Usui Kokusai Sangyo Kaisha Limited

Usui Co., Ltd.

Koichi Hayashi

Shoichiro Usui

Tetsuo Ogata

Hikari Tsuchiya

Masayoshi Usui

Eiji Watanabe

Yoshiyuki Serizawa

Nobuo Kato

Kazuteru Mizuno

Hiroyuki Nishizawa

Shuji Suzuki

Yasuaki Hashimoto

Mitsumasa Otaka

Toshiyuki Omura

Tadahiro Goto

Shu Yotsumoto

Nagahisa Amano

Shigeyuki Ishida

Koji Kurita

Haruo Nishihara

To obtain a gasoline direct injection rail in which a large load is unlikely to be concentrated on a boundary part between a rail body and an end cap, and damage to the boundary part can be prevented, even when high pressure is applied to the inside of the rail body. The gasoline direct injection rail comprises an end capcomposed of a top plateand a circumferential wall, and a rail bodyhaving an end partin which the circumferential wallof the end capis inserted and placed, wherein an inner circumference of the end partof the rail bodyhas a depression, the circumferential wallis placed in the depression, and there is no level difference at a boundary partbetween an inner circumferential surfaceof the circumferential walland an inner circumferential surfaceof the rail body

End cap

To obtain, at low cost, a fuel rail that maintains low hardness and good formability before being formed into a tube stock, can be made to form a welded pipe, and has high-strength properties with which the fuel rail can withstand a high fuel pressure even when formed so as to be relatively thin. A fuel rail for gasoline direct injection that is used at a fuel pressure of at least 30 MPa and is formed from an iron-alloy welded pipe. The fuel rail comprises an iron alloy that contains chemical components of C, Si, Mn, P, S, Nb, and Mo. The plate thickness t and the outer diameter D of the fuel rail have a ratio t/D of 0.2 or less. A bainitic structure can be precipitated by brazing the fuel rail in a furnace during manufacturing.

Method of manufacturing fuel rail for gasoline direct injection

To obtain a fuel rail that maintains low hardness and good formability before being formed into a tube stock, can be made to easily form a thin absorbing wall surface, and has a high hardness and pressure resistance so as to be usable not only at a fuel pressure of 400 kPa or less, but also at a relatively high fuel pressure of 400 kPa or more. A fuel rail for port injection that is provided with a fuel pressure absorbing wall surfaceand is used at a fuel pressure of 200 kPa to 1400 kPa. The fuel rail comprises an iron alloy that includes chemical components of C, Si, Mn, P, S, Nb, and Mo. The fuel rail has an internal volume of at least 60 cc and an amount of change in internal volume, when pressure is applied, of at least 0.5 cc/MPa. A bainitic structure can be precipitated by brazing the fuel rail in a furnace during manufacturing.

Fuel rail

High pressure fuel injection pipe

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 heat exchanger having excellent heat exchanging performance is obtainable by a simple production technique and at a low cost. This is achieved by providing a fin member and by increasing heat conductivity between the fin member and a meandering pipe body. Further, the heat exchanger is made compact for high degrees of layout freedom, enabling the heat exchanger to be installed in a tight space. Engagement grooves () are provided in both end surfaces (), which are opposite to each other, of a fin member () in which fins () are parallel arranged. Straight pipe sections () are parallelly arranged, with gaps ()in between, in the engagement grooves () of the fin member (). The straight pipe sections ()are connected at bent sections (). A pair of meandering sections () is arranged opposite to each other with an insertion gap () of the fin member () in between. On () of the meandering sections and the other meandering section () are connected by a connection pipe () to form a meandering pipe main body (). The straight pipe sections () of the one meandering section () are arranged in the engagement grooves () in the one end surface () of the fin member () inserted and arranged in the insertion gap () between the one meandering section () and the other meandering section () of the meandering pipe body (), and the straight pipe sections () of the other meandering section () are arranged and fixed in the engagement grooves () in the other end surface ().

Heat exchanger

A thick-wall small-diameter high-pressure fuel injection pipe has a spherical seat surface, an annular flange, and a conical surface continued from the seat surface at a connecting end of the pipe. If the pipe is configured so that t (thickness)/D (outer diameter)&#x3c;0.3, then an axial distance from the connecting head end to the back face of the annular flange is 0.38D to 0.6D, a spherical radius of the seat surface is 0.45D to 0.65D, the annular flange outer diameter is 1.2D to 1.4D, and an inner peripheral surface of the head has a substantially flat cylindrical surface or a conical surface. If the pipe is configured so that t (thickness)/D (outer diameter)&#x2267;0.3, then the axial distance from the connecting head end to the back face of the annular flange is 0.38D to 0.7D.

Connecting head structure for high-pressure fuel injection pipes

A connection head structure of a high pressure fuel injection tube is provided to avoid an interference between an annular flange and an opposing part by sufficiently maintaining an tube axial direction length of the connection head and to obtain a good sealability to prevent leaking during autofrettage processing with a high pressure of not less than 300 MPa. A connection head structure of a high pressure fuel injection tube includes, on a connection end portion of a thick walled fine steel tube, a spherical seat face, an annular flange, and a circular conic face that continuously extends from the seat face, wherein a washer and a fastening nut are assembled, characterized in that when a thick walled fine steel tube has t (wall thickness)/D (outer diameter)&#x3c;0.3, an tube axial direction distance Lfrom a connection head end to the back face of the annular flange is from 0.38 D to 0.7 D, a spherical body radius R of the seat face is from 0.45 D to 0.65 D, and an outer diameter Dof the annular flange is from 1.2 D to 1.4 D, wherein an inner circumferential face of the connection head includes a two stage tapered face having a cross section outline in a tube axial direction of the steel tube that broadens toward the aperture of the tube.

Connection head structure of high pressure fuel injection tube

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

A heat exchanger tube has an inner peripheral surface serving as an exhaust gas flow path with a flat cross-sectional shape. A thin structure is incorporated in the heat exchanger tube and has a substantially rectangular channel-shaped waveform in cross section. The corrugated fin structure has a curved surface forming waveform meandering with a predetermined wavelength in the lengthwise direction. The wave width of the channel-shaped waveform is H, the wavelength of the waveform meandering in the lengthwise direction is L and the amplitude of the waveform meandering in the lengthwise direction is A. The heat exchanger tube is formed so that H/L is set at 0.17 to 0.20 and the ration (G/H) of a gap G determined by H&#x2212;A to H is set at &#x2212;0.21 to 0.19.

Heat exchanger tube

An inlet portcommunicating with the interior of a fuel delivery pipe bodyto introduce fuel is made open in a center of a tubular jointhaving a smaller diameter than an inside diameter of a holder portionof an injectorconnected to a respective pipe end portionand a length from a center of this inlet portto the pipe end portionis set to 30 to 1000 mm, to thereby form the tubular jointThe tubular jointand the fuel delivery pipe bodyare fixed such that the inlet portof this tubular jointis communicatable with the interior of the fuel delivery pipe body

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.

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Mishima, Japan

Koichi Hayashi