KR20170086960A - A method for diagnosing failure of seperated hci system and an apparatus therefor - Google Patents

Abstract

The present invention relates to a method and an apparatus for diagnosing failure of a detachable HCI system. The method for diagnosing failure of the separate HCI system according to the present invention includes a line charging step S100 for opening the fuel shutoff valve 600 and the dosing valve 300 to charge the fuel line 500 and the dosing line 400 with fuel, ; A test step S200 for controlling whether the fuel shutoff valve 600 and the dosing valve 300 are opened or closed after the line charging step S100 and measuring the pressure in the pressure sensor 700 after a predetermined time, ); And a diagnostic step (S300) of determining whether the detachable HCI system is malfunctioning from the pressure measured in the test step (S200). It is possible to diagnose hardware failure of detachable HCI system such as valve sticking and fuel leak.

Description

TECHNICAL FIELD [0001] The present invention relates to a method and apparatus for diagnosing failure of a detachable HCI system,

The present invention relates to a method and apparatus for diagnosing failure of a separate HCI system, and more particularly, to a method and apparatus for diagnosing failure of a detachable HCI system capable of diagnosing hardware failure of a detachable HCI system, .

Diesel Particulate Filter (DPF), which is a PM abatement device, is being applied as the diesel particulate matter (PM) particulate matter emission regulation is strengthened. The DPF collects PM in the exhaust gas and then increases the exhaust gas temperature (Regeneration).

In order to overcome the oil dilution problem due to post injection and the exhaust gas temperature shortage problem in the commercial engine, the use of HCI (Hydro Carbon Injection) is required in order to raise the temperature of the exhaust gas for DPF regeneration, A separate fuel injection system is used.

The HCI system controls a fuel pump that pumps fuel from a fuel tank, a dosing valve that supplies fuel pumped in the fuel pump through a fuel line, and injects fuel to the front of the DOC through a nozzle, The DPF is regenerated.

However, since the HCI system as described above is mounted on the engine exhaust side at a high temperature, there is a danger that if leakage of fuel occurs, the vehicle may be fired. Further, when the fuel injection is excessive, there is a risk of damaging the exhaust device including the DPF.

Therefore, it is necessary to diagnose whether the HCI system is operating normally. In this case, the integrated HCI system in which the dosing valve, the pressure sensor and the fuel shut-off valve are integrated can easily grasp the performance of the dosing valve, the pressure sensor, the single fuel shutoff valve and the entire system formed by them, Reliability is high. On the other hand, the recent detachable HCI system has a problem in that the reliability of the fault diagnosis is low because it is difficult to easily grasp the performance of the dosing valve, the pressure sensor, the fuel cutoff valve and the system formed by them.

Japanese Laid-Open Patent Publication No. 2012-127320 (December 17, 2010)

SUMMARY OF THE INVENTION The present invention has been conceived in order to solve the above problems, and it is an object of the present invention to provide a system and method for diagnosing faults in a separate type HCI system, a dosing valve, a pressure sensor, A method and an apparatus for diagnosing whether or not a detachable HCI system is faulty.

The method for diagnosing failure of the separate HCI system according to the present invention includes a line charging step S100 for opening the fuel shutoff valve 600 and the dosing valve 300 to charge the fuel line 500 and the dosing line 400 with fuel, ; A test step S200 for controlling whether the fuel shutoff valve 600 and the dosing valve 300 are opened or closed after the line charging step S100 and measuring the pressure in the pressure sensor 700 after a predetermined time, ); And a diagnostic step (S300) of determining whether the detachable HCI system is malfunctioning from the pressure measured in the test step (S200).

The test step S200 includes a first test step of closing the fuel shutoff valve 600 and opening the dosing valve 300 and measuring a first pressure in the pressure sensor 700 after a predetermined first time Lt; RTI ID = 0.0 > S210). ≪ / RTI >

After the first test step S210, the test step S200 closes the fuel shutoff valve 600 and the dosing valve 300, and after a predetermined second time, the pressure sensor 700 detects the second And a second test step (S220) of measuring the pressure.

