Hitachi, Ltd.

Hitachi Automotive Systems, Ltd.

Hitachi Car Engineering Co., Ltd.

Hitachi Astemo Ltd.

Masahiko Hayatani

Motoyuki Abe

Satoshi Usui

Tohru Ishikawa

Shingo Tamura

Tatsuo Kawano

Kenichiro Tokuo

Hiroyuki Yamada

Takehiko Kowatari

Atsushi Sekine

Katsumi Miyazaki

Noriyuki Maekawa

Yasuo Namaizawa

Eiichi Kubota

Atsuji Saito

Hideki Machimura

Toru Ishikawa

Yusuke Irino

Syunsuke Aritomi

Takuya Shiraishi

Masayuki Suganami

Minoru Hashida

Masamichi Yagai

Atsushi Takaoku

Kouji Shibata

Kazuaki Tokumaru

Hideyuki Shikaki

Masahumi Nakano

Shuuichi Shimizu

Atsushi Hitachi Car Engineering Co Ltd Sekine

Provided is a high-pressure fuel pump which can fix a cylinder to a pump body using a simple structure, and can reduce a displacement amount inward in a radial direction of the cylinder. A high-pressure fuel pump includes a pump body which is formed with a pressing chamber and a cylinder which is inserted in a hole formed in the pump body. The cylinder is swaged to the hole by pressing a convex portion on an outside in a radial direction to fit into the hole on an opposite side to the pressing chamber, by screwing a formed screw thread into the hole, or by being swaged with the opposite side to the pressing chamber. The cylinder is formed with a clearance in the radial direction with respect to the hole of the pump body all over a region from a bonding portion to an upper end.

High-pressure fuel pump

A fuel pump includes an intake valve unit which is provided between a low-pressure chamber and a pressurizing chamber. The intake valve unit includes an intake valve configured to move in an axial direction of the intake valve unit and a valve stopper arranged between the intake valve and the pressurizing chamber. A plurality of fuel passages configured to allow fuel to communicate between the low-pressure chamber and the pressurizing chamber are formed on a radially outward of an outer peripheral surface of the valve stopper.

High-pressure fuel supply pump having electromagnetically-driven intake valve

A high-pressure fuel supply pump including an electromagnetically driven intake valve is configured such that a pressure equalizing hole is provided in the valve stopper positioned between the valve and a pressurizing chamber. The pressure equalization hole connects a spring storage space, provided between a valve and a valve stopper, with a surrounding fluid passage. The high-pressure fuel supply pump is further configured such that an opening of the pressure equalizing hole at the spring storage chamber side is open at a position at the inner side of a diameter of the spring. Since the pressure in the pressurizing chamber can be introduced into the inner side of the spring without traversing the spring, the unstable behavior of the spring or the valve due to the introduced pressure eliminated. Since the force applied to the valve when the valve closes is stabilized, the closing timing of the valve is stable.

High-pressure fuel supply pump including an electromagnetically driven intake valve

A high-pressure fuel supply pump includes a pressurizing chamber, a piston plunger, and an electromagnetically-driven intake valve mechanism. The piston plunger reciprocates within the pressurizing chamber. The electromagnetically-driven intake valve mechanism is provided at an inlet of the pressurizing chamber. The electromagnetically-driven intake valve mechanism includes an anchor which pulls a plunger rod, a fixed core which attracts the anchor, and a yoke in which inner peripheral part has the fixed core and the anchor. The fixed core is fixed to a bottom part of the yoke. A through hole is formed at a bottom part of the fixed core.

High pressure fuel pump includes a cylinder which is fitted in a concave portion formed in a pump housing and which defines a compression chamber of the pump and a plunger which pressurizes, by sliding against the cylinder, the fluid in the compression chamber. It is structured such that the fluid sucked into the compression chamber by reciprocating motion of the plunger is pressurized and is then discharged from the compression chamber. The cylinder is formed of a cylindrical member which has a ceiling portion and in which the compression chamber is partitionedly formed. A fuel suction path formed in the pump housing reaches the compression chamber through the cylinder and a fuel discharge path formed in the pump housing is connected to the compression chamber through the cylinder. The cylinder is pressed against the pump body by a fuel pressurizing force applied to the cylinder.

High pressure fuel pump

Responsiveness is improved in valve opening and valve closing of an electromagnetically driven intake valve unit in which a valve is provided on a pressurizing chamber side of a valve seat. The valve includes an annular abutting surface that abuts the valve seat to shut off a fuel intake passage and a bottomed cylindrical part provided at an inner peripheral part of the annular abutting surface. The bottomed cylindrical part is inserted into a fuel introduction hole formed in the valve housing inside the valve seat, and the outer surface of an end part of the bottomed cylindrical part is exposed to fuel in a low pressure fuel chamber provided upstream of the fuel introduction hole.

