Abstract: A fuel injection device includes: an injector, an electronic control device, a communication circuit, and a power supply circuit. A memory is provided in the injector for storing fuel injection control data set for each injector. The electronic control device controls a fuel injection of the injector based on the control data. The communication circuit is installed for each injector, and enables the electronic control device to access the memory via wireless communication. The power supply circuit is installed for each injector, has a power source that supplies electric power to the communication circuit, and receives electric power to charge the power source from a drive line that connects the electronic control device and a drive unit of the injector.

Abstract: A fuel injection valve includes a fixed core and a movable core. The fixed core includes a fixed-side high rigidity portion having high rigidity and a fixed-side low rigidity portion having rigidity lower than that of the fixed-side high rigidity portion. The movable core includes a movable-side high rigidity portion having high rigidity and a movable-side low rigidity portion having rigidity lower than that of the movable-side high rigidity portion. Current fed to a coil generates a magnetic attractive force to cause the movable core to move toward the fixed core together with a needle and to cause the movable-side high rigidity portion to abut on the fixed-side high rigidity portion.

Abstract: An electromagnetic valve includes a driving portion, a valve body, and a valve element. The driving portion generates a magnetic attractive force according to an energization. The valve body has an orifice through which a fluid flows, and a valve seat around an opening portion of the orifice. The valve element displaces according to the magnetic attractive force and a fluid force that is applied from the fluid, to vary a passage area between the valve element and the valve seat. When the valve element is placed at a position separated farthest from the valve seat, the passage area between the valve element and the valve seat is less than or equal to a passage area of the orifice.

Abstract: A fuel injection valve includes a body including a first chamber that supplies fuel of a first pressure, a second chamber that supplies fuel of a second pressure, and an injection hole, a valve chamber member including a valve chamber connectable to the first chamber and the second chamber, a control chamber member including a control chamber connectable to the first chamber, a needle pressed by pressure of fuel in the control chamber in a direction that causes fuel injection from the injection hole to stop, an actuator, a valve element that selectively connects the first chamber, second chamber, and the valve chamber according to the actuator extending and contracting, and a transmission mechanism that when the actuator extends, transmits the force to the needle as a force in a direction that causes fuel to be injected from the injection hole.

Abstract: In a nozzle, in a cross section including an axis of a nozzle body, a side surface and a seat surface are both smoothly connected to an arc of a circle inscribing both the side surface and the seat surface. A part of a needle which is adjacent to a tip end side of a seat portion is a cone having a diameter reduced toward a tip end side of the cone in the axial direction. Thus, no corner is on the seat surface or the side surface, and the two surfaces form one curved surface. Since a cavitation generated in a sack chamber can be reduced, even when an injection quantity is significantly small such that an injection port does not throttle an injection flow, a flow coefficient of the injection flow is improved and a penetration of a spray of the fuel can be maintained.

Abstract: A fuel injection valve includes a body including a first chamber that supplies fuel of a first pressure, a second chamber that supplies fuel of a second pressure, and an injection hole, a valve chamber member including a valve chamber connectable to the first chamber and the second chamber, a control chamber member including a control chamber connectable to the first chamber, a needle pressed by pressure of fuel in the control chamber in a direction that causes fuel injection from the injection hole to stop, an actuator, a valve element that selectively connects the first chamber, second chamber, and the valve chamber according to the actuator extending and contracting, and a transmission mechanism that when the actuator extends, transmits the force to the needle as a force in a direction that causes fuel to be injected from the injection hole.

Abstract: A fuel injector has a cylindrical nozzle body, a nozzle needle, a pressure chamber and an injection passage. The injection passage includes a first hole and a second hole. A minimum vertical distance between an outer periphery of a first nozzle hole outlet and a contact point relative to an axial center line of the first hole is defined as a vertical distance R. A minimum axial distance between the first nozzle hole outlet and the contact point relative to an axial center line of the first hole is defined as an axial distance L. An angle between the axial center line of the first nozzle hole and the outer periphery line of the fuel spray is defined as an injection angle ?. The vertical distance R, the axial distance L and the injection angle ? satisfy a formula: R/(L×tan ?)>6.0.

Abstract: A fuel injection nozzle of the present disclosure is a multi-hole type fuel injection nozzle where a plurality of injection holes are arranged along a circumferential direction about an axis of a nozzle body, and inject fuel radially outward from the axis of the nozzle body. Among two of the plurality of injection holes that are mutually adjacent along the circumferential direction, one injection hole has a larger spray angle and a shorter spray distance as compared to an other injection hole, and the other injection hole has a smaller spray angle and a longer spray distance as compared to the one injection hole. By arranging these injection holes alternately along the circumferential direction, a required inter-spray distance may be maintained and, at the same time, a space utilization ratio may be improved.

Abstract: An armature chamber receives an armature and includes a first armature chamber, which is placed adjacent to one end surface of the armature and is communicated with a spring chamber, and a second armature chamber, which is placed adjacent to the other end surface of the armature, which is opposite from the one end surface of the armature. The armature includes a primary communication passage that communicates between the first armature chamber and the second armature chamber. An opening end of the primary communication passage, which opens on a side where the first armature chamber is located, is placed at a corresponding location of the armature, which is opposed to the spring chamber.

Abstract: A fuel injector has a cylindrical nozzle body, a nozzle needle, a pressure chamber and an injection passage. The injection passage includes a first hole and a second hole. A minimum vertical distance between an outer periphery of a first nozzle hole outlet and a contact point relative to an axial center line of the first hole is defined as a vertical distance R. A minimum axial distance between the first nozzle hole outlet and the contact point relative to an axial center line of the first hole is defined as an axial distance L. An angle between the axial center line of the first nozzle hole and the outer periphery line of the fuel spray is defined as an injection angle ?. The vertical distance R, the axial distance L and the injection angle ?satisfy a formula: R/(L×tan?)>6.0.

