JP2003278527A - Exhaust processing device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust processing device suppressing the generation of white smoke, blue white smoke, and exhaust irritating odor at the time of cold starting, and protecting a battery by avoiding excessively energizing. <P>SOLUTION: This exhaust processing device comprises a branch portion 5 provided in a midpoint in an exhaust system 4, a plurality of branch pipes 6, 7 arranged in parallel downstream from the branch portion 5, and particulate filters F1, F2 or a catalyst interposed between the plural branch pipes 6, 7 as a plurality of exhaust processing devices. The particulate filters F1, F2 or the catalyst as the exhaust processing device are internally provided with electric heaters Fh1, Fh2 in an upstream side, and switching valves V1, V2 are interposed between the branch portions 5 of the plural branch pipes 6, 7. A control means 9 controlling the exhaust processing devices and an intake air heater 14 are equipped, and an engine cooling water temperature detecting means Tw and exhaust temperature detecting means T1, T2 are provided. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas treatment apparatus for an internal combustion engine having an intake air heater and having an alternating regeneration type particulate filter using an electric heater or an electrically heated catalyst.

[0002]

2. Description of the Related Art Particulate filter so-called "PF"
Alternatively, an engine with an exhaust catalyst reduces particulate matter “PM” and unburned hydrocarbons at normal temperature, but immediately after the engine is started at low temperature, steam and unburned hydrocarbons in the exhaust gas have low temperatures. It cools and condenses as it passes through the PF's and catalysts, producing temporary fog or bluish white smoke.

That is, there is a problem that the visibility of the rear portion of the vehicle is deteriorated and the visibility of the following vehicle is obstructed as compared with the case where "PF" or the exhaust catalyst is not used.

Further, in addition to a functional defect that oxidation by a catalyst is insufficient at low temperatures, there is also an environmental problem that a strong exhaust odor is generated.

Further, since an engine intake air heater that consumes a large amount of electric power is used at the time of cold start, if "PF" regeneration and heating and energization of the exhaust treatment device are simultaneously performed, the allowable current of the battery may be exceeded and the battery may be damaged. .

[0006]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-mentioned problems of the prior art, and produces less white smoke, bluish white smoke and exhaust irritating odor at cold start, and excessive energization. It is an object of the present invention to provide an exhaust treatment device that protects a battery by avoiding the above.

[0007]

The exhaust treatment apparatus of the present invention comprises a branch part (5) provided in the middle of the exhaust system (4) and a plurality of parallel parts arranged downstream of the branch part (5). An exhaust treatment device having a branch pipe (6, 7) and a particulate filter (F1, F2) or a catalyst which is a plurality of exhaust treatment devices interposed in each of the plurality of branch pipes (6, 7) In the particulate filter (F1, F2) or the catalyst, which is the exhaust treatment device, the electric heater (Fh1, Fh2) is provided on the upstream side and the filter body (Ff is provided on the downstream side.
1, Ff2) or a single catalyst, and a switching valve (V1) in a region between the branch portion (5) of each of the plurality of branch pipes (6, 7) and the particulate filter (F1, F2) or the catalyst. , V2) and has a control means (9) for controlling the exhaust treatment device, the intake system (12) includes an intake air heater (14) and an air heater relay (16), and an engine cooling system ( 10) is provided with engine cooling water temperature detecting means (Tw), and exhaust temperature detecting means (T) is provided upstream of the particulate filter (F1, F2) or the catalyst.
1, T2) are provided (claim 1: FIG. 1).

Further, the exhaust treatment apparatus of the present invention has a branch portion (5) provided in the middle of the exhaust system (4) and the branch portion (5).
A plurality of branch pipes (6, 7) arranged in parallel downstream of the
Particulate filters (F1, F) which are a plurality of exhaust treatment devices interposed in each of the plurality of branch pipes (6, 7)
2) or a catalyst, in the exhaust treatment device, the bypass pipe (B) parallel to the plurality of branch pipes (6, 7) is provided on the downstream side of the branch portion (5). The particulate filter (F1, F2) or the catalyst is equipped with an electric heater (Fh1, Fh2) on the upstream side and a filter body (Ff1, Ff2) or the catalyst alone on the downstream side, and the plurality of branch pipe branch pipes (6 , 7) each of the branch portions (5) and the particulate filter (F1, F)
2) or a switching valve (V1, V2) in a region between the catalyst and a bypass valve (Vb) in the bypass pipe (B), and control means (9) for controlling the exhaust treatment device. And an intake air heater (14) and an air heater relay (16) in the intake system (12), and an engine cooling water temperature detecting means (Tw) in the engine cooling system (10). (F1, F2) or exhaust temperature detecting means (T1, T2) is provided upstream of the catalyst (claim 2: FIG. 8).

