JPH05296024A - Exhaust filter regeneration device - Google Patents

Abstract

PURPOSE:To perform regeneration with certainty independently on self-burning propagation by heating whole of a filter to be a regeneration allowing temperature Ts or higher by means of a minimum electric power. CONSTITUTION:A temperature sensor 27 and a heater 28 are arranged in the vicinity of an inlet side end face of a particulates capturing filter 23. A bypass passage 24 is provided so as to bypass the filter 23, while a bypass side valve 26 is provided for opening and closing the passage. A filter side valve 25 which can be minutely opened is arranged on an upstream of the filter. When regeneration is started, electricity is supplied to the heater 28, the filter side valve 25 is fully closed, and a temperature Ti at the filter inlet is increased. When the detection temperature Ti reaches a first specified value T1, the filter side valve 25 is minutely opened. A temperature of the filter outlet To is increased by heat transmission due to weak exhaust flow. When the detection temperature Ti is lowered to a second specified value T2, the filter side valve 25 is fully closed again. With repetition of above operations, a temperature of a whole device is kept not less than a regeneration allowing temperature Ts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerator for forcibly regenerating an exhaust filter for collecting exhaust particulates of an internal combustion engine by heating a heater.

[0002]

2. Description of the Related Art In order to collect exhaust particles such as carbon discharged from an internal combustion engine such as a diesel engine, an exhaust filter made of a ceramic three-dimensional porous body, so-called ceramic foam, or a ceramic-sealed honeycomb filter is used. It has been conventionally considered to interpose it in the exhaust system, but with this exhaust filter, clogging over time becomes a problem, and some kind of regeneration means is indispensable. As one of the regeneration means, there is a regeneration device in which an electric heater is provided at an exhaust inlet of a filter made of ceramic foam or the like, and the heater is used to heat the filter to promote combustion of collected carbon and the like. It is known (for example, JP-A-57-153921).

During regeneration using such a heater or the like, a bypass passage bypassing the filter is provided in order to avoid cooling of the filter due to exhaust gas flow, and the exhaust flow is guided to the bypass passage side. Some have been done.

[0004]

However, in the above-mentioned conventional regenerator, since the combustion of the fine particles started in the vicinity of the heater depends on the self-combustion propagation which sequentially propagates to the downstream side of the filter, In order for the regeneration to be performed smoothly, a very large amount of fine particles must be collected during the regeneration. In this case, the pressure loss of the filter immediately before regeneration becomes very large, the back pressure of the engine rises, and the output performance and fuel consumption deteriorate. Moreover, there is a possibility that the temperature of the filter may be rapidly increased during regeneration, and the filter may be burnt.
Further, even if it is attempted to perform regeneration at a stage where the collected exhaust particulates are relatively small, the particulates do not propagate by self-combustion, so that regeneration is difficult on the downstream side of the filter where it is difficult to be heated by the heater.

In other words, in order to smoothly regenerate the entire filter without depending on self-combustion propagation, it is necessary to raise the temperature of the entire filter down to the downstream side by a heater, and a very large electric power is required. Is required. This is not preferable in an internal combustion engine for automobiles that depends on an on-vehicle battery. Alternatively, it is necessary to dispose a large number of heaters inside the filter, which leads to a complicated structure.

Even if the exhaust gas flow is bypassed during heating by the heater, the temperature on the filter inlet side close to the heater is high, but the temperature rise on the filter outlet side is slow, and rather heat transfer via the exhaust gas flow occurs. Since it does not exist, the temperature gradient on the inlet and outlet sides only increases.

[0007]

Therefore, in the present invention,
By making good use of heat transfer via a weak exhaust flow or air flow, the heater provided on the filter inlet side efficiently raises the temperature of the entire filter.

