JP2014238091A - Exhaust emission control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an operator from feeling physical disorder owing to an impact due to change in engine torque or change of engine noise during reproduction of an exhaust emission control device.SOLUTION: An exhaust emission control system includes: an exhaust emission control device arranged in an exhaust passage of an engine; a reproduction device for burning away particulate substances in the exhaust emission control device; reproduction prediction means 24 operating when the deposition amount of the particulate substances deposited in the exhaust emission control device exceeds a predetermined value; and reproduction permission input means of permitting the reproduction device to operate. When the deposition amount of the particulate substances deposited in the exhaust emission control device exceeds the predetermined value, the reproduction device is placed in operation once the reproduction permission input means indicates operation permission after the reproduction prediction means 24 gives notice that the reproduction device needs to be placed in operation.

Description

  The present invention relates to an exhaust gas purification system for an engine mounted on a work machine such as a construction machine, a farm work machine, and an engine generator.

  In recent years, as high-level exhaust gas regulations related to diesel engines (hereinafter simply referred to as engines) have been applied, air pollutants in exhaust gas have been introduced into construction machines, agricultural machines, and engine generators on which engines are mounted. There has been a demand for mounting an exhaust gas purification device for purification treatment. A diesel particulate filter (hereinafter referred to as DPF) is known as an exhaust gas purification device (see Patent Documents 1 and 2). The DPF is for collecting particulate matter (hereinafter referred to as PM) in the exhaust gas. In this case, if the PM collected by the DPF exceeds a specified amount, the flow resistance in the DPF increases and the engine output decreases, so the PM accumulated in the DPF is removed by the temperature rise of the exhaust gas, It is often performed to recover the PM collection ability of the DPF (regenerate the DPF).

JP 2000-145430 A Japanese Patent Laid-Open No. 2003-27922

  However, when the DPF is regenerated in the conventional configuration, it is necessary to increase the exhaust gas temperature (apply thermal energy to the exhaust gas), so that the fuel exceeds the amount of operation of the accelerator operating tool such as the throttle lever and the accelerator pedal. This will increase consumption and increase engine output. Then, an impact due to a change in engine torque and a change in engine sound occur, which makes the operator feel uncomfortable. There is no denying the possibility that an operator may mistake a sudden impact or a change in engine sound as an abnormality. In particular, in a construction machine such as a hydraulic excavator that performs precise work by relying on engine sound, sudden impacts and engine sound changes that occur during DPF regeneration are not preferable.

  In view of this, the present invention has a technical problem to provide an exhaust gas purification system that has been improved by examining the current situation.

  An exhaust gas purification system according to the present invention includes an engine, an exhaust gas purification device for collecting particulate matter in exhaust gas from the engine, and combustion removal of the particulate matter of the exhaust gas purification device. An exhaust gas purification system for an engine device mounted on a working machine having a regeneration device, and a regeneration notice means that operates when the amount of particulate matter deposited on the exhaust gas purification device exceeds a predetermined value; A regeneration permission input means for permitting the operation of the regeneration device, and when the amount of particulate matter accumulated in the exhaust gas purification device exceeds the predetermined value, the regeneration notice means includes the regeneration device. After informing that it is necessary to operate the playback device, the playback device is configured to operate when an operation permission instruction is given from the playback permission input means. That.

  In the exhaust gas purification system, the regeneration permission input means is a regeneration switch, the regeneration notice means is a regeneration lamp, and the amount of particulate matter deposited in the exhaust gas purification device exceeds the predetermined value. When the playback lamp blinks and informs that the playback device needs to be operated, and when the playback switch is operated and an operation permission is instructed, the playback device is operated and the playback is performed. The regeneration lamp may be turned on during operation of the apparatus.

  Further, as the operation mode of the regeneration device, a manual auxiliary regeneration mode that is executed when the clogged state of the exhaust gas purification device exceeds a specified level, and the exhaust gas purification device even if the manual auxiliary regeneration mode is executed A forced regeneration mode that is executed when the clogged state of the exhaust gas is not improved, and an emergency regeneration mode that is executed when the clogged state of the exhaust gas purifying device is not improved even if the forced regeneration mode is executed. When the operation of the regeneration device in the regeneration mode or the forced regeneration mode is necessary, the regeneration lamp blinks at a low speed, while when the operation of the regeneration device in the emergency regeneration mode is necessary, the regeneration lamp is slowed down. So that the flashing cycle of the regeneration lamp becomes shorter as the amount of accumulated particulate matter in the exhaust gas purification device increases. It may be as being constant.

  According to the present invention, the regeneration operation of the exhaust gas purification device can be prohibited by not performing the permission operation of the regeneration permission input means. That is, the regeneration operation of the exhaust gas purifying device can be prohibited by the operator's intention according to the state of the working machine to which the engine is mounted. For this reason, while the regeneration control for recovering the particulate matter collecting ability of the exhaust gas purifying apparatus can be executed, it is possible to smoothly perform the precise work performed by the operator relying on the engine sound. That is, it is possible to eliminate the drawbacks of the exhaust gas purification device regeneration operation that may hinder the precise operation.

  According to the present invention, during operation of the regenerator, in the idling state of the engine, the engine rotational speed is set to be higher than the low idle rotational speed, so that the exhaust gas temperature from the engine is set to a high temperature state. It becomes easy to hold. For this reason, the number of executions of the exhaust gas purification device regeneration operation can be reduced and the execution time can be shortened, so that the efficiency of regeneration of the exhaust gas purification device can be improved and the fuel efficiency can be suppressed.

  Furthermore, the exhaust gas temperature from the engine can be made higher by setting the engine rotation speed in the idling state to a high idle rotation speed higher than the low idle rotation speed during the operation of the regenerator. Become. Therefore, it is possible to further promote the efficiency of regeneration of the exhaust gas purification device.

  And when the clogged state of the exhaust gas purification device is improved after the regenerating device is operated, it is possible to return to the normal operation mode so that the operator does not need to perform a return operation for changing the mode, for example. Therefore, it is possible to save the labor and reduce the operation burden on the operator.

