JP3485344B2 - Exhaust particulate purification device for internal combustion engine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided in an exhaust pipe line of an internal combustion engine, such as a diesel engine, which discharges exhaust gas containing fine particles (particulates) mainly containing carbon particles. The present invention relates to an exhaust particulate purifying apparatus for an internal combustion engine, which has a function of collecting the particulates by a filter and incinerating the collected particulates to regenerate the collecting ability of the filter.

[0002]

2. Description of the Related Art Exhaust gas from a diesel engine contains fine particles composed mainly of carbon particles called "diesel particulates", which are also the causative agent of "black diesel smoke". In order to purify the exhaust gas, a porous and heat-resistant filter with good air permeability is provided in the exhaust pipe line to filter the exhaust gas and collect fine particles. Generally, porous ceramics are often used as a material for a filter for collecting fine particles.

When the exhaust gas is filtered by such a filter and the collection of the fine particles is continued, the collected fine particles are gradually deposited on the filter to lower the air permeability of the filter.
Exhaust gas passage resistance increases, which increases engine back pressure and degrades engine performance, so particulate matter trapped and deposited on the filter must sometimes be removed by some means.

As a means for removing the accumulated fine particles, generally, an electric heater attached to the filter is energized, or a flame generated by a light oil burner attached to the filter is applied to the filter to remove the particulate matter. Although a method of burning the deposited fine particles by heating the part and raising the temperature to a high temperature of about 650 ° C. or higher which is the ignition temperature of the fine particles is considered, these methods consume a large amount of electric power. However, there is a problem that the system configuration becomes complicated and the size becomes large.

As another means, the filter for collecting fine particles is made of a porous and heat-resistant inorganic material like the catalyst carrier of a normal catalytic converter, and it is placed in the exhaust pipe line. Therefore, the filter not only has the function of filtering particulates but also serves as a carrier for the catalyst so that the filter itself can carry the catalyst, and injects additional fuel into the exhaust gas to feed the fuel to the filter. There is known a method in which the temperature of the fine particles trapped in the filter is raised to a temperature higher than the ignition temperature and incinerated by the oxidation reaction heat generated at that time by oxidizing the catalyst carried. (See JP-A-58-38311.)

This prior art method will be described in more detail with reference to FIG. The diesel engine 1 is a four-cylinder engine having four cylinders # 1 to # 4, and each cylinder is supplied with fuel pressurized from a fuel pump 2 by a fuel line 3 and an injector 4, respectively. . Exhaust gas discharged from each cylinder passes through an exhaust device 5 and a common catalytic particulate filter 6
Flows in, is purified, and is discharged from the exhaust pipe 7 into the atmosphere.

In this case, the fuel injection is usually # 1 → # 3 → #
4 → # 2, the check valve 8 which can be operated electromagnetically is used to allow only the flow of fuel from the fuel line 3 of the cylinder # 2 to the fuel line 3 of the cylinder # 4. The check valve 8 is provided between the lines 3 so that when the control device 9 issues a control signal, the check valve 8 is opened so as to allow the fuel flow in the above-described direction, and is closed at other times. To maintain.

Since the # 2 cylinder and the # 4 cylinder are in a phase-shifted relationship such that the latter piston is at the bottom dead center when the former piston is at the top dead center, the former is in the compression stroke. The latter is at the end of the expansion stroke. Therefore, if the check valve 8 is opened at that time, normal fuel injection is performed in the # 2 cylinder, and additional fuel injection is performed at the end of the expansion stroke in which fuel is not normally supplied to the # 4 cylinder. This fuel is mixed into the exhaust gas and supplied to the catalytic particulate matter filter 6, which is oxidized by the catalyst carried on the filter 6 to generate heat, thereby removing the particulates deposited on the filter. Ignite by heating above the ignition temperature (about 650 ° C).

[0009]

The above-mentioned prior art has the advantage of enabling a simple and compact system configuration, but since it utilizes a catalyst, it is added to the exhaust gas at the end of the expansion stroke. Even if the fuel injection is performed, if the temperature of the catalyst carried on the filter is not higher than about 250 ° C, which is the temperature at which the catalyst is activated, the oxidation reaction of the added fuel by the catalyst is not performed, At the end of the expansion stroke, the temperature of the combustion gas or exhaust gas in the cylinder of the engine or in the exhaust pipe is considerably lowered, and it is unlikely that the additional fuel injected there is immediately ignited,
The additional fuel is discharged to the atmosphere from the exhaust pipe 7 as it is, and rather deteriorates the emission.

