JP2010112280A - Exhaust emission control method and device of diesel internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To self-regenerate a filter device by maintaining the exhaust gas temperature at the activation temperature or more of an oxidation catalyst, even when a vehicle mounted with a diesel internal combustion engine is in no-load deceleration operation. <P>SOLUTION: In this exhaust emission control method of the diesel internal combustion engine 10, the self-regeneration type filter device 32 having a compression opening type engine brake means mounted on the vehicle and oxidizing and removing captured particulate matter by the oxidation catalyst 36 by capturing the particulate matter in exhaust gas, is provided in an exhaust gas passage 24, and the oxidation temperature of the particulate matter is secured by performing post-injection P for supplying unburnt fuel to the exhaust gas passage. When the diesel internal combustion engine 10 is in the no-load deceleration operation, when a piston 16 is positioned in the compression top dead center vicinity, cylinder inside air is discharged in the exhaust gas passage 24 by operating a compression opening type engine brake means 40, and the oxidation temperature of the particulate matter is secured by simultaneously performing the post-injection P of fuel. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an exhaust gas purification apparatus for a diesel internal combustion engine that is mounted on a vehicle and includes a compression release type engine brake means and a self-regenerating filter device, and the compression release type engine brake means when the diesel internal combustion engine is not in combustion. The present invention relates to an exhaust gas purification method and apparatus which perform post injection of fuel in conjunction with each other.

The amount of particulate matter (hereinafter referred to as “PM”) emitted from diesel internal combustion engines mounted on vehicles such as trucks and buses is being regulated more and more year by year together with NO _x , CO and HC. A technique for collecting PM by a filter called a diesel particulate filter (DPF; Diesel Particulate Filter) to reduce PM emission has been developed.

  By supplying high-temperature exhaust gas to this filter device, self-regeneration that can burn and remove the PM collected by the filter becomes possible. In addition, there is a self-regenerative filter device in which PM is incinerated by high-temperature exhaust gas by providing an oxidation catalyst upstream of the filter or by supporting the oxidation catalyst on the filter.

In the former self-regenerative filter device, NO in exhaust gas is oxidized to NO ₂ by an oxidation catalyst supporting platinum or the like, and the PM collected in the downstream filter is oxidized by this NO ₂ to produce CO _2. To be removed. The latter self-regenerative filter device is composed of a filter with an oxidation catalyst such as cerium oxide CeO ₂ and oxidizes and removes PM collected on the filter by the oxidation catalyst. With these oxidation catalysts, PM can be oxidized and removed if the exhaust gas temperature is approximately 300 ° C. or higher.

  However, in idling operation, low load / low speed operation, etc., of the internal combustion engine, the exhaust gas temperature falls below the above temperature, so that the oxidation reaction by the oxidation catalyst is not promoted. Further, since NO is insufficient, the oxidation reaction does not proceed. For this reason, PM accumulation progresses and the filter is clogged.

  Therefore, post-injection (post-injection) of fuel is performed in the cylinder, fuel (HC) is supplied into the exhaust gas, fuel (HC) in the exhaust gas is burned (oxidized) with an oxidation catalyst, and the combustion heat generates an oxidation catalyst. By raising the temperature above the activation temperature, the PM collected by the filter is removed by oxidation to regenerate the filter.

  For example, in Patent Document 1 (Japanese Patent Laid-Open No. 2005-299418) or Patent Document 2 (Japanese Patent Laid-Open No. 2005-299438), the self-regenerative filter device is provided in the exhaust gas path of a diesel engine mounted on a vehicle. An exhaust gas purification system that performs post injection in a cylinder and oxidizes and removes PM collected by a filter is disclosed.

JP 2005-299418A JP 2005-299438 A

  As described above, as a precondition for performing the post injection, it is necessary to keep the exhaust gas temperature at a temperature (activation temperature) required for the oxidation catalyst to oxidize HC contained in the fuel, that is, 250 ° C. or more. Therefore, during the self-regeneration of the filter, it is necessary to operate the internal combustion engine so that the exhaust gas temperature rises above the temperature.

  However, in the case of a diesel engine mounted on a vehicle, during no-load deceleration operation such as when traveling on a downhill, the main injection of the engine is stopped and combustion does not occur in the cylinder. It is difficult to maintain the exhaust gas temperature above the activation temperature of the oxidation catalyst. Therefore, post injection cannot be used, and self-regeneration of the filter must be interrupted.