The control means (9) determines whether or not the air heater (14) is energized by the intake air heater relay (16), and while the air heater (14) is energized, an electric heater (for an exhaust treatment device) ( Fh1, Fh2) is controlled so as not to be energized (claim 3: FIG. 4,
(Fig. 12).

According to the exhaust treatment device having the above structure and performing the above control, the intake air heater (1
The combustion temperature rises due to the warming of the intake air by 4), that is, the exhaust temperature also rises, and the particulate filter (F1, F2) or catalyst, which is the exhaust treatment device, is warmed up by the electric heater (Fh1, Fh2). Since it is warmed up, it produces less white smoke, bluish white smoke and exhaust odor. Further, the intake air heater (14) and a particulate filter (F1, F2) which is an exhaust treatment device.
The electric heaters (Fh1, Fh2) or the electric heaters for catalysts are controlled so that they are not energized at the same time, so over-energization (over-discharge) can be avoided and the generator (20) and battery (30) can be extended and protected. .

The control means (9) includes the various sensors (S
p, Sn, Sa, T1, T2), and if there is an abnormality, the electric heaters (Fh1, Fh2) are controlled so as to be de-energized. It is preferable for safety (Fig. 4). Further, when the exhaust treatment device is provided with a bypass pipe having the bypass valve interposed (claim 2), the bypass valve (Vb) is opened after the electric heaters (Fh1, Fh2) are de-energized. It is preferable to control (Fig. 12). With such a configuration, even if an abnormality occurs, the exhaust system (4) is not blocked and damage to the exhaust treatment device (F1, F2) is prevented.

Further, the control means (9) exhausts the air from the intake air heater (14) until a second predetermined time elapses after it is detected that the power supply has been interrupted after the power is supplied to the intake air heater (14) for a first predetermined time. After energizing (warming up) the electric heaters (Fh1, Fh2) for the processing device and confirming the elapse of the second predetermined time (confirming warm-up for the predetermined time), the PM clogging amount is estimated and calculated,
It is preferable to control to start the regeneration operation of the exhaust treatment device (FIGS. 5 and 13).

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. First, the first embodiment will be described with reference to FIGS.

In FIG. 1, an exhaust pipe 4 is connected to an exhaust manifold 2 of an engine 1 via a turbocharger 3. A branch portion 5 is connected to the exhaust pipe 4, and a first branch pipe 6 and a second branch pipe 7 are connected in parallel to the branch portion 5, respectively. The rear end 6a of the first branch pipe 6 and the rear end 7a of the second branch pipe 7 are connected so as to merge with one tail pipe 8.

In the first branch pipe 6, a first switching valve V1 is provided on the upstream side, and a first particulate filter "PF" is provided on the downstream side. The processing device is simply a filter, or abbreviated as "PF") F1 is interposed. The second branch pipe 7 is provided with a second switching valve V2 on the upstream side and a second "PF" F2 on the downstream side.

In the first "PF" F1, a first electric heater Fh1 is installed on the upstream side of a first casing Fa1 forming the "PF", and a first filter body Ff1 is installed on the downstream side. There is. Further, the second "PF" F2 has "P
The second casing Fa2 constituting the F "is provided with a second upstream side.
The electric heater Fh2 of the second filter main body F on the downstream side.
The interior of f2.

The engine 1 has an engine rotation sensor Sn for detecting an engine speed, a supercharging pressure sensor Sa, and a cooling water temperature sensor Tw as an engine cooling water temperature detecting means in a cooling system 10 in which engine cooling water circulates. Is installed.

