U.S. patent application number 14/905491 was filed with the patent office on 2016-06-09 for machine body and working machine.
This patent application is currently assigned to Caterpillar SARL. The applicant listed for this patent is CATERPILLAR SARL. Invention is credited to Toru Imano, Shinichi Nishiyama, Junya Tokunaga, Kazuhira Watanabe.
Application Number | 20160160726 14/905491 |
Document ID | / |
Family ID | 51210456 |
Filed Date | 2016-06-09 |
United States Patent
Application |
20160160726 |
Kind Code |
A1 |
Imano; Toru ; et
al. |
June 9, 2016 |
Machine Body and Working Machine
Abstract
An injector injects urea water as a liquid reducing agent; a NOx
sensor detects concentration of nitrogen oxide in exhaust gas; and
an air duct including an inlet side opening and outlet side opening
cools at least either one of urea water in urea water hose, NOx
sensor or injector with cooling air introduced from outside of the
machine room. A ventilation opening at the outside of the machine
room communicates with the inlet side opening of the air duct using
negative pressure formed in a circumference of exhaust gas flow by
an ejector arranged in an exhaust pipe passage.
Inventors: |
Imano; Toru; (Tokyo, JP)
; Tokunaga; Junya; (Tokyo, JP) ; Nishiyama;
Shinichi; (Kobe-shi, Hyogo, JP) ; Watanabe;
Kazuhira; (Kobe-shi, Hyogo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CATERPILLAR SARL |
Geneva |
|
CH |
|
|
Assignee: |
Caterpillar SARL
Geneva
CH
|
Family ID: |
51210456 |
Appl. No.: |
14/905491 |
Filed: |
July 10, 2014 |
PCT Filed: |
July 10, 2014 |
PCT NO: |
PCT/EP2014/064850 |
371 Date: |
January 15, 2016 |
Current U.S.
Class: |
60/276 |
Current CPC
Class: |
F01N 2610/1453 20130101;
B60Y 2200/412 20130101; F01N 2610/148 20130101; Y02T 10/24
20130101; F01N 11/007 20130101; F01N 2590/08 20130101; F01N 2270/02
20130101; F01N 2610/11 20130101; Y02A 50/2325 20180101; F01N
2270/08 20130101; F01N 2470/30 20130101; F01N 2550/02 20130101;
F01N 2610/02 20130101; F01N 2260/022 20130101; F01N 2560/026
20130101; F01N 13/082 20130101; B60K 11/06 20130101; B60K 13/04
20130101; F01N 3/2066 20130101; Y02A 50/20 20180101; Y02T 10/12
20130101; E02F 9/0866 20130101 |
International
Class: |
F01N 3/20 20060101
F01N003/20; F01N 11/00 20060101 F01N011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 16, 2013 |
JP |
2013-147917 |
Claims
1. A machine body comprising: a machine room; an engine installed
in the machine room; an exhaust line through which exhaust gas from
the engine is discharged; an exhaust gas cleaning apparatus
provided in the exhaust line to execute a reducing process on
nitrogen oxide in exhaust gas; and a reducing agent supply
apparatus that supplies a liquid reducing agent to the exhaust gas
cleaning apparatus through a reducing agent supply pipe, wherein
the exhaust gas cleaning apparatus includes: an injector that
injects the liquid reducing agent supplied by the reducing agent
supply apparatus through the reducing agent supply pipe; a nitrogen
oxide sensor that detects a concentration of the nitrogen oxide in
the exhaust gas; an air passage body installed so as to surround at
least one of a part of the reducing agent supply pipe, a part of
the nitrogen oxide sensor, and a part of the injector to allow at
least one of the liquid reducing agent in the reducing agent supply
pipe, the nitrogen oxide sensor, and the injector to be cooled
using cooling air taken from an outside of the machine room, the
air passage body including an inlet side opening and an outlet side
opening; an outside air intake port which communicates with the
inlet side opening of the air passage body and which opens to the
outside of the machine room; and an ejector provided in the exhaust
line to forcibly discharge air in the air passage body through the
outlet side opening of the air passage body by utilizing a negative
pressure formed around an exhaust gas flow.
2. A working machine comprising: the machine body according to
claim 1; and a working apparatus mounted on the machine body.
Description
TECHNICAL FIELD
[0001] The present invention relates to a machine body and a
working machine both characterized by a cooling structure for an
exhaust gas cleaning apparatus.
