JP2010127253A - Common rail type diesel engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a malfunction due to over-deposition of PM (Particulate Matter) when regenerating a DPF (Diesel Particulate Filter) in a diesel engine. <P>SOLUTION: In this common rail type diesel engine which controls regeneration of DPF by using an intake throttle valve, an exhaust throttle valve and post injection in regeneration of DPF, a normal regeneration mode for processing regeneration of DPF at a normal speed and a high-speed regeneration mode for processing at a speed higher than the normal speed are selectively set for execution in an ECU. An automatic stop means is provided to automatically stop the diesel engine after forcibly concluding regeneration when operating the diesel engine after concluding the operation so as to forcibly regenerate DPF. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a common rail type diesel engine. In particular, the present invention relates to a DPF regeneration processing device for an engine, which relates to a DPF regeneration process for purifying exhaust gas.

In recent years, for example, a diesel engine having a DPF (diesel particulate filter) mounted on a vehicle for exhaust gas countermeasures has been disclosed. (For example, see Patent Document 1)
Since these DPFs are caused by the phenomenon that PM (particulate matter) accumulates on the filter, the accumulated PM is burned and the filter is automatically or manually regenerated, so that the DPF caused by PM deposition To avoid the failure.

As a measure for avoiding the failure of the DPF due to the PM accumulation, a relationship line between the differential pressure value of the automatic regeneration execution point for automatically regenerating the DPF and the accumulated ash content is set in advance, and the PM determined in a new state where the ash content is zero. The over-threshold threshold was set as the initial threshold for PM over-deposition, and the initial threshold was corrected by the automatic regeneration differential pressure value corresponding to the differential pressure measurement value and the ash content corresponding to the differential pressure value. There is disclosed a technique for performing DPF regeneration processing control that can improve the accuracy of determining the presence or absence of a DPF failure due to PM overdeposition, which makes it possible to determine the presence or absence of PM overdeposition using a correction threshold value. (For example, see Patent Document 2)
Japanese Utility Model Publication No. 5-65763 JP 2007-270695 A

  However, as described above, in order to improve the accuracy of determining whether there is a DPF failure due to PM overdeposition, it is a good measure for avoiding failures due to PM overdeposition during the DPF regeneration process. Since the exhaust gas temperature is related, a certain amount of processing time is required when performing the regeneration process. However, this DPF regeneration process time can be taken when there is sufficient time for other reasons such as work. In some cases, there is a problem that failure due to PM overdeposition is likely to occur when sufficient regeneration processing time cannot be obtained.

  Therefore, the present invention is intended to solve the problem caused by PM overdeposition during DPF regeneration processing in a diesel engine.

  In a common rail diesel engine that performs regeneration control by intake / exhaust throttle valve, post-injection, etc. during regeneration processing of the DPF, a normal regeneration mode in which regeneration of the DPF is processed at a normal speed, and a speed faster than the normal speed. This is a common rail type diesel engine characterized in that the high speed regeneration mode to be processed in is set in the ECU so that it can be selected and executed.

  With such a configuration, when there is a surplus in the DPF regeneration processing time, the exhaust temperature required for the DPF regeneration processing is controlled by selecting the normal regeneration mode by controlling the opening and the post injection amount of the intake / exhaust throttle valve. It is possible to perform regeneration processing control at a normal speed that can only be raised to the vicinity, and when there is not enough time for regeneration processing of the DPF, by selecting the high-speed regeneration mode, the intake and exhaust throttle valve opening and post-injection are selected. By controlling the amount or the like, the regeneration process control can be performed at a high speed faster than the normal speed by quickly raising the exhaust temperature to the temperature required for the DPF regeneration process.

  According to a second aspect of the present invention, there is provided an automatic stop means for automatically stopping the diesel engine after completion of the forced regeneration process when the diesel engine is operated after the work is finished to perform the forced regeneration process of the DPF. The common rail type diesel engine according to claim 1 is used.

  With such a configuration, in a common rail diesel engine, when the DPF forced regeneration process must be performed without stopping the engine for the convenience of the work after the completion of the work, the automatic stop means is automatically operated after the forced regeneration process is completed. The engine can be stopped.