  In view of the problems of the prior art, the present invention maintains the exhaust gas temperature above the activation temperature of the oxidation catalyst even when the internal combustion engine is in a non-combustion state, such as when a vehicle equipped with a diesel internal combustion engine is in a no-load deceleration operation. Thus, an object of the present invention is to enable the self-regeneration of the filter device by making the post injection available.

In order to solve the above problems, an exhaust gas purification method for a diesel internal combustion engine of the present invention includes:
A self-regenerative filter device, which is mounted on a vehicle and includes compression-release type engine braking means, is composed of an oxidation catalyst and a DPF, and oxidizes and removes particulate matter trapped in the DPF, is provided in the exhaust gas path. In the exhaust gas purification method of a diesel internal combustion engine in which post-injection for supplying fuel is performed to ensure the oxidation temperature of particulate matter,
During a no-load deceleration operation of the diesel internal combustion engine, when the piston is located near the compression top dead center, the compression release type engine brake means is operated to release the air in the cylinder into the exhaust gas path, and at the same time, the fuel is post-injected. Thus, the oxidation temperature of the particulate matter is ensured.

  The method of the present invention is directed to a diesel internal combustion engine mounted on a vehicle and provided with a compression release type engine brake means. In the compression process of a cylinder of a diesel internal combustion engine, when the piston reaches top dead center and the air in the cylinder is compressed, during normal operation, fuel is injected and burned at this stage, and the piston is pushed down with combustion energy. Get the rotational energy of the wheel.

  The compression release type engine brake means is known (see, for example, Japanese Patent Application Laid-Open No. 9-2105), and when the brake force is applied to the piston using the compression release type engine brake means, it is operated as follows. In the compression process, fuel is not injected, but the exhaust valve of the cylinder is opened to discharge the air in the cylinder. Therefore, air is not compressed in the cylinder and the kinetic energy of the piston is lost. Further, when the exhaust valve is closed in the expansion process after the piston has passed through the top dead center, a negative pressure is generated in the cylinder due to the lowering of the piston, and a force for lifting the piston is generated. By this operation, 85 to 90% of the required braking force can be secured.

In the method of the present invention, the compression-release type engine braking means is operated when the piston is located near the compression top dead center under the operating condition during the no-load deceleration operation of the diesel internal combustion engine. Thereby, since the compressed high-temperature air is discharged into the exhaust gas passage, the temperature of the oxidation catalyst of the self-regenerative filter device interposed in the exhaust gas passage can be increased.
Further, by performing post injection simultaneously with the operation of the compression release type engine brake means, unburned fuel (HC) can be burned by the oxidation catalyst, and the temperature of the oxidation catalyst can be raised by the exothermic reaction.
By these two heating actions, the temperature of the oxidation catalyst is raised to the oxidation reaction temperature or higher, and the PM collected by the self-regenerative filter device can be oxidized and removed. As a result, the self-regenerating filter device can self-regenerate even when the internal combustion engine is in the no-load deceleration operation.

  In the method of the present invention, since the post injection is performed when the piston is located near the compression top dead center, the atomization of the fuel injected into the cylinder can be promoted. Therefore, since the combustion reaction of unburned fuel can be promoted, the temperature of the oxidation catalyst can be increased efficiently. As a result, self-regeneration time can be shortened and fuel consumption can be improved.

  Further, since the post-injection is performed when the piston is located near the top dead center, the injected fuel is received by the piston surface, and the fuel does not adhere to the inner wall of the cylinder. Therefore, there is no possibility that the fuel enters the crank chamber and enters the lubricating oil to cause oil dilution (dilution).

In the method of the present invention, it is preferable to determine whether the diesel internal combustion engine is in a no-load deceleration operation from the presence or absence of the accelerator operation and the vehicle speed.
The presence / absence of the accelerator pedal and the vehicle speed correlate with the unloaded deceleration operation of the vehicle and correspond to each other uniquely, so it is possible to accurately determine whether or not the internal combustion engine is in the unloaded deceleration operation with these parameters. Treatment necessary for self-regeneration of the regenerative filter device can be performed with good timing.

