JP2002227631A - Exhaust emission purifying apparatus, method for determining regenerating timing of filter used therefor, program for determining regenerating timing of filter used therefor, and recording medium for storing the program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust emission purifying apparatus capable of having its manufacturing cost lowered. SOLUTION: A pressure sensor 24 is provided at a gaseous emission tube 11 at the upstream side of a filter 23. Based on a plurality of results of detected pressures detected by the pressure sensor 24 at delayed timings, it is so arranged to determine whether or not the quantity of particulates accumulated in the filter 23 has passed a tolerable quantity of accumulation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas purifying apparatus, a method for judging a regeneration time of a filter used in an exhaust gas purifying apparatus, a program for judging a regeneration time of a filter for an exhaust gas purifying apparatus, and a recording medium for storing the program. Things.

[0002]

2. Description of the Related Art The number of automobiles has increased exponentially since the turn of the century, and the amount of exhaust gas emitted from internal combustion engines of automobiles has been increasing rapidly.
In particular, various substances contained in exhaust gas emitted from a diesel engine cause pollution, and are now seriously affecting the world environment. In addition, recently, it has been reported that particulate matter such as soot contained in exhaust gas sometimes causes allergic disorders and a decrease in sperm count. In other words, it is considered that taking measures to remove particulates in exhaust gas is an urgent task for humanity.

[0003] Under such circumstances, various types of exhaust gas purifying devices have been proposed. This type of exhaust gas purification device includes a porous filter for removing particulates and the like discharged from an internal combustion engine such as a diesel engine. If this filter is used for a long time, the load on the engine increases due to the accumulation of the particulates. Therefore, it is necessary to remove the particulates. Generally, the filter is made of a heat-resistant material such as a ceramic, and the filter is heated by an electric heater or the like, and the filter is regenerated by burning and removing particulates. In order to efficiently regenerate the filter, it can be said that it is desirable to accurately detect the regeneration time of the filter.

[0004] Therefore, in the conventional exhaust gas purifying apparatus, pressure sensors are respectively provided at the upstream side and the downstream side of the filter. The pressure sensor installed on the upstream side detects the back pressure at the upstream portion of the filter, and the pressure sensor installed on the downstream side detects the back pressure or the atmospheric pressure at the downstream portion of the filter. Then, the pressure loss is calculated based on the detection results obtained simultaneously by the two pressure sensors, so that the amount of particulate accumulated on the filter can be detected. That is, if the pressure loss exceeds a predetermined value, it is determined that the amount of particulates accumulated on the filter exceeds the allowable accumulation amount. Here, the pressure loss means a value obtained by subtracting the back pressure value on the downstream side from the back pressure value on the upstream side of the filter. That is, it can be said that the higher the pressure loss, the larger the amount of particulates accumulated on the filter.

[0005]

However, in the conventional exhaust gas purifying apparatus, at least two or more pressure sensors are required to determine the filter regeneration time of the filter. Since the pressure sensor must have a heat-resistant structure that can withstand the high heat of the exhaust gas, the cost is very high. Moreover, as the number of pressure sensors increases, not only the number of steps for assembling them increases, but also the structure of the assembling location becomes complicated. Therefore, the cost of the entire exhaust gas purifying device increases.

In addition, if the number of pressure sensors is large, the number of man-hours for assembling the pressure sensors also increases, so that it is considered that the rate of occurrence of defective mounting due to human error increases. Therefore, there is a possibility that the reliability of the exhaust gas purifying device is reduced.

The present invention has been made in view of the above problems, and has as its object to detect whether or not the amount of particulates deposited on a filter exceeds an allowable deposition amount even when the number of pressure detecting means is reduced. It is an object of the present invention to provide an exhaust gas purifying apparatus and a method for determining a regeneration time of a filter used in the exhaust gas purifying apparatus, which can reduce the manufacturing cost.

