US20090183498A1 - Exhaust emission control device - Google Patents
Exhaust emission control device Download PDFInfo
- Publication number
- US20090183498A1 US20090183498A1 US12/320,205 US32020509A US2009183498A1 US 20090183498 A1 US20090183498 A1 US 20090183498A1 US 32020509 A US32020509 A US 32020509A US 2009183498 A1 US2009183498 A1 US 2009183498A1
- Authority
- US
- United States
- Prior art keywords
- exhaust gas
- valve
- adsorbent
- gas passage
- control device
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
- F01N3/0871—Regulation of absorbents or adsorbents, e.g. purging
- F01N3/0878—Bypassing absorbents or adsorbents
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
- F01N13/009—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
- F01N3/0828—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents characterised by the absorbed or adsorbed substances
- F01N3/0835—Hydrocarbons
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2240/00—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being
- F01N2240/18—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being an adsorber or absorber
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2550/00—Monitoring or diagnosing the deterioration of exhaust systems
- F01N2550/03—Monitoring or diagnosing the deterioration of exhaust systems of sorbing activity of adsorbents or absorbents
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2570/00—Exhaust treating apparatus eliminating, absorbing or adsorbing specific elements or compounds
- F01N2570/12—Hydrocarbons
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Exhaust Gas After Treatment (AREA)
Abstract
An exhaust emission control device includes an adsorbent trapper having an adsorbent for adsorbing and desorbing hydrocarbon in exhaust gas, a catalytic converter, a main exhaust gas passage with a first valve, a bypass exhaust gas passage with a second valve and a control unit. The bypass exhaust gas passage bypassing the first valve is connected with the adsorbent. The control unit controls the first and second valves to desorb the hydrocarbon from the adsorbent when a condition is satisfied. The condition is that the catalyst converter is in active, an oxygen adsorption amount of the catalyst converter is not less than a first predetermined amount and an exhaust gas amount is not more than a second predetermined amount. The first valve is opened and the second valve is closed when the condition is not satisfied during desorption of the hydrocarbon from the adsorbent.
Description
- 1. Field of the Invention
- The present invention relates to an exhaust emission control device that controls exhaust emission discharged from an internal combustion engine.
- 2. Description of the Related Art
- A conventional exhaust emission control device of this kind is disclosed in Japanese Patent Application Laid-Open Publication NO. 06-229235. This conventional exhaust emission control device has a main exhaust gas passage and a bypass exhaust gas passage that are arranged in parallel to each other at an upstream side of an exhaust emission control catalytic converter. The bypass exhaust gas passage is provided with an adsorbent that can adsorb hydrocarbon (HC) contained in an exhaust gas at a low temperature and desorb the HC adsorbed thereon at a high temperature. The conventional exhaust emission control device further has a valve for opening and closing the bypass exhaust gas passage. The valve is controlled by a control unit according to the temperature of the adsorbent.
- In this conventional exhaust emission control device, the exhaust gas discharged from an internal combustion engine is introduce into the bypass exhaust gas passage, where harmful components such as the HC is adsorbed on the adsorbent when the temperature of the exhaust gas is low, while the harmful components are desorbed from the adsorbent and this desorbed HC is purified by the catalytic converter when the temperature of the exhaust gas is high.
- However, in the above known conventional exhaust emission control device, there are a problem in that the purification performance of the catalytic converter is deteriorated due to lack of the oxygen adsorption amount of the catalytic converter because a large amount of the HC adsorbed on the adsorbent rapidly desorbs from the adsorbent when the exhaust gas flows into the bypass exhaust gas passage when the valve is controlled to open to flow the exhaust gas through the bypass exhaust gas passage.
- It is, therefore, an object of the present invention to provide an exhaust emission control device which overcomes the foregoing drawbacks and can suppress the deterioration, in a purifying performance of exhaust emission discharged from an internal combustion engine, due to the excess hydrocarbon emission desorbed from an adsorbent and lack of an oxygen adsorption amount of a catalyst.
- According to a first aspect of the present invention there is provided an exhaust emission control device including an adsorbent trapper, a catalytic converter, a main exhaust gas passage, a first valve, a bypass exhaust gas passage, a second valve and a control unit. The adsorbent trapper has an adsorbent that can adsorb hydrocarbon in exhaust gas discharged from an internal combustion engine on the adsorbent a low temperature thereof and desorb the hydrocarbon from the adsorbent at a high temperature thereof. The catalytic converter is arranged at a downstream side of the adsorbent trapper and has catalyst for purifying the exhaust gas. The main exhaust gas passage is arranged between the internal combustion engine and the catalytic converter so that the main exhaust passage can flow the exhaust gas discharged from the internal combustion engine to the catalytic converter. The first valve is arranged in the main exhaust gas passage and it is capable of opening and closing to flow the exhaust gas through the main exhaust gas passage and shut the main exhaust gas passage. The bypass exhaust gas passage has an upstream portion connected with an upstream portion of the main exhaust gas passage to bypass the first valve and have the adsorbent trapper in the bypass exhaust gas trapper. The second valve is arranged in the bypass exhaust gas passage and it is capable of opening and closing to flow the exhaust gas through the bypass exhaust gas passage and shut the bypass exhaust gas passage. The control unit controls the first valve and the second valve to open so that the exhaust gas flow through the main exhaust gas passage and the bypass exhaust gas passage so as to desorb the hydrocarbon from the adsorbent when a condition is satisfied, where the condition is that the catalyst converter is in active, an oxygen adsorption amount of the catalyst converter is not less than a first predetermined amount and an exhaust gas amount is not more than a second predetermined amount, while the control unit controls the first valve to open and the second valve to close when the condition is not satisfied during desorption of the hydrocarbon from the adsorbent.
- According to a second aspect of the present invention there is provided an exhaust emission control device including an adsorbent trapper, a catalytic converter, a main exhaust gas passage, a first valve, a bypass exhaust gas passage, a second valve and a control unit. The adsorbent trapper has an adsorbent that can adsorb hydrocarbon in exhaust gas discharged from an internal combustion engine on the adsorbent a low temperature thereof and desorb the hydrocarbon from the adsorbent at a high temperature thereof. The catalytic converter is arranged at a downstream side of the adsorbent trapper and has catalyst for purifying the exhaust gas. The main exhaust gas passage is arranged between the internal combustion engine and the catalytic converter so that the main exhaust passage can flow the exhaust gas discharged from the internal combustion engine to the catalytic converter. The first valve is arranged in the main exhaust gas passage and it is capable of opening and closing to flow the exhaust gas through the main exhaust gas passage and shut the main exhaust gas passage. The bypass exhaust gas passage has an upstream portion connected with an upstream portion of the main exhaust gas passage to bypass the first valve and have the adsorbent trapper in the bypass exhaust gas trapper. The second valve is arranged in the bypass exhaust gas passage and it is capable of opening and closing to flow the exhaust gas through the bypass exhaust gas passage and shut the bypass exhaust gas passage. The control unit controls the first valve to close and the second valve to open during from engine start to time where temperature of the adsorbent becomes a desorption temperature of the hydrocarbon, the control unit controlling the first valve to open and the second valve to close during from the time where the temperature of the adsorbent becomes the desorption temperature of the hydrocarbon to time where temperature of the catalyst becomes activation temperature thereof, the control unit controlling the first valve and the second valve to open during from the time where the temperature of the catalyst becomes the activation temperature to time where the hydrocarbon is desorbed from the adsorbent, and the control unit controlling the first valve to open and the second valve to close after the hydrocarbon is desorbed from the adsorbent.