FIG. 1 shows a regenerator according to claim 1 of the present invention. This regenerator is a filter 1 for collecting exhaust particulates which is interposed in an exhaust passage of an internal combustion engine, and the filter 1. A heater 2 provided at the exhaust inlet of the exhaust gas, a bypass passage 3 formed so as to bypass the filter 1, and an exhaust flow control mechanism 4 for controlling the exhaust flow to bypass.
A heater control means 5 that energizes the heater 2 during a predetermined regeneration period; and a predetermined initial temperature increase period immediately after the start of regeneration through the exhaust flow control mechanism 4 so that the entire amount of exhaust gas is bypassed by the bypass passage 3
And the temperature control means 7 for intermittently supplying a small amount of exhaust gas to the filter via the exhaust flow control mechanism 4 after the completion of the initial temperature increase. ..

The exhaust flow control mechanism 4 is, for example, as defined in claim 2.
As shown in FIG. 3, the exhaust gas filter 1 is configured to include a filter-side valve that opens and closes the upstream side of the exhaust filter 1 and a bypass-side valve that opens and closes the bypass passage 3. The filter-side valve is slightly opened to supply a small amount of exhaust You can

FIG. 2 shows a regenerator according to claim 3 of the present invention. This regenerator is a filter 1 for trapping exhaust particulates provided in an exhaust passage of an internal combustion engine and the filter 1. A heater 2 provided at the exhaust inlet of the exhaust gas, a bypass passage 3 formed so as to bypass the filter 1, and an exhaust flow control mechanism 4 for controlling the exhaust flow to bypass.
An air supply mechanism 11 for supplying air to the filter 1, a heater control means 5 for energizing the heater 2 for a predetermined regeneration period, and an exhaust flow control mechanism 4 for the entire amount of exhaust gas during the regeneration period. The bypass control means 12 for guiding the air to the bypass passage 3 and a small amount of air is intermittently passed through the air supply mechanism 11 after the completion of a predetermined initial temperature raising period.
And temperature control means 13 for supplying the

According to the invention of claim 4, the filter 1 is provided.
Is equipped with a temperature sensor at the exhaust inlet of the
The period until the temperature reaches the set temperature T1 is set as the initial temperature rising period, and the start and stop of the supply of a small amount of exhaust gas or air in the temperature control means is started and stopped at the first set temperature T1 and the second set temperature T2 (T2 < It was carried out at T1).

Further, in the invention of claim 5, the supply period of the small amount of exhaust gas in the temperature control means 7 is a period until the integrated value of the coefficients retrieved from the map using the engine operating condition as a parameter reaches a predetermined value, In addition, the suspension period and the initial temperature rising period are set to be constant periods.

[0013]

In the configuration shown in FIG. 1, normally, the entire amount of exhaust gas is guided to the filter 1 side, and exhaust particulates such as carbon in the exhaust gas are collected. When it becomes time to regenerate the exhaust particulate matter, the heater 2 is energized to heat the filter 1. At the same time, the entire amount of exhaust gas is guided to the bypass passage 3 side. As a result, the temperature at the inlet side of the filter 1 rises rapidly. When the predetermined initial temperature rise is completed, a small amount of exhaust gas is intermittently supplied to the filter 1 by, for example, switching the filter valve to the slightly open state or the fully closed state.

That is, when a small amount of exhaust gas flows through the filter 1, the temperature on the outlet side of the filter 1 rises and the temperature on the inlet side decreases due to heat transfer by the exhaust stream. Then, the supply of a small amount of exhaust gas is stopped before the inlet-side temperature is excessively lowered, so that the inlet-side temperature rises again. By repeating this action, the entire filter 1 is effectively heated above the regenerable temperature.

In the structure of claim 3 shown in FIG. 2, a small amount of air is intermittently supplied instead of supplying a small amount of exhaust gas. Therefore, similarly to the above, the heat is transferred by the air flow, so that the filter 1 is effectively heated to the outlet side.

Further, in the structure of the fourth aspect, the initial temperature raising period and the intermittent period of a small amount of exhaust gas and air are regulated by the temperature, and the detected temperature at the inlet side of the filter 1 is maintained in the range of T1 to T2. Therefore, the temperature of the entire filter 1 can be stably obtained.

