U.S. patent application number 10/582516 was filed with the patent office on 2007-06-21 for exhaust emission control device.
Invention is credited to Hiroshi Endou, Toshiki Ohya.
Application Number | 20070137188 10/582516 |
Document ID | / |
Family ID | 34675101 |
Filed Date | 2007-06-21 |
United States Patent
Application |
20070137188 |
Kind Code |
A1 |
Ohya; Toshiki ; et
al. |
June 21, 2007 |
Exhaust emission control device
Abstract
An object is to make it possible to accurately detect
temperature of exhaust directly flowing through a particulate
filter stored in a muffler. In an exhaust emission control device
with the particulate filter 9 stored in the muffler 1 which in turn
is incorporated in an exhaust pipe, a recess is formed by a cup 21
at a temperature detecting area on a casing 2 of the muffler 1. The
recess is concave up to a position in proximity to the particulate
filter 9 in the casing 2. A temperature sensor 22 is arranged to
penetrate a deepest portion of the recess formed by the cup 21.
Inventors: |
Ohya; Toshiki; (Tokyo,
JP) ; Endou; Hiroshi; (Saitama-ken, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Family ID: |
34675101 |
Appl. No.: |
10/582516 |
Filed: |
July 12, 2004 |
PCT Filed: |
July 12, 2004 |
PCT NO: |
PCT/JP04/09938 |
371 Date: |
June 9, 2006 |
Current U.S.
Class: |
60/311 ;
60/297 |
Current CPC
Class: |
F01N 3/0222 20130101;
Y02T 10/12 20130101; F01N 2230/02 20130101; F01N 3/0212 20130101;
F02D 2200/0802 20130101; F01N 3/0335 20130101 |
Class at
Publication: |
060/311 ;
060/297 |
International
Class: |
F01N 3/00 20060101
F01N003/00; F01N 3/02 20060101 F01N003/02 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 12, 2003 |
JP |
2003-414623 |
Claims
1. An exhaust emission control device with a particulate filter
stored in a muffler which in turn is incorporated in an exhaust
pipe, comprising a recess at a temperature detecting area on a
casing of the muffler, said recess being concave up to a position
in proximity to the particulate filter in the casing, and a
temperature sensor arranged to penetrate a deepest portion of said
recess.
2. The exhaust emission control device as claimed in claim 1,
wherein the recess is in the form of a cup and an operation space
is secured around the temperature sensor penetrating the recess to
allow for operation of a tool for attachment/detachment of said
temperature sensor.
Description
TECHNICAL FIELD
[0001] The present invention relates to an exhaust emission control
device.
Background Art
[0002] Particulates or particulate matter discharged from a diesel
engine is mainly constituted by carbonic soot and a soluble organic
fraction (SOF) of high-boiling hydrocarbons and contains a trace of
sulfate (misty sulfuric acid fraction). In order to suppress such
kind of particulates from being discharged into atmosphere, it has
been carried out that a particulate filter is incorporated in an
exhaust pipe through which the exhaust gas flows.
[0003] The particulate filter is a porous honeycomb structure made
of ceramics such as cordierite and having lattice-like
compartmentalized passages. Alternate ones of the passages have
plugged inlets and the remaining passages with unplugged open
inlets are plugged at their outlets. Thus, only the exhaust gas
passing through the thin porous compartment walls is discharged
downstream and the particulates are captured on inner surfaces of
the walls.
[0004] When such kind of particulate filter is to be mounted
especially to a vehicle such as a tractor with short wheel bases
and having various accessories laid out in mutually close
relationship, it is hard to secure a new mounting space for the
particulate filter so as not to interfere with the accessories. It
has been therefore under review to store the particulate filter in
a muffler and to efficiently arrange the both of them in one and
the same mounting space.
[0005] Gradually accumulated in the particulate filter is unburned
ash which derives from lubricant and cannot be burned out. It is
accordingly necessary to take out the particulate filter for direct
cleaning such as air cleaning or water washing or for replacement
of the filter with a new filter. Thus, the particulate filter must
be removably attached to the muffler.
[0006] For example, in the following Reference 1 by the same
applicant as that of the invention, an exhaust emission control
device has been proposed which has a box-shaped muffler with an
inner shell fixedly arranged therein. Inserted and fitted into the
inner shell is a particulate filter integrally carried by a
cartridge shell and unitized into a filter cartridge. Reference 1:
JP 2003-97248A
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0007] However, employment of such construction with the filter
cartridge removably fitted into the inner shell which in turn is
fixedly arranged in the box-shaped muffler causes the filter
cartridge to be stored in proximity of and away from the casing of
the muffler to secure a sound-muffling space therearound so that,
even if a temperature sensor is arranged to penetrate the casing, a
temperature detecting portion of the sensor is still away from the
particulate filter, inevitably resulting in detection of
temperature of the exhaust in the sound-muffling space as a
substitutive value for temperature of the exhaust directly flowing
into the particulate filter.