The exhaust gas purification apparatus for a diesel internal combustion engine of the present invention that can be directly used for carrying out the method of the present invention comprises:
A self-regenerative filter device, which is mounted on a vehicle and includes compression-release type engine braking means, is composed of an oxidation catalyst and a DPF, and oxidizes and removes particulate matter trapped in the DPF, is provided in the exhaust gas path. In the exhaust gas purification method of a diesel internal combustion engine in which post-injection for supplying fuel is performed to ensure the oxidation temperature of particulate matter,
When it is determined from the operation information of the diesel internal combustion engine that the diesel internal combustion engine is under no-load deceleration operation, the compression release type engine brake means is operated to release the in-cylinder air into the exhaust gas passage, and at the same time, post-injection of fuel It is provided with the control device which performs.

  In the device of the present invention, when the diesel internal combustion engine is in a no-load deceleration operation, the control device causes the compression release type engine brake means and the fuel injection device to operate synchronously to apply the engine brake force and post-inject the fuel. By carrying out simultaneously, it is possible to oxidize and remove PM collected by the self-regenerating filter device by raising the temperature of the oxidation catalyst to the oxidation reaction temperature or higher. As a result, the self-regenerating filter device can self-regenerate even when the internal combustion engine is in the no-load deceleration operation.

  In the device of the present invention, the operation information includes the presence / absence of accelerator operation and the vehicle speed, and when there is no accelerator operation, that is, when there is no main injection of fuel and the vehicle is decelerating, It is recommended that you do it.

  In the apparatus of the present invention, the operation of the compression release type engine brake means and the post injection may be performed when the piston is located near the top dead center. Thereby, the effect can be obtained.

In the apparatus of the present invention, an operation switch for operating the compression release type engine brake means is provided, and the post injection is performed together with the operation of the compression release type engine brake means only when the driver turns on the operation switch. It is good to.
Thus, only when the driver determines that self-regeneration of the self-regenerating filter device is necessary, it is possible to apply engine brake and post-injection to the cylinder.

  According to the method of the present invention, a self-regenerative filter device that is mounted on a vehicle and includes a compression release type engine brake means and that includes an oxidation catalyst and a DPF, and that oxidizes and removes particulate matter trapped in the DPF is provided in the exhaust gas path. In the exhaust gas purification method for a diesel internal combustion engine, which performs post injection for supplying unburned fuel to the exhaust gas path and ensures the oxidation temperature of the particulate matter, during the no-load deceleration operation of the diesel internal combustion engine, When the piston is located near the compression top dead center, the compression release type engine brake means is operated to release the air in the cylinder into the exhaust gas passage, and at the same time, the fuel post-injection is performed, so that the oxidation temperature of the particulate matter is increased. As a result, the oxidation catalyst of the self-regenerative filter device can be heated to a temperature higher than the oxidation reaction temperature even during no-load deceleration operation. To enable the self-regeneration of the filter apparatus.

  Further, according to the apparatus of the present invention, the self-regenerative filter device that is mounted on a vehicle and includes a compression release type engine brake means, and that includes an oxidation catalyst and a DPF and oxidizes and removes particulate matter trapped in the DPF is exhausted. A diesel internal combustion engine exhaust gas purification method comprising post-injection for supplying unburned fuel to an exhaust gas path to ensure an oxidation temperature of particulate matter, and from the operation information of the diesel internal combustion engine, Provided with a control device for operating the compression release type engine brake means to release the air in the cylinder to the exhaust gas passage and simultaneously performing fuel post-injection when it is determined that the engine is under no-load deceleration operation Thus, the same effects as those of the method of the present invention can be obtained.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified.

  An embodiment in which the present invention is applied to an exhaust gas purifying apparatus for a diesel engine mounted on a vehicle will be described with reference to FIGS. In FIG. 1, the diesel engine 10 includes a cylinder 12, a crank chamber 14 provided below the cylinder 12, and a piston 16 that is connected to a crank rod 18 and reciprocates within the cylinder 12.

  The head of the cylinder 12 is provided with an intake passage 20 for sucking combustion air, an intake valve 22 for opening and closing the intake passage 20, an exhaust passage 24 for discharging combustion exhaust gas, and an exhaust valve 26 for opening and closing the exhaust passage 24. Yes. An injector 28 for injecting fuel into the cylinder 12 is provided at the center of the head of the cylinder 12. Further, an engine control unit (ECU) 30 that controls the operation of the diesel engine 10 is provided.