Further, an intake air heater 14 for warming (heating) the intake air is provided in an intake system 12 of the engine 1, and an air heater relay 1 for relaying energization to the air heater 14 is provided.
A control circuit 15 including 6 is provided. In addition, the symbol L in the drawing indicates a wiring (power supply line or signal line).

The first and second filter bodies Ff1,
Immediately before Ff2, the first to detect the exhaust temperature before the filter
And a second exhaust gas temperature sensor (in claim 1 and claim 3, the exhaust gas temperature detecting means: hereinafter, the exhaust gas temperature detecting means is referred to as an exhaust gas temperature sensor) T1 and T2.

Further, a pressure sensor Sp which is a detecting means for detecting the filter upstream pressure is attached to the branch portion 5.

The sensors Sn, Sa, T1, T2,
Both Sp and the air heater relay 16 are input signal lines L
It is connected to the PF controller 9 which is a control means by i.

The first and second switching valves V1 and V2
Is opened and closed by the first and second air cylinders C1 and C2.

The first and second air cylinders C1 and C2
Are connected to the first and second solenoid valves SV1 and SV2 by air lines La1 and La2, respectively, and receive compressed air from an air supply source (not shown).

The first solenoid valve SV1 and the second solenoid valve SV2 are connected to the PF controller 9 by an output signal line Lo.

Further, the first electric heater Fh1 and the second electric heater Fh1
The electric heater Fh2 is supplied with the electric power of the battery 30 via the PF controller 9 or the electric power generated by the generator 20 driven by the engine 1 through the electric power supply lines Le and Ld.

The control circuit of the intake air heater 14 will be briefly described with reference to FIG. The intake air heater 14 is controlled by an engine control unit 18 for controlling the entire engine, which is different from the one for controlling the exhaust treatment device. That is, the engine control unit 18 operates the key switch 19 to excite the coil 16a of the air heater relay 16 on the basis of the temperature information of the cooling water temperature sensor Tw described above, and the B of the generator 20 is excited.
“Air heater 1 for intake of electric power from terminals or battery 30
Control to energize and relay to No. 4. 1 and 2 indicate the same unit (component).

FIG. 3 is an operation timing chart of the intake air heater. The key switch 19 is turned on (ON)
In the state, the air heater relay 16 is in the connected state (Tp
In the section shown by (1), the engine is started (ST: relay output within 30 seconds also at this time), and the engine rises to idle speed or more. In the section TA that is equal to or more than the idle rotation, the relay is in a connected state, that is, in the afterheat state, and the intake air is warmed up. The warm-up time TA is automatically increased / decreased according to the cooling water temperature Tw.

Next, the main control routine of the first embodiment will be described with reference to FIG. Start (power supply O
After N), initial setting is performed (flag down) in step S0.

In step S1, the PF controller 9 reads the parameters, which are data from the detection means Sn, Sa, T1, T2, Sp and the heater relay 16,
Go to step S2.

In step S2, the PF controller 9 determines whether or not an error or abnormality has occurred, and if it has occurred (YES in step S2), step S2 is executed.
3. If it has not occurred (NO), go to step S5.
Proceed to.

In step S3, the PF controller 9
An error is displayed and a warning is given, for example, by activating an alarm (not shown), and the process proceeds to the next step S4. In step S4, the PF electric heater Fh1 (or Fh
The power supply to 2) is cut off and the process returns to step S1.

In step S5, the PF controller 9
Determines whether the engine is rotating based on the information from the engine rotation sensor Sn. If it is rotating (YES in step S5), the process proceeds to step S6. If it is not rotating (NO in step S5), the control in step S4 and subsequent steps is performed.

In step S6, it is judged based on a signal from the heater relay 16 whether or not the intake air heater 14 is energized, and if energized (YE in step S6).
S), the control after the above-mentioned step S4 is performed, and when the power is not being supplied (NO in step S6), the process proceeds to step S7.

At step S7, depending on the presence or absence of the flag,
It is determined whether or not the PF is warming up (warming up). If it is warming up (YES in step S7), the warming up operation in step S8 is continued, and if it is not warming up (step S7). NO), the process proceeds to step S9.

