JP5135286B2 - Exhaust purification system - Google Patents

Description

  The present invention relates to an exhaust gas purification system for a diesel engine, and more particularly to an exhaust gas purification system that is mounted on a construction machine and performs a regeneration process for removing particulate matter accumulated in a filter by incineration.

  Regulations related to exhaust gas emitted from internal combustion engines such as diesel engines have been strengthened year by year, and in response to these regulations, exhaust gas filters and catalyst technology used in such filters have also advanced rapidly. ing. For example, as a technology for reducing particulate matter (Particulate Matter: hereinafter referred to as PM as appropriate) contained in exhaust gas discharged from a diesel engine, a particulate matter removal filter (Diesel Particulate Filter: hereinafter referred to as DPF as appropriate) Have been developed). Construction machinery is also equipped with a diesel engine and an exhaust purification system with a DPF to comply with regulations.

  The DPF collects PM contained in exhaust gas discharged from a diesel engine, thereby reducing the amount of PM discharged into the atmosphere. The DPF collects and recovers the collection ability by burning and removing the accumulated PM (regeneration of the DPF). Normally, PM accumulated in the DPF is burned and removed by exposure to high-temperature exhaust gas that exceeds a certain level (natural regeneration), but when the load on the diesel engine is light, the temperature of the exhaust gas is responsible for burning PM. Since the necessary high temperature is not reached, the DPF is not naturally regenerated, and if this state is left as it is, PM accumulates excessively and clogging of the DPF occurs.

  In order to prevent such a situation, a regenerative fuel injection device is provided to inject unburned fuel into the exhaust pipe, this fuel is burned from the oxidation catalyst in the DPF, and the PM accumulated in the filter is burned and removed by this combustion heat. It is necessary. Generally, control is performed such that regeneration processing is performed when a state quantity such as a PM accumulation quantity exceeds a predetermined threshold.

  However, if the temperature is below the activation temperature range of the oxidation catalyst, such as when the warm-up operation of the construction machine at the start of the work is insufficient or the outside air temperature is low, PM cannot be burned and removed satisfactorily, and a misfire will occur. There is also a possibility that the reproduction process will fail. If the clogging of the DPF is left unattended, the collecting ability of the DPF is lowered, and the exhaust pressure is excessively increased to cause problems such as damage to the DPF and deterioration of fuel consumption. For example, if the regeneration process fails, PM is accumulated without being burned and removed well, and while the regeneration process fails repeatedly, there is a possibility that the accumulated amount of PM exceeds a limit value and the DPF is damaged.

  As a technique for solving the problem when the outside air temperature is low, for example, Patent Document 1 describes a technique for acquiring the outside air temperature and prohibiting the regeneration process as the outside air temperature decreases. As a result, when the outside air temperature at which the regeneration process can be performed efficiently and reliably is high, the regeneration process is preferentially performed, thereby suppressing deterioration in fuel consumption.

JP 2007-255289 A

  However, the technique described in Patent Document 1 is based on the premise that the outside air temperature becomes high. When the outside air temperature does not become high, such as in a cold district, regeneration processing cannot be performed, and PM is contained in the DPF. There is a possibility that the accumulated amount of PM continues to accumulate and exceeds the limit value and the DPF is damaged. In particular, the construction machine is forwarded for each construction work, and it is assumed that the construction machine is forwarded from a warm region to a cold region. Construction work is often performed in inconvenient places, and if a failure such as a DPF breakage occurs, it will take a lot of work, such as a maintenance person visiting the site and repairing.

  An object of the present invention is to provide an exhaust purification system capable of reliably removing PM by combustion even when the outside air temperature is low, and preventing the collection ability from being lowered and the DPF from being damaged.

