Denso Corporation

Naofumi Adachi

Tsukasa Yamashita

Yoichi Kobane

Shuichi Matsumoto

Motoichi Murakami

Masayuki Suzuki

Hiroki Tanada

Yoshinori Okuno

Toshiaki Hijima

Keisuke Suzuki

Tomoyuki Tsuda

Fumihiro Fujikake

Koichi Ohata

Ryuichi Ezaki

Masato Yamada

Shingo Kitani

Kazuya Sassa

Motoya Kambara

Yoshiro Shogaki

A fuel injection valve includes a needle valve that controls communication between a high pressure chamber and an injection hole, a follower valve provided inside a control chamber controlled by fuel pressure inside an intermediate chamber, and an open-close valve that controls communication between a first passage and a low pressure passage and communication between a second passage and the low pressure passage. The fuel injection valve is configured to control the gradient of the fuel injection rate from the injection hole with an improved configuration.

Fuel injection valve

The present disclosure provides an electromagnetic actuator that drives an armature by an electromagnetic force. The electromagnetic actuator includes a stator, a coil, and an insulator. The stator is formed of a magnetic material and has a cylindrical portion. The coil is disposed outside of the stator. The coil generates a magnetic field when being energized. The insulator is disposed in a particular region of the stator facing the coil in a radial direction. The insulator extends partially along the stator in a circumferential direction and suppresses a current flowing through the stator in the circumferential direction. The stator is continuously formed entirely along the circumferential direction by the magnetic material.

Electromagnetic actuator

A fuel injection valve includes a nozzle needle that opens or closes an injection hole communicating with an internal combustion engine, and a high-pressure fuel is introduced into a control room to urge the nozzle needle to close the injection hole. An orifice body includes a discharge passage through which the fuel is discharged from the control room to a low pressure portion, and an orifice-body sheet surface that is flat and surrounds a downstream end part of the discharge passage. A valve body contacts with or separates from the orifice-body sheet surface to close or open the discharge passage. A chamfered part is provided on a corner part in which the orifice-body sheet surface intersects with the discharge passage.

A sub out-orifice and an in-orifice are respectively formed in a low pressure passage and a high pressure passage of a fixed plate. A control valve is provided at an outlet port of the low pressure passage. In a normal control, the control valve starts its control-valve opening operation when a movable plate is in contact with the fixed plate. In an interval-shortening control, the control valve starts the control-valve opening operation at an earlier timing than that in the normal control, namely during a course in which a valve body is still in its valve-body closing operation.

A movable plate is movably accommodated in a pressure control chamber. A fixed plate is arranged above the movable plate, so that the movable plate is brought into contact with the fixed plate. The fixed plate has a high pressure passage for supplying fuel into the pressure control chamber and a low pressure passage for discharging the fuel from the pressure control chamber. A high pressure port and a low pressure port are formed at a lower end surface of the fixed plate. A first contacting surface is formed at the lower end surface and a first groove is formed in the first contacting surface for holding a part of fuel in a plate-contacted condition.

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.

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.

The invention has an object for improving response of a fuel injection device. A flow-in recessed portion and a flow-out recessed portion are formed at a press-contacting surface of a floating plate, which is movably accommodated in a pressure control chamber. A flow-in port and a flow-out port are formed at a pressure control surface of a valve body. The flow-in port is opened to the flow-in recessed portion, while the flow-out port is opened to the flow-out recessed portion. When the floating plate is moved upwardly and the press-contacting surface is brought into contact with the pressure control surface, the flow-in port is surely closed.

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.

A solenoid valve is provided which may be used to inject fuel into an internal combustion engine for automotive vehicles. The solenoid valve includes an armature and stator attracting the armature to open a fluid passage. The solenoid valve also includes a retaining nut and an end body. The retaining nut engages a housing to retain a hollow cylindrical stator casing in the housing. The end body is joined to the casing in alignment therewith to hold the stator within the casing without subjecting the stator to the pressure produced by the engagement of the retaining nut with the housing. This minimizes undesirable loads on the stator.

Growing community of inventors

Takahama, Japan

Naofumi Adachi