  The ECU 30 is input with the presence / absence of the accelerator pedal operation a and the vehicle speed b, and controls the injector 28 during operation to control the fuel injection timing and the injection amount. Further, the diesel engine 10 includes a compression release type engine brake means 40. When the driver determines that the engine brake is necessary, the driver turns on the operation switch 44 to operate the engine brake operation unit 41. Then, the exhaust valve driving unit 42 is driven by the engine brake operation unit 41 to open and close the exhaust valve 26.

The compression release type engine brake means 40 operates as follows when the engine braking force is applied to the piston 16. That is, the fuel is not injected in the compression process, the exhaust valve 26 of the cylinder 12 is opened, and the air in the cylinder 12 is discharged to the exhaust passage 24. Therefore, air is not compressed in the cylinder 12 and the kinetic energy of the piston 16 is lost.
Further, when the exhaust valve 26 is closed in the expansion process after the piston 16 passes through the top dead center, the inside of the cylinder 12 becomes negative pressure due to the lowering of the piston 16, and the force for pulling up the piston 16, that is, the direction of normal rotation is A reverse force is generated. By this operation, auxiliary braking force can be secured.

  A self-regenerative filter device 32 is interposed in the exhaust path 24. In the self-regenerative filter device 32, an oxidation catalyst 36 and a DPF 38 are arranged in the exhaust gas passage in order from the upstream side in a container 34 interposed in the exhaust passage 24. An exhaust gas thermometer 33 is provided in the exhaust gas passage upstream of the oxidation catalyst 36, and a pressure gauge 35 for detecting a pressure loss of the exhaust gas in the DPF 38 is provided in the internal space of the DPF 38. The pressure gauge 35 can detect the degree of clogging due to PM deposited on the DPF 38.

  The oxidation catalyst 36 is, for example, an oxidation catalyst supporting platinum or the like, and the DPF 38 is configured by, for example, a ceramic honeycomb filter, or a filter made of ceramic or metal in the form of fibers.

The exhaust gas after the fuel burns in the cylinder 12 reaches the self-regenerating filter device 32 through the exhaust path 24. In the self-regenerative filter device 32, the oxidation catalyst 36 oxidizes NO in the exhaust gas to NO _2, and this NO ₂ oxidizes the PM collected in the downstream DPF 38 to remove it as CO ₂ . However, the oxidation reaction temperature of the oxidation catalyst 36 is 250 ° C. or higher, and no oxidation reaction occurs if the exhaust gas temperature is equal to or lower than the oxidation reaction temperature during no-load operation without main injection. Therefore, the self-regeneration of the DPF 38 becomes difficult.

FIG. 2 shows the lift timing of the exhaust valve 26 and the fuel injection timing of the diesel engine 10, (a) shows the case during normal operation, and (b) shows that the vehicle speed is constant during no-load deceleration operation. A case of a value (for example, 2 km / h) or more is shown, and (c) shows a conventional post injection method.
The determination during the no-load deceleration operation or the normal operation is performed based on whether the driver is stepping on the accelerator pedal and the vehicle speed.

  During the normal operation shown in FIG. 2A, the main injection M of fuel is performed when the piston 16 is in a position near the compression top dead center. Then, the piston 16 is lowered by the combustion of the fuel, and then the exhaust valve 26 is lifted in a process in which the piston 16 moves from the bottom dead center to the exhaust top dead center. Post injection P is performed in accordance with this timing, and combustion exhaust gas mixed with fuel is discharged to the exhaust passage 24.

  During normal operation, when the exhaust gas has a temperature of 250 ° C. or higher, fuel post-injection is performed in a process in which the piston 16 moves from bottom dead center to exhaust top dead center. Thereby, unburned fuel (HC) is supplied to the exhaust passage 24. By burning (oxidizing) the unburned fuel with the oxidation catalyst 36, the activation temperature of the oxidation catalyst 36 can be obtained, and the PM collected in the DPF 38 can be oxidized and removed.