To achieve the above Symbol object, the first invention is arranged in an exhaust system of the engine, a filter for trapping particulate matter contained in exhaust gas was accumulated in the filter by the fuel injection from the engine Based on the result of comparison between the regeneration means for performing the regeneration process for removing the particulate matter by incineration, the state quantity obtaining means for obtaining the predetermined state quantity, and the obtained state quantity and the threshold value related to the state quantity. An exhaust purification system comprising a regeneration control means for determining whether to perform or not, comprising an outside air temperature obtaining means for obtaining an outside air temperature, wherein the state quantity obtaining means accumulates the predetermined state quantity in the filter. comprising a storage amount acquiring unit that acquires an accumulation amount of particulate matter, the engine operating time acquisition unit for acquiring the operation time of the engine, the regeneration control means, the full as the threshold An accumulation amount threshold value calculation unit that calculates a threshold value related to the accumulation amount of the particulate matter accumulated in the filter, and an engine operation time threshold value calculation unit that calculates a threshold value related to the operation time of the engine, the accumulation amount threshold value calculation unit The threshold value calculated by the engine operating time threshold value calculation unit is set to be lower as the outside air temperature becomes lower, and the accumulated amount of particulate matter in the filter acquired by the accumulated amount acquisition unit and the When any of the engine operating times acquired by the engine operating time acquiring unit exceeds the threshold, it is determined that the regeneration process is performed .

  If the outside air temperature is low and below the activation temperature range of the oxidation catalyst, PM cannot be burned and removed well, and there is a possibility that the regeneration process may fail due to misfire. When the regeneration process is performed based on the threshold value at the standard temperature, if the regeneration process fails, PM is accumulated without being burned and removed well, and while the regeneration process failure is repeated, the collection ability of the DPF decreases, There is a possibility that the accumulated amount of PM exceeds the limit value and the DPF is damaged.

  In the present invention, as described above, when the outside air temperature is lower than the predetermined temperature, the threshold value is variably set so that the frequency of the regeneration process is increased as the outside air temperature is lowered. The frequency of processing increases. As a result, the trapping ability is recovered by burning and removing the accumulated PM frequently, so even when the outside air temperature is low, the PM can be reliably removed by burning, the trapping ability can be prevented from being lowered, and the DPF can be prevented from being damaged. .

  Moreover, even if the regeneration process fails, the regeneration process can be reliably completed by frequently (several times in a short interval) to complete the regeneration process, and the collection capacity can be reduced and the DPF can be prevented from being damaged.

  Furthermore, the amount of PM accumulated when the regeneration process fails is smaller than when the regeneration process is performed based on the threshold value at the standard temperature. Therefore, the next regeneration process can be attempted before the collection ability is reduced. Further, the next regeneration process can be attempted before the accumulated amount of PM exceeds the limit value. As a result, even when the outside air temperature is low, PM can be reliably removed by combustion, a reduction in the collection ability can be prevented, and damage to the DPF can be prevented.

In a second aspect based on the first aspect, when the reproduction control unit determines to perform a reproduction process, the reproduction unit performs the reproduction process.

  Thereby, automatic reproduction processing can be performed.

According to a third aspect of the present invention, in the first aspect of the present invention, the information processing apparatus further includes a display unit that displays a warning for prompting the start of the reproduction process, and a reproduction operation unit, and the reproduction control unit determines that the reproduction process is to be performed. When a warning display signal is output to the display means and an operation signal is input from the reproduction operation means, a control signal for performing a reproduction process is output to the reproduction means.

  Thereby, manual regeneration processing can be performed.

  According to the present invention, by increasing the frequency of the regeneration process, PM can be reliably removed by combustion even when the outside air temperature is low, and the collection capacity can be reduced and the DPF can be prevented from being damaged.

<First Embodiment>
~Constitution~
The configuration of the embodiment of the present invention will be described below with reference to the drawings.

  FIG. 1 is a view showing an exhaust purification system 1 according to an embodiment of the present invention together with an engine control system 2. The exhaust purification system 1 and the engine control system 2 are controlled by a control unit 3 which is a common control means.

  In FIG. 1, a diesel engine (hereinafter simply referred to as an engine) 21 includes an electronic governor 21 a that controls the rotational speed of the engine 21 and an exhaust pipe 22 that exhausts exhaust gas from the engine 21 to the outside. .