- The objects, features and advantages of the present invention will become apparent as the description proceeds when taken in conjunction with the accompanying drawings, in which:
-
FIG. 1 is a diagram showing an exhaust emission control device of a first embodiment according to the present invention; -
FIG. 2 is a flowchart of valve open/close control executed by an engine control unit that is used in the exhaust emission control device of the first embodiment; -
FIG. 3 is a diagram showing the exhaust emission control device of the first embodiment, with indicating a flow direction of exhaust gas, in a state where a first valve is closed and a second valve is opened when an engine is started; -
FIG. 4 is a diagram showing the exhaust emission control device of the first embodiment, with indicating the flow direction of the exhaust gas, in a state where the first valve is opened and the second valve is closed when HC starts to desorb from an adsorbent; -
FIG. 5 is a diagram showing the exhaust emission control device of the first embodiment, with indicating the flow directions of the exhaust gas, in a state where the first valve and a second valve are opened when a predetermined condition is satisfied; -
FIG. 6 is a flowchart of valve open/close control executed by an engine control unit that is used in an exhaust emission control device of the second embodiment according to the present invention; -
FIG. 7 is a diagram of experiment results, of a conventional exhaust emission device and that of the second embodiment, showing a relationship between an amount of HC emission, a vehicle speed and an elapsed time since an engine is started; -
FIG. 8 is a diagram of an exhaust emission control device of a third embodiment according to the present invention; -
FIG. 9 is a view showing a second catalytic converter with an adsorbent trapper and an engine control unit that are used in the exhaust emission control device of the third embodiment; -
FIG. 10 is a view of the second catalytic converter with the adsorbent trapper of the third embodiment, with indicating the flow directions of exhaust gas, in a state where a first valve is closed and a second valve is opened; -
FIG. 11 is a view of the second catalytic converter with the adsorbent trapper of the third embodiment, with indicating the flow direction of the exhaust gas, in a state where the first valve is opened and the second valve is closed; -
FIG. 12 is a view of the second catalytic converter with the adsorbent trapper of the third embodiment, with indicating the flow directions of the exhaust gas, in a state where the first valve and the second valve are opened; -
FIG. 13 is a view of the second catalytic converter with the adsorbent trapper of the third embodiment, with indicating the flow direction of the exhaust gas, in a state where the first valve is opened and the second valve is closed; -
FIG. 14 is a diagram showing experimental results of a relationship between the amount of HC emission and elapsed time; -
FIG. 15 is a table of a control table for controlling the first valve and the second valve; -
FIG. 16 is a view showing a second catalytic converter with an adsorbent trapper that is used in an exhaust emission control device of a fourth embodiment according to the present invention; -
FIG. 17 is a view of the second catalytic converter with the adsorbent trapper of fourth embodiment, with indicating a flow direction of exhaust gas, in a state where the first valve is closed and the second valve is opened; -
FIG. 18 is a view of the second catalytic converter with the adsorbent trapper of the fourth embodiment, with indicating the flow direction of the exhaust gas, in a state where the first valve is opened and the second valve is closed; -
FIG. 19 is view of the second catalytic converter with the adsorbent trapper of the fourth embodiment, with indicating the flow directions of the exhaust gas, in a state where the first valve and the second valve are opened; and -
FIG. 20 is a view of the second catalytic converter with the adsorbent trapper of the fourth embodiment, with indicating the flow direction of the exhaust gas, in a state where the first valve is opened and the second valve is closed. - Throughout the following detailed description, similar reference characters and numbers refer to similar elements in all figures of the drawings, and their descriptions are omitted for eliminating duplication.
- Referring to
FIG. 1 of the drawing, there is shown a first preferred embodiment of an exhaustemission control device 1 according to the present invention, which is mounted on a motor vehicle to be connected with aninternal combustion engine 2 in this embodiment. - This exhaust
emission control device 1 includes a first catalytic converter C1, a mainexhaust gas passage 4, a bypassexhaust gas passage 5, anadsorbent trapper 6, a second catalytic converter C2, a first valve V1, a second valve V2 and anengine control unit 8. The mainexhaust gas passage 4 and the bypassexhaust gas passage 5 are made of metal pipes. The second catalytic converter C2 corresponds to a catalytic converter of the present invention, and theengine control unit 8 corresponds to a control unit of the present invention. - The first catalytic converter C1 is connected with exhaust ports of the
internal combustion engine 2 at its upstream side portion through anexhaust manifold 3, and is connected at its downstream portion with a connectingpipe 3 a. The first catalytic converter C1 has a metal catalyst carrier or a ceramic catalyst carrier in a cylindrical case, where the catalyst carrier is constructed by a not-shown honeycomb structural body with catalyst on surfaces of cells thereof so that harmful components such as hydrocarbon (HC), carbon monoxide (CO) and nitrogen oxide (NOx) in exhaust gas can be changed to harmlessness components such as carbon dioxide (CO2) and water (H2O) due to the catalytic activity thereof while the exhaust gas enters from the first catalytic converter C1 and is discharged from the cells of the catalyst carrier. - The connecting
pipe 3 a is connected with an upstream side portion of the mainexhaust gas passage 4 - The main
exhaust gas passage 4 is provided with the first valve V1 at its intermediate portion. The bypassexhaust gas passage 5 is connected with an upstream portion and a downstream portion of the mainexhaust gas passage 4 to bypass the first valve V1. The bypassexhaust gas passage 5 is provided with theadsorbent trapper 6 and the second valve V2. - The
adsorbent trapper 6 has a not-shown honeycomb structural body in a cylindrical case, where adsorbent such as zeolite is coated on surfaces of cells thereof so that hydro carbon (HC) in the exhaust gas entering from an upstream side can be adsorbed thereto at a low temperature and be desorbed to be discharged toward a downstream side. - The second catalytic converter C2 is arranged in the main
exhaust gas passage 4 at a downstream side of the bypassexhaust gas passage 5. The second catalytic converter C2 is constructed similarly to the first catalytic converter C1, and accordingly its explanation is omitted. - The first valve V1 and the second valve V2 are electromagnetic valves that can be driven by not-shown actuators such electric motors so that they shifts between a close state and an open state to change the exhaust gas to flow through the main
exhaust gas passages 4 or thebypass exhaust passage 5, respectively. - A first temperature sensor SE1 is provided at an upstream side of the
adsorbent trapper 6 to detect the surface temperature of the adsorbent or the ambient temperature thereof, and a second temperature sensor SE2 is provided at an upstream side of the second catalytic converter C2 to detect the surface temperature of the catalyst or the ambient temperature thereof. In addition, a first oxygen sensor SE3 is provided at an upstream side of the second catalytic converter C2 to detect an oxygen concentration of the exhaust gas passing through the upstream side, and a second oxygen sensor SE4 is provided at a downstream side of the second catalytic converter C2 to detect an oxygen concentration of the exhaust gas passing through the downstream side. - Further, an airflow sensor SE5 is provided in an intake manifold 7of the
engine 2 to detect an amount of intake air. - The first temperature sensor SE1, the second temperature sensor SE2, the first oxygen sensor SE3, the second oxygen sensor SE4 and the airflow sensor SE5 are electrically connected to the
engine control unit 8 to send their detection signals thereto. - The
engine control unit 8 is further electrically connected to no-shown various sensors to receive an engine coolant temperature signal, an engine speed signal, an accelerator opening-degree signal, a vehicle speed signal, an ignition signal, a fuel injection amount signal and others so as to control theengine 2, the first valve V1 and the second valve V2. - The operation and effects of the exhaust
emission control device 1 of the first embodiment will be described. - In the exhaust
emission control device 1 of the first embodiment, theengine control unit 8 controls the first valve V1 and the second valve V2 to open and close according to a flowchart shown inFIG. 2 of valve open/close control executed by theengine control unit 8. - At step S1, the
engine control unit 8 starts the open/close control when it detects a start of theengine 1, and then the flow goes to step S2. - At the step S2, the first valve V1 is closed to shut the
main exhaust passage 4, the second valve V2 being opened to flow the full amount of the exhaust gas discharged from theengine 2 through the bypassexhaust gas passage 5, and then flow goes to step S3. - At the step S3, the
engine control unit 8 judges whether or not the adsorbent in theadsorbent trapper 6 begins to desorb the exhaust gas therefrom based on the temperature signal outputted from the first temperature sensor SE1. If YES, the flow goes to step S4, while, if NO, the flow returns to the step S2. The start of HC desorption is judged when the temperature detected by the first temperature sensor SE1 reaches a predetermined temperature, where the HC desorption temperature of the adsorbent is 250° C. in general. - At the step S4, the first valve V1 is opened to flow the full amount of the exhaust gas discharged from the
engine 2 through the mainexhaust gas passage 4, the second valve V2 being closed to shut thebypass exhaust passage 5, and then the flow goes to step S5. - At the step S5, the
engine control unit 8 judges, based on the detection signals of the second temperature sensor SE2, the first and the second oxygen sensors SE3 and SE4 and the airflow sensor SE5, whether or not the catalyst in the second catalytic converter C2 is activated, an oxygen adsorption amount of the second catalytic converter C2 is equal to or larger than a first predetermined amount, and the amount of the exhaust gas is equal to or smaller than a second predetermined amount. If Yes, the flow goes to step S6, while, if NO, the flow returns to the step S4. The activation of the second catalytic converter C2 is judged based on whether or not the temperature detected by the second temperature sensor SE2 reaches a predetermined temperature, where the activation temperature of the second catalytic converter C2 is equal to or higher than 350° C. in general. The first predetermined amount may be set appropriately, and it is set to be a value corresponding to approximately 50% of the maximum oxygen adsorption amount of the second catalytic converter C2 in this embodiment. The second predetermined amount may be set appropriately, and it is set to be a value corresponding to an amount of the exhaust gas discharged from theengine 2 that is running at a low speed in this embodiment. - Incidentally, in
FIG. 2 , the oxygen adsorption amount is indicated by “OA”, the first predetermined amount is indicated by “A1”, the exhaust gas amount is indicated by “EA”, and the second predetermined amount is indicated by “A2”. - Instead of this judgment, the activation of the second catalytic converter C2 may be judged based on whether or not the elapsed time has passed since the
engine 2 is started. In this case, the elapsed time may be set to change according to the temperature of the engine coolant detected when theengine 2 is started. - Further, instead of the above-described judgments, the activation of the second catalytic converter C2 may be judged based on an integrated value of the engine speed and the fuel injection amount.