  In FIG. 2B, when the vehicle is in a no-load deceleration operation and the piston 16 is in a position near the compression top dead center, the main fuel injection M is not performed, but instead the engine brake operation unit 41 performs exhaust. The valve drive unit 42 is driven to open the exhaust valve 26 and simultaneously perform the post injection P. By this operation, the cylinder air mixed with fuel is discharged to the exhaust passage 24.

Thus, when the piston 16 is at a position near the compression top dead center, the exhaust valve 26 is opened, and the compressed high-temperature air is discharged to the exhaust passage 24. The temperature can be raised.
Furthermore, the fuel (HC) mixed in the air can be oxidized by the oxidation catalyst 36, and the temperature of the oxidation catalyst 36 can be raised by the reaction heat generated at that time to oxidize and remove PM.

  In the conventional system shown in FIG. 2 (c), the main injection M of fuel is not performed near the compression top dead center, and the exhaust valve 26 is lifted in the process in which the piston 16 moves from the bottom dead center to the exhaust top dead center. Perform post-injection. As a result, the exhaust gas mixed with fuel is discharged to the exhaust passage 24.

In this conventional system, the post-injection P is performed when the piston 16 shifts from the bottom dead center to the exhaust top dead center, and therefore, the compressed air and the high temperature cannot be sent to the exhaust passage 24. Therefore, the temperature of the oxidation catalyst 36 cannot be raised. Therefore, when the exhaust gas temperature is 250 ° C. or lower, the self-regenerating filter device 30 cannot self-regenerate.
Further, since the post-injection is performed when the piston 16 is located at the bottom dead center, the injected fuel adheres to the inner wall surface of the cylinder 12, and the fuel adhering to the inner wall surface enters the crank chamber 14 and becomes an oil dire. There is a risk of accidents.

Next, the post injection procedure of the diesel engine 10 according to the present embodiment will be described with reference to FIG. In FIG. 3, first, when the self-regenerating filter device 32 does not perform self-regenerating processing, post injection is not performed (step 1 → step 7).
If the self-regenerating filter device 32 needs to perform self-regeneration, the information a on the presence or absence of the accelerator pedal operation input to the ECU 30 indicates that if the exhaust gas temperature has a temperature of 250 ° C. or higher when the accelerator is on, The conventional post injection shown in 2 (c) is performed (step 2 → step 7).

When the accelerator is off and the vehicle speed is 2 km / h or less, the vehicle has already stopped, so there is no need to operate the engine brake, and post injection shown in FIG. 2C is performed (step 3 → step 7). ).
When the accelerator is off and the vehicle speed is 2 km / h or higher, the main injection M is stopped by the ECU 30 (step 3 → step 4). On the other hand, when the driver determines that the braking force is necessary, the driver turns on the operation switch 44 to operate the compression release type engine brake (step 5).

When the operation switch 44 is turned on, the compression release type engine brake means 40 is operated (step 6), and the exhaust valve drive unit 42 is driven by the engine brake operation unit 41 to operate the exhaust valve 26. Injection P is performed (step 7).
As a result, as shown in FIG. 2B, when the piston 16 is located near the top dead center, the air in the cylinder 12 is released to the exhaust passage 24, so that an engine braking force is applied to the piston 16. .

  Further, since the fuel released into the exhaust passage 24 by the post injection P is mixed with fuel, the fuel mixed in the air is burned (oxidized) by the oxidation catalyst 36, and the oxidation heat is used to activate the oxidation catalyst 36. Since the temperature is raised to the above, the PM collected in the DPF 38 can be oxidized and removed to self-regenerate the DPF 38.

  Thus, according to the present embodiment, even when the diesel engine 10 mounted on the vehicle is in the no-load deceleration operation, the operation of the compression release type engine brake means 40 is used to exhaust the high-temperature air into the exhaust path. 24, and the fuel post-injection P is performed, so that the self-regenerating filter device 32 can be self-regenerated.

Further, since the post-injection P is performed when the piston 16 is located near the compression top dead center, the atomization of the fuel injected into the cylinder 12 can be promoted, and therefore the oxidation reaction in the self-regenerative filter device 32 can be promoted. Therefore, the exhaust gas temperature can be increased efficiently. As a result, self-regeneration time can be shortened and fuel consumption can be improved.
Further, since the post-injection is performed when the piston 16 is located near the top dead center, the injected fuel is received by the piston surface, and the fuel does not adhere to the inner wall of the cylinder 12. Therefore, there is no possibility that the fuel enters the crank chamber and enters the lubricating oil to cause oil dilution (dilution).