  The engine control system 2 includes an engine control dial 23 that instructs a target rotational speed of the engine 21, an engine rotational sensor 24 that detects the rotational speed of the engine 21, and an engine control unit 25 that is a part of the processing function of the control unit 3. And. The engine control unit 25 inputs signals from the engine control dial 23 and the engine rotation sensor 24, performs a predetermined calculation process, and outputs a control signal to the electronic governor 21a, whereby the rotation speed and torque of the engine 21 are obtained. Control.

  The exhaust purification system 1 is provided in the middle of the exhaust pipe 22 and is located upstream of a filter 4b that collects PM (Particulate Matter: hereinafter referred to as PM as appropriate) contained in the exhaust gas from the engine 21. A DPF (Diesel Particulate Filter: hereinafter referred to as DPF as appropriate) 4 having an oxidation catalyst 4a, and first and second pressure sensors 41 for detecting the pressure inside the exhaust pipe 22 upstream and downstream of the DPF 4. 42, an exhaust purification system control unit 10 that performs control processing such as regeneration processing as part of the processing function of the control unit 3, and a display unit 5 that displays various information based on the processing results of the exhaust purification system control unit 10. The regenerative fuel injection device 6 for injecting fuel into the upstream side of the DPF 4 for a predetermined time based on the processing result of the exhaust purification system control unit 10 and the outside for detecting the outside air temperature And a temperature sensor 7.

  The exhaust purification system control unit 10 includes processing functions of an outside air temperature acquisition unit 11, an accumulation amount threshold calculation unit 12, an engine operation time threshold calculation unit 13, an accumulation amount acquisition unit 14, an engine operation time acquisition unit 15, and a regeneration control unit 16. Have.

  The outside air temperature acquisition unit 11 inputs a pulse signal from the outside air temperature sensor 7, calculates the outside air temperature T, and outputs the calculation result to the accumulation amount threshold value calculation unit 12 and the engine operating time threshold value calculation unit 13.

  The accumulation amount threshold value calculation unit 12 receives a signal from the outside air temperature acquisition unit 11, calculates a threshold value Wa relating to the accumulation amount based on a first characteristic map (see FIG. 3A described later), and reproduces the calculation result. Output to the control unit 16.

  The engine operating time threshold value calculation unit 13 receives a signal from the outside air temperature acquisition unit 11, calculates a threshold value ta related to the engine operating time based on a second characteristic map (see FIG. 3B described later), and the calculation result. Is output to the reproduction control unit 16.

  The accumulation amount acquisition unit 14 inputs each pulse signal from the first pressure sensor 41 and the second pressure sensor 42, calculates the PM accumulation amount W based on the third characteristic map, and calculates the calculation result as the regeneration control unit 16. Output to. In the third characteristic map, the relationship between the differential pressure across the DPF 4 based on the detected pressures of the first pressure sensor 41 and the second pressure sensor 42 and the accumulated amount W of PM is determined through experiments, and the differential pressure across the front increases. Accordingly, it is assumed that PM accumulates in the filter 4b of the DPF 4 and the accumulation amount W increases.

  The engine operating time acquisition unit 15 receives a signal from the engine control unit 25, calculates the engine operating time t, and outputs the calculation result to the regeneration control unit 16. The engine control unit 25 calculates the engine operating time t based on, for example, an ON / OFF signal from the engine rotation sensor 25. The engine operating time refers to the engine operating time measured after the previous regeneration process.

  The regeneration control unit 16 inputs the threshold value Wa relating to the accumulation amount, the threshold value ta relating to the engine operation time, the acquisition amount W relating to the PM accumulation amount W, and the engine operation time t, and based on the arithmetic processing of the flowchart shown in FIG. Then, it is determined whether or not the regeneration process is to be performed. When it is determined that the regeneration process is to be performed, a control signal for performing the regeneration process is output to the regeneration fuel injection device 6.