After the second test step S220, the test step S200 opens the fuel shutoff valve 600 and closes the dosing valve 300. After the third predetermined time, the pressure sensor 700 And a third test step (S230) of measuring the third pressure.

After the third test step S230, the test step S200 closes the fuel shutoff valve 600 and the dosing valve 300, and after the predetermined fourth time, the pressure sensor 700 detects the fourth And a fourth test step (S240) of measuring the pressure.

The test step S200 may include opening the fuel shutoff valve 600 and the dosing valve 300 after the fourth test step S240, And a fifth test step (S250) of measuring the pressure.

In the diagnosis step S300, if the fourth pressure is less than the predetermined reference pressure, the first pressure is equal to or higher than the predetermined first reference pressure, and the fifth pressure is equal to or higher than the predetermined seventh reference pressure, (S310) for diagnosing that the dosing valve 300 is fixed in an open state.

In the diagnosis step S300, the first pressure is less than the predetermined first reference pressure, the third pressure is the predetermined fourth reference pressure or more, the fourth pressure is the predetermined fifth reference pressure or more, A dosing line leak diagnosis step S320 for diagnosing that a leaking occurs in the dosing line when the fifth pressure is equal to or greater than a predetermined seventh reference pressure and the difference between the maximum value and the minimum value of the fifth pressure is equal to or greater than a predetermined reference pressure difference ); ≪ / RTI >

In the diagnosis step S300, the third pressure is less than a predetermined fourth reference pressure, the first pressure is equal to or higher than a predetermined first reference pressure, the fourth pressure is equal to or higher than a predetermined reference pressure, The fuel cutoff valve 600 is closed when the fifth pressure is equal to or greater than a predetermined seventh reference pressure and the difference between the maximum value and the minimum value of the fifth pressure is equal to or greater than a preset reference pressure difference, 1 HCI system valve fixing diagnosis step (S330).

In the diagnosis step S300, the second pressure exceeds a predetermined third reference pressure, the fifth pressure is below a predetermined sixth reference pressure, and the difference between the maximum value and the minimum value of the fifth pressure is less than a preset reference The second HCI system which diagnoses that the fuel shutoff valve 600 is not fixed and the dosing valve 300 is fixed in a closed state or that the fuel shutoff valve 600 is fixed in an open state, And a valve fixing diagnosis step (S340).

The diagnostic step S300 includes a first pressure sensor failure diagnosis step S350 of diagnosing that the pressure sensor 700 is malfunctioning when the fifth pressure exceeds the preset reference pressure .

If the fifth pressure is less than the predetermined seventh reference pressure, the diagnostic step S300 may include a second pressure sensor failure diagnosis that diagnoses that the pressure sensor 700 is malfunctioning, or that leakage of the fuel line 500 has occurred And a diagnosis step (S360).

If the difference between the maximum value and the minimum value of the fifth pressure is equal to or less than the predetermined reference pressure difference, the signal of the pressure sensor 700 is stuck or the leak of the fuel line 500 occurs And a pressure sensor signal fixing diagnosis step (S370) for diagnosing the pressure sensor signal.

The storage medium according to the present invention stores a method for diagnosing the failure of the detachable HCI system.

An apparatus for diagnosing failure of a detachable HCI system according to the present invention comprises: a storage medium (100); A dosing nozzle (200) for injecting fuel into the exhaust pipe; A dosing valve 300 for controlling the amount of fuel supplied to the dosing nozzle 200; A dosing line 400 communicating the dosing nozzle 200 with the dosing valve 300; A fuel line (500) for supplying the fuel passing through the fuel filter (F) to the dosing valve (300); A fuel shutoff valve 600 mounted on the fuel line 500 for supplying or blocking fuel inside the fuel line 500 to the dosing valve 300; A pressure sensor (700) disposed between the dosing valve (300) and the fuel shutoff valve (600) for measuring the pressure of fuel in the fuel line (500); And fixing the dosing valve (300) and the fuel shutoff valve (600) according to a method of diagnosing the failure of the detachable HCI system stored in the storage medium (100) using the pressure measured by the pressure sensor Whether or not the dosing line 400 and the fuel line 500 are leaking, and whether the pressure sensor 700 is malfunctioning.

