By a News Reporter-Staff News Editor at Journal of Engineering -- From Alexandria, Virginia, VerticalNews journalists report that a patent by the inventors Hijima, Toshiaki (Nishio, JP); Arikawa, Fumiaki (Okazaki, JP); Kanbara, Motoya (Nishio, JP); Hashimoto, Yuuta (Nishio, JP); Utsunomiya, Atsushi (Kitanagoya, JP); Serizawa, Kazufumi (Obu, JP); Sano, Shinya (Anjo, JP), filed on January 20, 2015, was published online on February 7, 2017.
The patent's assignee for patent number 9562503 is DENSO CORPORATION (Kariya, JP).
News editors obtained the following quote from the background information supplied by the inventors: "Conventionally, a fuel injector supplying and injecting a fuel to an internal combustion engine includes a nozzle which injects the fuel and an actuator which drives to open or close the nozzle. The nozzle (fuel injection nozzle) used in the fuel injector includes a nozzle body which is a cylindrical shape and a needle which is received in the nozzle body and is slidable relative to an inner periphery of the nozzle body. In the nozzle, the inner periphery of the nozzle body includes a seat surface, and an injection port is placed at a tip end side of the seat surface in an axial direction of the nozzle body. The needle includes a seat portion which is removed from or seated on the seat surface to start or stop a fuel injection using the injection port.
"However, in a fuel injector in which a fuel with high pressure is directly injected into a cylinder of a diesel engine, a request of an emission reduction is high. Therefore, as an aspect of the emission reduction, it is considered that a penetration of a spray of the fuel is maintained to reduce a smoke generation even though a lifting amount of the needle is small and an injection quantity is significantly small.
"According to JP-H08-144895A, since a center diameter of a needle is greater than an inner diameter of a sack portion, a spray can be properly generated and a non-combustion gas can be reduced. However, when a lifting amount is small before a throttle portion of a flow of a fuel becomes an injection port in a nozzle, a flow-passage area is sharply enlarged toward downstream from a position where a diameter of the needle is the center diameter. Therefore, when the lifting amount is small, a cavitation is generated in the sack chamber such that a flow coefficient is deteriorated, and the penetration of the spray is decreased such that a smoke is readily generated."
As a supplement to the background information on this patent, VerticalNews correspondents also obtained the inventors' summary information for this patent: "The present disclosure is made in view of the above matters, and it is an object of the present disclosure to provide a fuel injection nozzle in which a deterioration of a flow coefficient is restrained to maintain a penetration of a spray even when a lifting amount is small such that an injection quantity is significantly small.
"According to an aspect of the present disclosure, the fuel injection nozzle includes a nozzle body which is a cylindrical shape and a needle which is received in the nozzle body and is slidable relative to an inner periphery of the nozzle body in an axial direction of the nozzle body. The inner periphery of the nozzle body includes a seat surface, and the needle includes a seat portion. The seat portion is removed from or seated on the seat surface to start or stop a fuel injection using an injection port disposed at a tip end side of the seat surface in the axial direction.
"The seat surface is a tapered shape. A diameter of the seat surface is reduced toward the tip end side of the seat surface in the axial direction. A sack chamber is disposed at a position adjacent to the tip end side of the seat surface and includes an inlet of the injection port. The side surface has a sharper slope than the seat surface and is coaxial with the seat surface. The bottom surface is a curved shape and covers the sack chamber at a tip end side of the side surface in the axial direction. The side surface and the bottom surface are smoothly connected to each other.
"In a cross section including an axis of the nozzle body, the side surface and the seat surface are both smoothly connected to an arc of a circle inscribing both the side surface and the seat surface. A part of the needle which is adjacent to a tip end side of the seat portion is a cone having a diameter reduced toward a tip end side of the cone in the axial direction.
"Thus, there is no corner on the seat surface or the side surface, and the seat surface and the side surface form one curved surface. Therefore, a generation of a separation of the injection flow of the fuel from the gap interposed between the seat surface and the seat portion to the outlet is reduced. Further, a portion that a flow-passage area of the fuel from the gap to the inlet is sharply enlarged does not exist. Since a cavitation generated in the sack chamber can be reduced, even when an injection quantity is significantly small such that the injection port does not throttle the injection flow, that is, even when the lifting amount is a significantly small value, a flow coefficient of the injection flow is improved and a penetration of a spray of the fuel can be maintained."
For additional information on this patent, see: Hijima, Toshiaki; Arikawa, Fumiaki; Kanbara, Motoya; Hashimoto, Yuuta; Utsunomiya, Atsushi; Serizawa, Kazufumi; Sano, Shinya. Fuel Injection Nozzle. U.S. Patent Number 9562503, filed January 20, 2015, and published online on February 7, 2017. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=9562503.PN.&OS=PN/9562503RS=PN/9562503
Keywords for this news article include: DENSO CORPORATION.
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