  FIG. 2 is a flowchart showing the calculation process of the reproduction control unit 16. The regeneration control unit 16 acquires the threshold value Wa relating to the accumulation amount and the threshold value ta relating to the engine operating time (step S11), and acquires the PM accumulation amount W and the engine operating time t (step S12). It is determined whether or not the amount W exceeds a threshold value Wa relating to the accumulated amount, that is, whether or not W> Wa (step S13). If W> Wa is not satisfied, it is determined whether or not the engine operating time t has exceeded a threshold ta related to the engine operating time, that is, t> ta (step S14). If W> Wa in step S13 or t> ta in step S14, it is determined that the regeneration process is to be performed, and a control signal for performing the regeneration process is output to the regeneration fuel injection device 6 (step S15). If t> ta is not satisfied in step S14, the process returns to step S11, and the processes in steps S11 to S14 are repeated. After outputting the control signal for performing the regeneration process to the regenerative fuel injection device 6, a status display signal indicating that the automatic regeneration process is being performed is output to the display unit 5 (step S16).

  In the above, the regenerated fuel injection device 6 constitutes a regenerating means for performing a regenerating process for incinerating and removing the particulate matter accumulated in the filter 4b by fuel injection from the engine 21, and the outside air temperature sensor 7 and the exhaust purification system control unit. Out of the 10 processing functions, the outside air temperature acquisition unit 11 constitutes outside air temperature acquisition means for acquiring the outside air temperature, and is stored among the processing functions of the first pressure sensor 41 and the second pressure sensor 42 and the exhaust purification system control unit 10. The quantity acquisition unit 14 and the engine operating time acquisition unit 15 constitute state quantity acquisition means for acquiring a predetermined state quantity, and among the processing functions of the exhaust purification system control unit 10, the accumulation amount threshold value calculation unit 12 and the engine operating time threshold value. The calculation unit 13 and the regeneration control unit 16 set the threshold value variably so that the frequency of the regeneration process increases as the outside air temperature decreases. Constitutes a reproduction control means for determining whether performing the reproducing process on the basis of the comparison between the state quantity and the threshold value according to the state quantity results.

~ Operation ~
<At standard temperature>
The operation of the reproduction process of this embodiment will be described.

  Exhaust gas from the engine 21 is guided to the DPF 4 via the exhaust pipe 22, and PM contained in the exhaust gas is collected by the filter 4b of the DPF 4. As the accumulation of PM in the DPF 4 progresses, the filter 4b is clogged, and the collection capability of the DPF 4 decreases.

  Here, when the outside air temperature is within the range of the standard temperature, the accumulation amount threshold value calculation unit 12 calculates a threshold value Wa (fixed value) related to a predetermined accumulation amount, and the engine operating time threshold value calculation unit 13 sets a predetermined value. Threshold value ta (fixed value) related to the engine operating time is calculated.

  The regeneration control unit 16 of the exhaust purification system control unit 10 inputs the threshold value Wa relating to the accumulation amount, the threshold value ta relating to the engine operation time, the accumulation amount W of PM, and the acquisition signal relating to the engine operation time t, and W> Wa If it is present or t> ta, it is determined that the regeneration process is to be performed, and a control signal is output to the regeneration fuel injection device 6 (S11 → S12 → S13 → S15 or S11 → S12 → S13 → S14 → S15).

  The regenerated fuel injection device 6 performs post-injection in the exhaust pipe 22 for a certain period of time at a timing later than normal combustion. The post-injection raises the temperature of the exhaust gas, and unburned fuel is supplied to the oxidation catalyst 4a for oxidation. Then, the exhaust gas temperature is further raised by the reaction heat, and the PM accumulated in the filter 4b is burned and removed by the high temperature exhaust gas. As a result, the DPF 4 recovers the collection ability.

  While the exhaust purification system 1 is performing the automatic regeneration process, the display unit 5 displays a status indicating that the automatic regeneration process is being performed (S16).

<Low temperature>
When the outside air temperature T is lower than the lower limit value (for example, 0 degrees Celsius) of the standard temperature range, PM cannot be burned and removed well, and there is a possibility that the regeneration process may fail due to misfire. If the clogging of the DPF 4 is left unattended, the collecting ability of the DPF 4 is lowered and various problems associated therewith are caused. For example, if the regeneration process fails, PM is accumulated without being burned and removed well, and the regeneration capacity of the DPF 4 decreases as the regeneration process fails, and the accumulated amount of PM exceeds a limit value and the DPF 4 There is a possibility of damage.