The dosing valve 300 and the fuel shutoff valve 600 are separately mounted.

The fuel line (500) includes a first fuel line (510) for communicating the fuel filter (F) and the fuel shutoff valve (600); And a second fuel line 520 communicating the fuel shutoff valve 600 and the dosing valve 300.

As described above, according to the present invention, it is possible to diagnose the hardware failure of the detachable HCI system such as the fixing of the valve and the fuel leak.

In addition, fuel purging is periodically performed during the diagnosis of the malfunction, so that caulking of the dosing nozzle can be prevented.

In addition, it is possible to diagnose the performance of the pressure sensor, such as whether the pressure sensor is fixed or not.

In addition, reliability of the fault diagnosis can be improved and fault diagnosis can be prevented.

1 is a flow chart of a method for diagnosing failure of a detachable HCI system according to the present invention.
Fig. 2 is a view for explaining the test step of Fig. 1; Fig.
Figs. 3 and 4 are diagrams illustrating the diagnostic steps of Fig. 1; Fig.
5 is a block diagram of an apparatus for diagnosing failure of a separate type HCI system according to the present invention.

It is to be understood that the words or words used in the present specification and claims are not to be construed in a conventional or dictionary sense and that the inventor can properly define the concept of a term to describe its invention in the best way And should be construed in accordance with the meaning and concept consistent with the technical idea of the present invention. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and are not intended to represent all of the technical ideas of the present invention. Therefore, various equivalents It should be understood that water and variations may be present. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a flow chart of a method for diagnosing failure of a separate type HCI system according to the present invention, FIG. 2 is a view for explaining a test step of FIG. 1, and FIGS. 3 and 4 are views for explaining the diagnostic step of FIG. Referring to FIGS. 1 to 4, a fault diagnosis method for a detachable HCI system according to the present invention includes a line charging step (S100), a testing step (S200), and a diagnostic step (S300). The method of diagnosing failure of the separate type HCI system as described above may be performed once for each target cumulative running time or once for each regeneration.

The line charging step S100 is a step of opening the fuel shutoff valve 600 and the dosing valve 300 to charge the fuel line 500 and the dosing line 400 with fuel. Thus, by filling the fuel on the line of the separate HCI system (LINE FILL), it is possible to prevent misdiagnosis in the fault diagnosis of the detachable HCI system.

The test step S200 may control whether the fuel shutoff valve 600 and the dosing valve 300 are opened or closed after the line charging step S100, . The test step S200 includes a first test step S210, a second test step S220, a third test step S230, a fourth test step S240, and a fifth test step S250.

In the first test step S210, the fuel shutoff valve 600 is closed, the dosing valve 300 is opened, and the first pressure is measured in the pressure sensor 700 after a predetermined first time. That is, after the fuel in the second fuel line 520 is drained, the first pressure is measured by the pressure sensor 700. The first pressure is set to be equal to or higher than a predetermined first reference pressure and lower than a predetermined second reference pressure. Therefore, when the first pressure deviates from the set range, the failure diagnostic condition (particularly, the dosing line leak described later) is satisfied. At this time, the predetermined first time, predetermined first reference pressure, and predetermined second reference pressure may be set differently depending on the intention of the designer, the type of vehicle, and the like.