- The oxygen adsorption amount of the second catalytic converter C2 is estimated based on the detection signals outputted from the first oxygen sensor SE3 and the second oxygen sensor SE4 or from the airflow sensor SE5.
- Instead of this estimate, the oxygen adsorption amount of the second catalytic converter C2 may be estimated based on the detection signal outputted from the airflow sensor SE5 and a fuel cut signal.
- The amount of the exhaust gas is estimated based on an airflow amount signal outputted from the airflow sensor SE5.
- At the step S6, both of the first valve V1 and the second valve V2 are opened to flow the exhaust gas through the main
exhaust gas passage 4 and the bypassexhaust gas passage 5, and then the flow goes to the step S7. - At the step S7, the
engine control unit 8 judges whether or not the detection signals newly detected can satisfy the same condition at the step S5. If YES, the flow goes to step S8, while, if NO, the flow returns to the step S4. - At the step S8, the
engine control unit 8 judges whether or not the adsorbent ends desorption of the hydrocarbon therefrom. If YES, the flow goes to step S9, while, if NO, the flow returns to the step S7. - The end of the HC desorption from the adsorbent is set to be time after a predetermined time has passed the
engine 2 is started. - Instead of this setting, the end of the HC desorption from the adsorbent may be estimated by adding a sensor for detecting an HC concentration to the
adsorbent trapper 6, or it may be judged by estimating a residual volume of HC on the adsorbent based on the signals of theengine control unit 8. - At the step S9, the first valve V1 is opened to flow the full amount of the exhaust gas through the main
exhaust gas passage 4, the second valve V2 being closed to shut thebypass exhaust passage 5, and then the flow ends. - In the exhaust
emission control device 1 of the first embodiment, for a while after theengine 2 is started, as shown inFIG. 3 , the first valve V1 is closed to shut the mainexhaust gas passage 4, the second valve V2 being opened to flow the exhaust gas discharged from theengine 2, according to the operation at thesteps 1 to 3, because it takes a while for the temperature of the exhaust gas to reach to the desorption temperature of the adsorbent. As a result, the full amount of the exhaust gas discharged from theengine 2 passes through theadsorbent trapper 6 and then enters the second catalytic converter C2 as indicated dashed line arrow inFIG. 3 . In this operation, the adsorbent adsorbs the HC contained in the exhaust gas while it passes through the adsorbent, while the catalysts of the first and second catalytic converter C1 and C2 does not work because the temperature of the exhaust gas is low. Thus, theadsorbent trapper 6 can prevent the HC in the exhaust gas from being discharged in the air during no catalytic activities of the first and second catalytic converters C1 and C2. - Then when the temperature of the exhaust gas rises to reach the desorption temperature of the adsorbent, as shown in
FIG. 4 , the first valve V1 is opened to flow the full amount of the exhaust gas through the mainexhaust gas passage 4, the second valve V2 being closed to shut the bypassexhaust gas passage 5, according to the operation at the step S4. As a result, the full amount of the exhaust gas discharged from theengine 2 enters the mainexhaust gas passage 4 and the second catalytic converter C2 arranged therein as indicated by a dashed line arrow inFIG. 4 . In this operation, the catalyst of the first catalytic converter C1 purifies the HC in the exhaust gas since the catalyst thereof is activated. - In addition, the
engine control unit 8 judges whether or not the catalyst in the second catalytic converter C2 is activated, an oxygen adsorption amount of the second catalytic converter C2 is equal to or larger than the first predetermined amount, and the amount of the exhaust gas is equal to or smaller than the second predetermined amount, according to the operation at the step S5. If the above condition is do not satisfied, the first and second valves V1 and V2 are kept being opened and closed, respectively. - On the other hand, if the above condition is satisfied, both of the first and second valves V1 and V2 are opened to flow the exhaust gas through the main
exhaust gas passage 4 and the bypassexhaust gas passage 5 as shown inFIG. 5 , according to the operation at the step S6. - As a result, the exhaust gas discharged from the
engine 2 flows through the mainexhaust gas passage 4 and the bypassexhaust gas passage 5 as indicated by dashed line arrows inFIG. 5 . In this operation, the harmful components such as the HC are purified by the second catalytic converter C2 in addition to the first catalytic converter C1. - After opening both the first and second valves V1 and V2, the
engine control unit 8 judges again whether or not the above condition is satisfied, according to the operation at the step S7. If the above condition is not satisfied, the first valve V1 is opened to flow the full amount of the exhaust gas through the mainexhaust gas passage 4 and the second valve V2 is closed to shut the bypassexhaust gas passage 5. - On the other hand, if the above condition is satisfied, the
engine control unit 8 judges whether or not the desorption of the HC from the adsorbent ends, according to the operation at the step S8. If the desorption does not end, the first and second valves V1 and V2 are maintained to open, while if it ends, the first valve V1 is opened to flow the full amount of the exhaust gas through themain exhaust passage 4 and the second valve V2 is closed to shut the bypassexhaust gas passage 5, according to the operation at the step S9. In the latter case, a part of the exhaust gas can be prevented from flowing through the bypassexhaust gas passage 5, so that the durability of theadsorbent trapper 6 can be improved. - As described above, in the exhaust
emission control device 1 of the first embodiment, the second valve V2 is opened and closed according to the condition at the steps S5 and S7 during time between the beginning of the desorption of the HC from the adsorbent and the end thereof. - Only when the oxygen adsorption amount is equal to or larger than the predetermined amount and the exhaust gas amount is equal to or smaller than the second determined amount, in other words, only when the second catalytic converter C2 stores sufficient oxygen and the amount of the exhaust gas passing through the adsorbent is small, the second valve V2 is opened to flow the HC desorbed from the adsorbent into the second catalytic converter C2.