[0008]

In order to solve the above-mentioned problems, according to the first aspect of the present invention, there is provided a casing provided in the middle of an exhaust pipe through which exhaust gas discharged from an internal combustion engine passes, and a casing provided in the casing. And a filter accommodated in the
In an exhaust gas purifying apparatus that collects particulates contained in exhaust gas by passing exhaust gas discharged from an internal combustion engine through a filter, a pressure that detects a pressure in an exhaust pipe upstream of the filter is used. Detecting means, and storing means for storing a past pressure detection result detected by the pressure detecting means, wherein the past pressure detecting result stored in the storing means and a pressure detecting result at a different timing thereafter. Accordingly, a gist for determining whether or not the amount of particulates deposited on the filter exceeds the allowable deposition amount based on the above is provided.

According to the second aspect of the present invention, in the exhaust gas purifying apparatus according to the first aspect, the timing at which the pressure is detected by the pressure detecting means is determined before the internal combustion engine operates and when the internal combustion engine operates. During operation, the determination means determines that the difference between the pre-operation pressure value detected before the internal combustion engine is operating and the operating pressure value detected when the internal combustion engine is operating is the operation of the internal combustion engine. The gist of the present invention is to determine whether or not the amount of particulates of exhaust gas has reached an allowable value depending on whether it is higher or lower than a reference pressure value set according to the state.

According to a third aspect of the present invention, in the exhaust gas purifying apparatus according to the second aspect, the storage means stores a pre-operation pressure value each time the internal combustion engine is operated, and stores the pre-operation pressure value in the storage means. The gist of the present invention is to include first correction means for correcting the latest pre-operation pressure value based on the plurality of pre-operation pressure values thus obtained.

According to a fourth aspect of the present invention, in the exhaust gas purifying apparatus according to the third aspect, the first correction means includes:
The gist is to correct the latest pre-operation pressure value based on a numerical value obtained by averaging a plurality of pre-operation pressure values stored in the storage unit before the latest pre-operation pressure value is detected. .

According to the fifth aspect of the present invention, the second to fourth aspects are provided.
In the exhaust gas purifying apparatus according to any one of the above, the pressure detecting means detects a post-operation pressure value after the internal combustion engine is stopped, and stores the pressure value in the storage means based on the post-operation pressure value. The gist of the present invention is that it has a second correction means for correcting the pre-operation pressure value.

According to the sixth aspect of the present invention, the first to fifth aspects are provided.
The exhaust gas purifying apparatus according to any one of the above, further comprising an electric system that is energized even when the internal combustion engine is operating and is not operating, wherein the electric system includes the pressure detection unit, the determination unit, and the storage unit. The gist is that the means, the first correction means, and the second correction means are electrically connected to each other.

According to the present invention, the casing is provided in the exhaust pipe through which the exhaust gas discharged from the internal combustion engine passes, and the exhaust gas discharged from the internal combustion engine is housed in the casing. In a method for determining the regeneration time of a filter in an exhaust gas purification device provided with a filter for trapping particulates contained in the filter, the detection timing is shifted by pressure detection means provided in an exhaust pipe upstream of the filter. The gist of the invention is that it is determined whether or not the amount of particulate accumulated on the filter exceeds an allowable accumulation amount based on a plurality of detected pressure detection results.

According to the present invention, a computer for judging a regeneration time of a filter used in an exhaust gas purifying apparatus includes a step of detecting a pressure in an exhaust pipe upstream of the filter, and a step of detecting the pressure. Storing the past pressure detection result detected in the step, and, based on the stored past pressure detection result and a pressure detection result at a different timing thereafter, the amount of particulates accumulated in the filter is allowed. And a step of determining whether or not the accumulation amount has been exceeded is executed.

According to a ninth aspect of the present invention, a computer program storing the program according to the eighth aspect is readable. Hereinafter, the “action” of the present invention will be described.

According to the first and seventh aspects of the present invention, the amount of particulates deposited on the filter exceeds the allowable deposition amount based on the past pressure detection results and the pressure detection results at different timings thereafter. Is determined. The regeneration time of the filter can be determined from this determination result. Therefore, since it is not necessary to arrange the pressure detecting means on the upstream side and the downstream side of the filter, the number of the pressure detecting means can be reduced.
Therefore, the manufacturing cost of the exhaust gas purification device can be reduced.

