JPH11153026A - Exhaust emission control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve fuel consumption and to prevent fouling of an exhaust gas system. SOLUTION: Exhaust gas exhausted from an engine 2 flows in a recombustion chamber 7 after oxygen is fed to a part, where an exhaust pressure of exhaust pulsation is decreased, by an oxygen feed means 11. In this case, a velocity of flow of exhaust gas is rapidly decreased by the recombustion chamber 7 to rapidly expand an exhaust passage, and break away is caused to occur to a flow by an eddy current generating means 8. A part where concentration of an unburnt component (CO, HC) is high and a part where oxygen concentration is high alternately occur at the periphery of an ignition plug 10. Further, a part where a quantity of unburning component is high in exhaust gas is ignited by an ignition means 10 and exhaust gas is caused to effect stratified combustion. This constitution effectively warms up a catalyst 5 and the catalyst is early activated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas purifying apparatus for an internal combustion engine which warms up a catalyst by reburning unburned components in exhaust gas so that a catalyst for purifying exhaust gas is activated early.

[0002]

2. Description of the Related Art In general, when an internal combustion engine is not sufficiently warmed immediately after starting and exhaust gas temperature is low, a catalyst such as a three-way catalyst for removing harmful components (CO, HC, etc.) in the exhaust gas. Is not sufficiently activated, the exhaust gas purifying ability of the catalyst is low, and the emission of harmful components in the exhaust gas increases. Therefore, in order to activate the catalyst at an early stage after the start of the internal combustion engine, a technique of burning the exhaust gas again to warm up the catalyst has been devised.

[0003] For example, the technique disclosed in Japanese Patent Publication No. 6-508409 increases the fuel injection amount to increase the concentrations of CO, H ₂ and HC in the exhaust gas and introduces secondary air into the exhaust system. Then, the oxygen concentration in the exhaust gas was increased, and the exhaust gas was ignited with an ignition plug and recombusted.The heat generated by the recombustion warmed the catalyst and activated the catalyst early. I have.

[0004]

However, in such a conventional technique, since the exhaust gas and the secondary air are uniformly mixed, CO, H ₂ , H contained in the exhaust gas are not included.
The C concentration becomes thin. Therefore, it was necessary to increase the amount of fuel diluted by the secondary air so that the CO, H ₂ , and HC concentrations of the exhaust gas to be reburned were in the combustible region. As a result, fuel economy is deteriorated, and an increase in unburned components causes an increase in fouling of the exhaust system.

[0005] Incidentally, without introducing secondary air, fuel in some cylinders of the engine is cut, and air discharged from some of the cylinders is introduced into exhaust gas discharged from other cylinders. Technology has already been devised (Japanese Unexamined Patent Application Publication No. 9-9).
No. 6216). However, even in this technique, CO, which is contained in exhaust gas discharged from other cylinders,
Since the H ₂ and HC concentrations are diluted by the air discharged from some of the cylinders, the C
In order to make the O and HC concentrations in the flammable region, it is necessary to increase the amount of fuel diluted by air, as in the case of the above-mentioned prior art. As a result, similar to the above-described prior art, this conventional technique causes deterioration of fuel consumption and also causes a problem of increased contamination of an exhaust system due to an increase in unburned components.

Therefore, the present invention provides an exhaust gas purifying apparatus for an internal combustion engine that can activate a catalyst early and exhibit an excellent exhaust gas purifying function without causing deterioration of fuel efficiency and increase in contamination of an exhaust system. The purpose is to do.

[0007]

According to the first aspect of the present invention, there is provided an operating state detecting means for detecting an operating state including a load and a rotation speed of an engine, and disposed in an exhaust system of the engine to reburn the exhaust gas.
Re-combustion means for warming up a catalyst for purifying exhaust gas, oxygen supply means connected to an exhaust system on the upstream side of the catalyst for supplying oxygen to exhaust gas in response to exhaust pulsation, and detection of the operation state detection means An exhaust gas purification device for an internal combustion engine, comprising: a control unit that controls the operation of the oxygen supply unit and the reburning unit based on a result. The reburning means includes a reburning chamber for rapidly expanding an exhaust passage, a vortex flow generating means for separating a flow to generate a vortex, and an ignition means for igniting exhaust gas at the vortex generating portion. ing. Further, the control means operates the oxygen supply means so that oxygen is supplied to a portion where the exhaust pressure during exhaust pulsation becomes small, and when a gas having a large amount of unburned components flows into the vortex generating portion. The ignition means is operated.