Depending on the operating conditions, such as during light load operation, the temperature of the exhaust gas is the catalyst activation temperature (about 250 ° C.).
Since it may be lower than C), the above-mentioned problem of emission deterioration occurs under such operating conditions.
Therefore, in order to carry out the regeneration of the filter by the catalyst without any problem under all operating conditions, under some operating conditions such that the temperature of the exhaust gas becomes lower than the catalyst activation temperature, the temperature of the catalyst is kept above the catalyst activation temperature by some means. Need to increase.

As a means of increasing the catalyst temperature to a temperature higher than the catalyst activation temperature when the temperature is low, a method of additionally injecting fuel in the expansion stroke can be considered in addition to the normal fuel injection. The additional injection to be performed has an optimum timing and an optimum injection amount, and if it deviates from that, the injected fuel is not burned and is supplied to the catalyst, and not only a sufficient temperature rise effect on the catalyst is not obtained, but also the additional injection is performed. Since the fuel that has not been burned even if supplied is not oxidized by the catalyst, there is a possibility that it will be emitted into the atmosphere as it is and deteriorate emission.

In the above-mentioned prior art, as shown in FIG. 9, the bypass passage by the check valve 8 is provided between the fuel lines 3 of the two cylinders. Since the timing of the additional injection in the # 2 cylinder is synchronized with the normal injection timing for the # 2 cylinder, it is limited to the end of the expansion stroke of the # 4 cylinder, and the additional injection amount is also the normal injection quantity for the # 2 cylinder. It is an amount determined depending on the normal injection amount, such as being limited to a fixed ratio to the injection amount, and it cannot be freely changed. It is not possible to freely select the injection amount. Therefore, since the optimum amount cannot be injected at the optimum time, the emission may worsen as described above.

According to the present invention, when a filter with a catalyst is used and additional fuel injection is performed in the expansion stroke or the exhaust stroke, the above-mentioned problems in the prior art are dealt with and the optimum time is optimized. Provides a means for injecting a quantity of fuel, thereby enabling regeneration of the filter with catalyst under all operating conditions and preventing emission deterioration under some operating conditions The purpose is to do.

[0014]

As a first means for solving the above-mentioned problems, the present invention is provided in an exhaust pipe line from an internal combustion engine to collect fine particles in exhaust gas and, at the same time, as such. A catalyst-carrying filter carrying a catalyst, a temperature detecting means for detecting the temperature of the catalyst-carrying filter, and a temperature signal of the catalyst-carrying filter output by the temperature detecting means are processed accordingly. The control means outputs a control signal, and fuel injection means for injecting fuel into the cylinder of the internal combustion engine to supply the fuel in response to the control signal output from the control means. During regeneration of the filter with catalyst on which the collected fine particles are accumulated, the temperature of the filter with catalyst detected by the temperature detecting means is equal to or lower than the activation temperature of the catalyst. When the touch necessary to medium to activate, the injection quantity of the additional and injection timing of fuel early in the expansion stroke of the internal combustion engine, the filter with catalyst
When the temperature of the catalyst-equipped filter is equal to or higher than the activation temperature of the catalyst, it is accumulated on the catalyst-equipped filter while the additional injection amount increases as the temperature of the catalyst increases. Fuel injection timing and additional fuel required for the expansion stroke and exhaust stroke to reach the combustion temperature
The amount of additional injection increases the temperature of the filter with catalyst.
The internal combustion engine is configured to perform a calculation so that the additional injection amount becomes smaller , and to output a signal of the calculated injection timing and injection amount of the fuel to the fuel injection means as a control signal. Exhaust particulate purifying device, and
Provided is a method for regenerating a filter with a catalyst by using such an exhaust particulate purification device.

As a second means for solving the above problems, the present invention is provided in an exhaust pipe line from an internal combustion engine to collect fine particles in exhaust gas and to carry a catalyst on itself. And a fuel injection means that is driven by a cam and injects fuel into the cylinder of the internal combustion engine to supply the fuel to the cylinder of the internal combustion engine. other cam protrusion which performs injection, at the time of reproduction of the catalyst-carried filter that trapped particulate is deposited, additional required microparticles with activating the catalysts to be reached in the combustion temperature There is provided an exhaust particulate purifying device for an internal combustion engine, comprising another cam convex portion for performing fuel injection in the expansion stroke and the exhaust stroke of the internal combustion engine.

