JPH0227132Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of application of the invention] The present invention is a particulate collection device that collects particulates contained in engine exhaust gas, and in particular, particulates collected in a filter are ignited and burned by a heater. This invention relates to a particulate collection device that allows the filter to be reused.

[Background Art] In diesel engines, particulates made of carbon, carbonized elements, metals, etc. are generated in the exhaust gas due to incomplete combustion of fuel.

If the exhaust gas containing the above-mentioned particulates is directly discharged from a vehicle, the exhaust gas becomes black smoke-like and is accompanied by an unpleasant odor.

Therefore, it is inconvenient to discharge such exhaust gas directly from the engine in terms of maintaining a clean and comfortable environment.

Therefore, this type of device is used to clean the exhaust gas by collecting the particulates contained in the exhaust gas.

In this type of device, the most upstream collected particles are ignited by the heater at a predetermined time before the engine output is reduced after a predetermined amount of particles are collected and accumulated in the particle collection filter. Then, the ignited particulates become a spark, and the downstream collected particulates self-combust due to the oxygen in the exhaust gas. This combustion completes the regeneration of the filter, making it possible to collect particulates again.

However, in conventional devices of this type,
Power was being applied to the heaters regardless of whether or not power was being applied to large current loads such as starters, glow plugs, and intake air heaters.
If energization to the heaters were started during these energizations, there was a risk that the capacity of the power supply would be insufficient.

For this reason, in the past, there was a problem in that a large-capacity battery was required.

[Purpose of the invention] The present invention was made in view of the above-mentioned conventional problems, and its purpose is to create a particulate collection device that can carry sufficient current for each current load even with a smaller capacity battery or alternator. Our goal is to provide the following.

[Summary of the invention] The particulate collection device according to the invention includes a trap including a filter that collects particulates contained in engine exhaust gas, a heater that ignites the particulates collected by the filter, and a particulate matter collection device of the filter. a power source that supplies current to a plurality of current loads including a heater; a load amount detector that detects a load amount of the power source including at least a voltage value or a current value of the power source; It has an energization control circuit that determines when to energize the heater based on the value detected by the collection detector and delays energization of the heater until the load amount of the power source at the time when energizes the heater falls within an allowable range. .

Therefore, if the voltage of the power supply is low at the time of energizing the heater, it is determined that a load is being applied to something other than the heater, and the energization of the heater is delayed.
Furthermore, if a predetermined amount of current from the power source is flowing, it is determined that a load other than the heater is operating, and energization of the heater is delayed. After that, when the power supply load falls within the allowable range, the delayed heater starts energizing and can be operated at different times than other loads. can be prevented.

[Embodiments of the invention] Examples of the particle collection device according to the invention will be described below based on the drawings.

FIG. 1 shows the overall configuration of the apparatus of this embodiment.

In the figure, an intake throttle valve 12 is provided on the intake side of a diesel engine 10, and the intake throttle valve 12 is driven by an actuator 14. Further, a fuel injection valve 16 for controlling the amount of fuel injected into the diesel engine 10 is provided, and an EGR valve 18 for circulating exhaust gas to the intake side is provided between the intake and exhaust.

A trap 20 is provided in the exhaust path of the diesel engine 10.

A casing 22 of this trap 20 is formed into a columnar shape with a substantially elliptical cross section with narrowed ends, and a filter 24 is filled in the casing 22. The filter 24 can collect particulate matter (particulate matter) contained in the exhaust gas of the diesel engine 10, and the particulates gradually accumulate from the exhaust inlet to the outlet of the filter 24.
Further, within the casing 22, a heater 26 is provided on the end surface of the filter 24 on the diesel engine 10 side for igniting the particulates collected by the filter 24.

Note that the filter 24 of this embodiment is made of foamed ceramic, and has a three-dimensional network structure skeleton having a large number of elliptical holes communicating with each other.

Further, the heater 26 of this embodiment has heating wires 30-1, 30-2, 30-3, 30-4 connected to terminals 28-1, 28-2, as shown in FIG.
30-5, 30-6, 30-7, and 30-8. Note that the heater 26 is grounded to the vehicle body.

