KR100977393B1 - System and method for diagonsisng error of fuel pump of vehicle - Google Patents

Abstract

A system and method for diagnosing a failure of a fuel pump of a vehicle for diagnosing various failures (fixing error and responsive delay error) of a bidirectional driving fuel pump is disclosed. This invention comprises a fuel pump driving in a reverse direction to return remaining fuel in a fuel line to a fuel tank during a power latch after an engine stop; A timer 1 for starting counting for a predetermined set time after reverse driving of the fuel pump; And a control module for diagnosing and determining a fixing error of the fuel pump based on the fuel pressure of the fuel line and a preset threshold range after the set time of the timer, wherein the system includes: counting after reverse driving of the fuel pump And a timer 2 for counting a delay time for the fuel pressure of the fuel line to reach within the threshold range, wherein the control module is configured to control the fuel pump based on a delay time of the timer 2 and a preset threshold time. And to diagnose and determine responsiveness delay errors.

Elpia vehicle, fuel pressure sensor, residual fuel pressure

Description

FUEL PUMP FAULT DIAGNOSIS SYSTEM AND METHOD {SYSTEM AND METHOD FOR DIAGONSISNG ERROR OF FUEL PUMP OF VEHICLE}

The present invention relates to a method for diagnosing a failure of a fuel pump capable of bidirectional driving, and more particularly, a fuel pump stuck error or fuel during reverse driving of a fuel pump for removing fuel remaining in a fuel line after an engine stop. A vehicle and a fuel pump failure system and method for accurately determining a responsive delay error of a pump are provided.

As is well known, an internal combustion engine is a device that generates power by burning fuel and air in an engine, and an automobile using the power of such an internal combustion engine has a fuel tank for storing fuel for supplying the engine.

Liquefied Petroleum Gas (Liquefied Petroleum Gas) fuel is used in some passenger cars and vans due to its high octane value, excellent heat resistance, and low fuel cost.

The LPI fuel supplied to the engine of the vehicle is a liquid phase, and when it is vaporized, it has a high flammability because of good mixing with air, so that knocking is less likely to occur than gasoline and diesel. Vapor-Lock or percolation As a substitute for gasoline or diesel fuel, its application range is gradually increasing.

The LPG Injection (LPI) vehicle or system adopted in the method of directly injecting the LPI fuel into the liquid injector maintains the liquid state by pressurizing the LPG (+5 bar relative to the fuel tank pressure) using a fuel pump. It consists of a structure that injects through the injector.

When the engine is turned off, fuel supply through the fuel tank is stopped and the shut-off valve is closed, leaving the fuel line with only the remaining LPG's evaporative gas pressure (approximately 2-3 bar).

The remaining fuel remaining in this fuel line is recovered into the fuel tank by reverse driving of the fuel pump for recovering fuel of the fuel line to the fuel tank.

However, in the event of a failure in such a bi-directional fuel pump, the boil-off gas pressure of the fuel line remains in the fuel line and pressurizes the injector due to the pressure difference from the injector ejection outlet, thereby causing fuel leakage. The leaked fuel is deposited at the injector outlet, causing the injector to become clogged, which is a fundamental cause of misfire and engine relief at subsequent start-up.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems, and is based on the time when the fuel pressure of the fuel line and the fuel pressure of the fuel line reach within a predetermined threshold range in the reverse driving of the fuel pump during the power latch after the engine stops. By diagnosing seismic error of the fuel pump or responsiveness delay of the fuel pump, it is possible to prevent the excess fuel remaining in the fuel line from leaking to the injector after the engine stops to prevent air pollution due to excess fuel leakage. It is possible to provide a system and method for diagnosing a failure of a fuel pump of a vehicle which can prevent tar from accumulating in the fuel injection port of the injector and causing an injector blockage.