[0016]

In the first exhaust particulate purifying means of the present invention, the temperature of the filter carrying the catalyst is detected by the temperature detecting means, and the control means sends the control signal to the fuel injection means in response to the temperature signal. Emits and injects fuel upstream of the filter. Moreover, the control unit, when the temperature of the filter during regeneration of the filter that the collected fine particles are deposited is equal to or less than the activation temperature of the catalyst is required in order to activate the catalyst, the expansion stroke Since the injection timing and injection amount of the additional fuel in the early stage of the fuel injection are calculated and output as the control signal to the fuel injection means, the optimum amount of fuel additionally injected at the optimum time in the expansion stroke has a relatively high temperature. Burning in the exhaust gas of, raises the temperature of the exhaust gas,
The catalyst carried on the filter is heated to reach the activation temperature.

When the catalyst reaches the activation temperature, the fuel additionally injected during the subsequent expansion stroke to exhaust stroke is oxidized by the catalyst. Then, the heat generated by the oxidation reaction by the catalyst heats the fine particles deposited on the filter to reach the ignition temperature, so that the fine particles are incinerated and the filter is regenerated. Therefore, even in a state where the temperature of the exhaust gas is low and the catalyst carried on the filter has not reached the activation temperature, the filter can be regenerated without deteriorating the emission.

In the second exhaust particulate purifying means of the present invention, there is provided fuel injection means for injecting fuel to the upstream side of the filter with catalyst by being driven by a cam, and the cam is normally provided to the main body of the internal combustion engine. performed in the other cam projection portion which performs fuel injection, the required additional fuel injection during the regeneration of the catalyst-filters the collected fine particles are deposited, in the expansion stroke and exhaust stroke of the internal combustion engine since another and a cam protrusion for, by selecting the shape of the cam protrusion appropriate, and additional injection of an appropriate amount of fuel at a time of optimum in the expansion stroke and exhaust stroke, the emission It activates the catalyst without deteriorating it, oxidizes the fuel additionally injected by the activated catalyst, heats the deposited particles by the heat of reaction, and reaches the combustion temperature to incinerate. Carry out the regeneration of the filter by.

[0019]

1 shows a system configuration of a first embodiment of the present invention. 10 is an internal combustion engine body (diesel engine), 11 is an electronically controlled fuel injection valve, 12 is an injection valve 11.
1 shows a fuel injection pump for supplying high-pressure fuel.
Reference numeral 13 is a fine particle collecting device, which has a built-in filter 14 with a catalyst supporting (for example, coating) a catalyst.

Reference numeral 15 is a differential pressure sensor for detecting the differential pressure across the filter 14. In order to determine the regeneration timing of the filter 14, other indicators such as the integrated value of the engine speed may be used instead of the differential pressure sensor 15. Reference numeral 16 is a temperature measuring body (temperature sensor) for detecting the temperature of the filter 14.
And is attached near the filter 14. 17
Is a control device, including a microcomputer, which controls the various types of control during normal traveling as well as the timing of regeneration of the filter 14 based on signals from the differential pressure sensor 15 and the temperature sensing element 16, The fuel injection timing and injection amount are controlled. 18 is an intake throttle valve (throttle valve),
It has a role of reducing the intake air amount as needed.

In such a particulate matter (exhaust particulates) collecting system for the diesel engine 10, the control device 17 causes the filter 14 to collect the particulates and the detection value of the differential pressure sensor 15 is a preset value. When the value exceeds, the operating state of the engine body 10, in particular, the injection pattern of fuel injection by the fuel injection valve 11 is changed according to a predetermined procedure for regenerating the filter 14.

FIG. 2 is a diagram showing an electronically controlled fuel injection system in the system shown in FIG. 1. The fuel injection valve 11 for injecting fuel in response to an electric signal from the controller 17 is provided with a fuel injection pump 12. Boosted to reservoir 1
A high-pressure fuel whose pressure inside 9 is adjusted to 20 to 100 MPa is constantly supplied. Depending on whether the engine body 10 is in a normal operating state or the filter 14 is in a regenerating state, different injection pulse signals are output as control signals from the control device 17 to the fuel injection valve 11,
A solenoid coil incorporated in the injection valve 11 or an actuator composed of a piezoelectric element or the like operates to inject fuel into each cylinder of the engine body 10.