According to the structure of claim 5, each period is appropriately provided without using the temperature sensor. That is, the temperature drop on the inlet side and the temperature rise on the outlet side when a small amount of exhaust gas is passed through the filter 1 differ depending on engine operating conditions.
For example, in the high-speed low-load region, the exhaust gas flow rate is large and the exhaust gas temperature is low, so the temperature drop on the inlet side and the temperature rise on the outlet side are relatively rapid. On the contrary, at low speed and high load, the temperature drop on the inlet side and the temperature rise on the outlet side become relatively slow. In consideration of these, the supply period of a small amount of exhaust gas is controlled.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 3 is a structural explanatory view showing the mechanical structure of the first embodiment of the present invention. An exhaust filter 23 for trapping exhaust particulates is interposed in the exhaust passage 22 of the diesel engine 21. Has been done. A bypass passage 24 is formed so as to bypass the filter 23. A butterfly valve type filter valve 25 for opening and closing the exhaust passage 22 is provided upstream of the filter 23 in the exhaust passage 22, more specifically, downstream of the branch portion of the bypass passage 24, and the bypass passage 24 is provided. A butterfly valve type bypass side valve 26 that opens and closes the bypass passage 24 is provided in the middle of the passage. The filter side valve 25 and the bypass side valve 26 constitute an exhaust flow control mechanism.

The above-mentioned filter 23 is a so-called plugging in which a number of fine flow paths are formed in a three-dimensional porous body of ceramics, so-called ceramic foam, or a ceramic block, and the flow path ends are alternately closed. The honeycomb filter is used as a filter element. An appropriate catalyst may be supported to accelerate the regeneration. This filter 2
A temperature sensor 27 composed of a thermocouple is arranged in the vicinity of the end face on the exhaust gas inlet side of 3, and a heater 28 is arranged slightly upstream thereof.

The filter-side valve 25 is driven to open and close by an actuator 29 composed of a solenoid or the like, and is switched between three positions of a fully open position, a fully open position and a slightly open slightly opened position. It is possible. The bypass valve 26 is opened and closed by an actuator 30 composed of a solenoid or the like, and can be switched between two positions, a fully closed position and a fully open position.

Pressure sensors 31 and 32 are provided on the upstream and downstream sides of the filter 23 in the exhaust passage 22 to detect the clogging of the filter 23 from the differential pressure across the filter 23.

Reference numeral 33 denotes a control unit which controls the regeneration process using the heater 28. The control unit 33 uses a so-called microcomputer system, to which the detection signals of the temperature sensor 27 and the pressure sensors 31 and 32 are input, and as will be described later, the heater 28 and the filter-side valve 25 according to a predetermined program. , The bypass side valve 26 is controlled.

Next, the operation of the above embodiment will be described.

During normal operation of the internal combustion engine 21, the filter valve 25 is fully open and the bypass valve 26 is fully closed. Therefore, the entire amount of exhaust gas flows through the filter 23, and fine particles such as carbon contained in the exhaust gas are collected.

As the collection proceeds, the pressure sensors 31, 32
When it detects that it is time to regenerate,
Energization of the heater 28 is started and the filter 23 is heated. At the same time, the bypass side valve 26 is fully opened,
Moreover, the filter side valve 25 is fully closed. Therefore, all the exhaust gas flows through the bypass passage 24 side, and the exhaust gas does not flow into the filter 23. Therefore, the filter inlet temperature Ti near the heater 28 quickly rises as shown in FIG. However, the filter outlet temperature To rises relatively slowly because heat in the filter 23 does not move much.

