JP6585555B2 - Diesel engine exhaust treatment equipment - Google Patents

Description

  The present invention relates to an exhaust treatment device for a diesel engine, and more particularly, to an exhaust treatment device for a diesel engine that can prevent unnecessary retry of catalyst warm-up processing.

Conventional diesel engine exhaust treatment devices include the following (see, for example, Patent Document 1).
A DPF disposed in the engine exhaust path, a combustible gas generator with a built-in gas generating catalyst, and an electronic control unit,
DPF regeneration processing is performed according to the command of the electronic control unit
In the DPF regeneration process, liquid fuel and air are supplied to the combustible gas generator while the engine is running, and a combustible gas is generated by the catalytic reaction of the gas mixture with the gas generating catalyst. An exhaust processing apparatus for a diesel engine, wherein the temperature of the engine exhaust is raised and PM accumulated in the DPF is incinerated by the heat of the engine exhaust.

  According to this type of exhaust treatment apparatus, there is an advantage that the DPF can be continuously used in the regeneration process of the DPF.

  In the invention of Patent Document 1, when the gas generating catalyst is warmed up before the regeneration process of the DPF, the catalyst warming-up process is retried even when the likelihood of a successful warm-up is low.

Japanese Patent Laying-Open No. 2006-8535 (see FIGS. 1 and 2)

<< Problem >> Unnecessary retry of the catalyst warm-up process may be allowed.
In the invention of Patent Document 1, since the catalyst warm-up process is retried even when the likelihood of a warm-up success is low, useless retry of the catalyst warm-up process may be allowed.

  An object of the present invention is to provide an exhaust treatment device for a diesel engine that can prevent unnecessary retry of catalyst warm-up treatment.

Invention specific matters of the invention according to claim 1 are as follows.
As illustrated in FIG. 1, a DPF (3) disposed in an engine exhaust path (2), a combustible gas generator (5) containing a gas generation catalyst (4), and an electronic control unit (1) Prepared,
The DPF (3) is regenerated according to the command of the electronic control unit (1),
In the regeneration process of the DPF (3), liquid fuel (6) and air (7) are supplied to the combustible gas generator (5) during engine operation, and a gas generation catalyst (4) of these air-fuel mixture (14). The combustible gas (8) is generated by the catalytic reaction of the engine, and the combustion of the combustible gas (8) raises the temperature of the engine exhaust (9). The heat of the engine exhaust (9) deposits on the DPF (3). In a diesel engine exhaust treatment device configured to incinerate PM,
The regeneration process of the DPF (3) is configured such that the temperature of the engine exhaust (9) is raised by the combustible gas (8) generated after the gas generator catalyst (4) is successfully warmed up, and is illustrated in FIG. As described above, in the catalyst warm-up process (S2) of the gas generation catalyst (4), when the catalyst temperature (T) reaches the predetermined warm-up success determination value (TJ) during the predetermined warm-up determination (S3). Is determined that the warm-up is successful and the catalyst warm-up process (S2) is terminated. If the warm-up success determination value (TJ) has not been reached, it is determined that the warm-up has failed and the catalyst warm-up process (S2) is performed. Retryed
As illustrated in FIG. 2, the number of times of warm-up determination (S3) (N) reaches a predetermined retry determination number of times (NJ), and the retry determination in which the warm-up determination (S3) is determined to have failed in warm-up. If the catalyst temperature (T) has risen to the predetermined retry determination temperature value (TR) at time (t1), the retry of the subsequent catalyst warm-up process (S2) is permitted (S14), and the retry is performed. Exhaust of a diesel engine characterized in that when the temperature has not risen to the determination temperature value (TR), retry of the subsequent catalyst warm-up process (S2) is prohibited (S10). Processing equipment.

(Invention of Claim 1)
The invention according to claim 1 has the following effects.
<Effect> It is possible to prevent unnecessary retry of the catalyst warm-up process.
As illustrated in FIG. 2, in the present invention, at the time of retry determination (t 1), when the temperature rise is insufficient due to a low possibility of successful warm-up due to the subsequent retry of the catalyst warm-up process (S 2). Since the subsequent retry is prohibited (S10), it is possible to prevent unnecessary retry of the catalyst warm-up process (S2).