Next, the control sequence during normal operation and regeneration will be described with reference to the flow chart of FIG. In step 1, the filter 14 detected by the differential pressure sensor 15
In step 2, it is determined whether or not the differential pressure ΔP before and after is taken in every moment, the collection progresses, and the value after correction using the engine speed and the exhaust temperature has reached the _set differential pressure ΔP _set . When it is determined that ΔP> ΔP _set , the reproduction operation is performed and the process proceeds to step 3. In step 3, in order to know the temperature of the filter 14, the temperature sensing element 16 attached either inside the filter 14 or in the vicinity of the front and rear end faces.
Signal T _fil of The temperature of the filter 14 indicated by the signal T _fil is the catalyst activation temperature T _cat (about 250 °
If C or above, in step 5, fuel injection is performed in the expansion stroke and exhaust stroke as indicated by the area II in the chart of FIG.

If the temperature T _{fil of the} filter with catalyst 14 is
Is below the activation temperature T _cat , in step 6, fuel injection is performed in the expansion stroke as indicated by the region I in FIG. The fuel additionally injected into the cylinder (combustion chamber) of the engine body 10 relatively early from the end of the expansion stroke mixes with the relatively high temperature combustion gas in the cylinder to combine with oxygen in the excess air. Burns and raises the temperature of the exhaust gas. The ignition temperature of the additional fuel at this time is about 500 ° C.

In this way, the temperature of the exhaust gas whose temperature has risen flows to the filter with catalyst 14, whereby the temperature of the catalyst carried on the filter 14 rises and reaches the activation temperature (about 250 ° C.). After that, the additional fuel will be oxidized by the catalyst. The heat of the oxidation reaction heats the particulates deposited on the filter 14 to the ignition temperature (about 650 ° C.) of the particulates.
Since the temperature is raised above C), the particulates ignite,
It will burn and be incinerated. The supply amount and the supply timing of the additional fuel are optimally controlled to meet such a process. FIG. 4 shows an example thereof.

The temperature T _{fil of the} filter 14 is about 650 ° C., which is the combustion temperature of the particulates (this is the set value T
_set ) and the time of exposure to the temperature exceeds the set time t _set of several seconds to several tens of seconds, it can be considered that the regeneration of the filter 14 is completed. The determination is made in step 7. That is,
If the temperature T _{fil of the} filter 14 exceeds the set value T _set and the duration thereof exceeds the set value t _set , the regeneration is completed and the fuel injection in the expansion stroke and the exhaust stroke is ended in step 8. , Return to normal operation.

FIG. 5 illustrates fuel injection patterns during normal operation and regeneration. A in the figure is for normal operation,
The fuel is injected only once at 5 to 20 ° CA before the top dead center of compression of the piston. However, for the purpose of noise reduction etc., a small amount of injection 1 to 2 times before the basic injection (pilot injection)
In some cases. This pilot injection is shown by the broken line in FIG.

On the other hand, B to D show injection patterns at the time of regeneration of the filter 14, and the filter with catalyst 1
The temperature T _{fil of} 4 is below the catalyst activation temperature T _cat ,
Moreover, the case where the temperature is relatively low is B, the case where it is relatively high is C, and the case where the temperature T _{fil of the} filter 14 is the catalyst activation temperature T _cat or higher is shown as D.

When the temperature T _{fil of the} filter 14 is equal to or lower than the catalyst activation temperature T _cat , an appropriate amount of fuel calculated in advance is used in the expansion stroke so that the catalyst is equal to or higher than the activation temperature without deteriorating the emission. The temperature of exhaust gas is raised by additionally injecting and burning the fuel from a time earlier than the end. Therefore, as shown by B or C, the amount of fuel injected in the expansion stroke is changed and adjusted according to the temperature T _{fil of the} filter 14. By such an operation, the filter 14
If the temperature becomes higher than the catalyst activation temperature _Tcat , or if it is already higher than the catalyst activation temperature at the start of regeneration, the fuel is injected in the exhaust stroke to filter the unburned additional fuel. 14 is supplied to the catalyst, and the particulate heat deposited on the filter 14 is incinerated and removed by the heat of oxidation reaction.

