WO2002042625A1

WO2002042625A1 - Exhaust emission control device of internal combustion engine and control device for car

Info

Publication number: WO2002042625A1
Application number: PCT/JP2000/008352
Authority: WO
Inventors: Toshio Manaka
Original assignee: Hitachi, Ltd.
Priority date: 2000-11-27
Filing date: 2000-11-27
Publication date: 2002-05-30
Also published as: JPWO2002042625A1

Abstract

An exhaust emission control device of internal combustion engine having a simple exhaust emission treatment device structure and capable of efficiently purifying HC within the adsborbing capability of HC adsorbent and a control device for car capable of preventing a drivability from being impaired largely, wherein the adsorbent comprises an adsborbing zone adsorbing unburned hydrocarbon and a desorbing zone allowing the unburned hydrocarbon adsorbed to be desorbed, detects whether a catalyst is in the activated state or not and, when the catalyst is not in the activated state, the output or torque of an engine is regulated so that the temperature of the adsorbent can be maintained in the adsorbing zone until the catalyst reaches the activated state so as to achieve the activated state, whereby, because the adsorbent and exhaust gas treating catalyst is provided in an exhaust gas flow path of the engine, the unburned hydrocarbon contained in the exhaust gas can be adsorbed temporarily to the adsorbent.

Description

Exhaust purification device for internal combustion engine and control device for automobile

Technical field

The present invention relates to an exhaust gas purification device for an internal combustion engine and a control device for a vehicle using the internal combustion engine as a drive source, and more particularly to an exhaust gas purification device for a gasoline engine equipped with an exhaust gas purification device using an exhaust gas treatment catalyst and this internal combustion engine. It relates to a control device for a vehicle driven by an engine. Background art

Carbon monoxide (CO), hydrocarbons (HC: hydrocarbons), nitrogen oxides (NOx), etc., contained in exhaust gas emitted from internal combustion engines of automobiles and the like are air pollutants. So far, great efforts have been made to reduce these emissions, and in addition to reducing the amount generated by improving the combustion method of the internal combustion engine, a method for purifying the exhaust gas using a catalyst etc. has been developed. Has been progressing and has achieved steady results. For gasoline-powered vehicles, the mainstream method is to use a three-way catalyst, Pt or Rh, as the main component of the activity, and simultaneously oxidize HC and CO and reduce NOX. By the way, due to its characteristics, the three-way catalyst effectively acts on and purifies the exhaust gas generated by burning near the theoretical air-fuel ratio called a window. However, the purification process had not been completed until the temperature of the three-way catalyst reached an activity (light exhaust gas can be purified) (light-off temperature, about 300 ° C).

Therefore, a method of maintaining the three-way catalyst at a temperature higher than the activation temperature by using a battery as a power source is disclosed in, for example, Japanese Patent Application Laid-Open No. H10-2808028. It is disclosed in Japanese Patent Application Publication No. 104448. However, the three-way catalyst It is necessary to consume and heat the battery until it is activated, and it is difficult to prevent unburned hydrocarbons from being released into the atmosphere before activation.

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Until the three-way catalyst is activated during the start-up operation, the exhausted unburned hydrocarbons are temporarily adsorbed, and when the temperature reaches a temperature at which the three-way catalyst can reach the light-off temperature, Research and development of HC adsorption catalysts that desorb adsorbed unburned hydrocarbons (hereinafter referred to as "HC") are being actively conducted.

For example, the Challenge of the Japan Society of Automotive Engineers, Academic Lecture Preprint, No. 19-00, The Cleanest Car—Second Report (20005188), a coaxial bypass HC adsorption system was adopted, Close the valve, introduce exhaust gas into the HC adsorbent on the outer cylinder to adsorb HC, and then activate the three-way catalyst.Open the two-way valve and introduce the desorbed HC into the three-way catalyst for purification. The processing is performed. This system is complicated and expensive because it is composed of a coaxial bypass passage and a two-way valve. Also, depending on the operation state at the time of starting the cold, the amount of HC in the exhaust gas is large, and the HC adsorbent reaches the limit of the adsorption capacity before the three-way catalyst is activated, and HC is released to the atmosphere as it is. There is a possibility.

In addition, the two-stage HC trap catalyst system is used for the zero emission technology (20005238) of the gasoline engine of the Japan Society of Automotive Engineers of Japan. This HC trap catalyst is a composite of the exhaust treatment function and the HC adsorbent. This system has a two-stage configuration (the HC trap and three-way catalyst hybrid structure are two-stage in the series) in order to increase the efficiency of purification. As with the previous example, this system is also complicated and expensive, and the HC adsorbent may reach its adsorption capacity before the three-way catalyst is activated, and HC may be released to the atmosphere as it is. There is also.

On the other hand, in order to maintain the capacity of the HC adsorbent, it is necessary to desorb the adsorbed HC in preparation for the next start-up operation. For example, Japanese Patent Application Laid-Open No. 5-149131 discloses that an exhaust pipe is provided with an HC adsorbent, a three-way catalyst, and a heat exchanger, and uses heat of exhaust gas. The temperature control for desorption of HC is proposed. Since this method uses a heat exchanger, the structure of the exhaust pipe is complicated and expensive, and no consideration is given to the adsorption capacity of the HC adsorbent during start-up operation.