(Invention of Claim 2)
The invention according to claim 2 has the following effect in addition to the effect of the invention according to claim 1.
<Effect> It is possible to accurately determine the possibility of successful warm-up by retry.
As illustrated in FIG. 2, in the present invention, the retry determination is performed by determining whether the catalyst temperature (T) of the gas generation catalyst (4) is a predetermined temperature rise value (T0) from the initial value (T0) before the catalyst warm-up process (S2). Since it is determined by whether or not the temperature is increased only by α), the possibility of successful warm-up by retry is accurately determined based on the temperature increase result from the initial state of the gas generating catalyst (4) to the retry determination time (t1). Can be determined.

(Invention of Claim 3)
The invention according to claim 3 has the following effect in addition to the effect of the invention according to claim 1 or claim 2.
<Effect> An excessive number of retries can be prevented.
As illustrated in FIG. 2, in the present invention, when the warm-up is failed at the final warm-up determination (t2) when the number of warm-up determination (S3) (N) reaches the limit number (NL), Since the retry of the catalyst warm-up process (S2) is prohibited (S13), an excessive number of retries can be prevented.

(Invention of Claim 4)
The invention according to claim 4 has the following effects in addition to the effects of the invention according to any one of claims 1 to 3.
<Effect> Accurate fault diagnosis can be performed.
In the present invention, the retry prohibition (S10) (S13) events with different reasons are stored in the storage device (70) with a failure diagnosis code that can identify these events. ) Can be confirmed for any reason, and accurate fault diagnosis can be performed.

(Invention according to claim 5)
The invention according to claim 5 has the following effects in addition to the effects of the invention according to any one of claims 1 to 4.
<Effect> The parts used for the catalyst warm-up process of the gas generating catalyst can be used together with those used for the combustible gas generating process.
As illustrated in FIGS. 1 and 2, in the present invention, the catalyst warm-up process (S2) of the gas generating catalyst (4) is similar to the generating process of the combustible gas (8). Since it is performed by supplying the air-fuel mixture (14) to the air-fuel mixture inlet, the parts used for the catalyst warm-up process (S2) of the gas generating catalyst (4) are also used for the combustible gas (8) generation process. can do.

It is a mimetic diagram of a loading machine of a diesel engine concerning an embodiment of the present invention. It is a time chart which shows the catalyst warm-up process and catalyst temperature which are made by embodiment of FIG. It is a flowchart of the catalyst warm-up process by the electronic controller used in the embodiment of FIG.

1 to 3 are diagrams illustrating a diesel engine-equipped machine according to an embodiment of the present invention.
This engine-equipped machine is equipped with a diesel engine (15), and includes a traveling unit (not shown) and a work device (not shown).
As the engine-equipped machine, an industrial machine including a traveling unit and a working device, such as an agricultural machine such as an agricultural tractor and a rice transplanter, a construction machine such as a backhoe, and a transport machine such as a forklift can be used.
As the working device, a rotary device or the like is used for an agricultural tractor, and a planting device or the like is used for a rice planting machine.

As shown in FIG. 1, a diesel engine (15) mounted on this engine-equipped machine includes a crankshaft (19) installed in a crankcase (18) and a piston (21 fitted in a cylinder (20)). ), A connecting rod (21a) interposed between the crankshaft (19) and the piston (21), a combustion chamber (22) formed in the cylinder (20), and an intake device (not shown). The fuel supply device (23), the electronic governor (30), and the exhaust device (24) are provided.

The intake device supplies air (7) to the combustion chamber (22).
The fuel supply device (23) includes a fuel tank (25), a fuel feed pump (26), a fuel injection pump (27), a fuel injection camshaft (28), and a fuel provided in the combustion chamber (22). An injection valve (29) is provided, and the liquid fuel (6) in the fuel tank (25) is pumped to the fuel injection pump (27) by the fuel feed pump (26) and driven by the fuel injection cam shaft (28). The fuel injection pump (27) injects the fuel from the fuel injection valve (29) into the combustion chamber (22) and burns with the compression heat of the air (7) in the combustion chamber (22). The liquid fuel (6) is light oil.

The electronic governor (30) controls the engine speed.
The electronic governor (30) includes a metering control unit of the electronic control device (1), a governor actuator (31), and a biasing component (32), and a fuel metering rack (33) of the fuel injection pump (27). is pressed against the governor actuator (31) by the biasing force of the biasing part (32), following to the metering position to the operation of the governor actuator (31) is adjusted.