By performing the injection control as described above,
Regardless of whether the temperature T _fil of the filter 14 is high or low, sufficient temperature rise of the filter 14 can be achieved without deteriorating the emission under almost all operating conditions, so that the filter 14 can be regenerated satisfactorily. .

FIG. 6 shows a second embodiment of the present invention.
A front member 20 such as a ceramic monolith having a small heat capacity is installed on the upstream side of the filter 14. Member 20
Also, a catalyst is supported (for example, coated), and the fuel supplied at the time of regeneration is first oxidized by the front member 20. Even when the temperature of the exhaust gas is low and equal to or lower than the catalyst activation temperature, since the front member 20 has a small heat capacity, the front member 20 can rise to the catalyst activation temperature or higher within a short time after the start of fuel injection in the expansion stroke. it can. Therefore, the additionally injected fuel is prevented from passing through, and moreover, the heat generated by the oxidation reaction of the fuel in the front member 20 is given to the main body of the filter 14 on the downstream side, so that the filter 14 is activated relatively quickly. The oxidization temperature can be reached.

FIG. 7 shows the system configuration of the third embodiment of the present invention, which is an example in which a row type injection pump 21 is used as a fuel injection pump. Similar to the first embodiment, in the housing of the particulate collection device 13 provided in the exhaust pipe line 22 of the diesel engine body 10, in order to collect particulates of exhaust gas, for example, ceramics A heat-resistant filter 14 in which a catalyst is carried on a honeycomb structure made of is provided. Further, the exhaust pipe line 22 is provided with a detection means (differential pressure sensor) 15 for detecting the differential pressure before and after the filter 14, and the patty collected by the filter 14 by the differential pressure detected by the detection means 15. Estimate the amount of curate.

The drive shaft 23 of the fuel injection pump 21 has two
The convex portions 24 and 25 of the cam are formed so that the stepwise injection (additional injection) can be performed, and can be engaged with the plunger 26. In a normal operating state where the filter 14 only collects particulates, the remote operation is performed so that the fuel in the pressure chamber 27 is not compressed or pressurized by the plunger 26 that is lifted by the two-stage injection cam convex portion 25 of the cam. The fuel in the pressure chamber 27 is allowed to escape to the fuel tank (not shown) in the direction shown by the arrow by opening the valve 28 which is opened and closed only by this time. When the plunger 26 is raised by the cam projection 24 for normal injection, the valve 28 is closed to compress the fuel in the pressure chamber 27, and the fuel is injected from the fuel injection valve 29 (29a to 29d) into the engine body 10. Supply. Reference numeral 30 is an injection pipe for sending high-pressure fuel.

When the amount of particulates collected in the filter with catalyst 14 reaches a predetermined value and the filter 14 needs to be regenerated, the valve 28 controls the temperature of the filter 14 to be the activation temperature of the catalyst. (About 250 ° C)
The valve is always closed to heat it up to the above, and the unburned additional fuel required for regenerating the filter 14 is mainly supplied into the engine body 10 in the expansion stroke. The fuel additionally supplied by the cam convex portion 25 for regeneration of the filter 14 is gasified and flows into the filter 14 through the exhaust pipe line 22 together with the exhaust gas. This fuel is used in the cam protrusion 2
With the setting of 5, it is possible to supply an appropriate amount at an appropriate time. The supplied additional fuel is oxidized by the catalyst carried on the filter 14, and the heat of reaction thereof heats and burns the particulates accumulated on the filter 14, so that the filter 14 can be regenerated well. become. As described above, the injection timing and injection amount of the additional fuel can be optimized by changing the shape of the cam convex portion 25.

FIG. 8 shows a fourth embodiment of the present invention.
This is an example in which a so-called distribution type fuel injection pump 31 is used instead of the column type fuel injection pump 21 of the third embodiment shown in FIG. 7. In addition to the normal fuel injection protrusions 33, the cam plate 32 includes a two-stage injection protrusion 34 for supplying unburned fuel gas to the catalyst-equipped filter 14, and a normal fuel injection protrusion 33. And are arranged alternately. During the period in which the particulate filter 14 collects the catalyst, as in the third embodiment, the two-stage injection convex portion 34 moves the plunger 35 to the right in FIG. 8 to move the pressure chamber 36 to the right. By opening the valve 28 so as not to compress and pressurize the fuel inside, the fuel is released to the fuel tank (not shown) in the direction of the arrow so that unburned fuel gas is not supplied to the catalyst-equipped filter 14.
However, the fuel supplied to the injection pipe 30 by the normal fuel injection convex portion 33 is supplied from the injection nozzle 29 (29a to 29d) into each cylinder of the engine body 10 by closing the valve 28. .

