JPH08177464A - Exhaust emission control device - Google Patents

Abstract

PURPOSE: To prevent breakage from being generated caused by the excessively raised temperature of an adsorbent in high loading, by preventing HC from being discharged with it not burnt through a process of improving the adsorption efficiency of the adsorbent by restraining the temperature rise of the adsorbent in starting of an engine. CONSTITUTION: An adsorbent 3 opened to an exhaust port 11 is fixed in an exhaust manifold 2 communicated with the exhaust port 11 of an internal combustion engine 1. An exhaust gas purifying catalyst 5 is arranged in an exhaust pipe 4 downstream from the exhaust manifold 2. A cooling fan 6 is provided behind the adsorbent 3, the cooling fan 6 is operated until the temperature of the catalyst 5, to be detected by a temperature sensor 51 reaches the activating temperature, and the temperature rise is restrained. In high loading, the cooling fan 6 is operated when the adsorbent 3 temperature detected by a temperature sensor 35 exceeds the specified temperature, and the temperature rise is restrained.

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 device for detoxifying a relatively large amount of hydrocarbons (HC) discharged during cold start of an internal combustion engine such as a gasoline engine.

[0002]

2. Description of the Related Art Conventionally, unburned components, such as hydrocarbons (HC), contained in the exhaust gas of an engine have been purified and discharged by a catalyst arranged in the exhaust passage. However, when the engine is started, the catalyst does not function sufficiently until it reaches a certain purification temperature.
There was a problem that it was discharged without being purified. For this reason, the HC adsorbent is arranged in the exhaust manifold of the engine so as to face the exhaust port, and immediately after the engine is started, the HC is collided with and captured by the adsorbent. There is an exhaust gas purification device that purifies the desorbed HC by a catalyst arranged in the exhaust pipe further downstream (Japanese Patent Laid-Open No. 6-212951).

In the above conventional apparatus, the adsorbent is housed in a container body having only one end face facing the exhaust port, and the exhaust gas is discharged to a downstream exhaust pipe without flowing through the adsorbent. To be done. That is, since the gas flow does not occur inside the adsorbent, the temperature rise of the adsorbent is slow, the time required to reach the HC desorption temperature (about 100 ° C.) is relatively long, and the exhaust gas temperature is high. There is an advantage that the adsorbent is not excessively heated even when the engine is under heavy load.

[0004]

However, even in the above apparatus, HC adsorbed before the downstream catalyst reaches the purification temperature may start desorbing and be discharged as unpurified. It is desired to suppress the temperature rise as much as possible and maintain it at a low temperature with a high adsorption capacity. Further, in the above device,
A part of the exhaust gas is allowed to flow out to the exhaust pipe as it is, and relatively lightweight HC particles are discharged along the flow of the exhaust gas flowing out to the exhaust pipe without colliding with the adsorbent. The adsorption efficiency was lower than that of the method in which the entire amount of the above was introduced into the adsorbent (Japanese Patent Laid-Open No. 2-135126, etc.).

At high load, normally, the air-fuel ratio is made rich to protect the catalyst so that the exhaust temperature does not rise too much. However, the catalyst is lowered to the underfloor position where the exhaust gas temperature becomes low, and at high load. In vehicles that operate near the stoichiometric air-fuel ratio (European vehicles, etc.), the exhaust gas discharged from the exhaust port becomes hot, and the temperature of the adsorbent may rise excessively, destroying its pore structure. . further,
Since almost no gas flow occurs in the adsorbent, HC is not sufficiently discharged even when the adsorbent temperature exceeds the desorption temperature,
There was a risk of carbonization in the pores and a decrease in adsorption capacity.

Therefore, an object of the present invention is to suppress the temperature rise of the adsorbent at the time of engine starting or to increase the amount of HC colliding with the adsorbent to improve the adsorption efficiency of the adsorbent.
It is to prevent the unpurified gas from being discharged.
It is also possible to prevent the temperature of the adsorbent from rising too high under high load and to prevent damage, and to prevent desorption of HC after the adsorbent reaches the desorption temperature to prevent deterioration of the adsorbent. It is for other purposes.