The electronic control unit (1) includes an accelerator sensor (35) for detecting the speed setting position information of the accelerator operating component (34), and an actual rotational speed sensor (36) for detecting the rotational speed information of the crankshaft (19). Are electrically connected.
The electronic governor (30) has a governor actuator (31) in a metering control unit of the electronic control unit (1) so that a rotational deviation between the target rotational speed detected based on the accelerator operation position information and the actual rotational speed becomes small. , The metering position of the fuel metering rack (33) of the fuel injection pump (27) is controlled, and the injection amount of the liquid fuel (6) injected from the fuel injection valve (29) into the combustion chamber (22) Adjust.

An engine ECU is used for the electronic control unit (1). The engine ECU is an abbreviation for engine electronic control unit and is a microcomputer.
A linear solenoid is used for the governor actuator (31).
An accelerator operating lever is used for the accelerator operating component (34). An accelerator operation pedal, an accelerator operation button, or an accelerator operation switch can be used for the accelerator operation component (34).

  A battery (37) and a key switch (12) are connected to the electronic control unit (1). When the key switch (12) is turned on to the engine operation position, the engine operation is performed by energizing each part of the engine from the battery (37). When the key switch (12) is turned on at the engine stop position, the power supply from the battery (37) to each part of the engine is stopped, and the urging force of the engine stop spring (not shown) in the governor actuator (31) The fuel metering rack (33) is pushed to the no fuel injection position, the injection of the liquid fuel (6) from the fuel injection valve (29) is stopped, and the diesel engine (15) is stopped.

The exhaust device (24) discharges the engine exhaust (9) from the combustion chamber (22).
The exhaust device (24) includes an engine exhaust path (2), and the engine exhaust path (2) is disposed on the exhaust downstream side of the exhaust port (38), the exhaust manifold (39), and the exhaust manifold (39). The engine exhaust treatment path (40) and the exhaust treatment device (41) provided in the engine exhaust treatment path (40) are provided. The engine exhaust (9) discharged from the combustion chamber (22) After being processed in 41), it is discharged to the atmosphere from the engine exhaust path (2).

The exhaust processing device (41) processes the engine exhaust (9).
The exhaust treatment device (41) includes a DPF (3) disposed in the engine exhaust path (2), a combustible gas generator (5) incorporating a gas generation catalyst (4), and an electronic control device (1). I have.
In the exhaust treatment device (41), the regeneration process of the DPF (3) is performed by a command of the electronic control device (1).
In the regeneration process of the DPF (3), liquid fuel (6) and air (7) are supplied to the combustible gas generator (5) during engine operation, and a gas generation catalyst (4) of these air-fuel mixture (14). The combustible gas (8) is generated by the catalytic reaction of the engine, and the combustion of the combustible gas (8) raises the temperature of the engine exhaust (9). The heat of the engine exhaust (9) deposits on the DPF (3). PM is incinerated.
This exhaust treatment device (41) has an advantage that the DPF (3) can be continuously used by regenerating the DPF (3).

The DPF (3) captures PM contained in the engine exhaust (9).
DPF is an abbreviation for diesel particulate filter, and PM is an abbreviation for particulate matter. In the DPF (3), a wall flow type ceramic honeycomb in which a large number of cells along the axial length direction are arranged in parallel and the inlets and outlets of adjacent cells are alternately sealed is used.
A DPF case (42) is disposed in the engine exhaust treatment path (40), and the DPF (3) is accommodated in the DPF case (42).
The electronic control unit (1) is a common item with the electronic governor (30).

A combustible gas generator (5) is provided in the engine exhaust treatment path (40) on the exhaust upstream side of the DPF (3).
The combustible gas generator (5) includes an air-fuel mixture mixer (43), a catalyst storage chamber (44) communicating with the air-fuel mixture outlet of the air-fuel mixture mixer (43), and a gas stored in the catalyst storage chamber (44). A production catalyst (4), a combustible gas passage (45) communicating with the gas outlet of the gas production catalyst (4), and a secondary air mixer (46) communicating with the gas outlet of the combustible gas passage (45); An ignition chamber (47) communicating with the gas outlet of the secondary air mixer (46) and a combustible gas merging exhaust passage (48) communicating with the gas outlet of the ignition chamber (47) are provided. 48) constitutes a part of the engine exhaust treatment path (40) on the exhaust upstream side of the DPF (3).
The combustible gas generator (5) includes a secondary air passage (66), and a secondary air mixer (46) communicates with the secondary air outlet (67). The secondary air mixer (46) is provided with a cap-shaped gas nozzle (68) communicating with the gas outlet of the combustible gas passage (45), and is ejected from the gas nozzle (68) in the radial direction of the secondary air mixer (46). The combustible gas (8) is mixed with the secondary air (7) swirling along the circumferential direction of the gas nozzle (68).