It is fuel system explanatory drawing of an engine. It is a functional block diagram which shows the relationship between an engine and an exhaust gas purification apparatus. It is a figure explaining the injection timing of fuel. It is explanatory drawing of an output characteristic map. It is explanatory drawing of an instrument panel. It is the first half part of the flowchart which shows the flow of DPF regeneration control. It is a latter half part of the flowchart which shows the flow of DPF regeneration control. It is a flowchart which shows an interruption process.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

(1). Engine and its Surrounding Structure First, the engine 70 and its surrounding structure will be described with reference to FIGS. As shown in FIG. 2, the engine 70 is a four-cylinder type diesel engine, and includes a cylinder block 75 having a cylinder head 72 fastened on the upper surface. An intake manifold 73 is connected to one side of the cylinder head 72, and an exhaust manifold 71 is connected to the other side. A common rail system 117 that supplies fuel to each cylinder of the engine 70 is provided below the intake manifold 73 on the side surface of the cylinder block 75. An intake pipe 76 connected to the intake upstream side of the intake manifold 73 is connected to an intake throttle device 81 and an air cleaner (not shown) for adjusting the intake pressure (intake amount) of the engine 70.

  As shown in FIG. 1, a fuel tank 118 is connected to injectors 115 for four cylinders in the engine 70 via a common rail system 117 and a fuel supply pump 116. Each injector 115 is provided with an electromagnetic switching control type fuel injection valve 119. The common rail system 117 includes a cylindrical common rail 120. A fuel tank 118 is connected to the suction side of the fuel supply pump 116 via a fuel filter 121 and a low pressure pipe 122. The fuel in the fuel tank 118 is sucked into the fuel supply pump 116 via the fuel filter 121 and the low pressure pipe 122. The fuel supply pump 116 of the embodiment is disposed in the vicinity of the intake manifold 73. On the other hand, a common rail 120 is connected to the discharge side of the fuel supply pump 116 via a high-pressure pipe 123. The common rail 120 is connected to injectors 115 for four cylinders via four fuel injection pipes 126.

  In the above configuration, the fuel in the fuel tank 118 is pumped to the common rail 120 by the fuel supply pump 116, and high-pressure fuel is stored in the common rail 120. Each fuel injection valve 119 is controlled to open and close, whereby high-pressure fuel in the common rail 120 is injected from each injector 115 to each cylinder of the engine 70. That is, by electronically controlling each fuel injection valve 119, the injection pressure, injection timing, and injection period (injection amount) of the fuel supplied from each injector 115 are controlled with high accuracy. Therefore, nitrogen oxide (NOx) from the engine 70 can be reduced, and noise and vibration of the engine 70 can be reduced.

  As shown in FIG. 3, the common rail system 117 is configured to execute the main injection A in the vicinity of the top dead center (TDC). In addition to the main injection A, the common rail system 117 executes a small amount of pilot injection B for the purpose of reducing NOx and noise at the time of the crank angle θ1 about 60 ° before the top dead center, Pre-injection C is executed for the purpose of noise reduction immediately before the crank angle θ2, and particulate matter (hereinafter referred to as PM) is reduced and exhaust gas is emitted at the crank angles θ3 and θ4 after top dead center. The after-injection D and the post-injection E are executed for the purpose of promoting purification.

  As shown in FIG. 1, a fuel supply pump 116 is connected to the fuel tank 118 via a fuel return pipe 129. A common rail return pipe 131 is connected to the end of the cylindrical common rail 120 in the longitudinal direction via a return pipe connector 130 that limits the pressure of fuel in the common rail 120. That is, surplus fuel from the fuel supply pump 116 and surplus fuel from the common rail 120 are collected in the fuel tank 118 via the fuel return pipe 129 and the common rail return pipe 131.

  An exhaust pipe 77 connected to the exhaust downstream side of the exhaust manifold 71 includes an exhaust throttle device 82 for adjusting the exhaust pressure of the engine 70 and a diesel particulate filter 50 (hereinafter referred to as DPF) which is an example of an exhaust gas purification device. Connected). Exhaust gas discharged from each cylinder to the exhaust manifold 71 is purified through the exhaust pipe 77, the exhaust throttle device 82, and the DPF 50, and then released to the outside.

  The DPF 50 is for collecting PM or the like in the exhaust gas. The DPF 50 according to the embodiment is configured by accommodating a diesel oxidation catalyst 53 such as platinum and a soot filter 54 in series in a substantially cylindrical filter case 52 in a casing 51 made of a refractory metal material. In the embodiment, the diesel oxidation catalyst 53 is disposed on the exhaust upstream side of the filter case 52, and the soot filter 54 is disposed on the exhaust downstream side. The soot filter 54 has a honeycomb structure having a large number of cells partitioned by porous (filterable) partition walls.

  An exhaust introduction port 55 that communicates with the exhaust downstream side of the exhaust throttle device 82 in the exhaust pipe 76 is provided on one side of the casing 51. One end of the casing 51 is closed by a first bottom plate 56, and one end of the filter case 52 facing the first bottom plate 56 is closed by a second bottom plate 57. The annular gap between the casing 51 and the filter case 52 and the gap between the bottom plates 56 and 57 are filled with a heat insulating material 58 such as glass wool so as to surround the diesel oxidation catalyst 53 and the soot filter 54. ing. The other side of the casing 51 is closed by two lid plates 59 and 60, and a substantially cylindrical exhaust outlet 61 passes through both the lid plates 59 and 60. In addition, a resonance chamber 63 that communicates with the inside of the filter case 52 via a plurality of communication pipes 62 is provided between the lid plates 59 and 60.

  An exhaust gas introduction pipe 65 is inserted into an exhaust introduction port 55 formed on one side of the casing 51. The tip of the exhaust gas introduction pipe 65 projects across the casing 51 to the side surface opposite to the exhaust introduction port 55. A plurality of communication holes 66 opening toward the filter case 52 are formed on the outer peripheral surface of the exhaust gas introduction pipe 65. A portion of the exhaust gas introduction pipe 65 that protrudes from the side surface opposite to the exhaust introduction port 55 is closed by a lid 67 that is detachably screwed to the portion.

  The DPF 50 is provided with a DPF temperature sensor 26 that detects an exhaust gas temperature in the DPF 50 as an example of a detection unit. The DPF temperature sensor 26 of the embodiment is mounted through the casing 51 and the filter case 52, and the tip thereof is located between the diesel oxidation catalyst 53 and the soot filter 54.

