U.S. patent application number 13/138150 was filed with the patent office on 2011-11-03 for exhaust throttle valve for internal combustion engine.
Invention is credited to Satoshi Ikeda, Naoto Noguchi, Akihiro Uto.
Application Number | 20110265466 13/138150 |
Document ID | / |
Family ID | 42395324 |
Filed Date | 2011-11-03 |
United States Patent
Application |
20110265466 |
Kind Code |
A1 |
Ikeda; Satoshi ; et
al. |
November 3, 2011 |
EXHAUST THROTTLE VALVE FOR INTERNAL COMBUSTION ENGINE
Abstract
An exhaust throttle valve 1 includes a housing 2 formed with a
gas passage 2a, first and second valve shafts 3 and 4 rotatably
journaled in the housing 2, a large valve body 5 connected to the
first valve shaft, and a small valve body 6 connected the second
valve shaft. A communication hole 17 is provided in the large valve
body, and urging means that urges the small valve body in a
direction of abutting against the large valve body is provided in
the second valve shaft. When the large valve body closes the gas
passage and pressure of a gas in the gas passage increases from a
state where the small valve body closes the communication hole
(FIG. 2(b)), the small valve body is separated from the large valve
body against an urging force of the urging means to open the
communication hole (FIG. 2(c)). With an easy configuration, exhaust
gas pressure can be adjusted without depending on a gas temperature
deference.
Inventors: |
Ikeda; Satoshi; (Aichi,
JP) ; Uto; Akihiro; (Aichi, JP) ; Noguchi;
Naoto; (Aichi, JP) |
Family ID: |
42395324 |
Appl. No.: |
13/138150 |
Filed: |
October 7, 2009 |
PCT Filed: |
October 7, 2009 |
PCT NO: |
PCT/JP2009/067470 |
371 Date: |
July 13, 2011 |
Current U.S.
Class: |
60/324 |
Current CPC
Class: |
F16K 1/223 20130101;
F02D 9/101 20130101; F02M 26/70 20160201; F02D 9/102 20130101; F02D
9/04 20130101 |
Class at
Publication: |
60/324 |
International
Class: |
F01N 1/00 20060101
F01N001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 30, 2009 |
JP |
2009-019540 |
Claims
1. An exhaust throttle valve for an internal combustion engine
comprising: a housing formed with a gas passage through which a gas
passes; a valve shaft rotatably journaled in said housing; and a
valve body that is connected to said valve shaft and opens and
closes said gas passage, characterized in that said valve shaft
includes a first valve shaft and a second valve shaft that are
coaxially provided and are relatively rotatable, said valve body
includes a large valve body that is connected to said first valve
shaft and formed to have substantially the same diameter as the gas
passage, a communication hole provided in said large valve body,
and a small valve body that is connected to said second valve shaft
and abuts against the large valve body to close said communication
hole, urging means that urges said second valve shaft in a
direction of said small valve body abutting against said large
valve body is provided outside the gas passage, and when pressure
of the gas in the gas passage increases with said large valve body
closing the gas passage, said small valve body is separated from
the large valve body against the urging force by said urging means
to open said communication hole.
2. The exhaust throttle valve for an internal combustion engine
according to claim 1, characterized in that said urging means is a
torsion coil spring surrounding said second valve shaft and
elastically fitted between said second valve shaft and the
housing.
3. The exhaust throttle valve for an internal combustion engine
according to claim 1, characterized in that a first through hole
and a second through hole are provided in said housing so as to
face each other with the gas passage therebetween, said first valve
shaft is provided in the first through hole, and said second valve
shaft is provided in the second through hole.