[0007]

The structure of an exhaust gas purifying apparatus of the present invention is shown in FIG. 1, and an exhaust port 11 of an internal combustion engine 1 is shown.
An adsorbent 3 for adsorbing unburned components in the exhaust gas discharged from the exhaust port 11 is fixed in a position facing the exhaust port 11 in the exhaust manifold 2 communicating with the exhaust manifold 2. 2 Downstream exhaust passage 4
Inside, a catalyst 5 for purifying exhaust gas is arranged. Then, based on the cooling means 6 for air-cooling the adsorbent 3, the temperature sensors 35 and 51 provided near the adsorbent 3 and the catalyst 5, and the detection signals from the temperature sensors 35 and 51, respectively, The control means 7 is provided to operate the cooling means 6 before the temperature of the catalyst 5 reaches the activation temperature or when the temperature of the adsorbent 3 exceeds a certain temperature (claim 1).

The cooling means is, for example, a cooling fan 6 arranged behind the adsorbent 3 (claim 2). Alternatively, as shown in FIG. 6, the cooling means is provided with a flow path 21 for the secondary air formed along the outer wall of the adsorbent 3 and the flow path 2
It may be configured by an air pump 23 that adjusts the amount of secondary air introduced into the air conditioner 1 (claim 3).

The exhaust gas purifying apparatus of the present invention is shown in FIG.
As described above, an air injector 8 provided below the exhaust port 11 for ejecting secondary air toward the adsorbent 3 that faces the exhaust port 11, and a temperature sensor 5 provided near the catalyst 5
1 and a control means 7 for operating the air injector 8 until the temperature of the catalyst 5 detected by the temperature sensor 51 reaches an activation temperature (claim 4).

Further, the exhaust gas purifying apparatus of the present invention is shown in FIG.
3 is located behind the adsorbent 3 and the adsorbent 3
An air chamber 36 communicating with the inside, an air pump 9 for introducing secondary air into the air chamber 36, a temperature sensor 51 provided near the catalyst 5, and a temperature of the catalyst 5 detected by the temperature sensor 51 When the temperature reaches the activation temperature or higher, the air pump 9 is operated to move the air from the air chamber 36 to the inside of the adsorbent 3.
A configuration may be provided in which the control means 7 for introducing the secondary air is provided (Claim 5).

[0011]

In the structure of claims 1 and 2, when the cooling fan 6 as the cooling means is operated at the time of cold start of the engine, the adsorbent 3 is air-cooled by the air blown from the cooling fan 6 and the temperature rise is suppressed. The HC is reliably retained until the downstream catalyst 5 reaches the activation temperature, and the adsorption capacity is greatly improved.
When the temperature of the catalyst 5 detected by the temperature sensor 51 reaches the activation temperature, the fan 6 is stopped, HC is desorbed, and the downstream catalyst 5 purifies the HC. Further, in this configuration, when the load is high, the cooling fan 6 is controlled to operate when the temperature of the adsorbent 3 exceeds a certain temperature. Therefore, even under operating conditions where the exhaust gas temperature becomes high,
The temperature of the adsorbent 3 does not rise excessively and prevents the pore structure from being destroyed. Also in the configuration of claim 3,
The same cooling effect can be obtained by circulating the secondary air through the flow path 21 by the air pump 23.

In the fourth aspect of the present invention, when the engine is cold-started, the air injector 8 is actuated to eject the secondary air toward the adsorbent 3 which is opposed thereto. Then, the relatively lightweight HC particles are also likely to ride on the flow of the secondary air and collide with the adsorbent 3. In addition, the adsorbent 3 is generated by the flow of the secondary air.
Temperature rise is suppressed. Therefore, the adsorption efficiency of HC is improved, and HC is retained to prevent unpurified HC from being discharged until the catalyst 5 reaches the activation temperature and the air injector 8 is stopped.

In the structure of claim 5, when the catalyst 5 reaches the activation temperature, the air pump 9 is operated to introduce the secondary air into the adsorbent 3 from the air chamber 36 behind the adsorbent 3.
The desorption H in the adsorbent 3 is carried along with the flow of the secondary air.
Since C is forcibly discharged from the front surface of the adsorbent 3, the remaining H
By C, the adsorption ability does not decrease when the engine is restarted, and stable repeatability can be obtained. Also, the residual H
It is prevented that C carbonizes at high temperature and blocks the pores.