BACKGROUND ART
[0002] An exhaust gas cleaning apparatus for a diesel engine
includes an injector that injects a reducing agent (DEF: Diesel
Exhaust Fluid; a urea aqueous solution, in general) and a nitrogen
oxide sensor (NOx sensor).
[0003] In general, the exhaust gas cleaning apparatus is installed
in an exhaust line. Hot exhaust gas flows through the exhaust line,
and thus, the exhaust line and the exhaust gas cleaning apparatus
become hot.
[0004] When the exhaust gas cleaning apparatus is hot, the injector
and NOx sensor installed in the exhaust gas cleaning apparatus are
also exposed to elevated temperatures. Moreover, a reducing agent
supply pipe (in general, a urea aqueous solution hose) through
which the reducing agent is supplied to the injector is partly
exposed to elevated temperatures. When the urea aqueous hose, the
NOx sensor, or the injector is exposed to elevated temperatures for
a long time, the durability thereof may be impaired for structural
reasons, and the temperature of the urea aqueous solution in the
urea aqueous solution hose rises to affect the reducing effect of
the urea aqueous solution.
[0005] In a traveling vehicle such as a car, the injector may be
cooled when exposed to outside air during traveling or when a cool
reducing agent flows into the injector, but cooling performance may
still be insufficient. For such a case, a technique has been
proposed which involves circular feeding of a refrigerant such as
cooling water to the injector (see, for example, Patent Document
1).
[0006] Another technique has been proposed which involves
introduction of cooling air throughout a housing chamber for the
exhaust gas cleaning apparatus based on an ejector effect for
engine exhaust gas (see, for example, Patent Document 2).
[0007] Patent Document 1: Japanese Patent Application Laid-Open No.
H9-96212
[0008] Patent Document 2: Japanese Patent Application Laid-Open No.
2003-41627
[0009] Patent Document 1 needs a dedicated cooling water circuit
through which a refrigerant such as cooling water flows around the
periphery of the injector. Such a cooling water circuit is a
large-scale, expensive cooling apparatus.
[0010] Patent Document 2 uses the structure in which cooling air is
introduced throughout the housing chamber for the exhaust gas
cleaning apparatus, and thus needs a large-scale isolation chamber.
This disadvantageously leads to the need for a large installation
space.
[0011] With these problems in view, it is an object of the present
invention to provide a machine body and a working machine which
need only low costs and a small space and which allow a desired
portion of an exhaust gas cleaning apparatus to be solely
cooled.
DISCLOSURE OF THE INVENTION
[0012] An invention set forth in claim 1 is a machine body
including a machine room, an engine installed in the machine room,
an exhaust line through which exhaust gas from the engine is
discharged, an exhaust gas cleaning apparatus provided in the
exhaust line to execute a reducing process on nitrogen oxide in
exhaust gas, and a reducing agent supply apparatus that supplies a
liquid reducing agent to the exhaust gas cleaning apparatus through
a reducing agent supply pipe, wherein the exhaust gas cleaning
apparatus includes an injector that injects the liquid reducing
agent supplied by the reducing agent supply apparatus through the
reducing agent supply pipe, a nitrogen oxide sensor that detects a
concentration of the nitrogen oxide in the exhaust gas, an air
passage body installed so as to surround at least one of a part of
the reducing agent supply pipe, a part of the nitrogen oxide
sensor, and a part of the injector to allow at least one of the
liquid reducing agent in the reducing agent supply pipe, the
nitrogen oxide sensor, and the injector to be cooled using cooling
air taken from an outside of the machine room, the air passage body
including an inlet side opening and an outlet side opening, an
outside air intake port which communicates with the inlet side
opening of the air passage body and which opens to the outside of
the machine room, and an ejector provided in the exhaust line to
forcibly discharge air in the air passage body through the outlet
side opening of the air passage body by utilizing a negative
pressure formed around an exhaust gas flow.
[0013] An invention set forth in claim 2 is a working machine
including the machine body set forth in claim 1 and a working
apparatus mounted on the machine body.
[0014] The invention set forth in claim 1 provides the structure in
which the inlet side opening of the air passage body is in
communication with the outside air intake port outside the machine
room and in which the ejector provided in the exhaust line utilizes
the negative pressure formed around the exhaust gas flow to suck
the air in the air passage body into the exhaust gas flow in the
exhaust gas line through the outlet side opening of the air passage
body, allowing the air to be forcibly discharged. Thus, while the
engine is being driven to discharge the exhaust gas, the outside
air is constantly introduced into the air passage body to enable
efficient cooling of at least one of the liquid reducing agent in
the reducing agent supply pipe, the nitrogen oxide sensor, and the
injector. Thus, a cooling effect can be exerted using a low-cost
duct structure without the need for a special cooling water line or
pump. Furthermore, the air passage body may be installed which
locally surrounds the cooling target area, allowing space to be
conserved.
