Hitachi Automotive Systems, Ltd.

Hitachi Astemo Ltd.

Tatsuo Kawano

Satoshi Usui

Kenichiro Tokuo

Hiroyuki Yamada

Katsumi Miyazaki

Shingo Tamura

Masahiko Hayatani

Masayuki Suganami

Hideki Machimura

Syunsuke Aritomi

Atsuji Saito

Shunsuke Aritomi

Masamichi Yagai

Kazuaki Tokumaru

Masashi Nemoto

Akihiro Munakata

Shigenori Tahara

Kenichirou Tokuo

An object of the present invention is to prevent generation of wear at a rod collision portion in an electromagnetic intake valve of a high-pressure fuel supply pump by reducing inclinations of the intake valve and a rod. A structure of the electromagnetic intake valve of the high-pressure fuel supply pump is configured as follows. A seat portion of an intake valve and a guide portion of a rod are configured as an integral part, and further, a rod guide is made to have a sufficiently long length so that it is possible to perform guide at one portion. Further, the intake valve seat portion and a surface where the rod collides with the intake valve are formed on the same plane.

High-pressure fuel supply pump provided with electromagnetic intake valve

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.

To reduce collision noise created by the operation of an electromagnetic suction valve provided on a high pressure fuel supply pump, the mass of a member which collides by magnetic attractive force is reduced. The noise generated when a core and an anchor collide with each other by magnetic attractive force depends on the magnitude of the kinetic energy of a moving element. The kinetic energy to be consumed in the collision is only the kinetic energy of the anchor. The kinetic energy of a rod, being absorbed by a spring, does not contribute to the noise; thus, the energy when the anchor and the core collide with each other can be reduced, whereby the noise to be created can be reduced.

High pressure fuel supply pump with electromagnetic suction valve

To reduce collision noise created by the operation of an electromagnetic suction valve provided on a high pressure fuel supply pump. In the present invention, in order to achieve the above object, the mass of a member which collides by magnetic attractive force is reduced to reduce the noise to be generated. The thus configured present invention provides the following advantageous effects. The noise generated when a core and an anchor collide with each other by magnetic attractive force depends on the magnitude of the kinetic energy of a moving element. The kinetic energy to be consumed in the collision is only the kinetic energy of the anchor. The kinetic energy of a rod, being absorbed by a spring, does not contribute to the noise; thus, the energy when the anchor and the core collide with each other can be reduced, whereby the noise to be created can be reduced.

A high-pressure fuel supply pump includes a plunger, a valve member, a valve seat, a pressurizing chamber, and a fuel passage. The fuel passage includes a gap passage portion formed in a gap between the valve seat and the valve member. The fuel passage also includes a bent passage portion extending in a bent direction with respect to the gap passage portion, on the downstream side of the gap passage portion. The inner surface of the valve member, on a side thereof that faces the valve seat, has a convex shape in an area of the valve member that is between the bent passage portion and the gap passage portion.

High-pressure fuel supply 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.

A high-pressure fuel supply pump which has no probability of discontinuity of a thin film of fuel at a sliding portion even when the fuel is not needed to be compressed to a high pressure is obtained. Two low-pressure fuel ports are provided on the high-pressure fuel supply pump in addition to a high-pressure discharge port to a high-pressure fuel capacity chamber. One of the two low-pressure fuel ports is connected to a low-pressure fuel capacity chamber and remaining one is connected to a low-pressure fuel supply pump. Accordingly, the interior of the high-pressure fuel supply pump is always filled with fresh fuel even in a mode in which a high-pressure fuel injecting valve does not inject fuel and only a low-pressure fuel injection valve injects fuel, so that a temperature rise of a plunger and a cylinder is prevented and locking of the plunger and the cylinder can be prevented.

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Hitachinaka, Japan

Tatsuo Kawano