[0014]

FIG. 1 shows an embodiment of the present invention, in which a gasoline engine 1 which is an internal combustion engine has an exhaust port 1 on its upper side surface.
1, the exhaust gas passes through the exhaust manifold 2 following the exhaust port 11, and is exhausted from the exhaust pipe 4 connected to the bottom surface of the exhaust manifold 2. The exhaust pipe 4 is provided with a large diameter part in the middle thereof, and at least HC
A catalytic converter 5 for purifying the is disposed.

Inside the exhaust manifold 2, an HC adsorbent 3 is arranged at a position facing the exhaust port 11. As shown in FIG. 2, the adsorbent 3 is formed by laminating a flat plate 31 and a corrugated plate 32 made of stainless steel foil having a thickness of about 50 μm on a carrier coated with an adsorbent such as zeolite. It is joined and fixed in a container body 33 having a U-shaped cross section that also serves as a wall (FIGS. 1 and 3), and only the front surface facing the exhaust port 11 is opened. Further, metal cooling fins 34 are provided on the outer wall of the container body 33 in which the adsorbent 3 is housed. The cooling fins 34 are formed by making a groove on a metal plate or welding or brazing the metal plate.

A cooling fan 6 is disposed behind the adsorbent 3 so that the adsorbent 3 can be blown and cooled. Further, in the adsorbent 3, a temperature sensor 35 for detecting the adsorbent temperature is provided, and in the exhaust pipe 4 downstream of the catalyst 5,
A temperature sensor 51 for detecting the catalyst temperature is provided, and the operation of the cooling fan 6 is controlled by the control circuit 7 based on the temperatures detected by these sensors 35, 51. Here, although the cooling fan 6 is a relatively small fan for cooling the adsorbent, a radiator fan or an air conditioner fan is used, and the duct is also configured to blow air to the adsorbent 3. May be.

Next, the operation of the present apparatus when the engine is cold started will be described with reference to the flowchart of FIG. Step 401
After the ignition switch is turned on,
In step 402, it is determined whether the engine is cold starting. If the engine is cold started, the cooling fan 6 is operated in step 403, and the engine is started in step 404. If the engine is not cold started, the process directly proceeds to step 404 to start the engine.

When the engine is cold, a large amount of unburned fuel particles (HC) are discharged from the exhaust port 11 immediately after the engine is started.
At this time, since the HC particles have a larger specific gravity than the exhaust gas,
It is linearly discharged by the inertial force at the time of discharge and enters the inside of the adsorbent 3 at the opposite position and is collected. At the same time, the cooling fan 6 cools the adsorbent 3 to keep its temperature low. After the complete explosion of the engine, the pressure in the adsorbent 3 rises, so that the gas flow does not enter the adsorbent 5, and the temperature rise is continuously suppressed by the action of the cooling fan 6. The HC thus collected is reliably retained by the adsorbent 5 until the downstream catalyst 5 reaches the activation temperature, and HC is not released to the atmosphere without being purified.

After the engine is started, the temperature of the catalyst 5 is detected by the temperature sensor 51 in step 405, and it is determined whether or not the temperature is higher than the activation temperature (for example, 400 ° C.). While the temperature of the catalyst 5 is below the activation temperature, the operation of the cooling fan 6 is continued, and when the temperature exceeds the activation temperature, the cooling fan 6 is stopped (step 406). After that, the adsorbent 3 quickly rises in temperature to start desorption of HC, but since the catalyst 5 has reached the activation temperature, HC is surely purified.

Next, the operation of this apparatus under high load is shown in FIG.
This will be described with reference to the flowchart of FIG. In step 501,
The temperature of the adsorbent 3 is detected by the temperature sensor 35, and the temperature T ₁ at which the pore structure of the adsorbent may be destroyed is detected.
When the temperature exceeds (generally about 700 ° C.), the cooling fan 6 is operated in step 502. Then step 50
3 Temperature Temperature of adsorbent 3 is less than T ₁ by T ₂ (e.g. 6
When the temperature of the cooling fan 6 falls below about 100 ° C., the cooling fan 6 is stopped in step 504. Here, the difference in temperature between T ₁ and T ₂ is that the cooling fan 6 is frequently turned on near T ₁ .
This is because a hysteresis is provided so that OFF is not repeated.