An ignition current is supplied to this heater 26 from a power supply battery 36 via an energization control circuit.
The energization control circuit is comprised of a chopper circuit 32 and an ECU 34 in FIG. The chopper circuit 32 opens and closes this main power supply circuit.
It consists of switching transistors 38 and 40 that chop the output current of the battery 36, and the chopping operation is controlled by an ECU 34 mainly composed of a microcomputer.

Furthermore, in FIG. 1, an exhaust passage 42 is formed bypassing the trap 20, and this exhaust passage 42 is provided with an exhaust flow rate regulating valve 44.
This exhaust flow rate control valve 44 is driven to open and close by a diaphragm 46.
It is driven by VSV48,50. and
The VSV 48 is connected to a vacuum pump (not shown), and the VSV 50 is open to the atmosphere, and both are controlled by the ECU 34.

As mentioned above, ECU34 is diesel engine 1
0, the heater 26 and the exhaust flow rate control valve 44 are controlled.
Various detection signals are supplied to the ECU 34.

In FIG. 1, the opening degree of the intake throttle valve 12 is determined by the opening degree sensor 52, and the opening degree of the diesel engine 10 is determined by the opening degree sensor 52.
The intake side pressure of the engine is detected by a pressure sensor 54, the engine water temperature by a temperature sensor 56, and the engine load by a load sensor 58.

Further, the rotation speed of the diesel engine 10 is detected by a rotation speed sensor 60, the vehicle speed is detected by a vehicle speed sensor 62, and the oxygen concentration in the exhaust gas is detected by an _O2 sensor 64.
Each has been detected by

Furthermore, diesel engine 10 to trap 20
The temperature of the exhaust gas discharged to the exhaust gas is detected by a temperature sensor 66, and the pressure thereof is detected by a pressure sensor 68. An operation sensor 72 detects whether or not a light control switch 70, which turns on and off the headlight, is operated.

The ECU 34 includes the above opening sensor 52, pressure sensor 54, temperature sensor 56, load sensor 58, rotation speed sensor 60, vehicle speed sensor 62, O ₂ sensor 64,
Temperature sensor 66, pressure sensor 68, operation sensor 7
The diesel engine 10 is configured to be able to be controlled based on various detection signals of 2.

Further, this device has a collected amount detector that detects the amount of collected particulates in the filter 24, and based on the detection signal, it is determined that a predetermined amount of particulates have been collected in the filter 24 and it is time to start energizing the filter 24. The structure is such that the energization control circuit can detect this.
In this embodiment, the load sensor 58, rotation speed sensor 60, and pressure sensor 68 can function as this collected amount detector, and the ECU 34 of the energization control circuit
If the pressure loss of the filter 24 exceeds a predetermined value due to these detection signals, a predetermined amount of fine particles will pass through the filter 24.
It is determined that the particles have been collected, and it is thus detected that it is time to start energizing the heater 26.

That is, the characteristic P shown in Fig. 3 is stored in the ROM of the ECU 34, and in the figure, the horizontal axis shows the engine rotational speed detection value N, and the vertical axis shows the engine load detection value. .

The ECU 34 has a load sensor 58 and a rotation speed sensor 6
Exhaust pressure reference value is determined using characteristic P from the detection signal of 0.
P0 is determined, and when the detected value of the pressure sensor 68 exceeds this reference value P0, it is determined that a predetermined amount of particulates have been collected by the filter 24, and the timing to start energizing the heater 26 is thereby detected.

Additionally, the ECU 34 can control the chopper circuit 32 to inhibit the supply of ignition current to the heater 26 until the trap 20 is warmed by the exhaust air, and to begin supplying ignition current only after the trap 20 has been warmed up.

This control includes a temperature sensor 66 and a temperature sensor 5.
The ECU 34 uses the detection signal of the temperature sensor 66 to confirm that a predetermined time has elapsed after the start of the diesel engine 10 and the temperature of the exhaust gas supplied to the trap 20 has exceeded a predetermined value. Then, when it is confirmed that the engine coolant temperature has exceeded the specified value, trap 2 is activated.
After determining that the heater 26 has warmed up, the supply of ignition current to the heater 26 can be controlled to start.