According to the second aspect of the present invention, if the difference between the pre-operation pressure value and the operation pressure value is larger than a reference pressure value set according to the operation state of the internal combustion engine, the fuel is deposited on the filter. It is determined that the particulate amount has exceeded the allowable deposition amount. On the other hand, if the difference between the pre-operation pressure value and the operation pressure value is smaller than the reference pressure value, it is determined that the amount of particulate accumulated on the filter does not exceed the allowable accumulation amount.

According to the third aspect of the present invention, the latest pre-operation pressure value is corrected based on the plurality of pre-operation pressure values stored in the storage means, so that the filter regeneration time can be more accurately determined. can do.

According to the fourth aspect of the present invention, the latest pre-operation pressure value is calculated based on a numerical value obtained by averaging a plurality of pre-operation pressure values accumulated before the latest pre-operation pressure value is detected. The pressure value is corrected. Therefore, the latest pre-operation pressure value can always be set to an appropriate value when determining the regeneration time of the filter.

According to the present invention, the pre-operation pressure value is corrected based on the post-operation pressure value detected after the internal combustion engine is stopped. Therefore, since the pre-operation pressure value can be finely corrected, the filter regeneration timing can be more accurately determined.

According to the sixth aspect of the invention, even when the internal combustion engine is not operating, processing such as detecting the pressure in the exhaust pipe, calculating the pressure value, and correcting the latest pre-operation pressure value is performed. be able to. Therefore, when starting or stopping the internal combustion engine, the waiting time spent for the processing can be eliminated, and the internal combustion engine can be operated smoothly.

According to the eighth aspect of the present invention, the step of detecting the pressure in the exhaust pipe upstream of the filter by the computer, the step of storing the past pressure detection result, the step of storing the past pressure detection result, A step of determining whether or not the amount of particulates accumulated on the filter exceeds the allowable accumulation amount based on the pressure detection results at different timings thereafter. This allows
Even if the number of pressure detecting means is reduced, it is possible to provide a program for judging the regeneration timing of a filter for an exhaust gas purifying device capable of detecting whether or not the amount of particulates accumulated on the filter exceeds an allowable accumulation amount. .

According to the ninth aspect of the present invention, there is provided a recording medium capable of detecting whether or not the amount of particulates accumulated on a filter exceeds an allowable accumulation amount even if the number of pressure detecting means is reduced. It becomes possible.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. As shown in FIG. 1, an exhaust gas purification device 20 is provided in the middle of an exhaust pipe 11 for exhausting exhaust gas from a diesel engine 10 which is an internal combustion engine. Each exhaust gas purification device 2
Reference numeral 0 denotes a casing 21 in which an exhaust gas purifying honeycomb filter 23 is accommodated.

The filter 23 is made of a sintered body of porous silicon carbide (SiC) and carries an exhaust gas purifying catalyst. The filter 23 has a very high thermal conductivity. Therefore, the heat quantity of the exhaust gas is effectively transmitted to the rear of the filter 23 and the radial direction.

A pressure sensor 24 is provided at a location located in the middle of the exhaust pipe 11 on the upstream side of the filter 23. In the present embodiment, only one pressure sensor 24 is provided. The pressure sensor 24 detects the pressure in the exhaust pipe 11 at a position upstream of the filter 23 and outputs a detection signal to the computer C.

The electric system of the vehicle on which the exhaust gas purifying device 20 is mounted is divided into two systems. One electric system is energized only when the diesel engine 10 is operating. On the other hand, the other electric system is energized not only when the diesel engine 10 is operating but also before the diesel engine 10 is operated. Here, "before the diesel engine 10 is operated" refers to a period from when the operation key 29 is inserted into the ignition switch 28 of the engine 10 to before the diesel engine 10 is started. Since the pressure sensor 24 and the computer C are connected to the other electric system, power can be supplied to the computer C if the above conditions are satisfied even when the diesel engine 10 is not operating. is there. Therefore, even if the diesel engine 10 is not operating, if the operation key 29 is inserted into the ignition switch 28, the pressure sensor 2
4 enables the pressure in the exhaust pipe 11 to be detected, and further allows the computer C to perform various calculations.