As described above, in this embodiment, by providing the cooling fan 6, the temperature rise of the adsorbent 3 can be suppressed, and the adsorption efficiency of HC at the time of engine start can be greatly improved. it can. Further, the pore structure of the adsorbent 3 is prevented from being destroyed when the load is high. Further, in this embodiment, since the cooling fins 34 are provided on the outer wall of the adsorbent 3, the heat dissipation effect of the adsorbent 3 is promoted and the cooling effect of the cooling fan 6 can be more effectively exhibited.

FIG. 6 shows a second embodiment of the present invention. In this embodiment, instead of the cooling fan 6 of the first embodiment, a flow path 21 for secondary air is provided along the outer circumference and the back surface of the adsorbent 3. An introduction path 22 for introducing secondary air is connected to the upper part of the flow path 21, and the flow rate thereof is adjusted by an air pump 23. A secondary air outlet passage 24 is connected to a lower portion of the flow passage 21, and an end portion thereof is open to the exhaust pipe 4 upstream of the catalyst 5. Further, a valve 25 for switching between introducing the secondary air into the catalyst 5 and opening it to the atmosphere is provided in the middle of the outlet passage 24. The operations of the air pump 23 and the valve 25 are controlled by the control circuit 7. The other structure is the same as that of the first embodiment. Further, the O ₂ concentration in the exhaust pipe 4 is detected by an O ₂ sensor (not shown) by a known O ₂ feedback control system, and the air-fuel ratio can be feedback-controlled.

The operation of the above apparatus will be described with reference to the flow chart of FIG. After the ignition is turned on (step 70
1), it is determined whether the engine is cold starting (step 702), and if it is cold starting, step 703.
Then, the valve 25 is switched so that the secondary air is introduced into the catalyst 5. Then, the secondary air amount corresponding to the increase in the fuel injection amount at the time of starting, which is increased / decreased by the engine water temperature, is supplied by the air pump 23 to the outer periphery of the adsorbent 3 and the catalyst
(Step 704). This secondary air is the catalyst 5
This is for making the gas flowing into the lean state and causing an oxidation reaction at an early stage. Next, at step 705, the engine is started.

At this time, HC in the exhaust gas exhausted from the exhaust port 11 collides with the adsorbent 3 facing it by an inertial force and is collected. On the other hand, the secondary air flowing through the flow path 21 promotes heat dissipation of the adsorbent 3 and suppresses its temperature rise. Thus, until the downstream catalyst 5 reaches the activation temperature, H
Retains C securely and prevents unpurified HC from being released.

Thereafter, at step 706, the temperature sensor 51
It is determined whether the catalyst 5 temperature is equal to or higher than the activation temperature.
When the temperature of the catalyst 5 reaches the activation temperature, the above-mentioned known O ₂
It is determined whether or not the area is in which feedback control is performed (step 707). This is usually determined from the engine water temperature and the like. When the O ₂ feedback region is reached, the air pump 23 is turned off in step 708, and step 709
Starts the O ₂ feedback control. After that, the adsorbent 3 gradually rises in temperature due to heat transfer from the exhaust gas, and begins to desorb the collected HC. The desorbed HC gradually becomes the exhaust pipe 4
And is purified by the catalyst 5. It should be noted that even if the air-fuel ratio of the exhaust gas flowing into the catalyst 5 changes due to the desorbed HC, the change is gradual, and since the O ₂ sensor is usually attached to the exhaust gas collecting portion downstream of the adsorbent 3, ₂ Feedback control is sufficient.

When the load is high, as shown in FIG.
In 01, when the temperature of the adsorbent 3 exceeds the temperature T ₁ (generally about 700 ° C.) at which the pore structure of the adsorbent may be destroyed, in step 802, the valve 25 is made to communicate with secondary air to the atmosphere. The air pump 23 is turned on in step 803. Then, in step 804, if the temperature of the adsorbent 3 falls below a temperature T ₂ (eg, about 600 ° C.) lower than T ₁ , the air pump 23 is operated in step 805.
To stop.