According to the technical means according to the first aspect of the present invention for achieving this object,

During fuel latch reverse operation during engine power stop after engine stop, during fuel pump settling error or fuel pump responsiveness delay error based on the time it takes for the fuel pressure of the fuel line and the fuel pressure of the fuel line to reach a predetermined threshold range Provide a fuel pump failure diagnosis system for diagnosing one or more,

The system comprises:

A fuel pump driving in a reverse direction to return remaining fuel in the fuel line to the fuel tank during the power latch after the engine stops;

A timer 1 for starting counting for a predetermined set time after reverse driving of the fuel pump; And

And a control module for diagnosing and determining a fixing error of the fuel pump based on the fuel pressure of the fuel line and a preset threshold range after the set time of the timer has elapsed.

The system comprises:

And a timer 2 for starting counting after reverse driving of the fuel pump and counting a delay time for the fuel pressure of the fuel line to reach the threshold range,

The control module,

And a responsive delay error of the fuel pump based on a delay time of the timer 2 and a preset threshold time.

The control module is characterized in that it is arranged to set the data value of the error diagnostic flag to a high level when determining one or more of an error of a stuck pump error or a responsive delay error of the fuel pump.

The control module,

A fuel pressure measurement unit configured to output an electrical signal by detecting a fuel pressure of a fuel line after a set time of the timer 1 elapses; And

And a fixing error determining unit determining that the fuel pressure of the fuel line received after the set time of the timer 1 does not exist within the threshold range as a fixing error of the fuel pump.

In addition, the control module,

When the fuel pressure of the fuel line is within the threshold range, the fixation error determiner receives the counting value of the timer 2 and then the counting value of the timer 2 and compares the counting value of the received timer with a predetermined threshold time. The apparatus further includes a responsive delay error determiner configured to determine a responsive delay error of the fuel pump.

Also according to the technical means according to the second aspect of the present invention,

During fuel latch reverse operation during engine power stop after engine stop, during fuel pump settling error or fuel pump responsiveness delay error based on the time it takes for the fuel pressure of the fuel line and the fuel pressure of the fuel line to reach a predetermined threshold range Provides a method of diagnosing fuel pump failures that diagnose one or more

The method,

a) driving the fuel pump in a reverse direction to return fuel remaining in the fuel line to the fuel tank during the power latch after engine stop;

b) starting counting timer 1 for counting a predetermined set time after counter-rotating operation of the fuel pump and timer 2 for counting a delay time for the fuel pressure of the fuel line to reach a threshold range;

c) receiving the fuel pressure of the fuel line after the elapse of the set time of the timer 1, and determining that the fuel pump is stuck in the fuel pump when the fuel pressure of the fuel line is not within a predetermined threshold range; And

d) in step c), when the fuel pressure of the fuel line is within a predetermined threshold range, and receives a counting value of the timer 2, the response of the fuel pump when the counting value of the timer 2 has passed a predetermined threshold time; And determining the sex delay error.

The method,

e) setting the data value of the error diagnostic flag to a high level by the determination of one of step c) or d);

The method,

f) displaying the data value of the error diagnostic flag.

As described above, the vehicle fuel pump failure diagnosis system and method according to the present invention, the fuel pressure of the fuel line and the fuel pressure of the fuel line in the reverse driving of the fuel pump during the power latch after the engine stop within the predetermined threshold range By diagnosing fuel pump settling errors or fuel pump responsiveness delay errors based on the time of arrival, it is possible to prevent excess fuel remaining in the fuel line from leaking to the injector after the engine stops. The air pollution can be prevented, and tar can accumulate at the fuel injection port of the injector, thereby obtaining an effect of preventing the injector clogging phenomenon.

Hereinafter, the most preferred embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention in detail.

1 is a view showing the configuration of a fuel pump failure diagnosis system of a vehicle according to the present invention.

As shown therein, the fuel pump failure diagnosis system for a vehicle according to the present invention is such that the fuel pressure of the fuel line and the fuel pressure of the fuel line reach within a predetermined threshold range during the reverse driving of the fuel pump during the power latch after the engine stops. The fuel pump 11, the timer 1 (13), the timer 2 (15), the fuel pressure measuring unit 17, for diagnosing the fixing error of the fuel pump or the responsive delay error of the fuel pump based on the delay time, A fixation error determining unit 19 and a responsiveness delay determining unit 21 are included.