  Further, since the operation switch 44 is provided and the engine brake is applied and post-injection is performed when the driver turns on the operation switch 44, the driver needs to self-regenerate the self-regenerative filter device 30. Only when it is judged, it is possible to choose to apply the engine brake and perform post-injection.

  In the above embodiment, the operation switch 44 is provided. Instead, the operation switch 44 is not provided, and when the accelerator is off and the vehicle speed is 2 km / h or higher, engine brake operation and post injection are automatically performed. You may comprise as follows. In this case, the operation of the operation switch 42 by the driver is not required, and the operation of the engine brake and the post injection can be automated.

  According to the present invention, the self-regenerating filter device can be self-regenerated even during the no-load deceleration operation of the diesel internal combustion engine mounted on the vehicle, and PM collection by the self-regenerating filter device can be continued.

It is a lineblock diagram of the diesel engine concerning one embodiment of the present invention. The lift operation and fuel injection timing of the exhaust valve according to the embodiment are shown, (a) during load operation, (b) during no-load deceleration operation according to the embodiment, and (c) as conventional no-load deceleration operation. FIG. It is a flowchart which shows the operation procedure of the engine brake which concerns on the said embodiment, and post injection.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Diesel engine 12 Cylinder 16 Piston 24 Exhaust path 26 Exhaust valve 28 Injector 30 ECU (control apparatus)
32 Self-regenerating filter device 36 Oxidation catalyst 38 DPF
40 Compression release type engine brake means 41 Engine brake operation part 42 Exhaust valve drive part 44 Actuation switch M Main injection P Post injection a Presence of accelerator operation b Vehicle speed

Claims (6)

A self-regenerative filter device, which is mounted on a vehicle and includes compression-release type engine braking means, is composed of an oxidation catalyst and a DPF, and oxidizes and removes particulate matter trapped in the DPF, is provided in the exhaust gas path. In the exhaust gas purification method of a diesel internal combustion engine in which post-injection for supplying fuel is performed to ensure the oxidation temperature of particulate matter,
During a no-load deceleration operation of the diesel internal combustion engine, when the piston is located near the compression top dead center, the compression release type engine brake means is operated to release the air in the cylinder into the exhaust gas path, and at the same time, the fuel is post-injected. Thus, the exhaust gas purification method for a diesel internal combustion engine, wherein the oxidation temperature of the particulate matter is ensured.   2. The exhaust gas purification method for a diesel internal combustion engine according to claim 1, wherein whether or not the diesel internal combustion engine is in a no-load deceleration operation is determined from the presence or absence of an accelerator operation and the vehicle speed. A self-regenerative filter device, which is mounted on a vehicle and includes compression-release type engine braking means, is composed of an oxidation catalyst and a DPF, and oxidizes and removes particulate matter trapped in the DPF, is provided in the exhaust gas path. In the exhaust gas purification device of a diesel internal combustion engine that performs post injection for supplying fuel and ensures the oxidation temperature of particulate matter,
When it is determined from the operation information of the diesel internal combustion engine that the diesel internal combustion engine is under no-load deceleration operation, the compression release type engine brake means is operated to release the in-cylinder air into the exhaust gas passage, and at the same time, post-injection of fuel An exhaust gas purifying device for a diesel internal combustion engine, characterized by comprising a control device for performing   The driving information includes the presence / absence of an accelerator operation and the vehicle speed, and the control device causes the operation of the compression release type engine brake means and the post injection when the accelerator operation is not performed and the vehicle is decelerating. The exhaust gas purification apparatus for a diesel internal combustion engine according to claim 3,   5. The diesel internal combustion engine according to claim 3, wherein the control device causes the operation of the compression release type engine brake means and post injection to be performed when the piston is located near top dead center. Exhaust gas purification equipment.   An operation switch for operating the compression release type engine brake means is provided, and the post injection is performed together with the operation of the compression release type engine brake means only when a driver turns on the operation switch. The exhaust gas purification apparatus for a diesel internal combustion engine according to any one of claims 3 to 5.

Images