The computer C includes an exhaust gas purifying device 20
A ROM 27 is provided as a recording medium for storing a control program necessary for controlling the system. Computer C is
A RAM 26 is provided as storage means for temporarily storing data such as a pressure value obtained with the execution of the control program. Further, the computer C includes a CPU 25 that reads out the control program from the ROM 27 and executes the control program.

The RAM 26 stores pressure detection values (pressure detection results) detected by the pressure sensor 24 at different timings. The detection timing refers to before the diesel engine 10 is operated and during the operation of the diesel engine 10. That is, the pressure sensor 24 causes the diesel engine 10
The pre-operation pressure value detected before the operation is performed is stored in the RAM 26. Then, the CPU 25 as determination means
Whether the particulate matter amount of the exhaust gas has reached the allowable value is determined based on whether the difference between the pre-operation pressure value and the operation pressure value is larger or smaller than a reference pressure value stored in the ROM 27 in advance. The reference pressure value is for diesel engine 1
0, in this embodiment, the diesel engine 10
Is set according to the number of rotations.

The RAM 26 stores a pre-operation pressure value every time the diesel engine 10 is operated. Therefore, R
The AM 26 stores a plurality of pre-operation pressure values (past pressure detection values) detected before. And CPU2
5 corrects the latest pre-operation pressure value based on the plurality of pre-operation pressure values stored in the RAM 26. Specifically, the CPU 25 averages a plurality of pre-operating pressure values accumulated in the RAM 26 by calculation, and compares the averaged value with the latest pre-operating pressure value to thereby obtain the latest pre-operating pressure. Correct the value to an appropriate value.

Further, immediately after the diesel engine 10 is stopped, the CPU 25 corrects the pre-operation pressure value stored in the RAM 26 based on the post-operation pressure value detected by the pressure sensor 24. Specifically, the CPU 25
Calculates the average value of the post-operation pressure value and the pre-operation pressure value by calculation, and compares the averaged value with the latest pre-operation pressure value to re-correct the latest pre-operation pressure value to an appropriate value. I do. As described above, in the present embodiment, the CPU
25 functions as a first correction unit and a second correction unit.

An indicator 30 provided as a notification means provided in the driver's cab of the vehicle is controlled on and off by the CPU 25. Then, as a result of the determination by the CPU 25, if the particulate amount exceeds the allowable value, the indicator 30 is turned on.

Next, a method of determining the regeneration time of the filter 23 by the exhaust gas purifying apparatus 20 configured as described above will be described. When the operation key 29 is inserted into the ignition switch 28 and the operation key 29 is turned to the start position, the diesel engine 10 is started. Between the time when the operation key 29 is inserted into the ignition switch 28 and the time when the diesel engine 10 is started, only the other of the two electric systems is supplied with power from a battery (not shown). The pre-operation pressure is detected by the pressure sensor 24, and the pre-operation pressure value is stored in the RAM 26. The pre-operation pressure value is stored in the RAM 26 before the diesel engine 10 is started. Then, an average value of a plurality of pre-operation pressure values stored before the latest pre-operation pressure value is calculated, the latest pre-operation pressure value is corrected based on the calculated value, and the corrected value is stored in the RAM 26. .

When the diesel engine 10 is started,
The exhaust gas passes through the filter 23 through the exhaust pipe 11. At this time, the particulate matter contained in the exhaust gas is collected by the filter 23, so that the exhaust gas is purified.

During the operation of the diesel engine 10, the operating pressure value (back pressure value of the exhaust gas) is detected by the pressure sensor 24. Next, the difference between the operating pressure value and the latest pre-operation pressure value stored in the RAM 26 is calculated, and if the value is larger than the reference pressure value, the amount of particulates deposited on the filter 23 becomes the allowable deposition amount. Is determined to have been exceeded. Then, the indicator 30 is turned on to notify the driver that the filter 23 is in the regeneration time. Incidentally, when the filter 23 is heated by an electric heater or the like (not shown), the particulates accumulated there are burnt and removed, and the filter 23 is regenerated. On the other hand, if the difference between the pre-operation pressure value and the operation pressure value is smaller than the reference pressure value, it is determined that the particulate amount does not exceed the allowable deposition amount.