Here, the fuel pump 11 is driven in the forward direction for supplying the fuel in the fuel tank to the injector through the fuel line when the ignition key is ON, and when the engine stop request, the fuel remaining in the fuel line to the fuel tank quickly It is provided to enable the bi-directional drive to drive in the reverse direction for easy recovery.

The timer 1 13 is then provided to count a predetermined set time simultaneously with the reverse driving of the fuel pump, and the timer 2 15 is also provided to start counting simultaneously with the reverse driving of the fuel pump. Preferably, the timer 2 15 counts a delay time when the fuel pressure of the fuel line output from the fuel pressure measuring unit 17 received after the set time of the timer 1 13 reaches within a predetermined threshold range. It is provided to.

On the other hand, the fuel pressure measuring unit 17 is provided to detect the fuel pressure of the fuel line after the set time of the timer 1 (13) is converted into an electrical signal, the electrical signal is fixed error determination unit 19 And the responsiveness delay determination unit 21.

The fixation error determination unit 19 is provided to determine whether the fuel pump 11 is a fixation error based on whether the fuel pressure of the received fuel pressure measuring unit 17 is within a preset threshold range. That is, when the fuel pressure of the fuel line does not exist within the threshold range, the fuel pump 11 determines that a fixing error has occurred.

On the other hand, the determination result of the fixation error determination unit 19 is provided to the responsiveness delay error determination unit 21.

The responsive delay error determining unit 21 receives the counting value of the timer 2 15 when the fuel pressure of the fuel line is within the threshold range as a result of the comparison of the fixation error determining unit 19. The counting value of the timer 2 15 is provided to determine that a responsive delay error of the fuel pump 11 has occurred when a predetermined threshold time has elapsed.

Then, according to the determination result of at least one of the fixation error determining unit 19 and the responsiveness delay error determining unit 21, to set the data value of the error diagnostic flag to a high level (the data value means '1'). It is provided. Here, the threshold range and the threshold time are the values set for driving the optimum fuel pump with the results obtained through a number of experiments.

Referring to FIG. 2, a fuel pump failure diagnosis process of a vehicle according to an exemplary embodiment of the present disclosure is described below.

First, under the control of an ECU (engine control unit: not shown), the fuel pump 11 is driven in the reverse direction during the power latch after the engine stops (step 101), and the timer 1 13 and the timer 15 are counted. Start (step 103). At this time, the timer 1 (13) counts a predetermined set time.

Thereafter, in step 105, it is determined whether the counting value is 0 because all of the predetermined setting time has elapsed in the timer 1 13, and if the setting time of the timer 1 13 has elapsed, the process proceeds to step 107. Proceed.

The fixing error determining unit 19 receives the fuel pressure of the fuel line provided from the fuel pressure measuring unit 17 through step 107, and then determines whether the received fuel pressure is within a predetermined threshold range. (Step 109).

Further, in step 109, if the fuel pressure does not exist within the threshold range, the fuel pump determines that a fixing error has occurred (step 111), and sets the data value of the error diagnostic flag to a high level (step 113). .

On the other hand, the responsive delay error determiner 21 receives the counting value of the timer 2 15 when the fuel pressure is within the threshold range in step 109 (step 115), and the timer 2 ( The counting value of 15 is compared with a predetermined threshold time (step 117).

At this time, when the counting value is greater than the threshold time as a result of the comparison of the step 117, it is determined through the step 119 that the responsiveness delay error of the fuel pump 11 has occurred and then proceeds to the step 113.

That is, the data value of the error diagnostic flag is set to high level.

However, if the counting value does not exceed the threshold time through the step 117, the data value of the error diagnostic flag is set to a low level (the data value is indicated as '0') through the step 121.