  An air introduction passage (50) led out from the air supply pump (49) and a fuel introduction passage (52) led out from the fuel supply pump (51) are connected to the air-fuel mixture mixer (43), and an air cleaner (53 ) And the liquid fuel (6) in the fuel tank (25) are introduced into the air-fuel mixture mixer (43), and the air-fuel mixture (14) of the liquid fuel (6) and air (7) is introduced. It is formed.

The gas generation catalyst (4) is an oxidation catalyst, promotes oxidation of the gas mixture (14) by catalytic reaction, thermally decomposes the liquid fuel (6) with the reaction heat, and combusts the low temperature ignitable combustible gas (8). Is generated. The catalyst carrier of the gas generating catalyst (4) is made by weaving iron chromium wire into a truncated cone shape, and rhodium is supported on this catalyst carrier as a catalyst component.
The secondary air mixer (46) communicates with the gas outlet of the combustible gas passage (45) and the secondary air outlet (67) of the secondary air passage (66). A secondary air introduction passage (55) led out from the air supply pump (49 ) is connected to the air inlet.

  Combustible gas (8) and secondary air (7) purified by an air cleaner (53) are introduced into the secondary air mixer (46). In the secondary air mixer (46), combustible gas (8) is introduced. ) And secondary air (7) are mixed, and the combustible gas (8) containing the secondary air (7) flows from the secondary air mixer (46) through the ignition chamber (47) (combustible gas combined exhaust passage ( 48) is combined with the engine exhaust (9) passing through 48) and sent to the DPF (3) on the exhaust downstream side. In the ignition chamber (47), the combustible gas (8) is ignited as necessary.

A starting catalyst (56) is provided at the gas mixture inlet of the gas generating catalyst (4), an electric heater (57) is inserted into the starting catalyst (56), and a catalyst is provided at the gas outlet side of the gas generating catalyst (4). A temperature sensor (58) is inserted.
The catalyst carrier of the starting catalyst (56) is an alumina fiber mat, and this catalyst carrier carries rhodium as a catalyst component. The catalyst carrier of the starting catalyst (56) has a narrow void in the tissue and high liquid fuel (6) retention compared to the catalyst carrier of the combustible gas generating catalyst (4).

The air supply pump (49) is an electric blower, and the fuel supply pump (51) is an electric pump.
Electric metering valves (50a), (52a) and (55a) are provided in the air introduction passage (50), the fuel introduction passage (52) and the secondary air introduction passage (55), respectively.
The air supply pump (49), the fuel supply pump (51), the metering valves (50a) (52a) (55a), the electric heater (57), and the catalyst temperature sensor (58) are all electronic control units (1). Is electrically connected.
In the regeneration process of the DPF (3), the electric heater (57) generates heat in response to a command from the electronic control unit (1), and the startup catalyst (56) is preheated by the heat, and then the mixture (14) is started up. When the gas generating catalyst (4) is warmed up by catalytic combustion of the starting catalyst (56) and the temperature of the gas generating catalyst (4) reaches a predetermined warm-up end temperature, the gas generating catalyst ( The supply amount of the air-fuel mixture (14) to 4) is increased, the air-fuel mixture (14) diffuses throughout the gas generating catalyst (4), and a combustible gas (8) is generated by the catalytic reaction.