Note that before the supply of ignition current to the heater 26 is started, the ECU 34 detects that the cumulative value of the vehicle speed and the cumulative value of the engine speed (for example, 200,000 revolutions) each exceed a predetermined value and the pressure sensor 68 is malfunctioning. You can confirm in advance that there are no

Furthermore, when starting the supply of ignition current to the heater 26, it is confirmed in advance as follows that the output current of the battery 36 will not exceed a permissible value due to the start of the supply.

In this device, from the battery 36 to the heater 26
Operating current is also supplied to other current loads. That is, in FIG. 1, from the battery 36 to the starter 7
4. Glow plug 76, intake air heater 7
Current is also supplied to the current load No. 8.

A current amount detector is provided to detect the amount of current output from the battery 36 of the power source to these current loads, and the detection signal is supplied to the energization control circuit. That is, in FIG. 1, the output voltage of the ST terminal of the starter 74, the glow plug 76,
Relay signals from relays 80 and 82 that are inserted in series with the intake air heater 78 and are driven by being energized are supplied to the ECU 34.

This ECU 34 monitors the voltages and signals of the starter 74, glow plug 76,
The amount of current output from the battery 36 can be recognized by detecting that the intake air heater 78 is energized.

Therefore, the starter 74 and the relays 80, 82 function as the above-mentioned current amount detectors, that is, load detectors.

Furthermore, when the ECU 34 determines that it is time to start energizing the heater 26 as described above,
When the starter 74, glow plug 76, and intake air heater 78 are not energized, the heater 2
6, it is determined that the output current of the battery 36 does not exceed the permissible value, and the start of the current supply can be permitted.

Furthermore, when the energized loads are energized, the ECU 34 determines that the output current of the battery 36 exceeds the allowable value due to the start of energization of the heater 26.
The start of energization can be prohibited, and the start of energization can be postponed until the energization of those current loads is finished.

Note that the output current and output voltage of the battery 36 are detected by the current detector 84 and the voltage detector 86, and the ECU 34 detects when the output current exceeds a predetermined value.
Alternatively, when the output voltage is below a predetermined value, starting the energization of the heater 26 can be prohibited.

Since the current detector 84 and the voltage detector 64 detect the output electric particles and voltage of the battery 36, they function as the load amount detectors.

After that, when the heater 26 is energized and the collected particulates are ignited, the ECU 34 adjusts the opening degree of the exhaust flow rate control valve 44 so that the collected particulates ignited by the heater 26 are properly combusted. The flow rate of exhaust gas flowing through 20 is controlled.

Also, at this time, the ECU 34 controls the exhaust flow rate control valve 44 according to the detection signals of the O2 sensor 64 and the temperature sensor 66.
By adjusting the opening degree of the trap 20, the flow velocity of the exhaust gas flowing through the trap 20 can be reduced to prevent the trap 20 from melting.

Further, the ECU 34 controls the value of the ignition current so that the value correlates with the power supply voltage when the headlamp is turned on.

In this embodiment, since the output voltage of the battery 36 depends on the engine rotation speed, the value of the ignition current supplied to the heater 26 is controlled according to the detection signal of the rotation speed sensor 60, that is, the engine rotation speed. That is, when the engine speed is low, the duty ratio D of the ignition current is decreased and its value is reduced, and when the engine speed is high, the duty ratio D is increased and its value is increased. At this time, the value I of the ignition current is controlled by its duty ratio D according to the characteristic 100 in FIG. As a result, the output voltage of the battery 36 is controlled to be substantially constant.

Further, the ECU 34 can gradually increase or decrease the value of the ignition current to the heater 26 when the headlamp is turned on.

The ECU 34 of this embodiment detects the lighting state of the headlamp based on the detection signal of the operation sensor 72, and gradually controls the duty ratio D of the ignition current to increase or decrease over time as shown by the characteristic 102 in FIG. ing. Furthermore, ECU34 is heating wire 30
-1,30-2,30-3,30-4,30-
5, 30-6, 30-7, 30-8 are energized one by one in the prescribed order, and the last heating wire 3
The switching transistors 38 and 40 of the chopper circuit 32 can be duty-controlled so that the value of the ignition current is gradually reduced when the ignition current is de-energized.

