Information
-
Patent Grant
-
6517044
-
Patent Number
6,517,044
-
Date Filed
Wednesday, September 19, 200122 years ago
-
Date Issued
Tuesday, February 11, 200321 years ago
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Inventors
-
Original Assignees
-
Examiners
- Yuen; Henry C.
- Bastianelli; John
Agents
-
CPC
-
US Classifications
Field of Search
US
- 251 64
- 251 12917
- 251 157
- 251 176
- 251 77
- 251 12919
- 251 12915
-
International Classifications
-
Abstract
An evaporative control valve includes a plunger reciprocable between a valve stop and a valve seat to open and close a controlled port. The plunger has a body, a flexible support member mounted on one end of the body and a resilient tip positioned on the support member for sealing engagement with the valve seat. When the resilient tip of the plunger impacts the valve seat, the flexible support member absorbs substantially all of the force of impact by deflecting in the direction opposite the plunger movement, increasing impact time and reducing noise which may be generated. The resilient tip may be positioned on the flexible support member to further define a stop cushion to further reduce impact of the plunger against the valve stop.
Description
TECHNICAL FIELD
The present invention relates to control valves and in particular, to an evaporative (EVAP) solenoid control valve including a plunger having noise reduction features.
BACKGROUND OF THE INVENTION
It is known in the art of automotive fuel systems to use an evaporative (EVAP) solenoid valve assembly to control the flow of fuel vapor through passageways connecting a purge canister and an intake manifold. One such EVAP control valve assembly includes a solenoid assembly actuated in response to a pulse width modulated (PWM) signal generated by the vehicle's central computer to induce a plunger to move toward a metal stop, opening a passageway to the flow of vapor. When the solenoid is de-energized, the plunger is pushed back toward a valve seat by a pre-loaded spring situated between the stop and the plunger, causing the plunger to seal the passageway.
The force of impact as a result of the plunger striking the valve stop or seat has been known to generate noise in some applications. Accordingly, EVAP control valve plungers have been designed to include a soft, rubber-like stop cushion at the interface with the valve stop and a rubber tip for sealing against the valve seat. At room temperature, noise due to impact with the stop or seat may be maintained at relatively low levels since the soft portions of the plunger exhibit relatively large deflection during impact, absorbing large amounts of the impact energy and extending the impact time to reduce the average impact force. However, where temperatures are close to or below the glass transition temperature of some kinds of rubber, those kinds of rubber tend to harden which may reduce the noise-dampening attributes.
SUMMARY OF THE INVENTION
The present invention provides an evaporative control valve including a plunger reciprocable between a valve stop and a valve seat to open and close a controlled port. The plunger has a body, a flexible support member mounted on one end of the body and a resilient tip positioned on the support member for sealing engagement with the valve seat. When the resilient tip of the plunger impacts the valve seat, the flexible support member absorbs substantially all of the force of impact by deflecting in the direction opposite the plunger movement, increasing impact time and reducing noise which may be generated. According to a further feature of this invention, the resilient tip may be positioned on the flexible support member to further define a stop cushion to further reduce impact of the plunger against the valve stop.
The above-described and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description, drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:
FIG. 1
is a cross-sectional view of an EVAP valve embodying all of the inventive aspects summarized above;
FIG. 2
is an enlarged cross-sectional view of a portion of the EVAP valve of
FIG. 1
showing the plunger normally positioned to close a controlled port;
FIG. 3
is an enlarged cross-sectional view of a portion of the EVAP valve of
FIG. 1
showing the plunger positioned toward a stop;
FIG. 4
is an enlarged cross-sectional view of a portion of the EVAP valve of
FIG. 1
showing the plunger impacting the stop;
FIG. 5
is an enlarged cross-sectional view of a portion of the EVAP valve of
FIG. 1
showing the flexible support member of the plunger deflecting in the direction opposite plunger movement;
FIG. 6
is an enlarged cross-sectional view of a portion of the EVAP valve of
FIG. 1
showing the plunger positioned toward a valve seat;
FIG. 7
is an enlarged cross-sectional view of a portion of the EVAP valve of
FIG. 1
showing the plunger impacting the valve seat;
FIG. 8
is an enlarged cross-sectional view of a portion of the EVAP valve of
FIG. 1
showing the flexible support member of the plunger deflecting in the direction opposite plunger movement; and
FIG. 9
is an enlarged cross-sectional view of a portion of the EVAP valve of
FIG. 1
showing the plunger positioned against the valve seat to close a controlled port.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A solenoid-actuated valve assembly for use in a fuel system is shown in FIG.