The second test step S220 may include closing the fuel shutoff valve 600 and the dosing valve 300 after the first test step S210, 2 It measures the pressure. That is, it is tested whether or not the fuel inside the second fuel line 520 can be discharged. The second pressure is set to be equal to or less than a predetermined third reference pressure. Therefore, when the second pressure exceeds the third reference pressure, the failure diagnosis condition (particularly, the second HCI system valve fixing described later) is satisfied. At this time, the predetermined second time and predetermined third reference pressure may be set differently depending on the intention of the designer, the type of the vehicle, and the like.

After the second test step S220, the third test step S230 opens the fuel shutoff valve 600 and closes the dosing valve 300. After the third predetermined time, The third pressure is measured. That is, the fuel is recharged into the second fuel line 520. The third pressure is set to be equal to or higher than a predetermined fourth reference pressure. Accordingly, when the third pressure becomes less than the fourth reference pressure, the failure diagnosis condition (particularly, the first HCI system valve fixing described later) is satisfied. At this time, the predetermined third time and predetermined fourth reference pressure may be set differently according to the designer's intention or the type of vehicle.

In the fourth test step S240, after the third test step S230, the fuel shutoff valve 600 and the dosing valve 300 are closed, and after a predetermined fourth time, 4 It measures the pressure. That is, it is tested whether or not the state in which the fuel is filled in the second fuel line 520 can be maintained. And the fourth pressure is set to be equal to or higher than a predetermined fifth reference pressure. Accordingly, when the fourth pressure becomes less than the fifth reference pressure, the failure diagnosis condition (particularly, the fixing of the dosing valve to be described later) is satisfied. At this time, the preset fourth time and predetermined fifth reference pressure may be set differently according to the intention of the designer, the type of the vehicle, and the like.

In the fifth test step S250, after the fourth test step S240, the fuel shutoff valve 600 and the dosing valve 300 are opened, and the pressure sensor 700 5 It measures the pressure. That is, injecting the fuel inside the dosing line 400 and the fuel line 500, particularly the second fuel line 520, through the dosing nozzle 200 into the exhaust pipe. At this time, the fifth pressure forms a flushing, and the fifth flushing pressure is set to be equal to or higher than a predetermined seventh reference pressure and lower than a predetermined sixth reference pressure. Therefore, when the fifth pressure deviates from the set range, the failure diagnosis condition (particularly, the first or second pressure sensor abnormality described later) is satisfied. At this time, the predetermined fifth time period and predetermined sixth and seventh reference pressures may be set differently according to the intention of the designer, the type of the vehicle, and the like.

In addition, the difference between the maximum value and the minimum value of the wave pressure of the fifth pressure is set to be equal to or greater than a preset reference pressure difference. Therefore, when the difference between the maximum value and the minimum value of the fifth pressure fluctuation is less than the predetermined reference pressure difference, the failure diagnosis condition (particularly, the signal sticking of the pressure sensor or the leak of the fuel line) to be described later is satisfied. At this time, the preset reference pressure difference may be set to 2 kPa, but it is not limited to this, and may be set differently depending on the designer's intention or the type of vehicle.

The first reference pressure to the seventh reference pressure in the test step S200 are not sequentially set according to the magnitude of the pressure but are values that can be set differently according to the intention of the designer or the type of the vehicle as described above.

The diagnosis step S300 is a step of determining whether or not the detachable HCI system is malfunctioning from the pressure measured in the test step S200. The diagnostic step S300 includes the steps of diagnosing the fastening of the dosing valve (S310), the dosing line leak diagnosis step (S320), the first HCI system valve fixing diagnosis step (S330), the second HCI system valve fixing diagnosis step (S340) 2 pressure sensor failure diagnosis step S360 and a pressure sensor signal adhesion diagnosis step S370.

In the dosing valve opening fixation diagnosis step S310, the fourth pressure is less than a predetermined fifth reference pressure, the first pressure is equal to or higher than a predetermined first reference pressure, and the fifth pressure is equal to or higher than a predetermined seventh reference pressure , It is diagnosed that the dosing valve 300 is fixed in an open state.