4. The exhaust throttle valve for an internal combustion engine
according to claim 3, characterized in that said large valve body
includes a first valve shaft holding portion that is formed on the
side of the first through hole and to which the first valve shaft
is connected, a second valve shaft passing portion that is formed
on the side of the second through hole and rotatably holds the
second valve shaft, a first flap protruding from the first valve
shaft holding portion and the second valve shaft passing portion,
and a second flap protruding from the side opposite to the first
flap, said small valve body includes a second valve shaft holding
portion located between the first valve shaft holding portion and
the second valve shaft passing portion of said large valve body and
to which the second valve shaft passing through said second valve
shaft holding portion is connected, and a third flap protruding
from said second valve shaft holding portion, a communication hole
having a smaller opening than said third flap is formed in said
first flap, and said urging means urges the third flap to abut
against the first flap from a downstream side of the gas passage
via the second valve shaft.
5. The exhaust throttle valve for an internal combustion engine
according to claim 1, characterized in that stopper means is
provided that holds the small valve body and the large valve body
at predetermined degrees of opening when said small valve body is
separated from the large valve body.
Description
TECHNICAL FIELD
[0001] The present invention relates to an exhaust throttle valve
for an internal combustion engine, and more particularly to an
exhaust throttle valve for an internal combustion engine including
a housing formed with a gas passage through which a gas passes, and
a valve body that opens and closes the gas passage.
BACKGROUND ART
[0002] Conventionally, an exhaust throttle valve for an internal
combustion engine is known including a housing formed with a gas
passage through which a gas passes and a through hole provided in a
direction perpendicular to the gas passage, a valve shaft rotatably
journaled in the through hole, and a valve body that is connected
to the valve shaft and opens and closes the gas passage.
[0003] As such an exhaust throttle valve, a valve is known in which
a communication hole is provided in a first valve body that opens
and closes a gas passage, a second valve body formed of a metal
leaf spring is provided to cover the communication hole, and the
second valve body is deformed to open the communication hole when
pressure of a gas in the gas passage becomes predetermined pressure
or more (Patent Document 1).
[0004] Also, as another exhaust pressure control device, a device
is known in which a bypass passage branching from a gas passage and
a bypass valve that opens and closes the bypass passage are
provided in a housing, and opening and closing of a valve body
provided in the gas passage and the bypass valve are controlled
(Patent Document 2).
PRIOR ART DOCUMENTS
Patent Documents
[0005] Patent Document 1: Japanese Patent Laid-Open No.
10-220253
[0006] Patent Document 2: Japanese Patent Laid-Open No.
2007-247488
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0007] However, for the exhaust throttle valve in Patent Document
1, the second valve body is made of metal and provided integrally
with the first valve body, and thus a temperature change of a gas
passing through the gas passage changes spring properties. Thus,
timing when the second valve body is opened changes to cause
variations in performance.
[0008] Also, for the exhaust pressure control device in Patent
Document 2, the bypass passage and the bypass valve need to be
newly provided to increase a size of the exhaust pressure control
device and increase costs.
[0009] In view of such problems, the present invention provides an
exhaust throttle valve for an internal combustion engine that is
easily configured and does not depend on a gas temperature
difference.
Means for Solving the Problems
[0010] Specifically, the present invention provides an exhaust
throttle valve for an internal combustion engine including: a
housing formed with a gas passage through which a gas passes; a
valve shaft rotatably journaled in the housing; and a valve body
that is connected to the valve shaft and opens and closes the gas
passage, characterized in that the valve shaft includes a first
valve shaft and a second valve shaft that are coaxially provided
and are relatively rotatable, the valve body includes a large valve
body that is connected to the first valve shaft and formed to have
substantially the same diameter as the gas passage, a communication
hole provided in the large valve body, and a small valve body that
is connected to the second valve shaft and abuts against the large
valve body to close the communication hole, urging means that urges
the second valve shaft in a direction of the small valve body
abutting against the large valve body is provided outside the gas
passage, and when pressure of the gas in the gas passage increases
with the large valve body closing the gas passage, the small valve
body is separated from the large valve body against the urging
force by the urging means to open the communication hole.