As described above, according to this embodiment as well, it is possible to suppress the temperature rise of the adsorbent 3 at the time of engine start and improve the adsorption efficiency. Further, it prevents the temperature of the adsorbent 3 from excessively rising under a high load and destroying the pore structure of the adsorbent. Further, in this embodiment, the secondary air used for cooling the adsorbent 3 is introduced upstream of the catalyst 5 to adjust the air-fuel ratio of the exhaust gas, so that the purification performance of the catalyst 5 can be further improved. Further, if the cooling fins 54 used in the first embodiment are provided on the inner wall of the secondary air flow passage 21 in the configuration of the present embodiment, it is possible to further improve the cooling efficiency of the adsorbent 3.

FIG. 9 shows a third embodiment of the present invention. In this embodiment, an air injector 8 that opens to the wall of the exhaust manifold 2 below the exhaust port 11 is provided, and the secondary air introduced from the nozzle 81 at the tip of the air injector 8 is ejected toward the front surface of the adsorbent 3 that faces it. It is done like this. The details are shown in FIGS. 10 (A) and 10 (B). The air injector 8 has an exhaust port 11 communicating with each cylinder of the engine.
And a delivery pipe 82 for distributing air to each nozzle 81 (FIG. 10 (B)). A slit 811 extending in the left-right direction in the drawing is formed at the tip of each nozzle 81.
Secondary air is blown out from No. 1. The ejection angle of the nozzle 81 is set so that the angle θ with the exhaust pipe 4 is 90 ° or less (FIG. 10 (A)). The air injector 8 is provided with 2 by the air pump 83.
Secondary air is introduced (FIG. 9), and the operation of the air pump 83 is controlled by the control circuit 7. The other basic configuration is the same as that of each of the above embodiments.

The operation of the above apparatus will be described with reference to the flowchart of FIG. After the ignition is turned on (step 110
1) It is determined whether the engine is cold starting (step 1102). Step 1 if the engine is cold started
At 103, the air pump 83 is turned on, and a secondary air amount corresponding to an increase in the injection amount at the time of start-up, which is increased / decreased by the engine water temperature, is sent to the air injector 8 and is ejected toward the front surface of the adsorbent 3. Next, step 110
Start the engine at 4.

As shown in FIG. 12 (A), at the time of cold start of the engine, the HC discharged from the exhaust port 11 and having a relatively large particle size is adsorbed by the adsorbent 3 that opposes due to its inertia.
Is collided with and collected. However, H, which has a relatively small particle size
C may flow into the exhaust pipe 3 along with the flow of exhaust gas. On the other hand, in the configuration of the present embodiment shown in FIG. 12 (B), HC having a relatively small particle size also collides with the adsorbent 3 while riding on the flow of secondary air ejected from the air injector 8, It can be collected and greatly improves the adsorption efficiency. Further, even after the complete explosion of the engine, there is also an effect of suppressing the temperature rise of the adsorbent 3 by continuously introducing the secondary air, so that the collected HC is surely retained in the adsorbent 3 and remains unpurified. Prevent it from being discharged.

Then, in step 1105, the temperature sensor 5
It is determined by 1 whether the temperature of the catalyst 5 is equal to or higher than the activation temperature. When the temperature of the catalyst 5 reaches the activation temperature, it is judged whether or not it is in the above-mentioned O ₂ feedback control region (step 1106). When you reach the O ₂ feedback area,
In step 1107, the air pump 83 is turned off, and in step 1108 the O ₂ feedback control is started. After that, the adsorbent 3 gradually rises in temperature due to heat transfer from the exhaust gas, and begins to desorb the collected HC. The desorbed HC gradually flows out to the exhaust pipe 4 and is purified by the catalyst 5.

FIG. 13 shows a fourth embodiment of the present invention. In this embodiment, an air chamber 36 is provided in the exhaust manifold 2 behind the adsorbent 3 so that the secondary air is introduced by the air pump 9. The adsorbent 3 has openings at both ends so that secondary air can be introduced into the adsorbent 3 from the air chamber 36. On the other hand, the secondary air introduced from the air pump 9 is branched midway to form a flow path 91 for introducing the secondary air upstream of the catalyst 5, and at the branch point, the secondary air is introduced into the air chamber 36 and the flow. A valve 92 for switching to the passage 91 is provided. The operation of the air pump 9 and the valve 91 is controlled by the control circuit 7, and
An O ₂ sensor 41 used for known O ₂ feedback control is provided upstream of the catalyst 5. The other basic configuration is the same as that of each of the above embodiments.