Similarly, in Japanese Patent Application Laid-Open No. 2000-88837, if the amount of HC adsorbed by the adsorbent is determined to be a predetermined amount, the adsorbed HC is released, and the three-way catalyst is activated at the activation temperature. It is disclosed that the operation of the engine be extended until the temperature of the engine is reached. Even with this method, no consideration is given to the adsorbing capacity of the HC adsorbent during the start-up operation.On the other hand, when considering the start of automobile operation, acceleration operation and other drivers' intentions from the start of the engine are considered. It is desirable to be able to shift to the driving state quickly and smoothly, and it is not preferable to make the driver of the vehicle feel shock or insufficient output in order to purify the exhaust gas. Disclosure of the invention

SUMMARY OF THE INVENTION An object of the present invention is to provide an exhaust gas purification apparatus for an internal combustion engine that has a simple structure of an exhaust treatment apparatus and that can efficiently purify HC in consideration of the adsorption capacity of an HC adsorbent, in view of the above-mentioned problems of the prior art. An object of the present invention is to provide an apparatus and a purification method.

It is another object of the present invention to provide a control device and a control method for an automobile, which can efficiently purify HC and that do not greatly impair drivability.

The above object can be solved by the following apparatus or method of the present invention. A feature of the present invention is that an adsorbent and a catalyst for exhaust gas treatment are provided in an exhaust gas flow path of an engine and are contained in exhaust gas. In the exhaust gas purifying apparatus for an internal combustion engine for temporarily adsorbing unburned hydrocarbons with the adsorbent, the adsorbent includes an adsorption zone for adsorbing unburned hydrocarbons, and a desorption zone for desorbing the adsorbed unburned hydrocarbons. A separation zone for detecting whether or not the catalyst is in an activated state. When the catalyst is not in an activated state, the temperature of the adsorbent is maintained until the catalyst reaches an activated state. The adsorption zone Another feature of the present invention is to adjust the output or the torque of the engine so as to maintain the exhaust gas in the exhaust gas passage of the engine. An exhaust gas purification device for an internal combustion engine that temporarily adsorbs unburned hydrocarbons contained in the adsorbent, wherein the adsorbent comprises: an adsorption zone for adsorbing unburned hydrocarbons; and an adsorbent zone for adsorbing the unburned hydrocarbons. A desorption zone for desorption, detecting whether the catalyst is in an activated state, and when the catalyst is not in an activated state, until the catalyst reaches an activated state, The engine output or torque is adjusted to maintain the temperature of the adsorbent in the adsorption zone, and the net output of the engine is varied by changing the load on the generator to offset the load adjustment. To the same level It is to.

One aspect of the present invention is a temperature region where HC is adsorbed in an exhaust gas flow path of an engine (adsorption zone) and a temperature region which is higher than the adsorption zone and in which adsorbed HC is desorbed (desorption region). An adsorbent having a separation zone) and a catalyst for treating exhaust gas are arranged. Until the catalyst reaches a temperature at which the catalyst is activated, HC contained in the exhaust gas is temporarily adsorbed by the adsorbent, and an HC adsorption zone is provided. Adjust the engine load and intake air volume so that the temperature does not exceed. Thereafter, when the temperature of the catalyst is activated, the engine load and the amount of intake air are increased, and the temperature is controlled so as to reach the HC desorption zone temperature. Can be purified.

When the engine load and intake air volume are adjusted so as not to exceed the HC adsorption zone temperature, the final output (driving force) of the vehicle is not changed, so the engine torque and output fluctuations are caused by the generator and high-power output provided in the engine. It can be corrected by the generator and driving mode of the vehicle. The correction may be made by changing the ignition timing of the engine or the EGR rate.

According to the present invention, HC adsorbed by the HC adsorbent 18 at the time of cooling is desorbed after the downstream ternary catalyst is activated, so that HC at the time of starting the cold can be significantly reduced. In addition, in the HC adsorbent temperature control by adjusting the engine output, the engine output fluctuation during control is corrected by the generator and the driving motor, so that the driver of the car does not feel the output or torque fluctuation. Hazardous emissions (unburned hydrocarbons) can be significantly reduced while maintaining smooth operation. Also, by performing regeneration treatment of the HC adsorbent, it is possible to always maintain the new performance (HC adsorption capacity).

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a system configuration diagram of an exhaust gas purification device for an internal combustion engine showing a typical embodiment of the present invention.

FIG. 2 is a flowchart showing a method for controlling the temperature of the HC adsorbent during HC adsorption in the embodiment of FIG.

FIG. 3 is a flowchart showing a control method of the HC adsorbent regeneration process at the time of regeneration in the embodiment of FIG.

FIG. 4 is an explanatory diagram of the adsorption, desorption, regeneration, and heat resistance limit zones of the HC adsorbent used in the embodiment of FIG.