[0008] As a result, even in trials of controlling combustion in an
engine so as to carry out addition of fuel through post injection
and/or elevation of exhaust temperature through post injection for
the purpose of positively burning out the particulates captured by
the particulate filter, the temperature of the exhaust directly
flowing into the particulate filter cannot be accurately detected,
resulting in a problem that more minute and more accurate control
of combustion in an engine is difficult to conduct.
[0009] The following is supplemental explanation on controlling
combustion in an engine: unburned fuel may be added through post
injection at non-ignition timing after passing of a compression top
dead center. Then, the added fuel undergoes oxidation reaction on
an oxidation catalyst carried by or arranged separately and
upstream of the particulate filter. Reaction heat due to the
oxidation reaction elevates temperature of a catalytic floor of the
particulate filter, thereby accelerating burnout of the
particulates.
[0010] Alternatively, the post injection may be added at
combustible timing just after main injection. Then, the fuel fed
through the post injection is burned at timing for the fuel hardly
converted into output so that thermal efficiency of the engine is
lowered to increase heating quantity not utilized for motive power
among heating quantity from motive power fuel, whereby temperature
of the exhaust is elevated to accelerate the burnout of the
particulates.
[0011] The present invention was made in view of the above and has
its object to make it possible to accurately detect a temperature
of exhaust directly flowing through a particulate filter stored in
a muffler.
Means or Measure for Solving the Problems
[0012] The invention is directed to an exhaust emission control
device with a particulate filter stored in a muffler which in turn
is incorporated in an exhaust pipe, comprising a recess at a
temperature detecting area on a casing of the muffler, said recess
being concave up to a position in proximity to the particulate
filter in the casing, and a temperature sensor being arranged to
penetrate a deepest portion of said recess.
[0013] Thus, the temperature sensor is arranged in proximity to the
particulate filter in the casing, so that temperature measurement
is fulfilled with a temperature detecting portion of the
temperature sensor being proximal to a center of an entry- or
exit-side end surface of the particulate filter, whereby
temperature of the exhaust directly flowing through the particulate
filter is accurately detected by the temperature sensor.
[0014] Further, it is preferable in the invention that the recess
is in the form of a cup and an operation space is secured around
the temperature sensor penetrating the recess to allow for
operation of a tool for attachment/detachment of said temperature
sensor. Then, when the temperature sensor is to be arranged to
penetrate the deepest portion of the recess, the operation space
secured in the recess can be utilized for reasonable operation of
the tool for easy attachment/detachment of the temperature
sensor.
Effects of the Invention
[0015] According to an exhaust emission control device of the
invention, various excellent effects can be obtained as mentioned
below.
[0016] (I) The temperature of the exhaust directly flowing through
the particulate filter stored in the muffler is accurately
detected, so that utilization of such accurately detected
temperature makes it possible to conduct various controls such as
control of combustion in the engine more minutely and more
accurately than is possible conventionally.
[0017] (II) The operation space can be secured around the
temperature sensor penetrating the recess so as to allow for
operation of a tool for attachment/detachment of the temperature
sensor, whereby the tool can be reasonably operated to easily
conduct attachment/detachment of the temperature sensor to the
deepest portion of the recess.
BRIEF DESCRIPTION OF DRAWINGS
[0018] [FIG. 1] A partly cut-out perspective view showing an
embodiment of the invention.
[0019] [FIG. 2] A vertical sectional view of the muffler shown in
FIG. 1.
[0020] [FIG. 3] A perspective view showing a recess formed at a
temperature detecting area on a muffler.
[0021] [FIG. 4] A sectional view looking in the direction of arrows
IV in FIG. 2.
EXPLANATION OF THE REFERENCE NUMERALS
[0022] 1 muffler [0023] 2 casing [0024] 9 particulate filter [0025]
14 exhaust pipe [0026] 15 exhaust gas [0027] 18 oxidation catalyst
[0028] 21 cup (recess) [0029] 22 temperature sensor [0030] 22a
temperature detecting portion [0031] 23 operation space
BEST MODE FOR CARRYING OUT THE INVENTION
[0032] An embodiment of the invention will be described in
conjunction with the drawings.
[0033] FIGS. 1-4 show an embodiment of the invention in which a
box-shaped muffler 1 has a casing 2 separated by separators 3 and 4
into three, i.e., first, second and third chambers 5, 6 and 7. A
cylindrical inner shell 8 is fixed arranged to penetrate the
separator 4 and extend throughout the second and third chambers 6
and 7. This inner shell 8 defines a storage space for a particulate
filter 9 within the casing 2 of the muffler 1.
[0034] The particulate filter 9 is integrally carried by a
cylindrical cartridge shell 10 and unitized into a filter cartridge
11, the filter cartridge 11 being adapted to be fitted into the
inner shell 8 by inserting the same through a rear surface on the
casing 2 of the muffler 1.