- Accordingly, in the exhaust
emission control device 1 of the first embodiment, the HC that is adsorbed on the adsorbent can be prevented from being rapidly and in large quantities desorbed from the adsorbent to enter the second catalytic converter C2, and its purification performance can be prevented from being deteriorated due to lack in the oxygen adsorption amount of the second catalytic converter C2. - Next, an exhaust gas emission control device of a second embodiment according to the second embodiment will be described with reference to the accompanying drawings.
- The exhaust gas
emission control device 1 of the second embodiment is constructed similarly to that of the first embodiment shown inFIG. 1 . In the exhaust gasemission control device 1 of the second embodiment, anengine control unit 8 executes valve open/close control according to a flowchart shown inFIG. 6 which is different from that inFIG. 2 of the first embodiment. - As shown in
FIG. 6 , its steps S1 to S4, S6, S8 and S9 are similar to those of the first embodiment except steps S50, S70 and S71, and accordingly the explanations of the similar steps are omitted. - At the step S50, the
engine control unit 8 judges whether or not a second catalytic converter C2 is activated, fuel injection is halted (or a motor vehicle is slowing down), and an amount of the exhaust gas discharged from theengine 2 is equal to or smaller than a second predetermined amount corresponding to the second predetermined amount of the first embodiment. If YES, the flow goes to the step S6 where both of a first valve V1 and a second valve V2 are opened to flow the exhaust gas through the mainexhaust gas passage 4 and the bypassexhaust gas passage 5, while, if NO, the flow returns to the step S4 where the first valve is opened to flow the full amount of the exhaust gas through the mainexhaust gas passage 4 and the second valve V2 is closed to shut the bypassexhaust gas passage 5. - At the step S70 after the step S6, the
engine control unit 8 judges again whether or not the second catalytic converter C2 is activated, the fuel injection is halted (or the motor vehicle is slowing down), and the amount of the exhaust gas discharged from theengine 2 is equal to or smaller than the second predetermined amount. If YES, the flow goes to the step S8 where theengine control unit 8 judges whether or not HC desorption from an adsorbent ends, while, if NO, the flow goes to the step S71. - At the step S71, the
engine 2 is controlled to be driven at a rich mixture where an air fuel ratio (the mass ratio of air to fuel present during combustion) is set less than the stoichiometric air-fuel mixture 14.7 for gasoline fuel, and then the flow returns to the step S4. - As described above, the exhaust
emission control device 1 of the second embodiment has the effects similar to those of the first embodiment. - In addition, when the fuel injection is halted or the motor vehicle is slowing down, the oxygen amount in the exhaust gas increases to a maximum of approximately 21% thereof, thereby generating a lean mixture (the air fuel ratio is more than the stoichiometric air-fuel mixture) state. This can skip an arithmetic processing for estimating the oxygen adsorption amount of a second catalytic converter C2.
- In a case where at least any one of the condition at the step S71 during the desorption of HC when the first and second valves V1 and V2 are opened at the step S6, the mixture to be supplied to the
engine 2 is controlled to be rich so that the oxygen amount in the exhaust gas is decreased for to exert the catalytic activity of the second catalytic converter C2 earlier. Thus, the catalyst of the second catalytic converter C2 can be prevented from being not activated for a short time because of the lean mixture state due to the excess oxygen absorption mount of the second catalytic converter C2. - In addition, although the NOx amount in the exhaust gas increases only in a case where the
engine 2 is driven merely at the lean mixture, the exhaustemission control device 1 of the second embodiment uses the lean mixture control with the fuel injection cut-off, so that the oxygen can be supplied to the second catalytic converter C2 without increase in NOx because the air fuel ratio is not changed. -
FIG. 7 shows experiment results, of a conventional exhaust emission device and that of the second embodiment, showing a relationship between the amount of HC emission, a vehicle speed and an elapsed time since theengine 2 is started. The vehicle speed is set according to a speed model that is used for experiments. The conventional exhaust emission control device is constructed in such a way that a first valve V1 and a second valve V2 are opened to flow the exhaust gas through the mainexhaust gas passage 4 and the bypassexhaust gas passage 5 immediately after a second catalytic converter C2 is activated and they are controlled to be maintained to open afterward. - As shown in
FIG. 7 , compared to the exhaust emission control device of the second embodiment and the conventional one, they need the almost same time from engine start to the time where the first catalytic converter C1 is activated to decrease the amount of HC emission, and the HC emission amount can be largely decreased during the declaration of the vehicle speed with the fuel injection cut-off in the exhaust emission control device of the second embodiment, while it largely increases after the second catalytic converter C2 is activated in the conventional one. - Next, an exhaust emission control device of a third embodiment according to the present invention will be described with the accompanying drawings.
- As shown in
FIG. 8 , the exhaustemission control device 11 includes a first catalytic converter C1, a mainexhaust gas passage 4, a bypassexhaust gas passage 5, a second catalytic converter C2 with an adsorbent trapper, a first valve V1, a second valve V2, a center muffler MF, a rear muffler MR and anemission control unit 12. The emission control unit corresponds to the control unit of the present invention. - The first catalytic converter C1 is constructed similarly to that of the first embodiment, and is connected with an
engine 2 at its upstream portion through anexhaust manifold 3 and with a connectingpipe 3 a at its downstream portion. - A downstream side end portion of the connecting
pipe 3 a is provided with a flange that is joined with aflange 25 of an upstream side end portion of the mainexhaust gas passage 4. - The second catalytic converter C2 with an adsorbent trapper includes a main case 20, an
adsorbent part 21 and acatalyst part 23. Theadsorbent part 21 has a metalexternal cylinder 21 a and an adsorbent 21 b that is formed in a cylindrical shape and is contained in theexternal cylinder 21 a. The adsorbent 21 b has cells that is penetrated in its axial direction and is coated with zeolite on their surfaces. Theadsorbent part 21 is formed at a center thereof with a hole to be penetrated through by a downstream portion of themain exhaust passage 4. - The main case 20 includes an
end plate 23 a, afirst cylinder 23 b, asecond cylinder 23 and adiffuser 24, which are made of metal material. - An upstream portion of the
external cylinder 21 a of the second catalytic converter C2 is connected with the firstcylindrical part 23 b, which is blocked off by theend plate part 23 a at its upstream portion. Theend portion plate 23 a is provided with two opening portions, so that a downstream side end portion of the bypassexhaust gas passage 5 is connected with one of the opening portion and an intermediate portion of the mainexhaust gas passage 4 penetrates the other opening portion. A first chamber R1 is formed among theend plate 23 a, thefirst cylinder 23 b and theadsorbent part 21, so that the first chamber R1 is arranged at an upstream side of theadsorbent part 21. A downstream portion of theexternal cylinder 21 a ofadsorbent part 21 is connected with thesecond cylinder 23 b, which is connected at its downstream portion with anexternal cylinder 22 a of thecatalyst part 22. - The
catalyst part 22 includes theexternal cylinder 22 a and acatalyst carrier 22 b that is formed like a cylindrical shape and is contained in theexternal cylinder 22 a. Thecatalyst carrier 22 b is a metal catalyst carrier or a ceramic catalyst carrier. The downstream side end portion of the mainexhaust gas passage 4 and an upstream side end portion of thecatalyst part 22 are connected with each other through apartition part 29 that is shaped like a funnel with a plurality of communicatingholes 29 a. The diameter of thepartition part 29 increases toward its downstream side. - A second chamber R2 is formed among the
adsorbent part 21, the secondexternal cylinder 23 c and thecatalyst part 22, so that the second chamber R2 is arranged at a downstream side of theadsorbent part 21 and at an upstream side of thecatalyst part 22. - Incidentally, the second catalytic converter C2 may have an external cylinder that contains the adsorbent 21 b and the
catalyst carrier 22 b, instead offirst cylinder 23 b, thesecond cylinder 23, theexternal cylinder 21 a and theexternal cylinder 22 a. - A downstream end portion of the
catalyst part 22 is connected with thediffuser 24 that decreases its diameter toward the downstream side and is provided with aflange 26. - The
flange 26 is connected with a flange of anexhaust pipe 9 a, which is further connected with the center muffler MF. The center muffler MF is connected with the rear muffler MR through anexhaust pipe 9 b. - The first valve V1 is provided in the main
exhaust gas passage 4 at the upstream side of thepartition part 29, and the second valve V2 is provided in the bypassexhaust gas passage 5 which is connected with the upstream portion of the mainexhaust gas passage 4 at an upstream side of the first valve V1. The first valve V1 and the second valve V2 employ butterfly valves, which are controlled to open and close by not-shown actuators such as electric motors, respectively. The actuators are electrically connected to and controlled by theemission control unit 12, which is further electrically connected to athird temperature sensor 27, afourth temperature sensor 28 and an engine control unit 14. - The
third temperature sensor 27 is arranged in the second chamber R2 near the downstream end portion of theadsorbent part 21 to detect a temperature of the adsorbent 21 b of theadsorbent part 21 or an ambient temperature thereof, while thefourth temperature sensor 28 is arranged in thediffuser 24 near the downstream end portion of thecatalyst part 22 to detect a temperature of thecatalyst carrier 22 b of thecatalyst part 22 or an ambient temperature thereof. - The engine control unit 14 is electrically connected to not-shown various sensors to receive an engine coolant temperature signal, an engine speed signal, an accelerator opening-degree signal, an airflow amount signal, a vehicle speed signal, an ignition signal, a fuel injection amount signal and others so as to control the
engine 2. - The other parts are constructed similarly to those of the first embodiment.