That is, when the dosing valve 300 is opened (S210 and S250), the assumption condition is not satisfied but when the dosing valve 300 is closed (S240), the failure diagnosis condition is satisfied. It is diagnosed as being fixed in the state. At this time, the fuel cutoff valve 600 is diagnosed as a normal state.

In the dosing line leak diagnosis step S320, the first pressure is less than a predetermined first reference pressure, the third pressure is equal to or higher than a predetermined fourth reference pressure, the fourth pressure is equal to or higher than a predetermined fifth reference pressure If the fifth pressure is equal to or greater than a predetermined seventh reference pressure and the difference between the maximum value and the minimum value of the fifth pressure is equal to or greater than a preset reference pressure difference, diagnosis is made that leakage has occurred in the dosing line.

That is, in the fifth test step S250, since the fifth pressure is equal to or higher than the predetermined seventh reference pressure, no abnormality of the pressure sensor or leakage of the fuel line occurs.

In addition, since the difference between the maximum value and the minimum value of the fifth pressure in the fifth test step (S250) is equal to or greater than the preset reference pressure difference, the problem of signal sticking of the pressure sensor 700 does not occur.

In addition, since the third pressure is equal to or higher than the predetermined fourth reference pressure in the third test step S230, the problem of the closure of the fuel shutoff valve 600 does not occur.

In addition, in the fourth test step S240, since the fourth pressure is equal to or higher than the fifth predetermined reference pressure, the problem of opening and closing of the dosing valve 300 does not occur.

Nevertheless, in the first test step (S210), the first pressure is too low to diagnose that a leak has occurred in the dosing line.

The first HCI system valve attachment diagnosis step S330 may be performed when the third pressure is less than the predetermined fourth reference pressure, the first pressure is equal to or higher than the predetermined first reference pressure, When the fifth pressure is equal to or higher than a predetermined seventh reference pressure and the difference between the maximum value and the minimum value of the fifth pressure is equal to or greater than a predetermined reference pressure difference, the fuel shutoff valve (600) .

That is, in the fifth test step S250, since the fifth pressure is equal to or higher than the predetermined seventh reference pressure, no abnormality of the pressure sensor or leakage of the fuel line occurs.

In addition, since the difference between the maximum value and the minimum value of the fifth pressure in the fifth test step (S250) is equal to or greater than the preset reference pressure difference, the problem of signal sticking of the pressure sensor 700 does not occur.

In addition, in the first test step S210, since the first pressure is equal to or higher than the predetermined first reference pressure, the problem of opening and closing of the dosing valve 300 does not occur.

In addition, in the fourth test step S240, since the fourth pressure is equal to or higher than the fifth predetermined reference pressure, the problem of opening and closing of the dosing valve 300 does not occur.

Nevertheless, in the third test step S210, since the third pressure is less than the fourth reference pressure, it is diagnosed that the fuel shutoff valve 600 is stuck in the closed state regardless of whether the dosing valve 300 is fixed .

The second HCI system valve fixing diagnosis step (S340) includes the step of determining whether the second pressure exceeds the predetermined third reference pressure, the fifth pressure is equal to or less than the predetermined sixth reference pressure, It is determined that the fuel shutoff valve 600 is not fixed and the dosing valve 300 is fixed in a closed state or the fuel shutoff valve 600 is fixed in an open state .

That is, in the fifth test step S250, since the fifth pressure is equal to or less than the predetermined sixth reference pressure, no abnormality of the pressure sensor occurs.

In addition, since the difference between the maximum value and the minimum value of the fifth pressure in the fifth test step (S250) is equal to or greater than the preset reference pressure difference, the problem of signal sticking of the pressure sensor 700 does not occur.

Nevertheless, in the second test step S220, since the second pressure exceeds the predetermined third reference pressure, the fuel shutoff valve 600 is not fixed and the dosing valve 300 is fixed in the closed state .