  In the first aspect of the present invention, as described above, when there is a margin in the DPF regeneration processing time, the normal regeneration mode is selected to perform the regeneration processing control at the normal speed, and there is no margin in the DPF regeneration processing time. In this case, select the high-speed playback mode and let the playback processing control be performed at a higher speed than the normal speed, and consider the time for the playback processing control in either the normal playback mode or the high-speed playback mode according to the circumstances at that time. Therefore, the regeneration process can be sufficiently controlled regardless of whether or not the DPF regeneration process time is sufficient, and the PM overdeposition can be performed with good DPF regeneration process by PM deposition. Can solve the problem.

  According to the second aspect of the invention, as described above, in the common rail diesel engine, when the forced regeneration process of the DPF is performed after the completion of the work, the engine is automatically stopped by the operation of the automatic stop means after the forced regeneration process is completed. Therefore, the forced regeneration process of the DPF can be performed conveniently without the troublesome necessity of monitoring when the vehicle is not used.

  In a common rail type diesel engine that performs regeneration control by an intake / exhaust throttle valve, post-injection, etc. during regeneration of the DPF, a normal regeneration mode that processes regeneration of the DPF at a normal speed, and a high-speed regeneration mode that processes at a speed faster than the normal speed Is set in the ECU so that it can be selected. In addition, in a common rail diesel engine equipped with a DPF mounted on a farm machine, an automatic stop means is provided for automatically stopping the engine after the forced regeneration process when performing the forced regeneration process by operating the engine after the work is completed. .

Embodiments of the present invention will be described below with reference to the drawings.
As shown in the system diagram of FIG. 1 for the common rail diesel engine E, the common rail type (accumulated fuel injection system) is a common rail 1 (accumulated pressure) that adjusts fuel injection to each cylinder to a required pressure. Room).

  The fuel in the fuel tank 3 is sucked into the high pressure pump 4 driven by the engine E through the fuel filter 7 through the suction passage, and the high pressure fuel pressurized by the high pressure pump 4 is led to the common rail 1 through the discharge passage 8. It is stored.

  The high-pressure fuel in the common rail 1 is supplied to the injectors 6 for five cylinders through the high-pressure fuel supply passages 9, and the injector 6 is opened for each cylinder 5 based on a command from the ECU 100. The fuel is injected into each combustion chamber of the engine E, and surplus fuel (return fuel) in each injector 6 is guided to a common fuel return passage 10a by each fuel return pipe 10 and returned to the fuel tank 3 by the fuel return passage 10a. It is.

  In addition, a pressure control valve 11 is provided in the high-pressure pump 4 to control the fuel pressure (common rail pressure) in the common rail 1. The pressure control valve 11 is connected to the fuel tank 3 from the high-pressure pump 4 by a duty signal from the ECU 100. The flow area of the fuel return passage 10a for surplus fuel to the fuel is adjusted, whereby the amount of fuel discharged to the common rail 1 side can be adjusted to control the common rail pressure.

  Specifically, the target common rail pressure is set according to the engine operating conditions, and the common rail pressure is feedback-controlled through the pressure control valve 11 so that the common rail pressure detected by the rail pressure sensor 2 matches the target common rail pressure. .

  As shown in FIG. 2, the ECU 100 of the common rail diesel engine E mounted on the agricultural machine has a droop control in which the output fluctuates due to the fluctuation of the rotation speed in the relationship between the rotation speed and the output torque, and the rotation speed even if the load fluctuates. Is set to three types of control modes: isochronous control in which the output is changed according to the load and heavy load control in which the rotational speed is increased and the output is increased when the isochronous control is close to the load limit.

  Droop control is used when the vehicle is traveling without farming as a travel mode. For example, when the travel speed is reduced or stopped by applying a brake, the engine speed is increased as the travel load increases. Therefore, traveling speed can be safely reduced and stopped.

  Isochronous control is used as a normal work mode when normal farm work is performed. Even when the load increases, the output fluctuates and the rotation speed is maintained, so that the operator can operate easily.

  Heavy load control is used as a heavy work mode, especially when farming near the load limit. For example, when plowing with a tractor, engine output even when encountering hard cultivated land Increases beyond the normal limit so that work is not interrupted.