[0015] The invention set forth in claim 2 can provide inexpensive
cooling means for a working machine that performs operations at a
fixed location, the cooling means allowing efficient cooling of at
least one of the liquid reducing agent in the reducing agent supply
pipe, the nitrogen oxide sensor, and the injector.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a schematic plan view showing an embodiment of a
machine room in a machine body according to the present
invention.
[0017] FIG. 2 is a perspective view showing an exhaust gas cleaning
apparatus in the machine body and a peripheral portion of the
exhaust gas cleaning apparatus.
[0018] FIG. 3 is a perspective view showing only the peripheral
portion of the exhaust gas cleaning apparatus in the machine
body.
[0019] FIG. 4 is a front view showing a working machine including
the machine body.
BEST MODE FOR CARRYING OUT THE INVENTION
[0020] The present invention will be described below based on an
embodiment shown in FIGS. 1 to 4.
[0021] As shown in FIG. 4, a working machine 10 like a hydraulic
excavator has a machine body 11 including a lower traveling body 12
and an upper slewing body 13 mounted on the lower traveling body 12
so as to be able to slew. A working apparatus 14 like a bucket is
mounted on the upper slewing body 13 of the machine body 11.
[0022] On the upper slewing body 13, a cab 15 in which an
operator's seat is provided and a storage box 16 with tools and the
like housed therein are provided across an area where the working
apparatus 14 is mounted. A fuel tank 17 and a hydraulic oil tank 18
are provided behind the storage box 16. A machine room (engine
room) 19 is installed on the upper slewing body 13 behind a slewing
bearing portion. A counterweight 20 is further installed behind the
machine room 19.
[0023] As shown in FIG. 1, an engine 21 is installed in the machine
room 19. A cooling fan 21f is located on one side of the engine 21
to blow cooling air sucked from the outside against a cooling
package including a radiator, an oil cooler and the like (not shown
in the drawings) to cool the cooling package. An exhaust gas
cleaning apparatus 22 is located on the other side of the engine 21
to execute an exhaust gas cleaning process on an exhaust system for
the engine 21.
[0024] As seen back in FIG. 4, an engine hood 23 is provided at the
top of the machine room 19 so as to be openable and closable. A tip
of an exhaust line 24 through which exhaust gas from the engine 21
is discharged projects from the engine hood 23. Furthermore, a side
door 25 is provided on an outer side surface side of the machine
room 19 so as to be openable and closable. A ventilation port 26
serving as an outside air intake port is formed in an upper portion
of the side door 25 and is open to the outside of the machine room
19.
[0025] As shown in FIG. 1 and FIG. 2, in the exhaust gas cleaning
apparatus 22, an exhaust opening of the engine 21 is connected, via
connection means 21e serving as a start point for the exhaust line
24, to an end portion 27a of a black exhaust removal apparatus
(diesel particulate filter) 27 that removes black exhaust contained
in exhaust gas discharged from the engine 21. A pipe connection
portion 27b provided at an opposite end portion of the end portion
27a of the black exhaust removal apparatus 27 is connected, via a
pipe 28a, to an opposite end portion 28b of a nitrogen oxide
reduction apparatus (selective catalytic reduction) 28 that
executes a reduction process on nitrogen oxide in exhaust gas. The
remaining portion of the exhaust line 24 is connected to a pipe
connection portion 28c provided at an end portion of the nitrogen
oxide reduction apparatus 28 which is opposite to the opposite end
portion 28b.
[0026] An injector 29 is attached to the pipe connection portion
27b of the black exhaust removal apparatus 27 to inject a liquid
reducing agent such as a urea aqueous solution toward the pipe 28a,
via which the black exhaust removal apparatus 27 and the nitrogen
oxide reduction apparatus 28 are in communication with each other.
An NOx sensor 30 is located near the injector 29 and serves as a
nitrogen oxide sensor that detects the concentration of nitrogen
oxide (NOx) in exhaust gas.
[0027] The NOx sensor 30 includes an upstream side NOx sensor main
body 30a provided in the pipe connection portion 27b of the black
exhaust removal apparatus 27, a downstream side NOx sensor main
body 30b provided in the pipe connection portion 28c of the
nitrogen oxide reduction apparatus 28, a control box 30A connected
to the upstream side NOx sensor main body 30a, and a control box
30B connected to the downstream side NOx sensor main body 30b.