- The operation and effects of the exhaust emission control device 10 of the third embodiment will be described.
- In the exhaust emission control device 10 of the third embodiment, the
emission control unit 12 receives the various signals outputted from theengine 2 and temperature signals outputted from the first andsecond temperature sensors emission control unit 12 controls the first valve V1 and the second valve V2 to open and close according to a control table shown inFIG. 15 . - While the temperature of the exhaust gas is lower than the desorption temperature of the HC from the adsorbent 21 b after the
engine 2 is started, the first valve V1 is closed to shut the mainexhaust gas passage 4, while the second valve V2 is opened to flow the full amount of the exhaust gas through the bypassexhaust gas passage 5 as shown inFIG. 10 . The flow directions of the exhaust gas are indicated by dashed line arrows. - In this operation, the full amount of the exhaust gas discharged from the
engine 2 in introduced into the first chamber R1 through the bypassexhaust gas passage 5, and then it passes through theadsorbent part 21, where the HC in the exhaust gas is adsorbed on the adsorbent 21b. The exhaust gas that has passed through theadsorbent part 21 is introduced into the second chamber R2, and then to thecatalyst part 22 through the communicatingholes 29 a of thepartition plate 29. - The exhaust gas passes through the
catalyst carrier 22b, and then through the center muffler MC and the rear muffler MR to be discharged in the air. - In this operation, although the first catalytic converter C1 and the
catalyst part 21, functioning as a second the second catalyst converter of the first and second embodiments, because the temperature of the exhaust gas is low, the HC is trapped by theadsorbent part 21 b, so that the HC is prevented from being emitted in the air. - While the temperature of the adsorbent 21 b is equal to or higher than the desorption temperature thereof and the temperature of the
catalyst carrier 22 b being lower than the activation temperature thereof, the first valve V1 is opened to flow the full amount of the exhaust gas through the mainexhaust gas passage 4 and the second valve V2 is closed to shut the bypassexhaust gas passage 5 as shown inFIG. 11 . The flow direction of the exhaust gas is indicated by a dashed line arrow. - In this operation, the temperature of the first catalytic converter C1 has reached to the activation temperature thereof, so that the HC in the exhaust gas discharged from the
engine 2 is purified by the catalyst of the first catalytic converter C2, although the catalyst of thecatalyst carrier 22 b cannot purify the exhaust gas. - The
partition part 29 prevents a part of the exhaust gas from being blown back to the adsorbent 21 b. - While the adsorbent 21 b are desorbing the HC therefrom and the temperature of the
catalyst carrier 22 b is equal to or higher than the activation temperature thereof, the first valve V1 and the second valve V2 are opened to flow the exhaust gas through the mainexhaust gas passage 4 and the bypassexhaust gas passage 5 as shown inFIG. 12 . The flow directions of the exhaust gas are indicated by dashed line arrows. - The end of the HC desorption from the adsorbent 21 b is estimated to be a predetermined time after the second valve V2 is opened. Instead of this estimation, a sensor for detecting an HC concentration may be provided in the second chamber R2, or the HC residual amount on the adsorbent 21 b may be estimated based on signals outputted from the
engine control unit 13 by using one of the conventional estimation methods. - In this operation, the adsorbent 21 b desorbs the HC adsorbed on the adsorbent 21 b to flow downstream side. The catalyst of the
catalyst carrier 22 b purifies the harmful components including the HC in the exhaust gas. This purified exhaust gas flows into the center muffler MC and the rear muffler MR, then being discharged in the air. - After the HC desorption from the adsorbent 21 b ends, the first valve V1 is opened to flow the full amount of the exhaust gas through the main
exhaust gas passage 4 and the second valve V2 is closed to shut the bypassexhaust gas passage 5 as shown inFIG. 13 . The flow direction of the exhaust gas is indicated by a dashed line arrow. - In this operation, the adsorbent 21 b becomes to be in an initial state where the HC is completely desorbed from the adsorbent 21 b. The catalyst of the
catalyst carrier 22 b purifies the exhaust gas to change the harmful components in the exhaust gas into the harmless components. This purified exhaust gas flows into the center muffler MC and the rear muffler MR, then being discharged in the air. - Therefore, the exhaust mission control device 10 of the third embodiment has the following effects in addition to those of the first and second embodiments.
- In the exhaust mission control device 10 of the third embodiment, after the substantially full amount of the HC is desorbed from the adsorbent 21 b, the second valve V2 closes to shut the bypass
exhaust gas passage 5. As a result, the exhaust gas does not pass through the adsorbent 22 b, so that the durability of the adsorbent 22 b can be improved compared to a conventional exhaust emission control device described in Japanese Patent Application Laid-Open No. 2006-194231 where a part of the exhaust gas passes through an adsorbent after the HC is desorbed from the adsorbent. - In addition, in the exhaust mission control device 10 of the third embodiment, the coating amount of zeolite and/or others on the adsorbent can be deceased, and the amount of catalyst can be also decreased. Therefore, costs of an adsorbent trapper and a catalytic converter can be decreased.
- Further, when a motor vehicle is running after the HC is desorbed from the adsorbent, the exhaust gas does not pass through the adsorbent, so that the flow resistance of the exhaust gas is reduced, thereby increasing output power of the
engine 2. -
FIG. 14 shows experimental results of a relationship between the HC emission amount and an elapsed time. InFIG. 14 , operation areas (1) to (4) correspond to the operation cases (1) to (4) where the first valve V1 and the second valve V2 are opened and/or closed in the control table inFIG. 15 . As understood from the experimental results inFIG. 14 , the exhaust emission control device 10 of the third embodiment can decrease the emission amount of the HC that is discharged in the air before the catalyst of thecatalyst carrier 22 b becomes to be active. - Next, an exhaust emission control device of a fourth embodiment according to the present invention will be described with reference to the accompanying drawings.