When the diesel engine 10 is operated continuously for a long time, the operating pressure value is intermittently detected after a certain period of time while the diesel engine 10 is operating. Then, it is determined whether or not the particulate amount exceeds the allowable deposition amount by a method similar to the above-described determination method. That is, while the vehicle is running,
After a certain period of time, it is repeatedly monitored whether the amount of particulates deposited on the filter 23 has reached the limit.

When the operation key 29 is returned from the on position to the off position, the diesel engine 10 is stopped. As a result, power is not supplied to one electric system,
When the operation key 29 is inserted into the ignition switch 28, power is continuously supplied to only the other electric system. During this time, the post-operation pressure value is detected by the pressure sensor 24, and the pre-operation pressure value stored in the RAM 26 is corrected based on the post-operation pressure value. Thereafter, when the diesel engine 10 is operated again, the regeneration timing of the filter 23 is determined by the series of operations described above.

Therefore, according to the present embodiment, the following effects can be obtained. (1) A pressure sensor 24 is provided in the exhaust pipe 11 upstream of the filter 23. Based on a plurality of pressure detection results detected at different timings by the pressure sensor 24, it is determined whether or not the amount of particulates accumulated on the filter 23 exceeds the allowable accumulation amount. Therefore, the regeneration time of the filter 23 can be determined by one pressure sensor 24 provided only on the upstream side without providing pressure sensors on the upstream side and the downstream side of the filter 23, respectively. Therefore, the number of expensive pressure sensors 24 can be reduced, so that the configuration of the exhaust gas purification device 20 can be simplified and the number of steps for assembling the pressure sensors 24 can be reduced. As a result, the manufacturing cost of the exhaust gas purification device 20 can be reduced.

(2) As the number of the pressure sensors 24 is reduced, the rate of occurrence of failures due to artificial factors such as incorrect mounting of the pressure sensors 24 can be reduced.
For this reason, the reliability of the exhaust gas purification device 20 can be improved.

(3) The exhaust pipe 11 is detected by the pressure sensor 24.
The timing at which the internal pressure is detected is before the operation of the diesel engine 10 and during the operation of the diesel engine 10. Then, by determining whether the difference between the pre-operation pressure value and the operation pressure value is larger or smaller than the reference pressure value, it is determined whether the particulate matter amount of the exhaust gas deposited on the filter 23 has reached an allowable value. Has been detected. Therefore, it is possible to accurately determine whether or not particulates are accumulated, that is, the regeneration time of the filter 23.

(4) The pre-operation pressure value is stored in the RAM 26 every time the diesel engine 10 is operated. The latest pre-operation pressure value is corrected by a numerical value obtained by calculating the accumulated pre-operation pressure value. Therefore, the regeneration time of the filter 23 can be more accurately determined.

(5) An average of a plurality of pre-operation pressure values stored in the RAM 26 before the latest pre-operation pressure value is detected is calculated, and the latest pre-operation pressure value is calculated based on the average value. Is corrected. With this configuration, the latest pre-operation pressure value can always be set to an appropriate value in determining the regeneration time of the filter 23.

(6) The pre-operation pressure value is corrected based on the post-operation pressure value detected after the diesel engine 10 stops. In short, after the diesel engine 10 is stopped, the pre-operation pressure value is corrected again. Therefore, since the pre-operation pressure value can be finely corrected, the determination of the regeneration time of the filter 23 can be more accurately performed.

(7) The electric system of the vehicle on which the exhaust gas purifying device 20 is mounted is designed to supply power not only when the diesel engine 10 is operating but also when the diesel engine 10 is not operating. Has become. Therefore, even if the diesel engine 10 is not operating, the pressure sensor 24 detects the pressure in the exhaust pipe 11,
Various calculations by the computer C and processing of correcting the latest pre-operation pressure value can be performed. As a result, these processes can be completed before the diesel engine 10 is started, so that the internal combustion engine can be started smoothly without causing a time lag.