1
and includes a valve body
12
that defines an inlet
14
, a controlled port
16
and a chamber
18
therebetween wherein the inlet
14
is connectable to a filtration canister (not shown) and the port
16
is connectable to an intake manifold (not shown). The controlled port
16
is formed on an axis
20
and extends into the chamber
18
to define a seat
22
at the interface between the controlled port
16
and the chamber
18
.
The valve body
12
also houses a solenoid assembly
24
within a cavity
26
formed adjacent the chamber
18
, the cavity
26
being defined by a primary plate
28
, a secondary plate
30
, and sleeve portions
32
,
34
. The solenoid assembly
24
includes an electromagnetic coil
36
wound about a spool
38
supported between the primary and secondary plates
28
,
30
, respectively. The spool
38
has a central bore
40
positionable coaxial with axis
20
when the spool is assembled within the body
12
. The bore
40
opens into an annular recess
42
formed in an end
44
of the spool
42
adjacent the primary plate
28
. The annular recess
42
is further aligned coaxially with an opening
46
formed in the primary plate
28
. Thus, the central bore
40
, the recess
42
of the spool
38
and the primary plate opening
46
are all in axial alignment with the controlled port
16
.
Affixed to an end
48
of the valve body
12
opposite the seat
22
along axis
20
is a stop
50
. A conductive body
52
is received within the central bore
40
of the spool
38
, to engage against stop
50
. The conductive body
52
includes a tapered end portion
54
extending into the recess
42
of the spool end
44
. A plastic insert
56
is secured to the tapered end of the conductive body
52
and extends through the opening
46
of the primary plate
28
into the chamber
18
.
A plunger
58
, movable between the seat
22
and stop
50
to open and close the controlled port
16
, is situated within the opening
46
of the primary plate
44
. The plunger
58
includes an annular body
60
defining a central bore
62
sized to receive the plastic insert
56
and tapered end
54
of the conductive body
52
. The central bore
62
of the plunger body
60
, like that of the spool
40
, opens into a recess
64
formed in an end
66
of the plunger body
60
proximal the seat
22
. An opposite end
68
of the plunger body
60
proximal the stop
50
includes an annular slot
70
extending radially for a predetermined width and axially for a predetermined depth. The annular slot
70
is adapted to receive a spring
72
with one end supported against a base
74
of the recess
42
.
Spanning the end
66
of the plunger body
60
proximal the seat
22
is a flexible disk shaped spring or washer
76
having an aperture
78
coaxially aligned with axis
20
. A resilient tip
80
is received within the aperture and has a surface
82
sealable in engagement with the valve seat
22
and a cushion
84
formed on an opposite side of the spring
72
proximal the valve stop
50
.
As shown in
FIGS. 2-9
, the plunger
58
reciprocates between the seat
22
and the stop
50
, operating to open and close the controlled port
16
, so that vapor passing into the chamber
18
from the filtration canister through the inlet
14
is selectively released through the controlled port
16
into the intake manifold. Normally, the surface
82
of the resilient tip
80
of the plunger
58
is seated against the seat
22
to close the controlled port
16
as shown in FIG.
2
. In other words, the solenoid control valve
10
is spring biased to a normally closed position as illustrated in FIG.