In step S9, the PF controller 9
Determines whether or not the filter body Ff1 (or Ff2) is being regenerated in the "PF" F1 (or F2) depending on the presence or absence of the flag. If regeneration is in progress (YES in step S9), the PF regeneration operation is set (step S10), and the control ends. If it is not being played (step S
No of 9) sets to collection operation (step S11), and control returns to step S1.

According to the exhaust treatment system of the internal combustion engine of the first embodiment having such a configuration and control method, the electric heater Fh1 of the PF is indispensable while the intake air heater 14 is energized.
Since Fh2 is controlled so that the energization is cut off, over-energization (over-discharging) cannot occur, and therefore the generator 2
0 and the battery 30 can be extended and protected. Further, since it has a fail-safe function of de-energizing the electric heaters Fh1 and Fh2 when the various sensors Sn, Sa, T1, T2, Sp become abnormal, even when an abnormality occurs. "PF" F1 and F2 can be prevented from being damaged.

Next, the control of the collection operation, which is a subroutine in FIG. 1, will be described with reference to FIG. In step S21, the PF controller 9 determines, based on a signal from the heater relay 16, whether or not the intake air heater 14 has been energized for a first predetermined time (T ₀ seconds) or more. When energized for a predetermined time (T ₀ seconds) or more (YE in step S21)
S) is regarded as after the low temperature start, and the process proceeds to step S22,
When the power is not supplied for the first predetermined time (T ₀ seconds) or more (YES in step S21), it is considered not after the low temperature start, and the process proceeds to step S24. Here, the intake air heater 14
As described above, the engine control unit (reference numeral 18 in FIG. 2) independently controls the above-mentioned control. In step S21, the energization time of the air heater (TA in FIG. 3) is simply determined.

In step S22, the PF controller 9
Determines whether or not a second predetermined time (T _B minutes) has elapsed after the air heater has been energized (after being de-energized). At this point, the energization of the intake air heater 14 is completed (TA in FIG. 3).
After that, one of "PF" F1 and F2 is warmed up,
If the second predetermined time _{(T B} min) has not elapsed (NO in step S22), and namely until passage, continued warming up "PF" (step S23). (T _{B in} FIG. 3
Interval) When the second predetermined time _{(T B} min) has elapsed (YES in step S22) considers the warm-up completion of the PF, the flow proceeds to step S24.

In step S24, the PF controller 9
Determines whether the clogging amount of PM exceeds a predetermined value. If it exceeds the predetermined value (threshold value) (step S24)
YES), the process proceeds to step S27, and if not exceeded (NO in step S24), the process proceeds to step S25.

In step S25, the PF controller 9 determines whether the pressure loss of the filter body Ff1 (or Ff2) exceeds a predetermined value (threshold value) based on the information from the pressure sensor Sp. If it exceeds (YES in step S25), the process proceeds to step S27, and if not (NO in step S25), the process proceeds to step S26.

Here, the predetermined value (threshold value) refers to a value of pressure loss in such a case that the fuel consumption deteriorates when the exhaust pressure becomes high, such as when climbing a hill or at a high speed / high load.

In step S26, the PF controller 9
Determines whether or not the collection operation duration time exceeds a predetermined value, and if it exceeds (YES in step S26), the process proceeds to step S27, and if not (step S25).
NO), the process proceeds to step S29. Incidentally, step S26
For example, the predetermined value (threshold value) is, for example, about 3 hours so that it is effective when operating in a region where exhaust flow rate and pressure are low and detection accuracy is low, that is, where soot accumulation is difficult to detect. Good to do.

In step S27, the PF controller 9 switches to close the first switching valve V1 or the second switching valve V2 if it is open (if it is not open, maintains the same state). Then, in step S28, "PF" F1 or F2 is set in the regeneration operation (regeneration operation subroutine of FIG. 6).

In step S29, the PF controller 9
Shuts off the power supply to the electric heater Fh1 or Fh2 of the PF, and the control returns to the original.

According to the exhaust treatment system of the internal combustion engine of the first embodiment which performs such control, the intake air heater 14 and the electric heater of the PF are not simultaneously energized, so that the generator 20 and the battery are not energized. 30 life extension
Can be protected.