  Further, the DPF 50 is provided with a differential pressure sensor 68 that detects a clogged state of the soot filter 54 as an example of a detection unit. The differential pressure sensor 68 of the embodiment detects a pressure difference (differential pressure) between the upstream and downstream sides of the soot filter 54 in the DPF 50. In this case, the upstream side exhaust pressure sensor 68 a constituting the differential pressure sensor 68 is attached to the lid 67 of the exhaust gas introduction pipe 65, and the downstream side exhaust pressure sensor 68 b is interposed between the soot filter 54 and the resonance chamber 63. It is installed. It is well known that there is a certain law between the pressure difference between the upstream and downstream of the DPF 50 and the amount of PM accumulated in the DPF 50. In the embodiment, the PM accumulation amount in the DPF 50 is estimated from the pressure difference detected by the differential pressure sensor 68, and the intake throttle device 81 and the common rail 120 are operated based on the estimation result, thereby regenerating the soot filter 54. Control (DPF regeneration control) is executed.

  The clogged state of the soot filter 54 is not limited to the differential pressure sensor 68 but may be an exhaust pressure sensor that detects the pressure upstream of the soot filter 54 in the DPF 50. When the exhaust pressure sensor is adopted, the pressure (reference pressure) on the upstream side of the soot filter 54 when PM is not deposited on the soot filter 54 is compared with the current pressure detected by the exhaust pressure sensor. As a result, the clogged state of the soot filter 54 is determined.

  In the above configuration, the exhaust gas from the engine 5 enters the exhaust gas introduction pipe 65 via the exhaust introduction port 55 and is ejected into the filter case 52 from each communication hole 66 formed in the exhaust gas introduction pipe 65. After being dispersed over a wide area in the filter case 52, the diesel oxidation catalyst 53 and the soot filter 54 are passed through in this order for purification. At this stage, PM in the exhaust gas is collected without passing through the porous partition wall between the cells in the soot filter 54. Thereafter, exhaust gas that has passed through the diesel oxidation catalyst 53 and the soot filter 54 is discharged from the exhaust outlet 61.

  When exhaust gas passes through the diesel oxidation catalyst 53 and the soot filter 54, if the exhaust gas temperature exceeds the regeneration boundary temperature (for example, about 300 ° C.), the action of the diesel oxidation catalyst 53 causes NO in the exhaust gas. (Nitric oxide) is oxidized to unstable NO2 (nitrogen dioxide). Then, the PM collecting ability of the soot filter 54 is recovered (DPF 50 is regenerated) by oxidizing and removing the PM deposited on the soot filter 54 with O (oxygen) released when NO 2 returns to NO. Become.

(2). Configuration Related to Engine Control Next, a configuration related to control of the engine 70 will be described with reference to FIGS. As shown in FIG. 1, an ECU 11 is provided for operating a fuel injection valve 119 for each cylinder in the engine 70. The ECU 11 includes a CPU 31 that executes various arithmetic processes and controls, a ROM 32 that stores various data fixedly in advance, an EEPROM 33 that stores control programs and various data in a rewritable manner, and temporarily stores control programs and various data. RAM 34, a timer 35 for time measurement, an input / output interface, and the like, which are arranged in the engine 70 or in the vicinity thereof.

  On the input side of the ECU 11, at least the rail pressure sensor 12 that detects the fuel pressure in the common rail 120, the electromagnetic clutch 13 that rotates or stops the fuel pump 116, and the rotational speed of the engine 70 (camshaft position of the crankshaft 74) are detected. An engine speed sensor 14 for detecting, an injection setting device 15 for detecting and setting the number of times of fuel injection of the injector 115 (number of times during the fuel injection period of one stroke), and a throttle position sensor 16 for detecting the operating position of an accelerator operating tool (not shown). An intake air temperature sensor 17 for detecting the intake air temperature in the intake passage, an exhaust temperature sensor 18 for detecting the exhaust gas temperature in the exhaust passage, a coolant temperature sensor 19 for detecting the coolant temperature of the engine 70, and the fuel in the common rail 120 The fuel temperature sensor 20 for detecting the temperature and the DPF 50 regeneration operation are selected and operated. Regeneration switch 21 as regeneration permission input means, differential pressure sensor 68 (upstream exhaust pressure sensor 68a and downstream exhaust pressure sensor 68b), DPF temperature sensor 26 for detecting the exhaust gas temperature in DPF 50, and brake the work implement The parking brake detection means 30 etc. which detect the on / off state (whether it is a braking state) of the parking brake operation means 29 which maintains the state are connected.

  At the output side of the ECU 11, electromagnetic solenoids of the fuel injection valves 119 for at least four cylinders are respectively connected. That is, the high-pressure fuel stored in the common rail 120 is injected from the fuel injection valve 119 in a plurality of times during one stroke while controlling the fuel injection pressure, the injection timing, the injection period, and the like, so that nitrogen oxide (NOx ), And complete combustion with reduced generation of soot and carbon dioxide is performed to improve fuel efficiency.

  Further, on the output side of the ECU 11, an intake throttle device 81 for adjusting the intake pressure (intake amount) of the engine 70, an exhaust throttle device 82 for adjusting the exhaust pressure of the engine 70, and a failure notification of the ECU 11 are notified. An ECU failure lamp 22, an exhaust temperature warning lamp 23 as an abnormally high temperature notification means for notifying an abnormally high exhaust gas temperature in the DPF 50, and a regeneration lamp 24 that is turned on in accordance with the DPF 50 regeneration operation are connected. Data relating to blinking of the lamps 22 to 24 is stored in the EEPROM 33 of the ECU 11 in advance. As will be described in detail later, the regeneration lamp 24 serves as a regeneration notice unit that operates when the clogged state of the DPF 50 exceeds a specified level, and also serves as a regeneration notification unit that informs that the DPF 50 regeneration operation is being performed. It constitutes a single indicator. As shown in FIG. 5, the regeneration switch 21 and the lamps 22 to 24 are provided on the instrument panel 40 in the working machine to be mounted with the engine 70.

  The regeneration switch 21 is of an alternate operation type. That is, the playback switch 21 is a lock-type push switch that is locked at the pressed position when pressed once and returns to the original position when pressed again. If the regeneration switch 21 is locked at the pressed position when the regeneration lamp 24 flashes to notify that the clogged state of the DPF 50 has reached the specified level, it can be shifted to each mode described later.