The operation of the above apparatus will be described with reference to the flow chart of FIG. After the ignition is turned on (step 140
1) It is determined whether the engine is cold starting (step 1402). Step 1 if the engine is cold started
In 403, the valve 92 is switched so that the secondary air is directly introduced into the catalyst 5, and in step 1404, the secondary air amount having a constant ratio to the intake air amount is introduced into the catalyst 5 by the air pump 9. (FIG. 15 (A)). At this time, by introducing the secondary air, the lean exhaust gas is sent to the catalyst 5 immediately after the engine is started, thereby playing a role of starting the oxidation reaction early. Next, in step 1405, the engine is started.

When the engine is started, the HC discharged from the exhaust port 11 collides with the adsorbent 3 facing the HC and is collected.
After the engine complete explosion, no gas flow occurs in the adsorbent 3, so that the temperature rise is suppressed and the HC is retained in the adsorbent 3. Then, in step 1406, the catalyst 5 is detected by the temperature sensor 51.
Determine whether the temperature is above the activation temperature. When the temperature of the catalyst 5 reaches the activation temperature, it is judged whether or not it is in the region where the O ₂ feedback control is performed (step 1407). When the O ₂ feedback region is reached (step 1408), the valve 92 is switched in step 1409 so that the secondary air is introduced into the air chamber 36 behind the adsorbent 3. At this time, the secondary air flows through the inside of the adsorbent 3 from the air chamber 36 and flows out to the exhaust pipe 4 from the front surface of the adsorbent 5 as shown in FIG. 15 (B). Since the temperature of the adsorbent 3 has reached the desorption temperature of HC (usually about 100 ° C.), the desorbed HC existing inside the adsorbent 3 is purged together with the secondary air and purified by the downstream catalyst 5. .

Here, the amount of secondary air is sufficiently smaller than the amount of exhaust gas, and the amount of heat given to the adsorbent 3 by the exhaust gas is larger than the amount of heat transferred from the adsorbent 3 by the secondary air. 3 The temperature rises gradually. After that, when the temperature of the adsorbent 3 reaches a temperature at which almost no HC can be adsorbed in step 1410, that is, the desorption completion temperature (generally about 400 ° C.), the air pump 9 is turned off in step 1411 and the process ends.

According to this embodiment, by circulating the secondary air in the adsorbent 5, the desorption of HC in the adsorbent 3 can be promoted and the HC can be completely discharged to the outside of the adsorbent 3. Therefore, it is possible to prevent the HC remaining in the adsorbent 3 from being carbonized to cause clogging, and to prevent the adsorption performance from deteriorating.

[0037]

As described above, according to the present invention, the temperature rise of the adsorbent at the time of engine starting is suppressed, or HC having a relatively small particle size is reliably collected, and the adsorption efficiency of the adsorbent is improved. Can be significantly improved, and HC can be prevented from being discharged unpurified. Further, by suppressing the temperature rise of the adsorbent, it is possible to prevent the temperature of the adsorbent from being excessively increased and being damaged when the load is high. Further, after the adsorbent reaches the desorption temperature, the discharge of HC from the adsorbent can be promoted to prevent deterioration of the adsorbent.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional schematic side view of an exhaust gas purifying apparatus showing a first embodiment of the present invention.

FIG. 2 is an overall perspective view of an adsorbent used in the present invention.

FIG. 3 is a perspective view showing a state in which a cooling fin is provided on the adsorbent used in the present invention.

FIG. 4 is a flowchart illustrating an operation of the exhaust gas purifying apparatus according to the first embodiment when starting an engine.

FIG. 5 is a flowchart for explaining the operation of the exhaust gas purification device of the first embodiment during high load operation.

FIG. 6 is a partial cross-sectional schematic side view of an exhaust gas purifying apparatus showing a second embodiment of the present invention.