The present embodiment has the above configuration, and its operation will be explained below.

FIG. 6 shows a main routine explaining the entire processing of the ECU 34, in which processing including control processing of the diesel engine 10 (step 200) and regeneration processing of the trap 20 is repeatedly performed.

In step 200, the basic injection amount and injection timing of fuel are first determined based on the amount of depression of the accelerator pedal, that is, the lever opening of the injection pump and the engine rotational speed. The basic injection amount and injection timing are corrected based on the engine coolant temperature, intake air temperature, etc., and the output of the diesel engine 10 is controlled using these corrections.

During operation of the diesel engine 10, the exhaust flow rate control valve 44 is closed and the exhaust gas is guided toward the trap 20, so that the particulates contained in the exhaust gas are gradually removed from the upstream surface of the filter 24 toward the downstream direction. Collected in the filter 24, the filter 24
is accumulated in

As a result, clean gas containing no particulates is emitted from the vehicle, thereby preventing any negative impact on the surrounding environment.

In step 202, the process shown in FIG. 7 is first performed.

In the process shown in FIG. 7, it is determined whether a predetermined amount of particles have been collected by the filter 24 in the following manner.

In FIG. 7, the ECU 34 uses the characteristic P shown in FIG. 3 from the detection signals of the load sensor 58 and rotational speed sensor 60 to determine whether the pressure loss of the filter 24 exceeds a predetermined value. is determined, and it is determined whether the detected value of the pressure sensor 68 exceeds this reference value P0 (step 300).

At this time, the detected value of the pressure sensor 68 is the reference value P0
When it is determined that the pressure loss of the filter 24 has exceeded the predetermined value, a predetermined amount of particulates have been collected in the filter 24, and the diesel engine 1
0 power loss has increased to a certain extent.

Next, the ECU 34 is the diesel engine 10
It is determined whether the integrated rotational speed value and the integrated vehicle speed value each exceed a set value (steps 302, 304).

If it is determined in step 302 that the cumulative rotational speed of the diesel engine 10 does not exceed the set value, the determination in step 300 is made, and if it is determined in step 304 that the cumulative value of the vehicle speed does not exceed the set value, the determination is made in step 300. , 302 are once invalidated.

In step 306, the determinations in steps 300 and 302 that were invalidated in steps 302 and 304 are examined. Note that step 30
It is preferable to omit steps 302, 304, and 306 when there is no risk that the reference value P0 used at 0 will be destroyed.

In this way, when it is detected that a certain amount of particulates have accumulated in the filter 24, if the collection of particulates continues, the loss on the exhaust side will increase and the output of the diesel engine 10 will decrease, so the filter 24 will be removed. The fine particles collected by the heater 24 are ignited and burned by the heater 26 in the following manner.

In this device, the supply of ignition current to the heater 26 is inhibited until the trap 20 is warmed by the exhaust air, and only then is started.

In FIG. 8, first the diesel engine 10
It is confirmed that the exhaust system has been warmed up after a predetermined period of time has elapsed since the engine was started (step 400).

Next, diesel engine 10 in trap 20
It is confirmed by the detection signal of the temperature sensor 66 that the temperature of the exhaust gas discharged from the exhaust gas is higher than a predetermined temperature (step 402).

Furthermore, the coolant temperature of diesel engine 10 is 6.
It is confirmed by the detection signal of the temperature sensor 56 that the temperature is 0° C. or higher (step 404).

In this way, in this embodiment, the diesel engine 1
It is determined that the trap 20 has been warmed when a predetermined period of time has elapsed since the start of the zero operation, the temperature of the exhaust gas has reached a predetermined temperature or higher, and the cooling water temperature has reached 60° C. or higher.

Note that a temperature sensor that directly detects the temperature of the trap 20 or the temperature of the exhaust system may be provided, and the detection signal may be used to confirm that the trap 20 has been warmed.

In this way, combustion of the particulates collected by the filter 24 starts after the trap 20 is warmed up, so thermal stress is prevented from occurring in the casing 22 and the filter 24, and damage to them is avoided. .