Advantages of the Invention
[0011] According to the above-described invention, the urging means
is provided outside the gas passage, and thus a change in timing
when the small valve body is opened based on a temperature
difference of the gas passing through the gas passage can be
prevented as much as possible, thereby obtaining a stable exhaust
pressure control function.
[0012] Also, there is no need for a bypass passage or a bypass
valve as in Patent Document 2, allowing an easy configuration and a
reduction in size.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a sectional view of an exhaust throttle valve
according to an embodiment; and
[0014] FIG. 2 is a sectional view taken along the line II-II in
FIG. 1 and shows an operation of the exhaust throttle valve.
BEST MODE FOR CARRYING OUT THE INVENTION
[0015] Now, a shown embodiment will be described. FIGS. 1 and 2
show an exhaust throttle valve 1 provided in an exhaust pipe of a
diesel engine as an internal combustion engine, and in FIG. 1, an
exhaust gas passes from the front to the back on the sheet plane,
and FIG. 2(b) shows a section taken along the line II-II in FIG.
1.
[0016] The exhaust throttle valve 1 for the internal combustion
engine includes a housing 2 formed with a gas passage 2a through
which the exhaust gas passes, a first valve shaft 3 and a second
valve shaft 4 rotatably journaled in the housing 2, a large valve
body 5 that is connected to the first valve shaft 3 and has
substantially the same diameter as the gas passage 2a, and a small
valve body 6 connected to the second valve shaft 4.
[0017] The gas passage 2a of the housing 2 has a substantially
circular shape, and a first through hole 2b shown on the left and a
second through hole 2c shown on the right are coaxially provided
with the gas passage 2a therebetween. The first valve shaft 3 is
rotatably held in the first through hole 2b via a bearing 7, and
the second valve shaft 4 is rotatably held in the second through
hole 2c via a bearing 7.
[0018] The first and second valve shafts 3 and 4 are journaled in
the first and second through holes 2b and 2c and thus rotate
coaxially, and in this embodiment, a tip of the first valve shaft 3
and a tip of the second valve shaft 4 are close to each other in a
position on the left in FIG. 1 with respect to the center of the
gas passage 2a.
[0019] The first valve shaft 3 is rotatably driven by an unshown
actuator via an arm 8 provided at the left end in FIG. 1, and
switches the large valve body 5 between an opened state in FIG.
2(a) and a closed state in FIGS. 2(b) and 2(c).
[0020] On the outside of the gas passage 2a, a first torsion coil
spring 9 is provided to surround the first valve shaft 3, and the
first torsion coil spring 9 is elastically fitted between the first
valve shaft 3 and the housing 2 to urge the first valve shaft 3
counterclockwise shown in each drawing of FIG. 2.
[0021] With such a configuration, in a non-operating state of the
exhaust throttle valve 1 shown in FIG. 2(a), the actuator holds the
large valve body 5 in the opened state, and the large valve body 5
is maintained in the opened state by the urging force by the first
torsion coil spring 9.
[0022] In an operating state of the exhaust throttle valve 1 shown
in FIGS. 2(b) and 2(c), the actuator rotates the first valve shaft
3 clockwise against the urging force by the first torsion coil
spring 9 to close the large valve body 5.
[0023] On the outside of the gas passage 2a, a second torsion coil
spring 10 as urging means is provided to surround the second valve
shaft 4, and the second torsion coil spring 10 is elastically
fitted between the second valve shaft 4 and the housing 2 to urge
the second valve shaft 4 counterclockwise shown in each drawing of
FIG. 2.
[0024] With such a configuration, in the states shown in FIGS. 2(a)
and 2(b), the small valve body 6 abuts against the large valve body
5 by the urging force of the second torsion coil spring 10, and
when pressure exceeding the urging force by the second torsion coil
spring 10 is applied to the small valve body 6 as shown in FIG.
2(c), the small valve body 6 rotates with respect to the large
valve body 5.