FIG. 7 is a flowchart illustrating an operation of the exhaust gas purifying apparatus according to the second embodiment when the engine is started.

FIG. 8 is a flowchart for explaining the operation of the exhaust gas purifying apparatus of the second embodiment during high load operation.

FIG. 9 is a partial cross-sectional schematic side view of an exhaust gas purifying apparatus showing a third embodiment of the present invention.

10 (A) is a partially enlarged sectional view of FIG. 9, and FIG. 10 (B) is a sectional view taken along line BB of FIG. 10 (A).

FIG. 11 is a flowchart for explaining the operation of the exhaust gas purification device of the third embodiment.

12 (A) and 12 (B) are partially enlarged cross-sectional views of an exhaust gas purification device for explaining the operation of the exhaust gas purification device of the third embodiment.

FIG. 13 is a schematic side view of a partial cross section of an exhaust gas purifying apparatus showing a fourth embodiment of the present invention.

FIG. 14 is a flowchart for explaining the operation of the exhaust gas purification device of the fourth embodiment.

15 (A) and 15 (B) are partially enlarged cross-sectional views of an exhaust gas purifying apparatus for explaining the operation of the exhaust gas purifying apparatus of the fourth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 engine (internal combustion engine) 11 exhaust port 2 exhaust manifold 21 secondary air flow path 23 air pump 3 adsorbent 35 temperature sensor 36 air chamber 4 exhaust pipe (exhaust passage) 5 catalytic converter 51 temperature sensor 6 cooling fan (cooling means) 7 Control circuit (control means) 8 Air injector 83 Air pump 9 Air pump

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location F01N 3/32 301 Z F01P 5/06 504 Z F02D 45/00 314 R (72) Inventor Yoshinaga Yu Nishio, Aichi prefecture 14 Iwatani, Shimohakaku-cho, Ichi, Japan, Japan Automotive Parts Research Institute

Claims (5)

[Claims] 1. An adsorbent for adsorbing unburned components in exhaust gas discharged from the exhaust port is fixed at a position facing the exhaust port in an exhaust manifold communicating with an exhaust port of an internal combustion engine, and In the exhaust passage downstream of the exhaust manifold, an exhaust gas purifying device having a catalyst for purifying exhaust gas, cooling means for air-cooling the adsorbent,
Temperature sensors provided in the vicinity of the adsorbent and the catalyst, respectively, based on the detection signals from these temperature sensors,
An exhaust gas purifying apparatus comprising: a control unit that operates the cooling unit before the catalyst temperature reaches the activation temperature or when the adsorbent temperature exceeds a certain temperature. 2. The exhaust gas purifying apparatus according to claim 1, wherein the cooling means is a cooling fan disposed behind the adsorbent. 3. The cooling means comprises a secondary air flow path formed along the outer wall of the adsorbent, and an air pump for adjusting the amount of secondary air introduced into the flow path. Exhaust gas purification device. 4. An adsorbent for adsorbing unburned components in exhaust gas discharged from the exhaust port is fixed at a position facing the exhaust port in an exhaust manifold communicating with an exhaust port of an internal combustion engine, and An exhaust gas purifying device in which a catalyst for purifying exhaust gas is disposed in an exhaust passage downstream of an exhaust manifold, and the secondary air is jetted toward the adsorbent facing the adsorbent, which is provided below the exhaust port. Exhaust gas purification, which is provided with an air injector, a temperature sensor provided in the vicinity of the catalyst, and control means for operating the air injector until the catalyst temperature detected by the temperature sensor reaches an activation temperature. apparatus. 5. An adsorbent for adsorbing unburned components in exhaust gas discharged from the exhaust port is fixed at a position facing the exhaust port in an exhaust manifold communicating with an exhaust port of an internal combustion engine, and An exhaust gas purifying device having an exhaust gas purifying catalyst disposed in an exhaust passage downstream of an exhaust manifold, the air chamber being located behind the adsorbent and communicating with the inside of the adsorbent, and the air chamber An air pump for introducing secondary air, a temperature sensor provided near the catalyst,
The air pump is operated when the catalyst temperature detected by the temperature sensor becomes equal to or higher than the activation temperature, and a control means for introducing secondary air into the adsorbent from the air chamber is provided. Exhaust gas purification device.