The embodiment of the present invention may be modified as follows. In the above embodiment, when the diesel engine 10 is stopped, the operation key 29 is returned from the on position to the off position, and if the operation key 29 is inserted into the ignition switch 28, power is supplied to the other electric system. Is maintained. Besides this,
Even after the operation key 29 is unplugged, power may be supplied to the other electric system for a certain period of time by, for example, measuring using a timer provided in the computer C. With this configuration, the pre-operation pressure value can be reliably corrected even if the operation key 29 is immediately pulled out of the ignition switch 28.

In the above embodiment, the reference pressure value is set according to the rotation speed of the diesel engine 10, but may be set according to the exhaust gas temperature of the diesel engine 10.

In the above-described embodiment, the post-operation pressure value is detected by the pressure sensor 24 immediately after the diesel engine 10 is stopped. However, the pressure value may be detected not only immediately after but also after a certain period of time.

The pre-operation pressure value stored in the RAM 26 is accumulated each time the diesel engine 10 is operated, but need not be separately accumulated. Alternatively, one pre-operation pressure value may be stored in the RAM 26.

If the difference between the average value of the plurality of pre-operation pressure values stored in the RAM 26 and the pre-operation pressure value is too large, for example, a failure of the pressure sensor 24, the filter 23
Can be seen as breakage. Therefore, if the computer C is provided with a diagnostic function, it is possible to self-diagnose a failure of the exhaust gas purifying device 20.

In the above embodiment, the pre-operation pressure value is represented by R
Although stored in the AM 26, the pressure value during operation and the pressure value after operation may be stored in the RAM 26. In the above-described embodiment, when the amount of particulates reaches the allowable value, the indicator 30 is turned on to notify the driver of the regeneration time of the filter 23. In addition to visually notifying by the indicator 30, the reproduction time may be notified by an alarm sound by an alarm. Further, the filter reproduction time may be notified by voice.

In the above-described embodiment, the control program necessary for controlling the exhaust gas purification device 20 is stored in the ROM 27 which is a semiconductor memory. Alternatively, the control program may be stored in an information storage unit such as a floppy (registered trademark) disk or a hard disk. Or CD-ROM,
The control program may be stored in optical reading means such as a DVD, that is, a portable recording medium. If a portable recording medium is used, it is easy to buy and sell it.

The recording medium of the computer C may be a readable / writable semiconductor memory, which may be connected to a LAN, a WAN such as the Internet, or a computer network such as a wireless communication network. When the control program is upgraded, the control program may be stored in the semiconductor memory via the computer network. Further, the control program recorded on the recording medium may be transferred to a recording medium of another computer via a computer network.

Next, in addition to the technical idea described in the claims, the technical idea grasped by the above-described embodiment will be described below. (1) The pressure is detected by the pressure detecting means before the internal combustion engine is operated and during the operation of the internal combustion engine, and the determining means detects the pressure before the internal combustion engine is operated. The difference between the pre-operating pressure value and the operating pressure value detected during operation is larger or smaller than a reference pressure value set according to the rotation speed of the internal combustion engine or the exhaust gas temperature. The exhaust gas purifying apparatus according to claim 1, wherein it is determined whether or not the amount of particulates of the exhaust gas has reached an allowable value.

(2) A storage means for storing a past pressure detection result obtained by detecting a pressure in an exhaust pipe upstream of the filter by a computer for judging a regeneration time of a filter used in the exhaust gas purifying apparatus. And whether or not the amount of particulates deposited on the filter exceeds an allowable deposition amount based on the past pressure detection results stored in the storage means and the pressure detection results at different timings thereafter. A program for judging a regeneration timing of a filter for an exhaust gas purifying device to function as a judging means.

(3) A program for judging the regeneration timing of a filter for an exhaust gas purifying device according to claim 8, wherein when it is determined that the amount of particulates has reached an allowable value, a step of notifying the determination result is executed.

