Valves and valve actuation – Electrically actuated valve – Including solenoid
Reexamination Certificate
2002-02-14
2003-12-23
Mancene, Gene (Department: 3754)
Valves and valve actuation
Electrically actuated valve
Including solenoid
Reexamination Certificate
active
06666432
ABSTRACT:
CROSS REFERENCE TO RELATED APPLICATION
This application relates to and incorporates herein by reference Japanese Patent Application No. 2001-40245 filed on Feb. 16, 2001 and Japanese Patent Application No. 2001-345027 filed on Nov. 9, 2001.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an idle speed control valve (ISCV) for controlling an air amount supplied to combustion chambers in an internal combustion engine. More particularly, the present invention relates to an idle speed control valve in which an adjusting screw including a stator core is sealed with a sealing material.
2. Description of Related Art
In general, in an internal combustion engine for a vehicle, a bypass pipe separate from an actual air intake pipe is provided to bypass a throttle valve. An idle speed control valve is provided in the bypass pipe to control an amount of fluid such as air flowing in the bypass pipe.
In a general idle speed control valve shown in
FIG. 5
, an adjusting screw
120
is inserted in a hole
115
provided in a valve body
111
and passes through a center of windings
130
. As shown in
FIG. 6
, the adjusting screw
120
has a threaded portion
122
on its outer peripheral surface to be threaded with an inner wall of the hole
115
. Adhesive is applied to the threaded portion
122
beforehand, so that the adjusting screw
120
fixes on the inner wall of the hole
115
at a desired position.
More specifically, first, an adjusting screw
120
in which the adhesive is not applied is temporary fitted in the hole
115
to adjust a spring for biasing a movable core
141
so that a movement area becomes a predetermined crossing area. Next, adjusting screw
120
is removed from the hole
115
and replaced with adjusting screw
120
with adhesive applied onto the threaded portion
122
. Then, the adjusting screw
120
is finally adjusted and fitted at a predetermined position. Next, a sealing material
150
such as silicon is applied around a head portion
121
of the adjusting screw
120
to improve air-tightness. The sealing material
150
passes between the head portion
121
and the inner wall of the hole
115
and enters the inside of the hole
115
. In this case, since the threaded portion
122
is bonded with the adhesive, the sealing material
150
stops at the threaded portion
122
. (Not shown)
Since a replacement of the adjusting screw
120
is required, mounting and assembly time increase and workability is worsened. Thus, if the adjusting screw
120
in which the adhesive is not applied to the threaded portion
122
is used without pre-adjustment and adjusted to the final position, the sealing material
150
applied around the head portion
121
enters deeper inside the control valve
110
beyond the threaded portion
122
. For example, when this sealing material
150
is hardened around a movable core
141
, operation of the movable core
141
is interrupted, and as a result, a valve
145
will not operate.
In order to prevent entering of the sealing material
150
around the movable core
141
in the idle speed control valve
110
, a rigid barricade portion may be provided on the outer periphery of the adjusting screw
120
. However, when the barricade portion is press-fitted on the adjusting screw
120
foreign material accumulates and is likely to enter the idle speed control valve
110
. Further, the adjusting screw having the barricade portion requires more torque to be inserted into the hole
115
when compared to that of the adjusting screw
120
without the barricade portion. Therefore, the inner wall defining the hole
115
, and the adjusting screw
120
, are likely to be damaged.
Accordingly, in a case where the adhesive is not applied to the threaded portion, the adjusting screw is required to be inserted without damage and also, the sealing material must be restricted from entering the idle speed control valve beyond the threaded portion.
SUMMARY OF THE INVENTION
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
According to one embodiment of the present invention, an adjusting screw has a ring-shaped flexible projection on the outer peripheral surface thereof between a threaded portion and a head portion. The flexible projection projects from the outer peripheral surface of the adjusting screw in a radial direction. A width or depth of the flexible projection in a radial direction is substantially equal to a distance between the outer peripheral surface of the adjusting screw and an inner wall of a hole provided in an idle speed control valve body. Therefore, a peak of the flexible projection contacts the inner wall of the hole when the adjusting screw is inserted into the hole.
Accordingly, a sealing material, which is applied around a head portion of the adjusting screw for sealing between the outer peripheral surface of the adjusting screw and the inner wall of the hole, is prevented from entering inside of the idle speed control valve beyond the flexible projection. The width of the flexible projection in the radial direction can be greater than the distance between the outer peripheral surface of the adjusting screw and the inner wall. In this case, the peak of the flexible projection is bent backward (opposite to the direction of insertion) when the adjusting screw is inserted into the hole. Therefore, the entering of the sealing material is effectively prevented at the flexible projection.
According to another embodiment of the present invention, the adjusting screw has a thin wall portion on which a ring-shaped projection is provided between the threaded portion and the head portion. A width of the projection in the radial direction is greater than a distance between the outer peripheral surface of the thin wall portion and the inner wall of the hole in the idle speed control valve body. Therefore, when the adjusting screw is inserted into the hole, a peak of the projection contacts the inner wall and the thin wall portion having the projection is deformed toward an axial line of the adjusting screw. Accordingly, the sealing material is prevented from entering the inside of the idle speed control valve beyond the projection. Further, a threading torque of the adjusting screw is reduced.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for the purpose of illustration only and are not intended to limit the scope of the invention.
REFERENCES:
patent: 4268041 (1981-05-01), Sovish et al.
patent: 4630799 (1986-12-01), Nolan et al.
patent: 5312050 (1994-05-01), Schumann et al.
patent: 5586747 (1996-12-01), Bennardo et al.
patent: 5992822 (1999-11-01), Nakao et al.
patent: 6102407 (2000-08-01), Moriya et al.
Hariu Tetsuo
Hasegawa Shigeru
Ishigaki Satoshi
Buechner Patrick
Denso Corporation
Nixon & Vanderhye P.C.
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