When the filter inlet temperature Ti detected by the temperature sensor 27 reaches a predetermined first set temperature T1, the filter valve 25 is opened slightly and a small amount of exhaust gas is introduced into the filter 23. .. The first set temperature T
1 is a renewable temperature Ts at which the oxidation and combustion of fine particles can occur.
Is set to exceed. The period until the first set temperature T1 is reached first is the initial temperature raising period. When a small amount of exhaust gas is introduced into the filter 23, heat transfer to the downstream side of the filter 23 is promoted by this exhaust gas flow, so that the filter outlet temperature To rapidly rises, as shown in FIG. On the contrary, the filter inlet temperature Ti decreases. Further, when the filter inlet temperature Ti detected by the temperature sensor due to the exhaust gas flow decreases to the second set temperature T2 (where Ts <T2 <T1), the filter side valve 25 is fully closed again. As a result, the filter inlet temperature Ti rises again and the filter outlet temperature To increases.
Decreases slowly. After that, when the filter inlet temperature Ti reaches the first set temperature T1, the filter side valve 25 is opened slightly, and when the temperature reaches the second set temperature T2, the filter side valve 25 is opened fully. , Supply a small amount of exhaust gas intermittently. This operation is continued until a predetermined period elapses so that the reproduction is sufficiently completed.

As a result of the above operation, the filter inlet temperature Ti is maintained between T2 and T1 as shown in FIG. The filter outlet temperature To is maintained in a temperature range slightly lower than this, and can always be maintained above the regenerable temperature Ts. Therefore, the filter 23
Is efficiently heated to a temperature equal to or higher than the regenerable temperature Ts, and reliable regeneration is possible without depending on self-combustion propagation even at a stage where the amount of collected particulates is small.

If the filter valve 25 is kept fully closed, as shown in FIG. 6, the filter inlet temperature Ti becomes very high, but the filter outlet temperature To is suppressed to a low level. If the heat energy of the heater 28 is the same, the entire filter 23 cannot be maintained at the reproducible temperature Ts. Further, if the filter side valve 25 is fixed in a slightly opened state, the amount of heat taken out to the outside by the exhaust flow becomes larger than in the case of the above-mentioned embodiment, so that as shown in FIG. Although the temperature gradient of 2 is small, it is still difficult to keep the entire filter 23 at the reproducible temperature Ts. In other words, by providing a weak exhaust flow intermittently as in the above embodiment, the filter 23 with the least heat energy is provided.
The entire temperature can be the reproducible temperature Ts.

FIG. 4 is a flow chart showing a specific flow of the reproduction control executed in the control unit 33, which will be described below. First, when it is determined in step 2 that the regeneration time is reached based on the pressure difference detected by the pressure sensors 31 and 32, the regeneration flag indicating that regeneration is in progress is turned on (step 3), and the bypass side valve 26 is fully opened. At the same time, the filter side valve 25 is fully closed (steps 4 and 5). At the same time, energization of the heater 28 is started (step 6). Once this reproduction is started, the process proceeds from step 1 to step 7 based on the reproduction flag.

In step 7, it is determined whether the filter valve 25 is in the fully closed state. Since it is in the fully closed state during the initial temperature rising period immediately after the start of regeneration, the routine proceeds to step 8, where it is judged whether the detected temperature Ti becomes equal to or higher than the first set temperature T1.
Also, the reproduction time is counted in step 12, and step 1
At 3, it is determined whether the reproduction time has reached a predetermined time.

When the detected temperature Ti reaches the first set temperature T1 with the filter side valve 25 fully closed, the process proceeds from steps 7 and 8 to step 9 and the filter side valve 2
5 is in a slightly opened state. Therefore, thereafter, the process proceeds from step 7 to step 10 and the detected temperature Ti is set to the second set temperature T2.
Compare with. The detected temperature Ti is the second set temperature T2.
When the temperature drops to 0, the process proceeds to step 11 and the filter side valve 25 is returned to the fully closed state. Further, if the detected temperature Ti rises again to the first set temperature T1 in this fully closed state, the process returns to the slightly opened state by the processing of steps 7-9.