In the regeneration process of the DPF (3), the temperature of the engine exhaust (9) is increased by the combustible gas (8) generated after the gas generator catalyst (4) is successfully warmed up. As shown in FIG. In the catalyst warm-up process (S2) of the catalyst (4), if the catalyst temperature (T) reaches the predetermined warm-up success determination value (TJ) at the predetermined warm-up determination (S3), the warm-up success is determined. When the catalyst warm-up process (S2) is determined and the warm-up success determination value (TJ) has not been reached, it is determined that the warm-up has failed and the catalyst warm-up process (S2) is retried.
As shown in FIG. 2, the number of times of warm-up determination (S3) (N) reaches a predetermined retry determination number of times (NJ), and when the retry determination has been determined that warm-up failure has been made in this warm-up determination (S3) If the catalyst temperature (T) has been raised to the predetermined retry determination temperature value (TR) at (t1), then retry of the catalyst warm-up process (S2) is permitted (S14) and the retry determination is made. If the temperature has not risen to the temperature value (TR), retry of the subsequent catalyst warm-up process (S2) is prohibited (S10).

  As shown in FIG. 2, in the exhaust treatment device (41), at the time of retry determination (t1), the temperature rise is insufficient due to the low possibility of successful warm-up due to the retry of the subsequent catalyst warm-up process (S2). If so, retry of the subsequent catalyst warm-up process (S2) is prohibited (S10), so that unnecessary retry of the catalyst warm-up process (S2) can be prevented.

In this exhaust treatment device (41), in the catalyst warm-up process (S2), the electric heater (57) continues for a predetermined time, and the supply of the air-fuel mixture (14) to the starting catalyst (56) continues for a predetermined time.
The warm-up determination (S3) is performed after the supply of the air-fuel mixture (14) is completed.
The warm-up success judgment value (TJ) is set to 250 ° C. The warm-up success determination value (TJ) may be another value.
The retry determination time (t1) is when the retry determination count value (NJ) is 3, that is, when the warm-up determination (S3) count (N) is the third time and the warm-up failure determination is made. Yes. The retry determination number value (NJ) may be another value.

As shown in FIG. 2, the retry determination temperature value (TR) is set to a predetermined temperature rise value (T0) to an initial value (T0) of the catalyst temperature (T) of the gas generation catalyst (4) before the catalyst warm-up process (S2). It is a value obtained by adding α).
In this exhaust treatment device (41), the retry determination is made based on whether or not the catalyst temperature (T) of the gas generating catalyst (4) has been increased by a predetermined temperature increase value (α) from the initial value (T0). Therefore, the possibility of a successful warm-up by retry can be accurately determined based on the temperature rise result from the initial state of the gas generation catalyst (4) to the retry determination time (t1).
The temperature elevation value (α) is set to 20 ° C. The temperature elevation value (α) may be another value.

As shown in FIG. 2, after the retry is permitted (S14), at the final warm-up determination time (t2) when the warm- up failure determination number (N) reaches a predetermined limit number (NL), the catalyst temperature ( When T) does not reach the predetermined warm-up success determination value (TJ), the retry of the subsequent catalyst warm-up process (S2) is prohibited (S13).
In this exhaust treatment device (41), if the warm-up failure occurs during the final warm-up determination when the warm-up failure determination count (N) reaches the limit count (NL), the subsequent catalyst warm-up processing (S2) is retried. Is prohibited (S13), so that excessive retries can be prevented.
The final warm-up determination time (t2) is when the retry determination count value (NJ) is 6, that is, when the warm-up determination (S3) count (N) is the sixth. The retry determination number value (NJ) may be another value.

As shown in FIG. 1, the exhaust treatment device (41) includes a storage device (70).
An event of prohibition of retry (S10) due to insufficient temperature rise performed at the time of retry determination (t1) shown in FIG. 2 or an event of prohibition of retry (S13) due to failure of warm-up performed at the time of final warm-up determination (t2) occurs. In the case of failure, a failure diagnosis code that can identify these events is stored in the storage device (70).
In this exhaust treatment device (41), the retry prohibition (S10) (S13) events for different reasons are stored in the storage device (70) with a failure diagnosis code that can identify these events, so that retry is prohibited during failure diagnosis. (S10) (S13) can be confirmed for what reason, and an accurate failure diagnosis can be performed.
The storage device (70) is a non-volatile memory such as a flash memory.
The failure diagnosis code is indicated by a multi-digit number or symbol.