Abstract: In a nozzle, in a cross section including an axis of a nozzle body, a side surface and a seat surface are both smoothly connected to an arc of a circle inscribing both the side surface and the seat surface. A part of a needle which is adjacent to a tip end side of a seat portion is a cone having a diameter reduced toward a tip end side of the cone in the axial direction. Thus, no corner is on the seat surface or the side surface, and the two surfaces form one curved surface. Since a cavitation generated in a sack chamber can be reduced, even when an injection quantity is significantly small such that an injection port does not throttle an injection flow, a flow coefficient of the injection flow is improved and a penetration of a spray of the fuel can be maintained.

Abstract: A first resilient member generates a resilient force to urge a valve portion in a valve-closing direction. A second resilient member generates a resilient force against the resilient force of the first resilient member. The resilient force of the first resilient member and the resilient force of the second resilient member are set to be balanced with each other when the valve portion is placed in a lift position that is between a full-closing position of the valve portion, in which the valve portion is seated against a valve seat to fully close a fluid passage, and a full-opening position of the valve portion, in which the valve portion is fully lifted away from the valve seat to fully open the fluid passage.

Abstract: An electromagnetic valve includes a driving portion, a valve body, and a valve element. The driving portion generates a magnetic attractive force according to an energization. The valve body has an orifice through which a fluid flows, and a valve seat around an opening portion of the orifice. The valve element displaces according to the magnetic attractive force and a fluid force that is applied from the fluid, to vary a passage area between the valve element and the valve seat. When the valve element is placed at a position separated farthest from the valve seat, the passage area between the valve element and the valve seat is less than or equal to a passage area of the orifice.

Abstract: It is equipped with an injector body 4z which has formed therein high-pressure paths 6az, 6bz, and 6cz through which high-pressure fuel flows to a spray hole and stores therein a piezo-actuator 2z (i.e., an opening/closing mechanism) and a back-pressure control mechanism 3z (i.e., an opening/closing mechanism) which open or close the spray hole, a stem 51z (i.e., an elastic body) which is installed in said body 4z and elastically deformed when subjected to pressure of the high-pressure fluid, and a strain gauge 52z (i.e., a sensing device) which converts the degree of strain occurring at the stem 51z into an electric signal and outputs it as a measured-pressure signal. Specifically, the stain gauge 52z is installed on the stem 51z that is constructed as being separate from the body 4z.

Abstract: An armature chamber receives an armature and includes a first armature chamber, which is placed adjacent to one end surface of the armature and is communicated with a spring chamber, and a second armature chamber, which is placed adjacent to the other end surface of the armature, which is opposite from the one end surface of the armature. The armature includes a primary communication passage that communicates between the first armature chamber and the second armature chamber. An opening end of the primary communication passage, which opens on a side where the first armature chamber is located, is placed at a corresponding location of the armature, which is opposed to the spring chamber.

Abstract: A fuel injector for an internal combustion engine is provided. The fuel injector is equipped with a fuel pressure sensor which is installed in a metallic injector body. The fuel injector also includes an amplifier working to amplify an output of the fuel pressure sensor and a thermal insulating member disposed between the metallic injector body and the amplifier to shield the amplifier thermally, thereby ensuring the accuracy in measuring the pressure of fuel within the fuel injector.

Abstract: It is equipped with an injector body 4z which has formed therein high-pressure paths 6az, 6bz, and 6cz through which high-pressure fuel flows to a spray hole and stores therein a piezo-actuator 2z (i.e., an opening/closing mechanism) and a back-pressure control mechanism 3z (i.e., an opening/closing mechanism) which open or close the spray hole, and a fuel pressure sensor 50z installed in the body 4z to measure the pressure of the high-pressure fuel. The body 4z has formed therein a branch path 6ez diverging from the high-pressure paths 6bz and 6cz to deliver the high-pressure fuel to the fuel pressure sensor 50z.

Abstract: A fuel injector for an internal combustion engine is provided. The fuel injector is to be installed in a cylinder head of the engine and has a fuel pressure sensor working to measure the pressure of fuel within a injector body. The fuel pressure sensor is installed in a portion of the injector body which is to be located away from the cylinder head of the engine across a portion of the injector body on which a mechanical pressure is exerted by an external member such as a fuel supply pipe or a fuel drain pipe, thereby keeping the fuel pressure sensor free from internal stress, as arising from the mechanical pressure exerted on the injector body, to ensure the accuracy in measuring the pressure of the fuel.

Abstract: A fuel injector for an internal combustion engine is provided. The fuel injector is equipped with a fuel pressure sensor, a sensor circuit such as an amplifier, and a valve actuator such as a piezoelectric actuator. The fuel injector also includes a conductive shield which is disposed between the sensor circuit and actuator drive terminals to supply electric power to the actuator and works to shield the sensor circuit from electric noises arising from the drive terminals, thereby minimizing the addition of the noises to an output of the fuel pressure sensor, as being processed in the sensor circuit, and ensuring the accuracy in determining the pressure of fuel based on the output of the fuel pressure sensor.

Abstract: It is equipped with an injector body 4z which has formed therein high-pressure paths 6az, 6bz, and 6cz through which high-pressure fuel flows to a spray hole and stores therein a piezo-actuator 2z (i.e., an opening/closing mechanism) and a back-pressure control mechanism 3z (i.e., an opening/closing mechanism) which open or close the spray hole, and a fuel pressure sensor 50z installed in the body 4z to measure the pressure of the high-pressure fuel. The body 4z has formed therein a branch path 6ez diverging from the high-pressure paths 6bz and 6cz to deliver the high-pressure fuel to the fuel pressure sensor 50z.