According to a second aspect of the present invention, there is provided an operating state detecting means for detecting an operating state including a load and a rotation speed of an engine, and a catalyst disposed in an exhaust system of the engine for reburning the exhaust gas and purifying the exhaust gas. Re-combustion means, an oxygen supply means connected to an exhaust system on the upstream side of the catalyst for supplying oxygen to exhaust gas in response to exhaust pulsation, and an oxygen supply means based on a detection result of the operation state detection means. And a control means for controlling the operation of the means. The reburning means includes a reburning chamber for rapidly expanding an exhaust passage, a vortex flow generating means for separating a flow to generate a vortex, and an ignition means for igniting exhaust gas at the vortex generating portion. ing. Further, the invention is characterized in that the control means operates the oxygen supply means such that oxygen is supplied to a portion where the exhaust pressure during exhaust pulsation decreases.

[0009] The invention of claim 3 is claim 1 or claim 2.
Wherein the oxygen supplied from the oxygen supply means is introduced into an exhaust system near the ignition means.

According to a fourth aspect of the present invention, there is provided an operating state detecting means for detecting an operating state of the engine, and a reburning means disposed in an exhaust system of the engine for reburning the exhaust gas and warming up a catalyst for purifying the exhaust gas. A fuel cut means for cutting fuel injection to a part of the cylinder of the engine when the catalyst is warmed up by the reburning means, a control means for operating the fuel cut means based on a detection result of the operating state detecting means, An exhaust gas purification device for an internal combustion engine comprising: The reburning means includes a reburning chamber for rapidly expanding an exhaust passage, a vortex flow generating means for separating a flow to generate a vortex, and an ignition means for igniting exhaust gas at the vortex generating portion. ing. Further, the exhaust gas of a part of the cylinders from which the fuel injection has been cut is introduced into the vicinity of the ignition means of the reburning means by the oxygen supply means.

The invention of claim 5 is the invention of claim 2 or 4
In the invention, the ignition means is a glow plug.

[0012] The invention of claim 6 is the invention of claim 1 or claim 2.
The present invention is characterized in that the oxygen supply means supplies a large amount of oxygen to a portion where the exhaust pressure during exhaust pulsation decreases, and supplies a small amount of oxygen to a portion where the exhaust pressure during the exhaust pulsation increases.

[0013] The invention of claim 7 is the invention of claim 1 or claim 2.
The present invention is characterized in that the oxygen supply means intermittently supplies oxygen to a portion where the exhaust pressure during exhaust pulsation decreases.

[0014] The invention of claim 8 is a reburning means arranged in the exhaust system of the engine for reburning the exhaust gas and warming up a catalyst for purifying the exhaust gas, and connected to an exhaust system upstream of the catalyst,
An oxygen purification device for an internal combustion engine, comprising: oxygen supply means for supplying oxygen into exhaust gas in response to exhaust pulsation, wherein the recombustion means includes a recombustion chamber that rapidly expands an exhaust flow path; Vortex generating means for peeling off and generating vortices, and igniting means for igniting exhaust gas in the vortex generating section, supplying oxygen to a portion where the exhaust pressure during exhaust pulsation becomes small, and supplying oxygen to the vortex generating section. It is characterized in that at least the ignition means is operated when a gas containing a large amount of unburned components flows.

[0015]

According to the present invention, the exhaust gas discharged from the engine is supplied to the portion where the exhaust pressure of the exhaust pulsation is reduced by the oxygen supply means. The gas flows into the reburning chamber. At this time, the reburning chamber, which rapidly expands the exhaust passage, rapidly reduces the flow velocity of the exhaust gas, and the vortex is generated by the vortex generating means causing the flow to separate, so that a vortex is generated. Around the means, a portion having a high concentration of unburned components (CO, H ₂ , HC) and a portion having a high oxygen concentration alternately occur. Then, the ignition means ignites a portion of the exhaust gas that has a large amount of unburned components to cause stratified combustion of the exhaust gas. As a result, the catalyst is effectively warmed up and the catalyst is activated early. As described above, according to the present invention, oxygen is supplied to a portion of the exhaust pulsation where the exhaust pressure is low, and a portion of the exhaust pulsation where the exhaust pressure is high (that is, a portion having a large amount of unburned components) is diluted with oxygen. Therefore, it is not necessary to increase the fuel injection amount by the amount corresponding to the dilution of the unburned components, so that the fuel efficiency can be improved and the exhaust system can be prevented from being contaminated due to the increased unburned components.