  In the EEPROM 33 of the ECU 11, an output characteristic map M (see FIG. 4) indicating the relationship between the rotational speed N of the engine 70 and the torque T (load) is stored in advance. The output characteristic map M is obtained by experiments or the like. In the output characteristic map M shown in FIG. 4, the rotational speed N is taken on the horizontal axis and the torque T is taken on the vertical axis. The output characteristic map M is a region surrounded by a solid line Tmx drawn upwardly. A solid line Tmx is a maximum torque line representing the maximum torque for each rotational speed N. In this case, if the model of the engine 70 is the same, the output characteristic maps M stored in the ECU 11 are all the same (common). As shown in FIG. 4, the output characteristic map M is divided vertically by a boundary line BL representing the relationship between the rotational speed N and the torque T when the exhaust gas temperature is the regeneration boundary temperature (about 300 ° C.). . The upper region across the boundary line BL is a reproducible region in which PM deposited on the soot filter 54 can be oxidized and removed (the oxidizing action of the oxidation catalyst 53 works), and the lower region is not oxidized and removed of PM. This is a non-reproducible region that accumulates on the soot filter 54.

  The ECU 11 basically calculates the torque T based on the output characteristic map M, the rotational speed N detected by the engine speed sensor 14, and the throttle position detected by the throttle position sensor 16 and performs target fuel injection. The fuel injection control for obtaining the amount and operating the common rail system 117 based on the calculation result is executed. Here, the fuel injection amount is adjusted by adjusting the valve opening period of each fuel injection valve 119 and changing the injection period to each injector 115.

(3). Aspects of DPF regeneration control Next, an example of DPF 50 regeneration control by the ECU 11 will be described with reference to the flowcharts of FIGS. As a control mode of the engine 70 (control format related to DPF 50 regeneration), at least when a normal operation mode for running on the road and various operations and when the clogged state of the DPF 50 exceeds a specified level, exhaust is performed when the regeneration switch 21 is pressed. Manual auxiliary regeneration mode for raising the gas temperature, reset regeneration mode for supplying fuel into the DPF 50 by post-injection E (may be referred to as forced regeneration mode), and fuel for supplying into the DPF 50 by post-injection E In addition, an emergency regeneration mode in which the rotational speed N of the engine 70 is maintained at a high idle rotational speed, and a limp home mode in which the engine 70 is driven to a minimum necessary driving state (a work machine having a necessary minimum traveling function). There is.

  In the manual auxiliary regeneration mode, the intake amount and the exhaust amount are limited by closing at least one of the intake throttle device 81 and the exhaust throttle device 82 to a predetermined opening based on the detection information of the differential pressure sensor 68. As a result, the load on the engine 70 increases. Accordingly, the engine 70 output is increased in conjunction with this, and the exhaust gas temperature from the engine 70 is increased. As a result, PM in the DPF 50 (soot filter 54) can be burned and removed.

  In the reset regeneration mode (forced regeneration mode), when the manual auxiliary regeneration mode is executed, the clogged state of the DPF 50 is not improved (PM remains), or the accumulated drive time Te of the engine 70 is set to a set time T0 (for example, about 100). It is executed when the time is exceeded. In the reset regeneration mode, fuel is supplied into the DPF 50 by the post-injection E, and the fuel is combusted by the diesel oxidation catalyst 53, thereby raising the exhaust gas temperature in the DPF 50 (about 560 ° C.). As a result, the PM in the DPF 50 (soot filter 54) can be forcibly burned and removed.

  The emergency regeneration mode is executed when the clogged state of the DPF 50 does not improve even when the reset regeneration mode is executed. In the emergency regeneration mode, in addition to the control mode of the reset regeneration mode described above (execution of post injection E), the engine 70 is maintained at a high idle rotational speed (maximum rotational speed) by maintaining the rotational speed N of the engine 70. The exhaust gas temperature is raised by post injection E even in the DPF 50 (about 600 ° C.). As a result, the PM in the DPF 50 (the soot filter 54) can be forcibly burned and removed under better conditions than the reset regeneration mode.

  In the limp home mode, even when the emergency regeneration mode is executed, the clogged state of the DPF 50 does not improve and the PM is over-deposited (the PM is highly likely to runaway), or the PM runs away in the DPF 50 It is executed when combustion has occurred. In the limp home mode, the upper limit of the engine 70 output (the rotational speed N and the torque T) and the driveable time of the engine 70 are limited, so that the engine 70 is maintained in the minimum necessary driving state. As a result, for example, the work machine can be escaped from the work place or moved to a store / service center. That is, the minimum necessary traveling function can be secured in the work machine.

  As can be understood from the description regarding the above modes, for example, the engine 70, the intake throttle device 81, the exhaust throttle device 82, the common rail system 117, and the like are members involved in the DPF 50 regeneration operation. These 70, 81, 82, and 117 constitute a regeneration device for burning and removing PM in the DPF 50.

  As shown in FIGS. 6 to 8, each of these modes is executed based on a command from the ECU 11. That is, the algorithm shown in the flowcharts of FIGS. 6 to 8 is stored in the EEPROM 33. Each mode described above is executed by calling the algorithm to the RAM 34 and then processing the CPU 31. Roughly speaking, steps S01 to S06 shown in FIG. 6 correspond to the normal operation mode, and step S07 corresponds to the manual auxiliary regeneration mode. Step S14 shown in FIG. 6 corresponds to the reset regeneration mode, and step S20 shown in FIG. 7 corresponds to the emergency regeneration mode. The step of S23 shown in FIG. 7 corresponds to the limp home mode.

  As shown in the flowcharts of FIGS. 6 and 7, in the DPF 50 regeneration control, first, it is determined whether or not the cumulative drive time Te of the engine 70 is equal to or longer than the set time T0 (S01). At this stage, the normal operation mode is executed. The set time T0 of the embodiment is set to about 100 hours, for example. The accumulated driving time Te of the engine 70 is measured using the time information of the timer 35 in the ECU 11 while the engine 70 is being driven, and is stored and accumulated in the EEPROM 33.

  If the cumulative drive time Te is equal to or longer than the set time T0 (S01: YES), the process proceeds to step S10 described later. If the cumulative drive time Te is less than the set time T0 (S01: NO), then, the PM accumulation amount in the DPF 50 is estimated based on the detection result from the differential pressure sensor 68, and the estimation result is a specified amount (specified level). It is determined whether or not this is the case (S02). When it is determined that the PM accumulation amount is less than the prescribed amount (S02: NO), the process returns to step S01 and the normal operation mode is continued. The prescribed amount in the embodiment is set to 8 g / l, for example. When it is determined that the PM accumulation amount is equal to or greater than the prescribed amount (S02: NO), the measurement based on the time information of the timer 35 is started and the regeneration lamp 24 is blinked at a low speed (S03). Notice the execution of the auxiliary playback mode. In this case, the blinking frequency of the regeneration lamp 24 is set to 1 Hz, for example.