  Conventionally, in a diesel engine, it is known to perform pilot injection that injects a small amount of fuel in a pulse manner prior to main injection, thereby shortening the ignition delay and reducing the so-called knocking noise peculiar to the diesel engine. .

  This pilot injection is performed once or twice before the main injection, but by using the system of the common rail 1, the state of the pilot injection is changed according to the state of the engine. The generation of white smoke or black smoke due to noise reduction or incomplete combustion can be suppressed.

  A tractor T equipped with a common rail type diesel engine E has front wheels 12 and rear wheels 13 at the front and rear portions of the fuselage as shown in the overall configuration of FIG. 3, and transmits the rotational power of the engine E mounted at the front of the fuselage. The transmission is appropriately changed by the transmission of the case 19 and is transmitted to the front wheel 12 and the rear wheel 13.

A steering handle 16 is supported on the handle post 15 in the cabin 14 at the center of the aircraft, and a seat 17 is provided behind the steering handle 16. Below the handle 16, the advancing direction of the aircraft is switched to the front-rear direction. A forward / reverse lever 18 is provided. When the forward / reverse lever 18 is moved to the front side, the aircraft moves forward, and when it is moved backward, the aircraft moves backward. Reference numeral 20 denotes a foot pedal.
The rotary device 21 is connected to the rear of the machine body by a link 22.

  The tractor T is equipped with a DPF for purifying exhaust gas, and this DPF collects and deposits PM on the filter. Therefore, it is necessary to remove the accumulated PM by regeneration processing as time passes. Therefore, this regeneration process is performed by controlling the opening and the post injection amount of the intake / exhaust throttle valve.

  In this regeneration process, the ECU 100 is set to two regeneration modes: a normal regeneration mode in which the processing time is controlled at a normal speed, and a high speed regeneration mode in which the process control is performed at a higher speed than the normal speed. It can be selected and switched by an operator's dial or switch operation as required.

  As shown in the flowchart of FIG. 4, it is checked whether or not the regeneration process of the DPF is necessary, and if necessary, the amount of PM collected is checked, and the amount of PM collected is within an appropriate range within the regeneration processing time. If there is a margin, select the normal regeneration mode, and control the engine speed, the intake / exhaust throttle valve opening, the post injection amount, etc., and regenerate at the normal speed that only increases to near the exhaust temperature required for the DPF regeneration process. Control processing. This regeneration process requires a certain amount of time, but the burden on the engine E is reduced.

  Next, when the amount of PM collected is within the appropriate range and there is no allowance for the regeneration processing time, the high speed regeneration mode is selected, and control of the engine speed, the intake / exhaust throttle valve opening, the post injection amount, etc. The regeneration process control is performed at a high speed faster than the normal speed by quickly raising the exhaust gas temperature to the exhaust temperature necessary for the DPF regeneration process. This regeneration process takes time, but the burden on the engine E increases.

  As described above, since the operator can appropriately select the regeneration process control in consideration of the time in either the normal regeneration mode or the high-speed regeneration mode according to the circumstances at that time, the margin for the regeneration process time of the DPF can be obtained. Regardless of the presence or absence of this, the regeneration process can be sufficiently controlled, and the regeneration process of the DPF by PM deposition can be performed satisfactorily to solve the problems caused by PM overdeposition.

  When the collected amount of PM is above the appropriate range, depending on the state of the DPF, a dangerous regeneration mode may be selected. Therefore, when the ECU 100 determines that the DPF is damaged, only the normal regeneration mode is selected. Play control is performed.

  Further, in the common rail diesel engine E, as shown in FIG. 5, the turbine 29a upstream side and the exhaust side exhaust passage 30 of the turbocharger 29 are connected to the exhaust manifold 31 of the cylinder 5 and the downstream side of the turbine 29a. A DOC 33 (oxidation catalyst) and a DPF 34 are respectively provided in the exhaust pipe 32 that is connected outwardly to the turbine 29a side, and then a DPF 34 is provided inside. An EGR path 36 is provided connected to the upstream side of the compressor 29b of the supercharger 29.