Further, the clogging amount of PM in the filter is estimated and calculated based on the output signals of the pressure detecting means Sp and Sa and the engine speed detecting means Sn. Close the switching valve V1 or V2,
The filter is switched to the regenerating operation, and when the clogging amount of PM is not more than the predetermined value, the electric heater Fh1 or Fh
Since h2 is controlled so as not to be energized, it is possible to prevent damage to the filters F1 and F2 due to excessive trapping of PM.

Next, the control of the "PF" regeneration operation, which is the subroutine in FIG. 1, will be described with reference to FIG.

In step S31, the upstream temperature of the PF during valve closing is detected by the temperature sensor T1 or T2, and in the next step S32, the PF controller 9
Duty-controls the current value of the electric heater of the PF during valve closing according to the detected temperature.

In the next step S33, the PF controller 9 sets a "reproducing" flag, outputs a signal, and proceeds to the next step S34.

In step S34, the PF controller 9
Determines whether or not the elapsed playback time exceeds the first set value. If it exceeds the first predetermined value (step S34)
YES), the process proceeds to step S35, and the electric heater Fh1
Alternatively, the power supply to Fh2 is cut off, and the control returns to the original. If the first set value is not exceeded (NO in step S34),
It returns to step S32.

Here, the first set value is the time required for filter regeneration during normal running (time for energizing the filter), and is set to 40 minutes, for example.

According to the exhaust gas treatment apparatus for the internal combustion engine of the first embodiment which performs such control, the current of the heaters Fh1 and Fh2 is duty-controlled in accordance with the temperature upstream of the "PF" F1 and F2, so that the power consumption is reduced. It is possible to keep the temperature to a minimum and prevent melting damage of the filter body due to overheating.

Next, the control of the "PF" warm-up operation which is the subroutine in FIG. 1 will be described with reference to FIG.

In step S41, the upstream temperature of the PF during valve closing is detected by the temperature sensor, and in the next step S41.
At 42, the PF controller 9 duty-controls the current value of the PF electric heater during valve closing according to the detected temperature.

In step S43, the PF controller 9 sets the "warm-up" flag and outputs a signal, and in the next step S44, the PF controller 9 sets the warm-up elapsed time to the second predetermined value ( For example, it is determined whether it has exceeded 5 minutes. If it exceeds the second set value (YES in step S44), the process proceeds to step S45, the power supply to the electric heater Fh1 or Fh2 is cut off, and the process proceeds to step S46.
Proceed to.

In step S46, the switching valve is switched to open and the control returns to the original.

If it does not exceed the second set value (NO in step S34), the process returns to step S42.

According to the exhaust treatment system of the internal combustion engine of the first embodiment which performs such control, the electric current of the electric heater is duty controlled according to the temperature of the PF upstream while the valve is closed, so that the power consumption is minimized. It is possible to prevent the filter body from being melted and damaged due to overheating.

Next, the second embodiment will be described with reference to FIGS. The configuration of the second embodiment of FIG. 8 is different from the configuration of the first embodiment of FIG. 1 in the following points, and is substantially the same in other respects, and only the different points will be described. The same parts and units are designated by the same reference numerals.

That is, between the branch portion 5 and the tail pipe 8 in FIG. 8 (FIG. 1), the bypass pipe B parallel to the first and second branch pipes 6 and 7 is provided with the branch portion 5 and the tail pipe 8. The pipe 8 is connected. A bypass valve Vb is provided on the side of the branch pipe 5 of the bypass pipe B, and the bypass valve Vb is opened / closed by a bypass air cylinder Cb. The bypass air cylinder Cb is connected to the bypass solenoid valve Sb by an air line Lab and receives supply of air from an air supply source (not shown). The bypass solenoid valve Sb is connected to the PF controller 9 via the output signal line Lo.

FIG. 9 shows one example of the air heater control circuit diagram in the second embodiment, and FIG. 10 shows another example. The difference between FIG. 9 and FIG. 10 is that there is one heater relay 16 in FIG. 9 and two heater relays 16 in FIG.
According to the method, the output of the heater is switched in two steps as shown in FIG.