  Next, it is determined whether or not the regeneration switch 21 is depressed (S04). If the regeneration switch 21 is not locked in the depressed state (S04: OFF), whether a predetermined time (for example, 30 minutes) has elapsed since the regeneration lamp 24 started blinking slowly. It is determined whether or not (S05). If the predetermined time has not elapsed (S05: NO), the process directly returns to step S03. When the predetermined time has elapsed (S05: YES), the process proceeds to step S16 described later. For this reason, in the steps of S03 to S05, the control mode of the engine 70 remains in the normal operation mode even though the PM accumulation amount is not less than the specified amount, and the current driving state of the engine 70 is maintained. become. That is, the transition to the manual auxiliary regeneration mode (which may be referred to as the DPF 50 regeneration operation or the operation of the regeneration device) is prohibited. The blinking cycle of the regeneration lamp 24 is set to be shorter as the PM accumulation amount in the DPF 50 increases (the regeneration lamp 24 blinks at shorter intervals as the PM accumulation amount in the DPF 50 increases). For this reason, the operator's attention can be alerted by the flashing speed of the regeneration lamp 24.

  In step S04, if the regeneration switch 21 is locked in the depressed state (S04: ON), the regeneration lamp 24 blinking at a low speed is turned on (S06), and then the manual auxiliary regeneration mode is executed (S07). In this way, when the DPF 50 regeneration notice and the subsequent DPF 50 regeneration notification (the fact that the regeneration device is operating) are displayed by changing the blinking mode of the regeneration lamp 24, the torque T fluctuation that occurs thereafter is displayed by the DPF 50 regeneration notice. An operator can assume in advance an impact or a change in engine 70 sound. Further, the DPF 50 regeneration notification allows the operator to easily grasp the transition to the DPF 50 regeneration operation. Therefore, the operator feels uncomfortable due to the DPF 50 regeneration operation. In addition, since the DPF 50 regeneration notice and the DPF 50 regeneration notification can be distinguished and recognized only by the blinking mode of the regeneration lamp 24, it is easy to grasp the presence or absence of the DPF 50 regeneration operation. In addition, it is not necessary to provide a reproduction notice unit and a reproduction notification unit, which can contribute to cost reduction of this type of display.

  In the manual auxiliary regeneration mode, as described above, the load on the engine 70 is increased by restricting the intake air amount or the exhaust air amount using at least one of the intake air throttle device 81 and the exhaust air throttle device 82, and the engine 70 output is increased accordingly. Increase the exhaust gas temperature. As a result, the PM in the DPF 50 is burned and removed, and the PM collection capability of the DPF 50 is restored. The manual auxiliary regeneration mode of the embodiment is executed, for example, for about 20 minutes, and after the passage of the time, the opening degree of the intake throttle device 81 and the exhaust throttle device 82 returns to the original state before narrowing.

  After the execution of the manual auxiliary regeneration mode, the PM accumulation amount in the DPF 50 is estimated again based on the detection result from the differential pressure sensor 68, and it is determined whether or not the estimation result is less than the allowable amount (S08). When it is determined that the PM accumulation amount is less than the allowable amount (S08: YES), the regeneration lamp 24 is turned off to notify the end of the manual auxiliary regeneration mode (S09), and the normal operation mode is performed by returning to step S01. The allowable amount of the embodiment is set to 4 g / l, for example. When it is determined that the PM accumulation amount exceeds the allowable amount (S08: NO), PM in the DPF 50 is not sufficiently removed despite the execution of the manual auxiliary regeneration mode (the clogging state does not improve). ) State, the measurement based on the time information of the timer 35 is started, the regeneration lamp 24 is blinked at a low speed (S11), and the operator is notified of the execution of the DPF 50 regeneration operation (reset regeneration mode). In this case, the blinking frequency of the regeneration lamp 24 is set to 1 Hz, for example, as in the manual auxiliary regeneration mode.

  Next, it is determined whether or not the regeneration switch 21 is pressed (S11). If it is not locked in the depressed state (S11: OFF), whether a predetermined time (for example, 30 minutes) has elapsed since the regeneration lamp 24 started blinking slowly. It is determined whether or not (S12). If the predetermined time has not elapsed (S12: NO), the process directly returns to step S10. When the predetermined time has elapsed (S12: YES), the process proceeds to step S16 described later. Therefore, in the steps S10 to S12, the current driving state of the engine 70 is maintained and the shift to the reset regeneration mode is prohibited although the clogged state of the DPF 50 is not improved. Also in this case, the blinking cycle of the regeneration lamp 24 is set so as to become shorter as the PM accumulation amount in the DPF 50 increases.

  In step S11, if the regeneration switch 21 is locked in the depressed state (S11: ON), the regeneration lamp 24 blinking at a low speed is turned on (S13), and the reset regeneration mode is executed (S14). In the reset regeneration mode, as described above, fuel is supplied into the DPF 50 by the post-injection E of the common rail system 117, and the fuel is combusted by the diesel oxidation catalyst 53, whereby the exhaust gas temperature in the DPF 50 is raised. As a result, the PM in the DPF 50 is forcibly burned and removed, and the PM collection capability of the DPF 50 is restored. The reset regeneration mode of the embodiment is executed for about 30 minutes, for example, and the common rail system 117 does not perform the post injection E after the lapse of the time. When the reset regeneration mode is executed, the cumulative driving time Te of the engine 70 is once reset and newly measured using the time information of the timer 35.

  During the manual auxiliary regeneration mode and the reset regeneration mode, the engine 70 is controlled by adjusting the fuel injection state (injection pressure, injection timing, injection period, etc.) to each cylinder by electronic control of the common rail system 117. It may be configured to maintain the rotational speed N in the idling state at a higher value than the low idle rotational speed (predetermined low rotational speed). With this configuration, since the exhaust gas temperature can be easily maintained at a high temperature, the number of executions of the DPF 50 regeneration operation can be reduced and the execution time can be shortened, so that the efficiency of the DPF 50 regeneration can be improved and the deterioration of fuel consumption can be suppressed. Also contributes. In particular, if the high idle rotation speed (maximum rotation speed) is maintained, the efficiency of regeneration of the DPF 50 can be further promoted. In this case, for example, it is more preferable that rotation speed setting means such as a dial type is provided on the instrument panel so that the maintenance rotation speed can be changed according to the operation position of the rotation speed setting means.