During regeneration of the filter 14 with catalyst,
While the unburned additional fuel necessary for regenerating the filter 14 is supplied, the valve 28 is always closed and the two-stage injection convex portion 34 supplies the fuel to the inside of the cylinder in which the piston of the engine body 10 is in the expansion stroke. And the unburned fuel gas is supplied to the filter 14. As a result, the fuel gas is oxidized under the interposition of the catalyst supported on the filter 14, and the reaction heat thereof heats the particulates trapped by the filter 14 to a temperature higher than the combustion temperature and incinerates them. Is played.

[0037]

The exhaust gas purifying apparatus for an internal combustion engine according to the present invention has the advantages that the structure is simple and the system can be easily downsized, and at the same time, the supply timing and supply amount of additional fuel can be freely controlled. Since the activation of the filter with catalyst can be achieved under the optimum conditions, the filter can be regenerated under all operating conditions without fear of worsening the emission.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a first embodiment.

FIG. 2 is a system configuration diagram showing only a fuel injection system.

FIG. 3 is a flowchart showing a control sequence of the first embodiment.

FIG. 4 is a chart for determining a fuel injection amount in an expansion stroke and an exhaust stroke.

FIG. 5 is a time chart showing a fuel injection pattern during normal operation and during regeneration.

FIG. 6 is a vertical cross-sectional view showing the main parts of the second embodiment.

FIG. 7 is a system configuration diagram of a third embodiment.

FIG. 8 is a system configuration diagram of a fourth embodiment.

FIG. 9 is a system configuration diagram showing a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Diesel engine 2 ... Fuel pump 3 ... Fuel line 4 ... Injector 6 ... Catalytic particulate matter filter 8 ... Check valve 9 ... Control device 10 ... Internal combustion engine body 11 ... Electronically controlled fuel injection valve 12 ... Fuel pump 13 ... Particulate collection device 14 ... Catalyst-carrying filter 15 ... Differential pressure sensor 16 ... Temperature measuring element (temperature sensor) 17 ... Control device 19 ... Reservoir 20 ... Front member 21 ... Row-type fuel injection pump 24 ... Cam convex portion (For normal injection) 25 ... Cam convex portion (for two-stage injection) 26 ... Plunger 27 ... Pressure chamber 28 ... Valve 29 ... Fuel injection valve 31 ... Distribution type fuel injection pump 32 ... Cam plate 33 ... Fuel injection convex portion (For normal injection) 34 ... Fuel injection projection (for two-stage injection) 35 ... Plunger 36 ... Pressure chamber T _cat ... Catalyst activation temperature (about 250 ° C.) T _{fi l} ... filter temperature T _set ... T _fil set temperature t _set ... T _set value of duration at temperature above T _set ΔP ... differential pressure across filter ΔP _set ... set value of ΔP

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takayuki Takeuchi 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Japan Auto Parts Research Institute, Inc. (56) Reference JP-A-57-97011 (JP, A) JP-A- 61-123709 (JP, A) JP-A-49-80415 (JP, A) JP-A-61-182412 (JP, A) JP-A-4-47115 (JP, A) Actual development 59-67520 (JP, A) U) Actual development Sho 63-191266 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F01N 3/02 F01N 3/24 F01N 3/36 F02D 41/04

Claims (7)