Alternatively, it can be diagnosed that the fuel cutoff valve 600 is fixed in an open state and fuel continues to flow into the second fuel line 500.

Table 1 below shows the dosing valve 300 and the fuel shut-off valve 300 in the first and second HCI system valve fixation diagnosis step S330 and the second HCI system valve fixation diagnosis step S340, Table 6 summarizes whether the valve 600 is in a fixed state. Referring to Table 1, the dosing valve 300 of the dosing valve opening fixing diagnosis step S310, the first HCI system valve fixing diagnosis step S330 and the second HCI system valve fixing diagnosis step S340, It is possible to clearly understand whether or not the shutoff valve 600 is in a fixed state.

Fuel shutoff valve 600, The dosing valve (300) Trouble shooting Steady state Steady state none Steady state Open fixation Closing the dosing valve (S310) Steady state Closure fixation
Clamping of the first HCI system valve
(S330)
Open fixation Steady state Open fixation Open fixation Open fixation Closure fixation Closure fixation Steady state
Clamping of the second HCI system valve
(S340) Closure fixation Open fixation Closure fixation Closure fixation

The first pressure sensor failure diagnosis step S350 is a step of diagnosing that the pressure sensor 700 is malfunctioning when the fifth pressure exceeds the predetermined sixth reference pressure. That is, in the fifth test step S250, the fuel injection through the dosing nozzle 200 is performed, so that the fifth pressure can not exceed the predetermined range, and in particular, can not exceed the sixth reference pressure. Accordingly, when the fifth pressure exceeds the preset reference pressure, the pressure sensor 700 is diagnosed as having a failure.

In the second pressure sensor failure diagnosis step S360, when the fifth pressure is lower than the predetermined seventh reference pressure, diagnosis is made that the pressure sensor 700 is malfunctioning or leakage of the fuel line 500 occurs to be. That is, in the fifth test step S250, fuel injection through the dosing nozzle 200 is performed, so that the fifth pressure can not be out of the predetermined range. Therefore, when the fifth pressure is less than the predetermined seventh reference pressure, it is diagnosed that the pressure sensor 700 is malfunctioning or the fifth pressure is abnormally lowered due to leakage of the fuel line 500.

In the pressure sensor signal fixing diagnosis step S370, when the difference between the maximum value and the minimum value of the fifth pressure is equal to or less than the set reference pressure difference, the signal of the pressure sensor 700 is stuck, Is diagnosed as having occurred.

That is, in the fifth test step S250, fuel injection through the dosing nozzle 200 is performed, so that the fifth pressure forms a flushing. Therefore, when the difference between the maximum value and the minimum value of the fifth pressure is less than the preset reference pressure difference, the pressure sensor 700 can not sense the FLU- And diagnoses that the signal is stuck.

Or the fuel is not injected with a sufficiently strong pressure in the dosing nozzle 200 and the fifth pressure does not form a flushing, so that the fuel line 500 is diagnosed to be leaking.

5 is a block diagram of an apparatus for diagnosing failure of a separate HCI system according to the present invention. Referring to FIG. 5, the fault diagnosis apparatus of the separate type HCI system according to the present invention includes: a storage medium 100 storing the fault diagnosis method of the separated type HCI system; A dosing nozzle (200) for injecting fuel into the exhaust pipe; A dosing valve 300 for controlling the amount of fuel supplied to the dosing nozzle 200; A dosing line 400 communicating the dosing nozzle 200 with the dosing valve 300; A fuel line (500) for supplying the fuel passing through the fuel filter (F) to the dosing valve (300); A fuel shutoff valve 600 mounted on the fuel line 500 for supplying or blocking fuel inside the fuel line 500 to the dosing valve 300; A pressure sensor (700) disposed between the dosing valve (300) and the fuel shutoff valve (600) for measuring the pressure of fuel in the fuel line (500); And fixing the dosing valve (300) and the fuel shutoff valve (600) according to a method of diagnosing the failure of the detachable HCI system stored in the storage medium (100) using the pressure measured by the pressure sensor Whether or not the dosing line 400 and the fuel line 500 are leaking, and whether the pressure sensor 700 is malfunctioning.