FIG. 5 is an HC purification rate characteristic diagram of the three-way catalyst used in the embodiment of FIG. FIG. 6 is a diagram showing the relationship between the exhaust gas temperature, the catalyst temperature, and the intake air amount in the control of FIG.

FIG. 7 is a characteristic diagram of the engine output change amount used for the control of FIG. FIG. 8 is a diagram showing an example of actual measurement data of HC emissions at the time of cold start according to the embodiment of FIG.

FIG. 9 is a configuration diagram of an HC adsorbent and a three-way catalyst according to another embodiment of the present invention.

FIG. 10 is a configuration diagram of an HC adsorbent and a three-way catalyst according to another embodiment of the present invention. FIG. 11 is a configuration diagram of an HC adsorbent and a three-way catalyst according to another embodiment of the present invention.

FIG. 12 is a system configuration diagram of an exhaust gas purifying apparatus for an internal combustion engine according to another embodiment of the present invention.

FIG. 13 is a flowchart showing a method for controlling the temperature of the HC adsorbent during adsorption in the embodiment of FIG.

FIG. 14 is a flowchart showing a method for controlling the HC adsorbent regeneration process during regeneration in the embodiment of FIG.

FIG. 15 is a system configuration diagram of an exhaust gas purification device for an internal combustion engine in a hybrid electric vehicle as another embodiment of the present invention.

FIG. 16 is a flowchart showing a method of controlling the temperature of the HC adsorbent during adsorption in the embodiment of FIG.

FIG. 17 is a flowchart showing a method of controlling the HC adsorbent regeneration process during regeneration in the embodiment of FIG.

FIG. 18 is a system configuration diagram of an exhaust gas purification device for an internal combustion engine in a simplified hybrid electric vehicle as another embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is an overall system configuration including an exhaust gas purification device for an internal combustion engine according to an embodiment of the present invention.

The internal combustion engine according to this embodiment includes a multi-cylinder engine 4 connected to an intake system, an exhaust system and an engine control unit (ECU) 25. The intake system includes an air flow sensor 12 provided in the intake passage downstream of the air cleaner 1, a throttle valve 3 with a motor, an injector 5, an intake temperature sensor 19, and the like. Injection time 5 is supplied with fuel from fuel tank 13 by fuel pump 12. Also, a multi-cylinder engine 4 with a spark plug 6 A knock sensor 26 and a water temperature sensor 28 are provided.

The exhaust system has a three-way catalyst 17 and an HC adsorbent 18 provided in an exhaust pipe 11 of the engine 4. The three-way catalyst 17 is provided with a catalyst for treating exhaust gas. The HC adsorbent 18 is composed of a temperature region (hereinafter referred to as an “adsorption zone”) that adsorbs unburned hydrocarbons in the exhaust gas passage of the engine and an unburned hydrocarbon adsorbed in a temperature region higher than the adsorption zone. It has a desorption temperature range (hereinafter referred to as "desorption zone"). Instead of arranging the three-way catalyst 17 and the HC adsorbent 18 in a series, the adsorbent may be combined with a catalyst function for exhaust gas treatment. The exhaust system further has an adsorbent oxygen concentration sensor (or A / F sensor) 19, an exhaust gas temperature sensor 20, an exhaust gas temperature sensor 21, and an exhaust gas temperature sensor 22. Reference numeral 15 denotes an EGR valve that controls the EGR rate (exhaust gas recirculation rate; a part of exhaust gas is mixed with intake air).

The ECU 25 is composed of an I / O LSI as an input / output interface, an arithmetic processing unit ΜΡ, a storage device RAM storing a large number of control programs, R0M, a timer counter, and the like. In addition to the signals detected by the above sensors, the ECU 25 includes the amount of depression of the accelerator pedal 7 detected by the load sensor 18 and the number of revolutions and rotations of the engine detected by the crank angle sensor 29. The corner signal is also entered. The control program of the ECU 25 includes a program for executing the H C adsorbent temperature control function 250 described below.

Reference numeral 51 denotes a generator, which is driven by the engine 4 and charges the battery 38 with its output. The rectifier and the power generation adjusting means 52 are controlled by the ECU 25 to adjust the output of the generator 51. A heater 23 is provided at the entrance of the three-way catalyst 17 so that electric power is supplied from a battery 38 via a switch 24 controlled by the ECU 25 so that the three-way catalyst 17 is activated quickly at the start. The three-way catalyst 17 is heated.

The internal combustion engine with the exhaust gas purification device having the above configuration operates as follows. First, the intake air to the engine is filtered by an air cleaner 11 and then measured by an air flow sensor 2, passes through a throttle valve 3 with a motor, and is further removed from the engine. The fuel is received from the fuel tank 5 and supplied to the engine 4 as a mixture. The air mouth sensor signal and other sensor signals are input to the ECU 25. The ECU 25 evaluates the operating state of the engine and the states of the HC adsorbent 18 and the three-way catalyst 17 to determine the operating air-fuel ratio, and controls the injection time of the injector 15 to control the fuel concentration of the air-fuel mixture. Set to a predetermined value.

The air-fuel mixture sucked into the cylinder 1 of the engine 4 is ignited by a spark plug 6 controlled by a signal from the ECU 25 and burns. The flue gas is led to the exhaust pipe 1.1. The exhaust pipe 11 is provided with an HC adsorbent 18. When the cold start is performed, HC is adsorbed by the HC adsorbent 18 until the temperature at which the three-way catalyst 17 is activated is reached. The temperature of the three-way catalyst 17 can be monitored by an estimated value calculated from the engine load, the amount of intake air, and the like. Alternatively, the activity of the three-way catalyst 17 may be determined by the purification rate 7? C by the exhaust sensors 21 and 21 instead of the temperature.

In the meantime, to ensure that the HC is adsorbed, the engine load and the HC adsorbent temperature must be kept below the maximum adsorbable temperature Tamax by the <3 11 25 11 温度 adsorbent temperature control function 250. The intake air amount Qa is adjusted. The temperature of the HC adsorbent is monitored by the exhaust gas sensor 22. Exhaust gas temperature Tex is reduced by reducing engine load L and intake air volume Qa, and as a result, HC adsorbent temperature is also reduced. The final load (torque) of the engine can be maintained at the same level by reducing the load (power generation) of the generator 51 as much as the engine load and intake air volume are reduced. There is no shortage. .

If the engine load L or the intake air amount Qa is increased to increase the temperature of the H C adsorption catalyst, increase the generator load (power generation amount) by the increased amount.

Next, the operation of the H C adsorbent temperature control function 250 of the ECU 25 will be described with reference to FIGS. FIG. 2 is a flowchart showing a method of controlling the temperature of the HC adsorbent during HC adsorption, and FIG. 3 is a flowchart showing a method of controlling the regeneration process of the HC adsorbent during regeneration.

First, in step 1002 of Fig. 2, the engine coolant temperature Tstar t is detected by the water temperature sensor 28. In step 103, the HC adsorbent inlet exhaust temperature Tex is detected. In step 104, the three-way catalyst temperature Teat is detected.

Figure 4 shows the relationship between the adsorption zone, desorption zone of the HC adsorbent 18, the regeneration zone for restoring the HC adsorbing capacity to the same level as that of a new product, and the heat-resistant zone where the adsorbent deteriorates and is damaged. In order to maintain the adsorption ability of the HC adsorbent 18, it is desirable to maintain the temperature of the HC adsorbent 18 at about the maximum adsorbable maximum temperature Tamax or lower. Conversely, in order to desorb HC and send it to the three-way catalyst 17, the temperature must be about Tamax or higher. Then, in order to regenerate the HC adsorbent 18 and restore the adsorption capacity to the same level as the new one, set the temperature to the regeneration zone, that is, Trmii! Must be maintained in the range of ~ Tng.

FIG. 5 shows the HC purification rate characteristics of the three-way catalyst 17 with respect to the temperature Teat. It can be seen that the HC adsorbent 18 has a sufficient purification rate at the maximum adsorbable temperature Tamax (> Tact). Tact indicates the three-way catalyst temperature at which sufficient purification efficiency can be obtained. At start-up, the three-way catalyst 17 is heated and controlled so as to exceed the activation temperature (light-off temperature) Tact by energizing the heater 23, and when the temperature exceeds this Tact, the heater 23 Power supply to 3 is stopped.

Therefore, it is determined in step 1005 of FIG. 2 whether the engine cooling water temperature Tstart at the start is equal to or lower than the predetermined temperature Tcold. Judge whether it is less than Tact. If YES, it is determined in step 1107 whether the HC adsorbent inlet exhaust gas temperature Tex is lower than the maximum HC adsorbable maximum temperature Tamax by a margin value or less. If YES, the engine output or torque is increased in step 108 to raise the temperature of the HC adsorbent. The engine intake air amount Qa may be increased by the throttle valve 3 with motor. FIG. 6 shows the exhaust gas temperature Tex at the inlet of the HC adsorbent 18 and the temperature of the three-way catalyst 17 with respect to the intake air amount Qa of the engine. The temperature can be increased by increasing the amount of intake air. At the same time, the engine output (load) also increases. For in-cylinder injection engines, increase the temperature by increasing the amount of fuel injected per cycle be able to.

FIG. 7 is a characteristic diagram of a change in engine output (or torque). The convergence time (response time) to the target temperature can be shortened by using a function of the target temperature deviation A Tex.

Next, the loads (power generation) of the generators 51 and 31 are increased in steps 100 and 9 in FIG. If the answer is NO in Step 107, the engine output or torque is reduced in Step 110. The engine intake air amount Qa may be reduced. In step 101, reduce the load (power generation) on generators 51 and 31. Since the heater 23 is provided at the entrance of the three-way catalyst 17, the generators 51 and 31 can be effectively used as loads even when the battery 38 has a large amount of stored power. If NO in step 1005, the engine cooling water temperature is warm, so go to ② (Fig. 3). If NO in step 106, release the temperature control of the HC adsorbent in step 102 and proceed to step ②.

In step 102 of FIG. 3, it is determined whether or not the HC adsorbent inlet exhaust gas temperature Tex is equal to or higher than the heat-resistant limit temperature Tng. If YES, the engine output or torque is reduced by mL in step 1021. The engine intake air amount Qa may be reduced. Further, the load (power generation) of the generators 51 and 31 is reduced in step 102.

If NO in step 1 0 2 0, it is determined in step 1 2 3 that the HC adsorbent inlet exhaust temperature Tex is equal to or higher than the maximum BC adsorbable temperature Tamax, and if YES, the HC adsorbent is It is determined whether the regeneration process has been completed.If NO, the engine output is set so that the HC adsorbent inlet exhaust temperature Tex falls within the range of the regeneration minimum temperature Train and the heat-resistant limit maximum temperature Tng for a predetermined time in step 1025. (Torque) to regenerate the HC adsorbent. If N0 in step 1023 or YES in step 1024, return to return.

FIG. 8 is a diagram showing an example of measured data of HC emissions at the time of cold start according to the embodiment of FIG. In the case of the conventional method, the HC adsorbent temperature rises with the running time, and HC adsorbed during cooling is desorbed before the three-way catalyst is activated. In addition, HC emissions increase. On the other hand, in the present invention, since the temperature of the HC adsorbent is controlled by the temperature, the increase during the desorption of HC is significantly suppressed.

Further, according to the present embodiment, the H C adsorbed by the H C adsorbent 18 during the cold operation is desorbed after the downstream three-way catalyst is activated, so that the H C at the start of the cold operation can be significantly reduced. In addition, in the HC adsorbent temperature control by adjusting the engine output, the engine output fluctuation during control is corrected by the generator and the driving motor, so that the driver of the vehicle does not feel shock, insufficient output, or torque fluctuation.

In order to detect the activated state (light-off temperature) of the three-way catalyst, instead of detecting the three-way catalyst temperature Tact, the HC purification rate 7? Shown in Fig. 5 was detected. The activation of the three-way catalyst may be determined when the HC purification rate reaches the predetermined value of 7 to c. Further, the activation of the three-way catalyst may be determined from the output signal waveforms of 02 arranged at the inlet and the outlet of the three-way catalyst.

FIG. 9 is a configuration diagram of an HC adsorbent and a three-way catalyst according to another embodiment of the present invention. In this embodiment, an example is shown in which the three-way catalyst downstream of the HC adsorbent is divided into 178 and 17B. The heat capacity is reduced by making it thinner, such as a three-way catalyst of 17 A, and it is improved so that it is activated quickly.

Similarly, the example shown in FIG. 10 is obtained by further reducing the diameter and thickness of the 17-A low-temperature catalyst, so that the heat capacity can be reduced and the catalyst can be quickly activated.

In the example shown in Fig. 11, the three-way catalyst 17A can be made small in a cone shape to reduce the heat capacity and activate quickly.

Next, FIG. 12 is a system configuration diagram of an exhaust gas purifying apparatus for an internal combustion engine according to another embodiment of the present invention. FIG. 13 is a flowchart showing a method for controlling the HC adsorbent temperature during adsorption in the embodiment of FIG. 12, and FIG. 14 is a flowchart showing a method for controlling the HC adsorbent temperature during regeneration. is there.

This embodiment is a case of so-called in-cylinder injection in which the injector 5 is provided in a cylinder of the internal combustion engine 4. In addition, instead of using the exhaust temperature sensor 29 shown in Fig. 1, the monitor for each temperature uses the engine load, engine speed, intake air amount Qa, vehicle speed, Estimation calculation is performed by using the characteristics shown in Fig. 6 due to overtime or the like.

In other words, in step 123 of FIG. 13, instead of detecting the HC adsorbent inlet exhaust gas temperature Tex, the ECU 25 estimates the ECU load based on the engine load, engine speed, intake air amount, vehicle speed, elapsed time after starting, etc. Obtain by calculation. Also, in step 124, the three-way catalyst temperature Teat is obtained by an estimation calculation. In addition, the ignition timing and injection timing are retarded so that the final engine output (torque) does not change in step 1209, and the EGR rate is increased by opening the valve 01 and the valve 01.

In the case of this embodiment, FIG. 2 If YES in step 10 ° 7, increase the injection amount per cycle to increase the temperature of the HC adsorbent in step 122 to increase the engine output or torque. Increase. In step 1209, to raise the HC adsorption catalyst temperature, the engine output (torque) is not changed by the amount of the engine load L, so that the ignition timing is retarded and the EGR rate is reduced by the EGR valve 15 As a result, the engine output will be reduced.

Next, if the answer is NO in Step 107, the injection amount per cycle is reduced in Step 122 to reduce the engine output or torque. Furthermore, it is determined whether the HC adsorbent inlet exhaust gas temperature Tex is equal to or higher than the heat-resistant limit temperature Tng in step 1020 of FIG. 14, and if YES, the injection amount per cycle is reduced in step 1021, and the engine Reduce output or torque.

Also in this embodiment, H C adsorbed by the H C adsorbent 18 at the time of cooling is desorbed after the downstream three-way catalyst is activated, so that H C at the time of starting the cooling can be significantly reduced. In addition, in the HC adsorbent temperature control by adjusting the engine output, the engine output fluctuation during control is corrected by the generator and the driving motor, so the driver of the vehicle may feel shock, insufficient output, or torque fluctuation. Do not let. Furthermore, by performing regeneration treatment of the HC adsorbent, it is possible to always maintain the new performance (HC adsorbing ability).

Regarding the temperature control of the HC adsorbent 18 and the regeneration treatment of the HC adsorbent, a part of the control method described in FIGS. 2 to 3 is applied to the apparatus of the embodiment in FIG. A part of the control method described in the embodiment of FIGS. 13 to 14 may be applied to the apparatus of the embodiment of FIG.

The exhaust gas purification device having the HC adsorbent temperature control function of the present invention can also be applied to a hybrid electric vehicle having a gasoline engine. In the case of a hybrid electric vehicle, the decrease in engine output can be compensated for by the driving mode.

FIG. 16 is a flowchart showing a method for controlling the temperature of the HC adsorbent at the time of HC adsorption in the embodiment of FIG. FIG. 17 is a flowchart showing a control method of the HC adsorbent regeneration process.

In FIG. 15, the hybrid electric vehicle has an engine 4 and a positive drive motor 33 as its driving sources. That is, the generator 31 is directly connected to the engine 4, and the driving motor 33 is further connected via the first electromagnetic clutch 32. The rotation of the driving motor 33 is transmitted to the axle of the vehicle via the second electromagnetic clutch 34, CVT 35. The output of the generator 31 is supplied to the battery 38 via the inverter 48 and the charger / discharger 49. On the other hand, power is supplied to the driving module 33 from the battery 38 via the charger / discharger 49 and the inverter 39. The hybrid vehicle includes an ECU 25, an inverter control unit 40, a battery control unit 41, a clutch, and a CVT control port unit 47. Each control unit is collectively controlled by a hybrid electric vehicle control unit 42.

In this embodiment, the HC adsorbent temperature control function 250 of the ECU 25 is configured to absorb engine output (torque) fluctuations for controlling the temperature of the HC adsorbent by the generator 31 and the driving module 33. , to correct.

That is, it is determined whether the HC adsorbent inlet exhaust gas temperature Tex is equal to or lower than the maximum HC adsorbable maximum temperature Tamax by a margin value in step 1107 of FIG. If YES, the engine output is increased to raise the temperature of the HC adsorbent in step 108. Or increase torque.

Next, in step 169, the loads (power generation) of the generator 31 and the drive motor 33 are increased. If the answer is NO in Step 1107, the engine output or torque is reduced by AL in Step 1100. The engine intake air amount Qa may be reduced. In step 1611, the loads (power generation) of the generator 31 and the drive motor 33 are reduced, and the decrease in engine output is corrected.

Also, it is determined whether the HC adsorbent inlet exhaust gas temperature Tex is equal to or higher than the heat-resistant limit temperature Tng in step 1020 of FIG. 17, and if YES, the engine output or the torque is reduced in step 1021. Further, in step 1622, the generator output 31 is corrected by the generator 31 and the drive module 33.

FIG. 18 is a system configuration diagram of an exhaust gas purification device for an internal combustion engine in a simplified hybrid electric vehicle as another embodiment of the present invention. In this embodiment, there is provided a motor generator 36 having a function of generating electricity by driving the engine and a function of assisting the driving of the engine. The exhaust gas purifying device and the control flow are the same as those of the embodiment described with reference to FIGS. 15 to 17. At step 1611 in Fig. 16, the engine output (torque) fluctuation for controlling the temperature of the HC adsorbent is absorbed and corrected by the generator 31. That is, the motor output generator 36 corrects the decrease in engine output. Further, in step 1622 of FIG. 17, the engine output reduction is corrected by the motor generator 36.

In each of the above-described embodiments, the three-way catalyst 17 and the HC adsorbent 18 are shown as being separated from each other. Instead, both the HC adsorbent and the catalyst for exhaust treatment are provided. It may be a composite catalyst.

According to the present invention, HC adsorbed by the HC adsorbent 18 at the time of cooling is desorbed after the downstream ternary catalyst is activated, so that HC at the time of starting the cold can be significantly reduced. In addition, in HC adsorbent temperature control by engine output adjustment, engine output fluctuations during control are corrected by generators and driving motors. I do not feel it. In this way, harmful exhaust gas (unburned hydrocarbons) can be significantly reduced while maintaining smooth operation. In addition, by performing the regeneration treatment of the HC adsorbent, it is possible to always maintain the new performance (HC adsorption capacity).

Claims

The scope of the claims

1. An exhaust gas purification apparatus for an internal combustion engine, which has an adsorbent and an exhaust gas treatment catalyst in an exhaust gas flow path of an engine and temporarily adsorbs the unburned hydrocarbons contained in exhaust gas to the adsorbent.

The adsorbent has an adsorption zone for adsorbing unburned hydrocarbons, and a desorption zone for desorbing the adsorbed unburned hydrocarbons,

Detecting whether the catalyst is in an activated state, and when the catalyst is not in an activated state, maintaining the temperature of the adsorbent in the adsorption zone until the catalyst reaches an activated state. The exhaust gas purifying apparatus for an internal combustion engine, wherein the output or the torque of the engine is adjusted as described above.

2. The engine according to claim 1, wherein the amount of intake air of the engine is adjusted so that the temperature of the adsorbent does not enter the desorption zone, and the engine is ignited so that fluctuations in engine output due to the adjustment of the amount of intake air are offset. An exhaust gas purification device for an internal combustion engine, characterized by changing the timing.

3. The method according to claim 1, wherein the intake air amount of the engine is adjusted so that the temperature of the adsorbent does not enter the desorption zone, and the engine output fluctuation due to the adjustment of the intake air amount is canceled. An exhaust purification device for an internal combustion engine, characterized in that the net output of the engine is maintained at the same level by changing the output.

4. The exhaust gas purification system for an internal combustion engine according to claim 1, wherein the engine output or the torque is adjusted so that the temperature becomes higher than a temperature at which the adsorbent can be regenerated after exceeding a temperature at which the catalyst functions. apparatus.

5. The engine according to claim 1, wherein the output or torque of the engine is adjusted so that the temperature of the adsorbent enters the regeneration zone, and the load of the generator is changed so as to offset the load adjustment. An exhaust gas purification device for an internal combustion engine, wherein the net output is maintained at the same level.

6. Having a generator driven by the engine, in the exhaust gas flow path of the engine A vehicle control device including an adsorbent and an exhaust gas treatment catalyst, and an exhaust purification device for temporarily absorbing unburned hydrocarbons contained in exhaust gas by the adsorbent.

Detecting whether the catalyst is in an activated state, and when the catalyst is not in an activated state, maintaining the temperature of the adsorbent in the adsorption zone until the catalyst reaches an activated state. Thus, by adjusting the output or torque of the engine and changing the load of the generator so as to offset the load adjustment, the net output of the engine is maintained at the same level. An automobile control device equipped with an exhaust gas purification device.

7. An engine, having a function of generating electricity by driving the engine and a function of assisting the driving of the engine; a generator having a function of generating electricity; and a battery charged by a power generation output based on the power generation function. A control device for a vehicle equipped with an exhaust gas purification device having an adsorbent and a catalyst for exhaust gas treatment in an exhaust gas passage of an engine, wherein the adsorbent comprises: an adsorption zone for adsorbing unburned hydrocarbons; A desorption zone for desorbing the adsorbed unburned hydrocarbon;

Detecting whether the catalyst is in the activated state, and when the catalyst is not in the activated state, maintaining the temperature of the adsorbent in the adsorption zone until the catalyst reaches the activated state. An exhaust gas control apparatus for an automobile, comprising: an exhaust gas purifying apparatus that adjusts an output or a torque of the engine so as to adjust the output or torque of the engine.

8. An engine, a generator driven by the engine, and a motor that assists driving of the engine or a motor that drives the vehicle instead of the engine, and has a power generation function and an engine driving assisted by the engine. A vehicle control device having an exhaust gas purification device having an evening function and having an adsorbent and an exhaust gas treatment catalyst in the exhaust gas flow path of the engine;

The adsorbent comprises: an adsorption zone for adsorbing unburned hydrocarbons; and the adsorbed unburned coal. A desorption zone for desorbing hydrogen hydride,

Detecting whether the catalyst is in an activated state, and when the catalyst is not in an activated state, maintaining the temperature of the adsorbent in the adsorption zone until the catalyst reaches an activated state. A control device for a vehicle having an exhaust emission control device, wherein the output or torque of the engine is adjusted as described above.

9. An exhaust gas purifying apparatus for an internal combustion engine, which has an adsorbent and an exhaust gas treatment catalyst in an exhaust gas flow path of an engine and temporarily adsorbs unburned hydrocarbons contained in exhaust gas to the adsorbent.

Detecting whether the catalyst is in an activated state, and when the catalyst is not in an activated state, maintaining the temperature of the adsorbent in the adsorption zone until the catalyst reaches an activated state. Thus, by adjusting the output or torque of the engine and changing the load of the generator so as to offset the load adjustment, the net output of the engine is maintained at the same level. An automotive control device equipped with an exhaust purification device.

10. It has a generator driven by the engine, has an adsorbent and a catalyst for exhaust gas treatment in the exhaust gas passage of the engine, and temporarily removes unburned hydrocarbons contained in the exhaust gas. A control device for an automobile having an exhaust purification device for adsorbing the adsorbent,

Detecting whether the catalyst is in an activated state, and when the catalyst is not in an activated state, maintaining the temperature of the adsorbent in the adsorption zone until the catalyst reaches an activated state. Thus, by adjusting the output or torque of the engine and changing the load of the generator so as to offset the load adjustment, the net output of the engine is maintained at the same level. Equipped with exhaust gas purification device Car control device.

11. An engine, a motor generator having a power generation function by driving the engine and a motor function for assisting engine driving, and a battery charged by a power generation output based on the power generation function, In a control device of a vehicle equipped with an exhaust gas purification device having an adsorbent and a catalyst for exhaust gas treatment in an exhaust gas flow path of an engine,

Detecting whether the catalyst is in an activated state, and when the catalyst is not in an activated state, maintaining the temperature of the adsorbent in the adsorption zone until the catalyst reaches an activated state. Thus, by adjusting the output or torque of the engine and changing the load of the generator so as to cancel the adjustment, or by changing the assist power of the motor generator, the net output of the engine is reduced. Exhaust gas purifier A vehicle control device equipped with an exhaust gas purifier that is maintained at the same level. 1 2. An engine, a generator driven by the engine, and a motor function for assisting the engine drive or a motor for driving the vehicle instead of the engine, and a power generation function by the engine drive and a motor function to assist the engine drive. A control device for an automobile, comprising: an exhaust gas purification device having an adsorbent and an exhaust gas treatment catalyst in an exhaust gas flow path of the engine.

The adsorbent has an adsorption zone for adsorbing unburned hydrocarbons, and a desorption zone for desorbing the adsorbed unburned carbon.

Detecting whether the catalyst is in an activated state, and when the catalyst is not in an activated state, maintaining the temperature of the adsorbent in the adsorption zone until the catalyst reaches an activated state. As described above, the output or torque of the engine is adjusted, and the load of the generator is changed so as to cancel the load adjustment, or the assist power of the motor is changed by changing the output of the motor. A control device for an automobile equipped with an exhaust gas purification device, characterized in that the net output is maintained at the same level.

13. The generator according to claim 9, wherein the output or torque of the engine is adjusted so that the temperature of the adsorbent is within the regeneration zone, and the load adjustment is offset. A control device for an automobile equipped with an exhaust emission control device, wherein the net output of the engine is maintained at the same level by changing the load.

14. The method according to claim 11, further comprising: a motor having a function of generating electricity by driving the engine and a function of assisting driving of the engine; and a battery charged by the power generation output. The output or torque of the engine is adjusted so that the engine enters the regeneration zone, and the net output of the engine is changed by changing the load on the generator so as to offset the load adjustment, or by changing the assist power of the motor. Control of vehicles equipped with exhaust emission control, characterized by maintaining the same level

15. The method according to claim 11, further comprising: a generator driven by the engine and a motor that assists in driving the engine or drives a vehicle instead of the engine. The engine output or torque is adjusted so as to enter the engine, and the net load of the engine is changed by changing the generator load so as to offset the load adjustment, or by changing the assist motor output in the above mode. A control device for an automobile equipped with an exhaust emission control device that maintains the output at the same level. .

16. In any one of claims 9 to 12, the amount of intake air of the engine is adjusted so that the temperature of the adsorbent enters the regeneration zone, and the engine output fluctuation due to the adjustment of the amount of intake air is offset. A vehicle control system equipped with an exhaust gas purifier that maintains the net output of the engine at the same level by changing the ignition timing of the engine and changing the EGR rate.

17. An internal combustion engine that has an adsorbent and an exhaust gas treatment catalyst in the exhaust gas passage of the engine, and temporarily adsorbs the unburned hydrocarbons contained in the exhaust gas to the adsorbent. In the control method of

Detecting whether the catalyst is in an activated state,

5 When the catalyst is not in the activated state, adjust the output or torque of the engine so as to maintain the temperature of the adsorbent in the adsorption zone until the catalyst reaches the activated state. A method for controlling an internal combustion engine.

18. Having a generator driven by the engine, having an adsorbent and a catalyst for exhaust gas treatment in the exhaust gas passage of the engine, and temporarily removing unburned hydrocarbons contained in the exhaust gas. A method for controlling an automobile having an exhaust purification device for adsorbing the adsorbent onto the vehicle,

Detecting whether the catalyst is in an activated state,

15 When the catalyst is not in the activated state, adjust the output or torque of the engine to maintain the temperature of the adsorbent in the adsorption zone until the catalyst reaches the activated state. A method for controlling an automobile having an exhaust emission control device, wherein the net output of the engine is maintained at the same level by changing the load of the generator so as to cancel the load adjustment.

20.19. An engine, a motor generator having a power generation function by driving the engine and a motor function to assist in driving the engine, and a battery charged by a power generation output based on the power generation function. A method for controlling an automobile, comprising: an exhaust gas purification device having an adsorbent and an exhaust gas treatment catalyst in an exhaust gas flow path of the engine.

25 The adsorbent has an adsorption zone for adsorbing unburned hydrocarbons, and a desorption zone for desorbing the adsorbed unburned hydrocarbons,

Detecting whether the catalyst is in an activated state, When the catalyst is not in the activated state, the output or torque of the engine is adjusted so that the temperature of the adsorbent is maintained in the adsorption zone until the catalyst reaches the activated state. An exhaust gas purifying apparatus, wherein the net output of the engine is maintained at the same level by changing the load of the generator so as to cancel Control method for a vehicle equipped with a device.