  After execution of the reset regeneration mode, it is determined whether or not the exhaust gas temperature TP in the DPF 50 detected by the DPF temperature sensor 26 is equal to or lower than a preset lower limit temperature TP0 (S15). The lower limit temperature TP0 is lower than the regeneration boundary temperature (for example, about 300 ° C.). That is, as the lower limit temperature TP0, a non-reproducible temperature at which PM is not oxidized and deposited on the soot filter 54 is employed. The lower limit temperature TP0 of the embodiment is set to about 250 ° C., for example. If the exhaust gas temperature TP in the DPF 50 exceeds the lower limit temperature TP0 (S15: NO), the process proceeds to step S09, the regeneration lamp 24 is turned off, and the end of the reset regeneration mode is notified. And it returns to step S01 and performs normal operation mode.

  If the exhaust gas temperature TP in the DPF 50 is equal to or lower than the lower limit temperature TP0 (S15: YES), the exhaust gas temperature has not risen and PM in the DPF 50 has not been removed even though the reset regeneration mode has been executed (clogged state). Is not improved). Accordingly, the regeneration lamp 24 is blinked at high speed (S16), and the operator is notified of the execution of the DPF 50 regeneration operation (emergency regeneration mode). In this case, the blinking frequency of the regeneration lamp 24 is set to a different frequency from that in the manual auxiliary regeneration mode and the reset regeneration mode. For example, the blinking frequency of the reproduction lamp 24 for emergency reproduction mode notification is set to 2 Hz. Even when a predetermined time (for example, about 30 minutes) elapses without executing the manual auxiliary regeneration mode and the reset regeneration mode, the process proceeds to step S16, and the regeneration lamp 24 is blinked at high speed (step in FIG. 6). (See S05 and S12).

  Next, it is determined whether or not both the regeneration switch 21 and the parking brake operation means 29 are in the on state (S17). This is intended to prohibit the transition to the emergency regeneration mode unless the operator intentionally stops the traveling of the work equipment and various operations in order to greatly increase the rotational speed N of the engine 70 in the emergency regeneration mode. It is. If both the regeneration switch 21 and the parking brake operation means 29 are in the on state (S17: YES), the regeneration lamp 24 that has been flashing at high speed is turned on (S19), and then the emergency regeneration mode is executed (S20). . It should be noted that it is possible to determine the on / off state of only the regeneration switch 21 or the on / off state of only the parking brake operation means 29. However, when both the regeneration switch 21 and the parking brake operation means 29 are provided, the interlock structure (malfunction prevention structure) for executing the emergency regeneration mode is more effective.

  In the emergency regeneration mode, as described above, fuel is supplied into the DPF 50 by the post injection E of the common rail system 117, and the fuel is burned by the diesel oxidation catalyst 53. In addition, the state of fuel injection to each cylinder is adjusted by electronic control of the common rail system 117, and the rotational speed N of the engine 70 is maintained at a high idle rotational speed (maximum rotational speed). For this reason, after the exhaust gas temperature from the engine 70 is raised, the exhaust gas temperature is also raised by the post injection E in the DPF 50 (about 600 ° C.). As a result, the PM in the DPF 50 can be forcibly burned and removed under better conditions than the reset regeneration mode, and the PM trapping ability of the DPF 50 can be recovered. The emergency regeneration mode of the embodiment is executed, for example, for about 15 minutes. After the time has elapsed, the common rail system 117 does not perform the post-injection E, and the fuel injection state to each cylinder is adjusted to The rotational speed N is returned to the original rotational speed before the high idle is fixed.

  After execution of the emergency regeneration mode, it is determined whether or not the exhaust gas temperature TP in the DPF 50 detected by the DPF temperature sensor 26 is equal to or lower than the lower limit temperature TP0 (S21). If the exhaust gas temperature TP in the DPF 50 exceeds the lower limit temperature TP0 (S21: NO), the process proceeds to step S09, the regeneration lamp 24 is turned off, and the end of the emergency regeneration mode is notified. And it returns to step S01 and performs normal operation mode.

  If the exhaust gas temperature TP in the DPF 50 is equal to or lower than the lower limit temperature TP0 (S21: YES), the PM over-deposition state in which the exhaust gas temperature does not rise and the clogged state of the DPF 50 does not improve despite the execution of the reset regeneration mode It is in. In this case, since there is a concern about the possibility of PM runaway combustion, the limp home flag LF is set (LF = 1, S22), and then the limp home mode is executed (S23). In the limp home mode, as described above, by limiting the upper limit values Nmx and Tmx of the engine 70 output (rotational speed N and torque T) and the driveable time Tmx of the engine 70, the engine 70 is driven to the minimum necessary driving state. Hold on. As a result, the minimum necessary traveling function can be secured in the work machine.

  The limp home flag LF corresponds to the fact that the limp home mode has been executed in the past, and is an external tool connected to the ECU 11 via a communication terminal line (for example, in a store / service center). The setting is not reset unless) is used. Therefore, once the limp home mode is executed, it is impossible to return to another mode unless the limp home flag LF is reset at a dealer / service center.

  In the limp home mode, when the current rotational speed N and torque T of the engine 70 are larger than the upper thresholds Nmx and Tmx, the rotational speed N and torque T of the engine 70 are gradually decreased to the upper thresholds Nmx and Tmx. Is set to For this reason, when shifting to the limp home mode, the rotation speed N and the torque T are prevented from suddenly changing (decreasing), the operator feels uncomfortable when executing the limp home mode, and the operator cannot respond to the engine. The problem of causing a stall can be avoided.

  In step S17, if both the regeneration switch 21 and the parking brake operation means 29 are not in the on state (S17: NO), it is determined whether or not a predetermined time (for example, 30 minutes) has elapsed since the regeneration lamp 24 started flashing rapidly. It discriminate | determines (S18). If the predetermined time has not elapsed (S18: NO), the process directly returns to step S18. If the predetermined time has elapsed (S18: YES), the emergency regeneration mode should be executed, but it is neglected. Therefore, after setting the limp home flag LF (LF = 1, S22), the limp home mode is executed (S23).

  Now, the ECU 11 of the embodiment is configured to execute the interrupt process shown in FIG. 8 during the execution of the DPF 50 regeneration control. The interruption process is to check the detection result of the DPF temperature sensor 26 at appropriate time intervals. In this case, as shown in the flowchart of FIG. 8, it is determined whether or not the limp home flag LF is reset (S31). If the limp home flag LF is set (S31: NO), the limp home mode is still set. Since it is in a state where it cannot return to another mode from step S25, the process proceeds to step S25, and the limp home mode is executed.