  Here, the accumulation amount threshold value calculation unit 12 calculates a threshold value Wa (variable value) related to the accumulation amount based on the first characteristic map, and the engine operation time threshold value calculation unit 13 calculates the engine operation time based on the second characteristic map. A threshold ta (variable value) is calculated.

  FIG. 3A is a first characteristic map showing the relationship between the outside air temperature T and the threshold value Wa relating to the accumulation amount. It is determined in advance based on experimental data so that the threshold value Wa relating to the accumulation amount is set lower as the outside air temperature T becomes lower.

  FIG. 3B is a second characteristic map showing the relationship between the outside air temperature T and the threshold value ta related to the engine operating time. It is determined in advance based on experimental data so that the threshold value ta related to the engine operating time is set lower as the outside air temperature T becomes lower.

  That is, the regeneration control unit 16 of the exhaust purification system control unit 10 inputs the threshold value Wa related to a lower accumulation amount and the threshold value ta related to a lower engine operating time as the outside air temperature T becomes lower (S11). Then, an acquisition signal related to the PM accumulation amount W and the engine operating time t is input. If W> Wa or t> ta, it is determined that the regeneration process is to be performed, and a control signal is sent to the regeneration fuel injection device 7. Is output (S12-> S13-> S15 or S12-> S13-> S14-> S15), the reproduction process is performed, and the status display indicating that the automatic reproduction process is in progress (S16).

  As described above, the threshold value Wa relating to the accumulation amount is set lower as the outside air temperature T becomes lower. Therefore, the regeneration process can be performed even with a small amount of PM accumulation compared with the standard temperature, and the frequency of the regeneration process can be increased. . Further, since the threshold value ta related to the engine operating time is set lower as the outside air temperature T becomes lower, the regeneration process can be performed at a shorter interval than the standard temperature, and the frequency of the regeneration process can be increased.

  As a result, even when the outside air temperature T is low, the DPF 4 recovers the collection capability by burning and removing frequently accumulated PM. That is, even when the outside air temperature is low, the PM can be reliably removed by combustion, and the collection capacity can be reduced and the DPF can be prevented from being damaged.

  Moreover, even if the regeneration process fails, the regeneration process can be completed reliably by frequently trying the next regeneration process (several times in a short interval), and the collection capacity can be reduced and the DPF 4 can be prevented from being damaged.

  Furthermore, the amount of PM accumulated when the regeneration process fails is smaller than when the regeneration process is performed based on the threshold value at the standard temperature. Therefore, the next regeneration process can be attempted before the collection ability is reduced. Further, the next regeneration process can be attempted before the accumulated amount of PM exceeds the limit value. Thereby, the collection capability fall when external temperature is low can be prevented, and damage to DPF can be prevented.

~effect~
As described above, in the present embodiment, as the outside air temperature T becomes lower, the frequency Wa of the regeneration process is increased by setting the threshold value Wa relating to the accumulation amount and the threshold value ta relating to the engine operating time to a lower value. Even when the temperature is low, the PM can be reliably removed by combustion, and the collection capacity can be reduced and the DPF can be prevented from being damaged.

  Moreover, even if the regeneration process fails, it is possible to prevent the collection ability from being lowered and the DPF from being damaged when the outside air temperature is low.

<Second Embodiment>
FIG. 4 is a view showing an exhaust purification system 1 </ b> A according to the second embodiment of the present invention together with the engine control system 2. In the figure, components equivalent to those shown in FIG. In FIG. 4, the exhaust purification system 1 </ b> A according to the present embodiment further includes a regeneration switch 8. The regeneration control unit 16 of the exhaust purification system control unit 10 of the first embodiment controls the automatic regeneration process, whereas the regeneration control unit of the exhaust purification system control unit 10A of the second embodiment. 16A controls manual regeneration processing.