  An exhaust throttle valve 37 is provided in the exhaust pipe 32 on the lower side of the inlet of the EGR path 36, and an EGR valve 38 is disposed at a junction between the EGR path 36 and the upstream position of the compressor 29b. The intake passage 40 on the intake side is connected to the intake manifold 41 of the cylinder 5 through the intercooler 39 from the downstream side.

  Both exhaust pressure sensors 42a and 42b are arranged close to each of the upstream side of the DOC 33 and the downstream side of the DPF 34 built in the exhaust pipe 32, and the exhaust temperature sensor 43 is arranged at an intermediate position between the DOC 33 and the DPF 34. The detection value is electrically connected to the ECU 100 so as to be transmitted, and an automatic stop switch 45 is provided to automatically stop the engine after the forced regeneration process by the DPF 34 is completed.

  With this configuration, as shown in the flowchart of FIG. 6, when a time lapses and the differential pressure value of the exhaust pressure sensors 42 a and 42 b decreases and the temperature value of the exhaust temperature sensor 43 decreases due to the forced regeneration start by the DPF 34. The key power is turned off to stop the engine E.

  As described above, when the forced regeneration process of the DPF is performed after the work is completed, the engine can be automatically stopped by the operation of the automatic stop switch 45 after the forced regeneration process is completed. Therefore, the forced regeneration process of the DPF can be performed conveniently.

  Further, in order to perform the regeneration process of the DPF, the temperature of the exhaust gas at the front stage of the DOC needs to be 250 degrees or more, and there is a problem that the regeneration temperature cannot be ensured by idling or low load operation.

  Therefore, in the configuration of the operation diagram shown in FIG. 5, as shown in FIG. 7, both exhaust pressures disposed close to the upstream side of the DOC 33 and the downstream side of the DPF 34, which are housed in the exhaust pipe 32. The amount of PM trapped is set by the differential pressure value of the two pressure sensors 42a and 42b according to the contents monitored by the ECU 100 with the detected values by the sensors 42a and 42b and the exhaust temperature sensor 43 disposed upstream of the DOC 33. When the temperature exceeds the value, if the temperature in the previous stage of the DOC 33 has not reached the DPF 34 regeneration temperature, fuel injection for regeneration of the DPF 34 is performed. The injection timing in the exhaust stroke for regeneration of the DPF 34 is set in the ECU 100.

  As shown in FIG. 8 (a), this fuel injection includes the cylinder 5, the injector 6, the piston a, the intake valve b, the exhaust valve c, and the exhaust port d. When it is estimated that the fuel pressure has reached, the fuel injection is performed and the temperature is raised until the temperature becomes necessary to regenerate the DPF 34 before the top dead center of the exhaust stroke.

  As shown in FIG. 8 (b), the fuel injection for performing the temperature raising action can be made uniform in density by injecting fuel in the cylinder 5 far from the outlet 31a of the exhaust manifold 31. May be made to inject fuel in all the cylinders 5 and is discharged together with the exhaust gas flow pushed out by the piston a, so that fuel adhesion to the cylinder 5 wall surface and fuel mixing into the lubricating oil are suppressed, and the DOC 33 is oxidized. Since the reaction can be activated, the regeneration process of the DPF 34 can be performed even in the idling operation.

  Conventionally, during forced (manual) regeneration, the engine is operated at medium speed, the exhaust throttle valve is closed, the exhaust gas temperature is raised to activate the DOC and DPF, and unburned fuel is flowed by exhaust gas by post injection or the like. Combustion with DOC is necessary, and the temperature inside the DPF needs to be increased until the soot is burned by PM. Normally, however, the temperature inside the cylinder does not rise sufficiently at the start of post injection, and some unburned Fuel may be discharged, accompanied by odors and white smoke.

  In order to prevent such a phenomenon, it is conceivable to arrange the second DOC on the downstream side of the DPF. However, arranging a DOC of the same size as the DOC in the previous stage in the subsequent stage is also easy to mount and cost. There is a problem that when the soot due to PM in the DPF burns rapidly, the subsequent DOC is exposed to a high temperature and deteriorates.