  If the limp home flag LF is in the reset state (S31: YES), it is determined whether or not the exhaust gas temperature TP in the DPF 50 detected by the DPF temperature sensor 26 exceeds a preset abnormal temperature TPex ( When the temperature exceeds the abnormal temperature TPex (S32: YES), the exhaust temperature warning lamp 23 as the abnormal high temperature notification means is turned on (S33), and then the limp home flag LF is set (S34). Then, the process proceeds to step S23 to execute the limp home mode. The abnormal temperature TPex of the embodiment is set to about 800 ° C., for example. The state in which the exhaust gas temperature TP in the DPF 50 exceeds the abnormal temperature TPex is understood to be that the over-deposited PM has runaway and burned. In this case, the DPF 50 is damaged (melted) or excessive emissions (air pollutants). May be discharged. Therefore, the limp home mode is promptly shifted.

  Note that it is also possible to adopt an interruption process in which it is determined whether or not an abnormal differential pressure has occurred from the detection result of the differential pressure sensor 68, and when the abnormal differential pressure has occurred, a transition to the limp home mode is made. When the abnormal differential pressure is generated, it is understood that the PM is in an over-deposited state in which the possibility of PM runaway combustion is a concern. Accordingly, in this case as well, it is desirable to promptly shift to the limp home mode.

(4). Summary As is apparent from the above description and FIGS. 1, 5, and 6, the exhaust gas purifying device 50 disposed in the exhaust path 77 of the engine 70 and the particulate matter in the exhaust gas purifying device 50 are burned and removed. The regenerators 70, 81, 82, and 117, the regeneration notifying means 24 that operates when the exhaust gas purifying device 50 is clogged above a specified level, and the regenerators 70, 81, 82, and 117 are in operation. And the playback notification means 24 for notifying that the playback notification means 24 is activated before the playback devices 70, 81, 82, 117 are operated. Thus, the operator can assume in advance the impact of the torque T fluctuation and the change of the engine 70 sound that occur thereafter. In addition, the regeneration notification allows the operator to easily grasp the transition to the exhaust gas purification device 50 regeneration operation. Therefore, there is an effect that the operator feels uncomfortable due to the regeneration operation of the exhaust gas purification device 50. For example, the exhaust gas purification device 50 regeneration operation, which may hinder the precise work performed by the operator using the engine 70 sound, can be compensated.

  As is clear from the above description and FIGS. 1, 5 and 6, the reproduction notice means 24 and the reproduction notification means 24 are composed of a single display 24, and the reproduction notice and the reproduction notice are different. Therefore, although the single display tool is used, the reproduction notice and the reproduction notification can be distinguished and recognized by the different modes. Therefore, there is an effect that it is easy for an operator to grasp the presence or absence of the regeneration operation of the exhaust gas purification device 50. In addition, it is not necessary to provide the reproduction notice unit 24 and the reproduction notification unit 24 individually, which can contribute to cost reduction of this type of display tool 24.

  As is apparent from the above description and FIGS. 1, 6 and 7, the exhaust gas purification device 50 disposed in the exhaust path 77 of the common rail engine 70, and the particulate matter in the exhaust gas purification device 50 Even if a reset regeneration mode for supplying fuel into the exhaust gas purification device 50 by post-injection E is executed, the exhaust gas purification is provided. When the clogged state of the device 50 does not improve, emergency regeneration is performed in which fuel is supplied into the exhaust gas purification device 50 by post-injection E and the rotational speed N of the engine 70 is maintained at a predetermined value (high idle rotational speed). Since it is configured to execute the mode, it is possible to prevent the particulate matter in the exhaust gas purifying device 50 from increasing to an over-deposited state that may cause runaway combustion. That the runaway combustion of the particulate matter occurs at the exhaust gas purifying device within 50 can be suppressed. Therefore, failure of the exhaust gas purifying device 50 and the engine 70 due to excessive deposition of particulate matter can be prevented in advance.

  As apparent from the above description and FIGS. 1 and 5 to 7, the regeneration notice means 24 that operates when the clogged state of the exhaust gas purifying device 50 exceeds a specified level, and the regeneration devices 70, 81, 82, A regeneration permission input means 21 for permitting the operation of 117, and if the clogged state of the exhaust gas purifying device 50 is not improved even when the reset regeneration mode is executed, the regeneration notice means 24 is activated, If the permission operation of the regeneration permission input means 21 is performed under the operation of the regeneration notice means 24, the emergency regeneration mode is executed. Do not execute. For this reason, in the emergency regeneration mode in which the rotational speed N of the engine 70 is significantly increased, the operator can assume in advance the impact of torque T fluctuation and the change of the engine 70 sound. Therefore, for example, it is possible to avoid an unexpected situation in which the working machine to be mounted with the engine accelerates rapidly.

  As is apparent from the above description and FIGS. 1 and 6 to 8, the parking brake operating means 29 is provided for maintaining the work machine equipped with the engine 70 in a braking state. When the braking operation is not performed, the emergency regeneration mode is not executed regardless of the clogged state of the exhaust gas purifying device 50 and the operation state of the regeneration permission input means 21. Thus, the transition to the emergency regeneration mode can be prohibited unless the traveling of the work implement and various operations are stopped. For this reason, in the emergency regeneration mode in which the rotational speed N of the engine 70 is significantly increased, it is possible to reliably avoid the occurrence of an unexpected situation in which, for example, the working machine is accelerated rapidly. That is, a higher effect can be exhibited as an interlock structure (malfunction prevention structure) for execution of the emergency regeneration mode.

  As is apparent from the above description and FIGS. 1, 7, and 8, the exhaust gas purification device 50 disposed in the exhaust path 77 of the engine 70 is provided, and the exhaust gas temperature TP in the exhaust gas purification device 50 is provided. When the temperature exceeds the abnormal temperature TPex, the upper limit thresholds Nmx and Tmx of the rotational speed N and torque T of the engine 70 and the limp home mode for limiting the driveable time of the engine 70 are executed. In the state where it is considered that the particulate matter has run away in the exhaust gas purification device 50, the engine 70 is held in the minimum required driving state by executing the limp home mode. That is, the minimum necessary traveling function can be ensured for the work machine equipped with the engine. Therefore, while preventing the exhaust gas purifying device 50 from being damaged (melted) and excessively discharged, the working machine can be removed from the work place or moved to a store / service center, for example. It is possible to evacuate to a safe place.