Further, in this embodiment, the supply of ignition current to the heater 26 is started after it is confirmed that the output current of the battery 36 does not exceed the permissible value by starting energization of the heater 26, and when the output current of the battery 36 exceeds the permissible value, the ignition current is supplied to the heater 26. Its start is postponed until the value is less than or equal to the value.

Therefore, the following processing is performed as shown in FIG.

After the process in step 404, it is first determined whether or not the starter 74 is energized based on the ST terminal output voltage of the starter 74 (step 406).
Next, whether or not the glow plug 76 is energized is determined based on the relay signal of the relay 80 (step 408), and whether or not the intake air heater 78 is energized is determined based on the relay signal of the relay 82 (step 408). 410). And finally,
Whether or not the output current of the battery 36 detected by the current detector 84 is equal to or higher than the reference value is determined by the voltage detector 86.
It is determined whether the output voltage of the battery 36 detected in step 412 is below a reference value.

At this time, the starter 74, the glow plug 76,
If the intake air heater 78 is not energized and it is determined that the output current of the battery 36 is below the reference value and its output voltage is above the reference value, immediately energization of the heater 26 is started.

In addition, it is determined that any one of the starter 74, glow plug 76, and intake air heater 78 is energized, or that the output current of the battery 36 is greater than or equal to the reference value or that its output voltage is less than or equal to the reference value. If so, step 406;
Return to steps 406, 408, 410, 41
2 is repeated until a negative determination is made in step 412.

In other words, if any of the starter 74, glow plug 76, and intake air heater 78 is energized, the ECU 34 will cause the output current of the battery 36 to exceed the allowable value when the heater 26 starts energizing. It is determined that the capacity of the battery 36 is insufficient, and the start of energization of the heater 26 is prohibited.

Furthermore, when the output current of the battery 36 exceeds the reference value and the output voltage is less than the reference value, the ECU 34 makes a similar judgment and prohibits the start of energization of the heater 26.

As a result, the ECU 34 allows the start of energization to the heater 26 after confirming that the output current of the battery 36 does not exceed the allowable value and that the battery 36 has a margin of current output at that time. .

Therefore, the start of energization of the heater 26 is delayed until the battery 36 has sufficient current output.

FIG. 9 shows a regeneration process 500 for the trap 20.

This process 500 is performed subsequent to step 412 described above, and in FIG. 9, step 406 is performed.
In this process, a process for controlling the ignition of the particulates collected by the filter 24 (step 502) and a process for adjusting and controlling the opening degree of the exhaust flow rate control valve 44 (step 504) are started at the same time.

FIG. 10 shows the ignition process at step 502, in which it is first determined whether the headlamp is lit or not based on the detection signal from the operation sensor 72 (step 600).

When it is determined that the head lamp is on, the rotation speed sensor 6 detects whether the rotation speed of the diesel engine 10 is high or low.
Determination is made based on a detection signal of 0. In this embodiment, when the rotation of the diesel engine 10 is 1000 rpm or more, it is determined that the rotation is high, and when it is less than 1000 rpm, it is determined that the rotation is low (step 60).
2).

Further, when it is determined in step 600 that the headlight is not on, the duty ratio of the ignition current supplied to the heater 26 is set to a large value (step 604), and it is determined that the engine speed is high when the headlight is on. When the engine speed is determined to be low, the duty ratio of the ignition current is set to a medium value (step 606), and when it is determined that the engine speed is low when the headlights are on, the duty ratio of the ignition current is set to a small value (step 606). 608).

Thereafter, the supply of the ignition current with the duty ratio set as described above is started (steps 610 and 612).

When the supply of the ignition current with the duty ratio set in steps 606 and 608 is started, the duty ratio is gradually increased as shown in FIG. 3
0-2, 30-3, 30-4, 30-5, 30-
6, 30-7, and 30-8 are ignited in a predetermined order (step 614).

At this time, the ignition time of the heater 26 is monitored, and when it is determined that a predetermined time has elapsed (step 616), the ignition of the heater 26 is terminated (step 608). In addition, when the ignition of this heater 26 is completed, each heating wire 30-1, 30-2, 30
-3,30-4,30-5,30-6,30-
7, 30-8, the duty ratio of the ignition current supplied to the last heating wire 30 is temporally different from that at the start of supply of the ignition current (Fig. 5). It is controlled to gradually reduce with the opposite characteristics.