According to the third aspect of the present invention, since the oxygen supplied from the oxygen supply means is introduced into the vicinity of the ignition plug, the concentration of the unburned component is prevented from being diluted by the oxygen more effectively. be able to.

According to the fourth aspect of the present invention, when the exhaust gas discharged from the engine flows into the reburning chamber, the flow rate of the exhaust gas is rapidly reduced by the reburning chamber which rapidly expands the exhaust passage, A vortex is generated by causing the flow to be separated by the vortex generating means, and flows around the ignition means. Then, oxygen is introduced from the fuel-cut cylinder to the vicinity of the ignition means. As a result, the exhaust gas in the vicinity of the ignition means forms a layer without completely mixing the portion with a large amount of unburned components and the portion with a large amount of oxygen. Then, the exhaust gas in the reburning chamber is ignited by the igniting means into a portion having a large amount of unburned components,
It stratifies and warms the catalyst, activating the catalyst early. As described above, according to the present invention, the oxygen of the fuel-cut cylinder is directly introduced into the vicinity of the ignition means, so that the oxygen is not completely mixed with the portion having a large amount of unburned components, Since the portion with a large amount of unburned components is not diluted by oxygen, it is not necessary to increase the fuel by the amount of dilution of the unburned components. An increase in dirt can be prevented.

According to the fifth aspect of the present invention, since the glow plug is used as the ignition means, it is not necessary to control the ignition timing of the ignition means. Operation control becomes easy.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] FIG. 1 is a schematic diagram showing an exhaust gas purifying apparatus 1 for an internal combustion engine according to an embodiment of the present invention. FIG. 2 is a block diagram showing the exhaust gas purifying apparatus 1. FIG.

In these figures, a fuel increasing means (for example, a fuel injection valve) 3 for increasing the amount of fuel supplied to the internal combustion engine 2 is arranged on the intake side of the internal combustion engine 2. on the other hand,
A catalyst 5 for purifying exhaust gas is disposed in the exhaust passage 4 of the internal combustion engine 2, and a reburning means 6 is disposed upstream of the catalyst 5. The reburning means 6 includes a reburning chamber 7 for rapidly expanding the exhaust passage 4, a vortex generating means 8 for separating the flow of exhaust gas flowing into the reburning chamber 7 to generate a vortex, and a vortex generating section. And an ignition plug (ignition means) 10 for igniting exhaust gas. Among them, the vortex generating means 8
Corresponds to a sharp edge portion of the exhaust passage 4 opening to the reburning chamber 7 (see FIGS. 4 and 5A). Here, when the exhaust gas flowing through the exhaust passage 4 flows into the reburning chamber 7, the exhaust gas rapidly expands, the flow velocity decreases, and separation occurs at the sharp edge portion 8. Occurs.

In the exhaust passage 4 between the internal combustion engine 2 and the reburning chamber 7, an oxygen supply means 11 for supplying secondary air into the exhaust gas is arranged. The oxygen supply means 11 includes a secondary air pump 13 disposed in the secondary air supply path 12, and an electromagnetic valve 14 disposed downstream of the secondary air pump 13 to open and close the secondary air supply path 12. It has. The operation of the secondary air pump 13 and the solenoid valve 14 is controlled by a control unit (control means) 15, and the unburned components (CO, H ₂ , Secondary air is intermittently supplied into the exhaust passage 4 according to the exhaust pulsation so that the HC) concentration and the oxygen concentration alternately increase. In order to detect the load of the engine related to the exhaust flow rate, a load sensor 16 including, for example, an air flow meter and a throttle valve opening sensor is disposed. This load sensor 1
6 outputs the detection signal to the control unit 15.

The control unit 15 detects the operating state of the internal combustion engine 2 based on signals from the engine cooling water temperature sensor 17, the engine rotation sensor 18, the load sensor 16, and the like.
Based on the detection result, the necessity of exhaust reburning is determined,
The operation of the fuel increasing means 3, the ignition plug 10, the secondary air pump 13, and the solenoid valve 14 is controlled. The load sensor 16, the engine cooling water temperature sensor 17, and the engine rotation sensor 18 constitute operating state detecting means for detecting the operating state of the engine.