[0057]

As described in detail above, according to the present invention,
It is an object of the present invention to provide an exhaust gas purifying apparatus capable of detecting whether or not the amount of particulates accumulated on a filter exceeds an allowable accumulated amount even if the number of pressure detecting means is reduced, and further reducing manufacturing costs. is there.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an exhaust gas purifying apparatus showing one embodiment.

[Explanation of symbols]

Reference Signs List 10: diesel engine (internal combustion engine), 11: exhaust pipe, 20: exhaust gas purification device, 21: casing, 23
... Filter, 24 ... Pressure sensor (pressure detecting means), 26
... RAM (storage means), 27 ... ROM (recording medium), 2
5: CPU (determination means, first correction means, second correction means), C: computer.

Claims (9)

[Claims] An exhaust pipe through which exhaust gas discharged from an internal combustion engine passes is provided, and a filter accommodated in the casing is provided, and the exhaust gas discharged from the internal combustion engine is passed through the filter. Thus, in the exhaust gas purifying device that collects particulates contained in the exhaust gas, a pressure detecting unit that detects a pressure in an exhaust pipe upstream of the filter is provided, and the pressure is detected by the pressure detecting unit. Storage means for storing the past pressure detection results obtained, based on the past pressure detection results stored in the storage means and the pressure detection results at different timings thereafter, the amount of particulates accumulated in the filter. An exhaust gas purifying apparatus provided with a judgment means for judging whether or not the amount exceeds an allowable accumulation amount. 2. The timing at which the pressure is detected by the pressure detecting means is before the internal combustion engine is operated and during the operation of the internal combustion engine, and the determination means is configured to execute the operation before the internal combustion engine is operated. Depending on whether the difference between the pre-operation pressure value detected during operation and the operating pressure value detected during operation is larger or smaller than a reference pressure value set according to the operation state of the internal combustion engine. The exhaust gas purifying apparatus according to claim 1, wherein it is determined whether or not a gas particulate amount has reached an allowable value. 3. The storage means stores a pre-operation pressure value each time the internal combustion engine is operated, and stores a latest pre-operation pressure value based on a plurality of pre-operation pressure values accumulated in the storage means. 3. The exhaust gas purifying apparatus according to claim 2, further comprising a first correcting unit that corrects the exhaust gas. 4. The first correction means, based on a numerical value obtained by calculating and averaging a plurality of pre-operation pressure values stored in the storage means before a latest pre-operation pressure value is detected,
The exhaust gas purifying apparatus according to claim 3, wherein the latest pre-operation pressure value is corrected. 5. The pressure detecting means detects a post-operation pressure value after the internal combustion engine is stopped, and calculates a pre-operation pressure value stored in the storage means based on the post-operation pressure value. The exhaust gas purifying apparatus according to any one of claims 2 to 4, further comprising a second correcting unit that corrects the exhaust gas. 6. An electric system which is energized when the internal combustion engine is operating and when it is not operating, wherein the electric system includes the pressure detecting means, the determining means, the storing means, the first correcting means, and the The exhaust gas purifying apparatus according to any one of claims 1 to 5, wherein the two correction means are electrically connected to each other. 7. A casing provided in an exhaust pipe through which exhaust gas discharged from the internal combustion engine passes, and a particulate contained in the exhaust gas discharged from the internal combustion engine while being accommodated in the casing. A method for determining a regeneration time of a filter in an exhaust gas purifying apparatus having a filter for collecting a plurality of pressures, wherein a plurality of pressure detections are detected at different detection timings by pressure detection means provided in an exhaust pipe upstream of the filter. A method for determining a regeneration time of a filter used in an exhaust gas purifying apparatus, wherein it is determined whether or not the amount of particulates deposited on the filter exceeds an allowable deposition amount based on a result. 8. A computer for judging regeneration time of a filter used in an exhaust gas purifying device, comprising: detecting a pressure in an exhaust pipe upstream of the filter; Storing a pressure detection result; and, based on the stored past pressure detection result and a pressure detection result at a different timing thereafter, whether or not the amount of particulates deposited on the filter exceeds an allowable deposition amount. Determining the regeneration timing of the filter for the exhaust gas purifying apparatus for executing the steps of: 9. A computer-readable recording medium storing the program according to claim 8.