Further, in FIG. 10, the signal line from the air heater 16 to the PF controller 9 is provided at the position A or B, and the position indicated by the same symbol (A or B) in the operation timing chart of FIG. Is regarded as That is, the range from point A or B to point C in the timing chart is the PF warm-up operation range.

Next, the main control routine of the second embodiment will be described with reference to FIG. 12 and also with reference to FIG. In step S51, the PF controller 9 opens the valve by energizing the bypass solenoid valve Sb via the bypass solenoid valve Sb to allow air to flow, thereby operating the bypass air cylinder Cb. ) The bypass valve Vb is closed.

In the next step S52, the PF controller 9 reads the parameters which are the data from the respective detecting means Sn, Sa, T1, T2, Sp and the heater relay 16, and proceeds to step S53.

In step S53, the PF controller 9
Judges whether or not an error or abnormality has occurred, and if it has occurred (YES in step S53), the process proceeds to step S54, and if not (NO), the process proceeds to step S57.

In step S54, the PF controller 9
Displays an error and gives a warning by, for example, activating an alarm (not shown), and proceeds to the next step S55. In step S55, the power supply to the PF heater or all the heaters is cut off, and the process proceeds to step S56.

In step S56, the supply air is shut off by, for example, shutting off the power supply to the bypass solenoid valve Sb, the normally open bypass valve Vb is closed, and the control returns to step S52.

In step S57, the PF controller 9
Determines whether the engine is rotating based on the information from the engine rotation sensor Sn. If it is rotating (YES in step S57), the process proceeds to step S58,
If it is not rotating (NO in step S7), the control in step S55 and subsequent steps is performed.

In step S58, the air heater relay 1
Based on the signal from 6, it is determined whether or not the intake air heater 14 is energized, and if it is energized (step S
(YES in 58), the control in step S55 and subsequent steps is performed, and if the power is not supplied (NO in step S55), the process proceeds to step S59.

In step S59, it is determined whether or not the PF is warming up based on the presence / absence of the flag. If the PF is warming up (YES in step S59), the process proceeds to step S60, and it is not warming up. If there is (step S59 N
O), and proceeds to step S61. In step S60, P
Keep F warmed up.

In step S61, the PF controller 9
Depending on the presence / absence of the flag, "PF" F1 (or F
It is determined whether or not 2) is being reproduced. If it is being reproduced (YES in step S61), step S62.
In step S52, control is performed while maintaining the PF regeneration operation.
Return to. If not being reproduced (N in step S61)
O) maintains the collection operation (step S63), and the control returns to step S52.

According to the exhaust treatment system of the internal combustion engine of the second embodiment having such a configuration and control method, the electric heater Fh1 of the PF must be always operated while the intake air heater 14 is energized.
Since Fh2 is controlled so that the energization is cut off, over-energization (over-discharging) cannot occur, and therefore the generator 2
0 and the battery 30 can be extended and protected. In addition, when the various sensors Sn, Sa, T1, T2, Sp become abnormal, in addition to de-energizing the electric heater, the bypass valve Vb is also opened to prevent the exhaust system 4 from being blocked. Therefore, even if an abnormality occurs, it is possible to prevent damage to the “PF” F1 and F2.

Bypass pipe B according to the second embodiment of FIG.
Regarding the control of the collection operation in the case of having
The control is substantially the same as that of the embodiment, and the subsequent description will be omitted.

Next, the filter regeneration operation control in the case of having the bypass pipe B which is the subroutine in FIG. 8 will be described with reference to FIG. In step S81, it is determined whether the filter pressure loss is larger than the second predetermined value (threshold value 2). Here, the second predetermined value means both the first filter F1 and the second filter F2, or the first and second filters F1 and F2.
Either the second fill or the other is close to the limit of collection (first
Is higher than the predetermined value of).

In the next step S82, the bypass valve Vb is opened and the process proceeds to the next step S83. Step S8
3, the PF controller 9 uses the temperature sensor T1 or T
The current value of the electric heater on the PF side during valve closing is duty-controlled in accordance with the temperature upstream of the filter body Ff1 or Ff2 obtained from No. 2, and "heater is energized" in step S84.
The flag is set and the signal is output. Incidentally, it is preferable to display the sign "energizing the heater" by a display means (not shown).