[0028] A reducing agent supply apparatus 31, which feeds a liquid
reducing agent such as a urea aqueous solution from the inside of
the storage box 16 located at a position not thermally affected by
the engine 21 as shown in FIG. 4 to the nitrogen oxide reduction
apparatus 28, is provided with respect to the injector 29.
[0029] As shown in FIG. 4, the reducing agent supply apparatus 31
includes a liquid reducing agent tank 32 installed in the storage
box 16 and in which the liquid reducing agent is stored and a
liquid reducing agent pump 33 serving as a liquid reducing agent
supply source that pumps up and ejects the liquid reducing agent in
the liquid reducing agent tank 32, and a urea aqueous solution hose
34 serving as a reducing agent supply pipe and disposed to extend
from the liquid reducing agent pump 33 through a piping path in the
machine body 11 to the injector 29 for injection of the liquid
reducing agent. An air passage body 35 is provided so as to
surround a part of a tip of the urea aqueous solution hose 34.
[0030] As shown in FIG. 1, the following are housed inside the air
passage body 35: a part of the injector 29, a part of the NOx
sensor 30, and a part of the urea aqueous solution hose 34 in which
the urea aqueous solution in the urea aqueous solution hose 34
serving as a liquid reducing agent is likely to be thermally
affected by the exhaust gas cleaning apparatus 22.
[0031] As shown in FIG. 2 and FIG. 3, the air passage body 35 is
shaped like a box fixedly installed on a plate 41. An inlet side
opening 42 is formed in a lower side surface of the air passage
body 35 and connects to a suction duct 43 and is in communication
with the suction duct 43. The suction duct 43 is in communication
with an opening 47 formed between the plate 41 and a plate 44 and
having a U-shaped cross section, via a corner passage 46 formed
between the upper plate 44 and a lower plate 45 and having a
U-shaped cross section. The opening 47 is formed to face the
ventilation port 26 in the side door 25. The ventilation port 26
serves as an inlet when cooling air is taken from the outside of
the machine room 19 into the air passage body 35.
[0032] The corner passage 46 has an open surface on the outside of
the corner passage 46 which is closed by a machine cover or a
member associated with the machine cover, to form a duct. The
suction duct 43 and the corner passage 46 form duct-like air
passages 43 and 46. The exhaust gas cleaning apparatus 22 is
fixedly installed on the plate 44 using a mounting plate 48.
[0033] As shown in FIG. 2, the exhaust line 24 is temporarily drawn
out, in the horizontal direction, from the pipe connection portion
28c of the nitrogen oxide reduction apparatus 28 and then routed
obliquely upward. The ejector 51 is provided in the middle of the
exhaust line 24. An intake port 52 formed in an outer side surface
of the ejector 51 is in communication, via a suction pipe 54, with
an outlet side opening 53 formed in an upper end surface portion of
the air passage body 35. The ejector 51 utilizes a negative
pressure formed around the periphery of an exhaust gas flow to
forcibly suck the air in the air passage body 35 through the outlet
side opening 53 of the air passage body 35.
[0034] As shown in FIG. 2 and FIG. 3, a wall body 55 is provided on
the plate 44 and arranged in an L shape so as to enclose the
outside of the exhaust gas cleaning apparatus 22. The urea aqueous
solution hose 34 is disposed along the wall body 55 using a hook 56
provided on an outer side surface of the wall body 55 and a fitting
57 installed on the plate 44. Moreover, the urea aqueous solution
hose 34 is drawn into the corner passage 46 through a pipe
introduction inlet portion 58 cut out in a part of the plate 44,
and is then inserted through the suction duct 43 into the air
passage body 35 and further connected to the injector 29.
[0035] Wiring in the air passage body 35 connected to the control
boxes 30A and 30B of the NOx sensor 30 is connected, via the
suction duct 43 and the like, to a controller (not shown in the
drawings) installed in the machine body 11 to control the liquid
reducing agent pump 33.
[0036] Now, the effects of the embodiment shown in FIG. 1 to FIG. 4
will be described.
[0037] The reducing agent supply apparatus 31 pumps up the urea
aqueous solution in the liquid reducing agent tank 32 in the
storage box 16 using the liquid reducing agent pump 33 and feeds
the urea aqueous solution to the exhaust gas cleaning apparatus 22
in the machine room 19 through the urea aqueous solution hose 34.