(57) [Claims] 1. A catalyst-equipped filter which is provided in an exhaust pipe from an internal combustion engine to collect particulates in exhaust gas and which carries a catalyst on itself, and to detect the temperature of the catalyst-equipped filter. Temperature detecting means, control means for processing the temperature signal of the catalyst-equipped filter output by the temperature detecting means, and outputting a control signal corresponding thereto, and the internal combustion engine according to the control signal output from the control means.
A fuel injection means for injecting and supplying fuel into the cylinder of the engine ; and the control means detects the temperature during regeneration of the filter with catalyst in which the collected fine particles are accumulated. when the temperature of the catalyst-carried filter detected by the unit is less than the activation temperature of the catalyst, the catalysts of the required to activate, the adding and injection timing in the early expansion stroke of the internal combustion engine The injection amount is the
When the temperature of the filter with catalyst is equal to or higher than the activation temperature of the catalyst, the amount of additional injection is increased as the temperature of the catalyst increases. The injection timing and the additional injection amount in the expansion stroke and the exhaust stroke required to reach the combustion temperature of the fine particles present as the temperature of the filter with catalyst increases.
An internal combustion engine characterized by being configured so that an additional injection amount is calculated to be small and a signal of the calculated injection timing and injection amount of the fuel is output to the fuel injection means as a control signal. Exhaust particulate purification device. 2. The catalyst-equipped filter is composed of two parts, a small-sized part placed on the upstream side and a relatively large-sized part placed on the downstream side.
An exhaust gas purification apparatus for an internal combustion engine as described. 3. A catalyst-equipped filter which is provided in an exhaust pipe from an internal combustion engine to collect particulates in exhaust gas and which carries a catalyst on itself, and a cylinder of the internal combustion engine driven by a cam. And a fuel injection means for injecting and supplying fuel into the interior of the internal combustion engine. Further, the cam includes a cam projection for performing normal fuel injection to the main body of the internal combustion engine, and the collected fine particles. during reproduction of the filter with catalyst that is deposited, an additional fuel injection required to bring the particles to the combustion temperature causes the active <br/> activatable said catalysts, the expansion stroke of the internal combustion engine and An exhaust particulate purifying apparatus for an internal combustion engine, comprising another cam convex portion for performing an exhaust stroke. 4. The exhaust gas purification apparatus for an internal combustion engine according to claim 3, wherein the fuel injection means includes a row-type fuel injection pump. 5. The exhaust particulate purifying apparatus for an internal combustion engine according to claim 3, wherein the fuel injection means includes a distributed fuel injection pump. 6. The fuel injection means is connected to a pressure chamber in order to avoid fuel injection by the another cam convex portion in a normal operating state of the internal combustion engine in which the filter with catalyst is not regenerated. The exhaust particulate purification system for an internal combustion engine according to any one of claims 3 to 5, further comprising an on-off valve. 7. A step of collecting fine particles in exhaust gas of the internal combustion engine by a filter with a catalyst provided in an exhaust pipe line from the internal combustion engine and carrying a catalyst on itself, and depositing on the filter with a catalyst. Determining the regeneration timing of the catalyst-equipped filter according to the amount of the particulates, the step of detecting the temperature of the catalyst-equipped filter by temperature detection means when the regeneration timing is determined, and the catalyst-equipped filter. If the temperature of equal to or less than the activation temperature of the catalyst, the control means receiving the temperature signal of the filter with catalyst, in accordance with the temperature of the filter with catalyst, required to activate the catalytic The fuel injection timing and the additional timing in the early stage of the expansion stroke of the internal combustion engine
The amount of additional injection increases the temperature of the filter with catalyst.
The step of calculating so as to increase the additional injection amount , and outputting it as a fuel injection signal which is a control signal of the control means, and the fuel output from the control means at an early stage of the expansion stroke of the internal combustion engine. The injection signal causes the internal combustion engine to
Injecting additional fuel into the cylinder and burning it to heat the filter with catalyst to activate the catalyst, and when the temperature of the filter with catalyst is equal to or higher than the activation temperature of the catalyst. the injection quantity of the additional and fuel injection timing in the expansion stroke and an exhaust stroke of the internal combustion engine required to reach the particulate combustion temperature, the catalyst-filled
So that the injection amount of the temperature is high and the more additional data becomes less
And outputting it as a fuel injection signal which is a control signal of the control means, and in an expansion stroke and an exhaust stroke of the internal combustion engine, an additional fuel injected to the upstream side of the catalyst-equipped filter is supplied. The reaction heat generated by oxidizing the fuel with the catalyst supported on the already activated filter heats the fine particles deposited on the filter with catalyst to the combustion temperature of the fine particles. A method of regenerating a filter with a catalyst in an exhaust gas purification apparatus for an internal combustion engine, comprising the step of causing the combustion by reaching.