FIG. 3 is a diagram for explaining the relationship between the concentration of unburned components (CO, H ₂ , HC) and the concentration of oxygen in the exhaust gas into which the secondary air is intermittently introduced.

As shown in FIG. 3, in the conventional exhaust gas purification apparatus, since the secondary air is introduced into the exhaust gas at a constant rate, the unburned components (CO, H ₂ , HC) in the exhaust gas.
Is diluted by the secondary air, and the oxygen concentration contained in the secondary air is diluted by the exhaust gas. as a result,
The concentration of the unburned components and the oxygen concentration of the secondary air are reduced as a whole. Therefore, in order to increase the concentration of the diluted exhaust gas to the flammable region, the diluted unburned components must be increased, and the fuel must be further increased. As a result, the exhaust system becomes dirty due to the deterioration of fuel efficiency and the increase of fuel. Since the exhaust gas pulsates in the exhaust pipe as shown in this figure, the unburned component concentration and the oxygen concentration slightly increase or decrease according to the amount of the exhaust gas.

On the other hand, as shown in FIG. 3, the exhaust gas purifying apparatus according to the present embodiment intermittently introduces secondary air in response to exhaust pulsation, and discharges secondary air when the amount of exhaust gas is small ( When the exhaust pressure is low, the exhaust gas is introduced into the exhaust gas. When the exhaust gas amount is large (the exhaust pressure is high), secondary air is not introduced into the exhaust gas. Combustion component (CO, HC) concentration hardly decreases. Therefore, the unburned component concentration and the oxygen concentration alternately increase. When the exhaust gas in which the unburned component concentration and the oxygen concentration are alternately increased flows into the reburning chamber 7 as described above, the flow velocity is rapidly reduced, and a vortex is generated to reach the vicinity of the ignition plug 10. At this time, as shown in FIG. 4, when a portion having a high concentration of unburned component flows into a portion having a high oxygen concentration, the ignition plug 10 ignites the exhaust gas to cause stratified combustion of the exhaust gas. Thus, according to the present embodiment, when the secondary air is introduced, the unburned components (CO, H ₂ , H
C) Since the concentration does not decrease, it is not necessary to further increase the amount of fuel, so that fuel efficiency is improved and dirt on the exhaust system can be reduced.

FIG. 6 is a diagram showing the timing of introduction of exhaust gas and secondary air taking a four-cylinder internal combustion engine as an example.

As shown in FIG. 6, FIG. 1, and FIG. 2, exhaust gas is sequentially discharged from each cylinder. As a result, the exhaust pressure in the exhaust passage 4 pulsates. Then, when the amount of exhaust gas is small, the secondary air is introduced, and when the amount of exhaust gas is large, the introduction of the secondary air is stopped. In order to accurately introduce the secondary air, it is necessary to grasp the pulsation state in the exhaust passage 4. Therefore, first, the timing at which the exhaust gas enters the reburning chamber 7 (the time from when the gas is discharged from the exhaust valve to when it flows into the reburning chamber 7) is considered. It can be seen that the volume slightly varies depending on the volume of the exhaust passage 4 from the valve to the reburning chamber 7 and the amount of exhaust gas (that is, load). In this case, since the volume of the exhaust passage 4 does not change, the timing can be known by detecting a load that affects the exhaust gas amount. Next, considering the interval between the peaks of the exhaust gas shown in FIG.
Since the exhaust gas is sequentially discharged from each cylinder, it is understood that the interval between the peaks of the exhaust gas can be easily known by detecting the rotation speed of the engine 2 with the engine rotation sensor 18. Therefore, if the control unit 15 operates the secondary air pump 13 and the solenoid valve 14 based on the load signal from the load sensor 16 and the rotation speed signal from the engine rotation sensor 18, the exhaust pulsation at the secondary air introduction position is estimated. And secondary air can be introduced into the exhaust gas accurately. The timing at which the exhaust gas is ignited in the reburning chamber 7 is determined by the control unit 15 based on the detection signals from the load sensor 16 and the engine rotation sensor 18 in the same manner as the timing of introducing the secondary air.
By controlling the operation of the exhaust gas, it is possible to accurately ignite the exhaust gas.