In the next step S85, the PF controller 9 determines whether or not the elapsed playback time exceeds the first set value. If it exceeds the first predetermined value (YES in step S85), the process proceeds to step S86, and if it does not exceed the first set value (NO in step S85), the process returns to step S81.

In step S86, the PF controller 9
De-energizes the electric heater and energizes the bypass solenoid valve Sb, whereby air operates the bypass valve actuation air cylinder Cb through the solenoid valve Sb to close the bypass valve Vb (step S87). ) Control returns.

Here, the first set value is the time required for filter regeneration during normal running (time for energizing the filter), and is set to, for example, 40 minutes.

According to the exhaust treatment system of the internal combustion engine of the seventh embodiment which performs such control, the current of the heaters Fh1 and Fh2 is duty-controlled in accordance with the temperature upstream of the "PF" F1 and F2, so that the power consumption is reduced. It is possible to keep the temperature to a minimum and prevent melting damage of the filter body due to overheating.

Next, the control of the "PF" warm-up operation which is the subroutine in FIG. 8 will be described with reference to FIG. In step S91, the bypass valve is opened, all PF switching valves are closed, and the temperature upstream of the filter body Ff1 or Ff2 is detected by the temperature sensor T1 or T2, and the process proceeds to the next step S92.

In step S92, the PF controller 9 determines the electric heaters Fh1 and Fh according to the detected temperature.
The current value of No. 2 is sequentially duty-controlled, and the process proceeds to step S93, where the PF controller 9 sets a "heater energized" flag and outputs a signal to the outside as necessary.

In the next step S94, the PF controller 9 determines whether or not the elapsed time of warming up (heater energization) exceeds the second set value (for example, 5 minutes) based on the signal from the heater relay 16. If it exceeds the second set value (YES in step S94), the process proceeds to step S95,
If it does not exceed the second set value (N in step S94)
O), and returns to step S92.

In step S95, the PF controller 9
Judges whether the warm-up has completed one cycle, and if it has completed one cycle (YES in step S95), step S96.
If it has not completed the cycle (step S95: N
O), and returns to step S92.

In step S96, the electric heater Fh
1. By shutting off the energization to Fh2, switching the switching valve V1 or V2 on the collection side to open, and energizing the bypass solenoid valve Sb, air is passed through the solenoid valve Sb to actuate a bypass valve air cylinder. Cb is operated and the bypass valve Vb is closed (step S97), and the control returns to the original.

According to the exhaust gas treatment apparatus for the internal combustion engine of the second embodiment which performs such PF warm-up operation control, the amount of heat for warm-up can be adjusted according to the temperature condition of the filter, and the set time can be adjusted. When the value exceeds, the electric power to the heater is cut off, so that the consumed electric power can be minimized.

The illustrated embodiment is merely an example,
It is additionally noted that the description is not intended to limit the technical scope of the present invention.

[0087]

The effects of the present invention will be described below. (A) At the time of cold start, since the particulate filter or the catalyst, which is the exhaust treatment device, is warmed up by the electric heater, white smoke, bluish white smoke, and exhaust odor are hardly generated. (B) Further, since the intake air heater and the electric heater of the particulate filter or the catalyst which is the exhaust treatment device are controlled not to be energized at the same time, over-energization can be avoided and the battery can be protected. (C) It is possible to prevent the exhaust treatment device from being damaged because it is determined whether or not an abnormality has occurred in each sensor, and when the abnormality has occurred, the electric heater is de-energized. (D) Depending on the temperature condition of the filter, the amount of heat for warming up can be adjusted by duty control, and if the set time is exceeded, the heater will be de-energized and the power consumed will be minimal. I'm done.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of a control circuit diagram of an air heater corresponding to the first embodiment of the invention.

FIG. 3 is an operation timing chart showing the operation timing of the air heater corresponding to the first embodiment of the present invention.

FIG. 4 is a main control flowchart according to the first embodiment of the present invention.

FIG. 5 is a PF trapping operation control flowchart according to the first embodiment of the present invention.

FIG. 6 is a PF regeneration operation control flowchart that is the first embodiment of the present invention.

FIG. 7 is a PF warm-up operation control flowchart that is the first embodiment of the present invention.