The injector 29 then injects the urea aqueous solution into the
pipe 28a connected to an upstream side of the nitrogen oxide
reduction apparatus 28.
[0038] At this time, the wall body 55, the corner passage 46, the
suction duct 43, and the air passage body 35 function as a heat
shielding structure that blocks heat radiated by the exhaust gas
cleaning apparatus 22 to protect the urea aqueous solution hose 34
from the heat. Furthermore, the ejector 51 provided in the exhaust
line 24 utilizes a negative pressure formed around the periphery of
the exhaust gas flow to suck the air in the air passage body 35
into the exhaust gas flow in the exhaust line 24 through the outlet
side opening 53 of the air passage body 35, allowing the air to be
forcibly discharged to the outside. Thus, cool outside air outside
the machine body 11 can be sucked into the air passage body 35
through the ventilation port 26, serving as an outside air intake
port of the side door 25, via the opening 47, the corner passage
46, and the suction duct 43.
[0039] Thus, while the engine 21 is in operation, the air passage
body 35 is internally cooled by the cool outside air, enabling
cooling of the urea aqueous solution in the urea aqueous solution
hose 34 fitted in the air passage body 35, the NOx sensor 30, and
the injector 29.
[0040] Thus, the inlet side opening 42 of the air passage body 35
is in communication with the ventilation port 26 outside the
machine room, and the ejector 51 provided in the exhaust line 24
utilizes the negative pressure formed around the periphery of the
exhaust gas flow to suck the air in the air passage body 35 into
the exhaust gas flow in the exhaust line 24 through the outlet side
opening 53 of the air passage body 35, allowing the air to be
forcibly discharged to the outside. Thus, while the engine 21 is
being driven to discharge the exhaust gas, the outside air is
constantly introduced into the air passage body 35 to enable
efficient cooling of the urea aqueous solution in the urea aqueous
solution hose 34, the NOx sensor 30, and the injector 29, which are
exposed to the elevated temperature of the exhaust gas cleaning
apparatus 22. Consequently, a cooling effect can be exerted using a
low-cost duct structure without the need for a special cooling
water line or pump. Furthermore, the air passage body 35 may be
installed which locally surrounds a part of the urea aqueous
solution hose 34, a part of the NOx sensor 30, and apart of the
injector 29, that is, the cooling target area, allowing space to be
conserved.
[0041] Furthermore, inexpensive cooling means for the working
machine 10 that performs operations at a fixed location can be
provided which means allows efficient cooling of the urea aqueous
solution in the urea aqueous solution hose 34, the NOx sensor 30,
and the injector 29, which are exposed to the elevated temperature
of the exhaust gas cleaning apparatus 22.
[0042] The air passage body 35 is not limited to the box-like shape
shown in FIG. 2 and FIG. 3. A part of the air passage body 35 from
the inlet side opening 42 to the outlet side opening 53 may be
shaped like a duct so that the part of the urea aqueous solution
hose 34 which is exposed to elevated temperatures, the NOx sensor
30, and a part of the injector 29 can be arranged in the duct. This
structure exerts similar effects.
[0043] Furthermore, the air passage body 35 allows cooling of the
urea aqueous solution in the urea aqueous solution hose 34, the NOx
sensor 30, and the injector 29. However, the air passage body 35
may be installed so as to surround one or two of the following:
apart of the urea aqueous solution hose 34, apart of the NOx sensor
30, and a part of the injector 29 to allow the one or two to be
cooled using cooling air externally obtained.
INDUSTRIAL APPLICABILITY
[0044] The present invention is available for manufactures involved
in manufacture of a machine body and a working machine
characterized by a cooling structure of an exhaust gas cleaning
apparatus.
EXPLANATION OF REFERENCE NUMERALS
[0045] 10 Working machine
[0046] 11 Machine body
[0047] 14 Working apparatus
[0048] 19 Machine room
[0049] 21 Engine
[0050] 22 Exhaust gas cleaning apparatus
[0051] 24 Exhaust line
[0052] 26 Ventilation port as outside air intake port
[0053] 29 Injector
[0054] 30 NOx sensor as nitrogen oxide sensor
[0055] 31 Reducing agent supply apparatus
[0056] 34 Urea aqueous solution hose as reducing agent supply
pipe
[0057] 35 Air passage body
[0058] 42 Inlet side opening
[0059] 51 Ejector
[0060] 53 Outlet side opening
* * * * *