2
. After receiving a pulse-width modulated signal generated by the central computer of the vehicle (not shown), the solenoid assembly
24
energizes, creating a magnetic field operable on the plunger
58
, that causes the plunger
58
to gradually move toward the stop
50
. Accordingly,
FIG. 3
illustrates the plunger body
60
moving through the opening
46
of the primary plate
28
and the recess
42
of the spool
38
toward the conductive body
52
of the stop
50
. As shown in
FIG. 4
, the stop cushion
84
of the plunger
58
eventually impacts the plastic insert
56
of the stop
50
. The force created by the impact between the stop cushion
84
and the stop
50
is absorbed by the flexible spring
72
, as shown in
FIG. 5
, which flexes in a direction opposite to the plunger body's
60
continuing movement toward the conductive body
52
of the stop
50
. In this manner, noise due to impact between the plunger
58
and stop
50
is greatly reduced, while minimizing wear on the stop cushion
84
.
When the solenoid assembly
24
de-energizes, the pre-load forces of the spring
72
against the base
44
of the recess
42
, urge the plunger
58
back toward the seat
22
to close the controlled port
16
(FIG.
6
). When the surface
82
of the resilient tip
80
impacts the seat
22
, as shown in
FIGS. 7 and 8
, the flexible spring
72
absorbs the resulting energy, and flexes in the direction opposite from the direction of movement of the plunger body
60
, bringing the plunger body
60
to a controlled halt without creating undue noise in response to impact with the seat. Since the flexible spring
72
absorbs most of the energy created by the plunger
58
in response to impact with the stop
50
and the seat
22
, the valve assembly
10
is quieter over a greater range of temperatures.
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.
Claims
- 1. A valve assembly comprising:a valve body defining a chamber with a controlled port having a valve seat associated therewith; a stop supported within the chamber of the valve body in axial alignment with the controlled port; and a plunger reciprocable between the stop and the seat to open and close the controlled port respectively, the plunger having a body, a resilient flexible washer mounted on an end of the body and a resilient tip secured to the washer for sealing engagement with the valve seat, wherein the flexible washer deflects in a direction opposite to the plunger movement for reducing a force of impact on the seat.
- 2. The valve assembly of claim 1 further comprising the resilient tip being secured to the washer to further define a stop cushion on an end facing the stop to reduce a force of impact on the stop.
- 3. The valve assembly of claim 1, wherein the washer is a disk shaped spring.
- 4. The valve assembly of claim 3, wherein the disk shaped spring includes a central aperture coaxially aligned with the controlled port, the resilient tip being received within the aperture.
- 5. The valve assembly of claim 1, further comprising a solenoid assembly operable to move the plunger toward the stop when the solenoid assembly is energized and toward the seat when the solenoid assembly is de-energized.
- 6. The valve assembly of claim 5, further comprising the plunger body being cylindrical with a cylindrical slot formed therein, and a pre-load spring disposed within the cylindrical slot for normally urging the plunger toward the stop when the solenoid assembly is de-energized.
- 7. A valve assembly comprising:a valve body defining a chamber with a controlled port having a valve seat associated therewith; a stop supported in the valve body coaxially aligned with the controlled port; and a solenoid assembly operable to move a plunger between opened and closed positions with respect to the controlled port, the plunger including a body, a flexible support member mounted on an end of the body and a resilient tip secured to the support member to define a first end adjacent the seat for sealing engagement with the seat, and a second end adjacent the stop for cushioning an impact of the plunger against the stop, wherein the flexible support member deflects in an opposite direction from a direction of movement of the plunger for reducing a force of impact on the seat and stop respectively.
- 8. The valve assembly of claim 7, wherein the flexible support member is a disk shaped spring interposed between the first and second ends of the resilient tip to define a sealing tip and stop cushion on the first and second ends respectively.
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Number |
Name |
Date |
Kind |
4250924 |
Sakakibara et al. |
Feb 1981 |
A |
5145152 |
Komuro et al. |
Sep 1992 |
A |
5374029 |
Bailey |
Dec 1994 |
A |
5967487 |
Cook et al. |
Oct 1999 |
A |