Next, the operating state of the exhaust gas purifying apparatus 1 is shown in FIG.
And FIG. 1 and FIG. First, in step 1, it is determined based on a detection signal from the engine cooling water temperature sensor 17 whether or not the cooling water temperature Twi at the time of starting the engine is equal to or lower than a predetermined temperature Kc. Here, when the cooling water temperature is equal to or lower than the predetermined temperature, it is determined that the catalyst has not been activated, and it is necessary to activate the catalyst early by reburning the exhaust gas. Then, in step 2, the fuel increasing means 3 is operated to increase the fuel injection amount. Next, in step 3, secondary air is intermittently introduced according to the pulsation of the exhaust gas. Here, the exhaust pulsation at the secondary air introduction position is estimated based on the engine speed and the load, and when the exhaust gas is small, the secondary air pump 13 and the solenoid valve 14 are operated to introduce the secondary air. In step 4, when the vicinity of the ignition plug 10 in the reburning chamber 7 reaches an easily combustible exhaust gas concentration (that is, a boundary layer between a gas having a high concentration of CO, H ₂ , and HC and a gas having a high oxygen concentration), ignition is performed. The plug 10 is operated to ignite the exhaust gas. Here, the ignition timing is estimated based on the engine speed and the load. Next, in step 5, it is determined whether or not a predetermined time has elapsed since the start of reburning. Here, when a predetermined time has elapsed since the start of reburning, the catalyst 5
Is determined to be sufficiently activated. Therefore, in step 6, the operation of the fuel increasing means 3 is stopped, the operations of the secondary air pump 13 and the solenoid valve 14 are stopped, and the fuel increase and the introduction of the secondary air are stopped. If the temperature of the cooling water exceeds the predetermined temperature in step 1, it is determined that the catalyst 5 has been sufficiently activated, and the catalyst 5 is warmed up by reburning the exhaust gas. Without this, the exhaust gas is purified by the catalyst 5. If it is determined in step 5 that the predetermined time has not elapsed since the start of the reburning, it is determined that the catalyst 5 has not been sufficiently activated, and the reburning operation is further continued.

[Second Embodiment] In the above embodiment, the configuration of FIG. 5A was described as the eddy current generating means 8, but the present invention is not limited to this, and the configuration as shown in FIG. It may be something. That is, in FIG. 5B, the reburning chamber 7
The exhaust introduction section 20 has a substantially conical shape, and the enlarged recombustion chamber wall 21 on the end side of the exhaust introduction section 20 expands more rapidly than the exhaust passage 4 on the upstream side. I have. At the center of the reburning chamber 7 in the vicinity of the exhaust introducing section 20, a disk-shaped or polygonal-plate-shaped eddy current generating means 8 whose end is bent is disposed. An ignition plug 10 is attached to a substantially central portion of the vortex generating means 8. The flow rate of the exhaust gas flowing into the reburning chamber 7 configured as described above rapidly decreases, and the flow is separated by the vortex flow generating means 8 to form a vortex flowing toward the center of the vortex flow generating means 8. The vortexed exhaust gas is ignited by the spark plug 10 located in the vortex generating portion and burns, thereby warming up the catalyst 5.

[Third Embodiment] In addition, eddy current generating means 8
May have the configuration shown in FIG. That is, FIG.
In (c), the reburn chamber 7 is the same as that shown in FIG. 5B, but the location and shape of the vortex generator 8 are different from those of the first and second embodiments. That is,
The vortex generating means 8 is provided in the substantially conical exhaust introduction portion 20 and is formed in a flat plate shape extending along the exhaust flow path 4. Then, the vortex flow generating means 8 and the reburning chamber wall 21
And an ignition plug is arranged between them. The flow rate of the exhaust gas that has flowed into the reburning chamber 7 configured as described above rapidly decreases, and the flow is separated by the vortex generating means 8 and flows between the vortex generating means 8 and the reburning chamber 7. It becomes such a vortex. And the vortex exhaust gas is
The catalyst is ignited and burned by the ignition plug 10 located at the vortex generating portion, and the catalyst 5 is warmed up.

[Fourth Embodiment] FIG. 8 shows a fourth embodiment of the present invention. In this embodiment, 2
The secondary air supply passage 12 is open to the reburning chamber 7 so that secondary air is directly introduced into the vicinity of the ignition plug 10. With such a configuration, the unburned components (CO,
The concentration of H ₂ and HC) and the concentration of oxygen are alternately increased.