In this way, the filter-side valve 25 is repeatedly closed and fully opened. Eventually, the regeneration time reaches a predetermined time (step 13), and at that time, the power supply to the heater 28 is stopped (step 14),
The regeneration time counter is reset (step 15), and the filter valve 25 is fully opened and the bypass valve 26 is fully closed (steps 16 and 17). Furthermore,
The reproduction flag is turned off (step 18), and a series of processing is ended.

Next, FIG. 8 shows a second embodiment of the present invention. The regenerator of this embodiment is provided with, for example, an electric secondary air supply pump 41 as an air supply mechanism for supplying a small amount of air to the filter 23, and the air supply passage 42 has a filter 23 in the exhaust passage 22. It is connected upstream and downstream from the filter valve 25. In the second embodiment, during the regeneration period, the filter side valve 25 is kept in the fully closed state even after the lapse of the initial temperature raising period, and the entire amount of exhaust gas is guided to the bypass passage 24 side.
Then, when the temperature Ti detected by the temperature sensor 27 reaches the first set temperature T1, the secondary air supply pump 41 operates and a small amount of air is supplied to the filter 23. Further, when the detected temperature Ti drops to the second set temperature T2 due to the air supply, the secondary air supply pump 41 is turned off and the air supply is stopped. That is, a small amount of air is intermittently supplied instead of introducing a small amount of exhaust gas in the first embodiment.

In the first embodiment described above, the flow rate of exhaust gas supplied to the filter 23 when the valve 25 on the filter side is in the slightly opened state changes depending on the operating state of the engine. However, according to the second embodiment, Since the secondary air supply pump 41 can always provide a constant amount of air regardless of the operating state, the temperature of the filter 23 can be controlled more accurately and more reliable regeneration can be performed.

Next, FIG. 9 shows a third embodiment of the present invention. Like the first embodiment, the regenerator of this embodiment is configured to introduce a small amount of exhaust gas by opening the filter-side valve 25 in a slightly opened state, and in particular, is equipped with a temperature sensor 27. There is no configuration. This third
In the example, the temperature Ti at the inlet of the filter after the regeneration is started
Until the first set temperature T1 is reached, that is, the initial temperature rise period t1 (see FIG. 10) is given as a fixed period that is experimentally obtained in advance. Then, the supply period t of a small amount of exhaust gas
2 (see FIG. 10) is variably given based on the engine operating conditions. Specifically, the engine speed and load (for example,
FIG. 1 with the lever opening of the fuel injection pump as a parameter
The coefficient C is obtained from the map shown in FIG. 1, and when the integrated value reaches a predetermined value, it is determined that the supply period t2 has elapsed, and the filter side valve 25 is switched from the slightly opened state to the fully closed state. In the high-speed and low-load region, a large amount of exhaust gas flows into the filter 23 and its temperature is low, so the filter inlet temperature T
i rapidly decreases, and the filter outlet temperature To reaches a peak in a short time. Therefore, a large coefficient C is given on the high speed and low load side. On the contrary, in the low speed and high load region, the time until the filter outlet temperature To reaches the peak becomes long, so the coefficient C on the low speed and high load side is given small. Therefore, by defining the supply period t2 as the integrated value, even if the operating conditions change, the filter inlet temperature Ti does not drop excessively, and a small amount of exhaust gas flows for an appropriate period. be able to. Further, the exhaust stop period t3 (see FIG. 10) is given as a fixed period that is experimentally obtained in advance, like the initial temperature increase period t1. This is because the temperature change when the filter-side valve 25 is fully closed does not depend so much on the engine operating conditions.

Therefore, according to the third embodiment, the temperature control of the filter 23 at the time of regeneration can be realized with a simple structure without the temperature sensor 27, and the cost of the regeneration device can be reduced.

FIG. 12 and FIG. 13 are flowcharts showing a concrete processing flow of the reproduction control of the third embodiment, which will be described below. Steps 101 to 106 are step 1 of the flowchart of FIG. 4 described above.
~ The same process as in step 6, and when it is determined that the reproduction time has come, the reproduction flag is turned ON (step 103),
Further, the bypass side valve 26 is fully opened and the filter side valve 25 is fully closed (steps 104, 10).
5). At the same time, energization of the heater 28 is started (step 106).