[0025] The large valve body 5 includes a tubular first valve shaft
holding portion 11 that is formed on the side of the first through
hole 2b and into which the first valve shaft 3 can be inserted, a
tubular second valve shaft passing portion 12 that is formed on the
side of the second through hole 2c and rotatably holds the second
valve shaft 4, a substantially semicircular first flap 13
protruding from the first valve shaft holding portion 11 and the
second valve shaft passing portion 12, and a substantially
semicircular second flap 14 protruding from the side opposite to
the first flap 13.
[0026] The first valve shaft 3 is inserted into the first valve
shaft holding portion 11 and connected and secured by a bolt, and
the second valve shaft 4 is rotatably journaled in the second valve
shaft passing portion 12 via the bearing 7 inserted into the second
valve shaft passing portion 12.
[0027] The small valve body 6 is located between the first valve
shaft holding portion 11 and the second valve shaft passing portion
12 of the large valve body 5, and includes a tubular second valve
shaft holding portion 15 into which the second valve shaft 4 can be
inserted, and a third flap 16 having a substantially semicircular
end protruding from the second valve shaft holding portion 15.
[0028] The second valve shaft 4 passing through the second valve
shaft passing portion 12 of the large valve body 5 is inserted into
the second valve shaft holding portion 15 and connected and secured
by a bolt.
[0029] The third flap 16 is provided in a position offset from the
center of the second valve shaft 4 as shown in each drawing of FIG.
2, and in a state where the large valve body 5 and the small valve
body 6 are closed, the first flap 13 and the third flap 16 are
brought into tight contact with each other.
[0030] In the first flap 13 of the large valve body 5, a
communication hole 17 is formed having a slightly smaller shape
than the third flap 16 of the small valve body 6.
[0031] Specifically, the communication hole 17 is formed to have
the same width as the third flap 16 in a base of the first flap 13,
and have, via a step, a smaller width than the width of the third
flap 16. An outer peripheral end of the communication hole 17 has a
substantially semicircular shape having a slightly smaller diameter
than the substantially semicircular shape on the outer peripheral
side of the third flap 16. Also, the communication hole 17 may have
any shape such as a rectangular or oval shape.
[0032] The communication hole 17 has such a shape, and thus when
the third flap 16 abuts against the first flap 13, the outer
peripheral portion of the third flap 16 abuts against the first
flap 13 so as to cover the outer peripheral portion of the
communication hole 17, and thus the communication hole 17 is closed
by the small valve body 6.
[0033] Further, a protrusion 18 as stopper means is formed on an
outer periphery of the second valve shaft holding portion 15 of the
small valve body 6, and as shown in FIG. 2(c), when the small valve
body 6 is opened to a predetermined degree of opening with respect
to the large valve body 5, the protrusion 18 abuts against the
second flap 14 of the large valve body 5 to hold the degrees of
opening of the small valve body 6 and the large valve body 5.
[0034] An operation of the exhaust throttle valve 1 having the
above-described configuration will be described. First, in the
non-operating state of the exhaust throttle valve 1 shown in FIG.
2(a), the large valve body 5 is held in the opened state by the
actuator, and the exhaust gas passing through the gas passage 2a
passes without being interrupted.
[0035] At this time, the second torsion coil spring 10 urges the
second valve shaft 4 and thus the third flap 16 of the small valve
body 6 abuts against the first flap 13 of the large valve body 5,
and the communication hole 17 is closed by the third flap 16.
[0036] Next, FIG. 2(b) shows the operating state of the exhaust
throttle valve 1 in which the large valve body 5 is closed by the
actuator, and the exhaust gas passing through the gas passage 2a is
interrupted by the large valve body 5 and the small valve body
6.
[0037] At this time, when the actuator rotates the first valve
shaft 3 clockwise, the first flap 13 presses the third flap 16 of
the small valve body 6 clockwise, and the gas passage 2a is closed
with the large valve body 5 and the small valve body 6 being
maintained closed.