The present invention eliminates a valve holder and accommodates a valve guide in a small space provided between a valve seat and a peripheral surface part of a pressure chamber to reduce the size of a pump. The valve guide guides a stroke of the valve and is provided inside the valve seat. The valve includes an annular abutting surface that abuts a valve seat formed in a valve housing to shut off a fuel intake passage and a bottomed cylindrical part is provided at an inner peripheral part of the annular abutting surface. The bottomed cylindrical part is inserted into a fuel introduction hole formed in the valve housing inside the valve seat. A member having a cylindrical surface part that supports a reciprocating motion of the valve, is fixed to the valve housing, face-to-face with an inner peripheral part of the bottomed cylindrical part.

In a fuel injection valve, it is intended to enhance valve-closing responsivity while maintaining durability (anti wear property) of a collision portion between a stationary core and a movable core and valve-opening responsivity. An annular end faceA of the movable corein the fuel injection valve is provided with a collision portionC that collides to a stationary corewhen the movable core is magnetically attracted toward the stationary core side and a non-collision portion that keeps a fluid gap between both cores at an area of an outer side or an inner side from the collision portion. The annular end faces of the stationary core and the movable core are coated with platingshaving anti wear property, and at least one of the platings of the stationary core and the movable core is formed in such a manner that the thickness thereof at the collision portionC is to be thicker and the thickness thereof at the non-collision portion is to be thinner.

Fuel injection valve for internal combustion engine

An injector used for an internal combustion engine includes a valve needle which closes a fuel passage by contacting a valve seat and opens the fuel passage by separating from the valve seat. A coil and a magnetic core are provided to drive the valve needle, and an anchor is held in a relatively displaceable state with respect to the valve needle. A first biasing device biases the valve needle in a direction opposite to a direction of a drive force, and a second biasing device biases the anchor in the direction of the drive force with a set load smaller than that of the first biasing device. A restricting feature restricts relative displacement of the anchor with respect to the valve needle in the direction of the drive force.

Electro-magneto fuel injector

In a fuel injection valve used for an internal combustion engine, a valve closing lag time due to fluid resistance in a fuel path is shortened to decrease a minimum injection limit. More specifically, in the fuel injection valve in which an anchor is attracted to an end face part of a stationary core having a fuel path formed at a center part thereof by means of electromagnetic force, and in which a fuel injection hole is opened and closed by controlling a valve disc driven in conjunction with the anchor, there are provided a fuel reservoir part at a center part of an upper end face part of the anchor, a through hole extending axially in a fashion that an end part thereof is open to the fuel reservoir part, and a fuel path extending radially outward from the fuel reservoir part so that fuel is fed to a magnetic attraction gap between an upper end face part of the anchor and a lower end face part of the stationary core. Further, an opening part of a through hole that is open to an upper end face part of the anchor is at least partially opposed to a fuel introduction bore formed in the stationary core, and on the opening part of the through hole, a fuel introduction part is provided for capturing fuel running radially outward from a center side part of the anchor and for guiding the fuel thus captured to the through hole.

Fuel injection valve

An electromagnetic fuel injection valve comprising: a metallic cylindrical-shaped vessel provided at a tip end thereof with a fuel injection port, the other end thereof being closed by a stationary core provided centrally thereof with a through-hole; a movable member arranged between the stationary core and the fuel injection port and provided at a tip end thereof with a valve element, which opens and closes the fuel injection port, a maximum outside diameter of the movable member being smaller than a minimum inside diameter of the through-hole; and an electromagnetic drive mechanism that reciprocates the movable member.

Electromagnetic fuel injector and method for assembling the same

In relation to injectors used for internal-combustion engines, it is important to decrease valve closing delay time and also the minimum injection quantity, while these are affected by remanent magnetism in the fixed core, surface tension of the fuel, etc. With reference to a fuel injection valve with a pipe-shaped member to enclose a fixed core and a movable part and further with coils and yokes to cover up the above pipe-shaped member, the anchor to drive the movable member has a plurality of through holes for fuel passage extending in the axial direction, while these through holes are arranged at a certain intervals in the circumferential direction, and projections formed to constitute a contacting surface to touch the fixed core arranged randomly in between the through holes.

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Hitachinaka, Japan

Masahiko Hayatani