  For this reason, as shown in FIG. 9, the DOC 33 and the DPF 34 are respectively provided on the exhaust pipe 32 near the turbine 29 a side of the turbocharger 29 on the downstream side of the turbine 29 a, and then the DPF 34. An exhaust pressure differential pressure sensor 42 is provided at the upstream side and the downstream side of the DPF 34, and exhaust temperature sensors 43a and 43b are provided at an intermediate position between the DOC 33 and the DPF 34 and a downstream side position of the DPF 34, respectively. Reference numeral 29b denotes a compressor of the turbocharger 29, 30 denotes an exhaust path, 39 denotes an intercooler, and 40 denotes an intake path.

Further, a bypass pipe 46 is branched and provided at a position downstream of the DPF 34 of the exhaust pipe 32, and a small DOC 33 a is disposed in the bypass pipe 46, and at the exhaust pipe 32 passage position corresponding to the DOC 33 a of the bypass pipe 46. An exhaust throttle valve 37 is provided in an interior, and the differential pressure sensor 42, exhaust temperature sensors 43a and 43b, and the exhaust throttle valve 37 are electrically connected to the ECU 100, respectively.

  With this configuration, during the temperature rising mode operation in which the exhaust throttle valve 37 is closed, the entire amount of exhaust gas flows to the DOC 33a of the rear bypass conduit 46, and when unburned fuel is flowed by post injection or the like, The unburned fuel that could not be oxidized can be oxidized and discharged by the DOC 33a of the post-stage bypass pipeline 46. Since the entire amount of exhaust gas flows through the DOC 33a only when the exhaust throttle valve 37 is closed, the DOC 33a can be reduced in size.

  Further, in the configuration of the operation diagram shown in FIG. 9, as shown in FIG. 10, the downstream branch pipe 46b of the DOC 33a arranged in the bypass pipe 46 branched from the exhaust pipe 32 is used for adjusting the flow rate (back pressure). By providing the restrictor v, the unburned fuel that could not be oxidized by the DOC 33 in the preceding stage when the unburned fuel was flowed by post injection or the like is sufficiently adjusted by adjusting the flow rate by the restrictor v in the DOC 33a of the rear bypass pipe 46. It can be oxidized and discharged.

  Further, in the configuration of the operation diagram shown in FIG. 9, as shown in FIG. 11, the downstream branch pipe 46 b of the DOC 33 a arranged in the bypass pipe 46 branched from the exhaust pipe 32 is used for adjusting the flow rate (back pressure). By providing the throttle valve w, the unburned fuel that could not be oxidized by the DOC 33 at the front stage when the unburned fuel was flowed by post injection or the like was finely adjusted by the throttle valve w at the DOC 33a of the rear stage bypass conduit 46. Can be oxidized and discharged more fully.

  Further, in the configuration of the operation diagram shown in FIG. 9, the exhaust throttle valve 37 disposed in the exhaust pipe 32 is connected to the exhaust pipe 32 passage positioned at the inlet of the upstream branch pipe 46a of the bypass pipe 46 as shown in FIG. When the exhaust throttle valve 37 is closed, the degree of sealing is good, the exhaust gas flows to the DOC 33a of the bypass line 46 sufficiently, and when unburned fuel is flowed by post injection or the like, The unburned fuel that could not be oxidized by the DOC 33 can be accurately oxidized and discharged by the DOC 33a of the rear-stage bypass pipeline 46.

  In general, the scraping work in the tractor is performed when the engine load factor is 20% to 30%, and the exhaust temperature is used in the vicinity of 250 to 300 degrees. In such a light load operation, the DPF cannot be regenerated because combustion is difficult even if the DPF is operated in a state of clogging with PM. Furthermore, in such a low temperature working area, SOF (soluble organic component) adheres to the soot component and accumulates, which may further increase the differential pressure and clog the DPF.

  For this reason, in the tractor T equipped with the common rail type diesel engine E, when performing the scraping operation in the scraping mode, as shown in FIG. 13 (a), in the case of a light load operation with a low load factor such as the scraping operation, Since the continuous regeneration disabled area becomes large and the DPF cannot be regenerated, the intake / exhaust throttle valve is throttled to raise the exhaust gas temperature and burn soot by PM as shown in FIG. 13B. It is possible to expand the possible region to a place where the load factor is low, enabling PM combustion of the DPF at a partial load, eliminating the clogging of the DPF during work, and saving the operator's trouble.

