Metal working – Method of mechanical manufacture – Valve or choke making
Reexamination Certificate
2000-11-13
2002-04-09
Rosenbaum, Icuda (Department: 3726)
Metal working
Method of mechanical manufacture
Valve or choke making
C029S464000
Reexamination Certificate
active
06367153
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates a method of manufacturing a fuel injection valve used for supplying fuel to various engines incorporated into an automobile. More particularly, the present invention relates a method of manufacturing a fuel injection valve by which fuel is whirled and supplied to a fuel injection path of a valve seat.
Conventionally, there is provided a fuel injection valve, the valve body of which is cylindrical, in which a valve such as a needle valve or ball valve is arranged and a valve seat having a fuel injection path is arranged at an outlet of the cylindrical valve main body, and fuel supplied from the outside the valve is whirled by a whirler so that fuel, which is supplied from the outside, can be fed to the fuel injection path.
FIG. 4
is a cross-sectional view showing an example of the conventional fuel injection device in which the above fuel injection valve is used.
FIG. 5
is an enlarged cross-sectional view of the fuel injection valve of the fuel injection device.
FIG. 6
is an enlarged cross-sectional view of another fuel injection valve of the fuel injection device.
In
FIG. 4
, reference numeral
1
is a fuel injection device, reference numeral
2
is a housing body of the fuel injection device
1
, and reference numeral
3
is a fuel injection valve which is supported by a lower end portion of the housing body
2
by means of calking. Reference numeral
4
is a fuel supply pipe, reference numeral
5
is a cylinder head of an engine, and reference numeral
6
is a valve operation device having an electromagnetic coil
61
and others for operating a needle valve
12
described later. A forward end portion of the fuel injection device
1
is inserted into a fuel injection device insertion hole
51
formed in a cylinder head
5
of the engine.
In
FIG. 5
, reference numeral
9
is a valve main body of the fuel injection valve
3
, reference numeral
11
is a valve seat, reference numeral
12
is a needle valve, and reference numeral
13
is a whirler. The valve main body
9
is a cylindrical body having an insertion port
91
into which the needle valve
12
is inserted, a small diameter section
92
and a large diameter section
93
. The valve seat
11
and the whirler
13
are fixed to the large diameter section
93
of the valve main body
9
which are arranged as shown in the drawing. At the center of the valve seat
11
, there is provided a fuel injection path
10
. At the center of the whirler
13
, there is provided a valve body sliding hole
131
. The needle valve
12
includes: an armature
121
, a large diameter section
122
, and a small diameter section
123
to be slid in the whirler. An outer diameter of the forward end section of the needle valve
12
, which continues to the section
123
to be slid in the whirler, is gradually reduced, and the forward end section of the needle valve
12
enters the fuel injection path
10
and closes the entrance opening of the fuel injection path
10
. An outer diameter of the large diameter section
122
is a little smaller than the inner diameter of the small diameter section
92
so that the large diameter section
122
can slide on the inner wall face of the small diameter section
92
of the valve main body
9
. An outer diameter of the section
123
to be slid in the whirler is a little smaller than the inner diameter of the valve body sliding hole
131
so that the section
123
to be slid in the whirler can penetrate the valve main body sliding hole
131
of the whirler
13
and slide on the inner wall of the valve body sliding hole
131
of the whirler
13
. Due to the foregoing, the entire needle valve
12
can go ahead and back in the valve main body
9
by the valve operation device
6
and armature
121
shown in
FIG. 4
so as to open and close the fuel injection path
10
of the valve seat
11
.
In this connection, in general, the whirler
13
can be inserted inside the large diameter section
93
of the valve main body
9
without being given any press-fitting pressure, however, the outer diameter of the whirler
13
is determined so that no clearance is substantially formed between the outer wall of the whirler
13
and the inner wall of the large diameter section
93
after the whirler
13
has been arranged in the large diameter section
93
. On the other hand, the outer diameter of the valve seat
11
is determined so that a press-fitting pressure can be required when the valve seat
11
is inserted inside the large diameter section
93
of the valve main body
9
. When the valve seat
11
is press-fitted inside the large diameter section
93
, it can be fixed inside the large diameter section
93
. At the same time, the valve seat
11
fixes the whirler
13
in the large diameter section
93
.
The fuel injection valve
3
shown in
FIG. 5
is manufactured in the following manufacturing process. First, the whirler
13
is inserted inside the large diameter section
93
of the valve main body
9
while the fuel introduction port face
132
is being directed to the forward end wall
921
of the small diameter section
92
of the valve main body
9
, and then the valve seat
11
is press-fitted inside the large diameter section
93
until the fuel introduction port face
132
of the whirler
13
comes into contact with the forward end wall
921
of the small diameter section
92
of the valve main body
9
. Due to the foregoing, the valve seat
11
is fixed inside the large diameter section
93
by the press-fitting pressure created by the valve seat
11
itself, and the whirler
13
is also fixed being interposed between the forward end wall face
921
of the small diameter section
92
and the valve seat
11
. Finally, the needle valve
12
is inserted into the valve main body
9
from the insertion hole
91
of the valve main body
9
, and the extreme end portion of the needle valve
12
penetrates the valve body sliding hole
131
of the whirler
13
and reaches the entrance opening of the fuel injection path
10
.
In this connection, the valve main body
9
, needle valve
12
, whirler
13
and valve seat
11
, which are used when the fuel injection valve
3
is manufactured by the above method, are previously designed so that these parts can have central axis A, which is shown in
FIG. 5
, in common. However, actually, the centers of these parts do not agree with central axis A because of the fluctuation of dimensional accuracy caused among the manufacturing lots. When the centers of these parts do not agree with central axis A, the following problems may be encountered. Since the whirler
13
and the needle valve
12
interfere with each other, it becomes difficult for the needle valve
12
to be inserted into the whirler. Even if the needle valve
12
can be inserted, the portion
123
of the needle valve
12
to be slid in the whirler
13
partially comes into contact with the inner wall of the whirler
13
in the valve main body sliding hole
131
as shown in
FIG. 6
(refer to portion B in FIG.
6
). Therefore, the yield and performance of products are affected as described later.
When the portion
123
of the needle valve
12
to be slid in the whirler
13
partially comes into contact with the inner wall of the whirler
13
in the valve body sliding hole
131
, an uneven clearance is caused between the outer wall of the section
123
to be slid in the whirler and the inner wall of the valve body sliding hole
131
of the whirler
13
. Accordingly, fuel can not be uniformly atomized, and further the extreme end portion of the needle valve
12
can not be appropriately set at the entrance opening of the fuel injection path
10
. Therefore, it becomes impossible to appropriately open and close the fuel path
10
, and the essential function of the fuel injection valve
3
can not be fully exhibited, or the essential function of the fuel injection valve
3
might be lost. In this connection, in order to prevent the section
123
of the needle valve
12
to be slid in the whirler from coming into partial contact with the valve main body sliding
Aota Masayuki
Fukutomi Norihisa
Matsunaga Kazuo
Mitsubishi Denki & Kabushiki Kaisha
Nguyen T.
Rosenbaum Icuda
LandOfFree
Method of manufacturing fuel injection valve does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of manufacturing fuel injection valve, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of manufacturing fuel injection valve will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2862934