Next, the valve control process performed in step 502 in FIG. 9 will be explained.

The fine particles collected by the filter 24 are transferred to the heater 26
When the trap 2 is ignited, the exhaust flow rate control valve 44 provided in the exhaust passage 42 is temporarily opened and most of the exhaust gas is flowed into the exhaust passage 42, and the trap 2 is ignited.
The amount of exhaust gas that flows to zero is limited.

As a result, the flow velocity of the exhaust gas flowing into the trap 20 is reduced, and the particulates collected in the filter 24 are smoothly ignited and burned.

Furthermore, under a predetermined exhaust temperature condition where the oxygen concentration in the exhaust becomes high, the exhaust flow rate control valve 44 is forcibly controlled to open. This control is performed for the following reason.

If high-load operation such as steep hill climbing or high-speed driving is performed continuously with a sufficient amount of particulates collected in the filter 24, the exhaust temperature will become considerably high, and the oxygen concentration in the exhaust will decrease. It is small because the amount of fuel injected is large.

If the accelerator pedal is opened or opened halfway during this high-load operation, the oxygen concentration in the exhaust gas will rapidly increase because a large amount of air is being supplied to the diesel engine 10.

Therefore, a large amount of oxygen is supplied to an area where the exhaust gas temperature is considerably high, so that the ignited collected particles are rapidly combusted.

As a result, there is a risk that the filter 24 will become hot and the trap 20 will melt.

For this reason, in this embodiment, when the oxygen concentration in the exhaust gas increases under exhaust temperature conditions where the exhaust gas is at a considerably high temperature, the valve 44 is forcibly opened and the amount of exhaust gas flowing through the trap 20 is reduced. Ru. Note that the temperature of the exhaust gas is detected from the detection signal of the temperature sensor 66, and the oxygen concentration is detected from the detection signal of the O2 sensor 64.

By performing the above-described ignition process (step 502) and valve control process (step 504), first, the part of the particulates collected and accumulated in the filter 24 at the most upstream side of the exhaust gas is ignited.

Since the collected particulates are flammable and sufficient oxygen is contained in the exhaust gas, the ignited collected particulates serve as a ignition source, and the combustion of the collected particulates progresses toward the downstream of the exhaust gas.

When this combustion is completed, the filter 24 is free of residual particulate matter, so that the pressure loss in the trap 20 is reduced to the initial loss. That is, the trap 20 is regenerated and can be reused.

As explained above, according to this embodiment, when a predetermined amount of particles are accumulated in the filter 24 and the pressure loss thereof exceeds a predetermined value, the collected particles are ignited, and the amount of captured particles and the pressure loss are Since the values correspond almost exactly, it is possible to regenerate the trap 20 at an optimal time.

On the other hand, if the regeneration timing of the trap 20 is determined solely based on the cumulative engine speed, vehicle mileage, cumulative engine operating time, etc., the amount of particulates collected may vary due to differences in driving conditions, etc. At different times, a large amount of fine particles may accumulate during the regeneration period, and if the collected fine particles are ignited at this time, the temperature of the trap 20 will rise abnormally. As a result, the trap 20 may be damaged or its durability may be reduced.

As described above, according to this embodiment, the trap 20 is regenerated at an optimal time, so that damage to the trap 20 can be prevented or its durability can be improved.

In this embodiment, the above pressure loss was detected by the electric pressure sensor 68, but a conduit is formed between the upstream side and the downstream side of the trap 20, and the trap 20 is inserted into the conduit. It is also possible to reduce costs by providing a mechanical switch such as a diaphragm that is activated when the pressure difference between the upstream side and the downstream side reaches a predetermined value, and using this instead of the pressure sensor 68. It is suitable from this point of view.

Further, according to this embodiment, after it is confirmed that the trap 20 has warmed up, the trap 24
Since the fine particles that have been trapped in the trap 20 are ignited, a large temperature difference is prevented from occurring in the trap 20 portion. Therefore, it is possible to avoid the inconvenience of damage to the trap 20 due to thermal stress caused by this temperature difference.
Therefore, it is possible to improve the durability of the device.

