Denso Corporation

Motoya Kanbara

Daiji Ueda

Hiroki Tanada

Fumiaki Arikawa

Toshiaki Hijima

Shinya Sano

Kazufumi Serizawa

Yuuta Hashimoto

Atsushi Utsunomiya

Naoki Toda

Hitoshi Maegawa

Satoshi Sugawara

When a main injection is performed, a first timing that is a time earlier than a second timing is selected as the valve opening starting timing, and a first period that is the period of time shorter than a second period is selected as the control period. Also, when a pilot injection is performed, the second timing that is the time later than the first timing is selected as the valve opening starting timing, and the second period that is the time longer than the first period is selected as the control period. Thus, in an injector with increased valve opening responsiveness, the valve opening behavior of a control valve of the injector in fuel injection with a minute injection quantity can be stabilized without replacing a control device, particularly an EDU with that of a large current specification.

Fuel injection device

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.

Fuel injection valve and fuel injection valve controller

A high-pressure-side valve portion makes contact with and moves from a high-pressure seat surface formed in a body to control communication between a control chamber communication passage and a high-pressure passage. A low-pressure-side valve portion makes contact with and moves from a low-pressure seat surface formed in the body to control communication between an exhaust passage and a second intermediate chamber. A releasing portion in the high-pressure-side valve portion communicates with the control chamber communication passage when the high-pressure seat surface is in contact with the high-pressure-side valve portion to block the control chamber communication passage from the high-pressure passage. A valve element internal passage is formed in the valve element to communicate the releasing portion with the second intermediate chamber.

Fuel injection valve

A valve cylinder partitions a first intermediate chamber from a second intermediate chamber. A first valve element in the first intermediate chamber includes a tubular high-pressure-side valve portion to control communication between a control chamber communication passage and the first intermediate chamber. A second valve element in the second intermediate chamber includes a low-pressure-side valve portion to control communication between an exhaust passage and the second intermediate chamber. A columnar rod portion located between the first valve element and the second valve element is slidably held at a cylinder hole of the valve cylinder. An internal passage communicates the control chamber communication passage with the second intermediate chamber. The high-pressure-side valve portion has an outer diameter greater than an outer diameter of the rod portion.

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.

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Nishio, Japan

Motoya Kanbara