  FIG. 5 is a flowchart showing the calculation processing of the reproduction control unit 16A. In FIG. 5, the same components as those shown in FIG. When the determination in step S13 or step S14 is affirmed, the reproduction control unit 16A determines that the reproduction process is to be performed, and outputs a warning display signal that displays a warning for prompting the start of the reproduction process to the display unit 5 (step S17). Then, it is determined whether or not the regeneration switch 8 is turned on (step S18). If not, the process is repeated. If it is on, a control signal for performing the regeneration process is output to the regeneration fuel injection device 6 (step S15A). ).

  Here, when the outside air temperature is within the range of the standard temperature, the accumulation amount threshold value calculation unit 12 calculates a threshold value Wa (fixed value) related to a predetermined accumulation amount, and the engine operating time threshold value calculation unit 13 sets a predetermined value. Threshold value ta (fixed value) related to the engine operating time is calculated. The regeneration control unit 16A inputs the threshold value Wa relating to the accumulation amount, the threshold value ta relating to the engine operation time, the accumulation amount W of PM, and the acquisition signal relating to the engine operation time t, and W> Wa or t> ta. If there is, it is determined that the reproduction process is to be performed, and a warning display signal is output to the display unit 5 (S11 → S12 → S13 → S17 or S11 → S12 → S13 → S14 → S17). When the operator who has recognized the warning display operates the regeneration switch 8, the regeneration control unit 16A inputs an operation signal from the regeneration switch 8 and outputs a control signal to the regeneration fuel injection device 6 (S18 → S15A).

  The regenerated fuel injection device 6 performs post-injection in the exhaust pipe 22 for a certain period of time at a timing later than normal combustion. The post-injection raises the temperature of the exhaust gas, and unburned fuel is supplied to the oxidation catalyst 4a for oxidation. Then, the exhaust gas temperature is further raised by the reaction heat, and the PM accumulated in the filter 4b is burned and removed by the high temperature exhaust gas. As a result, the DPF 4 recovers the collection ability.

  When the outside air temperature T is lower than the lower limit value (for example, 0 degrees Celsius) of the standard temperature range, the accumulation amount threshold value calculation unit 12 calculates a threshold value Wa (variable value) related to the accumulation amount based on the first characteristic map. The engine operating time threshold calculation unit 13 calculates a threshold ta (variable value) related to the engine operating time based on the second characteristic map.

  The regeneration control unit 16A inputs a threshold value Wa related to a lower accumulation amount and a threshold value ta related to a lower engine operating time as the outside air temperature T becomes lower (S11). Then, an acquisition signal related to the PM accumulation amount W and the engine operating time t is input, and if W> Wa or t> ta, it is determined that the regeneration process is performed, and a warning display signal is displayed on the display unit 5. When an operation signal is input from the regeneration switch 8 (S12 → S13 → S17 or S12 → S13 → S14 → S17), a control signal is output to the regeneration fuel injection device 6 (S18 → S15A), and a manual regeneration process is performed. .

  As described above, the threshold value Wa relating to the accumulation amount is set lower as the outside air temperature T becomes lower. Therefore, the regeneration process can be performed even with a small amount of PM accumulation compared with the standard temperature, and the frequency of the regeneration process can be increased. . Further, since the threshold value ta related to the engine operating time is set lower as the outside air temperature T becomes lower, the regeneration process can be performed at a shorter interval than the standard temperature, and the frequency of the regeneration process can be increased.

  As described above, also in the present embodiment, since the frequency of the regeneration process can be increased as the outside air temperature T becomes lower, the same effect as that of the first embodiment can be obtained.

<Third Embodiment>
The regeneration control unit 16 of the exhaust purification system control unit 10 of the first embodiment controls automatic regeneration processing, and the regeneration control unit 16A of the exhaust purification system control unit 10A of the second embodiment performs manual regeneration processing. Although control is performed, automatic regeneration processing and manual regeneration processing may be combined.

  In this embodiment, the automatic regeneration process is performed with priority over the manual regeneration process. In other words, the manual regeneration process is performed when PM cannot be successfully burned and removed even if the automatic regeneration process is performed.