  Moreover, the grain discharge | emission operation | work in a combine is normally performed when the load factor of an engine is 15 to 20%, and exhaust temperature is used by 200 to 250 degree | times vicinity. In such a light load operation, the DPF cannot be regenerated because combustion is difficult even if the DPF is operated in a state of clogging with PM. Furthermore, in such a low working temperature area, SOF adheres to the soot component and accumulates, which may further increase the differential pressure and clog the DPF.

  For this reason, in a combine equipped with a common rail type diesel engine E, when performing a grain discharging operation in the grain discharging mode, a light load with a low load factor such as a grain discharging operation is performed as shown in FIG. In the case of operation, since the continuous regeneration impossible region becomes large and the DPF cannot be regenerated, as shown in FIG. 14B, the intake / exhaust throttle valve is raised and the exhaust gas temperature is raised and held at around 350 ° C. By burning the soot produced by the above, it becomes possible to expand the continuously reproducible region to a place where the load factor is low, and it is possible to eliminate the clogging of the DPF during the work and save the operator's trouble.

  In addition, if the exhaust pipe from the engine has a bent portion just before the DPF, exhaust gas will flow in the circumferential direction due to the inertial force at the bent portion, and there is a strong possibility of PM segregation in the DPF, preventing segregation. Since a pressure loss occurs in a diffusion plate or the like for the purpose, it is ideal to provide a long straight portion immediately before the DPF, but there is a difficulty that a compact arrangement is difficult.

  For this reason, in the agricultural machine equipped with the DPF 34, as shown in FIG. 15, in order to mount the DPF 34 in a compact manner, the exhaust pipe 23 from the engine is formed with a bent portion r in the vicinity of the entrance of the DPF 34. There is an adverse effect that the gas is caused to flow in the circumferential direction due to the inertial force at the bending portion r, and that the PM z of PM is segregated to one side of the DPF 34.

  For this reason, as shown in FIG. 16, the bent portion r is formed by connecting the exhaust pipe 23 and the DPF 34 with a conical rectifier t having a larger exhaust pipe 23 side and a smaller DPF 34 side. The inertial force of the exhaust gas due to r is corrected at a short distance to enable forced rectification, and the exhaust gas can be uniformly introduced into the DPF 34, so that segregation of PM 煤 z to the DPF 34 is prevented. be able to.

  In addition, as shown in FIG. 17, it is not the method of using the conical rectification | straightening part t in the connection part of the exhaust pipe 23 and DPF34 in which the bending part r is formed, but in order to cancel the inertia force of exhaust gas, it connects with DPF34. By making the bent portion r of the exhaust pipe 23 bent at an acute angle α from a right angle, the inertia force of the exhaust gas by the bent portion r can be corrected with a simple configuration to enable rectification, and the exhaust gas can be uniformly distributed to the DPF 34 Therefore, segregation of PM to z DPF 34 can be prevented.

  In addition, a large space is required to equip a post-processing device such as DOC or DPF with an engine mounted on an agricultural machine. However, since the temperature becomes high during DPF regeneration, the thermal effect on wiring and electrical components is taken into account. Placement is required.

  Therefore, as shown in FIG. 18, the DOC 47 and DPF 48 as post-processing devices having an elliptical cross section are arranged in the vertical direction of the exhaust pipe 49 and fixed by the stopper s so as not to move by vibration, and the starter is provided as a main body. 50 is attached to the housing 50, and the generator is disposed at the right side position of the main body 50.

  With such a configuration, the DOC 47 and the DPF 48 as the post-processing device are arranged in the vertical direction as an elliptical shape, thereby making it possible to reduce the space in the horizontal direction and arranging the post-processing device on the left side of the main body 50. The heat effect can be reduced by concentrating the wiring, electrical components, etc. on the right side. It should be noted that since there is no wiring or electrical components in the arrangement portion of the post-processing device, the air flow around the post-processing device is improved, and the cooling efficiency of the surface of the post-processing device during regeneration can be improved.