- The exhaust emission control device of the fourth embodiment is constructed similarly to that of the third embodiment shown in
FIG. 8 . - A second catalytic converter C2 with an adsorbent trapper includes a
main case 23, anadsorbent part 21, acatalyst part 22 and adiffuser 24. Thecatalyst part 22 is arranged between a downstream side of the adsorbent 21 at an upstream side thereof and thediffuser 24 at a downstream side thereof. - The
adsorbent part 21 includes anexternal cylinder 21 a and an adsorbent 21 b arranged in theexternal cylinder 21 a, which has a diameter smaller than that of the third embodiment. Theexternal cylinder 21 a is fixed to and supported by afirst baffle pate 30 and asecond baffle plate 31. - The
first baffle plate 30 and thesecond baffle plate 31 are fixed on an inner surface of afirst cylinder 23 b of themain case 23, being away from each other in an axial direction of the second catalytic converter C2. - A main
exhaust gas passage 4 penetrates through a hole formed in thefirst baffle plate 30 with aclearance 30 a therebetween, and it is fixed to and supported by thesecond baffle plate 31 so that a downstream side opening of the mainexhaust gas passage 4 opens in a second chamber R2 that is formed by thesecond baffle plate 31, an upstream side end portion of acatalyst carrier 22 b and asecond cylinder 23 b of themain case 23. The diameter ofsecond cylinder 23 b is formed to be smaller toward its downstream side. On the other hand, a third chamber R3 is formed by thefirst cylinder 23 a, theexternal cylinder 21 a of theadsorbent part 21 and a pipe forming the mainexhaust gas passage 4. The third chamber R3 communicates only with a first chamber R1 through theclearance 30 a formed in thefirst baffle plate 30. The third chamber R3 corresponds to a sound attenuation means of the present invention. - The
diffuser 24 is formed like a cup and is connected with a downstream end portion of thecatalyst part 22. - The other parts of the exhaust emission control device of the fourth embodiment are constructed similarly to those of the third embodiment except that it has not the
partition part 29 of the third embodiment. - A first valve V1 and a second valve V2 are controlled by an
emission control unit 12 according to a control table shown inFIG. 15 . - The operation of the exhaust emission control device of the fourth embodiment is similar to that of the third embodiment. The exhaust emission control device of the fourth embodiment can obtain the effects similar to those of the first to third embodiments.
- In addition, in the exhaust emission control device of the fourth embodiment, the first chamber R1 and the third chamber R3 are communicated with each other through the
clearance 30 a. When the second valve V2 is opened and the exhaust gas flows through the bypass exhaust gas passage 5 (corresponding to the cases (1) and (3) in the control table inFIG. 15 ), a part of the exhaust gas in the first chamber R1 is introduced into the third chamber R3 through theclearance 30 a to resonate therein so that the third chamber R3 can function as a resonant chamber. Therefore, the noise of the exhaust gas can be decreased. - The resonance frequency of the third chamber R3 may be set appropriately according to a volume of the third chamber R3 and others.
- For example, it may be set according to a frequency of noise that might generate by confluence of the exhaust gasses that have passed through the main
exhaust gas passage 4 and the bypassexhaust gas passage 5 when the first valve V1 and the second valve V2 are opened (corresponding to case (3) in the control table inFIG. 15 ). - Alternatively, it may be set to decrease a noise, what is called, a muffled sound that generates at a low engine speed, equal to or less than 2000 r.p.m. of the engine speed obtained immediately after the engine starts and when the engine is driven at idle speed. This case corresponds to the case (1) in the control table in
FIG. 15 . - In addition, the exhaust emission control device of the fourth embodiment can decrease the noise generated when the exhaust gas enters the first chamber R1 through the bypass
exhaust gas passage 5 and when the exhaust gas enters the second chamber R2 through the mainexhaust gas passage 4, because of expansion effect of volumes thereof to reduce noise energy. - While there have been particularly shown and described with reference to preferred embodiments thereof, it will be understood that various modifications may be made therein, and it is intended to cover in the appended claims all such modifications as fall within the true spirit and scope of the invention.
- The control unit for controlling the first valve V1 and the second valve V2 may be separated from the engine control unit for controlling an engine, or it may be integrated with the engine control unit.
- The judging methods for estimating the activation of the catalytic converter, the oxygen adsorption amount of the catalytic converter and the emission amount may be employed appropriately.
- The temperature of the adsorbent and the temperature of the catalyst may be detected by appropriate various sensor and/or information instead of using the temperature sensors.
- The entire contents of Japanese Patent Applications No. 2008-038322 filed Feb. 20, 2008, No. 2008-011458 filed Jan. 22, 2008 and No. 2008-011459 filed Jan. 22, 2008 are incorporated herein by reference.
Claims (18)
1. An exhaust emission control device comprising:
an adsorbent trapper having an adsorbent that can adsorb hydrocarbon in exhaust gas discharged from an internal combustion engine on the adsorbent a low temperature thereof and desorb the hydrocarbon from the adsorbent at a high temperature thereof;
a catalytic converter that is arranged at a downstream side of the adsorbent trapper and has catalyst for purifying the exhaust gas;
a main exhaust gas passage arranged between the internal combustion engine and the catalytic converter so that the main exhaust passage can flow the exhaust gas discharged from the internal combustion engine to the catalytic converter;
a first valve that is arranged in the main exhaust gas passage and is capable of opening and closing to flow the exhaust gas through the main exhaust gas passage and shut the main exhaust gas passage;
a bypass exhaust gas passage that has an upstream portion connected with an upstream portion of the main exhaust gas passage to bypass the first valve and have the adsorbent trapper in the bypass exhaust gas trapper;
a second valve that is arranged in the bypass exhaust gas passage and is capable of opening and closing to flow the exhaust gas through the bypass exhaust gas passage and shut the bypass exhaust gas passage; and
a control unit that controls the first valve and the second valve, wherein
the control unit controls the first valve and the second valve to open so that the exhaust gas flow through the main exhaust gas passage and the bypass exhaust gas passage so as to desorb the hydrocarbon from the adsorbent when a condition is satisfied, where the condition is that the catalyst converter is in active, an oxygen adsorption amount of the catalyst converter is not less than a first predetermined amount and an exhaust gas amount is not more than a second predetermined amount, wherein
the control unit controls the first valve to open and the second valve to close when the condition is not satisfied during desorption of the hydrocarbon from the adsorbent.
2. The exhaust emission control device according to claim 1 , wherein
the control unit controls the second valve to open to flow the exhaust gas through the bypass exhaust gas passage so as to desorb the hydrocarbon from the adsorbent while a fuel injection is halted, a motor vehicle is slowing down and the exhaust gas amount is not more than a second predetermined amount after the catalytic converter becomes in an activation state.
3. The exhaust emission control device according to claim 1 , wherein
the internal combustion engine is supplied with rich mixture of fuel/air ratio when the second valve is closed to shut the bypass exhaust gas passage during a valve open/close control where the exhaust gas flows through the bypass exhaust gas passage.
4. The exhaust emission control device according to claim 1 , wherein
the first predetermined amount may be set appropriately, and it is set to be a value corresponding to approximately 50% of the maximum oxygen adsorption amount of the catalytic converter.
5. The exhaust emission control device according to claim 1 , wherein
The second predetermined amount is set to be an amount of the exhaust gas discharged from the internal combustion engine at a low engine speed.
6. The exhaust emission control device according to claim 1 , wherein
the adsorbent trapper and the catalytic converter are contained in a main case, and wherein
the main case is provided with a sound attenuation means for suppressing noise of the exhaust gas.
7. The exhaust emission control device according to claim 6 , wherein
the sound attenuation means is a resonant chamber.
8. The exhaust emission control device according to claim 6 , wherein
a resonance frequency of the sound attenuation means is set to suppresses the noise caused by the exhaust gas entering the bypass exhaust gas passage.
9. The exhaust emission control device according to claim 6 , wherein
a resonance frequency of the sound attenuation means is set to suppresses the noise caused by confluence of the exhaust gasses that have passed through the main exhaust gas passage and the bypass exhaust gas passage.
