. The nozzle plate has a nozzle hole through which fuel is injected from the injection side of the valve body. The sleeve makes contact with an end surface of the nozzle plate on an opposite side of the valve body with respect to the nozzle plate to partially cover the nozzle plate. Fuel is injected to an outside of the sleeve through the nozzle hole of the nozzle plate and an opening of the sleeve. The end surface of the nozzle plate makes contact with the sleeve in a contact portion. The contact portion has at least one groove that extends from the opening outwardly with respect to a substantially radial direction of the sleeve.

Abstract: A fuel injector for an internal combustion engine which has a spray hole designed geometrically to produce a spray of fuel so that substantially 70% or more of an amount of the spray hits a preselected area of a head of an intake valve of the engine when the intake valve is closed. The preselected area is one of a first and a second area of the intake valve head which are defined by a reference boundary line extending through a base end of a stem of the intake valve. The preselected area is the first area closer to an intake manifold, while the second area is closer to an exhaust valve. This avoids rich misfire and reduces HC emissions from the engine regardless of the intake valve is in a closed state or in an open state.

Abstract: A fuel injection valve includes a valve body having a valve seat, a nozzle plate arranged on an injection side of the valve body, a valve plug for intermitting fuel injection through the nozzle hole, and a sleeve. The nozzle plate has a nozzle hole through which fuel is injected from the injection side of the valve body. The sleeve makes contact with an end surface of the nozzle plate on an opposite side of the valve body with respect to the nozzle plate to partially cover the nozzle plate. Fuel is injected to an outside of the sleeve through the nozzle hole of the nozzle plate and an opening of the sleeve. The end surface of the nozzle plate makes contact with the sleeve in a contact portion. The contact portion has at least one groove that extends from the opening outwardly with respect to a substantially radial direction of the sleeve.

Abstract: A fuel injector for an internal combustion engine which has a spray hole designed geometrically to produce a spray of fuel so that substantially 70% or more of an amount of the spray hits a preselected area of a head of an intake valve of the engine when the intake valve is closed. The preselected area is one of a first and a second area of the intake valve head which are defined by a reference boundary line extending through a base end of a stem of the intake valve. The preselected area is the first area closer to an intake manifold, while the second area is closer to an exhaust valve. This avoids rich misfire and reduces HC emissions from the engine regardless of the intake valve is in a closed state or in an open state.

Abstract: A stationary core has a press fitting portion and is secured to an inner peripheral wall of a tubular member by press fitting, so that an outer peripheral wall of the press fitting portion of the stationary core is engaged with the inner peripheral wall of the tubular member, and a radial space is formed upstream of the press fitting portion of the stationary core between the stationary core and the tubular member. The stationary core can have a tapered annular outer surface section, which is arranged in an outer peripheral wall of a downstream end portion of the stationary core and is tapered toward a downstream end of the stationary core at a taper angle of 2 to 60 degrees to have a reduced outer diameter.

Abstract: A stationary core has a press fitting portion and is secured to an inner peripheral wall of a tubular member by press fitting, so that an outer peripheral wall of the press fitting portion of the stationary core is engaged with the inner peripheral wall of the tubular member, and a radial space is formed upstream of the press fitting portion of the stationary core between the stationary core and the tubular member. The stationary core can have a tapered annular outer surface section, which is arranged in an outer peripheral wall of a downstream end portion of the stationary core and is tapered toward a downstream end of the stationary core at a taper angle of 2 to 60 degrees to have a reduced outer diameter.