The dosing valve 300 and the fuel shutoff valve 600 are separately mounted.

The fuel line (500) includes a first fuel line (510) for communicating the fuel filter (F) and the fuel shutoff valve (600); And a second fuel line 520 communicating the fuel shutoff valve 600 and the dosing valve 300.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory only and are not restrictive of the invention, as claimed, and will be fully understood by those of ordinary skill in the art. The present invention is not limited thereto. It will be apparent to those skilled in the art that various substitutions, modifications and variations are possible within the scope of the present invention, and it is obvious that those parts easily changeable by those skilled in the art are included in the scope of the present invention .

100 storage medium
200 dosing nozzle
300 dosing valve
400 dosing line
500 fuel line
600 Fuel shutoff valve
700 pressure sensor
800 Department of Diagnosis
F fuel filter

Claims (17)

A line charging step S100 for opening the fuel shutoff valve 600 and the dosing valve 300 to fill the fuel line 500 and the dosing line 400 with fuel;
A test step S200 for controlling whether the fuel shutoff valve 600 and the dosing valve 300 are opened or closed after the line charging step S100 and measuring the pressure in the pressure sensor 700 after a predetermined time, ); And
A diagnostic step (S300) of judging from the pressure measured in the test step (S200) whether the detachable HCI system is faulty;
A method for diagnosing failure of a detachable HCI system. The method according to claim 1,
The test step S200 includes a first test step of closing the fuel shutoff valve 600 and opening the dosing valve 300 and measuring a first pressure in the pressure sensor 700 after a predetermined first time S210);
Wherein the fault diagnosis method comprises the steps of: 3. The method of claim 2,
After the first test step S210, the test step S200 closes the fuel shutoff valve 600 and the dosing valve 300, and after a predetermined second time, the pressure sensor 700 detects the second A second test step S220 of measuring pressure;
Wherein the fault diagnosis method comprises the steps of: The method of claim 3,
After the second test step S220, the test step S200 opens the fuel shutoff valve 600 and closes the dosing valve 300. After the third predetermined time, the pressure sensor 700 A third test step S230 for measuring the third pressure;
Wherein the fault diagnosis method comprises the steps of: 5. The method of claim 4,
After the third test step S230, the test step S200 closes the fuel shutoff valve 600 and the dosing valve 300, and after the predetermined fourth time, the pressure sensor 700 detects the fourth A fourth test step (S240) of measuring pressure;
Wherein the fault diagnosis method comprises the steps of: 6. The method of claim 5,
The test step S200 may include opening the fuel shutoff valve 600 and the dosing valve 300 after the fourth test step S240, A fifth test step (S250) of measuring the pressure;
Wherein the fault diagnosis method comprises the steps of: The method according to claim 6,
The diagnostic step (S300)
Wherein the fourth pressure is less than a predetermined fifth reference pressure,
The first pressure is equal to or higher than a predetermined first reference pressure,
When the fifth pressure is equal to or higher than a predetermined seventh reference pressure,
(S310) for diagnosing that the dosing valve (300) is fixed in an open state;
Wherein the fault diagnosis method comprises the steps of: The method according to claim 6,
The diagnostic step (S300)
Wherein the first pressure is less than a predetermined first reference pressure,
The third pressure is equal to or higher than a predetermined fourth reference pressure,
The fourth pressure is equal to or higher than a predetermined reference pressure,
The fifth pressure is not less than a predetermined seventh reference pressure,
When the difference between the maximum value and the minimum value of the fifth pressure is equal to or greater than a preset reference pressure difference,
A dosing line leak diagnosis step (S320) for diagnosing that a leakage has occurred in the dosing line;