As such, those skilled in the art to which the present invention pertains will understand that the present invention may be embodied in other specific forms without changing to the technical spirit or essential features of the present invention. Therefore, the above-described embodiments are to be understood in all respects as illustrative and not restrictive. The scope of the invention is indicated by the following claims rather than the above description, and it should be construed that all changes or modifications derived from the meaning and scope of the claims and their equivalents are included in the scope of the invention. .

The system and method for diagnosing a fuel pump failure of a vehicle according to the present invention is based on the time when the fuel pressure of the fuel line and the fuel pressure of the fuel line reach within a predetermined threshold range during the reverse driving of the fuel pump during the power latch after the engine stops. By diagnosing the fuel pump seizing error or the fuel pump responsiveness delay error, it is possible to prevent the excess fuel remaining in the fuel line from leaking to the injector after the engine stops, thereby preventing air pollution due to excess fuel leakage. In order to prevent the accumulation of tar at the fuel injection port of the injector, it is possible to prevent clogging of the injector. Not only for the use of the device but also for the possibility of marketing or sales Since the degree to which not only can be apparently carried out in reality the invention there is industrial applicability.

1 is a view showing the configuration of a fuel pump failure diagnosis system of a vehicle to which the present invention is applied.

2 is a flowchart illustrating a fuel pump failure diagnosis process of a vehicle according to an exemplary embodiment of the present invention.

 <Description of the symbols for the main parts of the drawings>

10: fuel pump 13: timer 1

15: timer 2 17: fuel pressure measuring unit

19: stuck error determining unit 21: responsiveness delay error determining unit

Claims (8)

A fuel pump driving in a reverse direction to return remaining fuel in the fuel line to the fuel tank during the power latch after the engine stops; A timer 1 for starting counting for a predetermined set time after reverse driving of the fuel pump; And And a control module for diagnosing and determining a fixing error of the fuel pump on the basis of the fuel pressure of the fuel line and a preset threshold range after the set time of the timer has elapsed. The system of claim 1, wherein the system is And a timer 2 for starting counting after reverse driving of the fuel pump and counting a delay time for the fuel pressure of the fuel line to reach the threshold range, The control module, And diagnosing and determining the responsiveness delay error of the fuel pump based on the delay time of the timer 2 and the preset threshold time. The vehicle according to claim 1 or 2, wherein the control module is arranged to set the data value of the error diagnostic flag to a high level when determining at least one error of a fixation error or a responsive delay error of the fuel pump. Fuel pump fault diagnosis system. The method according to claim 1, The control module, A fuel pressure measurement unit configured to output an electrical signal by detecting a fuel pressure of a fuel line after a set time of the timer 1 elapses; And And a fixation error determining unit for determining a fixing error of the fuel pump when the fuel pressure of the fuel line received after the set time of the timer 1 does not exist within the threshold range. According to claim 4, The control module, When the fuel pressure of the fuel line is within the threshold range, the fixation error determining unit receives the counting value of the timer 2 and then the counting value of the timer 2 and compares the counting value of the received timer with a predetermined threshold time. And a responsive delay error determination unit for determining a responsive delay error of the fuel pump through the vehicle. a) driving the fuel pump in a reverse direction to return fuel remaining in the fuel line to the fuel tank during the power latch after engine stop; b) starting counting timer 1 for counting a predetermined set time after counter-rotating operation of the fuel pump and timer 2 for counting a delay time for the fuel pressure of the fuel line to reach a threshold range; c) receiving the fuel pressure of the fuel line after the elapse of the set time of the timer 1, and determining that the fuel pump is stuck in the fuel pump when the fuel pressure of the fuel line is not within a predetermined threshold range; And d) in step c), when the fuel pressure of the fuel line is within a predetermined threshold range, and receives a counting value of the timer 2, the response of the fuel pump when the counting value of the timer 2 has passed a predetermined threshold time; Determining a sex delay error. The method according to claim 6, wherein the method, and e) setting the data value of the error diagnostic flag to a high level by the determination of one of step c) or d). The method according to claim 7, wherein the method, and f) displaying a data value of the error diagnosis flag.

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