Denso Corporation

Tsukasa Yamashita

Naofumi Adachi

Yoichi Kobane

Fumihiro Fujikake

Shuichi Matsumoto

Kazufumi Serizawa

Masato Yamada

Yukihiro Fukuta

A fuel injection valve includes a body that includes an injection hole through which fuel is injected, and a valve element that opens or closes the injection hole. The body includes a metallic base material configured to form the injection hole, a corrosion-resistant layer covering a surface of at least a part of the base material that forms the injection hole and being made of a less corrosive material than the base material, and a sacrificial corrosion layer located between the base material and the corrosion-resistant layer and made of a more corrosive material than the corrosion-resistant layer.

Fuel injection valve

A fuel injection device () includes a control body () provided with an injection hole (), a nozzle needle () that opens or closes the injection hole (), a pressure control chamber () controlling a movement of the nozzle needle (), an inflow channel () through which high-pressure fuel is introduced to the pressure control chamber (), an outflow channel () through which the fuel from the pressure control chamber () is discharged, and a floating plate () that opens or closes the inflow channel (). In the fuel injection device (), the control body () includes a cylinder () defining the pressure control chamber () in a radial direction thereof, and an inner wall portion () of the cylinder () includes a communication groove () which causes an inflow chamber () that is provided within the pressure control chamber () at a side of the inflow channel () relative to the floating plate (), to communicate with a back pressure chamber () that is provided within the pressure control chamber () at a side of the nozzle needle () relative to the floating plate ().

Fuel injection device

A fuel injection device includes a cylinder defining a pressure chamber at an end portion of a nozzle needle. In the cylinder, a floating plate is provided as a controlling member of fuel pressure. An orifice member and a nozzle body are lined by an annular positioning member, using a circular peripheral surface of the orifice member and a circular peripheral surface of the nozzle body as a reference surface. Thereby, radial locations of the nozzle body and the orifice member are defined. Furthermore, a location of the floating plate is defined by the nozzle body with the nozzle needle. Therefore, the floating plate can be located to a proper location relative to the orifice member.

In a fuel injection device, a pressing surface of a pressing member presses an opening wall surface to interrupt communication between an inflow port and a pressure control chamber when communication between an outflow port and a return channel is made by a pressure control valve, and the pressing surface of the pressing member is displaced and separated from the opening wall surface to open the inflow port of the opening wall surface to the pressure control chamber when the communication between the outflow port and the return channel is interrupted by the pressure control valve. One of the pressing surface of the pressing member and the opening wall surface of the control body is provided with an inflow depressed portion and an outflow depressed portion partitioned from each other, and a depressed dimension of the inflow depressed portion is larger than a depressed dimension of the outflow depressed portion.

A fuel injection device includes a cylinder that defines a pressure chamber at an end portion of a nozzle needle. A floating plate as a control member is placed in the cylinder. A cutout portion and multiple grooves are formed in the floating plate. The cutout portion and the grooves causes a gap between a large-diameter inner circumferential surface and an outer circumferential surface to communicate with the pressure chamber. The cutout portion and the grooves reduce a contact surface portion between the cylinder and the floating plate and divide the contact surface portion into multiple island portions. As a result, it is possible to reduce the contact surface portion.

In a fuel injection device, a control body has a pressure control chamber, an inflow port and an outflow port. The inflow port and the outflow port are opened at an abutting surface exposed to the pressure control chamber. In the pressure control chamber is arranged a floating plate for pressing the abutting surface by a pressing surface with the pressure of the fuel to interrupt communication between the inflow port and the pressure control chamber. The abutting surface of the control body is provided with an outer opposite surface portion opposite to an outer edge of the pressing surface in a displacement axis direction of the floating plate, and the outer opposite surface portion has a special depressed portion that is depressed in the displacement axis direction and that extends along the shape of the outer edge of the pressing surface.

In a fuel injection device, a pressure control valve is configured to make communication between an outflow port and a return channel and to interrupt the communication so as to control pressure of a fuel in a pressure control chamber, a valve member is configured to open and close a valve portion in response to the pressure of the fuel in the pressure control chamber, and a pressing member is arranged to be reciprocated and displaced in the pressure control chamber. The pressing member has an outer wall surface portion that is opposite to an inner wall surface portion of the control body to be capable of contacting the inner wall surface portion of the control body, and at least one of the outer wall surface portion of the pressing member and the inner wall surface portion of the control body is provided with a recess portion that is recessed to a side separated from the other one of the outer wall surface portion of the pressing member and the inner wall surface portion of the control body.

A fuel injection device has therein a recovery channel provided in a first valve body, and a fuel channel provided in the first valve body and a second valve body. The fuel channel is opened by openings at a first end surface of the first valve body and a second end surface of the second valve body. One of the first end surface and the second end surface is provided with an end surface groove connected to the recovery channel. In the fuel injection device, the end surface groove is provided to enclose at least a part of the opening and is separated from the opening by a clearance, and one of the first valve body and the second valve body has a side surface groove extending in a circumferential direction at an outer periphery of the one of the first valve body and the second valve body.

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Kariya, Japan

Tsukasa Yamashita