The exhaust treatment device (41) includes a monitor (71) and a port (72).
A failure diagnosis code is displayed on the monitor (71).
A plug of a failure diagnosis tool is inserted into the port (72), and a failure diagnosis code is displayed on the display of the failure diagnosis tool.
The monitor (71) and the port (72) are arranged on the dashboard (59) of the engine-equipped machine.
A liquid crystal display, an organic EL display, or the like can be used for the monitor (71). EL is an abbreviation for electroluminescence.
As the port (72), a USB port or the like can be used. USB is an abbreviation for Universal Serial Bus.
As the failure diagnosis tool, a notebook computer or a portable terminal installed with a failure diagnosis program can be used.

As shown in FIG. 1, this exhaust treatment device (41) includes an activation catalyst (56) provided at the gas mixture inlet of the gas generation catalyst (4) and an electric heater (57) in contact with the activation catalyst (56). I have.
As shown in FIG. 2, in the catalyst warm-up process (S2) of the gas generating catalyst (4), the mixture (14) is supplied to the starting catalyst (56) preheated by the heat generated by the electric heater (57), The gas generating catalyst (4) is heated by the catalytic reaction heat generated by the starting catalyst (56) of the gas mixture (14).
As shown in FIGS. 1 and 2, in this exhaust treatment device (41), the catalyst warm-up process (S2) of the gas generation catalyst (4) is the same as the generation process of the combustible gas (8). Since it is performed by supplying the air-fuel mixture (14) to the air-fuel mixture inlet of (4), the parts used for the catalyst warm-up process (S2) of the gas generating catalyst (4) are used for the combustible gas (8) generation process. It can also be used with what is used.

As shown in FIG. 3, after completion of the regeneration process of the DPF (3), a fuel purge process (S6) is performed.
In the fuel purge process (S6), the liquid fuel (6) remaining in the combustible gas generator (5) is purged.
In this exhaust treatment device (41), when the regeneration process of the DPF (3) is normally completed, the liquid fuel (6) does not remain in the combustible gas generator (5). The reproduction process becomes easy.

In the fuel purge process (S6), air (7) is supplied to the combustible gas generator (5), and a mixture of the air (7) and the liquid fuel (6) remaining in the combustible gas generator (5). The combustible gas (8) is generated by the catalytic reaction of the gas generating catalyst (4) of (14), and this combustible gas (8) is discharged into the engine exhaust path (2).
In this exhaust treatment device (41), the fuel purge process (S6) is performed in the same manner as the regeneration process of the DPF (3). Therefore, the parts and control used for the fuel purge process (S6) are regenerated. It can also be used for the processing.

The exhaust treatment device (41) includes a DOC (16) disposed on the exhaust upstream side of the DPF (3).
In the DPF regeneration process, the combustible gas (8) is catalytically combusted by the DOC (16) to raise the temperature of the engine exhaust (9).
For this reason, in this exhaust treatment device (41), it is possible to suppress the power consumption required for the regeneration process of the DPF (3) as compared with the case where the heat generated by the electric heater is used.

DOC is an abbreviation for diesel oxidation catalyst.
DOC (16) is a flow-through ceramic honeycomb having a cylindrical shape and a large number of cells extending in the axial direction along the inside. The oxidation catalyst component such as platinum or palladium rhodium is contained in the cell. It is supported.
The DOC (16) is accommodated in the DPF case (42) on the exhaust upstream side of the DPF (3).

The exhaust treatment device (41) includes an ignition component (17) disposed on the exhaust upstream side of the DOC (16).
In the DPF regeneration process, the combustible gas (8) is ignited by the ignition component (17) based on the estimated temperature of the DOC (16) not reaching the predetermined activation temperature, and the combustible gas (8). The engine exhaust (9) is heated by this flame combustion, and the DOC (16) is heated by the heat of the engine exhaust (9).
For this reason, in this exhaust treatment device (41), it is possible to regenerate the DPF (3) even when the temperature of the engine exhaust (9) is low.

The ignition component (17) is disposed in the ignition chamber (47) of the exhaust treatment device (41), the DOC inlet exhaust temperature sensor (62) is disposed at the exhaust inlet of the DOC (3), and the ignition component (17) and the DOC inlet are disposed. When the exhaust gas temperature sensor (62) is electrically connected to the electronic control unit (1) and the inlet exhaust temperature of the DOC (3) does not reach the activation temperature of the DOC (3), the inlet of the DOC (3) In response to a command from the electronic control device (1) based on the exhaust gas temperature information, the ignition component (17) generates heat, and the combustible gas (8) is ignited.
A glow plug is used for the ignition component (17). A spark plug or a burner can be used for the ignition component (17).
An ignition detection sensor (54) is arranged in the ignition chamber (47), and this ignition detection sensor (54) is electrically connected to the electronic control unit (1), and the ignition chamber detected by the ignition detection sensor (54). Based on the temperature information of (47), the electronic control unit (1) determines whether or not the combustible gas (8) is ignited.