Furthermore, according to this embodiment, when the trap 20 is regenerated when the headlamp is turned on, an ignition current with a duty ratio correlated to the output voltage of the battery 36 is supplied to the heater 26.
This prevents a decrease in the illuminance of the headlamp. For this reason, when driving at night, etc., the trap 2
Even if the zero regeneration process is started, good driving visibility is ensured, and therefore safe driving is possible. It is also preferable to configure the device so that a voltmeter is provided to detect the output voltage of the battery 36 and the duty ratio of the ignition current is controlled in accordance with the detection signal.

According to this embodiment, when the trap 20 is regenerated and the ignition current to the heater 26 is suddenly increased or decreased, such as when the heater 26 is turned on or off, the increase or decrease is done gradually, so that the headlamp is turned on. There is no sudden change in the supply voltage to the Therefore, even if the regeneration of the trap 20 starts or ends when the headlamp is turned on, the driver will not see any flickering of the headlamp light. Therefore, the driver does not feel anxious about the vehicle.

Further, according to the present embodiment, even if the oxygen concentration in the exhaust gas increases when the exhaust gas is under a predetermined exhaust temperature condition in which the exhaust gas is at a high temperature, the valve 44 is forcibly opened and the exhaust gas flows to the trap 20. Since the amount of particles trapped in the trap 20 is limited, abnormal combustion of the particulates collected in the trap 20 can be prevented. Therefore, the trap 20 can be prevented from melting and damage, and the reliability of the device can be improved.

Particularly, according to this embodiment, since the heater 26 is started to be energized after confirming that the output current of the battery 36 does not exceed its permissible value by starting the energization of the heater 26, the current load of the battery 36 is are sufficiently energized to ensure their reliable operation.

That is, the starter 74, the glow plug 76,
The intake air heater 78 operates reliably, and the collected particulates are reliably ignited by the heater 26.

Furthermore, the battery 36 is not over-discharged.

Furthermore, since the heater 26 is not energized at the same time as the other current loads, it is possible to use smaller power supply components such as the battery 36, and as a result, more space can be secured in the engine compartment. , the weight of the vehicle can be reduced.

[Effects of the invention] As explained above, according to the invention, since the energization of the heater for collecting particulate ignition does not overlap with the energization of other large current loads, each current load can be sufficiently energized. It becomes possible to operate the current load reliably, and it is also possible to prevent over-discharge of the battery power supply.

Furthermore, the power source to which these current loads are connected can be downsized, thereby making it possible to secure extra space, reduce the weight of the vehicle, and reduce the cost of the vehicle.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the overall configuration of the device according to the present invention,
Fig. 2 is an explanatory diagram of the configuration of the heater in Fig. 1, Fig. 3 is an explanatory diagram of the characteristics of the exhaust pressure reference value, Fig. 4 is a characteristic diagram showing the relationship between ignition current and its duty ratio, and Fig. 5 is a graph showing the relationship between the ignition current and its duty ratio. Explanatory diagram of control characteristics of duty ratio with respect to time, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 1
FIG. 0 is a flowchart explaining the control operation of the ECU in FIG. 1. 10... Diesel engine, 20... Trap, 24... Filter, 26... Heater, 32...
...Chiyotsupa circuit, 34...ECU, 36...Battery, 68...Pressure sensor, 74...Starter,
76... Glow plug, 78... Intake air heater, 80, 82... Relay, 84... Current detector, 86... Voltage detector.

Claims (1)

[Scope of utility model registration request] A trap including a filter that collects particulates contained in engine exhaust gas and a heater that ignites the particulates collected by the filter, a trapped amount detector that detects the amount of particulates collected by the filter, and a plurality of traps including a heater. A power source that supplies current to the current load, a load amount detector that detects the load amount of the power source including at least the voltage value or current value of the power source, and a time to energize the heater based on the detected value by the collection amount detector. and an energization control circuit that delays energization of the heater until the load amount of the power supply at the time of energization of the heater falls within an allowable range.