In step 107, an initial temperature rise flag indicating that the initial temperature rise is completed is determined. Before the completion of the initial temperature increase, the determination result is NO, and the process proceeds to steps 107 and 108,
While counting the elapsed time t1 of this initial temperature rise,
It is determined whether the elapsed time t1 has reached a predetermined time. Until the predetermined time is reached, the fully closed state of the filter valve 25 is maintained as the initial temperature raising period.

When the initial temperature raising period has elapsed, the initial temperature raising flag is turned on and the filter valve 25 is opened slightly (steps 110 and 111). The period t2 in which the slightly opened state is set is determined by the processing in steps 113 to 117. That is, the coefficient C is searched based on the above-mentioned map (see FIG. 11) (step 113), and this is sequentially integrated (step 114), and it is determined whether the integrated value has reached a predetermined value (step 115). .. The slightly opened state is continued until the predetermined value is reached. When the integrated value reaches a predetermined value, the integrated value is reset and the filter valve 25 is fully closed (steps 116 and 11).
7) In this way, when the filter valve 25 is fully closed, the elapsed time t3 in that state is counted in step 118, and the fully closed state is maintained until it reaches a predetermined time (step 119). This fully closed time t3
Reaches the predetermined time, reset the counter of t3,
Moreover, the filter-side valve 25 is returned to the slightly opened state (steps 120 and 121).

By repeating such processing, the filter-side valve 25 repeats the slightly opened state and the fully closed state. Eventually, the regeneration time counted in step 122 reaches a predetermined time (step 123), and at that time, the power supply to the heater 28 is stopped (step 12).
At the same time, the filter side valve 25 is fully opened and the bypass side valve 26 is fully closed (steps 126, 12).
7) In addition, various counters, flags, etc. are reset (steps 125, 128, 129) and a series of processing is ended.

In each of the above-described embodiments, since the exhaust gas flows along the front-rear direction of the filter 23, the heater 28 is arranged near the front end face of the filter 23. And the heater 28 is arranged on the inner peripheral side thereof and the exhaust gas is allowed to flow from the inner peripheral side to the outer peripheral side, or the heater 28 is arranged on the outer peripheral side and the exhaust gas is arranged from the outer peripheral side to the inner peripheral side. It is also possible to use a structure that allows flow. Moreover, as the filter 23, a metal foam type filter, a sintered filter of metal particles or metal fibers, a ceramic fiber filter, or the like can be used. In addition, as the determination of the reproduction time, in the above embodiment,
Although it is performed based on the pressure difference across the filter 23, the determination may be made based on the operating history of the engine, the traveling distance of the vehicle, or the like.

[0043]

As is apparent from the above description, according to the exhaust gas filter regenerating apparatus of the present invention, it is possible to efficiently utilize the heat energy of the heater to heat the entire filter. In other words, it is not necessary to arrange many heaters,
Moreover, the entire filter can be maintained at a temperature above the regenerable temperature with a minimum amount of electric power, and the entire filter can be reliably regenerated without depending on the self-combustion propagation of exhaust particulates. When the filter valve is opened slightly and a small amount of exhaust gas is introduced as in the second aspect, efficient heating of the entire filter can be realized without using a complicated configuration.

Further, when the air supply mechanism is provided as in the third aspect, the air flow can be stably applied regardless of the engine operating condition, and the regeneration can be performed more reliably. If a temperature sensor is provided as in claim 4 and the exhaust flow or the air flow is controlled based on the detected temperature,
The temperature control of the filter becomes more accurate.

Further, if each period is controlled as in the fifth aspect, the temperature sensor becomes unnecessary and the structure can be further simplified.

[Brief description of drawings]

FIG. 1 is a claim correspondence diagram showing a reproducing apparatus according to claim 1.

