Internal-combustion engines – Intake manifold – Manifold tuning – balancing or pressure regulating means
Reexamination Certificate
2002-06-14
2004-07-06
Argenbright, Tony M. (Department: 3747)
Internal-combustion engines
Intake manifold
Manifold tuning, balancing or pressure regulating means
Reexamination Certificate
active
06758182
ABSTRACT:
INCORPORATION BY REFERENCE
The disclosure of Japanese Patent Application No. 2001-186023 filed on Jun. 20, 2001, including the specification, drawings and abstract is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to a variable intake device of an internal combustion engine and a method for manufacturing the device.
2. Description of Related Art
A variable intake device, in which the length of an intake tube and flow area are variable, has been developed to be used with internal combustion engines. With the internal combustion engine equipped with the variable intake device, high volumetric efficiency in a wide operation area can be secured by appropriately adjusting the cycle of the intake pulse through changes in the length of the intake tube or flow area.
A variable intake device for an internal combustion engine has been well known through a Japanese Utility Model Laid-Open Publication No. 63-156421. The variable intake device in the publication, as shown in
FIG. 8
, includes an intake controlling valve
51
in a surge tank
50
and adopts a system that changes the length of an intake tube
40
according to running status of the engine.
According to the variable intake device, the intake tube
40
is divided into two passages
52
and
53
by a partition wall
54
downstream from a throttle valve
60
. The interior of the surge tank
50
is also divided into two chambers
55
and
56
which are connected to the passages
52
and
53
respectively. The intake tube
40
is further divided into each cylinder from both the chambers
55
and
56
through an intake manifold
61
. An actual length of the intake tube is changed by communicating and interrupting communication between the chambers
55
and
56
as the intake controlling valve
51
opens and closes.
FIG. 9
shows a perspective view of the structure of a model resin surge tank provided at the variable intake device with an upper part
111
taken off. The resin surge tank includes an integrally installed structure equivalent to the intake controlling valve
51
and the passages
52
and
53
in addition to a structure equivalent to the surge tank
50
in the variable intake device shown in FIG.
8
.
The surge tank mainly includes a surge tank body, which forms an outer wall of the surge tank
50
, and a valve unit
110
, at which the intake controlling valve
51
is provided.
The valve unit
110
mainly includes the intake throttle valve
51
and a structure for attaching the intake throttle valve
51
. In the resin surge tank, the valve unit
110
is provided as an integral unit including a valve body
110
A of the intake controlling valve
51
, a frame
110
B, an attachment flange
110
C, and a driving device
110
D. The attachment flange
110
C is for fixing the valve unit
110
on the outer wall of the surge tank. The driving device
110
D is for opening and closing the valve body
110
A.
The surge tank body is divided into three parts: the upper part
111
, a lower part
112
, and a center part
113
. The upper part mainly forms portions equivalent to an upper outer wall of the surge tank
50
and an upper outer wall of the passage
52
in FIG.
8
. The lower part
112
mainly forms portions equivalent to a lower outer wall of the surge tank
50
and a lower outer wall of the passage
53
in FIG.
8
. The center part
113
mainly forms portions equivalent to a side outer wall of the surge tank
50
, side outer walls of the passages
52
and
53
, and the partition wall
54
forming the passages
52
and
53
and both chambers
55
and
56
in FIG.
8
.
Each connector for connecting a throttle body (not shown), which is provided with the intake manifold
61
and the throttle valve
60
, to the resin surge tank is formed at the center part
113
. A partition wall
113
A (equivalent to the partition wall
54
in
FIG. 8
) for dividing the interior of the surge tank
50
into two chambers is also formed at the center part
113
. An opening of the partition wall
113
B, into which the valve unit
110
is installed, is formed at the partition wall
113
A. Furthermore, an attachment flange
113
C for fixing the valve unit
110
is provided at the center part
113
.
Each part (
111
,
112
, and
113
) is formed from resin. Many of the parts (the frame
110
B, for example) of the valve unit
110
are also formed from resin.
The above-described resin surge tank is manufactured through the following three steps:
(1) fixing each part together through welding to integrally assemble the surge tank;
(2) installing the valve unit
110
into the opening of the partition wall
113
B; and
(3) tightening the attachment flanges
110
and
113
together with a bolt
114
to fix the valve unit
110
to the center part
113
.
Because of the attachment structure of the above-described valve unit
110
, a clearance is formed to a certain extent between the outer margins of the frame
110
B and the opening of the partition wall
113
B or between both the attachment flanges
110
C and
113
C. To obviate the above-mentioned problem, gaskets
115
and
116
, which are formed from an elastic body such as rubber, are inserted into the clearance of the resin surge tank according to the present invention to secure sealing performance necessary for the resin surge tank.
The above-described variable intake device can be manufactured at low cost by forming the surge tank, in which the intake controlling valve
51
is housed from resin as described above. However, as described below, a variable intake device adopting the above-described attachment structure of the valve unit
110
has problems which must be addressed and resolved in order to further improvement of its productivity and intake performance.
The valve unit
110
of the resin surge tank is fixed to the attachment flange
110
C of the valve unit
110
and to the attachment flange
113
C of the center part
113
sufficiently. However, the outer margins of the frame
110
B and the opening of the partition wall
113
B are not completely fixed together since they are just connected through the gasket
116
. Therefore, the valve unit
110
is attached to the center part
113
as a cantilever supported by the attachment flange
110
C. Further, vibration from the frame
110
B may be generated as an internal combustion engine vibrates. As a result, a size of the valve body
110
A is restricted to avoid fatigue break of the valve unit
110
due to the vibration. Furthermore, restrictions such as the need for increasing the width and thickness of the frame
110
B are also considered in designing the variable intake device. Therefore, the restrictions become obstacles to securing intake performance and lightening the resin surge tank.
SUMMARY OF THE INVENTION
The present invention has been developed in consideration of the above-mentioned problems and its object is to allow a variable intake device with a resin surge tank, in which an intake controlling valve is housed, to be manufactured more appropriately.
The following describes means to achieve the above-mentioned object and action effects of the means.
A variable intake device for an internal combustion engine according to an aspect of the present invention includes a resin surge tank including a plurality of chambers divided by a partition wall and an opening of an outer wall and a valve unit including a control valve that selectively opens and closes to communicate and interrupt between the chambers by opening and closing the partition wall and a resin frame forming a peripheral frame of the control valve, wherein the valve unit is fixed at the opening of the outer wall and integrally fixed at least at a portion of a plurality of contact portions between an opening of the partition wall and the resin frame.
A method for manufacturing the variable intake device includes the following two steps. First, a valve unit, which includes a control valve for communicating and interrupting between chambers by opening and closing a partition wall and a resin frame forming
Katahira Natuhiko
Nakamura Hideo
Nomizo Fumio
Ali Hyder
Argenbright Tony M.
Toyota Jidosha & Kabushiki Kaisha
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