[Fifth Embodiment] In the above embodiment, the secondary air is intermittently introduced. However, in the present embodiment, as shown in FIG. Instead, a reed valve is arranged at the opening end of the secondary air supply passage 12 on the exhaust passage 4 side, and the reed valve 2
A large amount of secondary air is supplied, and a small amount of secondary air is supplied to a portion where the exhaust pressure of the exhaust pulsation is high. here,
Since the reed valve 22 opens and closes by the dynamic pressure of the exhaust gas, it is preferable to arrange the reed valve 22 near the exhaust valve of the internal combustion engine 2.

Even with such a configuration, the unburned component (C) is lower than that of the prior art in which the secondary air is introduced at a constant rate.
O, H ₂ , and HC) are less likely to be diluted with oxygen, so that it is not necessary to increase the amount of fuel accompanying the introduction of secondary air, thereby improving fuel efficiency. With such a configuration, the solenoid valve is not required, and the operation control of the exhaust gas purification device is facilitated.

Note that the reed valve 22 is not used, and the discharge amount differs depending on the exhaust pressure (that is, the discharge amount is large when the exhaust pressure is low and the discharge amount is small when the exhaust pressure is high). A pump may be used. Even in this case, the same effect as in the present embodiment can be obtained.

[Sixth Embodiment] FIG. 10 shows a sixth embodiment of the present invention. In this embodiment,
The fuel in some of the cylinders of the multi-cylinder internal combustion engine 2 is cut, and the gas discharged from some of the cylinders is discharged to the exhaust passage 2 of another cylinder.
An exhaust passage (oxygen supply means) 24 separate from the recombustion chamber 7
Unburned components (CO, H) of the exhaust gas introduced into the vicinity of the ignition plug 10 and discharged from the other cylinders and flowed into the reburning chamber 7.
₂ , HC) concentration and oxygen concentration are alternately increased. That is, in the present embodiment, oxygen in the exhaust of some of the cylinders whose fuel has been cut is used instead of the secondary air. Here, the fuel cut to a part of the cylinders is performed by a fuel cut means constituted by a control unit 15 for controlling the operation of a fuel injection valve (not shown). The fuel cut includes not only completely shutting off the supply of fuel to some of the cylinders, but also reducing the supply of fuel to only some of the cylinders. Further, the exhaust passage 24 of some cylinders may be connected to an exhaust passage (exhaust passage of another cylinder) 23 near the spark plug 10 on the upstream side of the reburning chamber 7.

According to this embodiment, the fuel efficiency can be improved in the same manner as in each of the above embodiments.

Seventh Embodiment In each of the above-described embodiments, the ignition timing of the ignition plug 10 is controlled by the control unit 15, but a glow plug is used as the ignition plug 10 and the glow plug is used. The plug may be constantly heated. Also in this case, it is possible to ignite the exhaust gas in which the unburned component (CO, H ₂ , HC) concentration and the oxygen concentration in the reburning chamber 7 are alternately increased, and the catalyst 5 can be warmed up. it can. Therefore, according to the present embodiment, the operation control of the exhaust gas purification device is facilitated.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an exhaust gas purification device for an internal combustion engine according to a first embodiment of the present invention.

FIG. 2 is a block diagram of the exhaust gas purification device.

FIG. 3 is a diagram showing a relationship between an unburned component concentration and an oxygen concentration in exhaust gas.

FIG. 4 is a diagram showing a flow state of gas flowing into a reburning chamber.

FIG. 5 is an enlarged view of the reburning means. 5A is a first enlarged view, FIG. 5B is a second enlarged view, and FIG. 5C is a third enlarged view.

FIG. 6 is a diagram showing timing of introducing exhaust gas and secondary air.

FIG. 7 is a flowchart showing an operation state of the exhaust gas purification device.

FIG. 8 is a configuration diagram of a reburning unit of an exhaust gas purification device according to a fourth embodiment of the present invention.

FIG. 9 is a main part configuration diagram of an exhaust emission control device showing a fifth embodiment of the present invention.

FIG. 10 is a schematic configuration diagram of an exhaust gas purification device according to a sixth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Exhaust gas purification apparatus 2 ... Internal combustion engine 5 ... Catalyst 6 ... Reburning means 7 ... Reburning chamber 8 ... Eddy current generation means 10 ... Spark plug (ignition means) 11 ... Oxygen supply means 15 ... Control unit (control means) 16 ... Load sensor (operating state detecting means) 17 ... Engine cooling water temperature sensor (operating state detecting means) 18 ... Engine rotation sensor (operating state detecting means) 24 ... Exhaust passage (oxygen supplying means)

Continuation of front page (72) Inventor Keiji Okada Nissan Motor Co., Ltd. 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa

Claims (8)

[Claims] 1. An operating state detecting means for detecting an operating state including a load and a rotation speed of an engine, and a reburning means disposed in an exhaust system of the engine for reburning the exhaust gas and warming up a catalyst for purifying the exhaust gas. An oxygen supply unit connected to an exhaust system on the upstream side of the catalyst and supplying oxygen to exhaust gas in response to exhaust pulsation; an oxygen supply unit and the reburn based on a detection result of the operation state detection unit Control means for controlling the operation of the means;
An exhaust gas purification device for an internal combustion engine, comprising: a reburning means, a reburning chamber that sharply expands an exhaust passage, and a vortex flow generating means that generates a vortex by separating a flow,
Ignition means for igniting exhaust gas at the vortex generating section, wherein the control means operates the oxygen supply means so as to supply oxygen to a portion where the exhaust pressure during exhaust pulsation decreases, and An exhaust gas purifying apparatus for an internal combustion engine, wherein the ignition means is activated when a gas having a large amount of unburned components flows into the generating section. 2. An operating state detecting means for detecting an operating state including a load and a rotational speed of the engine, and a reburning means disposed in an exhaust system of the engine for reburning the exhaust gas and warming up a catalyst for purifying the exhaust gas. An oxygen supply unit connected to an exhaust system on the upstream side of the catalyst and supplying oxygen to exhaust gas in response to exhaust pulsation; and an operation control of the oxygen supply unit based on a detection result of the operation state detection unit. Control means, and an exhaust purification device for an internal combustion engine, comprising: a reburning means, wherein the reburning means sharply expands an exhaust passage, and a vortex flow generating means for separating a flow to generate a vortex;
Ignition means for igniting exhaust gas in the vortex generating section, wherein the control means operates the oxygen supply means so that oxygen is supplied to a portion where exhaust pressure during exhaust pulsation becomes small. Exhaust purification device for an internal combustion engine. 3. An exhaust gas purifying apparatus for an internal combustion engine according to claim 1, wherein oxygen supplied from said oxygen supply means is introduced into an exhaust system near said ignition means. 4. An operating state detecting means for detecting an operating state of the engine; a reburning means disposed in an exhaust system of the engine for reburning the exhaust gas and warming up a catalyst for purifying the exhaust gas; An internal combustion engine comprising: fuel cut means for cutting fuel injection into some of the cylinders of the engine when the catalyst is warmed up; and control means for operating the fuel cut means based on the detection result of the operating state detecting means. An exhaust gas purifying apparatus, wherein the reburning means includes a reburning chamber that rapidly expands an exhaust flow path, and a vortex flow generating means that generates a vortex by separating a flow,
Ignition means for igniting the exhaust gas at the vortex generating section, wherein the exhaust gas of a part of the cylinders from which the fuel injection has been cut is introduced into the vicinity of the ignition means of the reburning means by the oxygen supply means. An exhaust gas purification device for an internal combustion engine. 5. The exhaust gas purifying apparatus for an internal combustion engine according to claim 2, wherein said ignition means is a glow plug. 6. The apparatus according to claim 1, wherein said oxygen supply means supplies a large amount of oxygen to a portion where the exhaust pressure during exhaust pulsation decreases, and supplies a small amount of oxygen to a portion where the exhaust pressure during the exhaust pulsation increases. 3. The exhaust gas purifying apparatus for an internal combustion engine according to claim 1 or 2. 7. The exhaust gas purifying apparatus for an internal combustion engine according to claim 1, wherein said oxygen supply means intermittently supplies oxygen to a portion where exhaust pressure during exhaust pulsation decreases. 8. A reburning means disposed in an exhaust system of the engine for reburning the exhaust gas and warming up a catalyst for purifying the exhaust gas, wherein the reburning means is connected to an exhaust system on the upstream side of the catalyst and responds to exhaust pulsation. An exhaust gas purification apparatus for an internal combustion engine, comprising: oxygen supply means for supplying oxygen into exhaust gas, wherein the re-combustion means comprises: a re-combustion chamber for rapidly expanding an exhaust flow path; Vortex flow generating means for generating
An ignition means for igniting exhaust gas in the vortex generating portion, and supplying oxygen to a portion where exhaust pressure during exhaust pulsation becomes small,
An exhaust purification device for an internal combustion engine, wherein at least the ignition means is operated when a gas having a large amount of unburned components flows into the vortex generating section.