The temperature of the engine exhaust (9) is controlled by adjusting the amount of combustible gas (8) produced.
A DPF inlet exhaust temperature sensor (63) is disposed at the exhaust inlet of the DPF (3), and a combustible gas (8) is generated by a command from the electronic control unit (1) based on DPF inlet exhaust temperature information detected by the sensor (63). ) Is adjusted, and the DPF inlet exhaust temperature is controlled to a predetermined regeneration temperature.
A DPF outlet exhaust temperature sensor (64) is disposed at the exhaust outlet of the DPF (3), and a command from the electronic control unit (1) based on the DPF outlet exhaust temperature information detected by the sensor (64) is used to output the DPF (3 ) Is stopped, and excessive combustion of PM in the DPF (3) is prevented.

The flow of the catalyst warm-up process by the electronic control device shown in FIG. 3 is as follows.
In step (S1), the regeneration start determination of DPF (3) is made. If the estimated accumulation value of PM deposited on the DPF (3) has reached a predetermined regeneration start determination value, the determination is affirmed and regeneration of the DPF (3) is started. If the determination is negative, step (S1) is repeated until the determination is positive. The PM accumulation estimated value is estimated by the electronic control unit (1) based on the differential pressure information at the inlet and outlet of the DPF (3) detected by the differential pressure sensor (65) shown in FIG.
When regeneration of DPF (3) is started, catalyst warm-up processing is performed in step (S2), and the process proceeds to step (S3).
In step (S3), when the warm-up success / failure determination is made and the determination is affirmative, that is, when it is determined that the warm-up is successful, the process proceeds to step (S4).

In step (S4), gas generation processing is performed, combustible gas (8) is generated, DPF (3) regeneration processing is performed, and the process proceeds to step (S5).
In step (S5), it is determined whether the regeneration of DPF (3) has ended. When the estimated accumulation value of PM deposited on the DPF (3) has reached a predetermined regeneration end determination value, the determination is affirmed, the regeneration of the DPF (3) is ended, and the determination is negative, Returning to step (S4), the regeneration of DPF (3) is continued. When regeneration of DPF (3) is completed, the process proceeds to step (S6).
In step (S6), fuel purge is performed, and the process returns to step (S1).

  When the determination in step (S3) is negative, that is, in the case of failure determination, the process proceeds to step (S7), where it is determined whether or not the failure determination is after the third time, and the determination is affirmed In step (S8), it is determined whether or not the failure determination is the third time. If the determination is affirmative, it is determined as a retry determination time (t1), and the process proceeds to step (S9).

In step (S9), a retry determination is made and it is determined whether or not the catalyst temperature (T) has increased to a predetermined retry determination temperature value (TR). If the determination is affirmative, step (S10) is determined. ).
In step (S10), a retry prohibiting process is performed, the fourth and subsequent retries are prohibited, and the process proceeds to step (S11).
In step (S11), a failure diagnosis code storage process is performed, and the process ends.

If the determination in step (S8) is negative, that is, if the failure determination is after the fourth time, the process proceeds to step (S12) to determine whether or not the failure determination is the sixth time. If the determination is affirmative, the process proceeds to step (S13).
In step (S13), a retry prohibiting process is performed, and then the retry of the catalyst warm-up process (S2) is prohibited. Then, the process proceeds to step (S11), a fault diagnosis code storing process is performed, and the process ends.

  If the determination in step (S7) is negative, if the determination in step (S12) is negative, that is, if the failure determination is the first, second, fourth, fifth determination failure, or If the determination in step (S9) is negative, that is, if the catalyst temperature (T) has been raised to some extent in the retry determination, the retry permission process is performed in step (S14) in any case. Then, the next catalyst warm-up process (S2) is retried.