10. An exhaust emission control device including:
an adsorbent trapper having an adsorbent that can adsorb hydrocarbon in exhaust gas discharged from an internal combustion engine on the adsorbent a low temperature thereof and desorb the hydrocarbon from the adsorbent at a high temperature thereof;
a catalytic converter that is arranged at a downstream side of the adsorbent trapper to purify exhaust gas;
a main exhaust gas passage arranged between the internal combustion engine and the catalytic converter so that the main exhaust passage can flow the exhaust gas discharged from the internal combustion engine to the catalytic converter;
a first valve that is arranged in the main exhaust gas passage and is capable of opening and closing to flow the exhaust gas through the main exhaust gas passage and shut the main exhaust gas passage;
a bypass exhaust gas passage that has an upstream portion connected with an upstream portion of the main exhaust gas passage to bypass the first valve and have the adsorbent trapper in the bypass exhaust gas trapper;
a second valve that is arranged in the bypass exhaust gas passage and is capable of opening and closing to flow the exhaust gas through the bypass exhaust gas passage and shut the bypass exhaust gas passage; and
a control unit that controls the first valve and the second valve, wherein
the control unit controls the first valve to close and the second valve to open during from engine start to time where temperature of the adsorbent becomes a desorption temperature of the hydrocarbon, the control unit controlling the first valve to open and the second valve to close during from the time where the temperature of the adsorbent becomes the desorption temperature of the hydrocarbon to time where temperature of the catalyst becomes activation temperature thereof, the control unit controlling the first valve and the second valve to open during from the time where the temperature of the catalyst becomes the activation temperature to time where the hydrocarbon is desorbed from the adsorbent, and the control unit controlling the first valve to open and the second valve to close after the hydrocarbon is desorbed from the adsorbent.
11. The exhaust emission control device according to claim 10 , wherein
the control unit controls the second valve to open to flow the exhaust gas through the bypass exhaust gas passage so as to desorb the hydrocarbon from the adsorbent while a fuel injection is halted, a motor vehicle is slowing down and the exhaust gas amount is not more than a second predetermined amount after the catalytic converter becomes in an activation state.
12. The exhaust emission control device according to claim 10 , wherein
the internal combustion engine is supplied with rich mixture of fuel/air ratio when the second valve is closed to shut the bypass exhaust gas passage during a valve open/close control where the exhaust gas flows through the bypass exhaust gas passage.
13. The exhaust emission control device according to claim 10 , wherein
the end of the desorption of the hydrocarbon from the adsorbent is set to be a predetermined time after the engine starts.
14. The exhaust emission control device according to claim 10 , wherein
the end of the desorption of the hydrocarbon from the adsorbent is judged based on a signal outputted from a sensor for detecting a hydrocarbon concentration.
15. The exhaust emission control device according to claim 10 , wherein
the adsorbent trapper and the catalytic converter are contained in a main case, and wherein
the main case is provided with a sound attenuation means for suppressing noise of the exhaust gas.
16. The exhaust emission control device according to claim 15 , wherein
the sound attenuation means is a resonant chamber.
17. The exhaust emission control device according to claim 15 , wherein
a resonance frequency of the sound attenuation means is set to suppresses the noise caused by the exhaust gas entering the bypass exhaust gas passage.
18. The exhaust emission control device according to claim 15 , wherein
a resonance frequency of the sound attenuation means is set to suppresses the noise caused by confluence of the exhaust gasses that have passed through the main exhaust gas passage and the bypass exhaust gas passage.
Applications Claiming Priority (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2008-011458 | 2008-01-22 | ||
JP2008-011459 | 2008-01-22 | ||
JP2008011459A JP2009174343A (en) | 2008-01-22 | 2008-01-22 | Catalytic converter with adsorption member |
JP2008011458A JP2009174342A (en) | 2008-01-22 | 2008-01-22 | Catalytic converter with adsorption member |
JP2008038322A JP2009197626A (en) | 2008-02-20 | 2008-02-20 | Exhaust emission control device for internal combustion engine |
JP2008-038322 | 2008-02-20 |
Publications (1)
Publication Number | Publication Date |
---|---|
US20090183498A1 true US20090183498A1 (en) | 2009-07-23 |
Family
ID=40875350
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/320,205 Abandoned US20090183498A1 (en) | 2008-01-22 | 2009-01-21 | Exhaust emission control device |
Country Status (1)
Country | Link |
---|---|
US (1) | US20090183498A1 (en) |
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20110296814A1 (en) * | 2010-06-02 | 2011-12-08 | Gm Global Technology Operations, Inc. | Cold start hydrocarbon emission reduction control strategy for active hydrocarbon adsorber |
US20160310887A1 (en) * | 2013-12-20 | 2016-10-27 | Koninklijke Philips N.V. | Sensor system and oxygen separator comprising a sensor system |
CN110529221A (en) * | 2019-09-05 | 2019-12-03 | 北京工业大学 | A kind of plug-in engine cold starting adsorption/desorption apparatus control method |
CN111852634A (en) * | 2020-04-03 | 2020-10-30 | 袁琦 | Automobile exhaust self-processing early warning emission device |
US11187124B2 (en) * | 2020-01-03 | 2021-11-30 | Saudi Arabian Oil Company | Internal combustion engine systems including criteria pollutant mitigation |
CN115045739A (en) * | 2022-05-16 | 2022-09-13 | 潍柴动力股份有限公司 | Emission control method, control device and control system of marine diesel engine |
US20220401899A1 (en) * | 2019-12-30 | 2022-12-22 | Marathon Petroleum Company Lp | Methods and systems for in-line mixing of hydrocarbon liquids |
US11662750B2 (en) | 2019-12-30 | 2023-05-30 | Marathon Petroleum Company Lp | Methods and systems for inline mixing of hydrocarbon liquids |
US20230235690A1 (en) * | 2022-01-27 | 2023-07-27 | Ford Global Technologies, Llc | Exhaust restriction device for improved sensor signal |
US11754225B2 (en) | 2021-03-16 | 2023-09-12 | Marathon Petroleum Company Lp | Systems and methods for transporting fuel and carbon dioxide in a dual fluid vessel |
US11752472B2 (en) | 2019-12-30 | 2023-09-12 | Marathon Petroleum Company Lp | Methods and systems for spillback control of in-line mixing of hydrocarbon liquids |
US11808013B1 (en) | 2022-05-04 | 2023-11-07 | Marathon Petroleum Company Lp | Systems, methods, and controllers to enhance heavy equipment warning |
US11807945B2 (en) | 2021-08-26 | 2023-11-07 | Marathon Petroleum Company Lp | Assemblies and methods for monitoring cathodic protection of structures |
US11815227B2 (en) | 2021-03-16 | 2023-11-14 | Marathon Petroleum Company Lp | Scalable greenhouse gas capture systems and methods |
US11852063B1 (en) * | 2022-12-13 | 2023-12-26 | Saudi Arabian Oil Company | Internal combustion engine systems including intermittent sorbent usage for emission reduction |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4203502A (en) * | 1978-08-28 | 1980-05-20 | Strader Walter F | Muffler |
US5410875A (en) * | 1992-08-21 | 1995-05-02 | Nippondenso Co., Ltd. | Exhaust-gas purification device for an internal combustion engine or the like |
US5589143A (en) * | 1992-09-16 | 1996-12-31 | Nippondenso Co., Ltd. | Exhaust gas purification apparatus for internal combustion engine |
US5934072A (en) * | 1997-02-26 | 1999-08-10 | Toyota Jidosha Kabushiki Kaisha | Exhaust gas purifying device for engine |