Wherein the fault diagnosis method comprises the steps of: The method according to claim 6,
The diagnostic step (S300)
The third pressure is less than a predetermined fourth reference pressure,
The first pressure is equal to or higher than a predetermined first reference pressure,
The fourth pressure is equal to or higher than a predetermined reference pressure,
The fifth pressure is not less than a predetermined seventh reference pressure,
When the difference between the maximum value and the minimum value of the fifth pressure is equal to or greater than a preset reference pressure difference,
A first HCI system valve sticking diagnosis step (S330) diagnosing that the fuel cutoff valve (600) is fixed in a closed state;
Wherein the fault diagnosis method comprises the steps of: The method according to claim 6,
The diagnostic step (S300)
The second pressure exceeds a predetermined third reference pressure,
The fifth pressure is equal to or less than a predetermined sixth reference pressure,
When the difference between the maximum value and the minimum value of the fifth pressure is equal to or greater than a preset reference pressure difference,
A second HCI system valve fixing diagnosis step (S340) for diagnosing that the fuel shutoff valve (600) is not fixed and the dosing valve (300) is fixed in a closed state or that the fuel shutoff valve );
Wherein the fault diagnosis method comprises the steps of: The method according to claim 6,
The diagnostic step (S300)
A first pressure sensor failure diagnosis step (S350) of diagnosing that the pressure sensor (700) is faulty if the fifth pressure exceeds a preset reference pressure;
Wherein the fault diagnosis method comprises the steps of: The method according to claim 6,
The diagnostic step (S300)
A second pressure sensor failure diagnosis step (S360) of diagnosing that the pressure sensor (700) is malfunctioning or leaking of the fuel line (500) occurs when the fifth pressure is lower than a predetermined seventh reference pressure;
Wherein the fault diagnosis method comprises the steps of: The method according to claim 6,
The diagnostic step (S300)
When the difference between the maximum value and the minimum value of the fifth pressure is equal to or less than a preset reference pressure difference, a signal from the pressure sensor 700 is fixed, or a pressure sensor signal fixing diagnosis for diagnosing that leakage of the fuel line 500 has occurred Step S370;
Wherein the fault diagnosis method comprises the steps of: A storage medium storing the diagnostic method for the failure of the separate type HCI system according to any one of claims 1 to 13. A storage medium (100) according to claim 14;
A dosing nozzle (200) for injecting fuel into the exhaust pipe;
A dosing valve 300 for controlling the amount of fuel supplied to the dosing nozzle 200;
A dosing line 400 communicating the dosing nozzle 200 with the dosing valve 300;
A fuel line (500) for supplying the fuel passing through the fuel filter (F) to the dosing valve (300);
A fuel shutoff valve 600 mounted on the fuel line 500 for supplying or blocking fuel inside the fuel line 500 to the dosing valve 300;
A pressure sensor (700) disposed between the dosing valve (300) and the fuel shutoff valve (600) for measuring the pressure of fuel in the fuel line (500); And
Whether the dosing valve 300 and the fuel shutoff valve 600 are fixed or not is determined according to the diagnostic method of the failure of the detachable HCI system stored in the storage medium 100 by using the pressure measured by the pressure sensor 700. [ A diagnosis unit 800 for diagnosing whether the dosing line 400 and the fuel line 500 are leaking, and whether the pressure sensor 700 is malfunctioning;
And a fault diagnosis unit for detecting a fault in the detachable HCI system. 16. The method of claim 15,
Wherein the dosing valve (300) and the fuel shutoff valve (600) are separately mounted. 16. The method of claim 15,
The fuel line (500) includes a first fuel line (510) for communicating the fuel filter (F) and the fuel shutoff valve (600); And
A second fuel line 520 communicating the fuel shutoff valve 600 and the dosing valve 300;
And a fault diagnosis unit for detecting a fault of the detachable HCI system.

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