Usui Kokusai Sangyo Kaisha Limited

Hikari Tsuchiya

Yoshiyuki Serizawa

Tetsuo Ogata

Kazuteru Mizuno

Koichi Hayashi

Masayoshi Usui

Kazunori Takikawa

Eiji Watanabe

Hiroyuki Nishizawa

Shoichiro Usui

Izumi Imura

Haruo Nishihara

A fuel rail for high-pressure direct-injection internal combustion engines has an injector holder and a fastening bracket directly attached to a main body of the fuel rail. Thermal deformation may occur at the time of temporary fitting or brazing when assembling the rail. However, positional accuracy of the injector holder can be assured, which results in having an excellent sealing property. Components of the fuel rail for direct-injection internal combustion engines are made of steel or stainless steel, and the components are joined reciprocally by brazing. The components joined by brazing are finished by cutting work and/or burnishing processing after the brazing step.

Fuel rail for high-pressure direct-injection internal combustion engines and method for manufacturing thereof

A fuel delivery pipe capable of reducing a pressure pulsation at the time of a fuel injection due to injection nozzles, preventing vibrations and noises at an underfloor pipe arrangement, and turning down a radiate sound from the fuel delivery pipe, wherein a flexible absorbing wall surfaceformed on a wall surface of a fuel delivery bodyis loosened due to internal pressure changes to render internal volume of the fuel delivery bodyincreasable, &#x3b1;/&#x221a;{square root over ( )}V determined by sonic speed &#x3b1;of fuel flowing through the fuel delivery bodyand the internal volume V of the fuel delivery bodyis set as 20&#xd7;10(m&#xb7;sec)&#x2266;&#x3b1;/&#x221a;{square root over ( )}V&#x2266;85&#xd7;10(m&#xb7;sec) while a ratio &#x3b1;/&#x3b1;of equivalent sonic speed &#x3b1;in a high frequency area to the sonic speed &#x3b1;of the fuel is set as &#x3b1;/&#x3b1;&#x2266;0.7, and the cross section shape in a perpendicular direction to an axis of the fuel delivery bodyis formed in a substantially double side concaved shape, a substantially flask shape, a substantially trapezoid shape, a substantially key shape, and a substantially goggles shape.

Fuel delivery pipe

In a fuel supplying mechanism in which fuel delivery pipes of a non-return type are disposed, the generation region of pulsation resonance is arbitrarily controlled, thereby eliminating various disadvantages otherwise occurring where the pulsation resonance point exists in a favorable rotation region for normal use of the engine. A pair of the fuel delivery pipesof a non-return type is disposed for each bank of a horizontal opposed type or V-type engine and coupled with a connection pipe. A characteristic period time of a pulsation wave induced by the pulsation wave generated during fuel injection of the injection nozzlesvia a connection pipecoupling between one to the other of the fuel delivery pipesis controlled to render the characteristic period time longer to shift the pulsation resonance point out of a low rotation region of the engine as well as to render the characteristic period time shorter to shift the pulsation resonance point out of a high rotation region of the engine.

Method of controlling pulsation resonance point generating area in opposed engine or in-line engine

A pulsation reducing system for a fuel line of an internal combustion engine, especially for an automotive engine equipped with an electronic fuel injection system is provided. The system includes a fuel delivery rail, a fuel tank, and a longitudinal main fuel pipe. A first flexible tube is arranged between the fuel delivery rail and the main fuel pipe. A second flexible tube is arranged between the main fuel pipe and the fuel tank. A small-ID tubular portion is arranged within the first tube or near the connecting portion of the first tube. The inside diameter of the small-ID tubular portion is smaller than that of the main fuel pipe. The length of the small-ID tubular portion is set between 10 to 50 times the inside diameter of the small-ID tubular portion itself. Thus, standing waves and resultant pressure pulsations caused by the fuel delivery rail are reduced by the small-ID tubular portion.

Pulsation reducing system for fuel line

A fuel pressure pulsation suppressing system of a fuel piping system for a gasoline engine having a plurality of cylinders disposed in a straight, V-shape or horizontal opposed shape with delivery pipes for distributing fuel to the cylinders of return-less type without a return circuit to a fuel tank, wherein the cross section of at least one of communication pipes forming the delivery pipes forms a flexible absorbing face, an orifice portion for damping pressure pulse wave caused by fuel injection is installed near a connection part between at least one delivery pipe and a supply pipe or a connection pipe, and the cross sectional area of the flow passage of the orifice should desirably be 0.2 times the sectional area of the flow passage of the connection pipe or the supply pipe or below.

Fuel pressure pulsation suppressing system

A fuel delivery rail assembly for supplying fuel to a plurality of fuel injectors in an engine includes an elongated conduit having a longitudinal fuel passage therein, a fuel inlet pipe, and a plurality of sockets. One wall of the conduit opposite to the socket mounting wall includes a flat or arcuate flexible absorbing surface. A high-frequency noise suppressing component such as a rib, a cavity or a clamp is applied to the one wall opposite to the absorbing surface. Thus, fuel pressure pulsations and shock waves are reduced by bending the absorbing surface, and emission of high-frequency noise is eliminated.

Fuel delivery rail assembly

A fuel delivery rail assembly for supplying fuel to a plurality of fuel injectors in an engine is provided. The assembly includes an elongate conduit having a longitudinal fuel passage therein, a fuel inlet pipe, and a plurality of sockets. One wall of the conduit opposite to the socket mounting wall includes a flat or arcuate flexible absorbing surface. A high-frequency noise suppressing device such as a binding member is fixed within the conduit for connecting the one wall and the socket mounting wall. The binding member includes is comprised of a pipe, a bar or a rigid block. The binding member may be a body portion of an extending socket terminating with the one wall. Thus, fuel pressure pulsations and shock waves are reduced by bending of the absorbing surface, and emission of high-frequency noise is eliminated.

A returnless type fuel delivery pipe is provided for each cylinder bank of an opposed type engine. A connecting pipe is connected to this pair of fuel delivery pipes, a supply pipe is connected to this connecting pipe, thus coupling the fuel delivery pipes with the fuel tank. The fuel delivery pipes are made to be capable of absorbing and reducing pressure pulsation through elastic deformation of the external walls thereof, and the supply pipe is connected to an intermediate section of the length of the connecting pipe. Pressure pulsations with opposite phases caused by fuel injection of the fuel delivery pipes interfere with and attenuate each other in the supply pipe at or near intersection thereof with the intermediate section of the connecting pipe.

Growing community of inventors

Gotenba, Japan

Hikari Tsuchiya