US6318076B1 (en) * | 1999-07-15 | 2001-11-20 | Hyundai Motor Company | Apparatus for treating the exhaust gas of an internal combustion engine |
US20040067177A1 (en) * | 2002-09-03 | 2004-04-08 | Thieman Graham F. | Emission abatement device and method of using same |
US20070180817A1 (en) * | 2004-06-21 | 2007-08-09 | Masayuki Yamashita | Exhaust cleaning-up device for internal combustion engine for vehicle |
US20070227807A1 (en) * | 2006-03-02 | 2007-10-04 | Meneely Vincent A | High-performance muffler assembly with multiple modes of operation |
-
2009
- 2009-01-21 US US12/320,205 patent/US20090183498A1/en not_active Abandoned
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4203502A (en) * | 1978-08-28 | 1980-05-20 | Strader Walter F | Muffler |
US5410875A (en) * | 1992-08-21 | 1995-05-02 | Nippondenso Co., Ltd. | Exhaust-gas purification device for an internal combustion engine or the like |
US5589143A (en) * | 1992-09-16 | 1996-12-31 | Nippondenso Co., Ltd. | Exhaust gas purification apparatus for internal combustion engine |
US5934072A (en) * | 1997-02-26 | 1999-08-10 | Toyota Jidosha Kabushiki Kaisha | Exhaust gas purifying device for engine |
US6318076B1 (en) * | 1999-07-15 | 2001-11-20 | Hyundai Motor Company | Apparatus for treating the exhaust gas of an internal combustion engine |
US20040067177A1 (en) * | 2002-09-03 | 2004-04-08 | Thieman Graham F. | Emission abatement device and method of using same |
US20070180817A1 (en) * | 2004-06-21 | 2007-08-09 | Masayuki Yamashita | Exhaust cleaning-up device for internal combustion engine for vehicle |
US20070227807A1 (en) * | 2006-03-02 | 2007-10-04 | Meneely Vincent A | High-performance muffler assembly with multiple modes of operation |
Cited By (25)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20110296814A1 (en) * | 2010-06-02 | 2011-12-08 | Gm Global Technology Operations, Inc. | Cold start hydrocarbon emission reduction control strategy for active hydrocarbon adsorber |
CN102330590A (en) * | 2010-06-02 | 2012-01-25 | 通用汽车环球科技运作有限责任公司 | Cold start hydrocarbon emission reduction control strategy for active hydrocarbon adsorber |
US8307631B2 (en) * | 2010-06-02 | 2012-11-13 | GM Global Technology Operations LLC | Cold start hydrocarbon emission reduction control strategy for active hydrocarbon adsorber |
US20160310887A1 (en) * | 2013-12-20 | 2016-10-27 | Koninklijke Philips N.V. | Sensor system and oxygen separator comprising a sensor system |
US10232303B2 (en) * | 2013-12-20 | 2019-03-19 | Koninklijke Philips N.V. | Sensor system and oxygen separator comprising a sensor system |
CN110529221A (en) * | 2019-09-05 | 2019-12-03 | 北京工业大学 | A kind of plug-in engine cold starting adsorption/desorption apparatus control method |
US11774990B2 (en) | 2019-12-30 | 2023-10-03 | Marathon Petroleum Company Lp | Methods and systems for inline mixing of hydrocarbon liquids based on density or gravity |
US11794153B2 (en) * | 2019-12-30 | 2023-10-24 | Marathon Petroleum Company Lp | Methods and systems for in-line mixing of hydrocarbon liquids |
US11752472B2 (en) | 2019-12-30 | 2023-09-12 | Marathon Petroleum Company Lp | Methods and systems for spillback control of in-line mixing of hydrocarbon liquids |
US20220401899A1 (en) * | 2019-12-30 | 2022-12-22 | Marathon Petroleum Company Lp | Methods and systems for in-line mixing of hydrocarbon liquids |
US11596910B2 (en) | 2019-12-30 | 2023-03-07 | Marathon Petroleum Company Lp | Methods and systems for in-line mixing of hydrocarbon liquids |
US11607654B2 (en) | 2019-12-30 | 2023-03-21 | Marathon Petroleum Company Lp | Methods and systems for in-line mixing of hydrocarbon liquids |
US11662750B2 (en) | 2019-12-30 | 2023-05-30 | Marathon Petroleum Company Lp | Methods and systems for inline mixing of hydrocarbon liquids |
US11187124B2 (en) * | 2020-01-03 | 2021-11-30 | Saudi Arabian Oil Company | Internal combustion engine systems including criteria pollutant mitigation |
CN111852634A (en) * | 2020-04-03 | 2020-10-30 | 袁琦 | Automobile exhaust self-processing early warning emission device |
US11754225B2 (en) | 2021-03-16 | 2023-09-12 | Marathon Petroleum Company Lp | Systems and methods for transporting fuel and carbon dioxide in a dual fluid vessel |
US11774042B2 (en) | 2021-03-16 | 2023-10-03 | Marathon Petroleum Company Lp | Systems and methods for transporting fuel and carbon dioxide in a dual fluid vessel |
US11815227B2 (en) | 2021-03-16 | 2023-11-14 | Marathon Petroleum Company Lp | Scalable greenhouse gas capture systems and methods |
US11807945B2 (en) | 2021-08-26 | 2023-11-07 | Marathon Petroleum Company Lp | Assemblies and methods for monitoring cathodic protection of structures |
US20230235690A1 (en) * | 2022-01-27 | 2023-07-27 | Ford Global Technologies, Llc | Exhaust restriction device for improved sensor signal |
US11746685B2 (en) * | 2022-01-27 | 2023-09-05 | Ford Global Technologies, Llc | Exhaust restriction device for improved sensor signal |
US11808013B1 (en) | 2022-05-04 | 2023-11-07 | Marathon Petroleum Company Lp | Systems, methods, and controllers to enhance heavy equipment warning |
US11965317B2 (en) | 2022-05-04 | 2024-04-23 | Marathon Petroleum Company Lp | Systems, methods, and controllers to enhance heavy equipment warning |
CN115045739A (en) * | 2022-05-16 | 2022-09-13 | 潍柴动力股份有限公司 | Emission control method, control device and control system of marine diesel engine |
US11852063B1 (en) * | 2022-12-13 | 2023-12-26 | Saudi Arabian Oil Company | Internal combustion engine systems including intermittent sorbent usage for emission reduction |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US20090183498A1 (en) | Exhaust emission control device | |
US6955159B2 (en) | Carbon canister for use in evaporative emission control system of internal combustion engine | |
EP0953738B1 (en) | Exhaust emission control system of internal combustion engine | |
JP3557925B2 (en) | Exhaust gas purification device for internal combustion engine | |
EP1359313B1 (en) | An air intake system for an internal combustion engine | |
US6209317B1 (en) | Exhaust gas purifying apparatus for internal combustion engine | |
JPH11270328A (en) | Exhaust emission control device for multi-cylinder internal combustion engine | |
JP2000230416A (en) | Failure detecting device for exhaust changeover valve in internal combustion engine | |
US5647206A (en) | Exhaust emission purification apparatus | |
US6401451B1 (en) | Degradation discrimination system of internal combustion engine exhaust gas purification system | |
JP2009167852A (en) | Exhaust emission control system of hydrogen engine | |
US20180334941A1 (en) | Engine system | |
JP4292671B2 (en) | Hydrocarbon emission reduction device for internal combustion engine | |
JP2003028012A (en) | Leaked fuel vapor removing device | |
US8161734B2 (en) | Exhaust gas purification device | |
JP4321615B2 (en) | INTERNAL COMBUSTION ENGINE DEVICE, ITS CONTROL METHOD, AND VEHICLE MOUNTED WITH INTERNAL COMBUSTION ENGINE DEVICE | |
WO2009110102A1 (en) | Exhaust gas purification system for internal combustion engine | |
JP6935787B2 (en) | Exhaust purification device and exhaust purification method for internal combustion engine | |
JP3587670B2 (en) | Exhaust gas purification equipment for automobiles | |
JP4501306B2 (en) | Exhaust gas purification device for internal combustion engine | |
JP3456008B2 (en) | Exhaust gas purification device for internal combustion engine | |
JP2009036153A (en) | Exhaust-emission purifying apparatus of internal combustion engine | |
JP2012207630A (en) | Exhaust emission control apparatus of internal combustion engine | |
JP3629953B2 (en) | Exhaust gas purification device for internal combustion engine | |
JP4233144B2 (en) | Exhaust gas purification device for turbocharged engine and control method thereof |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: CALSONIC KANSEI CORPORATION, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:UCHIDA, KAZUYA;NISHIZAWA, KIMIYOSHI;OOUCHI, KEN;AND OTHERS;REEL/FRAME:022353/0766 Effective date: 20090119 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |