JP2000179331A - Exhaust-gas purifying apparatus of cylinder-resting engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust-gas purifying apparatus of a cylinder-resting engine which is capable of improving fuel consumption while maintaining capability of a catalyst in the case where respective exhaust systems are independently provided to an operating cylinder and a resting cylinder. SOLUTION: This exhaust-gas purifying apparatus of a cylinder-resting engine 1 for operating both an operating cylinder 3 and a resting cylinder 4 in an all-cylinder operating state, while resting the resting cylinder 4 in a cylinder resting state includes: an operating-cylinder exhaust system 6 for emitting an exhaust gas of the operating cylinder 3; a resting-cylinder exhaust system 9 provided independently of the operating- cylinder exhaust system 6 for emitting an exhaust gas of the resting cylinder 4; a resting-cylinder electric-heating catalyst 11 disposed in the resting-cylinder exhaust system 9; a determining means 20 for determining whether the cylinder-resting engine 1 is operated in the all-cylinder operating state or the cylinder resting state; and a heating control means 20 for controlling heating of the resting-cylinder electric- heating catalyst 11 by conducting electricity thereto when the determining means 20 has determined that the cylinder-resting engine 1 is operated in the cylinder resting state.

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 a cylinder-disabled engine which is operated by switching between an all-cylinder operation for operating an active cylinder and a deactivated cylinder and a deactivated cylinder operation for deactivating the deactivated cylinder.

[0002]

2. Description of the Related Art A cylinder deactivated engine is configured to deactivate a part of the cylinders, for example, at the time of low load operation.
It is intended to improve fuel efficiency.
No. 45 discloses this. The cylinder deactivated engine particularly relates to a valve mechanism configured to shift the deactivation timing of the intake valve and the exhaust valve for the purpose of, for example, preventing residual combustion gas in the deactivated cylinder. Further, purification of exhaust gas of an internal combustion engine is generally performed by a three-way catalyst disposed in an exhaust system. Further, in the case of a multi-cylinder engine, it is known that two or more exhaust systems are provided independently of each other in order to reduce output loss and noise due to exhaust resistance. In this case, a three-way catalyst is used. It is arranged for each exhaust system.

[0003]

However, in the cylinder deactivated engine, in order to obtain the above-described advantages of the multiple exhaust systems, for example, an exhaust system independent of each other is provided for the working cylinder group and the deactivated cylinder group, and When the three-way catalyst is arranged in the exhaust system, the following problem occurs. That is, the three-way catalyst needs to be maintained at an activation temperature or higher and activated to exhibit its catalytic performance. On the other hand, when the cylinder deactivated engine is in the cylinder deactivated operation, the exhaust gas is not discharged to the exhaust system of the deactivated cylinder group, so that the temperature of the three-way catalyst of the deactivated cylinder group may decrease and fall below the activation temperature. When returning to all-cylinder operation from this state,
Since the three-way catalyst cannot sufficiently exhibit catalytic performance, exhaust gas deteriorates. Such a problem is caused by, for example, intermittently operating the idle cylinder group even during the idle cylinder operation, thereby supplying exhaust gas to the three-way catalyst.
It can be eliminated. However, in that case, the idle cylinder group is operated in order to warm the three-way catalyst, which causes deterioration of fuel efficiency.

The present invention has been made to solve such a problem, and aims to achieve both improvement in fuel efficiency and maintenance of catalyst performance when an independent exhaust system is provided for an active cylinder and a deactivated cylinder. An object of the present invention is to provide an exhaust gas purification device for a cylinder deactivated engine that can be achieved.

[0005]

In order to achieve this object, the invention according to claim 1 of the present invention operates an operating cylinder and an idle cylinder during all-cylinder operation and simultaneously operates an idle cylinder during idle cylinder operation. An exhaust gas purifying apparatus for a deactivated cylinder deactivated engine, comprising: an operating cylinder-side exhaust system (an operating cylinder-side exhaust pipe 6 in the embodiment (hereinafter the same in this section)) that discharges exhaust gas of an operating cylinder; A resting cylinder side exhaust system (displacement cylinder side exhaust pipe 9) which is provided independently of the side exhaust system and discharges exhaust gas of the rest cylinder, and a rest cylinder side electric heating type disposed in the rest cylinder side exhaust system. A catalyst (electrically heated catalyst 11); determining means (ECU 20, step 1 in FIG. 2) for determining whether the cylinder deactivated engine is operating in all cylinder operation or cylinder deactivated operation; means Heating control means (ECU 20, step in FIG. 2) for controlling the heating of the deactivated cylinder-side electrically heated catalyst by energizing the deactivated cylinder-side electrically heated catalyst when it is determined that the engine is operating in the deactivated cylinder operation. 9)
And characterized in that:

According to the exhaust gas purifying apparatus of the cylinder deactivated engine, the deactivated cylinder side electrically heated catalyst is disposed in the deactivated cylinder side exhaust system provided independently of the operating cylinder side exhaust system, and the heating control is performed. The means controls heating by energizing the deactivated cylinder-side electrically heated catalyst when it is determined by the determining means that the engine is operating in the cylinder deactivated operation. As described above, the deactivated cylinder-side electrically heated catalyst is disposed in the deactivated cylinder-side exhaust system, and is heated during the deactivated cylinder operation to maintain the temperature at or above the activation temperature. The catalytic performance of the deactivated cylinder-side exhaust system can be immediately exhibited, and the exhaust gas discharged from the deactivated cylinder at that time can be appropriately purified. Also, unlike before,
Since it is not necessary to intermittently operate the stopped cylinder during the cylinder deactivated operation, the fuel efficiency can be improved accordingly.

Further, according to a second aspect of the present invention, in the exhaust gas purifying apparatus of the first aspect, the heating control means includes an all-cylinder operation continuation period (all-cylinder operation time t1) before shifting to the cylinder-stop operation.
The start timing (delay time tDEL) and time (energization time tEH) of energization of the deactivated cylinder-side electrically heated catalyst
C) and at least one of the voltage (energization voltage VEHC) is controlled.

Generally, the temperature of the deactivated cylinder-side electrically heated catalyst at the time of transition to the cylinder deactivated operation becomes higher as the exhaust gas is warmed by exhaust gas as the all cylinder operation continuation period before that is longer. It has become. As described above, the all-cylinder operation continuation period satisfactorily reflects the temperature of the deactivated cylinder-side electrically heated catalyst at the time of transition to the deactivated cylinder operation. Therefore,
By controlling at least one of the start timing, time, and voltage of energization to the inactive cylinder-side electrically heated catalyst in accordance with the all-cylinder operation continuation period, the inactive cylinder-side electrically heated catalyst can be configured with a simple and inexpensive configuration. Can be operated efficiently and appropriately. As a result, the life of the deactivated cylinder-side electrically heated catalyst can be prolonged, and the power supply for supplying power thereto, for example, the power consumption of the alternator and the engine load for driving the catalyst can be minimized, and as a result, fuel consumption can be reduced. Can be further improved.

According to a third aspect of the present invention, in the exhaust gas purifying apparatus of the first aspect, a temperature detecting means (catalyst temperature sensor 2) for detecting a temperature state of the deactivated cylinder-side electrically heated catalyst is provided.
1), and the heating control means repeatedly executes the energization and stop of the deactivated cylinder-side electrically heated catalyst in accordance with the temperature state detected by the temperature detection means (FIG. 1).
2 (steps 33, 35 to 37, and (c) in FIG. 13).

In this exhaust gas purifying apparatus, during the cylinder deactivated operation, while the actual temperature state of the deactivated cylinder-side electrically heated catalyst is monitored by the temperature detecting means, the energization and the stop are repeatedly executed in accordance with the monitoring. The idle cylinder side electrically heated catalyst can be operated more finely and appropriately.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a cylinder deactivated engine 1
1 shows a schematic configuration of an exhaust gas purification device 2 to which the present invention is applied.

A cylinder deactivated engine (hereinafter simply referred to as an “engine”) 1 is of a V-type six-cylinder type, and includes three working cylinders 3 and deactivated cylinders 4. The operating cylinder 3 is operated during both the full cylinder operation and the closed cylinder operation of the engine 1, while the stopped cylinder 4 is operated.
In the cylinder closing operation, the operation of the intake / exhaust valve is stopped by a valve operating mechanism (neither is shown) so that the operation is stopped.

The three working cylinders 3 are assembled into one working cylinder side exhaust pipe 6 (working cylinder side exhaust system) via an exhaust port (not shown) and an exhaust manifold 5. A three-way catalyst 7 is arranged in the middle of the side exhaust pipe 6. Similarly, the three non-operating cylinders 4 are assembled into one non-operating cylinder side exhaust pipe 9 (non-operating cylinder side exhaust system) via an exhaust port (not shown) and an exhaust manifold 8.
In the middle of the deactivated cylinder side exhaust pipe 9, a two-bed three-way catalyst 1 is provided.
0, 10 and an electrically heated catalyst (hereinafter referred to as “EHC”) 11 as a deactivated cylinder side electrically heated catalyst interposed therebetween. The EHC 11 has a catalyst carrier supporting a catalyst and an electrothermal heater (both not shown).
The catalyst of the EHC 11 and the three-way catalysts 10 and 10 on both sides thereof are activated early by burning the unburned components of the exhaust gas passing therethrough to raise the ambient temperature. The energization of the heater of the EHC 11 is controlled by an ECU 20 described later as a determination unit and a heating control unit. The electric power of the EHC 11 is supplied from an alternator (not shown) driven by the engine 1.

A communication pipe 12 is provided between the working cylinder exhaust pipe 6 just downstream of the three-way catalyst 7 and the idle cylinder side exhaust pipe 9 just upstream of the three-way catalyst 10. The communication pipe 12 is opened and closed by a shutoff valve 13. The shut-off valve 13 has a rotatable opening / closing plate 14 mounted in the deactivated cylinder side exhaust pipe 9 and an opening / closing plate 14 at one end.
, A valve casing 16 that slidably accommodates the other end of the plunger 15, and a pipe 17 that is provided in the middle of a pipe 17 that communicates with a valve chamber 16 a of the valve casing 16. It is composed of a solenoid 18 or the like which switches and communicates with the atmosphere and the intake pipe.

According to the shut-off valve 13 having the above-described configuration, the valve casing 16 can be operated while the solenoid 18 is demagnetized.
The intake pipe internal pressure Pb is introduced into the valve chamber 16a, and the plunger 15 is driven to the side opposite to the open / close plate 14,
The opening / closing plate 14 rotates counterclockwise in FIG. 1 to close the downstream end of the communication pipe 12 opening to the inactive cylinder side exhaust pipe 9 and open the inactive cylinder side exhaust pipe 9 (see FIG. 1). Solid line position). On the other hand, when the solenoid 18 is excited, the atmospheric pressure Pa is introduced into the valve chamber 16a of the valve casing 16, and the plunger 15 is driven toward the opening / closing plate 14, so that the opening / closing plate 14 rotates clockwise in FIG. Then, the communication pipe 12 is opened, and the deactivated cylinder-side exhaust pipe 9 is closed (the position indicated by the broken line in the figure). Excitation and demagnetization of the solenoid 18, that is, opening and closing of the shut-off valve 13, is controlled by an ECU 20, which will be described later.

The ECU 20 also receives a CRK signal, which is a pulse signal, and a TD output from a crank angle sensor (both not shown) as the crankshaft rotates.
The C signal is input. As for the CRK signal, one pulse is output at every predetermined crank angle.
The engine speed is determined based on the signal, and the vehicle speed v is further determined from the gear ratio at that time. Also, TD
The C signal is a signal that is output before the top dead center at the start of each intake stroke of the active cylinder 3 and the deactivated cylinder 4, and is used as a trigger signal when the ECU 20 executes a control process such as the EHC 11.

The ECU 20 is constituted by a microcomputer (all not shown) including a CPU, a RAM, a ROM, an input / output interface, and the like. The above-described CRK signal and TDC signal, and other parameter signals indicating the operating state of the engine 1 are input to the CPU after being subjected to A / D conversion and shaping by the input interface. The CPU responds to these input signals based on a control program or a table stored in the ROM.
In addition to determining whether to operate in the all-cylinder operation or the suspension operation, the EHC 11 and the shut-off valve 1 are operated as described later.
3 is determined, and a drive signal based on the result is
These operations are controlled by outputting through an output interface.

FIG. 2 is a block diagram showing a first embodiment of the present invention.
5 is a flowchart showing a control process of the EHC 11 and the shutoff valve 13 performed by the CU 20. This processing is performed in accordance with the all-cylinder operation time when the all-cylinder operation time as the all-cylinder operation continuation period from the start is relatively short.
This is for controlling the power supply time to the power supply. This program
It is executed in synchronization with the generation of the TDC signal.

In this process, first, step 1 (“S1”)
It is illustrated. The same applies to the following), it is determined whether or not the engine 1 is in the cylinder-stopped operation. This determination is made, for example, based on a cylinder deactivation flag that is set to “1” during cylinder deactivation. When the answer to step 1 is No, that is, when the engine 1 is operating in all cylinders, the solenoid 18 of the shut-off valve 13 is demagnetized to close the shut-off valve 13 (step 2). Thereby, the opening / closing plate 14 of the shutoff valve 13
However, by closing the communication pipe 12 and opening the deactivated cylinder side exhaust pipe 9 at the same time as being located at the solid line position in FIG.
The flow path of the exhaust gas from the idle cylinder 4 during the all-cylinder operation is secured. Next, in step 3, the energization of the EHC 11 is stopped, the EHC 11 is turned off, and the process ends.

On the other hand, when the answer to step 1 is Yes, that is, when the engine 1 is in cylinder-stop operation, the solenoid 1
The shut-off valve 13 is opened by exciting 8 (step 4). As a result, the opening / closing plate 14 is driven to the position shown by the broken line in FIG.
By opening the communication pipe 12, the upstream side of the three-way catalyst 10 of the idle cylinder side exhaust pipe 9 is communicated with the downstream side of the three-way catalyst 7 of the active cylinder side exhaust pipe 6. Therefore, in this state, the pulsation of the exhaust gas discharged from the working cylinder 3 and purified by the three-way catalyst 7 is supplied to the three-way catalyst 10 and the EHC 11 on the idle cylinder 4 side through the communication pipe 12.

Next, in step 5, it is determined whether or not the current loop is the first loop after the transition to the cylinder-stop operation, and if the answer is Yes, the total cylinder operation time from the start time t0 is determined. The energization time t2 to the EHC 11 is determined according to t1 (see FIG. 4) (step 6). This decision
For example, this is performed by reading out t2 corresponding to t1 from the t1-t2 table shown in FIG. This t1-
In the t2 table, the energization time t2 is the total cylinder operation time t1.
Is set linearly so that the longer the is, the shorter it is.
Next, the energization time t2 determined in this way is set in the energization timer and started (step 7).

Next, it is determined whether or not the current supply timer started in step 7 has timed out (step 8). At this point, immediately after the start of the energization timer, the answer is No.
The energization of C11 is started, the state is turned on, and the present process ends.

If the answer to step 5 is No, that is, if the current loop is the second or subsequent loop after the shift to the cylinder-stop operation, steps 6 and 7 are skipped and the routine proceeds to step 8. If the answer to step 8 is No, that is, if the energization timer has not timed out, the process proceeds to step 9 and the energization to the EHC 11 is continued, while the answer is Yes,
That is, when the energization time t2 has elapsed after the transition to the cylinder-stop operation, the process proceeds to step 3, where the energization to the EHC 11 is stopped, and the present process ends.

FIG. 4 is a time chart showing an operation example of the EHC 11 and the shut-off valve 13 when the above-described control processing is executed. As shown in FIG.
Between 0 and the all-cylinder operation time t1, the shut-off valve 13 is closed and the power supply to the EHC 11 is stopped.
During this time, the temperature TEHC of the EHC 11 gradually rises due to the supply of the exhaust gas from the idle cylinder 4.
Then, when the operating state shifts from the all-cylinder operation to the closed-cylinder operation (time t1), at the same time, the shutoff valve 13 is opened and the energization to the EHC 11 is started. By this energization, the temperature TEHC of the EHC 11 rises rapidly by heating its heater, and its activation temperature T
E (for example, 350 ° C.). The energization of the EHC 11 is continued during the energization time t2 by the timing of the energization timer, and then stopped (time t3).

As is apparent from the above operation, the temperature TEHC1 of the EHC 11 at the transition from the all-cylinder operation to the closed-cylinder operation t1 changes according to the all-cylinder operation time t1.
Tend to increase as the length increases. On the other hand, the energization time t2 to the EHC 11 is set to be shorter as the all-cylinder operation time t1 is longer as described above. Therefore, according to the present embodiment, the energization time t2 to the EHC 11 can be appropriately set according to the temperature state, and the EHC 11 can be activated early while efficiently and appropriately operating.

FIG. 5 is a circuit diagram showing a second embodiment of the present invention.
4 is a flowchart illustrating a control process of the HC and the shutoff valve. This process controls the energization voltage to the EHC 11 according to the all-cylinder operation time from the start.

In this process, similarly to the process of the first embodiment described above, it is first determined whether or not the engine 1 is in the cylinder-stopped operation (step 11).
The shutoff valve 13 is closed (step 12) and the EH
The power supply to C11 is stopped (step 13).

On the other hand, when it is determined in step 11 that cylinder operation is to be performed, the shut-off valve 13 is opened (step 14).
Thereafter, the energization voltage VEHC of the EHC 11 is determined according to the all-cylinder operation time t1 (step 15). FIG. 6 shows two examples of the t1-VEHC table used for this determination. In each of the tables, the energizing voltage VE is shown.
HC is set to be shorter when the all-cylinder operation time t1 is longer. In the table of (a), the all-cylinder operation time t1 is divided into two regions, and a small predetermined VEHCL is used as the energizing voltage VEHC in the region where t1 is long.
In the region where 1 is short, a larger predetermined VEHCH is set, and in the table of FIG.
C is set linearly with respect to t1. Then
The EHC 11 is determined by the energizing voltage VEHC determined in this manner.
Is supplied (step 16), and this process ends.

FIG. 7 is a time chart showing an operation example in the case where the above-described control processing is executed. From the time when the operation state shifts to the cylinder-stop operation (time t1), the energizing voltage VEHC is started.
Energization to the EHC 11 is continuously performed, whereby the temperature TEHC of the EHC 11 is reduced to its activation temperature TE.
Rise quickly until over. As described above, the energization voltage VEHC to the EHC 11 at this time is set to be shorter as the all-cylinder operation time t1 is longer, that is, as the temperature TEHC1 of the EHC 11 at the time of transition to the cylinder-stop operation tends to be lower. Have been. Therefore, in the present embodiment, the energization voltage VEHC to the EHC 11 can be appropriately set in accordance with the temperature state.
11 can be activated early while efficiently and appropriately operating it.

FIG. 8 is a circuit diagram showing a third embodiment of the present invention.
4 is a flowchart illustrating a control process of the HC and the shutoff valve. This process controls the start timing of energizing the EHC 11 after the shift to the cylinder-stop operation according to the vehicle speed of the vehicle equipped with the engine 1 when the all-cylinder operation time is relatively long.

In this processing, similarly to the processing in the above-described embodiment, it is first determined whether or not the engine 1 is in the cylinder-stopped operation (step 21). (Step 22) and the EHC 11
The power supply to the power supply is stopped (step 23). When it is determined in step 21 that cylinder operation is to be performed, the shut-off valve 13 is opened (step 24), and then in step 25, it is determined whether or not the current loop is the first loop after the shift to cylinder-in operation. Is determined, and if the answer is Yes, a delay time tDEL as a start timing of energization to the EHC 11 is determined according to the vehicle speed v (step 26). FIG.
Shows an example of a v-tDEL table used for this determination, and the delay time tDEL is set linearly so as to be shorter as the vehicle speed v is larger. this is,
After shifting to the cylinder-stop operation, the temperature TEHC of the EHC 11
This is because the higher the vehicle speed v is, the more the vehicle speed v tends to decrease. Next, the delay time tDEL determined in this way is set in a delay timer and started (step 2).
7).

After executing step 27, or when the answer to step 25 is No, it is determined whether or not the time of the delay timer has expired (step 28).
If this answer is No, that is, if the time of the delay timer has not expired, the process proceeds to step 23, where the energization stop state to the EHC 11 is continued, while the answer is Yes, that is, the delay time tDEL is When the time has elapsed, the process proceeds to step 29, in which the energization of the EHC 11 is started, and the present process ends.

FIG. 10 is a time chart showing an operation example in the case where the above control processing is executed. In this example, since all the cylinder operation times are continued for a relatively long time, the EHC is performed.
The eleventh temperature TEHC is maintained at a temperature higher than the activation temperature TE. When the operation state shifts to the cylinder-stop operation from this state (time t4), at the same time, the shut-off valve 13 is opened, and the energization to the EHC 11 is suspended (t4-t).
5). As a result, the temperature TEHC of the EHC 11 becomes lower because exhaust gas is no longer supplied from the idle cylinder 4.
descend. On the other hand, opening of the shut-off valve 13 causes the EHC 11
From the working cylinder side exhaust pipe 6 side through the communication pipe 12,
A pulsation of the exhaust gas is provided, whereby the EHC
11 can be prevented from lowering. After the shift to the cylinder-stop operation, when the delay time tDEL has elapsed (time t5), the EHC1 is counted by the delay timer.
When the energization to 1 is started, the temperature TEHC of the EHC 11 starts to rise and is maintained at or above the activation temperature TE.

As described above, according to the present embodiment, the energization of the EHC 11 after the transition to the cylinder-stop operation is performed with the delay time tD
The start is delayed by EL and the delay time tD
As described above, EL increases as the vehicle speed v increases, that is, as the degree of temperature decrease of the EHC 11 tends to increase,
It is set to be shorter. Therefore, in the present embodiment, the start timing of energization to the EHC 11 can be optimally controlled, and the active state can be maintained while efficiently operating the EHC 11 appropriately.

FIGS. 11 to 13 show a fourth embodiment of the present invention. This embodiment is different from the above-described three embodiments in that the actual temperature of the catalyst on the deactivated cylinder 4 side is detected,
The control of the EHC 11 and the like is performed according to the detection result. For this reason, as shown in FIG.
0 is a catalyst temperature sensor 2 as a temperature detecting means, which includes a thermistor for detecting the temperature TCAT.
The detection signal is input to the ECU 20.

FIG. 12 is a flowchart showing a control process of the EHC 11 and the shutoff valve 13 according to the present embodiment. In this process, the determination of the operating state, the closing of the shut-off valve 13 during the all-cylinder operation and the stop of energization of the EHC 11, and the opening of the shut-off valve 13 during the cylinder-stopping operation are executed in the same manner as in the above-described embodiment (step 31). ~ 34). In addition, during the cylinder deactivated operation, the catalyst temperature TC detected by the catalyst temperature sensor 21 is used.
AT is a predetermined lower limit temperature T higher than its activation temperature TE.
It is determined whether the temperature is higher than CATL (for example, 450 ° C.) (step 35). This answer is No, ie TCAT ≦
In the case of TCATL, power is supplied to the EHC 11 (step 36). When the answer to the step 35 is Yes, it is determined whether or not the catalyst temperature TCAT is higher than a predetermined upper limit temperature TCATH (for example, 800 ° C.) higher than the lower limit temperature TCATL (step 37). This answer is No,
That is, when TCATL <TCAT ≦ TCATH, step 36 is executed, and the energization to the EHC 11 is continued. On the other hand, when the answer to step 37 is Yes, that is, when TCAT> TCATH, step 33 is executed, and the energization to the EHC 11 is stopped.

With the above control, as shown in the time chart of FIG. 13, the catalyst temperature TCAT quickly rises after the transition to the cylinder-stop operation, and the three-way catalyst 10 and the EHC
11 can be activated early, and after activation, their temperatures can be maintained in appropriate temperature ranges near the upper and lower limit temperatures TCATL and TCATH. Thus, according to the present embodiment, the detected actual catalyst temperature TCAT
Accordingly, the temperature of the three-way catalyst 10 and the temperature of the EHC 11 can be controlled more accurately while efficiently operating the EHC 11 appropriately.

As described above, according to each of the embodiments described above, by energizing the EHC 11 arranged in the deactivated cylinder-side exhaust pipe 9 during the deactivated cylinder operation, the temperature is raised to the activation temperature TE.
The three-way catalyst 1 is maintained when returning to the all-cylinder operation.
0 and the catalytic performance of the EHC 11 can be immediately exhibited, and at that time, the exhaust gas discharged from the idle cylinder can be appropriately purified. As a result, unlike the conventional case, it is not necessary to intermittently operate the deactivated cylinder during the deactivated cylinder operation.
The fuel efficiency can be improved accordingly.

In the first and second embodiments, the energization time t2 to the EHC 11 and the energization voltage VEHC are controlled in accordance with the all-cylinder operation time t1 after starting. In the third embodiment, the energization voltage VEHC is controlled in accordance with the vehicle speed v. To control the delay time tDEL of the start of energization,
Is a parameter that favorably reflects the temperature state of the EHC 11, so that EHC can be performed without using a temperature sensor or the like.
11 can be operated efficiently and appropriately. Further, in the fourth embodiment, the detected actual catalyst temperature TC
The temperature of the three-way catalyst 10 and the temperature of the EHC 11 can be controlled more accurately while the EHC 11 operates efficiently and appropriately according to the AT. Therefore, the life of the EHC 11 can be prolonged, and the power consumption of the alternator for supplying electric power to the EHC 11 and the engine load for driving the EHC 11 can be minimized, thereby further improving the fuel efficiency.

The present invention is not limited to the embodiments described above, but can be implemented in various modes.
For example, as a parameter representing the temperature state of the EHC 11, in the first and second embodiments, the all-cylinder operation time t1 is
In the third embodiment, the vehicle speeds v are respectively used, but these may be appropriately combined, or other appropriate parameters may be used instead of or together with these. Further, in the first to third embodiments, the EHC 11
Although the power supply time t2, the power supply voltage VEHC, and the power supply start delay time tDEL are controlled, two or more of these may be controlled simultaneously. In addition, it is possible to change the detailed configuration within the scope of the present invention.

[0041]

As described above, the exhaust gas purifying apparatus for a cylinder deactivated engine according to the present invention achieves both improvement of fuel efficiency and maintenance of catalyst performance when independent exhaust systems are provided for the active cylinder and the deactivated cylinder. And the like.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a cylinder deactivated engine and an exhaust gas purifying apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a control process according to the first embodiment of the present invention.

FIG. 3 is a diagram illustrating a table for determining an energization time to an EHC according to an all-cylinder operation time.

FIG. 4 is a time chart illustrating an operation example according to the flowchart of FIG. 2;

FIG. 5 is a flowchart illustrating a control process according to a second embodiment of the present invention.

FIG. 6 is a diagram showing a table for determining an energization voltage to an EHC according to an all-cylinder operation time.