FIG. 8 is a block diagram showing the configuration of a second embodiment of the present invention.

FIG. 9 is a diagram showing an example of a control circuit diagram of an air heater corresponding to the second embodiment of the invention.

FIG. 10 is a diagram showing another example of the control circuit diagram of the air heater corresponding to the second embodiment of the invention.

FIG. 11 is an operation timing chart showing the operation timing of the air heater corresponding to the second embodiment of the present invention.

FIG. 12 is a main control flowchart according to the second embodiment of the present invention.

FIG. 13 is a PF trapping operation control flowchart according to the second embodiment of the present invention.

FIG. 14 is a PF regeneration operation control flowchart that is the second embodiment of the present invention.

FIG. 15 is a PF warm-up operation control flowchart that is the second embodiment of the present invention.

[Explanation of symbols]

1 ... engine 2 ... Exhaust manifold 4 ... Exhaust pipe 5 ... Branch 6 ... First branch pipe 7 ... Second branch pipe 9 ... PF controller 10 ... Cooling system 14 ... Intake air heater 15 ... Air heater control system (control circuit) 16: Air heater relay B: Bypass pipe F1, F2 ... First and second PF Ff1, Ff2 ... First and second filter bodies Ff1, Ff2 ... First and second electric heaters V1, V2 ... First and second switching valves T1, T2 ... First and second exhaust gas temperature sensors Tw ... Cooling water temperature sensor

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F01N 3/24 F01N 3/24 G L M F02M 31/12 311 F02M 31/12 311N // B01D 46/42 B01D 46/42 BF term (reference) 3G090 AA04 AA06 BA04 CB12 CB24 DA03 DA18 EA04 3G091 AA10 AA28 AB01 AB13 BA04 BA11 CA03 CA12 CA13 DA08 DB10 EA01 EA16 EA17 EA26 EA26 EA26 MA58 B03B58B0B HAB HAB HA0 HA36 HA38 HA38 HA02 HA38 HA02 HA38 HA02 HA38 HA02 SA08

Claims (3)

[Claims] 1. A branch part provided in the middle of an exhaust system, a plurality of branch pipes arranged in parallel downstream of the branch part, and a plurality of exhaust treatment devices interposed in each of the plurality of branch pipes. In the exhaust treatment device having a particulate filter or a catalyst, which is a particulate filter or a catalyst that is the exhaust treatment device, an electric heater is installed on the upstream side, and a filter body or a simple substance of the catalyst is installed on the downstream side. A switching valve is provided in a region between each of the branch portions of each of the branch pipes and the particulate filter or the catalyst, and control means for controlling an exhaust treatment device is provided, and an intake air heater and an air heater relay are provided in an intake system. An internal combustion engine characterized in that engine cooling water temperature detecting means is provided in the engine cooling system, and exhaust gas temperature detecting means is provided upstream of the particulate filter or catalyst. Exhaust treatment equipment for engines. 2. A branch part provided in the middle of the exhaust system, a plurality of branch pipes arranged in parallel downstream of the branch part, and a plurality of exhaust treatment devices interposed in each of the plurality of branch pipes. In the exhaust treatment device having a particulate filter or a catalyst, a bypass pipe in parallel with the plurality of branch pipes is provided on the downstream side of the exhaust treatment branch portion, and the particulate filter or catalyst is a processing device. An electric heater is provided on the upstream side, a filter body or a single catalyst is provided on the downstream side, and a switching valve is provided in a region between each of the branch portions of the plurality of branch pipes and the particulate filter or the catalyst,
The bypass pipe is provided with a bypass valve, and has control means for controlling the exhaust treatment device, the intake system is provided with an intake air heater and an air heater relay, and the engine cooling system is provided with engine cooling water temperature detection means. An exhaust gas treatment device for an internal combustion engine, characterized in that an exhaust gas temperature detecting means is provided upstream of the particulate filter or the catalyst. 3. The control means determines whether or not the air heater is energized from the intake air heater relay, and controls so as not to energize the exhaust treatment device electric heater while the air heater is energized. The exhaust gas treatment device for an internal combustion engine according to any one of claims 1 and 2.