(1) Electronic control unit, (2) Engine exhaust path, (3) DPF, (4) Gas generating catalyst, (5) Combustible gas generator, (6) Liquid fuel, (7) ... Air, (8) ... Combustible gas, (9) ... Engine exhaust, (14) ... Air mixture, (56) ... Starting catalyst, (57) ... Electric heater, (70) ... Storage device, (S2) ... Catalyst warm-up process (S3) ... Warm-up determination, (S10) ... Retry prohibited, (S13) ... Retry prohibited, (S14) ... Retry allowed, (T) ... Catalyst temperature, (TJ) ... Warm-up success judgment value , (TR) ... retry determination temperature value, (T0) ... initial temperature value, (α) ... temperature rise value, (N) ... number of warm-up determinations, (NJ) ... number of retry determinations, (NL) ... limit Number of times, (t1): At the time of retry determination, (t2): At the time of final warm-up

Claims (5)

A DPF (3) disposed in the engine exhaust path (2), a combustible gas generator (5) containing a gas generation catalyst (4), and an electronic control unit (1),
The DPF (3) is regenerated according to the command of the electronic control unit (1),
In the regeneration process of the DPF (3), liquid fuel (6) and air (7) are supplied to the combustible gas generator (5) during engine operation, and a gas generation catalyst (4) of these air-fuel mixture (14). The combustible gas (8) is generated by the catalytic reaction of the engine, and the combustion of the combustible gas (8) raises the temperature of the engine exhaust (9). The heat of the engine exhaust (9) deposits on the DPF (3). In a diesel engine exhaust treatment device configured to incinerate PM,
The regeneration process of the DPF (3) is configured such that the temperature of the engine exhaust (9) is raised by the combustible gas (8) generated after the gas engine catalyst (4) is warmed up successfully. In the catalyst warm-up process (S2) of 4), if the catalyst temperature (T) reaches the predetermined warm-up success determination value (TJ) at the predetermined warm-up determination (S3), it is determined that the warm-up is successful. When the catalyst warm-up process (S2) is completed and the warm-up success determination value (TJ) has not been reached, it is determined that the warm-up has failed and the catalyst warm-up process (S2) is retried.
When the warm-up determination (S3) count (N) reaches a predetermined retry determination count value (NJ) and the warm-up determination (S3) is determined as a warm-up failure, the catalyst temperature When (T) has been heated to a predetermined retry determination temperature value (TR), the subsequent catalyst warm-up process (S2) is allowed to be retried (S14) and increased to the retry determination temperature value (TR). An exhaust treatment device for a diesel engine, characterized in that, if not warm, retry of the subsequent catalyst warm-up process (S2) is prohibited (S10). In the exhaust treatment device for a diesel engine according to claim 1,
The retry determination temperature value (TR) is obtained by adding a predetermined temperature increase value (α) to the initial value (T0) of the catalyst temperature (T) of the gas generation catalyst (4) before the catalyst warm-up process (S2). An exhaust treatment device for a diesel engine, characterized in that: In the exhaust treatment device for a diesel engine according to claim 1 or 2,
After the retry is permitted (S14), the catalyst temperature (T) is set at a predetermined time (t2) at the final warm-up determination (t2) when the number of times (N) of the warm-up determination (S3) reaches a predetermined limit number (NL). Exhaust processing of a diesel engine, characterized in that when the warm-up success judgment value (TJ) has not been reached, retry of the subsequent catalyst warm-up processing (S2) is prohibited (S13). apparatus. In the exhaust treatment device for a diesel engine according to claim 3,
A storage device (70);
When the retry prohibition (S10) event due to insufficient temperature rise made at the time of retry determination (t1) or the retry prohibition due to warm-up failure (S13) event made at the time of final warm-up determination (t2) occurs An exhaust treatment apparatus for a diesel engine, characterized in that a failure diagnosis code capable of identifying these events is configured so that the generated event is stored in the storage device (70). In the exhaust treatment device of the diesel engine according to any one of claims 1 to 4,
A starting catalyst (56) provided at the gas mixture inlet of the gas generating catalyst (4), and an electric heater (57) in contact with the starting catalyst (56),
In the catalyst warm-up process (S2) of the gas generating catalyst (4), the mixture (14) is supplied to the starting catalyst (56) preheated by the heat generated by the electric heater (57), and the mixture (14) An exhaust treatment apparatus for a diesel engine, characterized in that the temperature of the gas generating catalyst (4) is increased by the catalytic reaction heat generated by the starting catalyst (56).

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