Fluid sprinkling – spraying – and diffusing – Fluid pressure responsive discharge modifier* or flow... – Fuel injector or burner
Reexamination Certificate
1999-07-30
2001-04-10
Scherbel, David A. (Department: 3752)
Fluid sprinkling, spraying, and diffusing
Fluid pressure responsive discharge modifier* or flow...
Fuel injector or burner
C239S533200, C239S533300, C239S533900, C239S585100, C239S585400, C251S064000, C251S129210, C251S332000, C277S644000
Reexamination Certificate
active
06213413
ABSTRACT:
INCORPORATION BY REFERENCE
The disclosure of Japanese Patent Application No. HEI 10-260271 filed on Sep. 14, 1998 including the specification, drawings and abstract in incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fuel injection valve and a method of manufacturing the fuel injection valve and, more particularly, to a fuel injection valve for injecting gaseous fuel and a method of manufacturing such a fuel injection valve.
2. Description of the Related Art
Japanese Laid-Open Patent Application No. HEI 8-61152 discloses a fuel injection valve for injecting gaseous fuel. This fuel injection valve includes an injection nozzle provided with an injection hole for injecting gaseous fuel and a valve body for closing the injection hole. When a front end face of the valve body abuts on a wall surface of the injection nozzle, the valve body closes the injection hole of the injection nozzle, so that injection of gaseous fuel from the injection hole is suspended. In this fuel injection valve, an elastic body made of rubber or the like is attached to the front end face of the valve body, so as to attenuate an impact that is caused by the front end face of the valve body when it comes into abutment on the wall surface of the injection nozzle.
After gaseous fuel injection from the injection hole has been suspended, it is necessary to air-tightly shut off the injection hole. In the aforementioned fuel injection valve, the elastic body attached to the front end face of the valve body is pressed hard against the wall surface of the injection nozzle. At this time, there is a possibility that the elastic body is excessively pressed against the wall surface of the injection nozzle. In this case, the elastic body deteriorates in quality at an early stage.
SUMMARY OF THE INVENTION
It is an object of the present invention to prevent the elastic body attached to the valve body from deteriorating in quality at an early stage, while keeping the injection hole securely closed by the valve body in an air-tight manner.
In a first aspect of the present invention, there is provided a fuel injection valve including an injection nozzle provided with an injection hole for fuel injection, a valve body for closing the injection hole, and an elastic body provided either on a wall surface of the injection nozzle or on a wall surface of the valve body. In this fuel injection valve, the elastic body is provided such that when the valve body closes the injection hole, the wall surface of the valve body comes into abutment on the wall surface of the injection nozzle after the valve body has come into abutment on the injection nozzle through the elastic body.
According to the aforementioned first aspect, after the valve body has come into abutment on the injection nozzle through the elastic body, the wall surface of the valve body comes into abutment on the wall surface of the injection nozzle. Therefore, the elastic body attenuates an impact that is caused when the wall surface of the valve body comes into abutment on the wall surface of the injection nozzle. Consequently, the valve body is prevented from deteriorating in quality at an early stage. Furthermore, since the wall surface of the valve body abuts on the wall surface of the injection nozzle, the elastic body is not deformed beyond a predetermined degree. In other words, there is no possibility of the elastic body being deformed excessively. Accordingly, the elastic body is prevented from deteriorating in quality at an early stage.
In the aforementioned first aspect, a sum of maximal surface roughness values of the wall surface of the valve body and the wall surface of the injection nozzle, which abut on each other, may be substantially equal to or smaller than 4 &mgr;m. Furthermore, a maximal surface roughness value of each of the wall surfaces of the valve body and the injection nozzle, which abut on each other, may be substantially equal to or smaller than 2 &mgr;m.
In the aforementioned first aspect, the elastic body may be provided with a protruding portion that protrudes toward the other of the wall surface of the injection nozzle and the wall surface of the valve body.
Further, the elastic body may have an annular shape, and the protruding portion may be provided radially inwardly of a radially central portion of the elastic body.
Further, the elastic body may have an annular shape, and the elastic body may have a face that is located radially outwardly of the protruding portion and is recessed in such a direction as to move away from the other of the wall surface of the injection nozzle and the wall surface of the valve body.
Further, the elastic body may have an annular shape and may be disposed in an annular recess portion provided in one of the wall surface of the injection nozzle and the wall surface of the valve body. The elastic body may have an outer peripheral surface that is smaller in outer diameter than the annular recess portion.
Further, the elastic body may have an annular shape and may be disposed in an annular recess portion provided in one of the wall surface of the injection nozzle and the wall surface of the valve body. The recess portion may have a bottom face that is inclined such that the recess portion becomes shallower inwards in a radial direction of the injection nozzle or the valve body.
Further, the other of the wall surface of the injection nozzle and the wall surface of the valve body, on which the elastic body abuts, may be inclined in such a manner as to approach one of the injection nozzle and the valve body inwards in a radial direction of the injection nozzle or the valve body.
Further, the elastic body may have an annular shape and may be disposed in an annular recess portion provided in one of the wall surface of the injection nozzle and the wall surface of the valve body. The elastic body may have an inner peripheral face that is greater in inner diameter than the annular recess portion.
In the aforementioned aspect, gaseous fuel may be used.
In a second aspect of the present invention, there is provided a method of manufacturing a fuel injection valve that includes an injection nozzle provided with an injection hole for fuel injection, a valve body for closing the injection hole, and an elastic body provided either on a wall surface of the injection nozzle or on a wall surface of the valve body, wherein the elastic body is provided such that when the valve body closes the injection hole, the wall surface of the valve body comes into abutment with the wall surface of the injection nozzle after the valve body has come into abutment with the injection nozzle through the elastic body. This method includes the step of causing the wall surface of the valve body and the wall surface of the injection nozzle, which abut each other, to slidably contact each other so as to reduce a maximal surface roughness value of the wall surfaces that abut each other.
According to the second aspect, the wall surface of the valve body and the wall surface of the injection nozzle, which abut each other, are caused to slidably contact each other, so as to reduce a maximal surface roughness value of the wall surfaces abutting each other. Therefore, a high degree of sealability is obtained between the wall surface of the valve body and the wall surface of the injection nozzle.
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patent: 2610021 (1952-09-01), Smith
patent: 2959392 (1960-11-01), Platen et al.
patent: 2968464 (1961-01-01), Olson
patent: 2995057 (1961-08-01), Nenzell
patent: 3930656 (1976-01-01), Jelinek
patent: 4192520 (1980-03-01), Hasegawa
patent: 4682759 (1987-07-01), Hall et al.
patent: 4711400 (1987-12-01), Radaelli et al.
patent: 5116020 (1992-05-01), Peng et al.
patent: 5372313 (1994-12-01), Chabon et al.
patent: 7-229578 (1995-08-01), None
patent: 8-61152 (1996-03-01), None
Kojima Susumu
Takeda Keiso
Evans Robin O.
Oliff & Berridg,e PLC
Scherbel David A.
Toyota Jidosha & Kabushiki Kaisha
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