FIG. 2 is a claim correspondence diagram showing a reproducing apparatus according to claim 3;

FIG. 3 is a structural explanatory view showing a mechanical structure of the first embodiment of the present invention.

FIG. 4 is a flowchart showing the reproduction control of the first embodiment.

FIG. 5 is a time chart showing changes in filter inlet temperature Ti and outlet temperature To during regeneration in the first embodiment.

FIG. 6 is a time chart showing changes in the filter inlet temperature Ti and the outlet temperature To when the filter valve is fixed in the fully closed state.

FIG. 7 is a time chart showing changes in the filter inlet temperature Ti and the outlet temperature To when the filter valve is fixed in a slightly opened state.

FIG. 8 is a structural explanatory view showing a second embodiment of the present invention.

FIG. 9 is a structural explanatory view showing a third embodiment of the present invention.

FIG. 10 is a time chart showing changes in filter inlet temperature Ti and outlet temperature To during regeneration in the third embodiment.

FIG. 11 is a characteristic diagram showing a map of a coefficient C.

FIG. 12 is a flowchart showing the first half of the flow of reproduction control according to the third embodiment.

FIG. 13 is a flowchart showing the latter half of the flow of reproduction control according to the third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Filter 2 ... Heater 3 ... Bypass passage 4 ... Exhaust flow control mechanism 5 ... Heater control means 6 ... Initial temperature rise control means 7 ... Temperature control means 11 ... Air supply mechanism 12 ... Bypass control means 13 ... Temperature control means

Claims (5)

[Claims] 1. A filter for collecting exhaust particulate matter, which is interposed in an exhaust passage of an internal combustion engine, a heater provided at an exhaust inlet portion of the filter, and a bypass passage formed so as to bypass the filter. An exhaust flow control mechanism for controlling the bypassed exhaust flow, a heater control means for energizing the heater during a predetermined regeneration period, and an exhaust flow control mechanism for controlling the exhaust flow through the exhaust flow control mechanism during a predetermined initial temperature rising period immediately after the start of regeneration. An initial temperature rise control means for guiding the entire amount to the bypass passage, and a temperature control means for intermittently supplying a small amount of exhaust gas to the filter via the exhaust flow control mechanism after completion of the initial temperature rise are characterized. Exhaust filter regeneration device. 2. The exhaust flow control mechanism comprises a filter-side valve that opens and closes the upstream side of the exhaust filter and a bypass-side valve that opens and closes the bypass passage. A small amount of the valve is provided by opening the filter-side valve slightly. The exhaust filter regenerator according to claim 1, wherein exhaust gas is supplied. 3. A filter for collecting exhaust particulate matter, which is interposed in an exhaust passage of an internal combustion engine, a heater provided at an exhaust inlet portion of the filter, and a bypass passage formed so as to bypass the filter. An exhaust flow control mechanism for controlling the bypassed exhaust flow, an air supply mechanism for supplying air to the filter, a heater control means for energizing the heater during a predetermined regeneration period, and an exhaust flow control for the regeneration period A bypass control means for guiding the entire amount of exhaust gas to the bypass passage through the mechanism, and a temperature control means for intermittently supplying a small amount of air to the filter via the air supply mechanism after the completion of the predetermined initial temperature raising period. An exhaust filter regenerator characterized by being provided. 4. A temperature sensor is provided at an exhaust gas inlet portion of the filter, and a period until the detected temperature reaches a first set temperature T1 is the initial temperature raising period, and a small amount of exhaust gas in the temperature control means or The start and stop of air supply are controlled by the first set temperature T1 and the second set temperature T, respectively.
The exhaust gas regenerating apparatus according to any one of claims 1 to 3, wherein the regeneration is performed at 2 (T2 <T1). 5. A supply period of a small amount of exhaust gas in the temperature control means is a period until an integrated value of coefficients retrieved from a map using an engine operating condition as a parameter reaches a predetermined value, and the stop period and the initial period. The exhaust gas filter regeneration device according to claim 1 or 2, wherein the temperature raising period is set to a fixed period.