  As apparent from the above description and FIGS. 1, 7, and 8, after the limp home mode is executed, the engine 70 is configured to be unable to shift to a mode other than the limp home mode even if the engine 70 is restarted. Therefore, once the limp home mode is executed, the exhaust gas purifying device 50 is highly likely to be damaged, but it is necessary to inspect and maintain it at, for example, a store / service center. For this reason, there is an advantage that the possibility of using the exhaust gas purification device 50 in a damaged state can be avoided and excessive emission emission can be prevented.

  As apparent from the above description and FIGS. 1, 7, and 8, when the current rotational speed N and torque T of the engine 70 are larger than the upper thresholds Nmx and Tmx during execution of the limp home mode. Since the rotational speed N and the torque T of the engine 70 are gradually reduced to the upper limit thresholds Nmx and Tmx, the rotational speed N and the torque T are changed when the limp home mode is entered. Rapid change (decrease) can be prevented. This eliminates the operator's uncomfortable feeling when the limp home mode is executed, thereby avoiding the problem that the operator cannot cope with the engine stalling.

  As is apparent from the above description and FIGS. 1, 7, and 8, there is provided an abnormally high temperature notification means 23 that operates when the exhaust gas temperature TP in the exhaust gas purification device 50 is equal to or higher than the abnormal temperature TPex. Thus, the notification of the abnormally high temperature notification means 23 can notify the operator of an abnormal exhaust gas temperature (runaway combustion), which helps to prevent the expansion of damage such as melting of the exhaust gas purification device 50. Play.

  As apparent from the above description and FIGS. 1 and 6, the exhaust gas purification device 50 disposed in the exhaust path 77 of the engine 70, and the regeneration for removing the particulate matter in the exhaust gas purification device 50 by combustion. Regeneration permission means for permitting the operation of the regenerators 70, 81, 82, 117, the regeneration notice means 24 that operates when the clogged state of the exhaust gas purifying device 50 exceeds a specified level, and the regenerators 70, 81, 82, 117 And the input device 21, and is configured to operate the playback devices 70, 81, 82, and 117 when the playback permission input unit 21 is permitted to operate under the operation of the playback notice unit 24. Therefore, the regeneration operation of the exhaust gas purifying device 50 can be prohibited by not performing the permission operation of the regeneration permission input means 21. That is, the regeneration operation of the exhaust gas purifying device 50 can be prohibited by the operator's intention according to the state of the working machine to be mounted with the engine. For this reason, while the regeneration control for recovering the particulate matter collecting ability of the exhaust gas purifying device 50 can be executed, there is an effect that the operator can smoothly perform the precise work performed by relying on the engine sound. That is, it is possible to eliminate the disadvantage of the regeneration operation of the exhaust gas purification device 50 that may hinder the precise operation.

  As apparent from the above description and FIGS. 1 and 6, the rotational speed N of the engine 70 is set to the low idle rotational speed in the idling state of the engine 70 during the operation of the regeneration devices 70, 81, 82, 117. Since it is configured to be higher, the exhaust gas temperature from the engine 70 can be easily maintained at a high temperature. For this reason, the number of executions of the regeneration operation of the exhaust gas purification device 50 can be reduced and the execution time can be shortened, so that the regeneration of the exhaust gas purification device 50 can be improved and the fuel consumption can be suppressed.

  As apparent from the above description and FIGS. 1 and 6, during the operation of the regenerators 70, 81, 82, 117, the rotational speed N of the engine 70 in the idling state is less than the low idle rotational speed. Therefore, the exhaust gas temperature from the engine 70 can be made higher. Therefore, the efficiency of the regeneration of the exhaust gas purification device 50 can be further promoted.

  As apparent from the above description and FIGS. 1 and 6 to 8, when the clogged state of the exhaust gas purifying device 50 is improved after the regeneration devices 70, 81, 82, 117 are operated, the normal operation mode is set. Therefore, it is not necessary for the operator to perform a return operation for changing the mode, for example. Therefore, it is possible to save time and labor of the operator.

(5). Others The present invention is not limited to the above-described embodiment, and can be embodied in various forms. The configuration of each part is not limited to the illustrated embodiment, and various modifications can be made without departing from the spirit of the present invention.

11 ECU
21 Playback switch (playback permission input means)
23 Exhaust temperature warning lamp (Abnormal high temperature notification means)
24 Reproduction lamp (reproduction notice means / reproduction notification means)
26 DPF temperature sensor 27 Regeneration prohibition button (regeneration prohibition input means)
28 Reproduction prohibition lamp (reproduction prohibition notification means)
29 Parking brake operating means 50 DPF (exhaust gas purification device)
70 Engine 117 Common rail system 120 Common rail

Claims (3)

An engine, an exhaust gas purification device for collecting particulate matter in exhaust gas from the engine, and a regenerator for burning and removing particulate matter of the exhaust gas purification device are mounted on a working machine. An exhaust gas purification system for an engine device
A regeneration notice unit that operates when the amount of particulate matter deposited in the exhaust gas purification device exceeds a predetermined value, and a regeneration permission input unit that permits operation of the regeneration device,
When the amount of particulate matter accumulated in the exhaust gas purifier exceeds the predetermined value, the regeneration notice means informs that the regeneration apparatus needs to be operated, and then permits the operation from the regeneration permission input means. The exhaust gas purification system is configured to operate the regenerator when the instruction is given. On the instrument panel of the working machine, a regeneration switch as the regeneration permission input means and a regeneration lamp as the regeneration notice means are disposed,
When the amount of particulate matter accumulated in the exhaust gas purification device exceeds the predetermined value, the regeneration lamp blinks to notify that the regeneration device needs to be operated, and then the regeneration switch is operated. When the operation permission is instructed, the playback device is operated,
The exhaust gas purification system according to claim 1, wherein the regeneration lamp is turned on during operation of the regeneration device. As the operation mode of the regenerator, a manual auxiliary regeneration mode that is executed when the clogged state of the exhaust gas purifier exceeds a specified level, and the clogging of the exhaust gas purifier even when the manual auxiliary regeneration mode is executed. A forced regeneration mode that is executed when the state does not improve, and an emergency regeneration mode that is performed when the clogged state of the exhaust gas purification device is not improved even if the forced regeneration mode is executed,
When the operation of the regeneration device in the manual auxiliary regeneration mode or the forced regeneration mode is required, the regeneration lamp blinks at a low speed,
When the operation of the playback device in the emergency playback mode is required, the playback lamp is blinking at a low speed,
The exhaust gas purification system according to claim 2, wherein the flashing cycle of the regeneration lamp is set to be shorter as the amount of particulate matter accumulated in the exhaust gas purification device increases.

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