[0035] The cartridge shell 10, which carries the particulate filter
9, has a flange 12 on its end outward in a direction of insertion.
After the cartridge shell 10 is inserted and stored in the inner
shell 8, the flange 12 is bolt-fastened to the rear surface on the
casing 2 of the muffler 1 together with an outer edge of a cover 13
which closes an opening of the cartridge shell 10 outward in the
direction of insertion.
[0036] Moreover, an inlet pipe 16 for introduction of exhaust gas
15 from an upstream exhaust pipe 14 (see FIG. 2) is inserted via a
front surface on the casing 2 of the muffler 1 up to the first
separator 3 for closure of its tip such that the exhaust gas 15
introduced through the inlet pipe 16 is discharged via diffused air
holes 16a to the first chamber 5.
[0037] In the first chamber 5, a catalyst shell 17 is fixedly
arranged to penetrate the separator 3 so as to communicate with the
inner shell 8, a straight-flow type oxidation catalyst 18 being
stored in the catalyst shell 17 so as to assist burnout of the
particulates captured by the particulate filter 9, the exhaust gas
15 in the first chamber 5 being introduced, via slits 17a of the
catalyst shell 17, into an end of the oxidation catalyst 18 away
from the particulate filter 9.
[0038] The exhaust gas 15 having passed through the oxidation
catalyst 18 flows into the particulate filter 9 in the inner shell
8. After passing through the particulate filter 9 for capture of
the particulates, the exhaust gas is discharged to the third
chamber 7 via slits 10a of the cartridge shell 10 in proximity to
its end outward in the direction of insertion as well as
corresponding slits 8a on the inner shell 8.
[0039] An outlet pipe 19 for discharge of the exhaust gas 15
purified by the particulate filter 9 is inserted via the front
surface on the casing 2 of the muffler 1 up to the third chamber 7
and in parallel with the inlet pipe 16 and with its tip being
opened, so that the exhaust gas 15 discharged to the third chamber
7 is withdrawn via the outlet pipe 19 to a downstream exhaust pipe
(not shown).
[0040] With respect to the exhaust emission control device thus
constructed, in the embodiment and as shown in FIGS. 3 and 4, a
portion of the casing 2 of the muffler 1 at and around a boundary
between the oxidation catalyst 18 and the particulate filter 9
provides a temperature detecting area. Fitted to a mounting hole 20
opened at the area is a cup 21 concave inward of the casing 2, so
that the recess concave up to a position in proximity to the
particulate filter 9 is formed by the cup 21.
[0041] Moreover, the temperature sensor 22 is arranged to penetrate
a deepest portion of the recess formed by the cup 21, so that a
temperature detecting portion 22a of the temperature sensor 22 is
inserted between the oxidation catalyst 18 and particulate filter 9
through a cutout (not shown) on the inner shell 8.
[0042] An operation space 23 is secured around the penetrating
temperature sensor 22 in the cup 21 so as to allow for rotary
operation of a tool such as a spanner with a crooked tip for
attachment/detachment of the temperature sensor 22 through, for
example, a screwing mechanism.
[0043] Thus, with the exhaust emission control device of the
embodiment constructed as mentioned above, the temperature sensor
22 is arranged in proximity to the particulate filter 9 in the
casing 2 so that temperature measurement is fulfilled with the
temperature detecting portion 22a of the temperature sensor 22
being proximal to a center of an entry- or exit-side end surface of
the particulate filter 9, whereby temperature of the exhaust
directly flowing into the particulate filter 9 through the
oxidation catalyst 18 is accurately detected by the temperature
sensor 22.
[0044] Thus, according to the above embodiment, the temperature of
the exhaust directly flowing into the particulate filter 9 through
the oxidation catalyst 18 stored in the muffler 1 can be accurately
detected, so that utilization of such accurately detected
temperature makes it possible to conduct control of combustion in
the engine more minutely and accurately than is possible
conventionally.
[0045] Moreover, especially in the embodiment, the operation space
23 is secured around the temperature sensor 22 penetrating so as to
allow for operation of a tool for attachment/detachment of the
temperature sensor 22, so that the tool can be reasonably operated
using such operation space 23, whereby attachment/detachment of the
temperature sensor 22 can be easily conducted to the deepest
portion of the recess formed by the cup 21.
INDUSTRIAL APPLICABILITY
[0046] It is to be understood that an exhaust emission control
device according to the present invention is not limited to the
above-mentioned embodiment and that various changes and
modifications may be made within the gist of the invention. For
example, oxidation catalyst may not be necessarily arranged
upstream of and in series with the particulate filter. Measurement
may be carried out by the temperature detecting portion of the
temperature sensor in proximity to either an entry side or an exit
side of the particulate filter. The muffler may not necessarily be
box-shaped.
* * * * *