[0038] At this time, the second valve shaft 4 rotates clockwise
against the urging force of the second torsion coil spring 10, and
thus the third flap 16 of the small valve body 6 is maintained
abutting the first flap 13 of the large valve body 5 from a
downstream side of the gas passage 2a.
[0039] Thus, the communication hole 17 of the large valve body 5 is
maintained closed by the third flap 16 of the small valve body 6,
and the exhaust gas is interrupted by the closed large valve body 5
and small valve body 6.
[0040] Next, FIG. 2(c) shows a state where a part of the exhaust
gas is passed through the communication hole 17 to adjust pressure
in the gas passage 2a, compared with the state in FIG. 2(b).
[0041] When the gas passage 2a is interrupted as shown in FIG.
2(b), the pressure of the exhaust gas increases on an upstream side
of the large valve body 5 and the small valve body 6, and thus the
pressure of the exhaust gas applied to the third flap 16 of the
small valve body 6 exceeds the urging force of the second torsion
coil spring 10 that urges the second valve shaft 4.
[0042] Then, the second valve shaft 4 rotates against the urging
force by the second torsion coil spring 10, and the third flap 16
of the small valve body 6 is separated from the first flap 13 of
the large valve body 5 to open the communication hole 17.
[0043] The communication hole 17 is opened and the exhaust gas
passes through the communication hole 17, and thus the pressure of
the exhaust gas interrupted by the large valve body 5 and the small
valve body 6 decreases to adjust the pressure of the exhaust gas in
the gas passage 2a.
[0044] Timing when the third flap 16 is separated from the first
flap 13 to open the communication hole 17 can be arbitrarily set by
adjusting the urging force by the second torsion coil spring
10.
[0045] Then, when the third flap 16 is opened by a predetermined
angle with respect to the first flap 13, the protrusion 18 provided
on the small valve body 6 abuts against the second flap 14 of the
large valve body 5 to prevent the small valve body 6 from being
excessively opened with respect to the large valve body 5.
[0046] Then, the pressure of the exhaust gas decreases or the
exhaust throttle valve 1 is set to the non-operating state, and
thus the pressure of the exhaust gas applied to the third flap 16
of the small valve body 6 decreases, and thus the third flap 16
abuts against the first flap 13 by the urging force by the second
torsion coil spring 10 to close the communication hole 17.
[0047] With the above-described exhaust throttle valve 1, when the
pressure of the exhaust gas in the gas passage 2a increases when
the large valve body 5 is closed, the small valve body 6 is opened
to open the communication hole 17 formed in the large valve body 5,
thereby allowing the pressure of the exhaust gas to be
adjusted.
[0048] Also, the second valve shaft 4 to which the small valve body
6 is connected is urged by the second torsion coil spring 10
provided outside the housing 2, and thus a temperature change of
the gas in the gas passage 2a hardly changes the urging force by
the second torsion coil spring 10, thereby obtaining a stable
operation.
[0049] Instead of the above-described embodiment, for example, it
may be allowed that the second through hole 2c of the housing 2 is
omitted, the second valve shaft 4 is rotatably provided in the
first valve shaft 3, and the large valve body 5 and the small valve
body 6 are provided in the first and second valve shafts 3 and
4.
[0050] In this case, it may be allowed that the second torsion coil
spring 10 is elastically fitted between the first valve shaft 3 and
the second valve shaft 4, and the second torsion coil spring 10
urges the large valve body 5 and the small valve body 6 to be
closed.
[0051] The first and second torsion coil springs 9,10 may be
compression springs.
DESCRIPTION OF SYMBOLS
[0052] 1 exhaust throttle valve
[0053] 2 housing
[0054] 2a gas passage
[0055] 3 first valve shaft
[0056] 4 second valve shaft
[0057] 5 large valve body
[0058] 6 small valve body
[0059] 17 communication hole
* * * * *