Fluid handling – Processes – Cleaning – repairing – or assembling
Reexamination Certificate
2001-09-12
2003-10-28
Buiz, Michael Powell (Department: 3753)
Fluid handling
Processes
Cleaning, repairing, or assembling
C137S527400, C137S527600, C137S315160, C251S333000, C060S324000, C181S226000
Reexamination Certificate
active
06637449
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to mufflers for use in an exhaust system of an internal combustion engine of a motor vehicle, and more particularly to the exhaust mufflers of a type which can control the performance thereof in accordance with an operation condition of the engine. More specifically, the present invention is concerned with a pressure sensible valve for use in such controllable exhaust muffler.
2. Description of the Related Art
In order to clarify the task of the present invention, one known pressure sensible valve will be briefly described with reference to
FIG. 13
of the accompanying drawings, which is shown in laid-open Japanese Patent Application (Tokkai-Hei) 10-131738.
In
FIG. 13
, there is shown a controllable exhaust muffler
100
which has the known pressure sensible valve mounted therein. The muffler
100
comprises a casing
101
and two partition walls
101
A and
101
B which are arranged in the casing
101
to partition the interior of the casing
101
into three chambers A, B and C, as shown. The partition walls
101
A and
101
B are respectively formed with openings for mounting a passing pipe
102
which extends across the chamber B to connect the chambers A and C. The passing pipe
102
is welded to the partition walls
101
A and
100
B at the openings. The partition wall
101
A is formed around the opening thereof with a tapered depression
104
which is depressed toward the other partition wall
101
B. The depression
104
can be closed by a valve plate
107
which is pivotally held by stands
105
mounted on the partition wall
101
A. Thus, the tapered depression
104
can serve as a valve seat
103
. The valve plate
107
has a tapered periphery
108
that is shaped to mate with the tapered side surface of the depression
104
. A pivot shaft
106
extends between the stands
105
to allow the pivoting movement of the valve plate
107
relative to the stands
105
. A coil spring
109
is disposed around the pivot shaft
106
to bias the valve plate
107
in a direction to close the depression
104
, that is, in a direction to close an outlet opening of the passing pipe
102
which is exposed to the chamber A. The depression
104
has a sealing member
110
disposed on the tapered surface thereof, The sealing member
110
is made of a heat resistant material, such as wire mesh or the like. Usually, due to the biasing force of the coil spring
109
, the valve plate
107
is seated in the depression
104
closing the outlet opening of the passing pipe
102
, as shown in the drawing. While, when the exhaust pressure in the chamber C exceeds a predetermined value that corresponds to the biasing force of the coil spring
109
, the valve plate
107
is lifted from the depression
104
thereby to establish a fluid connection between the chambers A and C. Upon this, the performance of the muffler
100
changes.
However, due to difficulty in assembly, the above-mentioned pressure sensible valve fails to establish an accurate relative positioning between the tapered depression
104
(or valve seat
103
) and the valve plate
107
. That is, if the relative positioning is not accurately made, exhaust gas leakage tends to occur through the valve, which of course deteriorates the muffling performance of the muffler
100
.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a pressure sensible valve for an exhaust muffler, which is free of the above-mentioned drawback.
According to the present invention, there is provided a pressure sensible valve for use in an exhaust muffler, which can be readily assembled while assuring a positioning of a valve plate structure relative to a valve seat structure.
That is, according to the present invention, a sealed condition of the valve is assuredly made in a closed position of the same even when the valve plate structure makes a displacement by some degree relative to the valve seat structure.
According to a first aspect of the present invention, there is provided a valve for use in an exhaust muffler, which comprises a valve seat structure adapted to be secured to an outlet end of a passing pipe installed in the exhaust muffler, the valve seat structure including a flat seat surface portion which extends around the outlet end of the passing pipe; a valve plate structure pivotally connected to the valve seat structure, the valve plate structure including a valve plate portion and a flat sealing portion which forms a peripheral part of the valve plate portion, the valve plate structure having a close position wherein the valve plate portion closes the outlet end of the passing pipe having the flat sealing portion entirely pressed against the flat seat surface of the valve seat structure and an open position wherein the valve plate portion opens the outlet end of the passing pipe having the flat sealing portion separated from the flat seat surface; and a biasing structure which biases the valve plate structure to assume the close position.
According to a second aspect of the present invention, there is provided a valve for use with a passing pipe installed in an exhaust muffler, which comprises a valve seat structure adapted to be secured to an outlet end of a passing pipe installed in the exhaust mufflers the valve seat structure including a collar portion which is adapted to be disposed on an outlet end of the passing pipe and an annular flat seat surface portion which is defined on the collar portion in a manner to extend around the outlet end of the passing pipe; a valve plate structure including a circular valve plate portion and an annular flat sealing portion which forms a peripheral part of the circular valve plate portion, the valve plate structure having a close position wherein the circular valve plate portion closes a circular opening of the collar portion having the annular flat sealing portion entirely pressed against the annular flat seat surface of the valve seat structure and an open position wherein the circular valve plate portion opens the circular opening of the collar portion having the annular flat sealing portion separated from the annular flat seat surface; a pivot structure through which the valve plate structure is pivotally connected to the valve seat structure; an annular seal member which is fixed to one of the annular flat seat surface and the annular flat sealing portion, so that when the valve plate structure takes the close position, the annular seal member is compressed between the annular flat seat surface and the annular flat sealing portion thereby assuring sealing therebetween; and a biasing structure which biases the valve plate structure to assume the close position.
According to a third aspect of the present invention, there is provided a method of assembling a valve, which comprises the steps of (a) preparing a valve seat structure and a valve plate structure, the valve seat structure including a first pair of side wall portions which are formed with first aligned openings which are elliptic in shape, the valve plate structure including a second pair of side wall portions which are formed with second aligned openings which are circular in shape; (b) putting the second side wall portions between the first side wall portions and keeping the second and first side wall portions in such a manner that the first and second aligned openings are all aligned; (c) inserting a pivot shaft into the aligned first and second openings so that the valve plate structure becomes pivotal relative to the valve seat structure about the pivot shaft; (d) positioning the valve plate structure relative to the valve seat structure by moving the pivot shaft in the first aligned openings; and (e) welding the pivot shaft to the first side wall portions while keeping the positioning between the valve plate structure and the valve seat structure.
REFERENCES:
patent: 2494016 (1950-01-01), Taylor
patent: 2694358 (1954-11-01), Taylor
patent: 2960178 (1960-11-01), De Lorean
patent: 3234924 (1966-02-01), May
patent:
Nagai Tadashi
Shiraishi Kai
Buiz Michael Powell
Calsonic Kansei Corporation
Krishnamurthy Ramesh
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