FIG. 7 is a time chart illustrating an operation example according to the flowchart of FIG. 5;

FIG. 8 is a flowchart illustrating a control process according to a third embodiment of the present invention.

FIG. 9 is a diagram showing a table for determining a delay time for starting energization of an EHC according to a vehicle speed.

FIG. 10 is a time chart illustrating an operation example according to the flowchart of FIG. 8;

FIG. 11 is a block diagram showing a schematic configuration of a cylinder deactivated engine and an exhaust gas purifying apparatus according to a fourth embodiment of the present invention.

FIG. 12 is a flowchart illustrating a control process according to a fourth embodiment of the present invention.

FIG. 13 is a time chart illustrating an operation example according to the flowchart of FIG. 12;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder deactivated engine 2 Exhaust purification device 3 Activated cylinder 4 Activated cylinder 6 Activated cylinder side exhaust pipe (active cylinder side exhaust system) 9 Activated cylinder side exhaust pipe (activated cylinder side exhaust system) 11 Electrically heated catalyst (activated cylinder side electric power) Heating catalyst) 20 ECU (discriminating means, heating control means) 21 Catalyst temperature sensor (temperature detecting means) t1 All cylinder operation time (All cylinder operation continuation period) t2 Energization time VEHC energization voltage tDEL Delay time (Start timing)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02D 17/02 F02D 17/02 P 43/00 301 43/00 301H 301T 301Z (72) Inventor Ryuji Kono Saitama 1-4-1, Chuo, Wako-shi, Pref. Inside Honda R & D Co., Ltd. (72) Inventor Morio Fukuda 1-4-1, Chuo, Wako-shi, Saitama F-term in Honda R & D Co., Ltd. 3G004 AA01 DA02 DA24 3G084 AA03 BA13 BA23 BA24 DA02 DA28 EA07 FA00 FA05 FA33 FA39 3G091 AA02 AA29 AB03 BA03 BA04 BA14 BA15 BA19 BA32 CA03 CA12 CA13 CB06 CB08 DA07 DB10 EA01 EA18 EA26 EA30 EA31 EA39 FA02 HA04 FC03 HA03 FC04 FC03 AA14 AA15 CA07 CA08 CB02 DA11 DC12 DC15 DF02 DF08 DG06 EA11 EA16 EA17 FA15 FA24 GA14 HD02Z HE01Z HE04Z HE05Z HF21Z

Claims (3)

[Claims] 1. An exhaust gas purifying apparatus for a cylinder deactivated engine that operates an active cylinder and a deactivated cylinder during an all-cylinder operation, and deactivates the deactivated cylinder during a deactivated cylinder operation. A working cylinder-side exhaust system that discharges air, a working cylinder-side exhaust system that is provided independently of the working cylinder-side exhaust system, and that discharges exhaust gas of the working cylinder. A cylinder-side electrically-heated catalyst; determining means for determining whether the cylinder deactivated engine is operating in the all-cylinder operation or the deactivated cylinder operation; and operating in the deactivated cylinder operation by the determining means. Heating control means for controlling the heating of the inactive cylinder-side electrically heated catalyst by applying a current to the inactive cylinder-side electrically heated catalyst when it is determined that Exhaust gas purification device for a cylinder deactivated engine. 2. The heating control means, according to the all-cylinder operation continuation period before shifting to the cylinder-stop operation, includes at least a start timing, a time, and a voltage of energization of the deactivated cylinder-side electrically heated catalyst. The exhaust gas purifying apparatus for a cylinder deactivated engine according to claim 1, wherein one of the exhaust gas purifying apparatuses is controlled. 3. The system according to claim 1, further comprising a temperature detecting means for detecting a temperature state of said deactivated cylinder-side electrically heated catalyst, wherein said heating control means detects said temperature state detected by said temperature detecting means. The exhaust gas purifying apparatus for a cylinder deactivated engine according to claim 1, wherein energization of the electrically heated catalyst and its stop are repeatedly executed.