  At this time, the threshold relating to the accumulation amount in the automatic regeneration process is set lower than the threshold relating to the accumulation amount in the manual regeneration process, and the threshold relating to the engine operating time in the automatic regeneration process is lower than the threshold relating to the engine operating time in the manual regeneration process. Set. The first characteristic map in the automatic regeneration process is set to have a lower threshold than the first characteristic map in the manual regeneration process, and the second characteristic map in the automatic regeneration process has a lower threshold than the second characteristic map in the manual regeneration process. Set as follows. Thus, the automatic regeneration process can be performed with priority over the manual regeneration process.

  As described above, this embodiment also has the same configuration as the first embodiment and the second embodiment, and the same effect can be obtained.

1 is a diagram showing an exhaust purification system according to a first embodiment of the present invention together with an engine control system. It is a flowchart which shows the arithmetic processing of a reproduction | regeneration control part. (A) is a 1st characteristic map which shows the relationship between the outside temperature and the threshold value which concerns on the accumulation amount. (B) is the 2nd characteristic map which shows the relationship between the outside temperature and the threshold value which concerns on engine operating time. It is a figure which shows the exhaust gas purification system concerning the 2nd Embodiment of this invention with an engine control system. It is a flowchart which shows the arithmetic processing of a reproduction | regeneration control part.

1 Exhaust Purification System 2 Engine Control System 3, 3A Control Unit 4 DPF
4a Oxidation catalyst 4b Filter 5 Display device 6 Regenerated fuel injection device 7 Outside air temperature sensor 8 Regeneration switch 8
DESCRIPTION OF SYMBOLS 10,10A Exhaust gas purification system control part 11 Outside temperature acquisition part 12 Accumulation amount threshold value calculation part 13 Engine operating time threshold value calculation part 14 Accumulation amount acquisition part
15 Engine operating time acquisition unit 16, 16A Reproduction control unit 21 Engine 21a Electronic governor 22 Exhaust pipe 23 Engine rotation sensor 24 Engine control dial 25 Engine control unit 41 First pressure sensor 42 Second pressure sensor

Claims (3)

A filter that is disposed in the exhaust system of the engine and collects particulate matter contained in the exhaust gas; and a regeneration means that performs a regeneration process to incinerate and remove particulate matter accumulated in the filter by fuel injection from the engine; Exhaust gas comprising state quantity acquisition means for acquiring a predetermined state quantity, and regeneration control means for determining whether or not to perform regeneration processing based on a comparison result between the acquired state quantity and a threshold value related to the state quantity In the purification system,
An outside temperature acquisition means for acquiring outside temperature is provided,
The state quantity acquisition means includes an accumulation amount acquisition unit that acquires an accumulation amount of particulate matter accumulated in the filter as the predetermined state quantity, and an engine operation time acquisition unit that acquires an operation time of the engine. ,
The regeneration control means includes an accumulation amount threshold value calculation unit that calculates a threshold value related to the accumulation amount of particulate matter accumulated in the filter as the threshold value, and an engine operation time threshold value calculation unit that calculates a threshold value related to the engine operation time. The threshold value calculated by the accumulation amount threshold value calculation unit and the engine operating time threshold value calculation unit is set to be lower as the outside air temperature is lower, and is acquired by the accumulation amount acquisition unit. An exhaust purification system, characterized in that it determines that regeneration processing is to be performed when either the accumulated amount of particulate matter in the filter or the engine operating time acquired by the engine operating time acquiring unit exceeds the threshold value . The exhaust purification system according to claim 1,
When the regeneration control unit determines to perform the regeneration process, it outputs a control signal for performing the regeneration process to the regeneration unit. The exhaust purification system according to claim 1,
It further comprises display means for displaying a warning prompting the start of the reproduction process, and reproduction operation means,
The reproduction control means outputs a warning display signal to the display means when judging that the reproduction processing is performed, and outputs a control signal for performing reproduction processing to the reproduction means when an operation signal is inputted from the reproduction operation means. An exhaust purification system characterized by

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