  It can also be used for general vehicles including agricultural machines such as tractors and combines.

The system figure which shows the pressure accumulation type fuel injection diesel engine by a common rail. The diagram which shows the relationship between the engine speed and output torque by three types of control modes. The side view which shows the whole structure in a tractor. The flowchart which shows the procedure which switches normal reproduction mode and high-speed reproduction mode at the time of DPF reproduction | regeneration. The circuit diagram which shows the state which carried out interior arrangement | positioning of DOC and DPF in the exhaust pipe downstream of the turbine side of a turbocharger. The flowchart which shows the procedure which stops an engine automatically by the detection value fall of an exhaust pressure sensor and an exhaust temperature sensor at the time of DPF forced regeneration. The circuit diagram which shows the state which carried out interior arrangement | positioning of DOC and DPF in the exhaust pipe downstream of the turbine side of a turbocharger. (A) The partial side view which shows the fuel-injection state for DPF reproduction | regeneration before the top dead center of an exhaust stroke, when PM collection amount is more than a setting value. (B) A schematic plan view showing a state in which the fuel injection is performed in a cylinder far from the outlet of the exhaust manifold. The circuit diagram which shows the state which has arrange | positioned 2nd DOC in the bypass line in what arranged DOC and DPF internally in the exhaust pipe downstream of the turbine side of a turbocharger. The circuit diagram which shows the state which provided the aperture | diaphragm in what arranged DOC and DPF inside the exhaust pipe downstream of the turbine side of a turbocharger, and arrange | positioned 2nd DOC in the bypass line. The circuit diagram which shows the state which provided the throttle valve in what arranged DOC and DPF internally in the exhaust pipe of the turbine side downstream of a turbocharger, and arrange | positioned 2nd DOC in the bypass line. An exhaust throttle valve is provided in the exhaust pipe at the inlet position of the bypass pipe in the case where the DOC and DPF are arranged in the exhaust pipe downstream of the turbocharger and the second DOC is arranged in the bypass pipe. The circuit diagram which shows a state. (A) The diagram which shows the state where a continuous regeneration impossibility area | region is large in the case of light load driving | running | working in a tractor. (B) The diagram which shows the state which raises throttle temperature of an intake / exhaust throttle valve, and expands a continuously reproducible area | region. (A) The diagram which shows the state where a continuous regeneration impossibility area | region is large in the case of light load driving | running | working in a combine. (B) The diagram which shows the state which raises throttle temperature of an intake / exhaust throttle valve, and expands a continuously reproducible area | region. The side action figure which shows the state which the exhaust gas to DPF flows in the circumferential direction by the bending part of an exhaust pipe, and the soot of PM segregates to one side. The side action figure which shows the state which makes the flow of the exhaust gas to DPF by the bending part of an exhaust pipe uniform by a cone-shaped rectification | straightening part, and prevents the segregation to one side of PM soot. The side action figure which shows the state which equalizes the flow of the exhaust gas to DPF by the bent part of an exhaust pipe by the acute angle of an exhaust pipe bent part, and prevents the segregation to one side of PM soot. The schematic side view which shows the state which has arrange | positioned DOC and DPF with the ellipse in the vertical direction.

Explanation of symbols

29 Turbocharger 29a Turbine 32 Exhaust pipe 33 DOC
34 DPF
37 Exhaust throttle valve 42 Exhaust pressure sensor (differential pressure sensor)
43 Exhaust temperature sensor 45 Automatic stop switch 100 ECU

Claims (2)

  In a common rail type diesel engine that performs regeneration control by an intake / exhaust throttle valve, post-injection, etc. during regeneration of the DPF, a normal regeneration mode that processes regeneration of the DPF at a normal speed, and a high-speed regeneration mode that processes at a speed faster than the normal speed A common rail diesel engine characterized in that the ECU is set in the ECU so that it can be selectively implemented. The automatic stop means for automatically stopping the diesel engine after completion of the forced regeneration process is provided when the diesel engine is operated after the work is finished to perform the forced regeneration process of the DPF. Common rail diesel engine.

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